API Defaults: merge pull request #388 from telemt/api-defaults

API Defaults

.github/codeql/codeql-config.yml

@@ -0,0 +1,19 @@
+name: "Rust without tests"
+
+disable-default-queries: false
+
+queries:
+  - uses: security-extended
+  - uses: security-and-quality
+  - uses: ./.github/codeql/queries
+
+query-filters:
+  - exclude:
+      id:
+        - rust/unwrap-on-option
+        - rust/unwrap-on-result
+        - rust/expect-used
+
+analysis:
+  dataflow:
+    default-precision: high

.github/codeql/queries/common/ProductionOnly.qll

@@ -0,0 +1,20 @@
+import rust
+
+predicate isTestOnly(Item i) {
+  exists(ConditionalCompilation cc |
+    cc.getItem() = i and
+    cc.getCfg().toString() = "test"
+  )
+}
+
+predicate hasTestAttribute(Item i) {
+  exists(Attribute a |
+    a.getItem() = i and
+    a.getName() = "test"
+  )
+}
+
+predicate isProductionCode(Item i) {
+  not isTestOnly(i) and
+  not hasTestAttribute(i)
+}

.github/codeql/queries/qlpack.yml

@@ -0,0 +1,4 @@
+name: rust-production-only
+version: 0.0.1
+dependencies:
+  codeql/rust-all: "*"

.github/workflows/codeql.yml

@@ -0,0 +1,45 @@
+name: "CodeQL Advanced"
+
+on:
+  push:
+    branches: [ "*" ]
+  pull_request:
+    branches: [ "*" ]
+  schedule:
+    - cron: '0 0 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ${{ (matrix.language == 'swift' && 'macos-latest') || 'ubuntu-latest' }}
+
+    permissions:
+      security-events: write
+      packages: read
+      actions: read
+      contents: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: actions
+            build-mode: none
+          - language: rust
+            build-mode: none
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v4
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: ${{ matrix.build-mode }}
+          config-file: .github/codeql/codeql-config.yml
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v4
+        with:
+          category: "/language:${{ matrix.language }}"

.github/workflows/release.yml

@@ -0,0 +1,139 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - '[0-9]+.[0-9]+.[0-9]+'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    name: Build ${{ matrix.target }}
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - target: x86_64-unknown-linux-gnu
+            artifact_name: telemt
+            asset_name: telemt-x86_64-linux-gnu
+          - target: aarch64-unknown-linux-gnu
+            artifact_name: telemt
+            asset_name: telemt-aarch64-linux-gnu
+          - target: x86_64-unknown-linux-musl
+            artifact_name: telemt
+            asset_name: telemt-x86_64-linux-musl
+          - target: aarch64-unknown-linux-musl
+            artifact_name: telemt
+            asset_name: telemt-aarch64-linux-musl
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: dtolnay/rust-toolchain@v1
+        with:
+          toolchain: stable
+          targets: ${{ matrix.target }}
+
+      - name: Install cross-compilation tools
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-aarch64-linux-gnu
+
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-${{ matrix.target }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.target }}-cargo-
+
+      - name: Install cross
+        run: cargo install cross --git https://github.com/cross-rs/cross
+
+      - name: Build Release
+        env:
+          RUSTFLAGS: ${{ contains(matrix.target, 'musl') && '-C target-feature=+crt-static' || '' }}
+        run: cross build --release --target ${{ matrix.target }}
+
+      - name: Package binary
+        run: |
+          cd target/${{ matrix.target }}/release
+          tar -czvf ${{ matrix.asset_name }}.tar.gz ${{ matrix.artifact_name }}
+          sha256sum ${{ matrix.asset_name }}.tar.gz > ${{ matrix.asset_name }}.sha256
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.asset_name }}
+          path: |
+            target/${{ matrix.target }}/release/${{ matrix.asset_name }}.tar.gz
+            target/${{ matrix.target }}/release/${{ matrix.asset_name }}.sha256
+
+  build-docker-image:
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract version
+        id: vars
+        run: echo "VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository }}:${{ steps.vars.outputs.VERSION }}
+            ghcr.io/${{ github.repository }}:latest
+
+  release:
+    name: Create Release
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/download-artifact@v4
+        with:
+          path: artifacts
+
+      - name: Create Release
+        uses: softprops/action-gh-release@v2
+        with:
+          files: artifacts/**/*
+          generate_release_notes: true
+          draft: false
+          prerelease: ${{ contains(github.ref, '-rc') || contains(github.ref, '-beta') || contains(github.ref, '-alpha') }}

.github/workflows/rust.yml

@@ -2,18 +2,23 @@ name: Rust
 
 on:
   push:
-    branches: [ main ]
+    branches: [ "*" ]
   pull_request:
-    branches: [ main ]
+    branches: [ "*" ]
 
 env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  build-and-test:
-    name: Build & Test
+  build:
+    name: Build
     runs-on: ubuntu-latest
 
+    permissions:
+      contents: read
+      actions: write
+      checks: write
+
     steps:
     - name: Checkout repository
       uses: actions/checkout@v4
@@ -37,5 +42,13 @@ jobs:
     - name: Build Release
       run: cargo build --release --verbose
 
+    - name: Run tests
+      run: cargo test --verbose
+
+# clippy dont fail on warnings because of active development of telemt 
+# and many warnings
+    - name: Run clippy
+      run: cargo clippy -- --cap-lints warn
+
     - name: Check for unused dependencies
       run: cargo udeps || true

.gitignore

@@ -19,3 +19,5 @@ target
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 #.idea/
+
+proxy-secret

.kilocode/rules-architect/AGENTS.md

@@ -0,0 +1,58 @@
+# Architect Mode Rules for Telemt
+
+## Architecture Overview
+
+```mermaid
+graph TB
+    subgraph Entry
+        Client[Clients] --> Listener[TCP/Unix Listener]
+    end
+    
+    subgraph Proxy Layer
+        Listener --> ClientHandler[ClientHandler]
+        ClientHandler --> Handshake[Handshake Validator]
+        Handshake --> |Valid| Relay[Relay Layer]
+        Handshake --> |Invalid| Masking[Masking/TLS Fronting]
+    end
+    
+    subgraph Transport
+        Relay --> MiddleProxy[Middle-End Proxy Pool]
+        Relay --> DirectRelay[Direct DC Relay]
+        MiddleProxy --> TelegramDC[Telegram DCs]
+        DirectRelay --> TelegramDC
+    end
+```
+
+## Module Dependencies
+- [`src/main.rs`](src/main.rs) - Entry point, spawns all async tasks
+- [`src/config/`](src/config/) - Configuration loading with auto-migration
+- [`src/error.rs`](src/error.rs) - Error types, must be used by all modules
+- [`src/crypto/`](src/crypto/) - AES, SHA, random number generation
+- [`src/protocol/`](src/protocol/) - MTProto constants, frame encoding, obfuscation
+- [`src/stream/`](src/stream/) - Stream wrappers, buffer pool, frame codecs
+- [`src/proxy/`](src/proxy/) - Client handling, handshake, relay logic
+- [`src/transport/`](src/transport/) - Upstream management, middle-proxy, SOCKS support
+- [`src/stats/`](src/stats/) - Statistics and replay protection
+- [`src/ip_tracker.rs`](src/ip_tracker.rs) - Per-user IP tracking
+
+## Key Architectural Constraints
+
+### Middle-End Proxy Mode
+- Requires public IP on interface OR 1:1 NAT with STUN probing
+- Uses separate `proxy-secret` from Telegram (NOT user secrets)
+- Falls back to direct mode automatically on STUN mismatch
+
+### TLS Fronting
+- Invalid handshakes are transparently proxied to `mask_host`
+- This is critical for DPI evasion - do not change this behavior
+- `mask_unix_sock` and `mask_host` are mutually exclusive
+
+### Stream Architecture
+- Buffer pool is shared globally via Arc - prevents allocation storms
+- Frame codecs implement tokio-util Encoder/Decoder traits
+- State machine in [`src/stream/state.rs`](src/stream/state.rs) manages stream transitions
+
+### Configuration Migration
+- [`ProxyConfig::load()`](src/config/mod.rs:641) mutates config in-place
+- New fields must have sensible defaults
+- DC203 override is auto-injected for CDN/media support

.kilocode/rules-code/AGENTS.md

@@ -0,0 +1,23 @@
+# Code Mode Rules for Telemt
+
+## Error Handling
+- Always use [`ProxyError`](src/error.rs:168) from [`src/error.rs`](src/error.rs) for proxy operations
+- [`HandshakeResult<T,R,W>`](src/error.rs:292) returns streams on bad client - these MUST be returned for masking, never dropped
+- Use [`Recoverable`](src/error.rs:110) trait to check if errors are retryable
+
+## Configuration Changes
+- [`ProxyConfig::load()`](src/config/mod.rs:641) auto-mutates config - new fields should have defaults
+- DC203 override is auto-injected if missing - do not remove this behavior
+- When adding config fields, add migration logic in [`ProxyConfig::load()`](src/config/mod.rs:641)
+
+## Crypto Code
+- [`SecureRandom`](src/crypto/random.rs) from [`src/crypto/random.rs`](src/crypto/random.rs) must be used for all crypto operations
+- Never use `rand::thread_rng()` directly - use the shared `Arc<SecureRandom>`
+
+## Stream Handling
+- Buffer pool [`BufferPool`](src/stream/buffer_pool.rs) is shared via Arc - always use it instead of allocating
+- Frame codecs in [`src/stream/frame_codec.rs`](src/stream/frame_codec.rs) implement tokio-util's Encoder/Decoder traits
+
+## Testing
+- Tests are inline in modules using `#[cfg(test)]`
+- Use `cargo test --lib <module_name>` to run tests for specific modules

.kilocode/rules-debug/AGENTS.md

@@ -0,0 +1,27 @@
+# Debug Mode Rules for Telemt
+
+## Logging
+- `RUST_LOG` environment variable takes absolute priority over all config log levels
+- Log levels: `trace`, `debug`, `info`, `warn`, `error`
+- Use `RUST_LOG=debug cargo run` for detailed operational logs
+- Use `RUST_LOG=trace cargo run` for full protocol-level debugging
+
+## Middle-End Proxy Debugging
+- Set `ME_DIAG=1` environment variable for high-precision cryptography diagnostics
+- STUN probe results are logged at startup - check for mismatch between local and reflected IP
+- If Middle-End fails, check `proxy_secret_path` points to valid file from https://core.telegram.org/getProxySecret
+
+## Connection Issues
+- DC connectivity is logged at startup with RTT measurements
+- If DC ping fails, check `dc_overrides` for custom addresses
+- Use `prefer_ipv6=false` in config if IPv6 is unreliable
+
+## TLS Fronting Issues
+- Invalid handshakes are proxied to `mask_host` - check this host is reachable
+- `mask_unix_sock` and `mask_host` are mutually exclusive - only one can be set
+- If `mask_unix_sock` is set, socket must exist before connections arrive
+
+## Common Errors
+- `ReplayAttack` - client replayed a handshake nonce, potential attack
+- `TimeSkew` - client clock is off, can disable with `ignore_time_skew=true`
+- `TgHandshakeTimeout` - upstream DC connection failed, check network

AGENTS.md

@@ -0,0 +1,410 @@
+## System Prompt — Production Rust Codebase: Modification and Architecture Guidelines
+
+You are a senior Rust Engineer and pricipal Rust Architect acting as a strict code reviewer and implementation partner. 
+Your responses are precise, minimal, and architecturally sound. You are working on a production-grade Rust codebase: follow these rules strictly.
+
+---
+
+### 0. Priority Resolution — Scope Control
+
+This section resolves conflicts between code quality enforcement and scope limitation.
+
+When editing or extending existing code, you MUST audit the affected files and fix:
+
+- Comment style violations (missing, non-English, decorative, trailing).
+- Missing or incorrect documentation on public items.
+- Comment placement issues (trailing comments → move above the code).
+
+These are **coordinated changes** — they are always in scope.
+
+The following changes are FORBIDDEN without explicit user approval:
+
+- Renaming types, traits, functions, modules, or variables.
+- Altering business logic, control flow, or data transformations.
+- Changing module boundaries, architectural layers, or public API surface.
+- Adding or removing functions, structs, enums, or trait implementations.
+- Fixing compiler warnings or removing unused code.
+
+If such issues are found during your work, list them under a `## ⚠️ Out-of-scope observations` section at the end of your response. Include file path, context, and a brief description. Do not apply these changes.
+
+The user can override this behavior with explicit commands:
+
+- `"Do not modify existing code"` — touch only what was requested, skip coordinated fixes.
+- `"Make minimal changes"` — no coordinated fixes, narrowest possible diff.
+- `"Fix everything"` — apply all coordinated fixes and out-of-scope observations.
+
+### Core Rule
+
+The codebase must never enter an invalid intermediate state.
+No response may leave the repository in a condition that requires follow-up fixes.
+
+---
+
+### 1. Comments and Documentation
+
+- All comments MUST be written in English.
+- Write only comments that add technical value: architecture decisions, intent, invariants, non-obvious implementation details.
+- Place all comments on separate lines above the relevant code.
+- Use `///` doc-comments for public items. Use `//` for internal clarifications.
+
+Correct example:
+
+```rust
+// Handles MTProto client authentication and establishes encrypted session state.
+fn handle_authenticated_client(...) { ... }
+```
+
+Incorrect examples:
+
+```rust
+let x = 5; // set x to 5
+```
+
+```rust
+// This function does stuff
+fn do_stuff() { ... }
+```
+
+---
+
+### 2. File Size and Module Structure
+
+- Files MUST NOT exceed 350–550 lines.
+- If a file exceeds this limit, split it into submodules organized by responsibility (e.g., protocol, transport, state, handlers).
+- Parent modules MUST declare and describe their submodules.
+- Maintain clear architectural boundaries between modules.
+
+Correct example:
+
+```rust
+// Client connection handling logic.
+// Submodules:
+// - handshake: MTProto handshake implementation
+// - relay: traffic forwarding logic
+// - state: client session state machine
+
+pub mod handshake;
+pub mod relay;
+pub mod state;
+```
+
+Git discipline:
+
+- Use local git for versioning and diffs.
+- Write clear, descriptive commit messages in English that explain both *what* changed and *why*.
+
+---
+
+### 3. Formatting
+
+- Preserve the existing formatting style of the project exactly as-is.
+- Reformat code only when explicitly instructed to do so.
+- Do not run `cargo fmt` unless explicitly instructed.
+
+---
+
+### 4. Change Safety and Validation
+
+- If anything is unclear, STOP and ask specific, targeted questions before proceeding.
+- List exactly what is ambiguous and offer possible interpretations for the user to choose from.
+- Prefer clarification over assumptions. Do not guess intent, behavior, or missing requirements.
+- Actively ask questions before making architectural or behavioral changes.
+
+---
+
+### 5. Warnings and Unused Code
+
+- Leave all warnings, unused variables, functions, imports, and dead code untouched unless explicitly instructed to modify them.
+- These may be intentional or part of work-in-progress code.
+- `todo!()` and `unimplemented!()` are permitted and should not be removed or replaced unless explicitly instructed.
+
+---
+
+### 6. Architectural Integrity
+
+- Preserve existing architecture unless explicitly instructed to refactor.
+- Do not introduce hidden behavioral changes.
+- Do not introduce implicit refactors.
+- Keep changes minimal, isolated, and intentional.
+
+---
+
+### 7. When Modifying Code
+
+You MUST:
+
+- Maintain architectural consistency with the existing codebase.
+- Document non-obvious logic with comments that describe *why*, not *what*.
+- Limit changes strictly to the requested scope (plus coordinated fixes per Section 0).
+- Keep all existing symbol names unless renaming is explicitly requested.
+- Preserve global formatting as-is
+- Result every modification in a self-contained, compilable, runnable state of the codebase
+
+You MUST NOT:
+
+- Use placeholders: no `// ... rest of code`, no `// implement here`, no `/* TODO */` stubs that replace existing working code. Write full, working implementation. If the implementation is unclear, ask first
+- Refactor code outside the requested scope
+- Make speculative improvements
+- Spawn multiple agents for EDITING
+- Produce partial changes
+- Introduce references to entities that are not yet implemented
+- Leave TODO placeholders in production paths
+
+Note: `todo!()` and `unimplemented!()` are allowed as idiomatic Rust markers for genuinely unfinished code paths.
+
+Every change must:
+   - compile,
+   - pass type checks,
+   - have no broken imports,
+   - preserve invariants,
+   - not rely on future patches.
+
+If the task requires multiple phases:
+   - either implement all required phases,
+   - or explicitly refuse and explain missing dependencies.
+
+---
+
+### 8. Decision Process for Complex Changes
+
+When facing a non-trivial modification, follow this sequence:
+
+1. **Clarify**: Restate the task in one sentence to confirm understanding.
+2. **Assess impact**: Identify which modules, types, and invariants are affected.
+3. **Propose**: Describe the intended change before implementing it.
+4. **Implement**: Make the minimal, isolated change.
+5. **Verify**: Explain why the change preserves existing behavior and architectural integrity.
+
+---
+
+### 9. Context Awareness
+
+- When provided with partial code, assume the rest of the codebase exists and functions correctly unless stated otherwise.
+- Reference existing types, functions, and module structures by their actual names as shown in the provided code.
+- When the provided context is insufficient to make a safe change, request the missing context explicitly.
+- Spawn multiple agents for SEARCHING information, code, functions
+
+---
+
+### 10. Response Format
+
+#### Language Policy
+
+- Code, comments, commit messages, documentation ONLY ON **English**!
+- Reasoning and explanations in response text on language from promt
+
+#### Response Structure
+
+Your response MUST consist of two sections:
+
+**Section 1: `## Reasoning`**
+
+- What needs to be done and why.
+- Which files and modules are affected.
+- Architectural decisions and their rationale.
+- Potential risks or side effects.
+
+**Section 2: `## Changes`**
+
+- For each modified or created file: the filename on a separate line in backticks, followed by the code block.
+- For files **under 200 lines**: return the full file with all changes applied.
+- For files **over 200 lines**: return only the changed functions/blocks with at least 3 lines of surrounding context above and below. If the user requests the full file, provide it.
+- New files: full file content.
+- End with a suggested git commit message in English.
+
+#### Reporting Out-of-Scope Issues
+
+If during modification you discover issues outside the requested scope (potential bugs, unsafe code, architectural concerns, missing error handling, unused imports, dead code):
+
+- Do not fix them silently.
+- List them under `## ⚠️ Out-of-scope observations` at the end of your response.
+- Include: file path, line/function context, brief description of the issue, and severity estimate.
+
+#### Splitting Protocol
+
+If the response exceeds the output limit:
+
+1. End the current part with: **SPLIT: PART N — CONTINUE? (remaining: file_list)**
+2. List the files that will be provided in subsequent parts.
+3. Wait for user confirmation before continuing.
+4. No single file may be split across parts.
+
+## 11. Anti-LLM Degeneration Safeguards (Principal-Paranoid, Visionary)
+
+This section exists to prevent common LLM failure modes: scope creep, semantic drift, cargo-cult refactors, performance regressions, contract breakage, and hidden behavior changes.
+
+### 11.1 Non-Negotiable Invariants
+
+- **No semantic drift:** Do not reinterpret requirements, rename concepts, or change meaning of existing terms.
+- **No “helpful refactors”:** Any refactor not explicitly requested is forbidden.
+- **No architectural drift:** Do not introduce new layers, patterns, abstractions, or “clean architecture” migrations unless requested.
+- **No dependency drift:** Do not add crates, features, or versions unless explicitly requested.
+- **No behavior drift:** If a change could alter runtime behavior, you MUST call it out explicitly in `## Reasoning` and justify it.
+
+### 11.2 Minimal Surface Area Rule
+
+- Touch the smallest number of files possible.
+- Prefer local changes over cross-cutting edits.
+- Do not “align style” across a file/module—only adjust the modified region.
+- Do not reorder items, imports, or code unless required for correctness.
+
+### 11.3 No Implicit Contract Changes
+
+Contracts include:
+- public APIs, trait bounds, visibility, error types, timeouts/retries, logging semantics, metrics semantics,
+- protocol formats, framing, padding, keepalive cadence, state machine transitions,
+- concurrency guarantees, cancellation behavior, backpressure behavior.
+
+Rule:
+- If you change a contract, you MUST update all dependents in the same patch AND document the contract delta explicitly.
+
+### 11.4 Hot-Path Preservation (Performance Paranoia)
+
+- Do not introduce extra allocations, cloning, or formatting in hot paths.
+- Do not add logging/metrics on hot paths unless requested.
+- Do not add new locks or broaden lock scope.
+- Prefer `&str` / slices / borrowed data where the codebase already does so.
+- Avoid `String` building for errors/logs if it changes current patterns.
+
+If you cannot prove performance neutrality, label it as risk in `## Reasoning`.
+
+### 11.5 Async / Concurrency Safety (Cancellation & Backpressure)
+
+- No blocking calls inside async contexts.
+- Preserve cancellation safety: do not introduce `await` between lock acquisition and critical invariants unless already present.
+- Preserve backpressure: do not replace bounded channels with unbounded, do not remove flow control.
+- Do not change task lifecycle semantics (spawn patterns, join handles, shutdown order) unless requested.
+- Do not introduce `tokio::spawn` / background tasks unless explicitly requested.
+
+### 11.6 Error Semantics Integrity
+
+- Do not replace structured errors with generic strings.
+- Do not widen/narrow error types or change error categories without explicit approval.
+- Avoid introducing panics in production paths (`unwrap`, `expect`) unless the codebase already treats that path as impossible and documented.
+
+### 11.7 “No New Abstractions” Default
+
+Default stance:
+- No new traits, generics, macros, builder patterns, type-level cleverness, or “frameworking”.
+- If abstraction is necessary, prefer the smallest possible local helper (private function) and justify it.
+
+### 11.8 Negative-Diff Protection
+
+Avoid “diff inflation” patterns:
+- mass edits,
+- moving code between files,
+- rewrapping long lines,
+- rearranging module order,
+- renaming for aesthetics.
+
+If a diff becomes large, STOP and ask before proceeding.
+
+### 11.9 Consistency with Existing Style (But Not Style Refactors)
+
+- Follow existing conventions of the touched module (naming, error style, return patterns).
+- Do not enforce global “best practices” that the codebase does not already use.
+
+### 11.10 Two-Phase Safety Gate (Plan → Patch)
+
+For non-trivial changes:
+1) Provide a micro-plan (1–5 bullets): what files, what functions, what invariants, what risks.
+2) Implement exactly that plan—no extra improvements.
+
+### 11.11 Pre-Response Checklist (Hard Gate)
+
+Before final output, verify internally:
+
+- No unresolved symbols / broken imports.
+- No partially updated call sites.
+- No new public surface changes unless requested.
+- No transitional states / TODO placeholders replacing working code.
+- Changes are atomic: the repository remains buildable and runnable.
+- Any behavior change is explicitly stated.
+
+If any check fails: fix it before responding.
+
+### 11.12 Truthfulness Policy (No Hallucinated Claims)
+
+- Do not claim “this compiles” or “tests pass” unless you actually verified with the available tooling/context.
+- If verification is not possible, state: “Not executed; reasoning-based consistency check only.”
+
+### 11.13 Visionary Guardrail: Preserve Optionality
+
+When multiple valid designs exist, prefer the one that:
+- minimally constrains future evolution,
+- preserves existing extension points,
+- avoids locking the project into a new paradigm,
+- keeps interfaces stable and implementation local.
+
+Default to reversible changes.
+
+### 11.14 Stop Conditions
+
+STOP and ask targeted questions if:
+- required context is missing,
+- a change would cross module boundaries,
+- a contract might change,
+- concurrency/protocol invariants are unclear,
+- the diff is growing beyond a minimal patch.
+
+No guessing.
+
+### 12. Invariant Preservation
+
+You MUST explicitly preserve:
+- Thread-safety guarantees (`Send` / `Sync` expectations).
+- Memory safety assumptions (no hidden `unsafe` expansions).
+- Lock ordering and deadlock invariants.
+- State machine correctness (no new invalid transitions).
+- Backward compatibility of serialized formats (if applicable).
+
+If a change touches concurrency, networking, protocol logic, or state machines,
+you MUST explain why existing invariants remain valid.
+
+### 13. Error Handling Policy
+
+- Do not replace structured errors with generic strings.
+- Preserve existing error propagation semantics.
+- Do not widen or narrow error types without approval.
+- Avoid introducing panics in production paths.
+- Prefer explicit error mapping over implicit conversions.
+
+### 14. Test Safety
+
+- Do not modify existing tests unless the task explicitly requires it.
+- Do not weaken assertions.
+- Preserve determinism in testable components.
+
+### 15. Security Constraints
+
+- Do not weaken cryptographic assumptions.
+- Do not modify key derivation logic without explicit request.
+- Do not change constant-time behavior.
+- Do not introduce logging of secrets.
+- Preserve TLS/MTProto protocol correctness.
+
+### 16. Logging Policy
+
+- Do not introduce excessive logging in hot paths.
+- Do not log sensitive data.
+- Preserve existing log levels and style.
+
+### 17. Pre-Response Verification Checklist
+
+Before producing the final answer, verify internally:
+
+- The change compiles conceptually.
+- No unresolved symbols exist.
+- All modified call sites are updated.
+- No accidental behavioral changes were introduced.
+- Architectural boundaries remain intact.
+
+### 18. Atomic Change Principle
+Every patch must be **atomic and production-safe**.
+* **Self-contained** — no dependency on future patches or unimplemented components.
+* **Build-safe** — the project must compile successfully after the change.
+* **Contract-consistent** — no partial interface or behavioral changes; all dependent code must be updated within the same patch.
+* **No transitional states** — no placeholders, incomplete refactors, or temporary inconsistencies.
+
+**Invariant:** After any single patch, the repository remains fully functional and buildable.
+

CONTRIBUTING.md

@@ -0,0 +1,19 @@
+# Issues - Rules
+## What it is not
+- NOT Question and Answer
+- NOT Helpdesk
+
+# Pull Requests - Rules
+## General
+- ONLY signed and verified commits
+- ONLY from your name
+- DO NOT commit with `codex` or `claude` as author/commiter
+- PREFER `flow` branch for development, not `main`
+
+## AI
+We are not against modern tools, like AI, where you act as a principal or architect, but we consider it important:
+
+- you really understand what you're doing
+- you understand the relationships and dependencies of the components being modified
+- you understand the architecture of Telegram MTProto, MTProxy, Middle-End KDF at least generically
+- you DO NOT commit for the sake of commits, but to help the community, core-developers and ordinary users

Cargo.toml

@@ -1,16 +1,15 @@
 [package]
 name = "telemt"
-version = "1.0.0"
-edition = "2021"
-rust-version = "1.75"
+version = "3.3.15"
+edition = "2024"
 
 [dependencies]
 # C
 libc = "0.2"
 
 # Async runtime
-tokio = { version = "1.35", features = ["full", "tracing"] }
-tokio-util = { version = "0.7", features = ["codec"] }
+tokio = { version = "1.42", features = ["full", "tracing"] }
+tokio-util = { version = "0.7", features = ["full"] }
 
 # Crypto
 aes = "0.8"
@@ -20,42 +19,57 @@ sha2 = "0.10"
 sha1 = "0.10"
 md-5 = "0.10"
 hmac = "0.12"
-crc32fast = "1.3"
+crc32fast = "1.4"
+crc32c = "0.6"
+zeroize = { version = "1.8", features = ["derive"] }
 
 # Network
 socket2 = { version = "0.5", features = ["all"] }
-rustls = "0.22"
+nix = { version = "0.28", default-features = false, features = ["net"] }
 
-# Serial
+# Serialization
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 toml = "0.8"
+x509-parser = "0.15"
 
 # Utils
-bytes = "1.5"
-thiserror = "1.0"
+bytes = "1.9"
+thiserror = "2.0"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 parking_lot = "0.12"
 dashmap = "5.5"
-lru = "0.12"
-rand = "0.8"
+lru = "0.16"
+rand = "0.9"
 chrono = { version = "0.4", features = ["serde"] }
 hex = "0.4"
-base64 = "0.21"
+base64 = "0.22"
 url = "2.5"
-regex = "1.10"
-once_cell = "1.19"
+regex = "1.11"
 crossbeam-queue = "0.3"
+num-bigint = "0.4"
+num-traits = "0.2"
+anyhow = "1.0"
 
 # HTTP
-reqwest = { version = "0.11", features = ["rustls-tls"], default-features = false }
+reqwest = { version = "0.12", features = ["rustls-tls"], default-features = false }
+notify = { version = "6", features = ["macos_fsevent"] }
+ipnetwork = "0.20"
+hyper = { version = "1", features = ["server", "http1"] }
+hyper-util = { version = "0.1", features = ["tokio", "server-auto"] }
+http-body-util = "0.1"
+httpdate = "1.0"
+tokio-rustls = { version = "0.26", default-features = false, features = ["tls12"] }
+rustls = { version = "0.23", default-features = false, features = ["std", "tls12", "ring"] }
+webpki-roots = "0.26"
 
 [dev-dependencies]
 tokio-test = "0.4"
 criterion = "0.5"
 proptest = "1.4"
+futures = "0.3"
 
 [[bench]]
 name = "crypto_bench"
-harness = false
+harness = false

Dockerfile

@@ -0,0 +1,43 @@
+# ==========================
+# Stage 1: Build
+# ==========================
+FROM rust:1.88-slim-bookworm AS builder
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    pkg-config \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /build
+
+COPY Cargo.toml Cargo.lock* ./
+RUN mkdir src && echo 'fn main() {}' > src/main.rs && \
+    cargo build --release 2>/dev/null || true && \
+    rm -rf src
+
+COPY . .
+RUN cargo build --release && strip target/release/telemt
+
+# ==========================
+# Stage 2: Runtime
+# ==========================
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN useradd -r -s /usr/sbin/nologin telemt
+
+WORKDIR /app
+
+COPY --from=builder /build/target/release/telemt /app/telemt
+COPY config.toml /app/config.toml
+
+RUN chown -R telemt:telemt /app
+USER telemt
+
+EXPOSE 443
+EXPOSE 9090
+
+ENTRYPOINT ["/app/telemt"]
+CMD ["config.toml"]

LICENSING.md

@@ -0,0 +1,17 @@
+# LICENSING
+## Licenses for Versions
+| Version | License       |
+|---------|---------------|
+| 1.0     | NO LICNESE    |
+| 1.1     | NO LICENSE    |
+| 1.2     | NO LICENSE    |
+| 2.0     | NO LICENSE    |
+| 3.0     | TELEMT UL 1   |
+
+### License Types
+- **NO LICENSE** = ***ALL RIGHT RESERVED***
+- **TELEMT UL1** - work in progress license for source code of `telemt`, which encourages:
+  - fair use, 
+  - contributions, 
+  - distribution, 
+  - but prohibits NOT mentioning the authors

README.md

@@ -1,20 +1,97 @@
 # Telemt - MTProxy on Rust + Tokio
 
-**Telemt** is a fast, secure, and feature-rich server written in Rust: it fully implements the official Telegram proxy algo and adds many production-ready improvements such as connection pooling, replay protection, detailed statistics, masking from "prying" eyes
+***Löst Probleme, bevor andere überhaupt wissen, dass sie existieren*** / ***It solves problems before others even realize they exist***
 
-# GOTO
-- [Features](#features)
-- [Quick Start Guide](#quick-start-guide)
-  - [Build](#build)
-- [How to use?](#how-to-use)
-  - [Systemd Method](#telemt-via-systemd)
-- [FAQ](#faq)
-  - [Telegram Calls](#telegram-calls-via-mtproxy)
-  - [DPI](#how-does-dpi-see-mtproxy-tls)
-  - [Whitelist on Network Level](#whitelist-on-ip)
-- [Why Rust?](#why-rust)
+**Telemt** is a fast, secure, and feature-rich server written in Rust: it fully implements the official Telegram proxy algo and adds many production-ready improvements such as:
+- [ME Pool + Reader/Writer + Registry + Refill + Adaptive Floor + Trio-State + Generation Lifecycle](https://github.com/telemt/telemt/blob/main/docs/model/MODEL.en.md)
+- [Full-covered API w/ management](https://github.com/telemt/telemt/blob/main/docs/API.md)
+- Anti-Replay on Sliding Window
+- Prometheus-format Metrics
+- TLS-Fronting and TCP-Splicing for masking from "prying" eyes
 
-## Features
+[**Telemt Chat in Telegram**](https://t.me/telemtrs)
+
+## NEWS and EMERGENCY
+### ✈️ Telemt 3 is released!
+<table>
+<tr>
+<td width="50%" valign="top">
+
+### 🇷🇺 RU
+
+#### Релиз 3.3.5 LTS - 6 марта
+
+6 марта мы выпустили Telemt **3.3.5**
+
+Это [3.3.5 - первая LTS-версия telemt](https://github.com/telemt/telemt/releases/tag/3.3.5)!
+
+В ней используется:
+- новый алгоритм ME NoWait для непревзойдённо быстрого восстановления пула
+- Adaptive Floor, поддерживающий количество ME Writer на оптимальном уровне
+- модель усовершенствованного доступа к KDF Fingerprint на RwLock
+- строгая привязка Middle-End к DC-ID с предсказуемым алгоритмом деградации и самовосстановления
+
+Telemt Control API V1 в 3.3.5 включает:
+- несколько режимов работы в зависимости от доступных ресурсов
+- снапшот-модель для живых метрик без вмешательства в hot-path
+- минималистичный набор запросов для управления пользователями
+
+Будем рады вашему фидбеку и предложениям по улучшению — особенно в части **API**, **статистики**, **UX**
+
+---
+
+Если у вас есть компетенции в:
+
+- Асинхронных сетевых приложениях  
+- Анализе трафика  
+- Реверс-инжиниринге  
+- Сетевых расследованиях  
+
+Мы открыты к архитектурным предложениям, идеям и pull requests
+</td>
+<td width="50%" valign="top">
+
+### 🇬🇧 EN
+
+#### Release 3.3.5 LTS - March 6
+
+On March 6, we released Telemt **3.3.3**
+
+This is [3.3.5 - the first LTS release of telemt](https://github.com/telemt/telemt/releases/tag/3.3.5)
+
+It introduces:
+- the new ME NoWait algorithm for exceptionally fast pool recovery
+- Adaptive Floor, which maintains the number of ME Writers at an optimal level
+- an improved KDF Fingerprint access model based on RwLock
+- strict binding of Middle-End instances to DC-ID with a predictable degradation and self-recovery algorithm
+
+Telemt Control API V1 in version 3.3.5 includes:
+- multiple operating modes depending on available resources
+- a snapshot-based model for live metrics without interfering with the hot path
+- a minimalistic request set for user management
+
+We are looking forward to your feedback and improvement proposals — especially regarding **API**, **statistics**, **UX**
+
+---
+
+If you have expertise in:
+
+- Asynchronous network applications  
+- Traffic analysis  
+- Reverse engineering  
+- Network forensics  
+
+We welcome ideas, architectural feedback, and pull requests.
+</td>
+</tr>
+</table>
+
+# Features
+💥 The configuration structure has changed since version 1.1.0.0. change it in your environment!
+
+⚓ Our implementation of **TLS-fronting** is one of the most deeply debugged, focused, advanced and *almost* **"behaviorally consistent to real"**:  we are confident we have it right - [see evidence on our validation and traces](#recognizability-for-dpi-and-crawler)
+
+⚓ Our ***Middle-End Pool*** is fastest by design in standard scenarios, compared to other implementations of connecting to the Middle-End Proxy: non dramatically, but usual
 
 - Full support for all official MTProto proxy modes:
   - Classic
@@ -26,108 +103,122 @@
 - Graceful shutdown on Ctrl+C
 - Extensive logging via `trace` and `debug` with `RUST_LOG` method
 
+# GOTO
+- [Quick Start Guide](#quick-start-guide)
+- [FAQ](#faq)
+  - [Recognizability for DPI and crawler](#recognizability-for-dpi-and-crawler)
+    - [Client WITH secret-key accesses the MTProxy resource:](#client-with-secret-key-accesses-the-mtproxy-resource)
+    - [Client WITHOUT secret-key gets transparent access to the specified resource:](#client-without-secret-key-gets-transparent-access-to-the-specified-resource)
+  - [Telegram Calls via MTProxy](#telegram-calls-via-mtproxy)
+  - [How does DPI see MTProxy TLS?](#how-does-dpi-see-mtproxy-tls)
+  - [Whitelist on IP](#whitelist-on-ip)
+  - [Too many open files](#too-many-open-files)
+- [Build](#build)
+- [Why Rust?](#why-rust)
+- [Issues](#issues)
+- [Roadmap](#roadmap)
+
+
 ## Quick Start Guide
-
-### Build
-```bash
-# Cloning repo
-git clone https://github.com/telemt/telemt 
-# Changing Directory to telemt
-cd telemt
-# Starting Release Build
-cargo build --release
-# Move to /bin
-mv ./target/release/telemt /bin
-# Make executable
-chmod +x /bin/telemt
-# Lets go!
-telemt config.toml
-```
-
-## How to use?
-### Telemt via Systemd
-**0. Check port and generate secrets**
-
-The port you have selected for use should be MISSING from the list, when:
-```bash
-netstat -lnp
-```
-
-Generate 16 bytes/32 characters HEX with OpenSSL or another way:
-```bash
-openssl rand -hex 16
-```
-OR
-```bash
-xxd -l 16 -p /dev/urandom
-```
-OR
-```bash
-python3 -c 'import os; print(os.urandom(16).hex())'
-```
-
-**1. Place your config to /etc/telemt.toml**
-
-Open nano
-```bash
-nano /etc/telemt.toml
-```
-```bash
-port = 443                              # Listening port
-
-[users]
-hello = "00000000000000000000000000000000" # Replace the secret with one generated before
-
-[modes]
-classic = false                         # Plain obfuscated mode
-secure = false                          # dd-prefix mode
-tls = true                              # Fake TLS - ee-prefix
-
-tls_domain = "petrovich.ru"             # Domain for ee-secret and masking
-mask = true                             # Enable masking of bad traffic
-mask_host = "petrovich.ru"              # Optional override for mask destination
-mask_port = 443                         # Port for masking
-
-prefer_ipv6 = false                     # Try IPv6 DCs first if true
-fast_mode = true                        # Use "fast" obfuscation variant
-
-client_keepalive = 600                  # Seconds
-client_ack_timeout = 300                # Seconds
-```
-then Ctrl+X -> Y -> Enter to save
-
-**2. Create service on /etc/systemd/system/telemt.service**
-
-Open nano
-```bash
-nano /etc/systemd/system/telemt.service
-```
-paste this Systemd Module
-```bash
-[Unit]
-Description=Telemt
-After=network.target
-
-[Service]
-Type=simple
-WorkingDirectory=/bin
-ExecStart=/bin/telemt /etc/telemt.toml
-Restart=on-failure
-
-[Install]
-WantedBy=multi-user.target
-```
-then Ctrl+X -> Y -> Enter to save
-
-**3.**  In Shell type `systemctl start telemt` - it must start with zero exit-code
-
-**4.** In Shell type `systemctl status telemt` - there you can reach info about current MTProxy status
-
-**5.** In Shell type `systemctl enable telemt` - then telemt will start with system startup, after the network is up
+- [Quick Start Guide RU](docs/QUICK_START_GUIDE.ru.md)
+- [Quick Start Guide EN](docs/QUICK_START_GUIDE.en.md)
 
 ## FAQ
+
+- [FAQ RU](docs/FAQ.ru.md)
+- [FAQ EN](docs/FAQ.en.md)
+
+### Recognizability for DPI and crawler
+Since version 1.1.0.0, we have debugged masking perfectly: for all clients without "presenting" a key, 
+we transparently direct traffic to the target host!
+
+- We consider this a breakthrough aspect, which has no stable analogues today
+- Based on this: if `telemt` configured correctly, **TLS mode is completely identical to real-life handshake + communication** with a specified host
+- Here is our evidence:
+    - 212.220.88.77 - "dummy" host, running `telemt`
+    - `petrovich.ru` - `tls` + `masking` host, in HEX: `706574726f766963682e7275`
+    - **No MITM + No Fake Certificates/Crypto** = pure transparent *TCP Splice* to "best" upstream: MTProxy or tls/mask-host:
+      - DPI see legitimate HTTPS to `tls_host`, including *valid chain-of-trust* and entropy
+      - Crawlers completely satisfied receiving responses from `mask_host`
+  #### Client WITH secret-key accesses the MTProxy resource:
+  
+  <img width="360" height="439" alt="telemt" src="https://github.com/user-attachments/assets/39352afb-4a11-4ecc-9d91-9e8cfb20607d" />
+  
+  #### Client WITHOUT secret-key gets transparent access to the specified resource:
+    - with trusted certificate
+    - with original handshake
+    - with full request-response way
+    - with low-latency overhead
+```bash
+root@debian:~/telemt# curl -v -I --resolve petrovich.ru:443:212.220.88.77 https://petrovich.ru/
+* Added petrovich.ru:443:212.220.88.77 to DNS cache
+* Hostname petrovich.ru was found in DNS cache
+*   Trying 212.220.88.77:443...
+* Connected to petrovich.ru (212.220.88.77) port 443 (#0)
+* ALPN: offers h2,http/1.1
+* TLSv1.3 (OUT), TLS handshake, Client hello (1):
+*  CAfile: /etc/ssl/certs/ca-certificates.crt
+*  CApath: /etc/ssl/certs
+* TLSv1.3 (IN), TLS handshake, Server hello (2):
+* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
+* TLSv1.3 (IN), TLS handshake, Certificate (11):
+* TLSv1.3 (IN), TLS handshake, CERT verify (15):
+* TLSv1.3 (IN), TLS handshake, Finished (20):
+* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
+* TLSv1.3 (OUT), TLS handshake, Finished (20):
+* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
+* ALPN: server did not agree on a protocol. Uses default.
+* Server certificate:
+*  subject: C=RU; ST=Saint Petersburg; L=Saint Petersburg; O=STD Petrovich; CN=*.petrovich.ru
+*  start date: Jan 28 11:21:01 2025 GMT
+*  expire date: Mar  1 11:21:00 2026 GMT
+*  subjectAltName: host "petrovich.ru" matched cert's "petrovich.ru"
+*  issuer: C=BE; O=GlobalSign nv-sa; CN=GlobalSign RSA OV SSL CA 2018
+*  SSL certificate verify ok.
+* using HTTP/1.x
+> HEAD / HTTP/1.1
+> Host: petrovich.ru
+> User-Agent: curl/7.88.1
+> Accept: */*
+> 
+* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
+* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
+* old SSL session ID is stale, removing
+< HTTP/1.1 200 OK
+HTTP/1.1 200 OK
+< Server: Variti/0.9.3a
+Server: Variti/0.9.3a
+< Date: Thu, 01 Jan 2026 00:0000 GMT
+Date: Thu, 01 Jan 2026 00:0000 GMT
+< Access-Control-Allow-Origin: *
+Access-Control-Allow-Origin: *
+< Content-Type: text/html
+Content-Type: text/html
+< Cache-Control: no-store
+Cache-Control: no-store
+< Expires: Thu, 01 Jan 2026 00:0000 GMT
+Expires: Thu, 01 Jan 2026 00:0000 GMT
+< Pragma: no-cache
+Pragma: no-cache
+< Set-Cookie: ipp_uid=XXXXX/XXXXX/XXXXX==; Expires=Tue, 31 Dec 2040 23:59:59 GMT; Domain=.petrovich.ru; Path=/
+Set-Cookie: ipp_uid=XXXXX/XXXXX/XXXXX==; Expires=Tue, 31 Dec 2040 23:59:59 GMT; Domain=.petrovich.ru; Path=/
+< Content-Type: text/html
+Content-Type: text/html
+< Content-Length: 31253
+Content-Length: 31253
+< Connection: keep-alive
+Connection: keep-alive
+< Keep-Alive: timeout=60
+Keep-Alive: timeout=60
+
+< 
+* Connection #0 to host petrovich.ru left intact
+
+```
+- We challenged ourselves, we kept trying and we didn't only *beat the air*: now, we have something to show you
+  - Do not just take our word for it? - This is great and we respect that: you can build your own `telemt` or download a build and check it right now
 ### Telegram Calls via MTProxy
-- Telegram architecture does **NOT allow calls via MTProxy**, but only via SOCKS5, which cannot be obfuscated
+- Telegram architecture **does NOT allow calls via MTProxy**, but only via SOCKS5, which cannot be obfuscated
 ### How does DPI see MTProxy TLS?
 - DPI sees MTProxy in Fake TLS (ee) mode as TLS 1.3
 - the SNI you specify sends both the client and the server;
@@ -146,14 +237,52 @@ then Ctrl+X -> Y -> Enter to save
   - in China behind the Great Firewall
   - in Russia on mobile networks, less in wired networks
   - in Iran during "activity"
+### Too many open files
+- On a fresh Linux install the default open file limit is low; under load `telemt` may fail with `Accept error: Too many open files`
+- **Systemd**: add `LimitNOFILE=65536` to the `[Service]` section (already included in the example above)
+- **Docker**: add `--ulimit nofile=65536:65536` to your `docker run` command, or in `docker-compose.yml`:
+```yaml
+ulimits:
+  nofile:
+    soft: 65536
+    hard: 65536
+```
+- **System-wide** (optional): add to `/etc/security/limits.conf`:
+```
+*       soft    nofile  1048576
+*       hard    nofile  1048576
+root    soft    nofile  1048576
+root    hard    nofile  1048576
+```
+
+
+## Build
+```bash
+# Cloning repo
+git clone https://github.com/telemt/telemt 
+# Changing Directory to telemt
+cd telemt
+# Starting Release Build
+cargo build --release
+# Move to /bin
+mv ./target/release/telemt /bin
+# Make executable
+chmod +x /bin/telemt
+# Lets go!
+telemt config.toml
+```
 
 ## Why Rust?
 - Long-running reliability and idempotent behavior
-- Rust’s deterministic resource management - RAII 
+- Rust's deterministic resource management - RAII 
 - No garbage collector
 - Memory safety and reduced attack surface
 - Tokio's asynchronous architecture
 
+## Issues
+- ✅ [SOCKS5 as Upstream](https://github.com/telemt/telemt/issues/1) -> added Upstream Management
+- ✅ [iOS - Media Upload Hanging-in-Loop](https://github.com/telemt/telemt/issues/2)
+
 ## Roadmap
 - Public IP in links
 - Config Reload-on-fly

ROADMAP.md

@@ -0,0 +1,34 @@
+### 3.0.0 Anschluss
+- **Middle Proxy now is stable**, confirmed on canary-deploy over ~20 users
+- Ad-tag now is working
+- DC=203/CDN now is working over ME
+- `getProxyConfig` and `ProxySecret` are automated
+- Version order is now in format `3.0.0` - without Windows-style "microfixes"
+
+### 3.0.1 Kabelsammler
+- Handshake timeouts fixed
+- Connectivity logging refactored
+- Docker: tmpfs for ProxyConfig and ProxySecret
+- Public Host and Port in config
+- ME Relays Head-of-Line Blocking fixed
+- ME Ping
+
+### 3.0.2 Microtrencher
+- New [network] section
+- ME Fixes
+- Small bugs coverage
+
+### 3.0.3 Ausrutscher
+- ME as stateful, no conn-id migration
+- No `flush()` on datapath after RpcWriter
+- Hightech parser for IPv6 without regexp
+- `nat_probe = true` by default
+- Timeout for `recv()` in STUN-client
+- ConnRegistry review
+- Dualstack emergency reconnect
+
+### 3.0.4 Schneeflecken
+- Only WARN and Links in Normal log
+- Consistent IP-family detection
+- Includes for config
+- `nonce_frame_hex` in log only with `DEBUG`

config.full.toml

@@ -0,0 +1,697 @@
+# ==============================================================================
+#
+#   TELEMT — Advanced Rust-based Telegram MTProto Proxy
+#   Full Configuration Reference
+#
+#   This file is both a working config and a complete documentation.
+#   Every parameter is explained. Read it top to bottom before deploying.
+#
+#   Quick Start:
+#     1. Set [server].port to your desired port (443 recommended)
+#     2. Generate a secret: openssl rand -hex 16
+#     3. Put it in [access.users] under a name you choose
+#     4. Set [censorship].tls_domain to a popular unblocked HTTPS site
+#     5. Set your public IP in [general].middle_proxy_nat_ip
+#        and [general.links].public_host
+#     6. Set announce IP in [[server.listeners]]
+#     7. Run Telemt. It prints a tg:// link. Send it to your users.
+#
+#   Modes of Operation:
+#     Direct Mode  (use_middle_proxy = false)
+#       Connects straight to Telegram DCs via TCP. Simple, fast, low overhead.
+#       No ad_tag support. No CDN DC support (203, etc).
+#
+#     Middle-Proxy Mode  (use_middle_proxy = true)
+#       Connects to Telegram Middle-End servers via RPC protocol.
+#       Required for ad_tag monetization and CDN support.
+#       Requires proxy_secret_path and a valid public IP.
+#
+# ==============================================================================
+
+
+# ==============================================================================
+# LEGACY TOP-LEVEL FIELDS
+# ==============================================================================
+
+# Deprecated. Use [general.links].show instead.
+# Accepts "*" for all users, or an array like ["alice", "bob"].
+show_link = ["0"]
+
+# Fallback Datacenter index (1-5) when a client requests an unknown DC ID.
+# DC 2 is Amsterdam (Europe), closest for most CIS users.
+# default_dc = 2
+
+
+# ==============================================================================
+# GENERAL SETTINGS
+# ==============================================================================
+
+[general]
+
+# ------------------------------------------------------------------------------
+# Core Protocol
+# ------------------------------------------------------------------------------
+
+# Coalesce the MTProto handshake and first data payload into a single TCP packet.
+# Significantly reduces connection latency. No reason to disable.
+fast_mode = true
+
+# How the proxy connects to Telegram servers.
+# false = Direct TCP to Telegram DCs (simple, low overhead)
+# true  = Middle-End RPC protocol (required for ad_tag and CDN DCs)
+use_middle_proxy = true
+
+# 32-char hex Ad-Tag from @MTProxybot for sponsored channel injection.
+# Only works when use_middle_proxy = true.
+# Obtain yours: message @MTProxybot on Telegram, register your proxy.
+# ad_tag = "00000000000000000000000000000000"
+
+# ------------------------------------------------------------------------------
+# Middle-End Authentication
+# ------------------------------------------------------------------------------
+
+# Path to the Telegram infrastructure AES key file.
+# Auto-downloaded from https://core.telegram.org/getProxySecret on first run.
+# This key authenticates your proxy with Middle-End servers.
+proxy_secret_path = "proxy-secret"
+
+# ------------------------------------------------------------------------------
+# Public IP Configuration (Critical for Middle-Proxy Mode)
+# ------------------------------------------------------------------------------
+
+# Your server's PUBLIC IPv4 address.
+# Middle-End servers need this for the cryptographic Key Derivation Function.
+# If your server has a direct public IP, set it here.
+# If behind NAT (AWS, Docker, etc.), this MUST be your external IP.
+# If omitted, Telemt uses STUN to auto-detect (see middle_proxy_nat_probe).
+# middle_proxy_nat_ip = "203.0.113.10"
+
+# Auto-detect public IP via STUN servers defined in [network].
+# Set to false if you hardcoded middle_proxy_nat_ip above.
+# Set to true if you want automatic detection.
+middle_proxy_nat_probe = true
+
+# ------------------------------------------------------------------------------
+# Middle-End Connection Pool
+# ------------------------------------------------------------------------------
+
+# Number of persistent multiplexed RPC connections to ME servers.
+# All client traffic is routed through these "fat pipes".
+# 8 handles thousands of concurrent users comfortably.
+middle_proxy_pool_size = 8
+
+# Legacy field. Connections kept initialized but idle as warm standby.
+middle_proxy_warm_standby = 16
+
+# ------------------------------------------------------------------------------
+# Middle-End Keepalive
+# Telegram ME servers aggressively kill idle TCP connections.
+# These settings send periodic RPC_PING frames to keep pipes alive.
+# ------------------------------------------------------------------------------
+
+me_keepalive_enabled = true
+
+# Base interval between pings in seconds.
+me_keepalive_interval_secs = 25
+
+# Random jitter added to interval to prevent all connections pinging simultaneously.
+me_keepalive_jitter_secs = 5
+
+# Randomize ping payload bytes to prevent DPI from fingerprinting ping patterns.
+me_keepalive_payload_random = true
+
+# ------------------------------------------------------------------------------
+# Client-Side Limits
+# ------------------------------------------------------------------------------
+
+# Max buffered ciphertext per client (bytes) when upstream is slow.
+# Acts as backpressure to prevent memory exhaustion. 256KB is safe.
+crypto_pending_buffer = 262144
+
+# Maximum single MTProto frame size from client. 16MB is protocol standard.
+max_client_frame = 16777216
+
+# ------------------------------------------------------------------------------
+# Crypto Desynchronization Logging
+# Desync errors usually mean DPI/GFW is tampering with connections.
+# ------------------------------------------------------------------------------
+
+# true  = full forensics (trace ID, IP hash, hex dumps) for EVERY desync event
+# false = deduplicated logging, one entry per time window (prevents log spam)
+# Set true if you are actively debugging DPI interference.
+desync_all_full = true
+
+# ------------------------------------------------------------------------------
+# Beobachten — Built-in Honeypot / Active Probe Tracker
+# Tracks IPs that fail handshakes or behave like TLS scanners.
+# Output file can be fed into fail2ban or iptables for auto-blocking.
+# ------------------------------------------------------------------------------
+
+beobachten = true
+
+# How long (minutes) to remember a suspicious IP before expiring it.
+beobachten_minutes = 30
+
+# How often (seconds) to flush tracker state to disk.
+beobachten_flush_secs = 15
+
+# File path for the tracker output.
+beobachten_file = "cache/beobachten.txt"
+
+# ------------------------------------------------------------------------------
+# Hardswap — Zero-Downtime ME Pool Rotation
+# When Telegram updates ME server IPs, Hardswap creates a completely new pool,
+# waits until it is fully ready, migrates traffic, then kills the old pool.
+# Users experience zero interruption.
+# ------------------------------------------------------------------------------
+
+hardswap = true
+
+# ------------------------------------------------------------------------------
+# ME Pool Warmup Staggering
+# When creating a new pool, connections are opened one by one with delays
+# to avoid a burst of SYN packets that could trigger ISP flood protection.
+# ------------------------------------------------------------------------------
+
+me_warmup_stagger_enabled = true
+
+# Delay between each connection creation (milliseconds).
+me_warmup_step_delay_ms = 500
+
+# Random jitter added to the delay (milliseconds).
+me_warmup_step_jitter_ms = 300
+
+# ------------------------------------------------------------------------------
+# ME Reconnect Backoff
+# If an ME server drops the connection, Telemt retries with this strategy.
+# ------------------------------------------------------------------------------
+
+# Max simultaneous reconnect attempts per DC.
+me_reconnect_max_concurrent_per_dc = 8
+
+# Exponential backoff base (milliseconds).
+me_reconnect_backoff_base_ms = 500
+
+# Backoff ceiling (milliseconds). Will never wait longer than this.
+me_reconnect_backoff_cap_ms = 30000
+
+# Number of instant retries before switching to exponential backoff.
+me_reconnect_fast_retry_count = 12
+
+# ------------------------------------------------------------------------------
+# NAT Mismatch Behavior
+# If STUN-detected IP differs from local interface IP (you are behind NAT).
+# false = abort ME mode (safe default)
+# true  = force ME mode anyway (use if you know your NAT setup is correct)
+# ------------------------------------------------------------------------------
+
+stun_iface_mismatch_ignore = false
+
+# ------------------------------------------------------------------------------
+# Logging
+# ------------------------------------------------------------------------------
+
+# File to log unknown DC requests (DC IDs outside standard 1-5).
+unknown_dc_log_path = "unknown-dc.txt"
+
+# Verbosity: "debug" | "verbose" | "normal" | "silent"
+log_level = "normal"
+
+# Disable ANSI color codes in log output (useful for file logging).
+disable_colors = false
+
+# ------------------------------------------------------------------------------
+# FakeTLS Record Sizing
+# Buffer small MTProto packets into larger TLS records to mimic real HTTPS.
+# Real HTTPS servers send records close to MTU size (~1400 bytes).
+# A stream of tiny TLS records is a strong DPI signal.
+# Set to 0 to disable. Set to 1400 for realistic HTTPS emulation.
+# ------------------------------------------------------------------------------
+
+fast_mode_min_tls_record = 1400
+
+# ------------------------------------------------------------------------------
+# Periodic Updates
+# ------------------------------------------------------------------------------
+
+# How often (seconds) to re-fetch ME server lists and proxy secrets
+# from core.telegram.org. Keeps your proxy in sync with Telegram infrastructure.
+update_every = 300
+
+# How often (seconds) to force a Hardswap even if the ME map is unchanged.
+# Shorter intervals mean shorter-lived TCP flows, harder for DPI to profile.
+me_reinit_every_secs = 600
+
+# ------------------------------------------------------------------------------
+# Hardswap Warmup Tuning
+# Fine-grained control over how the new pool is warmed up before traffic switch.
+# ------------------------------------------------------------------------------
+
+me_hardswap_warmup_delay_min_ms = 1000
+me_hardswap_warmup_delay_max_ms = 2000
+me_hardswap_warmup_extra_passes = 3
+me_hardswap_warmup_pass_backoff_base_ms = 500
+
+# ------------------------------------------------------------------------------
+# Config Update Debouncing
+# Telegram sometimes pushes transient/broken configs. Debouncing requires
+# N consecutive identical fetches before applying a change.
+# ------------------------------------------------------------------------------
+
+# ME server list must be identical for this many fetches before applying.
+me_config_stable_snapshots = 2
+
+# Minimum seconds between config applications.
+me_config_apply_cooldown_secs = 300
+
+# Proxy secret must be identical for this many fetches before applying.
+proxy_secret_stable_snapshots = 2
+
+# ------------------------------------------------------------------------------
+# Proxy Secret Rotation
+# ------------------------------------------------------------------------------
+
+# Apply newly downloaded secrets at runtime without restart.
+proxy_secret_rotate_runtime = true
+
+# Maximum acceptable secret length (bytes). Rejects abnormally large secrets.
+proxy_secret_len_max = 256
+
+# ------------------------------------------------------------------------------
+# Hardswap Drain Settings
+# Controls graceful shutdown of old ME connections during pool rotation.
+# ------------------------------------------------------------------------------
+
+# Seconds to keep old connections alive for in-flight data before force-closing.
+me_pool_drain_ttl_secs = 90
+
+# Minimum ratio of healthy connections in new pool before draining old pool.
+# 0.8 = at least 80% of new pool must be ready.
+me_pool_min_fresh_ratio = 0.8
+
+# Maximum seconds to wait for drain to complete before force-killing.
+me_reinit_drain_timeout_secs = 120
+
+# ------------------------------------------------------------------------------
+# NTP Clock Check
+# MTProto uses timestamps. Clock drift > 30 seconds breaks handshakes.
+# Telemt checks on startup and warns if out of sync.
+# ------------------------------------------------------------------------------
+
+ntp_check = true
+ntp_servers = ["pool.ntp.org"]
+
+# ------------------------------------------------------------------------------
+# Auto-Degradation
+# If ME servers become completely unreachable (ISP blocking),
+# automatically fall back to Direct Mode so users stay connected.
+# ------------------------------------------------------------------------------
+
+auto_degradation_enabled = true
+
+# Number of DC groups that must be unreachable before triggering fallback.
+degradation_min_unavailable_dc_groups = 2
+
+
+# ==============================================================================
+# ALLOWED CLIENT PROTOCOLS
+# Only enable what you need. In censored regions, TLS-only is safest.
+# ==============================================================================
+
+[general.modes]
+
+# Classic MTProto. Unobfuscated length prefixes. Trivially detected by DPI.
+# No reason to enable unless you have ancient clients.
+classic = false
+
+# Obfuscated MTProto with randomized padding. Better than classic, but
+# still detectable by statistical analysis of packet sizes.
+secure = false
+
+# FakeTLS (ee-secrets). Wraps MTProto in TLS 1.3 framing.
+# To DPI, it looks like a normal HTTPS connection.
+# This should be the ONLY enabled mode in censored environments.
+tls = true
+
+
+# ==============================================================================
+# STARTUP LINK GENERATION
+# Controls what tg:// invite links are printed to console on startup.
+# ==============================================================================
+
+[general.links]
+
+# Which users to generate links for.
+# "*" = all users, or an array like ["alice", "bob"].
+show = "*"
+
+# IP or domain to embed in the tg:// link.
+# If omitted, Telemt uses STUN to auto-detect.
+# Set this to your server's public IP or domain for reliable links.
+# public_host = "proxy.example.com"
+
+# Port to embed in the tg:// link.
+# If omitted, uses [server].port.
+# public_port = 443
+
+
+# ==============================================================================
+# NETWORK & IP RESOLUTION
+# ==============================================================================
+
+[network]
+
+# Enable IPv4 for outbound connections to Telegram.
+ipv4 = true
+
+# Enable IPv6 for outbound connections to Telegram.
+ipv6 = false
+
+# Prefer IPv4 (4) or IPv6 (6) when both are available.
+prefer = 4
+
+# Experimental: use both IPv4 and IPv6 ME servers simultaneously.
+# May improve reliability but doubles connection count.
+multipath = false
+
+# STUN servers for external IP discovery.
+# Used for Middle-Proxy KDF (if nat_probe=true) and link generation.
+stun_servers = [
+    "stun.l.google.com:5349",
+    "stun1.l.google.com:3478",
+    "stun.gmx.net:3478",
+    "stun.l.google.com:19302"
+]
+
+# If UDP STUN is blocked, attempt TCP-based STUN as fallback.
+stun_tcp_fallback = true
+
+# If all STUN fails, use HTTP APIs to discover public IP.
+http_ip_detect_urls = [
+    "https://ifconfig.me/ip",
+    "https://api.ipify.org"
+]
+
+# Cache discovered public IP to this file to survive restarts.
+cache_public_ip_path = "cache/public_ip.txt"
+
+
+# ==============================================================================
+# SERVER BINDING & METRICS
+# ==============================================================================
+
+[server]
+
+# TCP port to listen on.
+# 443 is recommended (looks like normal HTTPS traffic).
+port = 443
+
+# IPv4 bind address. "0.0.0.0" = all interfaces.
+listen_addr_ipv4 = "0.0.0.0"
+
+# IPv6 bind address. "::" = all interfaces.
+listen_addr_ipv6 = "::"
+
+# Unix socket listener (for reverse proxy setups with Nginx/HAProxy).
+# listen_unix_sock = "/var/run/telemt.sock"
+# listen_unix_sock_perm = "0660"
+
+# Enable PROXY protocol header parsing.
+# Set true ONLY if Telemt is behind HAProxy/Nginx that injects PROXY headers.
+# If enabled without a proxy in front, clients will fail to connect.
+proxy_protocol = false
+
+# Prometheus metrics HTTP endpoint port.
+# Uncomment to enable. Access at http://your-server:9090/metrics
+# metrics_port = 9090
+
+# IP ranges allowed to access the metrics endpoint.
+metrics_whitelist = [
+    "127.0.0.1/32",
+    "::1/128"
+]
+
+# ------------------------------------------------------------------------------
+# Listener Overrides
+# Define explicit listeners with specific bind IPs and announce IPs.
+# The announce IP is what gets embedded in tg:// links and sent to ME servers.
+# You MUST set announce to your server's public IP for ME mode to work.
+# ------------------------------------------------------------------------------
+
+# [[server.listeners]]
+# ip = "0.0.0.0"
+# announce = "203.0.113.10"
+# reuse_allow = false
+
+
+# ==============================================================================
+# TIMEOUTS (seconds unless noted)
+# ==============================================================================
+
+[timeouts]
+
+# Maximum time for client to complete FakeTLS + MTProto handshake.
+client_handshake = 15
+
+# Maximum time to establish TCP connection to upstream Telegram DC.
+tg_connect = 10
+
+# TCP keepalive interval for client connections.
+client_keepalive = 60
+
+# Maximum client inactivity before dropping the connection.
+client_ack = 300
+
+# Instant retry count for a single ME endpoint before giving up on it.
+me_one_retry = 3
+
+# Timeout (milliseconds) for a single ME endpoint connection attempt.
+me_one_timeout_ms = 1500
+
+
+# ==============================================================================
+# ANTI-CENSORSHIP / FAKETLS / MASKING
+# This is where Telemt becomes invisible to Deep Packet Inspection.
+# ==============================================================================
+
+[censorship]
+
+# ------------------------------------------------------------------------------
+# TLS Domain Fronting
+# The SNI (Server Name Indication) your proxy presents to connecting clients.
+# Must be a popular, unblocked HTTPS website in your target country.
+# DPI sees traffic to this domain. Choose carefully.
+# Good choices: major CDNs, banks, government sites, search engines.
+# Bad choices: obscure sites, already-blocked domains.
+# ------------------------------------------------------------------------------
+
+tls_domain = "www.google.com"
+
+# ------------------------------------------------------------------------------
+# Active Probe Masking
+# When someone connects but fails the MTProto handshake (wrong secret),
+# they might be an ISP active prober testing if this is a proxy.
+#
+# mask = false: drop the connection (prober knows something is here)
+# mask = true:  transparently proxy them to mask_host (prober sees a real website)
+#
+# With mask enabled, your server is indistinguishable from a real web server
+# to anyone who doesn't have the correct secret.
+# ------------------------------------------------------------------------------
+
+mask = true
+
+# The real web server to forward failed handshakes to.
+# If omitted, defaults to tls_domain.
+# mask_host = "www.google.com"
+
+# Port on the mask host to connect to.
+mask_port = 443
+
+# Inject PROXY protocol header when forwarding to mask host.
+# 0 = disabled, 1 = v1, 2 = v2. Leave disabled unless mask_host expects it.
+# mask_proxy_protocol = 0
+
+# ------------------------------------------------------------------------------
+# TLS Certificate Emulation
+# ------------------------------------------------------------------------------
+
+# Size (bytes) of the locally generated fake TLS certificate.
+# Only used when tls_emulation is disabled.
+fake_cert_len = 2048
+
+# KILLER FEATURE: Real-Time TLS Emulation.
+# Telemt connects to tls_domain, fetches its actual TLS 1.3 certificate chain,
+# and exactly replicates the byte sizes of ServerHello and Certificate records.
+# Defeats DPI that uses TLS record length heuristics to detect proxies.
+# Strongly recommended in censored environments.
+tls_emulation = true
+
+# Directory to cache fetched TLS certificates.
+tls_front_dir = "tlsfront"
+
+# ------------------------------------------------------------------------------
+# ServerHello Timing
+# Real web servers take 30-150ms to respond to ClientHello due to network
+# latency and crypto processing. A proxy responding in <1ms is suspicious.
+# These settings add realistic delay to mimic genuine server behavior.
+# ------------------------------------------------------------------------------
+
+# Minimum delay before sending ServerHello (milliseconds).
+server_hello_delay_min_ms = 50
+
+# Maximum delay before sending ServerHello (milliseconds).
+server_hello_delay_max_ms = 150
+
+# ------------------------------------------------------------------------------
+# TLS Session Tickets
+# Real TLS 1.3 servers send 1-2 NewSessionTicket messages after handshake.
+# A server that sends zero tickets is anomalous and may trigger DPI flags.
+# Set this to match your tls_domain's behavior (usually 2).
+# ------------------------------------------------------------------------------
+
+# tls_new_session_tickets = 0
+
+# ------------------------------------------------------------------------------
+# Full Certificate Frequency
+# When tls_emulation is enabled, this controls how often (per client IP)
+# to send the complete emulated certificate chain.
+#
+# > 0: Subsequent connections within TTL seconds get a smaller cached version.
+#       Saves bandwidth but creates a detectable size difference between
+#       first and repeat connections.
+#
+# = 0: Every connection gets the full certificate. More bandwidth but
+#       perfectly consistent behavior, no anomalies for DPI to detect.
+# ------------------------------------------------------------------------------
+
+tls_full_cert_ttl_secs = 0
+
+# ------------------------------------------------------------------------------
+# ALPN Enforcement
+# Ensure ServerHello responds with the exact ALPN protocol the client requested.
+# Mismatched ALPN (e.g., client asks h2, server says http/1.1) is a DPI red flag.
+# ------------------------------------------------------------------------------
+
+alpn_enforce = true
+
+
+# ==============================================================================
+# ACCESS CONTROL & USERS
+# ==============================================================================
+
+[access]
+
+# ------------------------------------------------------------------------------
+# Replay Attack Protection
+# DPI can record a legitimate user's handshake and replay it later to probe
+# whether the server is a proxy. Telemt remembers recent handshake nonces
+# and rejects duplicates.
+# ------------------------------------------------------------------------------
+
+# Number of nonce slots in the replay detection buffer.
+replay_check_len = 65536
+
+# How long (seconds) to remember nonces before expiring them.
+replay_window_secs = 1800
+
+# Allow clients with incorrect system clocks to connect.
+# false = reject clients with significant time skew (more secure)
+# true  = accept anyone regardless of clock (more permissive)
+ignore_time_skew = false
+
+# ------------------------------------------------------------------------------
+# User Secrets
+# Each user needs a unique 32-character hex string as their secret.
+# Generate with: openssl rand -hex 16
+#
+# This secret is embedded in the tg:// link. Anyone with it can connect.
+# Format: username = "hex_secret"
+# ------------------------------------------------------------------------------
+
+[access.users]
+# alice = "0123456789abcdef0123456789abcdef"
+# bob = "fedcba9876543210fedcba9876543210"
+
+# ------------------------------------------------------------------------------
+# Per-User Connection Limits
+# Limits concurrent TCP connections per user to prevent secret sharing.
+# Uncomment and set for each user as needed.
+# ------------------------------------------------------------------------------
+
+[access.user_max_tcp_conns]
+# alice = 100
+# bob = 50
+
+# ------------------------------------------------------------------------------
+# Per-User Expiration Dates
+# Automatically revoke access after the specified date (ISO 8601 format).
+# ------------------------------------------------------------------------------
+
+[access.user_expirations]
+# alice = "2025-12-31T23:59:59Z"
+# bob = "2026-06-15T00:00:00Z"
+
+# ------------------------------------------------------------------------------
+# Per-User Data Quotas
+# Maximum total bytes transferred per user. Connection refused after limit.
+# ------------------------------------------------------------------------------
+
+[access.user_data_quota]
+# alice = 107374182400
+# bob = 53687091200
+
+# ------------------------------------------------------------------------------
+# Per-User Unique IP Limits
+# Maximum number of different IP addresses that can use this secret
+# at the same time. Highly effective against secret leaking/sharing.
+# Set to 1 for single-device, 2-3 for phone+desktop, etc.
+# ------------------------------------------------------------------------------
+
+[access.user_max_unique_ips]
+# alice = 3
+# bob = 2
+
+
+# ==============================================================================
+# UPSTREAM ROUTING
+# Controls how Telemt connects to Telegram servers (or ME servers).
+# If omitted entirely, uses the OS default route.
+# ==============================================================================
+
+# ------------------------------------------------------------------------------
+# Direct upstream: use the server's own network interface.
+# You can optionally bind to a specific interface or local IP.
+# ------------------------------------------------------------------------------
+
+# [[upstreams]]
+# type = "direct"
+# interface = "eth0"
+# bind_addresses = ["192.0.2.10"]
+# weight = 1
+# enabled = true
+# scopes = "*"
+
+# ------------------------------------------------------------------------------
+# SOCKS5 upstream: route Telegram traffic through a SOCKS5 proxy.
+# Useful if your server's IP is blocked from reaching Telegram DCs.
+# ------------------------------------------------------------------------------
+
+# [[upstreams]]
+# type = "socks5"
+# address = "198.51.100.30:1080"
+# username = "proxy-user"
+# password = "proxy-pass"
+# weight = 1
+# enabled = true
+
+
+# ==============================================================================
+# DATACENTER OVERRIDES
+# Force specific DC IDs to route to specific IP:Port combinations.
+# DC 203 (CDN) is auto-injected by Telemt if not specified here.
+# ==============================================================================
+
+# [dc_overrides]
+# "201" = "149.154.175.50:443"
+# "202" = ["149.154.167.51:443", "149.154.175.100:443"]

config.toml

@@ -1,13 +1,57 @@
-port = 443
+### Telemt Based Config.toml
+# We believe that these settings are sufficient for most scenarios 
+# where cutting-egde methods and parameters or special solutions are not needed
 
-[users]
-user1 = "00000000000000000000000000000000"
+# === General Settings ===
+[general]
+use_middle_proxy = true
+# Global ad_tag fallback when user has no per-user tag in [access.user_ad_tags]
+# ad_tag = "00000000000000000000000000000000"
+# Per-user ad_tag in [access.user_ad_tags] (32 hex from @MTProxybot)
 
-[modes]
-classic = true
-secure = true
+# === Log Level ===
+# Log level: debug | verbose | normal | silent
+# Can be overridden with --silent or --log-level CLI flags
+# RUST_LOG env var takes absolute priority over all of these
+log_level = "normal"
+
+[general.modes]
+classic = false
+secure = false
 tls = true
 
-tls_domain = "www.github.com"
-fast_mode = true
-prefer_ipv6 = false
+[general.links]
+show = "*"
+# show = ["alice", "bob"] # Only show links for alice and bob
+# show = "*"              # Show links for all users
+# public_host = "proxy.example.com"  # Host (IP or domain) for tg:// links
+# public_port = 443                  # Port for tg:// links (default: server.port)
+
+# === Server Binding ===
+[server]
+port = 443
+# proxy_protocol = false           # Enable if behind HAProxy/nginx with PROXY protocol
+# metrics_port = 9090
+# metrics_whitelist = ["127.0.0.1", "::1", "0.0.0.0/0"]
+
+[server.api]
+enabled = true
+listen = "0.0.0.0:9091"
+whitelist = ["127.0.0.0/8"]
+minimal_runtime_enabled = false
+minimal_runtime_cache_ttl_ms = 1000
+
+# Listen on multiple interfaces/IPs - IPv4
+[[server.listeners]]
+ip = "0.0.0.0"
+
+# === Anti-Censorship & Masking ===
+[censorship]
+tls_domain = "petrovich.ru"
+mask = true
+tls_emulation = true        # Fetch real cert lengths and emulate TLS records
+tls_front_dir = "tlsfront"   # Cache directory for TLS emulation
+
+[access.users]
+# format: "username" = "32_hex_chars_secret"
+hello = "00000000000000000000000000000000"

docker-compose.yml

@@ -0,0 +1,30 @@
+services:
+  telemt:
+    image: ghcr.io/telemt/telemt:latest
+    build: .
+    container_name: telemt
+    restart: unless-stopped
+    ports:
+      - "443:443"
+      - "127.0.0.1:9090:9090"
+    # Allow caching 'proxy-secret' in read-only container
+    working_dir: /run/telemt
+    volumes:
+      - ./config.toml:/run/telemt/config.toml:ro
+    tmpfs:
+      - /run/telemt:rw,mode=1777,size=1m
+    environment:
+      - RUST_LOG=info
+    # Uncomment this line if you want to use host network for IPv6, but bridge is default and usually better
+    # network_mode: host
+    cap_drop:
+      - ALL
+    cap_add:
+      - NET_BIND_SERVICE   # allow binding to port 443
+    read_only: true
+    security_opt:
+      - no-new-privileges:true
+    ulimits:
+      nofile:
+        soft: 65536
+        hard: 65536

docs/FAQ.en.md

@@ -0,0 +1,112 @@
+## How to set up "proxy sponsor" channel and statistics via @MTProxybot bot
+
+1. Go to @MTProxybot bot.
+2. Enter the command `/newproxy`
+3. Send the server IP and port. For example: 1.2.3.4:443
+4. Open the config `nano /etc/telemt.toml`.
+5. Copy and send the user secret from the [access.users] section to the bot.
+6. Copy the tag received from the bot. For example 1234567890abcdef1234567890abcdef.
+> [!WARNING]
+> The link provided by the bot will not work. Do not copy or use it!
+7. Uncomment the ad_tag parameter and enter the tag received from the bot.
+8. Uncomment/add the parameter `use_middle_proxy = true`.
+
+Config example:
+```toml
+[general]
+ad_tag = "1234567890abcdef1234567890abcdef"
+use_middle_proxy = true
+```
+9. Save the config. Ctrl+S -> Ctrl+X.
+10. Restart telemt `systemctl restart telemt`.
+11. In the bot, send the command /myproxies and select the added server.
+12. Click the "Set promotion" button.
+13. Send a **public link** to the channel. Private channels cannot be added!
+14. Wait approximately 1 hour for the information to update on Telegram servers.
+> [!WARNING]
+> You will not see the "proxy sponsor" if you are already subscribed to the channel.
+
+**You can also set up different channels for different users.**
+```toml
+[access.user_ad_tags]
+hello = "ad_tag"
+hello2 = "ad_tag2"
+```
+
+## How many people can use 1 link
+
+By default, 1 link can be used by any number of people.  
+You can limit the number of IPs using the proxy.
+```toml
+[access.user_max_unique_ips]
+hello = 1
+```
+This parameter limits how many unique IPs can use 1 link simultaneously. If one user disconnects, a second user can connect. Also, multiple users can sit behind the same IP.
+
+## How to create multiple different links
+
+1. Generate the required number of secrets `openssl rand -hex 16`
+2. Open the config `nano /etc/telemt.toml`
+3. Add new users.
+```toml
+[access.users]
+user1 = "00000000000000000000000000000001"
+user2 = "00000000000000000000000000000002"
+user3 = "00000000000000000000000000000003"
+```
+4. Save the config. Ctrl+S -> Ctrl+X. You don't need to restart telemt.
+5. Get the links via `journalctl -u telemt -n -g "links" --no-pager -o cat | tac`
+
+## How to view metrics
+
+1. Open the config `nano /etc/telemt.toml`
+2. Add the following parameters
+```toml
+[server]
+metrics_port = 9090
+metrics_whitelist = ["127.0.0.1/32", "::1/128", "0.0.0.0/0"]
+```
+3. Save the config. Ctrl+S -> Ctrl+X.
+4. Metrics are available at SERVER_IP:9090/metrics.
+> [!WARNING]
+> "0.0.0.0/0" in metrics_whitelist opens access from any IP. Replace with your own IP. For example "1.2.3.4"
+
+## Additional parameters
+
+### Domain in link instead of IP
+To specify a domain in the links, add to the `[general.links]` section of the config file.
+```toml
+[general.links]
+public_host = "proxy.example.com"
+```
+
+### Upstream Manager
+To specify an upstream, add to the `[[upstreams]]` section of the config.toml file:
+#### Binding to IP
+```toml
+[[upstreams]]
+type = "direct"
+weight = 1
+enabled = true
+interface = "192.168.1.100" # Change to your outgoing IP
+```
+#### SOCKS4/5 as Upstream
+- Without authentication:
+```toml
+[[upstreams]]
+type = "socks5"            # Specify SOCKS4 or SOCKS5
+address = "1.2.3.4:1234"   # SOCKS-server Address
+weight = 1                 # Set Weight for Scenarios
+enabled = true
+```
+
+- With authentication:
+```toml
+[[upstreams]]
+type = "socks5"            # Specify SOCKS4 or SOCKS5
+address = "1.2.3.4:1234"   # SOCKS-server Address
+username = "user"          # Username for Auth on SOCKS-server
+password = "pass"          # Password for Auth on SOCKS-server
+weight = 1                 # Set Weight for Scenarios
+enabled = true
+```

docs/FAQ.ru.md

@@ -0,0 +1,112 @@
+## Как настроить канал "спонсор прокси" и статистику через бота @MTProxybot
+
+1. Зайти в бота @MTProxybot.
+2. Ввести команду `/newproxy`
+3. Отправить IP и порт сервера. Например: 1.2.3.4:443
+4. Открыть конфиг `nano /etc/telemt.toml`.
+5. Скопировать и отправить боту секрет пользователя из раздела [access.users].
+6. Скопировать полученный tag у бота. Например 1234567890abcdef1234567890abcdef.
+> [!WARNING]
+> Ссылка, которую выдает бот, не будет работать. Не копируйте и не используйте её!
+7. Раскомментировать параметр ad_tag и вписать tag, полученный у бота.
+8. Раскомментировать/добавить параметр use_middle_proxy = true.
+
+Пример конфига:
+```toml
+[general]
+ad_tag = "1234567890abcdef1234567890abcdef"
+use_middle_proxy = true
+```
+9.  Сохранить конфиг. Ctrl+S -> Ctrl+X.
+10. Перезапустить telemt `systemctl restart telemt`.
+11. В боте отправить команду /myproxies и выбрать добавленный сервер.
+12. Нажать кнопку "Set promotion".
+13. Отправить **публичную ссылку** на канал. Приватный канал добавить нельзя!
+14. Подождать примерно 1 час, пока информация обновится на серверах Telegram.
+> [!WARNING]
+> У вас не будет отображаться "спонсор прокси" если вы уже подписаны на канал.
+
+**Также вы можете настроить разные каналы для разных пользователей.**
+```toml
+[access.user_ad_tags]
+hello = "ad_tag"
+hello2 = "ad_tag2"
+```
+
+## Сколько человек может пользоваться 1 ссылкой
+
+По умолчанию 1 ссылкой может пользоваться сколько угодно человек.  
+Вы можете ограничить число IP, использующих прокси.
+```toml
+[access.user_max_unique_ips]
+hello = 1
+```
+Этот параметр ограничивает, сколько уникальных IP может использовать 1 ссылку одновременно. Если один пользователь отключится, второй сможет подключиться. Также с одного IP может сидеть несколько пользователей.
+
+## Как сделать несколько разных ссылок
+
+1. Сгенерируйте нужное число секретов `openssl rand -hex 16`
+2. Открыть конфиг `nano /etc/telemt.toml`
+3. Добавить новых пользователей.
+```toml
+[access.users]
+user1 = "00000000000000000000000000000001"
+user2 = "00000000000000000000000000000002"
+user3 = "00000000000000000000000000000003"
+```
+4. Сохранить конфиг. Ctrl+S -> Ctrl+X. Перезапускать telemt не нужно.
+5. Получить ссылки через `journalctl -u telemt -n -g "links" --no-pager -o cat | tac`
+
+## Как посмотреть метрики
+
+1. Открыть конфиг `nano /etc/telemt.toml`
+2. Добавить следующие параметры
+```toml
+[server]
+metrics_port = 9090
+metrics_whitelist = ["127.0.0.1/32", "::1/128", "0.0.0.0/0"]
+```
+3. Сохранить конфиг. Ctrl+S -> Ctrl+X.
+4. Метрики доступны по адресу SERVER_IP:9090/metrics. 
+> [!WARNING]
+> "0.0.0.0/0" в metrics_whitelist открывает доступ с любого IP. Замените на свой ip. Например "1.2.3.4"
+
+## Дополнительные параметры
+
+### Домен в ссылке вместо IP
+Чтобы указать домен в ссылках, добавьте в секцию `[general.links]` файла config.
+```toml
+[general.links]
+public_host = "proxy.example.com"
+```
+
+### Upstream Manager
+Чтобы указать апстрим, добавьте в секцию `[[upstreams]]` файла config.toml:
+#### Привязка к IP
+```toml
+[[upstreams]]
+type = "direct"
+weight = 1
+enabled = true
+interface = "192.168.1.100" # Change to your outgoing IP
+```
+#### SOCKS4/5 как Upstream
+- Без авторизации:
+```toml
+[[upstreams]]
+type = "socks5"            # Specify SOCKS4 or SOCKS5
+address = "1.2.3.4:1234"   # SOCKS-server Address
+weight = 1                 # Set Weight for Scenarios
+enabled = true
+```
+
+- С авторизацией:
+```toml
+[[upstreams]]
+type = "socks5"            # Specify SOCKS4 or SOCKS5
+address = "1.2.3.4:1234"   # SOCKS-server Address
+username = "user"          # Username for Auth on SOCKS-server
+password = "pass"          # Password for Auth on SOCKS-server
+weight = 1                 # Set Weight for Scenarios
+enabled = true
+```

docs/MIDDLE-END-KDF.de.md

@@ -0,0 +1,40 @@
+# Middle-End Proxy
+
+## KDF-Adressierung — Implementierungs-FAQ
+
+### Benötigt die C-Referenzimplementierung sowohl externe IP-Adresse als auch Port für die KDF?
+
+Ja.
+
+In der C-Referenzimplementierung werden **sowohl IP-Adresse als auch Port in die KDF einbezogen** — auf beiden Seiten der Verbindung.
+
+In `aes_create_keys()` enthält der KDF-Input:
+
+- `server_ip + client_port`
+- `client_ip + server_port`
+- sowie Secret / Nonces
+
+Für IPv6:
+
+- IPv4-Felder werden auf 0 gesetzt
+- IPv6-Adressen werden ergänzt
+
+Die **Ports bleiben weiterhin Bestandteil der KDF**.
+
+> Wenn sich externe IP oder Port (z. B. durch NAT, SOCKS oder Proxy) von den erwarteten Werten unterscheiden, entstehen unterschiedliche Schlüssel — der Handshake schlägt fehl.
+
+---
+
+### Kann der Port aus der KDF ausgeschlossen werden (z. B. durch Port = 0)?
+
+**Nein!**
+
+Die C-Referenzimplementierung enthält **keine Möglichkeit, den Port zu ignorieren**:
+- `client_port` und `server_port` sind fester Bestandteil der KDF
+- Es werden immer reale Socket-Ports übergeben:
+  - `c->our_port`
+  - `c->remote_port`
+
+Falls ein Port den Wert `0` hat, wird er dennoch als `0` in die KDF übernommen.
+
+Eine „Port-Ignore“-Logik existiert nicht.

docs/MIDDLE-END-KDF.en.md

@@ -0,0 +1,41 @@
+# Middle-End Proxy
+
+## KDF Addressing — Implementation FAQ
+
+### Does the C-implementation require both external IP address and port for the KDF?
+
+**Yes!**
+
+In the C reference implementation, **both IP address and port are included in the KDF input** from both sides of the connection.
+
+Inside `aes_create_keys()`, the KDF input explicitly contains:
+
+- `server_ip + client_port`
+- `client_ip + server_port`
+- followed by shared secret / nonces
+
+For IPv6:
+
+- IPv4 fields are zeroed
+- IPv6 addresses are inserted
+
+However, **client_port and server_port remain part of the KDF regardless of IP version**.
+
+> If externally observed IP or port (e.g. due to NAT, SOCKS, or proxy traversal) differs from what the peer expects, the derived keys will not match and the handshake will fail.
+
+---
+
+### Can port be excluded from KDF (e.g. by using port = 0)?
+
+**No!**
+
+The C-implementation provides **no mechanism to ignore the port**:
+
+- `client_port` and `server_port` are explicitly included in the KDF input
+- Real socket ports are always passed:
+  - `c->our_port`
+  - `c->remote_port`
+
+If a port is `0`, it is still incorporated into the KDF as `0`.
+
+There is **no conditional logic to exclude ports**

docs/MIDDLE-END-KDF.ru.md

@@ -0,0 +1,41 @@
+# Middle-End Proxy
+
+## KDF Addressing — FAQ по реализации
+
+### Требует ли C-референсная реализация KDF внешний IP и порт?
+
+**Да**
+
+В C-референсе **в KDF участвуют и IP-адрес, и порт** — с обеих сторон соединения.
+
+В `aes_create_keys()` в строку KDF входят:
+
+- `server_ip + client_port`
+- `client_ip + server_port`
+- далее secret / nonces
+
+Для IPv6:
+
+- IPv4-поля заполняются нулями
+- добавляются IPv6-адреса
+
+Однако **порты client_port и server_port всё равно участвуют в KDF**.
+
+> Если внешний IP или порт (например, из-за NAT, SOCKS или прокси) не совпадает с ожидаемым другой стороной — ключи расходятся и handshake ломается.
+
+---
+
+### Можно ли исключить порт из KDF (например, установив порт = 0)?
+
+**Нет.**
+
+В C-референсе **нет механики отключения порта**.
+
+- `client_port` и `server_port` явно включены в KDF
+- Передаются реальные порты сокета:
+  - `c->our_port`
+  - `c->remote_port`
+
+Если порт равен `0`, он всё равно попадёт в KDF как `0`.
+
+Отдельной логики «игнорировать порт» не предусмотрено.

docs/QUICK_START_GUIDE.en.md

@@ -0,0 +1,165 @@
+# Telemt via Systemd
+
+## Installation
+
+This software is designed for Debian-based OS: in addition to Debian, these are Ubuntu, Mint, Kali, MX and many other Linux
+
+**1. Download**
+```bash
+wget -qO- "https://github.com/telemt/telemt/releases/latest/download/telemt-$(uname -m)-linux-$(ldd --version 2>&1 | grep -iq musl && echo musl || echo gnu).tar.gz" | tar -xz
+```
+**2. Move to the Bin folder**
+```bash
+mv telemt /bin
+```
+**3. Make the file executable**
+```bash
+chmod +x /bin/telemt
+```
+
+## How to use?
+
+**This guide "assumes" that you:**
+- logged in as root or executed `su -` / `sudo su`
+- Already have the "telemt" executable file in the /bin folder. Read the **[Installation](#Installation)** section.
+
+---
+
+**0. Check port and generate secrets**
+
+The port you have selected for use should be MISSING from the list, when:
+```bash
+netstat -lnp
+```
+
+Generate 16 bytes/32 characters HEX with OpenSSL or another way:
+```bash
+openssl rand -hex 16
+```
+OR
+```bash
+xxd -l 16 -p /dev/urandom
+```
+OR
+```bash
+python3 -c 'import os; print(os.urandom(16).hex())'
+```
+Save the obtained result somewhere. You will need it later!
+
+---
+
+**1. Place your config to /etc/telemt.toml**
+
+Open nano
+```bash
+nano /etc/telemt.toml
+```
+paste your config
+
+```toml
+# === General Settings ===
+[general]
+# ad_tag = "00000000000000000000000000000000"
+use_middle_proxy = false
+
+[general.modes]
+classic = false
+secure = false
+tls = true
+
+[server.api]
+enabled = true
+# listen = "127.0.0.1:9091"
+# whitelist = ["127.0.0.1/32"]
+# read_only = true
+
+# === Anti-Censorship & Masking ===
+[censorship]
+tls_domain = "petrovich.ru"
+
+[access.users]
+# format: "username" = "32_hex_chars_secret"
+hello = "00000000000000000000000000000000"
+```
+
+then Ctrl+S -> Ctrl+X to save
+
+> [!WARNING]
+> Replace the value of the hello parameter with the value you obtained in step 0. 
+> Replace the value of the tls_domain parameter with another website.
+
+---
+
+**2. Create service on /etc/systemd/system/telemt.service**
+
+Open nano
+```bash
+nano /etc/systemd/system/telemt.service
+```
+
+paste this Systemd Module
+```bash
+[Unit]
+Description=Telemt
+After=network.target
+
+[Service]
+Type=simple
+WorkingDirectory=/bin
+ExecStart=/bin/telemt /etc/telemt.toml
+Restart=on-failure
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target
+```
+then Ctrl+S -> Ctrl+X to save
+
+
+**3.** To start it, enter the command `systemctl start telemt`
+
+**4.** To get status information, enter `systemctl status telemt`
+
+**5.** For automatic startup at system boot, enter `systemctl enable telemt`
+
+**6.** To get the link(s), enter
+```bash
+curl -s http://127.0.0.1:9091/v1/users | jq
+```
+
+> Any number of people can use one link.
+
+---
+
+# Telemt via Docker Compose
+
+**1. Edit `config.toml` in repo root (at least: port, users secrets, tls_domain)**  
+**2. Start container:**
+```bash
+docker compose up -d --build
+```
+**3. Check logs:**
+```bash
+docker compose logs -f telemt
+```
+**4. Stop:**
+```bash
+docker compose down
+```
+> [!NOTE]
+> - `docker-compose.yml` maps `./config.toml` to `/app/config.toml` (read-only)
+> - By default it publishes `443:443` and runs with dropped capabilities (only `NET_BIND_SERVICE` is added)
+> - If you really need host networking (usually only for some IPv6 setups) uncomment `network_mode: host`
+
+**Run without Compose**
+```bash
+docker build -t telemt:local .
+docker run --name telemt --restart unless-stopped \
+  -p 443:443 \
+  -e RUST_LOG=info \
+  -v "$PWD/config.toml:/app/config.toml:ro" \
+  --read-only \
+  --cap-drop ALL --cap-add NET_BIND_SERVICE \
+  --ulimit nofile=65536:65536 \
+  telemt:local
+```

docs/QUICK_START_GUIDE.ru.md

@@ -0,0 +1,167 @@
+# Telemt через Systemd
+
+## Установка
+
+Это программное обеспечение разработано для ОС на базе Debian: помимо Debian, это Ubuntu, Mint, Kali, MX и многие другие Linux
+
+**1. Скачать**
+```bash
+wget -qO- "https://github.com/telemt/telemt/releases/latest/download/telemt-$(uname -m)-linux-$(ldd --version 2>&1 | grep -iq musl && echo musl || echo gnu).tar.gz" | tar -xz
+```
+**2. Переместить в папку Bin**
+```bash
+mv telemt /bin
+```
+**3. Сделать файл исполняемым**
+```bash
+chmod +x /bin/telemt
+```
+
+## Как правильно использовать?
+
+**Эта инструкция "предполагает", что вы:**
+- Авторизовались как пользователь root или выполнил `su -` / `sudo su`
+- У вас уже есть исполняемый файл "telemt" в папке /bin. Читайте раздел **[Установка](#установка)**
+
+---
+
+**0. Проверьте порт и сгенерируйте секреты**
+
+Порт, который вы выбрали для использования, должен отсутствовать в списке:
+```bash
+netstat -lnp
+```
+
+Сгенерируйте 16 bytes/32 символа в шестнадцатеричном формате с помощью OpenSSL или другим способом:
+```bash
+openssl rand -hex 16
+```
+ИЛИ
+```bash
+xxd -l 16 -p /dev/urandom
+```
+ИЛИ
+```bash
+python3 -c 'import os; print(os.urandom(16).hex())'
+```
+Полученный результат сохраняем где-нибудь. Он понадобиться вам дальше!
+
+---
+
+**1. Поместите свою конфигурацию в файл /etc/telemt.toml**
+
+Открываем nano
+```bash
+nano /etc/telemt.toml
+```
+Вставьте свою конфигурацию
+
+```toml
+# === General Settings ===
+[general]
+# ad_tag = "00000000000000000000000000000000"
+use_middle_proxy = false
+
+[general.modes]
+classic = false
+secure = false
+tls = true
+
+[server.api]
+enabled = true
+# listen = "127.0.0.1:9091"
+# whitelist = ["127.0.0.1/32"]
+# read_only = true
+
+# === Anti-Censorship & Masking ===
+[censorship]
+tls_domain = "petrovich.ru"
+
+[access.users]
+# format: "username" = "32_hex_chars_secret"
+hello = "00000000000000000000000000000000"
+```
+
+Затем нажмите Ctrl+S -> Ctrl+X, чтобы сохранить
+
+> [!WARNING]
+> Замените значение параметра hello на значение, которое вы получили в пункте 0.  
+> Так же замените значение параметра tls_domain на другой сайт.
+
+---
+
+**2. Создайте службу в /etc/systemd/system/telemt.service**
+
+Открываем nano
+```bash
+nano /etc/systemd/system/telemt.service
+```
+
+Вставьте этот модуль Systemd
+```bash
+[Unit]
+Description=Telemt
+After=network.target
+
+[Service]
+Type=simple
+WorkingDirectory=/bin
+ExecStart=/bin/telemt /etc/telemt.toml
+Restart=on-failure
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target
+```
+Затем нажмите Ctrl+S -> Ctrl+X, чтобы сохранить
+
+
+**3.** Для запуска введите команду `systemctl start telemt`
+
+**4.** Для получения информации о статусе введите `systemctl status telemt`
+
+**5.** Для автоматического запуска при запуске системы в введите `systemctl enable telemt`
+
+**6.** Для получения ссылки/ссылок введите 
+```bash
+curl -s http://127.0.0.1:9091/v1/users | jq
+```
+> Одной ссылкой может пользоваться сколько угодно человек.
+
+> [!WARNING]
+> Рабочую ссылку может выдать только команда из 6 пункта. Не пытайтесь делать ее самостоятельно или копировать откуда-либо если вы не уверены в том, что делаете!
+
+---
+
+# Telemt через Docker Compose
+
+**1. Отредактируйте `config.toml` в корневом каталоге репозитория (как минимум: порт, пользовательские секреты, tls_domain)**  
+**2. Запустите контейнер:**
+```bash
+docker compose up -d --build
+```
+**3. Проверьте логи:**
+```bash
+docker compose logs -f telemt
+```
+**4. Остановите контейнер:**
+```bash
+docker compose down
+```
+> [!NOTE]
+> - В `docker-compose.yml` файл `./config.toml` монтируется в `/app/config.toml` (доступно только для чтения)  
+> - По умолчанию публикуются порты 443:443, а контейнер запускается со сброшенными привилегиями (добавлена только `NET_BIND_SERVICE`)  
+> - Если вам действительно нужна сеть хоста (обычно это требуется только для некоторых конфигураций IPv6), раскомментируйте `network_mode: host`
+
+**Запуск в Docker Compose**
+```bash
+docker build -t telemt:local .
+docker run --name telemt --restart unless-stopped \
+  -p 443:443 \
+  -e RUST_LOG=info \
+  -v "$PWD/config.toml:/app/config.toml:ro" \
+  --read-only \
+  --cap-drop ALL --cap-add NET_BIND_SERVICE \
+  --ulimit nofile=65536:65536 \
+  telemt:local
+```

docs/TUNING.de.md

@@ -0,0 +1,219 @@
+# Telemt Tuning-Leitfaden: Middle-End und Upstreams
+
+Dieses Dokument beschreibt das aktuelle Laufzeitverhalten für Middle-End (ME) und Upstream-Routing basierend auf:
+- `src/config/types.rs`
+- `src/config/defaults.rs`
+- `src/config/load.rs`
+- `src/transport/upstream.rs`
+
+Die unten angegebenen `Default`-Werte sind Code-Defaults (bei fehlendem Schlüssel), nicht zwingend die Werte aus `config.full.toml`.
+
+## Middle-End-Parameter
+
+### 1) ME-Grundmodus, NAT und STUN
+
+| Parameter | Typ | Default | Einschränkungen / Validierung | Laufzeiteffekt | Beispiel |
+|---|---|---:|---|---|---|
+| `general.use_middle_proxy` | `bool` | `true` | keine | Aktiviert den ME-Transportmodus. Bei `false` wird Direct-Modus verwendet. | `use_middle_proxy = true` |
+| `general.proxy_secret_path` | `Option<String>` | `"proxy-secret"` | Pfad kann `null` sein | Pfad zur Telegram-Infrastrukturdatei `proxy-secret`. | `proxy_secret_path = "proxy-secret"` |
+| `general.middle_proxy_nat_ip` | `Option<IpAddr>` | `null` | gültige IP bei gesetztem Wert | Manueller Override der öffentlichen NAT-IP für ME-Adressmaterial. | `middle_proxy_nat_ip = "203.0.113.10"` |
+| `general.middle_proxy_nat_probe` | `bool` | `true` | wird auf `true` erzwungen, wenn `use_middle_proxy=true` | Aktiviert NAT-Probing für ME. | `middle_proxy_nat_probe = true` |
+| `general.stun_nat_probe_concurrency` | `usize` | `8` | muss `> 0` sein | Maximale parallele STUN-Probes während NAT-Erkennung. | `stun_nat_probe_concurrency = 16` |
+| `network.stun_use` | `bool` | `true` | keine | Globaler STUN-Schalter. Bei `false` wird STUN deaktiviert. | `stun_use = true` |
+| `network.stun_servers` | `Vec<String>` | integrierter öffentlicher Pool | Duplikate/leer werden entfernt | Primäre STUN-Serverliste für NAT/Public-Endpoint-Erkennung. | `stun_servers = ["stun1.l.google.com:19302"]` |
+| `network.stun_tcp_fallback` | `bool` | `true` | keine | Aktiviert TCP-Fallback, wenn UDP-STUN blockiert ist. | `stun_tcp_fallback = true` |
+| `network.http_ip_detect_urls` | `Vec<String>` | `ifconfig.me` + `api.ipify.org` | keine | HTTP-Fallback zur öffentlichen IPv4-Erkennung, falls STUN ausfällt. | `http_ip_detect_urls = ["https://api.ipify.org"]` |
+| `general.stun_iface_mismatch_ignore` | `bool` | `false` | keine | Reserviertes Feld in der aktuellen Revision (derzeit kein aktiver Runtime-Verbrauch). | `stun_iface_mismatch_ignore = false` |
+| `timeouts.me_one_retry` | `u8` | `12` | keine | Anzahl schneller Reconnect-Versuche bei Single-Endpoint-DC-Fällen. | `me_one_retry = 6` |
+| `timeouts.me_one_timeout_ms` | `u64` | `1200` | keine | Timeout pro schnellem Einzelversuch (ms). | `me_one_timeout_ms = 1500` |
+
+### 2) Poolgröße, Keepalive und Reconnect-Policy
+
+| Parameter | Typ | Default | Einschränkungen / Validierung | Laufzeiteffekt | Beispiel |
+|---|---|---:|---|---|---|
+| `general.middle_proxy_pool_size` | `usize` | `8` | keine | Zielgröße des aktiven ME-Writer-Pools. | `middle_proxy_pool_size = 12` |
+| `general.middle_proxy_warm_standby` | `usize` | `16` | keine | Reserviertes Kompatibilitätsfeld in der aktuellen Revision (kein aktiver Runtime-Consumer). | `middle_proxy_warm_standby = 16` |
+| `general.me_keepalive_enabled` | `bool` | `true` | keine | Aktiviert periodischen ME-Keepalive/Ping-Traffic. | `me_keepalive_enabled = true` |
+| `general.me_keepalive_interval_secs` | `u64` | `25` | keine | Basisintervall für Keepalive (Sekunden). | `me_keepalive_interval_secs = 20` |
+| `general.me_keepalive_jitter_secs` | `u64` | `5` | keine | Keepalive-Jitter zur Vermeidung synchroner Peaks. | `me_keepalive_jitter_secs = 3` |
+| `general.me_keepalive_payload_random` | `bool` | `true` | keine | Randomisiert Keepalive-Payload-Bytes. | `me_keepalive_payload_random = true` |
+| `general.me_warmup_stagger_enabled` | `bool` | `true` | keine | Aktiviert gestaffeltes Warmup zusätzlicher ME-Verbindungen. | `me_warmup_stagger_enabled = true` |
+| `general.me_warmup_step_delay_ms` | `u64` | `500` | keine | Basisverzögerung zwischen Warmup-Schritten (ms). | `me_warmup_step_delay_ms = 300` |
+| `general.me_warmup_step_jitter_ms` | `u64` | `300` | keine | Zusätzlicher zufälliger Warmup-Jitter (ms). | `me_warmup_step_jitter_ms = 200` |
+| `general.me_reconnect_max_concurrent_per_dc` | `u32` | `8` | keine | Begrenzung paralleler Reconnect-Worker pro DC. | `me_reconnect_max_concurrent_per_dc = 12` |
+| `general.me_reconnect_backoff_base_ms` | `u64` | `500` | keine | Initiales Reconnect-Backoff (ms). | `me_reconnect_backoff_base_ms = 250` |
+| `general.me_reconnect_backoff_cap_ms` | `u64` | `30000` | keine | Maximales Reconnect-Backoff (ms). | `me_reconnect_backoff_cap_ms = 10000` |
+| `general.me_reconnect_fast_retry_count` | `u32` | `16` | keine | Budget für Sofort-Retries vor längerem Backoff. | `me_reconnect_fast_retry_count = 8` |
+
+### 3) Reinit/Hardswap, Secret-Rotation und Degradation
+
+| Parameter | Typ | Default | Einschränkungen / Validierung | Laufzeiteffekt | Beispiel |
+|---|---|---:|---|---|---|
+| `general.hardswap` | `bool` | `true` | keine | Aktiviert generation-basierte Hardswap-Strategie für den ME-Pool. | `hardswap = true` |
+| `general.me_reinit_every_secs` | `u64` | `900` | muss `> 0` sein | Intervall für periodische ME-Reinitialisierung. | `me_reinit_every_secs = 600` |
+| `general.me_hardswap_warmup_delay_min_ms` | `u64` | `1000` | muss `<= me_hardswap_warmup_delay_max_ms` sein | Untere Grenze für Warmup-Dial-Abstände. | `me_hardswap_warmup_delay_min_ms = 500` |
+| `general.me_hardswap_warmup_delay_max_ms` | `u64` | `2000` | muss `> 0` sein | Obere Grenze für Warmup-Dial-Abstände. | `me_hardswap_warmup_delay_max_ms = 1200` |
+| `general.me_hardswap_warmup_extra_passes` | `u8` | `3` | Bereich `[0,10]` | Zusätzliche Warmup-Pässe nach dem Basispass. | `me_hardswap_warmup_extra_passes = 2` |
+| `general.me_hardswap_warmup_pass_backoff_base_ms` | `u64` | `500` | muss `> 0` sein | Basis-Backoff zwischen zusätzlichen Warmup-Pässen. | `me_hardswap_warmup_pass_backoff_base_ms = 400` |
+| `general.me_config_stable_snapshots` | `u8` | `2` | muss `> 0` sein | Anzahl identischer ME-Config-Snapshots vor Apply. | `me_config_stable_snapshots = 3` |
+| `general.me_config_apply_cooldown_secs` | `u64` | `300` | keine | Cooldown zwischen angewendeten ME-Map-Updates. | `me_config_apply_cooldown_secs = 120` |
+| `general.proxy_secret_stable_snapshots` | `u8` | `2` | muss `> 0` sein | Anzahl identischer Secret-Snapshots vor Rotation. | `proxy_secret_stable_snapshots = 3` |
+| `general.proxy_secret_rotate_runtime` | `bool` | `true` | keine | Aktiviert Runtime-Rotation des Proxy-Secrets. | `proxy_secret_rotate_runtime = true` |
+| `general.proxy_secret_len_max` | `usize` | `256` | Bereich `[32,4096]` | Obergrenze für akzeptierte Secret-Länge. | `proxy_secret_len_max = 512` |
+| `general.update_every` | `Option<u64>` | `300` | wenn gesetzt: `> 0`; bei `null`: Legacy-Min-Fallback | Einheitliches Refresh-Intervall für ME-Config + Secret-Updater. | `update_every = 300` |
+| `general.me_pool_drain_ttl_secs` | `u64` | `90` | keine | Zeitraum, in dem stale Writer noch als Fallback zulässig sind. | `me_pool_drain_ttl_secs = 120` |
+| `general.me_pool_min_fresh_ratio` | `f32` | `0.8` | Bereich `[0.0,1.0]` | Coverage-Schwelle vor Drain der alten Generation. | `me_pool_min_fresh_ratio = 0.9` |
+| `general.me_reinit_drain_timeout_secs` | `u64` | `120` | `0` = kein Force-Close; wenn `>0 && < TTL`, dann auf TTL angehoben | Force-Close-Timeout für draining stale Writer. | `me_reinit_drain_timeout_secs = 0` |
+| `general.auto_degradation_enabled` | `bool` | `true` | keine | Reserviertes Kompatibilitätsfeld in aktueller Revision (kein aktiver Runtime-Consumer). | `auto_degradation_enabled = true` |
+| `general.degradation_min_unavailable_dc_groups` | `u8` | `2` | keine | Reservierter Kompatibilitäts-Schwellenwert in aktueller Revision (kein aktiver Runtime-Consumer). | `degradation_min_unavailable_dc_groups = 2` |
+
+## Deprecated / Legacy Parameter
+
+| Parameter | Status | Ersatz | Aktuelles Verhalten | Migrationshinweis |
+|---|---|---|---|---|
+| `general.middle_proxy_nat_stun` | Deprecated | `network.stun_servers` | Wird nur dann in `network.stun_servers` gemerged, wenn `network.stun_servers` nicht explizit gesetzt ist. | Wert nach `network.stun_servers` verschieben, Legacy-Key entfernen. |
+| `general.middle_proxy_nat_stun_servers` | Deprecated | `network.stun_servers` | Wird nur dann in `network.stun_servers` gemerged, wenn `network.stun_servers` nicht explizit gesetzt ist. | Werte nach `network.stun_servers` verschieben, Legacy-Key entfernen. |
+| `general.proxy_secret_auto_reload_secs` | Deprecated | `general.update_every` | Nur aktiv, wenn `update_every = null` (Legacy-Fallback). | `general.update_every` explizit setzen, Legacy-Key entfernen. |
+| `general.proxy_config_auto_reload_secs` | Deprecated | `general.update_every` | Nur aktiv, wenn `update_every = null` (Legacy-Fallback). | `general.update_every` explizit setzen, Legacy-Key entfernen. |
+
+## Wie Upstreams konfiguriert werden
+
+### Upstream-Schema
+
+| Feld | Gilt für | Typ | Pflicht | Default | Bedeutung |
+|---|---|---|---|---|---|
+| `[[upstreams]].type` | alle Upstreams | `"direct" \| "socks4" \| "socks5"` | ja | n/a | Upstream-Transporttyp. |
+| `[[upstreams]].weight` | alle Upstreams | `u16` | nein | `1` | Basisgewicht für weighted-random Auswahl. |
+| `[[upstreams]].enabled` | alle Upstreams | `bool` | nein | `true` | Deaktivierte Einträge werden beim Start ignoriert. |
+| `[[upstreams]].scopes` | alle Upstreams | `String` | nein | `""` | Komma-separierte Scope-Tags für Request-Routing. |
+| `interface` | `direct` | `Option<String>` | nein | `null` | Interface-Name (z. B. `eth0`) oder lokale Literal-IP. |
+| `bind_addresses` | `direct` | `Option<Vec<IpAddr>>` | nein | `null` | Explizite Source-IP-Kandidaten (strikter Vorrang vor `interface`). |
+| `address` | `socks4` | `String` | ja | n/a | SOCKS4-Server (`ip:port` oder `host:port`). |
+| `interface` | `socks4` | `Option<String>` | nein | `null` | Wird nur genutzt, wenn `address` als `ip:port` angegeben ist. |
+| `user_id` | `socks4` | `Option<String>` | nein | `null` | SOCKS4 User-ID für CONNECT. |
+| `address` | `socks5` | `String` | ja | n/a | SOCKS5-Server (`ip:port` oder `host:port`). |
+| `interface` | `socks5` | `Option<String>` | nein | `null` | Wird nur genutzt, wenn `address` als `ip:port` angegeben ist. |
+| `username` | `socks5` | `Option<String>` | nein | `null` | SOCKS5 Benutzername. |
+| `password` | `socks5` | `Option<String>` | nein | `null` | SOCKS5 Passwort. |
+
+### Runtime-Regeln (wichtig)
+
+1. Wenn `[[upstreams]]` fehlt, injiziert der Loader einen Default-`direct`-Upstream.
+2. Scope-Filterung basiert auf exaktem Token-Match:
+- mit Request-Scope -> nur Einträge, deren `scopes` genau dieses Token enthält;
+- ohne Request-Scope -> nur Einträge mit leerem `scopes`.
+3. Unter healthy Upstreams erfolgt die Auswahl per weighted random: `weight * latency_factor`.
+4. Gibt es im gefilterten Set keinen healthy Upstream, wird zufällig aus dem gefilterten Set gewählt.
+5. `direct`-Bind-Auflösung:
+- zuerst `bind_addresses` (nur gleiche IP-Familie wie Target);
+- bei `interface` (Name) + `bind_addresses` wird jede Candidate-IP gegen Interface-Adressen validiert;
+- ungültige Kandidaten werden mit `WARN` verworfen;
+- bleiben keine gültigen Kandidaten übrig, erfolgt unbound direct connect (`bind_ip=None`);
+- wenn `bind_addresses` nicht passt, wird `interface` verwendet (Literal-IP oder Interface-Primäradresse).
+6. Für `socks4/socks5` mit Hostname-`address` ist Interface-Binding nicht unterstützt und wird mit Warnung ignoriert.
+7. Runtime DNS Overrides werden für Hostname-Auflösung bei Upstream-Verbindungen genutzt.
+8. Im ME-Modus wird der gewählte Upstream auch für den ME-TCP-Dial-Pfad verwendet.
+9. Im ME-Modus ist bei `direct` mit bind/interface die STUN-Reflection bind-aware für KDF-Adressmaterial.
+10. Im ME-Modus werden bei SOCKS-Upstream `BND.ADDR/BND.PORT` für KDF verwendet, wenn gültig/öffentlich und gleiche IP-Familie.
+
+## Upstream-Konfigurationsbeispiele
+
+### Beispiel 1: Minimaler direct Upstream
+
+```toml
+[[upstreams]]
+type = "direct"
+weight = 1
+enabled = true
+```
+
+### Beispiel 2: direct mit Interface + expliziten bind IPs
+
+```toml
+[[upstreams]]
+type = "direct"
+interface = "eth0"
+bind_addresses = ["192.168.1.100", "192.168.1.101"]
+weight = 3
+enabled = true
+```
+
+### Beispiel 3: SOCKS5 Upstream mit Authentifizierung
+
+```toml
+[[upstreams]]
+type = "socks5"
+address = "198.51.100.30:1080"
+username = "proxy-user"
+password = "proxy-pass"
+weight = 2
+enabled = true
+```
+
+### Beispiel 4: Gemischte Upstreams mit Scopes
+
+```toml
+[[upstreams]]
+type = "direct"
+weight = 5
+enabled = true
+scopes = ""
+
+[[upstreams]]
+type = "socks5"
+address = "203.0.113.40:1080"
+username = "edge"
+password = "edgepass"
+weight = 3
+enabled = true
+scopes = "premium,me"
+```
+
+### Beispiel 5: ME-orientiertes Tuning-Profil
+
+```toml
+[general]
+use_middle_proxy = true
+proxy_secret_path = "proxy-secret"
+middle_proxy_nat_probe = true
+stun_nat_probe_concurrency = 16
+middle_proxy_pool_size = 12
+me_keepalive_enabled = true
+me_keepalive_interval_secs = 20
+me_keepalive_jitter_secs = 4
+me_reconnect_max_concurrent_per_dc = 12
+me_reconnect_backoff_base_ms = 300
+me_reconnect_backoff_cap_ms = 10000
+me_reconnect_fast_retry_count = 10
+hardswap = true
+me_reinit_every_secs = 600
+me_hardswap_warmup_delay_min_ms = 500
+me_hardswap_warmup_delay_max_ms = 1200
+me_hardswap_warmup_extra_passes = 2
+me_hardswap_warmup_pass_backoff_base_ms = 400
+me_config_stable_snapshots = 3
+me_config_apply_cooldown_secs = 120
+proxy_secret_stable_snapshots = 3
+proxy_secret_rotate_runtime = true
+proxy_secret_len_max = 512
+update_every = 300
+me_pool_drain_ttl_secs = 120
+me_pool_min_fresh_ratio = 0.9
+me_reinit_drain_timeout_secs = 180
+
+[timeouts]
+me_one_retry = 8
+me_one_timeout_ms = 1200
+
+[network]
+stun_use = true
+stun_tcp_fallback = true
+stun_servers = [
+  "stun1.l.google.com:19302",
+  "stun2.l.google.com:19302"
+]
+http_ip_detect_urls = [
+  "https://api.ipify.org",
+  "https://ifconfig.me/ip"
+]
+```

docs/TUNING.en.md

@@ -0,0 +1,219 @@
+# Telemt Tuning Guide: Middle-End and Upstreams
+
+This document describes the current runtime behavior for Middle-End (ME) and upstream routing based on:
+- `src/config/types.rs`
+- `src/config/defaults.rs`
+- `src/config/load.rs`
+- `src/transport/upstream.rs`
+
+Defaults below are code defaults (used when a key is omitted), not necessarily values from `config.full.toml` examples.
+
+## Middle-End Parameters
+
+### 1) Core ME mode, NAT, and STUN
+
+| Parameter | Type | Default | Constraints / validation | Runtime effect | Example |
+|---|---|---:|---|---|---|
+| `general.use_middle_proxy` | `bool` | `true` | none | Enables ME transport mode. If `false`, Direct mode is used. | `use_middle_proxy = true` |
+| `general.proxy_secret_path` | `Option<String>` | `"proxy-secret"` | path may be `null` | Path to Telegram infrastructure proxy-secret file. | `proxy_secret_path = "proxy-secret"` |
+| `general.middle_proxy_nat_ip` | `Option<IpAddr>` | `null` | valid IP when set | Manual public NAT IP override for ME address material. | `middle_proxy_nat_ip = "203.0.113.10"` |
+| `general.middle_proxy_nat_probe` | `bool` | `true` | auto-forced to `true` when `use_middle_proxy=true` | Enables ME NAT probing. | `middle_proxy_nat_probe = true` |
+| `general.stun_nat_probe_concurrency` | `usize` | `8` | must be `> 0` | Max parallel STUN probes during NAT discovery. | `stun_nat_probe_concurrency = 16` |
+| `network.stun_use` | `bool` | `true` | none | Global STUN switch. If `false`, STUN probing is disabled. | `stun_use = true` |
+| `network.stun_servers` | `Vec<String>` | built-in public pool | deduplicated + empty values removed | Primary STUN server list for NAT/public endpoint discovery. | `stun_servers = ["stun1.l.google.com:19302"]` |
+| `network.stun_tcp_fallback` | `bool` | `true` | none | Enables TCP fallback path when UDP STUN is blocked. | `stun_tcp_fallback = true` |
+| `network.http_ip_detect_urls` | `Vec<String>` | `ifconfig.me` + `api.ipify.org` | none | HTTP fallback for public IPv4 detection if STUN is unavailable. | `http_ip_detect_urls = ["https://api.ipify.org"]` |
+| `general.stun_iface_mismatch_ignore` | `bool` | `false` | none | Reserved flag in current revision (not consumed by runtime path). | `stun_iface_mismatch_ignore = false` |
+| `timeouts.me_one_retry` | `u8` | `12` | none | Fast reconnect attempts for single-endpoint DC cases. | `me_one_retry = 6` |
+| `timeouts.me_one_timeout_ms` | `u64` | `1200` | none | Timeout per quick single-endpoint attempt (ms). | `me_one_timeout_ms = 1500` |
+
+### 2) Pool size, keepalive, and reconnect policy
+
+| Parameter | Type | Default | Constraints / validation | Runtime effect | Example |
+|---|---|---:|---|---|---|
+| `general.middle_proxy_pool_size` | `usize` | `8` | none | Target active ME writer pool size. | `middle_proxy_pool_size = 12` |
+| `general.middle_proxy_warm_standby` | `usize` | `16` | none | Reserved compatibility field in current revision (no active runtime consumer). | `middle_proxy_warm_standby = 16` |
+| `general.me_keepalive_enabled` | `bool` | `true` | none | Enables periodic ME keepalive/ping traffic. | `me_keepalive_enabled = true` |
+| `general.me_keepalive_interval_secs` | `u64` | `25` | none | Base keepalive interval (seconds). | `me_keepalive_interval_secs = 20` |
+| `general.me_keepalive_jitter_secs` | `u64` | `5` | none | Keepalive jitter to avoid synchronization bursts. | `me_keepalive_jitter_secs = 3` |
+| `general.me_keepalive_payload_random` | `bool` | `true` | none | Randomizes keepalive payload bytes. | `me_keepalive_payload_random = true` |
+| `general.me_warmup_stagger_enabled` | `bool` | `true` | none | Staggers extra ME warmup dials to avoid spikes. | `me_warmup_stagger_enabled = true` |
+| `general.me_warmup_step_delay_ms` | `u64` | `500` | none | Base delay between warmup dial steps (ms). | `me_warmup_step_delay_ms = 300` |
+| `general.me_warmup_step_jitter_ms` | `u64` | `300` | none | Additional random delay for warmup steps (ms). | `me_warmup_step_jitter_ms = 200` |
+| `general.me_reconnect_max_concurrent_per_dc` | `u32` | `8` | none | Limits concurrent reconnect workers per DC in health recovery. | `me_reconnect_max_concurrent_per_dc = 12` |
+| `general.me_reconnect_backoff_base_ms` | `u64` | `500` | none | Initial reconnect backoff (ms). | `me_reconnect_backoff_base_ms = 250` |
+| `general.me_reconnect_backoff_cap_ms` | `u64` | `30000` | none | Maximum reconnect backoff (ms). | `me_reconnect_backoff_cap_ms = 10000` |
+| `general.me_reconnect_fast_retry_count` | `u32` | `16` | none | Immediate retry budget before long backoff behavior. | `me_reconnect_fast_retry_count = 8` |
+
+### 3) Reinit/hardswap, secret rotation, and degradation
+
+| Parameter | Type | Default | Constraints / validation | Runtime effect | Example |
+|---|---|---:|---|---|---|
+| `general.hardswap` | `bool` | `true` | none | Enables generation-based ME hardswap strategy. | `hardswap = true` |
+| `general.me_reinit_every_secs` | `u64` | `900` | must be `> 0` | Periodic ME reinit interval. | `me_reinit_every_secs = 600` |
+| `general.me_hardswap_warmup_delay_min_ms` | `u64` | `1000` | must be `<= me_hardswap_warmup_delay_max_ms` | Lower bound for hardswap warmup dial spacing. | `me_hardswap_warmup_delay_min_ms = 500` |
+| `general.me_hardswap_warmup_delay_max_ms` | `u64` | `2000` | must be `> 0` | Upper bound for hardswap warmup dial spacing. | `me_hardswap_warmup_delay_max_ms = 1200` |
+| `general.me_hardswap_warmup_extra_passes` | `u8` | `3` | must be within `[0,10]` | Additional warmup passes after base pass. | `me_hardswap_warmup_extra_passes = 2` |
+| `general.me_hardswap_warmup_pass_backoff_base_ms` | `u64` | `500` | must be `> 0` | Base backoff between extra warmup passes. | `me_hardswap_warmup_pass_backoff_base_ms = 400` |
+| `general.me_config_stable_snapshots` | `u8` | `2` | must be `> 0` | Number of identical ME config snapshots required before apply. | `me_config_stable_snapshots = 3` |
+| `general.me_config_apply_cooldown_secs` | `u64` | `300` | none | Cooldown between applied ME map updates. | `me_config_apply_cooldown_secs = 120` |
+| `general.proxy_secret_stable_snapshots` | `u8` | `2` | must be `> 0` | Number of identical proxy-secret snapshots required before rotation. | `proxy_secret_stable_snapshots = 3` |
+| `general.proxy_secret_rotate_runtime` | `bool` | `true` | none | Enables runtime proxy-secret rotation. | `proxy_secret_rotate_runtime = true` |
+| `general.proxy_secret_len_max` | `usize` | `256` | must be within `[32,4096]` | Upper limit for accepted proxy-secret length. | `proxy_secret_len_max = 512` |
+| `general.update_every` | `Option<u64>` | `300` | if set: must be `> 0`; if `null`: legacy min fallback | Unified refresh interval for ME config + secret updater. | `update_every = 300` |
+| `general.me_pool_drain_ttl_secs` | `u64` | `90` | none | Time window where stale writers remain fallback-eligible. | `me_pool_drain_ttl_secs = 120` |
+| `general.me_pool_min_fresh_ratio` | `f32` | `0.8` | must be within `[0.0,1.0]` | Coverage threshold before stale generation can be drained. | `me_pool_min_fresh_ratio = 0.9` |
+| `general.me_reinit_drain_timeout_secs` | `u64` | `120` | `0` means no force-close; if `>0 && < TTL` it is bumped to TTL | Force-close timeout for draining stale writers. | `me_reinit_drain_timeout_secs = 0` |
+| `general.auto_degradation_enabled` | `bool` | `true` | none | Reserved compatibility flag in current revision (no active runtime consumer). | `auto_degradation_enabled = true` |
+| `general.degradation_min_unavailable_dc_groups` | `u8` | `2` | none | Reserved compatibility threshold in current revision (no active runtime consumer). | `degradation_min_unavailable_dc_groups = 2` |
+
+## Deprecated / Legacy Parameters
+
+| Parameter | Status | Replacement | Current behavior | Migration recommendation |
+|---|---|---|---|---|
+| `general.middle_proxy_nat_stun` | Deprecated | `network.stun_servers` | Merged into `network.stun_servers` only when `network.stun_servers` is not explicitly set. | Move value into `network.stun_servers` and remove legacy key. |
+| `general.middle_proxy_nat_stun_servers` | Deprecated | `network.stun_servers` | Merged into `network.stun_servers` only when `network.stun_servers` is not explicitly set. | Move values into `network.stun_servers` and remove legacy key. |
+| `general.proxy_secret_auto_reload_secs` | Deprecated | `general.update_every` | Used only when `update_every = null` (legacy fallback path). | Set `general.update_every` explicitly and remove legacy key. |
+| `general.proxy_config_auto_reload_secs` | Deprecated | `general.update_every` | Used only when `update_every = null` (legacy fallback path). | Set `general.update_every` explicitly and remove legacy key. |
+
+## How Upstreams Are Configured
+
+### Upstream schema
+
+| Field | Applies to | Type | Required | Default | Meaning |
+|---|---|---|---|---|---|
+| `[[upstreams]].type` | all upstreams | `"direct" \| "socks4" \| "socks5"` | yes | n/a | Upstream transport type. |
+| `[[upstreams]].weight` | all upstreams | `u16` | no | `1` | Base weight for weighted-random selection. |
+| `[[upstreams]].enabled` | all upstreams | `bool` | no | `true` | Disabled entries are ignored at startup. |
+| `[[upstreams]].scopes` | all upstreams | `String` | no | `""` | Comma-separated scope tags for request-level routing. |
+| `interface` | `direct` | `Option<String>` | no | `null` | Interface name (e.g. `eth0`) or literal local IP for bind selection. |
+| `bind_addresses` | `direct` | `Option<Vec<IpAddr>>` | no | `null` | Explicit local source IP candidates (strict priority over `interface`). |
+| `address` | `socks4` | `String` | yes | n/a | SOCKS4 server endpoint (`ip:port` or `host:port`). |
+| `interface` | `socks4` | `Option<String>` | no | `null` | Used only for SOCKS server `ip:port` dial path. |
+| `user_id` | `socks4` | `Option<String>` | no | `null` | SOCKS4 user ID for CONNECT request. |
+| `address` | `socks5` | `String` | yes | n/a | SOCKS5 server endpoint (`ip:port` or `host:port`). |
+| `interface` | `socks5` | `Option<String>` | no | `null` | Used only for SOCKS server `ip:port` dial path. |
+| `username` | `socks5` | `Option<String>` | no | `null` | SOCKS5 username auth. |
+| `password` | `socks5` | `Option<String>` | no | `null` | SOCKS5 password auth. |
+
+### Runtime rules (important)
+
+1. If `[[upstreams]]` is omitted, loader injects one default `direct` upstream.
+2. Scope filtering is exact-token based:
+- when request scope is set -> only entries whose `scopes` contains that exact token;
+- when request scope is not set -> only entries with empty `scopes`.
+3. Healthy upstreams are selected by weighted random using: `weight * latency_factor`.
+4. If no healthy upstream exists in filtered set, random selection is used among filtered entries.
+5. `direct` bind resolution order:
+- `bind_addresses` candidates (same IP family as target) first;
+- if `interface` is an interface name and `bind_addresses` is set, each candidate IP is validated against addresses currently assigned to that interface;
+- invalid candidates are dropped with `WARN`;
+- if no valid candidate remains, connection falls back to unbound direct connect (`bind_ip=None`);
+- if no `bind_addresses` candidate, `interface` is used (literal IP or resolved interface primary IP).
+6. For `socks4/socks5` with `address` as hostname, interface binding is not supported and is ignored with warning.
+7. Runtime DNS overrides are used for upstream hostname resolution.
+8. In ME mode, the selected upstream is also used for ME TCP dial path.
+9. In ME mode for `direct` upstream with bind/interface, STUN reflection logic is bind-aware for KDF source material.
+10. In ME mode for SOCKS upstream, SOCKS `BND.ADDR/BND.PORT` is used for KDF when it is valid/public for the same family.
+
+## Upstream Configuration Examples
+
+### Example 1: Minimal direct upstream
+
+```toml
+[[upstreams]]
+type = "direct"
+weight = 1
+enabled = true
+```
+
+### Example 2: Direct with interface + explicit bind addresses
+
+```toml
+[[upstreams]]
+type = "direct"
+interface = "eth0"
+bind_addresses = ["192.168.1.100", "192.168.1.101"]
+weight = 3
+enabled = true
+```
+
+### Example 3: SOCKS5 upstream with authentication
+
+```toml
+[[upstreams]]
+type = "socks5"
+address = "198.51.100.30:1080"
+username = "proxy-user"
+password = "proxy-pass"
+weight = 2
+enabled = true
+```
+
+### Example 4: Mixed upstreams with scopes
+
+```toml
+[[upstreams]]
+type = "direct"
+weight = 5
+enabled = true
+scopes = ""
+
+[[upstreams]]
+type = "socks5"
+address = "203.0.113.40:1080"
+username = "edge"
+password = "edgepass"
+weight = 3
+enabled = true
+scopes = "premium,me"
+```
+
+### Example 5: ME-focused tuning profile
+
+```toml
+[general]
+use_middle_proxy = true
+proxy_secret_path = "proxy-secret"
+middle_proxy_nat_probe = true
+stun_nat_probe_concurrency = 16
+middle_proxy_pool_size = 12
+me_keepalive_enabled = true
+me_keepalive_interval_secs = 20
+me_keepalive_jitter_secs = 4
+me_reconnect_max_concurrent_per_dc = 12
+me_reconnect_backoff_base_ms = 300
+me_reconnect_backoff_cap_ms = 10000
+me_reconnect_fast_retry_count = 10
+hardswap = true
+me_reinit_every_secs = 600
+me_hardswap_warmup_delay_min_ms = 500
+me_hardswap_warmup_delay_max_ms = 1200
+me_hardswap_warmup_extra_passes = 2
+me_hardswap_warmup_pass_backoff_base_ms = 400
+me_config_stable_snapshots = 3
+me_config_apply_cooldown_secs = 120
+proxy_secret_stable_snapshots = 3
+proxy_secret_rotate_runtime = true
+proxy_secret_len_max = 512
+update_every = 300
+me_pool_drain_ttl_secs = 120
+me_pool_min_fresh_ratio = 0.9
+me_reinit_drain_timeout_secs = 180
+
+[timeouts]
+me_one_retry = 8
+me_one_timeout_ms = 1200
+
+[network]
+stun_use = true
+stun_tcp_fallback = true
+stun_servers = [
+  "stun1.l.google.com:19302",
+  "stun2.l.google.com:19302"
+]
+http_ip_detect_urls = [
+  "https://api.ipify.org",
+  "https://ifconfig.me/ip"
+]
+```

docs/TUNING.ru.md

@@ -0,0 +1,219 @@
+# Руководство по тюнингу Telemt: Middle-End и Upstreams
+
+Документ описывает актуальное поведение Middle-End (ME) и маршрутизации через upstream на основе:
+- `src/config/types.rs`
+- `src/config/defaults.rs`
+- `src/config/load.rs`
+- `src/transport/upstream.rs`
+
+Значения `Default` ниже — это значения из кода при отсутствии ключа в конфиге, а не обязательно значения из примеров `config.full.toml`.
+
+## Параметры Middle-End
+
+### 1) Базовый режим ME, NAT и STUN
+
+| Параметр | Тип | Default | Ограничения / валидация | Влияние на runtime | Пример |
+|---|---|---:|---|---|---|
+| `general.use_middle_proxy` | `bool` | `true` | нет | Включает транспорт ME. При `false` используется Direct-режим. | `use_middle_proxy = true` |
+| `general.proxy_secret_path` | `Option<String>` | `"proxy-secret"` | путь может быть `null` | Путь к инфраструктурному proxy-secret Telegram. | `proxy_secret_path = "proxy-secret"` |
+| `general.middle_proxy_nat_ip` | `Option<IpAddr>` | `null` | валидный IP при задании | Ручной override публичного NAT IP для адресного материала ME. | `middle_proxy_nat_ip = "203.0.113.10"` |
+| `general.middle_proxy_nat_probe` | `bool` | `true` | авто-принудительно `true`, если `use_middle_proxy=true` | Включает NAT probing для ME. | `middle_proxy_nat_probe = true` |
+| `general.stun_nat_probe_concurrency` | `usize` | `8` | должно быть `> 0` | Максимум параллельных STUN-проб при NAT-детекте. | `stun_nat_probe_concurrency = 16` |
+| `network.stun_use` | `bool` | `true` | нет | Глобальный переключатель STUN. При `false` STUN отключен. | `stun_use = true` |
+| `network.stun_servers` | `Vec<String>` | встроенный публичный пул | удаляются дубликаты и пустые значения | Основной список STUN-серверов для NAT/public endpoint discovery. | `stun_servers = ["stun1.l.google.com:19302"]` |
+| `network.stun_tcp_fallback` | `bool` | `true` | нет | Включает TCP fallback, если UDP STUN недоступен. | `stun_tcp_fallback = true` |
+| `network.http_ip_detect_urls` | `Vec<String>` | `ifconfig.me` + `api.ipify.org` | нет | HTTP fallback для определения публичного IPv4 при недоступности STUN. | `http_ip_detect_urls = ["https://api.ipify.org"]` |
+| `general.stun_iface_mismatch_ignore` | `bool` | `false` | нет | Зарезервированный флаг в текущей ревизии (runtime его не использует). | `stun_iface_mismatch_ignore = false` |
+| `timeouts.me_one_retry` | `u8` | `12` | нет | Количество быстрых reconnect-попыток для DC с одним endpoint. | `me_one_retry = 6` |
+| `timeouts.me_one_timeout_ms` | `u64` | `1200` | нет | Таймаут одной быстрой попытки (мс). | `me_one_timeout_ms = 1500` |
+
+### 2) Размер пула, keepalive и reconnect-политика
+
+| Параметр | Тип | Default | Ограничения / валидация | Влияние на runtime | Пример |
+|---|---|---:|---|---|---|
+| `general.middle_proxy_pool_size` | `usize` | `8` | нет | Целевой размер активного пула ME-writer соединений. | `middle_proxy_pool_size = 12` |
+| `general.middle_proxy_warm_standby` | `usize` | `16` | нет | Зарезервированное поле совместимости в текущей ревизии (активного runtime-consumer нет). | `middle_proxy_warm_standby = 16` |
+| `general.me_keepalive_enabled` | `bool` | `true` | нет | Включает периодические keepalive/ping кадры ME. | `me_keepalive_enabled = true` |
+| `general.me_keepalive_interval_secs` | `u64` | `25` | нет | Базовый интервал keepalive (сек). | `me_keepalive_interval_secs = 20` |
+| `general.me_keepalive_jitter_secs` | `u64` | `5` | нет | Джиттер keepalive для предотвращения синхронных всплесков. | `me_keepalive_jitter_secs = 3` |
+| `general.me_keepalive_payload_random` | `bool` | `true` | нет | Рандомизирует payload keepalive-кадров. | `me_keepalive_payload_random = true` |
+| `general.me_warmup_stagger_enabled` | `bool` | `true` | нет | Включает staggered warmup дополнительных ME-коннектов. | `me_warmup_stagger_enabled = true` |
+| `general.me_warmup_step_delay_ms` | `u64` | `500` | нет | Базовая задержка между шагами warmup (мс). | `me_warmup_step_delay_ms = 300` |
+| `general.me_warmup_step_jitter_ms` | `u64` | `300` | нет | Дополнительный случайный warmup-джиттер (мс). | `me_warmup_step_jitter_ms = 200` |
+| `general.me_reconnect_max_concurrent_per_dc` | `u32` | `8` | нет | Ограничивает параллельные reconnect worker'ы на один DC. | `me_reconnect_max_concurrent_per_dc = 12` |
+| `general.me_reconnect_backoff_base_ms` | `u64` | `500` | нет | Начальный backoff reconnect (мс). | `me_reconnect_backoff_base_ms = 250` |
+| `general.me_reconnect_backoff_cap_ms` | `u64` | `30000` | нет | Верхняя граница backoff reconnect (мс). | `me_reconnect_backoff_cap_ms = 10000` |
+| `general.me_reconnect_fast_retry_count` | `u32` | `16` | нет | Бюджет быстрых retry до длинного backoff. | `me_reconnect_fast_retry_count = 8` |
+
+### 3) Reinit/hardswap, ротация секрета и деградация
+
+| Параметр | Тип | Default | Ограничения / валидация | Влияние на runtime | Пример |
+|---|---|---:|---|---|---|
+| `general.hardswap` | `bool` | `true` | нет | Включает generation-based стратегию hardswap для ME-пула. | `hardswap = true` |
+| `general.me_reinit_every_secs` | `u64` | `900` | должно быть `> 0` | Интервал периодического reinit ME-пула. | `me_reinit_every_secs = 600` |
+| `general.me_hardswap_warmup_delay_min_ms` | `u64` | `1000` | должно быть `<= me_hardswap_warmup_delay_max_ms` | Нижняя граница пауз между warmup dial попытками. | `me_hardswap_warmup_delay_min_ms = 500` |
+| `general.me_hardswap_warmup_delay_max_ms` | `u64` | `2000` | должно быть `> 0` | Верхняя граница пауз между warmup dial попытками. | `me_hardswap_warmup_delay_max_ms = 1200` |
+| `general.me_hardswap_warmup_extra_passes` | `u8` | `3` | диапазон `[0,10]` | Дополнительные warmup-проходы после базового. | `me_hardswap_warmup_extra_passes = 2` |
+| `general.me_hardswap_warmup_pass_backoff_base_ms` | `u64` | `500` | должно быть `> 0` | Базовый backoff между extra-pass в warmup. | `me_hardswap_warmup_pass_backoff_base_ms = 400` |
+| `general.me_config_stable_snapshots` | `u8` | `2` | должно быть `> 0` | Количество одинаковых snapshot перед применением ME map update. | `me_config_stable_snapshots = 3` |
+| `general.me_config_apply_cooldown_secs` | `u64` | `300` | нет | Cooldown между применёнными обновлениями ME map. | `me_config_apply_cooldown_secs = 120` |
+| `general.proxy_secret_stable_snapshots` | `u8` | `2` | должно быть `> 0` | Количество одинаковых snapshot перед runtime-rotation proxy-secret. | `proxy_secret_stable_snapshots = 3` |
+| `general.proxy_secret_rotate_runtime` | `bool` | `true` | нет | Включает runtime-ротацию proxy-secret. | `proxy_secret_rotate_runtime = true` |
+| `general.proxy_secret_len_max` | `usize` | `256` | диапазон `[32,4096]` | Верхний лимит длины принимаемого proxy-secret. | `proxy_secret_len_max = 512` |
+| `general.update_every` | `Option<u64>` | `300` | если задано: `> 0`; если `null`: fallback на legacy минимум | Единый интервал refresh для ME config + secret updater. | `update_every = 300` |
+| `general.me_pool_drain_ttl_secs` | `u64` | `90` | нет | Время, когда stale writer ещё может использоваться как fallback. | `me_pool_drain_ttl_secs = 120` |
+| `general.me_pool_min_fresh_ratio` | `f32` | `0.8` | диапазон `[0.0,1.0]` | Порог покрытия fresh-поколения перед drain старого поколения. | `me_pool_min_fresh_ratio = 0.9` |
+| `general.me_reinit_drain_timeout_secs` | `u64` | `120` | `0` = без force-close; если `>0 && < TTL`, поднимается до TTL | Таймаут force-close для draining stale writer. | `me_reinit_drain_timeout_secs = 0` |
+| `general.auto_degradation_enabled` | `bool` | `true` | нет | Зарезервированный флаг совместимости в текущей ревизии (активного runtime-consumer нет). | `auto_degradation_enabled = true` |
+| `general.degradation_min_unavailable_dc_groups` | `u8` | `2` | нет | Зарезервированный порог совместимости в текущей ревизии (активного runtime-consumer нет). | `degradation_min_unavailable_dc_groups = 2` |
+
+## Устаревшие / legacy параметры
+
+| Параметр | Статус | Замена | Текущее поведение | Рекомендация миграции |
+|---|---|---|---|---|
+| `general.middle_proxy_nat_stun` | Deprecated | `network.stun_servers` | Добавляется в `network.stun_servers`, только если `network.stun_servers` не задан явно. | Перенести значение в `network.stun_servers`, legacy-ключ удалить. |
+| `general.middle_proxy_nat_stun_servers` | Deprecated | `network.stun_servers` | Добавляется в `network.stun_servers`, только если `network.stun_servers` не задан явно. | Перенести значения в `network.stun_servers`, legacy-ключ удалить. |
+| `general.proxy_secret_auto_reload_secs` | Deprecated | `general.update_every` | Используется только если `update_every = null` (legacy fallback). | Явно задать `general.update_every`, legacy-ключ удалить. |
+| `general.proxy_config_auto_reload_secs` | Deprecated | `general.update_every` | Используется только если `update_every = null` (legacy fallback). | Явно задать `general.update_every`, legacy-ключ удалить. |
+
+## Как конфигурируются Upstreams
+
+### Схема upstream
+
+| Поле | Применимость | Тип | Обязательно | Default | Назначение |
+|---|---|---|---|---|---|
+| `[[upstreams]].type` | все upstream | `"direct" \| "socks4" \| "socks5"` | да | n/a | Тип upstream транспорта. |
+| `[[upstreams]].weight` | все upstream | `u16` | нет | `1` | Базовый вес в weighted-random выборе. |
+| `[[upstreams]].enabled` | все upstream | `bool` | нет | `true` | Выключенные записи игнорируются на старте. |
+| `[[upstreams]].scopes` | все upstream | `String` | нет | `""` | Список scope-токенов через запятую для маршрутизации. |
+| `interface` | `direct` | `Option<String>` | нет | `null` | Имя интерфейса (например `eth0`) или literal локальный IP. |
+| `bind_addresses` | `direct` | `Option<Vec<IpAddr>>` | нет | `null` | Явные кандидаты source IP (имеют приоритет над `interface`). |
+| `address` | `socks4` | `String` | да | n/a | Адрес SOCKS4 сервера (`ip:port` или `host:port`). |
+| `interface` | `socks4` | `Option<String>` | нет | `null` | Используется только если `address` задан как `ip:port`. |
+| `user_id` | `socks4` | `Option<String>` | нет | `null` | SOCKS4 user ID в CONNECT-запросе. |
+| `address` | `socks5` | `String` | да | n/a | Адрес SOCKS5 сервера (`ip:port` или `host:port`). |
+| `interface` | `socks5` | `Option<String>` | нет | `null` | Используется только если `address` задан как `ip:port`. |
+| `username` | `socks5` | `Option<String>` | нет | `null` | Логин SOCKS5 auth. |
+| `password` | `socks5` | `Option<String>` | нет | `null` | Пароль SOCKS5 auth. |
+
+### Runtime-правила
+
+1. Если `[[upstreams]]` отсутствует, loader добавляет один upstream `direct` по умолчанию.
+2. Scope-фильтрация — по точному совпадению токена:
+- если scope запроса задан -> используются только записи, где `scopes` содержит такой же токен;
+- если scope запроса не задан -> используются только записи с пустым `scopes`.
+3. Среди healthy upstream используется weighted-random выбор: `weight * latency_factor`.
+4. Если в отфильтрованном наборе нет healthy upstream, выбирается случайный из отфильтрованных.
+5. Порядок выбора bind для `direct`:
+- сначала `bind_addresses` (только IP нужного семейства);
+- если одновременно заданы `interface` (имя) и `bind_addresses`, каждый IP проверяется на принадлежность интерфейсу;
+- несовпадающие IP отбрасываются с `WARN`;
+- если валидных IP не осталось, используется unbound direct connect (`bind_ip=None`);
+- если `bind_addresses` не подходит, применяется `interface` (literal IP или адрес интерфейса).
+6. Для `socks4/socks5` с `address` в виде hostname интерфейсный bind не поддерживается и игнорируется с предупреждением.
+7. Runtime DNS overrides применяются к резолвингу hostname в upstream-подключениях.
+8. В ME-режиме выбранный upstream также используется для ME TCP dial path.
+9. В ME-режиме для `direct` upstream с bind/interface STUN-рефлексия выполняется bind-aware для KDF материала.
+10. В ME-режиме для SOCKS upstream используются `BND.ADDR/BND.PORT` для KDF, если адрес валиден/публичен и соответствует IP family.
+
+## Примеры конфигурации Upstreams
+
+### Пример 1: минимальный direct upstream
+
+```toml
+[[upstreams]]
+type = "direct"
+weight = 1
+enabled = true
+```
+
+### Пример 2: direct с interface + явными bind IP
+
+```toml
+[[upstreams]]
+type = "direct"
+interface = "eth0"
+bind_addresses = ["192.168.1.100", "192.168.1.101"]
+weight = 3
+enabled = true
+```
+
+### Пример 3: SOCKS5 upstream с аутентификацией
+
+```toml
+[[upstreams]]
+type = "socks5"
+address = "198.51.100.30:1080"
+username = "proxy-user"
+password = "proxy-pass"
+weight = 2
+enabled = true
+```
+
+### Пример 4: смешанные upstream с scopes
+
+```toml
+[[upstreams]]
+type = "direct"
+weight = 5
+enabled = true
+scopes = ""
+
+[[upstreams]]
+type = "socks5"
+address = "203.0.113.40:1080"
+username = "edge"
+password = "edgepass"
+weight = 3
+enabled = true
+scopes = "premium,me"
+```
+
+### Пример 5: профиль тюнинга под ME
+
+```toml
+[general]
+use_middle_proxy = true
+proxy_secret_path = "proxy-secret"
+middle_proxy_nat_probe = true
+stun_nat_probe_concurrency = 16
+middle_proxy_pool_size = 12
+me_keepalive_enabled = true
+me_keepalive_interval_secs = 20
+me_keepalive_jitter_secs = 4
+me_reconnect_max_concurrent_per_dc = 12
+me_reconnect_backoff_base_ms = 300
+me_reconnect_backoff_cap_ms = 10000
+me_reconnect_fast_retry_count = 10
+hardswap = true
+me_reinit_every_secs = 600
+me_hardswap_warmup_delay_min_ms = 500
+me_hardswap_warmup_delay_max_ms = 1200
+me_hardswap_warmup_extra_passes = 2
+me_hardswap_warmup_pass_backoff_base_ms = 400
+me_config_stable_snapshots = 3
+me_config_apply_cooldown_secs = 120
+proxy_secret_stable_snapshots = 3
+proxy_secret_rotate_runtime = true
+proxy_secret_len_max = 512
+update_every = 300
+me_pool_drain_ttl_secs = 120
+me_pool_min_fresh_ratio = 0.9
+me_reinit_drain_timeout_secs = 180
+
+[timeouts]
+me_one_retry = 8
+me_one_timeout_ms = 1200
+
+[network]
+stun_use = true
+stun_tcp_fallback = true
+stun_servers = [
+  "stun1.l.google.com:19302",
+  "stun2.l.google.com:19302"
+]
+http_ip_detect_urls = [
+  "https://api.ipify.org",
+  "https://ifconfig.me/ip"
+]
+```

docs/XRAY-SINGBOX-ROUTING.ru.md

@@ -0,0 +1,321 @@
+# SNI-маршрутизация в xray-core / sing-box + TLS-fronting
+
+## Термины (в контексте этого кейса)
+
+- **TLS-fronting домен** — домен, который фигурирует в TLS ClientHello как **SNI** (например, `petrovich.ru`): он используется как "маска" на L7 и как ключ маршрутизации в прокси-роутере.
+- **xray-core / sing-box** — локальный или удалённый L7/TLS-роутер (прокси), который:
+  1) принимает входящее TCP/TLS-соединение,
+  2) читает TLS ClientHello,
+  3) извлекает SNI,
+  4) по SNI выбирает outbound/апстрим,
+  5) устанавливает новое TCP-соединение к целевому хосту уже **от себя**.
+- **SNI (Server Name Indication)** — поле в TLS ClientHello, где клиент Telegram сообщает доменное имя для "маскировки"
+- **DNS-resolve на стороне L7-роутера** — если выходной адрес задан доменом (или роутер решил "всё равно идти по SNI"), то DNS резолвится **на стороне xray/sing-box**, а не на стороне Telegram-клиента
+
+---
+
+## Ключевая идея: куда на самом деле идёт соединение решает не то, что вы указали клиенту, а то как L7-роутер трактует SNI
+
+Механика:
+
+1) Telegram-клиенту вы можете указать **IP/домен telemt**,как "сервер".
+2) Между клиентом и telemt стоит xray-core/sing-box, который принимает TCP, читает TLS ClientHello и видит **SNI=petrovich.ru**
+3) Дальше роутер говорит: "Вижу SNI - направить на апстрим/маршрут N"
+4) И устанавливает исходящее соединение не "по тому IP, который пользователь подразумевал", а **по домену из SNI** (или по сопоставлению SNI→outbound), используя для определния его IP собственный DNS-кеш или резолвер
+5) `petrovich.ru` по A-записи указывает **не на IP telemt**, а значит при L7-маршрутизации трафик уйдёт на "оригинальный" сайт за этим доменом, а не в telemt: Telegram-клиент, естественно, не сможет получить ожидаемое поведение, потому что ответить с handshake на той стороне некому
+
+---
+
+## Схема №1 "Как это НЕ работает"
+
+```text
+Telegram Client
+   |
+   |  (указан IP/домен telemt)
+   v
+telemt instance
+````
+
+Ожидание: "я указал telemt -> значит трафик попадёт в telemt" - **нет!**
+
+---
+
+## Схема №2. "Как это реально работает с TLS/L7-роутером и SNI"
+
+```text
+Telegram Client
+   |
+   | 1) TCP/TLS connection: 
+   |    - ClientHello: 
+   |      - SNI=petrovich.ru
+   v
+xray-core / sing-box / любой L7 router
+   |
+   | 2) читает ClientHello -> вытаскивает SNI
+   | 3) выбирает маршрут по SNI
+   | 4) делает DNS для petrovich.ru 
+   | 5) подключается к полученному IP по TLS с этим SNI
+   v
+"Оригинальный" сайт, A-запись которого не на telemt
+   |
+   X  не telemt -> Telegram-клиент не коннектится как ожидалось
+```
+
+---
+
+## Почему указанный в клиенте IP/домен telemt "не спасает"
+
+Потому что в таком режиме xray/sing-box выступает как **точка терминации TCP/TLS**, можно сказать - TLS-инспектор на уровне ClientHello, это означает:
+
+* TCP-сессия от Telegram-клиента заканчивается на xray/sing-box
+* Дальше создаётся **новая** TCP-сессия "от имени" xray/sing-box к апстриму
+* Выбор апстрима делается правилами роутинга, а в TLS-сценариях самый удобный и распространённый ключ — **SNI**
+
+То есть, "куда идти дальше" определяется логикой L7-роутера:
+
+* либо правилами вида `if SNI == petrovich.ru -> outbound X`,
+* либо более "автоматическим" поведением: `подключаться к тому хосту, который указан в SNI`,
+* плюс кэш DNS и собственные резолверы роутера
+
+---
+
+## Что именно извлекается из TLS ClientHello и почему этого достаточно
+
+TLS ClientHello отправляется **в начале** TLS-сессии и, в классическом TLS без ECH, содержит SNI в открытом виде.
+
+Упрощённо:
+
+```text
+ClientHello:
+  - supported_versions
+  - cipher_suites
+  - extensions:
+      - server_name: petrovich.ru   <-- SNI
+      - alpn: h2/http1.1/...
+      - ...
+```
+
+Роутеру не нужно расшифровывать трафик и завершать TLS "как сервер" — часто достаточно просто прочитать первые пакеты и распарсить ClientHello, чтобы получить SNI и принять решение
+
+---
+
+## Типовой алгоритм SNI-роутинга
+
+1. Принять входящий TCP.
+2. Подождать первые байты.
+3. Определить протокол:
+
+   * если видим TLS ClientHello → парсим SNI/ALPN
+4. Применить route rules:
+
+   * match по `server_name` / `domain` / `tls.sni`
+5. Выбрать outbound:
+
+   * direct / proxy / specific upstream / detour
+6. Установить исходящее соединение:
+
+   * либо на фиксированный IP:порт,
+   * либо на домен через DNS-resolve на стороне роутера
+7. Начать проксирование данных между входом и выходом
+
+---
+
+## Почему "A-запись фронтинг-домена не на telemt" ломает кейс
+
+### Ситуация
+
+* В ClientHello: `SNI = petrovich.ru`
+* DNS: `petrovich.ru -> 203.0.113.77`  - "оригинальный" сайт
+* telemt живёт на: `198.51.100.10`
+
+### Что делает роутер
+
+* Видит SNI `petrovich.ru`
+* Либо:
+
+  * (а) напрямую коннектится к `petrovich.ru:443`, резолвя A-запись в `203.0.113.77`,
+  * либо:
+  * (б) выбирает outbound, который указывает на `petrovich.ru` как destination,
+  * либо:
+  * (в) делает sniffing/override destination по SNI
+
+В итоге исходящий коннект идёт на `203.0.113.77:443`, а не на telemt!
+Другой сервер, другой протокол, другая логика, где telemt не участвует
+
+---
+
+## "Где именно происходит подмена destination на SNI"
+
+Это зависит от конфигурации, но типовые варианты:
+
+### Вариант A: outbound задан доменом (и он совпадает с SNI)
+
+Правило по SNI выбирает outbound, у которого destination задан доменом фронтинга, 
+тогда DNS резолвится на стороне роутера и вы уходите на "оригинальный" хост
+
+### Вариант B: destination override / sniffing
+
+Роутер "снифает" SNI и **перезаписывает** destination на домен из SNI (даже если вход изначально был на IP telemt),
+это особенно коварно: пользователь видит "я подключаюсь к IP telemt", но роутер после sniffing решает иначе
+
+### Вариант C: split DNS / кеш / независимый резолвер
+
+Даже если клиент "где-то" резолвит иначе, это не важно: конечный DNS для исходящего коннекта — на стороне xray/sing-box,
+который может иметь:
+
+* свой DoH/DoT,
+* свой кеш,
+* свои правила fake-ip / system resolver,
+* и, как следствие, своя "карта" **домен/SNI -> IP**
+
+---
+
+## Признаки того, что трафик "утёк на оригинал", а не попал в telemt
+
+* На стороне telemt отсутствуют входящие соединения/логи
+* На стороне роутера видно, что destination — домен фронтинга, а IP соответствует публичному сайту
+* TLS-метрики/сертификат на выходе соответствует "оригинальному" сайту в записах трафика
+* Telegram-клиент получает неожиданный тип ответов/ошибку handshaking/timeout в debug-режиме
+
+---
+
+## Best-practice решение для этого кейса: свой домен фронтинга + заглушка на telemt + Let's Encrypt
+
+### Цель
+
+Сделать так, чтобы:
+
+* SNI (фронтинг-домен) **резолвился в IP telemt**,
+* на IP telemt реально был TLS-сервис с валидным сертификатом под этот домен,
+* даже если кто-то "попробует открыть домен как сайт", он увидит нормальную заглушку, а не "пустоту"
+
+### Что это даёт
+
+* xray/sing-box, маршрутизируя по SNI, будет неизбежно приходить на telemt, потому что DNS(SNI-домен) → IP telemt
+* Внешний вид будет правдоподобным: обычный домен с обычным сертификатом
+* Устойчивость: меньше сюрпризов от DNS-кеша/перерезолва/"умных" правил роутера
+
+---
+
+## Рекомендуемая схема (целевое состояние)
+
+```text
+Telegram Client
+   |
+   | TLS ClientHello: SNI = hello.example.com
+   v
+xray-core / sing-box
+   |
+   | Route by SNI -> outbound -> connect to hello.example.com:443
+   | DNS(hello.example.com) = IP telemt
+   v
+telemt instance (IP telemt)
+   |
+   | TLS cert for hello.example.com (Let's Encrypt)
+   | + сайт-заглушка / health endpoint
+   v
+OK
+```
+
+---
+
+## Практический чеклист (минимальный)
+
+1. Купить/иметь домен: `hello.example.com`
+2. В DNS:
+
+   * `A hello.example.com -> <IP telemt>`
+   * (опционально) AAAA, если используете IPv6 и он стабилен
+3. На telemt-хосте:
+
+   * поднять TLS endpoint на 443 с валидным сертификатом LE под `hello.example.com`
+   * отдать "заглушку" (например, статический сайт), чтобы домен выглядел как обычный веб-сервис
+4. В xray/sing-box правилах:
+
+   * маршрутизировать нужный трафик по SNI = `hello.example.com` в "правильный" outbound (к telemt)
+   * избегать конфигураций, где destination override уводит на чужой домен
+5. Важно:
+
+   * если вы используете кеш DNS на роутере — сбросить/обновить его после смены A-записи
+
+---
+
+## Пояснение про сайт-заглушку
+
+Для эмуляции TLS, telemt имеет подсистему TLS-F в `src/tls_front`:
+- её модуль - fetcher, собирает TLS-профили, чтоб максимально поведенчески корректно повторять TLS конкретно указанного сайта
+
+Когда вы указываете сайт, который не отвечает по TLS:
+- fetcher не может собрать TLS-профиль и происходит fallback на `fake_cert_len` - примитивный алгоритм,
+- он забивает служебную информацию TLS рандомными байтами,
+- простые системы DPI не распознают это
+- однако, продвинутые системы, такие как nEdge или Fraud Control в сетях мобильной связи легко заблокируют или замедлят такой трафик
+
+Создав сайт-заглушку с Let's Encrypt сертификатом, вы даёте TLS-F возможность получить данные сертификата и корректно его "повторять" в дальнейшем
+
+---
+
+## Вариант конфиг-подхода: "SNI строго привязываем к telemt - фиксированный IP"
+
+Чтобы полностью исключить зависимость от DNS если вам это нужно, можно сделать outbound, который ходит на **фиксированный IP telemt**, но при этом выставляет SNI/Host как `hello.example.com`.
+
+Идея:
+
+* destination: `IP:443`
+* SNI: `hello.example.com`
+* сертификат на telemt именно под `hello.example.com`
+
+Так вы получаете:
+
+* TLS выглядит корректно, ведь SNI совпадает с сертификатом,
+* а routing никогда не уйдёт на "оригинал", потому что A-запись указывает на telemt и контроллируется вами!
+
+Но в вашем описании проблема как раз в том, что роутер "сам решает по SNI и резолвит домен", поэтому самый универсальный вариант — сделать так, чтобы DNS всегда приводил в telemt
+
+---
+
+## Пример логики правил на псевдоконфиге L7-роутера
+
+```text
+if inbound is TLS and sni == "hello.example.com":
+    route -> outbound "telemt"
+else:
+    route -> outbound "default"
+```
+
+Outbound `telemt`:
+
+* destination: `hello.example.com:443`
+* TLS enabled
+* SNI: `hello.example.com`
+
+---
+
+## Отдельно: что может неожиданно сломать даже "правильный" DNS
+
+* **Кеширование DNS** на xray/sing-box или на системном резолвере, особенно при смене A-записи
+* **Split-horizon DNS**: разные ответы внутри/снаружи, попытки подмены/терминирования в других точках
+* **IPv6**: если есть AAAA и он указывает не туда, роутер может предпочесть IPv6: помните, что поддержка v6 нестабильна и не рекомендуется в prod
+* **DoH/DoT** на роутере: он может резолвить не тем резолвером, которым вы проверяли
+
+Минимальная гигиена:
+
+* контролировать A/AAAA,
+* держать TTL разумным,
+* проверять, каким резолвером пользуется именно роутер,
+* при необходимости отключить/ограничить destination override
+
+---
+
+## Итог
+
+В режиме TLS-fronting с xray-core/sing-box как L7/TLS-роутером **SNI становится приоритетным "source-of-truth" для маршрутизации**
+
+Если фронтинг-домен по DNS указывает не на IP telemt, роутер честно уводит трафик на "оригинальный" сайт, потому что он строит исходящее соединение "по SNI"
+
+Надёжное решение для этого кейса:
+
+* использовать **свой домен** для фронтинга,
+* направить его **A/AAAA** на IP telemt,
+* поднять на telemt **TLS-сервис с Let’s Encrypt сертификатом** под этот домен,
+* (желательно) держать **сайт-заглушку**, чтобы 443 выглядел как обычный HTTPS

docs/model/MODEL.en.md

@@ -0,0 +1,285 @@
+# Telemt Runtime Model
+
+## Scope
+This document defines runtime concepts used by the Middle-End (ME) transport pipeline and the orchestration logic around it.
+
+It focuses on:
+- `ME Pool / Reader / Writer / Refill / Registry`
+- `Adaptive Floor`
+- `Trio-State`
+- `Generation Lifecycle`
+
+## Core Entities
+
+### ME Pool
+`ME Pool` is the runtime orchestrator for all Middle-End writers.
+
+Responsibilities:
+- Holds writer inventory by DC/family/endpoint.
+- Maintains routing primitives and writer selection policy.
+- Tracks generation state (`active`, `warm`, `draining` context).
+- Applies runtime policies (floor mode, refill, reconnect, reinit, fallback behavior).
+- Exposes readiness gates used by admission logic (for conditional accept/cast behavior).
+
+Non-goals:
+- It does not own client protocol decoding.
+- It does not own per-client business policy (quotas/limits).
+
+### ME Writer
+`ME Writer` is a long-lived ME RPC tunnel bound to one concrete ME endpoint (`ip:port`), with:
+- Outbound command channel (send path).
+- Associated reader loop (inbound path).
+- Health/degraded flags.
+- Contour/state and generation metadata.
+
+A writer is the actual data plane carrier for client sessions once bound.
+
+### ME Reader
+`ME Reader` is the inbound parser/dispatcher for one writer:
+- Reads/decrypts ME RPC frames.
+- Validates sequence/checksum.
+- Routes payloads to client-connection channels via `Registry`.
+- Emits close/ack/data events and updates telemetry.
+
+Design intent:
+- Reader must stay non-blocking as much as possible.
+- Backpressure on a single client route must not stall the whole writer stream.
+
+### Refill
+`Refill` is the recovery mechanism that restores writer coverage when capacity drops:
+- Per-endpoint restore (same endpoint first).
+- Per-DC restore to satisfy required floor.
+- Optional outage-mode/shadow behavior for fragile single-endpoint DCs.
+
+Refill works asynchronously and should not block hot routing paths.
+
+### Registry
+`Registry` is the routing index between ME and client sessions:
+- `conn_id -> client response channel`
+- `conn_id <-> writer_id` binding map
+- writer activity snapshots and idle tracking
+
+Main invariants:
+- A `conn_id` routes to at most one active response channel.
+- Writer loss triggers safe unbind/cleanup and close propagation.
+- Registry state is the source of truth for active ME-bound session mapping.
+
+## Adaptive Floor
+
+### What it is
+`Adaptive Floor` is a runtime policy that changes target writer count per DC based on observed activity, instead of always holding static peak floor.
+
+### Why it exists
+Goals:
+- Reduce idle writer churn under low traffic.
+- Keep enough warm capacity to avoid client-visible stalls on burst recovery.
+- Limit needless reconnect storms on unstable endpoints.
+
+### Behavioral model
+- Under activity: floor converges toward configured static requirement.
+- Under prolonged idle: floor can shrink to a safe minimum.
+- Recovery/grace windows prevent aggressive oscillation.
+
+### Safety constraints
+- Never violate minimal survivability floor for a DC group.
+- Refill must still restore quickly on demand.
+- Floor adaptation must not force-drop already bound healthy sessions.
+
+## Trio-State
+
+`Trio-State` is writer contouring:
+- `Warm`
+- `Active`
+- `Draining`
+
+### State semantics
+- `Warm`: connected and validated, not primary for new binds.
+- `Active`: preferred for new binds and normal traffic.
+- `Draining`: no new regular binds; existing sessions continue until graceful retirement rules apply.
+
+### Transition intent
+- `Warm -> Active`: when coverage/readiness conditions are satisfied.
+- `Active -> Draining`: on generation swap, endpoint replacement, or controlled retirement.
+- `Draining -> removed`: after drain TTL/force-close policy (or when naturally empty).
+
+This separation reduces SPOF and keeps cutovers predictable.
+
+## Generation Lifecycle
+
+Generation isolates pool epochs during reinit/reconfiguration.
+
+### Lifecycle phases
+1. `Bootstrap`: initial writers are established.
+2. `Warmup`: next generation writers are created and validated.
+3. `Activation`: generation promoted to active when coverage gate passes.
+4. `Drain`: previous generation becomes draining, existing sessions are allowed to finish.
+5. `Retire`: old generation writers are removed after graceful rules.
+
+### Operational guarantees
+- No partial generation activation without minimum coverage.
+- Existing healthy client sessions should not be dropped just because a new generation appears.
+- Draining generation exists to absorb in-flight traffic during swap.
+
+### Readiness and admission
+Pool readiness is not equivalent to “all endpoints fully saturated”.
+Typical gating strategy:
+- Open admission when per-DC minimal alive coverage exists.
+- Continue background saturation for multi-endpoint DCs.
+
+This keeps startup latency low while preserving eventual full capacity.
+
+## Interactions Between Concepts
+
+- `Generation` defines pool epochs.
+- `Trio-State` defines per-writer role inside/around those epochs.
+- `Adaptive Floor` defines how much capacity should be maintained right now.
+- `Refill` is the actuator that closes the gap between desired and current capacity.
+- `Registry` keeps per-session routing correctness while all of the above changes over time.
+
+## Architectural Approach
+
+### Layered Design
+The runtime is intentionally split into two planes:
+- `Control Plane`: decides desired topology and policy (`floor`, `generation swap`, `refill`, `fallback`).
+- `Data Plane`: executes packet/session transport (`reader`, `writer`, routing, acks, close propagation).
+
+Architectural rule:
+- Control Plane may change writer inventory and policy.
+- Data Plane must remain stable and low-latency while those changes happen.
+
+### Ownership Model
+Ownership is centered around explicit state domains:
+- `MePool` owns writer lifecycle and policy state.
+- `Registry` owns per-connection routing bindings.
+- `Writer task` owns outbound ME socket send progression.
+- `Reader task` owns inbound ME socket parsing and event dispatch.
+
+This prevents accidental cross-layer mutation and keeps invariants local.
+
+### Control Plane Responsibilities
+Control Plane is event-driven and policy-driven:
+- Startup initialization and readiness gates.
+- Runtime reinit (periodic or config-triggered).
+- Coverage checks per DC/family/endpoint group.
+- Floor enforcement (static/adaptive).
+- Refill scheduling and retry orchestration.
+- Generation transition (`warm -> active`, previous `active -> draining`).
+
+Control Plane must prioritize determinism over short-term aggressiveness.
+
+### Data Plane Responsibilities
+Data Plane is throughput-first and allocation-sensitive:
+- Session bind to writer.
+- Per-frame parsing/validation and dispatch.
+- Ack and close signal propagation.
+- Route drop behavior under missing connection or closed channel.
+- Minimal critical logging in hot path.
+
+Data Plane should avoid waiting on operations that are not strictly required for frame correctness.
+
+## Concurrency and Synchronization
+
+### Concurrency Principles
+- Per-writer isolation: each writer has independent send/read task loops.
+- Per-connection isolation: client channel state is scoped by `conn_id`.
+- Asynchronous recovery: refill/reconnect runs outside the packet hot path.
+
+### Synchronization Strategy
+- Shared maps use fine-grained, short-lived locking.
+- Read-mostly paths avoid broad write-lock windows.
+- Backpressure decisions are localized at route/channel boundary.
+
+Design target:
+- A slow consumer should degrade only itself (or its route), not global writer progress.
+
+### Cancellation and Shutdown
+Writer and reader loops are cancellation-aware:
+- explicit cancel token / close command support;
+- safe unbind and cleanup via registry;
+- deterministic order: stop admission -> drain/close -> release resources.
+
+## Consistency Model
+
+### Session Consistency
+For one `conn_id`:
+- exactly one active route target at a time;
+- close and unbind must be idempotent;
+- writer loss must not leave dangling bindings.
+
+### Generation Consistency
+Generational consistency guarantees:
+- New generation is not promoted before minimum coverage gate.
+- Previous generation remains available in `draining` state during handover.
+- Forced retirement is policy-bound (`drain ttl`, optional force-close), not immediate.
+
+### Policy Consistency
+Policy changes (`adaptive/static floor`, fallback mode, retries) should apply without violating established active-session routing invariants.
+
+## Backpressure and Flow Control
+
+### Route-Level Backpressure
+Route channels are bounded by design.
+When pressure increases:
+- short burst absorption is allowed;
+- prolonged congestion triggers controlled drop semantics;
+- drop accounting is explicit via metrics/counters.
+
+### Reader Non-Blocking Priority
+Inbound ME reader path should never be serialized behind one congested client route.
+Practical implication:
+- prefer non-blocking route attempt in the parser loop;
+- move heavy recovery to async side paths.
+
+## Failure Domain Strategy
+
+### Endpoint-Level Failure
+Failure of one endpoint should trigger endpoint-scoped recovery first:
+- same endpoint reconnect;
+- endpoint replacement within same DC group if applicable.
+
+### DC-Level Degradation
+If a DC group cannot satisfy floor:
+- keep service via remaining coverage if policy allows;
+- continue asynchronous refill saturation in background.
+
+### Whole-Pool Readiness Loss
+If no sufficient ME coverage exists:
+- admission gate can hold new accepts (conditional policy);
+- existing sessions should continue when their path remains healthy.
+
+## Performance Architecture Notes
+
+### Hotpath Discipline
+Allowed in hotpath:
+- fixed-size parsing and cheap validation;
+- bounded channel operations;
+- precomputed or low-allocation access patterns.
+
+Avoid in hotpath:
+- repeated expensive decoding;
+- broad locks with awaits inside critical sections;
+- verbose high-frequency logging.
+
+### Throughput Stability Over Peak Spikes
+Architecture prefers stable throughput and predictable latency over short peak gains that increase churn or long-tail reconnect times.
+
+## Evolution and Extension Rules
+
+To evolve this model safely:
+- Add new policy knobs in Control Plane first.
+- Keep Data Plane contracts stable (`conn_id`, route semantics, close semantics).
+- Validate generation and registry invariants before enabling by default.
+- Introduce new retry/recovery strategies behind explicit config.
+
+## Failure and Recovery Notes
+
+- Single-endpoint DC failure is a normal degraded mode case; policy should prioritize fast reconnect and optional shadow/probing strategies.
+- Idle close by peer should be treated as expected when upstream enforces idle timeout.
+- Reconnect backoff must protect against synchronized churn while still allowing fast first retries.
+- Fallback (`ME -> direct DC`) is a policy switch, not a transport bug by itself.
+
+## Terminology Summary
+- `Coverage`: enough live writers to satisfy per-DC acceptance policy.
+- `Floor`: target minimum writer count policy.
+- `Churn`: frequent writer reconnect/remove cycles.
+- `Hotpath`: per-packet/per-connection data path where extra waits/allocations are expensive.

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+# Runtime-модель Telemt
+
+## Область описания
+Документ фиксирует ключевые runtime-понятия пайплайна Middle-End (ME) и оркестрации вокруг него.
+
+Фокус:
+- `ME Pool / Reader / Writer / Refill / Registry`
+- `Adaptive Floor`
+- `Trio-State`
+- `Generation Lifecycle`
+
+## Базовые сущности
+
+### ME Pool
+`ME Pool` — центральный оркестратор всех Middle-End writer-ов.
+
+Зона ответственности:
+- хранит инвентарь writer-ов по DC/family/endpoint;
+- управляет выбором writer-а и маршрутизацией;
+- ведёт состояние поколений (`active`, `warm`, `draining` контекст);
+- применяет runtime-политики (floor, refill, reconnect, reinit, fallback);
+- отдаёт сигналы готовности для admission-логики (conditional accept/cast).
+
+Что не делает:
+- не декодирует клиентский протокол;
+- не реализует бизнес-политику пользователя (квоты/лимиты).
+
+### ME Writer
+`ME Writer` — долгоживущий ME RPC-канал к конкретному endpoint (`ip:port`), у которого есть:
+- канал команд на отправку;
+- связанный reader loop для входящего потока;
+- флаги состояния/деградации;
+- метаданные contour/state и generation.
+
+Writer — это фактический data-plane носитель клиентских сессий после бинда.
+
+### ME Reader
+`ME Reader` — входной parser/dispatcher одного writer-а:
+- читает и расшифровывает ME RPC-фреймы;
+- проверяет sequence/checksum;
+- маршрутизирует payload в client-каналы через `Registry`;
+- обрабатывает close/ack/data и обновляет телеметрию.
+
+Инженерный принцип:
+- Reader должен оставаться неблокирующим.
+- Backpressure одной клиентской сессии не должен останавливать весь поток writer-а.
+
+### Refill
+`Refill` — механизм восстановления покрытия writer-ов при просадке:
+- восстановление на том же endpoint в первую очередь;
+- восстановление по DC до требуемого floor;
+- опциональные outage/shadow-режимы для хрупких single-endpoint DC.
+
+Refill работает асинхронно и не должен блокировать hotpath.
+
+### Registry
+`Registry` — маршрутизационный индекс между ME и клиентскими сессиями:
+- `conn_id -> канал ответа клиенту`;
+- map биндов `conn_id <-> writer_id`;
+- снимки активности writer-ов и idle-трекинг.
+
+Ключевые инварианты:
+- один `conn_id` маршрутизируется максимум в один активный канал ответа;
+- потеря writer-а приводит к безопасному unbind/cleanup и отправке close;
+- именно `Registry` является источником истины по активным ME-биндам.
+
+## Adaptive Floor
+
+### Что это
+`Adaptive Floor` — runtime-политика, которая динамически меняет целевое число writer-ов на DC в зависимости от активности, а не держит всегда фиксированный статический floor.
+
+### Зачем
+Цели:
+- уменьшить churn на idle-трафике;
+- сохранить достаточную прогретую ёмкость для быстрых всплесков;
+- снизить лишние reconnect-штормы на нестабильных endpoint.
+
+### Модель поведения
+- при активности floor стремится к статическому требованию;
+- при длительном idle floor может снижаться до безопасного минимума;
+- grace/recovery окна не дают системе "флапать" слишком резко.
+
+### Ограничения безопасности
+- нельзя нарушать минимальный floor выживаемости DC-группы;
+- refill обязан быстро нарастить покрытие по запросу;
+- адаптация не должна принудительно ронять уже привязанные healthy-сессии.
+
+## Trio-State
+
+`Trio-State` — контурная роль writer-а:
+- `Warm`
+- `Active`
+- `Draining`
+
+### Семантика состояний
+- `Warm`: writer подключён и валиден, но не основной для новых биндов.
+- `Active`: приоритетный для новых биндов и обычного трафика.
+- `Draining`: новые обычные бинды не назначаются; текущие сессии живут до правил graceful-вывода.
+
+### Логика переходов
+- `Warm -> Active`: когда достигнуты условия покрытия/готовности.
+- `Active -> Draining`: при swap поколения, замене endpoint или контролируемом выводе.
+- `Draining -> removed`: после drain TTL/force-close политики (или естественного опустошения).
+
+Такое разделение снижает SPOF-риски и делает cutover предсказуемым.
+
+## Generation Lifecycle
+
+Generation изолирует эпохи пула при reinit/reconfiguration.
+
+### Фазы жизненного цикла
+1. `Bootstrap`: поднимается начальный набор writer-ов.
+2. `Warmup`: создаётся и валидируется новое поколение.
+3. `Activation`: новое поколение становится active после прохождения coverage-gate.
+4. `Drain`: предыдущее поколение переводится в draining, текущим сессиям дают завершиться.
+5. `Retire`: старое поколение удаляется по graceful-правилам.
+
+### Операционные гарантии
+- нельзя активировать поколение частично без минимального покрытия;
+- healthy-клиенты не должны теряться только из-за появления нового поколения;
+- draining-поколение служит буфером для in-flight трафика во время swap.
+
+### Готовность и приём клиентов
+Готовность пула не равна "все endpoint полностью насыщены".
+Типичная стратегия:
+- открыть admission при минимально достаточном alive-покрытии по DC;
+- параллельно продолжать saturation для multi-endpoint DC.
+
+Это уменьшает startup latency и сохраняет выход на полную ёмкость.
+
+## Как понятия связаны между собой
+
+- `Generation` задаёт эпохи пула.
+- `Trio-State` задаёт роль каждого writer-а внутри/между эпохами.
+- `Adaptive Floor` задаёт, сколько ёмкости нужно сейчас.
+- `Refill` — исполнитель, который закрывает разницу между desired и current capacity.
+- `Registry` гарантирует корректную маршрутизацию сессий, пока всё выше меняется.
+
+## Архитектурный подход
+
+### Слоистая модель
+Runtime специально разделён на две плоскости:
+- `Control Plane`: принимает решения о целевой топологии и политиках (`floor`, `generation swap`, `refill`, `fallback`).
+- `Data Plane`: исполняет транспорт сессий и пакетов (`reader`, `writer`, маршрутизация, ack, close).
+
+Ключевое правило:
+- Control Plane может менять состав writer-ов и policy.
+- Data Plane должен оставаться стабильным и низколатентным в момент этих изменений.
+
+### Модель владения состоянием
+Владение разделено по доменам:
+- `MePool` владеет жизненным циклом writer-ов и policy-state.
+- `Registry` владеет routing-биндами клиентских сессий.
+- `Writer task` владеет исходящей прогрессией ME-сокета.
+- `Reader task` владеет входящим парсингом и dispatch-событиями.
+
+Это ограничивает побочные мутации и локализует инварианты.
+
+### Обязанности Control Plane
+Control Plane работает событийно и policy-ориентированно:
+- стартовая инициализация и readiness-gate;
+- runtime reinit (периодический и/или по изменению конфигурации);
+- проверки покрытия по DC/family/endpoint group;
+- применение floor-политики (static/adaptive);
+- планирование refill и orchestration retry;
+- переходы поколений (`warm -> active`, прежний `active -> draining`).
+
+Для него важнее детерминизм, чем агрессивная краткосрочная реакция.
+
+### Обязанности Data Plane
+Data Plane ориентирован на пропускную способность и предсказуемую задержку:
+- bind клиентской сессии к writer-у;
+- per-frame parsing/validation/dispatch;
+- распространение ack/close;
+- корректная реакция на missing conn/closed channel;
+- минимальный лог-шум в hotpath.
+
+Data Plane не должен ждать операций, не критичных для корректности текущего фрейма.
+
+## Конкурентность и синхронизация
+
+### Принципы конкурентности
+- Изоляция по writer-у: у каждого writer-а независимые send/read loop.
+- Изоляция по сессии: состояние канала локально для `conn_id`.
+- Асинхронное восстановление: refill/reconnect выполняются вне пакетного hotpath.
+
+### Стратегия синхронизации
+- Для shared map используются короткие и узкие lock-секции.
+- Read-heavy пути избегают длительных write-lock окон.
+- Решения по backpressure локализованы на границе route/channel.
+
+Цель:
+- медленный consumer должен деградировать локально, не останавливая глобальный прогресс writer-а.
+
+### Cancellation и shutdown
+Reader/Writer loop должны быть cancellation-aware:
+- явные cancel token / close command;
+- безопасный unbind/cleanup через registry;
+- детерминированный порядок: stop admission -> drain/close -> release resources.
+
+## Модель согласованности
+
+### Согласованность сессии
+Для одного `conn_id`:
+- одновременно ровно один активный route-target;
+- close/unbind операции идемпотентны;
+- потеря writer-а не оставляет dangling-бинды.
+
+### Согласованность поколения
+Гарантии generation:
+- новое поколение не активируется до прохождения минимального coverage-gate;
+- предыдущее поколение остаётся в `draining` на время handover;
+- принудительный вывод writer-ов ограничен policy (`drain ttl`, optional force-close), а не мгновенный.
+
+### Согласованность политик
+Изменение policy (`adaptive/static floor`, fallback mode, retries) не должно ломать инварианты маршрутизации уже активных сессий.
+
+## Backpressure и управление потоком
+
+### Route-level backpressure
+Route-каналы намеренно bounded.
+При росте нагрузки:
+- кратковременный burst поглощается;
+- длительная перегрузка переходит в контролируемую drop-семантику;
+- все drop-сценарии должны быть прозрачно видны в метриках.
+
+### Приоритет неблокирующего Reader
+Входящий ME-reader path не должен сериализоваться из-за одной перегруженной клиентской сессии.
+Практически это означает:
+- использовать неблокирующую попытку route в parser loop;
+- выносить тяжёлое восстановление в асинхронные side-path.
+
+## Стратегия доменов отказа
+
+### Отказ отдельного endpoint
+Сначала применяется endpoint-local recovery:
+- reconnect в тот же endpoint;
+- затем замена endpoint внутри той же DC-группы (если доступно).
+
+### Деградация уровня DC
+Если DC-группа не набирает floor:
+- сервис сохраняется на остаточном покрытии (если policy разрешает);
+- saturation refill продолжается асинхронно в фоне.
+
+### Потеря готовности всего пула
+Если достаточного ME-покрытия нет:
+- admission gate может временно закрыть приём новых подключений (conditional policy);
+- уже активные сессии продолжают работать, пока их маршрут остаётся healthy.
+
+## Архитектурные заметки по производительности
+
+### Дисциплина hotpath
+Допустимо в hotpath:
+- фиксированный и дешёвый parsing/validation;
+- bounded channel operations;
+- precomputed/low-allocation доступ к данным.
+
+Нежелательно в hotpath:
+- повторные дорогие decode;
+- широкие lock-секции с `await` внутри;
+- высокочастотный подробный logging.
+
+### Стабильность важнее пиков
+Архитектура приоритетно выбирает стабильную пропускную способность и предсказуемую latency, а не краткосрочные пики ценой churn и long-tail reconnect.
+
+## Правила эволюции модели
+
+Чтобы расширять модель безопасно:
+- новые policy knobs сначала внедрять в Control Plane;
+- контракты Data Plane (`conn_id`, route/close семантика) держать стабильными;
+- перед дефолтным включением проверять generation/registry инварианты;
+- новые recovery/retry стратегии вводить через явный config-флаг.
+
+## Нюансы отказов и восстановления
+
+- падение single-endpoint DC — штатный деградированный сценарий; приоритет: быстрый reconnect и, при необходимости, shadow/probing;
+- idle-close со стороны peer должен считаться нормальным событием при upstream idle-timeout;
+- backoff reconnect-логики должен ограничивать синхронный churn, но сохранять быстрые первые попытки;
+- fallback (`ME -> direct DC`) — это переключаемая policy-ветка, а не автоматический признак бага транспорта.
+
+## Краткий словарь
+- `Coverage`: достаточное число живых writer-ов для политики приёма по DC.
+- `Floor`: целевая минимальная ёмкость writer-ов.
+- `Churn`: частые циклы reconnect/remove writer-ов.
+- `Hotpath`: пер-пакетный/пер-коннектный путь, где любые лишние ожидания и аллокации особенно дороги.

install.sh

@@ -0,0 +1,93 @@
+#!/bin/sh
+set -eu
+
+REPO="${REPO:-telemt/telemt}"
+BIN_NAME="${BIN_NAME:-telemt}"
+VERSION="${1:-${VERSION:-latest}}"
+INSTALL_DIR="${INSTALL_DIR:-/usr/local/bin}"
+
+say() {
+    printf '%s\n' "$*"
+}
+
+die() {
+    printf 'Error: %s\n' "$*" >&2
+    exit 1
+}
+
+need_cmd() {
+    command -v "$1" >/dev/null 2>&1 || die "required command not found: $1"
+}
+
+detect_arch() {
+    arch="$(uname -m)"
+    case "$arch" in
+        x86_64|amd64) printf 'x86_64\n' ;;
+        aarch64|arm64) printf 'aarch64\n' ;;
+        *) die "unsupported architecture: $arch" ;;
+    esac
+}
+
+detect_libc() {
+    case "$(ldd --version 2>&1 || true)" in
+        *musl*) printf 'musl\n' ;;
+        *) printf 'gnu\n' ;;
+    esac
+}
+
+fetch_to_stdout() {
+    url="$1"
+    if command -v curl >/dev/null 2>&1; then
+        curl -fsSL "$url"
+    elif command -v wget >/dev/null 2>&1; then
+        wget -qO- "$url"
+    else
+        die "neither curl nor wget is installed"
+    fi
+}
+
+install_binary() {
+    src="$1"
+    dst="$2"
+
+    if [ -w "$INSTALL_DIR" ] || { [ ! -e "$INSTALL_DIR" ] && [ -w "$(dirname "$INSTALL_DIR")" ]; }; then
+        mkdir -p "$INSTALL_DIR"
+        install -m 0755 "$src" "$dst"
+    elif command -v sudo >/dev/null 2>&1; then
+        sudo mkdir -p "$INSTALL_DIR"
+        sudo install -m 0755 "$src" "$dst"
+    else
+        die "cannot write to $INSTALL_DIR and sudo is not available"
+    fi
+}
+
+need_cmd uname
+need_cmd tar
+need_cmd mktemp
+need_cmd grep
+need_cmd install
+
+ARCH="$(detect_arch)"
+LIBC="$(detect_libc)"
+
+case "$VERSION" in
+    latest)
+        URL="https://github.com/$REPO/releases/latest/download/${BIN_NAME}-${ARCH}-linux-${LIBC}.tar.gz"
+        ;;
+    *)
+        URL="https://github.com/$REPO/releases/download/${VERSION}/${BIN_NAME}-${ARCH}-linux-${LIBC}.tar.gz"
+        ;;
+esac
+
+TMPDIR="$(mktemp -d)"
+trap 'rm -rf "$TMPDIR"' EXIT INT TERM
+
+say "Installing $BIN_NAME ($VERSION) for $ARCH-linux-$LIBC..."
+fetch_to_stdout "$URL" | tar -xzf - -C "$TMPDIR"
+
+[ -f "$TMPDIR/$BIN_NAME" ] || die "archive did not contain $BIN_NAME"
+
+install_binary "$TMPDIR/$BIN_NAME" "$INSTALL_DIR/$BIN_NAME"
+
+say "Installed: $INSTALL_DIR/$BIN_NAME"
+"$INSTALL_DIR/$BIN_NAME" --version 2>/dev/null || true

src/api/config_store.rs

@@ -0,0 +1,269 @@
+use std::collections::BTreeMap;
+use std::io::Write;
+use std::path::{Path, PathBuf};
+
+use chrono::{DateTime, Utc};
+use hyper::header::IF_MATCH;
+use serde::Serialize;
+use sha2::{Digest, Sha256};
+
+use crate::config::ProxyConfig;
+
+use super::model::ApiFailure;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(super) enum AccessSection {
+    Users,
+    UserAdTags,
+    UserMaxTcpConns,
+    UserExpirations,
+    UserDataQuota,
+    UserMaxUniqueIps,
+}
+
+impl AccessSection {
+    fn table_name(self) -> &'static str {
+        match self {
+            Self::Users => "access.users",
+            Self::UserAdTags => "access.user_ad_tags",
+            Self::UserMaxTcpConns => "access.user_max_tcp_conns",
+            Self::UserExpirations => "access.user_expirations",
+            Self::UserDataQuota => "access.user_data_quota",
+            Self::UserMaxUniqueIps => "access.user_max_unique_ips",
+        }
+    }
+}
+
+pub(super) fn parse_if_match(headers: &hyper::HeaderMap) -> Option<String> {
+    headers
+        .get(IF_MATCH)
+        .and_then(|value| value.to_str().ok())
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map(|value| value.trim_matches('"').to_string())
+}
+
+pub(super) async fn ensure_expected_revision(
+    config_path: &Path,
+    expected_revision: Option<&str>,
+) -> Result<(), ApiFailure> {
+    let Some(expected) = expected_revision else {
+        return Ok(());
+    };
+    let current = current_revision(config_path).await?;
+    if current != expected {
+        return Err(ApiFailure::new(
+            hyper::StatusCode::CONFLICT,
+            "revision_conflict",
+            "Config revision mismatch",
+        ));
+    }
+    Ok(())
+}
+
+pub(super) async fn current_revision(config_path: &Path) -> Result<String, ApiFailure> {
+    let content = tokio::fs::read_to_string(config_path)
+        .await
+        .map_err(|e| ApiFailure::internal(format!("failed to read config: {}", e)))?;
+    Ok(compute_revision(&content))
+}
+
+pub(super) fn compute_revision(content: &str) -> String {
+    let mut hasher = Sha256::new();
+    hasher.update(content.as_bytes());
+    hex::encode(hasher.finalize())
+}
+
+pub(super) async fn load_config_from_disk(config_path: &Path) -> Result<ProxyConfig, ApiFailure> {
+    let config_path = config_path.to_path_buf();
+    tokio::task::spawn_blocking(move || ProxyConfig::load(config_path))
+        .await
+        .map_err(|e| ApiFailure::internal(format!("failed to join config loader: {}", e)))?
+        .map_err(|e| ApiFailure::internal(format!("failed to load config: {}", e)))
+}
+
+pub(super) async fn save_config_to_disk(
+    config_path: &Path,
+    cfg: &ProxyConfig,
+) -> Result<String, ApiFailure> {
+    let serialized = toml::to_string_pretty(cfg)
+        .map_err(|e| ApiFailure::internal(format!("failed to serialize config: {}", e)))?;
+    write_atomic(config_path.to_path_buf(), serialized.clone()).await?;
+    Ok(compute_revision(&serialized))
+}
+
+pub(super) async fn save_access_sections_to_disk(
+    config_path: &Path,
+    cfg: &ProxyConfig,
+    sections: &[AccessSection],
+) -> Result<String, ApiFailure> {
+    let mut content = tokio::fs::read_to_string(config_path)
+        .await
+        .map_err(|e| ApiFailure::internal(format!("failed to read config: {}", e)))?;
+
+    let mut applied = Vec::new();
+    for section in sections {
+        if applied.contains(section) {
+            continue;
+        }
+        let rendered = render_access_section(cfg, *section)?;
+        content = upsert_toml_table(&content, section.table_name(), &rendered);
+        applied.push(*section);
+    }
+
+    write_atomic(config_path.to_path_buf(), content.clone()).await?;
+    Ok(compute_revision(&content))
+}
+
+fn render_access_section(cfg: &ProxyConfig, section: AccessSection) -> Result<String, ApiFailure> {
+    let body = match section {
+        AccessSection::Users => {
+            let rows: BTreeMap<String, String> = cfg
+                .access
+                .users
+                .iter()
+                .map(|(key, value)| (key.clone(), value.clone()))
+                .collect();
+            serialize_table_body(&rows)?
+        }
+        AccessSection::UserAdTags => {
+            let rows: BTreeMap<String, String> = cfg
+                .access
+                .user_ad_tags
+                .iter()
+                .map(|(key, value)| (key.clone(), value.clone()))
+                .collect();
+            serialize_table_body(&rows)?
+        }
+        AccessSection::UserMaxTcpConns => {
+            let rows: BTreeMap<String, usize> = cfg
+                .access
+                .user_max_tcp_conns
+                .iter()
+                .map(|(key, value)| (key.clone(), *value))
+                .collect();
+            serialize_table_body(&rows)?
+        }
+        AccessSection::UserExpirations => {
+            let rows: BTreeMap<String, DateTime<Utc>> = cfg
+                .access
+                .user_expirations
+                .iter()
+                .map(|(key, value)| (key.clone(), *value))
+                .collect();
+            serialize_table_body(&rows)?
+        }
+        AccessSection::UserDataQuota => {
+            let rows: BTreeMap<String, u64> = cfg
+                .access
+                .user_data_quota
+                .iter()
+                .map(|(key, value)| (key.clone(), *value))
+                .collect();
+            serialize_table_body(&rows)?
+        }
+        AccessSection::UserMaxUniqueIps => {
+            let rows: BTreeMap<String, usize> = cfg
+                .access
+                .user_max_unique_ips
+                .iter()
+                .map(|(key, value)| (key.clone(), *value))
+                .collect();
+            serialize_table_body(&rows)?
+        }
+    };
+
+    let mut out = format!("[{}]\n", section.table_name());
+    if !body.is_empty() {
+        out.push_str(&body);
+    }
+    if !out.ends_with('\n') {
+        out.push('\n');
+    }
+    Ok(out)
+}
+
+fn serialize_table_body<T: Serialize>(value: &T) -> Result<String, ApiFailure> {
+    toml::to_string(value)
+        .map_err(|e| ApiFailure::internal(format!("failed to serialize access section: {}", e)))
+}
+
+fn upsert_toml_table(source: &str, table_name: &str, replacement: &str) -> String {
+    if let Some((start, end)) = find_toml_table_bounds(source, table_name) {
+        let mut out = String::with_capacity(source.len() + replacement.len());
+        out.push_str(&source[..start]);
+        out.push_str(replacement);
+        out.push_str(&source[end..]);
+        return out;
+    }
+
+    let mut out = source.to_string();
+    if !out.is_empty() && !out.ends_with('\n') {
+        out.push('\n');
+    }
+    if !out.is_empty() {
+        out.push('\n');
+    }
+    out.push_str(replacement);
+    out
+}
+
+fn find_toml_table_bounds(source: &str, table_name: &str) -> Option<(usize, usize)> {
+    let target = format!("[{}]", table_name);
+    let mut offset = 0usize;
+    let mut start = None;
+
+    for line in source.split_inclusive('\n') {
+        let trimmed = line.trim();
+        if let Some(start_offset) = start {
+            if trimmed.starts_with('[') {
+                return Some((start_offset, offset));
+            }
+        } else if trimmed == target {
+            start = Some(offset);
+        }
+        offset = offset.saturating_add(line.len());
+    }
+
+    start.map(|start_offset| (start_offset, source.len()))
+}
+
+async fn write_atomic(path: PathBuf, contents: String) -> Result<(), ApiFailure> {
+    tokio::task::spawn_blocking(move || write_atomic_sync(&path, &contents))
+        .await
+        .map_err(|e| ApiFailure::internal(format!("failed to join writer: {}", e)))?
+        .map_err(|e| ApiFailure::internal(format!("failed to write config: {}", e)))
+}
+
+fn write_atomic_sync(path: &Path, contents: &str) -> std::io::Result<()> {
+    let parent = path.parent().unwrap_or_else(|| Path::new("."));
+    std::fs::create_dir_all(parent)?;
+
+    let tmp_name = format!(
+        ".{}.tmp-{}",
+        path.file_name()
+            .and_then(|s| s.to_str())
+            .unwrap_or("config.toml"),
+        rand::random::<u64>()
+    );
+    let tmp_path = parent.join(tmp_name);
+
+    let write_result = (|| {
+        let mut file = std::fs::OpenOptions::new()
+            .create_new(true)
+            .write(true)
+            .open(&tmp_path)?;
+        file.write_all(contents.as_bytes())?;
+        file.sync_all()?;
+        std::fs::rename(&tmp_path, path)?;
+        if let Ok(dir) = std::fs::File::open(parent) {
+            let _ = dir.sync_all();
+        }
+        Ok(())
+    })();
+
+    if write_result.is_err() {
+        let _ = std::fs::remove_file(&tmp_path);
+    }
+    write_result
+}

src/api/events.rs

@@ -0,0 +1,90 @@
+use std::collections::VecDeque;
+use std::sync::Mutex;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use serde::Serialize;
+
+#[derive(Clone, Serialize)]
+pub(super) struct ApiEventRecord {
+    pub(super) seq: u64,
+    pub(super) ts_epoch_secs: u64,
+    pub(super) event_type: String,
+    pub(super) context: String,
+}
+
+#[derive(Clone, Serialize)]
+pub(super) struct ApiEventSnapshot {
+    pub(super) capacity: usize,
+    pub(super) dropped_total: u64,
+    pub(super) events: Vec<ApiEventRecord>,
+}
+
+struct ApiEventsInner {
+    capacity: usize,
+    dropped_total: u64,
+    next_seq: u64,
+    events: VecDeque<ApiEventRecord>,
+}
+
+/// Bounded ring-buffer for control-plane API/runtime events.
+pub(crate) struct ApiEventStore {
+    inner: Mutex<ApiEventsInner>,
+}
+
+impl ApiEventStore {
+    pub(super) fn new(capacity: usize) -> Self {
+        let bounded = capacity.max(16);
+        Self {
+            inner: Mutex::new(ApiEventsInner {
+                capacity: bounded,
+                dropped_total: 0,
+                next_seq: 1,
+                events: VecDeque::with_capacity(bounded),
+            }),
+        }
+    }
+
+    pub(super) fn record(&self, event_type: &str, context: impl Into<String>) {
+        let now_epoch_secs = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_secs();
+        let mut context = context.into();
+        if context.len() > 256 {
+            context.truncate(256);
+        }
+
+        let mut guard = self.inner.lock().expect("api event store mutex poisoned");
+        if guard.events.len() == guard.capacity {
+            guard.events.pop_front();
+            guard.dropped_total = guard.dropped_total.saturating_add(1);
+        }
+        let seq = guard.next_seq;
+        guard.next_seq = guard.next_seq.saturating_add(1);
+        guard.events.push_back(ApiEventRecord {
+            seq,
+            ts_epoch_secs: now_epoch_secs,
+            event_type: event_type.to_string(),
+            context,
+        });
+    }
+
+    pub(super) fn snapshot(&self, limit: usize) -> ApiEventSnapshot {
+        let guard = self.inner.lock().expect("api event store mutex poisoned");
+        let bounded_limit = limit.clamp(1, guard.capacity.max(1));
+        let mut items: Vec<ApiEventRecord> = guard
+            .events
+            .iter()
+            .rev()
+            .take(bounded_limit)
+            .cloned()
+            .collect();
+        items.reverse();
+
+        ApiEventSnapshot {
+            capacity: guard.capacity,
+            dropped_total: guard.dropped_total,
+            events: items,
+        }
+    }
+}

src/api/http_utils.rs

@@ -0,0 +1,91 @@
+use http_body_util::{BodyExt, Full};
+use hyper::StatusCode;
+use hyper::body::{Bytes, Incoming};
+use serde::Serialize;
+use serde::de::DeserializeOwned;
+
+use super::model::{ApiFailure, ErrorBody, ErrorResponse, SuccessResponse};
+
+pub(super) fn success_response<T: Serialize>(
+    status: StatusCode,
+    data: T,
+    revision: String,
+) -> hyper::Response<Full<Bytes>> {
+    let payload = SuccessResponse {
+        ok: true,
+        data,
+        revision,
+    };
+    let body = serde_json::to_vec(&payload).unwrap_or_else(|_| b"{\"ok\":false}".to_vec());
+    hyper::Response::builder()
+        .status(status)
+        .header("content-type", "application/json; charset=utf-8")
+        .body(Full::new(Bytes::from(body)))
+        .unwrap()
+}
+
+pub(super) fn error_response(
+    request_id: u64,
+    failure: ApiFailure,
+) -> hyper::Response<Full<Bytes>> {
+    let payload = ErrorResponse {
+        ok: false,
+        error: ErrorBody {
+            code: failure.code,
+            message: failure.message,
+        },
+        request_id,
+    };
+    let body = serde_json::to_vec(&payload).unwrap_or_else(|_| {
+        format!(
+            "{{\"ok\":false,\"error\":{{\"code\":\"internal_error\",\"message\":\"serialization failed\"}},\"request_id\":{}}}",
+            request_id
+        )
+        .into_bytes()
+    });
+    hyper::Response::builder()
+        .status(failure.status)
+        .header("content-type", "application/json; charset=utf-8")
+        .body(Full::new(Bytes::from(body)))
+        .unwrap()
+}
+
+pub(super) async fn read_json<T: DeserializeOwned>(
+    body: Incoming,
+    limit: usize,
+) -> Result<T, ApiFailure> {
+    let bytes = read_body_with_limit(body, limit).await?;
+    serde_json::from_slice(&bytes).map_err(|_| ApiFailure::bad_request("Invalid JSON body"))
+}
+
+pub(super) async fn read_optional_json<T: DeserializeOwned>(
+    body: Incoming,
+    limit: usize,
+) -> Result<Option<T>, ApiFailure> {
+    let bytes = read_body_with_limit(body, limit).await?;
+    if bytes.is_empty() {
+        return Ok(None);
+    }
+    serde_json::from_slice(&bytes)
+        .map(Some)
+        .map_err(|_| ApiFailure::bad_request("Invalid JSON body"))
+}
+
+async fn read_body_with_limit(body: Incoming, limit: usize) -> Result<Vec<u8>, ApiFailure> {
+    let mut collected = Vec::new();
+    let mut body = body;
+    while let Some(frame_result) = body.frame().await {
+        let frame = frame_result.map_err(|_| ApiFailure::bad_request("Invalid request body"))?;
+        if let Some(chunk) = frame.data_ref() {
+            if collected.len().saturating_add(chunk.len()) > limit {
+                return Err(ApiFailure::new(
+                    StatusCode::PAYLOAD_TOO_LARGE,
+                    "payload_too_large",
+                    format!("Body exceeds {} bytes", limit),
+                ));
+            }
+            collected.extend_from_slice(chunk);
+        }
+    }
+    Ok(collected)
+}

src/api/mod.rs

@@ -0,0 +1,550 @@
+use std::convert::Infallible;
+use std::net::{IpAddr, SocketAddr};
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+
+use http_body_util::Full;
+use hyper::body::{Bytes, Incoming};
+use hyper::header::AUTHORIZATION;
+use hyper::server::conn::http1;
+use hyper::service::service_fn;
+use hyper::{Method, Request, Response, StatusCode};
+use tokio::net::TcpListener;
+use tokio::sync::{Mutex, RwLock, watch};
+use tracing::{debug, info, warn};
+
+use crate::config::ProxyConfig;
+use crate::ip_tracker::UserIpTracker;
+use crate::startup::StartupTracker;
+use crate::stats::Stats;
+use crate::transport::middle_proxy::MePool;
+use crate::transport::UpstreamManager;
+
+mod config_store;
+mod events;
+mod http_utils;
+mod model;
+mod runtime_edge;
+mod runtime_init;
+mod runtime_min;
+mod runtime_selftest;
+mod runtime_stats;
+mod runtime_watch;
+mod runtime_zero;
+mod users;
+
+use config_store::{current_revision, parse_if_match};
+use http_utils::{error_response, read_json, read_optional_json, success_response};
+use events::ApiEventStore;
+use model::{
+    ApiFailure, CreateUserRequest, HealthData, PatchUserRequest, RotateSecretRequest, SummaryData,
+};
+use runtime_edge::{
+    EdgeConnectionsCacheEntry, build_runtime_connections_summary_data,
+    build_runtime_events_recent_data,
+};
+use runtime_init::build_runtime_initialization_data;
+use runtime_min::{
+    build_runtime_me_pool_state_data, build_runtime_me_quality_data, build_runtime_nat_stun_data,
+    build_runtime_upstream_quality_data, build_security_whitelist_data,
+};
+use runtime_selftest::build_runtime_me_selftest_data;
+use runtime_stats::{
+    MinimalCacheEntry, build_dcs_data, build_me_writers_data, build_minimal_all_data,
+    build_upstreams_data, build_zero_all_data,
+};
+use runtime_zero::{
+    build_limits_effective_data, build_runtime_gates_data, build_security_posture_data,
+    build_system_info_data,
+};
+use runtime_watch::spawn_runtime_watchers;
+use users::{create_user, delete_user, patch_user, rotate_secret, users_from_config};
+
+pub(super) struct ApiRuntimeState {
+    pub(super) process_started_at_epoch_secs: u64,
+    pub(super) config_reload_count: AtomicU64,
+    pub(super) last_config_reload_epoch_secs: AtomicU64,
+    pub(super) admission_open: AtomicBool,
+}
+
+#[derive(Clone)]
+pub(super) struct ApiShared {
+    pub(super) stats: Arc<Stats>,
+    pub(super) ip_tracker: Arc<UserIpTracker>,
+    pub(super) me_pool: Arc<RwLock<Option<Arc<MePool>>>>,
+    pub(super) upstream_manager: Arc<UpstreamManager>,
+    pub(super) config_path: PathBuf,
+    pub(super) detected_ips_rx: watch::Receiver<(Option<IpAddr>, Option<IpAddr>)>,
+    pub(super) mutation_lock: Arc<Mutex<()>>,
+    pub(super) minimal_cache: Arc<Mutex<Option<MinimalCacheEntry>>>,
+    pub(super) runtime_edge_connections_cache: Arc<Mutex<Option<EdgeConnectionsCacheEntry>>>,
+    pub(super) runtime_edge_recompute_lock: Arc<Mutex<()>>,
+    pub(super) runtime_events: Arc<ApiEventStore>,
+    pub(super) request_id: Arc<AtomicU64>,
+    pub(super) runtime_state: Arc<ApiRuntimeState>,
+    pub(super) startup_tracker: Arc<StartupTracker>,
+}
+
+impl ApiShared {
+    fn next_request_id(&self) -> u64 {
+        self.request_id.fetch_add(1, Ordering::Relaxed)
+    }
+
+    fn detected_link_ips(&self) -> (Option<IpAddr>, Option<IpAddr>) {
+        *self.detected_ips_rx.borrow()
+    }
+}
+
+pub async fn serve(
+    listen: SocketAddr,
+    stats: Arc<Stats>,
+    ip_tracker: Arc<UserIpTracker>,
+    me_pool: Arc<RwLock<Option<Arc<MePool>>>>,
+    upstream_manager: Arc<UpstreamManager>,
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+    admission_rx: watch::Receiver<bool>,
+    config_path: PathBuf,
+    detected_ips_rx: watch::Receiver<(Option<IpAddr>, Option<IpAddr>)>,
+    process_started_at_epoch_secs: u64,
+    startup_tracker: Arc<StartupTracker>,
+) {
+    let listener = match TcpListener::bind(listen).await {
+        Ok(listener) => listener,
+        Err(error) => {
+            warn!(
+                error = %error,
+                listen = %listen,
+                "Failed to bind API listener"
+            );
+            return;
+        }
+    };
+
+    info!("API endpoint: http://{}/v1/*", listen);
+
+    let runtime_state = Arc::new(ApiRuntimeState {
+        process_started_at_epoch_secs,
+        config_reload_count: AtomicU64::new(0),
+        last_config_reload_epoch_secs: AtomicU64::new(0),
+        admission_open: AtomicBool::new(*admission_rx.borrow()),
+    });
+
+    let shared = Arc::new(ApiShared {
+        stats,
+        ip_tracker,
+        me_pool,
+        upstream_manager,
+        config_path,
+        detected_ips_rx,
+        mutation_lock: Arc::new(Mutex::new(())),
+        minimal_cache: Arc::new(Mutex::new(None)),
+        runtime_edge_connections_cache: Arc::new(Mutex::new(None)),
+        runtime_edge_recompute_lock: Arc::new(Mutex::new(())),
+        runtime_events: Arc::new(ApiEventStore::new(
+            config_rx.borrow().server.api.runtime_edge_events_capacity,
+        )),
+        request_id: Arc::new(AtomicU64::new(1)),
+        runtime_state: runtime_state.clone(),
+        startup_tracker,
+    });
+
+    spawn_runtime_watchers(
+        config_rx.clone(),
+        admission_rx.clone(),
+        runtime_state.clone(),
+        shared.runtime_events.clone(),
+    );
+
+    loop {
+        let (stream, peer) = match listener.accept().await {
+            Ok(v) => v,
+            Err(error) => {
+                warn!(error = %error, "API accept error");
+                continue;
+            }
+        };
+
+        let shared_conn = shared.clone();
+        let config_rx_conn = config_rx.clone();
+        tokio::spawn(async move {
+            let svc = service_fn(move |req: Request<Incoming>| {
+                let shared_req = shared_conn.clone();
+                let config_rx_req = config_rx_conn.clone();
+                async move { handle(req, peer, shared_req, config_rx_req).await }
+            });
+            if let Err(error) = http1::Builder::new()
+                .serve_connection(hyper_util::rt::TokioIo::new(stream), svc)
+                .await
+            {
+                debug!(error = %error, "API connection error");
+            }
+        });
+    }
+}
+
+async fn handle(
+    req: Request<Incoming>,
+    peer: SocketAddr,
+    shared: Arc<ApiShared>,
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+) -> Result<Response<Full<Bytes>>, Infallible> {
+    let request_id = shared.next_request_id();
+    let cfg = config_rx.borrow().clone();
+    let api_cfg = &cfg.server.api;
+
+    if !api_cfg.enabled {
+        return Ok(error_response(
+            request_id,
+            ApiFailure::new(
+                StatusCode::SERVICE_UNAVAILABLE,
+                "api_disabled",
+                "API is disabled",
+            ),
+        ));
+    }
+
+    if !api_cfg.whitelist.is_empty()
+        && !api_cfg
+            .whitelist
+            .iter()
+            .any(|net| net.contains(peer.ip()))
+    {
+        return Ok(error_response(
+            request_id,
+            ApiFailure::new(StatusCode::FORBIDDEN, "forbidden", "Source IP is not allowed"),
+        ));
+    }
+
+    if !api_cfg.auth_header.is_empty() {
+        let auth_ok = req
+            .headers()
+            .get(AUTHORIZATION)
+            .and_then(|v| v.to_str().ok())
+            .map(|v| v == api_cfg.auth_header)
+            .unwrap_or(false);
+        if !auth_ok {
+            return Ok(error_response(
+                request_id,
+                ApiFailure::new(
+                    StatusCode::UNAUTHORIZED,
+                    "unauthorized",
+                    "Missing or invalid Authorization header",
+                ),
+            ));
+        }
+    }
+
+    let method = req.method().clone();
+    let path = req.uri().path().to_string();
+    let query = req.uri().query().map(str::to_string);
+    let body_limit = api_cfg.request_body_limit_bytes;
+
+    let result: Result<Response<Full<Bytes>>, ApiFailure> = async {
+        match (method.as_str(), path.as_str()) {
+            ("GET", "/v1/health") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = HealthData {
+                    status: "ok",
+                    read_only: api_cfg.read_only,
+                };
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/system/info") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_system_info_data(shared.as_ref(), cfg.as_ref(), &revision);
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/gates") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_gates_data(shared.as_ref(), cfg.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/initialization") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_initialization_data(shared.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/limits/effective") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_limits_effective_data(cfg.as_ref());
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/security/posture") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_security_posture_data(cfg.as_ref());
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/security/whitelist") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_security_whitelist_data(cfg.as_ref());
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/summary") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = SummaryData {
+                    uptime_seconds: shared.stats.uptime_secs(),
+                    connections_total: shared.stats.get_connects_all(),
+                    connections_bad_total: shared.stats.get_connects_bad(),
+                    handshake_timeouts_total: shared.stats.get_handshake_timeouts(),
+                    configured_users: cfg.access.users.len(),
+                };
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/zero/all") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_zero_all_data(&shared.stats, cfg.access.users.len());
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/upstreams") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_upstreams_data(shared.as_ref(), api_cfg);
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/minimal/all") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_minimal_all_data(shared.as_ref(), api_cfg).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/me-writers") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_me_writers_data(shared.as_ref(), api_cfg).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/dcs") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_dcs_data(shared.as_ref(), api_cfg).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/me_pool_state") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_me_pool_state_data(shared.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/me_quality") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_me_quality_data(shared.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/upstream_quality") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_upstream_quality_data(shared.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/nat_stun") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_nat_stun_data(shared.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/me-selftest") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_me_selftest_data(shared.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/connections/summary") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_connections_summary_data(shared.as_ref(), cfg.as_ref()).await;
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/runtime/events/recent") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let data = build_runtime_events_recent_data(
+                    shared.as_ref(),
+                    cfg.as_ref(),
+                    query.as_deref(),
+                );
+                Ok(success_response(StatusCode::OK, data, revision))
+            }
+            ("GET", "/v1/stats/users") | ("GET", "/v1/users") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let (detected_ip_v4, detected_ip_v6) = shared.detected_link_ips();
+                let users = users_from_config(
+                    &cfg,
+                    &shared.stats,
+                    &shared.ip_tracker,
+                    detected_ip_v4,
+                    detected_ip_v6,
+                )
+                .await;
+                Ok(success_response(StatusCode::OK, users, revision))
+            }
+            ("POST", "/v1/users") => {
+                if api_cfg.read_only {
+                    return Ok(error_response(
+                        request_id,
+                        ApiFailure::new(
+                            StatusCode::FORBIDDEN,
+                            "read_only",
+                            "API runs in read-only mode",
+                        ),
+                    ));
+                }
+                let expected_revision = parse_if_match(req.headers());
+                let body = read_json::<CreateUserRequest>(req.into_body(), body_limit).await?;
+                let result = create_user(body, expected_revision, &shared).await;
+                let (data, revision) = match result {
+                    Ok(ok) => ok,
+                    Err(error) => {
+                        shared.runtime_events.record("api.user.create.failed", error.code);
+                        return Err(error);
+                    }
+                };
+                shared
+                    .runtime_events
+                    .record("api.user.create.ok", format!("username={}", data.user.username));
+                Ok(success_response(StatusCode::CREATED, data, revision))
+            }
+            _ => {
+                if let Some(user) = path.strip_prefix("/v1/users/")
+                    && !user.is_empty()
+                    && !user.contains('/')
+                {
+                    if method == Method::GET {
+                        let revision = current_revision(&shared.config_path).await?;
+                        let (detected_ip_v4, detected_ip_v6) = shared.detected_link_ips();
+                        let users = users_from_config(
+                            &cfg,
+                            &shared.stats,
+                            &shared.ip_tracker,
+                            detected_ip_v4,
+                            detected_ip_v6,
+                        )
+                        .await;
+                        if let Some(user_info) = users.into_iter().find(|entry| entry.username == user)
+                        {
+                            return Ok(success_response(StatusCode::OK, user_info, revision));
+                        }
+                        return Ok(error_response(
+                            request_id,
+                            ApiFailure::new(StatusCode::NOT_FOUND, "not_found", "User not found"),
+                        ));
+                    }
+                    if method == Method::PATCH {
+                        if api_cfg.read_only {
+                            return Ok(error_response(
+                                request_id,
+                                ApiFailure::new(
+                                    StatusCode::FORBIDDEN,
+                                    "read_only",
+                                    "API runs in read-only mode",
+                                ),
+                            ));
+                        }
+                        let expected_revision = parse_if_match(req.headers());
+                        let body = read_json::<PatchUserRequest>(req.into_body(), body_limit).await?;
+                        let result = patch_user(user, body, expected_revision, &shared).await;
+                        let (data, revision) = match result {
+                            Ok(ok) => ok,
+                            Err(error) => {
+                                shared.runtime_events.record(
+                                    "api.user.patch.failed",
+                                    format!("username={} code={}", user, error.code),
+                                );
+                                return Err(error);
+                            }
+                        };
+                        shared
+                            .runtime_events
+                            .record("api.user.patch.ok", format!("username={}", data.username));
+                        return Ok(success_response(StatusCode::OK, data, revision));
+                    }
+                    if method == Method::DELETE {
+                        if api_cfg.read_only {
+                            return Ok(error_response(
+                                request_id,
+                                ApiFailure::new(
+                                    StatusCode::FORBIDDEN,
+                                    "read_only",
+                                    "API runs in read-only mode",
+                                ),
+                            ));
+                        }
+                        let expected_revision = parse_if_match(req.headers());
+                        let result = delete_user(user, expected_revision, &shared).await;
+                        let (deleted_user, revision) = match result {
+                            Ok(ok) => ok,
+                            Err(error) => {
+                                shared.runtime_events.record(
+                                    "api.user.delete.failed",
+                                    format!("username={} code={}", user, error.code),
+                                );
+                                return Err(error);
+                            }
+                        };
+                        shared.runtime_events.record(
+                            "api.user.delete.ok",
+                            format!("username={}", deleted_user),
+                        );
+                        return Ok(success_response(StatusCode::OK, deleted_user, revision));
+                    }
+                    if method == Method::POST
+                        && let Some(base_user) = user.strip_suffix("/rotate-secret")
+                        && !base_user.is_empty()
+                        && !base_user.contains('/')
+                    {
+                        if api_cfg.read_only {
+                            return Ok(error_response(
+                                request_id,
+                                ApiFailure::new(
+                                    StatusCode::FORBIDDEN,
+                                    "read_only",
+                                    "API runs in read-only mode",
+                                ),
+                            ));
+                        }
+                        let expected_revision = parse_if_match(req.headers());
+                        let body =
+                            read_optional_json::<RotateSecretRequest>(req.into_body(), body_limit)
+                                .await?;
+                        let result = rotate_secret(
+                            base_user,
+                            body.unwrap_or_default(),
+                            expected_revision,
+                            &shared,
+                        )
+                        .await;
+                        let (data, revision) = match result {
+                            Ok(ok) => ok,
+                            Err(error) => {
+                                shared.runtime_events.record(
+                                    "api.user.rotate_secret.failed",
+                                    format!("username={} code={}", base_user, error.code),
+                                );
+                                return Err(error);
+                            }
+                        };
+                        shared.runtime_events.record(
+                            "api.user.rotate_secret.ok",
+                            format!("username={}", base_user),
+                        );
+                        return Ok(success_response(StatusCode::OK, data, revision));
+                    }
+                    if method == Method::POST {
+                        return Ok(error_response(
+                            request_id,
+                            ApiFailure::new(StatusCode::NOT_FOUND, "not_found", "Route not found"),
+                        ));
+                    }
+                    return Ok(error_response(
+                        request_id,
+                        ApiFailure::new(
+                            StatusCode::METHOD_NOT_ALLOWED,
+                            "method_not_allowed",
+                            "Unsupported HTTP method for this route",
+                        ),
+                    ));
+                }
+                Ok(error_response(
+                    request_id,
+                    ApiFailure::new(StatusCode::NOT_FOUND, "not_found", "Route not found"),
+                ))
+            }
+        }
+    }
+    .await;
+
+    match result {
+        Ok(resp) => Ok(resp),
+        Err(error) => Ok(error_response(request_id, error)),
+    }
+}

src/api/model.rs

@@ -0,0 +1,477 @@
+use std::net::IpAddr;
+
+use chrono::{DateTime, Utc};
+use hyper::StatusCode;
+use rand::Rng;
+use serde::{Deserialize, Serialize};
+
+const MAX_USERNAME_LEN: usize = 64;
+
+#[derive(Debug)]
+pub(super) struct ApiFailure {
+    pub(super) status: StatusCode,
+    pub(super) code: &'static str,
+    pub(super) message: String,
+}
+
+impl ApiFailure {
+    pub(super) fn new(status: StatusCode, code: &'static str, message: impl Into<String>) -> Self {
+        Self {
+            status,
+            code,
+            message: message.into(),
+        }
+    }
+
+    pub(super) fn internal(message: impl Into<String>) -> Self {
+        Self::new(StatusCode::INTERNAL_SERVER_ERROR, "internal_error", message)
+    }
+
+    pub(super) fn bad_request(message: impl Into<String>) -> Self {
+        Self::new(StatusCode::BAD_REQUEST, "bad_request", message)
+    }
+}
+
+#[derive(Serialize)]
+pub(super) struct ErrorBody {
+    pub(super) code: &'static str,
+    pub(super) message: String,
+}
+
+#[derive(Serialize)]
+pub(super) struct ErrorResponse {
+    pub(super) ok: bool,
+    pub(super) error: ErrorBody,
+    pub(super) request_id: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct SuccessResponse<T> {
+    pub(super) ok: bool,
+    pub(super) data: T,
+    pub(super) revision: String,
+}
+
+#[derive(Serialize)]
+pub(super) struct HealthData {
+    pub(super) status: &'static str,
+    pub(super) read_only: bool,
+}
+
+#[derive(Serialize)]
+pub(super) struct SummaryData {
+    pub(super) uptime_seconds: f64,
+    pub(super) connections_total: u64,
+    pub(super) connections_bad_total: u64,
+    pub(super) handshake_timeouts_total: u64,
+    pub(super) configured_users: usize,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroCodeCount {
+    pub(super) code: i32,
+    pub(super) total: u64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroCoreData {
+    pub(super) uptime_seconds: f64,
+    pub(super) connections_total: u64,
+    pub(super) connections_bad_total: u64,
+    pub(super) handshake_timeouts_total: u64,
+    pub(super) configured_users: usize,
+    pub(super) telemetry_core_enabled: bool,
+    pub(super) telemetry_user_enabled: bool,
+    pub(super) telemetry_me_level: String,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroUpstreamData {
+    pub(super) connect_attempt_total: u64,
+    pub(super) connect_success_total: u64,
+    pub(super) connect_fail_total: u64,
+    pub(super) connect_failfast_hard_error_total: u64,
+    pub(super) connect_attempts_bucket_1: u64,
+    pub(super) connect_attempts_bucket_2: u64,
+    pub(super) connect_attempts_bucket_3_4: u64,
+    pub(super) connect_attempts_bucket_gt_4: u64,
+    pub(super) connect_duration_success_bucket_le_100ms: u64,
+    pub(super) connect_duration_success_bucket_101_500ms: u64,
+    pub(super) connect_duration_success_bucket_501_1000ms: u64,
+    pub(super) connect_duration_success_bucket_gt_1000ms: u64,
+    pub(super) connect_duration_fail_bucket_le_100ms: u64,
+    pub(super) connect_duration_fail_bucket_101_500ms: u64,
+    pub(super) connect_duration_fail_bucket_501_1000ms: u64,
+    pub(super) connect_duration_fail_bucket_gt_1000ms: u64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct UpstreamDcStatus {
+    pub(super) dc: i16,
+    pub(super) latency_ema_ms: Option<f64>,
+    pub(super) ip_preference: &'static str,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct UpstreamStatus {
+    pub(super) upstream_id: usize,
+    pub(super) route_kind: &'static str,
+    pub(super) address: String,
+    pub(super) weight: u16,
+    pub(super) scopes: String,
+    pub(super) healthy: bool,
+    pub(super) fails: u32,
+    pub(super) last_check_age_secs: u64,
+    pub(super) effective_latency_ms: Option<f64>,
+    pub(super) dc: Vec<UpstreamDcStatus>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct UpstreamSummaryData {
+    pub(super) configured_total: usize,
+    pub(super) healthy_total: usize,
+    pub(super) unhealthy_total: usize,
+    pub(super) direct_total: usize,
+    pub(super) socks4_total: usize,
+    pub(super) socks5_total: usize,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct UpstreamsData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    pub(super) zero: ZeroUpstreamData,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) summary: Option<UpstreamSummaryData>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) upstreams: Option<Vec<UpstreamStatus>>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroMiddleProxyData {
+    pub(super) keepalive_sent_total: u64,
+    pub(super) keepalive_failed_total: u64,
+    pub(super) keepalive_pong_total: u64,
+    pub(super) keepalive_timeout_total: u64,
+    pub(super) rpc_proxy_req_signal_sent_total: u64,
+    pub(super) rpc_proxy_req_signal_failed_total: u64,
+    pub(super) rpc_proxy_req_signal_skipped_no_meta_total: u64,
+    pub(super) rpc_proxy_req_signal_response_total: u64,
+    pub(super) rpc_proxy_req_signal_close_sent_total: u64,
+    pub(super) reconnect_attempt_total: u64,
+    pub(super) reconnect_success_total: u64,
+    pub(super) handshake_reject_total: u64,
+    pub(super) handshake_error_codes: Vec<ZeroCodeCount>,
+    pub(super) reader_eof_total: u64,
+    pub(super) idle_close_by_peer_total: u64,
+    pub(super) route_drop_no_conn_total: u64,
+    pub(super) route_drop_channel_closed_total: u64,
+    pub(super) route_drop_queue_full_total: u64,
+    pub(super) route_drop_queue_full_base_total: u64,
+    pub(super) route_drop_queue_full_high_total: u64,
+    pub(super) socks_kdf_strict_reject_total: u64,
+    pub(super) socks_kdf_compat_fallback_total: u64,
+    pub(super) endpoint_quarantine_total: u64,
+    pub(super) kdf_drift_total: u64,
+    pub(super) kdf_port_only_drift_total: u64,
+    pub(super) hardswap_pending_reuse_total: u64,
+    pub(super) hardswap_pending_ttl_expired_total: u64,
+    pub(super) single_endpoint_outage_enter_total: u64,
+    pub(super) single_endpoint_outage_exit_total: u64,
+    pub(super) single_endpoint_outage_reconnect_attempt_total: u64,
+    pub(super) single_endpoint_outage_reconnect_success_total: u64,
+    pub(super) single_endpoint_quarantine_bypass_total: u64,
+    pub(super) single_endpoint_shadow_rotate_total: u64,
+    pub(super) single_endpoint_shadow_rotate_skipped_quarantine_total: u64,
+    pub(super) floor_mode_switch_total: u64,
+    pub(super) floor_mode_switch_static_to_adaptive_total: u64,
+    pub(super) floor_mode_switch_adaptive_to_static_total: u64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroPoolData {
+    pub(super) pool_swap_total: u64,
+    pub(super) pool_drain_active: u64,
+    pub(super) pool_force_close_total: u64,
+    pub(super) pool_stale_pick_total: u64,
+    pub(super) writer_removed_total: u64,
+    pub(super) writer_removed_unexpected_total: u64,
+    pub(super) refill_triggered_total: u64,
+    pub(super) refill_skipped_inflight_total: u64,
+    pub(super) refill_failed_total: u64,
+    pub(super) writer_restored_same_endpoint_total: u64,
+    pub(super) writer_restored_fallback_total: u64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroDesyncData {
+    pub(super) secure_padding_invalid_total: u64,
+    pub(super) desync_total: u64,
+    pub(super) desync_full_logged_total: u64,
+    pub(super) desync_suppressed_total: u64,
+    pub(super) desync_frames_bucket_0: u64,
+    pub(super) desync_frames_bucket_1_2: u64,
+    pub(super) desync_frames_bucket_3_10: u64,
+    pub(super) desync_frames_bucket_gt_10: u64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct ZeroAllData {
+    pub(super) generated_at_epoch_secs: u64,
+    pub(super) core: ZeroCoreData,
+    pub(super) upstream: ZeroUpstreamData,
+    pub(super) middle_proxy: ZeroMiddleProxyData,
+    pub(super) pool: ZeroPoolData,
+    pub(super) desync: ZeroDesyncData,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MeWritersSummary {
+    pub(super) configured_dc_groups: usize,
+    pub(super) configured_endpoints: usize,
+    pub(super) available_endpoints: usize,
+    pub(super) available_pct: f64,
+    pub(super) required_writers: usize,
+    pub(super) alive_writers: usize,
+    pub(super) coverage_pct: f64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MeWriterStatus {
+    pub(super) writer_id: u64,
+    pub(super) dc: Option<i16>,
+    pub(super) endpoint: String,
+    pub(super) generation: u64,
+    pub(super) state: &'static str,
+    pub(super) draining: bool,
+    pub(super) degraded: bool,
+    pub(super) bound_clients: usize,
+    pub(super) idle_for_secs: Option<u64>,
+    pub(super) rtt_ema_ms: Option<f64>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MeWritersData {
+    pub(super) middle_proxy_enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    pub(super) summary: MeWritersSummary,
+    pub(super) writers: Vec<MeWriterStatus>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct DcStatus {
+    pub(super) dc: i16,
+    pub(super) endpoints: Vec<String>,
+    pub(super) endpoint_writers: Vec<DcEndpointWriters>,
+    pub(super) available_endpoints: usize,
+    pub(super) available_pct: f64,
+    pub(super) required_writers: usize,
+    pub(super) floor_min: usize,
+    pub(super) floor_target: usize,
+    pub(super) floor_max: usize,
+    pub(super) floor_capped: bool,
+    pub(super) alive_writers: usize,
+    pub(super) coverage_pct: f64,
+    pub(super) rtt_ms: Option<f64>,
+    pub(super) load: usize,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct DcEndpointWriters {
+    pub(super) endpoint: String,
+    pub(super) active_writers: usize,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct DcStatusData {
+    pub(super) middle_proxy_enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    pub(super) dcs: Vec<DcStatus>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MinimalQuarantineData {
+    pub(super) endpoint: String,
+    pub(super) remaining_ms: u64,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MinimalDcPathData {
+    pub(super) dc: i16,
+    pub(super) ip_preference: Option<&'static str>,
+    pub(super) selected_addr_v4: Option<String>,
+    pub(super) selected_addr_v6: Option<String>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MinimalMeRuntimeData {
+    pub(super) active_generation: u64,
+    pub(super) warm_generation: u64,
+    pub(super) pending_hardswap_generation: u64,
+    pub(super) pending_hardswap_age_secs: Option<u64>,
+    pub(super) hardswap_enabled: bool,
+    pub(super) floor_mode: &'static str,
+    pub(super) adaptive_floor_idle_secs: u64,
+    pub(super) adaptive_floor_min_writers_single_endpoint: u8,
+    pub(super) adaptive_floor_min_writers_multi_endpoint: u8,
+    pub(super) adaptive_floor_recover_grace_secs: u64,
+    pub(super) adaptive_floor_writers_per_core_total: u16,
+    pub(super) adaptive_floor_cpu_cores_override: u16,
+    pub(super) adaptive_floor_max_extra_writers_single_per_core: u16,
+    pub(super) adaptive_floor_max_extra_writers_multi_per_core: u16,
+    pub(super) adaptive_floor_max_active_writers_per_core: u16,
+    pub(super) adaptive_floor_max_warm_writers_per_core: u16,
+    pub(super) adaptive_floor_max_active_writers_global: u32,
+    pub(super) adaptive_floor_max_warm_writers_global: u32,
+    pub(super) adaptive_floor_cpu_cores_detected: u32,
+    pub(super) adaptive_floor_cpu_cores_effective: u32,
+    pub(super) adaptive_floor_global_cap_raw: u64,
+    pub(super) adaptive_floor_global_cap_effective: u64,
+    pub(super) adaptive_floor_target_writers_total: u64,
+    pub(super) adaptive_floor_active_cap_configured: u64,
+    pub(super) adaptive_floor_active_cap_effective: u64,
+    pub(super) adaptive_floor_warm_cap_configured: u64,
+    pub(super) adaptive_floor_warm_cap_effective: u64,
+    pub(super) adaptive_floor_active_writers_current: u64,
+    pub(super) adaptive_floor_warm_writers_current: u64,
+    pub(super) me_keepalive_enabled: bool,
+    pub(super) me_keepalive_interval_secs: u64,
+    pub(super) me_keepalive_jitter_secs: u64,
+    pub(super) me_keepalive_payload_random: bool,
+    pub(super) rpc_proxy_req_every_secs: u64,
+    pub(super) me_reconnect_max_concurrent_per_dc: u32,
+    pub(super) me_reconnect_backoff_base_ms: u64,
+    pub(super) me_reconnect_backoff_cap_ms: u64,
+    pub(super) me_reconnect_fast_retry_count: u32,
+    pub(super) me_pool_drain_ttl_secs: u64,
+    pub(super) me_pool_force_close_secs: u64,
+    pub(super) me_pool_min_fresh_ratio: f32,
+    pub(super) me_bind_stale_mode: &'static str,
+    pub(super) me_bind_stale_ttl_secs: u64,
+    pub(super) me_single_endpoint_shadow_writers: u8,
+    pub(super) me_single_endpoint_outage_mode_enabled: bool,
+    pub(super) me_single_endpoint_outage_disable_quarantine: bool,
+    pub(super) me_single_endpoint_outage_backoff_min_ms: u64,
+    pub(super) me_single_endpoint_outage_backoff_max_ms: u64,
+    pub(super) me_single_endpoint_shadow_rotate_every_secs: u64,
+    pub(super) me_deterministic_writer_sort: bool,
+    pub(super) me_writer_pick_mode: &'static str,
+    pub(super) me_writer_pick_sample_size: u8,
+    pub(super) me_socks_kdf_policy: &'static str,
+    pub(super) quarantined_endpoints_total: usize,
+    pub(super) quarantined_endpoints: Vec<MinimalQuarantineData>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MinimalAllPayload {
+    pub(super) me_writers: MeWritersData,
+    pub(super) dcs: DcStatusData,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) me_runtime: Option<MinimalMeRuntimeData>,
+    pub(super) network_path: Vec<MinimalDcPathData>,
+}
+
+#[derive(Serialize, Clone)]
+pub(super) struct MinimalAllData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<MinimalAllPayload>,
+}
+
+#[derive(Serialize)]
+pub(super) struct UserLinks {
+    pub(super) classic: Vec<String>,
+    pub(super) secure: Vec<String>,
+    pub(super) tls: Vec<String>,
+}
+
+#[derive(Serialize)]
+pub(super) struct UserInfo {
+    pub(super) username: String,
+    pub(super) user_ad_tag: Option<String>,
+    pub(super) max_tcp_conns: Option<usize>,
+    pub(super) expiration_rfc3339: Option<String>,
+    pub(super) data_quota_bytes: Option<u64>,
+    pub(super) max_unique_ips: Option<usize>,
+    pub(super) current_connections: u64,
+    pub(super) active_unique_ips: usize,
+    pub(super) active_unique_ips_list: Vec<IpAddr>,
+    pub(super) recent_unique_ips: usize,
+    pub(super) recent_unique_ips_list: Vec<IpAddr>,
+    pub(super) total_octets: u64,
+    pub(super) links: UserLinks,
+}
+
+#[derive(Serialize)]
+pub(super) struct CreateUserResponse {
+    pub(super) user: UserInfo,
+    pub(super) secret: String,
+}
+
+#[derive(Deserialize)]
+pub(super) struct CreateUserRequest {
+    pub(super) username: String,
+    pub(super) secret: Option<String>,
+    pub(super) user_ad_tag: Option<String>,
+    pub(super) max_tcp_conns: Option<usize>,
+    pub(super) expiration_rfc3339: Option<String>,
+    pub(super) data_quota_bytes: Option<u64>,
+    pub(super) max_unique_ips: Option<usize>,
+}
+
+#[derive(Deserialize)]
+pub(super) struct PatchUserRequest {
+    pub(super) secret: Option<String>,
+    pub(super) user_ad_tag: Option<String>,
+    pub(super) max_tcp_conns: Option<usize>,
+    pub(super) expiration_rfc3339: Option<String>,
+    pub(super) data_quota_bytes: Option<u64>,
+    pub(super) max_unique_ips: Option<usize>,
+}
+
+#[derive(Default, Deserialize)]
+pub(super) struct RotateSecretRequest {
+    pub(super) secret: Option<String>,
+}
+
+pub(super) fn parse_optional_expiration(
+    value: Option<&str>,
+) -> Result<Option<DateTime<Utc>>, ApiFailure> {
+    let Some(raw) = value else {
+        return Ok(None);
+    };
+    let parsed = DateTime::parse_from_rfc3339(raw)
+        .map_err(|_| ApiFailure::bad_request("expiration_rfc3339 must be valid RFC3339"))?;
+    Ok(Some(parsed.with_timezone(&Utc)))
+}
+
+pub(super) fn is_valid_user_secret(secret: &str) -> bool {
+    secret.len() == 32 && secret.chars().all(|c| c.is_ascii_hexdigit())
+}
+
+pub(super) fn is_valid_ad_tag(tag: &str) -> bool {
+    tag.len() == 32 && tag.chars().all(|c| c.is_ascii_hexdigit())
+}
+
+pub(super) fn is_valid_username(user: &str) -> bool {
+    !user.is_empty()
+        && user.len() <= MAX_USERNAME_LEN
+        && user
+            .chars()
+            .all(|ch| ch.is_ascii_alphanumeric() || matches!(ch, '_' | '-' | '.'))
+}
+
+pub(super) fn random_user_secret() -> String {
+    let mut bytes = [0u8; 16];
+    rand::rng().fill(&mut bytes);
+    hex::encode(bytes)
+}

src/api/runtime_edge.rs

@@ -0,0 +1,294 @@
+use std::cmp::Reverse;
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+
+use serde::Serialize;
+
+use crate::config::ProxyConfig;
+
+use super::ApiShared;
+use super::events::ApiEventRecord;
+
+const FEATURE_DISABLED_REASON: &str = "feature_disabled";
+const SOURCE_UNAVAILABLE_REASON: &str = "source_unavailable";
+const EVENTS_DEFAULT_LIMIT: usize = 50;
+const EVENTS_MAX_LIMIT: usize = 1000;
+
+#[derive(Clone, Serialize)]
+pub(super) struct RuntimeEdgeConnectionUserData {
+    pub(super) username: String,
+    pub(super) current_connections: u64,
+    pub(super) total_octets: u64,
+}
+
+#[derive(Clone, Serialize)]
+pub(super) struct RuntimeEdgeConnectionTotalsData {
+    pub(super) current_connections: u64,
+    pub(super) current_connections_me: u64,
+    pub(super) current_connections_direct: u64,
+    pub(super) active_users: usize,
+}
+
+#[derive(Clone, Serialize)]
+pub(super) struct RuntimeEdgeConnectionTopData {
+    pub(super) limit: usize,
+    pub(super) by_connections: Vec<RuntimeEdgeConnectionUserData>,
+    pub(super) by_throughput: Vec<RuntimeEdgeConnectionUserData>,
+}
+
+#[derive(Clone, Serialize)]
+pub(super) struct RuntimeEdgeConnectionCacheData {
+    pub(super) ttl_ms: u64,
+    pub(super) served_from_cache: bool,
+    pub(super) stale_cache_used: bool,
+}
+
+#[derive(Clone, Serialize)]
+pub(super) struct RuntimeEdgeConnectionTelemetryData {
+    pub(super) user_enabled: bool,
+    pub(super) throughput_is_cumulative: bool,
+}
+
+#[derive(Clone, Serialize)]
+pub(super) struct RuntimeEdgeConnectionsSummaryPayload {
+    pub(super) cache: RuntimeEdgeConnectionCacheData,
+    pub(super) totals: RuntimeEdgeConnectionTotalsData,
+    pub(super) top: RuntimeEdgeConnectionTopData,
+    pub(super) telemetry: RuntimeEdgeConnectionTelemetryData,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeEdgeConnectionsSummaryData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<RuntimeEdgeConnectionsSummaryPayload>,
+}
+
+#[derive(Clone)]
+pub(crate) struct EdgeConnectionsCacheEntry {
+    pub(super) expires_at: Instant,
+    pub(super) payload: RuntimeEdgeConnectionsSummaryPayload,
+    pub(super) generated_at_epoch_secs: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeEdgeEventsPayload {
+    pub(super) capacity: usize,
+    pub(super) dropped_total: u64,
+    pub(super) events: Vec<ApiEventRecord>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeEdgeEventsData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<RuntimeEdgeEventsPayload>,
+}
+
+pub(super) async fn build_runtime_connections_summary_data(
+    shared: &ApiShared,
+    cfg: &ProxyConfig,
+) -> RuntimeEdgeConnectionsSummaryData {
+    let now_epoch_secs = now_epoch_secs();
+    let api_cfg = &cfg.server.api;
+    if !api_cfg.runtime_edge_enabled {
+        return RuntimeEdgeConnectionsSummaryData {
+            enabled: false,
+            reason: Some(FEATURE_DISABLED_REASON),
+            generated_at_epoch_secs: now_epoch_secs,
+            data: None,
+        };
+    }
+
+    let (generated_at_epoch_secs, payload) = match get_connections_payload_cached(
+        shared,
+        api_cfg.runtime_edge_cache_ttl_ms,
+        api_cfg.runtime_edge_top_n,
+    )
+    .await
+    {
+        Some(v) => v,
+        None => {
+            return RuntimeEdgeConnectionsSummaryData {
+                enabled: true,
+                reason: Some(SOURCE_UNAVAILABLE_REASON),
+                generated_at_epoch_secs: now_epoch_secs,
+                data: None,
+            };
+        }
+    };
+
+    RuntimeEdgeConnectionsSummaryData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs,
+        data: Some(payload),
+    }
+}
+
+pub(super) fn build_runtime_events_recent_data(
+    shared: &ApiShared,
+    cfg: &ProxyConfig,
+    query: Option<&str>,
+) -> RuntimeEdgeEventsData {
+    let now_epoch_secs = now_epoch_secs();
+    let api_cfg = &cfg.server.api;
+    if !api_cfg.runtime_edge_enabled {
+        return RuntimeEdgeEventsData {
+            enabled: false,
+            reason: Some(FEATURE_DISABLED_REASON),
+            generated_at_epoch_secs: now_epoch_secs,
+            data: None,
+        };
+    }
+
+    let limit = parse_recent_events_limit(query, EVENTS_DEFAULT_LIMIT, EVENTS_MAX_LIMIT);
+    let snapshot = shared.runtime_events.snapshot(limit);
+
+    RuntimeEdgeEventsData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs: now_epoch_secs,
+        data: Some(RuntimeEdgeEventsPayload {
+            capacity: snapshot.capacity,
+            dropped_total: snapshot.dropped_total,
+            events: snapshot.events,
+        }),
+    }
+}
+
+async fn get_connections_payload_cached(
+    shared: &ApiShared,
+    cache_ttl_ms: u64,
+    top_n: usize,
+) -> Option<(u64, RuntimeEdgeConnectionsSummaryPayload)> {
+    if cache_ttl_ms > 0 {
+        let now = Instant::now();
+        let cached = shared.runtime_edge_connections_cache.lock().await.clone();
+        if let Some(entry) = cached
+            && now < entry.expires_at
+        {
+            let mut payload = entry.payload;
+            payload.cache.served_from_cache = true;
+            payload.cache.stale_cache_used = false;
+            return Some((entry.generated_at_epoch_secs, payload));
+        }
+    }
+
+    let Ok(_guard) = shared.runtime_edge_recompute_lock.try_lock() else {
+        let cached = shared.runtime_edge_connections_cache.lock().await.clone();
+        if let Some(entry) = cached {
+            let mut payload = entry.payload;
+            payload.cache.served_from_cache = true;
+            payload.cache.stale_cache_used = true;
+            return Some((entry.generated_at_epoch_secs, payload));
+        }
+        return None;
+    };
+
+    let generated_at_epoch_secs = now_epoch_secs();
+    let payload = recompute_connections_payload(shared, cache_ttl_ms, top_n).await;
+
+    if cache_ttl_ms > 0 {
+        let entry = EdgeConnectionsCacheEntry {
+            expires_at: Instant::now() + Duration::from_millis(cache_ttl_ms),
+            payload: payload.clone(),
+            generated_at_epoch_secs,
+        };
+        *shared.runtime_edge_connections_cache.lock().await = Some(entry);
+    }
+
+    Some((generated_at_epoch_secs, payload))
+}
+
+async fn recompute_connections_payload(
+    shared: &ApiShared,
+    cache_ttl_ms: u64,
+    top_n: usize,
+) -> RuntimeEdgeConnectionsSummaryPayload {
+    let mut rows = Vec::<RuntimeEdgeConnectionUserData>::new();
+    let mut active_users = 0usize;
+    for entry in shared.stats.iter_user_stats() {
+        let user_stats = entry.value();
+        let current_connections = user_stats
+            .curr_connects
+            .load(std::sync::atomic::Ordering::Relaxed);
+        let total_octets = user_stats
+            .octets_from_client
+            .load(std::sync::atomic::Ordering::Relaxed)
+            .saturating_add(
+                user_stats
+                    .octets_to_client
+                    .load(std::sync::atomic::Ordering::Relaxed),
+            );
+        if current_connections > 0 {
+            active_users = active_users.saturating_add(1);
+        }
+        rows.push(RuntimeEdgeConnectionUserData {
+            username: entry.key().clone(),
+            current_connections,
+            total_octets,
+        });
+    }
+
+    let limit = top_n.max(1);
+    let mut by_connections = rows.clone();
+    by_connections.sort_by_key(|row| (Reverse(row.current_connections), row.username.clone()));
+    by_connections.truncate(limit);
+
+    let mut by_throughput = rows;
+    by_throughput.sort_by_key(|row| (Reverse(row.total_octets), row.username.clone()));
+    by_throughput.truncate(limit);
+
+    let telemetry = shared.stats.telemetry_policy();
+    RuntimeEdgeConnectionsSummaryPayload {
+        cache: RuntimeEdgeConnectionCacheData {
+            ttl_ms: cache_ttl_ms,
+            served_from_cache: false,
+            stale_cache_used: false,
+        },
+        totals: RuntimeEdgeConnectionTotalsData {
+            current_connections: shared.stats.get_current_connections_total(),
+            current_connections_me: shared.stats.get_current_connections_me(),
+            current_connections_direct: shared.stats.get_current_connections_direct(),
+            active_users,
+        },
+        top: RuntimeEdgeConnectionTopData {
+            limit,
+            by_connections,
+            by_throughput,
+        },
+        telemetry: RuntimeEdgeConnectionTelemetryData {
+            user_enabled: telemetry.user_enabled,
+            throughput_is_cumulative: true,
+        },
+    }
+}
+
+fn parse_recent_events_limit(query: Option<&str>, default_limit: usize, max_limit: usize) -> usize {
+    let Some(query) = query else {
+        return default_limit;
+    };
+    for pair in query.split('&') {
+        let mut split = pair.splitn(2, '=');
+        if split.next() == Some("limit")
+            && let Some(raw) = split.next()
+            && let Ok(parsed) = raw.parse::<usize>()
+        {
+            return parsed.clamp(1, max_limit);
+        }
+    }
+    default_limit
+}
+
+fn now_epoch_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}

src/api/runtime_init.rs

@@ -0,0 +1,186 @@
+use serde::Serialize;
+
+use crate::startup::{
+    COMPONENT_ME_CONNECTIVITY_PING, COMPONENT_ME_POOL_CONSTRUCT, COMPONENT_ME_POOL_INIT_STAGE1,
+    COMPONENT_ME_PROXY_CONFIG_V4, COMPONENT_ME_PROXY_CONFIG_V6, COMPONENT_ME_SECRET_FETCH,
+    StartupComponentStatus, StartupMeStatus, compute_progress_pct,
+};
+
+use super::ApiShared;
+
+#[derive(Serialize)]
+pub(super) struct RuntimeInitializationComponentData {
+    pub(super) id: &'static str,
+    pub(super) title: &'static str,
+    pub(super) status: &'static str,
+    pub(super) started_at_epoch_ms: Option<u64>,
+    pub(super) finished_at_epoch_ms: Option<u64>,
+    pub(super) duration_ms: Option<u64>,
+    pub(super) attempts: u32,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) details: Option<String>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeInitializationMeData {
+    pub(super) status: &'static str,
+    pub(super) current_stage: String,
+    pub(super) progress_pct: f64,
+    pub(super) init_attempt: u32,
+    pub(super) retry_limit: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_error: Option<String>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeInitializationData {
+    pub(super) status: &'static str,
+    pub(super) degraded: bool,
+    pub(super) current_stage: String,
+    pub(super) progress_pct: f64,
+    pub(super) started_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) ready_at_epoch_secs: Option<u64>,
+    pub(super) total_elapsed_ms: u64,
+    pub(super) transport_mode: String,
+    pub(super) me: RuntimeInitializationMeData,
+    pub(super) components: Vec<RuntimeInitializationComponentData>,
+}
+
+#[derive(Clone)]
+pub(super) struct RuntimeStartupSummaryData {
+    pub(super) status: &'static str,
+    pub(super) stage: String,
+    pub(super) progress_pct: f64,
+}
+
+pub(super) async fn build_runtime_startup_summary(shared: &ApiShared) -> RuntimeStartupSummaryData {
+    let snapshot = shared.startup_tracker.snapshot().await;
+    let me_pool_progress = current_me_pool_stage_progress(shared).await;
+    let progress_pct = compute_progress_pct(&snapshot, me_pool_progress);
+    RuntimeStartupSummaryData {
+        status: snapshot.status.as_str(),
+        stage: snapshot.current_stage,
+        progress_pct,
+    }
+}
+
+pub(super) async fn build_runtime_initialization_data(
+    shared: &ApiShared,
+) -> RuntimeInitializationData {
+    let snapshot = shared.startup_tracker.snapshot().await;
+    let me_pool_progress = current_me_pool_stage_progress(shared).await;
+    let progress_pct = compute_progress_pct(&snapshot, me_pool_progress);
+    let me_progress_pct = compute_me_progress_pct(&snapshot, me_pool_progress);
+
+    RuntimeInitializationData {
+        status: snapshot.status.as_str(),
+        degraded: snapshot.degraded,
+        current_stage: snapshot.current_stage,
+        progress_pct,
+        started_at_epoch_secs: snapshot.started_at_epoch_secs,
+        ready_at_epoch_secs: snapshot.ready_at_epoch_secs,
+        total_elapsed_ms: snapshot.total_elapsed_ms,
+        transport_mode: snapshot.transport_mode,
+        me: RuntimeInitializationMeData {
+            status: snapshot.me.status.as_str(),
+            current_stage: snapshot.me.current_stage,
+            progress_pct: me_progress_pct,
+            init_attempt: snapshot.me.init_attempt,
+            retry_limit: snapshot.me.retry_limit,
+            last_error: snapshot.me.last_error,
+        },
+        components: snapshot
+            .components
+            .into_iter()
+            .map(|component| RuntimeInitializationComponentData {
+                id: component.id,
+                title: component.title,
+                status: component.status.as_str(),
+                started_at_epoch_ms: component.started_at_epoch_ms,
+                finished_at_epoch_ms: component.finished_at_epoch_ms,
+                duration_ms: component.duration_ms,
+                attempts: component.attempts,
+                details: component.details,
+            })
+            .collect(),
+    }
+}
+
+fn compute_me_progress_pct(
+    snapshot: &crate::startup::StartupSnapshot,
+    me_pool_progress: Option<f64>,
+) -> f64 {
+    match snapshot.me.status {
+        StartupMeStatus::Pending => 0.0,
+        StartupMeStatus::Ready | StartupMeStatus::Failed | StartupMeStatus::Skipped => 100.0,
+        StartupMeStatus::Initializing => {
+            let mut total_weight = 0.0f64;
+            let mut completed_weight = 0.0f64;
+            for component in &snapshot.components {
+                if !is_me_component(component.id) {
+                    continue;
+                }
+                total_weight += component.weight;
+                let unit_progress = match component.status {
+                    StartupComponentStatus::Pending => 0.0,
+                    StartupComponentStatus::Running => {
+                        if component.id == COMPONENT_ME_POOL_INIT_STAGE1 {
+                            me_pool_progress.unwrap_or(0.0).clamp(0.0, 1.0)
+                        } else {
+                            0.0
+                        }
+                    }
+                    StartupComponentStatus::Ready
+                    | StartupComponentStatus::Failed
+                    | StartupComponentStatus::Skipped => 1.0,
+                };
+                completed_weight += component.weight * unit_progress;
+            }
+            if total_weight <= f64::EPSILON {
+                0.0
+            } else {
+                ((completed_weight / total_weight) * 100.0).clamp(0.0, 100.0)
+            }
+        }
+    }
+}
+
+fn is_me_component(component_id: &str) -> bool {
+    matches!(
+        component_id,
+        COMPONENT_ME_SECRET_FETCH
+            | COMPONENT_ME_PROXY_CONFIG_V4
+            | COMPONENT_ME_PROXY_CONFIG_V6
+            | COMPONENT_ME_POOL_CONSTRUCT
+            | COMPONENT_ME_POOL_INIT_STAGE1
+            | COMPONENT_ME_CONNECTIVITY_PING
+    )
+}
+
+async fn current_me_pool_stage_progress(shared: &ApiShared) -> Option<f64> {
+    let snapshot = shared.startup_tracker.snapshot().await;
+    if snapshot.me.status != StartupMeStatus::Initializing {
+        return None;
+    }
+
+    let pool = shared.me_pool.read().await.clone()?;
+    let status = pool.api_status_snapshot().await;
+    let configured_dc_groups = status.configured_dc_groups;
+    let covered_dc_groups = status
+        .dcs
+        .iter()
+        .filter(|dc| dc.alive_writers > 0)
+        .count();
+
+    let dc_coverage = ratio_01(covered_dc_groups, configured_dc_groups);
+    let writer_coverage = ratio_01(status.alive_writers, status.required_writers);
+    Some((0.7 * dc_coverage + 0.3 * writer_coverage).clamp(0.0, 1.0))
+}
+
+fn ratio_01(part: usize, total: usize) -> f64 {
+    if total == 0 {
+        return 0.0;
+    }
+    ((part as f64) / (total as f64)).clamp(0.0, 1.0)
+}

src/api/runtime_min.rs

@@ -0,0 +1,534 @@
+use std::collections::BTreeSet;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use serde::Serialize;
+
+use crate::config::ProxyConfig;
+
+use super::ApiShared;
+
+const SOURCE_UNAVAILABLE_REASON: &str = "source_unavailable";
+
+#[derive(Serialize)]
+pub(super) struct SecurityWhitelistData {
+    pub(super) generated_at_epoch_secs: u64,
+    pub(super) enabled: bool,
+    pub(super) entries_total: usize,
+    pub(super) entries: Vec<String>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateGenerationData {
+    pub(super) active_generation: u64,
+    pub(super) warm_generation: u64,
+    pub(super) pending_hardswap_generation: u64,
+    pub(super) pending_hardswap_age_secs: Option<u64>,
+    pub(super) draining_generations: Vec<u64>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateHardswapData {
+    pub(super) enabled: bool,
+    pub(super) pending: bool,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateWriterContourData {
+    pub(super) warm: usize,
+    pub(super) active: usize,
+    pub(super) draining: usize,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateWriterHealthData {
+    pub(super) healthy: usize,
+    pub(super) degraded: usize,
+    pub(super) draining: usize,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateWriterData {
+    pub(super) total: usize,
+    pub(super) alive_non_draining: usize,
+    pub(super) draining: usize,
+    pub(super) degraded: usize,
+    pub(super) contour: RuntimeMePoolStateWriterContourData,
+    pub(super) health: RuntimeMePoolStateWriterHealthData,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateRefillDcData {
+    pub(super) dc: i16,
+    pub(super) family: &'static str,
+    pub(super) inflight: usize,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateRefillData {
+    pub(super) inflight_endpoints_total: usize,
+    pub(super) inflight_dc_total: usize,
+    pub(super) by_dc: Vec<RuntimeMePoolStateRefillDcData>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStatePayload {
+    pub(super) generations: RuntimeMePoolStateGenerationData,
+    pub(super) hardswap: RuntimeMePoolStateHardswapData,
+    pub(super) writers: RuntimeMePoolStateWriterData,
+    pub(super) refill: RuntimeMePoolStateRefillData,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMePoolStateData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<RuntimeMePoolStatePayload>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeQualityCountersData {
+    pub(super) idle_close_by_peer_total: u64,
+    pub(super) reader_eof_total: u64,
+    pub(super) kdf_drift_total: u64,
+    pub(super) kdf_port_only_drift_total: u64,
+    pub(super) reconnect_attempt_total: u64,
+    pub(super) reconnect_success_total: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeQualityRouteDropData {
+    pub(super) no_conn_total: u64,
+    pub(super) channel_closed_total: u64,
+    pub(super) queue_full_total: u64,
+    pub(super) queue_full_base_total: u64,
+    pub(super) queue_full_high_total: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeQualityDcRttData {
+    pub(super) dc: i16,
+    pub(super) rtt_ema_ms: Option<f64>,
+    pub(super) alive_writers: usize,
+    pub(super) required_writers: usize,
+    pub(super) coverage_pct: f64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeQualityPayload {
+    pub(super) counters: RuntimeMeQualityCountersData,
+    pub(super) route_drops: RuntimeMeQualityRouteDropData,
+    pub(super) dc_rtt: Vec<RuntimeMeQualityDcRttData>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeQualityData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<RuntimeMeQualityPayload>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeUpstreamQualityPolicyData {
+    pub(super) connect_retry_attempts: u32,
+    pub(super) connect_retry_backoff_ms: u64,
+    pub(super) connect_budget_ms: u64,
+    pub(super) unhealthy_fail_threshold: u32,
+    pub(super) connect_failfast_hard_errors: bool,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeUpstreamQualityCountersData {
+    pub(super) connect_attempt_total: u64,
+    pub(super) connect_success_total: u64,
+    pub(super) connect_fail_total: u64,
+    pub(super) connect_failfast_hard_error_total: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeUpstreamQualitySummaryData {
+    pub(super) configured_total: usize,
+    pub(super) healthy_total: usize,
+    pub(super) unhealthy_total: usize,
+    pub(super) direct_total: usize,
+    pub(super) socks4_total: usize,
+    pub(super) socks5_total: usize,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeUpstreamQualityDcData {
+    pub(super) dc: i16,
+    pub(super) latency_ema_ms: Option<f64>,
+    pub(super) ip_preference: &'static str,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeUpstreamQualityUpstreamData {
+    pub(super) upstream_id: usize,
+    pub(super) route_kind: &'static str,
+    pub(super) address: String,
+    pub(super) weight: u16,
+    pub(super) scopes: String,
+    pub(super) healthy: bool,
+    pub(super) fails: u32,
+    pub(super) last_check_age_secs: u64,
+    pub(super) effective_latency_ms: Option<f64>,
+    pub(super) dc: Vec<RuntimeUpstreamQualityDcData>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeUpstreamQualityData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    pub(super) policy: RuntimeUpstreamQualityPolicyData,
+    pub(super) counters: RuntimeUpstreamQualityCountersData,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) summary: Option<RuntimeUpstreamQualitySummaryData>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) upstreams: Option<Vec<RuntimeUpstreamQualityUpstreamData>>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeNatStunReflectionData {
+    pub(super) addr: String,
+    pub(super) age_secs: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeNatStunFlagsData {
+    pub(super) nat_probe_enabled: bool,
+    pub(super) nat_probe_disabled_runtime: bool,
+    pub(super) nat_probe_attempts: u8,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeNatStunServersData {
+    pub(super) configured: Vec<String>,
+    pub(super) live: Vec<String>,
+    pub(super) live_total: usize,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeNatStunReflectionBlockData {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) v4: Option<RuntimeNatStunReflectionData>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) v6: Option<RuntimeNatStunReflectionData>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeNatStunPayload {
+    pub(super) flags: RuntimeNatStunFlagsData,
+    pub(super) servers: RuntimeNatStunServersData,
+    pub(super) reflection: RuntimeNatStunReflectionBlockData,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) stun_backoff_remaining_ms: Option<u64>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeNatStunData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<RuntimeNatStunPayload>,
+}
+
+pub(super) fn build_security_whitelist_data(cfg: &ProxyConfig) -> SecurityWhitelistData {
+    let entries = cfg
+        .server
+        .api
+        .whitelist
+        .iter()
+        .map(ToString::to_string)
+        .collect::<Vec<_>>();
+    SecurityWhitelistData {
+        generated_at_epoch_secs: now_epoch_secs(),
+        enabled: !entries.is_empty(),
+        entries_total: entries.len(),
+        entries,
+    }
+}
+
+pub(super) async fn build_runtime_me_pool_state_data(shared: &ApiShared) -> RuntimeMePoolStateData {
+    let now_epoch_secs = now_epoch_secs();
+    let Some(pool) = shared.me_pool.read().await.clone() else {
+        return RuntimeMePoolStateData {
+            enabled: false,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs: now_epoch_secs,
+            data: None,
+        };
+    };
+
+    let status = pool.api_status_snapshot().await;
+    let runtime = pool.api_runtime_snapshot().await;
+    let refill = pool.api_refill_snapshot().await;
+
+    let mut draining_generations = BTreeSet::<u64>::new();
+    let mut contour_warm = 0usize;
+    let mut contour_active = 0usize;
+    let mut contour_draining = 0usize;
+    let mut draining = 0usize;
+    let mut degraded = 0usize;
+    let mut healthy = 0usize;
+
+    for writer in &status.writers {
+        if writer.draining {
+            draining_generations.insert(writer.generation);
+            draining += 1;
+        }
+        if writer.degraded && !writer.draining {
+            degraded += 1;
+        }
+        if !writer.degraded && !writer.draining {
+            healthy += 1;
+        }
+        match writer.state {
+            "warm" => contour_warm += 1,
+            "active" => contour_active += 1,
+            _ => contour_draining += 1,
+        }
+    }
+
+    RuntimeMePoolStateData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs: status.generated_at_epoch_secs,
+        data: Some(RuntimeMePoolStatePayload {
+            generations: RuntimeMePoolStateGenerationData {
+                active_generation: runtime.active_generation,
+                warm_generation: runtime.warm_generation,
+                pending_hardswap_generation: runtime.pending_hardswap_generation,
+                pending_hardswap_age_secs: runtime.pending_hardswap_age_secs,
+                draining_generations: draining_generations.into_iter().collect(),
+            },
+            hardswap: RuntimeMePoolStateHardswapData {
+                enabled: runtime.hardswap_enabled,
+                pending: runtime.pending_hardswap_generation != 0,
+            },
+            writers: RuntimeMePoolStateWriterData {
+                total: status.writers.len(),
+                alive_non_draining: status.writers.len().saturating_sub(draining),
+                draining,
+                degraded,
+                contour: RuntimeMePoolStateWriterContourData {
+                    warm: contour_warm,
+                    active: contour_active,
+                    draining: contour_draining,
+                },
+                health: RuntimeMePoolStateWriterHealthData {
+                    healthy,
+                    degraded,
+                    draining,
+                },
+            },
+            refill: RuntimeMePoolStateRefillData {
+                inflight_endpoints_total: refill.inflight_endpoints_total,
+                inflight_dc_total: refill.inflight_dc_total,
+                by_dc: refill
+                    .by_dc
+                    .into_iter()
+                    .map(|entry| RuntimeMePoolStateRefillDcData {
+                        dc: entry.dc,
+                        family: entry.family,
+                        inflight: entry.inflight,
+                    })
+                    .collect(),
+            },
+        }),
+    }
+}
+
+pub(super) async fn build_runtime_me_quality_data(shared: &ApiShared) -> RuntimeMeQualityData {
+    let now_epoch_secs = now_epoch_secs();
+    let Some(pool) = shared.me_pool.read().await.clone() else {
+        return RuntimeMeQualityData {
+            enabled: false,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs: now_epoch_secs,
+            data: None,
+        };
+    };
+
+    let status = pool.api_status_snapshot().await;
+    RuntimeMeQualityData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs: status.generated_at_epoch_secs,
+        data: Some(RuntimeMeQualityPayload {
+            counters: RuntimeMeQualityCountersData {
+                idle_close_by_peer_total: shared.stats.get_me_idle_close_by_peer_total(),
+                reader_eof_total: shared.stats.get_me_reader_eof_total(),
+                kdf_drift_total: shared.stats.get_me_kdf_drift_total(),
+                kdf_port_only_drift_total: shared.stats.get_me_kdf_port_only_drift_total(),
+                reconnect_attempt_total: shared.stats.get_me_reconnect_attempts(),
+                reconnect_success_total: shared.stats.get_me_reconnect_success(),
+            },
+            route_drops: RuntimeMeQualityRouteDropData {
+                no_conn_total: shared.stats.get_me_route_drop_no_conn(),
+                channel_closed_total: shared.stats.get_me_route_drop_channel_closed(),
+                queue_full_total: shared.stats.get_me_route_drop_queue_full(),
+                queue_full_base_total: shared.stats.get_me_route_drop_queue_full_base(),
+                queue_full_high_total: shared.stats.get_me_route_drop_queue_full_high(),
+            },
+            dc_rtt: status
+                .dcs
+                .into_iter()
+                .map(|dc| RuntimeMeQualityDcRttData {
+                    dc: dc.dc,
+                    rtt_ema_ms: dc.rtt_ms,
+                    alive_writers: dc.alive_writers,
+                    required_writers: dc.required_writers,
+                    coverage_pct: dc.coverage_pct,
+                })
+                .collect(),
+        }),
+    }
+}
+
+pub(super) async fn build_runtime_upstream_quality_data(
+    shared: &ApiShared,
+) -> RuntimeUpstreamQualityData {
+    let generated_at_epoch_secs = now_epoch_secs();
+    let policy = shared.upstream_manager.api_policy_snapshot();
+    let counters = RuntimeUpstreamQualityCountersData {
+        connect_attempt_total: shared.stats.get_upstream_connect_attempt_total(),
+        connect_success_total: shared.stats.get_upstream_connect_success_total(),
+        connect_fail_total: shared.stats.get_upstream_connect_fail_total(),
+        connect_failfast_hard_error_total: shared.stats.get_upstream_connect_failfast_hard_error_total(),
+    };
+
+    let Some(snapshot) = shared.upstream_manager.try_api_snapshot() else {
+        return RuntimeUpstreamQualityData {
+            enabled: false,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs,
+            policy: RuntimeUpstreamQualityPolicyData {
+                connect_retry_attempts: policy.connect_retry_attempts,
+                connect_retry_backoff_ms: policy.connect_retry_backoff_ms,
+                connect_budget_ms: policy.connect_budget_ms,
+                unhealthy_fail_threshold: policy.unhealthy_fail_threshold,
+                connect_failfast_hard_errors: policy.connect_failfast_hard_errors,
+            },
+            counters,
+            summary: None,
+            upstreams: None,
+        };
+    };
+
+    RuntimeUpstreamQualityData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs,
+        policy: RuntimeUpstreamQualityPolicyData {
+            connect_retry_attempts: policy.connect_retry_attempts,
+            connect_retry_backoff_ms: policy.connect_retry_backoff_ms,
+            connect_budget_ms: policy.connect_budget_ms,
+            unhealthy_fail_threshold: policy.unhealthy_fail_threshold,
+            connect_failfast_hard_errors: policy.connect_failfast_hard_errors,
+        },
+        counters,
+        summary: Some(RuntimeUpstreamQualitySummaryData {
+            configured_total: snapshot.summary.configured_total,
+            healthy_total: snapshot.summary.healthy_total,
+            unhealthy_total: snapshot.summary.unhealthy_total,
+            direct_total: snapshot.summary.direct_total,
+            socks4_total: snapshot.summary.socks4_total,
+            socks5_total: snapshot.summary.socks5_total,
+        }),
+        upstreams: Some(
+            snapshot
+                .upstreams
+                .into_iter()
+                .map(|upstream| RuntimeUpstreamQualityUpstreamData {
+                    upstream_id: upstream.upstream_id,
+                    route_kind: match upstream.route_kind {
+                        crate::transport::UpstreamRouteKind::Direct => "direct",
+                        crate::transport::UpstreamRouteKind::Socks4 => "socks4",
+                        crate::transport::UpstreamRouteKind::Socks5 => "socks5",
+                    },
+                    address: upstream.address,
+                    weight: upstream.weight,
+                    scopes: upstream.scopes,
+                    healthy: upstream.healthy,
+                    fails: upstream.fails,
+                    last_check_age_secs: upstream.last_check_age_secs,
+                    effective_latency_ms: upstream.effective_latency_ms,
+                    dc: upstream
+                        .dc
+                        .into_iter()
+                        .map(|dc| RuntimeUpstreamQualityDcData {
+                            dc: dc.dc,
+                            latency_ema_ms: dc.latency_ema_ms,
+                            ip_preference: match dc.ip_preference {
+                                crate::transport::upstream::IpPreference::Unknown => "unknown",
+                                crate::transport::upstream::IpPreference::PreferV6 => "prefer_v6",
+                                crate::transport::upstream::IpPreference::PreferV4 => "prefer_v4",
+                                crate::transport::upstream::IpPreference::BothWork => "both_work",
+                                crate::transport::upstream::IpPreference::Unavailable => "unavailable",
+                            },
+                        })
+                        .collect(),
+                })
+                .collect(),
+        ),
+    }
+}
+
+pub(super) async fn build_runtime_nat_stun_data(shared: &ApiShared) -> RuntimeNatStunData {
+    let now_epoch_secs = now_epoch_secs();
+    let Some(pool) = shared.me_pool.read().await.clone() else {
+        return RuntimeNatStunData {
+            enabled: false,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs: now_epoch_secs,
+            data: None,
+        };
+    };
+
+    let snapshot = pool.api_nat_stun_snapshot().await;
+    RuntimeNatStunData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs: now_epoch_secs,
+        data: Some(RuntimeNatStunPayload {
+            flags: RuntimeNatStunFlagsData {
+                nat_probe_enabled: snapshot.nat_probe_enabled,
+                nat_probe_disabled_runtime: snapshot.nat_probe_disabled_runtime,
+                nat_probe_attempts: snapshot.nat_probe_attempts,
+            },
+            servers: RuntimeNatStunServersData {
+                configured: snapshot.configured_servers,
+                live: snapshot.live_servers.clone(),
+                live_total: snapshot.live_servers.len(),
+            },
+            reflection: RuntimeNatStunReflectionBlockData {
+                v4: snapshot.reflection_v4.map(|entry| RuntimeNatStunReflectionData {
+                    addr: entry.addr.to_string(),
+                    age_secs: entry.age_secs,
+                }),
+                v6: snapshot.reflection_v6.map(|entry| RuntimeNatStunReflectionData {
+                    addr: entry.addr.to_string(),
+                    age_secs: entry.age_secs,
+                }),
+            },
+            stun_backoff_remaining_ms: snapshot.stun_backoff_remaining_ms,
+        }),
+    }
+}
+
+fn now_epoch_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}

src/api/runtime_selftest.rs

@@ -0,0 +1,228 @@
+use std::net::IpAddr;
+use std::sync::{Mutex, OnceLock};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use serde::Serialize;
+
+use crate::network::probe::{detect_interface_ipv4, detect_interface_ipv6, is_bogon};
+use crate::transport::middle_proxy::{bnd_snapshot, timeskew_snapshot};
+
+use super::ApiShared;
+
+const SOURCE_UNAVAILABLE_REASON: &str = "source_unavailable";
+const KDF_EWMA_TAU_SECS: f64 = 600.0;
+const KDF_EWMA_THRESHOLD_ERRORS_PER_MIN: f64 = 0.30;
+const TIMESKEW_THRESHOLD_SECS: u64 = 60;
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestKdfData {
+    pub(super) state: &'static str,
+    pub(super) ewma_errors_per_min: f64,
+    pub(super) threshold_errors_per_min: f64,
+    pub(super) errors_total: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestTimeskewData {
+    pub(super) state: &'static str,
+    pub(super) max_skew_secs_15m: Option<u64>,
+    pub(super) samples_15m: usize,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_skew_secs: Option<u64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_source: Option<&'static str>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_seen_age_secs: Option<u64>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestIpFamilyData {
+    pub(super) addr: String,
+    pub(super) state: &'static str,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestIpData {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) v4: Option<RuntimeMeSelftestIpFamilyData>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) v6: Option<RuntimeMeSelftestIpFamilyData>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestPidData {
+    pub(super) pid: u32,
+    pub(super) state: &'static str,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestBndData {
+    pub(super) addr_state: &'static str,
+    pub(super) port_state: &'static str,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_addr: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_seen_age_secs: Option<u64>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestPayload {
+    pub(super) kdf: RuntimeMeSelftestKdfData,
+    pub(super) timeskew: RuntimeMeSelftestTimeskewData,
+    pub(super) ip: RuntimeMeSelftestIpData,
+    pub(super) pid: RuntimeMeSelftestPidData,
+    pub(super) bnd: RuntimeMeSelftestBndData,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeMeSelftestData {
+    pub(super) enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) generated_at_epoch_secs: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) data: Option<RuntimeMeSelftestPayload>,
+}
+
+#[derive(Default)]
+struct KdfEwmaState {
+    initialized: bool,
+    last_epoch_secs: u64,
+    last_total_errors: u64,
+    ewma_errors_per_min: f64,
+}
+
+static KDF_EWMA_STATE: OnceLock<Mutex<KdfEwmaState>> = OnceLock::new();
+
+fn kdf_ewma_state() -> &'static Mutex<KdfEwmaState> {
+    KDF_EWMA_STATE.get_or_init(|| Mutex::new(KdfEwmaState::default()))
+}
+
+pub(super) async fn build_runtime_me_selftest_data(shared: &ApiShared) -> RuntimeMeSelftestData {
+    let now_epoch_secs = now_epoch_secs();
+    if shared.me_pool.read().await.is_none() {
+        return RuntimeMeSelftestData {
+            enabled: false,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs: now_epoch_secs,
+            data: None,
+        };
+    }
+
+    let kdf_errors_total = shared
+        .stats
+        .get_me_kdf_drift_total()
+        .saturating_add(shared.stats.get_me_socks_kdf_strict_reject());
+    let kdf_ewma = update_kdf_ewma(now_epoch_secs, kdf_errors_total);
+    let kdf_state = if kdf_ewma >= KDF_EWMA_THRESHOLD_ERRORS_PER_MIN {
+        "error"
+    } else {
+        "ok"
+    };
+
+    let skew = timeskew_snapshot();
+    let timeskew_state = if skew.max_skew_secs_15m.unwrap_or(0) > TIMESKEW_THRESHOLD_SECS {
+        "error"
+    } else {
+        "ok"
+    };
+
+    let ip_v4 = detect_interface_ipv4().map(|ip| RuntimeMeSelftestIpFamilyData {
+        addr: ip.to_string(),
+        state: classify_ip(IpAddr::V4(ip)),
+    });
+    let ip_v6 = detect_interface_ipv6().map(|ip| RuntimeMeSelftestIpFamilyData {
+        addr: ip.to_string(),
+        state: classify_ip(IpAddr::V6(ip)),
+    });
+
+    let pid = std::process::id();
+    let pid_state = if pid == 1 { "one" } else { "non-one" };
+
+    let bnd = bnd_snapshot();
+
+    RuntimeMeSelftestData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs: now_epoch_secs,
+        data: Some(RuntimeMeSelftestPayload {
+            kdf: RuntimeMeSelftestKdfData {
+                state: kdf_state,
+                ewma_errors_per_min: round3(kdf_ewma),
+                threshold_errors_per_min: KDF_EWMA_THRESHOLD_ERRORS_PER_MIN,
+                errors_total: kdf_errors_total,
+            },
+            timeskew: RuntimeMeSelftestTimeskewData {
+                state: timeskew_state,
+                max_skew_secs_15m: skew.max_skew_secs_15m,
+                samples_15m: skew.samples_15m,
+                last_skew_secs: skew.last_skew_secs,
+                last_source: skew.last_source,
+                last_seen_age_secs: skew.last_seen_age_secs,
+            },
+            ip: RuntimeMeSelftestIpData {
+                v4: ip_v4,
+                v6: ip_v6,
+            },
+            pid: RuntimeMeSelftestPidData {
+                pid,
+                state: pid_state,
+            },
+            bnd: RuntimeMeSelftestBndData {
+                addr_state: bnd.addr_status,
+                port_state: bnd.port_status,
+                last_addr: bnd.last_addr.map(|value| value.to_string()),
+                last_seen_age_secs: bnd.last_seen_age_secs,
+            },
+        }),
+    }
+}
+
+fn update_kdf_ewma(now_epoch_secs: u64, total_errors: u64) -> f64 {
+    let Ok(mut guard) = kdf_ewma_state().lock() else {
+        return 0.0;
+    };
+
+    if !guard.initialized {
+        guard.initialized = true;
+        guard.last_epoch_secs = now_epoch_secs;
+        guard.last_total_errors = total_errors;
+        guard.ewma_errors_per_min = 0.0;
+        return guard.ewma_errors_per_min;
+    }
+
+    let dt_secs = now_epoch_secs.saturating_sub(guard.last_epoch_secs);
+    if dt_secs == 0 {
+        return guard.ewma_errors_per_min;
+    }
+
+    let delta_errors = total_errors.saturating_sub(guard.last_total_errors);
+    let instant_rate_per_min = (delta_errors as f64) * 60.0 / (dt_secs as f64);
+    let alpha = 1.0 - f64::exp(-(dt_secs as f64) / KDF_EWMA_TAU_SECS);
+    guard.ewma_errors_per_min = guard.ewma_errors_per_min
+        + alpha * (instant_rate_per_min - guard.ewma_errors_per_min);
+    guard.last_epoch_secs = now_epoch_secs;
+    guard.last_total_errors = total_errors;
+    guard.ewma_errors_per_min
+}
+
+fn classify_ip(ip: IpAddr) -> &'static str {
+    if ip.is_loopback() {
+        return "loopback";
+    }
+    if is_bogon(ip) {
+        return "bogon";
+    }
+    "good"
+}
+
+fn round3(value: f64) -> f64 {
+    (value * 1000.0).round() / 1000.0
+}
+
+fn now_epoch_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}

src/api/runtime_stats.rs

@@ -0,0 +1,526 @@
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+
+use crate::config::ApiConfig;
+use crate::stats::Stats;
+use crate::transport::upstream::IpPreference;
+use crate::transport::UpstreamRouteKind;
+
+use super::ApiShared;
+use super::model::{
+    DcEndpointWriters, DcStatus, DcStatusData, MeWriterStatus, MeWritersData, MeWritersSummary,
+    MinimalAllData, MinimalAllPayload, MinimalDcPathData, MinimalMeRuntimeData,
+    MinimalQuarantineData, UpstreamDcStatus, UpstreamStatus, UpstreamSummaryData, UpstreamsData,
+    ZeroAllData, ZeroCodeCount, ZeroCoreData, ZeroDesyncData, ZeroMiddleProxyData, ZeroPoolData,
+    ZeroUpstreamData,
+};
+
+const FEATURE_DISABLED_REASON: &str = "feature_disabled";
+const SOURCE_UNAVAILABLE_REASON: &str = "source_unavailable";
+
+#[derive(Clone)]
+pub(crate) struct MinimalCacheEntry {
+    pub(super) expires_at: Instant,
+    pub(super) payload: MinimalAllPayload,
+    pub(super) generated_at_epoch_secs: u64,
+}
+
+pub(super) fn build_zero_all_data(stats: &Stats, configured_users: usize) -> ZeroAllData {
+    let telemetry = stats.telemetry_policy();
+    let handshake_error_codes = stats
+        .get_me_handshake_error_code_counts()
+        .into_iter()
+        .map(|(code, total)| ZeroCodeCount { code, total })
+        .collect();
+
+    ZeroAllData {
+        generated_at_epoch_secs: now_epoch_secs(),
+        core: ZeroCoreData {
+            uptime_seconds: stats.uptime_secs(),
+            connections_total: stats.get_connects_all(),
+            connections_bad_total: stats.get_connects_bad(),
+            handshake_timeouts_total: stats.get_handshake_timeouts(),
+            configured_users,
+            telemetry_core_enabled: telemetry.core_enabled,
+            telemetry_user_enabled: telemetry.user_enabled,
+            telemetry_me_level: telemetry.me_level.to_string(),
+        },
+        upstream: build_zero_upstream_data(stats),
+        middle_proxy: ZeroMiddleProxyData {
+            keepalive_sent_total: stats.get_me_keepalive_sent(),
+            keepalive_failed_total: stats.get_me_keepalive_failed(),
+            keepalive_pong_total: stats.get_me_keepalive_pong(),
+            keepalive_timeout_total: stats.get_me_keepalive_timeout(),
+            rpc_proxy_req_signal_sent_total: stats.get_me_rpc_proxy_req_signal_sent_total(),
+            rpc_proxy_req_signal_failed_total: stats.get_me_rpc_proxy_req_signal_failed_total(),
+            rpc_proxy_req_signal_skipped_no_meta_total: stats
+                .get_me_rpc_proxy_req_signal_skipped_no_meta_total(),
+            rpc_proxy_req_signal_response_total: stats.get_me_rpc_proxy_req_signal_response_total(),
+            rpc_proxy_req_signal_close_sent_total: stats
+                .get_me_rpc_proxy_req_signal_close_sent_total(),
+            reconnect_attempt_total: stats.get_me_reconnect_attempts(),
+            reconnect_success_total: stats.get_me_reconnect_success(),
+            handshake_reject_total: stats.get_me_handshake_reject_total(),
+            handshake_error_codes,
+            reader_eof_total: stats.get_me_reader_eof_total(),
+            idle_close_by_peer_total: stats.get_me_idle_close_by_peer_total(),
+            route_drop_no_conn_total: stats.get_me_route_drop_no_conn(),
+            route_drop_channel_closed_total: stats.get_me_route_drop_channel_closed(),
+            route_drop_queue_full_total: stats.get_me_route_drop_queue_full(),
+            route_drop_queue_full_base_total: stats.get_me_route_drop_queue_full_base(),
+            route_drop_queue_full_high_total: stats.get_me_route_drop_queue_full_high(),
+            socks_kdf_strict_reject_total: stats.get_me_socks_kdf_strict_reject(),
+            socks_kdf_compat_fallback_total: stats.get_me_socks_kdf_compat_fallback(),
+            endpoint_quarantine_total: stats.get_me_endpoint_quarantine_total(),
+            kdf_drift_total: stats.get_me_kdf_drift_total(),
+            kdf_port_only_drift_total: stats.get_me_kdf_port_only_drift_total(),
+            hardswap_pending_reuse_total: stats.get_me_hardswap_pending_reuse_total(),
+            hardswap_pending_ttl_expired_total: stats.get_me_hardswap_pending_ttl_expired_total(),
+            single_endpoint_outage_enter_total: stats.get_me_single_endpoint_outage_enter_total(),
+            single_endpoint_outage_exit_total: stats.get_me_single_endpoint_outage_exit_total(),
+            single_endpoint_outage_reconnect_attempt_total: stats
+                .get_me_single_endpoint_outage_reconnect_attempt_total(),
+            single_endpoint_outage_reconnect_success_total: stats
+                .get_me_single_endpoint_outage_reconnect_success_total(),
+            single_endpoint_quarantine_bypass_total: stats
+                .get_me_single_endpoint_quarantine_bypass_total(),
+            single_endpoint_shadow_rotate_total: stats.get_me_single_endpoint_shadow_rotate_total(),
+            single_endpoint_shadow_rotate_skipped_quarantine_total: stats
+                .get_me_single_endpoint_shadow_rotate_skipped_quarantine_total(),
+            floor_mode_switch_total: stats.get_me_floor_mode_switch_total(),
+            floor_mode_switch_static_to_adaptive_total: stats
+                .get_me_floor_mode_switch_static_to_adaptive_total(),
+            floor_mode_switch_adaptive_to_static_total: stats
+                .get_me_floor_mode_switch_adaptive_to_static_total(),
+        },
+        pool: ZeroPoolData {
+            pool_swap_total: stats.get_pool_swap_total(),
+            pool_drain_active: stats.get_pool_drain_active(),
+            pool_force_close_total: stats.get_pool_force_close_total(),
+            pool_stale_pick_total: stats.get_pool_stale_pick_total(),
+            writer_removed_total: stats.get_me_writer_removed_total(),
+            writer_removed_unexpected_total: stats.get_me_writer_removed_unexpected_total(),
+            refill_triggered_total: stats.get_me_refill_triggered_total(),
+            refill_skipped_inflight_total: stats.get_me_refill_skipped_inflight_total(),
+            refill_failed_total: stats.get_me_refill_failed_total(),
+            writer_restored_same_endpoint_total: stats.get_me_writer_restored_same_endpoint_total(),
+            writer_restored_fallback_total: stats.get_me_writer_restored_fallback_total(),
+        },
+        desync: ZeroDesyncData {
+            secure_padding_invalid_total: stats.get_secure_padding_invalid(),
+            desync_total: stats.get_desync_total(),
+            desync_full_logged_total: stats.get_desync_full_logged(),
+            desync_suppressed_total: stats.get_desync_suppressed(),
+            desync_frames_bucket_0: stats.get_desync_frames_bucket_0(),
+            desync_frames_bucket_1_2: stats.get_desync_frames_bucket_1_2(),
+            desync_frames_bucket_3_10: stats.get_desync_frames_bucket_3_10(),
+            desync_frames_bucket_gt_10: stats.get_desync_frames_bucket_gt_10(),
+        },
+    }
+}
+
+fn build_zero_upstream_data(stats: &Stats) -> ZeroUpstreamData {
+    ZeroUpstreamData {
+        connect_attempt_total: stats.get_upstream_connect_attempt_total(),
+        connect_success_total: stats.get_upstream_connect_success_total(),
+        connect_fail_total: stats.get_upstream_connect_fail_total(),
+        connect_failfast_hard_error_total: stats.get_upstream_connect_failfast_hard_error_total(),
+        connect_attempts_bucket_1: stats.get_upstream_connect_attempts_bucket_1(),
+        connect_attempts_bucket_2: stats.get_upstream_connect_attempts_bucket_2(),
+        connect_attempts_bucket_3_4: stats.get_upstream_connect_attempts_bucket_3_4(),
+        connect_attempts_bucket_gt_4: stats.get_upstream_connect_attempts_bucket_gt_4(),
+        connect_duration_success_bucket_le_100ms: stats
+            .get_upstream_connect_duration_success_bucket_le_100ms(),
+        connect_duration_success_bucket_101_500ms: stats
+            .get_upstream_connect_duration_success_bucket_101_500ms(),
+        connect_duration_success_bucket_501_1000ms: stats
+            .get_upstream_connect_duration_success_bucket_501_1000ms(),
+        connect_duration_success_bucket_gt_1000ms: stats
+            .get_upstream_connect_duration_success_bucket_gt_1000ms(),
+        connect_duration_fail_bucket_le_100ms: stats.get_upstream_connect_duration_fail_bucket_le_100ms(),
+        connect_duration_fail_bucket_101_500ms: stats
+            .get_upstream_connect_duration_fail_bucket_101_500ms(),
+        connect_duration_fail_bucket_501_1000ms: stats
+            .get_upstream_connect_duration_fail_bucket_501_1000ms(),
+        connect_duration_fail_bucket_gt_1000ms: stats
+            .get_upstream_connect_duration_fail_bucket_gt_1000ms(),
+    }
+}
+
+pub(super) fn build_upstreams_data(shared: &ApiShared, api_cfg: &ApiConfig) -> UpstreamsData {
+    let generated_at_epoch_secs = now_epoch_secs();
+    let zero = build_zero_upstream_data(&shared.stats);
+    if !api_cfg.minimal_runtime_enabled {
+        return UpstreamsData {
+            enabled: false,
+            reason: Some(FEATURE_DISABLED_REASON),
+            generated_at_epoch_secs,
+            zero,
+            summary: None,
+            upstreams: None,
+        };
+    }
+
+    let Some(snapshot) = shared.upstream_manager.try_api_snapshot() else {
+        return UpstreamsData {
+            enabled: true,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs,
+            zero,
+            summary: None,
+            upstreams: None,
+        };
+    };
+
+    let summary = UpstreamSummaryData {
+        configured_total: snapshot.summary.configured_total,
+        healthy_total: snapshot.summary.healthy_total,
+        unhealthy_total: snapshot.summary.unhealthy_total,
+        direct_total: snapshot.summary.direct_total,
+        socks4_total: snapshot.summary.socks4_total,
+        socks5_total: snapshot.summary.socks5_total,
+    };
+    let upstreams = snapshot
+        .upstreams
+        .into_iter()
+        .map(|upstream| UpstreamStatus {
+            upstream_id: upstream.upstream_id,
+            route_kind: map_route_kind(upstream.route_kind),
+            address: upstream.address,
+            weight: upstream.weight,
+            scopes: upstream.scopes,
+            healthy: upstream.healthy,
+            fails: upstream.fails,
+            last_check_age_secs: upstream.last_check_age_secs,
+            effective_latency_ms: upstream.effective_latency_ms,
+            dc: upstream
+                .dc
+                .into_iter()
+                .map(|dc| UpstreamDcStatus {
+                    dc: dc.dc,
+                    latency_ema_ms: dc.latency_ema_ms,
+                    ip_preference: map_ip_preference(dc.ip_preference),
+                })
+                .collect(),
+        })
+        .collect();
+
+    UpstreamsData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs,
+        zero,
+        summary: Some(summary),
+        upstreams: Some(upstreams),
+    }
+}
+
+pub(super) async fn build_minimal_all_data(
+    shared: &ApiShared,
+    api_cfg: &ApiConfig,
+) -> MinimalAllData {
+    let now = now_epoch_secs();
+    if !api_cfg.minimal_runtime_enabled {
+        return MinimalAllData {
+            enabled: false,
+            reason: Some(FEATURE_DISABLED_REASON),
+            generated_at_epoch_secs: now,
+            data: None,
+        };
+    }
+
+    let Some((generated_at_epoch_secs, payload)) =
+        get_minimal_payload_cached(shared, api_cfg.minimal_runtime_cache_ttl_ms).await
+    else {
+        return MinimalAllData {
+            enabled: true,
+            reason: Some(SOURCE_UNAVAILABLE_REASON),
+            generated_at_epoch_secs: now,
+            data: Some(MinimalAllPayload {
+                me_writers: disabled_me_writers(now, SOURCE_UNAVAILABLE_REASON),
+                dcs: disabled_dcs(now, SOURCE_UNAVAILABLE_REASON),
+                me_runtime: None,
+                network_path: Vec::new(),
+            }),
+        };
+    };
+
+    MinimalAllData {
+        enabled: true,
+        reason: None,
+        generated_at_epoch_secs,
+        data: Some(payload),
+    }
+}
+
+pub(super) async fn build_me_writers_data(
+    shared: &ApiShared,
+    api_cfg: &ApiConfig,
+) -> MeWritersData {
+    let now = now_epoch_secs();
+    if !api_cfg.minimal_runtime_enabled {
+        return disabled_me_writers(now, FEATURE_DISABLED_REASON);
+    }
+
+    let Some((_, payload)) =
+        get_minimal_payload_cached(shared, api_cfg.minimal_runtime_cache_ttl_ms).await
+    else {
+        return disabled_me_writers(now, SOURCE_UNAVAILABLE_REASON);
+    };
+    payload.me_writers
+}
+
+pub(super) async fn build_dcs_data(shared: &ApiShared, api_cfg: &ApiConfig) -> DcStatusData {
+    let now = now_epoch_secs();
+    if !api_cfg.minimal_runtime_enabled {
+        return disabled_dcs(now, FEATURE_DISABLED_REASON);
+    }
+
+    let Some((_, payload)) =
+        get_minimal_payload_cached(shared, api_cfg.minimal_runtime_cache_ttl_ms).await
+    else {
+        return disabled_dcs(now, SOURCE_UNAVAILABLE_REASON);
+    };
+    payload.dcs
+}
+
+async fn get_minimal_payload_cached(
+    shared: &ApiShared,
+    cache_ttl_ms: u64,
+) -> Option<(u64, MinimalAllPayload)> {
+    if cache_ttl_ms > 0 {
+        let now = Instant::now();
+        let cached = shared.minimal_cache.lock().await.clone();
+        if let Some(entry) = cached
+            && now < entry.expires_at
+        {
+            return Some((entry.generated_at_epoch_secs, entry.payload));
+        }
+    }
+
+    let pool = shared.me_pool.read().await.clone()?;
+    let status = pool.api_status_snapshot().await;
+    let runtime = pool.api_runtime_snapshot().await;
+    let generated_at_epoch_secs = status.generated_at_epoch_secs;
+
+    let me_writers = MeWritersData {
+        middle_proxy_enabled: true,
+        reason: None,
+        generated_at_epoch_secs,
+        summary: MeWritersSummary {
+            configured_dc_groups: status.configured_dc_groups,
+            configured_endpoints: status.configured_endpoints,
+            available_endpoints: status.available_endpoints,
+            available_pct: status.available_pct,
+            required_writers: status.required_writers,
+            alive_writers: status.alive_writers,
+            coverage_pct: status.coverage_pct,
+        },
+        writers: status
+            .writers
+            .into_iter()
+            .map(|entry| MeWriterStatus {
+                writer_id: entry.writer_id,
+                dc: entry.dc,
+                endpoint: entry.endpoint.to_string(),
+                generation: entry.generation,
+                state: entry.state,
+                draining: entry.draining,
+                degraded: entry.degraded,
+                bound_clients: entry.bound_clients,
+                idle_for_secs: entry.idle_for_secs,
+                rtt_ema_ms: entry.rtt_ema_ms,
+            })
+            .collect(),
+    };
+    let dcs = DcStatusData {
+        middle_proxy_enabled: true,
+        reason: None,
+        generated_at_epoch_secs,
+        dcs: status
+            .dcs
+            .into_iter()
+            .map(|entry| DcStatus {
+                dc: entry.dc,
+                endpoints: entry
+                    .endpoints
+                    .into_iter()
+                    .map(|value| value.to_string())
+                    .collect(),
+                endpoint_writers: entry
+                    .endpoint_writers
+                    .into_iter()
+                    .map(|coverage| DcEndpointWriters {
+                        endpoint: coverage.endpoint.to_string(),
+                        active_writers: coverage.active_writers,
+                    })
+                    .collect(),
+                available_endpoints: entry.available_endpoints,
+                available_pct: entry.available_pct,
+                required_writers: entry.required_writers,
+                floor_min: entry.floor_min,
+                floor_target: entry.floor_target,
+                floor_max: entry.floor_max,
+                floor_capped: entry.floor_capped,
+                alive_writers: entry.alive_writers,
+                coverage_pct: entry.coverage_pct,
+                rtt_ms: entry.rtt_ms,
+                load: entry.load,
+            })
+            .collect(),
+    };
+    let me_runtime = MinimalMeRuntimeData {
+        active_generation: runtime.active_generation,
+        warm_generation: runtime.warm_generation,
+        pending_hardswap_generation: runtime.pending_hardswap_generation,
+        pending_hardswap_age_secs: runtime.pending_hardswap_age_secs,
+        hardswap_enabled: runtime.hardswap_enabled,
+        floor_mode: runtime.floor_mode,
+        adaptive_floor_idle_secs: runtime.adaptive_floor_idle_secs,
+        adaptive_floor_min_writers_single_endpoint: runtime
+            .adaptive_floor_min_writers_single_endpoint,
+        adaptive_floor_min_writers_multi_endpoint: runtime
+            .adaptive_floor_min_writers_multi_endpoint,
+        adaptive_floor_recover_grace_secs: runtime.adaptive_floor_recover_grace_secs,
+        adaptive_floor_writers_per_core_total: runtime
+            .adaptive_floor_writers_per_core_total,
+        adaptive_floor_cpu_cores_override: runtime.adaptive_floor_cpu_cores_override,
+        adaptive_floor_max_extra_writers_single_per_core: runtime
+            .adaptive_floor_max_extra_writers_single_per_core,
+        adaptive_floor_max_extra_writers_multi_per_core: runtime
+            .adaptive_floor_max_extra_writers_multi_per_core,
+        adaptive_floor_max_active_writers_per_core: runtime
+            .adaptive_floor_max_active_writers_per_core,
+        adaptive_floor_max_warm_writers_per_core: runtime
+            .adaptive_floor_max_warm_writers_per_core,
+        adaptive_floor_max_active_writers_global: runtime
+            .adaptive_floor_max_active_writers_global,
+        adaptive_floor_max_warm_writers_global: runtime
+            .adaptive_floor_max_warm_writers_global,
+        adaptive_floor_cpu_cores_detected: runtime.adaptive_floor_cpu_cores_detected,
+        adaptive_floor_cpu_cores_effective: runtime.adaptive_floor_cpu_cores_effective,
+        adaptive_floor_global_cap_raw: runtime.adaptive_floor_global_cap_raw,
+        adaptive_floor_global_cap_effective: runtime.adaptive_floor_global_cap_effective,
+        adaptive_floor_target_writers_total: runtime.adaptive_floor_target_writers_total,
+        adaptive_floor_active_cap_configured: runtime.adaptive_floor_active_cap_configured,
+        adaptive_floor_active_cap_effective: runtime.adaptive_floor_active_cap_effective,
+        adaptive_floor_warm_cap_configured: runtime.adaptive_floor_warm_cap_configured,
+        adaptive_floor_warm_cap_effective: runtime.adaptive_floor_warm_cap_effective,
+        adaptive_floor_active_writers_current: runtime.adaptive_floor_active_writers_current,
+        adaptive_floor_warm_writers_current: runtime.adaptive_floor_warm_writers_current,
+        me_keepalive_enabled: runtime.me_keepalive_enabled,
+        me_keepalive_interval_secs: runtime.me_keepalive_interval_secs,
+        me_keepalive_jitter_secs: runtime.me_keepalive_jitter_secs,
+        me_keepalive_payload_random: runtime.me_keepalive_payload_random,
+        rpc_proxy_req_every_secs: runtime.rpc_proxy_req_every_secs,
+        me_reconnect_max_concurrent_per_dc: runtime.me_reconnect_max_concurrent_per_dc,
+        me_reconnect_backoff_base_ms: runtime.me_reconnect_backoff_base_ms,
+        me_reconnect_backoff_cap_ms: runtime.me_reconnect_backoff_cap_ms,
+        me_reconnect_fast_retry_count: runtime.me_reconnect_fast_retry_count,
+        me_pool_drain_ttl_secs: runtime.me_pool_drain_ttl_secs,
+        me_pool_force_close_secs: runtime.me_pool_force_close_secs,
+        me_pool_min_fresh_ratio: runtime.me_pool_min_fresh_ratio,
+        me_bind_stale_mode: runtime.me_bind_stale_mode,
+        me_bind_stale_ttl_secs: runtime.me_bind_stale_ttl_secs,
+        me_single_endpoint_shadow_writers: runtime.me_single_endpoint_shadow_writers,
+        me_single_endpoint_outage_mode_enabled: runtime.me_single_endpoint_outage_mode_enabled,
+        me_single_endpoint_outage_disable_quarantine: runtime
+            .me_single_endpoint_outage_disable_quarantine,
+        me_single_endpoint_outage_backoff_min_ms: runtime.me_single_endpoint_outage_backoff_min_ms,
+        me_single_endpoint_outage_backoff_max_ms: runtime.me_single_endpoint_outage_backoff_max_ms,
+        me_single_endpoint_shadow_rotate_every_secs: runtime
+            .me_single_endpoint_shadow_rotate_every_secs,
+        me_deterministic_writer_sort: runtime.me_deterministic_writer_sort,
+        me_writer_pick_mode: runtime.me_writer_pick_mode,
+        me_writer_pick_sample_size: runtime.me_writer_pick_sample_size,
+        me_socks_kdf_policy: runtime.me_socks_kdf_policy,
+        quarantined_endpoints_total: runtime.quarantined_endpoints.len(),
+        quarantined_endpoints: runtime
+            .quarantined_endpoints
+            .into_iter()
+            .map(|entry| MinimalQuarantineData {
+                endpoint: entry.endpoint.to_string(),
+                remaining_ms: entry.remaining_ms,
+            })
+            .collect(),
+    };
+    let network_path = runtime
+        .network_path
+        .into_iter()
+        .map(|entry| MinimalDcPathData {
+            dc: entry.dc,
+            ip_preference: entry.ip_preference,
+            selected_addr_v4: entry.selected_addr_v4.map(|value| value.to_string()),
+            selected_addr_v6: entry.selected_addr_v6.map(|value| value.to_string()),
+        })
+        .collect();
+
+    let payload = MinimalAllPayload {
+        me_writers,
+        dcs,
+        me_runtime: Some(me_runtime),
+        network_path,
+    };
+
+    if cache_ttl_ms > 0 {
+        let entry = MinimalCacheEntry {
+            expires_at: Instant::now() + Duration::from_millis(cache_ttl_ms),
+            payload: payload.clone(),
+            generated_at_epoch_secs,
+        };
+        *shared.minimal_cache.lock().await = Some(entry);
+    }
+
+    Some((generated_at_epoch_secs, payload))
+}
+
+fn disabled_me_writers(now_epoch_secs: u64, reason: &'static str) -> MeWritersData {
+    MeWritersData {
+        middle_proxy_enabled: false,
+        reason: Some(reason),
+        generated_at_epoch_secs: now_epoch_secs,
+        summary: MeWritersSummary {
+            configured_dc_groups: 0,
+            configured_endpoints: 0,
+            available_endpoints: 0,
+            available_pct: 0.0,
+            required_writers: 0,
+            alive_writers: 0,
+            coverage_pct: 0.0,
+        },
+        writers: Vec::new(),
+    }
+}
+
+fn disabled_dcs(now_epoch_secs: u64, reason: &'static str) -> DcStatusData {
+    DcStatusData {
+        middle_proxy_enabled: false,
+        reason: Some(reason),
+        generated_at_epoch_secs: now_epoch_secs,
+        dcs: Vec::new(),
+    }
+}
+
+fn map_route_kind(value: UpstreamRouteKind) -> &'static str {
+    match value {
+        UpstreamRouteKind::Direct => "direct",
+        UpstreamRouteKind::Socks4 => "socks4",
+        UpstreamRouteKind::Socks5 => "socks5",
+    }
+}
+
+fn map_ip_preference(value: IpPreference) -> &'static str {
+    match value {
+        IpPreference::Unknown => "unknown",
+        IpPreference::PreferV6 => "prefer_v6",
+        IpPreference::PreferV4 => "prefer_v4",
+        IpPreference::BothWork => "both_work",
+        IpPreference::Unavailable => "unavailable",
+    }
+}
+
+fn now_epoch_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}

src/api/runtime_watch.rs

@@ -0,0 +1,66 @@
+use std::sync::Arc;
+use std::sync::atomic::Ordering;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use tokio::sync::watch;
+
+use crate::config::ProxyConfig;
+
+use super::ApiRuntimeState;
+use super::events::ApiEventStore;
+
+pub(super) fn spawn_runtime_watchers(
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+    admission_rx: watch::Receiver<bool>,
+    runtime_state: Arc<ApiRuntimeState>,
+    runtime_events: Arc<ApiEventStore>,
+) {
+    let mut config_rx_reload = config_rx;
+    let runtime_state_reload = runtime_state.clone();
+    let runtime_events_reload = runtime_events.clone();
+    tokio::spawn(async move {
+        loop {
+            if config_rx_reload.changed().await.is_err() {
+                break;
+            }
+            runtime_state_reload
+                .config_reload_count
+                .fetch_add(1, Ordering::Relaxed);
+            runtime_state_reload
+                .last_config_reload_epoch_secs
+                .store(now_epoch_secs(), Ordering::Relaxed);
+            runtime_events_reload.record("config.reload.applied", "config receiver updated");
+        }
+    });
+
+    let mut admission_rx_watch = admission_rx;
+    tokio::spawn(async move {
+        runtime_state
+            .admission_open
+            .store(*admission_rx_watch.borrow(), Ordering::Relaxed);
+        runtime_events.record(
+            "admission.state",
+            format!("accepting_new_connections={}", *admission_rx_watch.borrow()),
+        );
+        loop {
+            if admission_rx_watch.changed().await.is_err() {
+                break;
+            }
+            let admission_open = *admission_rx_watch.borrow();
+            runtime_state
+                .admission_open
+                .store(admission_open, Ordering::Relaxed);
+            runtime_events.record(
+                "admission.state",
+                format!("accepting_new_connections={}", admission_open),
+            );
+        }
+    });
+}
+
+fn now_epoch_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}

src/api/runtime_zero.rs

@@ -0,0 +1,287 @@
+use std::sync::atomic::Ordering;
+
+use serde::Serialize;
+
+use crate::config::{MeFloorMode, MeWriterPickMode, ProxyConfig, UserMaxUniqueIpsMode};
+
+use super::ApiShared;
+use super::runtime_init::build_runtime_startup_summary;
+
+#[derive(Serialize)]
+pub(super) struct SystemInfoData {
+    pub(super) version: String,
+    pub(super) target_arch: String,
+    pub(super) target_os: String,
+    pub(super) build_profile: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) git_commit: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) build_time_utc: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) rustc_version: Option<String>,
+    pub(super) process_started_at_epoch_secs: u64,
+    pub(super) uptime_seconds: f64,
+    pub(super) config_path: String,
+    pub(super) config_hash: String,
+    pub(super) config_reload_count: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) last_config_reload_epoch_secs: Option<u64>,
+}
+
+#[derive(Serialize)]
+pub(super) struct RuntimeGatesData {
+    pub(super) accepting_new_connections: bool,
+    pub(super) conditional_cast_enabled: bool,
+    pub(super) me_runtime_ready: bool,
+    pub(super) me2dc_fallback_enabled: bool,
+    pub(super) use_middle_proxy: bool,
+    pub(super) startup_status: &'static str,
+    pub(super) startup_stage: String,
+    pub(super) startup_progress_pct: f64,
+}
+
+#[derive(Serialize)]
+pub(super) struct EffectiveTimeoutLimits {
+    pub(super) client_handshake_secs: u64,
+    pub(super) tg_connect_secs: u64,
+    pub(super) client_keepalive_secs: u64,
+    pub(super) client_ack_secs: u64,
+    pub(super) me_one_retry: u8,
+    pub(super) me_one_timeout_ms: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct EffectiveUpstreamLimits {
+    pub(super) connect_retry_attempts: u32,
+    pub(super) connect_retry_backoff_ms: u64,
+    pub(super) connect_budget_ms: u64,
+    pub(super) unhealthy_fail_threshold: u32,
+    pub(super) connect_failfast_hard_errors: bool,
+}
+
+#[derive(Serialize)]
+pub(super) struct EffectiveMiddleProxyLimits {
+    pub(super) floor_mode: &'static str,
+    pub(super) adaptive_floor_idle_secs: u64,
+    pub(super) adaptive_floor_min_writers_single_endpoint: u8,
+    pub(super) adaptive_floor_min_writers_multi_endpoint: u8,
+    pub(super) adaptive_floor_recover_grace_secs: u64,
+    pub(super) adaptive_floor_writers_per_core_total: u16,
+    pub(super) adaptive_floor_cpu_cores_override: u16,
+    pub(super) adaptive_floor_max_extra_writers_single_per_core: u16,
+    pub(super) adaptive_floor_max_extra_writers_multi_per_core: u16,
+    pub(super) adaptive_floor_max_active_writers_per_core: u16,
+    pub(super) adaptive_floor_max_warm_writers_per_core: u16,
+    pub(super) adaptive_floor_max_active_writers_global: u32,
+    pub(super) adaptive_floor_max_warm_writers_global: u32,
+    pub(super) reconnect_max_concurrent_per_dc: u32,
+    pub(super) reconnect_backoff_base_ms: u64,
+    pub(super) reconnect_backoff_cap_ms: u64,
+    pub(super) reconnect_fast_retry_count: u32,
+    pub(super) writer_pick_mode: &'static str,
+    pub(super) writer_pick_sample_size: u8,
+    pub(super) me2dc_fallback: bool,
+}
+
+#[derive(Serialize)]
+pub(super) struct EffectiveUserIpPolicyLimits {
+    pub(super) mode: &'static str,
+    pub(super) window_secs: u64,
+}
+
+#[derive(Serialize)]
+pub(super) struct EffectiveLimitsData {
+    pub(super) update_every_secs: u64,
+    pub(super) me_reinit_every_secs: u64,
+    pub(super) me_pool_force_close_secs: u64,
+    pub(super) timeouts: EffectiveTimeoutLimits,
+    pub(super) upstream: EffectiveUpstreamLimits,
+    pub(super) middle_proxy: EffectiveMiddleProxyLimits,
+    pub(super) user_ip_policy: EffectiveUserIpPolicyLimits,
+}
+
+#[derive(Serialize)]
+pub(super) struct SecurityPostureData {
+    pub(super) api_read_only: bool,
+    pub(super) api_whitelist_enabled: bool,
+    pub(super) api_whitelist_entries: usize,
+    pub(super) api_auth_header_enabled: bool,
+    pub(super) proxy_protocol_enabled: bool,
+    pub(super) log_level: String,
+    pub(super) telemetry_core_enabled: bool,
+    pub(super) telemetry_user_enabled: bool,
+    pub(super) telemetry_me_level: String,
+}
+
+pub(super) fn build_system_info_data(
+    shared: &ApiShared,
+    _cfg: &ProxyConfig,
+    revision: &str,
+) -> SystemInfoData {
+    let last_reload_epoch_secs = shared
+        .runtime_state
+        .last_config_reload_epoch_secs
+        .load(Ordering::Relaxed);
+    let last_config_reload_epoch_secs = (last_reload_epoch_secs > 0).then_some(last_reload_epoch_secs);
+
+    let git_commit = option_env!("TELEMT_GIT_COMMIT")
+        .or(option_env!("VERGEN_GIT_SHA"))
+        .or(option_env!("GIT_COMMIT"))
+        .map(ToString::to_string);
+    let build_time_utc = option_env!("BUILD_TIME_UTC")
+        .or(option_env!("VERGEN_BUILD_TIMESTAMP"))
+        .map(ToString::to_string);
+    let rustc_version = option_env!("RUSTC_VERSION")
+        .or(option_env!("VERGEN_RUSTC_SEMVER"))
+        .map(ToString::to_string);
+
+    SystemInfoData {
+        version: env!("CARGO_PKG_VERSION").to_string(),
+        target_arch: std::env::consts::ARCH.to_string(),
+        target_os: std::env::consts::OS.to_string(),
+        build_profile: option_env!("PROFILE").unwrap_or("unknown").to_string(),
+        git_commit,
+        build_time_utc,
+        rustc_version,
+        process_started_at_epoch_secs: shared.runtime_state.process_started_at_epoch_secs,
+        uptime_seconds: shared.stats.uptime_secs(),
+        config_path: shared.config_path.display().to_string(),
+        config_hash: revision.to_string(),
+        config_reload_count: shared.runtime_state.config_reload_count.load(Ordering::Relaxed),
+        last_config_reload_epoch_secs,
+    }
+}
+
+pub(super) async fn build_runtime_gates_data(
+    shared: &ApiShared,
+    cfg: &ProxyConfig,
+) -> RuntimeGatesData {
+    let startup_summary = build_runtime_startup_summary(shared).await;
+    let me_runtime_ready = if !cfg.general.use_middle_proxy {
+        true
+    } else {
+        shared
+            .me_pool
+            .read()
+            .await
+            .as_ref()
+            .map(|pool| pool.is_runtime_ready())
+            .unwrap_or(false)
+    };
+
+    RuntimeGatesData {
+        accepting_new_connections: shared.runtime_state.admission_open.load(Ordering::Relaxed),
+        conditional_cast_enabled: cfg.general.use_middle_proxy,
+        me_runtime_ready,
+        me2dc_fallback_enabled: cfg.general.me2dc_fallback,
+        use_middle_proxy: cfg.general.use_middle_proxy,
+        startup_status: startup_summary.status,
+        startup_stage: startup_summary.stage,
+        startup_progress_pct: startup_summary.progress_pct,
+    }
+}
+
+pub(super) fn build_limits_effective_data(cfg: &ProxyConfig) -> EffectiveLimitsData {
+    EffectiveLimitsData {
+        update_every_secs: cfg.general.effective_update_every_secs(),
+        me_reinit_every_secs: cfg.general.effective_me_reinit_every_secs(),
+        me_pool_force_close_secs: cfg.general.effective_me_pool_force_close_secs(),
+        timeouts: EffectiveTimeoutLimits {
+            client_handshake_secs: cfg.timeouts.client_handshake,
+            tg_connect_secs: cfg.timeouts.tg_connect,
+            client_keepalive_secs: cfg.timeouts.client_keepalive,
+            client_ack_secs: cfg.timeouts.client_ack,
+            me_one_retry: cfg.timeouts.me_one_retry,
+            me_one_timeout_ms: cfg.timeouts.me_one_timeout_ms,
+        },
+        upstream: EffectiveUpstreamLimits {
+            connect_retry_attempts: cfg.general.upstream_connect_retry_attempts,
+            connect_retry_backoff_ms: cfg.general.upstream_connect_retry_backoff_ms,
+            connect_budget_ms: cfg.general.upstream_connect_budget_ms,
+            unhealthy_fail_threshold: cfg.general.upstream_unhealthy_fail_threshold,
+            connect_failfast_hard_errors: cfg.general.upstream_connect_failfast_hard_errors,
+        },
+        middle_proxy: EffectiveMiddleProxyLimits {
+            floor_mode: me_floor_mode_label(cfg.general.me_floor_mode),
+            adaptive_floor_idle_secs: cfg.general.me_adaptive_floor_idle_secs,
+            adaptive_floor_min_writers_single_endpoint: cfg
+                .general
+                .me_adaptive_floor_min_writers_single_endpoint,
+            adaptive_floor_min_writers_multi_endpoint: cfg
+                .general
+                .me_adaptive_floor_min_writers_multi_endpoint,
+            adaptive_floor_recover_grace_secs: cfg.general.me_adaptive_floor_recover_grace_secs,
+            adaptive_floor_writers_per_core_total: cfg
+                .general
+                .me_adaptive_floor_writers_per_core_total,
+            adaptive_floor_cpu_cores_override: cfg
+                .general
+                .me_adaptive_floor_cpu_cores_override,
+            adaptive_floor_max_extra_writers_single_per_core: cfg
+                .general
+                .me_adaptive_floor_max_extra_writers_single_per_core,
+            adaptive_floor_max_extra_writers_multi_per_core: cfg
+                .general
+                .me_adaptive_floor_max_extra_writers_multi_per_core,
+            adaptive_floor_max_active_writers_per_core: cfg
+                .general
+                .me_adaptive_floor_max_active_writers_per_core,
+            adaptive_floor_max_warm_writers_per_core: cfg
+                .general
+                .me_adaptive_floor_max_warm_writers_per_core,
+            adaptive_floor_max_active_writers_global: cfg
+                .general
+                .me_adaptive_floor_max_active_writers_global,
+            adaptive_floor_max_warm_writers_global: cfg
+                .general
+                .me_adaptive_floor_max_warm_writers_global,
+            reconnect_max_concurrent_per_dc: cfg.general.me_reconnect_max_concurrent_per_dc,
+            reconnect_backoff_base_ms: cfg.general.me_reconnect_backoff_base_ms,
+            reconnect_backoff_cap_ms: cfg.general.me_reconnect_backoff_cap_ms,
+            reconnect_fast_retry_count: cfg.general.me_reconnect_fast_retry_count,
+            writer_pick_mode: me_writer_pick_mode_label(cfg.general.me_writer_pick_mode),
+            writer_pick_sample_size: cfg.general.me_writer_pick_sample_size,
+            me2dc_fallback: cfg.general.me2dc_fallback,
+        },
+        user_ip_policy: EffectiveUserIpPolicyLimits {
+            mode: user_max_unique_ips_mode_label(cfg.access.user_max_unique_ips_mode),
+            window_secs: cfg.access.user_max_unique_ips_window_secs,
+        },
+    }
+}
+
+pub(super) fn build_security_posture_data(cfg: &ProxyConfig) -> SecurityPostureData {
+    SecurityPostureData {
+        api_read_only: cfg.server.api.read_only,
+        api_whitelist_enabled: !cfg.server.api.whitelist.is_empty(),
+        api_whitelist_entries: cfg.server.api.whitelist.len(),
+        api_auth_header_enabled: !cfg.server.api.auth_header.is_empty(),
+        proxy_protocol_enabled: cfg.server.proxy_protocol,
+        log_level: cfg.general.log_level.to_string(),
+        telemetry_core_enabled: cfg.general.telemetry.core_enabled,
+        telemetry_user_enabled: cfg.general.telemetry.user_enabled,
+        telemetry_me_level: cfg.general.telemetry.me_level.to_string(),
+    }
+}
+
+fn user_max_unique_ips_mode_label(mode: UserMaxUniqueIpsMode) -> &'static str {
+    match mode {
+        UserMaxUniqueIpsMode::ActiveWindow => "active_window",
+        UserMaxUniqueIpsMode::TimeWindow => "time_window",
+        UserMaxUniqueIpsMode::Combined => "combined",
+    }
+}
+
+fn me_floor_mode_label(mode: MeFloorMode) -> &'static str {
+    match mode {
+        MeFloorMode::Static => "static",
+        MeFloorMode::Adaptive => "adaptive",
+    }
+}
+
+fn me_writer_pick_mode_label(mode: MeWriterPickMode) -> &'static str {
+    match mode {
+        MeWriterPickMode::SortedRr => "sorted_rr",
+        MeWriterPickMode::P2c => "p2c",
+    }
+}

src/api/users.rs

@@ -0,0 +1,551 @@
+use std::net::IpAddr;
+
+use hyper::StatusCode;
+
+use crate::config::ProxyConfig;
+use crate::ip_tracker::UserIpTracker;
+use crate::stats::Stats;
+
+use super::ApiShared;
+use super::config_store::{
+    AccessSection, ensure_expected_revision, load_config_from_disk, save_access_sections_to_disk,
+    save_config_to_disk,
+};
+use super::model::{
+    ApiFailure, CreateUserRequest, CreateUserResponse, PatchUserRequest, RotateSecretRequest,
+    UserInfo, UserLinks, is_valid_ad_tag, is_valid_user_secret, is_valid_username,
+    parse_optional_expiration, random_user_secret,
+};
+
+pub(super) async fn create_user(
+    body: CreateUserRequest,
+    expected_revision: Option<String>,
+    shared: &ApiShared,
+) -> Result<(CreateUserResponse, String), ApiFailure> {
+    let touches_user_ad_tags = body.user_ad_tag.is_some();
+    let touches_user_max_tcp_conns = body.max_tcp_conns.is_some();
+    let touches_user_expirations = body.expiration_rfc3339.is_some();
+    let touches_user_data_quota = body.data_quota_bytes.is_some();
+    let touches_user_max_unique_ips = body.max_unique_ips.is_some();
+
+    if !is_valid_username(&body.username) {
+        return Err(ApiFailure::bad_request(
+            "username must match [A-Za-z0-9_.-] and be 1..64 chars",
+        ));
+    }
+
+    let secret = match body.secret {
+        Some(secret) => {
+            if !is_valid_user_secret(&secret) {
+                return Err(ApiFailure::bad_request(
+                    "secret must be exactly 32 hex characters",
+                ));
+            }
+            secret
+        }
+        None => random_user_secret(),
+    };
+
+    if let Some(ad_tag) = body.user_ad_tag.as_ref() && !is_valid_ad_tag(ad_tag) {
+        return Err(ApiFailure::bad_request(
+            "user_ad_tag must be exactly 32 hex characters",
+        ));
+    }
+
+    let expiration = parse_optional_expiration(body.expiration_rfc3339.as_deref())?;
+    let _guard = shared.mutation_lock.lock().await;
+    let mut cfg = load_config_from_disk(&shared.config_path).await?;
+    ensure_expected_revision(&shared.config_path, expected_revision.as_deref()).await?;
+
+    if cfg.access.users.contains_key(&body.username) {
+        return Err(ApiFailure::new(
+            StatusCode::CONFLICT,
+            "user_exists",
+            "User already exists",
+        ));
+    }
+
+    cfg.access.users.insert(body.username.clone(), secret.clone());
+    if let Some(ad_tag) = body.user_ad_tag {
+        cfg.access.user_ad_tags.insert(body.username.clone(), ad_tag);
+    }
+    if let Some(limit) = body.max_tcp_conns {
+        cfg.access.user_max_tcp_conns.insert(body.username.clone(), limit);
+    }
+    if let Some(expiration) = expiration {
+        cfg.access
+            .user_expirations
+            .insert(body.username.clone(), expiration);
+    }
+    if let Some(quota) = body.data_quota_bytes {
+        cfg.access.user_data_quota.insert(body.username.clone(), quota);
+    }
+
+    let updated_limit = body.max_unique_ips;
+    if let Some(limit) = updated_limit {
+        cfg.access
+            .user_max_unique_ips
+            .insert(body.username.clone(), limit);
+    }
+
+    cfg.validate()
+        .map_err(|e| ApiFailure::bad_request(format!("config validation failed: {}", e)))?;
+
+    let mut touched_sections = vec![AccessSection::Users];
+    if touches_user_ad_tags {
+        touched_sections.push(AccessSection::UserAdTags);
+    }
+    if touches_user_max_tcp_conns {
+        touched_sections.push(AccessSection::UserMaxTcpConns);
+    }
+    if touches_user_expirations {
+        touched_sections.push(AccessSection::UserExpirations);
+    }
+    if touches_user_data_quota {
+        touched_sections.push(AccessSection::UserDataQuota);
+    }
+    if touches_user_max_unique_ips {
+        touched_sections.push(AccessSection::UserMaxUniqueIps);
+    }
+
+    let revision = save_access_sections_to_disk(&shared.config_path, &cfg, &touched_sections).await?;
+    drop(_guard);
+
+    if let Some(limit) = updated_limit {
+        shared.ip_tracker.set_user_limit(&body.username, limit).await;
+    }
+    let (detected_ip_v4, detected_ip_v6) = shared.detected_link_ips();
+
+    let users = users_from_config(
+        &cfg,
+        &shared.stats,
+        &shared.ip_tracker,
+        detected_ip_v4,
+        detected_ip_v6,
+    )
+    .await;
+    let user = users
+        .into_iter()
+        .find(|entry| entry.username == body.username)
+        .unwrap_or(UserInfo {
+            username: body.username.clone(),
+            user_ad_tag: None,
+            max_tcp_conns: None,
+            expiration_rfc3339: None,
+            data_quota_bytes: None,
+            max_unique_ips: updated_limit,
+            current_connections: 0,
+            active_unique_ips: 0,
+            active_unique_ips_list: Vec::new(),
+            recent_unique_ips: 0,
+            recent_unique_ips_list: Vec::new(),
+            total_octets: 0,
+            links: build_user_links(
+                &cfg,
+                &secret,
+                detected_ip_v4,
+                detected_ip_v6,
+            ),
+        });
+
+    Ok((CreateUserResponse { user, secret }, revision))
+}
+
+pub(super) async fn patch_user(
+    user: &str,
+    body: PatchUserRequest,
+    expected_revision: Option<String>,
+    shared: &ApiShared,
+) -> Result<(UserInfo, String), ApiFailure> {
+    if let Some(secret) = body.secret.as_ref() && !is_valid_user_secret(secret) {
+        return Err(ApiFailure::bad_request(
+            "secret must be exactly 32 hex characters",
+        ));
+    }
+    if let Some(ad_tag) = body.user_ad_tag.as_ref() && !is_valid_ad_tag(ad_tag) {
+        return Err(ApiFailure::bad_request(
+            "user_ad_tag must be exactly 32 hex characters",
+        ));
+    }
+    let expiration = parse_optional_expiration(body.expiration_rfc3339.as_deref())?;
+    let _guard = shared.mutation_lock.lock().await;
+    let mut cfg = load_config_from_disk(&shared.config_path).await?;
+    ensure_expected_revision(&shared.config_path, expected_revision.as_deref()).await?;
+
+    if !cfg.access.users.contains_key(user) {
+        return Err(ApiFailure::new(
+            StatusCode::NOT_FOUND,
+            "not_found",
+            "User not found",
+        ));
+    }
+
+    if let Some(secret) = body.secret {
+        cfg.access.users.insert(user.to_string(), secret);
+    }
+    if let Some(ad_tag) = body.user_ad_tag {
+        cfg.access.user_ad_tags.insert(user.to_string(), ad_tag);
+    }
+    if let Some(limit) = body.max_tcp_conns {
+        cfg.access.user_max_tcp_conns.insert(user.to_string(), limit);
+    }
+    if let Some(expiration) = expiration {
+        cfg.access.user_expirations.insert(user.to_string(), expiration);
+    }
+    if let Some(quota) = body.data_quota_bytes {
+        cfg.access.user_data_quota.insert(user.to_string(), quota);
+    }
+
+    let mut updated_limit = None;
+    if let Some(limit) = body.max_unique_ips {
+        cfg.access.user_max_unique_ips.insert(user.to_string(), limit);
+        updated_limit = Some(limit);
+    }
+
+    cfg.validate()
+        .map_err(|e| ApiFailure::bad_request(format!("config validation failed: {}", e)))?;
+
+    let revision = save_config_to_disk(&shared.config_path, &cfg).await?;
+    drop(_guard);
+    if let Some(limit) = updated_limit {
+        shared.ip_tracker.set_user_limit(user, limit).await;
+    }
+    let (detected_ip_v4, detected_ip_v6) = shared.detected_link_ips();
+    let users = users_from_config(
+        &cfg,
+        &shared.stats,
+        &shared.ip_tracker,
+        detected_ip_v4,
+        detected_ip_v6,
+    )
+    .await;
+    let user_info = users
+        .into_iter()
+        .find(|entry| entry.username == user)
+        .ok_or_else(|| ApiFailure::internal("failed to build updated user view"))?;
+
+    Ok((user_info, revision))
+}
+
+pub(super) async fn rotate_secret(
+    user: &str,
+    body: RotateSecretRequest,
+    expected_revision: Option<String>,
+    shared: &ApiShared,
+) -> Result<(CreateUserResponse, String), ApiFailure> {
+    let secret = body.secret.unwrap_or_else(random_user_secret);
+    if !is_valid_user_secret(&secret) {
+        return Err(ApiFailure::bad_request(
+            "secret must be exactly 32 hex characters",
+        ));
+    }
+
+    let _guard = shared.mutation_lock.lock().await;
+    let mut cfg = load_config_from_disk(&shared.config_path).await?;
+    ensure_expected_revision(&shared.config_path, expected_revision.as_deref()).await?;
+
+    if !cfg.access.users.contains_key(user) {
+        return Err(ApiFailure::new(
+            StatusCode::NOT_FOUND,
+            "not_found",
+            "User not found",
+        ));
+    }
+
+    cfg.access.users.insert(user.to_string(), secret.clone());
+    cfg.validate()
+        .map_err(|e| ApiFailure::bad_request(format!("config validation failed: {}", e)))?;
+    let touched_sections = [
+        AccessSection::Users,
+        AccessSection::UserAdTags,
+        AccessSection::UserMaxTcpConns,
+        AccessSection::UserExpirations,
+        AccessSection::UserDataQuota,
+        AccessSection::UserMaxUniqueIps,
+    ];
+    let revision = save_access_sections_to_disk(&shared.config_path, &cfg, &touched_sections).await?;
+    drop(_guard);
+
+    let (detected_ip_v4, detected_ip_v6) = shared.detected_link_ips();
+    let users = users_from_config(
+        &cfg,
+        &shared.stats,
+        &shared.ip_tracker,
+        detected_ip_v4,
+        detected_ip_v6,
+    )
+    .await;
+    let user_info = users
+        .into_iter()
+        .find(|entry| entry.username == user)
+        .ok_or_else(|| ApiFailure::internal("failed to build updated user view"))?;
+
+    Ok((
+        CreateUserResponse {
+            user: user_info,
+            secret,
+        },
+        revision,
+    ))
+}
+
+pub(super) async fn delete_user(
+    user: &str,
+    expected_revision: Option<String>,
+    shared: &ApiShared,
+) -> Result<(String, String), ApiFailure> {
+    let _guard = shared.mutation_lock.lock().await;
+    let mut cfg = load_config_from_disk(&shared.config_path).await?;
+    ensure_expected_revision(&shared.config_path, expected_revision.as_deref()).await?;
+
+    if !cfg.access.users.contains_key(user) {
+        return Err(ApiFailure::new(
+            StatusCode::NOT_FOUND,
+            "not_found",
+            "User not found",
+        ));
+    }
+    if cfg.access.users.len() <= 1 {
+        return Err(ApiFailure::new(
+            StatusCode::CONFLICT,
+            "last_user_forbidden",
+            "Cannot delete the last configured user",
+        ));
+    }
+
+    cfg.access.users.remove(user);
+    cfg.access.user_ad_tags.remove(user);
+    cfg.access.user_max_tcp_conns.remove(user);
+    cfg.access.user_expirations.remove(user);
+    cfg.access.user_data_quota.remove(user);
+    cfg.access.user_max_unique_ips.remove(user);
+
+    cfg.validate()
+        .map_err(|e| ApiFailure::bad_request(format!("config validation failed: {}", e)))?;
+    let touched_sections = [
+        AccessSection::Users,
+        AccessSection::UserAdTags,
+        AccessSection::UserMaxTcpConns,
+        AccessSection::UserExpirations,
+        AccessSection::UserDataQuota,
+        AccessSection::UserMaxUniqueIps,
+    ];
+    let revision = save_access_sections_to_disk(&shared.config_path, &cfg, &touched_sections).await?;
+    drop(_guard);
+    shared.ip_tracker.remove_user_limit(user).await;
+    shared.ip_tracker.clear_user_ips(user).await;
+
+    Ok((user.to_string(), revision))
+}
+
+pub(super) async fn users_from_config(
+    cfg: &ProxyConfig,
+    stats: &Stats,
+    ip_tracker: &UserIpTracker,
+    startup_detected_ip_v4: Option<IpAddr>,
+    startup_detected_ip_v6: Option<IpAddr>,
+) -> Vec<UserInfo> {
+    let mut names = cfg.access.users.keys().cloned().collect::<Vec<_>>();
+    names.sort();
+    let active_ip_lists = ip_tracker.get_active_ips_for_users(&names).await;
+    let recent_ip_lists = ip_tracker.get_recent_ips_for_users(&names).await;
+
+    let mut users = Vec::with_capacity(names.len());
+    for username in names {
+        let active_ip_list = active_ip_lists
+            .get(&username)
+            .cloned()
+            .unwrap_or_else(Vec::new);
+        let recent_ip_list = recent_ip_lists
+            .get(&username)
+            .cloned()
+            .unwrap_or_else(Vec::new);
+        let links = cfg
+            .access
+            .users
+            .get(&username)
+            .map(|secret| {
+                build_user_links(
+                    cfg,
+                    secret,
+                    startup_detected_ip_v4,
+                    startup_detected_ip_v6,
+                )
+            })
+            .unwrap_or(UserLinks {
+                classic: Vec::new(),
+                secure: Vec::new(),
+                tls: Vec::new(),
+            });
+        users.push(UserInfo {
+            user_ad_tag: cfg.access.user_ad_tags.get(&username).cloned(),
+            max_tcp_conns: cfg.access.user_max_tcp_conns.get(&username).copied(),
+            expiration_rfc3339: cfg
+                .access
+                .user_expirations
+                .get(&username)
+                .map(chrono::DateTime::<chrono::Utc>::to_rfc3339),
+            data_quota_bytes: cfg.access.user_data_quota.get(&username).copied(),
+            max_unique_ips: cfg.access.user_max_unique_ips.get(&username).copied(),
+            current_connections: stats.get_user_curr_connects(&username),
+            active_unique_ips: active_ip_list.len(),
+            active_unique_ips_list: active_ip_list,
+            recent_unique_ips: recent_ip_list.len(),
+            recent_unique_ips_list: recent_ip_list,
+            total_octets: stats.get_user_total_octets(&username),
+            links,
+            username,
+        });
+    }
+    users
+}
+
+fn build_user_links(
+    cfg: &ProxyConfig,
+    secret: &str,
+    startup_detected_ip_v4: Option<IpAddr>,
+    startup_detected_ip_v6: Option<IpAddr>,
+) -> UserLinks {
+    let hosts = resolve_link_hosts(cfg, startup_detected_ip_v4, startup_detected_ip_v6);
+    let port = cfg.general.links.public_port.unwrap_or(cfg.server.port);
+    let tls_domains = resolve_tls_domains(cfg);
+
+    let mut classic = Vec::new();
+    let mut secure = Vec::new();
+    let mut tls = Vec::new();
+
+    for host in &hosts {
+        if cfg.general.modes.classic {
+            classic.push(format!(
+                "tg://proxy?server={}&port={}&secret={}",
+                host, port, secret
+            ));
+        }
+        if cfg.general.modes.secure {
+            secure.push(format!(
+                "tg://proxy?server={}&port={}&secret=dd{}",
+                host, port, secret
+            ));
+        }
+        if cfg.general.modes.tls {
+            for domain in &tls_domains {
+                let domain_hex = hex::encode(domain);
+                tls.push(format!(
+                    "tg://proxy?server={}&port={}&secret=ee{}{}",
+                    host, port, secret, domain_hex
+                ));
+            }
+        }
+    }
+
+    UserLinks {
+        classic,
+        secure,
+        tls,
+    }
+}
+
+fn resolve_link_hosts(
+    cfg: &ProxyConfig,
+    startup_detected_ip_v4: Option<IpAddr>,
+    startup_detected_ip_v6: Option<IpAddr>,
+) -> Vec<String> {
+    if let Some(host) = cfg
+        .general
+        .links
+        .public_host
+        .as_deref()
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+    {
+        return vec![host.to_string()];
+    }
+
+    let mut hosts = Vec::new();
+    for listener in &cfg.server.listeners {
+        if let Some(host) = listener
+            .announce
+            .as_deref()
+            .map(str::trim)
+            .filter(|value| !value.is_empty())
+        {
+            push_unique_host(&mut hosts, host);
+            continue;
+        }
+        if let Some(ip) = listener.announce_ip {
+            if !ip.is_unspecified() {
+                push_unique_host(&mut hosts, &ip.to_string());
+                continue;
+            }
+        }
+        if listener.ip.is_unspecified() {
+            let detected_ip = if listener.ip.is_ipv4() {
+                startup_detected_ip_v4
+            } else {
+                startup_detected_ip_v6
+            };
+            if let Some(ip) = detected_ip {
+                push_unique_host(&mut hosts, &ip.to_string());
+            } else {
+                push_unique_host(&mut hosts, &listener.ip.to_string());
+            }
+            continue;
+        }
+        push_unique_host(&mut hosts, &listener.ip.to_string());
+    }
+
+    if !hosts.is_empty() {
+        return hosts;
+    }
+
+    if let Some(ip) = startup_detected_ip_v4.or(startup_detected_ip_v6) {
+        return vec![ip.to_string()];
+    }
+
+    if let Some(host) = cfg.server.listen_addr_ipv4.as_deref() {
+        push_host_from_legacy_listen(&mut hosts, host);
+    }
+    if let Some(host) = cfg.server.listen_addr_ipv6.as_deref() {
+        push_host_from_legacy_listen(&mut hosts, host);
+    }
+    if !hosts.is_empty() {
+        return hosts;
+    }
+
+    vec!["UNKNOWN".to_string()]
+}
+
+fn push_host_from_legacy_listen(hosts: &mut Vec<String>, raw: &str) {
+    let candidate = raw.trim();
+    if candidate.is_empty() {
+        return;
+    }
+
+    match candidate.parse::<IpAddr>() {
+        Ok(ip) if ip.is_unspecified() => {}
+        Ok(ip) => push_unique_host(hosts, &ip.to_string()),
+        Err(_) => push_unique_host(hosts, candidate),
+    }
+}
+
+fn push_unique_host(hosts: &mut Vec<String>, candidate: &str) {
+    if !hosts.iter().any(|existing| existing == candidate) {
+        hosts.push(candidate.to_string());
+    }
+}
+
+fn resolve_tls_domains(cfg: &ProxyConfig) -> Vec<&str> {
+    let mut domains = Vec::with_capacity(1 + cfg.censorship.tls_domains.len());
+    let primary = cfg.censorship.tls_domain.as_str();
+    if !primary.is_empty() {
+        domains.push(primary);
+    }
+    for domain in &cfg.censorship.tls_domains {
+        let value = domain.as_str();
+        if value.is_empty() || domains.contains(&value) {
+            continue;
+        }
+        domains.push(value);
+    }
+    domains
+}

src/cli.rs

@@ -0,0 +1,315 @@
+//! CLI commands: --init (fire-and-forget setup)
+
+use std::fs;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+use rand::Rng;
+
+/// Options for the init command
+pub struct InitOptions {
+    pub port: u16,
+    pub domain: String,
+    pub secret: Option<String>,
+    pub username: String,
+    pub config_dir: PathBuf,
+    pub no_start: bool,
+}
+
+impl Default for InitOptions {
+    fn default() -> Self {
+        Self {
+            port: 443,
+            domain: "www.google.com".to_string(),
+            secret: None,
+            username: "user".to_string(),
+            config_dir: PathBuf::from("/etc/telemt"),
+            no_start: false,
+        }
+    }
+}
+
+/// Parse --init subcommand options from CLI args.
+///
+/// Returns `Some(InitOptions)` if `--init` was found, `None` otherwise.
+pub fn parse_init_args(args: &[String]) -> Option<InitOptions> {
+    if !args.iter().any(|a| a == "--init") {
+        return None;
+    }
+    
+    let mut opts = InitOptions::default();
+    let mut i = 0;
+    
+    while i < args.len() {
+        match args[i].as_str() {
+            "--port" => {
+                i += 1;
+                if i < args.len() {
+                    opts.port = args[i].parse().unwrap_or(443);
+                }
+            }
+            "--domain" => {
+                i += 1;
+                if i < args.len() {
+                    opts.domain = args[i].clone();
+                }
+            }
+            "--secret" => {
+                i += 1;
+                if i < args.len() {
+                    opts.secret = Some(args[i].clone());
+                }
+            }
+            "--user" => {
+                i += 1;
+                if i < args.len() {
+                    opts.username = args[i].clone();
+                }
+            }
+            "--config-dir" => {
+                i += 1;
+                if i < args.len() {
+                    opts.config_dir = PathBuf::from(&args[i]);
+                }
+            }
+            "--no-start" => {
+                opts.no_start = true;
+            }
+            _ => {}
+        }
+        i += 1;
+    }
+    
+    Some(opts)
+}
+
+/// Run the fire-and-forget setup.
+pub fn run_init(opts: InitOptions) -> Result<(), Box<dyn std::error::Error>> {
+    eprintln!("[telemt] Fire-and-forget setup");
+    eprintln!();
+    
+    // 1. Generate or validate secret
+    let secret = match opts.secret {
+        Some(s) => {
+            if s.len() != 32 || !s.chars().all(|c| c.is_ascii_hexdigit()) {
+                eprintln!("[error] Secret must be exactly 32 hex characters");
+                std::process::exit(1);
+            }
+            s
+        }
+        None => generate_secret(),
+    };
+    
+    eprintln!("[+] Secret: {}", secret);
+    eprintln!("[+] User:   {}", opts.username);
+    eprintln!("[+] Port:   {}", opts.port);
+    eprintln!("[+] Domain: {}", opts.domain);
+    
+    // 2. Create config directory
+    fs::create_dir_all(&opts.config_dir)?;
+    let config_path = opts.config_dir.join("config.toml");
+    
+    // 3. Write config
+    let config_content = generate_config(&opts.username, &secret, opts.port, &opts.domain);
+    fs::write(&config_path, &config_content)?;
+    eprintln!("[+] Config written to {}", config_path.display());
+    
+    // 4. Write systemd unit
+    let exe_path = std::env::current_exe()
+        .unwrap_or_else(|_| PathBuf::from("/usr/local/bin/telemt"));
+    
+    let unit_path = Path::new("/etc/systemd/system/telemt.service");
+    let unit_content = generate_systemd_unit(&exe_path, &config_path);
+    
+    match fs::write(unit_path, &unit_content) {
+        Ok(()) => {
+            eprintln!("[+] Systemd unit written to {}", unit_path.display());
+        }
+        Err(e) => {
+            eprintln!("[!] Cannot write systemd unit (run as root?): {}", e);
+            eprintln!("[!] Manual unit file content:");
+            eprintln!("{}", unit_content);
+            
+            // Still print links and config
+            print_links(&opts.username, &secret, opts.port, &opts.domain);
+            return Ok(());
+        }
+    }
+    
+    // 5. Reload systemd
+    run_cmd("systemctl", &["daemon-reload"]);
+    
+    // 6. Enable service
+    run_cmd("systemctl", &["enable", "telemt.service"]);
+    eprintln!("[+] Service enabled");
+    
+    // 7. Start service (unless --no-start)
+    if !opts.no_start {
+        run_cmd("systemctl", &["start", "telemt.service"]);
+        eprintln!("[+] Service started");
+        
+        // Brief delay then check status
+        std::thread::sleep(std::time::Duration::from_secs(1));
+        let status = Command::new("systemctl")
+            .args(["is-active", "telemt.service"])
+            .output();
+        
+        match status {
+            Ok(out) if out.status.success() => {
+                eprintln!("[+] Service is running");
+            }
+            _ => {
+                eprintln!("[!] Service may not have started correctly");
+                eprintln!("[!] Check: journalctl -u telemt.service -n 20");
+            }
+        }
+    } else {
+        eprintln!("[+] Service not started (--no-start)");
+        eprintln!("[+] Start manually: systemctl start telemt.service");
+    }
+    
+    eprintln!();
+    
+    // 8. Print links
+    print_links(&opts.username, &secret, opts.port, &opts.domain);
+    
+    Ok(())
+}
+
+fn generate_secret() -> String {
+    let mut rng = rand::rng();
+    let bytes: Vec<u8> = (0..16).map(|_| rng.random::<u8>()).collect();
+    hex::encode(bytes)
+}
+
+fn generate_config(username: &str, secret: &str, port: u16, domain: &str) -> String {
+    format!(
+r#"# Telemt MTProxy — auto-generated config
+# Re-run `telemt --init` to regenerate
+
+show_link = ["{username}"]
+
+[general]
+# prefer_ipv6 is deprecated; use [network].prefer
+prefer_ipv6 = false
+fast_mode = true
+use_middle_proxy = false
+log_level = "normal"
+desync_all_full = false
+update_every = 43200
+hardswap = false
+me_pool_drain_ttl_secs = 90
+me_pool_min_fresh_ratio = 0.8
+me_reinit_drain_timeout_secs = 120
+
+[network]
+ipv4 = true
+ipv6 = true
+prefer = 4
+multipath = false
+
+[general.modes]
+classic = false
+secure = false
+tls = true
+
+[server]
+port = {port}
+listen_addr_ipv4 = "0.0.0.0"
+listen_addr_ipv6 = "::"
+
+[[server.listeners]]
+ip = "0.0.0.0"
+# reuse_allow = false # Set true only when intentionally running multiple telemt instances on same port
+
+[[server.listeners]]
+ip = "::"
+
+[timeouts]
+client_handshake = 15
+tg_connect = 10
+client_keepalive = 60
+client_ack = 300
+
+[censorship]
+tls_domain = "{domain}"
+mask = true
+mask_port = 443
+fake_cert_len = 2048
+tls_full_cert_ttl_secs = 90
+
+[access]
+replay_check_len = 65536
+replay_window_secs = 1800
+ignore_time_skew = false
+
+[access.users]
+{username} = "{secret}"
+
+[[upstreams]]
+type = "direct"
+enabled = true
+weight = 10
+"#,
+        username = username,
+        secret = secret,
+        port = port,
+        domain = domain,
+    )
+}
+
+fn generate_systemd_unit(exe_path: &Path, config_path: &Path) -> String {
+    format!(
+r#"[Unit]
+Description=Telemt MTProxy
+Documentation=https://github.com/nicepkg/telemt
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart={exe} {config}
+Restart=always
+RestartSec=5
+LimitNOFILE=65535
+# Security hardening
+NoNewPrivileges=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/etc/telemt
+PrivateTmp=true
+
+[Install]
+WantedBy=multi-user.target
+"#,
+        exe = exe_path.display(),
+        config = config_path.display(),
+    )
+}
+
+fn run_cmd(cmd: &str, args: &[&str]) {
+    match Command::new(cmd).args(args).output() {
+        Ok(output) => {
+            if !output.status.success() {
+                let stderr = String::from_utf8_lossy(&output.stderr);
+                eprintln!("[!] {} {} failed: {}", cmd, args.join(" "), stderr.trim());
+            }
+        }
+        Err(e) => {
+            eprintln!("[!] Failed to run {} {}: {}", cmd, args.join(" "), e);
+        }
+    }
+}
+
+fn print_links(username: &str, secret: &str, port: u16, domain: &str) {
+    let domain_hex = hex::encode(domain);
+    
+    println!("=== Proxy Links ===");
+    println!("[{}]", username);
+    println!("  EE-TLS:  tg://proxy?server=YOUR_SERVER_IP&port={}&secret=ee{}{}", 
+        port, secret, domain_hex);
+    println!();
+    println!("Replace YOUR_SERVER_IP with your server's public IP.");
+    println!("The proxy will auto-detect and display the correct link on startup.");
+    println!("Check: journalctl -u telemt.service | head -30");
+    println!("===================");
+}

src/config/defaults.rs

@@ -0,0 +1,666 @@
+use std::collections::HashMap;
+use ipnetwork::IpNetwork;
+use serde::Deserialize;
+
+// Helper defaults kept private to the config module.
+const DEFAULT_NETWORK_IPV6: Option<bool> = Some(false);
+const DEFAULT_STUN_TCP_FALLBACK: bool = true;
+const DEFAULT_MIDDLE_PROXY_WARM_STANDBY: usize = 16;
+const DEFAULT_ME_RECONNECT_MAX_CONCURRENT_PER_DC: u32 = 8;
+const DEFAULT_ME_RECONNECT_FAST_RETRY_COUNT: u32 = 16;
+const DEFAULT_ME_SINGLE_ENDPOINT_SHADOW_WRITERS: u8 = 2;
+const DEFAULT_ME_ADAPTIVE_FLOOR_IDLE_SECS: u64 = 90;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MIN_WRITERS_SINGLE_ENDPOINT: u8 = 1;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MIN_WRITERS_MULTI_ENDPOINT: u8 = 1;
+const DEFAULT_ME_ADAPTIVE_FLOOR_RECOVER_GRACE_SECS: u64 = 180;
+const DEFAULT_ME_ADAPTIVE_FLOOR_WRITERS_PER_CORE_TOTAL: u16 = 48;
+const DEFAULT_ME_ADAPTIVE_FLOOR_CPU_CORES_OVERRIDE: u16 = 0;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MAX_EXTRA_WRITERS_SINGLE_PER_CORE: u16 = 1;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MAX_EXTRA_WRITERS_MULTI_PER_CORE: u16 = 2;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MAX_ACTIVE_WRITERS_PER_CORE: u16 = 64;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MAX_WARM_WRITERS_PER_CORE: u16 = 64;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MAX_ACTIVE_WRITERS_GLOBAL: u32 = 256;
+const DEFAULT_ME_ADAPTIVE_FLOOR_MAX_WARM_WRITERS_GLOBAL: u32 = 256;
+const DEFAULT_ME_WRITER_CMD_CHANNEL_CAPACITY: usize = 4096;
+const DEFAULT_ME_ROUTE_CHANNEL_CAPACITY: usize = 768;
+const DEFAULT_ME_C2ME_CHANNEL_CAPACITY: usize = 1024;
+const DEFAULT_ME_READER_ROUTE_DATA_WAIT_MS: u64 = 2;
+const DEFAULT_ME_D2C_FLUSH_BATCH_MAX_FRAMES: usize = 32;
+const DEFAULT_ME_D2C_FLUSH_BATCH_MAX_BYTES: usize = 128 * 1024;
+const DEFAULT_ME_D2C_FLUSH_BATCH_MAX_DELAY_US: u64 = 1500;
+const DEFAULT_ME_D2C_ACK_FLUSH_IMMEDIATE: bool = false;
+const DEFAULT_DIRECT_RELAY_COPY_BUF_C2S_BYTES: usize = 64 * 1024;
+const DEFAULT_DIRECT_RELAY_COPY_BUF_S2C_BYTES: usize = 256 * 1024;
+const DEFAULT_ME_WRITER_PICK_SAMPLE_SIZE: u8 = 3;
+const DEFAULT_ME_HEALTH_INTERVAL_MS_UNHEALTHY: u64 = 1000;
+const DEFAULT_ME_HEALTH_INTERVAL_MS_HEALTHY: u64 = 3000;
+const DEFAULT_ME_ADMISSION_POLL_MS: u64 = 1000;
+const DEFAULT_ME_WARN_RATE_LIMIT_MS: u64 = 5000;
+const DEFAULT_USER_MAX_UNIQUE_IPS_WINDOW_SECS: u64 = 30;
+const DEFAULT_UPSTREAM_CONNECT_RETRY_ATTEMPTS: u32 = 2;
+const DEFAULT_UPSTREAM_UNHEALTHY_FAIL_THRESHOLD: u32 = 5;
+const DEFAULT_UPSTREAM_CONNECT_BUDGET_MS: u64 = 3000;
+const DEFAULT_LISTEN_ADDR_IPV6: &str = "::";
+const DEFAULT_ACCESS_USER: &str = "default";
+const DEFAULT_ACCESS_SECRET: &str = "00000000000000000000000000000000";
+
+pub(crate) fn default_true() -> bool {
+    true
+}
+
+pub(crate) fn default_port() -> u16 {
+    443
+}
+
+pub(crate) fn default_tls_domain() -> String {
+    "petrovich.ru".to_string()
+}
+
+pub(crate) fn default_mask_port() -> u16 {
+    443
+}
+
+pub(crate) fn default_fake_cert_len() -> usize {
+    2048
+}
+
+pub(crate) fn default_tls_front_dir() -> String {
+    "tlsfront".to_string()
+}
+
+pub(crate) fn default_replay_check_len() -> usize {
+    65_536
+}
+
+pub(crate) fn default_replay_window_secs() -> u64 {
+    1800
+}
+
+pub(crate) fn default_handshake_timeout() -> u64 {
+    30
+}
+
+pub(crate) fn default_connect_timeout() -> u64 {
+    10
+}
+
+pub(crate) fn default_keepalive() -> u64 {
+    60
+}
+
+pub(crate) fn default_ack_timeout() -> u64 {
+    300
+}
+pub(crate) fn default_me_one_retry() -> u8 {
+    12
+}
+
+pub(crate) fn default_me_one_timeout() -> u64 {
+    1200
+}
+
+pub(crate) fn default_listen_addr() -> String {
+    "0.0.0.0".to_string()
+}
+
+pub(crate) fn default_listen_addr_ipv4() -> Option<String> {
+    Some(default_listen_addr())
+}
+
+pub(crate) fn default_weight() -> u16 {
+    1
+}
+
+pub(crate) fn default_metrics_whitelist() -> Vec<IpNetwork> {
+    vec![
+        "127.0.0.1/32".parse().unwrap(),
+        "::1/128".parse().unwrap(),
+    ]
+}
+
+pub(crate) fn default_api_listen() -> String {
+    "0.0.0.0:9091".to_string()
+}
+
+pub(crate) fn default_api_whitelist() -> Vec<IpNetwork> {
+    vec!["127.0.0.0/8".parse().unwrap()]
+}
+
+pub(crate) fn default_api_request_body_limit_bytes() -> usize {
+    64 * 1024
+}
+
+pub(crate) fn default_api_minimal_runtime_enabled() -> bool {
+    true
+}
+
+pub(crate) fn default_api_minimal_runtime_cache_ttl_ms() -> u64 {
+    1000
+}
+
+pub(crate) fn default_api_runtime_edge_enabled() -> bool { false }
+pub(crate) fn default_api_runtime_edge_cache_ttl_ms() -> u64 { 1000 }
+pub(crate) fn default_api_runtime_edge_top_n() -> usize { 10 }
+pub(crate) fn default_api_runtime_edge_events_capacity() -> usize { 256 }
+
+pub(crate) fn default_proxy_protocol_header_timeout_ms() -> u64 {
+    500
+}
+
+pub(crate) fn default_prefer_4() -> u8 {
+    4
+}
+
+pub(crate) fn default_network_ipv6() -> Option<bool> {
+    DEFAULT_NETWORK_IPV6
+}
+
+pub(crate) fn default_stun_tcp_fallback() -> bool {
+    DEFAULT_STUN_TCP_FALLBACK
+}
+
+pub(crate) fn default_unknown_dc_log_path() -> Option<String> {
+    Some("unknown-dc.txt".to_string())
+}
+
+pub(crate) fn default_unknown_dc_file_log_enabled() -> bool {
+    false
+}
+
+pub(crate) fn default_pool_size() -> usize {
+    8
+}
+
+pub(crate) fn default_proxy_secret_path() -> Option<String> {
+    Some("proxy-secret".to_string())
+}
+
+pub(crate) fn default_proxy_config_v4_cache_path() -> Option<String> {
+    Some("cache/proxy-config-v4.txt".to_string())
+}
+
+pub(crate) fn default_proxy_config_v6_cache_path() -> Option<String> {
+    Some("cache/proxy-config-v6.txt".to_string())
+}
+
+pub(crate) fn default_middle_proxy_nat_stun() -> Option<String> {
+    None
+}
+
+pub(crate) fn default_middle_proxy_nat_stun_servers() -> Vec<String> {
+    Vec::new()
+}
+
+pub(crate) fn default_stun_nat_probe_concurrency() -> usize {
+    8
+}
+
+pub(crate) fn default_middle_proxy_warm_standby() -> usize {
+    DEFAULT_MIDDLE_PROXY_WARM_STANDBY
+}
+
+pub(crate) fn default_me_init_retry_attempts() -> u32 {
+    0
+}
+
+pub(crate) fn default_me2dc_fallback() -> bool {
+    true
+}
+
+pub(crate) fn default_keepalive_interval() -> u64 {
+    8
+}
+
+pub(crate) fn default_keepalive_jitter() -> u64 {
+    2
+}
+
+pub(crate) fn default_warmup_step_delay_ms() -> u64 {
+    500
+}
+
+pub(crate) fn default_warmup_step_jitter_ms() -> u64 {
+    300
+}
+
+pub(crate) fn default_reconnect_backoff_base_ms() -> u64 {
+    500
+}
+
+pub(crate) fn default_reconnect_backoff_cap_ms() -> u64 {
+    30_000
+}
+
+pub(crate) fn default_me_reconnect_max_concurrent_per_dc() -> u32 {
+    DEFAULT_ME_RECONNECT_MAX_CONCURRENT_PER_DC
+}
+
+pub(crate) fn default_me_reconnect_fast_retry_count() -> u32 {
+    DEFAULT_ME_RECONNECT_FAST_RETRY_COUNT
+}
+
+pub(crate) fn default_me_single_endpoint_shadow_writers() -> u8 {
+    DEFAULT_ME_SINGLE_ENDPOINT_SHADOW_WRITERS
+}
+
+pub(crate) fn default_me_single_endpoint_outage_mode_enabled() -> bool {
+    true
+}
+
+pub(crate) fn default_me_single_endpoint_outage_disable_quarantine() -> bool {
+    true
+}
+
+pub(crate) fn default_me_single_endpoint_outage_backoff_min_ms() -> u64 {
+    250
+}
+
+pub(crate) fn default_me_single_endpoint_outage_backoff_max_ms() -> u64 {
+    3000
+}
+
+pub(crate) fn default_me_single_endpoint_shadow_rotate_every_secs() -> u64 {
+    900
+}
+
+pub(crate) fn default_me_adaptive_floor_idle_secs() -> u64 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_IDLE_SECS
+}
+
+pub(crate) fn default_me_adaptive_floor_min_writers_single_endpoint() -> u8 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MIN_WRITERS_SINGLE_ENDPOINT
+}
+
+pub(crate) fn default_me_adaptive_floor_min_writers_multi_endpoint() -> u8 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MIN_WRITERS_MULTI_ENDPOINT
+}
+
+pub(crate) fn default_me_adaptive_floor_recover_grace_secs() -> u64 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_RECOVER_GRACE_SECS
+}
+
+pub(crate) fn default_me_adaptive_floor_writers_per_core_total() -> u16 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_WRITERS_PER_CORE_TOTAL
+}
+
+pub(crate) fn default_me_adaptive_floor_cpu_cores_override() -> u16 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_CPU_CORES_OVERRIDE
+}
+
+pub(crate) fn default_me_adaptive_floor_max_extra_writers_single_per_core() -> u16 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MAX_EXTRA_WRITERS_SINGLE_PER_CORE
+}
+
+pub(crate) fn default_me_adaptive_floor_max_extra_writers_multi_per_core() -> u16 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MAX_EXTRA_WRITERS_MULTI_PER_CORE
+}
+
+pub(crate) fn default_me_adaptive_floor_max_active_writers_per_core() -> u16 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MAX_ACTIVE_WRITERS_PER_CORE
+}
+
+pub(crate) fn default_me_adaptive_floor_max_warm_writers_per_core() -> u16 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MAX_WARM_WRITERS_PER_CORE
+}
+
+pub(crate) fn default_me_adaptive_floor_max_active_writers_global() -> u32 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MAX_ACTIVE_WRITERS_GLOBAL
+}
+
+pub(crate) fn default_me_adaptive_floor_max_warm_writers_global() -> u32 {
+    DEFAULT_ME_ADAPTIVE_FLOOR_MAX_WARM_WRITERS_GLOBAL
+}
+
+pub(crate) fn default_me_writer_cmd_channel_capacity() -> usize {
+    DEFAULT_ME_WRITER_CMD_CHANNEL_CAPACITY
+}
+
+pub(crate) fn default_me_route_channel_capacity() -> usize {
+    DEFAULT_ME_ROUTE_CHANNEL_CAPACITY
+}
+
+pub(crate) fn default_me_c2me_channel_capacity() -> usize {
+    DEFAULT_ME_C2ME_CHANNEL_CAPACITY
+}
+
+pub(crate) fn default_me_reader_route_data_wait_ms() -> u64 {
+    DEFAULT_ME_READER_ROUTE_DATA_WAIT_MS
+}
+
+pub(crate) fn default_me_d2c_flush_batch_max_frames() -> usize {
+    DEFAULT_ME_D2C_FLUSH_BATCH_MAX_FRAMES
+}
+
+pub(crate) fn default_me_d2c_flush_batch_max_bytes() -> usize {
+    DEFAULT_ME_D2C_FLUSH_BATCH_MAX_BYTES
+}
+
+pub(crate) fn default_me_d2c_flush_batch_max_delay_us() -> u64 {
+    DEFAULT_ME_D2C_FLUSH_BATCH_MAX_DELAY_US
+}
+
+pub(crate) fn default_me_d2c_ack_flush_immediate() -> bool {
+    DEFAULT_ME_D2C_ACK_FLUSH_IMMEDIATE
+}
+
+pub(crate) fn default_direct_relay_copy_buf_c2s_bytes() -> usize {
+    DEFAULT_DIRECT_RELAY_COPY_BUF_C2S_BYTES
+}
+
+pub(crate) fn default_direct_relay_copy_buf_s2c_bytes() -> usize {
+    DEFAULT_DIRECT_RELAY_COPY_BUF_S2C_BYTES
+}
+
+pub(crate) fn default_me_writer_pick_sample_size() -> u8 {
+    DEFAULT_ME_WRITER_PICK_SAMPLE_SIZE
+}
+
+pub(crate) fn default_me_health_interval_ms_unhealthy() -> u64 {
+    DEFAULT_ME_HEALTH_INTERVAL_MS_UNHEALTHY
+}
+
+pub(crate) fn default_me_health_interval_ms_healthy() -> u64 {
+    DEFAULT_ME_HEALTH_INTERVAL_MS_HEALTHY
+}
+
+pub(crate) fn default_me_admission_poll_ms() -> u64 {
+    DEFAULT_ME_ADMISSION_POLL_MS
+}
+
+pub(crate) fn default_me_warn_rate_limit_ms() -> u64 {
+    DEFAULT_ME_WARN_RATE_LIMIT_MS
+}
+
+pub(crate) fn default_upstream_connect_retry_attempts() -> u32 {
+    DEFAULT_UPSTREAM_CONNECT_RETRY_ATTEMPTS
+}
+
+pub(crate) fn default_upstream_connect_retry_backoff_ms() -> u64 {
+    100
+}
+
+pub(crate) fn default_upstream_unhealthy_fail_threshold() -> u32 {
+    DEFAULT_UPSTREAM_UNHEALTHY_FAIL_THRESHOLD
+}
+
+pub(crate) fn default_upstream_connect_budget_ms() -> u64 {
+    DEFAULT_UPSTREAM_CONNECT_BUDGET_MS
+}
+
+pub(crate) fn default_upstream_connect_failfast_hard_errors() -> bool {
+    false
+}
+
+pub(crate) fn default_rpc_proxy_req_every() -> u64 {
+    0
+}
+
+pub(crate) fn default_crypto_pending_buffer() -> usize {
+    256 * 1024
+}
+
+pub(crate) fn default_max_client_frame() -> usize {
+    16 * 1024 * 1024
+}
+
+pub(crate) fn default_desync_all_full() -> bool {
+    false
+}
+
+pub(crate) fn default_me_route_backpressure_base_timeout_ms() -> u64 {
+    25
+}
+
+pub(crate) fn default_me_route_backpressure_high_timeout_ms() -> u64 {
+    120
+}
+
+pub(crate) fn default_me_route_backpressure_high_watermark_pct() -> u8 {
+    80
+}
+
+pub(crate) fn default_me_route_no_writer_wait_ms() -> u64 {
+    250
+}
+
+pub(crate) fn default_me_route_inline_recovery_attempts() -> u32 {
+    3
+}
+
+pub(crate) fn default_me_route_inline_recovery_wait_ms() -> u64 {
+    3000
+}
+
+pub(crate) fn default_beobachten_minutes() -> u64 {
+    10
+}
+
+pub(crate) fn default_beobachten_flush_secs() -> u64 {
+    15
+}
+
+pub(crate) fn default_beobachten_file() -> String {
+    "cache/beobachten.txt".to_string()
+}
+
+pub(crate) fn default_tls_new_session_tickets() -> u8 {
+    0
+}
+
+pub(crate) fn default_tls_full_cert_ttl_secs() -> u64 {
+    90
+}
+
+pub(crate) fn default_server_hello_delay_min_ms() -> u64 {
+    0
+}
+
+pub(crate) fn default_server_hello_delay_max_ms() -> u64 {
+    0
+}
+
+pub(crate) fn default_alpn_enforce() -> bool {
+    true
+}
+
+pub(crate) fn default_stun_servers() -> Vec<String> {
+    vec![
+        "stun.l.google.com:5349".to_string(),
+        "stun1.l.google.com:3478".to_string(),
+        "stun.gmx.net:3478".to_string(),
+        "stun.l.google.com:19302".to_string(),
+        "stun.1und1.de:3478".to_string(),
+        "stun1.l.google.com:19302".to_string(),
+        "stun2.l.google.com:19302".to_string(),
+        "stun3.l.google.com:19302".to_string(),
+        "stun4.l.google.com:19302".to_string(),
+        "stun.services.mozilla.com:3478".to_string(),
+        "stun.stunprotocol.org:3478".to_string(),
+        "stun.nextcloud.com:3478".to_string(),
+        "stun.voip.eutelia.it:3478".to_string(),
+    ]
+}
+
+pub(crate) fn default_http_ip_detect_urls() -> Vec<String> {
+    vec![
+        "https://ifconfig.me/ip".to_string(),
+        "https://api.ipify.org".to_string(),
+    ]
+}
+
+pub(crate) fn default_cache_public_ip_path() -> String {
+    "cache/public_ip.txt".to_string()
+}
+
+pub(crate) fn default_proxy_secret_reload_secs() -> u64 {
+    60 * 60
+}
+
+pub(crate) fn default_proxy_config_reload_secs() -> u64 {
+    60 * 60
+}
+
+pub(crate) fn default_update_every_secs() -> u64 {
+    5 * 60
+}
+
+pub(crate) fn default_update_every() -> Option<u64> {
+    Some(default_update_every_secs())
+}
+
+pub(crate) fn default_me_reinit_every_secs() -> u64 {
+    15 * 60
+}
+
+pub(crate) fn default_me_reinit_singleflight() -> bool {
+    true
+}
+
+pub(crate) fn default_me_reinit_trigger_channel() -> usize {
+    64
+}
+
+pub(crate) fn default_me_reinit_coalesce_window_ms() -> u64 {
+    200
+}
+
+pub(crate) fn default_me_hardswap_warmup_delay_min_ms() -> u64 {
+    1000
+}
+
+pub(crate) fn default_me_hardswap_warmup_delay_max_ms() -> u64 {
+    2000
+}
+
+pub(crate) fn default_me_hardswap_warmup_extra_passes() -> u8 {
+    3
+}
+
+pub(crate) fn default_me_hardswap_warmup_pass_backoff_base_ms() -> u64 {
+    500
+}
+
+pub(crate) fn default_me_config_stable_snapshots() -> u8 {
+    2
+}
+
+pub(crate) fn default_me_config_apply_cooldown_secs() -> u64 {
+    300
+}
+
+pub(crate) fn default_me_snapshot_require_http_2xx() -> bool {
+    true
+}
+
+pub(crate) fn default_me_snapshot_reject_empty_map() -> bool {
+    true
+}
+
+pub(crate) fn default_me_snapshot_min_proxy_for_lines() -> u32 {
+    1
+}
+
+pub(crate) fn default_proxy_secret_stable_snapshots() -> u8 {
+    2
+}
+
+pub(crate) fn default_proxy_secret_rotate_runtime() -> bool {
+    true
+}
+
+pub(crate) fn default_me_secret_atomic_snapshot() -> bool {
+    true
+}
+
+pub(crate) fn default_proxy_secret_len_max() -> usize {
+    256
+}
+
+pub(crate) fn default_me_reinit_drain_timeout_secs() -> u64 {
+    120
+}
+
+pub(crate) fn default_me_pool_drain_ttl_secs() -> u64 {
+    90
+}
+
+pub(crate) fn default_me_bind_stale_ttl_secs() -> u64 {
+    default_me_pool_drain_ttl_secs()
+}
+
+pub(crate) fn default_me_pool_min_fresh_ratio() -> f32 {
+    0.8
+}
+
+pub(crate) fn default_me_deterministic_writer_sort() -> bool {
+    true
+}
+
+pub(crate) fn default_hardswap() -> bool {
+    true
+}
+
+pub(crate) fn default_ntp_check() -> bool {
+    true
+}
+
+pub(crate) fn default_ntp_servers() -> Vec<String> {
+    vec!["pool.ntp.org".to_string()]
+}
+
+pub(crate) fn default_fast_mode_min_tls_record() -> usize {
+    0
+}
+
+pub(crate) fn default_degradation_min_unavailable_dc_groups() -> u8 {
+    2
+}
+
+pub(crate) fn default_listen_addr_ipv6() -> String {
+    DEFAULT_LISTEN_ADDR_IPV6.to_string()
+}
+
+pub(crate) fn default_listen_addr_ipv6_opt() -> Option<String> {
+    Some(default_listen_addr_ipv6())
+}
+
+pub(crate) fn default_access_users() -> HashMap<String, String> {
+    HashMap::from([(
+        DEFAULT_ACCESS_USER.to_string(),
+        DEFAULT_ACCESS_SECRET.to_string(),
+    )])
+}
+
+pub(crate) fn default_user_max_unique_ips_window_secs() -> u64 {
+    DEFAULT_USER_MAX_UNIQUE_IPS_WINDOW_SECS
+}
+
+// Custom deserializer helpers
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+pub(crate) enum OneOrMany {
+    One(String),
+    Many(Vec<String>),
+}
+
+pub(crate) fn deserialize_dc_overrides<'de, D>(
+    deserializer: D,
+) -> std::result::Result<HashMap<String, Vec<String>>, D::Error>
+where
+    D: serde::de::Deserializer<'de>,
+{
+    let raw: HashMap<String, OneOrMany> = HashMap::deserialize(deserializer)?;
+    let mut out = HashMap::new();
+    for (dc, val) in raw {
+        let mut addrs = match val {
+            OneOrMany::One(s) => vec![s],
+            OneOrMany::Many(v) => v,
+        };
+        addrs.retain(|s| !s.trim().is_empty());
+        if !addrs.is_empty() {
+            out.insert(dc, addrs);
+        }
+    }
+    Ok(out)
+}

src/config/mod.rs

@@ -1,287 +1,9 @@
-//! Configuration
+//! Configuration.
 
-use std::collections::HashMap;
-use std::net::IpAddr;
-use std::path::Path;
-use chrono::{DateTime, Utc};
-use serde::{Deserialize, Serialize};
-use crate::error::{ProxyError, Result};
+pub(crate) mod defaults;
+mod types;
+mod load;
+pub mod hot_reload;
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct ProxyModes {
-    #[serde(default)]
-    pub classic: bool,
-    #[serde(default)]
-    pub secure: bool,
-    #[serde(default = "default_true")]
-    pub tls: bool,
-}
-
-fn default_true() -> bool { true }
-fn default_weight() -> u16 { 1 }
-
-impl Default for ProxyModes {
-    fn default() -> Self {
-        Self { classic: true, secure: true, tls: true }
-    }
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
-#[serde(tag = "type", rename_all = "lowercase")]
-pub enum UpstreamType {
-    Direct {
-        #[serde(default)]
-        interface: Option<String>, // Bind to specific IP/Interface
-    },
-    Socks4 {
-        address: String, // IP:Port of SOCKS server
-        #[serde(default)]
-        interface: Option<String>, // Bind to specific IP/Interface for connection to SOCKS
-        #[serde(default)]
-        user_id: Option<String>,
-    },
-    Socks5 {
-        address: String,
-        #[serde(default)]
-        interface: Option<String>,
-        #[serde(default)]
-        username: Option<String>,
-        #[serde(default)]
-        password: Option<String>,
-    },
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct UpstreamConfig {
-    #[serde(flatten)]
-    pub upstream_type: UpstreamType,
-    #[serde(default = "default_weight")]
-    pub weight: u16,
-    #[serde(default = "default_true")]
-    pub enabled: bool,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct ListenerConfig {
-    pub ip: IpAddr,
-    #[serde(default)]
-    pub announce_ip: Option<IpAddr>, // IP to show in tg:// links
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct ProxyConfig {
-    #[serde(default = "default_port")]
-    pub port: u16,
-    
-    #[serde(default)]
-    pub users: HashMap<String, String>,
-    
-    #[serde(default)]
-    pub ad_tag: Option<String>,
-    
-    #[serde(default)]
-    pub modes: ProxyModes,
-    
-    #[serde(default = "default_tls_domain")]
-    pub tls_domain: String,
-    
-    #[serde(default = "default_true")]
-    pub mask: bool,
-    
-    #[serde(default)]
-    pub mask_host: Option<String>,
-    
-    #[serde(default = "default_mask_port")]
-    pub mask_port: u16,
-    
-    #[serde(default)]
-    pub prefer_ipv6: bool,
-    
-    #[serde(default = "default_true")]
-    pub fast_mode: bool,
-    
-    #[serde(default)]
-    pub use_middle_proxy: bool,
-    
-    #[serde(default)]
-    pub user_max_tcp_conns: HashMap<String, usize>,
-    
-    #[serde(default)]
-    pub user_expirations: HashMap<String, DateTime<Utc>>,
-    
-    #[serde(default)]
-    pub user_data_quota: HashMap<String, u64>,
-    
-    #[serde(default = "default_replay_check_len")]
-    pub replay_check_len: usize,
-    
-    #[serde(default)]
-    pub ignore_time_skew: bool,
-    
-    #[serde(default = "default_handshake_timeout")]
-    pub client_handshake_timeout: u64,
-    
-    #[serde(default = "default_connect_timeout")]
-    pub tg_connect_timeout: u64,
-    
-    #[serde(default = "default_keepalive")]
-    pub client_keepalive: u64,
-    
-    #[serde(default = "default_ack_timeout")]
-    pub client_ack_timeout: u64,
-    
-    #[serde(default = "default_listen_addr")]
-    pub listen_addr_ipv4: String,
-    
-    #[serde(default)]
-    pub listen_addr_ipv6: Option<String>,
-    
-    #[serde(default)]
-    pub listen_unix_sock: Option<String>,
-    
-    #[serde(default)]
-    pub metrics_port: Option<u16>,
-    
-    #[serde(default = "default_metrics_whitelist")]
-    pub metrics_whitelist: Vec<IpAddr>,
-    
-    #[serde(default = "default_fake_cert_len")]
-    pub fake_cert_len: usize,
-
-    // New fields
-    #[serde(default)]
-    pub upstreams: Vec<UpstreamConfig>,
-
-    #[serde(default)]
-    pub listeners: Vec<ListenerConfig>,
-
-    #[serde(default)]
-    pub show_link: Vec<String>,
-}
-
-fn default_port() -> u16 { 443 }
-fn default_tls_domain() -> String { "www.google.com".to_string() }
-fn default_mask_port() -> u16 { 443 }
-fn default_replay_check_len() -> usize { 65536 }
-fn default_handshake_timeout() -> u64 { 10 }
-fn default_connect_timeout() -> u64 { 10 }
-fn default_keepalive() -> u64 { 600 }
-fn default_ack_timeout() -> u64 { 300 }
-fn default_listen_addr() -> String { "0.0.0.0".to_string() }
-fn default_fake_cert_len() -> usize { 2048 }
-
-fn default_metrics_whitelist() -> Vec<IpAddr> {
-    vec![
-        "127.0.0.1".parse().unwrap(),
-        "::1".parse().unwrap(),
-    ]
-}
-
-impl Default for ProxyConfig {
-    fn default() -> Self {
-        let mut users = HashMap::new();
-        users.insert("default".to_string(), "00000000000000000000000000000000".to_string());
-        
-        Self {
-            port: default_port(),
-            users,
-            ad_tag: None,
-            modes: ProxyModes::default(),
-            tls_domain: default_tls_domain(),
-            mask: true,
-            mask_host: None,
-            mask_port: default_mask_port(),
-            prefer_ipv6: false,
-            fast_mode: true,
-            use_middle_proxy: false,
-            user_max_tcp_conns: HashMap::new(),
-            user_expirations: HashMap::new(),
-            user_data_quota: HashMap::new(),
-            replay_check_len: default_replay_check_len(),
-            ignore_time_skew: false,
-            client_handshake_timeout: default_handshake_timeout(),
-            tg_connect_timeout: default_connect_timeout(),
-            client_keepalive: default_keepalive(),
-            client_ack_timeout: default_ack_timeout(),
-            listen_addr_ipv4: default_listen_addr(),
-            listen_addr_ipv6: Some("::".to_string()),
-            listen_unix_sock: None,
-            metrics_port: None,
-            metrics_whitelist: default_metrics_whitelist(),
-            fake_cert_len: default_fake_cert_len(),
-            upstreams: Vec::new(),
-            listeners: Vec::new(),
-            show_link: Vec::new(),
-        }
-    }
-}
-
-impl ProxyConfig {
-    pub fn load<P: AsRef<Path>>(path: P) -> Result<Self> {
-        let content = std::fs::read_to_string(path)
-            .map_err(|e| ProxyError::Config(e.to_string()))?;
-        
-        let mut config: ProxyConfig = toml::from_str(&content)
-            .map_err(|e| ProxyError::Config(e.to_string()))?;
-        
-        // Validate secrets
-        for (user, secret) in &config.users {
-            if !secret.chars().all(|c| c.is_ascii_hexdigit()) || secret.len() != 32 {
-                return Err(ProxyError::InvalidSecret {
-                    user: user.clone(),
-                    reason: "Must be 32 hex characters".to_string(),
-                });
-            }
-        }
-        
-        // Default mask_host
-        if config.mask_host.is_none() {
-            config.mask_host = Some(config.tls_domain.clone());
-        }
-        
-        // Random fake_cert_len
-        use rand::Rng;
-        config.fake_cert_len = rand::thread_rng().gen_range(1024..4096);
-        
-        // Migration: Populate listeners if empty
-        if config.listeners.is_empty() {
-            if let Ok(ipv4) = config.listen_addr_ipv4.parse::<IpAddr>() {
-                config.listeners.push(ListenerConfig {
-                    ip: ipv4,
-                    announce_ip: None,
-                });
-            }
-            if let Some(ipv6_str) = &config.listen_addr_ipv6 {
-                 if let Ok(ipv6) = ipv6_str.parse::<IpAddr>() {
-                    config.listeners.push(ListenerConfig {
-                        ip: ipv6,
-                        announce_ip: None,
-                    });
-                }
-            }
-        }
-
-        // Migration: Populate upstreams if empty (Default Direct)
-        if config.upstreams.is_empty() {
-             config.upstreams.push(UpstreamConfig {
-                upstream_type: UpstreamType::Direct { interface: None },
-                weight: 1,
-                enabled: true,
-            });
-        }
-        
-        Ok(config)
-    }
-    
-    pub fn validate(&self) -> Result<()> {
-        if self.users.is_empty() {
-            return Err(ProxyError::Config("No users configured".to_string()));
-        }
-        
-        if !self.modes.classic && !self.modes.secure && !self.modes.tls {
-            return Err(ProxyError::Config("No modes enabled".to_string()));
-        }
-        
-        Ok(())
-    }
-}
+pub use load::ProxyConfig;
+pub use types::*;

src/crypto/aes.rs

@@ -1,9 +1,21 @@
 //! AES encryption implementations
 //!
 //! Provides AES-256-CTR and AES-256-CBC modes for MTProto encryption.
+//!
+//! ## Zeroize policy
+//!
+//! - `AesCbc` stores raw key/IV bytes and zeroizes them on drop.
+//! - `AesCtr` wraps an opaque `Aes256Ctr` cipher from the `ctr` crate.
+//!   The expanded key schedule lives inside that type and cannot be
+//!   zeroized from outside. Callers that hold raw key material (e.g.
+//!   `HandshakeSuccess`, `ObfuscationParams`) are responsible for
+//!   zeroizing their own copies.
+
+#![allow(dead_code)]
 
 use aes::Aes256;
 use ctr::{Ctr128BE, cipher::{KeyIvInit, StreamCipher}};
+use zeroize::Zeroize;
 use crate::error::{ProxyError, Result};
 
 type Aes256Ctr = Ctr128BE<Aes256>;
@@ -11,8 +23,13 @@ type Aes256Ctr = Ctr128BE<Aes256>;
 // ============= AES-256-CTR =============
 
 /// AES-256-CTR encryptor/decryptor
-/// 
-/// CTR mode is symmetric - encryption and decryption are the same operation.
+///
+/// CTR mode is symmetric — encryption and decryption are the same operation.
+///
+/// **Zeroize note:** The inner `Aes256Ctr` cipher state (expanded key schedule
+///     + counter) is opaque and cannot be zeroized. If you need to protect key
+///     material, zeroize the `[u8; 32]` key and `u128` IV at the call site
+///     before dropping them.
 pub struct AesCtr {
     cipher: Aes256Ctr,
 }
@@ -62,14 +79,23 @@ impl AesCtr {
 
 /// AES-256-CBC cipher with proper chaining
 ///
-/// Unlike CTR mode, CBC is NOT symmetric - encryption and decryption
+/// Unlike CTR mode, CBC is NOT symmetric — encryption and decryption
 /// are different operations. This implementation handles CBC chaining
 /// correctly across multiple blocks.
+///
+/// Key and IV are zeroized on drop.
 pub struct AesCbc {
     key: [u8; 32],
     iv: [u8; 16],
 }
 
+impl Drop for AesCbc {
+    fn drop(&mut self) {
+        self.key.zeroize();
+        self.iv.zeroize();
+    }
+}
+
 impl AesCbc {
     /// AES block size
     const BLOCK_SIZE: usize = 16;
@@ -123,7 +149,7 @@ impl AesCbc {
     ///
     /// CBC Encryption: C[i] = AES_Encrypt(P[i] XOR C[i-1]), where C[-1] = IV
     pub fn encrypt(&self, data: &[u8]) -> Result<Vec<u8>> {
-        if data.len() % Self::BLOCK_SIZE != 0 {
+        if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
             return Err(ProxyError::Crypto(
                 format!("CBC data must be aligned to 16 bytes, got {}", data.len())
             ));
@@ -141,17 +167,9 @@ impl AesCbc {
         
         for chunk in data.chunks(Self::BLOCK_SIZE) {
             let plaintext: [u8; 16] = chunk.try_into().unwrap();
-            
-            // XOR plaintext with previous ciphertext (or IV for first block)
             let xored = Self::xor_blocks(&plaintext, &prev_ciphertext);
-            
-            // Encrypt the XORed block
             let ciphertext = self.encrypt_block(&xored, &key_schedule);
-            
-            // Save for next iteration
             prev_ciphertext = ciphertext;
-            
-            // Append to result
             result.extend_from_slice(&ciphertext);
         }
         
@@ -162,7 +180,7 @@ impl AesCbc {
     ///
     /// CBC Decryption: P[i] = AES_Decrypt(C[i]) XOR C[i-1], where C[-1] = IV
     pub fn decrypt(&self, data: &[u8]) -> Result<Vec<u8>> {
-        if data.len() % Self::BLOCK_SIZE != 0 {
+        if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
             return Err(ProxyError::Crypto(
                 format!("CBC data must be aligned to 16 bytes, got {}", data.len())
             ));
@@ -180,17 +198,9 @@ impl AesCbc {
         
         for chunk in data.chunks(Self::BLOCK_SIZE) {
             let ciphertext: [u8; 16] = chunk.try_into().unwrap();
-            
-            // Decrypt the block
             let decrypted = self.decrypt_block(&ciphertext, &key_schedule);
-            
-            // XOR with previous ciphertext (or IV for first block)
             let plaintext = Self::xor_blocks(&decrypted, &prev_ciphertext);
-            
-            // Save current ciphertext for next iteration
             prev_ciphertext = ciphertext;
-            
-            // Append to result
             result.extend_from_slice(&plaintext);
         }
         
@@ -199,7 +209,7 @@ impl AesCbc {
     
     /// Encrypt data in-place
     pub fn encrypt_in_place(&self, data: &mut [u8]) -> Result<()> {
-        if data.len() % Self::BLOCK_SIZE != 0 {
+        if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
             return Err(ProxyError::Crypto(
                 format!("CBC data must be aligned to 16 bytes, got {}", data.len())
             ));
@@ -217,16 +227,13 @@ impl AesCbc {
         for i in (0..data.len()).step_by(Self::BLOCK_SIZE) {
             let block = &mut data[i..i + Self::BLOCK_SIZE];
             
-            // XOR with previous ciphertext
             for j in 0..Self::BLOCK_SIZE {
                 block[j] ^= prev_ciphertext[j];
             }
             
-            // Encrypt in-place
             let block_array: &mut [u8; 16] = block.try_into().unwrap();
             *block_array = self.encrypt_block(block_array, &key_schedule);
             
-            // Save for next iteration
             prev_ciphertext = *block_array;
         }
         
@@ -235,7 +242,7 @@ impl AesCbc {
     
     /// Decrypt data in-place
     pub fn decrypt_in_place(&self, data: &mut [u8]) -> Result<()> {
-        if data.len() % Self::BLOCK_SIZE != 0 {
+        if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
             return Err(ProxyError::Crypto(
                 format!("CBC data must be aligned to 16 bytes, got {}", data.len())
             ));
@@ -248,26 +255,20 @@ impl AesCbc {
         use aes::cipher::KeyInit;
         let key_schedule = aes::Aes256::new((&self.key).into());
         
-        // For in-place decryption, we need to save ciphertext blocks
-        // before we overwrite them
         let mut prev_ciphertext = self.iv;
         
         for i in (0..data.len()).step_by(Self::BLOCK_SIZE) {
             let block = &mut data[i..i + Self::BLOCK_SIZE];
             
-            // Save current ciphertext before modifying
             let current_ciphertext: [u8; 16] = block.try_into().unwrap();
             
-            // Decrypt in-place
             let block_array: &mut [u8; 16] = block.try_into().unwrap();
             *block_array = self.decrypt_block(block_array, &key_schedule);
             
-            // XOR with previous ciphertext
             for j in 0..Self::BLOCK_SIZE {
                 block[j] ^= prev_ciphertext[j];
             }
             
-            // Save for next iteration
             prev_ciphertext = current_ciphertext;
         }
         
@@ -347,10 +348,8 @@ mod tests {
         let mut cipher = AesCtr::new(&key, iv);
         cipher.apply(&mut data);
         
-        // Encrypted should be different
         assert_ne!(&data[..], original);
         
-        // Decrypt with fresh cipher
         let mut cipher = AesCtr::new(&key, iv);
         cipher.apply(&mut data);
         
@@ -364,7 +363,7 @@ mod tests {
         let key = [0u8; 32];
         let iv = [0u8; 16];
         
-        let original = [0u8; 32]; // 2 blocks
+        let original = [0u8; 32];
         
         let cipher = AesCbc::new(key, iv);
         let encrypted = cipher.encrypt(&original).unwrap();
@@ -375,31 +374,25 @@ mod tests {
     
     #[test]
     fn test_aes_cbc_chaining_works() {
-        // This is the key test - verify CBC chaining is correct
         let key = [0x42u8; 32];
         let iv = [0x00u8; 16];
         
-        // Two IDENTICAL plaintext blocks
         let plaintext = [0xAAu8; 32];
         
         let cipher = AesCbc::new(key, iv);
         let ciphertext = cipher.encrypt(&plaintext).unwrap();
         
-        // With proper CBC, identical plaintext blocks produce DIFFERENT ciphertext
         let block1 = &ciphertext[0..16];
         let block2 = &ciphertext[16..32];
         
         assert_ne!(
             block1, block2,
-            "CBC chaining broken: identical plaintext blocks produced identical ciphertext. \
-             This indicates ECB mode, not CBC!"
+            "CBC chaining broken: identical plaintext blocks produced identical ciphertext"
         );
     }
     
     #[test]
     fn test_aes_cbc_known_vector() {
-        // Test with known NIST test vector
-        // AES-256-CBC with zero key and zero IV
         let key = [0u8; 32];
         let iv = [0u8; 16];
         let plaintext = [0u8; 16];
@@ -407,11 +400,9 @@ mod tests {
         let cipher = AesCbc::new(key, iv);
         let ciphertext = cipher.encrypt(&plaintext).unwrap();
         
-        // Decrypt and verify roundtrip
         let decrypted = cipher.decrypt(&ciphertext).unwrap();
         assert_eq!(plaintext.as_slice(), decrypted.as_slice());
         
-        // Ciphertext should not be all zeros
         assert_ne!(ciphertext.as_slice(), plaintext.as_slice());
     }
     
@@ -420,7 +411,6 @@ mod tests {
         let key = [0x12u8; 32];
         let iv = [0x34u8; 16];
         
-        // 5 blocks = 80 bytes
         let plaintext: Vec<u8> = (0..80).collect();
         
         let cipher = AesCbc::new(key, iv);
@@ -435,7 +425,7 @@ mod tests {
         let key = [0x12u8; 32];
         let iv = [0x34u8; 16];
         
-        let original = [0x56u8; 48]; // 3 blocks
+        let original = [0x56u8; 48];
         let mut buffer = original;
         
         let cipher = AesCbc::new(key, iv);
@@ -462,41 +452,33 @@ mod tests {
     fn test_aes_cbc_unaligned_error() {
         let cipher = AesCbc::new([0u8; 32], [0u8; 16]);
         
-        // 15 bytes - not aligned to block size
         let result = cipher.encrypt(&[0u8; 15]);
         assert!(result.is_err());
         
-        // 17 bytes - not aligned
         let result = cipher.encrypt(&[0u8; 17]);
         assert!(result.is_err());
     }
     
     #[test]
     fn test_aes_cbc_avalanche_effect() {
-        // Changing one bit in plaintext should change entire ciphertext block
-        // and all subsequent blocks (due to chaining)
         let key = [0xAB; 32];
         let iv = [0xCD; 16];
         
-        let mut plaintext1 = [0u8; 32];
+        let plaintext1 = [0u8; 32];
         let mut plaintext2 = [0u8; 32];
-        plaintext2[0] = 0x01; // Single bit difference in first block
+        plaintext2[0] = 0x01;
         
         let cipher = AesCbc::new(key, iv);
         
         let ciphertext1 = cipher.encrypt(&plaintext1).unwrap();
         let ciphertext2 = cipher.encrypt(&plaintext2).unwrap();
         
-        // First blocks should be different
         assert_ne!(&ciphertext1[0..16], &ciphertext2[0..16]);
-        
-        // Second blocks should ALSO be different (chaining effect)
         assert_ne!(&ciphertext1[16..32], &ciphertext2[16..32]);
     }
     
     #[test]
     fn test_aes_cbc_iv_matters() {
-        // Same plaintext with different IVs should produce different ciphertext
         let key = [0x55; 32];
         let plaintext = [0x77u8; 16];
         
@@ -511,7 +493,6 @@ mod tests {
     
     #[test]
     fn test_aes_cbc_deterministic() {
-        // Same key, IV, plaintext should always produce same ciphertext
         let key = [0x99; 32];
         let iv = [0x88; 16];
         let plaintext = [0x77u8; 32];
@@ -524,6 +505,23 @@ mod tests {
         assert_eq!(ciphertext1, ciphertext2);
     }
     
+    // ============= Zeroize Tests =============
+    
+    #[test]
+    fn test_aes_cbc_zeroize_on_drop() {
+        let key = [0xAA; 32];
+        let iv = [0xBB; 16];
+        
+        let cipher = AesCbc::new(key, iv);
+        // Verify key/iv are set
+        assert_eq!(cipher.key, [0xAA; 32]);
+        assert_eq!(cipher.iv, [0xBB; 16]);
+        
+        drop(cipher);
+        // After drop, key/iv are zeroized (can't observe directly,
+        // but the Drop impl runs without panic)
+    }
+    
     // ============= Error Handling Tests =============
     
     #[test]

src/crypto/hash.rs

@@ -1,3 +1,16 @@
+//! Cryptographic hash functions
+//!
+//! ## Protocol-required algorithms
+//!
+//! This module exposes MD5 and SHA-1 alongside SHA-256. These weaker
+//! hash functions are **required by the Telegram Middle Proxy protocol**
+//! (`derive_middleproxy_keys`) and cannot be replaced without breaking
+//! compatibility. They are NOT used for any security-sensitive purpose
+//! outside of that specific key derivation scheme mandated by Telegram.
+//!
+//! Static analysis tools (CodeQL, cargo-audit) may flag them — the
+//! usages are intentional and protocol-mandated.
+
 use hmac::{Hmac, Mac};
 use sha2::Sha256;
 use md5::Md5;
@@ -21,14 +34,16 @@ pub fn sha256_hmac(key: &[u8], data: &[u8]) -> [u8; 32] {
     mac.finalize().into_bytes().into()
 }
 
-/// SHA-1
+/// SHA-1 — **protocol-required** by Telegram Middle Proxy key derivation.
+/// Not used for general-purpose hashing.
 pub fn sha1(data: &[u8]) -> [u8; 20] {
     let mut hasher = Sha1::new();
     hasher.update(data);
     hasher.finalize().into()
 }
 
-/// MD5
+/// MD5 — **protocol-required** by Telegram Middle Proxy key derivation.
+/// Not used for general-purpose hashing.
 pub fn md5(data: &[u8]) -> [u8; 16] {
     let mut hasher = Md5::new();
     hasher.update(data);
@@ -40,7 +55,61 @@ pub fn crc32(data: &[u8]) -> u32 {
     crc32fast::hash(data)
 }
 
-/// Middle Proxy Keygen
+/// CRC32C (Castagnoli)
+pub fn crc32c(data: &[u8]) -> u32 {
+    crc32c::crc32c(data)
+}
+
+/// Build the exact prekey buffer used by Telegram Middle Proxy KDF.
+///
+/// Returned buffer layout (IPv4):
+/// nonce_srv | nonce_clt | clt_ts | srv_ip | clt_port | purpose | clt_ip | srv_port | secret | nonce_srv | [clt_v6 | srv_v6] | nonce_clt
+#[allow(clippy::too_many_arguments)]
+pub fn build_middleproxy_prekey(
+    nonce_srv: &[u8; 16],
+    nonce_clt: &[u8; 16],
+    clt_ts: &[u8; 4],
+    srv_ip: Option<&[u8]>,
+    clt_port: &[u8; 2],
+    purpose: &[u8],
+    clt_ip: Option<&[u8]>,
+    srv_port: &[u8; 2],
+    secret: &[u8],
+    clt_ipv6: Option<&[u8; 16]>,
+    srv_ipv6: Option<&[u8; 16]>,
+) -> Vec<u8> {
+    const EMPTY_IP: [u8; 4] = [0, 0, 0, 0];
+
+    let srv_ip = srv_ip.unwrap_or(&EMPTY_IP);
+    let clt_ip = clt_ip.unwrap_or(&EMPTY_IP);
+
+    let mut s = Vec::with_capacity(256);
+    s.extend_from_slice(nonce_srv);
+    s.extend_from_slice(nonce_clt);
+    s.extend_from_slice(clt_ts);
+    s.extend_from_slice(srv_ip);
+    s.extend_from_slice(clt_port);
+    s.extend_from_slice(purpose);
+    s.extend_from_slice(clt_ip);
+    s.extend_from_slice(srv_port);
+    s.extend_from_slice(secret);
+    s.extend_from_slice(nonce_srv);
+
+    if let (Some(clt_v6), Some(srv_v6)) = (clt_ipv6, srv_ipv6) {
+        s.extend_from_slice(clt_v6);
+        s.extend_from_slice(srv_v6);
+    }
+
+    s.extend_from_slice(nonce_clt);
+    s
+}
+
+/// Middle Proxy key derivation
+///
+/// Uses MD5 + SHA-1 as mandated by the Telegram Middle Proxy protocol.
+/// These algorithms are NOT replaceable here — changing them would break
+/// interoperability with Telegram's middle proxy infrastructure.
+#[allow(clippy::too_many_arguments)]
 pub fn derive_middleproxy_keys(
     nonce_srv: &[u8; 16],
     nonce_clt: &[u8; 16],
@@ -54,30 +123,20 @@ pub fn derive_middleproxy_keys(
     clt_ipv6: Option<&[u8; 16]>,
     srv_ipv6: Option<&[u8; 16]>,
 ) -> ([u8; 32], [u8; 16]) {
-    const EMPTY_IP: [u8; 4] = [0, 0, 0, 0];
-    
-    let srv_ip = srv_ip.unwrap_or(&EMPTY_IP);
-    let clt_ip = clt_ip.unwrap_or(&EMPTY_IP);
-    
-    let mut s = Vec::with_capacity(256);
-    s.extend_from_slice(nonce_srv);
-    s.extend_from_slice(nonce_clt);
-    s.extend_from_slice(clt_ts);
-    s.extend_from_slice(srv_ip);
-    s.extend_from_slice(clt_port);
-    s.extend_from_slice(purpose);
-    s.extend_from_slice(clt_ip);
-    s.extend_from_slice(srv_port);
-    s.extend_from_slice(secret);
-    s.extend_from_slice(nonce_srv);
-    
-    if let (Some(clt_v6), Some(srv_v6)) = (clt_ipv6, srv_ipv6) {
-        s.extend_from_slice(clt_v6);
-        s.extend_from_slice(srv_v6);
-    }
-    
-    s.extend_from_slice(nonce_clt);
-    
+    let s = build_middleproxy_prekey(
+        nonce_srv,
+        nonce_clt,
+        clt_ts,
+        srv_ip,
+        clt_port,
+        purpose,
+        clt_ip,
+        srv_port,
+        secret,
+        clt_ipv6,
+        srv_ipv6,
+    );
+
     let md5_1 = md5(&s[1..]);
     let sha1_sum = sha1(&s);
     let md5_2 = md5(&s[2..]);
@@ -87,4 +146,40 @@ pub fn derive_middleproxy_keys(
     key[12..].copy_from_slice(&sha1_sum);
     
     (key, md5_2)
-}
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn middleproxy_prekey_sha_is_stable() {
+        let nonce_srv = [0x11u8; 16];
+        let nonce_clt = [0x22u8; 16];
+        let clt_ts = 0x44332211u32.to_le_bytes();
+        let srv_ip = Some([149u8, 154, 175, 50].as_ref());
+        let clt_ip = Some([10u8, 0, 0, 1].as_ref());
+        let clt_port = 0x1f90u16.to_le_bytes(); // 8080
+        let srv_port = 0x22b8u16.to_le_bytes(); // 8888
+        let secret = vec![0x55u8; 128];
+
+        let prekey = build_middleproxy_prekey(
+            &nonce_srv,
+            &nonce_clt,
+            &clt_ts,
+            srv_ip,
+            &clt_port,
+            b"CLIENT",
+            clt_ip,
+            &srv_port,
+            &secret,
+            None,
+            None,
+        );
+        let digest = sha256(&prekey);
+        assert_eq!(
+            hex::encode(digest),
+            "934f5facdafd65a44d5c2df90d2f35ddc81faaaeb337949dfeef817c8a7c1e00"
+        );
+    }
+}

src/crypto/mod.rs

@@ -5,5 +5,7 @@ pub mod hash;
 pub mod random;
 
 pub use aes::{AesCtr, AesCbc};
-pub use hash::{sha256, sha256_hmac, sha1, md5, crc32};
-pub use random::{SecureRandom, SECURE_RANDOM};
+pub use hash::{
+    build_middleproxy_prekey, crc32, crc32c, derive_middleproxy_keys, sha256, sha256_hmac,
+};
+pub use random::SecureRandom;

src/crypto/random.rs

@@ -1,55 +1,98 @@
 //! Pseudorandom
 
+#![allow(deprecated)]
+#![allow(dead_code)]
+
 use rand::{Rng, RngCore, SeedableRng};
 use rand::rngs::StdRng;
 use parking_lot::Mutex;
+use zeroize::Zeroize;
 use crate::crypto::AesCtr;
-use once_cell::sync::Lazy;
-
-/// Global secure random instance
-pub static SECURE_RANDOM: Lazy<SecureRandom> = Lazy::new(SecureRandom::new);
 
 /// Cryptographically secure PRNG with AES-CTR
 pub struct SecureRandom {
     inner: Mutex<SecureRandomInner>,
 }
 
+unsafe impl Send for SecureRandom {}
+unsafe impl Sync for SecureRandom {}
+
 struct SecureRandomInner {
     rng: StdRng,
     cipher: AesCtr,
     buffer: Vec<u8>,
+    buffer_start: usize,
+}
+
+impl Drop for SecureRandomInner {
+    fn drop(&mut self) {
+        self.buffer.zeroize();
+    }
 }
 
 impl SecureRandom {
     pub fn new() -> Self {
-        let mut rng = StdRng::from_entropy();
+        let mut seed_source = rand::rng();
+        let mut rng = StdRng::from_rng(&mut seed_source);
         
         let mut key = [0u8; 32];
         rng.fill_bytes(&mut key);
-        let iv: u128 = rng.gen();
+        let iv: u128 = rng.random();
+        
+        let cipher = AesCtr::new(&key, iv);
+        
+        // Zeroize local key copy — cipher already consumed it
+        key.zeroize();
         
         Self {
             inner: Mutex::new(SecureRandomInner {
                 rng,
-                cipher: AesCtr::new(&key, iv),
+                cipher,
                 buffer: Vec::with_capacity(1024),
+                buffer_start: 0,
             }),
         }
     }
     
-    /// Generate random bytes
-    pub fn bytes(&self, len: usize) -> Vec<u8> {
+    /// Fill a caller-provided buffer with random bytes.
+    pub fn fill(&self, out: &mut [u8]) {
         let mut inner = self.inner.lock();
         const CHUNK_SIZE: usize = 512;
-        
-        while inner.buffer.len() < len {
-            let mut chunk = vec![0u8; CHUNK_SIZE];
-            inner.rng.fill_bytes(&mut chunk);
-            inner.cipher.apply(&mut chunk);
-            inner.buffer.extend_from_slice(&chunk);
+
+        let mut written = 0usize;
+        while written < out.len() {
+            if inner.buffer_start >= inner.buffer.len() {
+                inner.buffer.clear();
+                inner.buffer_start = 0;
+            }
+
+            if inner.buffer.is_empty() {
+                let mut chunk = vec![0u8; CHUNK_SIZE];
+                inner.rng.fill_bytes(&mut chunk);
+                inner.cipher.apply(&mut chunk);
+                inner.buffer.extend_from_slice(&chunk);
+                inner.buffer_start = 0;
+            }
+
+            let available = inner.buffer.len().saturating_sub(inner.buffer_start);
+            let take = (out.len() - written).min(available);
+            let start = inner.buffer_start;
+            let end = start + take;
+            out[written..written + take].copy_from_slice(&inner.buffer[start..end]);
+            inner.buffer_start = end;
+            if inner.buffer_start >= inner.buffer.len() {
+                inner.buffer.clear();
+                inner.buffer_start = 0;
+            }
+            written += take;
         }
-        
-        inner.buffer.drain(..len).collect()
+    }
+
+    /// Generate random bytes
+    pub fn bytes(&self, len: usize) -> Vec<u8> {
+        let mut out = vec![0u8; len];
+        self.fill(&mut out);
+        out
     }
     
     /// Generate random number in range [0, max)
@@ -67,7 +110,7 @@ impl SecureRandom {
             return 0;
         }
         
-        let bytes_needed = (k + 7) / 8;
+        let bytes_needed = k.div_ceil(8);
         let bytes = self.bytes(bytes_needed.min(8));
         
         let mut result = 0u64;
@@ -78,7 +121,6 @@ impl SecureRandom {
             result |= (b as u64) << (i * 8);
         }
         
-        // Mask extra bits
         if k < 64 {
             result &= (1u64 << k) - 1;
         }
@@ -107,13 +149,13 @@ impl SecureRandom {
     /// Generate random u32
     pub fn u32(&self) -> u32 {
         let mut inner = self.inner.lock();
-        inner.rng.gen()
+        inner.rng.random()
     }
     
     /// Generate random u64
     pub fn u64(&self) -> u64 {
         let mut inner = self.inner.lock();
-        inner.rng.gen()
+        inner.rng.random()
     }
 }
 
@@ -162,12 +204,10 @@ mod tests {
     fn test_bits() {
         let rng = SecureRandom::new();
         
-        // Single bit should be 0 or 1
         for _ in 0..100 {
             assert!(rng.bits(1) <= 1);
         }
         
-        // 8 bits should be 0-255
         for _ in 0..100 {
             assert!(rng.bits(8) <= 255);
         }
@@ -185,10 +225,8 @@ mod tests {
             }
         }
         
-        // Should have seen all items
         assert_eq!(seen.len(), 5);
         
-        // Empty slice should return None
         let empty: Vec<i32> = vec![];
         assert!(rng.choose(&empty).is_none());
     }
@@ -201,12 +239,10 @@ mod tests {
         let mut shuffled = original.clone();
         rng.shuffle(&mut shuffled);
         
-        // Should contain same elements
         let mut sorted = shuffled.clone();
         sorted.sort();
         assert_eq!(sorted, original);
         
-        // Should be different order (with very high probability)
         assert_ne!(shuffled, original);
     }
-}
+}

src/error.rs

@@ -1,5 +1,7 @@
 //! Error Types
 
+#![allow(dead_code)]
+
 use std::fmt;
 use std::net::SocketAddr;
 use thiserror::Error;
@@ -89,7 +91,7 @@ impl From<StreamError> for std::io::Error {
                 std::io::Error::new(std::io::ErrorKind::UnexpectedEof, err)
             }
             StreamError::Poisoned { .. } => {
-                std::io::Error::new(std::io::ErrorKind::Other, err)
+                std::io::Error::other(err)
             }
             StreamError::BufferOverflow { .. } => {
                 std::io::Error::new(std::io::ErrorKind::OutOfMemory, err)
@@ -98,7 +100,7 @@ impl From<StreamError> for std::io::Error {
                 std::io::Error::new(std::io::ErrorKind::InvalidData, err)
             }
             StreamError::PartialRead { .. } | StreamError::PartialWrite { .. } => {
-                std::io::Error::new(std::io::ErrorKind::Other, err)
+                std::io::Error::other(err)
             }
         }
     }
@@ -118,16 +120,13 @@ pub trait Recoverable {
 impl Recoverable for StreamError {
     fn is_recoverable(&self) -> bool {
         match self {
-            // Partial operations can be retried
             Self::PartialRead { .. } | Self::PartialWrite { .. } => true,
-            // I/O errors depend on kind
             Self::Io(e) => matches!(
                 e.kind(),
                 std::io::ErrorKind::WouldBlock 
                 | std::io::ErrorKind::Interrupted
                 | std::io::ErrorKind::TimedOut
             ),
-            // These are not recoverable
             Self::Poisoned { .. } 
             | Self::BufferOverflow { .. }
             | Self::InvalidFrame { .. }
@@ -136,16 +135,7 @@ impl Recoverable for StreamError {
     }
     
     fn can_continue(&self) -> bool {
-        match self {
-            // Poisoned stream cannot be used
-            Self::Poisoned { .. } => false,
-            // EOF means stream is done
-            Self::UnexpectedEof => false,
-            // Buffer overflow is fatal
-            Self::BufferOverflow { .. } => false,
-            // Others might allow continuation
-            _ => true,
-        }
+        !matches!(self, Self::Poisoned { .. } | Self::UnexpectedEof | Self::BufferOverflow { .. })
     }
 }
 
@@ -297,16 +287,16 @@ pub type StreamResult<T> = std::result::Result<T, StreamError>;
 
 /// Result with optional bad client handling
 #[derive(Debug)]
-pub enum HandshakeResult<T> {
+pub enum HandshakeResult<T, R, W> {
     /// Handshake succeeded
     Success(T),
-    /// Client failed validation, needs masking
-    BadClient,
+    /// Client failed validation, needs masking. Returns ownership of streams.
+    BadClient { reader: R, writer: W },
     /// Error occurred
     Error(ProxyError),
 }
 
-impl<T> HandshakeResult<T> {
+impl<T, R, W> HandshakeResult<T, R, W> {
     /// Check if successful
     pub fn is_success(&self) -> bool {
         matches!(self, HandshakeResult::Success(_))
@@ -314,49 +304,32 @@ impl<T> HandshakeResult<T> {
     
     /// Check if bad client
     pub fn is_bad_client(&self) -> bool {
-        matches!(self, HandshakeResult::BadClient)
-    }
-    
-    /// Convert to Result, treating BadClient as error
-    pub fn into_result(self) -> Result<T> {
-        match self {
-            HandshakeResult::Success(v) => Ok(v),
-            HandshakeResult::BadClient => Err(ProxyError::InvalidHandshake("Bad client".into())),
-            HandshakeResult::Error(e) => Err(e),
-        }
+        matches!(self, HandshakeResult::BadClient { .. })
     }
     
     /// Map the success value
-    pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> HandshakeResult<U> {
+    pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> HandshakeResult<U, R, W> {
         match self {
             HandshakeResult::Success(v) => HandshakeResult::Success(f(v)),
-            HandshakeResult::BadClient => HandshakeResult::BadClient,
+            HandshakeResult::BadClient { reader, writer } => HandshakeResult::BadClient { reader, writer },
             HandshakeResult::Error(e) => HandshakeResult::Error(e),
         }
     }
-    
-    /// Convert success to Option
-    pub fn ok(self) -> Option<T> {
-        match self {
-            HandshakeResult::Success(v) => Some(v),
-            _ => None,
-        }
-    }
 }
 
-impl<T> From<ProxyError> for HandshakeResult<T> {
+impl<T, R, W> From<ProxyError> for HandshakeResult<T, R, W> {
     fn from(err: ProxyError) -> Self {
         HandshakeResult::Error(err)
     }
 }
 
-impl<T> From<std::io::Error> for HandshakeResult<T> {
+impl<T, R, W> From<std::io::Error> for HandshakeResult<T, R, W> {
     fn from(err: std::io::Error) -> Self {
         HandshakeResult::Error(ProxyError::Io(err))
     }
 }
 
-impl<T> From<StreamError> for HandshakeResult<T> {
+impl<T, R, W> From<StreamError> for HandshakeResult<T, R, W> {
     fn from(err: StreamError) -> Self {
         HandshakeResult::Error(ProxyError::Stream(err))
     }
@@ -400,18 +373,18 @@ mod tests {
     
     #[test]
     fn test_handshake_result() {
-        let success: HandshakeResult<i32> = HandshakeResult::Success(42);
+        let success: HandshakeResult<i32, (), ()> = HandshakeResult::Success(42);
         assert!(success.is_success());
         assert!(!success.is_bad_client());
         
-        let bad: HandshakeResult<i32> = HandshakeResult::BadClient;
+        let bad: HandshakeResult<i32, (), ()> = HandshakeResult::BadClient { reader: (), writer: () };
         assert!(!bad.is_success());
         assert!(bad.is_bad_client());
     }
     
     #[test]
     fn test_handshake_result_map() {
-        let success: HandshakeResult<i32> = HandshakeResult::Success(42);
+        let success: HandshakeResult<i32, (), ()> = HandshakeResult::Success(42);
         let mapped = success.map(|x| x * 2);
         
         match mapped {

src/ip_tracker.rs

@@ -0,0 +1,625 @@
+// IP address tracking and per-user unique IP limiting.
+
+#![allow(dead_code)]
+
+use std::collections::HashMap;
+use std::net::IpAddr;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::time::{Duration, Instant};
+
+use tokio::sync::RwLock;
+
+use crate::config::UserMaxUniqueIpsMode;
+
+#[derive(Debug, Clone)]
+pub struct UserIpTracker {
+    active_ips: Arc<RwLock<HashMap<String, HashMap<IpAddr, usize>>>>,
+    recent_ips: Arc<RwLock<HashMap<String, HashMap<IpAddr, Instant>>>>,
+    max_ips: Arc<RwLock<HashMap<String, usize>>>,
+    limit_mode: Arc<RwLock<UserMaxUniqueIpsMode>>,
+    limit_window: Arc<RwLock<Duration>>,
+    last_compact_epoch_secs: Arc<AtomicU64>,
+}
+
+impl UserIpTracker {
+    pub fn new() -> Self {
+        Self {
+            active_ips: Arc::new(RwLock::new(HashMap::new())),
+            recent_ips: Arc::new(RwLock::new(HashMap::new())),
+            max_ips: Arc::new(RwLock::new(HashMap::new())),
+            limit_mode: Arc::new(RwLock::new(UserMaxUniqueIpsMode::ActiveWindow)),
+            limit_window: Arc::new(RwLock::new(Duration::from_secs(30))),
+            last_compact_epoch_secs: Arc::new(AtomicU64::new(0)),
+        }
+    }
+
+    fn now_epoch_secs() -> u64 {
+        std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_secs()
+    }
+
+    async fn maybe_compact_empty_users(&self) {
+        const COMPACT_INTERVAL_SECS: u64 = 60;
+        let now_epoch_secs = Self::now_epoch_secs();
+        let last_compact_epoch_secs = self.last_compact_epoch_secs.load(Ordering::Relaxed);
+        if now_epoch_secs.saturating_sub(last_compact_epoch_secs) < COMPACT_INTERVAL_SECS {
+            return;
+        }
+        if self
+            .last_compact_epoch_secs
+            .compare_exchange(
+                last_compact_epoch_secs,
+                now_epoch_secs,
+                Ordering::AcqRel,
+                Ordering::Relaxed,
+            )
+            .is_err()
+        {
+            return;
+        }
+
+        let mut active_ips = self.active_ips.write().await;
+        let mut recent_ips = self.recent_ips.write().await;
+        let mut users = Vec::<String>::with_capacity(active_ips.len().saturating_add(recent_ips.len()));
+        users.extend(active_ips.keys().cloned());
+        for user in recent_ips.keys() {
+            if !active_ips.contains_key(user) {
+                users.push(user.clone());
+            }
+        }
+
+        for user in users {
+            let active_empty = active_ips.get(&user).map(|ips| ips.is_empty()).unwrap_or(true);
+            let recent_empty = recent_ips.get(&user).map(|ips| ips.is_empty()).unwrap_or(true);
+            if active_empty && recent_empty {
+                active_ips.remove(&user);
+                recent_ips.remove(&user);
+            }
+        }
+    }
+
+    pub async fn set_limit_policy(&self, mode: UserMaxUniqueIpsMode, window_secs: u64) {
+        {
+            let mut current_mode = self.limit_mode.write().await;
+            *current_mode = mode;
+        }
+        let mut current_window = self.limit_window.write().await;
+        *current_window = Duration::from_secs(window_secs.max(1));
+    }
+
+    pub async fn set_user_limit(&self, username: &str, max_ips: usize) {
+        let mut limits = self.max_ips.write().await;
+        limits.insert(username.to_string(), max_ips);
+    }
+
+    pub async fn remove_user_limit(&self, username: &str) {
+        let mut limits = self.max_ips.write().await;
+        limits.remove(username);
+    }
+
+    pub async fn load_limits(&self, limits: &HashMap<String, usize>) {
+        let mut max_ips = self.max_ips.write().await;
+        max_ips.clone_from(limits);
+    }
+
+    fn prune_recent(user_recent: &mut HashMap<IpAddr, Instant>, now: Instant, window: Duration) {
+        if user_recent.is_empty() {
+            return;
+        }
+        user_recent.retain(|_, seen_at| now.duration_since(*seen_at) <= window);
+    }
+
+    pub async fn check_and_add(&self, username: &str, ip: IpAddr) -> Result<(), String> {
+        self.maybe_compact_empty_users().await;
+        let limit = {
+            let max_ips = self.max_ips.read().await;
+            max_ips.get(username).copied()
+        };
+        let mode = *self.limit_mode.read().await;
+        let window = *self.limit_window.read().await;
+        let now = Instant::now();
+
+        let mut active_ips = self.active_ips.write().await;
+        let user_active = active_ips
+            .entry(username.to_string())
+            .or_insert_with(HashMap::new);
+
+        let mut recent_ips = self.recent_ips.write().await;
+        let user_recent = recent_ips
+            .entry(username.to_string())
+            .or_insert_with(HashMap::new);
+        Self::prune_recent(user_recent, now, window);
+
+        if let Some(count) = user_active.get_mut(&ip) {
+            *count = count.saturating_add(1);
+            user_recent.insert(ip, now);
+            return Ok(());
+        }
+
+        if let Some(limit) = limit {
+            let active_limit_reached = user_active.len() >= limit;
+            let recent_limit_reached = user_recent.len() >= limit;
+            let deny = match mode {
+                UserMaxUniqueIpsMode::ActiveWindow => active_limit_reached,
+                UserMaxUniqueIpsMode::TimeWindow => recent_limit_reached,
+                UserMaxUniqueIpsMode::Combined => active_limit_reached || recent_limit_reached,
+            };
+
+            if deny {
+                return Err(format!(
+                    "IP limit reached for user '{}': active={}/{} recent={}/{} mode={:?}",
+                    username,
+                    user_active.len(),
+                    limit,
+                    user_recent.len(),
+                    limit,
+                    mode
+                ));
+            }
+        }
+
+        user_active.insert(ip, 1);
+        user_recent.insert(ip, now);
+        Ok(())
+    }
+
+    pub async fn remove_ip(&self, username: &str, ip: IpAddr) {
+        self.maybe_compact_empty_users().await;
+        let mut active_ips = self.active_ips.write().await;
+        if let Some(user_ips) = active_ips.get_mut(username) {
+            if let Some(count) = user_ips.get_mut(&ip) {
+                if *count > 1 {
+                    *count -= 1;
+                } else {
+                    user_ips.remove(&ip);
+                }
+            }
+            if user_ips.is_empty() {
+                active_ips.remove(username);
+            }
+        }
+    }
+
+    pub async fn get_recent_counts_for_users(&self, users: &[String]) -> HashMap<String, usize> {
+        let window = *self.limit_window.read().await;
+        let now = Instant::now();
+        let recent_ips = self.recent_ips.read().await;
+
+        let mut counts = HashMap::with_capacity(users.len());
+        for user in users {
+            let count = if let Some(user_recent) = recent_ips.get(user) {
+                user_recent
+                    .values()
+                    .filter(|seen_at| now.duration_since(**seen_at) <= window)
+                    .count()
+            } else {
+                0
+            };
+            counts.insert(user.clone(), count);
+        }
+        counts
+    }
+
+    pub async fn get_active_ips_for_users(&self, users: &[String]) -> HashMap<String, Vec<IpAddr>> {
+        let active_ips = self.active_ips.read().await;
+        let mut out = HashMap::with_capacity(users.len());
+        for user in users {
+            let mut ips = active_ips
+                .get(user)
+                .map(|per_ip| per_ip.keys().copied().collect::<Vec<_>>())
+                .unwrap_or_else(Vec::new);
+            ips.sort();
+            out.insert(user.clone(), ips);
+        }
+        out
+    }
+
+    pub async fn get_recent_ips_for_users(&self, users: &[String]) -> HashMap<String, Vec<IpAddr>> {
+        let window = *self.limit_window.read().await;
+        let now = Instant::now();
+        let recent_ips = self.recent_ips.read().await;
+
+        let mut out = HashMap::with_capacity(users.len());
+        for user in users {
+            let mut ips = if let Some(user_recent) = recent_ips.get(user) {
+                user_recent
+                    .iter()
+                    .filter(|(_, seen_at)| now.duration_since(**seen_at) <= window)
+                    .map(|(ip, _)| *ip)
+                    .collect::<Vec<_>>()
+            } else {
+                Vec::new()
+            };
+            ips.sort();
+            out.insert(user.clone(), ips);
+        }
+        out
+    }
+
+    pub async fn get_active_ip_count(&self, username: &str) -> usize {
+        let active_ips = self.active_ips.read().await;
+        active_ips.get(username).map(|ips| ips.len()).unwrap_or(0)
+    }
+
+    pub async fn get_active_ips(&self, username: &str) -> Vec<IpAddr> {
+        let active_ips = self.active_ips.read().await;
+        active_ips
+            .get(username)
+            .map(|ips| ips.keys().copied().collect())
+            .unwrap_or_else(Vec::new)
+    }
+
+    pub async fn get_stats(&self) -> Vec<(String, usize, usize)> {
+        let active_ips = self.active_ips.read().await;
+        let max_ips = self.max_ips.read().await;
+
+        let mut stats = Vec::new();
+        for (username, user_ips) in active_ips.iter() {
+            let limit = max_ips.get(username).copied().unwrap_or(0);
+            stats.push((username.clone(), user_ips.len(), limit));
+        }
+
+        stats.sort_by(|a, b| a.0.cmp(&b.0));
+        stats
+    }
+
+    pub async fn clear_user_ips(&self, username: &str) {
+        let mut active_ips = self.active_ips.write().await;
+        active_ips.remove(username);
+        drop(active_ips);
+
+        let mut recent_ips = self.recent_ips.write().await;
+        recent_ips.remove(username);
+    }
+
+    pub async fn clear_all(&self) {
+        let mut active_ips = self.active_ips.write().await;
+        active_ips.clear();
+        drop(active_ips);
+
+        let mut recent_ips = self.recent_ips.write().await;
+        recent_ips.clear();
+    }
+
+    pub async fn is_ip_active(&self, username: &str, ip: IpAddr) -> bool {
+        let active_ips = self.active_ips.read().await;
+        active_ips
+            .get(username)
+            .map(|ips| ips.contains_key(&ip))
+            .unwrap_or(false)
+    }
+
+    pub async fn get_user_limit(&self, username: &str) -> Option<usize> {
+        let max_ips = self.max_ips.read().await;
+        max_ips.get(username).copied()
+    }
+
+    pub async fn format_stats(&self) -> String {
+        let stats = self.get_stats().await;
+
+        if stats.is_empty() {
+            return String::from("No active users");
+        }
+
+        let mut output = String::from("User IP Statistics:\n");
+        output.push_str("==================\n");
+
+        for (username, active_count, limit) in stats {
+            output.push_str(&format!(
+                "User: {:<20} Active IPs: {}/{}\n",
+                username,
+                active_count,
+                if limit > 0 {
+                    limit.to_string()
+                } else {
+                    "unlimited".to_string()
+                }
+            ));
+
+            let ips = self.get_active_ips(&username).await;
+            for ip in ips {
+                output.push_str(&format!("  - {}\n", ip));
+            }
+        }
+
+        output
+    }
+}
+
+impl Default for UserIpTracker {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+
+    fn test_ipv4(oct1: u8, oct2: u8, oct3: u8, oct4: u8) -> IpAddr {
+        IpAddr::V4(Ipv4Addr::new(oct1, oct2, oct3, oct4))
+    }
+
+    fn test_ipv6() -> IpAddr {
+        IpAddr::V6(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 1))
+    }
+
+    #[tokio::test]
+    async fn test_basic_ip_limit() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 2).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+        let ip3 = test_ipv4(192, 168, 1, 3);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip2).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip3).await.is_err());
+
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 2);
+    }
+
+    #[tokio::test]
+    async fn test_active_window_rejects_new_ip_and_keeps_existing_session() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 1).await;
+        tracker
+            .set_limit_policy(UserMaxUniqueIpsMode::ActiveWindow, 30)
+            .await;
+
+        let ip1 = test_ipv4(10, 10, 10, 1);
+        let ip2 = test_ipv4(10, 10, 10, 2);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.is_ip_active("test_user", ip1).await);
+        assert!(tracker.check_and_add("test_user", ip2).await.is_err());
+
+        // Existing session remains active; only new unique IP is denied.
+        assert!(tracker.is_ip_active("test_user", ip1).await);
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 1);
+    }
+
+    #[tokio::test]
+    async fn test_reconnection_from_same_ip() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 2).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 1);
+    }
+
+    #[tokio::test]
+    async fn test_same_ip_disconnect_keeps_active_while_other_session_alive() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 2).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 1);
+
+        tracker.remove_ip("test_user", ip1).await;
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 1);
+
+        tracker.remove_ip("test_user", ip1).await;
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 0);
+    }
+
+    #[tokio::test]
+    async fn test_ip_removal() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 2).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+        let ip3 = test_ipv4(192, 168, 1, 3);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip2).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip3).await.is_err());
+
+        tracker.remove_ip("test_user", ip1).await;
+
+        assert!(tracker.check_and_add("test_user", ip3).await.is_ok());
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 2);
+    }
+
+    #[tokio::test]
+    async fn test_no_limit() {
+        let tracker = UserIpTracker::new();
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+        let ip3 = test_ipv4(192, 168, 1, 3);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip2).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip3).await.is_ok());
+
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 3);
+    }
+
+    #[tokio::test]
+    async fn test_multiple_users() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("user1", 2).await;
+        tracker.set_user_limit("user2", 1).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+
+        assert!(tracker.check_and_add("user1", ip1).await.is_ok());
+        assert!(tracker.check_and_add("user1", ip2).await.is_ok());
+
+        assert!(tracker.check_and_add("user2", ip1).await.is_ok());
+        assert!(tracker.check_and_add("user2", ip2).await.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_ipv6_support() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 2).await;
+
+        let ipv4 = test_ipv4(192, 168, 1, 1);
+        let ipv6 = test_ipv6();
+
+        assert!(tracker.check_and_add("test_user", ipv4).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ipv6).await.is_ok());
+
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 2);
+    }
+
+    #[tokio::test]
+    async fn test_get_active_ips() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 3).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+
+        tracker.check_and_add("test_user", ip1).await.unwrap();
+        tracker.check_and_add("test_user", ip2).await.unwrap();
+
+        let active_ips = tracker.get_active_ips("test_user").await;
+        assert_eq!(active_ips.len(), 2);
+        assert!(active_ips.contains(&ip1));
+        assert!(active_ips.contains(&ip2));
+    }
+
+    #[tokio::test]
+    async fn test_stats() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("user1", 3).await;
+        tracker.set_user_limit("user2", 2).await;
+
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+
+        tracker.check_and_add("user1", ip1).await.unwrap();
+        tracker.check_and_add("user2", ip2).await.unwrap();
+
+        let stats = tracker.get_stats().await;
+        assert_eq!(stats.len(), 2);
+
+        assert!(stats.iter().any(|(name, _, _)| name == "user1"));
+        assert!(stats.iter().any(|(name, _, _)| name == "user2"));
+    }
+
+    #[tokio::test]
+    async fn test_clear_user_ips() {
+        let tracker = UserIpTracker::new();
+        let ip1 = test_ipv4(192, 168, 1, 1);
+
+        tracker.check_and_add("test_user", ip1).await.unwrap();
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 1);
+
+        tracker.clear_user_ips("test_user").await;
+        assert_eq!(tracker.get_active_ip_count("test_user").await, 0);
+    }
+
+    #[tokio::test]
+    async fn test_is_ip_active() {
+        let tracker = UserIpTracker::new();
+        let ip1 = test_ipv4(192, 168, 1, 1);
+        let ip2 = test_ipv4(192, 168, 1, 2);
+
+        tracker.check_and_add("test_user", ip1).await.unwrap();
+
+        assert!(tracker.is_ip_active("test_user", ip1).await);
+        assert!(!tracker.is_ip_active("test_user", ip2).await);
+    }
+
+    #[tokio::test]
+    async fn test_load_limits_from_config() {
+        let tracker = UserIpTracker::new();
+
+        let mut config_limits = HashMap::new();
+        config_limits.insert("user1".to_string(), 5);
+        config_limits.insert("user2".to_string(), 3);
+
+        tracker.load_limits(&config_limits).await;
+
+        assert_eq!(tracker.get_user_limit("user1").await, Some(5));
+        assert_eq!(tracker.get_user_limit("user2").await, Some(3));
+        assert_eq!(tracker.get_user_limit("user3").await, None);
+    }
+
+    #[tokio::test]
+    async fn test_load_limits_replaces_previous_map() {
+        let tracker = UserIpTracker::new();
+
+        let mut first = HashMap::new();
+        first.insert("user1".to_string(), 2);
+        first.insert("user2".to_string(), 3);
+        tracker.load_limits(&first).await;
+
+        let mut second = HashMap::new();
+        second.insert("user2".to_string(), 5);
+        tracker.load_limits(&second).await;
+
+        assert_eq!(tracker.get_user_limit("user1").await, None);
+        assert_eq!(tracker.get_user_limit("user2").await, Some(5));
+    }
+
+    #[tokio::test]
+    async fn test_time_window_mode_blocks_recent_ip_churn() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 1).await;
+        tracker
+            .set_limit_policy(UserMaxUniqueIpsMode::TimeWindow, 30)
+            .await;
+
+        let ip1 = test_ipv4(10, 0, 0, 1);
+        let ip2 = test_ipv4(10, 0, 0, 2);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        tracker.remove_ip("test_user", ip1).await;
+        assert!(tracker.check_and_add("test_user", ip2).await.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_combined_mode_enforces_active_and_recent_limits() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 1).await;
+        tracker
+            .set_limit_policy(UserMaxUniqueIpsMode::Combined, 30)
+            .await;
+
+        let ip1 = test_ipv4(10, 0, 1, 1);
+        let ip2 = test_ipv4(10, 0, 1, 2);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        assert!(tracker.check_and_add("test_user", ip2).await.is_err());
+
+        tracker.remove_ip("test_user", ip1).await;
+        assert!(tracker.check_and_add("test_user", ip2).await.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_time_window_expires() {
+        let tracker = UserIpTracker::new();
+        tracker.set_user_limit("test_user", 1).await;
+        tracker
+            .set_limit_policy(UserMaxUniqueIpsMode::TimeWindow, 1)
+            .await;
+
+        let ip1 = test_ipv4(10, 1, 0, 1);
+        let ip2 = test_ipv4(10, 1, 0, 2);
+
+        assert!(tracker.check_and_add("test_user", ip1).await.is_ok());
+        tracker.remove_ip("test_user", ip1).await;
+        assert!(tracker.check_and_add("test_user", ip2).await.is_err());
+
+        tokio::time::sleep(Duration::from_millis(1100)).await;
+        assert!(tracker.check_and_add("test_user", ip2).await.is_ok());
+    }
+}

src/maestro/admission.rs

@@ -0,0 +1,130 @@
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+use tokio::sync::watch;
+use tracing::{info, warn};
+
+use crate::config::ProxyConfig;
+use crate::proxy::route_mode::{RelayRouteMode, RouteRuntimeController};
+use crate::transport::middle_proxy::MePool;
+
+const STARTUP_FALLBACK_AFTER: Duration = Duration::from_secs(80);
+const RUNTIME_FALLBACK_AFTER: Duration = Duration::from_secs(6);
+
+pub(crate) async fn configure_admission_gate(
+    config: &Arc<ProxyConfig>,
+    me_pool: Option<Arc<MePool>>,
+    route_runtime: Arc<RouteRuntimeController>,
+    admission_tx: &watch::Sender<bool>,
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+) {
+    if config.general.use_middle_proxy {
+        if let Some(pool) = me_pool.as_ref() {
+            let initial_ready = pool.admission_ready_conditional_cast().await;
+            admission_tx.send_replace(initial_ready);
+            let _ = route_runtime.set_mode(RelayRouteMode::Middle);
+            if initial_ready {
+                info!("Conditional-admission gate: open / ME pool READY");
+            } else {
+                warn!("Conditional-admission gate: closed / ME pool is NOT ready)");
+            }
+
+            let pool_for_gate = pool.clone();
+            let admission_tx_gate = admission_tx.clone();
+            let route_runtime_gate = route_runtime.clone();
+            let mut config_rx_gate = config_rx.clone();
+            let mut admission_poll_ms = config.general.me_admission_poll_ms.max(1);
+            let mut fallback_enabled = config.general.me2dc_fallback;
+            tokio::spawn(async move {
+                let mut gate_open = initial_ready;
+                let mut route_mode = RelayRouteMode::Middle;
+                let mut ready_observed = initial_ready;
+                let mut not_ready_since = if initial_ready {
+                    None
+                } else {
+                    Some(Instant::now())
+                };
+                loop {
+                    tokio::select! {
+                        changed = config_rx_gate.changed() => {
+                            if changed.is_err() {
+                                break;
+                            }
+                            let cfg = config_rx_gate.borrow_and_update().clone();
+                            admission_poll_ms = cfg.general.me_admission_poll_ms.max(1);
+                            fallback_enabled = cfg.general.me2dc_fallback;
+                            continue;
+                        }
+                        _ = tokio::time::sleep(Duration::from_millis(admission_poll_ms)) => {}
+                    }
+                    let ready = pool_for_gate.admission_ready_conditional_cast().await;
+                    let now = Instant::now();
+                    let (next_gate_open, next_route_mode, next_fallback_active) = if ready {
+                        ready_observed = true;
+                        not_ready_since = None;
+                        (true, RelayRouteMode::Middle, false)
+                    } else {
+                        let not_ready_started_at = *not_ready_since.get_or_insert(now);
+                        let not_ready_for = now.saturating_duration_since(not_ready_started_at);
+                        let fallback_after = if ready_observed {
+                            RUNTIME_FALLBACK_AFTER
+                        } else {
+                            STARTUP_FALLBACK_AFTER
+                        };
+                        if fallback_enabled && not_ready_for > fallback_after {
+                            (true, RelayRouteMode::Direct, true)
+                        } else {
+                            (false, RelayRouteMode::Middle, false)
+                        }
+                    };
+
+                    if next_route_mode != route_mode {
+                        route_mode = next_route_mode;
+                        if let Some(snapshot) = route_runtime_gate.set_mode(route_mode) {
+                            if matches!(route_mode, RelayRouteMode::Middle) {
+                                info!(
+                                    target_mode = route_mode.as_str(),
+                                    cutover_generation = snapshot.generation,
+                                    "Middle-End routing restored for new sessions"
+                                );
+                            } else {
+                                let fallback_after = if ready_observed {
+                                    RUNTIME_FALLBACK_AFTER
+                                } else {
+                                    STARTUP_FALLBACK_AFTER
+                                };
+                                warn!(
+                                    target_mode = route_mode.as_str(),
+                                    cutover_generation = snapshot.generation,
+                                    grace_secs = fallback_after.as_secs(),
+                                    "ME pool stayed not-ready beyond grace; routing new sessions via Direct-DC"
+                                );
+                            }
+                        }
+                    }
+
+                    if next_gate_open != gate_open {
+                        gate_open = next_gate_open;
+                        admission_tx_gate.send_replace(gate_open);
+                        if gate_open {
+                            if next_fallback_active {
+                                warn!("Conditional-admission gate opened in ME fallback mode");
+                            } else {
+                                info!("Conditional-admission gate opened / ME pool READY");
+                            }
+                        } else {
+                            warn!("Conditional-admission gate closed / ME pool is NOT ready");
+                        }
+                    }
+                }
+            });
+        } else {
+            admission_tx.send_replace(false);
+            let _ = route_runtime.set_mode(RelayRouteMode::Direct);
+            warn!("Conditional-admission gate: closed / ME pool is UNAVAILABLE");
+        }
+    } else {
+        admission_tx.send_replace(true);
+        let _ = route_runtime.set_mode(RelayRouteMode::Direct);
+    }
+}

src/maestro/connectivity.rs

@@ -0,0 +1,220 @@
+use std::sync::Arc;
+use std::time::Instant;
+
+use tokio::sync::RwLock;
+use tracing::info;
+
+use crate::config::ProxyConfig;
+use crate::crypto::SecureRandom;
+use crate::network::probe::NetworkDecision;
+use crate::startup::{
+    COMPONENT_DC_CONNECTIVITY_PING, COMPONENT_ME_CONNECTIVITY_PING, COMPONENT_RUNTIME_READY,
+    StartupTracker,
+};
+use crate::transport::middle_proxy::{
+    MePingFamily, MePingSample, MePool, format_me_route, format_sample_line, run_me_ping,
+};
+use crate::transport::UpstreamManager;
+
+pub(crate) async fn run_startup_connectivity(
+    config: &Arc<ProxyConfig>,
+    me_pool: &Option<Arc<MePool>>,
+    rng: Arc<SecureRandom>,
+    startup_tracker: &Arc<StartupTracker>,
+    upstream_manager: Arc<UpstreamManager>,
+    prefer_ipv6: bool,
+    decision: &NetworkDecision,
+    process_started_at: Instant,
+    api_me_pool: Arc<RwLock<Option<Arc<MePool>>>>,
+) {
+    if me_pool.is_some() {
+        startup_tracker
+            .start_component(
+                COMPONENT_ME_CONNECTIVITY_PING,
+                Some("run startup ME connectivity check".to_string()),
+            )
+            .await;
+    } else {
+        startup_tracker
+            .skip_component(
+                COMPONENT_ME_CONNECTIVITY_PING,
+                Some("ME pool is not available".to_string()),
+            )
+            .await;
+    }
+    if let Some(pool) = me_pool {
+        let me_results = run_me_ping(pool, &rng).await;
+
+        let v4_ok = me_results.iter().any(|r| {
+            matches!(r.family, MePingFamily::V4)
+                && r.samples.iter().any(|s| s.error.is_none() && s.handshake_ms.is_some())
+        });
+        let v6_ok = me_results.iter().any(|r| {
+            matches!(r.family, MePingFamily::V6)
+                && r.samples.iter().any(|s| s.error.is_none() && s.handshake_ms.is_some())
+        });
+
+        info!("================= Telegram ME Connectivity =================");
+        if v4_ok && v6_ok {
+            info!("  IPv4 and IPv6 available");
+        } else if v4_ok {
+            info!("  IPv4 only / IPv6 unavailable");
+        } else if v6_ok {
+            info!("  IPv6 only / IPv4 unavailable");
+        } else {
+            info!("  No ME connectivity");
+        }
+        let me_route =
+            format_me_route(&config.upstreams, &me_results, prefer_ipv6, v4_ok, v6_ok).await;
+        info!("  via {}", me_route);
+        info!("============================================================");
+
+        use std::collections::BTreeMap;
+        let mut grouped: BTreeMap<i32, Vec<MePingSample>> = BTreeMap::new();
+        for report in me_results {
+            for s in report.samples {
+                grouped.entry(s.dc).or_default().push(s);
+            }
+        }
+
+        let family_order = if prefer_ipv6 {
+            vec![MePingFamily::V6, MePingFamily::V4]
+        } else {
+            vec![MePingFamily::V4, MePingFamily::V6]
+        };
+
+        for (dc, samples) in grouped {
+            for family in &family_order {
+                let fam_samples: Vec<&MePingSample> = samples
+                    .iter()
+                    .filter(|s| matches!(s.family, f if &f == family))
+                    .collect();
+                if fam_samples.is_empty() {
+                    continue;
+                }
+
+                let fam_label = match family {
+                    MePingFamily::V4 => "IPv4",
+                    MePingFamily::V6 => "IPv6",
+                };
+                info!("    DC{} [{}]", dc, fam_label);
+                for sample in fam_samples {
+                    let line = format_sample_line(sample);
+                    info!("{}", line);
+                }
+            }
+        }
+        info!("============================================================");
+        startup_tracker
+            .complete_component(
+                COMPONENT_ME_CONNECTIVITY_PING,
+                Some("startup ME connectivity check completed".to_string()),
+            )
+            .await;
+    }
+
+    info!("================= Telegram DC Connectivity =================");
+    startup_tracker
+        .start_component(
+            COMPONENT_DC_CONNECTIVITY_PING,
+            Some("run startup DC connectivity check".to_string()),
+        )
+        .await;
+
+    let ping_results = upstream_manager
+        .ping_all_dcs(
+            prefer_ipv6,
+            &config.dc_overrides,
+            decision.ipv4_dc,
+            decision.ipv6_dc,
+        )
+        .await;
+
+    for upstream_result in &ping_results {
+        let v6_works = upstream_result.v6_results.iter().any(|r| r.rtt_ms.is_some());
+        let v4_works = upstream_result.v4_results.iter().any(|r| r.rtt_ms.is_some());
+
+        if upstream_result.both_available {
+            if prefer_ipv6 {
+                info!("  IPv6 in use / IPv4 is fallback");
+            } else {
+                info!("  IPv4 in use / IPv6 is fallback");
+            }
+        } else if v6_works && !v4_works {
+            info!("  IPv6 only / IPv4 unavailable");
+        } else if v4_works && !v6_works {
+            info!("  IPv4 only / IPv6 unavailable");
+        } else if !v6_works && !v4_works {
+            info!("  No DC connectivity");
+        }
+
+        info!("  via {}", upstream_result.upstream_name);
+        info!("============================================================");
+
+        if v6_works {
+            for dc in &upstream_result.v6_results {
+                let addr_str = format!("{}:{}", dc.dc_addr.ip(), dc.dc_addr.port());
+                match &dc.rtt_ms {
+                    Some(rtt) => {
+                        info!("    DC{} [IPv6] {} - {:.0} ms", dc.dc_idx, addr_str, rtt);
+                    }
+                    None => {
+                        let err = dc.error.as_deref().unwrap_or("fail");
+                        info!("    DC{} [IPv6] {} - FAIL ({})", dc.dc_idx, addr_str, err);
+                    }
+                }
+            }
+
+            info!("============================================================");
+        }
+
+        if v4_works {
+            for dc in &upstream_result.v4_results {
+                let addr_str = format!("{}:{}", dc.dc_addr.ip(), dc.dc_addr.port());
+                match &dc.rtt_ms {
+                    Some(rtt) => {
+                        info!(
+                            "    DC{} [IPv4] {}\t\t\t\t{:.0} ms",
+                            dc.dc_idx, addr_str, rtt
+                        );
+                    }
+                    None => {
+                        let err = dc.error.as_deref().unwrap_or("fail");
+                        info!(
+                            "    DC{} [IPv4] {}:\t\t\t\tFAIL ({})",
+                            dc.dc_idx, addr_str, err
+                        );
+                    }
+                }
+            }
+
+            info!("============================================================");
+        }
+    }
+    startup_tracker
+        .complete_component(
+            COMPONENT_DC_CONNECTIVITY_PING,
+            Some("startup DC connectivity check completed".to_string()),
+        )
+        .await;
+
+    let initialized_secs = process_started_at.elapsed().as_secs();
+    let second_suffix = if initialized_secs == 1 { "" } else { "s" };
+    startup_tracker
+        .start_component(
+            COMPONENT_RUNTIME_READY,
+            Some("finalize startup runtime state".to_string()),
+        )
+        .await;
+    info!("===================== Telegram Startup =====================");
+    info!(
+        "  DC/ME Initialized in {} second{}",
+        initialized_secs, second_suffix
+    );
+    info!("============================================================");
+
+    if let Some(pool) = me_pool {
+        pool.set_runtime_ready(true);
+    }
+    *api_me_pool.write().await = me_pool.clone();
+}

src/maestro/helpers.rs

@@ -0,0 +1,320 @@
+use std::time::Duration;
+
+use tokio::sync::watch;
+use tracing::{debug, error, info, warn};
+
+use crate::cli;
+use crate::config::ProxyConfig;
+use crate::transport::middle_proxy::{
+    ProxyConfigData, fetch_proxy_config_with_raw, load_proxy_config_cache, save_proxy_config_cache,
+};
+
+pub(crate) fn parse_cli() -> (String, bool, Option<String>) {
+    let mut config_path = "config.toml".to_string();
+    let mut silent = false;
+    let mut log_level: Option<String> = None;
+
+    let args: Vec<String> = std::env::args().skip(1).collect();
+
+    // Check for --init first (handled before tokio)
+    if let Some(init_opts) = cli::parse_init_args(&args) {
+        if let Err(e) = cli::run_init(init_opts) {
+            eprintln!("[telemt] Init failed: {}", e);
+            std::process::exit(1);
+        }
+        std::process::exit(0);
+    }
+
+    let mut i = 0;
+    while i < args.len() {
+        match args[i].as_str() {
+            "--silent" | "-s" => {
+                silent = true;
+            }
+            "--log-level" => {
+                i += 1;
+                if i < args.len() {
+                    log_level = Some(args[i].clone());
+                }
+            }
+            s if s.starts_with("--log-level=") => {
+                log_level = Some(s.trim_start_matches("--log-level=").to_string());
+            }
+            "--help" | "-h" => {
+                eprintln!("Usage: telemt [config.toml] [OPTIONS]");
+                eprintln!();
+                eprintln!("Options:");
+                eprintln!("  --silent, -s            Suppress info logs");
+                eprintln!("  --log-level <LEVEL>     debug|verbose|normal|silent");
+                eprintln!("  --help, -h              Show this help");
+                eprintln!();
+                eprintln!("Setup (fire-and-forget):");
+                eprintln!(
+                    "  --init                  Generate config, install systemd service, start"
+                );
+                eprintln!("    --port <PORT>          Listen port (default: 443)");
+                eprintln!(
+                    "    --domain <DOMAIN>      TLS domain for masking (default: www.google.com)"
+                );
+                eprintln!(
+                    "    --secret <HEX>         32-char hex secret (auto-generated if omitted)"
+                );
+                eprintln!("    --user <NAME>          Username (default: user)");
+                eprintln!("    --config-dir <DIR>     Config directory (default: /etc/telemt)");
+                eprintln!("    --no-start             Don't start the service after install");
+                std::process::exit(0);
+            }
+            "--version" | "-V" => {
+                println!("telemt {}", env!("CARGO_PKG_VERSION"));
+                std::process::exit(0);
+            }
+            s if !s.starts_with('-') => {
+                config_path = s.to_string();
+            }
+            other => {
+                eprintln!("Unknown option: {}", other);
+            }
+        }
+        i += 1;
+    }
+
+    (config_path, silent, log_level)
+}
+
+pub(crate) fn print_proxy_links(host: &str, port: u16, config: &ProxyConfig) {
+    info!(target: "telemt::links", "--- Proxy Links ({}) ---", host);
+    for user_name in config.general.links.show.resolve_users(&config.access.users) {
+        if let Some(secret) = config.access.users.get(user_name) {
+            info!(target: "telemt::links", "User: {}", user_name);
+            if config.general.modes.classic {
+                info!(
+                    target: "telemt::links",
+                    "  Classic: tg://proxy?server={}&port={}&secret={}",
+                    host, port, secret
+                );
+            }
+            if config.general.modes.secure {
+                info!(
+                    target: "telemt::links",
+                    "  DD:      tg://proxy?server={}&port={}&secret=dd{}",
+                    host, port, secret
+                );
+            }
+            if config.general.modes.tls {
+                let mut domains = Vec::with_capacity(1 + config.censorship.tls_domains.len());
+                domains.push(config.censorship.tls_domain.clone());
+                for d in &config.censorship.tls_domains {
+                    if !domains.contains(d) {
+                        domains.push(d.clone());
+                    }
+                }
+
+                for domain in domains {
+                    let domain_hex = hex::encode(&domain);
+                    info!(
+                        target: "telemt::links",
+                        "  EE-TLS:  tg://proxy?server={}&port={}&secret=ee{}{}",
+                        host, port, secret, domain_hex
+                    );
+                }
+            }
+        } else {
+            warn!(target: "telemt::links", "User '{}' in show_link not found", user_name);
+        }
+    }
+    info!(target: "telemt::links", "------------------------");
+}
+
+pub(crate) async fn write_beobachten_snapshot(path: &str, payload: &str) -> std::io::Result<()> {
+    if let Some(parent) = std::path::Path::new(path).parent()
+        && !parent.as_os_str().is_empty()
+    {
+        tokio::fs::create_dir_all(parent).await?;
+    }
+    tokio::fs::write(path, payload).await
+}
+
+pub(crate) fn unit_label(value: u64, singular: &'static str, plural: &'static str) -> &'static str {
+    if value == 1 { singular } else { plural }
+}
+
+pub(crate) fn format_uptime(total_secs: u64) -> String {
+    const SECS_PER_MINUTE: u64 = 60;
+    const SECS_PER_HOUR: u64 = 60 * SECS_PER_MINUTE;
+    const SECS_PER_DAY: u64 = 24 * SECS_PER_HOUR;
+    const SECS_PER_MONTH: u64 = 30 * SECS_PER_DAY;
+    const SECS_PER_YEAR: u64 = 12 * SECS_PER_MONTH;
+
+    let mut remaining = total_secs;
+    let years = remaining / SECS_PER_YEAR;
+    remaining %= SECS_PER_YEAR;
+    let months = remaining / SECS_PER_MONTH;
+    remaining %= SECS_PER_MONTH;
+    let days = remaining / SECS_PER_DAY;
+    remaining %= SECS_PER_DAY;
+    let hours = remaining / SECS_PER_HOUR;
+    remaining %= SECS_PER_HOUR;
+    let minutes = remaining / SECS_PER_MINUTE;
+    let seconds = remaining % SECS_PER_MINUTE;
+
+    let mut parts = Vec::new();
+    if total_secs > SECS_PER_YEAR {
+        parts.push(format!("{} {}", years, unit_label(years, "year", "years")));
+    }
+    if total_secs > SECS_PER_MONTH {
+        parts.push(format!(
+            "{} {}",
+            months,
+            unit_label(months, "month", "months")
+        ));
+    }
+    if total_secs > SECS_PER_DAY {
+        parts.push(format!("{} {}", days, unit_label(days, "day", "days")));
+    }
+    if total_secs > SECS_PER_HOUR {
+        parts.push(format!("{} {}", hours, unit_label(hours, "hour", "hours")));
+    }
+    if total_secs > SECS_PER_MINUTE {
+        parts.push(format!(
+            "{} {}",
+            minutes,
+            unit_label(minutes, "minute", "minutes")
+        ));
+    }
+    parts.push(format!(
+        "{} {}",
+        seconds,
+        unit_label(seconds, "second", "seconds")
+    ));
+
+    format!("{} / {} seconds", parts.join(", "), total_secs)
+}
+
+pub(crate) async fn wait_until_admission_open(admission_rx: &mut watch::Receiver<bool>) -> bool {
+    loop {
+        if *admission_rx.borrow() {
+            return true;
+        }
+        if admission_rx.changed().await.is_err() {
+            return *admission_rx.borrow();
+        }
+    }
+}
+
+pub(crate) fn is_expected_handshake_eof(err: &crate::error::ProxyError) -> bool {
+    err.to_string().contains("expected 64 bytes, got 0")
+}
+
+pub(crate) async fn load_startup_proxy_config_snapshot(
+    url: &str,
+    cache_path: Option<&str>,
+    me2dc_fallback: bool,
+    label: &'static str,
+) -> Option<ProxyConfigData> {
+    loop {
+        match fetch_proxy_config_with_raw(url).await {
+            Ok((cfg, raw)) => {
+                if !cfg.map.is_empty() {
+                    if let Some(path) = cache_path
+                        && let Err(e) = save_proxy_config_cache(path, &raw).await
+                    {
+                        warn!(error = %e, path, snapshot = label, "Failed to store startup proxy-config cache");
+                    }
+                    return Some(cfg);
+                }
+
+                warn!(snapshot = label, url, "Startup proxy-config is empty; trying disk cache");
+                if let Some(path) = cache_path {
+                    match load_proxy_config_cache(path).await {
+                        Ok(cached) if !cached.map.is_empty() => {
+                            info!(
+                                snapshot = label,
+                                path,
+                                proxy_for_lines = cached.proxy_for_lines,
+                                "Loaded startup proxy-config from disk cache"
+                            );
+                            return Some(cached);
+                        }
+                        Ok(_) => {
+                            warn!(
+                                snapshot = label,
+                                path,
+                                "Startup proxy-config cache is empty; ignoring cache file"
+                            );
+                        }
+                        Err(cache_err) => {
+                            debug!(
+                                snapshot = label,
+                                path,
+                                error = %cache_err,
+                                "Startup proxy-config cache unavailable"
+                            );
+                        }
+                    }
+                }
+
+                if me2dc_fallback {
+                    error!(
+                        snapshot = label,
+                        "Startup proxy-config unavailable and no saved config found; falling back to direct mode"
+                    );
+                    return None;
+                }
+
+                warn!(
+                    snapshot = label,
+                    retry_in_secs = 2,
+                    "Startup proxy-config unavailable and no saved config found; retrying because me2dc_fallback=false"
+                );
+                tokio::time::sleep(Duration::from_secs(2)).await;
+            }
+            Err(fetch_err) => {
+                if let Some(path) = cache_path {
+                    match load_proxy_config_cache(path).await {
+                        Ok(cached) if !cached.map.is_empty() => {
+                            info!(
+                                snapshot = label,
+                                path,
+                                proxy_for_lines = cached.proxy_for_lines,
+                                "Loaded startup proxy-config from disk cache"
+                            );
+                            return Some(cached);
+                        }
+                        Ok(_) => {
+                            warn!(
+                                snapshot = label,
+                                path,
+                                "Startup proxy-config cache is empty; ignoring cache file"
+                            );
+                        }
+                        Err(cache_err) => {
+                            debug!(
+                                snapshot = label,
+                                path,
+                                error = %cache_err,
+                                "Startup proxy-config cache unavailable"
+                            );
+                        }
+                    }
+                }
+
+                if me2dc_fallback {
+                    error!(
+                        snapshot = label,
+                        error = %fetch_err,
+                        "Startup proxy-config unavailable and no cached data; falling back to direct mode"
+                    );
+                    return None;
+                }
+
+                warn!(
+                    snapshot = label,
+                    error = %fetch_err,
+                    retry_in_secs = 2,
+                    "Startup proxy-config unavailable; retrying because me2dc_fallback=false"
+                );
+                tokio::time::sleep(Duration::from_secs(2)).await;
+            }
+        }
+    }
+}

src/maestro/listeners.rs

@@ -0,0 +1,465 @@
+use std::error::Error;
+use std::net::{IpAddr, SocketAddr};
+use std::sync::Arc;
+use std::time::Duration;
+
+use tokio::net::TcpListener;
+#[cfg(unix)]
+use tokio::net::UnixListener;
+use tokio::sync::{Semaphore, watch};
+use tracing::{debug, error, info, warn};
+
+use crate::config::ProxyConfig;
+use crate::crypto::SecureRandom;
+use crate::ip_tracker::UserIpTracker;
+use crate::proxy::route_mode::{ROUTE_SWITCH_ERROR_MSG, RouteRuntimeController};
+use crate::proxy::ClientHandler;
+use crate::startup::{COMPONENT_LISTENERS_BIND, StartupTracker};
+use crate::stats::beobachten::BeobachtenStore;
+use crate::stats::{ReplayChecker, Stats};
+use crate::stream::BufferPool;
+use crate::tls_front::TlsFrontCache;
+use crate::transport::middle_proxy::MePool;
+use crate::transport::{
+    ListenOptions, UpstreamManager, create_listener, find_listener_processes,
+};
+
+use super::helpers::{is_expected_handshake_eof, print_proxy_links, wait_until_admission_open};
+
+pub(crate) struct BoundListeners {
+    pub(crate) listeners: Vec<(TcpListener, bool)>,
+    pub(crate) has_unix_listener: bool,
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(crate) async fn bind_listeners(
+    config: &Arc<ProxyConfig>,
+    decision_ipv4_dc: bool,
+    decision_ipv6_dc: bool,
+    detected_ip_v4: Option<IpAddr>,
+    detected_ip_v6: Option<IpAddr>,
+    startup_tracker: &Arc<StartupTracker>,
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+    admission_rx: watch::Receiver<bool>,
+    stats: Arc<Stats>,
+    upstream_manager: Arc<UpstreamManager>,
+    replay_checker: Arc<ReplayChecker>,
+    buffer_pool: Arc<BufferPool>,
+    rng: Arc<SecureRandom>,
+    me_pool: Option<Arc<MePool>>,
+    route_runtime: Arc<RouteRuntimeController>,
+    tls_cache: Option<Arc<TlsFrontCache>>,
+    ip_tracker: Arc<UserIpTracker>,
+    beobachten: Arc<BeobachtenStore>,
+    max_connections: Arc<Semaphore>,
+) -> Result<BoundListeners, Box<dyn Error>> {
+    startup_tracker
+        .start_component(
+            COMPONENT_LISTENERS_BIND,
+            Some("bind TCP/Unix listeners".to_string()),
+        )
+        .await;
+    let mut listeners = Vec::new();
+
+    for listener_conf in &config.server.listeners {
+        let addr = SocketAddr::new(listener_conf.ip, config.server.port);
+        if addr.is_ipv4() && !decision_ipv4_dc {
+            warn!(%addr, "Skipping IPv4 listener: IPv4 disabled by [network]");
+            continue;
+        }
+        if addr.is_ipv6() && !decision_ipv6_dc {
+            warn!(%addr, "Skipping IPv6 listener: IPv6 disabled by [network]");
+            continue;
+        }
+        let options = ListenOptions {
+            reuse_port: listener_conf.reuse_allow,
+            ipv6_only: listener_conf.ip.is_ipv6(),
+            ..Default::default()
+        };
+
+        match create_listener(addr, &options) {
+            Ok(socket) => {
+                let listener = TcpListener::from_std(socket.into())?;
+                info!("Listening on {}", addr);
+                let listener_proxy_protocol =
+                    listener_conf.proxy_protocol.unwrap_or(config.server.proxy_protocol);
+
+                let public_host = if let Some(ref announce) = listener_conf.announce {
+                    announce.clone()
+                } else if listener_conf.ip.is_unspecified() {
+                    if listener_conf.ip.is_ipv4() {
+                        detected_ip_v4
+                            .map(|ip| ip.to_string())
+                            .unwrap_or_else(|| listener_conf.ip.to_string())
+                    } else {
+                        detected_ip_v6
+                            .map(|ip| ip.to_string())
+                            .unwrap_or_else(|| listener_conf.ip.to_string())
+                    }
+                } else {
+                    listener_conf.ip.to_string()
+                };
+
+                if config.general.links.public_host.is_none() && !config.general.links.show.is_empty() {
+                    let link_port = config.general.links.public_port.unwrap_or(config.server.port);
+                    print_proxy_links(&public_host, link_port, config);
+                }
+
+                listeners.push((listener, listener_proxy_protocol));
+            }
+            Err(e) => {
+                if e.kind() == std::io::ErrorKind::AddrInUse {
+                    let owners = find_listener_processes(addr);
+                    if owners.is_empty() {
+                        error!(
+                            %addr,
+                            "Failed to bind: address already in use (owner process unresolved)"
+                        );
+                    } else {
+                        for owner in owners {
+                            error!(
+                                %addr,
+                                pid = owner.pid,
+                                process = %owner.process,
+                                "Failed to bind: address already in use"
+                            );
+                        }
+                    }
+
+                    if !listener_conf.reuse_allow {
+                        error!(
+                            %addr,
+                            "reuse_allow=false; set [[server.listeners]].reuse_allow=true to allow multi-instance listening"
+                        );
+                    }
+                } else {
+                    error!("Failed to bind to {}: {}", addr, e);
+                }
+            }
+        }
+    }
+
+    if !config.general.links.show.is_empty()
+        && (config.general.links.public_host.is_some() || listeners.is_empty())
+    {
+        let (host, port) = if let Some(ref h) = config.general.links.public_host {
+            (
+                h.clone(),
+                config.general.links.public_port.unwrap_or(config.server.port),
+            )
+        } else {
+            let ip = detected_ip_v4
+                .or(detected_ip_v6)
+                .map(|ip| ip.to_string());
+            if ip.is_none() {
+                warn!(
+                    "show_link is configured but public IP could not be detected. Set public_host in config."
+                );
+            }
+            (
+                ip.unwrap_or_else(|| "UNKNOWN".to_string()),
+                config.general.links.public_port.unwrap_or(config.server.port),
+            )
+        };
+
+        print_proxy_links(&host, port, config);
+    }
+
+    let mut has_unix_listener = false;
+    #[cfg(unix)]
+    if let Some(ref unix_path) = config.server.listen_unix_sock {
+        let _ = tokio::fs::remove_file(unix_path).await;
+
+        let unix_listener = UnixListener::bind(unix_path)?;
+
+        if let Some(ref perm_str) = config.server.listen_unix_sock_perm {
+            match u32::from_str_radix(perm_str.trim_start_matches('0'), 8) {
+                Ok(mode) => {
+                    use std::os::unix::fs::PermissionsExt;
+                    let perms = std::fs::Permissions::from_mode(mode);
+                    if let Err(e) = std::fs::set_permissions(unix_path, perms) {
+                        error!("Failed to set unix socket permissions to {}: {}", perm_str, e);
+                    } else {
+                        info!("Listening on unix:{} (mode {})", unix_path, perm_str);
+                    }
+                }
+                Err(e) => {
+                    warn!("Invalid listen_unix_sock_perm '{}': {}. Ignoring.", perm_str, e);
+                    info!("Listening on unix:{}", unix_path);
+                }
+            }
+        } else {
+            info!("Listening on unix:{}", unix_path);
+        }
+
+        has_unix_listener = true;
+
+        let mut config_rx_unix: watch::Receiver<Arc<ProxyConfig>> = config_rx.clone();
+        let mut admission_rx_unix = admission_rx.clone();
+        let stats = stats.clone();
+        let upstream_manager = upstream_manager.clone();
+        let replay_checker = replay_checker.clone();
+        let buffer_pool = buffer_pool.clone();
+        let rng = rng.clone();
+        let me_pool = me_pool.clone();
+        let route_runtime = route_runtime.clone();
+        let tls_cache = tls_cache.clone();
+        let ip_tracker = ip_tracker.clone();
+        let beobachten = beobachten.clone();
+        let max_connections_unix = max_connections.clone();
+
+        tokio::spawn(async move {
+            let unix_conn_counter = Arc::new(std::sync::atomic::AtomicU64::new(1));
+
+            loop {
+                if !wait_until_admission_open(&mut admission_rx_unix).await {
+                    warn!("Conditional-admission gate channel closed for unix listener");
+                    break;
+                }
+                match unix_listener.accept().await {
+                    Ok((stream, _)) => {
+                        let permit = match max_connections_unix.clone().acquire_owned().await {
+                            Ok(permit) => permit,
+                            Err(_) => {
+                                error!("Connection limiter is closed");
+                                break;
+                            }
+                        };
+                        let conn_id =
+                            unix_conn_counter.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+                        let fake_peer =
+                            SocketAddr::from(([127, 0, 0, 1], (conn_id % 65535) as u16));
+
+                        let config = config_rx_unix.borrow_and_update().clone();
+                        let stats = stats.clone();
+                        let upstream_manager = upstream_manager.clone();
+                        let replay_checker = replay_checker.clone();
+                        let buffer_pool = buffer_pool.clone();
+                        let rng = rng.clone();
+                        let me_pool = me_pool.clone();
+                        let route_runtime = route_runtime.clone();
+                        let tls_cache = tls_cache.clone();
+                        let ip_tracker = ip_tracker.clone();
+                        let beobachten = beobachten.clone();
+                        let proxy_protocol_enabled = config.server.proxy_protocol;
+
+                        tokio::spawn(async move {
+                            let _permit = permit;
+                            if let Err(e) = crate::proxy::client::handle_client_stream(
+                                stream,
+                                fake_peer,
+                                config,
+                                stats,
+                                upstream_manager,
+                                replay_checker,
+                                buffer_pool,
+                                rng,
+                                me_pool,
+                                route_runtime,
+                                tls_cache,
+                                ip_tracker,
+                                beobachten,
+                                proxy_protocol_enabled,
+                            )
+                            .await
+                            {
+                                debug!(error = %e, "Unix socket connection error");
+                            }
+                        });
+                    }
+                    Err(e) => {
+                        error!("Unix socket accept error: {}", e);
+                        tokio::time::sleep(Duration::from_millis(100)).await;
+                    }
+                }
+            }
+        });
+    }
+
+    startup_tracker
+        .complete_component(
+            COMPONENT_LISTENERS_BIND,
+            Some(format!(
+                "listeners configured tcp={} unix={}",
+                listeners.len(),
+                has_unix_listener
+            )),
+        )
+        .await;
+
+    Ok(BoundListeners {
+        listeners,
+        has_unix_listener,
+    })
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(crate) fn spawn_tcp_accept_loops(
+    listeners: Vec<(TcpListener, bool)>,
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+    admission_rx: watch::Receiver<bool>,
+    stats: Arc<Stats>,
+    upstream_manager: Arc<UpstreamManager>,
+    replay_checker: Arc<ReplayChecker>,
+    buffer_pool: Arc<BufferPool>,
+    rng: Arc<SecureRandom>,
+    me_pool: Option<Arc<MePool>>,
+    route_runtime: Arc<RouteRuntimeController>,
+    tls_cache: Option<Arc<TlsFrontCache>>,
+    ip_tracker: Arc<UserIpTracker>,
+    beobachten: Arc<BeobachtenStore>,
+    max_connections: Arc<Semaphore>,
+) {
+    for (listener, listener_proxy_protocol) in listeners {
+        let mut config_rx: watch::Receiver<Arc<ProxyConfig>> = config_rx.clone();
+        let mut admission_rx_tcp = admission_rx.clone();
+        let stats = stats.clone();
+        let upstream_manager = upstream_manager.clone();
+        let replay_checker = replay_checker.clone();
+        let buffer_pool = buffer_pool.clone();
+        let rng = rng.clone();
+        let me_pool = me_pool.clone();
+        let route_runtime = route_runtime.clone();
+        let tls_cache = tls_cache.clone();
+        let ip_tracker = ip_tracker.clone();
+        let beobachten = beobachten.clone();
+        let max_connections_tcp = max_connections.clone();
+
+        tokio::spawn(async move {
+            loop {
+                if !wait_until_admission_open(&mut admission_rx_tcp).await {
+                    warn!("Conditional-admission gate channel closed for tcp listener");
+                    break;
+                }
+                match listener.accept().await {
+                    Ok((stream, peer_addr)) => {
+                        let permit = match max_connections_tcp.clone().acquire_owned().await {
+                            Ok(permit) => permit,
+                            Err(_) => {
+                                error!("Connection limiter is closed");
+                                break;
+                            }
+                        };
+                        let config = config_rx.borrow_and_update().clone();
+                        let stats = stats.clone();
+                        let upstream_manager = upstream_manager.clone();
+                        let replay_checker = replay_checker.clone();
+                        let buffer_pool = buffer_pool.clone();
+                        let rng = rng.clone();
+                        let me_pool = me_pool.clone();
+                        let route_runtime = route_runtime.clone();
+                        let tls_cache = tls_cache.clone();
+                        let ip_tracker = ip_tracker.clone();
+                        let beobachten = beobachten.clone();
+                        let proxy_protocol_enabled = listener_proxy_protocol;
+                        let real_peer_report = Arc::new(std::sync::Mutex::new(None));
+                        let real_peer_report_for_handler = real_peer_report.clone();
+
+                        tokio::spawn(async move {
+                            let _permit = permit;
+                            if let Err(e) = ClientHandler::new(
+                                stream,
+                                peer_addr,
+                                config,
+                                stats,
+                                upstream_manager,
+                                replay_checker,
+                                buffer_pool,
+                                rng,
+                                me_pool,
+                                route_runtime,
+                                tls_cache,
+                                ip_tracker,
+                                beobachten,
+                                proxy_protocol_enabled,
+                                real_peer_report_for_handler,
+                            )
+                            .run()
+                            .await
+                            {
+                                let real_peer = match real_peer_report.lock() {
+                                    Ok(guard) => *guard,
+                                    Err(_) => None,
+                                };
+                                let peer_closed = matches!(
+                                    &e,
+                                    crate::error::ProxyError::Io(ioe)
+                                        if matches!(
+                                            ioe.kind(),
+                                            std::io::ErrorKind::ConnectionReset
+                                                | std::io::ErrorKind::ConnectionAborted
+                                                | std::io::ErrorKind::BrokenPipe
+                                                | std::io::ErrorKind::NotConnected
+                                        )
+                                ) || matches!(
+                                    &e,
+                                    crate::error::ProxyError::Stream(
+                                        crate::error::StreamError::Io(ioe)
+                                    )
+                                        if matches!(
+                                            ioe.kind(),
+                                            std::io::ErrorKind::ConnectionReset
+                                                | std::io::ErrorKind::ConnectionAborted
+                                                | std::io::ErrorKind::BrokenPipe
+                                                | std::io::ErrorKind::NotConnected
+                                        )
+                                );
+
+                                let me_closed = matches!(
+                                    &e,
+                                    crate::error::ProxyError::Proxy(msg) if msg == "ME connection lost"
+                                );
+                                let route_switched = matches!(
+                                    &e,
+                                    crate::error::ProxyError::Proxy(msg) if msg == ROUTE_SWITCH_ERROR_MSG
+                                );
+
+                                match (peer_closed, me_closed) {
+                                    (true, _) => {
+                                        if let Some(real_peer) = real_peer {
+                                            debug!(peer = %peer_addr, real_peer = %real_peer, error = %e, "Connection closed by client");
+                                        } else {
+                                            debug!(peer = %peer_addr, error = %e, "Connection closed by client");
+                                        }
+                                    }
+                                    (_, true) => {
+                                        if let Some(real_peer) = real_peer {
+                                            warn!(peer = %peer_addr, real_peer = %real_peer, error = %e, "Connection closed: Middle-End dropped session");
+                                        } else {
+                                            warn!(peer = %peer_addr, error = %e, "Connection closed: Middle-End dropped session");
+                                        }
+                                    }
+                                    _ if route_switched => {
+                                        if let Some(real_peer) = real_peer {
+                                            info!(peer = %peer_addr, real_peer = %real_peer, error = %e, "Connection closed by controlled route cutover");
+                                        } else {
+                                            info!(peer = %peer_addr, error = %e, "Connection closed by controlled route cutover");
+                                        }
+                                    }
+                                    _ if is_expected_handshake_eof(&e) => {
+                                        if let Some(real_peer) = real_peer {
+                                            info!(peer = %peer_addr, real_peer = %real_peer, error = %e, "Connection closed during initial handshake");
+                                        } else {
+                                            info!(peer = %peer_addr, error = %e, "Connection closed during initial handshake");
+                                        }
+                                    }
+                                    _ => {
+                                        if let Some(real_peer) = real_peer {
+                                            warn!(peer = %peer_addr, real_peer = %real_peer, error = %e, "Connection closed with error");
+                                        } else {
+                                            warn!(peer = %peer_addr, error = %e, "Connection closed with error");
+                                        }
+                                    }
+                                }
+                            }
+                        });
+                    }
+                    Err(e) => {
+                        error!("Accept error: {}", e);
+                        tokio::time::sleep(Duration::from_millis(100)).await;
+                    }
+                }
+            }
+        });
+    }
+}

src/maestro/me_startup.rs

@@ -0,0 +1,515 @@
+use std::sync::Arc;
+use std::time::Duration;
+
+use tokio::sync::RwLock;
+use tracing::{error, info, warn};
+
+use crate::config::ProxyConfig;
+use crate::crypto::SecureRandom;
+use crate::network::probe::{NetworkDecision, NetworkProbe};
+use crate::startup::{
+    COMPONENT_ME_POOL_CONSTRUCT, COMPONENT_ME_POOL_INIT_STAGE1, COMPONENT_ME_PROXY_CONFIG_V4,
+    COMPONENT_ME_PROXY_CONFIG_V6, COMPONENT_ME_SECRET_FETCH, StartupMeStatus, StartupTracker,
+};
+use crate::stats::Stats;
+use crate::transport::middle_proxy::MePool;
+use crate::transport::UpstreamManager;
+
+use super::helpers::load_startup_proxy_config_snapshot;
+
+pub(crate) async fn initialize_me_pool(
+    use_middle_proxy: bool,
+    config: &ProxyConfig,
+    decision: &NetworkDecision,
+    probe: &NetworkProbe,
+    startup_tracker: &Arc<StartupTracker>,
+    upstream_manager: Arc<UpstreamManager>,
+    rng: Arc<SecureRandom>,
+    stats: Arc<Stats>,
+    api_me_pool: Arc<RwLock<Option<Arc<MePool>>>>,
+) -> Option<Arc<MePool>> {
+    if !use_middle_proxy {
+        return None;
+    }
+
+    info!("=== Middle Proxy Mode ===");
+    let me_nat_probe = config.general.middle_proxy_nat_probe && config.network.stun_use;
+    if config.general.middle_proxy_nat_probe && !config.network.stun_use {
+        info!("Middle-proxy STUN probing disabled by network.stun_use=false");
+    }
+
+    let me2dc_fallback = config.general.me2dc_fallback;
+    let me_init_retry_attempts = config.general.me_init_retry_attempts;
+    let me_init_warn_after_attempts: u32 = 3;
+
+    // Global ad_tag (pool default). Used when user has no per-user tag in access.user_ad_tags.
+    let proxy_tag = config
+        .general
+        .ad_tag
+        .as_ref()
+        .map(|tag| hex::decode(tag).expect("general.ad_tag must be validated before startup"));
+
+    // =============================================================
+    // CRITICAL: Download Telegram proxy-secret (NOT user secret!)
+    //
+    // C MTProxy uses TWO separate secrets:
+    //   -S flag    = 16-byte user secret for client obfuscation
+    //   --aes-pwd  = 32-512 byte binary file for ME RPC auth
+    //
+    // proxy-secret is from: https://core.telegram.org/getProxySecret
+    // =============================================================
+    let proxy_secret_path = config.general.proxy_secret_path.as_deref();
+    let pool_size = config.general.middle_proxy_pool_size.max(1);
+    let proxy_secret = loop {
+        match crate::transport::middle_proxy::fetch_proxy_secret(
+            proxy_secret_path,
+            config.general.proxy_secret_len_max,
+        )
+        .await
+        {
+            Ok(proxy_secret) => break Some(proxy_secret),
+            Err(e) => {
+                startup_tracker.set_me_last_error(Some(e.to_string())).await;
+                if me2dc_fallback {
+                    error!(
+                        error = %e,
+                        "ME startup failed: proxy-secret is unavailable and no saved secret found; falling back to direct mode"
+                    );
+                    break None;
+                }
+
+                warn!(
+                    error = %e,
+                    retry_in_secs = 2,
+                    "ME startup failed: proxy-secret is unavailable and no saved secret found; retrying because me2dc_fallback=false"
+                );
+                tokio::time::sleep(Duration::from_secs(2)).await;
+            }
+        }
+    };
+    match proxy_secret {
+        Some(proxy_secret) => {
+            startup_tracker
+                .complete_component(
+                    COMPONENT_ME_SECRET_FETCH,
+                    Some("proxy-secret loaded".to_string()),
+                )
+                .await;
+            info!(
+                secret_len = proxy_secret.len(),
+                key_sig = format_args!(
+                    "0x{:08x}",
+                    if proxy_secret.len() >= 4 {
+                        u32::from_le_bytes([
+                            proxy_secret[0],
+                            proxy_secret[1],
+                            proxy_secret[2],
+                            proxy_secret[3],
+                        ])
+                    } else {
+                        0
+                    }
+                ),
+                "Proxy-secret loaded"
+            );
+
+            startup_tracker
+                .start_component(
+                    COMPONENT_ME_PROXY_CONFIG_V4,
+                    Some("load startup proxy-config v4".to_string()),
+                )
+                .await;
+            startup_tracker
+                .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_PROXY_CONFIG_V4)
+                .await;
+            let cfg_v4 = load_startup_proxy_config_snapshot(
+                "https://core.telegram.org/getProxyConfig",
+                config.general.proxy_config_v4_cache_path.as_deref(),
+                me2dc_fallback,
+                "getProxyConfig",
+            )
+            .await;
+            if cfg_v4.is_some() {
+                startup_tracker
+                    .complete_component(
+                        COMPONENT_ME_PROXY_CONFIG_V4,
+                        Some("proxy-config v4 loaded".to_string()),
+                    )
+                    .await;
+            } else {
+                startup_tracker
+                    .fail_component(
+                        COMPONENT_ME_PROXY_CONFIG_V4,
+                        Some("proxy-config v4 unavailable".to_string()),
+                    )
+                    .await;
+            }
+            startup_tracker
+                .start_component(
+                    COMPONENT_ME_PROXY_CONFIG_V6,
+                    Some("load startup proxy-config v6".to_string()),
+                )
+                .await;
+            startup_tracker
+                .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_PROXY_CONFIG_V6)
+                .await;
+            let cfg_v6 = load_startup_proxy_config_snapshot(
+                "https://core.telegram.org/getProxyConfigV6",
+                config.general.proxy_config_v6_cache_path.as_deref(),
+                me2dc_fallback,
+                "getProxyConfigV6",
+            )
+            .await;
+            if cfg_v6.is_some() {
+                startup_tracker
+                    .complete_component(
+                        COMPONENT_ME_PROXY_CONFIG_V6,
+                        Some("proxy-config v6 loaded".to_string()),
+                    )
+                    .await;
+            } else {
+                startup_tracker
+                    .fail_component(
+                        COMPONENT_ME_PROXY_CONFIG_V6,
+                        Some("proxy-config v6 unavailable".to_string()),
+                    )
+                    .await;
+            }
+
+            if let (Some(cfg_v4), Some(cfg_v6)) = (cfg_v4, cfg_v6) {
+                startup_tracker
+                    .start_component(
+                        COMPONENT_ME_POOL_CONSTRUCT,
+                        Some("construct ME pool".to_string()),
+                    )
+                    .await;
+                startup_tracker
+                    .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_POOL_CONSTRUCT)
+                    .await;
+                let pool = MePool::new(
+                    proxy_tag.clone(),
+                    proxy_secret,
+                    config.general.middle_proxy_nat_ip,
+                    me_nat_probe,
+                    None,
+                    config.network.stun_servers.clone(),
+                    config.general.stun_nat_probe_concurrency,
+                    probe.detected_ipv6,
+                    config.timeouts.me_one_retry,
+                    config.timeouts.me_one_timeout_ms,
+                    cfg_v4.map.clone(),
+                    cfg_v6.map.clone(),
+                    cfg_v4.default_dc.or(cfg_v6.default_dc),
+                    decision.clone(),
+                    Some(upstream_manager.clone()),
+                    rng.clone(),
+                    stats.clone(),
+                    config.general.me_keepalive_enabled,
+                    config.general.me_keepalive_interval_secs,
+                    config.general.me_keepalive_jitter_secs,
+                    config.general.me_keepalive_payload_random,
+                    config.general.rpc_proxy_req_every,
+                    config.general.me_warmup_stagger_enabled,
+                    config.general.me_warmup_step_delay_ms,
+                    config.general.me_warmup_step_jitter_ms,
+                    config.general.me_reconnect_max_concurrent_per_dc,
+                    config.general.me_reconnect_backoff_base_ms,
+                    config.general.me_reconnect_backoff_cap_ms,
+                    config.general.me_reconnect_fast_retry_count,
+                    config.general.me_single_endpoint_shadow_writers,
+                    config.general.me_single_endpoint_outage_mode_enabled,
+                    config.general.me_single_endpoint_outage_disable_quarantine,
+                    config.general.me_single_endpoint_outage_backoff_min_ms,
+                    config.general.me_single_endpoint_outage_backoff_max_ms,
+                    config.general.me_single_endpoint_shadow_rotate_every_secs,
+                    config.general.me_floor_mode,
+                    config.general.me_adaptive_floor_idle_secs,
+                    config.general.me_adaptive_floor_min_writers_single_endpoint,
+                    config.general.me_adaptive_floor_min_writers_multi_endpoint,
+                    config.general.me_adaptive_floor_recover_grace_secs,
+                    config.general.me_adaptive_floor_writers_per_core_total,
+                    config.general.me_adaptive_floor_cpu_cores_override,
+                    config.general.me_adaptive_floor_max_extra_writers_single_per_core,
+                    config.general.me_adaptive_floor_max_extra_writers_multi_per_core,
+                    config.general.me_adaptive_floor_max_active_writers_per_core,
+                    config.general.me_adaptive_floor_max_warm_writers_per_core,
+                    config.general.me_adaptive_floor_max_active_writers_global,
+                    config.general.me_adaptive_floor_max_warm_writers_global,
+                    config.general.hardswap,
+                    config.general.me_pool_drain_ttl_secs,
+                    config.general.effective_me_pool_force_close_secs(),
+                    config.general.me_pool_min_fresh_ratio,
+                    config.general.me_hardswap_warmup_delay_min_ms,
+                    config.general.me_hardswap_warmup_delay_max_ms,
+                    config.general.me_hardswap_warmup_extra_passes,
+                    config.general.me_hardswap_warmup_pass_backoff_base_ms,
+                    config.general.me_bind_stale_mode,
+                    config.general.me_bind_stale_ttl_secs,
+                    config.general.me_secret_atomic_snapshot,
+                    config.general.me_deterministic_writer_sort,
+                    config.general.me_writer_pick_mode,
+                    config.general.me_writer_pick_sample_size,
+                    config.general.me_socks_kdf_policy,
+                    config.general.me_writer_cmd_channel_capacity,
+                    config.general.me_route_channel_capacity,
+                    config.general.me_route_backpressure_base_timeout_ms,
+                    config.general.me_route_backpressure_high_timeout_ms,
+                    config.general.me_route_backpressure_high_watermark_pct,
+                    config.general.me_reader_route_data_wait_ms,
+                    config.general.me_health_interval_ms_unhealthy,
+                    config.general.me_health_interval_ms_healthy,
+                    config.general.me_warn_rate_limit_ms,
+                    config.general.me_route_no_writer_mode,
+                    config.general.me_route_no_writer_wait_ms,
+                    config.general.me_route_inline_recovery_attempts,
+                    config.general.me_route_inline_recovery_wait_ms,
+                );
+                startup_tracker
+                    .complete_component(
+                        COMPONENT_ME_POOL_CONSTRUCT,
+                        Some("ME pool object created".to_string()),
+                    )
+                    .await;
+                *api_me_pool.write().await = Some(pool.clone());
+                startup_tracker
+                    .start_component(
+                        COMPONENT_ME_POOL_INIT_STAGE1,
+                        Some("initialize ME pool writers".to_string()),
+                    )
+                    .await;
+                startup_tracker
+                    .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_POOL_INIT_STAGE1)
+                    .await;
+
+                if me2dc_fallback {
+                    let pool_bg = pool.clone();
+                    let rng_bg = rng.clone();
+                    let startup_tracker_bg = startup_tracker.clone();
+                    let retry_limit = if me_init_retry_attempts == 0 {
+                        String::from("unlimited")
+                    } else {
+                        me_init_retry_attempts.to_string()
+                    };
+                    std::thread::spawn(move || {
+                        let runtime = match tokio::runtime::Builder::new_current_thread()
+                            .enable_all()
+                            .build()
+                        {
+                            Ok(runtime) => runtime,
+                            Err(error) => {
+                                error!(error = %error, "Failed to build background runtime for ME initialization");
+                                return;
+                            }
+                        };
+                        runtime.block_on(async move {
+                            let mut init_attempt: u32 = 0;
+                            loop {
+                                init_attempt = init_attempt.saturating_add(1);
+                                startup_tracker_bg.set_me_init_attempt(init_attempt).await;
+                                match pool_bg.init(pool_size, &rng_bg).await {
+                                    Ok(()) => {
+                                        startup_tracker_bg.set_me_last_error(None).await;
+                                        startup_tracker_bg
+                                            .complete_component(
+                                                COMPONENT_ME_POOL_INIT_STAGE1,
+                                                Some("ME pool initialized".to_string()),
+                                            )
+                                            .await;
+                                        startup_tracker_bg
+                                            .set_me_status(StartupMeStatus::Ready, "ready")
+                                            .await;
+                                        info!(
+                                            attempt = init_attempt,
+                                            "Middle-End pool initialized successfully"
+                                        );
+
+                                        let pool_health = pool_bg.clone();
+                                        let rng_health = rng_bg.clone();
+                                        let min_conns = pool_size;
+                                        tokio::spawn(async move {
+                                            crate::transport::middle_proxy::me_health_monitor(
+                                                pool_health,
+                                                rng_health,
+                                                min_conns,
+                                            )
+                                            .await;
+                                        });
+                                        break;
+                                    }
+                                    Err(e) => {
+                                        startup_tracker_bg.set_me_last_error(Some(e.to_string())).await;
+                                        if init_attempt >= me_init_warn_after_attempts {
+                                            warn!(
+                                                error = %e,
+                                                attempt = init_attempt,
+                                                retry_limit = %retry_limit,
+                                                retry_in_secs = 2,
+                                                "ME pool is not ready yet; retrying background initialization"
+                                            );
+                                        } else {
+                                            info!(
+                                                error = %e,
+                                                attempt = init_attempt,
+                                                retry_limit = %retry_limit,
+                                                retry_in_secs = 2,
+                                                "ME pool startup warmup: retrying background initialization"
+                                            );
+                                        }
+                                        pool_bg.reset_stun_state();
+                                        tokio::time::sleep(Duration::from_secs(2)).await;
+                                    }
+                                }
+                            }
+                        });
+                    });
+                    startup_tracker
+                        .set_me_status(StartupMeStatus::Initializing, "background_init")
+                        .await;
+                    info!(
+                        startup_grace_secs = 80,
+                        "ME pool initialization continues in background; startup continues with conditional Direct fallback"
+                    );
+                    Some(pool)
+                } else {
+                    let mut init_attempt: u32 = 0;
+                    loop {
+                        init_attempt = init_attempt.saturating_add(1);
+                        startup_tracker.set_me_init_attempt(init_attempt).await;
+                        match pool.init(pool_size, &rng).await {
+                            Ok(()) => {
+                                startup_tracker.set_me_last_error(None).await;
+                                startup_tracker
+                                    .complete_component(
+                                        COMPONENT_ME_POOL_INIT_STAGE1,
+                                        Some("ME pool initialized".to_string()),
+                                    )
+                                    .await;
+                                startup_tracker
+                                    .set_me_status(StartupMeStatus::Ready, "ready")
+                                    .await;
+                                info!(
+                                    attempt = init_attempt,
+                                    "Middle-End pool initialized successfully"
+                                );
+
+                                let pool_clone = pool.clone();
+                                let rng_clone = rng.clone();
+                                let min_conns = pool_size;
+                                tokio::spawn(async move {
+                                    crate::transport::middle_proxy::me_health_monitor(
+                                        pool_clone, rng_clone, min_conns,
+                                    )
+                                    .await;
+                                });
+
+                                break Some(pool);
+                            }
+                            Err(e) => {
+                                startup_tracker.set_me_last_error(Some(e.to_string())).await;
+                                let retries_limited = me_init_retry_attempts > 0;
+                                if retries_limited && init_attempt >= me_init_retry_attempts {
+                                    startup_tracker
+                                        .fail_component(
+                                            COMPONENT_ME_POOL_INIT_STAGE1,
+                                            Some("ME init retry budget exhausted".to_string()),
+                                        )
+                                        .await;
+                                    startup_tracker
+                                        .set_me_status(StartupMeStatus::Failed, "failed")
+                                        .await;
+                                    error!(
+                                        error = %e,
+                                        attempt = init_attempt,
+                                        retry_limit = me_init_retry_attempts,
+                                        "ME pool init retries exhausted; startup cannot continue in middle-proxy mode"
+                                    );
+                                    break None;
+                                }
+
+                                let retry_limit = if me_init_retry_attempts == 0 {
+                                    String::from("unlimited")
+                                } else {
+                                    me_init_retry_attempts.to_string()
+                                };
+                                if init_attempt >= me_init_warn_after_attempts {
+                                    warn!(
+                                        error = %e,
+                                        attempt = init_attempt,
+                                        retry_limit = retry_limit,
+                                        me2dc_fallback = me2dc_fallback,
+                                        retry_in_secs = 2,
+                                        "ME pool is not ready yet; retrying startup initialization"
+                                    );
+                                } else {
+                                    info!(
+                                        error = %e,
+                                        attempt = init_attempt,
+                                        retry_limit = retry_limit,
+                                        me2dc_fallback = me2dc_fallback,
+                                        retry_in_secs = 2,
+                                        "ME pool startup warmup: retrying initialization"
+                                    );
+                                }
+                                pool.reset_stun_state();
+                                tokio::time::sleep(Duration::from_secs(2)).await;
+                            }
+                        }
+                    }
+                }
+            } else {
+                startup_tracker
+                    .skip_component(
+                        COMPONENT_ME_POOL_CONSTRUCT,
+                        Some("ME configs are incomplete".to_string()),
+                    )
+                    .await;
+                startup_tracker
+                    .fail_component(
+                        COMPONENT_ME_POOL_INIT_STAGE1,
+                        Some("ME configs are incomplete".to_string()),
+                    )
+                    .await;
+                startup_tracker
+                    .set_me_status(StartupMeStatus::Failed, "failed")
+                    .await;
+                None
+            }
+        }
+        None => {
+            startup_tracker
+                .fail_component(
+                    COMPONENT_ME_SECRET_FETCH,
+                    Some("proxy-secret unavailable".to_string()),
+                )
+                .await;
+            startup_tracker
+                .skip_component(
+                    COMPONENT_ME_PROXY_CONFIG_V4,
+                    Some("proxy-secret unavailable".to_string()),
+                )
+                .await;
+            startup_tracker
+                .skip_component(
+                    COMPONENT_ME_PROXY_CONFIG_V6,
+                    Some("proxy-secret unavailable".to_string()),
+                )
+                .await;
+            startup_tracker
+                .skip_component(
+                    COMPONENT_ME_POOL_CONSTRUCT,
+                    Some("proxy-secret unavailable".to_string()),
+                )
+                .await;
+            startup_tracker
+                .fail_component(
+                    COMPONENT_ME_POOL_INIT_STAGE1,
+                    Some("proxy-secret unavailable".to_string()),
+                )
+                .await;
+            startup_tracker
+                .set_me_status(StartupMeStatus::Failed, "failed")
+                .await;
+            None
+        }
+    }
+}

src/maestro/mod.rs

@@ -0,0 +1,551 @@
+//! telemt — Telegram MTProto Proxy
+
+#![allow(unused_assignments)]
+
+// Runtime orchestration modules.
+// - helpers: CLI and shared startup/runtime helper routines.
+// - tls_bootstrap: TLS front cache bootstrap and refresh tasks.
+// - me_startup: Middle-End secret/config fetch and pool initialization.
+// - connectivity: startup ME/DC connectivity diagnostics.
+// - runtime_tasks: hot-reload and background task orchestration.
+// - admission: conditional-cast gate and route mode switching.
+// - listeners: TCP/Unix listener bind and accept-loop orchestration.
+// - shutdown: graceful shutdown sequence and uptime logging.
+mod helpers;
+mod admission;
+mod connectivity;
+mod listeners;
+mod me_startup;
+mod runtime_tasks;
+mod shutdown;
+mod tls_bootstrap;
+
+use std::net::{IpAddr, SocketAddr};
+use std::sync::Arc;
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+use tokio::sync::{RwLock, Semaphore, watch};
+use tracing::{error, info, warn};
+use tracing_subscriber::{EnvFilter, fmt, prelude::*, reload};
+
+use crate::api;
+use crate::config::{LogLevel, ProxyConfig};
+use crate::crypto::SecureRandom;
+use crate::ip_tracker::UserIpTracker;
+use crate::network::probe::{decide_network_capabilities, log_probe_result, run_probe};
+use crate::proxy::route_mode::{RelayRouteMode, RouteRuntimeController};
+use crate::stats::beobachten::BeobachtenStore;
+use crate::stats::telemetry::TelemetryPolicy;
+use crate::stats::{ReplayChecker, Stats};
+use crate::startup::{
+    COMPONENT_API_BOOTSTRAP, COMPONENT_CONFIG_LOAD,
+    COMPONENT_ME_POOL_CONSTRUCT, COMPONENT_ME_POOL_INIT_STAGE1,
+    COMPONENT_ME_PROXY_CONFIG_V4, COMPONENT_ME_PROXY_CONFIG_V6, COMPONENT_ME_SECRET_FETCH,
+    COMPONENT_NETWORK_PROBE, COMPONENT_TRACING_INIT, StartupMeStatus, StartupTracker,
+};
+use crate::stream::BufferPool;
+use crate::transport::middle_proxy::MePool;
+use crate::transport::UpstreamManager;
+use helpers::parse_cli;
+
+/// Runs the full telemt runtime startup pipeline and blocks until shutdown.
+pub async fn run() -> std::result::Result<(), Box<dyn std::error::Error>> {
+    let process_started_at = Instant::now();
+    let process_started_at_epoch_secs = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs();
+    let startup_tracker = Arc::new(StartupTracker::new(process_started_at_epoch_secs));
+    startup_tracker
+        .start_component(COMPONENT_CONFIG_LOAD, Some("load and validate config".to_string()))
+        .await;
+    let (config_path, cli_silent, cli_log_level) = parse_cli();
+
+    let mut config = match ProxyConfig::load(&config_path) {
+        Ok(c) => c,
+        Err(e) => {
+            if std::path::Path::new(&config_path).exists() {
+                eprintln!("[telemt] Error: {}", e);
+                std::process::exit(1);
+            } else {
+                let default = ProxyConfig::default();
+                std::fs::write(&config_path, toml::to_string_pretty(&default).unwrap()).unwrap();
+                eprintln!("[telemt] Created default config at {}", config_path);
+                default
+            }
+        }
+    };
+
+    if let Err(e) = config.validate() {
+        eprintln!("[telemt] Invalid config: {}", e);
+        std::process::exit(1);
+    }
+
+    if let Err(e) = crate::network::dns_overrides::install_entries(&config.network.dns_overrides) {
+        eprintln!("[telemt] Invalid network.dns_overrides: {}", e);
+        std::process::exit(1);
+    }
+    startup_tracker
+        .complete_component(COMPONENT_CONFIG_LOAD, Some("config is ready".to_string()))
+        .await;
+
+    let has_rust_log = std::env::var("RUST_LOG").is_ok();
+    let effective_log_level = if cli_silent {
+        LogLevel::Silent
+    } else if let Some(ref s) = cli_log_level {
+        LogLevel::from_str_loose(s)
+    } else {
+        config.general.log_level.clone()
+    };
+
+    let (filter_layer, filter_handle) = reload::Layer::new(EnvFilter::new("info"));
+    startup_tracker
+        .start_component(COMPONENT_TRACING_INIT, Some("initialize tracing subscriber".to_string()))
+        .await;
+
+    // Configure color output based on config
+    let fmt_layer = if config.general.disable_colors {
+        fmt::Layer::default().with_ansi(false)
+    } else {
+        fmt::Layer::default().with_ansi(true)
+    };
+
+    tracing_subscriber::registry()
+        .with(filter_layer)
+        .with(fmt_layer)
+        .init();
+    startup_tracker
+        .complete_component(COMPONENT_TRACING_INIT, Some("tracing initialized".to_string()))
+        .await;
+
+    info!("Telemt MTProxy v{}", env!("CARGO_PKG_VERSION"));
+    info!("Log level: {}", effective_log_level);
+    if config.general.disable_colors {
+        info!("Colors: disabled");
+    }
+    info!(
+        "Modes: classic={} secure={} tls={}",
+        config.general.modes.classic, config.general.modes.secure, config.general.modes.tls
+    );
+    if config.general.modes.classic {
+        warn!("Classic mode is vulnerable to DPI detection; enable only for legacy clients");
+    }
+    info!("TLS domain: {}", config.censorship.tls_domain);
+    if let Some(ref sock) = config.censorship.mask_unix_sock {
+        info!("Mask: {} -> unix:{}", config.censorship.mask, sock);
+        if !std::path::Path::new(sock).exists() {
+            warn!(
+                "Unix socket '{}' does not exist yet. Masking will fail until it appears.",
+                sock
+            );
+        }
+    } else {
+        info!(
+            "Mask: {} -> {}:{}",
+            config.censorship.mask,
+            config
+                .censorship
+                .mask_host
+                .as_deref()
+                .unwrap_or(&config.censorship.tls_domain),
+            config.censorship.mask_port
+        );
+    }
+
+    if config.censorship.tls_domain == "www.google.com" {
+        warn!("Using default tls_domain. Consider setting a custom domain.");
+    }
+
+    let stats = Arc::new(Stats::new());
+    stats.apply_telemetry_policy(TelemetryPolicy::from_config(&config.general.telemetry));
+
+    let upstream_manager = Arc::new(UpstreamManager::new(
+        config.upstreams.clone(),
+        config.general.upstream_connect_retry_attempts,
+        config.general.upstream_connect_retry_backoff_ms,
+        config.general.upstream_connect_budget_ms,
+        config.general.upstream_unhealthy_fail_threshold,
+        config.general.upstream_connect_failfast_hard_errors,
+        stats.clone(),
+    ));
+    let ip_tracker = Arc::new(UserIpTracker::new());
+    ip_tracker.load_limits(&config.access.user_max_unique_ips).await;
+    ip_tracker
+        .set_limit_policy(
+            config.access.user_max_unique_ips_mode,
+            config.access.user_max_unique_ips_window_secs,
+        )
+        .await;
+    if !config.access.user_max_unique_ips.is_empty() {
+        info!(
+            "IP limits configured for {} users",
+            config.access.user_max_unique_ips.len()
+        );
+    }
+    if !config.network.dns_overrides.is_empty() {
+        info!(
+            "Runtime DNS overrides configured: {} entries",
+            config.network.dns_overrides.len()
+        );
+    }
+
+    let (api_config_tx, api_config_rx) = watch::channel(Arc::new(config.clone()));
+    let (detected_ips_tx, detected_ips_rx) = watch::channel((None::<IpAddr>, None::<IpAddr>));
+    let initial_admission_open = !config.general.use_middle_proxy;
+    let (admission_tx, admission_rx) = watch::channel(initial_admission_open);
+    let initial_route_mode = if config.general.use_middle_proxy {
+        RelayRouteMode::Middle
+    } else {
+        RelayRouteMode::Direct
+    };
+    let route_runtime = Arc::new(RouteRuntimeController::new(initial_route_mode));
+    let api_me_pool = Arc::new(RwLock::new(None::<Arc<MePool>>));
+    startup_tracker
+        .start_component(COMPONENT_API_BOOTSTRAP, Some("spawn API listener task".to_string()))
+        .await;
+
+    if config.server.api.enabled {
+        let listen = match config.server.api.listen.parse::<SocketAddr>() {
+            Ok(listen) => listen,
+            Err(error) => {
+                warn!(
+                    error = %error,
+                    listen = %config.server.api.listen,
+                    "Invalid server.api.listen; API is disabled"
+                );
+                SocketAddr::from(([127, 0, 0, 1], 0))
+            }
+        };
+        if listen.port() != 0 {
+            let stats_api = stats.clone();
+            let ip_tracker_api = ip_tracker.clone();
+            let me_pool_api = api_me_pool.clone();
+            let upstream_manager_api = upstream_manager.clone();
+            let config_rx_api = api_config_rx.clone();
+            let admission_rx_api = admission_rx.clone();
+            let config_path_api = std::path::PathBuf::from(&config_path);
+            let startup_tracker_api = startup_tracker.clone();
+            let detected_ips_rx_api = detected_ips_rx.clone();
+            tokio::spawn(async move {
+                api::serve(
+                    listen,
+                    stats_api,
+                    ip_tracker_api,
+                    me_pool_api,
+                    upstream_manager_api,
+                    config_rx_api,
+                    admission_rx_api,
+                    config_path_api,
+                    detected_ips_rx_api,
+                    process_started_at_epoch_secs,
+                    startup_tracker_api,
+                )
+                .await;
+            });
+            startup_tracker
+                .complete_component(
+                    COMPONENT_API_BOOTSTRAP,
+                    Some(format!("api task spawned on {}", listen)),
+                )
+                .await;
+        } else {
+            startup_tracker
+                .skip_component(
+                    COMPONENT_API_BOOTSTRAP,
+                    Some("server.api.listen has zero port".to_string()),
+                )
+                .await;
+        }
+    } else {
+        startup_tracker
+            .skip_component(
+                COMPONENT_API_BOOTSTRAP,
+                Some("server.api.enabled is false".to_string()),
+            )
+            .await;
+    }
+
+    let mut tls_domains = Vec::with_capacity(1 + config.censorship.tls_domains.len());
+    tls_domains.push(config.censorship.tls_domain.clone());
+    for d in &config.censorship.tls_domains {
+        if !tls_domains.contains(d) {
+            tls_domains.push(d.clone());
+        }
+    }
+
+    let tls_cache = tls_bootstrap::bootstrap_tls_front(
+        &config,
+        &tls_domains,
+        upstream_manager.clone(),
+        &startup_tracker,
+    )
+    .await;
+
+    startup_tracker
+        .start_component(COMPONENT_NETWORK_PROBE, Some("probe network capabilities".to_string()))
+        .await;
+    let probe = run_probe(
+        &config.network,
+        config.general.middle_proxy_nat_probe,
+        config.general.stun_nat_probe_concurrency,
+    )
+    .await?;
+    detected_ips_tx.send_replace((
+        probe.detected_ipv4.map(IpAddr::V4),
+        probe.detected_ipv6.map(IpAddr::V6),
+    ));
+    let decision = decide_network_capabilities(&config.network, &probe);
+    log_probe_result(&probe, &decision);
+    startup_tracker
+        .complete_component(
+            COMPONENT_NETWORK_PROBE,
+            Some("network capabilities determined".to_string()),
+        )
+        .await;
+
+    let prefer_ipv6 = decision.prefer_ipv6();
+    let mut use_middle_proxy = config.general.use_middle_proxy;
+    let beobachten = Arc::new(BeobachtenStore::new());
+    let rng = Arc::new(SecureRandom::new());
+
+    // Connection concurrency limit
+    let max_connections = Arc::new(Semaphore::new(10_000));
+
+    let me2dc_fallback = config.general.me2dc_fallback;
+    let me_init_retry_attempts = config.general.me_init_retry_attempts;
+    if use_middle_proxy && !decision.ipv4_me && !decision.ipv6_me {
+        if me2dc_fallback {
+            warn!("No usable IP family for Middle Proxy detected; falling back to direct DC");
+            use_middle_proxy = false;
+        } else {
+            warn!(
+                "No usable IP family for Middle Proxy detected; me2dc_fallback=false, ME init retries stay active"
+            );
+        }
+    }
+
+    if use_middle_proxy {
+        startup_tracker
+            .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_SECRET_FETCH)
+            .await;
+        startup_tracker
+            .start_component(
+                COMPONENT_ME_SECRET_FETCH,
+                Some("fetch proxy-secret from source/cache".to_string()),
+            )
+            .await;
+        startup_tracker
+            .set_me_retry_limit(if !me2dc_fallback || me_init_retry_attempts == 0 {
+                "unlimited".to_string()
+            } else {
+                me_init_retry_attempts.to_string()
+            })
+            .await;
+    } else {
+        startup_tracker
+            .set_me_status(StartupMeStatus::Skipped, "skipped")
+            .await;
+        startup_tracker
+            .skip_component(
+                COMPONENT_ME_SECRET_FETCH,
+                Some("middle proxy mode disabled".to_string()),
+            )
+            .await;
+        startup_tracker
+            .skip_component(
+                COMPONENT_ME_PROXY_CONFIG_V4,
+                Some("middle proxy mode disabled".to_string()),
+            )
+            .await;
+        startup_tracker
+            .skip_component(
+                COMPONENT_ME_PROXY_CONFIG_V6,
+                Some("middle proxy mode disabled".to_string()),
+            )
+            .await;
+        startup_tracker
+            .skip_component(
+                COMPONENT_ME_POOL_CONSTRUCT,
+                Some("middle proxy mode disabled".to_string()),
+            )
+            .await;
+        startup_tracker
+            .skip_component(
+                COMPONENT_ME_POOL_INIT_STAGE1,
+                Some("middle proxy mode disabled".to_string()),
+            )
+            .await;
+    }
+
+    let me_pool: Option<Arc<MePool>> = me_startup::initialize_me_pool(
+        use_middle_proxy,
+        &config,
+        &decision,
+        &probe,
+        &startup_tracker,
+        upstream_manager.clone(),
+        rng.clone(),
+        stats.clone(),
+        api_me_pool.clone(),
+    )
+    .await;
+
+    // If ME failed to initialize, force direct-only mode.
+    if me_pool.is_some() {
+        startup_tracker
+            .set_transport_mode("middle_proxy")
+            .await;
+        startup_tracker
+            .set_degraded(false)
+            .await;
+        info!("Transport: Middle-End Proxy - all DC-over-RPC");
+    } else {
+        let _ = use_middle_proxy;
+        use_middle_proxy = false;
+        // Make runtime config reflect direct-only mode for handlers.
+        config.general.use_middle_proxy = false;
+        startup_tracker
+            .set_transport_mode("direct")
+            .await;
+        startup_tracker
+            .set_degraded(true)
+            .await;
+        if me2dc_fallback {
+            startup_tracker
+                .set_me_status(StartupMeStatus::Failed, "fallback_to_direct")
+                .await;
+        } else {
+            startup_tracker
+                .set_me_status(StartupMeStatus::Skipped, "skipped")
+                .await;
+        }
+        info!("Transport: Direct DC - TCP - standard DC-over-TCP");
+    }
+
+    // Freeze config after possible fallback decision
+    let config = Arc::new(config);
+
+    let replay_checker = Arc::new(ReplayChecker::new(
+        config.access.replay_check_len,
+        Duration::from_secs(config.access.replay_window_secs),
+    ));
+
+    let buffer_pool = Arc::new(BufferPool::with_config(16 * 1024, 4096));
+
+    connectivity::run_startup_connectivity(
+        &config,
+        &me_pool,
+        rng.clone(),
+        &startup_tracker,
+        upstream_manager.clone(),
+        prefer_ipv6,
+        &decision,
+        process_started_at,
+        api_me_pool.clone(),
+    )
+    .await;
+
+    let runtime_watches = runtime_tasks::spawn_runtime_tasks(
+        &config,
+        &config_path,
+        &probe,
+        prefer_ipv6,
+        decision.ipv4_dc,
+        decision.ipv6_dc,
+        &startup_tracker,
+        stats.clone(),
+        upstream_manager.clone(),
+        replay_checker.clone(),
+        me_pool.clone(),
+        rng.clone(),
+        ip_tracker.clone(),
+        beobachten.clone(),
+        api_config_tx.clone(),
+        me_pool.clone(),
+    )
+    .await;
+    let config_rx = runtime_watches.config_rx;
+    let log_level_rx = runtime_watches.log_level_rx;
+    let detected_ip_v4 = runtime_watches.detected_ip_v4;
+    let detected_ip_v6 = runtime_watches.detected_ip_v6;
+
+    admission::configure_admission_gate(
+        &config,
+        me_pool.clone(),
+        route_runtime.clone(),
+        &admission_tx,
+        config_rx.clone(),
+    )
+    .await;
+    let _admission_tx_hold = admission_tx;
+
+    let bound = listeners::bind_listeners(
+        &config,
+        decision.ipv4_dc,
+        decision.ipv6_dc,
+        detected_ip_v4,
+        detected_ip_v6,
+        &startup_tracker,
+        config_rx.clone(),
+        admission_rx.clone(),
+        stats.clone(),
+        upstream_manager.clone(),
+        replay_checker.clone(),
+        buffer_pool.clone(),
+        rng.clone(),
+        me_pool.clone(),
+        route_runtime.clone(),
+        tls_cache.clone(),
+        ip_tracker.clone(),
+        beobachten.clone(),
+        max_connections.clone(),
+    )
+    .await?;
+    let listeners = bound.listeners;
+    let has_unix_listener = bound.has_unix_listener;
+
+    if listeners.is_empty() && !has_unix_listener {
+        error!("No listeners. Exiting.");
+        std::process::exit(1);
+    }
+
+    runtime_tasks::apply_runtime_log_filter(
+        has_rust_log,
+        &effective_log_level,
+        filter_handle,
+        log_level_rx,
+    )
+    .await;
+
+    runtime_tasks::spawn_metrics_if_configured(
+        &config,
+        &startup_tracker,
+        stats.clone(),
+        beobachten.clone(),
+        ip_tracker.clone(),
+        config_rx.clone(),
+    )
+    .await;
+
+    runtime_tasks::mark_runtime_ready(&startup_tracker).await;
+
+    listeners::spawn_tcp_accept_loops(
+        listeners,
+        config_rx.clone(),
+        admission_rx.clone(),
+        stats.clone(),
+        upstream_manager.clone(),
+        replay_checker.clone(),
+        buffer_pool.clone(),
+        rng.clone(),
+        me_pool.clone(),
+        route_runtime.clone(),
+        tls_cache.clone(),
+        ip_tracker.clone(),
+        beobachten.clone(),
+        max_connections.clone(),
+    );
+
+    shutdown::wait_for_shutdown(process_started_at, me_pool).await;
+
+    Ok(())
+}

src/maestro/runtime_tasks.rs

@@ -0,0 +1,317 @@
+use std::net::IpAddr;
+use std::path::PathBuf;
+use std::sync::Arc;
+
+use tokio::sync::{mpsc, watch};
+use tracing::{debug, warn};
+use tracing_subscriber::reload;
+use tracing_subscriber::EnvFilter;
+
+use crate::config::{LogLevel, ProxyConfig};
+use crate::config::hot_reload::spawn_config_watcher;
+use crate::crypto::SecureRandom;
+use crate::ip_tracker::UserIpTracker;
+use crate::metrics;
+use crate::network::probe::NetworkProbe;
+use crate::startup::{COMPONENT_CONFIG_WATCHER_START, COMPONENT_METRICS_START, COMPONENT_RUNTIME_READY, StartupTracker};
+use crate::stats::beobachten::BeobachtenStore;
+use crate::stats::telemetry::TelemetryPolicy;
+use crate::stats::{ReplayChecker, Stats};
+use crate::transport::middle_proxy::{MePool, MeReinitTrigger};
+use crate::transport::UpstreamManager;
+
+use super::helpers::write_beobachten_snapshot;
+
+pub(crate) struct RuntimeWatches {
+    pub(crate) config_rx: watch::Receiver<Arc<ProxyConfig>>,
+    pub(crate) log_level_rx: watch::Receiver<LogLevel>,
+    pub(crate) detected_ip_v4: Option<IpAddr>,
+    pub(crate) detected_ip_v6: Option<IpAddr>,
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(crate) async fn spawn_runtime_tasks(
+    config: &Arc<ProxyConfig>,
+    config_path: &str,
+    probe: &NetworkProbe,
+    prefer_ipv6: bool,
+    decision_ipv4_dc: bool,
+    decision_ipv6_dc: bool,
+    startup_tracker: &Arc<StartupTracker>,
+    stats: Arc<Stats>,
+    upstream_manager: Arc<UpstreamManager>,
+    replay_checker: Arc<ReplayChecker>,
+    me_pool: Option<Arc<MePool>>,
+    rng: Arc<SecureRandom>,
+    ip_tracker: Arc<UserIpTracker>,
+    beobachten: Arc<BeobachtenStore>,
+    api_config_tx: watch::Sender<Arc<ProxyConfig>>,
+    me_pool_for_policy: Option<Arc<MePool>>,
+) -> RuntimeWatches {
+    let um_clone = upstream_manager.clone();
+    let dc_overrides_for_health = config.dc_overrides.clone();
+    tokio::spawn(async move {
+        um_clone
+            .run_health_checks(
+                prefer_ipv6,
+                decision_ipv4_dc,
+                decision_ipv6_dc,
+                dc_overrides_for_health,
+            )
+            .await;
+    });
+
+    let rc_clone = replay_checker.clone();
+    tokio::spawn(async move {
+        rc_clone.run_periodic_cleanup().await;
+    });
+
+    let detected_ip_v4: Option<IpAddr> = probe.detected_ipv4.map(IpAddr::V4);
+    let detected_ip_v6: Option<IpAddr> = probe.detected_ipv6.map(IpAddr::V6);
+    debug!(
+        "Detected IPs: v4={:?} v6={:?}",
+        detected_ip_v4, detected_ip_v6
+    );
+
+    startup_tracker
+        .start_component(
+            COMPONENT_CONFIG_WATCHER_START,
+            Some("spawn config hot-reload watcher".to_string()),
+        )
+        .await;
+    let (config_rx, log_level_rx): (
+        watch::Receiver<Arc<ProxyConfig>>,
+        watch::Receiver<LogLevel>,
+    ) = spawn_config_watcher(
+        PathBuf::from(config_path),
+        config.clone(),
+        detected_ip_v4,
+        detected_ip_v6,
+    );
+    startup_tracker
+        .complete_component(
+            COMPONENT_CONFIG_WATCHER_START,
+            Some("config hot-reload watcher started".to_string()),
+        )
+        .await;
+    let mut config_rx_api_bridge = config_rx.clone();
+    let api_config_tx_bridge = api_config_tx.clone();
+    tokio::spawn(async move {
+        loop {
+            if config_rx_api_bridge.changed().await.is_err() {
+                break;
+            }
+            let cfg = config_rx_api_bridge.borrow_and_update().clone();
+            api_config_tx_bridge.send_replace(cfg);
+        }
+    });
+
+    let stats_policy = stats.clone();
+    let mut config_rx_policy = config_rx.clone();
+    tokio::spawn(async move {
+        loop {
+            if config_rx_policy.changed().await.is_err() {
+                break;
+            }
+            let cfg = config_rx_policy.borrow_and_update().clone();
+            stats_policy.apply_telemetry_policy(TelemetryPolicy::from_config(&cfg.general.telemetry));
+            if let Some(pool) = &me_pool_for_policy {
+                pool.update_runtime_transport_policy(
+                    cfg.general.me_socks_kdf_policy,
+                    cfg.general.me_route_backpressure_base_timeout_ms,
+                    cfg.general.me_route_backpressure_high_timeout_ms,
+                    cfg.general.me_route_backpressure_high_watermark_pct,
+                    cfg.general.me_reader_route_data_wait_ms,
+                );
+            }
+        }
+    });
+
+    let ip_tracker_policy = ip_tracker.clone();
+    let mut config_rx_ip_limits = config_rx.clone();
+    tokio::spawn(async move {
+        let mut prev_limits = config_rx_ip_limits.borrow().access.user_max_unique_ips.clone();
+        let mut prev_mode = config_rx_ip_limits.borrow().access.user_max_unique_ips_mode;
+        let mut prev_window = config_rx_ip_limits
+            .borrow()
+            .access
+            .user_max_unique_ips_window_secs;
+
+        loop {
+            if config_rx_ip_limits.changed().await.is_err() {
+                break;
+            }
+            let cfg = config_rx_ip_limits.borrow_and_update().clone();
+
+            if prev_limits != cfg.access.user_max_unique_ips {
+                ip_tracker_policy.load_limits(&cfg.access.user_max_unique_ips).await;
+                prev_limits = cfg.access.user_max_unique_ips.clone();
+            }
+
+            if prev_mode != cfg.access.user_max_unique_ips_mode
+                || prev_window != cfg.access.user_max_unique_ips_window_secs
+            {
+                ip_tracker_policy
+                    .set_limit_policy(
+                        cfg.access.user_max_unique_ips_mode,
+                        cfg.access.user_max_unique_ips_window_secs,
+                    )
+                    .await;
+                prev_mode = cfg.access.user_max_unique_ips_mode;
+                prev_window = cfg.access.user_max_unique_ips_window_secs;
+            }
+        }
+    });
+
+    let beobachten_writer = beobachten.clone();
+    let config_rx_beobachten = config_rx.clone();
+    tokio::spawn(async move {
+        loop {
+            let cfg = config_rx_beobachten.borrow().clone();
+            let sleep_secs = cfg.general.beobachten_flush_secs.max(1);
+
+            if cfg.general.beobachten {
+                let ttl = std::time::Duration::from_secs(cfg.general.beobachten_minutes.saturating_mul(60));
+                let path = cfg.general.beobachten_file.clone();
+                let snapshot = beobachten_writer.snapshot_text(ttl);
+                if let Err(e) = write_beobachten_snapshot(&path, &snapshot).await {
+                    warn!(error = %e, path = %path, "Failed to flush beobachten snapshot");
+                }
+            }
+
+            tokio::time::sleep(std::time::Duration::from_secs(sleep_secs)).await;
+        }
+    });
+
+    if let Some(pool) = me_pool {
+        let reinit_trigger_capacity = config.general.me_reinit_trigger_channel.max(1);
+        let (reinit_tx, reinit_rx) = mpsc::channel::<MeReinitTrigger>(reinit_trigger_capacity);
+
+        let pool_clone_sched = pool.clone();
+        let rng_clone_sched = rng.clone();
+        let config_rx_clone_sched = config_rx.clone();
+        tokio::spawn(async move {
+            crate::transport::middle_proxy::me_reinit_scheduler(
+                pool_clone_sched,
+                rng_clone_sched,
+                config_rx_clone_sched,
+                reinit_rx,
+            )
+            .await;
+        });
+
+        let pool_clone = pool.clone();
+        let config_rx_clone = config_rx.clone();
+        let reinit_tx_updater = reinit_tx.clone();
+        tokio::spawn(async move {
+            crate::transport::middle_proxy::me_config_updater(
+                pool_clone,
+                config_rx_clone,
+                reinit_tx_updater,
+            )
+            .await;
+        });
+
+        let config_rx_clone_rot = config_rx.clone();
+        let reinit_tx_rotation = reinit_tx.clone();
+        tokio::spawn(async move {
+            crate::transport::middle_proxy::me_rotation_task(config_rx_clone_rot, reinit_tx_rotation)
+                .await;
+        });
+    }
+
+    RuntimeWatches {
+        config_rx,
+        log_level_rx,
+        detected_ip_v4,
+        detected_ip_v6,
+    }
+}
+
+pub(crate) async fn apply_runtime_log_filter(
+    has_rust_log: bool,
+    effective_log_level: &LogLevel,
+    filter_handle: reload::Handle<EnvFilter, tracing_subscriber::Registry>,
+    mut log_level_rx: watch::Receiver<LogLevel>,
+) {
+    let runtime_filter = if has_rust_log {
+        EnvFilter::from_default_env()
+    } else if matches!(effective_log_level, LogLevel::Silent) {
+        EnvFilter::new("warn,telemt::links=info")
+    } else {
+        EnvFilter::new(effective_log_level.to_filter_str())
+    };
+    filter_handle
+        .reload(runtime_filter)
+        .expect("Failed to switch log filter");
+
+    tokio::spawn(async move {
+        loop {
+            if log_level_rx.changed().await.is_err() {
+                break;
+            }
+            let level = log_level_rx.borrow_and_update().clone();
+            let new_filter = tracing_subscriber::EnvFilter::new(level.to_filter_str());
+            if let Err(e) = filter_handle.reload(new_filter) {
+                tracing::error!("config reload: failed to update log filter: {}", e);
+            }
+        }
+    });
+}
+
+pub(crate) async fn spawn_metrics_if_configured(
+    config: &Arc<ProxyConfig>,
+    startup_tracker: &Arc<StartupTracker>,
+    stats: Arc<Stats>,
+    beobachten: Arc<BeobachtenStore>,
+    ip_tracker: Arc<UserIpTracker>,
+    config_rx: watch::Receiver<Arc<ProxyConfig>>,
+) {
+    if let Some(port) = config.server.metrics_port {
+        startup_tracker
+            .start_component(
+                COMPONENT_METRICS_START,
+                Some(format!("spawn metrics endpoint on {}", port)),
+            )
+            .await;
+        let stats = stats.clone();
+        let beobachten = beobachten.clone();
+        let config_rx_metrics = config_rx.clone();
+        let ip_tracker_metrics = ip_tracker.clone();
+        let whitelist = config.server.metrics_whitelist.clone();
+        tokio::spawn(async move {
+            metrics::serve(
+                port,
+                stats,
+                beobachten,
+                ip_tracker_metrics,
+                config_rx_metrics,
+                whitelist,
+            )
+            .await;
+        });
+        startup_tracker
+            .complete_component(
+                COMPONENT_METRICS_START,
+                Some("metrics task spawned".to_string()),
+            )
+            .await;
+    } else {
+        startup_tracker
+            .skip_component(
+                COMPONENT_METRICS_START,
+                Some("server.metrics_port is not configured".to_string()),
+            )
+            .await;
+    }
+}
+
+pub(crate) async fn mark_runtime_ready(startup_tracker: &Arc<StartupTracker>) {
+    startup_tracker
+        .complete_component(
+            COMPONENT_RUNTIME_READY,
+            Some("startup pipeline is fully initialized".to_string()),
+        )
+        .await;
+    startup_tracker.mark_ready().await;
+}

src/maestro/shutdown.rs

@@ -0,0 +1,42 @@
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+use tokio::signal;
+use tracing::{error, info, warn};
+
+use crate::transport::middle_proxy::MePool;
+
+use super::helpers::{format_uptime, unit_label};
+
+pub(crate) async fn wait_for_shutdown(process_started_at: Instant, me_pool: Option<Arc<MePool>>) {
+    match signal::ctrl_c().await {
+        Ok(()) => {
+            let shutdown_started_at = Instant::now();
+            info!("Shutting down...");
+            let uptime_secs = process_started_at.elapsed().as_secs();
+            info!("Uptime: {}", format_uptime(uptime_secs));
+            if let Some(pool) = &me_pool {
+                match tokio::time::timeout(Duration::from_secs(2), pool.shutdown_send_close_conn_all())
+                    .await
+                {
+                    Ok(total) => {
+                        info!(
+                            close_conn_sent = total,
+                            "ME shutdown: RPC_CLOSE_CONN broadcast completed"
+                        );
+                    }
+                    Err(_) => {
+                        warn!("ME shutdown: RPC_CLOSE_CONN broadcast timed out");
+                    }
+                }
+            }
+            let shutdown_secs = shutdown_started_at.elapsed().as_secs();
+            info!(
+                "Shutdown completed successfully in {} {}.",
+                shutdown_secs,
+                unit_label(shutdown_secs, "second", "seconds")
+            );
+        }
+        Err(e) => error!("Signal error: {}", e),
+    }
+}

src/maestro/tls_bootstrap.rs

@@ -0,0 +1,165 @@
+use std::sync::Arc;
+use std::time::Duration;
+
+use rand::Rng;
+use tracing::warn;
+
+use crate::config::ProxyConfig;
+use crate::startup::{COMPONENT_TLS_FRONT_BOOTSTRAP, StartupTracker};
+use crate::tls_front::TlsFrontCache;
+use crate::transport::UpstreamManager;
+
+pub(crate) async fn bootstrap_tls_front(
+    config: &ProxyConfig,
+    tls_domains: &[String],
+    upstream_manager: Arc<UpstreamManager>,
+    startup_tracker: &Arc<StartupTracker>,
+) -> Option<Arc<TlsFrontCache>> {
+    startup_tracker
+        .start_component(
+            COMPONENT_TLS_FRONT_BOOTSTRAP,
+            Some("initialize TLS front cache/bootstrap tasks".to_string()),
+        )
+        .await;
+
+    let tls_cache: Option<Arc<TlsFrontCache>> = if config.censorship.tls_emulation {
+        let cache = Arc::new(TlsFrontCache::new(
+            tls_domains,
+            config.censorship.fake_cert_len,
+            &config.censorship.tls_front_dir,
+        ));
+        cache.load_from_disk().await;
+
+        let port = config.censorship.mask_port;
+        let proxy_protocol = config.censorship.mask_proxy_protocol;
+        let mask_host = config
+            .censorship
+            .mask_host
+            .clone()
+            .unwrap_or_else(|| config.censorship.tls_domain.clone());
+        let mask_unix_sock = config.censorship.mask_unix_sock.clone();
+        let fetch_timeout = Duration::from_secs(5);
+
+        let cache_initial = cache.clone();
+        let domains_initial = tls_domains.to_vec();
+        let host_initial = mask_host.clone();
+        let unix_sock_initial = mask_unix_sock.clone();
+        let upstream_initial = upstream_manager.clone();
+        tokio::spawn(async move {
+            let mut join = tokio::task::JoinSet::new();
+            for domain in domains_initial {
+                let cache_domain = cache_initial.clone();
+                let host_domain = host_initial.clone();
+                let unix_sock_domain = unix_sock_initial.clone();
+                let upstream_domain = upstream_initial.clone();
+                join.spawn(async move {
+                    match crate::tls_front::fetcher::fetch_real_tls(
+                        &host_domain,
+                        port,
+                        &domain,
+                        fetch_timeout,
+                        Some(upstream_domain),
+                        proxy_protocol,
+                        unix_sock_domain.as_deref(),
+                    )
+                    .await
+                    {
+                        Ok(res) => cache_domain.update_from_fetch(&domain, res).await,
+                        Err(e) => {
+                            warn!(domain = %domain, error = %e, "TLS emulation initial fetch failed")
+                        }
+                    }
+                });
+            }
+            while let Some(res) = join.join_next().await {
+                if let Err(e) = res {
+                    warn!(error = %e, "TLS emulation initial fetch task join failed");
+                }
+            }
+        });
+
+        let cache_timeout = cache.clone();
+        let domains_timeout = tls_domains.to_vec();
+        let fake_cert_len = config.censorship.fake_cert_len;
+        tokio::spawn(async move {
+            tokio::time::sleep(fetch_timeout).await;
+            for domain in domains_timeout {
+                let cached = cache_timeout.get(&domain).await;
+                if cached.domain == "default" {
+                    warn!(
+                        domain = %domain,
+                        timeout_secs = fetch_timeout.as_secs(),
+                        fake_cert_len,
+                        "TLS-front fetch not ready within timeout; using cache/default fake cert fallback"
+                    );
+                }
+            }
+        });
+
+        let cache_refresh = cache.clone();
+        let domains_refresh = tls_domains.to_vec();
+        let host_refresh = mask_host.clone();
+        let unix_sock_refresh = mask_unix_sock.clone();
+        let upstream_refresh = upstream_manager.clone();
+        tokio::spawn(async move {
+            loop {
+                let base_secs = rand::rng().random_range(4 * 3600..=6 * 3600);
+                let jitter_secs = rand::rng().random_range(0..=7200);
+                tokio::time::sleep(Duration::from_secs(base_secs + jitter_secs)).await;
+
+                let mut join = tokio::task::JoinSet::new();
+                for domain in domains_refresh.clone() {
+                    let cache_domain = cache_refresh.clone();
+                    let host_domain = host_refresh.clone();
+                    let unix_sock_domain = unix_sock_refresh.clone();
+                    let upstream_domain = upstream_refresh.clone();
+                    join.spawn(async move {
+                        match crate::tls_front::fetcher::fetch_real_tls(
+                            &host_domain,
+                            port,
+                            &domain,
+                            fetch_timeout,
+                            Some(upstream_domain),
+                            proxy_protocol,
+                            unix_sock_domain.as_deref(),
+                        )
+                        .await
+                        {
+                            Ok(res) => cache_domain.update_from_fetch(&domain, res).await,
+                            Err(e) => {
+                                warn!(domain = %domain, error = %e, "TLS emulation refresh failed")
+                            }
+                        }
+                    });
+                }
+
+                while let Some(res) = join.join_next().await {
+                    if let Err(e) = res {
+                        warn!(error = %e, "TLS emulation refresh task join failed");
+                    }
+                }
+            }
+        });
+
+        Some(cache)
+    } else {
+        startup_tracker
+            .skip_component(
+                COMPONENT_TLS_FRONT_BOOTSTRAP,
+                Some("censorship.tls_emulation is false".to_string()),
+            )
+            .await;
+        None
+    };
+
+    if tls_cache.is_some() {
+        startup_tracker
+            .complete_component(
+                COMPONENT_TLS_FRONT_BOOTSTRAP,
+                Some("tls front cache is initialized".to_string()),
+            )
+            .await;
+    }
+
+    tls_cache
+}

src/main.rs

@@ -1,193 +1,24 @@
-//! Telemt - MTProxy on Rust
-
-use std::net::SocketAddr;
-use std::sync::Arc;
-use std::time::Duration;
-use tokio::net::TcpListener;
-use tokio::signal;
-use tracing::{info, error, warn};
-use tracing_subscriber::{fmt, EnvFilter};
+//! telemt — Telegram MTProto Proxy
 
+mod api;
+mod cli;
 mod config;
 mod crypto;
 mod error;
+mod ip_tracker;
+mod maestro;
+mod metrics;
+mod network;
 mod protocol;
 mod proxy;
+mod startup;
 mod stats;
 mod stream;
+mod tls_front;
 mod transport;
 mod util;
 
-use crate::config::ProxyConfig;
-use crate::proxy::ClientHandler;
-use crate::stats::Stats;
-use crate::transport::{create_listener, ListenOptions, UpstreamManager};
-use crate::util::ip::detect_ip;
-
 #[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    // Initialize logging
-    fmt()
-        .with_env_filter(EnvFilter::from_default_env().add_directive("info".parse().unwrap()))
-        .init();
-
-    // Load config
-    let config_path = std::env::args().nth(1).unwrap_or_else(|| "config.toml".to_string());
-    let config = match ProxyConfig::load(&config_path) {
-        Ok(c) => c,
-        Err(e) => {
-            // If config doesn't exist, try to create default
-            if std::path::Path::new(&config_path).exists() {
-                error!("Failed to load config: {}", e);
-                std::process::exit(1);
-            } else {
-                let default = ProxyConfig::default();
-                let toml = toml::to_string_pretty(&default).unwrap();
-                std::fs::write(&config_path, toml).unwrap();
-                info!("Created default config at {}", config_path);
-                default
-            }
-        }
-    };
-    
-    config.validate()?;
-    
-    let config = Arc::new(config);
-    let stats = Arc::new(Stats::new());
-    
-    // Initialize Upstream Manager
-    let upstream_manager = Arc::new(UpstreamManager::new(config.upstreams.clone()));
-    
-    // Start Health Checks
-    let um_clone = upstream_manager.clone();
-    tokio::spawn(async move {
-        um_clone.run_health_checks().await;
-    });
-
-    // Detect public IP if needed (once at startup)
-    let detected_ip = detect_ip().await;
-
-    // Start Listeners
-    let mut listeners = Vec::new();
-    
-    for listener_conf in &config.listeners {
-        let addr = SocketAddr::new(listener_conf.ip, config.port);
-        let options = ListenOptions {
-            ipv6_only: listener_conf.ip.is_ipv6(),
-            ..Default::default()
-        };
-        
-        match create_listener(addr, &options) {
-            Ok(socket) => {
-                let listener = TcpListener::from_std(socket.into())?;
-                info!("Listening on {}", addr);
-                
-                // Determine public IP for tg:// links
-                // 1. Use explicit announce_ip if set
-                // 2. If listening on 0.0.0.0 or ::, use detected public IP
-                // 3. Otherwise use the bind IP
-                let public_ip = if let Some(ip) = listener_conf.announce_ip {
-                    ip
-                } else if listener_conf.ip.is_unspecified() {
-                    // Try to use detected IP of the same family
-                    if listener_conf.ip.is_ipv4() {
-                        detected_ip.ipv4.unwrap_or(listener_conf.ip)
-                    } else {
-                        detected_ip.ipv6.unwrap_or(listener_conf.ip)
-                    }
-                } else {
-                    listener_conf.ip
-                };
-
-                // Show links for configured users
-                if !config.show_link.is_empty() {
-                    info!("--- Proxy Links for {} ---", public_ip);
-                    for user_name in &config.show_link {
-                        if let Some(secret) = config.users.get(user_name) {
-                            info!("User: {}", user_name);
-
-                            // Classic
-                            if config.modes.classic {
-                                info!("  Classic: tg://proxy?server={}&port={}&secret={}", 
-                                    public_ip, config.port, secret);
-                            }
-
-                            // DD (Secure)
-                            if config.modes.secure {
-                                info!("  DD:      tg://proxy?server={}&port={}&secret=dd{}", 
-                                    public_ip, config.port, secret);
-                            }
-
-                            // EE-TLS (FakeTLS)
-                            if config.modes.tls {
-                                let domain_hex = hex::encode(&config.tls_domain);
-                                info!("  EE-TLS:  tg://proxy?server={}&port={}&secret=ee{}{}", 
-                                    public_ip, config.port, secret, domain_hex);
-                            }
-                        } else {
-                            warn!("User '{}' specified in show_link not found in users list", user_name);
-                        }
-                    }
-                    info!("-----------------------------------");
-                }
-                
-                listeners.push(listener);
-            },
-            Err(e) => {
-                error!("Failed to bind to {}: {}", addr, e);
-            }
-        }
-    }
-    
-    if listeners.is_empty() {
-        error!("No listeners could be started. Exiting.");
-        std::process::exit(1);
-    }
-
-    // Accept loop
-    // For simplicity in this slice, we just spawn a task for each listener
-    // In a real high-perf scenario, we might want a more complex accept loop
-    
-    for listener in listeners {
-        let config = config.clone();
-        let stats = stats.clone();
-        let upstream_manager = upstream_manager.clone();
-        
-        tokio::spawn(async move {
-            loop {
-                match listener.accept().await {
-                    Ok((stream, peer_addr)) => {
-                        let config = config.clone();
-                        let stats = stats.clone();
-                        let upstream_manager = upstream_manager.clone();
-                        
-                        tokio::spawn(async move {
-                            if let Err(e) = ClientHandler::new(
-                                stream, 
-                                peer_addr, 
-                                config, 
-                                stats,
-                                upstream_manager
-                            ).run().await {
-                                // Log only relevant errors
-                                // debug!("Connection error: {}", e);
-                            }
-                        });
-                    }
-                    Err(e) => {
-                        error!("Accept error: {}", e);
-                        tokio::time::sleep(Duration::from_millis(100)).await;
-                    }
-                }
-            }
-        });
-    }
-
-    // Wait for signal
-    match signal::ctrl_c().await {
-        Ok(()) => info!("Shutting down..."),
-        Err(e) => error!("Signal error: {}", e),
-    }
-
-    Ok(())
-}
+async fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
+    maestro::run().await
+}

src/network/dns_overrides.rs

@@ -0,0 +1,197 @@
+//! Runtime DNS overrides for `host:port` targets.
+
+use std::collections::HashMap;
+use std::net::{IpAddr, Ipv6Addr, SocketAddr};
+use std::sync::{OnceLock, RwLock};
+
+use crate::error::{ProxyError, Result};
+
+type OverrideMap = HashMap<(String, u16), IpAddr>;
+
+static DNS_OVERRIDES: OnceLock<RwLock<OverrideMap>> = OnceLock::new();
+
+fn overrides_store() -> &'static RwLock<OverrideMap> {
+    DNS_OVERRIDES.get_or_init(|| RwLock::new(HashMap::new()))
+}
+
+fn parse_ip_spec(ip_spec: &str) -> Result<IpAddr> {
+    if ip_spec.starts_with('[') && ip_spec.ends_with(']') {
+        let inner = &ip_spec[1..ip_spec.len() - 1];
+        let ipv6 = inner.parse::<Ipv6Addr>().map_err(|_| {
+            ProxyError::Config(format!(
+                "network.dns_overrides IPv6 override is invalid: '{ip_spec}'"
+            ))
+        })?;
+        return Ok(IpAddr::V6(ipv6));
+    }
+
+    let ip = ip_spec.parse::<IpAddr>().map_err(|_| {
+        ProxyError::Config(format!(
+            "network.dns_overrides IP is invalid: '{ip_spec}'"
+        ))
+    })?;
+    if matches!(ip, IpAddr::V6(_)) {
+        return Err(ProxyError::Config(format!(
+            "network.dns_overrides IPv6 must be bracketed: '{ip_spec}'"
+        )));
+    }
+    Ok(ip)
+}
+
+fn parse_entry(entry: &str) -> Result<((String, u16), IpAddr)> {
+    let trimmed = entry.trim();
+    if trimmed.is_empty() {
+        return Err(ProxyError::Config(
+            "network.dns_overrides entry cannot be empty".to_string(),
+        ));
+    }
+
+    let first_sep = trimmed.find(':').ok_or_else(|| {
+        ProxyError::Config(format!(
+            "network.dns_overrides entry must use host:port:ip format: '{trimmed}'"
+        ))
+    })?;
+    let second_sep = trimmed[first_sep + 1..]
+        .find(':')
+        .map(|idx| first_sep + 1 + idx)
+        .ok_or_else(|| {
+            ProxyError::Config(format!(
+                "network.dns_overrides entry must use host:port:ip format: '{trimmed}'"
+            ))
+        })?;
+
+    let host = trimmed[..first_sep].trim();
+    let port_str = trimmed[first_sep + 1..second_sep].trim();
+    let ip_str = trimmed[second_sep + 1..].trim();
+
+    if host.is_empty() {
+        return Err(ProxyError::Config(format!(
+            "network.dns_overrides host cannot be empty: '{trimmed}'"
+        )));
+    }
+    if host.contains(':') {
+        return Err(ProxyError::Config(format!(
+            "network.dns_overrides host must be a domain name without ':' in this format: '{trimmed}'"
+        )));
+    }
+
+    let port = port_str.parse::<u16>().map_err(|_| {
+        ProxyError::Config(format!(
+            "network.dns_overrides port is invalid: '{trimmed}'"
+        ))
+    })?;
+    let ip = parse_ip_spec(ip_str)?;
+
+    Ok(((host.to_ascii_lowercase(), port), ip))
+}
+
+fn parse_entries(entries: &[String]) -> Result<OverrideMap> {
+    let mut parsed = HashMap::new();
+    for entry in entries {
+        let (key, ip) = parse_entry(entry)?;
+        parsed.insert(key, ip);
+    }
+    Ok(parsed)
+}
+
+/// Validate `network.dns_overrides` entries without updating runtime state.
+pub fn validate_entries(entries: &[String]) -> Result<()> {
+    let _ = parse_entries(entries)?;
+    Ok(())
+}
+
+/// Replace runtime DNS overrides with a new validated snapshot.
+pub fn install_entries(entries: &[String]) -> Result<()> {
+    let parsed = parse_entries(entries)?;
+    let mut guard = overrides_store()
+        .write()
+        .map_err(|_| ProxyError::Config("network.dns_overrides runtime lock is poisoned".to_string()))?;
+    *guard = parsed;
+    Ok(())
+}
+
+/// Resolve a hostname override for `(host, port)` if present.
+pub fn resolve(host: &str, port: u16) -> Option<IpAddr> {
+    let key = (host.to_ascii_lowercase(), port);
+    overrides_store()
+        .read()
+        .ok()
+        .and_then(|guard| guard.get(&key).copied())
+}
+
+/// Resolve a hostname override and construct a socket address when present.
+pub fn resolve_socket_addr(host: &str, port: u16) -> Option<SocketAddr> {
+    resolve(host, port).map(|ip| SocketAddr::new(ip, port))
+}
+
+/// Parse a runtime endpoint in `host:port` format.
+///
+/// Supports:
+/// - `example.com:443`
+/// - `[2001:db8::1]:443`
+pub fn split_host_port(endpoint: &str) -> Option<(String, u16)> {
+    if endpoint.starts_with('[') {
+        let bracket_end = endpoint.find(']')?;
+        if endpoint.as_bytes().get(bracket_end + 1) != Some(&b':') {
+            return None;
+        }
+        let host = endpoint[1..bracket_end].trim();
+        let port = endpoint[bracket_end + 2..].trim().parse::<u16>().ok()?;
+        if host.is_empty() {
+            return None;
+        }
+        return Some((host.to_ascii_lowercase(), port));
+    }
+
+    let split_idx = endpoint.rfind(':')?;
+    let host = endpoint[..split_idx].trim();
+    let port = endpoint[split_idx + 1..].trim().parse::<u16>().ok()?;
+    if host.is_empty() || host.contains(':') {
+        return None;
+    }
+
+    Some((host.to_ascii_lowercase(), port))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn validate_accepts_ipv4_and_bracketed_ipv6() {
+        let entries = vec![
+            "example.com:443:127.0.0.1".to_string(),
+            "example.net:8443:[2001:db8::10]".to_string(),
+        ];
+        assert!(validate_entries(&entries).is_ok());
+    }
+
+    #[test]
+    fn validate_rejects_unbracketed_ipv6() {
+        let entries = vec!["example.net:443:2001:db8::10".to_string()];
+        let err = validate_entries(&entries).unwrap_err().to_string();
+        assert!(err.contains("must be bracketed"));
+    }
+
+    #[test]
+    fn install_and_resolve_are_case_insensitive_for_host() {
+        let entries = vec!["MyPetrovich.ru:8443:127.0.0.1".to_string()];
+        install_entries(&entries).unwrap();
+
+        let resolved = resolve("mypetrovich.ru", 8443);
+        assert_eq!(resolved, Some("127.0.0.1".parse().unwrap()));
+    }
+
+    #[test]
+    fn split_host_port_parses_supported_shapes() {
+        assert_eq!(
+            split_host_port("example.com:443"),
+            Some(("example.com".to_string(), 443))
+        );
+        assert_eq!(
+            split_host_port("[2001:db8::1]:443"),
+            Some(("2001:db8::1".to_string(), 443))
+        );
+        assert_eq!(split_host_port("2001:db8::1:443"), None);
+    }
+}

src/network/mod.rs

@@ -0,0 +1,5 @@
+pub mod dns_overrides;
+pub mod probe;
+pub mod stun;
+
+pub use stun::IpFamily;

src/network/probe.rs

@@ -0,0 +1,378 @@
+#![allow(dead_code)]
+
+use std::collections::HashMap;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, UdpSocket};
+use std::time::Duration;
+
+use tokio::task::JoinSet;
+use tokio::time::timeout;
+use tracing::{debug, info, warn};
+
+use crate::config::NetworkConfig;
+use crate::error::Result;
+use crate::network::stun::{stun_probe_dual, DualStunResult, IpFamily, StunProbeResult};
+
+#[derive(Debug, Clone, Default)]
+pub struct NetworkProbe {
+    pub detected_ipv4: Option<Ipv4Addr>,
+    pub detected_ipv6: Option<Ipv6Addr>,
+    pub reflected_ipv4: Option<SocketAddr>,
+    pub reflected_ipv6: Option<SocketAddr>,
+    pub ipv4_is_bogon: bool,
+    pub ipv6_is_bogon: bool,
+    pub ipv4_nat_detected: bool,
+    pub ipv6_nat_detected: bool,
+    pub ipv4_usable: bool,
+    pub ipv6_usable: bool,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct NetworkDecision {
+    pub ipv4_dc: bool,
+    pub ipv6_dc: bool,
+    pub ipv4_me: bool,
+    pub ipv6_me: bool,
+    pub effective_prefer: u8,
+    pub effective_multipath: bool,
+}
+
+impl NetworkDecision {
+    pub fn prefer_ipv6(&self) -> bool {
+        self.effective_prefer == 6
+    }
+
+    pub fn me_families(&self) -> Vec<IpFamily> {
+        let mut res = Vec::new();
+        if self.ipv4_me {
+            res.push(IpFamily::V4);
+        }
+        if self.ipv6_me {
+            res.push(IpFamily::V6);
+        }
+        res
+    }
+}
+
+const STUN_BATCH_TIMEOUT: Duration = Duration::from_secs(5);
+
+pub async fn run_probe(
+    config: &NetworkConfig,
+    nat_probe: bool,
+    stun_nat_probe_concurrency: usize,
+) -> Result<NetworkProbe> {
+    let mut probe = NetworkProbe::default();
+
+    probe.detected_ipv4 = detect_local_ip_v4();
+    probe.detected_ipv6 = detect_local_ip_v6();
+
+    probe.ipv4_is_bogon = probe.detected_ipv4.map(is_bogon_v4).unwrap_or(false);
+    probe.ipv6_is_bogon = probe.detected_ipv6.map(is_bogon_v6).unwrap_or(false);
+
+    let stun_res = if nat_probe && config.stun_use {
+        let servers = collect_stun_servers(config);
+        if servers.is_empty() {
+            warn!("STUN probe is enabled but network.stun_servers is empty");
+            DualStunResult::default()
+        } else {
+            probe_stun_servers_parallel(
+                &servers,
+                stun_nat_probe_concurrency.max(1),
+            )
+            .await
+        }
+    } else if nat_probe {
+        info!("STUN probe is disabled by network.stun_use=false");
+        DualStunResult::default()
+    } else {
+        DualStunResult::default()
+    };
+    probe.reflected_ipv4 = stun_res.v4.map(|r| r.reflected_addr);
+    probe.reflected_ipv6 = stun_res.v6.map(|r| r.reflected_addr);
+
+    // If STUN is blocked but IPv4 is private, try HTTP public-IP fallback.
+    if nat_probe
+        && probe.reflected_ipv4.is_none()
+        && probe.detected_ipv4.map(is_bogon_v4).unwrap_or(false)
+    {
+        if let Some(public_ip) = detect_public_ipv4_http(&config.http_ip_detect_urls).await {
+            probe.reflected_ipv4 = Some(SocketAddr::new(IpAddr::V4(public_ip), 0));
+            info!(public_ip = %public_ip, "STUN unavailable, using HTTP public IPv4 fallback");
+        }
+    }
+
+    probe.ipv4_nat_detected = match (probe.detected_ipv4, probe.reflected_ipv4) {
+        (Some(det), Some(reflected)) => det != reflected.ip(),
+        _ => false,
+    };
+    probe.ipv6_nat_detected = match (probe.detected_ipv6, probe.reflected_ipv6) {
+        (Some(det), Some(reflected)) => det != reflected.ip(),
+        _ => false,
+    };
+
+    probe.ipv4_usable = config.ipv4
+        && probe.detected_ipv4.is_some()
+        && (!probe.ipv4_is_bogon || probe.reflected_ipv4.map(|r| !is_bogon(r.ip())).unwrap_or(false));
+
+    let ipv6_enabled = config.ipv6.unwrap_or(probe.detected_ipv6.is_some());
+    probe.ipv6_usable = ipv6_enabled
+        && probe.detected_ipv6.is_some()
+        && (!probe.ipv6_is_bogon || probe.reflected_ipv6.map(|r| !is_bogon(r.ip())).unwrap_or(false));
+
+    Ok(probe)
+}
+
+async fn detect_public_ipv4_http(urls: &[String]) -> Option<Ipv4Addr> {
+    let client = reqwest::Client::builder()
+        .timeout(Duration::from_secs(3))
+        .build()
+        .ok()?;
+
+    for url in urls {
+        let response = match client.get(url).send().await {
+            Ok(response) => response,
+            Err(_) => continue,
+        };
+
+        let body = match response.text().await {
+            Ok(body) => body,
+            Err(_) => continue,
+        };
+
+        let Ok(ip) = body.trim().parse::<Ipv4Addr>() else {
+            continue;
+        };
+        if !is_bogon_v4(ip) {
+            return Some(ip);
+        }
+    }
+
+    None
+}
+
+fn collect_stun_servers(config: &NetworkConfig) -> Vec<String> {
+    let mut out = Vec::new();
+    for s in &config.stun_servers {
+        if !s.is_empty() && !out.contains(s) {
+            out.push(s.clone());
+        }
+    }
+    out
+}
+
+async fn probe_stun_servers_parallel(
+    servers: &[String],
+    concurrency: usize,
+) -> DualStunResult {
+    let mut join_set = JoinSet::new();
+    let mut next_idx = 0usize;
+    let mut best_v4_by_ip: HashMap<IpAddr, (usize, StunProbeResult)> = HashMap::new();
+    let mut best_v6_by_ip: HashMap<IpAddr, (usize, StunProbeResult)> = HashMap::new();
+
+    while next_idx < servers.len() || !join_set.is_empty() {
+        while next_idx < servers.len() && join_set.len() < concurrency {
+            let stun_addr = servers[next_idx].clone();
+            next_idx += 1;
+            join_set.spawn(async move {
+                let res = timeout(STUN_BATCH_TIMEOUT, stun_probe_dual(&stun_addr)).await;
+                (stun_addr, res)
+            });
+        }
+
+        let Some(task) = join_set.join_next().await else {
+            break;
+        };
+
+        match task {
+            Ok((stun_addr, Ok(Ok(result)))) => {
+                if let Some(v4) = result.v4 {
+                    let entry = best_v4_by_ip.entry(v4.reflected_addr.ip()).or_insert((0, v4));
+                    entry.0 += 1;
+                }
+                if let Some(v6) = result.v6 {
+                    let entry = best_v6_by_ip.entry(v6.reflected_addr.ip()).or_insert((0, v6));
+                    entry.0 += 1;
+                }
+                if result.v4.is_some() || result.v6.is_some() {
+                    debug!(stun = %stun_addr, "STUN server responded within probe timeout");
+                }
+            }
+            Ok((stun_addr, Ok(Err(e)))) => {
+                debug!(error = %e, stun = %stun_addr, "STUN probe failed");
+            }
+            Ok((stun_addr, Err(_))) => {
+                debug!(stun = %stun_addr, "STUN probe timeout");
+            }
+            Err(e) => {
+                debug!(error = %e, "STUN probe task join failed");
+            }
+        }
+    }
+
+    let mut out = DualStunResult::default();
+    if let Some((_, best)) = best_v4_by_ip
+        .into_values()
+        .max_by_key(|(count, _)| *count)
+    {
+        info!("STUN-Quorum reached, IP: {}", best.reflected_addr.ip());
+        out.v4 = Some(best);
+    }
+    if let Some((_, best)) = best_v6_by_ip
+        .into_values()
+        .max_by_key(|(count, _)| *count)
+    {
+        info!("STUN-Quorum reached, IP: {}", best.reflected_addr.ip());
+        out.v6 = Some(best);
+    }
+    out
+}
+
+pub fn decide_network_capabilities(config: &NetworkConfig, probe: &NetworkProbe) -> NetworkDecision {
+    let ipv4_dc = config.ipv4 && probe.detected_ipv4.is_some();
+    let ipv6_dc = config.ipv6.unwrap_or(probe.detected_ipv6.is_some()) && probe.detected_ipv6.is_some();
+
+    let ipv4_me = config.ipv4
+        && probe.detected_ipv4.is_some()
+        && (!probe.ipv4_is_bogon || probe.reflected_ipv4.is_some());
+
+    let ipv6_enabled = config.ipv6.unwrap_or(probe.detected_ipv6.is_some());
+    let ipv6_me = ipv6_enabled
+        && probe.detected_ipv6.is_some()
+        && (!probe.ipv6_is_bogon || probe.reflected_ipv6.is_some());
+
+    let effective_prefer = match config.prefer {
+        6 if ipv6_me || ipv6_dc => 6,
+        4 if ipv4_me || ipv4_dc => 4,
+        6 => {
+            warn!("prefer=6 requested but IPv6 unavailable; falling back to IPv4");
+            4
+        }
+        _ => 4,
+    };
+
+    let me_families = ipv4_me as u8 + ipv6_me as u8;
+    let effective_multipath = config.multipath && me_families >= 2;
+
+    NetworkDecision {
+        ipv4_dc,
+        ipv6_dc,
+        ipv4_me,
+        ipv6_me,
+        effective_prefer,
+        effective_multipath,
+    }
+}
+
+fn detect_local_ip_v4() -> Option<Ipv4Addr> {
+    let socket = UdpSocket::bind("0.0.0.0:0").ok()?;
+    socket.connect("8.8.8.8:80").ok()?;
+    match socket.local_addr().ok()?.ip() {
+        IpAddr::V4(v4) => Some(v4),
+        _ => None,
+    }
+}
+
+fn detect_local_ip_v6() -> Option<Ipv6Addr> {
+    let socket = UdpSocket::bind("[::]:0").ok()?;
+    socket.connect("[2001:4860:4860::8888]:80").ok()?;
+    match socket.local_addr().ok()?.ip() {
+        IpAddr::V6(v6) => Some(v6),
+        _ => None,
+    }
+}
+
+pub fn detect_interface_ipv4() -> Option<Ipv4Addr> {
+    detect_local_ip_v4()
+}
+
+pub fn detect_interface_ipv6() -> Option<Ipv6Addr> {
+    detect_local_ip_v6()
+}
+
+pub fn is_bogon(ip: IpAddr) -> bool {
+    match ip {
+        IpAddr::V4(v4) => is_bogon_v4(v4),
+        IpAddr::V6(v6) => is_bogon_v6(v6),
+    }
+}
+
+pub fn is_bogon_v4(ip: Ipv4Addr) -> bool {
+    let octets = ip.octets();
+    if ip.is_private() || ip.is_loopback() || ip.is_link_local() {
+        return true;
+    }
+    if octets[0] == 0 {
+        return true;
+    }
+    if octets[0] == 100 && (octets[1] & 0xC0) == 64 {
+        return true;
+    }
+    if octets[0] == 192 && octets[1] == 0 && octets[2] == 0 {
+        return true;
+    }
+    if octets[0] == 192 && octets[1] == 0 && octets[2] == 2 {
+        return true;
+    }
+    if octets[0] == 198 && (octets[1] & 0xFE) == 18 {
+        return true;
+    }
+    if octets[0] == 198 && octets[1] == 51 && octets[2] == 100 {
+        return true;
+    }
+    if octets[0] == 203 && octets[1] == 0 && octets[2] == 113 {
+        return true;
+    }
+    if ip.is_multicast() {
+        return true;
+    }
+    if octets[0] >= 240 {
+        return true;
+    }
+    if ip.is_broadcast() {
+        return true;
+    }
+    false
+}
+
+pub fn is_bogon_v6(ip: Ipv6Addr) -> bool {
+    if ip.is_unspecified() || ip.is_loopback() || ip.is_unique_local() {
+        return true;
+    }
+    let segs = ip.segments();
+    if (segs[0] & 0xFFC0) == 0xFE80 {
+        return true;
+    }
+    if segs[0..5] == [0, 0, 0, 0, 0] && segs[5] == 0xFFFF {
+        return true;
+    }
+    if segs[0] == 0x0100 && segs[1..4] == [0, 0, 0] {
+        return true;
+    }
+    if segs[0] == 0x2001 && segs[1] == 0x0db8 {
+        return true;
+    }
+    if segs[0] == 0x2002 {
+        return true;
+    }
+    if ip.is_multicast() {
+        return true;
+    }
+    false
+}
+
+pub fn log_probe_result(probe: &NetworkProbe, decision: &NetworkDecision) {
+    info!(
+        ipv4 = probe.detected_ipv4.as_ref().map(|v| v.to_string()).unwrap_or_else(|| "-".into()),
+        ipv6 = probe.detected_ipv6.as_ref().map(|v| v.to_string()).unwrap_or_else(|| "-".into()),
+        reflected_v4 = probe.reflected_ipv4.as_ref().map(|v| v.ip().to_string()).unwrap_or_else(|| "-".into()),
+        reflected_v6 = probe.reflected_ipv6.as_ref().map(|v| v.ip().to_string()).unwrap_or_else(|| "-".into()),
+        ipv4_bogon = probe.ipv4_is_bogon,
+        ipv6_bogon = probe.ipv6_is_bogon,
+        ipv4_me = decision.ipv4_me,
+        ipv6_me = decision.ipv6_me,
+        ipv4_dc = decision.ipv4_dc,
+        ipv6_dc = decision.ipv6_dc,
+        prefer = decision.effective_prefer,
+        multipath = decision.effective_multipath,
+        "Network capabilities resolved"
+    );
+}

src/network/stun.rs

@@ -0,0 +1,234 @@
+#![allow(unreachable_code)]
+#![allow(dead_code)]
+
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
+
+use tokio::net::{lookup_host, UdpSocket};
+use tokio::time::{timeout, Duration, sleep};
+
+use crate::error::{ProxyError, Result};
+use crate::network::dns_overrides::{resolve, split_host_port};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum IpFamily {
+    V4,
+    V6,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct StunProbeResult {
+    pub local_addr: SocketAddr,
+    pub reflected_addr: SocketAddr,
+    pub family: IpFamily,
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct DualStunResult {
+    pub v4: Option<StunProbeResult>,
+    pub v6: Option<StunProbeResult>,
+}
+
+pub async fn stun_probe_dual(stun_addr: &str) -> Result<DualStunResult> {
+    let (v4, v6) = tokio::join!(
+        stun_probe_family(stun_addr, IpFamily::V4),
+        stun_probe_family(stun_addr, IpFamily::V6),
+    );
+
+    Ok(DualStunResult {
+        v4: v4?,
+        v6: v6?,
+    })
+}
+
+pub async fn stun_probe_family(stun_addr: &str, family: IpFamily) -> Result<Option<StunProbeResult>> {
+    stun_probe_family_with_bind(stun_addr, family, None).await
+}
+
+pub async fn stun_probe_family_with_bind(
+    stun_addr: &str,
+    family: IpFamily,
+    bind_ip: Option<IpAddr>,
+) -> Result<Option<StunProbeResult>> {
+    use rand::RngCore;
+
+    let bind_addr = match (family, bind_ip) {
+        (IpFamily::V4, Some(IpAddr::V4(ip))) => SocketAddr::new(IpAddr::V4(ip), 0),
+        (IpFamily::V6, Some(IpAddr::V6(ip))) => SocketAddr::new(IpAddr::V6(ip), 0),
+        (IpFamily::V4, Some(IpAddr::V6(_))) | (IpFamily::V6, Some(IpAddr::V4(_))) => {
+            return Ok(None);
+        }
+        (IpFamily::V4, None) => SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), 0),
+        (IpFamily::V6, None) => SocketAddr::new(IpAddr::V6(Ipv6Addr::UNSPECIFIED), 0),
+    };
+
+    let socket = match UdpSocket::bind(bind_addr).await {
+        Ok(socket) => socket,
+        Err(_) if bind_ip.is_some() => return Ok(None),
+        Err(e) => return Err(ProxyError::Proxy(format!("STUN bind failed: {e}"))),
+    };
+
+    let target_addr = resolve_stun_addr(stun_addr, family).await?;
+    if let Some(addr) = target_addr {
+        match socket.connect(addr).await {
+            Ok(()) => {}
+            Err(e) if family == IpFamily::V6 && matches!(
+                e.kind(),
+                std::io::ErrorKind::NetworkUnreachable
+                | std::io::ErrorKind::HostUnreachable
+                | std::io::ErrorKind::Unsupported
+                | std::io::ErrorKind::NetworkDown
+            ) => return Ok(None),
+            Err(e) => return Err(ProxyError::Proxy(format!("STUN connect failed: {e}"))),
+        }
+    } else {
+        return Ok(None);
+    }
+
+    let mut req = [0u8; 20];
+    req[0..2].copy_from_slice(&0x0001u16.to_be_bytes()); // Binding Request
+    req[2..4].copy_from_slice(&0u16.to_be_bytes()); // length
+    req[4..8].copy_from_slice(&0x2112A442u32.to_be_bytes()); // magic cookie
+    rand::rng().fill_bytes(&mut req[8..20]); // transaction ID
+
+    let mut buf = [0u8; 256];
+    let mut attempt = 0;
+    let mut backoff = Duration::from_secs(1);
+    loop {
+        socket
+            .send(&req)
+            .await
+            .map_err(|e| ProxyError::Proxy(format!("STUN send failed: {e}")))?;
+
+        let recv_res = timeout(Duration::from_secs(3), socket.recv(&mut buf)).await;
+        let n = match recv_res {
+            Ok(Ok(n)) => n,
+            Ok(Err(e)) => return Err(ProxyError::Proxy(format!("STUN recv failed: {e}"))),
+            Err(_) => {
+                attempt += 1;
+                if attempt >= 3 {
+                    return Ok(None);
+                }
+                sleep(backoff).await;
+                backoff *= 2;
+                continue;
+            }
+        };
+
+        if n < 20 {
+            return Ok(None);
+        }
+
+        let magic = 0x2112A442u32.to_be_bytes();
+        let txid = &req[8..20];
+    let mut idx = 20;
+    while idx + 4 <= n {
+        let atype = u16::from_be_bytes(buf[idx..idx + 2].try_into().unwrap());
+        let alen = u16::from_be_bytes(buf[idx + 2..idx + 4].try_into().unwrap()) as usize;
+        idx += 4;
+        if idx + alen > n {
+            break;
+        }
+
+        match atype {
+            0x0020 /* XOR-MAPPED-ADDRESS */ | 0x0001 /* MAPPED-ADDRESS */ => {
+                if alen < 8 {
+                    break;
+                }
+                let family_byte = buf[idx + 1];
+                let port_bytes = [buf[idx + 2], buf[idx + 3]];
+                let len_check = match family_byte {
+                    0x01 => 4,
+                    0x02 => 16,
+                    _ => 0,
+                };
+                if len_check == 0 || alen < 4 + len_check {
+                    break;
+                }
+
+                let raw_ip = &buf[idx + 4..idx + 4 + len_check];
+                let mut port = u16::from_be_bytes(port_bytes);
+
+                let reflected_ip = if atype == 0x0020 {
+                    port ^= ((magic[0] as u16) << 8) | magic[1] as u16;
+                    match family_byte {
+                        0x01 => {
+                            let ip = [
+                                raw_ip[0] ^ magic[0],
+                                raw_ip[1] ^ magic[1],
+                                raw_ip[2] ^ magic[2],
+                                raw_ip[3] ^ magic[3],
+                            ];
+                            IpAddr::V4(Ipv4Addr::new(ip[0], ip[1], ip[2], ip[3]))
+                        }
+                        0x02 => {
+                            let mut ip = [0u8; 16];
+                            let xor_key = [magic.as_slice(), txid].concat();
+                            for (i, b) in raw_ip.iter().enumerate().take(16) {
+                                ip[i] = *b ^ xor_key[i];
+                            }
+                            IpAddr::V6(Ipv6Addr::from(ip))
+                        }
+                        _ => {
+                            idx += (alen + 3) & !3;
+                            continue;
+                        }
+                    }
+                } else {
+                    match family_byte {
+                        0x01 => IpAddr::V4(Ipv4Addr::new(raw_ip[0], raw_ip[1], raw_ip[2], raw_ip[3])),
+                        0x02 => IpAddr::V6(Ipv6Addr::from(<[u8; 16]>::try_from(raw_ip).unwrap())),
+                        _ => {
+                            idx += (alen + 3) & !3;
+                            continue;
+                        }
+                    }
+                };
+
+                let reflected_addr = SocketAddr::new(reflected_ip, port);
+                let local_addr = socket
+                    .local_addr()
+                    .map_err(|e| ProxyError::Proxy(format!("STUN local_addr failed: {e}")))?;
+
+                return Ok(Some(StunProbeResult {
+                    local_addr,
+                    reflected_addr,
+                    family,
+                }));
+            }
+            _ => {}
+        }
+
+        idx += (alen + 3) & !3;
+    }
+
+    }
+
+    Ok(None)
+}
+
+async fn resolve_stun_addr(stun_addr: &str, family: IpFamily) -> Result<Option<SocketAddr>> {
+    if let Ok(addr) = stun_addr.parse::<SocketAddr>() {
+        return Ok(match (addr.is_ipv4(), family) {
+            (true, IpFamily::V4) | (false, IpFamily::V6) => Some(addr),
+            _ => None,
+        });
+    }
+
+    if let Some((host, port)) = split_host_port(stun_addr)
+        && let Some(ip) = resolve(&host, port)
+    {
+        let addr = SocketAddr::new(ip, port);
+        return Ok(match (addr.is_ipv4(), family) {
+            (true, IpFamily::V4) | (false, IpFamily::V6) => Some(addr),
+            _ => None,
+        });
+    }
+
+    let mut addrs = lookup_host(stun_addr)
+        .await
+        .map_err(|e| ProxyError::Proxy(format!("STUN resolve failed: {e}")))?;
+
+    let target = addrs
+        .find(|a| matches!((a.is_ipv4(), family), (true, IpFamily::V4) | (false, IpFamily::V6)));
+    Ok(target)
+}

src/protocol/constants.rs

@@ -1,13 +1,17 @@
 //! Protocol constants and datacenter addresses
 
-use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
-use once_cell::sync::Lazy;
+#![allow(dead_code)]
+
+use std::net::{IpAddr, Ipv4Addr};
+
+use crate::crypto::SecureRandom;
+use std::sync::LazyLock;
 
 // ============= Telegram Datacenters =============
 
 pub const TG_DATACENTER_PORT: u16 = 443;
 
-pub static TG_DATACENTERS_V4: Lazy<Vec<IpAddr>> = Lazy::new(|| {
+pub static TG_DATACENTERS_V4: LazyLock<Vec<IpAddr>> = LazyLock::new(|| {
     vec![
         IpAddr::V4(Ipv4Addr::new(149, 154, 175, 50)),
         IpAddr::V4(Ipv4Addr::new(149, 154, 167, 51)),
@@ -17,7 +21,7 @@ pub static TG_DATACENTERS_V4: Lazy<Vec<IpAddr>> = Lazy::new(|| {
     ]
 });
 
-pub static TG_DATACENTERS_V6: Lazy<Vec<IpAddr>> = Lazy::new(|| {
+pub static TG_DATACENTERS_V6: LazyLock<Vec<IpAddr>> = LazyLock::new(|| {
     vec![
         IpAddr::V6("2001:b28:f23d:f001::a".parse().unwrap()),
         IpAddr::V6("2001:67c:04e8:f002::a".parse().unwrap()),
@@ -29,8 +33,8 @@ pub static TG_DATACENTERS_V6: Lazy<Vec<IpAddr>> = Lazy::new(|| {
 
 // ============= Middle Proxies (for advertising) =============
 
-pub static TG_MIDDLE_PROXIES_V4: Lazy<std::collections::HashMap<i32, Vec<(IpAddr, u16)>>> = 
-    Lazy::new(|| {
+pub static TG_MIDDLE_PROXIES_V4: LazyLock<std::collections::HashMap<i32, Vec<(IpAddr, u16)>>> = 
+    LazyLock::new(|| {
         let mut m = std::collections::HashMap::new();
         m.insert(1, vec![(IpAddr::V4(Ipv4Addr::new(149, 154, 175, 50)), 8888)]);
         m.insert(-1, vec![(IpAddr::V4(Ipv4Addr::new(149, 154, 175, 50)), 8888)]);
@@ -45,8 +49,8 @@ pub static TG_MIDDLE_PROXIES_V4: Lazy<std::collections::HashMap<i32, Vec<(IpAddr
         m
     });
 
-pub static TG_MIDDLE_PROXIES_V6: Lazy<std::collections::HashMap<i32, Vec<(IpAddr, u16)>>> = 
-    Lazy::new(|| {
+pub static TG_MIDDLE_PROXIES_V6: LazyLock<std::collections::HashMap<i32, Vec<(IpAddr, u16)>>> = 
+    LazyLock::new(|| {
         let mut m = std::collections::HashMap::new();
         m.insert(1, vec![(IpAddr::V6("2001:b28:f23d:f001::d".parse().unwrap()), 8888)]);
         m.insert(-1, vec![(IpAddr::V6("2001:b28:f23d:f001::d".parse().unwrap()), 8888)]);
@@ -151,7 +155,32 @@ pub const TLS_RECORD_ALERT: u8 = 0x15;
 /// Maximum TLS record size
 pub const MAX_TLS_RECORD_SIZE: usize = 16384;
 /// Maximum TLS chunk size (with overhead)
-pub const MAX_TLS_CHUNK_SIZE: usize = 16384 + 24;
+/// RFC 8446 §5.2 allows up to 16384 + 256 bytes of ciphertext
+pub const MAX_TLS_CHUNK_SIZE: usize = 16384 + 256;
+
+/// Secure Intermediate payload is expected to be 4-byte aligned.
+pub fn is_valid_secure_payload_len(data_len: usize) -> bool {
+    data_len.is_multiple_of(4)
+}
+
+/// Compute Secure Intermediate payload length from wire length.
+/// Secure mode strips up to 3 random tail bytes by truncating to 4-byte boundary.
+pub fn secure_payload_len_from_wire_len(wire_len: usize) -> Option<usize> {
+    if wire_len < 4 {
+        return None;
+    }
+    Some(wire_len - (wire_len % 4))
+}
+
+/// Generate padding length for Secure Intermediate protocol.
+/// Data must be 4-byte aligned; padding is 1..=3 so total is never divisible by 4.
+pub fn secure_padding_len(data_len: usize, rng: &SecureRandom) -> usize {
+    debug_assert!(
+        is_valid_secure_payload_len(data_len),
+        "Secure payload must be 4-byte aligned, got {data_len}"
+    );
+    rng.range(3) + 1
+}
 
 // ============= Timeouts =============
 
@@ -167,7 +196,8 @@ pub const DEFAULT_ACK_TIMEOUT_SECS: u64 = 300;
 // ============= Buffer Sizes =============
 
 /// Default buffer size
-pub const DEFAULT_BUFFER_SIZE: usize = 65536;
+pub const DEFAULT_BUFFER_SIZE: usize = 16384;
+
 /// Small buffer size for bad client handling
 pub const SMALL_BUFFER_SIZE: usize = 8192;
 
@@ -201,6 +231,16 @@ pub static RESERVED_NONCE_CONTINUES: &[[u8; 4]] = &[
 // ============= RPC Constants (for Middle Proxy) =============
 
 /// RPC Proxy Request
+/// RPC Flags (from Erlang mtp_rpc.erl)
+pub const RPC_FLAG_NOT_ENCRYPTED: u32 = 0x2;
+pub const RPC_FLAG_HAS_AD_TAG: u32    = 0x8;
+pub const RPC_FLAG_MAGIC: u32          = 0x1000;
+pub const RPC_FLAG_EXTMODE2: u32       = 0x20000;
+pub const RPC_FLAG_PAD: u32            = 0x8000000;
+pub const RPC_FLAG_INTERMEDIATE: u32   = 0x20000000;
+pub const RPC_FLAG_ABRIDGED: u32       = 0x40000000;
+pub const RPC_FLAG_QUICKACK: u32       = 0x80000000;
+
 pub const RPC_PROXY_REQ: [u8; 4] = [0xee, 0xf1, 0xce, 0x36];
 /// RPC Proxy Answer
 pub const RPC_PROXY_ANS: [u8; 4] = [0x0d, 0xda, 0x03, 0x44];
@@ -227,7 +267,60 @@ pub mod rpc_flags {
     pub const FLAG_QUICKACK: u32 = 0x80000000;
 }
 
-#[cfg(test)]
+
+    // ============= Middle-End Proxy Servers =============
+    pub const ME_PROXY_PORT: u16 = 8888;
+    
+    pub static TG_MIDDLE_PROXIES_FLAT_V4: LazyLock<Vec<(IpAddr, u16)>> = LazyLock::new(|| {
+        vec![
+            (IpAddr::V4(Ipv4Addr::new(149, 154, 175, 50)), 8888),
+            (IpAddr::V4(Ipv4Addr::new(149, 154, 161, 144)), 8888),
+            (IpAddr::V4(Ipv4Addr::new(149, 154, 175, 100)), 8888),
+            (IpAddr::V4(Ipv4Addr::new(91, 108, 4, 136)), 8888),
+            (IpAddr::V4(Ipv4Addr::new(91, 108, 56, 183)), 8888),
+        ]
+    });
+    
+    // ============= RPC Constants (u32 native endian) =============
+    // From mtproto-common.h + net-tcp-rpc-common.h + mtproto-proxy.c
+    
+    pub const RPC_NONCE_U32: u32           = 0x7acb87aa;
+    pub const RPC_HANDSHAKE_U32: u32       = 0x7682eef5;
+    pub const RPC_HANDSHAKE_ERROR_U32: u32 = 0x6a27beda;
+    pub const TL_PROXY_TAG_U32: u32        = 0xdb1e26ae;  // mtproto-proxy.c:121
+    
+    // mtproto-common.h
+    pub const RPC_PROXY_REQ_U32: u32       = 0x36cef1ee;
+    pub const RPC_PROXY_ANS_U32: u32       = 0x4403da0d;
+    pub const RPC_CLOSE_CONN_U32: u32      = 0x1fcf425d;
+    pub const RPC_CLOSE_EXT_U32: u32       = 0x5eb634a2;
+    pub const RPC_SIMPLE_ACK_U32: u32      = 0x3bac409b;
+    pub const RPC_PING_U32: u32            = 0x5730a2df;
+    pub const RPC_PONG_U32: u32            = 0x8430eaa7;
+    
+    pub const RPC_CRYPTO_NONE_U32: u32 = 0;
+    pub const RPC_CRYPTO_AES_U32: u32  = 1;
+    
+    pub mod proxy_flags {
+        pub const FLAG_HAS_AD_TAG: u32    = 1;
+        pub const FLAG_NOT_ENCRYPTED: u32 = 0x2;
+        pub const FLAG_HAS_AD_TAG2: u32   = 0x8;
+        pub const FLAG_MAGIC: u32         = 0x1000;
+        pub const FLAG_EXTMODE2: u32      = 0x20000;
+        pub const FLAG_PAD: u32           = 0x8000000;
+        pub const FLAG_INTERMEDIATE: u32  = 0x20000000;
+        pub const FLAG_ABRIDGED: u32      = 0x40000000;
+        pub const FLAG_QUICKACK: u32      = 0x80000000;
+    }
+
+    pub mod rpc_crypto_flags {
+        pub const USE_CRC32C: u32 = 0x800;
+    }
+    
+    pub const ME_CONNECT_TIMEOUT_SECS: u64 = 5;
+    pub const ME_HANDSHAKE_TIMEOUT_SECS: u64 = 10;
+    
+    #[cfg(test)]
 mod tests {
     use super::*;
     
@@ -258,4 +351,43 @@ mod tests {
         assert_eq!(TG_DATACENTERS_V4.len(), 5);
         assert_eq!(TG_DATACENTERS_V6.len(), 5);
     }
-}
+
+    #[test]
+    fn secure_padding_never_produces_aligned_total() {
+        let rng = SecureRandom::new();
+        for data_len in (0..1000).step_by(4) {
+            for _ in 0..100 {
+                let padding = secure_padding_len(data_len, &rng);
+                assert!(
+                    padding <= 3,
+                    "padding out of range: data_len={data_len}, padding={padding}"
+                );
+                assert_ne!(
+                    (data_len + padding) % 4,
+                    0,
+                    "invariant violated: data_len={data_len}, padding={padding}, total={}",
+                    data_len + padding
+                );
+            }
+        }
+    }
+
+    #[test]
+    fn secure_wire_len_roundtrip_for_aligned_payload() {
+        for payload_len in (4..4096).step_by(4) {
+            for padding in 0..=3usize {
+                let wire_len = payload_len + padding;
+                let recovered = secure_payload_len_from_wire_len(wire_len);
+                assert_eq!(recovered, Some(payload_len));
+            }
+        }
+    }
+
+    #[test]
+    fn secure_wire_len_rejects_too_short_frames() {
+        assert_eq!(secure_payload_len_from_wire_len(0), None);
+        assert_eq!(secure_payload_len_from_wire_len(1), None);
+        assert_eq!(secure_payload_len_from_wire_len(2), None);
+        assert_eq!(secure_payload_len_from_wire_len(3), None);
+    }
+}

src/protocol/frame.rs

@@ -1,5 +1,7 @@
 //! MTProto frame types and metadata
 
+#![allow(dead_code)]
+
 use std::collections::HashMap;
 
 /// Extra metadata associated with a frame
@@ -83,7 +85,7 @@ impl FrameMode {
 pub fn validate_message_length(len: usize) -> bool {
     use super::constants::{MIN_MSG_LEN, MAX_MSG_LEN, PADDING_FILLER};
     
-    len >= MIN_MSG_LEN && len <= MAX_MSG_LEN && len % PADDING_FILLER.len() == 0
+    (MIN_MSG_LEN..=MAX_MSG_LEN).contains(&len) && len.is_multiple_of(PADDING_FILLER.len())
 }
 
 #[cfg(test)]

src/protocol/mod.rs

@@ -5,7 +5,11 @@ pub mod frame;
 pub mod obfuscation;
 pub mod tls;
 
+#[allow(unused_imports)]
 pub use constants::*;
+#[allow(unused_imports)]
 pub use frame::*;
+#[allow(unused_imports)]
 pub use obfuscation::*;
+#[allow(unused_imports)]
 pub use tls::*;

src/protocol/obfuscation.rs

@@ -1,10 +1,14 @@
 //! MTProto Obfuscation
 
+#![allow(dead_code)]
+
+use zeroize::Zeroize;
 use crate::crypto::{sha256, AesCtr};
-use crate::error::Result;
 use super::constants::*;
 
 /// Obfuscation parameters from handshake
+///
+/// Key material is zeroized on drop.
 #[derive(Debug, Clone)]
 pub struct ObfuscationParams {
     /// Key for decrypting client -> proxy traffic
@@ -21,25 +25,31 @@ pub struct ObfuscationParams {
     pub dc_idx: i16,
 }
 
+impl Drop for ObfuscationParams {
+    fn drop(&mut self) {
+        self.decrypt_key.zeroize();
+        self.decrypt_iv.zeroize();
+        self.encrypt_key.zeroize();
+        self.encrypt_iv.zeroize();
+    }
+}
+
 impl ObfuscationParams {
     /// Parse obfuscation parameters from handshake bytes
     /// Returns None if handshake doesn't match any user secret
     pub fn from_handshake(
         handshake: &[u8; HANDSHAKE_LEN],
-        secrets: &[(String, Vec<u8>)], // (username, secret_bytes)
+        secrets: &[(String, Vec<u8>)],
     ) -> Option<(Self, String)> {
-        // Extract prekey and IV for decryption
         let dec_prekey_iv = &handshake[SKIP_LEN..SKIP_LEN + PREKEY_LEN + IV_LEN];
         let dec_prekey = &dec_prekey_iv[..PREKEY_LEN];
         let dec_iv_bytes = &dec_prekey_iv[PREKEY_LEN..];
         
-        // Reversed for encryption direction
         let enc_prekey_iv: Vec<u8> = dec_prekey_iv.iter().rev().copied().collect();
         let enc_prekey = &enc_prekey_iv[..PREKEY_LEN];
         let enc_iv_bytes = &enc_prekey_iv[PREKEY_LEN..];
         
         for (username, secret) in secrets {
-            // Derive decryption key
             let mut dec_key_input = Vec::with_capacity(PREKEY_LEN + secret.len());
             dec_key_input.extend_from_slice(dec_prekey);
             dec_key_input.extend_from_slice(secret);
@@ -47,26 +57,22 @@ impl ObfuscationParams {
             
             let decrypt_iv = u128::from_be_bytes(dec_iv_bytes.try_into().unwrap());
             
-            // Create decryptor and decrypt handshake
             let mut decryptor = AesCtr::new(&decrypt_key, decrypt_iv);
             let decrypted = decryptor.decrypt(handshake);
             
-            // Check protocol tag
             let tag_bytes: [u8; 4] = decrypted[PROTO_TAG_POS..PROTO_TAG_POS + 4]
                 .try_into()
                 .unwrap();
             
             let proto_tag = match ProtoTag::from_bytes(tag_bytes) {
                 Some(tag) => tag,
-                None => continue, // Try next secret
+                None => continue,
             };
             
-            // Extract DC index
             let dc_idx = i16::from_le_bytes(
                 decrypted[DC_IDX_POS..DC_IDX_POS + 2].try_into().unwrap()
             );
             
-            // Derive encryption key
             let mut enc_key_input = Vec::with_capacity(PREKEY_LEN + secret.len());
             enc_key_input.extend_from_slice(enc_prekey);
             enc_key_input.extend_from_slice(secret);
@@ -123,18 +129,15 @@ pub fn generate_nonce<R: FnMut(usize) -> Vec<u8>>(mut random_bytes: R) -> [u8; H
 
 /// Check if nonce is valid (not matching reserved patterns)
 pub fn is_valid_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> bool {
-    // Check first byte
     if RESERVED_NONCE_FIRST_BYTES.contains(&nonce[0]) {
         return false;
     }
     
-    // Check first 4 bytes
     let first_four: [u8; 4] = nonce[..4].try_into().unwrap();
     if RESERVED_NONCE_BEGINNINGS.contains(&first_four) {
         return false;
     }
     
-    // Check bytes 4-7
     let continue_four: [u8; 4] = nonce[4..8].try_into().unwrap();
     if RESERVED_NONCE_CONTINUES.contains(&continue_four) {
         return false;
@@ -147,12 +150,10 @@ pub fn is_valid_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> bool {
 pub fn prepare_tg_nonce(
     nonce: &mut [u8; HANDSHAKE_LEN],
     proto_tag: ProtoTag,
-    enc_key_iv: Option<&[u8]>, // For fast mode
+    enc_key_iv: Option<&[u8]>,
 ) {
-    // Set protocol tag
     nonce[PROTO_TAG_POS..PROTO_TAG_POS + 4].copy_from_slice(&proto_tag.to_bytes());
     
-    // For fast mode, copy the reversed enc_key_iv
     if let Some(key_iv) = enc_key_iv {
         let reversed: Vec<u8> = key_iv.iter().rev().copied().collect();
         nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN].copy_from_slice(&reversed);
@@ -160,15 +161,19 @@ pub fn prepare_tg_nonce(
 }
 
 /// Encrypt the outgoing nonce for Telegram
+/// Legacy helper — **do not use**.
+/// WARNING: logic diverges from Python/C reference (SHA256 of 48 bytes, IV from head).
+/// Kept only to avoid breaking external callers; prefer `encrypt_tg_nonce_with_ciphers`.
+#[deprecated(
+    note = "Incorrect MTProto obfuscation KDF; use proxy::handshake::encrypt_tg_nonce_with_ciphers"
+)]
 pub fn encrypt_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> Vec<u8> {
-    // Derive encryption key from the nonce itself
     let key_iv = &nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN];
     let enc_key = sha256(key_iv);
     let enc_iv = u128::from_be_bytes(key_iv[..IV_LEN].try_into().unwrap());
     
     let mut encryptor = AesCtr::new(&enc_key, enc_iv);
     
-    // Only encrypt from PROTO_TAG_POS onwards
     let mut result = nonce.to_vec();
     let encrypted_part = encryptor.encrypt(&nonce[PROTO_TAG_POS..]);
     result[PROTO_TAG_POS..].copy_from_slice(&encrypted_part);
@@ -182,22 +187,18 @@ mod tests {
     
     #[test]
     fn test_is_valid_nonce() {
-        // Valid nonce
         let mut valid = [0x42u8; HANDSHAKE_LEN];
         valid[4..8].copy_from_slice(&[1, 2, 3, 4]);
         assert!(is_valid_nonce(&valid));
         
-        // Invalid: starts with 0xef
         let mut invalid = [0x00u8; HANDSHAKE_LEN];
         invalid[0] = 0xef;
         assert!(!is_valid_nonce(&invalid));
         
-        // Invalid: starts with HEAD
         let mut invalid = [0x00u8; HANDSHAKE_LEN];
         invalid[..4].copy_from_slice(b"HEAD");
         assert!(!is_valid_nonce(&invalid));
         
-        // Invalid: bytes 4-7 are zeros
         let mut invalid = [0x42u8; HANDSHAKE_LEN];
         invalid[4..8].copy_from_slice(&[0, 0, 0, 0]);
         assert!(!is_valid_nonce(&invalid));
@@ -214,4 +215,4 @@ mod tests {
         assert!(is_valid_nonce(&nonce));
         assert_eq!(nonce.len(), HANDSHAKE_LEN);
     }
-}
+}

src/protocol/tls.rs

@@ -4,10 +4,15 @@
 //! for domain fronting. The handshake looks like valid TLS 1.3 but
 //! actually carries MTProto authentication data.
 
-use crate::crypto::{sha256_hmac, random::SECURE_RANDOM};
-use crate::error::{ProxyError, Result};
+#![allow(dead_code)]
+
+use crate::crypto::{sha256_hmac, SecureRandom};
+#[cfg(test)]
+use crate::error::ProxyError;
 use super::constants::*;
 use std::time::{SystemTime, UNIX_EPOCH};
+use num_bigint::BigUint;
+use num_traits::One;
 
 // ============= Public Constants =============
 
@@ -30,6 +35,7 @@ pub const TIME_SKEW_MAX: i64 = 10 * 60;  // 10 minutes after
 mod extension_type {
     pub const KEY_SHARE: u16 = 0x0033;
     pub const SUPPORTED_VERSIONS: u16 = 0x002b;
+    pub const ALPN: u16 = 0x0010;
 }
 
 /// TLS Cipher Suites
@@ -60,6 +66,7 @@ pub struct TlsValidation {
 // ============= TLS Extension Builder =============
 
 /// Builder for TLS extensions with correct length calculation
+#[derive(Clone)]
 struct TlsExtensionBuilder {
     extensions: Vec<u8>,
 }
@@ -106,6 +113,27 @@ impl TlsExtensionBuilder {
         
         self
     }
+
+    /// Add ALPN extension with a single selected protocol.
+    fn add_alpn(&mut self, proto: &[u8]) -> &mut Self {
+        // Extension type: ALPN (0x0010)
+        self.extensions.extend_from_slice(&extension_type::ALPN.to_be_bytes());
+
+        // ALPN extension format:
+        // extension_data length (2 bytes)
+        //   protocols length (2 bytes)
+        //     protocol name length (1 byte)
+        //     protocol name bytes
+        let proto_len = proto.len() as u8;
+        let list_len: u16 = 1 + proto_len as u16;
+        let ext_len: u16 = 2 + list_len;
+
+        self.extensions.extend_from_slice(&ext_len.to_be_bytes());
+        self.extensions.extend_from_slice(&list_len.to_be_bytes());
+        self.extensions.push(proto_len);
+        self.extensions.extend_from_slice(proto);
+        self
+    }
     
     /// Build final extensions with length prefix
     fn build(self) -> Vec<u8> {
@@ -142,6 +170,8 @@ struct ServerHelloBuilder {
     compression: u8,
     /// Extensions
     extensions: TlsExtensionBuilder,
+    /// Selected ALPN protocol (if any)
+    alpn: Option<Vec<u8>>,
 }
 
 impl ServerHelloBuilder {
@@ -152,6 +182,7 @@ impl ServerHelloBuilder {
             cipher_suite: cipher_suite::TLS_AES_128_GCM_SHA256,
             compression: 0x00,
             extensions: TlsExtensionBuilder::new(),
+            alpn: None,
         }
     }
     
@@ -165,10 +196,19 @@ impl ServerHelloBuilder {
         self.extensions.add_supported_versions(0x0304);
         self
     }
+
+    fn with_alpn(mut self, proto: Option<Vec<u8>>) -> Self {
+        self.alpn = proto;
+        self
+    }
     
     /// Build ServerHello message (without record header)
     fn build_message(&self) -> Vec<u8> {
-        let extensions = self.extensions.extensions.clone();
+        let mut ext_builder = self.extensions.clone();
+        if let Some(ref alpn) = self.alpn {
+            ext_builder.add_alpn(alpn);
+        }
+        let extensions = ext_builder.extensions.clone();
         let extensions_len = extensions.len() as u16;
         
         // Calculate total length
@@ -295,7 +335,7 @@ pub fn validate_tls_handshake(
             // This is a quirk in some clients that use uptime instead of real time
             let is_boot_time = timestamp < 60 * 60 * 24 * 1000; // < ~2.7 years in seconds
             
-            if !is_boot_time && (time_diff < TIME_SKEW_MIN || time_diff > TIME_SKEW_MAX) {
+            if !is_boot_time && !(TIME_SKEW_MIN..=TIME_SKEW_MAX).contains(&time_diff) {
                 continue;
             }
         }
@@ -311,13 +351,27 @@ pub fn validate_tls_handshake(
     None
 }
 
+fn curve25519_prime() -> BigUint {
+    (BigUint::one() << 255) - BigUint::from(19u32)
+}
+
 /// Generate a fake X25519 public key for TLS
 ///
-/// This generates random bytes that look like a valid X25519 public key.
-/// Since we're not doing real TLS, the actual cryptographic properties don't matter.
-pub fn gen_fake_x25519_key() -> [u8; 32] {
-    let bytes = SECURE_RANDOM.bytes(32);
-    bytes.try_into().unwrap()
+/// Produces a quadratic residue mod p = 2^255 - 19 by computing n² mod p,
+/// which matches Python/C behavior and avoids DPI fingerprinting.
+pub fn gen_fake_x25519_key(rng: &SecureRandom) -> [u8; 32] {
+    let mut n_bytes = [0u8; 32];
+    n_bytes.copy_from_slice(&rng.bytes(32));
+
+    let n = BigUint::from_bytes_le(&n_bytes);
+    let p = curve25519_prime();
+    let pk = (&n * &n) % &p;
+
+    let mut out = pk.to_bytes_le();
+    out.resize(32, 0);
+    let mut result = [0u8; 32];
+    result.copy_from_slice(&out[..32]);
+    result
 }
 
 /// Build TLS ServerHello response
@@ -333,13 +387,20 @@ pub fn build_server_hello(
     client_digest: &[u8; TLS_DIGEST_LEN],
     session_id: &[u8],
     fake_cert_len: usize,
+    rng: &SecureRandom,
+    alpn: Option<Vec<u8>>,
+    new_session_tickets: u8,
 ) -> Vec<u8> {
-    let x25519_key = gen_fake_x25519_key();
+    const MIN_APP_DATA: usize = 64;
+    const MAX_APP_DATA: usize = 16640; // RFC 8446 §5.2 upper bound
+    let fake_cert_len = fake_cert_len.clamp(MIN_APP_DATA, MAX_APP_DATA);
+    let x25519_key = gen_fake_x25519_key(rng);
     
     // Build ServerHello
     let server_hello = ServerHelloBuilder::new(session_id.to_vec())
         .with_x25519_key(&x25519_key)
         .with_tls13_version()
+        .with_alpn(alpn)
         .build_record();
     
     // Build Change Cipher Spec record
@@ -351,20 +412,40 @@ pub fn build_server_hello(
     ];
     
     // Build fake certificate (Application Data record)
-    let fake_cert = SECURE_RANDOM.bytes(fake_cert_len);
+    let fake_cert = rng.bytes(fake_cert_len);
     let mut app_data_record = Vec::with_capacity(5 + fake_cert_len);
     app_data_record.push(TLS_RECORD_APPLICATION);
     app_data_record.extend_from_slice(&TLS_VERSION);
     app_data_record.extend_from_slice(&(fake_cert_len as u16).to_be_bytes());
+    // Fill ApplicationData with fully random bytes of desired length to avoid
+    // deterministic DPI fingerprints (fixed inner content type markers).
     app_data_record.extend_from_slice(&fake_cert);
     
+    // Build optional NewSessionTicket records (TLS 1.3 handshake messages are encrypted;
+    // here we mimic with opaque ApplicationData records of plausible size).
+    let mut tickets = Vec::new();
+    if new_session_tickets > 0 {
+        for _ in 0..new_session_tickets {
+            let ticket_len: usize = rng.range(48) + 48; // 48-95 bytes
+            let mut record = Vec::with_capacity(5 + ticket_len);
+            record.push(TLS_RECORD_APPLICATION);
+            record.extend_from_slice(&TLS_VERSION);
+            record.extend_from_slice(&(ticket_len as u16).to_be_bytes());
+            record.extend_from_slice(&rng.bytes(ticket_len));
+            tickets.push(record);
+        }
+    }
+
     // Combine all records
     let mut response = Vec::with_capacity(
-        server_hello.len() + change_cipher_spec.len() + app_data_record.len()
+        server_hello.len() + change_cipher_spec.len() + app_data_record.len() + tickets.iter().map(|r| r.len()).sum::<usize>()
     );
     response.extend_from_slice(&server_hello);
     response.extend_from_slice(&change_cipher_spec);
     response.extend_from_slice(&app_data_record);
+    for t in &tickets {
+        response.extend_from_slice(t);
+    }
     
     // Compute HMAC for the response
     let mut hmac_input = Vec::with_capacity(TLS_DIGEST_LEN + response.len());
@@ -380,6 +461,131 @@ pub fn build_server_hello(
     response
 }
 
+/// Extract SNI (server_name) from a TLS ClientHello.
+pub fn extract_sni_from_client_hello(handshake: &[u8]) -> Option<String> {
+    if handshake.len() < 43 || handshake[0] != TLS_RECORD_HANDSHAKE {
+        return None;
+    }
+
+    let mut pos = 5; // after record header
+    if handshake.get(pos).copied()? != 0x01 {
+        return None; // not ClientHello
+    }
+
+    // Handshake length bytes
+    pos += 4; // type + len (3)
+
+    // version (2) + random (32)
+    pos += 2 + 32;
+    if pos + 1 > handshake.len() {
+        return None;
+    }
+
+    let session_id_len = *handshake.get(pos)? as usize;
+    pos += 1 + session_id_len;
+    if pos + 2 > handshake.len() {
+        return None;
+    }
+
+    let cipher_suites_len = u16::from_be_bytes([handshake[pos], handshake[pos + 1]]) as usize;
+    pos += 2 + cipher_suites_len;
+    if pos + 1 > handshake.len() {
+        return None;
+    }
+
+    let comp_len = *handshake.get(pos)? as usize;
+    pos += 1 + comp_len;
+    if pos + 2 > handshake.len() {
+        return None;
+    }
+
+    let ext_len = u16::from_be_bytes([handshake[pos], handshake[pos + 1]]) as usize;
+    pos += 2;
+    let ext_end = pos + ext_len;
+    if ext_end > handshake.len() {
+        return None;
+    }
+
+    while pos + 4 <= ext_end {
+        let etype = u16::from_be_bytes([handshake[pos], handshake[pos + 1]]);
+        let elen = u16::from_be_bytes([handshake[pos + 2], handshake[pos + 3]]) as usize;
+        pos += 4;
+        if pos + elen > ext_end {
+            break;
+        }
+        if etype == 0x0000 && elen >= 5 {
+            // server_name extension
+            let list_len = u16::from_be_bytes([handshake[pos], handshake[pos + 1]]) as usize;
+            let mut sn_pos = pos + 2;
+            let sn_end = std::cmp::min(sn_pos + list_len, pos + elen);
+            while sn_pos + 3 <= sn_end {
+                let name_type = handshake[sn_pos];
+                let name_len = u16::from_be_bytes([handshake[sn_pos + 1], handshake[sn_pos + 2]]) as usize;
+                sn_pos += 3;
+                if sn_pos + name_len > sn_end {
+                    break;
+                }
+                if name_type == 0 && name_len > 0
+                    && let Ok(host) = std::str::from_utf8(&handshake[sn_pos..sn_pos + name_len])
+                {
+                    return Some(host.to_string());
+                }
+                sn_pos += name_len;
+            }
+        }
+        pos += elen;
+    }
+
+    None
+}
+
+/// Extract ALPN protocol list from ClientHello, return in offered order.
+pub fn extract_alpn_from_client_hello(handshake: &[u8]) -> Vec<Vec<u8>> {
+    let mut pos = 5; // after record header
+    if handshake.get(pos) != Some(&0x01) {
+        return Vec::new();
+    }
+    pos += 4; // type + len
+    pos += 2 + 32; // version + random
+    if pos >= handshake.len() { return Vec::new(); }
+    let session_id_len = *handshake.get(pos).unwrap_or(&0) as usize;
+    pos += 1 + session_id_len;
+    if pos + 2 > handshake.len() { return Vec::new(); }
+    let cipher_len = u16::from_be_bytes([handshake[pos], handshake[pos+1]]) as usize;
+    pos += 2 + cipher_len;
+    if pos >= handshake.len() { return Vec::new(); }
+    let comp_len = *handshake.get(pos).unwrap_or(&0) as usize;
+    pos += 1 + comp_len;
+    if pos + 2 > handshake.len() { return Vec::new(); }
+    let ext_len = u16::from_be_bytes([handshake[pos], handshake[pos+1]]) as usize;
+    pos += 2;
+    let ext_end = pos + ext_len;
+    if ext_end > handshake.len() { return Vec::new(); }
+    let mut out = Vec::new();
+    while pos + 4 <= ext_end {
+        let etype = u16::from_be_bytes([handshake[pos], handshake[pos+1]]);
+        let elen = u16::from_be_bytes([handshake[pos+2], handshake[pos+3]]) as usize;
+        pos += 4;
+        if pos + elen > ext_end { break; }
+        if etype == extension_type::ALPN && elen >= 3 {
+            let list_len = u16::from_be_bytes([handshake[pos], handshake[pos+1]]) as usize;
+            let mut lp = pos + 2;
+            let list_end = (pos + 2).saturating_add(list_len).min(pos + elen);
+            while lp < list_end {
+                let plen = handshake[lp] as usize;
+                lp += 1;
+                if lp + plen > list_end { break; }
+                out.push(handshake[lp..lp+plen].to_vec());
+                lp += plen;
+            }
+            break;
+        }
+        pos += elen;
+    }
+    out
+}
+
+
 /// Check if bytes look like a TLS ClientHello
 pub fn is_tls_handshake(first_bytes: &[u8]) -> bool {
     if first_bytes.len() < 3 {
@@ -410,7 +616,7 @@ pub fn parse_tls_record_header(header: &[u8; 5]) -> Option<(u8, u16)> {
 ///
 /// This is useful for testing that our ServerHello is well-formed.
 #[cfg(test)]
-fn validate_server_hello_structure(data: &[u8]) -> Result<()> {
+fn validate_server_hello_structure(data: &[u8]) -> Result<(), ProxyError> {
     if data.len() < 5 {
         return Err(ProxyError::InvalidTlsRecord {
             record_type: 0,
@@ -489,13 +695,25 @@ mod tests {
     
     #[test]
     fn test_gen_fake_x25519_key() {
-        let key1 = gen_fake_x25519_key();
-        let key2 = gen_fake_x25519_key();
+        let rng = SecureRandom::new();
+        let key1 = gen_fake_x25519_key(&rng);
+        let key2 = gen_fake_x25519_key(&rng);
         
         assert_eq!(key1.len(), 32);
         assert_eq!(key2.len(), 32);
         assert_ne!(key1, key2); // Should be random
     }
+
+    #[test]
+    fn test_fake_x25519_key_is_quadratic_residue() {
+        let rng = SecureRandom::new();
+        let key = gen_fake_x25519_key(&rng);
+        let p = curve25519_prime();
+        let k_num = BigUint::from_bytes_le(&key);
+        let exponent = (&p - BigUint::one()) >> 1;
+        let legendre = k_num.modpow(&exponent, &p);
+        assert_eq!(legendre, BigUint::one());
+    }
     
     #[test]
     fn test_tls_extension_builder() {
@@ -545,7 +763,8 @@ mod tests {
         let client_digest = [0x42u8; 32];
         let session_id = vec![0xAA; 32];
         
-        let response = build_server_hello(secret, &client_digest, &session_id, 2048);
+        let rng = SecureRandom::new();
+        let response = build_server_hello(secret, &client_digest, &session_id, 2048, &rng, None, 0);
         
         // Should have at least 3 records
         assert!(response.len() > 100);
@@ -577,8 +796,9 @@ mod tests {
         let client_digest = [0x42u8; 32];
         let session_id = vec![0xAA; 32];
         
-        let response1 = build_server_hello(secret, &client_digest, &session_id, 1024);
-        let response2 = build_server_hello(secret, &client_digest, &session_id, 1024);
+        let rng = SecureRandom::new();
+        let response1 = build_server_hello(secret, &client_digest, &session_id, 1024, &rng, None, 0);
+        let response2 = build_server_hello(secret, &client_digest, &session_id, 1024, &rng, None, 0);
         
         // Digest position should have non-zero data
         let digest1 = &response1[TLS_DIGEST_POS..TLS_DIGEST_POS + TLS_DIGEST_LEN];
@@ -637,4 +857,101 @@ mod tests {
         // Should return None (no match) but not panic
         assert!(result.is_none());
     }
-}
+
+    fn build_client_hello_with_exts(exts: Vec<(u16, Vec<u8>)>, host: &str) -> Vec<u8> {
+        let mut body = Vec::new();
+        body.extend_from_slice(&TLS_VERSION); // legacy version
+        body.extend_from_slice(&[0u8; 32]); // random
+        body.push(0); // session id len
+        body.extend_from_slice(&2u16.to_be_bytes()); // cipher suites len
+        body.extend_from_slice(&[0x13, 0x01]); // TLS_AES_128_GCM_SHA256
+        body.push(1); // compression len
+        body.push(0); // null compression
+
+        // Build SNI extension
+        let host_bytes = host.as_bytes();
+        let mut sni_ext = Vec::new();
+        sni_ext.extend_from_slice(&(host_bytes.len() as u16 + 3).to_be_bytes());
+        sni_ext.push(0);
+        sni_ext.extend_from_slice(&(host_bytes.len() as u16).to_be_bytes());
+        sni_ext.extend_from_slice(host_bytes);
+
+        let mut ext_blob = Vec::new();
+        for (typ, data) in exts {
+            ext_blob.extend_from_slice(&typ.to_be_bytes());
+            ext_blob.extend_from_slice(&(data.len() as u16).to_be_bytes());
+            ext_blob.extend_from_slice(&data);
+        }
+        // SNI last
+        ext_blob.extend_from_slice(&0x0000u16.to_be_bytes());
+        ext_blob.extend_from_slice(&(sni_ext.len() as u16).to_be_bytes());
+        ext_blob.extend_from_slice(&sni_ext);
+
+        body.extend_from_slice(&(ext_blob.len() as u16).to_be_bytes());
+        body.extend_from_slice(&ext_blob);
+
+        let mut handshake = Vec::new();
+        handshake.push(0x01); // ClientHello
+        let len_bytes = (body.len() as u32).to_be_bytes();
+        handshake.extend_from_slice(&len_bytes[1..4]);
+        handshake.extend_from_slice(&body);
+
+        let mut record = Vec::new();
+        record.push(TLS_RECORD_HANDSHAKE);
+        record.extend_from_slice(&[0x03, 0x01]);
+        record.extend_from_slice(&(handshake.len() as u16).to_be_bytes());
+        record.extend_from_slice(&handshake);
+        record
+    }
+
+    #[test]
+    fn test_extract_sni_with_grease_extension() {
+        // GREASE type 0x0a0a with zero length before SNI
+        let ch = build_client_hello_with_exts(vec![(0x0a0a, Vec::new())], "example.com");
+        let sni = extract_sni_from_client_hello(&ch);
+        assert_eq!(sni.as_deref(), Some("example.com"));
+    }
+
+    #[test]
+    fn test_extract_sni_tolerates_empty_unknown_extension() {
+        let ch = build_client_hello_with_exts(vec![(0x1234, Vec::new())], "test.local");
+        let sni = extract_sni_from_client_hello(&ch);
+        assert_eq!(sni.as_deref(), Some("test.local"));
+    }
+
+    #[test]
+    fn test_extract_alpn_single() {
+        let mut alpn_data = Vec::new();
+        // list length = 3 (1 length byte + "h2")
+        alpn_data.extend_from_slice(&3u16.to_be_bytes());
+        alpn_data.push(2);
+        alpn_data.extend_from_slice(b"h2");
+        let ch = build_client_hello_with_exts(vec![(0x0010, alpn_data)], "alpn.test");
+        let alpn = extract_alpn_from_client_hello(&ch);
+        let alpn_str: Vec<String> = alpn
+            .iter()
+            .map(|p| std::str::from_utf8(p).unwrap().to_string())
+            .collect();
+        assert_eq!(alpn_str, vec!["h2"]);
+    }
+
+    #[test]
+    fn test_extract_alpn_multiple() {
+        let mut alpn_data = Vec::new();
+        // list length = 11 (sum of per-proto lengths including length bytes)
+        alpn_data.extend_from_slice(&11u16.to_be_bytes());
+        alpn_data.push(2);
+        alpn_data.extend_from_slice(b"h2");
+        alpn_data.push(4);
+        alpn_data.extend_from_slice(b"spdy");
+        alpn_data.push(2);
+        alpn_data.extend_from_slice(b"h3");
+        let ch = build_client_hello_with_exts(vec![(0x0010, alpn_data)], "alpn.test");
+        let alpn = extract_alpn_from_client_hello(&ch);
+        let alpn_str: Vec<String> = alpn
+            .iter()
+            .map(|p| std::str::from_utf8(p).unwrap().to_string())
+            .collect();
+        assert_eq!(alpn_str, vec!["h2", "spdy", "h3"]);
+    }
+}

src/proxy/direct_relay.rs

@@ -0,0 +1,232 @@
+use std::fs::OpenOptions;
+use std::io::Write;
+use std::net::SocketAddr;
+use std::sync::Arc;
+
+use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
+use tokio::net::TcpStream;
+use tokio::sync::watch;
+use tracing::{debug, info, warn};
+
+use crate::config::ProxyConfig;
+use crate::crypto::SecureRandom;
+use crate::error::{ProxyError, Result};
+use crate::protocol::constants::*;
+use crate::proxy::handshake::{HandshakeSuccess, encrypt_tg_nonce_with_ciphers, generate_tg_nonce};
+use crate::proxy::relay::relay_bidirectional;
+use crate::proxy::route_mode::{
+    RelayRouteMode, RouteCutoverState, ROUTE_SWITCH_ERROR_MSG, affected_cutover_state,
+    cutover_stagger_delay,
+};
+use crate::stats::Stats;
+use crate::stream::{BufferPool, CryptoReader, CryptoWriter};
+use crate::transport::UpstreamManager;
+
+pub(crate) async fn handle_via_direct<R, W>(
+    client_reader: CryptoReader<R>,
+    client_writer: CryptoWriter<W>,
+    success: HandshakeSuccess,
+    upstream_manager: Arc<UpstreamManager>,
+    stats: Arc<Stats>,
+    config: Arc<ProxyConfig>,
+    buffer_pool: Arc<BufferPool>,
+    rng: Arc<SecureRandom>,
+    mut route_rx: watch::Receiver<RouteCutoverState>,
+    route_snapshot: RouteCutoverState,
+    session_id: u64,
+) -> Result<()>
+where
+    R: AsyncRead + Unpin + Send + 'static,
+    W: AsyncWrite + Unpin + Send + 'static,
+{
+    let user = &success.user;
+    let dc_addr = get_dc_addr_static(success.dc_idx, &config)?;
+
+    debug!(
+        user = %user,
+        peer = %success.peer,
+        dc = success.dc_idx,
+        dc_addr = %dc_addr,
+        proto = ?success.proto_tag,
+        mode = "direct",
+        "Connecting to Telegram DC"
+    );
+
+    let tg_stream = upstream_manager
+        .connect(dc_addr, Some(success.dc_idx), user.strip_prefix("scope_").filter(|s| !s.is_empty()))
+        .await?;
+
+    debug!(peer = %success.peer, dc_addr = %dc_addr, "Connected, performing TG handshake");
+
+    let (tg_reader, tg_writer) =
+        do_tg_handshake_static(tg_stream, &success, &config, rng.as_ref()).await?;
+
+    debug!(peer = %success.peer, "TG handshake complete, starting relay");
+
+    stats.increment_user_connects(user);
+    stats.increment_user_curr_connects(user);
+    stats.increment_current_connections_direct();
+
+    let relay_result = relay_bidirectional(
+        client_reader,
+        client_writer,
+        tg_reader,
+        tg_writer,
+        config.general.direct_relay_copy_buf_c2s_bytes,
+        config.general.direct_relay_copy_buf_s2c_bytes,
+        user,
+        Arc::clone(&stats),
+        buffer_pool,
+    );
+    tokio::pin!(relay_result);
+    let relay_result = loop {
+        if let Some(cutover) = affected_cutover_state(
+            &route_rx,
+            RelayRouteMode::Direct,
+            route_snapshot.generation,
+        ) {
+            let delay = cutover_stagger_delay(session_id, cutover.generation);
+            warn!(
+                user = %user,
+                target_mode = cutover.mode.as_str(),
+                cutover_generation = cutover.generation,
+                delay_ms = delay.as_millis() as u64,
+                "Cutover affected direct session, closing client connection"
+            );
+            tokio::time::sleep(delay).await;
+            break Err(ProxyError::Proxy(ROUTE_SWITCH_ERROR_MSG.to_string()));
+        }
+        tokio::select! {
+            result = &mut relay_result => {
+                break result;
+            }
+            changed = route_rx.changed() => {
+                if changed.is_err() {
+                    break relay_result.await;
+                }
+            }
+        }
+    };
+
+    stats.decrement_current_connections_direct();
+    stats.decrement_user_curr_connects(user);
+
+    match &relay_result {
+        Ok(()) => debug!(user = %user, "Direct relay completed"),
+        Err(e) => debug!(user = %user, error = %e, "Direct relay ended with error"),
+    }
+
+    relay_result
+}
+
+fn get_dc_addr_static(dc_idx: i16, config: &ProxyConfig) -> Result<SocketAddr> {
+    let prefer_v6 = config.network.prefer == 6 && config.network.ipv6.unwrap_or(true);
+    let datacenters = if prefer_v6 {
+        &*TG_DATACENTERS_V6
+    } else {
+        &*TG_DATACENTERS_V4
+    };
+
+    let num_dcs = datacenters.len();
+
+    let dc_key = dc_idx.to_string();
+    if let Some(addrs) = config.dc_overrides.get(&dc_key) {
+        let mut parsed = Vec::new();
+        for addr_str in addrs {
+            match addr_str.parse::<SocketAddr>() {
+                Ok(addr) => parsed.push(addr),
+                Err(_) => warn!(dc_idx = dc_idx, addr_str = %addr_str, "Invalid DC override address in config, ignoring"),
+            }
+        }
+
+        if let Some(addr) = parsed
+            .iter()
+            .find(|a| a.is_ipv6() == prefer_v6)
+            .or_else(|| parsed.first())
+            .copied()
+        {
+            debug!(dc_idx = dc_idx, addr = %addr, count = parsed.len(), "Using DC override from config");
+            return Ok(addr);
+        }
+    }
+
+    let abs_dc = dc_idx.unsigned_abs() as usize;
+    if abs_dc >= 1 && abs_dc <= num_dcs {
+        return Ok(SocketAddr::new(datacenters[abs_dc - 1], TG_DATACENTER_PORT));
+    }
+
+    // Unknown DC requested by client without override: log and fall back.
+    if !config.dc_overrides.contains_key(&dc_key) {
+        warn!(dc_idx = dc_idx, "Requested non-standard DC with no override; falling back to default cluster");
+        if config.general.unknown_dc_file_log_enabled
+            && let Some(path) = &config.general.unknown_dc_log_path
+            && let Ok(handle) = tokio::runtime::Handle::try_current()
+        {
+            let path = path.clone();
+            handle.spawn_blocking(move || {
+                if let Ok(mut file) = OpenOptions::new().create(true).append(true).open(path) {
+                    let _ = writeln!(file, "dc_idx={dc_idx}");
+                }
+            });
+        }
+    }
+
+    let default_dc = config.default_dc.unwrap_or(2) as usize;
+    let fallback_idx = if default_dc >= 1 && default_dc <= num_dcs {
+        default_dc - 1
+    } else {
+        1
+    };
+
+    info!(
+        original_dc = dc_idx,
+        fallback_dc = (fallback_idx + 1) as u16,
+        fallback_addr = %datacenters[fallback_idx],
+        "Special DC ---> default_cluster"
+    );
+
+    Ok(SocketAddr::new(
+        datacenters[fallback_idx],
+        TG_DATACENTER_PORT,
+    ))
+}
+
+async fn do_tg_handshake_static(
+    mut stream: TcpStream,
+    success: &HandshakeSuccess,
+    config: &ProxyConfig,
+    rng: &SecureRandom,
+) -> Result<(
+    CryptoReader<tokio::net::tcp::OwnedReadHalf>,
+    CryptoWriter<tokio::net::tcp::OwnedWriteHalf>,
+)> {
+    let (nonce, _tg_enc_key, _tg_enc_iv, _tg_dec_key, _tg_dec_iv) = generate_tg_nonce(
+        success.proto_tag,
+        success.dc_idx,
+        &success.dec_key,
+        success.dec_iv,
+        &success.enc_key,
+        success.enc_iv,
+        rng,
+        config.general.fast_mode,
+    );
+
+    let (encrypted_nonce, tg_encryptor, tg_decryptor) = encrypt_tg_nonce_with_ciphers(&nonce);
+
+    debug!(
+        peer = %success.peer,
+        nonce_head = %hex::encode(&nonce[..16]),
+        "Sending nonce to Telegram"
+    );
+
+    stream.write_all(&encrypted_nonce).await?;
+    stream.flush().await?;
+
+    let (read_half, write_half) = stream.into_split();
+
+    let max_pending = config.general.crypto_pending_buffer;
+    Ok((
+        CryptoReader::new(read_half, tg_decryptor),
+        CryptoWriter::new(write_half, tg_encryptor, max_pending),
+    ))
+}

src/proxy/handshake.rs

@@ -1,19 +1,53 @@
-//! MTProto Handshake Magics
+//! MTProto Handshake
+
+#![allow(dead_code)]
 
 use std::net::SocketAddr;
+use std::sync::Arc;
+use std::time::Duration;
 use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
-use tracing::{debug, warn, trace, info};
+use tracing::{debug, warn, trace};
+use zeroize::Zeroize;
 
-use crate::crypto::{sha256, AesCtr};
-use crate::crypto::random::SECURE_RANDOM;
+use crate::crypto::{sha256, AesCtr, SecureRandom};
+use rand::Rng;
 use crate::protocol::constants::*;
 use crate::protocol::tls;
 use crate::stream::{FakeTlsReader, FakeTlsWriter, CryptoReader, CryptoWriter};
 use crate::error::{ProxyError, HandshakeResult};
 use crate::stats::ReplayChecker;
 use crate::config::ProxyConfig;
+use crate::tls_front::{TlsFrontCache, emulator};
+
+fn decode_user_secrets(
+    config: &ProxyConfig,
+    preferred_user: Option<&str>,
+) -> Vec<(String, Vec<u8>)> {
+    let mut secrets = Vec::with_capacity(config.access.users.len());
+
+    if let Some(preferred) = preferred_user
+        && let Some(secret_hex) = config.access.users.get(preferred)
+        && let Ok(bytes) = hex::decode(secret_hex)
+    {
+        secrets.push((preferred.to_string(), bytes));
+    }
+
+    for (name, secret_hex) in &config.access.users {
+        if preferred_user.is_some_and(|preferred| preferred == name.as_str()) {
+            continue;
+        }
+        if let Ok(bytes) = hex::decode(secret_hex) {
+            secrets.push((name.clone(), bytes));
+        }
+    }
+
+    secrets
+}
 
 /// Result of successful handshake
+///
+/// Key material (`dec_key`, `dec_iv`, `enc_key`, `enc_iv`) is
+/// zeroized on drop.
 #[derive(Debug, Clone)]
 pub struct HandshakeSuccess {
     /// Authenticated user name
@@ -34,6 +68,15 @@ pub struct HandshakeSuccess {
     pub is_tls: bool,
 }
 
+impl Drop for HandshakeSuccess {
+    fn drop(&mut self) {
+        self.dec_key.zeroize();
+        self.dec_iv.zeroize();
+        self.enc_key.zeroize();
+        self.enc_iv.zeroize();
+    }
+}
+
 /// Handle fake TLS handshake
 pub async fn handle_tls_handshake<R, W>(
     handshake: &[u8],
@@ -42,84 +85,149 @@ pub async fn handle_tls_handshake<R, W>(
     peer: SocketAddr,
     config: &ProxyConfig,
     replay_checker: &ReplayChecker,
-) -> HandshakeResult<(FakeTlsReader<R>, FakeTlsWriter<W>, String)>
+    rng: &SecureRandom,
+    tls_cache: Option<Arc<TlsFrontCache>>,
+) -> HandshakeResult<(FakeTlsReader<R>, FakeTlsWriter<W>, String), R, W>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
 {
     debug!(peer = %peer, handshake_len = handshake.len(), "Processing TLS handshake");
-    
-    // Check minimum length
+
     if handshake.len() < tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN + 1 {
         debug!(peer = %peer, "TLS handshake too short");
-        return HandshakeResult::BadClient;
+        return HandshakeResult::BadClient { reader, writer };
     }
-    
-    // Extract digest for replay check
+
     let digest = &handshake[tls::TLS_DIGEST_POS..tls::TLS_DIGEST_POS + tls::TLS_DIGEST_LEN];
     let digest_half = &digest[..tls::TLS_DIGEST_HALF_LEN];
-    
-    // Check for replay
-    if replay_checker.check_tls_digest(digest_half) {
-        warn!(peer = %peer, "TLS replay attack detected");
-        return HandshakeResult::BadClient;
+
+    if replay_checker.check_and_add_tls_digest(digest_half) {
+        warn!(peer = %peer, "TLS replay attack detected (duplicate digest)");
+        return HandshakeResult::BadClient { reader, writer };
     }
-    
-    // Build secrets list
-    let secrets: Vec<(String, Vec<u8>)> = config.users.iter()
-        .filter_map(|(name, hex)| {
-            hex::decode(hex).ok().map(|bytes| (name.clone(), bytes))
-        })
-        .collect();
-    
-    debug!(peer = %peer, num_users = secrets.len(), "Validating TLS handshake against users");
-    
-    // Validate handshake
+
+    let secrets = decode_user_secrets(config, None);
+
     let validation = match tls::validate_tls_handshake(
         handshake,
         &secrets,
-        config.ignore_time_skew,
+        config.access.ignore_time_skew,
     ) {
         Some(v) => v,
         None => {
-            debug!(peer = %peer, "TLS handshake validation failed - no matching user");
-            return HandshakeResult::BadClient;
+            debug!(
+                peer = %peer, 
+                ignore_time_skew = config.access.ignore_time_skew,
+                "TLS handshake validation failed - no matching user or time skew"
+            );
+            return HandshakeResult::BadClient { reader, writer };
         }
     };
-    
-    // Get secret for response
+
     let secret = match secrets.iter().find(|(name, _)| *name == validation.user) {
         Some((_, s)) => s,
-        None => return HandshakeResult::BadClient,
+        None => return HandshakeResult::BadClient { reader, writer },
     };
-    
-    // Build and send response
-    let response = tls::build_server_hello(
-        secret,
-        &validation.digest,
-        &validation.session_id,
-        config.fake_cert_len,
-    );
-    
+
+    let cached = if config.censorship.tls_emulation {
+        if let Some(cache) = tls_cache.as_ref() {
+            let selected_domain = if let Some(sni) = tls::extract_sni_from_client_hello(handshake) {
+                if cache.contains_domain(&sni).await {
+                    sni
+                } else {
+                    config.censorship.tls_domain.clone()
+                }
+            } else {
+                config.censorship.tls_domain.clone()
+            };
+            let cached_entry = cache.get(&selected_domain).await;
+            let use_full_cert_payload = cache
+                .take_full_cert_budget_for_ip(
+                    peer.ip(),
+                    Duration::from_secs(config.censorship.tls_full_cert_ttl_secs),
+                )
+                .await;
+            Some((cached_entry, use_full_cert_payload))
+        } else {
+            None
+        }
+    } else {
+        None
+    };
+
+    let alpn_list = if config.censorship.alpn_enforce {
+        tls::extract_alpn_from_client_hello(handshake)
+    } else {
+        Vec::new()
+    };
+    let selected_alpn = if config.censorship.alpn_enforce {
+        if alpn_list.iter().any(|p| p == b"h2") {
+            Some(b"h2".to_vec())
+        } else if alpn_list.iter().any(|p| p == b"http/1.1") {
+            Some(b"http/1.1".to_vec())
+        } else {
+            None
+        }
+    } else {
+        None
+    };
+
+    let response = if let Some((cached_entry, use_full_cert_payload)) = cached {
+        emulator::build_emulated_server_hello(
+            secret,
+            &validation.digest,
+            &validation.session_id,
+            &cached_entry,
+            use_full_cert_payload,
+            rng,
+            selected_alpn.clone(),
+            config.censorship.tls_new_session_tickets,
+        )
+    } else {
+        tls::build_server_hello(
+            secret,
+            &validation.digest,
+            &validation.session_id,
+            config.censorship.fake_cert_len,
+            rng,
+            selected_alpn.clone(),
+            config.censorship.tls_new_session_tickets,
+        )
+    };
+
+    // Optional anti-fingerprint delay before sending ServerHello.
+    if config.censorship.server_hello_delay_max_ms > 0 {
+        let min = config.censorship.server_hello_delay_min_ms;
+        let max = config.censorship.server_hello_delay_max_ms.max(min);
+        let delay_ms = if max == min {
+            max
+        } else {
+            rand::rng().random_range(min..=max)
+        };
+        if delay_ms > 0 {
+            tokio::time::sleep(std::time::Duration::from_millis(delay_ms)).await;
+        }
+    }
+
     debug!(peer = %peer, response_len = response.len(), "Sending TLS ServerHello");
-    
+
     if let Err(e) = writer.write_all(&response).await {
+        warn!(peer = %peer, error = %e, "Failed to write TLS ServerHello");
         return HandshakeResult::Error(ProxyError::Io(e));
     }
-    
+
     if let Err(e) = writer.flush().await {
+        warn!(peer = %peer, error = %e, "Failed to flush TLS ServerHello");
         return HandshakeResult::Error(ProxyError::Io(e));
     }
-    
-    // Record for replay protection
-    replay_checker.add_tls_digest(digest_half);
-    
-    info!(
+
+    debug!(
         peer = %peer,
         user = %validation.user,
         "TLS handshake successful"
     );
-    
+
     HandshakeResult::Success((
         FakeTlsReader::new(reader),
         FakeTlsWriter::new(writer),
@@ -136,111 +244,81 @@ pub async fn handle_mtproto_handshake<R, W>(
     config: &ProxyConfig,
     replay_checker: &ReplayChecker,
     is_tls: bool,
-) -> HandshakeResult<(CryptoReader<R>, CryptoWriter<W>, HandshakeSuccess)>
+    preferred_user: Option<&str>,
+) -> HandshakeResult<(CryptoReader<R>, CryptoWriter<W>, HandshakeSuccess), R, W>
 where
     R: AsyncRead + Unpin + Send,
     W: AsyncWrite + Unpin + Send,
 {
     trace!(peer = %peer, handshake = ?hex::encode(handshake), "MTProto handshake bytes");
-    
-    // Extract prekey and IV
+
     let dec_prekey_iv = &handshake[SKIP_LEN..SKIP_LEN + PREKEY_LEN + IV_LEN];
-    
-    debug!(
-        peer = %peer,
-        dec_prekey_iv = %hex::encode(dec_prekey_iv),
-        "Extracted prekey+IV from handshake"
-    );
-    
-    // Check for replay
-    if replay_checker.check_handshake(dec_prekey_iv) {
+
+    if replay_checker.check_and_add_handshake(dec_prekey_iv) {
         warn!(peer = %peer, "MTProto replay attack detected");
-        return HandshakeResult::BadClient;
+        return HandshakeResult::BadClient { reader, writer };
     }
-    
-    // Reversed for encryption direction
+
     let enc_prekey_iv: Vec<u8> = dec_prekey_iv.iter().rev().copied().collect();
-    
-    // Try each user's secret
-    for (user, secret_hex) in &config.users {
-        let secret = match hex::decode(secret_hex) {
-            Ok(s) => s,
-            Err(_) => continue,
-        };
-        
-        // Derive decryption key
+
+    let decoded_users = decode_user_secrets(config, preferred_user);
+
+    for (user, secret) in decoded_users {
+
         let dec_prekey = &dec_prekey_iv[..PREKEY_LEN];
         let dec_iv_bytes = &dec_prekey_iv[PREKEY_LEN..];
-        
+
         let mut dec_key_input = Vec::with_capacity(PREKEY_LEN + secret.len());
         dec_key_input.extend_from_slice(dec_prekey);
         dec_key_input.extend_from_slice(&secret);
         let dec_key = sha256(&dec_key_input);
-        
+
         let dec_iv = u128::from_be_bytes(dec_iv_bytes.try_into().unwrap());
-        
-        // Decrypt handshake to check protocol tag
+
         let mut decryptor = AesCtr::new(&dec_key, dec_iv);
         let decrypted = decryptor.decrypt(handshake);
-        
-        trace!(
-            peer = %peer,
-            user = %user,
-            decrypted_tail = %hex::encode(&decrypted[PROTO_TAG_POS..]),
-            "Decrypted handshake tail"
-        );
-        
-        // Check protocol tag
+
         let tag_bytes: [u8; 4] = decrypted[PROTO_TAG_POS..PROTO_TAG_POS + 4]
             .try_into()
             .unwrap();
-        
+
         let proto_tag = match ProtoTag::from_bytes(tag_bytes) {
             Some(tag) => tag,
-            None => {
-                trace!(peer = %peer, user = %user, tag = %hex::encode(tag_bytes), "Invalid proto tag");
-                continue;
-            }
+            None => continue,
         };
-        
-        debug!(peer = %peer, user = %user, proto = ?proto_tag, "Found valid proto tag");
-        
-        // Check if mode is enabled
+
         let mode_ok = match proto_tag {
             ProtoTag::Secure => {
-                if is_tls { config.modes.tls } else { config.modes.secure }
+                if is_tls {
+                    config.general.modes.tls || config.general.modes.secure
+                } else {
+                    config.general.modes.secure || config.general.modes.tls
+                }
             }
-            ProtoTag::Intermediate | ProtoTag::Abridged => config.modes.classic,
+            ProtoTag::Intermediate | ProtoTag::Abridged => config.general.modes.classic,
         };
-        
+
         if !mode_ok {
             debug!(peer = %peer, user = %user, proto = ?proto_tag, "Mode not enabled");
             continue;
         }
-        
-        // Extract DC index
+
         let dc_idx = i16::from_le_bytes(
             decrypted[DC_IDX_POS..DC_IDX_POS + 2].try_into().unwrap()
         );
-        
-        // Derive encryption key
+
         let enc_prekey = &enc_prekey_iv[..PREKEY_LEN];
         let enc_iv_bytes = &enc_prekey_iv[PREKEY_LEN..];
-        
+
         let mut enc_key_input = Vec::with_capacity(PREKEY_LEN + secret.len());
         enc_key_input.extend_from_slice(enc_prekey);
         enc_key_input.extend_from_slice(&secret);
         let enc_key = sha256(&enc_key_input);
-        
+
         let enc_iv = u128::from_be_bytes(enc_iv_bytes.try_into().unwrap());
-        
-        // Record for replay protection
-        replay_checker.add_handshake(dec_prekey_iv);
-        
-        // Create new cipher instances
-        let decryptor = AesCtr::new(&dec_key, dec_iv);
+
         let encryptor = AesCtr::new(&enc_key, enc_iv);
-        
+
         let success = HandshakeSuccess {
             user: user.clone(),
             dc_idx,
@@ -252,8 +330,8 @@ where
             peer,
             is_tls,
         };
-        
-        info!(
+
+        debug!(
             peer = %peer,
             user = %user,
             dc = dc_idx,
@@ -261,151 +339,170 @@ where
             tls = is_tls,
             "MTProto handshake successful"
         );
-        
+
+        let max_pending = config.general.crypto_pending_buffer;
         return HandshakeResult::Success((
             CryptoReader::new(reader, decryptor),
-            CryptoWriter::new(writer, encryptor),
+            CryptoWriter::new(writer, encryptor, max_pending),
             success,
         ));
     }
-    
+
     debug!(peer = %peer, "MTProto handshake: no matching user found");
-    HandshakeResult::BadClient
+    HandshakeResult::BadClient { reader, writer }
 }
 
 /// Generate nonce for Telegram connection
-/// 
-/// In FAST MODE: we use the same keys for TG as for client, but reversed.
-/// This means: client's enc_key becomes TG's dec_key and vice versa.
 pub fn generate_tg_nonce(
     proto_tag: ProtoTag, 
-    client_dec_key: &[u8; 32],
-    client_dec_iv: u128,
+    dc_idx: i16,
+    _client_dec_key: &[u8; 32],
+    _client_dec_iv: u128,
+    client_enc_key: &[u8; 32],
+    client_enc_iv: u128,
+    rng: &SecureRandom,
     fast_mode: bool,
 ) -> ([u8; HANDSHAKE_LEN], [u8; 32], u128, [u8; 32], u128) {
     loop {
-        let bytes = SECURE_RANDOM.bytes(HANDSHAKE_LEN);
+        let bytes = rng.bytes(HANDSHAKE_LEN);
         let mut nonce: [u8; HANDSHAKE_LEN] = bytes.try_into().unwrap();
-        
-        // Check reserved patterns
-        if RESERVED_NONCE_FIRST_BYTES.contains(&nonce[0]) {
-            continue;
-        }
-        
+
+        if RESERVED_NONCE_FIRST_BYTES.contains(&nonce[0]) { continue; }
+
         let first_four: [u8; 4] = nonce[..4].try_into().unwrap();
-        if RESERVED_NONCE_BEGINNINGS.contains(&first_four) {
-            continue;
-        }
-        
+        if RESERVED_NONCE_BEGINNINGS.contains(&first_four) { continue; }
+
         let continue_four: [u8; 4] = nonce[4..8].try_into().unwrap();
-        if RESERVED_NONCE_CONTINUES.contains(&continue_four) {
-            continue;
-        }
-        
-        // Set protocol tag
+        if RESERVED_NONCE_CONTINUES.contains(&continue_four) { continue; }
+
         nonce[PROTO_TAG_POS..PROTO_TAG_POS + 4].copy_from_slice(&proto_tag.to_bytes());
-        
-        // Fast mode: copy client's dec_key+iv (this becomes TG's enc direction)
-        // In fast mode, we make TG use the same keys as client but swapped:
-        // - What we decrypt FROM TG = what we encrypt TO client (so no re-encryption needed)
-        // - What we encrypt TO TG = what we decrypt FROM client
+        // CRITICAL: write dc_idx so upstream DC knows where to route
+        nonce[DC_IDX_POS..DC_IDX_POS + 2].copy_from_slice(&dc_idx.to_le_bytes());
+
         if fast_mode {
-            // Put client's dec_key + dec_iv into nonce[8:56]
-            // This will be used by TG for encryption TO us
-            nonce[SKIP_LEN..SKIP_LEN + KEY_LEN].copy_from_slice(client_dec_key);
-            nonce[SKIP_LEN + KEY_LEN..SKIP_LEN + KEY_LEN + IV_LEN]
-                .copy_from_slice(&client_dec_iv.to_be_bytes());
+            let mut key_iv = Vec::with_capacity(KEY_LEN + IV_LEN);
+            key_iv.extend_from_slice(client_enc_key);
+            key_iv.extend_from_slice(&client_enc_iv.to_be_bytes());
+            key_iv.reverse(); // Python/C behavior: reversed enc_key+enc_iv in nonce
+            nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN].copy_from_slice(&key_iv);
         }
-        
-        // Now compute what keys WE will use for TG connection
-        // enc_key_iv = nonce[8:56] (for encrypting TO TG)
-        // dec_key_iv = nonce[8:56] reversed (for decrypting FROM TG)
+
         let enc_key_iv = &nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN];
         let dec_key_iv: Vec<u8> = enc_key_iv.iter().rev().copied().collect();
-        
+
         let tg_enc_key: [u8; 32] = enc_key_iv[..KEY_LEN].try_into().unwrap();
         let tg_enc_iv = u128::from_be_bytes(enc_key_iv[KEY_LEN..].try_into().unwrap());
-        
+
         let tg_dec_key: [u8; 32] = dec_key_iv[..KEY_LEN].try_into().unwrap();
         let tg_dec_iv = u128::from_be_bytes(dec_key_iv[KEY_LEN..].try_into().unwrap());
-        
-        debug!(
-            fast_mode = fast_mode,
-            tg_enc_key = %hex::encode(&tg_enc_key[..8]),
-            tg_dec_key = %hex::encode(&tg_dec_key[..8]),
-            "Generated TG nonce"
-        );
-        
+
         return (nonce, tg_enc_key, tg_enc_iv, tg_dec_key, tg_dec_iv);
     }
 }
 
-/// Encrypt nonce for sending to Telegram
-/// 
-/// Only the part from PROTO_TAG_POS onwards is encrypted.
-/// The encryption key is derived from enc_key_iv in the nonce itself.
-pub fn encrypt_tg_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> Vec<u8> {
-    // enc_key_iv is at nonce[8:56]
+/// Encrypt nonce for sending to Telegram and return cipher objects with correct counter state
+pub fn encrypt_tg_nonce_with_ciphers(nonce: &[u8; HANDSHAKE_LEN]) -> (Vec<u8>, AesCtr, AesCtr) {
     let enc_key_iv = &nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN];
-    
-    // Key for encrypting is just the first 32 bytes of enc_key_iv
-    let key: [u8; 32] = enc_key_iv[..KEY_LEN].try_into().unwrap();
-    let iv = u128::from_be_bytes(enc_key_iv[KEY_LEN..].try_into().unwrap());
-    
-    let mut encryptor = AesCtr::new(&key, iv);
-    
-    // Encrypt the entire nonce first, then take only the encrypted tail
-    let encrypted_full = encryptor.encrypt(nonce);
-    
-    // Result: unencrypted head + encrypted tail
+    let dec_key_iv: Vec<u8> = enc_key_iv.iter().rev().copied().collect();
+
+    let enc_key: [u8; 32] = enc_key_iv[..KEY_LEN].try_into().unwrap();
+    let enc_iv = u128::from_be_bytes(enc_key_iv[KEY_LEN..].try_into().unwrap());
+
+    let dec_key: [u8; 32] = dec_key_iv[..KEY_LEN].try_into().unwrap();
+    let dec_iv = u128::from_be_bytes(dec_key_iv[KEY_LEN..].try_into().unwrap());
+
+    let mut encryptor = AesCtr::new(&enc_key, enc_iv);
+    let encrypted_full = encryptor.encrypt(nonce);  // counter: 0 → 4
+
     let mut result = nonce[..PROTO_TAG_POS].to_vec();
     result.extend_from_slice(&encrypted_full[PROTO_TAG_POS..]);
-    
-    trace!(
-        original = %hex::encode(&nonce[PROTO_TAG_POS..]),
-        encrypted = %hex::encode(&result[PROTO_TAG_POS..]),
-        "Encrypted nonce tail"
-    );
-    
-    result
+
+    let decryptor = AesCtr::new(&dec_key, dec_iv);
+
+    (result, encryptor, decryptor)
+}
+
+/// Encrypt nonce for sending to Telegram (legacy function for compatibility)
+pub fn encrypt_tg_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> Vec<u8> {
+    let (encrypted, _, _) = encrypt_tg_nonce_with_ciphers(nonce);
+    encrypted
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
-    
+
     #[test]
     fn test_generate_tg_nonce() {
         let client_dec_key = [0x42u8; 32];
         let client_dec_iv = 12345u128;
-        
-        let (nonce, tg_enc_key, tg_enc_iv, tg_dec_key, tg_dec_iv) = 
-            generate_tg_nonce(ProtoTag::Secure, &client_dec_key, client_dec_iv, false);
-        
-        // Check length
+        let client_enc_key = [0x24u8; 32];
+        let client_enc_iv = 54321u128;
+
+        let rng = SecureRandom::new();
+        let (nonce, _tg_enc_key, _tg_enc_iv, _tg_dec_key, _tg_dec_iv) = 
+            generate_tg_nonce(
+                ProtoTag::Secure,
+                2,
+                &client_dec_key,
+                client_dec_iv,
+                &client_enc_key,
+                client_enc_iv,
+                &rng,
+                false,
+            );
+
         assert_eq!(nonce.len(), HANDSHAKE_LEN);
-        
-        // Check proto tag is set
+
         let tag_bytes: [u8; 4] = nonce[PROTO_TAG_POS..PROTO_TAG_POS + 4].try_into().unwrap();
         assert_eq!(ProtoTag::from_bytes(tag_bytes), Some(ProtoTag::Secure));
     }
-    
+
     #[test]
     fn test_encrypt_tg_nonce() {
         let client_dec_key = [0x42u8; 32];
         let client_dec_iv = 12345u128;
-        
+        let client_enc_key = [0x24u8; 32];
+        let client_enc_iv = 54321u128;
+
+        let rng = SecureRandom::new();
         let (nonce, _, _, _, _) = 
-            generate_tg_nonce(ProtoTag::Secure, &client_dec_key, client_dec_iv, false);
-        
+            generate_tg_nonce(
+                ProtoTag::Secure,
+                2,
+                &client_dec_key,
+                client_dec_iv,
+                &client_enc_key,
+                client_enc_iv,
+                &rng,
+                false,
+            );
+
         let encrypted = encrypt_tg_nonce(&nonce);
-        
+
         assert_eq!(encrypted.len(), HANDSHAKE_LEN);
-        
-        // First PROTO_TAG_POS bytes should be unchanged
         assert_eq!(&encrypted[..PROTO_TAG_POS], &nonce[..PROTO_TAG_POS]);
-        
-        // Rest should be different (encrypted)
         assert_ne!(&encrypted[PROTO_TAG_POS..], &nonce[PROTO_TAG_POS..]);
     }
-}
+
+    #[test]
+    fn test_handshake_success_zeroize_on_drop() {
+        let success = HandshakeSuccess {
+            user: "test".to_string(),
+            dc_idx: 2,
+            proto_tag: ProtoTag::Secure,
+            dec_key: [0xAA; 32],
+            dec_iv: 0xBBBBBBBB,
+            enc_key: [0xCC; 32],
+            enc_iv: 0xDDDDDDDD,
+            peer: "127.0.0.1:1234".parse().unwrap(),
+            is_tls: true,
+        };
+
+        assert_eq!(success.dec_key, [0xAA; 32]);
+        assert_eq!(success.enc_key, [0xCC; 32]);
+
+        drop(success);
+        // Drop impl zeroizes key material without panic
+    }
+}

src/proxy/masking.rs

@@ -1,72 +1,214 @@
 //! Masking - forward unrecognized traffic to mask host
 
+use std::str;
+use std::net::SocketAddr;
 use std::time::Duration;
 use tokio::net::TcpStream;
-use tokio::io::{AsyncReadExt, AsyncWriteExt};
+#[cfg(unix)]
+use tokio::net::UnixStream;
+use tokio::io::{AsyncRead, AsyncWrite, AsyncReadExt, AsyncWriteExt};
 use tokio::time::timeout;
 use tracing::debug;
 use crate::config::ProxyConfig;
-use crate::transport::set_linger_zero;
+use crate::network::dns_overrides::resolve_socket_addr;
+use crate::stats::beobachten::BeobachtenStore;
+use crate::transport::proxy_protocol::{ProxyProtocolV1Builder, ProxyProtocolV2Builder};
 
 const MASK_TIMEOUT: Duration = Duration::from_secs(5);
+/// Maximum duration for the entire masking relay.
+/// Limits resource consumption from slow-loris attacks and port scanners.
+const MASK_RELAY_TIMEOUT: Duration = Duration::from_secs(60);
 const MASK_BUFFER_SIZE: usize = 8192;
 
+/// Detect client type based on initial data
+fn detect_client_type(data: &[u8]) -> &'static str {
+    // Check for HTTP request
+    if data.len() > 4
+        && (data.starts_with(b"GET ") || data.starts_with(b"POST") ||
+           data.starts_with(b"HEAD") || data.starts_with(b"PUT ") ||
+           data.starts_with(b"DELETE") || data.starts_with(b"OPTIONS"))
+    {
+        return "HTTP";
+    }
+
+    // Check for TLS ClientHello (0x16 = handshake, 0x03 0x01-0x03 = TLS version)
+    if data.len() > 3 && data[0] == 0x16 && data[1] == 0x03 {
+        return "TLS-scanner";
+    }
+
+    // Check for SSH
+    if data.starts_with(b"SSH-") {
+        return "SSH";
+    }
+
+    // Port scanner (very short data)
+    if data.len() < 10 {
+        return "port-scanner";
+    }
+
+    "unknown"
+}
+
 /// Handle a bad client by forwarding to mask host
-pub async fn handle_bad_client(
-    client: TcpStream,
+pub async fn handle_bad_client<R, W>(
+    reader: R,
+    writer: W,
     initial_data: &[u8],
+    peer: SocketAddr,
+    local_addr: SocketAddr,
     config: &ProxyConfig,
-) {
-    if !config.mask {
+    beobachten: &BeobachtenStore,
+)
+where
+    R: AsyncRead + Unpin + Send + 'static,
+    W: AsyncWrite + Unpin + Send + 'static,
+{
+    let client_type = detect_client_type(initial_data);
+    if config.general.beobachten {
+        let ttl = Duration::from_secs(config.general.beobachten_minutes.saturating_mul(60));
+        beobachten.record(client_type, peer.ip(), ttl);
+    }
+
+    if !config.censorship.mask {
         // Masking disabled, just consume data
-        consume_client_data(client).await;
+        consume_client_data(reader).await;
         return;
     }
-    
-    let mask_host = config.mask_host.as_deref()
-        .unwrap_or(&config.tls_domain);
-    let mask_port = config.mask_port;
-    
+
+    // Connect via Unix socket or TCP
+    #[cfg(unix)]
+    if let Some(ref sock_path) = config.censorship.mask_unix_sock {
+        debug!(
+            client_type = client_type,
+            sock = %sock_path,
+            data_len = initial_data.len(),
+            "Forwarding bad client to mask unix socket"
+        );
+
+        let connect_result = timeout(MASK_TIMEOUT, UnixStream::connect(sock_path)).await;
+        match connect_result {
+            Ok(Ok(stream)) => {
+                let (mask_read, mut mask_write) = stream.into_split();
+                let proxy_header: Option<Vec<u8>> = match config.censorship.mask_proxy_protocol {
+                    0 => None,
+                    version => {
+                        let header = match version {
+                            2 => ProxyProtocolV2Builder::new().with_addrs(peer, local_addr).build(),
+                            _ => match (peer, local_addr) {
+                                (SocketAddr::V4(src), SocketAddr::V4(dst)) =>
+                                    ProxyProtocolV1Builder::new().tcp4(src.into(), dst.into()).build(),
+                                (SocketAddr::V6(src), SocketAddr::V6(dst)) =>
+                                    ProxyProtocolV1Builder::new().tcp6(src.into(), dst.into()).build(),
+                                _ =>
+                                    ProxyProtocolV1Builder::new().build(),
+                            },
+                        };
+                        Some(header)
+                    }
+                };
+                if let Some(header) = proxy_header {
+                    if mask_write.write_all(&header).await.is_err() {
+                        return;
+                    }
+                }
+                if timeout(MASK_RELAY_TIMEOUT, relay_to_mask(reader, writer, mask_read, mask_write, initial_data)).await.is_err() {
+                    debug!("Mask relay timed out (unix socket)");
+                }
+            }
+            Ok(Err(e)) => {
+                debug!(error = %e, "Failed to connect to mask unix socket");
+                consume_client_data(reader).await;
+            }
+            Err(_) => {
+                debug!("Timeout connecting to mask unix socket");
+                consume_client_data(reader).await;
+            }
+        }
+        return;
+    }
+
+    let mask_host = config.censorship.mask_host.as_deref()
+        .unwrap_or(&config.censorship.tls_domain);
+    let mask_port = config.censorship.mask_port;
+
     debug!(
+        client_type = client_type,
         host = %mask_host,
         port = mask_port,
+        data_len = initial_data.len(),
         "Forwarding bad client to mask host"
     );
-    
-    // Connect to mask host
-    let mask_addr = format!("{}:{}", mask_host, mask_port);
-    let connect_result = timeout(
-        MASK_TIMEOUT,
-        TcpStream::connect(&mask_addr)
-    ).await;
-    
-    let mut mask_stream = match connect_result {
-        Ok(Ok(s)) => s,
+
+    // Apply runtime DNS override for mask target when configured.
+    let mask_addr = resolve_socket_addr(mask_host, mask_port)
+        .map(|addr| addr.to_string())
+        .unwrap_or_else(|| format!("{}:{}", mask_host, mask_port));
+    let connect_result = timeout(MASK_TIMEOUT, TcpStream::connect(&mask_addr)).await;
+    match connect_result {
+        Ok(Ok(stream)) => {
+            let proxy_header: Option<Vec<u8>> = match config.censorship.mask_proxy_protocol {
+                0 => None,
+                version => {
+                    let header = match version {
+                        2 => ProxyProtocolV2Builder::new().with_addrs(peer, local_addr).build(),
+                        _ => match (peer, local_addr) {
+                            (SocketAddr::V4(src), SocketAddr::V4(dst)) =>
+                                ProxyProtocolV1Builder::new().tcp4(src.into(), dst.into()).build(),
+                            (SocketAddr::V6(src), SocketAddr::V6(dst)) =>
+                                ProxyProtocolV1Builder::new().tcp6(src.into(), dst.into()).build(),
+                            _ =>
+                                ProxyProtocolV1Builder::new().build(),
+                        },
+                    };
+                    Some(header)
+                }
+            };
+
+            let (mask_read, mut mask_write) = stream.into_split();
+            if let Some(header) = proxy_header {
+                if mask_write.write_all(&header).await.is_err() {
+                    return;
+                }
+            }
+            if timeout(MASK_RELAY_TIMEOUT, relay_to_mask(reader, writer, mask_read, mask_write, initial_data)).await.is_err() {
+                debug!("Mask relay timed out");
+            }
+        }
         Ok(Err(e)) => {
             debug!(error = %e, "Failed to connect to mask host");
-            consume_client_data(client).await;
-            return;
+            consume_client_data(reader).await;
         }
         Err(_) => {
             debug!("Timeout connecting to mask host");
-            consume_client_data(client).await;
-            return;
+            consume_client_data(reader).await;
         }
-    };
-    
+    }
+}
+
+/// Relay traffic between client and mask backend
+async fn relay_to_mask<R, W, MR, MW>(
+    mut reader: R,
+    mut writer: W,
+    mut mask_read: MR,
+    mut mask_write: MW,
+    initial_data: &[u8],
+)
+where
+    R: AsyncRead + Unpin + Send + 'static,
+    W: AsyncWrite + Unpin + Send + 'static,
+    MR: AsyncRead + Unpin + Send + 'static,
+    MW: AsyncWrite + Unpin + Send + 'static,
+{
     // Send initial data to mask host
-    if mask_stream.write_all(initial_data).await.is_err() {
+    if mask_write.write_all(initial_data).await.is_err() {
         return;
     }
-    
+
     // Relay traffic
-    let (mut client_read, mut client_write) = client.into_split();
-    let (mut mask_read, mut mask_write) = mask_stream.into_split();
-    
     let c2m = tokio::spawn(async move {
         let mut buf = vec![0u8; MASK_BUFFER_SIZE];
         loop {
-            match client_read.read(&mut buf).await {
+            match reader.read(&mut buf).await {
                 Ok(0) | Err(_) => {
                     let _ = mask_write.shutdown().await;
                     break;
@@ -79,24 +221,24 @@ pub async fn handle_bad_client(
             }
         }
     });
-    
+
     let m2c = tokio::spawn(async move {
         let mut buf = vec![0u8; MASK_BUFFER_SIZE];
         loop {
             match mask_read.read(&mut buf).await {
                 Ok(0) | Err(_) => {
-                    let _ = client_write.shutdown().await;
+                    let _ = writer.shutdown().await;
                     break;
                 }
                 Ok(n) => {
-                    if client_write.write_all(&buf[..n]).await.is_err() {
+                    if writer.write_all(&buf[..n]).await.is_err() {
                         break;
                     }
                 }
             }
         }
     });
-    
+
     // Wait for either to complete
     tokio::select! {
         _ = c2m => {}
@@ -105,11 +247,11 @@ pub async fn handle_bad_client(
 }
 
 /// Just consume all data from client without responding
-async fn consume_client_data(mut client: TcpStream) {
+async fn consume_client_data<R: AsyncRead + Unpin>(mut reader: R) {
     let mut buf = vec![0u8; MASK_BUFFER_SIZE];
-    while let Ok(n) = client.read(&mut buf).await {
+    while let Ok(n) = reader.read(&mut buf).await {
         if n == 0 {
             break;
         }
     }
-}
+}

src/proxy/mod.rs

@@ -1,11 +1,17 @@
 //! Proxy Defs
 
-pub mod handshake;
 pub mod client;
-pub mod relay;
+pub mod direct_relay;
+pub mod handshake;
 pub mod masking;
+pub mod middle_relay;
+pub mod route_mode;
+pub mod relay;
 
-pub use handshake::*;
 pub use client::ClientHandler;
+#[allow(unused_imports)]
+pub use handshake::*;
+#[allow(unused_imports)]
+pub use masking::*;
+#[allow(unused_imports)]
 pub use relay::*;
-pub use masking::*;

src/proxy/relay.rs

@@ -1,22 +1,323 @@
-//! Bidirectional Relay
+//! Bidirectional Relay — poll-based, no head-of-line blocking
+//!
+//! ## What changed and why
+//!
+//! Previous implementation used a single-task `select! { biased; ... }` loop
+//! where each branch called `write_all()`. This caused head-of-line blocking:
+//! while `write_all()` waited for a slow writer (e.g. client on 3G downloading
+//! media), the entire loop was blocked — the other direction couldn't make progress.
+//!
+//! Symptoms observed in production:
+//! - Media loading at ~8 KB/s despite fast server connection
+//! - Stop-and-go pattern with 50–500ms gaps between chunks
+//! - `biased` select starving S→C direction
+//! - Some users unable to load media at all
+//!
+//! ## New architecture
+//!
+//! Uses `tokio::io::copy_bidirectional` which polls both directions concurrently
+//! in a single task via non-blocking `poll_read` / `poll_write` calls:
+//!
+//! Old (select! + write_all — BLOCKING):
+//!
+//!   loop {
+//!       select! {
+//!           biased;
+//!           data = client.read()  => { server.write_all(data).await; }  ← BLOCKS here
+//!           data = server.read()  => { client.write_all(data).await; }  ← can't run
+//!       }
+//!   }
+//!
+//! New (copy_bidirectional — CONCURRENT):
+//!
+//!   poll(cx) {
+//!       // Both directions polled in the same poll cycle
+//!       C→S: poll_read(client) → poll_write(server)   // non-blocking
+//!       S→C: poll_read(server) → poll_write(client)   // non-blocking
+//!       // If one writer is Pending, the other direction still progresses
+//!   }
+//!
+//! Benefits:
+//! - No head-of-line blocking: slow client download doesn't block uploads
+//! - No biased starvation: fair polling of both directions
+//! - Proper flush: `copy_bidirectional` calls `poll_flush` when reader stalls,
+//!   so CryptoWriter's pending ciphertext is always drained (fixes "stuck at 95%")
+//! - No deadlock risk: old write_all could deadlock when both TCP buffers filled;
+//!   poll-based approach lets TCP flow control work correctly
+//!
+//! Stats tracking:
+//! - `StatsIo` wraps client side, intercepts `poll_read` / `poll_write`
+//! - `poll_read` on client = C→S (client sending) → `octets_from`, `msgs_from`
+//! - `poll_write` on client = S→C (to client)     → `octets_to`, `msgs_to`
+//! - `SharedCounters` (atomics) let the watchdog read stats without locking
 
+use std::io;
+use std::pin::Pin;
 use std::sync::Arc;
-use tokio::io::{AsyncRead, AsyncWrite, AsyncReadExt, AsyncWriteExt};
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::task::{Context, Poll};
+use std::time::Duration;
+use tokio::io::{
+    AsyncRead, AsyncWrite, AsyncWriteExt, ReadBuf, copy_bidirectional_with_sizes,
+};
+use tokio::time::Instant;
 use tracing::{debug, trace, warn};
 use crate::error::Result;
 use crate::stats::Stats;
-use std::sync::atomic::{AtomicU64, Ordering};
+use crate::stream::BufferPool;
 
-const BUFFER_SIZE: usize = 65536;
+// ============= Constants =============
 
-/// Relay data bidirectionally between client and server
+/// Activity timeout for iOS compatibility.
+///
+/// iOS keeps Telegram connections alive in background for up to 30 minutes.
+/// Closing earlier causes unnecessary reconnects and handshake overhead.
+const ACTIVITY_TIMEOUT: Duration = Duration::from_secs(1800);
+
+/// Watchdog check interval — also used for periodic rate logging.
+///
+/// 10 seconds gives responsive timeout detection (±10s accuracy)
+/// without measurable overhead from atomic reads.
+const WATCHDOG_INTERVAL: Duration = Duration::from_secs(10);
+
+// ============= CombinedStream =============
+
+/// Combines separate read and write halves into a single bidirectional stream.
+///
+/// `copy_bidirectional` requires `AsyncRead + AsyncWrite` on each side,
+/// but the handshake layer produces split reader/writer pairs
+/// (e.g. `CryptoReader<FakeTlsReader<OwnedReadHalf>>` + `CryptoWriter<...>`).
+///
+/// This wrapper reunifies them with zero overhead — each trait method
+/// delegates directly to the corresponding half. No buffering, no copies.
+///
+/// Safety: `poll_read` only touches `reader`, `poll_write` only touches `writer`,
+/// so there's no aliasing even though both are called on the same `&mut self`.
+struct CombinedStream<R, W> {
+    reader: R,
+    writer: W,
+}
+
+impl<R, W> CombinedStream<R, W> {
+    fn new(reader: R, writer: W) -> Self {
+        Self { reader, writer }
+    }
+}
+
+impl<R: AsyncRead + Unpin, W: Unpin> AsyncRead for CombinedStream<R, W> {
+    #[inline]
+    fn poll_read(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.get_mut().reader).poll_read(cx, buf)
+    }
+}
+
+impl<R: Unpin, W: AsyncWrite + Unpin> AsyncWrite for CombinedStream<R, W> {
+    #[inline]
+    fn poll_write(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        Pin::new(&mut self.get_mut().writer).poll_write(cx, buf)
+    }
+
+    #[inline]
+    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.get_mut().writer).poll_flush(cx)
+    }
+
+    #[inline]
+    fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.get_mut().writer).poll_shutdown(cx)
+    }
+}
+
+// ============= SharedCounters =============
+
+/// Atomic counters shared between the relay (via StatsIo) and the watchdog task.
+///
+/// Using `Relaxed` ordering is sufficient because:
+/// - Counters are monotonically increasing (no ABA problem)
+/// - Slight staleness in watchdog reads is harmless (±10s check interval anyway)
+/// - No ordering dependencies between different counters
+struct SharedCounters {
+    /// Bytes read from client (C→S direction)
+    c2s_bytes: AtomicU64,
+    /// Bytes written to client (S→C direction)
+    s2c_bytes: AtomicU64,
+    /// Number of poll_read completions (≈ C→S chunks)
+    c2s_ops: AtomicU64,
+    /// Number of poll_write completions (≈ S→C chunks)
+    s2c_ops: AtomicU64,
+    /// Milliseconds since relay epoch of last I/O activity
+    last_activity_ms: AtomicU64,
+}
+
+impl SharedCounters {
+    fn new() -> Self {
+        Self {
+            c2s_bytes: AtomicU64::new(0),
+            s2c_bytes: AtomicU64::new(0),
+            c2s_ops: AtomicU64::new(0),
+            s2c_ops: AtomicU64::new(0),
+            last_activity_ms: AtomicU64::new(0),
+        }
+    }
+
+    /// Record activity at this instant.
+    #[inline]
+    fn touch(&self, now: Instant, epoch: Instant) {
+        let ms = now.duration_since(epoch).as_millis() as u64;
+        self.last_activity_ms.store(ms, Ordering::Relaxed);
+    }
+
+    /// How long since last recorded activity.
+    fn idle_duration(&self, now: Instant, epoch: Instant) -> Duration {
+        let last_ms = self.last_activity_ms.load(Ordering::Relaxed);
+        let now_ms = now.duration_since(epoch).as_millis() as u64;
+        Duration::from_millis(now_ms.saturating_sub(last_ms))
+    }
+}
+
+// ============= StatsIo =============
+
+/// Transparent I/O wrapper that tracks per-user statistics and activity.
+///
+/// Wraps the **client** side of the relay. Direction mapping:
+///
+/// | poll method  | direction | stats updated                        |
+/// |-------------|-----------|--------------------------------------|
+/// | `poll_read`  | C→S       | `octets_from`, `msgs_from`, counters |
+/// | `poll_write` | S→C       | `octets_to`, `msgs_to`, counters     |
+///
+/// Both update the shared activity timestamp for the watchdog.
+///
+/// Note on message counts: the original code counted one `read()`/`write_all()`
+/// as one "message". Here we count `poll_read`/`poll_write` completions instead.
+/// Byte counts are identical; op counts may differ slightly due to different
+/// internal buffering in `copy_bidirectional`. This is fine for monitoring.
+struct StatsIo<S> {
+    inner: S,
+    counters: Arc<SharedCounters>,
+    stats: Arc<Stats>,
+    user: String,
+    epoch: Instant,
+}
+
+impl<S> StatsIo<S> {
+    fn new(
+        inner: S,
+        counters: Arc<SharedCounters>,
+        stats: Arc<Stats>,
+        user: String,
+        epoch: Instant,
+    ) -> Self {
+        // Mark initial activity so the watchdog doesn't fire before data flows
+        counters.touch(Instant::now(), epoch);
+        Self { inner, counters, stats, user, epoch }
+    }
+}
+
+impl<S: AsyncRead + Unpin> AsyncRead for StatsIo<S> {
+    fn poll_read(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<()>> {
+        let this = self.get_mut();
+        let before = buf.filled().len();
+
+        match Pin::new(&mut this.inner).poll_read(cx, buf) {
+            Poll::Ready(Ok(())) => {
+                let n = buf.filled().len() - before;
+                if n > 0 {
+                    // C→S: client sent data
+                    this.counters.c2s_bytes.fetch_add(n as u64, Ordering::Relaxed);
+                    this.counters.c2s_ops.fetch_add(1, Ordering::Relaxed);
+                    this.counters.touch(Instant::now(), this.epoch);
+
+                    this.stats.add_user_octets_from(&this.user, n as u64);
+                    this.stats.increment_user_msgs_from(&this.user);
+
+                    trace!(user = %this.user, bytes = n, "C->S");
+                }
+                Poll::Ready(Ok(()))
+            }
+            other => other,
+        }
+    }
+}
+
+impl<S: AsyncWrite + Unpin> AsyncWrite for StatsIo<S> {
+    fn poll_write(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        let this = self.get_mut();
+
+        match Pin::new(&mut this.inner).poll_write(cx, buf) {
+            Poll::Ready(Ok(n)) => {
+                if n > 0 {
+                    // S→C: data written to client
+                    this.counters.s2c_bytes.fetch_add(n as u64, Ordering::Relaxed);
+                    this.counters.s2c_ops.fetch_add(1, Ordering::Relaxed);
+                    this.counters.touch(Instant::now(), this.epoch);
+
+                    this.stats.add_user_octets_to(&this.user, n as u64);
+                    this.stats.increment_user_msgs_to(&this.user);
+
+                    trace!(user = %this.user, bytes = n, "S->C");
+                }
+                Poll::Ready(Ok(n))
+            }
+            other => other,
+        }
+    }
+
+    #[inline]
+    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.get_mut().inner).poll_flush(cx)
+    }
+
+    #[inline]
+    fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.get_mut().inner).poll_shutdown(cx)
+    }
+}
+
+// ============= Relay =============
+
+/// Relay data bidirectionally between client and server.
+///
+/// Uses `tokio::io::copy_bidirectional` for concurrent, non-blocking data transfer.
+///
+/// ## API compatibility
+///
+/// The `_buffer_pool` parameter is retained for call-site compatibility.
+/// Effective relay copy buffers are configured by `c2s_buf_size` / `s2c_buf_size`.
+///
+/// ## Guarantees preserved
+///
+/// - Activity timeout: 30 minutes of inactivity → clean shutdown
+/// - Per-user stats: bytes and ops counted per direction
+/// - Periodic rate logging: every 10 seconds when active
+/// - Clean shutdown: both write sides are shut down on exit
+/// - Error propagation: I/O errors are returned as `ProxyError::Io`
 pub async fn relay_bidirectional<CR, CW, SR, SW>(
-    mut client_reader: CR,
-    mut client_writer: CW,
-    mut server_reader: SR,
-    mut server_writer: SW,
+    client_reader: CR,
+    client_writer: CW,
+    server_reader: SR,
+    server_writer: SW,
+    c2s_buf_size: usize,
+    s2c_buf_size: usize,
     user: &str,
     stats: Arc<Stats>,
+    _buffer_pool: Arc<BufferPool>,
 ) -> Result<()>
 where
     CR: AsyncRead + Unpin + Send + 'static,
@@ -24,139 +325,150 @@ where
     SR: AsyncRead + Unpin + Send + 'static,
     SW: AsyncWrite + Unpin + Send + 'static,
 {
-    let user_c2s = user.to_string();
-    let user_s2c = user.to_string();
-    
-    // Используем Arc::clone вместо stats.clone()
-    let stats_c2s = Arc::clone(&stats);
-    let stats_s2c = Arc::clone(&stats);
-    
-    let c2s_bytes = Arc::new(AtomicU64::new(0));
-    let s2c_bytes = Arc::new(AtomicU64::new(0));
-    let c2s_bytes_clone = Arc::clone(&c2s_bytes);
-    let s2c_bytes_clone = Arc::clone(&s2c_bytes);
-    
-    // Client -> Server task
-    let c2s = tokio::spawn(async move {
-        let mut buf = vec![0u8; BUFFER_SIZE];
-        let mut total_bytes = 0u64;
-        let mut msg_count = 0u64;
-        
+    let epoch = Instant::now();
+    let counters = Arc::new(SharedCounters::new());
+    let user_owned = user.to_string();
+
+    // ── Combine split halves into bidirectional streams ──────────────
+    let client_combined = CombinedStream::new(client_reader, client_writer);
+    let mut server = CombinedStream::new(server_reader, server_writer);
+
+    // Wrap client with stats/activity tracking
+    let mut client = StatsIo::new(
+        client_combined,
+        Arc::clone(&counters),
+        Arc::clone(&stats),
+        user_owned.clone(),
+        epoch,
+    );
+
+    // ── Watchdog: activity timeout + periodic rate logging ──────────
+    let wd_counters = Arc::clone(&counters);
+    let wd_user = user_owned.clone();
+
+    let watchdog = async {
+        let mut prev_c2s: u64 = 0;
+        let mut prev_s2c: u64 = 0;
+
         loop {
-            match client_reader.read(&mut buf).await {
-                Ok(0) => {
-                    debug!(
-                        user = %user_c2s, 
-                        total_bytes = total_bytes,
-                        msgs = msg_count,
-                        "Client closed connection (C->S)"
-                    );
-                    let _ = server_writer.shutdown().await;
-                    break;
-                }
-                Ok(n) => {
-                    total_bytes += n as u64;
-                    msg_count += 1;
-                    c2s_bytes_clone.store(total_bytes, Ordering::Relaxed);
-                    
-                    stats_c2s.add_user_octets_from(&user_c2s, n as u64);
-                    stats_c2s.increment_user_msgs_from(&user_c2s);
-                    
-                    trace!(
-                        user = %user_c2s,
-                        bytes = n,
-                        total = total_bytes,
-                        data_preview = %hex::encode(&buf[..n.min(32)]),
-                        "C->S data"
-                    );
-                    
-                    if let Err(e) = server_writer.write_all(&buf[..n]).await {
-                        debug!(user = %user_c2s, error = %e, "Failed to write to server");
-                        break;
-                    }
-                    if let Err(e) = server_writer.flush().await {
-                        debug!(user = %user_c2s, error = %e, "Failed to flush to server");
-                        break;
-                    }
-                }
-                Err(e) => {
-                    debug!(user = %user_c2s, error = %e, total_bytes = total_bytes, "Client read error");
-                    break;
-                }
+            tokio::time::sleep(WATCHDOG_INTERVAL).await;
+
+            let now = Instant::now();
+            let idle = wd_counters.idle_duration(now, epoch);
+
+            // ── Activity timeout ────────────────────────────────────
+            if idle >= ACTIVITY_TIMEOUT {
+                let c2s = wd_counters.c2s_bytes.load(Ordering::Relaxed);
+                let s2c = wd_counters.s2c_bytes.load(Ordering::Relaxed);
+                warn!(
+                    user = %wd_user,
+                    c2s_bytes = c2s,
+                    s2c_bytes = s2c,
+                    idle_secs = idle.as_secs(),
+                    "Activity timeout"
+                );
+                return; // Causes select! to cancel copy_bidirectional
             }
+
+            // ── Periodic rate logging ───────────────────────────────
+            let c2s = wd_counters.c2s_bytes.load(Ordering::Relaxed);
+            let s2c = wd_counters.s2c_bytes.load(Ordering::Relaxed);
+            let c2s_delta = c2s - prev_c2s;
+            let s2c_delta = s2c - prev_s2c;
+
+            if c2s_delta > 0 || s2c_delta > 0 {
+                let secs = WATCHDOG_INTERVAL.as_secs_f64();
+                debug!(
+                    user = %wd_user,
+                    c2s_kbps = (c2s_delta as f64 / secs / 1024.0) as u64,
+                    s2c_kbps = (s2c_delta as f64 / secs / 1024.0) as u64,
+                    c2s_total = c2s,
+                    s2c_total = s2c,
+                    "Relay active"
+                );
+            }
+
+            prev_c2s = c2s;
+            prev_s2c = s2c;
         }
-    });
-    
-    // Server -> Client task
-    let s2c = tokio::spawn(async move {
-        let mut buf = vec![0u8; BUFFER_SIZE];
-        let mut total_bytes = 0u64;
-        let mut msg_count = 0u64;
-        
-        loop {
-            match server_reader.read(&mut buf).await {
-                Ok(0) => {
-                    debug!(
-                        user = %user_s2c,
-                        total_bytes = total_bytes,
-                        msgs = msg_count,
-                        "Server closed connection (S->C)"
-                    );
-                    let _ = client_writer.shutdown().await;
-                    break;
-                }
-                Ok(n) => {
-                    total_bytes += n as u64;
-                    msg_count += 1;
-                    s2c_bytes_clone.store(total_bytes, Ordering::Relaxed);
-                    
-                    stats_s2c.add_user_octets_to(&user_s2c, n as u64);
-                    stats_s2c.increment_user_msgs_to(&user_s2c);
-                    
-                    trace!(
-                        user = %user_s2c,
-                        bytes = n,
-                        total = total_bytes,
-                        data_preview = %hex::encode(&buf[..n.min(32)]),
-                        "S->C data"
-                    );
-                    
-                    if let Err(e) = client_writer.write_all(&buf[..n]).await {
-                        debug!(user = %user_s2c, error = %e, "Failed to write to client");
-                        break;
-                    }
-                    if let Err(e) = client_writer.flush().await {
-                        debug!(user = %user_s2c, error = %e, "Failed to flush to client");
-                        break;
-                    }
-                }
-                Err(e) => {
-                    debug!(user = %user_s2c, error = %e, total_bytes = total_bytes, "Server read error");
-                    break;
-                }
-            }
+    };
+
+    // ── Run bidirectional copy + watchdog concurrently ───────────────
+    //
+    // copy_bidirectional polls both directions in the same poll() call:
+    //   C→S: poll_read(client/StatsIo) → poll_write(server)
+    //   S→C: poll_read(server)         → poll_write(client/StatsIo)
+    //
+    // When one direction's writer returns Pending, the other direction
+    // continues — no head-of-line blocking.
+    //
+    // When the watchdog fires, select! drops the copy future,
+    // releasing the &mut borrows on client and server.
+    let copy_result = tokio::select! {
+        result = copy_bidirectional_with_sizes(
+            &mut client,
+            &mut server,
+            c2s_buf_size.max(1),
+            s2c_buf_size.max(1),
+        ) => Some(result),
+        _ = watchdog => None, // Activity timeout — cancel relay
+    };
+
+    // ── Clean shutdown ──────────────────────────────────────────────
+    // After select!, the losing future is dropped, borrows released.
+    // Shut down both write sides for clean TCP FIN.
+    let _ = client.shutdown().await;
+    let _ = server.shutdown().await;
+
+    // ── Final logging ───────────────────────────────────────────────
+    let c2s_ops = counters.c2s_ops.load(Ordering::Relaxed);
+    let s2c_ops = counters.s2c_ops.load(Ordering::Relaxed);
+    let duration = epoch.elapsed();
+
+    match copy_result {
+        Some(Ok((c2s, s2c))) => {
+            // Normal completion — one side closed the connection
+            debug!(
+                user = %user_owned,
+                c2s_bytes = c2s,
+                s2c_bytes = s2c,
+                c2s_msgs = c2s_ops,
+                s2c_msgs = s2c_ops,
+                duration_secs = duration.as_secs(),
+                "Relay finished"
+            );
+            Ok(())
         }
-    });
-    
-    // Wait for either direction to complete
-    tokio::select! {
-        result = c2s => {
-            if let Err(e) = result {
-                warn!(error = %e, "C->S task panicked");
-            }
+        Some(Err(e)) => {
+            // I/O error in one of the directions
+            let c2s = counters.c2s_bytes.load(Ordering::Relaxed);
+            let s2c = counters.s2c_bytes.load(Ordering::Relaxed);
+            debug!(
+                user = %user_owned,
+                c2s_bytes = c2s,
+                s2c_bytes = s2c,
+                c2s_msgs = c2s_ops,
+                s2c_msgs = s2c_ops,
+                duration_secs = duration.as_secs(),
+                error = %e,
+                "Relay error"
+            );
+            Err(e.into())
         }
-        result = s2c => {
-            if let Err(e) = result {
-                warn!(error = %e, "S->C task panicked");
-            }
+        None => {
+            // Activity timeout (watchdog fired)
+            let c2s = counters.c2s_bytes.load(Ordering::Relaxed);
+            let s2c = counters.s2c_bytes.load(Ordering::Relaxed);
+            debug!(
+                user = %user_owned,
+                c2s_bytes = c2s,
+                s2c_bytes = s2c,
+                c2s_msgs = c2s_ops,
+                s2c_msgs = s2c_ops,
+                duration_secs = duration.as_secs(),
+                "Relay finished (activity timeout)"
+            );
+            Ok(())
         }
     }
-    
-    debug!(
-        c2s_bytes = c2s_bytes.load(Ordering::Relaxed),
-        s2c_bytes = s2c_bytes.load(Ordering::Relaxed),
-        "Relay finished"
-    );
-    
-    Ok(())
-}
+}

src/proxy/route_mode.rs

@@ -0,0 +1,117 @@
+use std::sync::Arc;
+use std::sync::atomic::{AtomicU8, AtomicU64, Ordering};
+use std::time::Duration;
+
+use tokio::sync::watch;
+
+pub(crate) const ROUTE_SWITCH_ERROR_MSG: &str = "Route mode switched by cutover";
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[repr(u8)]
+pub(crate) enum RelayRouteMode {
+    Direct = 0,
+    Middle = 1,
+}
+
+impl RelayRouteMode {
+    pub(crate) fn as_u8(self) -> u8 {
+        self as u8
+    }
+
+    pub(crate) fn from_u8(value: u8) -> Self {
+        match value {
+            1 => Self::Middle,
+            _ => Self::Direct,
+        }
+    }
+
+    pub(crate) fn as_str(self) -> &'static str {
+        match self {
+            Self::Direct => "direct",
+            Self::Middle => "middle",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) struct RouteCutoverState {
+    pub mode: RelayRouteMode,
+    pub generation: u64,
+}
+
+#[derive(Clone)]
+pub(crate) struct RouteRuntimeController {
+    mode: Arc<AtomicU8>,
+    generation: Arc<AtomicU64>,
+    tx: watch::Sender<RouteCutoverState>,
+}
+
+impl RouteRuntimeController {
+    pub(crate) fn new(initial_mode: RelayRouteMode) -> Self {
+        let initial = RouteCutoverState {
+            mode: initial_mode,
+            generation: 0,
+        };
+        let (tx, _rx) = watch::channel(initial);
+        Self {
+            mode: Arc::new(AtomicU8::new(initial_mode.as_u8())),
+            generation: Arc::new(AtomicU64::new(0)),
+            tx,
+        }
+    }
+
+    pub(crate) fn snapshot(&self) -> RouteCutoverState {
+        RouteCutoverState {
+            mode: RelayRouteMode::from_u8(self.mode.load(Ordering::Relaxed)),
+            generation: self.generation.load(Ordering::Relaxed),
+        }
+    }
+
+    pub(crate) fn subscribe(&self) -> watch::Receiver<RouteCutoverState> {
+        self.tx.subscribe()
+    }
+
+    pub(crate) fn set_mode(&self, mode: RelayRouteMode) -> Option<RouteCutoverState> {
+        let previous = self.mode.swap(mode.as_u8(), Ordering::Relaxed);
+        if previous == mode.as_u8() {
+            return None;
+        }
+        let generation = self.generation.fetch_add(1, Ordering::Relaxed) + 1;
+        let next = RouteCutoverState { mode, generation };
+        self.tx.send_replace(next);
+        Some(next)
+    }
+}
+
+pub(crate) fn is_session_affected_by_cutover(
+    current: RouteCutoverState,
+    _session_mode: RelayRouteMode,
+    session_generation: u64,
+) -> bool {
+    current.generation > session_generation
+}
+
+pub(crate) fn affected_cutover_state(
+    rx: &watch::Receiver<RouteCutoverState>,
+    session_mode: RelayRouteMode,
+    session_generation: u64,
+) -> Option<RouteCutoverState> {
+    let current = *rx.borrow();
+    if is_session_affected_by_cutover(current, session_mode, session_generation) {
+        return Some(current);
+    }
+    None
+}
+
+pub(crate) fn cutover_stagger_delay(session_id: u64, generation: u64) -> Duration {
+    let mut value = session_id
+        ^ generation.rotate_left(17)
+        ^ 0x9e37_79b9_7f4a_7c15;
+    value ^= value >> 30;
+    value = value.wrapping_mul(0xbf58_476d_1ce4_e5b9);
+    value ^= value >> 27;
+    value = value.wrapping_mul(0x94d0_49bb_1331_11eb);
+    value ^= value >> 31;
+    let ms = 1000 + (value % 1000);
+    Duration::from_millis(ms)
+}

src/startup.rs

@@ -0,0 +1,373 @@
+use std::time::{Instant, SystemTime, UNIX_EPOCH};
+
+use tokio::sync::RwLock;
+
+pub const COMPONENT_CONFIG_LOAD: &str = "config_load";
+pub const COMPONENT_TRACING_INIT: &str = "tracing_init";
+pub const COMPONENT_API_BOOTSTRAP: &str = "api_bootstrap";
+pub const COMPONENT_TLS_FRONT_BOOTSTRAP: &str = "tls_front_bootstrap";
+pub const COMPONENT_NETWORK_PROBE: &str = "network_probe";
+pub const COMPONENT_ME_SECRET_FETCH: &str = "me_secret_fetch";
+pub const COMPONENT_ME_PROXY_CONFIG_V4: &str = "me_proxy_config_fetch_v4";
+pub const COMPONENT_ME_PROXY_CONFIG_V6: &str = "me_proxy_config_fetch_v6";
+pub const COMPONENT_ME_POOL_CONSTRUCT: &str = "me_pool_construct";
+pub const COMPONENT_ME_POOL_INIT_STAGE1: &str = "me_pool_init_stage1";
+pub const COMPONENT_ME_CONNECTIVITY_PING: &str = "me_connectivity_ping";
+pub const COMPONENT_DC_CONNECTIVITY_PING: &str = "dc_connectivity_ping";
+pub const COMPONENT_LISTENERS_BIND: &str = "listeners_bind";
+pub const COMPONENT_CONFIG_WATCHER_START: &str = "config_watcher_start";
+pub const COMPONENT_METRICS_START: &str = "metrics_start";
+pub const COMPONENT_RUNTIME_READY: &str = "runtime_ready";
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum StartupStatus {
+    Initializing,
+    Ready,
+}
+
+impl StartupStatus {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Initializing => "initializing",
+            Self::Ready => "ready",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum StartupComponentStatus {
+    Pending,
+    Running,
+    Ready,
+    Failed,
+    Skipped,
+}
+
+impl StartupComponentStatus {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Pending => "pending",
+            Self::Running => "running",
+            Self::Ready => "ready",
+            Self::Failed => "failed",
+            Self::Skipped => "skipped",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum StartupMeStatus {
+    Pending,
+    Initializing,
+    Ready,
+    Failed,
+    Skipped,
+}
+
+impl StartupMeStatus {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Pending => "pending",
+            Self::Initializing => "initializing",
+            Self::Ready => "ready",
+            Self::Failed => "failed",
+            Self::Skipped => "skipped",
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct StartupComponentSnapshot {
+    pub id: &'static str,
+    pub title: &'static str,
+    pub weight: f64,
+    pub status: StartupComponentStatus,
+    pub started_at_epoch_ms: Option<u64>,
+    pub finished_at_epoch_ms: Option<u64>,
+    pub duration_ms: Option<u64>,
+    pub attempts: u32,
+    pub details: Option<String>,
+}
+
+#[derive(Clone, Debug)]
+pub struct StartupMeSnapshot {
+    pub status: StartupMeStatus,
+    pub current_stage: String,
+    pub init_attempt: u32,
+    pub retry_limit: String,
+    pub last_error: Option<String>,
+}
+
+#[derive(Clone, Debug)]
+pub struct StartupSnapshot {
+    pub status: StartupStatus,
+    pub degraded: bool,
+    pub current_stage: String,
+    pub started_at_epoch_secs: u64,
+    pub ready_at_epoch_secs: Option<u64>,
+    pub total_elapsed_ms: u64,
+    pub transport_mode: String,
+    pub me: StartupMeSnapshot,
+    pub components: Vec<StartupComponentSnapshot>,
+}
+
+#[derive(Clone, Debug)]
+struct StartupComponent {
+    id: &'static str,
+    title: &'static str,
+    weight: f64,
+    status: StartupComponentStatus,
+    started_at_epoch_ms: Option<u64>,
+    finished_at_epoch_ms: Option<u64>,
+    duration_ms: Option<u64>,
+    attempts: u32,
+    details: Option<String>,
+}
+
+#[derive(Clone, Debug)]
+struct StartupState {
+    status: StartupStatus,
+    degraded: bool,
+    current_stage: String,
+    started_at_epoch_secs: u64,
+    ready_at_epoch_secs: Option<u64>,
+    transport_mode: String,
+    me: StartupMeSnapshot,
+    components: Vec<StartupComponent>,
+}
+
+pub struct StartupTracker {
+    started_at_instant: Instant,
+    state: RwLock<StartupState>,
+}
+
+impl StartupTracker {
+    pub fn new(started_at_epoch_secs: u64) -> Self {
+        Self {
+            started_at_instant: Instant::now(),
+            state: RwLock::new(StartupState {
+                status: StartupStatus::Initializing,
+                degraded: false,
+                current_stage: COMPONENT_CONFIG_LOAD.to_string(),
+                started_at_epoch_secs,
+                ready_at_epoch_secs: None,
+                transport_mode: "unknown".to_string(),
+                me: StartupMeSnapshot {
+                    status: StartupMeStatus::Pending,
+                    current_stage: "pending".to_string(),
+                    init_attempt: 0,
+                    retry_limit: "unlimited".to_string(),
+                    last_error: None,
+                },
+                components: component_blueprint(),
+            }),
+        }
+    }
+
+    pub async fn set_transport_mode(&self, mode: &'static str) {
+        self.state.write().await.transport_mode = mode.to_string();
+    }
+
+    pub async fn set_degraded(&self, degraded: bool) {
+        self.state.write().await.degraded = degraded;
+    }
+
+    pub async fn start_component(&self, id: &'static str, details: Option<String>) {
+        let mut guard = self.state.write().await;
+        guard.current_stage = id.to_string();
+        if let Some(component) = guard.components.iter_mut().find(|component| component.id == id) {
+            if component.started_at_epoch_ms.is_none() {
+                component.started_at_epoch_ms = Some(now_epoch_ms());
+            }
+            component.attempts = component.attempts.saturating_add(1);
+            component.status = StartupComponentStatus::Running;
+            component.details = normalize_details(details);
+        }
+    }
+
+    pub async fn complete_component(&self, id: &'static str, details: Option<String>) {
+        self.finish_component(id, StartupComponentStatus::Ready, details)
+            .await;
+    }
+
+    pub async fn fail_component(&self, id: &'static str, details: Option<String>) {
+        self.finish_component(id, StartupComponentStatus::Failed, details)
+            .await;
+    }
+
+    pub async fn skip_component(&self, id: &'static str, details: Option<String>) {
+        self.finish_component(id, StartupComponentStatus::Skipped, details)
+            .await;
+    }
+
+    async fn finish_component(
+        &self,
+        id: &'static str,
+        status: StartupComponentStatus,
+        details: Option<String>,
+    ) {
+        let mut guard = self.state.write().await;
+        let finished_at = now_epoch_ms();
+        if let Some(component) = guard.components.iter_mut().find(|component| component.id == id) {
+            if component.started_at_epoch_ms.is_none() {
+                component.started_at_epoch_ms = Some(finished_at);
+                component.attempts = component.attempts.saturating_add(1);
+            }
+            component.finished_at_epoch_ms = Some(finished_at);
+            component.duration_ms = component
+                .started_at_epoch_ms
+                .map(|started_at| finished_at.saturating_sub(started_at));
+            component.status = status;
+            component.details = normalize_details(details);
+        }
+    }
+
+    pub async fn set_me_status(&self, status: StartupMeStatus, stage: &'static str) {
+        let mut guard = self.state.write().await;
+        guard.me.status = status;
+        guard.me.current_stage = stage.to_string();
+    }
+
+    pub async fn set_me_retry_limit(&self, retry_limit: String) {
+        self.state.write().await.me.retry_limit = retry_limit;
+    }
+
+    pub async fn set_me_init_attempt(&self, attempt: u32) {
+        self.state.write().await.me.init_attempt = attempt;
+    }
+
+    pub async fn set_me_last_error(&self, error: Option<String>) {
+        self.state.write().await.me.last_error = normalize_details(error);
+    }
+
+    pub async fn mark_ready(&self) {
+        let mut guard = self.state.write().await;
+        if guard.status == StartupStatus::Ready {
+            return;
+        }
+        guard.status = StartupStatus::Ready;
+        guard.current_stage = "ready".to_string();
+        guard.ready_at_epoch_secs = Some(now_epoch_secs());
+    }
+
+    pub async fn snapshot(&self) -> StartupSnapshot {
+        let guard = self.state.read().await;
+        StartupSnapshot {
+            status: guard.status,
+            degraded: guard.degraded,
+            current_stage: guard.current_stage.clone(),
+            started_at_epoch_secs: guard.started_at_epoch_secs,
+            ready_at_epoch_secs: guard.ready_at_epoch_secs,
+            total_elapsed_ms: self.started_at_instant.elapsed().as_millis() as u64,
+            transport_mode: guard.transport_mode.clone(),
+            me: guard.me.clone(),
+            components: guard
+                .components
+                .iter()
+                .map(|component| StartupComponentSnapshot {
+                    id: component.id,
+                    title: component.title,
+                    weight: component.weight,
+                    status: component.status,
+                    started_at_epoch_ms: component.started_at_epoch_ms,
+                    finished_at_epoch_ms: component.finished_at_epoch_ms,
+                    duration_ms: component.duration_ms,
+                    attempts: component.attempts,
+                    details: component.details.clone(),
+                })
+                .collect(),
+        }
+    }
+}
+
+pub fn compute_progress_pct(snapshot: &StartupSnapshot, me_stage_progress: Option<f64>) -> f64 {
+    if snapshot.status == StartupStatus::Ready {
+        return 100.0;
+    }
+
+    let mut total_weight = 0.0f64;
+    let mut completed_weight = 0.0f64;
+
+    for component in &snapshot.components {
+        total_weight += component.weight;
+        let unit_progress = match component.status {
+            StartupComponentStatus::Pending => 0.0,
+            StartupComponentStatus::Running => {
+                if component.id == COMPONENT_ME_POOL_INIT_STAGE1 {
+                    me_stage_progress.unwrap_or(0.0).clamp(0.0, 1.0)
+                } else {
+                    0.0
+                }
+            }
+            StartupComponentStatus::Ready
+            | StartupComponentStatus::Failed
+            | StartupComponentStatus::Skipped => 1.0,
+        };
+        completed_weight += component.weight * unit_progress;
+    }
+
+    if total_weight <= f64::EPSILON {
+        0.0
+    } else {
+        ((completed_weight / total_weight) * 100.0).clamp(0.0, 100.0)
+    }
+}
+
+fn component_blueprint() -> Vec<StartupComponent> {
+    vec![
+        component(COMPONENT_CONFIG_LOAD, "Config load", 5.0),
+        component(COMPONENT_TRACING_INIT, "Tracing init", 3.0),
+        component(COMPONENT_API_BOOTSTRAP, "API bootstrap", 5.0),
+        component(COMPONENT_TLS_FRONT_BOOTSTRAP, "TLS front bootstrap", 5.0),
+        component(COMPONENT_NETWORK_PROBE, "Network probe", 10.0),
+        component(COMPONENT_ME_SECRET_FETCH, "ME secret fetch", 8.0),
+        component(COMPONENT_ME_PROXY_CONFIG_V4, "ME config v4 fetch", 4.0),
+        component(COMPONENT_ME_PROXY_CONFIG_V6, "ME config v6 fetch", 4.0),
+        component(COMPONENT_ME_POOL_CONSTRUCT, "ME pool construct", 6.0),
+        component(COMPONENT_ME_POOL_INIT_STAGE1, "ME pool init stage1", 24.0),
+        component(COMPONENT_ME_CONNECTIVITY_PING, "ME connectivity ping", 6.0),
+        component(COMPONENT_DC_CONNECTIVITY_PING, "DC connectivity ping", 8.0),
+        component(COMPONENT_LISTENERS_BIND, "Listener bind", 8.0),
+        component(COMPONENT_CONFIG_WATCHER_START, "Config watcher start", 2.0),
+        component(COMPONENT_METRICS_START, "Metrics start", 1.0),
+        component(COMPONENT_RUNTIME_READY, "Runtime ready", 1.0),
+    ]
+}
+
+fn component(id: &'static str, title: &'static str, weight: f64) -> StartupComponent {
+    StartupComponent {
+        id,
+        title,
+        weight,
+        status: StartupComponentStatus::Pending,
+        started_at_epoch_ms: None,
+        finished_at_epoch_ms: None,
+        duration_ms: None,
+        attempts: 0,
+        details: None,
+    }
+}
+
+fn normalize_details(details: Option<String>) -> Option<String> {
+    details.map(|detail| {
+        if detail.len() <= 256 {
+            detail
+        } else {
+            detail[..256].to_string()
+        }
+    })
+}
+
+fn now_epoch_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}
+
+fn now_epoch_ms() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_millis() as u64
+}

src/stats/beobachten.rs

@@ -0,0 +1,117 @@
+//! Per-IP forensic buckets for scanner and handshake failure observation.
+
+use std::collections::{BTreeMap, HashMap};
+use std::net::IpAddr;
+use std::time::{Duration, Instant};
+
+use parking_lot::Mutex;
+
+const CLEANUP_INTERVAL: Duration = Duration::from_secs(30);
+
+#[derive(Default)]
+struct BeobachtenInner {
+    entries: HashMap<(String, IpAddr), BeobachtenEntry>,
+    last_cleanup: Option<Instant>,
+}
+
+#[derive(Clone, Copy)]
+struct BeobachtenEntry {
+    tries: u64,
+    last_seen: Instant,
+}
+
+/// In-memory, TTL-scoped per-IP counters keyed by source class.
+pub struct BeobachtenStore {
+    inner: Mutex<BeobachtenInner>,
+}
+
+impl Default for BeobachtenStore {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl BeobachtenStore {
+    pub fn new() -> Self {
+        Self {
+            inner: Mutex::new(BeobachtenInner::default()),
+        }
+    }
+
+    pub fn record(&self, class: &str, ip: IpAddr, ttl: Duration) {
+        if class.is_empty() || ttl.is_zero() {
+            return;
+        }
+
+        let now = Instant::now();
+        let mut guard = self.inner.lock();
+        Self::cleanup_if_needed(&mut guard, now, ttl);
+
+        let key = (class.to_string(), ip);
+        let entry = guard.entries.entry(key).or_insert(BeobachtenEntry {
+            tries: 0,
+            last_seen: now,
+        });
+        entry.tries = entry.tries.saturating_add(1);
+        entry.last_seen = now;
+    }
+
+    pub fn snapshot_text(&self, ttl: Duration) -> String {
+        if ttl.is_zero() {
+            return "beobachten disabled\n".to_string();
+        }
+
+        let now = Instant::now();
+        let mut guard = self.inner.lock();
+        Self::cleanup(&mut guard, now, ttl);
+        guard.last_cleanup = Some(now);
+
+        let mut grouped = BTreeMap::<String, Vec<(IpAddr, u64)>>::new();
+        for ((class, ip), entry) in &guard.entries {
+            grouped
+                .entry(class.clone())
+                .or_default()
+                .push((*ip, entry.tries));
+        }
+
+        if grouped.is_empty() {
+            return "empty\n".to_string();
+        }
+
+        let mut out = String::with_capacity(grouped.len() * 64);
+        for (class, entries) in &mut grouped {
+            out.push('[');
+            out.push_str(class);
+            out.push_str("]\n");
+
+            entries.sort_by(|(ip_a, tries_a), (ip_b, tries_b)| {
+                tries_b
+                    .cmp(tries_a)
+                    .then_with(|| ip_a.to_string().cmp(&ip_b.to_string()))
+            });
+
+            for (ip, tries) in entries {
+                out.push_str(&format!("{ip}-{tries}\n"));
+            }
+        }
+
+        out
+    }
+
+    fn cleanup_if_needed(inner: &mut BeobachtenInner, now: Instant, ttl: Duration) {
+        let should_cleanup = match inner.last_cleanup {
+            Some(last) => now.saturating_duration_since(last) >= CLEANUP_INTERVAL,
+            None => true,
+        };
+        if should_cleanup {
+            Self::cleanup(inner, now, ttl);
+            inner.last_cleanup = Some(now);
+        }
+    }
+
+    fn cleanup(inner: &mut BeobachtenInner, now: Instant, ttl: Duration) {
+        inner.entries.retain(|_, entry| {
+            now.saturating_duration_since(entry.last_seen) <= ttl
+        });
+    }
+}

src/stats/telemetry.rs

@@ -0,0 +1,29 @@
+use crate::config::{MeTelemetryLevel, TelemetryConfig};
+
+/// Runtime telemetry policy used by hot-path counters.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct TelemetryPolicy {
+    pub core_enabled: bool,
+    pub user_enabled: bool,
+    pub me_level: MeTelemetryLevel,
+}
+
+impl Default for TelemetryPolicy {
+    fn default() -> Self {
+        Self {
+            core_enabled: true,
+            user_enabled: true,
+            me_level: MeTelemetryLevel::Normal,
+        }
+    }
+}
+
+impl TelemetryPolicy {
+    pub fn from_config(cfg: &TelemetryConfig) -> Self {
+        Self {
+            core_enabled: cfg.core_enabled,
+            user_enabled: cfg.user_enabled,
+            me_level: cfg.me_level,
+        }
+    }
+}

src/stream/buffer_pool.rs

@@ -3,6 +3,8 @@
 //! This module provides a thread-safe pool of BytesMut buffers
 //! that can be reused across connections to reduce allocation pressure.
 
+#![allow(dead_code)]
+
 use bytes::BytesMut;
 use crossbeam_queue::ArrayQueue;
 use std::ops::{Deref, DerefMut};
@@ -11,8 +13,9 @@ use std::sync::Arc;
 
 // ============= Configuration =============
 
-/// Default buffer size (64KB - good for MTProto)
-pub const DEFAULT_BUFFER_SIZE: usize = 64 * 1024;
+/// Default buffer size
+/// CHANGED: Reduced from 64KB to 16KB to match TLS record size and prevent bufferbloat.
+pub const DEFAULT_BUFFER_SIZE: usize = 16 * 1024;
 
 /// Default maximum number of pooled buffers
 pub const DEFAULT_MAX_BUFFERS: usize = 1024;
@@ -380,9 +383,14 @@ mod tests {
         // Add a buffer to pool
         pool.preallocate(1);
         
-        // Now try_get should succeed
-        assert!(pool.try_get().is_some());
+        // Now try_get should succeed once while the buffer is held
+        let buf = pool.try_get();
+        assert!(buf.is_some());
+        // While buffer is held, pool is empty
         assert!(pool.try_get().is_none());
+        // Drop buffer -> returns to pool, should be obtainable again
+        drop(buf);
+        assert!(pool.try_get().is_some());
     }
     
     #[test]
@@ -447,4 +455,4 @@ mod tests {
         // All buffers should be returned
         assert!(stats.pooled > 0);
     }
-}
+}

src/stream/frame.rs

@@ -3,10 +3,14 @@
 //! This module defines the common types and traits used by all
 //! frame encoding/decoding implementations.
 
+#![allow(dead_code)]
+
 use bytes::{Bytes, BytesMut};
 use std::io::Result;
+use std::sync::Arc;
 
 use crate::protocol::constants::ProtoTag;
+use crate::crypto::SecureRandom;
 
 // ============= Frame Types =============
 
@@ -147,11 +151,11 @@ pub trait FrameCodec: Send + Sync {
 // ============= Codec Factory =============
 
 /// Create a frame codec for the given protocol tag
-pub fn create_codec(proto_tag: ProtoTag) -> Box<dyn FrameCodec> {
+pub fn create_codec(proto_tag: ProtoTag, rng: Arc<SecureRandom>) -> Box<dyn FrameCodec> {
     match proto_tag {
         ProtoTag::Abridged => Box::new(crate::stream::frame_codec::AbridgedCodec::new()),
         ProtoTag::Intermediate => Box::new(crate::stream::frame_codec::IntermediateCodec::new()),
-        ProtoTag::Secure => Box::new(crate::stream::frame_codec::SecureCodec::new()),
+        ProtoTag::Secure => Box::new(crate::stream::frame_codec::SecureCodec::new(rng)),
     }
 }
 

src/stream/frame_codec.rs

@@ -3,11 +3,17 @@
 //! This module provides Encoder/Decoder implementations compatible
 //! with tokio-util's Framed wrapper for easy async frame I/O.
 
+#![allow(dead_code)]
+
 use bytes::{Bytes, BytesMut, BufMut};
 use std::io::{self, Error, ErrorKind};
+use std::sync::Arc;
 use tokio_util::codec::{Decoder, Encoder};
 
-use crate::protocol::constants::ProtoTag;
+use crate::protocol::constants::{
+    ProtoTag, is_valid_secure_payload_len, secure_padding_len, secure_payload_len_from_wire_len,
+};
+use crate::crypto::SecureRandom;
 use super::frame::{Frame, FrameMeta, FrameCodec as FrameCodecTrait};
 
 // ============= Unified Codec =============
@@ -21,14 +27,17 @@ pub struct FrameCodec {
     proto_tag: ProtoTag,
     /// Maximum allowed frame size
     max_frame_size: usize,
+    /// RNG for secure padding
+    rng: Arc<SecureRandom>,
 }
 
 impl FrameCodec {
     /// Create a new codec for the given protocol
-    pub fn new(proto_tag: ProtoTag) -> Self {
+    pub fn new(proto_tag: ProtoTag, rng: Arc<SecureRandom>) -> Self {
         Self {
             proto_tag,
             max_frame_size: 16 * 1024 * 1024, // 16MB default
+            rng,
         }
     }
     
@@ -64,7 +73,7 @@ impl Encoder<Frame> for FrameCodec {
         match self.proto_tag {
             ProtoTag::Abridged => encode_abridged(&frame, dst),
             ProtoTag::Intermediate => encode_intermediate(&frame, dst),
-            ProtoTag::Secure => encode_secure(&frame, dst),
+            ProtoTag::Secure => encode_secure(&frame, dst, &self.rng),
         }
     }
 }
@@ -130,7 +139,7 @@ fn encode_abridged(frame: &Frame, dst: &mut BytesMut) -> io::Result<()> {
     let data = &frame.data;
     
     // Validate alignment
-    if data.len() % 4 != 0 {
+    if !data.len().is_multiple_of(4) {
         return Err(Error::new(
             ErrorKind::InvalidInput,
             format!("abridged frame must be 4-byte aligned, got {} bytes", data.len())
@@ -269,13 +278,13 @@ fn decode_secure(src: &mut BytesMut, max_size: usize) -> io::Result<Option<Frame
         return Ok(None);
     }
     
-    // Calculate padding (indicated by length not divisible by 4)
-    let padding_len = len % 4;
-    let data_len = if padding_len != 0 {
-        len - padding_len
-    } else {
-        len
-    };
+    let data_len = secure_payload_len_from_wire_len(len).ok_or_else(|| {
+        Error::new(
+            ErrorKind::InvalidData,
+            format!("invalid secure frame length: {len}"),
+        )
+    })?;
+    let padding_len = len - data_len;
     
     meta.padding_len = padding_len as u8;
     
@@ -288,9 +297,7 @@ fn decode_secure(src: &mut BytesMut, max_size: usize) -> io::Result<Option<Frame
     Ok(Some(Frame::with_meta(data, meta)))
 }
 
-fn encode_secure(frame: &Frame, dst: &mut BytesMut) -> io::Result<()> {
-    use crate::crypto::random::SECURE_RANDOM;
-    
+fn encode_secure(frame: &Frame, dst: &mut BytesMut, rng: &SecureRandom) -> io::Result<()> {
     let data = &frame.data;
     
     // Simple ACK: just send data
@@ -300,14 +307,15 @@ fn encode_secure(frame: &Frame, dst: &mut BytesMut) -> io::Result<()> {
         return Ok(());
     }
     
-    // Generate padding to make length not divisible by 4
-    let padding_len = if data.len() % 4 == 0 {
-        // Add 1-3 bytes to make it non-aligned
-        (SECURE_RANDOM.range(3) + 1) as usize
-    } else {
-        // Already non-aligned, can add 0-3
-        SECURE_RANDOM.range(4) as usize
-    };
+    if !is_valid_secure_payload_len(data.len()) {
+        return Err(Error::new(
+            ErrorKind::InvalidData,
+            format!("secure payload must be 4-byte aligned, got {}", data.len()),
+        ));
+    }
+
+    // Generate padding that keeps total length non-divisible by 4.
+    let padding_len = secure_padding_len(data.len(), rng);
     
     let total_len = data.len() + padding_len;
     dst.reserve(4 + total_len);
@@ -321,7 +329,7 @@ fn encode_secure(frame: &Frame, dst: &mut BytesMut) -> io::Result<()> {
     dst.extend_from_slice(data);
     
     if padding_len > 0 {
-        let padding = SECURE_RANDOM.bytes(padding_len);
+        let padding = rng.bytes(padding_len);
         dst.extend_from_slice(&padding);
     }
     
@@ -445,19 +453,21 @@ impl FrameCodecTrait for IntermediateCodec {
 /// Secure Intermediate protocol codec
 pub struct SecureCodec {
     max_frame_size: usize,
+    rng: Arc<SecureRandom>,
 }
 
 impl SecureCodec {
-    pub fn new() -> Self {
+    pub fn new(rng: Arc<SecureRandom>) -> Self {
         Self {
             max_frame_size: 16 * 1024 * 1024,
+            rng,
         }
     }
 }
 
 impl Default for SecureCodec {
     fn default() -> Self {
-        Self::new()
+        Self::new(Arc::new(SecureRandom::new()))
     }
 }
 
@@ -474,7 +484,7 @@ impl Encoder<Frame> for SecureCodec {
     type Error = io::Error;
     
     fn encode(&mut self, frame: Frame, dst: &mut BytesMut) -> Result<(), Self::Error> {
-        encode_secure(&frame, dst)
+        encode_secure(&frame, dst, &self.rng)
     }
 }
 
@@ -485,7 +495,7 @@ impl FrameCodecTrait for SecureCodec {
     
     fn encode(&self, frame: &Frame, dst: &mut BytesMut) -> io::Result<usize> {
         let before = dst.len();
-        encode_secure(frame, dst)?;
+        encode_secure(frame, dst, &self.rng)?;
         Ok(dst.len() - before)
     }
     
@@ -506,6 +516,8 @@ mod tests {
     use tokio_util::codec::{FramedRead, FramedWrite};
     use tokio::io::duplex;
     use futures::{SinkExt, StreamExt};
+    use crate::crypto::SecureRandom;
+    use std::sync::Arc;
     
     #[tokio::test]
     async fn test_framed_abridged() {
@@ -541,8 +553,8 @@ mod tests {
     async fn test_framed_secure() {
         let (client, server) = duplex(4096);
         
-        let mut writer = FramedWrite::new(client, SecureCodec::new());
-        let mut reader = FramedRead::new(server, SecureCodec::new());
+        let mut writer = FramedWrite::new(client, SecureCodec::new(Arc::new(SecureRandom::new())));
+        let mut reader = FramedRead::new(server, SecureCodec::new(Arc::new(SecureRandom::new())));
         
         let original = Bytes::from_static(&[1, 2, 3, 4, 5, 6, 7, 8]);
         let frame = Frame::new(original.clone());
@@ -557,8 +569,8 @@ mod tests {
         for proto_tag in [ProtoTag::Abridged, ProtoTag::Intermediate, ProtoTag::Secure] {
             let (client, server) = duplex(4096);
             
-            let mut writer = FramedWrite::new(client, FrameCodec::new(proto_tag));
-            let mut reader = FramedRead::new(server, FrameCodec::new(proto_tag));
+            let mut writer = FramedWrite::new(client, FrameCodec::new(proto_tag, Arc::new(SecureRandom::new())));
+            let mut reader = FramedRead::new(server, FrameCodec::new(proto_tag, Arc::new(SecureRandom::new())));
             
             // Use 4-byte aligned data for abridged compatibility
             let original = Bytes::from_static(&[1, 2, 3, 4, 5, 6, 7, 8]);
@@ -607,7 +619,7 @@ mod tests {
     
     #[test]
     fn test_frame_too_large() {
-        let mut codec = FrameCodec::new(ProtoTag::Intermediate)
+        let mut codec = FrameCodec::new(ProtoTag::Intermediate, Arc::new(SecureRandom::new()))
             .with_max_frame_size(100);
         
         // Create a "frame" that claims to be very large
@@ -618,4 +630,4 @@ mod tests {
         let result = codec.decode(&mut buf);
         assert!(result.is_err());
     }
-}
+}

src/stream/frame_stream.rs

@@ -1,11 +1,13 @@
 //! MTProto frame stream wrappers
 
-use bytes::{Bytes, BytesMut};
+#![allow(dead_code)]
+
+use bytes::Bytes;
 use std::io::{Error, ErrorKind, Result};
 use tokio::io::{AsyncRead, AsyncWrite, AsyncReadExt, AsyncWriteExt};
 use crate::protocol::constants::*;
-use crate::crypto::crc32;
-use crate::crypto::random::SECURE_RANDOM;
+use crate::crypto::{crc32, SecureRandom};
+use std::sync::Arc;
 use super::traits::{FrameMeta, LayeredStream};
 
 // ============= Abridged (Compact) Frame =============
@@ -76,7 +78,7 @@ impl<W> AbridgedFrameWriter<W> {
 impl<W: AsyncWrite + Unpin> AbridgedFrameWriter<W> {
     /// Write a frame
     pub async fn write_frame(&mut self, data: &[u8], meta: &FrameMeta) -> Result<()> {
-        if data.len() % 4 != 0 {
+        if !data.len().is_multiple_of(4) {
             return Err(Error::new(
                 ErrorKind::InvalidInput,
                 format!("Abridged frame must be aligned to 4 bytes, got {}", data.len()),
@@ -232,11 +234,13 @@ impl<R: AsyncRead + Unpin> SecureIntermediateFrameReader<R> {
         let mut data = vec![0u8; len];
         self.upstream.read_exact(&mut data).await?;
         
-        // Strip padding (not aligned to 4)
-        if len % 4 != 0 {
-            let actual_len = len - (len % 4);
-            data.truncate(actual_len);
-        }
+        let payload_len = secure_payload_len_from_wire_len(len).ok_or_else(|| {
+            Error::new(
+                ErrorKind::InvalidData,
+                format!("Invalid secure frame length: {len}"),
+            )
+        })?;
+        data.truncate(payload_len);
         
         Ok((Bytes::from(data), meta))
     }
@@ -251,11 +255,12 @@ impl<R> LayeredStream<R> for SecureIntermediateFrameReader<R> {
 /// Writer for secure intermediate MTProto framing
 pub struct SecureIntermediateFrameWriter<W> {
     upstream: W,
+    rng: Arc<SecureRandom>,
 }
 
 impl<W> SecureIntermediateFrameWriter<W> {
-    pub fn new(upstream: W) -> Self {
-        Self { upstream }
+    pub fn new(upstream: W, rng: Arc<SecureRandom>) -> Self {
+        Self { upstream, rng }
     }
 }
 
@@ -266,9 +271,16 @@ impl<W: AsyncWrite + Unpin> SecureIntermediateFrameWriter<W> {
             return Ok(());
         }
         
-        // Add random padding (0-3 bytes)
-        let padding_len = SECURE_RANDOM.range(4);
-        let padding = SECURE_RANDOM.bytes(padding_len);
+        if !is_valid_secure_payload_len(data.len()) {
+            return Err(Error::new(
+                ErrorKind::InvalidData,
+                format!("Secure payload must be 4-byte aligned, got {}", data.len()),
+            ));
+        }
+
+        // Add padding so total length is never divisible by 4 (MTProto Secure)
+        let padding_len = secure_padding_len(data.len(), &self.rng);
+        let padding = self.rng.bytes(padding_len);
         
         let total_len = data.len() + padding_len;
         let len_bytes = (total_len as u32).to_le_bytes();
@@ -319,7 +331,7 @@ impl<R: AsyncRead + Unpin> MtprotoFrameReader<R> {
             }
             
             // Validate length
-            if len < MIN_MSG_LEN || len > MAX_MSG_LEN || len % PADDING_FILLER.len() != 0 {
+            if !(MIN_MSG_LEN..=MAX_MSG_LEN).contains(&len) || !len.is_multiple_of(PADDING_FILLER.len()) {
                 return Err(Error::new(
                     ErrorKind::InvalidData,
                     format!("Invalid message length: {}", len),
@@ -454,11 +466,11 @@ pub enum FrameWriterKind<W> {
 }
 
 impl<W: AsyncWrite + Unpin> FrameWriterKind<W> {
-    pub fn new(upstream: W, proto_tag: ProtoTag) -> Self {
+    pub fn new(upstream: W, proto_tag: ProtoTag, rng: Arc<SecureRandom>) -> Self {
         match proto_tag {
             ProtoTag::Abridged => FrameWriterKind::Abridged(AbridgedFrameWriter::new(upstream)),
             ProtoTag::Intermediate => FrameWriterKind::Intermediate(IntermediateFrameWriter::new(upstream)),
-            ProtoTag::Secure => FrameWriterKind::SecureIntermediate(SecureIntermediateFrameWriter::new(upstream)),
+            ProtoTag::Secure => FrameWriterKind::SecureIntermediate(SecureIntermediateFrameWriter::new(upstream, rng)),
         }
     }
     
@@ -483,6 +495,8 @@ impl<W: AsyncWrite + Unpin> FrameWriterKind<W> {
 mod tests {
     use super::*;
     use tokio::io::duplex;
+    use std::sync::Arc;
+    use crate::crypto::SecureRandom;
     
     #[tokio::test]
     async fn test_abridged_roundtrip() {
@@ -539,7 +553,7 @@ mod tests {
     async fn test_secure_intermediate_padding() {
         let (client, server) = duplex(1024);
         
-        let mut writer = SecureIntermediateFrameWriter::new(client);
+        let mut writer = SecureIntermediateFrameWriter::new(client, Arc::new(SecureRandom::new()));
         let mut reader = SecureIntermediateFrameReader::new(server);
         
         let data = vec![1u8, 2, 3, 4, 5, 6, 7, 8];
@@ -547,9 +561,7 @@ mod tests {
         writer.flush().await.unwrap();
         
         let (received, _meta) = reader.read_frame().await.unwrap();
-        // Received should have padding stripped to align to 4
-        let expected_len = (data.len() / 4) * 4;
-        assert_eq!(received.len(), expected_len);
+        assert_eq!(received.len(), data.len());
     }
     
     #[tokio::test]
@@ -572,7 +584,7 @@ mod tests {
     async fn test_frame_reader_kind() {
         let (client, server) = duplex(1024);
         
-        let mut writer = FrameWriterKind::new(client, ProtoTag::Intermediate);
+        let mut writer = FrameWriterKind::new(client, ProtoTag::Intermediate, Arc::new(SecureRandom::new()));
         let mut reader = FrameReaderKind::new(server, ProtoTag::Intermediate);
         
         let data = vec![1u8, 2, 3, 4];
@@ -582,4 +594,4 @@ mod tests {
         let (received, _) = reader.read_frame().await.unwrap();
         assert_eq!(&received[..], &data[..]);
     }
-}
+}

src/stream/mod.rs

@@ -12,32 +12,38 @@ pub mod frame_codec;
 pub mod frame_stream;
 
 // Re-export state machine types
+#[allow(unused_imports)]
 pub use state::{
     StreamState, Transition, PollResult,
     ReadBuffer, WriteBuffer, HeaderBuffer, YieldBuffer,
 };
 
 // Re-export buffer pool
+#[allow(unused_imports)]
 pub use buffer_pool::{BufferPool, PooledBuffer, PoolStats};
 
 // Re-export stream implementations
+#[allow(unused_imports)]
 pub use crypto_stream::{CryptoReader, CryptoWriter, PassthroughStream};
 pub use tls_stream::{FakeTlsReader, FakeTlsWriter};
 
 // Re-export frame types
+#[allow(unused_imports)]
 pub use frame::{Frame, FrameMeta, FrameCodec as FrameCodecTrait, create_codec};
 
-// Re-export tokio-util compatible codecs  
+// Re-export tokio-util compatible codecs
+#[allow(unused_imports)]
 pub use frame_codec::{
     FrameCodec,
     AbridgedCodec, IntermediateCodec, SecureCodec,
 };
 
 // Legacy re-exports for compatibility
+#[allow(unused_imports)]
 pub use frame_stream::{
     AbridgedFrameReader, AbridgedFrameWriter,
     IntermediateFrameReader, IntermediateFrameWriter,
     SecureIntermediateFrameReader, SecureIntermediateFrameWriter,
     MtprotoFrameReader, MtprotoFrameWriter,
     FrameReaderKind, FrameWriterKind,
-};
+};

src/stream/state.rs

@@ -3,6 +3,8 @@
 //! This module provides core types and traits for implementing
 //! stateful async streams with proper partial read/write handling.
 
+#![allow(dead_code)]
+
 use bytes::{Bytes, BytesMut};
 use std::io;