Update Cargo.toml

Fix similar username in discovered items in zabbix template

.github/workflows/release.yml

@@ -3,11 +3,12 @@ name: Release
 on:
   push:
     tags:
-      - '[0-9]+.[0-9]+.[0-9]+'  # Matches tags like 3.0.0, 3.1.2, etc.
-  workflow_dispatch:  # Manual trigger from GitHub Actions UI
+      - '[0-9]+.[0-9]+.[0-9]+'
+  workflow_dispatch:
 
 permissions:
   contents: read
+  packages: write
 
 env:
   CARGO_TERM_COLOR: always
@@ -37,11 +38,9 @@ jobs:
             asset_name: telemt-aarch64-linux-musl
 
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
 
-      - name: Install stable Rust toolchain
-        uses: dtolnay/rust-toolchain@888c2e1ea69ab0d4330cbf0af1ecc7b68f368cc1 # v1
+      - uses: dtolnay/rust-toolchain@v1
         with:
           toolchain: stable
           targets: ${{ matrix.target }}
@@ -51,8 +50,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y gcc-aarch64-linux-gnu
 
-      - name: Cache cargo registry & build artifacts
-        uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4.2.2
+      - uses: actions/cache@v4
         with:
           path: |
             ~/.cargo/registry
@@ -76,14 +74,46 @@ jobs:
           tar -czvf ${{ matrix.asset_name }}.tar.gz ${{ matrix.artifact_name }}
           sha256sum ${{ matrix.asset_name }}.tar.gz > ${{ matrix.asset_name }}.sha256
 
-      - name: Upload artifact
-        uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0
+      - 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
@@ -92,40 +122,14 @@ jobs:
       contents: write
 
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-          token: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Download all artifacts
-        uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
+      - uses: actions/download-artifact@v4
         with:
           path: artifacts
 
-      - name: Update version in Cargo.toml and Cargo.lock
-        run: |
-          # Extract version from tag (remove 'v' prefix if present)
-          VERSION="${GITHUB_REF#refs/tags/}"
-          VERSION="${VERSION#v}"
-          
-          # Install cargo-edit for version bumping
-          cargo install cargo-edit
-          
-          # Update Cargo.toml version
-          cargo set-version "$VERSION"
-          
-          # Configure git
-          git config user.name "github-actions[bot]"
-          git config user.email "github-actions[bot]@users.noreply.github.com"
-          
-          # Commit and push changes
-          #git add Cargo.toml Cargo.lock
-          #git commit -m "chore: bump version to $VERSION" || echo "No changes to commit"
-          #git push origin HEAD:main
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
       - name: Create Release
         uses: softprops/action-gh-release@v2
         with:

.gitignore

@@ -19,3 +19,7 @@ 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/
+*.rs
+target
+Cargo.lock
+src

AGENTS.md

@@ -1,40 +1,410 @@
-# AGENTS.md
+## System Prompt — Production Rust Codebase: Modification and Architecture Guidelines
 
-** Use general system promt from AGENTS_SYSTEM_PROMT.md **
-** Additional techiques and architectury details are here **
+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.
 
-This file provides guidance to agents when working with code in this repository.
+---
 
-## Build & Test Commands
-```bash
-cargo build --release          # Production build
-cargo test                     # Run all tests
-cargo test --lib error         # Run tests for specific module (error module)
-cargo bench --bench crypto_bench  # Run crypto benchmarks
-cargo clippy -- -D warnings    # Lint with clippy
+### 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(...) { ... }
 ```
 
-## Project-Specific Conventions
+Incorrect examples:
 
-### Rust Edition
-- Uses **Rust edition 2024** (not 2021) - specified in Cargo.toml
+```rust
+let x = 5; // set x to 5
+```
 
-### Error Handling Pattern
-- Custom [`Recoverable`](src/error.rs:110) trait distinguishes recoverable vs fatal errors
-- [`HandshakeResult<T,R,W>`](src/error.rs:292) returns streams on bad client for masking - do not drop them
-- Always use [`ProxyError`](src/error.rs:168) from [`src/error.rs`](src/error.rs) for proxy operations
+```rust
+// This function does stuff
+fn do_stuff() { ... }
+```
 
-### Configuration Auto-Migration
-- [`ProxyConfig::load()`](src/config/mod.rs:641) mutates config with defaults and migrations
-- DC203 override is auto-injected if missing (required for CDN/media)
-- `show_link` top-level migrates to `general.links.show`
+---
 
-### Middle-End Proxy Requirements
-- Requires public IP on interface OR 1:1 NAT with STUN probing
-- Falls back to direct mode on STUN/interface mismatch unless `stun_iface_mismatch_ignore=true`
-- Proxy-secret from Telegram is separate from user secrets
+### 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.
 
-### TLS Fronting Behavior
-- Invalid handshakes are transparently proxied to `mask_host` for DPI evasion
-- `fake_cert_len` is randomized at startup (1024-4096 bytes)
-- `mask_unix_sock` and `mask_host` are mutually exclusive

AGENTS_SYSTEM_PROMT.md

@@ -1,207 +0,0 @@
-## System Prompt — Production Rust Codebase: Modification and Architecture Guidelines
-
-You are a senior Rust systems engineer 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.
-
----
-
-### 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.
-
-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.
-
-Note: `todo!()` and `unimplemented!()` are allowed as idiomatic Rust markers for genuinely unfinished code paths.
-
----
-
-### 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.
-
----
-
-### 10. Response Format
-
-#### Language Policy
-
-- Code, comments, commit messages, documentation: **English**.
-- Reasoning and explanations in response text: **Russian**.
-
-#### Response Structure
-
-Your response MUST consist of two sections:
-
-**Section 1: `## Reasoning` (in Russian)**
-
-- 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.

Cargo.lock

@@ -55,6 +55,45 @@ version = "1.0.101"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5f0e0fee31ef5ed1ba1316088939cea399010ed7731dba877ed44aeb407a75ea"
 
+[[package]]
+name = "asn1-rs"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f6fd5ddaf0351dff5b8da21b2fb4ff8e08ddd02857f0bf69c47639106c0fff0"
+dependencies = [
+ "asn1-rs-derive",
+ "asn1-rs-impl",
+ "displaydoc",
+ "nom",
+ "num-traits",
+ "rusticata-macros",
+ "thiserror 1.0.69",
+ "time",
+]
+
+[[package]]
+name = "asn1-rs-derive"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "726535892e8eae7e70657b4c8ea93d26b8553afb1ce617caee529ef96d7dee6c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+ "synstructure 0.12.6",
+]
+
+[[package]]
+name = "asn1-rs-impl"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2777730b2039ac0f95f093556e61b6d26cebed5393ca6f152717777cec3a42ed"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "atomic-waker"
 version = "1.1.2"
@@ -88,6 +127,12 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
 
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "bitflags"
 version = "2.10.0"
@@ -155,6 +200,12 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
+
 [[package]]
 name = "cfg_aliases"
 version = "0.2.1"
@@ -252,6 +303,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "crc32c"
+version = "0.6.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a47af21622d091a8f0fb295b88bc886ac74efcc613efc19f5d0b21de5c89e47"
+dependencies = [
+ "rustc_version",
+]
+
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -297,6 +357,15 @@ dependencies = [
  "itertools",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.6"
@@ -369,6 +438,35 @@ dependencies = [
  "parking_lot_core",
 ]
 
+[[package]]
+name = "data-encoding"
+version = "2.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7a1e2f27636f116493b8b860f5546edb47c8d8f8ea73e1d2a20be88e28d1fea"
+
+[[package]]
+name = "der-parser"
+version = "8.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbd676fbbab537128ef0278adb5576cf363cff6aa22a7b24effe97347cfab61e"
+dependencies = [
+ "asn1-rs",
+ "displaydoc",
+ "nom",
+ "num-bigint",
+ "num-traits",
+ "rusticata-macros",
+]
+
+[[package]]
+name = "deranged"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7cd812cc2bc1d69d4764bd80df88b4317eaef9e773c75226407d9bc0876b211c"
+dependencies = [
+ "powerfmt",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -388,7 +486,7 @@ checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -419,6 +517,17 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "filetime"
+version = "0.2.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f98844151eee8917efc50bd9e8318cb963ae8b297431495d3f758616ea5c57db"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "libredox",
+]
+
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.9"
@@ -452,6 +561,15 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "fsevent-sys"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76ee7a02da4d231650c7cea31349b889be2f45ddb3ef3032d2ec8185f6313fd2"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.31"
@@ -508,7 +626,7 @@ checksum = "162ee34ebcb7c64a8abebc059ce0fee27c2262618d7b60ed8faf72fef13c3650"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -756,7 +874,7 @@ dependencies = [
  "tokio",
  "tokio-rustls",
  "tower-service",
- "webpki-roots",
+ "webpki-roots 1.0.6",
 ]
 
 [[package]]
@@ -926,6 +1044,26 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "inotify"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8069d3ec154eb856955c1c0fbffefbf5f3c40a104ec912d4797314c1801abff"
+dependencies = [
+ "bitflags 1.3.2",
+ "inotify-sys",
+ "libc",
+]
+
+[[package]]
+name = "inotify-sys"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "inout"
 version = "0.1.4"
@@ -942,6 +1080,15 @@ version = "2.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "469fb0b9cefa57e3ef31275ee7cacb78f2fdca44e4765491884a2b119d4eb130"
 
+[[package]]
+name = "ipnetwork"
+version = "0.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf466541e9d546596ee94f9f69590f89473455f88372423e0008fc1a7daf100e"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "iri-string"
 version = "0.7.10"
@@ -988,6 +1135,26 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "kqueue"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eac30106d7dce88daf4a3fcb4879ea939476d5074a9b7ddd0fb97fa4bed5596a"
+dependencies = [
+ "kqueue-sys",
+ "libc",
+]
+
+[[package]]
+name = "kqueue-sys"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed9625ffda8729b85e45cf04090035ac368927b8cebc34898e7c120f52e4838b"
+dependencies = [
+ "bitflags 1.3.2",
+ "libc",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.5.0"
@@ -1006,6 +1173,17 @@ version = "0.2.181"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "459427e2af2b9c839b132acb702a1c654d95e10f8c326bfc2ad11310e458b1c5"
 
+[[package]]
+name = "libredox"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d0b95e02c851351f877147b7deea7b1afb1df71b63aa5f8270716e0c5720616"
+dependencies = [
+ "bitflags 2.10.0",
+ "libc",
+ "redox_syscall 0.7.1",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.11.0"
@@ -1073,6 +1251,33 @@ version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
+[[package]]
+name = "memoffset"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "488016bfae457b036d996092f6cb448677611ce4449e970ceaf42695203f218a"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "minimal-lexical"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
+[[package]]
+name = "mio"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
+dependencies = [
+ "libc",
+ "log",
+ "wasi",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "mio"
 version = "1.1.1"
@@ -1084,6 +1289,48 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "nix"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
+dependencies = [
+ "bitflags 2.10.0",
+ "cfg-if",
+ "cfg_aliases 0.1.1",
+ "libc",
+ "memoffset",
+]
+
+[[package]]
+name = "nom"
+version = "7.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d273983c5a657a70a3e8f2a01329822f3b8c8172b73826411a55751e404a0a4a"
+dependencies = [
+ "memchr",
+ "minimal-lexical",
+]
+
+[[package]]
+name = "notify"
+version = "6.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6205bd8bb1e454ad2e27422015fb5e4f2bcc7e08fa8f27058670d208324a4d2d"
+dependencies = [
+ "bitflags 2.10.0",
+ "crossbeam-channel",
+ "filetime",
+ "fsevent-sys",
+ "inotify",
+ "kqueue",
+ "libc",
+ "log",
+ "mio 0.8.11",
+ "walkdir",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.50.3"
@@ -1103,6 +1350,12 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-conv"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf97ec579c3c42f953ef76dbf8d55ac91fb219dde70e49aa4a6b7d74e9919050"
+
 [[package]]
 name = "num-integer"
 version = "0.1.46"
@@ -1121,6 +1374,15 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "oid-registry"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9bedf36ffb6ba96c2eb7144ef6270557b52e54b20c0a8e1eb2ff99a6c6959bff"
+dependencies = [
+ "asn1-rs",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -1151,7 +1413,7 @@ checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
 dependencies = [
  "cfg-if",
  "libc",
- "redox_syscall",
+ "redox_syscall 0.5.18",
  "smallvec",
  "windows-link",
 ]
@@ -1211,6 +1473,12 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "powerfmt"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.21"
@@ -1227,7 +1495,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "479ca8adacdd7ce8f1fb39ce9ecccbfe93a3f1344b3d0d97f20bc0196208f62b"
 dependencies = [
  "proc-macro2",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -1247,7 +1515,7 @@ checksum = "37566cb3fdacef14c0737f9546df7cfeadbfbc9fef10991038bf5015d0c80532"
 dependencies = [
  "bit-set",
  "bit-vec",
- "bitflags",
+ "bitflags 2.10.0",
  "num-traits",
  "rand",
  "rand_chacha",
@@ -1271,14 +1539,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9e20a958963c291dc322d98411f541009df2ced7b5a4f2bd52337638cfccf20"
 dependencies = [
  "bytes",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "pin-project-lite",
  "quinn-proto",
  "quinn-udp",
  "rustc-hash",
  "rustls",
  "socket2 0.6.2",
- "thiserror",
+ "thiserror 2.0.18",
  "tokio",
  "tracing",
  "web-time",
@@ -1299,7 +1567,7 @@ dependencies = [
  "rustls",
  "rustls-pki-types",
  "slab",
- "thiserror",
+ "thiserror 2.0.18",
  "tinyvec",
  "tracing",
  "web-time",
@@ -1311,7 +1579,7 @@ version = "0.5.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "addec6a0dcad8a8d96a771f815f0eaf55f9d1805756410b39f5fa81332574cbd"
 dependencies = [
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
  "once_cell",
  "socket2 0.6.2",
@@ -1398,7 +1666,16 @@ version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags",
+ "bitflags 2.10.0",
+]
+
+[[package]]
+name = "redox_syscall"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35985aa610addc02e24fc232012c86fd11f14111180f902b67e2d5331f8ebf2b"
+dependencies = [
+ "bitflags 2.10.0",
 ]
 
 [[package]]
@@ -1465,7 +1742,7 @@ dependencies = [
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
- "webpki-roots",
+ "webpki-roots 1.0.6",
 ]
 
 [[package]]
@@ -1488,13 +1765,31 @@ version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
 
+[[package]]
+name = "rustc_version"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
+dependencies = [
+ "semver",
+]
+
+[[package]]
+name = "rusticata-macros"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "faf0c4a6ece9950b9abdb62b1cfcf2a68b3b67a10ba445b3bb85be2a293d0632"
+dependencies = [
+ "nom",
+]
+
 [[package]]
 name = "rustix"
 version = "1.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "146c9e247ccc180c1f61615433868c99f3de3ae256a30a43b49f67c2d9171f34"
 dependencies = [
- "bitflags",
+ "bitflags 2.10.0",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -1608,7 +1903,7 @@ checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -1736,6 +2031,17 @@ version = "2.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.114"
@@ -1756,6 +2062,18 @@ dependencies = [
  "futures-core",
 ]
 
+[[package]]
+name = "synstructure"
+version = "0.12.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f36bdaa60a83aca3921b5259d5400cbf5e90fc51931376a9bd4a0eb79aa7210f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+ "unicode-xid",
+]
+
 [[package]]
 name = "synstructure"
 version = "0.13.2"
@@ -1764,18 +2082,20 @@ checksum = "728a70f3dbaf5bab7f0c4b1ac8d7ae5ea60a4b5549c8a5914361c99147a709d2"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
 name = "telemt"
-version = "3.0.0"
+version = "3.0.13"
 dependencies = [
  "aes",
+ "anyhow",
  "base64",
  "bytes",
  "cbc",
  "chrono",
+ "crc32c",
  "crc32fast",
  "criterion",
  "crossbeam-queue",
@@ -1788,9 +2108,12 @@ dependencies = [
  "httpdate",
  "hyper",
  "hyper-util",
+ "ipnetwork",
  "libc",
  "lru",
  "md-5",
+ "nix",
+ "notify",
  "num-bigint",
  "num-traits",
  "parking_lot",
@@ -1798,19 +2121,23 @@ dependencies = [
  "rand",
  "regex",
  "reqwest",
+ "rustls",
  "serde",
  "serde_json",
  "sha1",
  "sha2",
  "socket2 0.5.10",
- "thiserror",
+ "thiserror 2.0.18",
  "tokio",
+ "tokio-rustls",
  "tokio-test",
  "tokio-util",
  "toml",
  "tracing",
  "tracing-subscriber",
  "url",
+ "webpki-roots 0.26.11",
+ "x509-parser",
  "zeroize",
 ]
 
@@ -1827,13 +2154,33 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
+dependencies = [
+ "thiserror-impl 1.0.69",
+]
+
 [[package]]
 name = "thiserror"
 version = "2.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4288b5bcbc7920c07a1149a35cf9590a2aa808e0bc1eafaade0b80947865fbc4"
 dependencies = [
- "thiserror-impl",
+ "thiserror-impl 2.0.18",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -1844,7 +2191,7 @@ checksum = "ebc4ee7f67670e9b64d05fa4253e753e016c6c95ff35b89b7941d6b856dec1d5"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -1856,6 +2203,37 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "time"
+version = "0.3.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "743bd48c283afc0388f9b8827b976905fb217ad9e647fae3a379a9283c4def2c"
+dependencies = [
+ "deranged",
+ "itoa",
+ "num-conv",
+ "powerfmt",
+ "serde_core",
+ "time-core",
+ "time-macros",
+]
+
+[[package]]
+name = "time-core"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7694e1cfe791f8d31026952abf09c69ca6f6fa4e1a1229e18988f06a04a12dca"
+
+[[package]]
+name = "time-macros"
+version = "0.2.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e70e4c5a0e0a8a4823ad65dfe1a6930e4f4d756dcd9dd7939022b5e8c501215"
+dependencies = [
+ "num-conv",
+ "time-core",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.8.2"
@@ -1899,7 +2277,7 @@ checksum = "72a2903cd7736441aac9df9d7688bd0ce48edccaadf181c3b90be801e81d3d86"
 dependencies = [
  "bytes",
  "libc",
- "mio",
+ "mio 1.1.1",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
@@ -1917,7 +2295,7 @@ checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -2031,7 +2409,7 @@ version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4e6559d53cc268e5031cd8429d05415bc4cb4aefc4aa5d6cc35fbf5b924a1f8"
 dependencies = [
- "bitflags",
+ "bitflags 2.10.0",
  "bytes",
  "futures-util",
  "http",
@@ -2074,7 +2452,7 @@ checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -2280,7 +2658,7 @@ dependencies = [
  "bumpalo",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
  "wasm-bindgen-shared",
 ]
 
@@ -2321,7 +2699,7 @@ version = "0.244.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47b807c72e1bac69382b3a6fb3dbe8ea4c0ed87ff5629b8685ae6b9a611028fe"
 dependencies = [
- "bitflags",
+ "bitflags 2.10.0",
  "hashbrown 0.15.5",
  "indexmap",
  "semver",
@@ -2347,6 +2725,15 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webpki-roots"
+version = "0.26.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "521bc38abb08001b01866da9f51eb7c5d647a19260e00054a8c7fd5f9e57f7a9"
+dependencies = [
+ "webpki-roots 1.0.6",
+]
+
 [[package]]
 name = "webpki-roots"
 version = "1.0.6"
@@ -2386,7 +2773,7 @@ checksum = "053e2e040ab57b9dc951b72c264860db7eb3b0200ba345b4e4c3b14f67855ddf"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -2397,7 +2784,7 @@ checksum = "3f316c4a2570ba26bbec722032c4099d8c8bc095efccdc15688708623367e358"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -2424,6 +2811,15 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
+dependencies = [
+ "windows-targets 0.48.5",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
@@ -2451,6 +2847,21 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-targets"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
+dependencies = [
+ "windows_aarch64_gnullvm 0.48.5",
+ "windows_aarch64_msvc 0.48.5",
+ "windows_i686_gnu 0.48.5",
+ "windows_i686_msvc 0.48.5",
+ "windows_x86_64_gnu 0.48.5",
+ "windows_x86_64_gnullvm 0.48.5",
+ "windows_x86_64_msvc 0.48.5",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.52.6"
@@ -2484,6 +2895,12 @@ dependencies = [
  "windows_x86_64_msvc 0.53.1",
 ]
 
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.6"
@@ -2496,6 +2913,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
 
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
+
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.6"
@@ -2508,6 +2931,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
 
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
+
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.6"
@@ -2532,6 +2961,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
 
+[[package]]
+name = "windows_i686_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.6"
@@ -2544,6 +2979,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
 
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
+
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.6"
@@ -2556,6 +2997,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
 
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.6"
@@ -2568,6 +3015,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
 
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
+
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.6"
@@ -2619,7 +3072,7 @@ dependencies = [
  "heck",
  "indexmap",
  "prettyplease",
- "syn",
+ "syn 2.0.114",
  "wasm-metadata",
  "wit-bindgen-core",
  "wit-component",
@@ -2635,7 +3088,7 @@ dependencies = [
  "prettyplease",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
  "wit-bindgen-core",
  "wit-bindgen-rust",
 ]
@@ -2647,7 +3100,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d66ea20e9553b30172b5e831994e35fbde2d165325bec84fc43dbf6f4eb9cb2"
 dependencies = [
  "anyhow",
- "bitflags",
+ "bitflags 2.10.0",
  "indexmap",
  "log",
  "serde",
@@ -2683,6 +3136,23 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9edde0db4769d2dc68579893f2306b26c6ecfbe0ef499b013d731b7b9247e0b9"
 
+[[package]]
+name = "x509-parser"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7069fba5b66b9193bd2c5d3d4ff12b839118f6bcbef5328efafafb5395cf63da"
+dependencies = [
+ "asn1-rs",
+ "data-encoding",
+ "der-parser",
+ "lazy_static",
+ "nom",
+ "oid-registry",
+ "rusticata-macros",
+ "thiserror 1.0.69",
+ "time",
+]
+
 [[package]]
 name = "yoke"
 version = "0.8.1"
@@ -2702,8 +3172,8 @@ checksum = "b659052874eb698efe5b9e8cf382204678a0086ebf46982b79d6ca3182927e5d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
- "synstructure",
+ "syn 2.0.114",
+ "synstructure 0.13.2",
 ]
 
 [[package]]
@@ -2723,7 +3193,7 @@ checksum = "4122cd3169e94605190e77839c9a40d40ed048d305bfdc146e7df40ab0f3e517"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -2743,8 +3213,8 @@ checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
- "synstructure",
+ "syn 2.0.114",
+ "synstructure 0.13.2",
 ]
 
 [[package]]
@@ -2764,7 +3234,7 @@ checksum = "85a5b4158499876c763cb03bc4e49185d3cccbabb15b33c627f7884f43db852e"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -2797,7 +3267,7 @@ checksum = "eadce39539ca5cb3985590102671f2567e659fca9666581ad3411d59207951f3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.114",
 ]
 
 [[package]]

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "telemt"
-version = "3.0.6"
+version = "3.0.14"
 edition = "2024"
 
 [dependencies]
@@ -20,6 +20,7 @@ sha1 = "0.10"
 md-5 = "0.10"
 hmac = "0.12"
 crc32fast = "1.4"
+crc32c = "0.6"
 zeroize = { version = "1.8", features = ["derive"] }
 
 # Network

Dockerfile

@@ -1,7 +1,7 @@
 # ==========================
 # Stage 1: Build
 # ==========================
-FROM rust:1.85-slim-bookworm AS builder
+FROM rust:1.88-slim-bookworm AS builder
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
     pkg-config \
@@ -40,4 +40,4 @@ EXPOSE 443
 EXPOSE 9090
 
 ENTRYPOINT ["/app/telemt"]
-CMD ["config.toml"]
+CMD ["config.toml"]

README.md

@@ -10,41 +10,77 @@
 
 ### 🇷🇺 RU
 
-18 февраля мы опубликовали `telemt 3.0.3`, он имеет:
+#### Драфтинг LTS и текущие улучшения
 
-- улучшенный механизм Middle-End Health Check
-- высокоскоростное восстановление инициализации Middle-End
-- меньше задержек на hot-path
-- более корректную работу в Dualstack, а именно - IPv6 Middle-End
-- аккуратное переподключение клиента без дрифта сессий между Middle-End
-- автоматическая деградация на Direct-DC при массовой (>2 ME-DC-групп) недоступности Middle-End
-- автодетект IP за NAT, при возможности - будет выполнен хендшейк с ME, при неудаче - автодеградация
-- единственный известный специальный DC=203 уже добавлен в код: медиа загружаются с CDN в Direct-DC режиме
+С 21 февраля мы начали подготовку LTS-версии.
 
-[Здесь вы можете найти релиз](https://github.com/telemt/telemt/releases/tag/3.0.3)
+Мы внимательно анализируем весь доступный фидбек.  
+Наша цель — сделать LTS-кандидаты максимально стабильными, тщательно отлаженными и готовыми к long-run и highload production-сценариям.
 
-Если у вас есть компетенции в асинхронных сетевых приложениях, анализе трафика, реверс-инжиниринге или сетевых расследованиях - мы открыты к идеям и pull requests!
+---
 
+#### Улучшения от 23 февраля
+
+23 февраля были внесены улучшения производительности в режимах **DC** и **Middle-End (ME)**, с акцентом на обратный канал (путь клиент → DC / ME).
+
+Дополнительно реализован ряд изменений, направленных на повышение устойчивости системы:
+
+- Смягчение сетевой нестабильности  
+- Повышение устойчивости к десинхронизации криптографии  
+- Снижение дрейфа сессий при неблагоприятных условиях  
+- Улучшение обработки ошибок в edge-case транспортных сценариях  
+
+Релиз:  
+[3.0.12](https://github.com/telemt/telemt/releases/tag/3.0.12)
+
+---
+
+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
 
-On February 18, we released `telemt 3.0.3`. This version introduces:
+#### LTS Drafting and Ongoing Improvements
 
-- improved Middle-End Health Check method  
-- high-speed recovery of Middle-End init
-- reduced latency on the hot path  
-- correct Dualstack support: proper handling of IPv6 Middle-End  
-- *clean* client reconnection without session "drift" between Middle-End
-- automatic degradation to Direct-DC mode in case of large-scale (>2 ME-DC groups) Middle-End unavailability  
-- automatic public IP detection behind NAT; first - Middle-End handshake is performed, otherwise automatic degradation is applied  
-- known special DC=203 is now handled natively: media is delivered from the CDN via Direct-DC mode  
+Starting February 21, we began drafting the upcoming LTS version.
 
-[Release is available here](https://github.com/telemt/telemt/releases/tag/3.0.3)
+We are carefully reviewing and analyzing all available feedback.  
+The goal is to ensure that LTS candidates are максимально stable, thoroughly debugged, and ready for long-run and high-load production scenarios.
 
-If you have expertise in asynchronous network applications, traffic analysis, reverse engineering, or network forensics - we welcome ideas and pull requests!
+---
 
+#### February 23 Improvements
+
+On February 23, we introduced performance improvements for both **DC** and **Middle-End (ME)** modes, specifically optimizing the reverse channel (client → DC / ME data path).
+
+Additionally, we implemented a set of robustness enhancements designed to:
+
+- Mitigate network-related instability
+- Improve resilience against cryptographic desynchronization
+- Reduce session drift under adverse conditions
+- Improve error handling in edge-case transport scenarios
+
+Release:  
+[3.0.12](https://github.com/telemt/telemt/releases/tag/3.0.12)
+
+---
+
+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>
@@ -178,147 +214,21 @@ then Ctrl+X -> Y -> Enter to save
 ```toml
 # === General Settings ===
 [general]
-fast_mode = true
-use_middle_proxy = true
 # ad_tag = "00000000000000000000000000000000"
-# Path to proxy-secret binary (auto-downloaded if missing).
-proxy_secret_path = "proxy-secret"
-# disable_colors = false  # Disable colored output in logs (useful for files/systemd)
-
-# === 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"
-
-# === Middle Proxy - ME ===
-# Public IP override for ME KDF when behind NAT; leave unset to auto-detect.
-# middle_proxy_nat_ip = "203.0.113.10"
-# Enable STUN probing to discover public IP:port for ME.
-middle_proxy_nat_probe = true
-# Primary STUN server (host:port); defaults to Telegram STUN when empty.
-middle_proxy_nat_stun = "stun.l.google.com:19302"
-# Optional fallback STUN servers list.
-middle_proxy_nat_stun_servers = ["stun1.l.google.com:19302", "stun2.l.google.com:19302"]
-# Desired number of concurrent ME writers in pool.
-middle_proxy_pool_size = 16
-# Pre-initialized warm-standby ME connections kept idle.
-middle_proxy_warm_standby = 8
-# Ignore STUN/interface mismatch and keep ME enabled even if IP differs.
-stun_iface_mismatch_ignore = false
-# Keepalive padding frames - fl==4
-me_keepalive_enabled = true
-me_keepalive_interval_secs = 25           # Period between keepalives
-me_keepalive_jitter_secs = 5              # Jitter added to interval
-me_keepalive_payload_random = true        # Randomize 4-byte payload (vs zeros)
-# Stagger extra ME connections on warmup to de-phase lifecycles.
-me_warmup_stagger_enabled = true
-me_warmup_step_delay_ms = 500             # Base delay between extra connects
-me_warmup_step_jitter_ms = 300            # Jitter for warmup delay
-# Reconnect policy knobs.
-me_reconnect_max_concurrent_per_dc = 1    # Parallel reconnects per DC - EXPERIMENTAL! UNSTABLE!
-me_reconnect_backoff_base_ms = 500        # Backoff start
-me_reconnect_backoff_cap_ms = 30000       # Backoff cap
-me_reconnect_fast_retry_count = 11        # Quick retries before backoff
 
 [general.modes]
 classic = false
 secure = false
 tls = true
 
-[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)
-
-# === Network Parameters ===
-[network]
-# Enable/disable families: true/false/auto(None)
-ipv4 = true
-ipv6 = false # UNSTABLE WITH ME
-# prefer = 4 or 6
-prefer = 4
-multipath = false # EXPERIMENTAL!
-
-# === Server Binding ===
-[server]
-port = 443
-listen_addr_ipv4 = "0.0.0.0"
-listen_addr_ipv6 = "::"
-# listen_unix_sock = "/var/run/telemt.sock" # Unix socket
-# listen_unix_sock_perm = "0666" # Socket file permissions
-# metrics_port = 9090
-# metrics_whitelist = [
-#    "192.168.0.0/24",
-#    "172.16.0.0/12",
-#    "127.0.0.1/32",
-#    "::1/128"
-#]
-
-# Listen on multiple interfaces/IPs - IPv4
-[[server.listeners]]
-ip = "0.0.0.0"
-
-# Listen on multiple interfaces/IPs - IPv6
-[[server.listeners]]
-ip = "::"
-
-# === Timeouts (in seconds) ===
-[timeouts]
-client_handshake = 30
-tg_connect = 10
-client_keepalive = 60
-client_ack = 300
-# Quick ME reconnects for single-address DCs (count and per-attempt timeout, ms).
-me_one_retry = 12
-me_one_timeout_ms = 1200
-
 # === Anti-Censorship & Masking ===
 [censorship]
 tls_domain = "petrovich.ru"
-mask = true
-mask_port = 443
-# mask_host = "petrovich.ru" # Defaults to tls_domain if not set
-# mask_unix_sock = "/var/run/nginx.sock" # Unix socket (mutually exclusive with mask_host)
-fake_cert_len = 2048
-
-# === Access Control & Users ===
-[access]
-replay_check_len = 65536
-replay_window_secs = 1800
-ignore_time_skew = false
 
 [access.users]
 # format: "username" = "32_hex_chars_secret"
 hello = "00000000000000000000000000000000"
 
-# [access.user_max_tcp_conns]
-# hello = 50
-
-# [access.user_max_unique_ips]
-# hello = 5
-
-# [access.user_data_quota]
-# hello = 1073741824 # 1 GB
-
-# === Upstreams & Routing ===
-[[upstreams]]
-type = "direct"
-enabled = true
-weight = 10
-
-# [[upstreams]]
-# type = "socks5"
-# address = "127.0.0.1:1080"
-# enabled = false
-# weight = 1
-
-# === DC Address Overrides ===
-# [dc_overrides]
-# "203" = "91.105.192.100:443"
-
 ```
 ### Advanced
 #### Adtag

config.toml

@@ -23,7 +23,7 @@ middle_proxy_nat_stun = "stun.l.google.com:19302"
 # Optional fallback STUN servers list.
 middle_proxy_nat_stun_servers = ["stun1.l.google.com:19302", "stun2.l.google.com:19302"]
 # Desired number of concurrent ME writers in pool.
-middle_proxy_pool_size = 16
+middle_proxy_pool_size = 8
 # Pre-initialized warm-standby ME connections kept idle.
 middle_proxy_warm_standby = 8
 # Ignore STUN/interface mismatch and keep ME enabled even if IP differs.
@@ -38,10 +38,20 @@ me_warmup_stagger_enabled = true
 me_warmup_step_delay_ms = 500             # Base delay between extra connects
 me_warmup_step_jitter_ms = 300            # Jitter for warmup delay
 # Reconnect policy knobs.
-me_reconnect_max_concurrent_per_dc = 1    # Parallel reconnects per DC - EXPERIMENTAL! UNSTABLE!
+me_reconnect_max_concurrent_per_dc = 4    # Parallel reconnects per DC - EXPERIMENTAL! UNSTABLE!
 me_reconnect_backoff_base_ms = 500        # Backoff start
 me_reconnect_backoff_cap_ms = 30000       # Backoff cap
 me_reconnect_fast_retry_count = 11        # Quick retries before backoff
+update_every = 7200                       # Resolve the active updater interval for ME infrastructure refresh tasks.
+crypto_pending_buffer = 262144            # Max pending ciphertext buffer per client writer (bytes). Controls FakeTLS backpressure vs throughput.
+max_client_frame = 16777216               # Maximum allowed client MTProto frame size (bytes).
+desync_all_full = false                   # Emit full crypto-desync forensic logs for every event. When false, full forensic details are emitted once per key window.
+auto_degradation_enabled = true           # Enable auto-degradation from ME to Direct-DC.
+degradation_min_unavailable_dc_groups = 2 # Minimum unavailable ME DC groups before degrading.
+hardswap = true                           # Enable C-like hard-swap for ME pool generations. When true, Telemt prewarms a new generation and switches once full coverage is reached.
+me_pool_drain_ttl_secs = 90               # Drain-TTL in seconds for stale ME writers after endpoint map changes. During TTL, stale writers may be used only as fallback for new bindings.
+me_pool_min_fresh_ratio = 0.8             # Minimum desired-DC coverage ratio required before draining stale writers. Range: 0.0..=1.0.
+me_reinit_drain_timeout_secs = 120        # Drain timeout in seconds for stale ME writers after endpoint map changes. Set to 0 to keep stale writers draining indefinitely (no force-close).
 
 [general.modes]
 classic = false
@@ -124,6 +134,10 @@ hello = "00000000000000000000000000000000"
 # [access.user_data_quota]
 # hello = 1073741824 # 1 GB
 
+# [access.user_expirations]
+# format: username = "[year]-[month]-[day]T[hour]:[minute]:[second]Z" UTC
+# hello = "2027-01-01T00:00:00Z"
+
 # === Upstreams & Routing ===
 [[upstreams]]
 type = "direct"

proxy-secret

@@ -0,0 +1 @@
+ΔωϊΚ–xζ»H­l~,εΐ<CEB5>D0d]UJέλUA<55>M¦'!ΠFκ«nR«©ZD>Ο³F>y Zfa*ί<>®Ϊ‹ι¨

src/cli.rs

@@ -194,6 +194,12 @@ 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
@@ -213,6 +219,7 @@ 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 = "::"
@@ -228,6 +235,7 @@ tls_domain = "{domain}"
 mask = true
 mask_port = 443
 fake_cert_len = 2048
+tls_full_cert_ttl_secs = 90
 
 [access]
 replay_check_len = 65536

src/config/defaults.rs

@@ -1,4 +1,3 @@
-use std::net::IpAddr;
 use std::collections::HashMap;
 use ipnetwork::IpNetwork;
 use serde::Deserialize;
@@ -83,7 +82,7 @@ pub(crate) fn default_unknown_dc_log_path() -> Option<String> {
 }
 
 pub(crate) fn default_pool_size() -> usize {
-    2
+    8
 }
 
 pub(crate) fn default_keepalive_interval() -> u64 {
@@ -110,6 +109,131 @@ pub(crate) fn default_reconnect_backoff_cap_ms() -> u64 {
     30_000
 }
 
+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_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 {
+    30 * 60
+}
+
+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_proxy_secret_stable_snapshots() -> u8 {
+    2
+}
+
+pub(crate) fn default_proxy_secret_rotate_runtime() -> 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_pool_min_fresh_ratio() -> f32 {
+    0.8
+}
+
+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
+}
+
 // Custom deserializer helpers
 
 #[derive(Deserialize)]

src/config/hot_reload.rs

@@ -10,6 +10,12 @@
 //! | `general` | `ad_tag`                      | Passed on next connection         |
 //! | `general` | `middle_proxy_pool_size`      | Passed on next connection         |
 //! | `general` | `me_keepalive_*`              | Passed on next connection         |
+//! | `general` | `desync_all_full`             | Applied immediately               |
+//! | `general` | `update_every`                | Applied to ME updater immediately |
+//! | `general` | `hardswap`                    | Applied on next ME map update     |
+//! | `general` | `me_pool_drain_ttl_secs`      | Applied on next ME map update     |
+//! | `general` | `me_pool_min_fresh_ratio`     | Applied on next ME map update     |
+//! | `general` | `me_reinit_drain_timeout_secs`| Applied on next ME map update     |
 //! | `access`  | All user/quota fields         | Effective immediately             |
 //!
 //! Fields that require re-binding sockets (`server.port`, `censorship.*`,
@@ -34,6 +40,12 @@ pub struct HotFields {
     pub log_level:               LogLevel,
     pub ad_tag:                  Option<String>,
     pub middle_proxy_pool_size:  usize,
+    pub desync_all_full:         bool,
+    pub update_every_secs:       u64,
+    pub hardswap:                bool,
+    pub me_pool_drain_ttl_secs:  u64,
+    pub me_pool_min_fresh_ratio: f32,
+    pub me_reinit_drain_timeout_secs: u64,
     pub me_keepalive_enabled:    bool,
     pub me_keepalive_interval_secs: u64,
     pub me_keepalive_jitter_secs:   u64,
@@ -47,6 +59,12 @@ impl HotFields {
             log_level:               cfg.general.log_level.clone(),
             ad_tag:                  cfg.general.ad_tag.clone(),
             middle_proxy_pool_size:  cfg.general.middle_proxy_pool_size,
+            desync_all_full:         cfg.general.desync_all_full,
+            update_every_secs:       cfg.general.effective_update_every_secs(),
+            hardswap:                cfg.general.hardswap,
+            me_pool_drain_ttl_secs:  cfg.general.me_pool_drain_ttl_secs,
+            me_pool_min_fresh_ratio: cfg.general.me_pool_min_fresh_ratio,
+            me_reinit_drain_timeout_secs: cfg.general.me_reinit_drain_timeout_secs,
             me_keepalive_enabled:    cfg.general.me_keepalive_enabled,
             me_keepalive_interval_secs: cfg.general.me_keepalive_interval_secs,
             me_keepalive_jitter_secs:   cfg.general.me_keepalive_jitter_secs,
@@ -175,6 +193,48 @@ fn log_changes(
         );
     }
 
+    if old_hot.desync_all_full != new_hot.desync_all_full {
+        info!(
+            "config reload: desync_all_full: {} → {}",
+            old_hot.desync_all_full, new_hot.desync_all_full,
+        );
+    }
+
+    if old_hot.update_every_secs != new_hot.update_every_secs {
+        info!(
+            "config reload: update_every(effective): {}s → {}s",
+            old_hot.update_every_secs, new_hot.update_every_secs,
+        );
+    }
+
+    if old_hot.hardswap != new_hot.hardswap {
+        info!(
+            "config reload: hardswap: {} → {}",
+            old_hot.hardswap, new_hot.hardswap,
+        );
+    }
+
+    if old_hot.me_pool_drain_ttl_secs != new_hot.me_pool_drain_ttl_secs {
+        info!(
+            "config reload: me_pool_drain_ttl_secs: {}s → {}s",
+            old_hot.me_pool_drain_ttl_secs, new_hot.me_pool_drain_ttl_secs,
+        );
+    }
+
+    if (old_hot.me_pool_min_fresh_ratio - new_hot.me_pool_min_fresh_ratio).abs() > f32::EPSILON {
+        info!(
+            "config reload: me_pool_min_fresh_ratio: {:.3} → {:.3}",
+            old_hot.me_pool_min_fresh_ratio, new_hot.me_pool_min_fresh_ratio,
+        );
+    }
+
+    if old_hot.me_reinit_drain_timeout_secs != new_hot.me_reinit_drain_timeout_secs {
+        info!(
+            "config reload: me_reinit_drain_timeout_secs: {}s → {}s",
+            old_hot.me_reinit_drain_timeout_secs, new_hot.me_reinit_drain_timeout_secs,
+        );
+    }
+
     if old_hot.me_keepalive_enabled        != new_hot.me_keepalive_enabled
     || old_hot.me_keepalive_interval_secs  != new_hot.me_keepalive_interval_secs
     || old_hot.me_keepalive_jitter_secs    != new_hot.me_keepalive_jitter_secs
@@ -316,118 +376,106 @@ pub fn spawn_config_watcher(
     let (config_tx, config_rx) = watch::channel(initial);
     let (log_tx, log_rx)       = watch::channel(initial_level);
 
-    // Bridge: sync notify callback → async task via mpsc.
+    // Bridge: sync notify callbacks → async task via mpsc.
     let (notify_tx, mut notify_rx) = mpsc::channel::<()>(4);
 
-    // Canonicalize the config path so it matches what notify returns in events
-    // (notify always gives absolute paths, but config_path may be relative).
+    // Canonicalize so path matches what notify returns (absolute) in events.
     let config_path = match config_path.canonicalize() {
         Ok(p) => p,
-        Err(_) => config_path.to_path_buf(), // file doesn't exist yet, use as-is
+        Err(_) => config_path.to_path_buf(),
     };
 
     // Watch the parent directory rather than the file itself, because many
-    // editors (vim, nano, systemd-sysusers) write via rename, which would
-    // cause inotify to lose track of the original inode.
+    // editors (vim, nano) and systemd write via rename, which would cause
+    // inotify to lose track of the original inode.
     let watch_dir = config_path
         .parent()
         .unwrap_or_else(|| std::path::Path::new("."))
         .to_path_buf();
 
+    // ── inotify watcher (instant on local fs) ────────────────────────────
     let config_file = config_path.clone();
-    let tx_clone    = notify_tx.clone();
-
-    let watcher_result = recommended_watcher(move |res: notify::Result<notify::Event>| {
+    let tx_inotify  = notify_tx.clone();
+    let inotify_ok = match recommended_watcher(move |res: notify::Result<notify::Event>| {
         let Ok(event) = res else { return };
-
         let is_our_file = event.paths.iter().any(|p| p == &config_file);
-        if !is_our_file {
-            return;
+        if !is_our_file { return; }
+        if matches!(event.kind, EventKind::Modify(_) | EventKind::Create(_) | EventKind::Remove(_)) {
+            let _ = tx_inotify.try_send(());
         }
-        let relevant = matches!(
-            event.kind,
-            EventKind::Modify(_) | EventKind::Create(_) | EventKind::Remove(_)
-        );
-        if relevant {
-            let _ = tx_clone.try_send(());
+    }) {
+        Ok(mut w) => match w.watch(&watch_dir, RecursiveMode::NonRecursive) {
+            Ok(()) => {
+                info!("config watcher: inotify active on {:?}", config_path);
+                Box::leak(Box::new(w));
+                true
+            }
+            Err(e) => { warn!("config watcher: inotify watch failed: {}", e); false }
+        },
+        Err(e) => { warn!("config watcher: inotify unavailable: {}", e); false }
+    };
+
+    // ── poll watcher (always active, fixes Docker bind mounts / NFS) ─────
+    // inotify does not receive events for files mounted from the host into
+    // a container. PollWatcher compares file contents every 3 s and fires
+    // on any change regardless of the underlying fs.
+    let config_file2 = config_path.clone();
+    let tx_poll      = notify_tx.clone();
+    match notify::poll::PollWatcher::new(
+        move |res: notify::Result<notify::Event>| {
+            let Ok(event) = res else { return };
+            let is_our_file = event.paths.iter().any(|p| p == &config_file2);
+            if !is_our_file { return; }
+            if matches!(event.kind, EventKind::Modify(_) | EventKind::Create(_) | EventKind::Remove(_)) {
+                let _ = tx_poll.try_send(());
+            }
+        },
+        notify::Config::default()
+            .with_poll_interval(std::time::Duration::from_secs(3))
+            .with_compare_contents(true),
+    ) {
+        Ok(mut w) => match w.watch(&config_path, RecursiveMode::NonRecursive) {
+            Ok(()) => {
+                if inotify_ok {
+                    info!("config watcher: poll watcher also active (Docker/NFS safe)");
+                } else {
+                    info!("config watcher: poll watcher active on {:?} (3s interval)", config_path);
+                }
+                Box::leak(Box::new(w));
+            }
+            Err(e) => warn!("config watcher: poll watch failed: {}", e),
+        },
+        Err(e) => warn!("config watcher: poll watcher unavailable: {}", e),
+    }
+
+    // ── event loop ───────────────────────────────────────────────────────
+    tokio::spawn(async move {
+        #[cfg(unix)]
+        let mut sighup = {
+            use tokio::signal::unix::{SignalKind, signal};
+            signal(SignalKind::hangup()).expect("Failed to register SIGHUP handler")
+        };
+
+        loop {
+            #[cfg(unix)]
+            tokio::select! {
+                msg = notify_rx.recv() => {
+                    if msg.is_none() { break; }
+                }
+                _ = sighup.recv() => {
+                    info!("SIGHUP received — reloading {:?}", config_path);
+                }
+            }
+            #[cfg(not(unix))]
+            if notify_rx.recv().await.is_none() { break; }
+
+            // Debounce: drain extra events that arrive within 50 ms.
+            tokio::time::sleep(std::time::Duration::from_millis(50)).await;
+            while notify_rx.try_recv().is_ok() {}
+
+            reload_config(&config_path, &config_tx, &log_tx, detected_ip_v4, detected_ip_v6);
         }
     });
 
-    match watcher_result {
-        Ok(mut watcher) => {
-            match watcher.watch(&watch_dir, RecursiveMode::NonRecursive) {
-                Ok(()) => info!("config watcher: watching {:?} via inotify", config_path),
-                Err(e) => warn!(
-                    "config watcher: failed to watch {:?}: {}; use SIGHUP to reload",
-                    watch_dir, e
-                ),
-            }
-
-            tokio::spawn(async move {
-                let _watcher = watcher; // keep alive
-
-                #[cfg(unix)]
-                let mut sighup = {
-                    use tokio::signal::unix::{SignalKind, signal};
-                    signal(SignalKind::hangup()).expect("Failed to register SIGHUP handler")
-                };
-
-                loop {
-                    #[cfg(unix)]
-                    tokio::select! {
-                        msg = notify_rx.recv() => {
-                            if msg.is_none() { break; }
-                        }
-                        _ = sighup.recv() => {
-                            info!("SIGHUP received — reloading {:?}", config_path);
-                        }
-                    }
-                    #[cfg(not(unix))]
-                    if notify_rx.recv().await.is_none() { break; }
-
-                    // Debounce: drain extra events fired within 50ms.
-                    tokio::time::sleep(std::time::Duration::from_millis(50)).await;
-                    while notify_rx.try_recv().is_ok() {}
-
-                    reload_config(
-                        &config_path,
-                        &config_tx,
-                        &log_tx,
-                        detected_ip_v4,
-                        detected_ip_v6,
-                    );
-                }
-            });
-        }
-        Err(e) => {
-            warn!(
-                "config watcher: inotify unavailable ({}); only SIGHUP will trigger reload",
-                e
-            );
-            // Fall back to SIGHUP-only.
-            tokio::spawn(async move {
-                #[cfg(unix)]
-                {
-                    use tokio::signal::unix::{SignalKind, signal};
-                    let mut sighup = signal(SignalKind::hangup())
-                        .expect("Failed to register SIGHUP handler");
-                    loop {
-                        sighup.recv().await;
-                        info!("SIGHUP received — reloading {:?}", config_path);
-                        reload_config(
-                            &config_path,
-                            &config_tx,
-                            &log_tx,
-                            detected_ip_v4,
-                            detected_ip_v6,
-                        );
-                    }
-                }
-                #[cfg(not(unix))]
-                let _ = (config_tx, log_tx, config_path);
-            });
-        }
-    }
-
     (config_rx, log_rx)
 }

src/config/load.rs

@@ -1,3 +1,5 @@
+#![allow(deprecated)]
+
 use std::collections::HashMap;
 use std::net::IpAddr;
 use std::path::Path;
@@ -117,6 +119,70 @@ impl ProxyConfig {
         let mut config: ProxyConfig =
             toml::from_str(&processed).map_err(|e| ProxyError::Config(e.to_string()))?;
 
+        if let Some(update_every) = config.general.update_every {
+            if update_every == 0 {
+                return Err(ProxyError::Config(
+                    "general.update_every must be > 0".to_string(),
+                ));
+            }
+        } else {
+            let legacy_secret = config.general.proxy_secret_auto_reload_secs;
+            let legacy_config = config.general.proxy_config_auto_reload_secs;
+            let effective = legacy_secret.min(legacy_config);
+            if effective == 0 {
+                return Err(ProxyError::Config(
+                    "legacy proxy_*_auto_reload_secs values must be > 0 when general.update_every is not set".to_string(),
+                ));
+            }
+
+            if legacy_secret != default_proxy_secret_reload_secs()
+                || legacy_config != default_proxy_config_reload_secs()
+            {
+                warn!(
+                    proxy_secret_auto_reload_secs = legacy_secret,
+                    proxy_config_auto_reload_secs = legacy_config,
+                    effective_update_every_secs = effective,
+                    "proxy_*_auto_reload_secs are deprecated; set general.update_every"
+                );
+            }
+        }
+
+        if config.general.me_config_stable_snapshots == 0 {
+            return Err(ProxyError::Config(
+                "general.me_config_stable_snapshots must be > 0".to_string(),
+            ));
+        }
+
+        if config.general.proxy_secret_stable_snapshots == 0 {
+            return Err(ProxyError::Config(
+                "general.proxy_secret_stable_snapshots must be > 0".to_string(),
+            ));
+        }
+
+        if !(32..=4096).contains(&config.general.proxy_secret_len_max) {
+            return Err(ProxyError::Config(
+                "general.proxy_secret_len_max must be within [32, 4096]".to_string(),
+            ));
+        }
+
+        if !(0.0..=1.0).contains(&config.general.me_pool_min_fresh_ratio) {
+            return Err(ProxyError::Config(
+                "general.me_pool_min_fresh_ratio must be within [0.0, 1.0]".to_string(),
+            ));
+        }
+
+        if config.general.effective_me_pool_force_close_secs() > 0
+            && config.general.effective_me_pool_force_close_secs()
+                < config.general.me_pool_drain_ttl_secs
+        {
+            warn!(
+                me_pool_drain_ttl_secs = config.general.me_pool_drain_ttl_secs,
+                me_reinit_drain_timeout_secs = config.general.effective_me_pool_force_close_secs(),
+                "force-close timeout is lower than drain TTL; bumping force-close timeout to TTL"
+            );
+            config.general.me_reinit_drain_timeout_secs = config.general.me_pool_drain_ttl_secs;
+        }
+
         // Validate secrets.
         for (user, secret) in &config.access.users {
             if !secret.chars().all(|c| c.is_ascii_hexdigit()) || secret.len() != 32 {
@@ -227,24 +293,28 @@ impl ProxyConfig {
                     announce: None,
                     announce_ip: None,
                     proxy_protocol: None,
+                    reuse_allow: false,
                 });
             }
-            if let Some(ipv6_str) = &config.server.listen_addr_ipv6 {
-                if let Ok(ipv6) = ipv6_str.parse::<IpAddr>() {
-                    config.server.listeners.push(ListenerConfig {
-                        ip: ipv6,
-                        announce: None,
-                        announce_ip: None,
-                        proxy_protocol: None,
-                    });
-                }
+            if let Some(ipv6_str) = &config.server.listen_addr_ipv6
+                && let Ok(ipv6) = ipv6_str.parse::<IpAddr>()
+            {
+                config.server.listeners.push(ListenerConfig {
+                    ip: ipv6,
+                    announce: None,
+                    announce_ip: None,
+                    proxy_protocol: None,
+                    reuse_allow: false,
+                });
             }
         }
 
         // Migration: announce_ip → announce for each listener.
         for listener in &mut config.server.listeners {
-            if listener.announce.is_none() && listener.announce_ip.is_some() {
-                listener.announce = Some(listener.announce_ip.unwrap().to_string());
+            if listener.announce.is_none()
+                && let Some(ip) = listener.announce_ip.take()
+            {
+                listener.announce = Some(ip.to_string());
             }
         }
 
@@ -345,4 +415,169 @@ mod tests {
             .unwrap_or(false));
         let _ = std::fs::remove_file(path);
     }
+
+    #[test]
+    fn update_every_overrides_legacy_fields() {
+        let toml = r#"
+            [general]
+            update_every = 123
+            proxy_secret_auto_reload_secs = 700
+            proxy_config_auto_reload_secs = 800
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_update_every_override_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let cfg = ProxyConfig::load(&path).unwrap();
+        assert_eq!(cfg.general.effective_update_every_secs(), 123);
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn update_every_fallback_to_legacy_min() {
+        let toml = r#"
+            [general]
+            proxy_secret_auto_reload_secs = 600
+            proxy_config_auto_reload_secs = 120
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_update_every_legacy_min_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let cfg = ProxyConfig::load(&path).unwrap();
+        assert_eq!(cfg.general.update_every, None);
+        assert_eq!(cfg.general.effective_update_every_secs(), 120);
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn update_every_zero_is_rejected() {
+        let toml = r#"
+            [general]
+            update_every = 0
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_update_every_zero_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.update_every must be > 0"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn me_config_stable_snapshots_zero_is_rejected() {
+        let toml = r#"
+            [general]
+            me_config_stable_snapshots = 0
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_me_config_stable_snapshots_zero_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.me_config_stable_snapshots must be > 0"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn proxy_secret_stable_snapshots_zero_is_rejected() {
+        let toml = r#"
+            [general]
+            proxy_secret_stable_snapshots = 0
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_proxy_secret_stable_snapshots_zero_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.proxy_secret_stable_snapshots must be > 0"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn proxy_secret_len_max_out_of_range_is_rejected() {
+        let toml = r#"
+            [general]
+            proxy_secret_len_max = 16
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_proxy_secret_len_max_out_of_range_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.proxy_secret_len_max must be within [32, 4096]"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn me_pool_min_fresh_ratio_out_of_range_is_rejected() {
+        let toml = r#"
+            [general]
+            me_pool_min_fresh_ratio = 1.5
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_me_pool_min_ratio_invalid_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.me_pool_min_fresh_ratio must be within [0.0, 1.0]"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn force_close_bumped_when_below_drain_ttl() {
+        let toml = r#"
+            [general]
+            me_pool_drain_ttl_secs = 90
+            me_reinit_drain_timeout_secs = 30
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_force_close_bump_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let cfg = ProxyConfig::load(&path).unwrap();
+        assert_eq!(cfg.general.me_reinit_drain_timeout_secs, 90);
+        let _ = std::fs::remove_file(path);
+    }
 }

src/config/types.rs

@@ -74,8 +74,8 @@ pub struct ProxyModes {
 impl Default for ProxyModes {
     fn default() -> Self {
         Self {
-            classic: true,
-            secure: true,
+            classic: false,
+            secure: false,
             tls: true,
         }
     }
@@ -96,15 +96,35 @@ pub struct NetworkConfig {
 
     #[serde(default)]
     pub multipath: bool,
+
+    /// STUN servers list for public IP discovery.
+    #[serde(default = "default_stun_servers")]
+    pub stun_servers: Vec<String>,
+
+    /// Enable TCP STUN fallback when UDP is blocked.
+    #[serde(default)]
+    pub stun_tcp_fallback: bool,
+
+    /// HTTP-based public IP detection endpoints (fallback after STUN).
+    #[serde(default = "default_http_ip_detect_urls")]
+    pub http_ip_detect_urls: Vec<String>,
+
+    /// Cache file path for detected public IP.
+    #[serde(default = "default_cache_public_ip_path")]
+    pub cache_public_ip_path: String,
 }
 
 impl Default for NetworkConfig {
     fn default() -> Self {
         Self {
             ipv4: true,
-            ipv6: None,
+            ipv6: Some(false),
             prefer: 4,
             multipath: false,
+            stun_servers: default_stun_servers(),
+            stun_tcp_fallback: true,
+            http_ip_detect_urls: default_http_ip_detect_urls(),
+            cache_public_ip_path: default_cache_public_ip_path(),
         }
     }
 }
@@ -172,6 +192,25 @@ pub struct GeneralConfig {
     #[serde(default = "default_true")]
     pub me_keepalive_payload_random: bool,
 
+    /// Max pending ciphertext buffer per client writer (bytes).
+    /// Controls FakeTLS backpressure vs throughput.
+    #[serde(default = "default_crypto_pending_buffer")]
+    pub crypto_pending_buffer: usize,
+
+    /// Maximum allowed client MTProto frame size (bytes).
+    #[serde(default = "default_max_client_frame")]
+    pub max_client_frame: usize,
+
+    /// Emit full crypto-desync forensic logs for every event.
+    /// When false, full forensic details are emitted once per key window.
+    #[serde(default = "default_desync_all_full")]
+    pub desync_all_full: bool,
+
+    /// Enable C-like hard-swap for ME pool generations.
+    /// When true, Telemt prewarms a new generation and switches once full coverage is reached.
+    #[serde(default = "default_hardswap")]
+    pub hardswap: bool,
+
     /// Enable staggered warmup of extra ME writers.
     #[serde(default = "default_true")]
     pub me_warmup_stagger_enabled: bool,
@@ -218,6 +257,76 @@ pub struct GeneralConfig {
     /// [general.links] — proxy link generation overrides.
     #[serde(default)]
     pub links: LinksConfig,
+
+    /// Minimum TLS record size when fast_mode coalescing is enabled (0 = disabled).
+    #[serde(default = "default_fast_mode_min_tls_record")]
+    pub fast_mode_min_tls_record: usize,
+
+    /// Unified ME updater interval in seconds for getProxyConfig/getProxyConfigV6/getProxySecret.
+    /// When omitted, effective value falls back to legacy proxy_*_auto_reload_secs fields.
+    #[serde(default)]
+    pub update_every: Option<u64>,
+
+    /// Number of identical getProxyConfig snapshots required before applying ME map updates.
+    #[serde(default = "default_me_config_stable_snapshots")]
+    pub me_config_stable_snapshots: u8,
+
+    /// Cooldown in seconds between applied ME map updates.
+    #[serde(default = "default_me_config_apply_cooldown_secs")]
+    pub me_config_apply_cooldown_secs: u64,
+
+    /// Number of identical getProxySecret snapshots required before runtime secret rotation.
+    #[serde(default = "default_proxy_secret_stable_snapshots")]
+    pub proxy_secret_stable_snapshots: u8,
+
+    /// Enable runtime proxy-secret rotation from getProxySecret.
+    #[serde(default = "default_proxy_secret_rotate_runtime")]
+    pub proxy_secret_rotate_runtime: bool,
+
+    /// Maximum allowed proxy-secret length in bytes for startup and runtime refresh.
+    #[serde(default = "default_proxy_secret_len_max")]
+    pub proxy_secret_len_max: usize,
+
+    /// Drain-TTL in seconds for stale ME writers after endpoint map changes.
+    /// During TTL, stale writers may be used only as fallback for new bindings.
+    #[serde(default = "default_me_pool_drain_ttl_secs")]
+    pub me_pool_drain_ttl_secs: u64,
+
+    /// Minimum desired-DC coverage ratio required before draining stale writers.
+    /// Range: 0.0..=1.0.
+    #[serde(default = "default_me_pool_min_fresh_ratio")]
+    pub me_pool_min_fresh_ratio: f32,
+
+    /// Drain timeout in seconds for stale ME writers after endpoint map changes.
+    /// Set to 0 to keep stale writers draining indefinitely (no force-close).
+    #[serde(default = "default_me_reinit_drain_timeout_secs")]
+    pub me_reinit_drain_timeout_secs: u64,
+
+    /// Deprecated legacy setting; kept for backward compatibility fallback.
+    /// Use `update_every` instead.
+    #[serde(default = "default_proxy_secret_reload_secs")]
+    pub proxy_secret_auto_reload_secs: u64,
+
+    /// Deprecated legacy setting; kept for backward compatibility fallback.
+    /// Use `update_every` instead.
+    #[serde(default = "default_proxy_config_reload_secs")]
+    pub proxy_config_auto_reload_secs: u64,
+
+    /// Enable NTP drift check at startup.
+    #[serde(default = "default_ntp_check")]
+    pub ntp_check: bool,
+
+    /// NTP servers for drift check.
+    #[serde(default = "default_ntp_servers")]
+    pub ntp_servers: Vec<String>,
+
+    /// Enable auto-degradation from ME to Direct-DC.
+    #[serde(default = "default_true")]
+    pub auto_degradation_enabled: bool,
+
+    /// Minimum unavailable ME DC groups before degrading.
+    #[serde(default = "default_degradation_min_unavailable_dc_groups")]
+    pub degradation_min_unavailable_dc_groups: u8,
 }
 
 impl Default for GeneralConfig {
@@ -234,7 +343,7 @@ impl Default for GeneralConfig {
             middle_proxy_nat_stun: None,
             middle_proxy_nat_stun_servers: Vec::new(),
             middle_proxy_pool_size: default_pool_size(),
-            middle_proxy_warm_standby: 0,
+            middle_proxy_warm_standby: 16,
             me_keepalive_enabled: true,
             me_keepalive_interval_secs: default_keepalive_interval(),
             me_keepalive_jitter_secs: default_keepalive_jitter(),
@@ -242,19 +351,54 @@ impl Default for GeneralConfig {
             me_warmup_stagger_enabled: true,
             me_warmup_step_delay_ms: default_warmup_step_delay_ms(),
             me_warmup_step_jitter_ms: default_warmup_step_jitter_ms(),
-            me_reconnect_max_concurrent_per_dc: 1,
+            me_reconnect_max_concurrent_per_dc: 8,
             me_reconnect_backoff_base_ms: default_reconnect_backoff_base_ms(),
             me_reconnect_backoff_cap_ms: default_reconnect_backoff_cap_ms(),
-            me_reconnect_fast_retry_count: 1,
+            me_reconnect_fast_retry_count: 8,
             stun_iface_mismatch_ignore: false,
             unknown_dc_log_path: default_unknown_dc_log_path(),
             log_level: LogLevel::Normal,
             disable_colors: false,
             links: LinksConfig::default(),
+            crypto_pending_buffer: default_crypto_pending_buffer(),
+            max_client_frame: default_max_client_frame(),
+            desync_all_full: default_desync_all_full(),
+            hardswap: default_hardswap(),
+            fast_mode_min_tls_record: default_fast_mode_min_tls_record(),
+            update_every: Some(default_update_every_secs()),
+            me_config_stable_snapshots: default_me_config_stable_snapshots(),
+            me_config_apply_cooldown_secs: default_me_config_apply_cooldown_secs(),
+            proxy_secret_stable_snapshots: default_proxy_secret_stable_snapshots(),
+            proxy_secret_rotate_runtime: default_proxy_secret_rotate_runtime(),
+            proxy_secret_len_max: default_proxy_secret_len_max(),
+            me_pool_drain_ttl_secs: default_me_pool_drain_ttl_secs(),
+            me_pool_min_fresh_ratio: default_me_pool_min_fresh_ratio(),
+            me_reinit_drain_timeout_secs: default_me_reinit_drain_timeout_secs(),
+            proxy_secret_auto_reload_secs: default_proxy_secret_reload_secs(),
+            proxy_config_auto_reload_secs: default_proxy_config_reload_secs(),
+            ntp_check: default_ntp_check(),
+            ntp_servers: default_ntp_servers(),
+            auto_degradation_enabled: true,
+            degradation_min_unavailable_dc_groups: default_degradation_min_unavailable_dc_groups(),
         }
     }
 }
 
+impl GeneralConfig {
+    /// Resolve the active updater interval for ME infrastructure refresh tasks.
+    /// `update_every` has priority, otherwise legacy proxy_*_auto_reload_secs are used.
+    pub fn effective_update_every_secs(&self) -> u64 {
+        self.update_every
+            .unwrap_or_else(|| self.proxy_secret_auto_reload_secs.min(self.proxy_config_auto_reload_secs))
+    }
+
+    /// Resolve force-close timeout for stale writers.
+    /// `me_reinit_drain_timeout_secs` remains backward-compatible alias.
+    pub fn effective_me_pool_force_close_secs(&self) -> u64 {
+        self.me_reinit_drain_timeout_secs
+    }
+}
+
 /// `[general.links]` — proxy link generation settings.
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
 pub struct LinksConfig {
@@ -395,6 +539,28 @@ pub struct AntiCensorshipConfig {
     /// Directory to store TLS front cache (on disk).
     #[serde(default = "default_tls_front_dir")]
     pub tls_front_dir: String,
+
+    /// Minimum server_hello delay in milliseconds (anti-fingerprint).
+    #[serde(default = "default_server_hello_delay_min_ms")]
+    pub server_hello_delay_min_ms: u64,
+
+    /// Maximum server_hello delay in milliseconds.
+    #[serde(default = "default_server_hello_delay_max_ms")]
+    pub server_hello_delay_max_ms: u64,
+
+    /// Number of NewSessionTicket messages to emit post-handshake.
+    #[serde(default = "default_tls_new_session_tickets")]
+    pub tls_new_session_tickets: u8,
+
+    /// TTL in seconds for sending full certificate payload per client IP.
+    /// First client connection per (SNI domain, client IP) gets full cert payload.
+    /// Subsequent handshakes within TTL use compact cert metadata payload.
+    #[serde(default = "default_tls_full_cert_ttl_secs")]
+    pub tls_full_cert_ttl_secs: u64,
+
+    /// Enforce ALPN echo of client preference.
+    #[serde(default = "default_alpn_enforce")]
+    pub alpn_enforce: bool,
 }
 
 impl Default for AntiCensorshipConfig {
@@ -409,6 +575,11 @@ impl Default for AntiCensorshipConfig {
             fake_cert_len: default_fake_cert_len(),
             tls_emulation: false,
             tls_front_dir: default_tls_front_dir(),
+            server_hello_delay_min_ms: default_server_hello_delay_min_ms(),
+            server_hello_delay_max_ms: default_server_hello_delay_max_ms(),
+            tls_new_session_tickets: default_tls_new_session_tickets(),
+            tls_full_cert_ttl_secs: default_tls_full_cert_ttl_secs(),
+            alpn_enforce: default_alpn_enforce(),
         }
     }
 }
@@ -517,6 +688,10 @@ pub struct ListenerConfig {
     /// Per-listener PROXY protocol override. When set, overrides global server.proxy_protocol.
     #[serde(default)]
     pub proxy_protocol: Option<bool>,
+    /// Allow multiple telemt instances to listen on the same IP:port (SO_REUSEPORT).
+    /// Default is false for safety.
+    #[serde(default)]
+    pub reuse_allow: bool,
 }
 
 // ============= ShowLink =============
@@ -527,9 +702,10 @@ pub struct ListenerConfig {
 /// - `show_link = "*"`          — show links for all users
 /// - `show_link = ["a", "b"]`   — show links for specific users
 /// - omitted                    — show no links (default)
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub enum ShowLink {
     /// Don't show any links (default when omitted).
+    #[default]
     None,
     /// Show links for all configured users.
     All,
@@ -537,12 +713,6 @@ pub enum ShowLink {
     Specific(Vec<String>),
 }
 
-impl Default for ShowLink {
-    fn default() -> Self {
-        ShowLink::None
-    }
-}
-
 impl ShowLink {
     /// Returns true if no links should be shown.
     pub fn is_empty(&self) -> bool {

src/crypto/aes.rs

@@ -11,6 +11,8 @@
 //!   `HandshakeSuccess`, `ObfuscationParams`) are responsible for
 //!   zeroizing their own copies.
 
+#![allow(dead_code)]
+
 use aes::Aes256;
 use ctr::{Ctr128BE, cipher::{KeyIvInit, StreamCipher}};
 use zeroize::Zeroize;
@@ -21,13 +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.
 ///
 /// **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.
+///     + 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,
 }
@@ -147,7 +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())
             ));
@@ -178,7 +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())
             ));
@@ -207,7 +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())
             ));
@@ -240,7 +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())
             ));

src/crypto/hash.rs

@@ -55,10 +55,16 @@ pub fn crc32(data: &[u8]) -> u32 {
     crc32fast::hash(data)
 }
 
+/// 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],
@@ -103,6 +109,7 @@ pub fn build_middleproxy_prekey(
 /// 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],

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, derive_middleproxy_keys, build_middleproxy_prekey};
+pub use hash::{
+    build_middleproxy_prekey, crc32, crc32c, derive_middleproxy_keys, sha256, sha256_hmac,
+};
 pub use random::SecureRandom;

src/crypto/random.rs

@@ -1,5 +1,8 @@
 //! Pseudorandom
 
+#![allow(deprecated)]
+#![allow(dead_code)]
+
 use rand::{Rng, RngCore, SeedableRng};
 use rand::rngs::StdRng;
 use parking_lot::Mutex;
@@ -49,19 +52,32 @@ impl SecureRandom {
         }
     }
     
-    /// 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.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);
+            }
+
+            let take = (out.len() - written).min(inner.buffer.len());
+            out[written..written + take].copy_from_slice(&inner.buffer[..take]);
+            inner.buffer.drain(..take);
+            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)
@@ -79,7 +95,7 @@ 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;

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)
             }
         }
     }
@@ -133,12 +135,7 @@ impl Recoverable for StreamError {
     }
     
     fn can_continue(&self) -> bool {
-        match self {
-            Self::Poisoned { .. } => false,
-            Self::UnexpectedEof => false,
-            Self::BufferOverflow { .. } => false,
-            _ => true,
-        }
+        !matches!(self, Self::Poisoned { .. } | Self::UnexpectedEof | Self::BufferOverflow { .. })
     }
 }
 

src/ip_tracker.rs

@@ -1,5 +1,7 @@
 // src/ip_tracker.rs
-// Модуль для отслеживания и ограничения уникальных IP-адресов пользователей
+// IP address tracking and limiting for users
+
+#![allow(dead_code)]
 
 use std::collections::{HashMap, HashSet};
 use std::net::IpAddr;

src/main.rs

@@ -1,5 +1,7 @@
 //! telemt — Telegram MTProto Proxy
 
+#![allow(unused_assignments)]
+
 use std::net::SocketAddr;
 use std::sync::Arc;
 use std::time::Duration;
@@ -38,7 +40,7 @@ use crate::stream::BufferPool;
 use crate::transport::middle_proxy::{
     MePool, fetch_proxy_config, run_me_ping, MePingFamily, MePingSample, format_sample_line,
 };
-use crate::transport::{ListenOptions, UpstreamManager, create_listener};
+use crate::transport::{ListenOptions, UpstreamManager, create_listener, find_listener_processes};
 use crate::tls_front::TlsFrontCache;
 
 fn parse_cli() -> (String, bool, Option<String>) {
@@ -213,6 +215,9 @@ async fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
         "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);
@@ -262,7 +267,7 @@ async fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
     }
 
     // Connection concurrency limit
-    let _max_connections = Arc::new(Semaphore::new(10_000));
+    let max_connections = Arc::new(Semaphore::new(10_000));
 
     if use_middle_proxy && !decision.ipv4_me && !decision.ipv6_me {
         warn!("No usable IP family for Middle Proxy detected; falling back to direct DC");
@@ -293,25 +298,30 @@ async fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
         // proxy-secret is from: https://core.telegram.org/getProxySecret
         // =============================================================
         let proxy_secret_path = config.general.proxy_secret_path.as_deref();
-match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).await {
-    Ok(proxy_secret) => {
-        info!(
-            secret_len = proxy_secret.len() as usize,  // ← ЯВНЫЙ ТИП usize
-            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"
-        );
+        match crate::transport::middle_proxy::fetch_proxy_secret(
+            proxy_secret_path,
+            config.general.proxy_secret_len_max,
+        )
+        .await
+        {
+            Ok(proxy_secret) => {
+                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"
+                );
 
                 // Load ME config (v4/v6) + default DC
                 let mut cfg_v4 = fetch_proxy_config(
@@ -359,6 +369,10 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                     config.general.me_reconnect_backoff_base_ms,
                     config.general.me_reconnect_backoff_cap_ms,
                     config.general.me_reconnect_fast_retry_count,
+                    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,
                 );
 
                 let pool_size = config.general.middle_proxy_pool_size.max(1);
@@ -389,18 +403,6 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                             .await;
                         });
 
-                        // Periodic updater: getProxyConfig + proxy-secret
-                        let pool_clone2 = pool.clone();
-                        let rng_clone2 = rng.clone();
-                        tokio::spawn(async move {
-                            crate::transport::middle_proxy::me_config_updater(
-                                pool_clone2,
-                                rng_clone2,
-                                std::time::Duration::from_secs(12 * 3600),
-                            )
-                            .await;
-                        });
-
                         Some(pool)
                     }
                     Err(e) => {
@@ -422,6 +424,7 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
     if me_pool.is_some() {
         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;
@@ -458,10 +461,12 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
         cache.load_from_disk().await;
 
         let port = config.censorship.mask_port;
+        let mask_host = config.censorship.mask_host.clone()
+            .unwrap_or_else(|| config.censorship.tls_domain.clone());
         // Initial synchronous fetch to warm cache before serving clients.
         for domain in tls_domains.clone() {
             match crate::tls_front::fetcher::fetch_real_tls(
-                &domain,
+                &mask_host,
                 port,
                 &domain,
                 Duration::from_secs(5),
@@ -485,7 +490,7 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                 tokio::time::sleep(Duration::from_secs(base_secs + jitter_secs)).await;
                 for domain in &domains {
                     match crate::tls_front::fetcher::fetch_real_tls(
-                        domain,
+                        &mask_host,
                         port,
                         domain,
                         Duration::from_secs(5),
@@ -597,14 +602,12 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
 			} 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");
-			}
+		} 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);
@@ -697,6 +700,20 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
         detected_ip_v6,
     );
 
+    if let Some(ref pool) = me_pool {
+        let pool_clone = pool.clone();
+        let rng_clone = rng.clone();
+        let config_rx_clone = config_rx.clone();
+        tokio::spawn(async move {
+            crate::transport::middle_proxy::me_config_updater(
+                pool_clone,
+                rng_clone,
+                config_rx_clone,
+            )
+            .await;
+        });
+    }
+
     let mut listeners = Vec::new();
 
     for listener_conf in &config.server.listeners {
@@ -710,6 +727,7 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
             continue;
         }
         let options = ListenOptions {
+            reuse_port: listener_conf.reuse_allow,
             ipv6_only: listener_conf.ip.is_ipv6(),
             ..Default::default()
         };
@@ -748,7 +766,33 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                 listeners.push((listener, listener_proxy_protocol));
             }
             Err(e) => {
-                error!("Failed to bind to {}: {}", addr, 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);
+                }
             }
         }
     }
@@ -812,6 +856,7 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
         let me_pool = me_pool.clone();
         let tls_cache = tls_cache.clone();
         let ip_tracker = ip_tracker.clone();
+        let max_connections_unix = max_connections.clone();
 
         tokio::spawn(async move {
             let unix_conn_counter = std::sync::Arc::new(std::sync::atomic::AtomicU64::new(1));
@@ -819,6 +864,13 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
             loop {
                 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));
 
@@ -834,6 +886,7 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                         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,
@@ -901,11 +954,19 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
         let me_pool = me_pool.clone();
         let tls_cache = tls_cache.clone();
         let ip_tracker = ip_tracker.clone();
+        let max_connections_tcp = max_connections.clone();
 
         tokio::spawn(async move {
             loop {
                 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();
@@ -918,6 +979,7 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                         let proxy_protocol_enabled = listener_proxy_protocol;
 
                         tokio::spawn(async move {
+                            let _permit = permit;
                             if let Err(e) = ClientHandler::new(
                                 stream,
                                 peer_addr,
@@ -935,7 +997,40 @@ match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).awai
                             .run()
                             .await
                             {
-                                warn!(peer = %peer_addr, error = %e, "Connection closed with error");
+                                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"
+                                );
+
+                                match (peer_closed, me_closed) {
+                                    (true, _) => debug!(peer = %peer_addr, error = %e, "Connection closed by client"),
+                                    (_, true) => warn!(peer = %peer_addr, error = %e, "Connection closed: Middle-End dropped session"),
+                                    _ => warn!(peer = %peer_addr, error = %e, "Connection closed with error"),
+                                }
                             }
                         });
                     }

src/metrics.rs

@@ -2,7 +2,7 @@ use std::convert::Infallible;
 use std::net::SocketAddr;
 use std::sync::Arc;
 
-use http_body_util::{Full, BodyExt};
+use http_body_util::Full;
 use hyper::body::Bytes;
 use hyper::server::conn::http1;
 use hyper::service::service_fn;
@@ -100,6 +100,14 @@ fn render_metrics(stats: &Stats) -> String {
     let _ = writeln!(out, "# TYPE telemt_me_keepalive_failed_total counter");
     let _ = writeln!(out, "telemt_me_keepalive_failed_total {}", stats.get_me_keepalive_failed());
 
+    let _ = writeln!(out, "# HELP telemt_me_keepalive_pong_total ME keepalive pong replies");
+    let _ = writeln!(out, "# TYPE telemt_me_keepalive_pong_total counter");
+    let _ = writeln!(out, "telemt_me_keepalive_pong_total {}", stats.get_me_keepalive_pong());
+
+    let _ = writeln!(out, "# HELP telemt_me_keepalive_timeout_total ME keepalive ping timeouts");
+    let _ = writeln!(out, "# TYPE telemt_me_keepalive_timeout_total counter");
+    let _ = writeln!(out, "telemt_me_keepalive_timeout_total {}", stats.get_me_keepalive_timeout());
+
     let _ = writeln!(out, "# HELP telemt_me_reconnect_attempts_total ME reconnect attempts");
     let _ = writeln!(out, "# TYPE telemt_me_reconnect_attempts_total counter");
     let _ = writeln!(out, "telemt_me_reconnect_attempts_total {}", stats.get_me_reconnect_attempts());
@@ -108,6 +116,89 @@ fn render_metrics(stats: &Stats) -> String {
     let _ = writeln!(out, "# TYPE telemt_me_reconnect_success_total counter");
     let _ = writeln!(out, "telemt_me_reconnect_success_total {}", stats.get_me_reconnect_success());
 
+    let _ = writeln!(out, "# HELP telemt_me_crc_mismatch_total ME CRC mismatches");
+    let _ = writeln!(out, "# TYPE telemt_me_crc_mismatch_total counter");
+    let _ = writeln!(out, "telemt_me_crc_mismatch_total {}", stats.get_me_crc_mismatch());
+
+    let _ = writeln!(out, "# HELP telemt_me_seq_mismatch_total ME sequence mismatches");
+    let _ = writeln!(out, "# TYPE telemt_me_seq_mismatch_total counter");
+    let _ = writeln!(out, "telemt_me_seq_mismatch_total {}", stats.get_me_seq_mismatch());
+
+    let _ = writeln!(out, "# HELP telemt_me_route_drop_no_conn_total ME route drops: no conn");
+    let _ = writeln!(out, "# TYPE telemt_me_route_drop_no_conn_total counter");
+    let _ = writeln!(out, "telemt_me_route_drop_no_conn_total {}", stats.get_me_route_drop_no_conn());
+
+    let _ = writeln!(out, "# HELP telemt_me_route_drop_channel_closed_total ME route drops: channel closed");
+    let _ = writeln!(out, "# TYPE telemt_me_route_drop_channel_closed_total counter");
+    let _ = writeln!(out, "telemt_me_route_drop_channel_closed_total {}", stats.get_me_route_drop_channel_closed());
+
+    let _ = writeln!(out, "# HELP telemt_me_route_drop_queue_full_total ME route drops: queue full");
+    let _ = writeln!(out, "# TYPE telemt_me_route_drop_queue_full_total counter");
+    let _ = writeln!(out, "telemt_me_route_drop_queue_full_total {}", stats.get_me_route_drop_queue_full());
+
+    let _ = writeln!(out, "# HELP telemt_secure_padding_invalid_total Invalid secure frame lengths");
+    let _ = writeln!(out, "# TYPE telemt_secure_padding_invalid_total counter");
+    let _ = writeln!(out, "telemt_secure_padding_invalid_total {}", stats.get_secure_padding_invalid());
+
+    let _ = writeln!(out, "# HELP telemt_desync_total Total crypto-desync detections");
+    let _ = writeln!(out, "# TYPE telemt_desync_total counter");
+    let _ = writeln!(out, "telemt_desync_total {}", stats.get_desync_total());
+
+    let _ = writeln!(out, "# HELP telemt_desync_full_logged_total Full forensic desync logs emitted");
+    let _ = writeln!(out, "# TYPE telemt_desync_full_logged_total counter");
+    let _ = writeln!(out, "telemt_desync_full_logged_total {}", stats.get_desync_full_logged());
+
+    let _ = writeln!(out, "# HELP telemt_desync_suppressed_total Suppressed desync forensic events");
+    let _ = writeln!(out, "# TYPE telemt_desync_suppressed_total counter");
+    let _ = writeln!(out, "telemt_desync_suppressed_total {}", stats.get_desync_suppressed());
+
+    let _ = writeln!(out, "# HELP telemt_desync_frames_bucket_total Desync count by frames_ok bucket");
+    let _ = writeln!(out, "# TYPE telemt_desync_frames_bucket_total counter");
+    let _ = writeln!(
+        out,
+        "telemt_desync_frames_bucket_total{{bucket=\"0\"}} {}",
+        stats.get_desync_frames_bucket_0()
+    );
+    let _ = writeln!(
+        out,
+        "telemt_desync_frames_bucket_total{{bucket=\"1_2\"}} {}",
+        stats.get_desync_frames_bucket_1_2()
+    );
+    let _ = writeln!(
+        out,
+        "telemt_desync_frames_bucket_total{{bucket=\"3_10\"}} {}",
+        stats.get_desync_frames_bucket_3_10()
+    );
+    let _ = writeln!(
+        out,
+        "telemt_desync_frames_bucket_total{{bucket=\"gt_10\"}} {}",
+        stats.get_desync_frames_bucket_gt_10()
+    );
+
+    let _ = writeln!(out, "# HELP telemt_pool_swap_total Successful ME pool swaps");
+    let _ = writeln!(out, "# TYPE telemt_pool_swap_total counter");
+    let _ = writeln!(out, "telemt_pool_swap_total {}", stats.get_pool_swap_total());
+
+    let _ = writeln!(out, "# HELP telemt_pool_drain_active Active draining ME writers");
+    let _ = writeln!(out, "# TYPE telemt_pool_drain_active gauge");
+    let _ = writeln!(out, "telemt_pool_drain_active {}", stats.get_pool_drain_active());
+
+    let _ = writeln!(out, "# HELP telemt_pool_force_close_total Forced close events for draining writers");
+    let _ = writeln!(out, "# TYPE telemt_pool_force_close_total counter");
+    let _ = writeln!(
+        out,
+        "telemt_pool_force_close_total {}",
+        stats.get_pool_force_close_total()
+    );
+
+    let _ = writeln!(out, "# HELP telemt_pool_stale_pick_total Stale writer fallback picks for new binds");
+    let _ = writeln!(out, "# TYPE telemt_pool_stale_pick_total counter");
+    let _ = writeln!(
+        out,
+        "telemt_pool_stale_pick_total {}",
+        stats.get_pool_stale_pick_total()
+    );
+
     let _ = writeln!(out, "# HELP telemt_user_connections_total Per-user total connections");
     let _ = writeln!(out, "# TYPE telemt_user_connections_total counter");
     let _ = writeln!(out, "# HELP telemt_user_connections_current Per-user active connections");
@@ -138,6 +229,7 @@ fn render_metrics(stats: &Stats) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use http_body_util::BodyExt;
 
     #[test]
     fn test_render_metrics_format() {

src/network/probe.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, UdpSocket};
 
 use tracing::{info, warn};
@@ -93,23 +95,21 @@ pub async fn run_probe(config: &NetworkConfig, stun_addr: Option<String>, nat_pr
 }
 
 pub fn decide_network_capabilities(config: &NetworkConfig, probe: &NetworkProbe) -> NetworkDecision {
-    let mut decision = NetworkDecision::default();
+    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();
 
-    decision.ipv4_dc = config.ipv4 && probe.detected_ipv4.is_some();
-    decision.ipv6_dc = config.ipv6.unwrap_or(probe.detected_ipv6.is_some()) && probe.detected_ipv6.is_some();
-
-    decision.ipv4_me = config.ipv4
+    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());
-    decision.ipv6_me = ipv6_enabled
+    let ipv6_me = ipv6_enabled
         && probe.detected_ipv6.is_some()
         && (!probe.ipv6_is_bogon || probe.reflected_ipv6.is_some());
 
-    decision.effective_prefer = match config.prefer {
-        6 if decision.ipv6_me || decision.ipv6_dc => 6,
-        4 if decision.ipv4_me || decision.ipv4_dc => 4,
+    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
@@ -117,10 +117,17 @@ pub fn decide_network_capabilities(config: &NetworkConfig, probe: &NetworkProbe)
         _ => 4,
     };
 
-    let me_families = decision.ipv4_me as u8 + decision.ipv6_me as u8;
-    decision.effective_multipath = config.multipath && me_families >= 2;
+    let me_families = ipv4_me as u8 + ipv6_me as u8;
+    let effective_multipath = config.multipath && me_families >= 2;
 
-    decision
+    NetworkDecision {
+        ipv4_dc,
+        ipv6_dc,
+        ipv4_me,
+        ipv6_me,
+        effective_prefer,
+        effective_multipath,
+    }
 }
 
 fn detect_local_ip_v4() -> Option<Ipv4Addr> {

src/network/stun.rs

@@ -1,3 +1,6 @@
+#![allow(unreachable_code)]
+#![allow(dead_code)]
+
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
 
 use tokio::net::{lookup_host, UdpSocket};
@@ -195,16 +198,11 @@ async fn resolve_stun_addr(stun_addr: &str, family: IpFamily) -> Result<Option<S
         });
     }
 
-    let addrs = lookup_host(stun_addr)
+    let mut addrs = lookup_host(stun_addr)
         .await
         .map_err(|e| ProxyError::Proxy(format!("STUN resolve failed: {e}")))?;
 
     let target = addrs
-        .filter(|a| match (a.is_ipv4(), family) {
-            (true, IpFamily::V4) => true,
-            (false, IpFamily::V6) => true,
-            _ => false,
-        })
-        .next();
+        .find(|a| matches!((a.is_ipv4(), family), (true, IpFamily::V4) | (false, IpFamily::V6)));
     Ok(target)
 }

src/protocol/constants.rs

@@ -1,6 +1,10 @@
 //! Protocol constants and datacenter addresses
 
-use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+#![allow(dead_code)]
+
+use std::net::{IpAddr, Ipv4Addr};
+
+use crate::crypto::SecureRandom;
 use std::sync::LazyLock;
 
 // ============= Telegram Datacenters =============
@@ -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 =============
 
@@ -202,7 +231,6 @@ 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;
@@ -284,6 +312,10 @@ pub mod rpc_flags {
         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;
@@ -319,4 +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

@@ -1,8 +1,9 @@
 //! MTProto Obfuscation
 
+#![allow(dead_code)]
+
 use zeroize::Zeroize;
 use crate::crypto::{sha256, AesCtr};
-use crate::error::Result;
 use super::constants::*;
 
 /// Obfuscation parameters from handshake

src/protocol/tls.rs

@@ -4,8 +4,11 @@
 //! for domain fronting. The handshake looks like valid TLS 1.3 but
 //! actually carries MTProto authentication data.
 
+#![allow(dead_code)]
+
 use crate::crypto::{sha256_hmac, SecureRandom};
-use crate::error::{ProxyError, Result};
+#[cfg(test)]
+use crate::error::ProxyError;
 use super::constants::*;
 use std::time::{SystemTime, UNIX_EPOCH};
 use num_bigint::BigUint;
@@ -32,6 +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
@@ -62,6 +66,7 @@ pub struct TlsValidation {
 // ============= TLS Extension Builder =============
 
 /// Builder for TLS extensions with correct length calculation
+#[derive(Clone)]
 struct TlsExtensionBuilder {
     extensions: Vec<u8>,
 }
@@ -108,6 +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> {
@@ -144,6 +170,8 @@ struct ServerHelloBuilder {
     compression: u8,
     /// Extensions
     extensions: TlsExtensionBuilder,
+    /// Selected ALPN protocol (if any)
+    alpn: Option<Vec<u8>>,
 }
 
 impl ServerHelloBuilder {
@@ -154,6 +182,7 @@ impl ServerHelloBuilder {
             cipher_suite: cipher_suite::TLS_AES_128_GCM_SHA256,
             compression: 0x00,
             extensions: TlsExtensionBuilder::new(),
+            alpn: None,
         }
     }
     
@@ -167,10 +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
@@ -297,7 +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;
             }
         }
@@ -350,16 +388,19 @@ pub fn build_server_hello(
     session_id: &[u8],
     fake_cert_len: usize,
     rng: &SecureRandom,
+    alpn: Option<Vec<u8>>,
+    new_session_tickets: u8,
 ) -> Vec<u8> {
     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.max(MIN_APP_DATA).min(MAX_APP_DATA);
+    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
@@ -376,21 +417,35 @@ pub fn build_server_hello(
     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());
-    if fake_cert_len > 17 {
-        app_data_record.extend_from_slice(&fake_cert[..fake_cert_len - 17]);
-        app_data_record.push(0x16); // inner content type marker
-        app_data_record.extend_from_slice(&rng.bytes(16)); // AEAD-like tag mimic
-    } else {
-        app_data_record.extend_from_slice(&fake_cert);
-    }
+    // 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());
@@ -470,10 +525,10 @@ pub fn extract_sni_from_client_hello(handshake: &[u8]) -> Option<String> {
                 if sn_pos + name_len > sn_end {
                     break;
                 }
-                if name_type == 0 && name_len > 0 {
-                    if let Ok(host) = std::str::from_utf8(&handshake[sn_pos..sn_pos + name_len]) {
-                        return Some(host.to_string());
-                    }
+                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;
             }
@@ -484,85 +539,53 @@ pub fn extract_sni_from_client_hello(handshake: &[u8]) -> Option<String> {
     None
 }
 
-/// Extract ALPN protocol list from TLS ClientHello.
-pub fn extract_alpn_from_client_hello(handshake: &[u8]) -> Option<Vec<String>> {
-    if handshake.len() < 43 || handshake[0] != TLS_RECORD_HANDSHAKE {
-        return 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).copied()? != 0x01 {
-        return None; // not ClientHello
+    if handshake.get(pos) != Some(&0x01) {
+        return Vec::new();
     }
-
-    // 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 += 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 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;
+    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 None;
-    }
-
-    let ext_len = u16::from_be_bytes([handshake[pos], handshake[pos + 1]]) as usize;
+    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 None;
-    }
-
+    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;
+        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 {
+        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;
         }
-
-        if etype == 0x0010 && elen >= 3 {
-            // ALPN
-            let list_len = u16::from_be_bytes([handshake[pos], handshake[pos + 1]]) as usize;
-            let mut alpn_pos = pos + 2;
-            let list_end = std::cmp::min(alpn_pos + list_len, pos + elen);
-            let mut protocols = Vec::new();
-            while alpn_pos < list_end {
-                let proto_len = *handshake.get(alpn_pos)? as usize;
-                alpn_pos += 1;
-                if alpn_pos + proto_len > list_end {
-                    break;
-                }
-                if let Ok(p) = std::str::from_utf8(&handshake[alpn_pos..alpn_pos + proto_len]) {
-                    protocols.push(p.to_string());
-                }
-                alpn_pos += proto_len;
-            }
-            return Some(protocols);
-        }
-
         pos += elen;
     }
-
-    None
+    out
 }
 
+
 /// Check if bytes look like a TLS ClientHello
 pub fn is_tls_handshake(first_bytes: &[u8]) -> bool {
     if first_bytes.len() < 3 {
@@ -593,7 +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,
@@ -741,7 +764,7 @@ mod tests {
         let session_id = vec![0xAA; 32];
         
         let rng = SecureRandom::new();
-        let response = build_server_hello(secret, &client_digest, &session_id, 2048, &rng);
+        let response = build_server_hello(secret, &client_digest, &session_id, 2048, &rng, None, 0);
         
         // Should have at least 3 records
         assert!(response.len() > 100);
@@ -774,8 +797,8 @@ mod tests {
         let session_id = vec![0xAA; 32];
         
         let rng = SecureRandom::new();
-        let response1 = build_server_hello(secret, &client_digest, &session_id, 1024, &rng);
-        let response2 = build_server_hello(secret, &client_digest, &session_id, 1024, &rng);
+        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];
@@ -904,8 +927,12 @@ mod tests {
         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).unwrap();
-        assert_eq!(alpn, vec!["h2"]);
+        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]
@@ -920,7 +947,11 @@ mod tests {
         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).unwrap();
-        assert_eq!(alpn, vec!["h2", "spdy", "h3"]);
+        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/client.rs

@@ -271,7 +271,7 @@ impl RunningClientHandler {
 
         self.peer = normalize_ip(self.peer);
         let peer = self.peer;
-        let ip_tracker = self.ip_tracker.clone();
+        let _ip_tracker = self.ip_tracker.clone();
         debug!(peer = %peer, "New connection");
 
         if let Err(e) = configure_client_socket(
@@ -331,7 +331,7 @@ impl RunningClientHandler {
 
         let is_tls = tls::is_tls_handshake(&first_bytes[..3]);
         let peer = self.peer;
-        let ip_tracker = self.ip_tracker.clone();
+        let _ip_tracker = self.ip_tracker.clone();
 
         debug!(peer = %peer, is_tls = is_tls, "Handshake type detected");
 
@@ -344,7 +344,7 @@ impl RunningClientHandler {
 
     async fn handle_tls_client(mut self, first_bytes: [u8; 5]) -> Result<HandshakeOutcome> {
         let peer = self.peer;
-        let ip_tracker = self.ip_tracker.clone();
+        let _ip_tracker = self.ip_tracker.clone();
 
         let tls_len = u16::from_be_bytes([first_bytes[3], first_bytes[4]]) as usize;
 
@@ -440,7 +440,7 @@ impl RunningClientHandler {
 
     async fn handle_direct_client(mut self, first_bytes: [u8; 5]) -> Result<HandshakeOutcome> {
         let peer = self.peer;
-        let ip_tracker = self.ip_tracker.clone();
+        let _ip_tracker = self.ip_tracker.clone();
 
         if !self.config.general.modes.classic && !self.config.general.modes.secure {
             debug!(peer = %peer, "Non-TLS modes disabled");
@@ -594,18 +594,18 @@ impl RunningClientHandler {
         peer_addr: SocketAddr,
         ip_tracker: &UserIpTracker,
     ) -> Result<()> {
-        if let Some(expiration) = config.access.user_expirations.get(user) {
-            if chrono::Utc::now() > *expiration {
-                return Err(ProxyError::UserExpired {
-                    user: user.to_string(),
-                });
-            }
+        if let Some(expiration) = config.access.user_expirations.get(user)
+            && chrono::Utc::now() > *expiration
+        {
+            return Err(ProxyError::UserExpired {
+                user: user.to_string(),
+            });
         }
 
         // IP limit check
         if let Err(reason) = ip_tracker.check_and_add(user, peer_addr.ip()).await {
             warn!(
-                user = %user, 
+                user = %user,
                 ip = %peer_addr.ip(),
                 reason = %reason,
                 "IP limit exceeded"
@@ -615,20 +615,20 @@ impl RunningClientHandler {
             });
         }
 
-        if let Some(limit) = config.access.user_max_tcp_conns.get(user) {
-            if stats.get_user_curr_connects(user) >= *limit as u64 {
-                return Err(ProxyError::ConnectionLimitExceeded {
-                    user: user.to_string(),
-                });
-            }
+        if let Some(limit) = config.access.user_max_tcp_conns.get(user)
+            && stats.get_user_curr_connects(user) >= *limit as u64
+        {
+            return Err(ProxyError::ConnectionLimitExceeded {
+                user: user.to_string(),
+            });
         }
 
-        if let Some(quota) = config.access.user_data_quota.get(user) {
-            if stats.get_user_total_octets(user) >= *quota {
-                return Err(ProxyError::DataQuotaExceeded {
-                    user: user.to_string(),
-                });
-            }
+        if let Some(quota) = config.access.user_data_quota.get(user)
+            && stats.get_user_total_octets(user) >= *quota
+        {
+            return Err(ProxyError::DataQuotaExceeded {
+                user: user.to_string(),
+            });
         }
 
         Ok(())

src/proxy/direct_relay.rs

@@ -118,10 +118,10 @@ fn get_dc_addr_static(dc_idx: i16, config: &ProxyConfig) -> Result<SocketAddr> {
     // 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 let Some(path) = &config.general.unknown_dc_log_path {
-            if let Ok(mut file) = OpenOptions::new().create(true).append(true).open(path) {
-                let _ = writeln!(file, "dc_idx={dc_idx}");
-            }
+        if let Some(path) = &config.general.unknown_dc_log_path
+            && let Ok(mut file) = OpenOptions::new().create(true).append(true).open(path)
+        {
+            let _ = writeln!(file, "dc_idx={dc_idx}");
         }
     }
 
@@ -178,8 +178,9 @@ async fn do_tg_handshake_static(
 
     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),
+        CryptoWriter::new(write_half, tg_encryptor, max_pending),
     ))
 }

src/proxy/handshake.rs

@@ -1,12 +1,16 @@
 //! 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 zeroize::Zeroize;
 
 use crate::crypto::{sha256, AesCtr, SecureRandom};
+use rand::Rng;
 use crate::protocol::constants::*;
 use crate::protocol::tls;
 use crate::stream::{FakeTlsReader, FakeTlsWriter, CryptoReader, CryptoWriter};
@@ -107,11 +111,23 @@ where
 
     let cached = if config.censorship.tls_emulation {
         if let Some(cache) = tls_cache.as_ref() {
-            if let Some(sni) = tls::extract_sni_from_client_hello(handshake) {
-                Some(cache.get(&sni).await)
+            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 {
-                Some(cache.get(&config.censorship.tls_domain).await)
-            }
+                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
         }
@@ -119,13 +135,33 @@ where
         None
     };
 
-    let response = if let Some(cached_entry) = cached {
+    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(
@@ -134,9 +170,25 @@ where
             &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 {
@@ -217,7 +269,11 @@ where
 
         let mode_ok = match proto_tag {
             ProtoTag::Secure => {
-                if is_tls { config.general.modes.tls } else { config.general.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.general.modes.classic,
         };
@@ -264,9 +320,10 @@ where
             "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,
         ));
     }

src/proxy/masking.rs

@@ -19,12 +19,12 @@ 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 {
-        if data.starts_with(b"GET ") || data.starts_with(b"POST") ||
+    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";
-        }
+           data.starts_with(b"DELETE") || data.starts_with(b"OPTIONS"))
+    {
+        return "HTTP";
     }
 
     // Check for TLS ClientHello (0x16 = handshake, 0x03 0x01-0x03 = TLS version)

src/proxy/middle_relay.rs

@@ -1,25 +1,178 @@
-use std::net::SocketAddr;
-use std::sync::Arc;
+use std::collections::HashMap;
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
+use std::net::{IpAddr, SocketAddr};
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::{Arc, Mutex, OnceLock};
+use std::time::{Duration, Instant};
 
 use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
-use tracing::{debug, info, trace};
+use tokio::sync::{mpsc, oneshot};
+use tracing::{debug, info, trace, warn};
 
 use crate::config::ProxyConfig;
 use crate::crypto::SecureRandom;
 use crate::error::{ProxyError, Result};
-use crate::protocol::constants::*;
+use crate::protocol::constants::{*, secure_padding_len};
 use crate::proxy::handshake::HandshakeSuccess;
 use crate::stats::Stats;
 use crate::stream::{BufferPool, CryptoReader, CryptoWriter};
 use crate::transport::middle_proxy::{MePool, MeResponse, proto_flags_for_tag};
 
+enum C2MeCommand {
+    Data { payload: Vec<u8>, flags: u32 },
+    Close,
+}
+
+const DESYNC_DEDUP_WINDOW: Duration = Duration::from_secs(60);
+const DESYNC_ERROR_CLASS: &str = "frame_too_large_crypto_desync";
+static DESYNC_DEDUP: OnceLock<Mutex<HashMap<u64, Instant>>> = OnceLock::new();
+
+struct RelayForensicsState {
+    trace_id: u64,
+    conn_id: u64,
+    user: String,
+    peer: SocketAddr,
+    peer_hash: u64,
+    started_at: Instant,
+    bytes_c2me: u64,
+    bytes_me2c: Arc<AtomicU64>,
+    desync_all_full: bool,
+}
+
+fn hash_value<T: Hash>(value: &T) -> u64 {
+    let mut hasher = DefaultHasher::new();
+    value.hash(&mut hasher);
+    hasher.finish()
+}
+
+fn hash_ip(ip: IpAddr) -> u64 {
+    hash_value(&ip)
+}
+
+fn should_emit_full_desync(key: u64, all_full: bool, now: Instant) -> bool {
+    if all_full {
+        return true;
+    }
+
+    let dedup = DESYNC_DEDUP.get_or_init(|| Mutex::new(HashMap::new()));
+    let mut guard = dedup.lock().expect("desync dedup mutex poisoned");
+    guard.retain(|_, seen_at| now.duration_since(*seen_at) < DESYNC_DEDUP_WINDOW);
+
+    match guard.get_mut(&key) {
+        Some(seen_at) => {
+            if now.duration_since(*seen_at) >= DESYNC_DEDUP_WINDOW {
+                *seen_at = now;
+                true
+            } else {
+                false
+            }
+        }
+        None => {
+            guard.insert(key, now);
+            true
+        }
+    }
+}
+
+fn report_desync_frame_too_large(
+    state: &RelayForensicsState,
+    proto_tag: ProtoTag,
+    frame_counter: u64,
+    max_frame: usize,
+    len: usize,
+    raw_len_bytes: Option<[u8; 4]>,
+    stats: &Stats,
+) -> ProxyError {
+    let len_buf = raw_len_bytes.unwrap_or((len as u32).to_le_bytes());
+    let looks_like_tls = raw_len_bytes
+        .map(|b| b[0] == 0x16 && b[1] == 0x03)
+        .unwrap_or(false);
+    let looks_like_http = raw_len_bytes
+        .map(|b| matches!(b[0], b'G' | b'P' | b'H' | b'C' | b'D'))
+        .unwrap_or(false);
+    let now = Instant::now();
+    let dedup_key = hash_value(&(
+        state.user.as_str(),
+        state.peer_hash,
+        proto_tag,
+        DESYNC_ERROR_CLASS,
+    ));
+    let emit_full = should_emit_full_desync(dedup_key, state.desync_all_full, now);
+    let duration_ms = state.started_at.elapsed().as_millis() as u64;
+    let bytes_me2c = state.bytes_me2c.load(Ordering::Relaxed);
+
+    stats.increment_desync_total();
+    stats.observe_desync_frames_ok(frame_counter);
+    if emit_full {
+        stats.increment_desync_full_logged();
+        warn!(
+            trace_id = format_args!("0x{:016x}", state.trace_id),
+            conn_id = state.conn_id,
+            user = %state.user,
+            peer_hash = format_args!("0x{:016x}", state.peer_hash),
+            proto = ?proto_tag,
+            mode = "middle_proxy",
+            is_tls = true,
+            duration_ms,
+            bytes_c2me = state.bytes_c2me,
+            bytes_me2c,
+            raw_len = len,
+            raw_len_hex = format_args!("0x{:08x}", len),
+            raw_bytes = format_args!(
+                "{:02x} {:02x} {:02x} {:02x}",
+                len_buf[0], len_buf[1], len_buf[2], len_buf[3]
+            ),
+            max_frame,
+            tls_like = looks_like_tls,
+            http_like = looks_like_http,
+            frames_ok = frame_counter,
+            dedup_window_secs = DESYNC_DEDUP_WINDOW.as_secs(),
+            desync_all_full = state.desync_all_full,
+            full_reason = if state.desync_all_full { "desync_all_full" } else { "first_in_dedup_window" },
+            error_class = DESYNC_ERROR_CLASS,
+            "Frame too large — crypto desync forensics"
+        );
+        debug!(
+            trace_id = format_args!("0x{:016x}", state.trace_id),
+            conn_id = state.conn_id,
+            user = %state.user,
+            peer = %state.peer,
+            "Frame too large forensic peer detail"
+        );
+    } else {
+        stats.increment_desync_suppressed();
+        debug!(
+            trace_id = format_args!("0x{:016x}", state.trace_id),
+            conn_id = state.conn_id,
+            user = %state.user,
+            peer_hash = format_args!("0x{:016x}", state.peer_hash),
+            proto = ?proto_tag,
+            duration_ms,
+            bytes_c2me = state.bytes_c2me,
+            bytes_me2c,
+            raw_len = len,
+            frames_ok = frame_counter,
+            dedup_window_secs = DESYNC_DEDUP_WINDOW.as_secs(),
+            error_class = DESYNC_ERROR_CLASS,
+            "Frame too large — crypto desync forensic suppressed"
+        );
+    }
+
+    ProxyError::Proxy(format!(
+        "Frame too large: {len} (max {max_frame}), frames_ok={frame_counter}, conn_id={}, trace_id=0x{:016x}",
+        state.conn_id,
+        state.trace_id
+    ))
+}
+
 pub(crate) async fn handle_via_middle_proxy<R, W>(
     mut crypto_reader: CryptoReader<R>,
-    mut crypto_writer: CryptoWriter<W>,
+    crypto_writer: CryptoWriter<W>,
     success: HandshakeSuccess,
     me_pool: Arc<MePool>,
     stats: Arc<Stats>,
-    _config: Arc<ProxyConfig>,
+    config: Arc<ProxyConfig>,
     _buffer_pool: Arc<BufferPool>,
     local_addr: SocketAddr,
     rng: Arc<SecureRandom>,
@@ -31,6 +184,7 @@ where
     let user = success.user.clone();
     let peer = success.peer;
     let proto_tag = success.proto_tag;
+    let pool_generation = me_pool.current_generation();
 
     info!(
         user = %user,
@@ -38,80 +192,233 @@ where
         dc = success.dc_idx,
         proto = ?proto_tag,
         mode = "middle_proxy",
+        pool_generation,
         "Routing via Middle-End"
     );
 
-    let (conn_id, mut me_rx) = me_pool.registry().register().await;
+    let (conn_id, me_rx) = me_pool.registry().register().await;
+    let trace_id = conn_id;
+    let bytes_me2c = Arc::new(AtomicU64::new(0));
+    let mut forensics = RelayForensicsState {
+        trace_id,
+        conn_id,
+        user: user.clone(),
+        peer,
+        peer_hash: hash_ip(peer.ip()),
+        started_at: Instant::now(),
+        bytes_c2me: 0,
+        bytes_me2c: bytes_me2c.clone(),
+        desync_all_full: config.general.desync_all_full,
+    };
 
     stats.increment_user_connects(&user);
     stats.increment_user_curr_connects(&user);
 
     let proto_flags = proto_flags_for_tag(proto_tag, me_pool.has_proxy_tag());
     debug!(
+        trace_id = format_args!("0x{:016x}", trace_id),
         user = %user,
         conn_id,
+        peer_hash = format_args!("0x{:016x}", forensics.peer_hash),
+        desync_all_full = forensics.desync_all_full,
         proto_flags = format_args!("0x{:08x}", proto_flags),
+        pool_generation,
         "ME relay started"
     );
 
     let translated_local_addr = me_pool.translate_our_addr(local_addr);
 
-    let result: Result<()> = loop {
-        tokio::select! {
-            client_frame = read_client_payload(&mut crypto_reader, proto_tag) => {
-                match client_frame {
-                    Ok(Some((payload, quickack))) => {
-                        trace!(conn_id, bytes = payload.len(), "C->ME frame");
-                        stats.add_user_octets_from(&user, payload.len() as u64);
-                        let mut flags = proto_flags;
-                        if quickack {
-                            flags |= RPC_FLAG_QUICKACK;
-                        }
-                        if payload.len() >= 8 && payload[..8].iter().all(|b| *b == 0) {
-                            flags |= RPC_FLAG_NOT_ENCRYPTED;
-                        }
-                        me_pool.send_proxy_req(
-                            conn_id,
-                            success.dc_idx,
-                            peer,
-                            translated_local_addr,
-                            &payload,
-                            flags,
-                        ).await?;
-                    }
-                    Ok(None) => {
-                        debug!(conn_id, "Client EOF");
-                        let _ = me_pool.send_close(conn_id).await;
-                        break Ok(());
-                    }
-                    Err(e) => break Err(e),
+    let frame_limit = config.general.max_client_frame;
+
+    let (c2me_tx, mut c2me_rx) = mpsc::channel::<C2MeCommand>(1024);
+    let me_pool_c2me = me_pool.clone();
+    let c2me_sender = tokio::spawn(async move {
+        while let Some(cmd) = c2me_rx.recv().await {
+            match cmd {
+                C2MeCommand::Data { payload, flags } => {
+                    me_pool_c2me.send_proxy_req(
+                        conn_id,
+                        success.dc_idx,
+                        peer,
+                        translated_local_addr,
+                        &payload,
+                        flags,
+                    ).await?;
                 }
-            }
-            me_msg = me_rx.recv() => {
-                match me_msg {
-                    Some(MeResponse::Data { flags, data }) => {
-                        trace!(conn_id, bytes = data.len(), flags, "ME->C data");
-                        stats.add_user_octets_to(&user, data.len() as u64);
-                        write_client_payload(&mut crypto_writer, proto_tag, flags, &data, rng.as_ref()).await?;
-                    }
-                    Some(MeResponse::Ack(confirm)) => {
-                        trace!(conn_id, confirm, "ME->C quickack");
-                        write_client_ack(&mut crypto_writer, proto_tag, confirm).await?;
-                    }
-                    Some(MeResponse::Close) => {
-                        debug!(conn_id, "ME sent close");
-                        break Ok(());
-                    }
-                    None => {
-                        debug!(conn_id, "ME channel closed");
-                        break Err(ProxyError::Proxy("ME connection lost".into()));
-                    }
+                C2MeCommand::Close => {
+                    let _ = me_pool_c2me.send_close(conn_id).await;
+                    return Ok(());
                 }
             }
         }
+        Ok(())
+    });
+
+    let (stop_tx, mut stop_rx) = oneshot::channel::<()>();
+    let mut me_rx_task = me_rx;
+    let stats_clone = stats.clone();
+    let rng_clone = rng.clone();
+    let user_clone = user.clone();
+    let bytes_me2c_clone = bytes_me2c.clone();
+    let me_writer = tokio::spawn(async move {
+        let mut writer = crypto_writer;
+        let mut frame_buf = Vec::with_capacity(16 * 1024);
+        loop {
+            tokio::select! {
+                msg = me_rx_task.recv() => {
+                    match msg {
+                        Some(MeResponse::Data { flags, data }) => {
+                            trace!(conn_id, bytes = data.len(), flags, "ME->C data");
+                            bytes_me2c_clone.fetch_add(data.len() as u64, Ordering::Relaxed);
+                            stats_clone.add_user_octets_to(&user_clone, data.len() as u64);
+                            write_client_payload(
+                                &mut writer,
+                                proto_tag,
+                                flags,
+                                &data,
+                                rng_clone.as_ref(),
+                                &mut frame_buf,
+                            )
+                            .await?;
+
+                            // Drain all immediately queued ME responses and flush once.
+                            while let Ok(next) = me_rx_task.try_recv() {
+                                match next {
+                                    MeResponse::Data { flags, data } => {
+                                        trace!(conn_id, bytes = data.len(), flags, "ME->C data (batched)");
+                                        bytes_me2c_clone.fetch_add(data.len() as u64, Ordering::Relaxed);
+                                        stats_clone.add_user_octets_to(&user_clone, data.len() as u64);
+                                        write_client_payload(
+                                            &mut writer,
+                                            proto_tag,
+                                            flags,
+                                            &data,
+                                            rng_clone.as_ref(),
+                                            &mut frame_buf,
+                                        ).await?;
+                                    }
+                                    MeResponse::Ack(confirm) => {
+                                        trace!(conn_id, confirm, "ME->C quickack (batched)");
+                                        write_client_ack(&mut writer, proto_tag, confirm).await?;
+                                    }
+                                    MeResponse::Close => {
+                                        debug!(conn_id, "ME sent close (batched)");
+                                        let _ = writer.flush().await;
+                                        return Ok(());
+                                    }
+                                }
+                            }
+
+                            writer.flush().await.map_err(ProxyError::Io)?;
+                        }
+                        Some(MeResponse::Ack(confirm)) => {
+                            trace!(conn_id, confirm, "ME->C quickack");
+                            write_client_ack(&mut writer, proto_tag, confirm).await?;
+                        }
+                        Some(MeResponse::Close) => {
+                            debug!(conn_id, "ME sent close");
+                            let _ = writer.flush().await;
+                            return Ok(());
+                        }
+                        None => {
+                            debug!(conn_id, "ME channel closed");
+                            return Err(ProxyError::Proxy("ME connection lost".into()));
+                        }
+                    }
+                }
+                _ = &mut stop_rx => {
+                    debug!(conn_id, "ME writer stop signal");
+                    return Ok(());
+                }
+            }
+        }
+    });
+
+    let mut main_result: Result<()> = Ok(());
+    let mut client_closed = false;
+    let mut frame_counter: u64 = 0;
+    loop {
+        match read_client_payload(
+            &mut crypto_reader,
+            proto_tag,
+            frame_limit,
+            &forensics,
+            &mut frame_counter,
+            &stats,
+        ).await {
+            Ok(Some((payload, quickack))) => {
+                trace!(conn_id, bytes = payload.len(), "C->ME frame");
+                forensics.bytes_c2me = forensics
+                    .bytes_c2me
+                    .saturating_add(payload.len() as u64);
+                stats.add_user_octets_from(&user, payload.len() as u64);
+                let mut flags = proto_flags;
+                if quickack {
+                    flags |= RPC_FLAG_QUICKACK;
+                }
+                if payload.len() >= 8 && payload[..8].iter().all(|b| *b == 0) {
+                    flags |= RPC_FLAG_NOT_ENCRYPTED;
+                }
+                // Keep client read loop lightweight: route heavy ME send path via a dedicated task.
+                if c2me_tx
+                    .send(C2MeCommand::Data { payload, flags })
+                    .await
+                    .is_err()
+                {
+                    main_result = Err(ProxyError::Proxy("ME sender channel closed".into()));
+                    break;
+                }
+            }
+            Ok(None) => {
+                debug!(conn_id, "Client EOF");
+                client_closed = true;
+                let _ = c2me_tx.send(C2MeCommand::Close).await;
+                break;
+            }
+            Err(e) => {
+                main_result = Err(e);
+                break;
+            }
+        }
+    }
+
+    drop(c2me_tx);
+    let c2me_result = c2me_sender
+        .await
+        .unwrap_or_else(|e| Err(ProxyError::Proxy(format!("ME sender join error: {e}"))));
+
+    let _ = stop_tx.send(());
+    let mut writer_result = me_writer
+        .await
+        .unwrap_or_else(|e| Err(ProxyError::Proxy(format!("ME writer join error: {e}"))));
+
+    // When client closes, but ME channel stopped as unregistered - it isnt error
+    if client_closed
+        && matches!(
+            writer_result,
+            Err(ProxyError::Proxy(ref msg)) if msg == "ME connection lost"
+        )
+    {
+        writer_result = Ok(());
+    }
+
+    let result = match (main_result, c2me_result, writer_result) {
+        (Ok(()), Ok(()), Ok(())) => Ok(()),
+        (Err(e), _, _) => Err(e),
+        (_, Err(e), _) => Err(e),
+        (_, _, Err(e)) => Err(e),
     };
 
-    debug!(user = %user, conn_id, "ME relay cleanup");
+    debug!(
+        user = %user,
+        conn_id,
+        trace_id = format_args!("0x{:016x}", trace_id),
+        duration_ms = forensics.started_at.elapsed().as_millis() as u64,
+        bytes_c2me = forensics.bytes_c2me,
+        bytes_me2c = forensics.bytes_me2c.load(Ordering::Relaxed),
+        frames_ok = frame_counter,
+        "ME relay cleanup"
+    );
     me_pool.registry().unregister(conn_id).await;
     stats.decrement_user_curr_connects(&user);
     result
@@ -120,66 +427,111 @@ where
 async fn read_client_payload<R>(
     client_reader: &mut CryptoReader<R>,
     proto_tag: ProtoTag,
+    max_frame: usize,
+    forensics: &RelayForensicsState,
+    frame_counter: &mut u64,
+    stats: &Stats,
 ) -> Result<Option<(Vec<u8>, bool)>>
 where
     R: AsyncRead + Unpin + Send + 'static,
 {
-    let (len, quickack) = match proto_tag {
-        ProtoTag::Abridged => {
-            let mut first = [0u8; 1];
-            match client_reader.read_exact(&mut first).await {
-                Ok(_) => {}
-                Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
-                Err(e) => return Err(ProxyError::Io(e)),
+    loop {
+        let (len, quickack, raw_len_bytes) = match proto_tag {
+            ProtoTag::Abridged => {
+                let mut first = [0u8; 1];
+                match client_reader.read_exact(&mut first).await {
+                    Ok(_) => {}
+                    Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
+                    Err(e) => return Err(ProxyError::Io(e)),
+                }
+
+                let quickack = (first[0] & 0x80) != 0;
+                let len_words = if (first[0] & 0x7f) == 0x7f {
+                    let mut ext = [0u8; 3];
+                    client_reader
+                        .read_exact(&mut ext)
+                        .await
+                        .map_err(ProxyError::Io)?;
+                    u32::from_le_bytes([ext[0], ext[1], ext[2], 0]) as usize
+                } else {
+                    (first[0] & 0x7f) as usize
+                };
+
+                let len = len_words
+                    .checked_mul(4)
+                    .ok_or_else(|| ProxyError::Proxy("Abridged frame length overflow".into()))?;
+                (len, quickack, None)
             }
-
-            let quickack = (first[0] & 0x80) != 0;
-            let len_words = if (first[0] & 0x7f) == 0x7f {
-                let mut ext = [0u8; 3];
-                client_reader
-                    .read_exact(&mut ext)
-                    .await
-                    .map_err(ProxyError::Io)?;
-                u32::from_le_bytes([ext[0], ext[1], ext[2], 0]) as usize
-            } else {
-                (first[0] & 0x7f) as usize
-            };
-
-            let len = len_words
-                .checked_mul(4)
-                .ok_or_else(|| ProxyError::Proxy("Abridged frame length overflow".into()))?;
-            (len, quickack)
-        }
-        ProtoTag::Intermediate | ProtoTag::Secure => {
-            let mut len_buf = [0u8; 4];
-            match client_reader.read_exact(&mut len_buf).await {
-                Ok(_) => {}
-                Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
-                Err(e) => return Err(ProxyError::Io(e)),
+            ProtoTag::Intermediate | ProtoTag::Secure => {
+                let mut len_buf = [0u8; 4];
+                match client_reader.read_exact(&mut len_buf).await {
+                    Ok(_) => {}
+                    Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
+                    Err(e) => return Err(ProxyError::Io(e)),
+                }
+                let quickack = (len_buf[3] & 0x80) != 0;
+                (
+                    (u32::from_le_bytes(len_buf) & 0x7fff_ffff) as usize,
+                    quickack,
+                    Some(len_buf),
+                )
             }
-            let quickack = (len_buf[3] & 0x80) != 0;
-            ((u32::from_le_bytes(len_buf) & 0x7fff_ffff) as usize, quickack)
+        };
+
+        if len == 0 {
+            continue;
         }
-    };
-
-    if len > 16 * 1024 * 1024 {
-        return Err(ProxyError::Proxy(format!("Frame too large: {len}")));
-    }
-
-    let mut payload = vec![0u8; len];
-    client_reader
-        .read_exact(&mut payload)
-        .await
-        .map_err(ProxyError::Io)?;
-
-    // Secure Intermediate: remove random padding (last len%4 bytes)
-    if proto_tag == ProtoTag::Secure {
-        let rem = len % 4;
-        if rem != 0 && payload.len() >= rem {
-            payload.truncate(len - rem);
+        if len < 4 && proto_tag != ProtoTag::Abridged {
+            warn!(
+                trace_id = format_args!("0x{:016x}", forensics.trace_id),
+                conn_id = forensics.conn_id,
+                user = %forensics.user,
+                len,
+                proto = ?proto_tag,
+                "Frame too small — corrupt or probe"
+            );
+            return Err(ProxyError::Proxy(format!("Frame too small: {len}")));
         }
+
+        if len > max_frame {
+            return Err(report_desync_frame_too_large(
+                forensics,
+                proto_tag,
+                *frame_counter,
+                max_frame,
+                len,
+                raw_len_bytes,
+                stats,
+            ));
+        }
+
+        let secure_payload_len = if proto_tag == ProtoTag::Secure {
+            match secure_payload_len_from_wire_len(len) {
+                Some(payload_len) => payload_len,
+                None => {
+                    stats.increment_secure_padding_invalid();
+                    return Err(ProxyError::Proxy(format!(
+                        "Invalid secure frame length: {len}"
+                    )));
+                }
+            }
+        } else {
+            len
+        };
+
+        let mut payload = vec![0u8; len];
+        client_reader
+            .read_exact(&mut payload)
+            .await
+            .map_err(ProxyError::Io)?;
+
+        // Secure Intermediate: strip validated trailing padding bytes.
+        if proto_tag == ProtoTag::Secure {
+            payload.truncate(secure_payload_len);
+        }
+        *frame_counter += 1;
+        return Ok(Some((payload, quickack)));
     }
-    Ok(Some((payload, quickack)))
 }
 
 async fn write_client_payload<W>(
@@ -188,6 +540,7 @@ async fn write_client_payload<W>(
     flags: u32,
     data: &[u8],
     rng: &SecureRandom,
+    frame_buf: &mut Vec<u8>,
 ) -> Result<()>
 where
     W: AsyncWrite + Unpin + Send + 'static,
@@ -196,7 +549,7 @@ where
 
     match proto_tag {
         ProtoTag::Abridged => {
-            if data.len() % 4 != 0 {
+            if !data.len().is_multiple_of(4) {
                 return Err(ProxyError::Proxy(format!(
                     "Abridged payload must be 4-byte aligned, got {}",
                     data.len()
@@ -209,8 +562,12 @@ where
                 if quickack {
                     first |= 0x80;
                 }
+                frame_buf.clear();
+                frame_buf.reserve(1 + data.len());
+                frame_buf.push(first);
+                frame_buf.extend_from_slice(data);
                 client_writer
-                    .write_all(&[first])
+                    .write_all(frame_buf)
                     .await
                     .map_err(ProxyError::Io)?;
             } else if len_words < (1 << 24) {
@@ -219,8 +576,12 @@ where
                     first |= 0x80;
                 }
                 let lw = (len_words as u32).to_le_bytes();
+                frame_buf.clear();
+                frame_buf.reserve(4 + data.len());
+                frame_buf.extend_from_slice(&[first, lw[0], lw[1], lw[2]]);
+                frame_buf.extend_from_slice(data);
                 client_writer
-                    .write_all(&[first, lw[0], lw[1], lw[2]])
+                    .write_all(frame_buf)
                     .await
                     .map_err(ProxyError::Io)?;
             } else {
@@ -229,47 +590,40 @@ where
                     data.len()
                 )));
             }
-
-            client_writer
-                .write_all(data)
-                .await
-                .map_err(ProxyError::Io)?;
         }
         ProtoTag::Intermediate | ProtoTag::Secure => {
             let padding_len = if proto_tag == ProtoTag::Secure {
-                (rng.bytes(1)[0] % 4) as usize
+                if !is_valid_secure_payload_len(data.len()) {
+                    return Err(ProxyError::Proxy(format!(
+                        "Secure payload must be 4-byte aligned, got {}",
+                        data.len()
+                    )));
+                }
+                secure_padding_len(data.len(), rng)
             } else {
                 0
             };
-            let mut len = (data.len() + padding_len) as u32;
+            let mut len_val = (data.len() + padding_len) as u32;
             if quickack {
-                len |= 0x8000_0000;
+                len_val |= 0x8000_0000;
             }
-            client_writer
-                .write_all(&len.to_le_bytes())
-                .await
-                .map_err(ProxyError::Io)?;
-            client_writer
-                .write_all(data)
-                .await
-                .map_err(ProxyError::Io)?;
+            let total = 4 + data.len() + padding_len;
+            frame_buf.clear();
+            frame_buf.reserve(total);
+            frame_buf.extend_from_slice(&len_val.to_le_bytes());
+            frame_buf.extend_from_slice(data);
             if padding_len > 0 {
-                let pad = rng.bytes(padding_len);
-                client_writer
-                    .write_all(&pad)
-                    .await
-                    .map_err(ProxyError::Io)?;
+                let start = frame_buf.len();
+                frame_buf.resize(start + padding_len, 0);
+                rng.fill(&mut frame_buf[start..]);
             }
+            client_writer
+                .write_all(frame_buf)
+                .await
+                .map_err(ProxyError::Io)?;
         }
     }
 
-    // Avoid unconditional per-frame flush (throughput killer on large downloads).
-    // Flush only when low-latency ack semantics are requested or when
-    // CryptoWriter has buffered pending ciphertext that must be drained.
-    if quickack || client_writer.has_pending() {
-        client_writer.flush().await.map_err(ProxyError::Io)?;
-    }
-
     Ok(())
 }
 

src/proxy/mod.rs

@@ -8,6 +8,9 @@ pub mod middle_relay;
 pub mod relay;
 
 pub use client::ClientHandler;
+#[allow(unused_imports)]
 pub use handshake::*;
+#[allow(unused_imports)]
 pub use masking::*;
+#[allow(unused_imports)]
 pub use relay::*;

src/stats/mod.rs

@@ -1,7 +1,8 @@
 //! Statistics and replay protection
 
+#![allow(dead_code)]
+
 use std::sync::atomic::{AtomicU64, Ordering};
-use std::sync::Arc;
 use std::time::{Instant, Duration};
 use dashmap::DashMap;
 use parking_lot::Mutex;
@@ -21,8 +22,27 @@ pub struct Stats {
     handshake_timeouts: AtomicU64,
     me_keepalive_sent: AtomicU64,
     me_keepalive_failed: AtomicU64,
+    me_keepalive_pong: AtomicU64,
+    me_keepalive_timeout: AtomicU64,
     me_reconnect_attempts: AtomicU64,
     me_reconnect_success: AtomicU64,
+    me_crc_mismatch: AtomicU64,
+    me_seq_mismatch: AtomicU64,
+    me_route_drop_no_conn: AtomicU64,
+    me_route_drop_channel_closed: AtomicU64,
+    me_route_drop_queue_full: AtomicU64,
+    secure_padding_invalid: AtomicU64,
+    desync_total: AtomicU64,
+    desync_full_logged: AtomicU64,
+    desync_suppressed: AtomicU64,
+    desync_frames_bucket_0: AtomicU64,
+    desync_frames_bucket_1_2: AtomicU64,
+    desync_frames_bucket_3_10: AtomicU64,
+    desync_frames_bucket_gt_10: AtomicU64,
+    pool_swap_total: AtomicU64,
+    pool_drain_active: AtomicU64,
+    pool_force_close_total: AtomicU64,
+    pool_stale_pick_total: AtomicU64,
     user_stats: DashMap<String, UserStats>,
     start_time: parking_lot::RwLock<Option<Instant>>,
 }
@@ -49,14 +69,132 @@ impl Stats {
     pub fn increment_handshake_timeouts(&self) { self.handshake_timeouts.fetch_add(1, Ordering::Relaxed); }
     pub fn increment_me_keepalive_sent(&self) { self.me_keepalive_sent.fetch_add(1, Ordering::Relaxed); }
     pub fn increment_me_keepalive_failed(&self) { self.me_keepalive_failed.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_keepalive_pong(&self) { self.me_keepalive_pong.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_keepalive_timeout(&self) { self.me_keepalive_timeout.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_keepalive_timeout_by(&self, value: u64) {
+        self.me_keepalive_timeout.fetch_add(value, Ordering::Relaxed);
+    }
     pub fn increment_me_reconnect_attempt(&self) { self.me_reconnect_attempts.fetch_add(1, Ordering::Relaxed); }
     pub fn increment_me_reconnect_success(&self) { self.me_reconnect_success.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_crc_mismatch(&self) { self.me_crc_mismatch.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_seq_mismatch(&self) { self.me_seq_mismatch.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_route_drop_no_conn(&self) { self.me_route_drop_no_conn.fetch_add(1, Ordering::Relaxed); }
+    pub fn increment_me_route_drop_channel_closed(&self) {
+        self.me_route_drop_channel_closed.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_me_route_drop_queue_full(&self) {
+        self.me_route_drop_queue_full.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_secure_padding_invalid(&self) {
+        self.secure_padding_invalid.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_desync_total(&self) {
+        self.desync_total.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_desync_full_logged(&self) {
+        self.desync_full_logged.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_desync_suppressed(&self) {
+        self.desync_suppressed.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn observe_desync_frames_ok(&self, frames_ok: u64) {
+        match frames_ok {
+            0 => {
+                self.desync_frames_bucket_0.fetch_add(1, Ordering::Relaxed);
+            }
+            1..=2 => {
+                self.desync_frames_bucket_1_2.fetch_add(1, Ordering::Relaxed);
+            }
+            3..=10 => {
+                self.desync_frames_bucket_3_10.fetch_add(1, Ordering::Relaxed);
+            }
+            _ => {
+                self.desync_frames_bucket_gt_10.fetch_add(1, Ordering::Relaxed);
+            }
+        }
+    }
+    pub fn increment_pool_swap_total(&self) {
+        self.pool_swap_total.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_pool_drain_active(&self) {
+        self.pool_drain_active.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn decrement_pool_drain_active(&self) {
+        let mut current = self.pool_drain_active.load(Ordering::Relaxed);
+        loop {
+            if current == 0 {
+                break;
+            }
+            match self.pool_drain_active.compare_exchange_weak(
+                current,
+                current - 1,
+                Ordering::Relaxed,
+                Ordering::Relaxed,
+            ) {
+                Ok(_) => break,
+                Err(actual) => current = actual,
+            }
+        }
+    }
+    pub fn increment_pool_force_close_total(&self) {
+        self.pool_force_close_total.fetch_add(1, Ordering::Relaxed);
+    }
+    pub fn increment_pool_stale_pick_total(&self) {
+        self.pool_stale_pick_total.fetch_add(1, Ordering::Relaxed);
+    }
     pub fn get_connects_all(&self) -> u64 { self.connects_all.load(Ordering::Relaxed) }
     pub fn get_connects_bad(&self) -> u64 { self.connects_bad.load(Ordering::Relaxed) }
     pub fn get_me_keepalive_sent(&self) -> u64 { self.me_keepalive_sent.load(Ordering::Relaxed) }
     pub fn get_me_keepalive_failed(&self) -> u64 { self.me_keepalive_failed.load(Ordering::Relaxed) }
+    pub fn get_me_keepalive_pong(&self) -> u64 { self.me_keepalive_pong.load(Ordering::Relaxed) }
+    pub fn get_me_keepalive_timeout(&self) -> u64 { self.me_keepalive_timeout.load(Ordering::Relaxed) }
     pub fn get_me_reconnect_attempts(&self) -> u64 { self.me_reconnect_attempts.load(Ordering::Relaxed) }
     pub fn get_me_reconnect_success(&self) -> u64 { self.me_reconnect_success.load(Ordering::Relaxed) }
+    pub fn get_me_crc_mismatch(&self) -> u64 { self.me_crc_mismatch.load(Ordering::Relaxed) }
+    pub fn get_me_seq_mismatch(&self) -> u64 { self.me_seq_mismatch.load(Ordering::Relaxed) }
+    pub fn get_me_route_drop_no_conn(&self) -> u64 { self.me_route_drop_no_conn.load(Ordering::Relaxed) }
+    pub fn get_me_route_drop_channel_closed(&self) -> u64 {
+        self.me_route_drop_channel_closed.load(Ordering::Relaxed)
+    }
+    pub fn get_me_route_drop_queue_full(&self) -> u64 {
+        self.me_route_drop_queue_full.load(Ordering::Relaxed)
+    }
+    pub fn get_secure_padding_invalid(&self) -> u64 {
+        self.secure_padding_invalid.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_total(&self) -> u64 {
+        self.desync_total.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_full_logged(&self) -> u64 {
+        self.desync_full_logged.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_suppressed(&self) -> u64 {
+        self.desync_suppressed.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_frames_bucket_0(&self) -> u64 {
+        self.desync_frames_bucket_0.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_frames_bucket_1_2(&self) -> u64 {
+        self.desync_frames_bucket_1_2.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_frames_bucket_3_10(&self) -> u64 {
+        self.desync_frames_bucket_3_10.load(Ordering::Relaxed)
+    }
+    pub fn get_desync_frames_bucket_gt_10(&self) -> u64 {
+        self.desync_frames_bucket_gt_10.load(Ordering::Relaxed)
+    }
+    pub fn get_pool_swap_total(&self) -> u64 {
+        self.pool_swap_total.load(Ordering::Relaxed)
+    }
+    pub fn get_pool_drain_active(&self) -> u64 {
+        self.pool_drain_active.load(Ordering::Relaxed)
+    }
+    pub fn get_pool_force_close_total(&self) -> u64 {
+        self.pool_force_close_total.load(Ordering::Relaxed)
+    }
+    pub fn get_pool_stale_pick_total(&self) -> u64 {
+        self.pool_stale_pick_total.load(Ordering::Relaxed)
+    }
     
     pub fn increment_user_connects(&self, user: &str) {
         self.user_stats.entry(user.to_string()).or_default()
@@ -70,7 +208,22 @@ impl Stats {
     
     pub fn decrement_user_curr_connects(&self, user: &str) {
         if let Some(stats) = self.user_stats.get(user) {
-            stats.curr_connects.fetch_sub(1, Ordering::Relaxed);
+            let counter = &stats.curr_connects;
+            let mut current = counter.load(Ordering::Relaxed);
+            loop {
+                if current == 0 {
+                    break;
+                }
+                match counter.compare_exchange_weak(
+                    current,
+                    current - 1,
+                    Ordering::Relaxed,
+                    Ordering::Relaxed,
+                ) {
+                    Ok(_) => break,
+                    Err(actual) => current = actual,
+                }
+            }
         }
     }
     
@@ -173,10 +326,10 @@ impl ReplayShard {
             
             // Use key.as_ref() to get &[u8] — avoids Borrow<Q> ambiguity
             // between Borrow<[u8]> and Borrow<Box<[u8]>>
-            if let Some(entry) = self.cache.peek(key.as_ref()) {
-                if entry.seq == queue_seq {
-                    self.cache.pop(key.as_ref());
-                }
+            if let Some(entry) = self.cache.peek(key.as_ref())
+                && entry.seq == queue_seq
+            {
+                self.cache.pop(key.as_ref());
             }
         }
     }
@@ -344,6 +497,7 @@ impl ReplayStats {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::sync::Arc;
     
     #[test]
     fn test_stats_shared_counters() {

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};

src/stream/crypto_stream.rs

@@ -18,6 +18,8 @@
 //!   is either written to upstream or stored in our pending buffer
 //! - when upstream is pending -> ciphertext is buffered/bounded and backpressure is applied
 //!
+
+#![allow(dead_code)]
 //! =======================
 //! Writer state machine
 //! =======================
@@ -34,7 +36,7 @@
 //! └────────────────────────────────────────┘
 //!
 //! Backpressure
-//! - pending ciphertext buffer is bounded (MAX_PENDING_WRITE)
+//! - pending ciphertext buffer is bounded (configurable per connection)
 //! - pending is full and upstream is pending 
 //!   -> poll_write returns Poll::Pending
 //!   -> do not accept any plaintext
@@ -45,7 +47,7 @@
 //! - when upstream is Pending but pending still has room: accept `to_accept` bytes and
 //!   encrypt+append ciphertext directly into pending (in-place encryption of appended range)
 
-//! Encrypted stream wrappers using AES-CTR
+//!   Encrypted stream wrappers using AES-CTR
 //!
 //! This module provides stateful async stream wrappers that handle
 //! encryption/decryption with proper partial read/write handling.
@@ -55,17 +57,16 @@ use std::io::{self, ErrorKind, Result};
 use std::pin::Pin;
 use std::task::{Context, Poll};
 use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
-use tracing::{debug, trace, warn};
+use tracing::{debug, trace};
 
 use crate::crypto::AesCtr;
 use super::state::{StreamState, YieldBuffer};
 
 // ============= Constants =============
 
-/// Maximum size for pending ciphertext buffer (bounded backpressure).
-/// Reduced to 64KB to prevent bufferbloat on mobile networks.
-/// 512KB was causing high latency on 3G/LTE connections.
-const MAX_PENDING_WRITE: usize = 64 * 1024;
+/// Default size for pending ciphertext buffer (bounded backpressure).
+/// Actual limit is supplied at runtime from configuration.
+const DEFAULT_MAX_PENDING_WRITE: usize = 64 * 1024;
 
 /// Default read buffer capacity (reader mostly decrypts in-place into caller buffer).
 const DEFAULT_READ_CAPACITY: usize = 16 * 1024;
@@ -152,9 +153,9 @@ impl<R> CryptoReader<R> {
     fn take_poison_error(&mut self) -> io::Error {
         match &mut self.state {
             CryptoReaderState::Poisoned { error } => error.take().unwrap_or_else(|| {
-                io::Error::new(ErrorKind::Other, "stream previously poisoned")
+                io::Error::other("stream previously poisoned")
             }),
-            _ => io::Error::new(ErrorKind::Other, "stream not poisoned"),
+            _ => io::Error::other("stream not poisoned"),
         }
     }
 }
@@ -167,6 +168,7 @@ impl<R: AsyncRead + Unpin> AsyncRead for CryptoReader<R> {
     ) -> Poll<Result<()>> {
         let this = self.get_mut();
 
+        #[allow(clippy::never_loop)]
         loop {
             match &mut this.state {
                 CryptoReaderState::Poisoned { .. } => {
@@ -427,15 +429,22 @@ pub struct CryptoWriter<W> {
     encryptor: AesCtr,
     state: CryptoWriterState,
     scratch: BytesMut,
+    max_pending_write: usize,
 }
 
 impl<W> CryptoWriter<W> {
-    pub fn new(upstream: W, encryptor: AesCtr) -> Self {
+    pub fn new(upstream: W, encryptor: AesCtr, max_pending_write: usize) -> Self {
+        let max_pending = if max_pending_write == 0 {
+            DEFAULT_MAX_PENDING_WRITE
+        } else {
+            max_pending_write
+        };
         Self {
             upstream,
             encryptor,
             state: CryptoWriterState::Idle,
             scratch: BytesMut::with_capacity(16 * 1024),
+            max_pending_write: max_pending.max(4 * 1024),
         }
     }
 
@@ -477,17 +486,17 @@ impl<W> CryptoWriter<W> {
     fn take_poison_error(&mut self) -> io::Error {
         match &mut self.state {
             CryptoWriterState::Poisoned { error } => error.take().unwrap_or_else(|| {
-                io::Error::new(ErrorKind::Other, "stream previously poisoned")
+                io::Error::other("stream previously poisoned")
             }),
-            _ => io::Error::new(ErrorKind::Other, "stream not poisoned"),
+            _ => io::Error::other("stream not poisoned"),
         }
     }
 
     /// Ensure we are in Flushing state and return mutable pending buffer.
-    fn ensure_pending<'a>(state: &'a mut CryptoWriterState) -> &'a mut PendingCiphertext {
+    fn ensure_pending(state: &mut CryptoWriterState, max_pending: usize) -> &mut PendingCiphertext {
         if matches!(state, CryptoWriterState::Idle) {
             *state = CryptoWriterState::Flushing {
-                pending: PendingCiphertext::new(MAX_PENDING_WRITE),
+                pending: PendingCiphertext::new(max_pending),
             };
         }
 
@@ -498,14 +507,14 @@ impl<W> CryptoWriter<W> {
     }
 
     /// Select how many plaintext bytes can be accepted in buffering path
-    fn select_to_accept_for_buffering(state: &CryptoWriterState, buf_len: usize) -> usize {
+    fn select_to_accept_for_buffering(state: &CryptoWriterState, buf_len: usize, max_pending: usize) -> usize {
         if buf_len == 0 {
             return 0;
         }
 
         match state {
             CryptoWriterState::Flushing { pending } => buf_len.min(pending.remaining_capacity()),
-            CryptoWriterState::Idle => buf_len.min(MAX_PENDING_WRITE),
+            CryptoWriterState::Idle => buf_len.min(max_pending),
             CryptoWriterState::Poisoned { .. } => 0,
         }
     }
@@ -603,7 +612,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for CryptoWriter<W> {
                 Poll::Pending => {
                     // Upstream blocked. Apply ideal backpressure
                     let to_accept =
-                        Self::select_to_accept_for_buffering(&this.state, buf.len());
+                        Self::select_to_accept_for_buffering(&this.state, buf.len(), this.max_pending_write);
 
                     if to_accept == 0 {
                         trace!(
@@ -618,7 +627,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for CryptoWriter<W> {
 
                     // Disjoint borrows
                     let encryptor = &mut this.encryptor;
-                    let pending = Self::ensure_pending(&mut this.state);
+                    let pending = Self::ensure_pending(&mut this.state, this.max_pending_write);
 
                     if let Err(e) = pending.push_encrypted(encryptor, plaintext) {
                         if e.kind() == ErrorKind::WouldBlock {
@@ -635,7 +644,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for CryptoWriter<W> {
         // 2) Fast path: pending empty -> write-through
         debug_assert!(matches!(this.state, CryptoWriterState::Idle));
 
-        let to_accept = buf.len().min(MAX_PENDING_WRITE);
+        let to_accept = buf.len().min(this.max_pending_write);
         let plaintext = &buf[..to_accept];
 
         Self::encrypt_into_scratch(&mut this.encryptor, &mut this.scratch, plaintext);
@@ -645,7 +654,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for CryptoWriter<W> {
                 // Upstream blocked: buffer FULL ciphertext for accepted bytes.
                 let ciphertext = std::mem::take(&mut this.scratch);
 
-                let pending = Self::ensure_pending(&mut this.state);
+                let pending = Self::ensure_pending(&mut this.state, this.max_pending_write);
                 pending.replace_with(ciphertext);
 
                 Poll::Ready(Ok(to_accept))
@@ -672,7 +681,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for CryptoWriter<W> {
                 let remainder = this.scratch.split_off(n);
                 this.scratch.clear();
 
-                let pending = Self::ensure_pending(&mut this.state);
+                let pending = Self::ensure_pending(&mut this.state, this.max_pending_write);
                 pending.replace_with(remainder);
 
                 Poll::Ready(Ok(to_accept))
@@ -767,4 +776,4 @@ impl<S: AsyncWrite + Unpin> AsyncWrite for PassthroughStream<S> {
     fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
         Pin::new(&mut self.inner).poll_shutdown(cx)
     }
-}
+}

src/stream/frame.rs

@@ -3,6 +3,8 @@
 //! 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;

src/stream/frame_codec.rs

@@ -3,12 +3,16 @@
 //! 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};
 
@@ -135,7 +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())
@@ -274,13 +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;
     
@@ -303,14 +307,15 @@ fn encode_secure(frame: &Frame, dst: &mut BytesMut, rng: &SecureRandom) -> io::R
         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
-        (rng.range(3) + 1) as usize
-    } else {
-        // Already non-aligned, can add 0-3
-        rng.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);
@@ -625,4 +630,4 @@ mod tests {
         let result = codec.decode(&mut buf);
         assert!(result.is_err());
     }
-}
+}

src/stream/frame_stream.rs

@@ -1,6 +1,8 @@
 //! 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::*;
@@ -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))
     }
@@ -267,8 +271,15 @@ impl<W: AsyncWrite + Unpin> SecureIntermediateFrameWriter<W> {
             return Ok(());
         }
         
-        // Add random padding (0-3 bytes)
-        let padding_len = self.rng.range(4);
+        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;
@@ -320,7 +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),
@@ -550,9 +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]
@@ -585,4 +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;
 

src/stream/tls_stream.rs

@@ -18,6 +18,8 @@
 //! - Explicit state machines for all async operations
 //! - Never lose data on partial reads
 //! - Atomic TLS record formation for writes
+
+#![allow(dead_code)]
 //! - Proper handling of all TLS record types
 //!
 //! Important nuance (Telegram FakeTLS):
@@ -25,7 +27,8 @@
 //! - However, the on-the-wire record length can exceed 16384 because TLS 1.3
 //!   uses AEAD and can include tag/overhead/padding.
 //! - Telegram FakeTLS clients (notably iOS) may send Application Data records
-//!   with length up to 16384 + 24 bytes. We accept that as MAX_TLS_CHUNK_SIZE.
+//!   with length up to 16384 + 256 bytes (RFC 8446 §5.2). We accept that as
+//!   MAX_TLS_CHUNK_SIZE.
 //!
 //! If you reject those (e.g. validate length <= 16384), you will see errors like:
 //!   "TLS record too large: 16408 bytes"
@@ -52,9 +55,8 @@ use super::state::{StreamState, HeaderBuffer, YieldBuffer, WriteBuffer};
 const TLS_HEADER_SIZE: usize = 5;
 
 /// Maximum TLS fragment size we emit for Application Data.
-/// Real TLS 1.3 ciphertexts often add ~16-24 bytes AEAD overhead, so to mimic
-/// on-the-wire record sizes we allow up to 16384 + 24 bytes of plaintext.
-const MAX_TLS_PAYLOAD: usize = 16384 + 24;
+/// Real TLS 1.3 allows up to 16384 + 256 bytes of ciphertext (incl. tag).
+const MAX_TLS_PAYLOAD: usize = 16384 + 256;
 
 /// Maximum pending write buffer for one record remainder.
 /// Note: we never queue unlimited amount of data here; state holds at most one record.
@@ -91,7 +93,7 @@ impl TlsRecordHeader {
     /// - We accept TLS 1.0 header version for ClientHello-like records (0x03 0x01),
     ///   and TLS 1.2/1.3 style version bytes for the rest (we use TLS_VERSION = 0x03 0x03).
     /// - For Application Data, Telegram FakeTLS may send payload length up to
-    ///   MAX_TLS_CHUNK_SIZE (16384 + 24).
+    ///   MAX_TLS_CHUNK_SIZE (16384 + 256).
     /// - For other record types we keep stricter bounds to avoid memory abuse.
     fn validate(&self) -> Result<()> {
         // Version: accept TLS 1.0 header (ClientHello quirk) and TLS_VERSION (0x0303).
@@ -105,7 +107,7 @@ impl TlsRecordHeader {
         let len = self.length as usize;
 
         // Length checks depend on record type.
-        // Telegram FakeTLS: ApplicationData length may be 16384 + 24.
+        // Telegram FakeTLS: ApplicationData length may be 16384 + 256.
         match self.record_type {
             TLS_RECORD_APPLICATION => {
                 if len > MAX_TLS_CHUNK_SIZE {
@@ -133,7 +135,7 @@ impl TlsRecordHeader {
     }
 
     /// Build header bytes
-    fn to_bytes(&self) -> [u8; 5] {
+    fn to_bytes(self) -> [u8; 5] {
         [
             self.record_type,
             self.version[0],
@@ -258,9 +260,9 @@ impl<R> FakeTlsReader<R> {
     fn take_poison_error(&mut self) -> io::Error {
         match &mut self.state {
             TlsReaderState::Poisoned { error } => error.take().unwrap_or_else(|| {
-                io::Error::new(ErrorKind::Other, "stream previously poisoned")
+                io::Error::other("stream previously poisoned")
             }),
-            _ => io::Error::new(ErrorKind::Other, "stream not poisoned"),
+            _ => io::Error::other("stream not poisoned"),
         }
     }
 }
@@ -295,7 +297,7 @@ impl<R: AsyncRead + Unpin> AsyncRead for FakeTlsReader<R> {
                 TlsReaderState::Poisoned { error } => {
                     this.state = TlsReaderState::Poisoned { error: None };
                     let err = error.unwrap_or_else(|| {
-                        io::Error::new(ErrorKind::Other, "stream previously poisoned")
+                        io::Error::other("stream previously poisoned")
                     });
                     return Poll::Ready(Err(err));
                 }
@@ -614,9 +616,9 @@ impl<W> FakeTlsWriter<W> {
     fn take_poison_error(&mut self) -> io::Error {
         match &mut self.state {
             TlsWriterState::Poisoned { error } => error.take().unwrap_or_else(|| {
-                io::Error::new(ErrorKind::Other, "stream previously poisoned")
+                io::Error::other("stream previously poisoned")
             }),
-            _ => io::Error::new(ErrorKind::Other, "stream not poisoned"),
+            _ => io::Error::other("stream not poisoned"),
         }
     }
 
@@ -680,7 +682,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for FakeTlsWriter<W> {
             TlsWriterState::Poisoned { error } => {
                 this.state = TlsWriterState::Poisoned { error: None };
                 let err = error.unwrap_or_else(|| {
-                    Error::new(ErrorKind::Other, "stream previously poisoned")
+                    Error::other("stream previously poisoned")
                 });
                 return Poll::Ready(Err(err));
             }
@@ -755,9 +757,6 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for FakeTlsWriter<W> {
                     payload_size: chunk_size,
                 };
 
-                // Wake to retry flushing soon.
-                cx.waker().wake_by_ref();
-
                 Poll::Ready(Ok(chunk_size))
             }
         }
@@ -772,7 +771,7 @@ impl<W: AsyncWrite + Unpin> AsyncWrite for FakeTlsWriter<W> {
             TlsWriterState::Poisoned { error } => {
                 this.state = TlsWriterState::Poisoned { error: None };
                 let err = error.unwrap_or_else(|| {
-                    Error::new(ErrorKind::Other, "stream previously poisoned")
+                    Error::other("stream previously poisoned")
                 });
                 return Poll::Ready(Err(err));
             }

src/stream/traits.rs

@@ -1,5 +1,7 @@
 //! Stream traits and common types
 
+#![allow(dead_code)]
+
 use bytes::Bytes;
 use std::io::Result;
 use std::pin::Pin;

src/tls_front/cache.rs

@@ -1,7 +1,8 @@
 use std::collections::HashMap;
+use std::net::IpAddr;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
-use std::time::{SystemTime, Duration};
+use std::time::{Duration, Instant, SystemTime};
 
 use tokio::sync::RwLock;
 use tokio::time::sleep;
@@ -14,9 +15,11 @@ use crate::tls_front::types::{CachedTlsData, ParsedServerHello, TlsFetchResult};
 pub struct TlsFrontCache {
     memory: RwLock<HashMap<String, Arc<CachedTlsData>>>,
     default: Arc<CachedTlsData>,
+    full_cert_sent: RwLock<HashMap<IpAddr, Instant>>,
     disk_path: PathBuf,
 }
 
+#[allow(dead_code)]
 impl TlsFrontCache {
     pub fn new(domains: &[String], default_len: usize, disk_path: impl AsRef<Path>) -> Self {
         let default_template = ParsedServerHello {
@@ -31,6 +34,7 @@ impl TlsFrontCache {
         let default = Arc::new(CachedTlsData {
             server_hello_template: default_template,
             cert_info: None,
+            cert_payload: None,
             app_data_records_sizes: vec![default_len],
             total_app_data_len: default_len,
             fetched_at: SystemTime::now(),
@@ -45,6 +49,7 @@ impl TlsFrontCache {
         Self {
             memory: RwLock::new(map),
             default,
+            full_cert_sent: RwLock::new(HashMap::new()),
             disk_path: disk_path.as_ref().to_path_buf(),
         }
     }
@@ -54,6 +59,45 @@ impl TlsFrontCache {
         guard.get(sni).cloned().unwrap_or_else(|| self.default.clone())
     }
 
+    pub async fn contains_domain(&self, domain: &str) -> bool {
+        self.memory.read().await.contains_key(domain)
+    }
+
+    /// Returns true when full cert payload should be sent for client_ip
+    /// according to TTL policy.
+    pub async fn take_full_cert_budget_for_ip(
+        &self,
+        client_ip: IpAddr,
+        ttl: Duration,
+    ) -> bool {
+        if ttl.is_zero() {
+            self.full_cert_sent
+                .write()
+                .await
+                .insert(client_ip, Instant::now());
+            return true;
+        }
+
+        let now = Instant::now();
+        let mut guard = self.full_cert_sent.write().await;
+        guard.retain(|_, seen_at| now.duration_since(*seen_at) < ttl);
+
+        match guard.get_mut(&client_ip) {
+            Some(seen_at) => {
+                if now.duration_since(*seen_at) >= ttl {
+                    *seen_at = now;
+                    true
+                } else {
+                    false
+                }
+            }
+            None => {
+                guard.insert(client_ip, now);
+                true
+            }
+        }
+    }
+
     pub async fn set(&self, domain: &str, data: CachedTlsData) {
         let mut guard = self.memory.write().await;
         guard.insert(domain.to_string(), Arc::new(data));
@@ -71,12 +115,32 @@ impl TlsFrontCache {
                     if !name.ends_with(".json") {
                         continue;
                     }
-                    if let Ok(data) = tokio::fs::read(entry.path()).await {
-                        if let Ok(cached) = serde_json::from_slice::<CachedTlsData>(&data) {
-                            let domain = cached.domain.clone();
-                            self.set(&domain, cached).await;
-                            loaded += 1;
+                    if let Ok(data) = tokio::fs::read(entry.path()).await
+                        && let Ok(mut cached) = serde_json::from_slice::<CachedTlsData>(&data)
+                    {
+                        if cached.domain.is_empty()
+                            || cached.domain.len() > 255
+                            || !cached.domain.chars().all(|c| c.is_ascii_alphanumeric() || c == '.' || c == '-')
+                        {
+                            warn!(file = %name, "Skipping TLS cache entry with invalid domain");
+                            continue;
                         }
+                        // fetched_at is skipped during deserialization; approximate with file mtime if available.
+                        if let Ok(meta) = entry.metadata().await
+                            && let Ok(modified) = meta.modified()
+                        {
+                            cached.fetched_at = modified;
+                        }
+                        // Drop entries older than 72h
+                        if let Ok(age) = cached.fetched_at.elapsed()
+                            && age > Duration::from_secs(72 * 3600)
+                        {
+                            warn!(domain = %cached.domain, "Skipping stale TLS cache entry (>72h)");
+                            continue;
+                        }
+                        let domain = cached.domain.clone();
+                        self.set(&domain, cached).await;
+                        loaded += 1;
                     }
                 }
             }
@@ -110,7 +174,7 @@ impl TlsFrontCache {
         tokio::spawn(async move {
             loop {
                 for domain in &domains {
-                    fetcher(domain.clone()).await;
+                    let _ = fetcher(domain.clone()).await;
                 }
                 sleep(interval).await;
             }
@@ -122,6 +186,7 @@ impl TlsFrontCache {
         let data = CachedTlsData {
             server_hello_template: fetched.server_hello_parsed,
             cert_info: fetched.cert_info,
+            cert_payload: fetched.cert_payload,
             app_data_records_sizes: fetched.app_data_records_sizes.clone(),
             total_app_data_len: fetched.total_app_data_len,
             fetched_at: SystemTime::now(),
@@ -141,3 +206,50 @@ impl TlsFrontCache {
         &self.disk_path
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn test_take_full_cert_budget_for_ip_uses_ttl() {
+        let cache = TlsFrontCache::new(
+            &["example.com".to_string()],
+            1024,
+            "tlsfront-test-cache",
+        );
+        let ip: IpAddr = "127.0.0.1".parse().expect("ip");
+        let ttl = Duration::from_millis(80);
+
+        assert!(cache
+            .take_full_cert_budget_for_ip(ip, ttl)
+            .await);
+        assert!(!cache
+            .take_full_cert_budget_for_ip(ip, ttl)
+            .await);
+
+        tokio::time::sleep(Duration::from_millis(90)).await;
+
+        assert!(cache
+            .take_full_cert_budget_for_ip(ip, ttl)
+            .await);
+    }
+
+    #[tokio::test]
+    async fn test_take_full_cert_budget_for_ip_zero_ttl_always_allows_full_payload() {
+        let cache = TlsFrontCache::new(
+            &["example.com".to_string()],
+            1024,
+            "tlsfront-test-cache",
+        );
+        let ip: IpAddr = "127.0.0.1".parse().expect("ip");
+        let ttl = Duration::ZERO;
+
+        assert!(cache
+            .take_full_cert_budget_for_ip(ip, ttl)
+            .await);
+        assert!(cache
+            .take_full_cert_budget_for_ip(ip, ttl)
+            .await);
+    }
+}

src/tls_front/emulator.rs

@@ -3,7 +3,7 @@ use crate::protocol::constants::{
     TLS_RECORD_APPLICATION, TLS_RECORD_CHANGE_CIPHER, TLS_RECORD_HANDSHAKE, TLS_VERSION,
 };
 use crate::protocol::tls::{TLS_DIGEST_LEN, TLS_DIGEST_POS, gen_fake_x25519_key};
-use crate::tls_front::types::CachedTlsData;
+use crate::tls_front::types::{CachedTlsData, ParsedCertificateInfo};
 
 const MIN_APP_DATA: usize = 64;
 const MAX_APP_DATA: usize = 16640; // RFC 8446 §5.2 allows up to 2^14 + 256
@@ -12,7 +12,7 @@ fn jitter_and_clamp_sizes(sizes: &[usize], rng: &SecureRandom) -> Vec<usize> {
     sizes
         .iter()
         .map(|&size| {
-            let base = size.max(MIN_APP_DATA).min(MAX_APP_DATA);
+            let base = size.clamp(MIN_APP_DATA, MAX_APP_DATA);
             let jitter_range = ((base as f64) * 0.03).round() as i64;
             if jitter_range == 0 {
                 return base;
@@ -27,13 +27,84 @@ fn jitter_and_clamp_sizes(sizes: &[usize], rng: &SecureRandom) -> Vec<usize> {
         .collect()
 }
 
+fn app_data_body_capacity(sizes: &[usize]) -> usize {
+    sizes.iter().map(|&size| size.saturating_sub(17)).sum()
+}
+
+fn ensure_payload_capacity(mut sizes: Vec<usize>, payload_len: usize) -> Vec<usize> {
+    if payload_len == 0 {
+        return sizes;
+    }
+
+    let mut body_total = app_data_body_capacity(&sizes);
+    if body_total >= payload_len {
+        return sizes;
+    }
+
+    if let Some(last) = sizes.last_mut() {
+        let free = MAX_APP_DATA.saturating_sub(*last);
+        let grow = free.min(payload_len - body_total);
+        *last += grow;
+        body_total += grow;
+    }
+
+    while body_total < payload_len {
+        let remaining = payload_len - body_total;
+        let chunk = (remaining + 17).clamp(MIN_APP_DATA, MAX_APP_DATA);
+        sizes.push(chunk);
+        body_total += chunk.saturating_sub(17);
+    }
+
+    sizes
+}
+
+fn build_compact_cert_info_payload(cert_info: &ParsedCertificateInfo) -> Option<Vec<u8>> {
+    let mut fields = Vec::new();
+
+    if let Some(subject) = cert_info.subject_cn.as_deref() {
+        fields.push(format!("CN={subject}"));
+    }
+    if let Some(issuer) = cert_info.issuer_cn.as_deref() {
+        fields.push(format!("ISSUER={issuer}"));
+    }
+    if let Some(not_before) = cert_info.not_before_unix {
+        fields.push(format!("NB={not_before}"));
+    }
+    if let Some(not_after) = cert_info.not_after_unix {
+        fields.push(format!("NA={not_after}"));
+    }
+    if !cert_info.san_names.is_empty() {
+        let san = cert_info
+            .san_names
+            .iter()
+            .take(8)
+            .map(String::as_str)
+            .collect::<Vec<_>>()
+            .join(",");
+        fields.push(format!("SAN={san}"));
+    }
+
+    if fields.is_empty() {
+        return None;
+    }
+
+    let mut payload = fields.join(";").into_bytes();
+    if payload.len() > 512 {
+        payload.truncate(512);
+    }
+    Some(payload)
+}
+
 /// Build a ServerHello + CCS + ApplicationData sequence using cached TLS metadata.
 pub fn build_emulated_server_hello(
     secret: &[u8],
     client_digest: &[u8; TLS_DIGEST_LEN],
     session_id: &[u8],
     cached: &CachedTlsData,
+    use_full_cert_payload: bool,
     rng: &SecureRandom,
+    alpn: Option<Vec<u8>>,
+    new_session_tickets: u8,
 ) -> Vec<u8> {
     // --- ServerHello ---
     let mut extensions = Vec::new();
@@ -48,6 +119,15 @@ pub fn build_emulated_server_hello(
     extensions.extend_from_slice(&0x002bu16.to_be_bytes());
     extensions.extend_from_slice(&(2u16).to_be_bytes());
     extensions.extend_from_slice(&0x0304u16.to_be_bytes());
+    if let Some(alpn_proto) = &alpn {
+        extensions.extend_from_slice(&0x0010u16.to_be_bytes());
+        let list_len: u16 = 1 + alpn_proto.len() as u16;
+        let ext_len: u16 = 2 + list_len;
+        extensions.extend_from_slice(&ext_len.to_be_bytes());
+        extensions.extend_from_slice(&list_len.to_be_bytes());
+        extensions.push(alpn_proto.len() as u8);
+        extensions.extend_from_slice(alpn_proto);
+    }
 
     let extensions_len = extensions.len() as u16;
 
@@ -98,15 +178,52 @@ pub fn build_emulated_server_hello(
     if sizes.is_empty() {
         sizes.push(cached.total_app_data_len.max(1024));
     }
-    let sizes = jitter_and_clamp_sizes(&sizes, rng);
+    let mut sizes = jitter_and_clamp_sizes(&sizes, rng);
+    let compact_payload = cached
+        .cert_info
+        .as_ref()
+        .and_then(build_compact_cert_info_payload);
+    let selected_payload: Option<&[u8]> = if use_full_cert_payload {
+        cached
+            .cert_payload
+            .as_ref()
+            .map(|payload| payload.certificate_message.as_slice())
+            .filter(|payload| !payload.is_empty())
+            .or(compact_payload.as_deref())
+    } else {
+        compact_payload.as_deref()
+    };
+
+    if let Some(payload) = selected_payload {
+        sizes = ensure_payload_capacity(sizes, payload.len());
+    }
 
     let mut app_data = Vec::new();
+    let mut payload_offset = 0usize;
     for size in sizes {
         let mut rec = Vec::with_capacity(5 + size);
         rec.push(TLS_RECORD_APPLICATION);
         rec.extend_from_slice(&TLS_VERSION);
         rec.extend_from_slice(&(size as u16).to_be_bytes());
-        if size > 17 {
+
+        if let Some(payload) = selected_payload {
+            if size > 17 {
+                let body_len = size - 17;
+                let remaining = payload.len().saturating_sub(payload_offset);
+                let copy_len = remaining.min(body_len);
+                if copy_len > 0 {
+                    rec.extend_from_slice(&payload[payload_offset..payload_offset + copy_len]);
+                    payload_offset += copy_len;
+                }
+                if body_len > copy_len {
+                    rec.extend_from_slice(&rng.bytes(body_len - copy_len));
+                }
+                rec.push(0x16); // inner content type marker (handshake)
+                rec.extend_from_slice(&rng.bytes(16)); // AEAD-like tag
+            } else {
+                rec.extend_from_slice(&rng.bytes(size));
+            }
+        } else if size > 17 {
             let body_len = size - 17;
             rec.extend_from_slice(&rng.bytes(body_len));
             rec.push(0x16); // inner content type marker (handshake)
@@ -118,10 +235,25 @@ pub fn build_emulated_server_hello(
     }
 
     // --- Combine ---
-    let mut response = Vec::with_capacity(server_hello.len() + change_cipher_spec.len() + app_data.len());
+    // Optional NewSessionTicket mimic records (opaque ApplicationData for fingerprint).
+    let mut tickets = Vec::new();
+    if new_session_tickets > 0 {
+        for _ in 0..new_session_tickets {
+            let ticket_len: usize = rng.range(48) + 48;
+            let mut rec = Vec::with_capacity(5 + ticket_len);
+            rec.push(TLS_RECORD_APPLICATION);
+            rec.extend_from_slice(&TLS_VERSION);
+            rec.extend_from_slice(&(ticket_len as u16).to_be_bytes());
+            rec.extend_from_slice(&rng.bytes(ticket_len));
+            tickets.extend_from_slice(&rec);
+        }
+    }
+
+    let mut response = Vec::with_capacity(server_hello.len() + change_cipher_spec.len() + app_data.len() + tickets.len());
     response.extend_from_slice(&server_hello);
     response.extend_from_slice(&change_cipher_spec);
     response.extend_from_slice(&app_data);
+    response.extend_from_slice(&tickets);
 
     // --- HMAC ---
     let mut hmac_input = Vec::with_capacity(TLS_DIGEST_LEN + response.len());
@@ -132,3 +264,125 @@ pub fn build_emulated_server_hello(
 
     response
 }
+
+#[cfg(test)]
+mod tests {
+    use std::time::SystemTime;
+
+    use crate::tls_front::types::{CachedTlsData, ParsedServerHello, TlsCertPayload};
+
+    use super::build_emulated_server_hello;
+    use crate::crypto::SecureRandom;
+    use crate::protocol::constants::{
+        TLS_RECORD_APPLICATION, TLS_RECORD_CHANGE_CIPHER, TLS_RECORD_HANDSHAKE,
+    };
+
+    fn first_app_data_payload(response: &[u8]) -> &[u8] {
+        let hello_len = u16::from_be_bytes([response[3], response[4]]) as usize;
+        let ccs_start = 5 + hello_len;
+        let ccs_len = u16::from_be_bytes([response[ccs_start + 3], response[ccs_start + 4]]) as usize;
+        let app_start = ccs_start + 5 + ccs_len;
+        let app_len = u16::from_be_bytes([response[app_start + 3], response[app_start + 4]]) as usize;
+        &response[app_start + 5..app_start + 5 + app_len]
+    }
+
+    fn make_cached(cert_payload: Option<TlsCertPayload>) -> CachedTlsData {
+        CachedTlsData {
+            server_hello_template: ParsedServerHello {
+                version: [0x03, 0x03],
+                random: [0u8; 32],
+                session_id: Vec::new(),
+                cipher_suite: [0x13, 0x01],
+                compression: 0,
+                extensions: Vec::new(),
+            },
+            cert_info: None,
+            cert_payload,
+            app_data_records_sizes: vec![64],
+            total_app_data_len: 64,
+            fetched_at: SystemTime::now(),
+            domain: "example.com".to_string(),
+        }
+    }
+
+    #[test]
+    fn test_build_emulated_server_hello_uses_cached_cert_payload() {
+        let cert_msg = vec![0x0b, 0x00, 0x00, 0x05, 0x00, 0xaa, 0xbb, 0xcc, 0xdd];
+        let cached = make_cached(Some(TlsCertPayload {
+            cert_chain_der: vec![vec![0x30, 0x01, 0x00]],
+            certificate_message: cert_msg.clone(),
+        }));
+        let rng = SecureRandom::new();
+        let response = build_emulated_server_hello(
+            b"secret",
+            &[0x11; 32],
+            &[0x22; 16],
+            &cached,
+            true,
+            &rng,
+            None,
+            0,
+        );
+
+        assert_eq!(response[0], TLS_RECORD_HANDSHAKE);
+        let hello_len = u16::from_be_bytes([response[3], response[4]]) as usize;
+        let ccs_start = 5 + hello_len;
+        assert_eq!(response[ccs_start], TLS_RECORD_CHANGE_CIPHER);
+        let app_start = ccs_start + 6;
+        assert_eq!(response[app_start], TLS_RECORD_APPLICATION);
+
+        let payload = first_app_data_payload(&response);
+        assert!(payload.starts_with(&cert_msg));
+    }
+
+    #[test]
+    fn test_build_emulated_server_hello_random_fallback_when_no_cert_payload() {
+        let cached = make_cached(None);
+        let rng = SecureRandom::new();
+        let response = build_emulated_server_hello(
+            b"secret",
+            &[0x22; 32],
+            &[0x33; 16],
+            &cached,
+            true,
+            &rng,
+            None,
+            0,
+        );
+
+        let payload = first_app_data_payload(&response);
+        assert!(payload.len() >= 64);
+        assert_eq!(payload[payload.len() - 17], 0x16);
+    }
+
+    #[test]
+    fn test_build_emulated_server_hello_uses_compact_payload_after_first() {
+        let cert_msg = vec![0x0b, 0x00, 0x00, 0x05, 0x00, 0xaa, 0xbb, 0xcc, 0xdd];
+        let mut cached = make_cached(Some(TlsCertPayload {
+            cert_chain_der: vec![vec![0x30, 0x01, 0x00]],
+            certificate_message: cert_msg,
+        }));
+        cached.cert_info = Some(crate::tls_front::types::ParsedCertificateInfo {
+            not_after_unix: Some(1_900_000_000),
+            not_before_unix: Some(1_700_000_000),
+            issuer_cn: Some("Issuer".to_string()),
+            subject_cn: Some("example.com".to_string()),
+            san_names: vec!["example.com".to_string(), "www.example.com".to_string()],
+        });
+
+        let rng = SecureRandom::new();
+        let response = build_emulated_server_hello(
+            b"secret",
+            &[0x44; 32],
+            &[0x55; 16],
+            &cached,
+            false,
+            &rng,
+            None,
+            0,
+        );
+
+        let payload = first_app_data_payload(&response);
+        assert!(payload.starts_with(b"CN=example.com"));
+    }
+}

src/tls_front/fetcher.rs

@@ -1,7 +1,7 @@
 use std::sync::Arc;
 use std::time::Duration;
 
-use anyhow::{Context, Result, anyhow};
+use anyhow::{Result, anyhow};
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpStream;
 use tokio::time::timeout;
@@ -19,7 +19,13 @@ use x509_parser::certificate::X509Certificate;
 
 use crate::crypto::SecureRandom;
 use crate::protocol::constants::{TLS_RECORD_APPLICATION, TLS_RECORD_HANDSHAKE};
-use crate::tls_front::types::{ParsedServerHello, TlsExtension, TlsFetchResult, ParsedCertificateInfo};
+use crate::tls_front::types::{
+    ParsedCertificateInfo,
+    ParsedServerHello,
+    TlsCertPayload,
+    TlsExtension,
+    TlsFetchResult,
+};
 
 /// No-op verifier: accept any certificate (we only need lengths and metadata).
 #[derive(Debug)]
@@ -315,6 +321,46 @@ fn parse_cert_info(certs: &[CertificateDer<'static>]) -> Option<ParsedCertificat
     })
 }
 
+fn u24_bytes(value: usize) -> Option<[u8; 3]> {
+    if value > 0x00ff_ffff {
+        return None;
+    }
+    Some([
+        ((value >> 16) & 0xff) as u8,
+        ((value >> 8) & 0xff) as u8,
+        (value & 0xff) as u8,
+    ])
+}
+
+fn encode_tls13_certificate_message(cert_chain_der: &[Vec<u8>]) -> Option<Vec<u8>> {
+    if cert_chain_der.is_empty() {
+        return None;
+    }
+
+    let mut certificate_list = Vec::new();
+    for cert in cert_chain_der {
+        if cert.is_empty() {
+            return None;
+        }
+        certificate_list.extend_from_slice(&u24_bytes(cert.len())?);
+        certificate_list.extend_from_slice(cert);
+        certificate_list.extend_from_slice(&0u16.to_be_bytes()); // cert_entry extensions
+    }
+
+    // Certificate = context_len(1) + certificate_list_len(3) + entries
+    let body_len = 1usize
+        .checked_add(3)?
+        .checked_add(certificate_list.len())?;
+
+    let mut message = Vec::with_capacity(4 + body_len);
+    message.push(0x0b); // HandshakeType::certificate
+    message.extend_from_slice(&u24_bytes(body_len)?);
+    message.push(0x00); // certificate_request_context length
+    message.extend_from_slice(&u24_bytes(certificate_list.len())?);
+    message.extend_from_slice(&certificate_list);
+    Some(message)
+}
+
 async fn fetch_via_raw_tls(
     host: &str,
     port: u16,
@@ -338,7 +384,7 @@ async fn fetch_via_raw_tls(
     for _ in 0..4 {
         match timeout(connect_timeout, read_tls_record(&mut stream)).await {
             Ok(Ok(rec)) => records.push(rec),
-            Ok(Err(e)) => return Err(e.into()),
+            Ok(Err(e)) => return Err(e),
             Err(_) => break,
         }
         if records.len() >= 3 && records.iter().any(|(t, _)| *t == TLS_RECORD_APPLICATION) {
@@ -368,26 +414,18 @@ async fn fetch_via_raw_tls(
         },
         total_app_data_len,
         cert_info: None,
+        cert_payload: None,
     })
 }
 
-/// Fetch real TLS metadata for the given SNI: negotiated cipher and cert lengths.
-pub async fn fetch_real_tls(
+async fn fetch_via_rustls(
     host: &str,
     port: u16,
     sni: &str,
     connect_timeout: Duration,
     upstream: Option<std::sync::Arc<crate::transport::UpstreamManager>>,
 ) -> Result<TlsFetchResult> {
-    // Preferred path: raw TLS probe for accurate record sizing
-    match fetch_via_raw_tls(host, port, sni, connect_timeout).await {
-        Ok(res) => return Ok(res),
-        Err(e) => {
-            warn!(sni = %sni, error = %e, "Raw TLS fetch failed, falling back to rustls");
-        }
-    }
-
-    // Fallback: rustls handshake to at least get certificate sizes
+    // rustls handshake path for certificate and basic negotiated metadata.
     let stream = if let Some(manager) = upstream {
         // Resolve host to SocketAddr
         if let Ok(mut addrs) = tokio::net::lookup_host((host, port)).await {
@@ -429,8 +467,19 @@ pub async fn fetch_real_tls(
         .peer_certificates()
         .map(|slice| slice.to_vec())
         .unwrap_or_default();
+    let cert_chain_der: Vec<Vec<u8>> = certs.iter().map(|c| c.as_ref().to_vec()).collect();
+    let cert_payload = encode_tls13_certificate_message(&cert_chain_der).map(|certificate_message| {
+        TlsCertPayload {
+            cert_chain_der: cert_chain_der.clone(),
+            certificate_message,
+        }
+    });
 
-    let total_cert_len: usize = certs.iter().map(|c| c.len()).sum::<usize>().max(1024);
+    let total_cert_len = cert_payload
+        .as_ref()
+        .map(|payload| payload.certificate_message.len())
+        .unwrap_or_else(|| cert_chain_der.iter().map(Vec::len).sum::<usize>())
+        .max(1024);
     let cert_info = parse_cert_info(&certs);
 
     // Heuristic: split across two records if large to mimic real servers a bit.
@@ -453,6 +502,7 @@ pub async fn fetch_real_tls(
         sni = %sni,
         len = total_cert_len,
         cipher = format!("0x{:04x}", u16::from_be_bytes(cipher_suite)),
+        has_cert_payload = cert_payload.is_some(),
         "Fetched TLS metadata via rustls"
     );
 
@@ -461,5 +511,81 @@ pub async fn fetch_real_tls(
         app_data_records_sizes: app_data_records_sizes.clone(),
         total_app_data_len: app_data_records_sizes.iter().sum(),
         cert_info,
+        cert_payload,
     })
 }
+
+/// Fetch real TLS metadata for the given SNI.
+///
+/// Strategy:
+/// 1) Probe raw TLS for realistic ServerHello and ApplicationData record sizes.
+/// 2) Fetch certificate chain via rustls to build cert payload.
+/// 3) Merge both when possible; otherwise auto-fallback to whichever succeeded.
+pub async fn fetch_real_tls(
+    host: &str,
+    port: u16,
+    sni: &str,
+    connect_timeout: Duration,
+    upstream: Option<std::sync::Arc<crate::transport::UpstreamManager>>,
+) -> Result<TlsFetchResult> {
+    let raw_result = match fetch_via_raw_tls(host, port, sni, connect_timeout).await {
+        Ok(res) => Some(res),
+        Err(e) => {
+            warn!(sni = %sni, error = %e, "Raw TLS fetch failed");
+            None
+        }
+    };
+
+    match fetch_via_rustls(host, port, sni, connect_timeout, upstream).await {
+        Ok(rustls_result) => {
+            if let Some(mut raw) = raw_result {
+                raw.cert_info = rustls_result.cert_info;
+                raw.cert_payload = rustls_result.cert_payload;
+                debug!(sni = %sni, "Fetched TLS metadata via raw probe + rustls cert chain");
+                Ok(raw)
+            } else {
+                Ok(rustls_result)
+            }
+        }
+        Err(e) => {
+            if let Some(raw) = raw_result {
+                warn!(sni = %sni, error = %e, "Rustls cert fetch failed, using raw TLS metadata only");
+                Ok(raw)
+            } else {
+                Err(e)
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::encode_tls13_certificate_message;
+
+    fn read_u24(bytes: &[u8]) -> usize {
+        ((bytes[0] as usize) << 16) | ((bytes[1] as usize) << 8) | (bytes[2] as usize)
+    }
+
+    #[test]
+    fn test_encode_tls13_certificate_message_single_cert() {
+        let cert = vec![0x30, 0x03, 0x02, 0x01, 0x01];
+        let message = encode_tls13_certificate_message(&[cert.clone()]).expect("message");
+
+        assert_eq!(message[0], 0x0b);
+        assert_eq!(read_u24(&message[1..4]), message.len() - 4);
+        assert_eq!(message[4], 0x00);
+
+        let cert_list_len = read_u24(&message[5..8]);
+        assert_eq!(cert_list_len, cert.len() + 5);
+
+        let cert_len = read_u24(&message[8..11]);
+        assert_eq!(cert_len, cert.len());
+        assert_eq!(&message[11..11 + cert.len()], cert.as_slice());
+        assert_eq!(&message[11 + cert.len()..13 + cert.len()], &[0x00, 0x00]);
+    }
+
+    #[test]
+    fn test_encode_tls13_certificate_message_empty_chain() {
+        assert!(encode_tls13_certificate_message(&[]).is_none());
+    }
+}

src/tls_front/mod.rs

@@ -4,4 +4,5 @@ pub mod fetcher;
 pub mod emulator;
 
 pub use cache::TlsFrontCache;
+#[allow(unused_imports)]
 pub use types::{CachedTlsData, TlsFetchResult};

src/tls_front/types.rs

@@ -29,11 +29,23 @@ pub struct ParsedCertificateInfo {
     pub san_names: Vec<String>,
 }
 
+/// TLS certificate payload captured from profiled upstream.
+///
+/// `certificate_message` stores an encoded TLS 1.3 Certificate handshake
+/// message body that can be replayed as opaque ApplicationData bytes in FakeTLS.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct TlsCertPayload {
+    pub cert_chain_der: Vec<Vec<u8>>,
+    pub certificate_message: Vec<u8>,
+}
+
 /// Cached data per SNI used by the emulator.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct CachedTlsData {
     pub server_hello_template: ParsedServerHello,
     pub cert_info: Option<ParsedCertificateInfo>,
+    #[serde(default)]
+    pub cert_payload: Option<TlsCertPayload>,
     pub app_data_records_sizes: Vec<usize>,
     pub total_app_data_len: usize,
     #[serde(default = "now_system_time", skip_serializing, skip_deserializing)]
@@ -52,4 +64,5 @@ pub struct TlsFetchResult {
     pub app_data_records_sizes: Vec<usize>,
     pub total_app_data_len: usize,
     pub cert_info: Option<ParsedCertificateInfo>,
+    pub cert_payload: Option<TlsCertPayload>,
 }

src/transport/middle_proxy/codec.rs

@@ -1,6 +1,6 @@
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
-use crate::crypto::{AesCbc, crc32};
+use crate::crypto::{AesCbc, crc32, crc32c};
 use crate::error::{ProxyError, Result};
 use crate::protocol::constants::*;
 
@@ -8,17 +8,46 @@ use crate::protocol::constants::*;
 pub(crate) enum WriterCommand {
     Data(Vec<u8>),
     DataAndFlush(Vec<u8>),
-    Keepalive,
     Close,
 }
 
-pub(crate) fn build_rpc_frame(seq_no: i32, payload: &[u8]) -> Vec<u8> {
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum RpcChecksumMode {
+    Crc32,
+    Crc32c,
+}
+
+impl RpcChecksumMode {
+    pub(crate) fn from_handshake_flags(flags: u32) -> Self {
+        if (flags & rpc_crypto_flags::USE_CRC32C) != 0 {
+            Self::Crc32c
+        } else {
+            Self::Crc32
+        }
+    }
+
+    pub(crate) fn advertised_flags(self) -> u32 {
+        match self {
+            Self::Crc32 => 0,
+            Self::Crc32c => rpc_crypto_flags::USE_CRC32C,
+        }
+    }
+}
+
+pub(crate) fn rpc_crc(mode: RpcChecksumMode, data: &[u8]) -> u32 {
+    match mode {
+        RpcChecksumMode::Crc32 => crc32(data),
+        RpcChecksumMode::Crc32c => crc32c(data),
+    }
+}
+
+pub(crate) fn build_rpc_frame(seq_no: i32, payload: &[u8], crc_mode: RpcChecksumMode) -> Vec<u8> {
     let total_len = (4 + 4 + payload.len() + 4) as u32;
     let mut frame = Vec::with_capacity(total_len as usize);
     frame.extend_from_slice(&total_len.to_le_bytes());
     frame.extend_from_slice(&seq_no.to_le_bytes());
     frame.extend_from_slice(payload);
-    let c = crc32(&frame);
+    let c = rpc_crc(crc_mode, &frame);
     frame.extend_from_slice(&c.to_le_bytes());
     frame
 }
@@ -45,7 +74,7 @@ pub(crate) async fn read_rpc_frame_plaintext(
 
     let crc_offset = total_len - 4;
     let expected_crc = u32::from_le_bytes(full[crc_offset..crc_offset + 4].try_into().unwrap());
-    let actual_crc = crc32(&full[..crc_offset]);
+    let actual_crc = rpc_crc(RpcChecksumMode::Crc32, &full[..crc_offset]);
     if expected_crc != actual_crc {
         return Err(ProxyError::InvalidHandshake(format!(
             "CRC mismatch: 0x{expected_crc:08x} vs 0x{actual_crc:08x}"
@@ -95,26 +124,53 @@ pub(crate) fn build_handshake_payload(
     our_port: u16,
     peer_ip: [u8; 4],
     peer_port: u16,
+    flags: u32,
 ) -> [u8; 32] {
     let mut p = [0u8; 32];
     p[0..4].copy_from_slice(&RPC_HANDSHAKE_U32.to_le_bytes());
+    p[4..8].copy_from_slice(&flags.to_le_bytes());
 
-    // Keep C memory layout compatibility for PID IPv4 bytes.
+    // process_id sender_pid
     p[8..12].copy_from_slice(&our_ip);
     p[12..14].copy_from_slice(&our_port.to_le_bytes());
-    let pid = (std::process::id() & 0xffff) as u16;
-    p[14..16].copy_from_slice(&pid.to_le_bytes());
-    let utime = std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .unwrap_or_default()
-        .as_secs() as u32;
-    p[16..20].copy_from_slice(&utime.to_le_bytes());
+    p[14..16].copy_from_slice(&process_pid16().to_le_bytes());
+    p[16..20].copy_from_slice(&process_utime().to_le_bytes());
 
+    // process_id peer_pid
     p[20..24].copy_from_slice(&peer_ip);
     p[24..26].copy_from_slice(&peer_port.to_le_bytes());
+    p[26..28].copy_from_slice(&0u16.to_le_bytes());
+    p[28..32].copy_from_slice(&0u32.to_le_bytes());
     p
 }
 
+pub(crate) fn parse_handshake_flags(payload: &[u8]) -> Result<u32> {
+    if payload.len() != 32 {
+        return Err(ProxyError::InvalidHandshake(format!(
+            "Bad handshake payload len: {}",
+            payload.len()
+        )));
+    }
+    let hs_type = u32::from_le_bytes(payload[0..4].try_into().unwrap());
+    if hs_type != RPC_HANDSHAKE_U32 {
+        return Err(ProxyError::InvalidHandshake(format!(
+            "Expected HANDSHAKE 0x{RPC_HANDSHAKE_U32:08x}, got 0x{hs_type:08x}"
+        )));
+    }
+    Ok(u32::from_le_bytes(payload[4..8].try_into().unwrap()))
+}
+
+fn process_pid16() -> u16 {
+    (std::process::id() & 0xffff) as u16
+}
+
+fn process_utime() -> u32 {
+    std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs() as u32
+}
+
 pub(crate) fn cbc_encrypt_padded(
     key: &[u8; 32],
     iv: &[u8; 16],
@@ -160,12 +216,13 @@ pub(crate) struct RpcWriter {
     pub(crate) key: [u8; 32],
     pub(crate) iv: [u8; 16],
     pub(crate) seq_no: i32,
+    pub(crate) crc_mode: RpcChecksumMode,
 }
 
 impl RpcWriter {
     pub(crate) async fn send(&mut self, payload: &[u8]) -> Result<()> {
-        let frame = build_rpc_frame(self.seq_no, payload);
-        self.seq_no += 1;
+        let frame = build_rpc_frame(self.seq_no, payload, self.crc_mode);
+        self.seq_no = self.seq_no.wrapping_add(1);
 
         let pad = (16 - (frame.len() % 16)) % 16;
         let mut buf = frame;
@@ -189,12 +246,4 @@ impl RpcWriter {
         self.send(payload).await?;
         self.writer.flush().await.map_err(ProxyError::Io)
     }
-
-    pub(crate) async fn send_keepalive(&mut self, payload: [u8; 4]) -> Result<()> {
-        // Keepalive is a frame with fl == 4 and 4 bytes payload.
-        let mut frame = Vec::with_capacity(8);
-        frame.extend_from_slice(&4u32.to_le_bytes());
-        frame.extend_from_slice(&payload);
-        self.send(&frame).await
-    }
 }

src/transport/middle_proxy/config_updater.rs

@@ -1,15 +1,18 @@
 use std::collections::HashMap;
+use std::hash::{DefaultHasher, Hash, Hasher};
 use std::net::IpAddr;
 use std::sync::Arc;
 use std::time::Duration;
 
 use httpdate;
+use tokio::sync::watch;
 use tracing::{debug, info, warn};
 
+use crate::config::ProxyConfig;
 use crate::error::Result;
 
 use super::MePool;
-use super::secret::download_proxy_secret;
+use super::secret::download_proxy_secret_with_max_len;
 use crate::crypto::SecureRandom;
 use std::time::SystemTime;
 
@@ -37,15 +40,103 @@ pub struct ProxyConfigData {
     pub default_dc: Option<i32>,
 }
 
-fn parse_host_port(s: &str) -> Option<(IpAddr, u16)> {
-    if let Some(bracket_end) = s.rfind(']') {
-        if s.starts_with('[') && bracket_end + 1 < s.len() && s.as_bytes().get(bracket_end + 1) == Some(&b':') {
-            let host = &s[1..bracket_end];
-            let port_str = &s[bracket_end + 2..];
-            let ip = host.parse::<IpAddr>().ok()?;
-            let port = port_str.parse::<u16>().ok()?;
-            return Some((ip, port));
+#[derive(Debug, Default)]
+struct StableSnapshot {
+    candidate_hash: Option<u64>,
+    candidate_hits: u8,
+    applied_hash: Option<u64>,
+}
+
+impl StableSnapshot {
+    fn observe(&mut self, hash: u64) -> u8 {
+        if self.candidate_hash == Some(hash) {
+            self.candidate_hits = self.candidate_hits.saturating_add(1);
+        } else {
+            self.candidate_hash = Some(hash);
+            self.candidate_hits = 1;
         }
+        self.candidate_hits
+    }
+
+    fn is_applied(&self, hash: u64) -> bool {
+        self.applied_hash == Some(hash)
+    }
+
+    fn mark_applied(&mut self, hash: u64) {
+        self.applied_hash = Some(hash);
+    }
+}
+
+#[derive(Debug, Default)]
+struct UpdaterState {
+    config_v4: StableSnapshot,
+    config_v6: StableSnapshot,
+    secret: StableSnapshot,
+    last_map_apply_at: Option<tokio::time::Instant>,
+}
+
+fn hash_proxy_config(cfg: &ProxyConfigData) -> u64 {
+    let mut hasher = DefaultHasher::new();
+    cfg.default_dc.hash(&mut hasher);
+
+    let mut by_dc: Vec<(i32, Vec<(IpAddr, u16)>)> =
+        cfg.map.iter().map(|(dc, addrs)| (*dc, addrs.clone())).collect();
+    by_dc.sort_by_key(|(dc, _)| *dc);
+    for (dc, mut addrs) in by_dc {
+        dc.hash(&mut hasher);
+        addrs.sort_unstable();
+        for (ip, port) in addrs {
+            ip.hash(&mut hasher);
+            port.hash(&mut hasher);
+        }
+    }
+
+    hasher.finish()
+}
+
+fn hash_secret(secret: &[u8]) -> u64 {
+    let mut hasher = DefaultHasher::new();
+    secret.hash(&mut hasher);
+    hasher.finish()
+}
+
+fn map_apply_cooldown_ready(
+    last_applied: Option<tokio::time::Instant>,
+    cooldown: Duration,
+) -> bool {
+    if cooldown.is_zero() {
+        return true;
+    }
+    match last_applied {
+        Some(ts) => ts.elapsed() >= cooldown,
+        None => true,
+    }
+}
+
+fn map_apply_cooldown_remaining_secs(
+    last_applied: tokio::time::Instant,
+    cooldown: Duration,
+) -> u64 {
+    if cooldown.is_zero() {
+        return 0;
+    }
+    cooldown
+        .checked_sub(last_applied.elapsed())
+        .map(|d| d.as_secs())
+        .unwrap_or(0)
+}
+
+fn parse_host_port(s: &str) -> Option<(IpAddr, u16)> {
+    if let Some(bracket_end) = s.rfind(']')
+        && s.starts_with('[')
+        && bracket_end + 1 < s.len()
+        && s.as_bytes().get(bracket_end + 1) == Some(&b':')
+    {
+        let host = &s[1..bracket_end];
+        let port_str = &s[bracket_end + 2..];
+        let ip = host.parse::<IpAddr>().ok()?;
+        let port = port_str.parse::<u16>().ok()?;
+        return Some((ip, port));
     }
 
     let idx = s.rfind(':')?;
@@ -82,20 +173,18 @@ pub async fn fetch_proxy_config(url: &str) -> Result<ProxyConfigData> {
         .map_err(|e| crate::error::ProxyError::Proxy(format!("fetch_proxy_config GET failed: {e}")))?
         ;
 
-    if let Some(date) = resp.headers().get(reqwest::header::DATE) {
-        if let Ok(date_str) = date.to_str() {
-            if let Ok(server_time) = httpdate::parse_http_date(date_str) {
-                if let Ok(skew) = SystemTime::now().duration_since(server_time).or_else(|e| {
-                    server_time.duration_since(SystemTime::now()).map_err(|_| e)
-                }) {
-                    let skew_secs = skew.as_secs();
-                    if skew_secs > 60 {
-                        warn!(skew_secs, "Time skew >60s detected from fetch_proxy_config Date header");
-                    } else if skew_secs > 30 {
-                        warn!(skew_secs, "Time skew >30s detected from fetch_proxy_config Date header");
-                    }
-                }
-            }
+    if let Some(date) = resp.headers().get(reqwest::header::DATE)
+        && let Ok(date_str) = date.to_str()
+        && let Ok(server_time) = httpdate::parse_http_date(date_str)
+        && let Ok(skew) = SystemTime::now().duration_since(server_time).or_else(|e| {
+            server_time.duration_since(SystemTime::now()).map_err(|_| e)
+        })
+    {
+        let skew_secs = skew.as_secs();
+        if skew_secs > 60 {
+            warn!(skew_secs, "Time skew >60s detected from fetch_proxy_config Date header");
+        } else if skew_secs > 30 {
+            warn!(skew_secs, "Time skew >30s detected from fetch_proxy_config Date header");
         }
     }
 
@@ -128,50 +217,224 @@ pub async fn fetch_proxy_config(url: &str) -> Result<ProxyConfigData> {
     Ok(ProxyConfigData { map, default_dc })
 }
 
-pub async fn me_config_updater(pool: Arc<MePool>, rng: Arc<SecureRandom>, interval: Duration) {
-    let mut tick = tokio::time::interval(interval);
-    // skip immediate tick to avoid double-fetch right after startup
-    tick.tick().await;
-    loop {
-        tick.tick().await;
+async fn run_update_cycle(
+    pool: &Arc<MePool>,
+    rng: &Arc<SecureRandom>,
+    cfg: &ProxyConfig,
+    state: &mut UpdaterState,
+) {
+    pool.update_runtime_reinit_policy(
+        cfg.general.hardswap,
+        cfg.general.me_pool_drain_ttl_secs,
+        cfg.general.effective_me_pool_force_close_secs(),
+        cfg.general.me_pool_min_fresh_ratio,
+    );
 
-        // Update proxy config v4
-        let cfg_v4 = retry_fetch("https://core.telegram.org/getProxyConfig").await;
-        if let Some(cfg) = cfg_v4 {
-            let changed = pool.update_proxy_maps(cfg.map.clone(), None).await;
-            if let Some(dc) = cfg.default_dc {
-                pool.default_dc.store(dc, std::sync::atomic::Ordering::Relaxed);
-            }
-            if changed {
-                info!("ME config updated (v4), reconciling connections");
-                pool.reconcile_connections(&rng).await;
-            } else {
-                debug!("ME config v4 unchanged");
-            }
+    let required_cfg_snapshots = cfg.general.me_config_stable_snapshots.max(1);
+    let required_secret_snapshots = cfg.general.proxy_secret_stable_snapshots.max(1);
+    let apply_cooldown = Duration::from_secs(cfg.general.me_config_apply_cooldown_secs);
+    let mut maps_changed = false;
+
+    let mut ready_v4: Option<(ProxyConfigData, u64)> = None;
+    let cfg_v4 = retry_fetch("https://core.telegram.org/getProxyConfig").await;
+    if let Some(cfg_v4) = cfg_v4 {
+        let cfg_v4_hash = hash_proxy_config(&cfg_v4);
+        let stable_hits = state.config_v4.observe(cfg_v4_hash);
+        if stable_hits < required_cfg_snapshots {
+            debug!(
+                stable_hits,
+                required_cfg_snapshots,
+                snapshot = format_args!("0x{cfg_v4_hash:016x}"),
+                "ME config v4 candidate observed"
+            );
+        } else if state.config_v4.is_applied(cfg_v4_hash) {
+            debug!(
+                snapshot = format_args!("0x{cfg_v4_hash:016x}"),
+                "ME config v4 stable snapshot already applied"
+            );
+        } else {
+            ready_v4 = Some((cfg_v4, cfg_v4_hash));
         }
+    }
 
-        // Update proxy config v6 (optional)
-        let cfg_v6 = retry_fetch("https://core.telegram.org/getProxyConfigV6").await;
-        if let Some(cfg_v6) = cfg_v6 {
-            let changed = pool.update_proxy_maps(HashMap::new(), Some(cfg_v6.map)).await;
-            if changed {
-                info!("ME config updated (v6), reconciling connections");
-                pool.reconcile_connections(&rng).await;
-            } else {
-                debug!("ME config v6 unchanged");
-            }
+    let mut ready_v6: Option<(ProxyConfigData, u64)> = None;
+    let cfg_v6 = retry_fetch("https://core.telegram.org/getProxyConfigV6").await;
+    if let Some(cfg_v6) = cfg_v6 {
+        let cfg_v6_hash = hash_proxy_config(&cfg_v6);
+        let stable_hits = state.config_v6.observe(cfg_v6_hash);
+        if stable_hits < required_cfg_snapshots {
+            debug!(
+                stable_hits,
+                required_cfg_snapshots,
+                snapshot = format_args!("0x{cfg_v6_hash:016x}"),
+                "ME config v6 candidate observed"
+            );
+        } else if state.config_v6.is_applied(cfg_v6_hash) {
+            debug!(
+                snapshot = format_args!("0x{cfg_v6_hash:016x}"),
+                "ME config v6 stable snapshot already applied"
+            );
+        } else {
+            ready_v6 = Some((cfg_v6, cfg_v6_hash));
         }
-        pool.reset_stun_state();
+    }
 
-        // Update proxy-secret
-        match download_proxy_secret().await {
+    if ready_v4.is_some() || ready_v6.is_some() {
+        if map_apply_cooldown_ready(state.last_map_apply_at, apply_cooldown) {
+            let update_v4 = ready_v4
+                .as_ref()
+                .map(|(snapshot, _)| snapshot.map.clone())
+                .unwrap_or_default();
+            let update_v6 = ready_v6
+                .as_ref()
+                .map(|(snapshot, _)| snapshot.map.clone());
+
+            let changed = pool.update_proxy_maps(update_v4, update_v6).await;
+
+            if let Some((snapshot, hash)) = ready_v4 {
+                if let Some(dc) = snapshot.default_dc {
+                    pool.default_dc
+                        .store(dc, std::sync::atomic::Ordering::Relaxed);
+                }
+                state.config_v4.mark_applied(hash);
+            }
+
+            if let Some((_snapshot, hash)) = ready_v6 {
+                state.config_v6.mark_applied(hash);
+            }
+
+            state.last_map_apply_at = Some(tokio::time::Instant::now());
+
+            if changed {
+                maps_changed = true;
+                info!("ME config update applied after stable-gate");
+            } else {
+                debug!("ME config stable-gate applied with no map delta");
+            }
+        } else if let Some(last) = state.last_map_apply_at {
+            let wait_secs = map_apply_cooldown_remaining_secs(last, apply_cooldown);
+            debug!(
+                wait_secs,
+                "ME config stable snapshot deferred by cooldown"
+            );
+        }
+    }
+
+    if maps_changed {
+        pool.zero_downtime_reinit_after_map_change(rng.as_ref())
+            .await;
+    }
+
+    pool.reset_stun_state();
+
+    if cfg.general.proxy_secret_rotate_runtime {
+        match download_proxy_secret_with_max_len(cfg.general.proxy_secret_len_max).await {
             Ok(secret) => {
-                if pool.update_secret(secret).await {
-                    info!("proxy-secret updated and pool reconnect scheduled");
+                let secret_hash = hash_secret(&secret);
+                let stable_hits = state.secret.observe(secret_hash);
+                if stable_hits < required_secret_snapshots {
+                    debug!(
+                        stable_hits,
+                        required_secret_snapshots,
+                        snapshot = format_args!("0x{secret_hash:016x}"),
+                        "proxy-secret candidate observed"
+                    );
+                } else if state.secret.is_applied(secret_hash) {
+                    debug!(
+                        snapshot = format_args!("0x{secret_hash:016x}"),
+                        "proxy-secret stable snapshot already applied"
+                    );
+                } else {
+                    let rotated = pool.update_secret(secret).await;
+                    state.secret.mark_applied(secret_hash);
+                    if rotated {
+                        info!("proxy-secret rotated after stable-gate");
+                    } else {
+                        debug!("proxy-secret stable snapshot confirmed as unchanged");
+                    }
                 }
             }
             Err(e) => warn!(error = %e, "proxy-secret update failed"),
         }
+    } else {
+        debug!("proxy-secret runtime rotation disabled by config");
+    }
+}
+
+pub async fn me_config_updater(
+    pool: Arc<MePool>,
+    rng: Arc<SecureRandom>,
+    mut config_rx: watch::Receiver<Arc<ProxyConfig>>,
+) {
+    let mut state = UpdaterState::default();
+    let mut update_every_secs = config_rx
+        .borrow()
+        .general
+        .effective_update_every_secs()
+        .max(1);
+    let mut update_every = Duration::from_secs(update_every_secs);
+    let mut next_tick = tokio::time::Instant::now() + update_every;
+    info!(update_every_secs, "ME config updater started");
+
+    loop {
+        let sleep = tokio::time::sleep_until(next_tick);
+        tokio::pin!(sleep);
+
+        tokio::select! {
+            _ = &mut sleep => {
+                let cfg = config_rx.borrow().clone();
+                run_update_cycle(&pool, &rng, cfg.as_ref(), &mut state).await;
+                let refreshed_secs = cfg.general.effective_update_every_secs().max(1);
+                if refreshed_secs != update_every_secs {
+                    info!(
+                        old_update_every_secs = update_every_secs,
+                        new_update_every_secs = refreshed_secs,
+                        "ME config updater interval changed"
+                    );
+                    update_every_secs = refreshed_secs;
+                    update_every = Duration::from_secs(update_every_secs);
+                }
+                next_tick = tokio::time::Instant::now() + update_every;
+            }
+            changed = config_rx.changed() => {
+                if changed.is_err() {
+                    warn!("ME config updater stopped: config channel closed");
+                    break;
+                }
+                let cfg = config_rx.borrow().clone();
+                pool.update_runtime_reinit_policy(
+                    cfg.general.hardswap,
+                    cfg.general.me_pool_drain_ttl_secs,
+                    cfg.general.effective_me_pool_force_close_secs(),
+                    cfg.general.me_pool_min_fresh_ratio,
+                );
+                let new_secs = cfg.general.effective_update_every_secs().max(1);
+                if new_secs == update_every_secs {
+                    continue;
+                }
+
+                if new_secs < update_every_secs {
+                    info!(
+                        old_update_every_secs = update_every_secs,
+                        new_update_every_secs = new_secs,
+                        "ME config updater interval decreased, running immediate refresh"
+                    );
+                    update_every_secs = new_secs;
+                    update_every = Duration::from_secs(update_every_secs);
+                    run_update_cycle(&pool, &rng, cfg.as_ref(), &mut state).await;
+                    next_tick = tokio::time::Instant::now() + update_every;
+                } else {
+                    info!(
+                        old_update_every_secs = update_every_secs,
+                        new_update_every_secs = new_secs,
+                        "ME config updater interval increased"
+                    );
+                    update_every_secs = new_secs;
+                    update_every = Duration::from_secs(update_every_secs);
+                    next_tick = tokio::time::Instant::now() + update_every;
+                }
+            }
+        }
     }
 }
 

src/transport/middle_proxy/handshake.rs

@@ -18,13 +18,14 @@ use crate::crypto::{SecureRandom, build_middleproxy_prekey, derive_middleproxy_k
 use crate::error::{ProxyError, Result};
 use crate::network::IpFamily;
 use crate::protocol::constants::{
-    ME_CONNECT_TIMEOUT_SECS, ME_HANDSHAKE_TIMEOUT_SECS, RPC_CRYPTO_AES_U32, RPC_HANDSHAKE_ERROR_U32,
-    RPC_HANDSHAKE_U32, RPC_PING_U32, RPC_PONG_U32, RPC_NONCE_U32,
+    ME_CONNECT_TIMEOUT_SECS, ME_HANDSHAKE_TIMEOUT_SECS, RPC_CRYPTO_AES_U32,
+    RPC_HANDSHAKE_ERROR_U32, rpc_crypto_flags,
 };
 
 use super::codec::{
-    build_handshake_payload, build_nonce_payload, build_rpc_frame, cbc_decrypt_inplace,
-    cbc_encrypt_padded, parse_nonce_payload, read_rpc_frame_plaintext,
+    RpcChecksumMode, build_handshake_payload, build_nonce_payload, build_rpc_frame,
+    cbc_decrypt_inplace, cbc_encrypt_padded, parse_handshake_flags, parse_nonce_payload,
+    read_rpc_frame_plaintext, rpc_crc,
 };
 use super::wire::{extract_ip_material, IpMaterial};
 use super::MePool;
@@ -37,6 +38,7 @@ pub(crate) struct HandshakeOutput {
     pub read_iv: [u8; 16],
     pub write_key: [u8; 32],
     pub write_iv: [u8; 16],
+    pub crc_mode: RpcChecksumMode,
     pub handshake_ms: f64,
 }
 
@@ -45,21 +47,21 @@ impl MePool {
     pub(crate) async fn connect_tcp(&self, addr: SocketAddr) -> Result<(TcpStream, f64)> {
         let start = Instant::now();
         let connect_fut = async {
-            if addr.is_ipv6() {
-                if let Some(v6) = self.detected_ipv6 {
-                    match TcpSocket::new_v6() {
-                        Ok(sock) => {
-                            if let Err(e) = sock.bind(SocketAddr::new(IpAddr::V6(v6), 0)) {
-                                debug!(error = %e, bind_ip = %v6, "ME IPv6 bind failed, falling back to default bind");
-                            } else {
-                                match sock.connect(addr).await {
-                                    Ok(stream) => return Ok(stream),
-                                    Err(e) => debug!(error = %e, target = %addr, "ME IPv6 bound connect failed, retrying default connect"),
-                                }
+            if addr.is_ipv6()
+                && let Some(v6) = self.detected_ipv6
+            {
+                match TcpSocket::new_v6() {
+                    Ok(sock) => {
+                        if let Err(e) = sock.bind(SocketAddr::new(IpAddr::V6(v6), 0)) {
+                            debug!(error = %e, bind_ip = %v6, "ME IPv6 bind failed, falling back to default bind");
+                        } else {
+                            match sock.connect(addr).await {
+                                Ok(stream) => return Ok(stream),
+                                Err(e) => debug!(error = %e, target = %addr, "ME IPv6 bound connect failed, retrying default connect"),
                             }
                         }
-                        Err(e) => debug!(error = %e, "ME IPv6 socket creation failed, falling back to default connect"),
                     }
+                    Err(e) => debug!(error = %e, "ME IPv6 socket creation failed, falling back to default connect"),
                 }
             }
             TcpStream::connect(addr).await
@@ -146,7 +148,7 @@ impl MePool {
 
         let ks = self.key_selector().await;
         let nonce_payload = build_nonce_payload(ks, crypto_ts, &my_nonce);
-        let nonce_frame = build_rpc_frame(-2, &nonce_payload);
+        let nonce_frame = build_rpc_frame(-2, &nonce_payload, RpcChecksumMode::Crc32);
         let dump = hex_dump(&nonce_frame[..nonce_frame.len().min(44)]);
         debug!(
             key_selector = format_args!("0x{ks:08x}"),
@@ -284,8 +286,15 @@ impl MePool {
             srv_v6_opt.as_ref(),
         );
 
-        let hs_payload = build_handshake_payload(hs_our_ip, local_addr.port(), hs_peer_ip, peer_addr.port());
-        let hs_frame = build_rpc_frame(-1, &hs_payload);
+        let requested_crc_mode = RpcChecksumMode::Crc32c;
+        let hs_payload = build_handshake_payload(
+            hs_our_ip,
+            local_addr.port(),
+            hs_peer_ip,
+            peer_addr.port(),
+            requested_crc_mode.advertised_flags(),
+        );
+        let hs_frame = build_rpc_frame(-1, &hs_payload, RpcChecksumMode::Crc32);
         if diag_level >= 1 {
             info!(
                 write_key = %hex_dump(&wk),
@@ -314,7 +323,7 @@ impl MePool {
             );
         }
 
-        let (encrypted_hs, mut write_iv) = cbc_encrypt_padded(&wk, &wi, &hs_frame)?;
+        let (encrypted_hs, write_iv) = cbc_encrypt_padded(&wk, &wi, &hs_frame)?;
         if diag_level >= 1 {
             info!(
                 hs_cipher = %hex_dump(&encrypted_hs),
@@ -328,6 +337,7 @@ impl MePool {
         let mut enc_buf = BytesMut::with_capacity(256);
         let mut dec_buf = BytesMut::with_capacity(256);
         let mut read_iv = ri;
+        let mut negotiated_crc_mode = RpcChecksumMode::Crc32;
         let mut handshake_ok = false;
 
         while Instant::now() < deadline && !handshake_ok {
@@ -375,17 +385,23 @@ impl MePool {
                 let frame = dec_buf.split_to(fl);
                 let pe = fl - 4;
                 let ec = u32::from_le_bytes(frame[pe..pe + 4].try_into().unwrap());
-                let ac = crate::crypto::crc32(&frame[..pe]);
+                let ac = rpc_crc(RpcChecksumMode::Crc32, &frame[..pe]);
                 if ec != ac {
                     return Err(ProxyError::InvalidHandshake(format!(
                         "HS CRC mismatch: 0x{ec:08x} vs 0x{ac:08x}"
                     )));
                 }
 
-                let hs_type = u32::from_le_bytes(frame[8..12].try_into().unwrap());
+                let hs_payload = &frame[8..pe];
+                if hs_payload.len() < 4 {
+                    return Err(ProxyError::InvalidHandshake(
+                        "Handshake payload too short".to_string(),
+                    ));
+                }
+                let hs_type = u32::from_le_bytes(hs_payload[0..4].try_into().unwrap());
                 if hs_type == RPC_HANDSHAKE_ERROR_U32 {
-                    let err_code = if frame.len() >= 16 {
-                        i32::from_le_bytes(frame[12..16].try_into().unwrap())
+                    let err_code = if hs_payload.len() >= 8 {
+                        i32::from_le_bytes(hs_payload[4..8].try_into().unwrap())
                     } else {
                         -1
                     };
@@ -393,11 +409,21 @@ impl MePool {
                         "ME rejected handshake (error={err_code})"
                     )));
                 }
-                if hs_type != RPC_HANDSHAKE_U32 {
+                let hs_flags = parse_handshake_flags(hs_payload)?;
+                if hs_flags & 0xff != 0 {
                     return Err(ProxyError::InvalidHandshake(format!(
-                        "Expected HANDSHAKE 0x{RPC_HANDSHAKE_U32:08x}, got 0x{hs_type:08x}"
+                        "Unsupported handshake flags: 0x{hs_flags:08x}"
                     )));
                 }
+                negotiated_crc_mode = if (hs_flags & requested_crc_mode.advertised_flags()) != 0 {
+                    RpcChecksumMode::from_handshake_flags(hs_flags)
+                } else if (hs_flags & rpc_crypto_flags::USE_CRC32C) != 0 {
+                    return Err(ProxyError::InvalidHandshake(format!(
+                        "Peer negotiated unsupported CRC flags: 0x{hs_flags:08x}"
+                    )));
+                } else {
+                    RpcChecksumMode::Crc32
+                };
 
                 handshake_ok = true;
                 break;
@@ -418,6 +444,7 @@ impl MePool {
             read_iv,
             write_key: wk,
             write_iv,
+            crc_mode: negotiated_crc_mode,
             handshake_ms,
         })
     }

src/transport/middle_proxy/health.rs

@@ -14,6 +14,7 @@ use super::MePool;
 
 const HEALTH_INTERVAL_SECS: u64 = 1;
 const JITTER_FRAC_NUM: u64 = 2; // jitter up to 50% of backoff
+#[allow(dead_code)]
 const MAX_CONCURRENT_PER_DC_DEFAULT: usize = 1;
 
 pub async fn me_health_monitor(pool: Arc<MePool>, rng: Arc<SecureRandom>, _min_connections: usize) {
@@ -68,6 +69,7 @@ async fn check_family(
         .read()
         .await
         .iter()
+        .filter(|w| !w.draining.load(std::sync::atomic::Ordering::Relaxed))
         .map(|w| w.addr)
         .collect();
 
@@ -90,10 +92,10 @@ async fn check_family(
 
         let key = (dc, family);
         let now = Instant::now();
-        if let Some(ts) = next_attempt.get(&key) {
-            if now < *ts {
-                continue;
-            }
+        if let Some(ts) = next_attempt.get(&key)
+            && now < *ts
+        {
+            continue;
         }
 
         let max_concurrent = pool.me_reconnect_max_concurrent_per_dc.max(1) as usize;

src/transport/middle_proxy/mod.rs

@@ -17,8 +17,10 @@ mod wire;
 use bytes::Bytes;
 
 pub use health::me_health_monitor;
+#[allow(unused_imports)]
 pub use ping::{run_me_ping, format_sample_line, MePingReport, MePingSample, MePingFamily};
 pub use pool::MePool;
+#[allow(unused_imports)]
 pub use pool_nat::{stun_probe, detect_public_ip};
 pub use registry::ConnRegistry;
 pub use secret::fetch_proxy_secret;

src/transport/middle_proxy/ping.rs

@@ -24,6 +24,7 @@ pub struct MePingSample {
 }
 
 #[derive(Debug, Clone)]
+#[allow(dead_code)]
 pub struct MePingReport {
     pub dc: i32,
     pub family: MePingFamily,

src/transport/middle_proxy/pool.rs

@@ -1,14 +1,14 @@
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::net::{IpAddr, Ipv6Addr, SocketAddr};
 use std::sync::Arc;
-use std::sync::atomic::{AtomicBool, AtomicI32, AtomicU64, AtomicUsize, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicI32, AtomicU32, AtomicU64, AtomicUsize, Ordering};
 use bytes::BytesMut;
 use rand::Rng;
 use rand::seq::SliceRandom;
 use tokio::sync::{Mutex, RwLock, mpsc, Notify};
 use tokio_util::sync::CancellationToken;
 use tracing::{debug, info, warn};
-use std::time::{Duration, Instant};
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 
 use crate::crypto::SecureRandom;
 use crate::error::{ProxyError, Result};
@@ -17,24 +17,26 @@ use crate::network::IpFamily;
 use crate::protocol::constants::*;
 
 use super::ConnRegistry;
-use super::registry::{BoundConn, ConnMeta};
+use super::registry::BoundConn;
 use super::codec::{RpcWriter, WriterCommand};
 use super::reader::reader_loop;
-use super::MeResponse;
 const ME_ACTIVE_PING_SECS: u64 = 25;
 const ME_ACTIVE_PING_JITTER_SECS: i64 = 5;
-const ME_KEEPALIVE_PAYLOAD_LEN: usize = 4;
 
 #[derive(Clone)]
 pub struct MeWriter {
     pub id: u64,
     pub addr: SocketAddr,
+    pub generation: u64,
     pub tx: mpsc::Sender<WriterCommand>,
     pub cancel: CancellationToken,
     pub degraded: Arc<AtomicBool>,
     pub draining: Arc<AtomicBool>,
+    pub draining_started_at_epoch_secs: Arc<AtomicU64>,
+    pub allow_drain_fallback: Arc<AtomicBool>,
 }
 
+#[allow(dead_code)]
 pub struct MePool {
     pub(super) registry: Arc<ConnRegistry>,
     pub(super) writers: Arc<RwLock<Vec<MeWriter>>>,
@@ -75,6 +77,11 @@ pub struct MePool {
     pub(super) writer_available: Arc<Notify>,
     pub(super) conn_count: AtomicUsize,
     pub(super) stats: Arc<crate::stats::Stats>,
+    pub(super) generation: AtomicU64,
+    pub(super) hardswap: AtomicBool,
+    pub(super) me_pool_drain_ttl_secs: AtomicU64,
+    pub(super) me_pool_force_close_secs: AtomicU64,
+    pub(super) me_pool_min_fresh_ratio_permille: AtomicU32,
     pool_size: usize,
 }
 
@@ -85,6 +92,22 @@ pub struct NatReflectionCache {
 }
 
 impl MePool {
+    fn ratio_to_permille(ratio: f32) -> u32 {
+        let clamped = ratio.clamp(0.0, 1.0);
+        (clamped * 1000.0).round() as u32
+    }
+
+    fn permille_to_ratio(permille: u32) -> f32 {
+        (permille.min(1000) as f32) / 1000.0
+    }
+
+    fn now_epoch_secs() -> u64 {
+        SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_secs()
+    }
+
     pub fn new(
         proxy_tag: Option<Vec<u8>>,
         proxy_secret: Vec<u8>,
@@ -112,6 +135,10 @@ impl MePool {
         me_reconnect_backoff_base_ms: u64,
         me_reconnect_backoff_cap_ms: u64,
         me_reconnect_fast_retry_count: u32,
+        hardswap: bool,
+        me_pool_drain_ttl_secs: u64,
+        me_pool_force_close_secs: u64,
+        me_pool_min_fresh_ratio: f32,
     ) -> Arc<Self> {
         Arc::new(Self {
             registry: Arc::new(ConnRegistry::new()),
@@ -154,6 +181,11 @@ impl MePool {
             nat_reflection_cache: Arc::new(Mutex::new(NatReflectionCache::default())),
             writer_available: Arc::new(Notify::new()),
             conn_count: AtomicUsize::new(0),
+            generation: AtomicU64::new(1),
+            hardswap: AtomicBool::new(hardswap),
+            me_pool_drain_ttl_secs: AtomicU64::new(me_pool_drain_ttl_secs),
+            me_pool_force_close_secs: AtomicU64::new(me_pool_force_close_secs),
+            me_pool_min_fresh_ratio_permille: AtomicU32::new(Self::ratio_to_permille(me_pool_min_fresh_ratio)),
         })
     }
 
@@ -161,6 +193,25 @@ impl MePool {
         self.proxy_tag.is_some()
     }
 
+    pub fn current_generation(&self) -> u64 {
+        self.generation.load(Ordering::Relaxed)
+    }
+
+    pub fn update_runtime_reinit_policy(
+        &self,
+        hardswap: bool,
+        drain_ttl_secs: u64,
+        force_close_secs: u64,
+        min_fresh_ratio: f32,
+    ) {
+        self.hardswap.store(hardswap, Ordering::Relaxed);
+        self.me_pool_drain_ttl_secs.store(drain_ttl_secs, Ordering::Relaxed);
+        self.me_pool_force_close_secs
+            .store(force_close_secs, Ordering::Relaxed);
+        self.me_pool_min_fresh_ratio_permille
+            .store(Self::ratio_to_permille(min_fresh_ratio), Ordering::Relaxed);
+    }
+
     pub fn reset_stun_state(&self) {
         self.nat_probe_attempts.store(0, Ordering::Relaxed);
         self.nat_probe_disabled.store(false, Ordering::Relaxed);
@@ -179,8 +230,43 @@ impl MePool {
         self.writers.clone()
     }
 
+    fn force_close_timeout(&self) -> Option<Duration> {
+        let secs = self.me_pool_force_close_secs.load(Ordering::Relaxed);
+        if secs == 0 {
+            None
+        } else {
+            Some(Duration::from_secs(secs))
+        }
+    }
+
+    fn coverage_ratio(
+        desired_by_dc: &HashMap<i32, HashSet<SocketAddr>>,
+        active_writer_addrs: &HashSet<SocketAddr>,
+    ) -> (f32, Vec<i32>) {
+        if desired_by_dc.is_empty() {
+            return (1.0, Vec::new());
+        }
+
+        let mut missing_dc = Vec::<i32>::new();
+        let mut covered = 0usize;
+        for (dc, endpoints) in desired_by_dc {
+            if endpoints.is_empty() {
+                continue;
+            }
+            if endpoints.iter().any(|addr| active_writer_addrs.contains(addr)) {
+                covered += 1;
+            } else {
+                missing_dc.push(*dc);
+            }
+        }
+
+        missing_dc.sort_unstable();
+        let total = desired_by_dc.len().max(1);
+        let ratio = (covered as f32) / (total as f32);
+        (ratio, missing_dc)
+    }
+
     pub async fn reconcile_connections(self: &Arc<Self>, rng: &SecureRandom) {
-        use std::collections::HashSet;
         let writers = self.writers.read().await;
         let current: HashSet<SocketAddr> = writers
             .iter()
@@ -212,6 +298,181 @@ impl MePool {
         }
     }
 
+    async fn desired_dc_endpoints(&self) -> HashMap<i32, HashSet<SocketAddr>> {
+        let mut out: HashMap<i32, HashSet<SocketAddr>> = HashMap::new();
+
+        if self.decision.ipv4_me {
+            let map_v4 = self.proxy_map_v4.read().await.clone();
+            for (dc, addrs) in map_v4 {
+                let entry = out.entry(dc.abs()).or_default();
+                for (ip, port) in addrs {
+                    entry.insert(SocketAddr::new(ip, port));
+                }
+            }
+        }
+
+        if self.decision.ipv6_me {
+            let map_v6 = self.proxy_map_v6.read().await.clone();
+            for (dc, addrs) in map_v6 {
+                let entry = out.entry(dc.abs()).or_default();
+                for (ip, port) in addrs {
+                    entry.insert(SocketAddr::new(ip, port));
+                }
+            }
+        }
+
+        out
+    }
+
+    async fn warmup_generation_for_all_dcs(
+        self: &Arc<Self>,
+        rng: &SecureRandom,
+        generation: u64,
+        desired_by_dc: &HashMap<i32, HashSet<SocketAddr>>,
+    ) {
+        for endpoints in desired_by_dc.values() {
+            if endpoints.is_empty() {
+                continue;
+            }
+
+            let has_fresh = {
+                let ws = self.writers.read().await;
+                ws.iter().any(|w| {
+                    !w.draining.load(Ordering::Relaxed)
+                        && w.generation == generation
+                        && endpoints.contains(&w.addr)
+                })
+            };
+
+            if has_fresh {
+                continue;
+            }
+
+            let mut shuffled: Vec<SocketAddr> = endpoints.iter().copied().collect();
+            shuffled.shuffle(&mut rand::rng());
+            for addr in shuffled {
+                if self.connect_one(addr, rng).await.is_ok() {
+                    break;
+                }
+            }
+        }
+    }
+
+    pub async fn zero_downtime_reinit_after_map_change(
+        self: &Arc<Self>,
+        rng: &SecureRandom,
+    ) {
+        let desired_by_dc = self.desired_dc_endpoints().await;
+        if desired_by_dc.is_empty() {
+            warn!("ME endpoint map is empty after update; skipping stale writer drain");
+            return;
+        }
+
+        let previous_generation = self.current_generation();
+        let generation = self.generation.fetch_add(1, Ordering::Relaxed) + 1;
+        let hardswap = self.hardswap.load(Ordering::Relaxed);
+
+        if hardswap {
+            self.warmup_generation_for_all_dcs(rng, generation, &desired_by_dc)
+                .await;
+        } else {
+            self.reconcile_connections(rng).await;
+        }
+
+        let writers = self.writers.read().await;
+        let active_writer_addrs: HashSet<SocketAddr> = writers
+            .iter()
+            .filter(|w| !w.draining.load(Ordering::Relaxed))
+            .map(|w| w.addr)
+            .collect();
+        let min_ratio = Self::permille_to_ratio(
+            self.me_pool_min_fresh_ratio_permille
+                .load(Ordering::Relaxed),
+        );
+        let (coverage_ratio, missing_dc) = Self::coverage_ratio(&desired_by_dc, &active_writer_addrs);
+        if !hardswap && coverage_ratio < min_ratio {
+            warn!(
+                previous_generation,
+                generation,
+                coverage_ratio = format_args!("{coverage_ratio:.3}"),
+                min_ratio = format_args!("{min_ratio:.3}"),
+                missing_dc = ?missing_dc,
+                "ME reinit coverage below threshold; keeping stale writers"
+            );
+            return;
+        }
+
+        if hardswap {
+            let fresh_writer_addrs: HashSet<SocketAddr> = writers
+                .iter()
+                .filter(|w| !w.draining.load(Ordering::Relaxed))
+                .filter(|w| w.generation == generation)
+                .map(|w| w.addr)
+                .collect();
+            let (fresh_ratio, fresh_missing_dc) =
+                Self::coverage_ratio(&desired_by_dc, &fresh_writer_addrs);
+            if !fresh_missing_dc.is_empty() {
+                warn!(
+                    previous_generation,
+                    generation,
+                    fresh_ratio = format_args!("{fresh_ratio:.3}"),
+                    missing_dc = ?fresh_missing_dc,
+                    "ME hardswap pending: fresh generation coverage incomplete"
+                );
+                return;
+            }
+        } else if !missing_dc.is_empty() {
+            warn!(
+                missing_dc = ?missing_dc,
+                // Keep stale writers alive when fresh coverage is incomplete.
+                "ME reinit coverage incomplete after map update; keeping stale writers"
+            );
+            return;
+        }
+
+        let desired_addrs: HashSet<SocketAddr> = desired_by_dc
+            .values()
+            .flat_map(|set| set.iter().copied())
+            .collect();
+
+        let stale_writer_ids: Vec<u64> = writers
+            .iter()
+            .filter(|w| !w.draining.load(Ordering::Relaxed))
+            .filter(|w| {
+                if hardswap {
+                    w.generation < generation
+                } else {
+                    !desired_addrs.contains(&w.addr)
+                }
+            })
+            .map(|w| w.id)
+            .collect();
+        drop(writers);
+
+        if stale_writer_ids.is_empty() {
+            debug!("ME map update completed with no stale writers");
+            return;
+        }
+
+        let drain_timeout = self.force_close_timeout();
+        let drain_timeout_secs = drain_timeout.map(|d| d.as_secs()).unwrap_or(0);
+        info!(
+            stale_writers = stale_writer_ids.len(),
+            previous_generation,
+            generation,
+            hardswap,
+            coverage_ratio = format_args!("{coverage_ratio:.3}"),
+            min_ratio = format_args!("{min_ratio:.3}"),
+            drain_timeout_secs,
+            "ME map update covered; draining stale writers"
+        );
+        self.stats.increment_pool_swap_total();
+        for writer_id in stale_writer_ids {
+            self.mark_writer_draining_with_timeout(writer_id, drain_timeout, !hardswap)
+                .await;
+        }
+    }
+
     pub async fn update_proxy_maps(
         &self,
         new_v4: HashMap<i32, Vec<(IpAddr, u16)>>,
@@ -237,10 +498,10 @@ impl MePool {
             let mut guard = self.proxy_map_v4.write().await;
             let keys: Vec<i32> = guard.keys().cloned().collect();
             for k in keys.iter().cloned().filter(|k| *k > 0) {
-                if !guard.contains_key(&-k) {
-                    if let Some(addrs) = guard.get(&k).cloned() {
-                        guard.insert(-k, addrs);
-                    }
+                if !guard.contains_key(&-k)
+                    && let Some(addrs) = guard.get(&k).cloned()
+                {
+                    guard.insert(-k, addrs);
                 }
             }
         }
@@ -248,10 +509,10 @@ impl MePool {
             let mut guard = self.proxy_map_v6.write().await;
             let keys: Vec<i32> = guard.keys().cloned().collect();
             for k in keys.iter().cloned().filter(|k| *k > 0) {
-                if !guard.contains_key(&-k) {
-                    if let Some(addrs) = guard.get(&k).cloned() {
-                        guard.insert(-k, addrs);
-                    }
+                if !guard.contains_key(&-k)
+                    && let Some(addrs) = guard.get(&k).cloned()
+                {
+                    guard.insert(-k, addrs);
                 }
             }
         }
@@ -361,7 +622,6 @@ impl MePool {
 
         // Additional connections up to pool_size total (round-robin across DCs), staggered to de-phase lifecycles.
         if self.me_warmup_stagger_enabled {
-            let mut delay_ms = 0u64;
             for (dc, addrs) in dc_addrs.iter() {
                 for (ip, port) in addrs {
                     if self.connection_count() >= pool_size {
@@ -369,7 +629,7 @@ impl MePool {
                     }
                     let addr = SocketAddr::new(*ip, *port);
                     let jitter = rand::rng().random_range(0..=self.me_warmup_step_jitter.as_millis() as u64);
-                    delay_ms = delay_ms.saturating_add(self.me_warmup_step_delay.as_millis() as u64 + jitter);
+                    let delay_ms = self.me_warmup_step_delay.as_millis() as u64 + jitter;
                     tokio::time::sleep(Duration::from_millis(delay_ms)).await;
                     if let Err(e) = self.connect_one(addr, rng.as_ref()).await {
                         debug!(%addr, dc = %dc, error = %e, "Extra ME connect failed (staggered)");
@@ -414,18 +674,19 @@ impl MePool {
         let hs = self.handshake_only(stream, addr, rng).await?;
 
         let writer_id = self.next_writer_id.fetch_add(1, Ordering::Relaxed);
+        let generation = self.current_generation();
         let cancel = CancellationToken::new();
         let degraded = Arc::new(AtomicBool::new(false));
         let draining = Arc::new(AtomicBool::new(false));
+        let draining_started_at_epoch_secs = Arc::new(AtomicU64::new(0));
+        let allow_drain_fallback = Arc::new(AtomicBool::new(false));
         let (tx, mut rx) = mpsc::channel::<WriterCommand>(4096);
-        let tx_for_keepalive = tx.clone();
-        let keepalive_random = self.me_keepalive_payload_random;
-        let stats = self.stats.clone();
         let mut rpc_writer = RpcWriter {
             writer: hs.wr,
             key: hs.write_key,
             iv: hs.write_iv,
             seq_no: 0,
+            crc_mode: hs.crc_mode,
         };
         let cancel_wr = cancel.clone();
         tokio::spawn(async move {
@@ -439,21 +700,6 @@ impl MePool {
                             Some(WriterCommand::DataAndFlush(payload)) => {
                                 if rpc_writer.send_and_flush(&payload).await.is_err() { break; }
                             }
-                            Some(WriterCommand::Keepalive) => {
-                                let mut payload = [0u8; ME_KEEPALIVE_PAYLOAD_LEN];
-                                if keepalive_random {
-                                    rand::rng().fill(&mut payload);
-                                }
-                                match rpc_writer.send_keepalive(payload).await {
-                                    Ok(()) => {
-                                        stats.increment_me_keepalive_sent();
-                                    }
-                                    Err(_) => {
-                                        stats.increment_me_keepalive_failed();
-                                        break;
-                                    }
-                                }
-                            }
                             Some(WriterCommand::Close) | None => break,
                         }
                     }
@@ -464,19 +710,25 @@ impl MePool {
         let writer = MeWriter {
             id: writer_id,
             addr,
+            generation,
             tx: tx.clone(),
             cancel: cancel.clone(),
             degraded: degraded.clone(),
             draining: draining.clone(),
+            draining_started_at_epoch_secs: draining_started_at_epoch_secs.clone(),
+            allow_drain_fallback: allow_drain_fallback.clone(),
         };
         self.writers.write().await.push(writer.clone());
         self.conn_count.fetch_add(1, Ordering::Relaxed);
-        self.writer_available.notify_waiters();
+        self.writer_available.notify_one();
 
         let reg = self.registry.clone();
         let writers_arc = self.writers_arc();
         let ping_tracker = self.ping_tracker.clone();
+        let ping_tracker_reader = ping_tracker.clone();
         let rtt_stats = self.rtt_stats.clone();
+        let stats_reader = self.stats.clone();
+        let stats_ping = self.stats.clone();
         let pool = Arc::downgrade(self);
         let cancel_ping = cancel.clone();
         let tx_ping = tx.clone();
@@ -489,31 +741,31 @@ impl MePool {
         let keepalive_jitter = self.me_keepalive_jitter;
         let cancel_reader_token = cancel.clone();
         let cancel_ping_token = cancel_ping.clone();
-        let cancel_keepalive_token = cancel.clone();
 
         tokio::spawn(async move {
             let res = reader_loop(
                 hs.rd,
                 hs.read_key,
                 hs.read_iv,
+                hs.crc_mode,
                 reg.clone(),
                 BytesMut::new(),
                 BytesMut::new(),
                 tx.clone(),
-                ping_tracker.clone(),
+                ping_tracker_reader,
                 rtt_stats.clone(),
+                stats_reader,
                 writer_id,
                 degraded.clone(),
                 cancel_reader_token.clone(),
             )
             .await;
-            if let Some(pool) = pool.upgrade() {
-                if cleanup_for_reader
+            if let Some(pool) = pool.upgrade()
+                && cleanup_for_reader
                     .compare_exchange(false, true, Ordering::AcqRel, Ordering::Relaxed)
                     .is_ok()
-                {
-                    pool.remove_writer_and_close_clients(writer_id).await;
-                }
+            {
+                pool.remove_writer_and_close_clients(writer_id).await;
             }
             if let Err(e) = res {
                 warn!(error = %e, "ME reader ended");
@@ -526,15 +778,40 @@ impl MePool {
         let pool_ping = Arc::downgrade(self);
         tokio::spawn(async move {
             let mut ping_id: i64 = rand::random::<i64>();
-            loop {
+            // Per-writer jittered start to avoid phase sync.
+            let startup_jitter = if keepalive_enabled {
+                let jitter_cap_ms = keepalive_interval.as_millis() / 2;
+                let effective_jitter_ms = keepalive_jitter.as_millis().min(jitter_cap_ms).max(1);
+                Duration::from_millis(rand::rng().random_range(0..=effective_jitter_ms as u64))
+            } else {
                 let jitter = rand::rng()
                     .random_range(-ME_ACTIVE_PING_JITTER_SECS..=ME_ACTIVE_PING_JITTER_SECS);
                 let wait = (ME_ACTIVE_PING_SECS as i64 + jitter).max(5) as u64;
+                Duration::from_secs(wait)
+            };
+            tokio::select! {
+                _ = cancel_ping_token.cancelled() => return,
+                _ = tokio::time::sleep(startup_jitter) => {}
+            }
+            loop {
+                let wait = if keepalive_enabled {
+                    let jitter_cap_ms = keepalive_interval.as_millis() / 2;
+                    let effective_jitter_ms = keepalive_jitter.as_millis().min(jitter_cap_ms).max(1);
+                    keepalive_interval
+                        + Duration::from_millis(
+                            rand::rng().random_range(0..=effective_jitter_ms as u64)
+                        )
+                } else {
+                    let jitter = rand::rng()
+                        .random_range(-ME_ACTIVE_PING_JITTER_SECS..=ME_ACTIVE_PING_JITTER_SECS);
+                    let secs = (ME_ACTIVE_PING_SECS as i64 + jitter).max(5) as u64;
+                    Duration::from_secs(secs)
+                };
                 tokio::select! {
                     _ = cancel_ping_token.cancelled() => {
                         break;
                     }
-                    _ = tokio::time::sleep(Duration::from_secs(wait)) => {}
+                    _ = tokio::time::sleep(wait) => {}
                 }
                 let sent_id = ping_id;
                 let mut p = Vec::with_capacity(12);
@@ -542,45 +819,32 @@ impl MePool {
                 p.extend_from_slice(&sent_id.to_le_bytes());
                 {
                     let mut tracker = ping_tracker_ping.lock().await;
+                    let before = tracker.len();
                     tracker.retain(|_, (ts, _)| ts.elapsed() < Duration::from_secs(120));
+                    let expired = before.saturating_sub(tracker.len());
+                    if expired > 0 {
+                        stats_ping.increment_me_keepalive_timeout_by(expired as u64);
+                    }
                     tracker.insert(sent_id, (std::time::Instant::now(), writer_id));
                 }
                 ping_id = ping_id.wrapping_add(1);
+                stats_ping.increment_me_keepalive_sent();
                 if tx_ping.send(WriterCommand::DataAndFlush(p)).await.is_err() {
-                    debug!("Active ME ping failed, removing dead writer");
+                    stats_ping.increment_me_keepalive_failed();
+                    debug!("ME ping failed, removing dead writer");
                     cancel_ping.cancel();
-                    if let Some(pool) = pool_ping.upgrade() {
-                        if cleanup_for_ping
+                    if let Some(pool) = pool_ping.upgrade()
+                        && cleanup_for_ping
                             .compare_exchange(false, true, Ordering::AcqRel, Ordering::Relaxed)
                             .is_ok()
-                        {
-                            pool.remove_writer_and_close_clients(writer_id).await;
-                        }
+                    {
+                        pool.remove_writer_and_close_clients(writer_id).await;
                     }
                     break;
                 }
             }
         });
 
-        if keepalive_enabled {
-            let tx_keepalive = tx_for_keepalive;
-            let cancel_keepalive = cancel_keepalive_token;
-            tokio::spawn(async move {
-                // Per-writer jittered start to avoid phase sync.
-                let initial_jitter_ms = rand::rng().random_range(0..=keepalive_jitter.as_millis().max(1) as u64);
-                tokio::time::sleep(Duration::from_millis(initial_jitter_ms)).await;
-                loop {
-                    tokio::select! {
-                        _ = cancel_keepalive.cancelled() => break,
-                        _ = tokio::time::sleep(keepalive_interval + Duration::from_millis(rand::rng().random_range(0..=keepalive_jitter.as_millis() as u64))) => {}
-                    }
-                    if tx_keepalive.send(WriterCommand::Keepalive).await.is_err() {
-                        break;
-                    }
-                }
-            });
-        }
-
         Ok(())
     }
 
@@ -617,51 +881,113 @@ impl MePool {
     }
 
     async fn remove_writer_only(&self, writer_id: u64) -> Vec<BoundConn> {
+        let mut close_tx: Option<mpsc::Sender<WriterCommand>> = None;
         {
             let mut ws = self.writers.write().await;
             if let Some(pos) = ws.iter().position(|w| w.id == writer_id) {
                 let w = ws.remove(pos);
+                if w.draining.load(Ordering::Relaxed) {
+                    self.stats.decrement_pool_drain_active();
+                }
                 w.cancel.cancel();
-                let _ = w.tx.send(WriterCommand::Close).await;
+                close_tx = Some(w.tx.clone());
                 self.conn_count.fetch_sub(1, Ordering::Relaxed);
             }
         }
+        if let Some(tx) = close_tx {
+            let _ = tx.send(WriterCommand::Close).await;
+        }
         self.rtt_stats.lock().await.remove(&writer_id);
         self.registry.writer_lost(writer_id).await
     }
 
-    pub(crate) async fn mark_writer_draining(self: &Arc<Self>, writer_id: u64) {
-        {
+    pub(crate) async fn mark_writer_draining_with_timeout(
+        self: &Arc<Self>,
+        writer_id: u64,
+        timeout: Option<Duration>,
+        allow_drain_fallback: bool,
+    ) {
+        let timeout = timeout.filter(|d| !d.is_zero());
+        let found = {
             let mut ws = self.writers.write().await;
             if let Some(w) = ws.iter_mut().find(|w| w.id == writer_id) {
+                let already_draining = w.draining.swap(true, Ordering::Relaxed);
+                w.allow_drain_fallback
+                    .store(allow_drain_fallback, Ordering::Relaxed);
+                w.draining_started_at_epoch_secs
+                    .store(Self::now_epoch_secs(), Ordering::Relaxed);
+                if !already_draining {
+                    self.stats.increment_pool_drain_active();
+                }
                 w.draining.store(true, Ordering::Relaxed);
+                true
+            } else {
+                false
             }
+        };
+
+        if !found {
+            return;
         }
 
+        let timeout_secs = timeout.map(|d| d.as_secs()).unwrap_or(0);
+        debug!(
+            writer_id,
+            timeout_secs,
+            allow_drain_fallback,
+            "ME writer marked draining"
+        );
+
         let pool = Arc::downgrade(self);
         tokio::spawn(async move {
-            let deadline = Instant::now() + Duration::from_secs(300);
-            loop {
-                if let Some(p) = pool.upgrade() {
-                    if Instant::now() >= deadline {
-                        warn!(writer_id, "Drain timeout, force-closing");
-                        let _ = p.remove_writer_and_close_clients(writer_id).await;
-                        break;
-                    }
-                    if p.registry.is_writer_empty(writer_id).await {
-                        let _ = p.remove_writer_only(writer_id).await;
-                        break;
-                    }
-                    tokio::time::sleep(Duration::from_secs(1)).await;
-                } else {
+            let deadline = timeout.map(|t| Instant::now() + t);
+            while let Some(p) = pool.upgrade() {
+                if let Some(deadline_at) = deadline
+                    && Instant::now() >= deadline_at
+                {
+                    warn!(writer_id, "Drain timeout, force-closing");
+                    p.stats.increment_pool_force_close_total();
+                    let _ = p.remove_writer_and_close_clients(writer_id).await;
                     break;
                 }
+                if p.registry.is_writer_empty(writer_id).await {
+                    let _ = p.remove_writer_only(writer_id).await;
+                    break;
+                }
+                tokio::time::sleep(Duration::from_secs(1)).await;
             }
         });
     }
 
+    pub(crate) async fn mark_writer_draining(self: &Arc<Self>, writer_id: u64) {
+        self.mark_writer_draining_with_timeout(writer_id, Some(Duration::from_secs(300)), false)
+            .await;
+    }
+
+    pub(super) fn writer_accepts_new_binding(&self, writer: &MeWriter) -> bool {
+        if !writer.draining.load(Ordering::Relaxed) {
+            return true;
+        }
+        if !writer.allow_drain_fallback.load(Ordering::Relaxed) {
+            return false;
+        }
+
+        let ttl_secs = self.me_pool_drain_ttl_secs.load(Ordering::Relaxed);
+        if ttl_secs == 0 {
+            return true;
+        }
+
+        let started = writer.draining_started_at_epoch_secs.load(Ordering::Relaxed);
+        if started == 0 {
+            return false;
+        }
+
+        Self::now_epoch_secs().saturating_sub(started) <= ttl_secs
+    }
+
 }
 
+#[allow(dead_code)]
 fn hex_dump(data: &[u8]) -> String {
     const MAX: usize = 64;
     let mut out = String::with_capacity(data.len() * 2 + 3);

src/transport/middle_proxy/pool_nat.rs

@@ -1,7 +1,7 @@
 use std::net::{IpAddr, Ipv4Addr};
 use std::time::Duration;
 
-use tracing::{info, warn, debug};
+use tracing::{info, warn};
 
 use crate::error::{ProxyError, Result};
 use crate::network::probe::is_bogon;
@@ -9,11 +9,14 @@ use crate::network::stun::{stun_probe_dual, IpFamily, StunProbeResult};
 
 use super::MePool;
 use std::time::Instant;
+
+#[allow(dead_code)]
 pub async fn stun_probe(stun_addr: Option<String>) -> Result<crate::network::stun::DualStunResult> {
     let stun_addr = stun_addr.unwrap_or_else(|| "stun.l.google.com:19302".to_string());
     stun_probe_dual(&stun_addr).await
 }
 
+#[allow(dead_code)]
 pub async fn detect_public_ip() -> Option<IpAddr> {
     fetch_public_ipv4_with_retry().await.ok().flatten().map(IpAddr::V4)
 }
@@ -22,7 +25,7 @@ impl MePool {
     pub(super) fn translate_ip_for_nat(&self, ip: IpAddr) -> IpAddr {
         let nat_ip = self
             .nat_ip_cfg
-            .or_else(|| self.nat_ip_detected.try_read().ok().and_then(|g| (*g).clone()));
+            .or_else(|| self.nat_ip_detected.try_read().ok().and_then(|g| *g));
 
         let Some(nat_ip) = nat_ip else {
             return ip;
@@ -72,7 +75,7 @@ impl MePool {
             return None;
         }
 
-        if let Some(ip) = self.nat_ip_detected.read().await.clone() {
+        if let Some(ip) = *self.nat_ip_detected.read().await {
             return Some(ip);
         }
 
@@ -99,17 +102,17 @@ impl MePool {
     ) -> Option<std::net::SocketAddr> {
         const STUN_CACHE_TTL: Duration = Duration::from_secs(600);
         // Backoff window
-        if let Some(until) = *self.stun_backoff_until.read().await {
-            if Instant::now() < until {
-                if let Ok(cache) = self.nat_reflection_cache.try_lock() {
-                    let slot = match family {
-                        IpFamily::V4 => cache.v4,
-                        IpFamily::V6 => cache.v6,
-                    };
-                    return slot.map(|(_, addr)| addr);
-                }
-                return None;
+        if let Some(until) = *self.stun_backoff_until.read().await
+            && Instant::now() < until
+        {
+            if let Ok(cache) = self.nat_reflection_cache.try_lock() {
+                let slot = match family {
+                    IpFamily::V4 => cache.v4,
+                    IpFamily::V6 => cache.v6,
+                };
+                return slot.map(|(_, addr)| addr);
             }
+            return None;
         }
 
         if let Ok(mut cache) = self.nat_reflection_cache.try_lock() {
@@ -117,10 +120,10 @@ impl MePool {
                 IpFamily::V4 => &mut cache.v4,
                 IpFamily::V6 => &mut cache.v6,
             };
-            if let Some((ts, addr)) = slot {
-                if ts.elapsed() < STUN_CACHE_TTL {
-                    return Some(*addr);
-                }
+            if let Some((ts, addr)) = slot
+                && ts.elapsed() < STUN_CACHE_TTL
+            {
+                return Some(*addr);
             }
         }
 

src/transport/middle_proxy/reader.rs

@@ -10,31 +10,33 @@ use tokio::sync::{Mutex, mpsc};
 use tokio_util::sync::CancellationToken;
 use tracing::{debug, trace, warn};
 
-use crate::crypto::{AesCbc, crc32};
+use crate::crypto::AesCbc;
 use crate::error::{ProxyError, Result};
 use crate::protocol::constants::*;
+use crate::stats::Stats;
 
-use super::codec::WriterCommand;
+use super::codec::{RpcChecksumMode, WriterCommand, rpc_crc};
+use super::registry::RouteResult;
 use super::{ConnRegistry, MeResponse};
 
 pub(crate) async fn reader_loop(
     mut rd: tokio::io::ReadHalf<TcpStream>,
     dk: [u8; 32],
     mut div: [u8; 16],
+    crc_mode: RpcChecksumMode,
     reg: Arc<ConnRegistry>,
     enc_leftover: BytesMut,
     mut dec: BytesMut,
     tx: mpsc::Sender<WriterCommand>,
     ping_tracker: Arc<Mutex<HashMap<i64, (Instant, u64)>>>,
     rtt_stats: Arc<Mutex<HashMap<u64, (f64, f64)>>>,
+    stats: Arc<Stats>,
     _writer_id: u64,
     degraded: Arc<AtomicBool>,
     cancel: CancellationToken,
 ) -> Result<()> {
     let mut raw = enc_leftover;
     let mut expected_seq: i32 = 0;
-    let mut crc_errors = 0u32;
-    let mut seq_mismatch = 0u32;
 
     loop {
         let mut tmp = [0u8; 16_384];
@@ -80,26 +82,28 @@ pub(crate) async fn reader_loop(
             let frame = dec.split_to(fl);
             let pe = fl - 4;
             let ec = u32::from_le_bytes(frame[pe..pe + 4].try_into().unwrap());
-            if crc32(&frame[..pe]) != ec {
-                warn!("CRC mismatch in data frame");
-                crc_errors += 1;
-                if crc_errors > 3 {
-                    return Err(ProxyError::Proxy("Too many CRC mismatches".into()));
-                }
-                continue;
+            let actual_crc = rpc_crc(crc_mode, &frame[..pe]);
+            if actual_crc != ec {
+                stats.increment_me_crc_mismatch();
+                warn!(
+                    frame_len = fl,
+                    expected_crc = format_args!("0x{ec:08x}"),
+                    actual_crc = format_args!("0x{actual_crc:08x}"),
+                    "CRC mismatch — CBC crypto desync, aborting ME connection"
+                );
+                return Err(ProxyError::Proxy("CRC mismatch (crypto desync)".into()));
             }
 
             let seq_no = i32::from_le_bytes(frame[4..8].try_into().unwrap());
             if seq_no != expected_seq {
+                stats.increment_me_seq_mismatch();
                 warn!(seq_no, expected = expected_seq, "ME RPC seq mismatch");
-                seq_mismatch += 1;
-                if seq_mismatch > 10 {
-                    return Err(ProxyError::Proxy("Too many seq mismatches".into()));
-                }
-                expected_seq = seq_no.wrapping_add(1);
-            } else {
-                expected_seq = expected_seq.wrapping_add(1);
+                return Err(ProxyError::SeqNoMismatch {
+                    expected: expected_seq,
+                    got: seq_no,
+                });
             }
+            expected_seq = expected_seq.wrapping_add(1);
 
             let payload = &frame[8..pe];
             if payload.len() < 4 {
@@ -116,7 +120,13 @@ pub(crate) async fn reader_loop(
                 trace!(cid, flags, len = data.len(), "RPC_PROXY_ANS");
 
                 let routed = reg.route(cid, MeResponse::Data { flags, data }).await;
-                if !routed {
+                if !matches!(routed, RouteResult::Routed) {
+                    match routed {
+                        RouteResult::NoConn => stats.increment_me_route_drop_no_conn(),
+                        RouteResult::ChannelClosed => stats.increment_me_route_drop_channel_closed(),
+                        RouteResult::QueueFull => stats.increment_me_route_drop_queue_full(),
+                        RouteResult::Routed => {}
+                    }
                     reg.unregister(cid).await;
                     send_close_conn(&tx, cid).await;
                 }
@@ -126,7 +136,13 @@ pub(crate) async fn reader_loop(
                 trace!(cid, cfm, "RPC_SIMPLE_ACK");
 
                 let routed = reg.route(cid, MeResponse::Ack(cfm)).await;
-                if !routed {
+                if !matches!(routed, RouteResult::Routed) {
+                    match routed {
+                        RouteResult::NoConn => stats.increment_me_route_drop_no_conn(),
+                        RouteResult::ChannelClosed => stats.increment_me_route_drop_channel_closed(),
+                        RouteResult::QueueFull => stats.increment_me_route_drop_queue_full(),
+                        RouteResult::Routed => {}
+                    }
                     reg.unregister(cid).await;
                     send_close_conn(&tx, cid).await;
                 }
@@ -152,6 +168,7 @@ pub(crate) async fn reader_loop(
                 }
             } else if pt == RPC_PONG_U32 && body.len() >= 8 {
                 let ping_id = i64::from_le_bytes(body[0..8].try_into().unwrap());
+                stats.increment_me_keepalive_pong();
                 if let Some((sent, wid)) = {
                     let mut guard = ping_tracker.lock().await;
                     guard.remove(&ping_id)

src/transport/middle_proxy/registry.rs

@@ -1,14 +1,27 @@
 use std::collections::{HashMap, HashSet};
 use std::net::SocketAddr;
 use std::sync::atomic::{AtomicU64, Ordering};
-use std::sync::Arc;
+use std::time::Duration;
 
-use tokio::sync::{mpsc, Mutex, RwLock};
+use tokio::sync::{mpsc, RwLock};
+use tokio::sync::mpsc::error::TrySendError;
 
 use super::codec::WriterCommand;
 use super::MeResponse;
 
+const ROUTE_CHANNEL_CAPACITY: usize = 4096;
+const ROUTE_BACKPRESSURE_TIMEOUT: Duration = Duration::from_millis(25);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum RouteResult {
+    Routed,
+    NoConn,
+    ChannelClosed,
+    QueueFull,
+}
+
 #[derive(Clone)]
+#[allow(dead_code)]
 pub struct ConnMeta {
     pub target_dc: i16,
     pub client_addr: SocketAddr,
@@ -17,6 +30,7 @@ pub struct ConnMeta {
 }
 
 #[derive(Clone)]
+#[allow(dead_code)]
 pub struct BoundConn {
     pub conn_id: u64,
     pub meta: ConnMeta,
@@ -64,7 +78,7 @@ impl ConnRegistry {
 
     pub async fn register(&self) -> (u64, mpsc::Receiver<MeResponse>) {
         let id = self.next_id.fetch_add(1, Ordering::Relaxed);
-        let (tx, rx) = mpsc::channel(1024);
+        let (tx, rx) = mpsc::channel(ROUTE_CHANNEL_CAPACITY);
         self.inner.write().await.map.insert(id, tx);
         (id, rx)
     }
@@ -83,12 +97,27 @@ impl ConnRegistry {
         None
     }
 
-    pub async fn route(&self, id: u64, resp: MeResponse) -> bool {
-        let inner = self.inner.read().await;
-        if let Some(tx) = inner.map.get(&id) {
-            tx.try_send(resp).is_ok()
-        } else {
-            false
+    pub async fn route(&self, id: u64, resp: MeResponse) -> RouteResult {
+        let tx = {
+            let inner = self.inner.read().await;
+            inner.map.get(&id).cloned()
+        };
+
+        let Some(tx) = tx else {
+            return RouteResult::NoConn;
+        };
+
+        match tx.try_send(resp) {
+            Ok(()) => RouteResult::Routed,
+            Err(TrySendError::Closed(_)) => RouteResult::ChannelClosed,
+            Err(TrySendError::Full(resp)) => {
+                // Absorb short bursts without dropping/closing the session immediately.
+                match tokio::time::timeout(ROUTE_BACKPRESSURE_TIMEOUT, tx.send(resp)).await {
+                    Ok(Ok(())) => RouteResult::Routed,
+                    Ok(Err(_)) => RouteResult::ChannelClosed,
+                    Err(_) => RouteResult::QueueFull,
+                }
+            }
         }
     }
 
@@ -140,6 +169,7 @@ impl ConnRegistry {
         out
     }
 
+    #[allow(dead_code)]
     pub async fn get_meta(&self, conn_id: u64) -> Option<ConnMeta> {
         let inner = self.inner.read().await;
         inner.meta.get(&conn_id).cloned()

src/transport/middle_proxy/secret.rs

@@ -1,17 +1,45 @@
-use std::time::Duration;
-
 use tracing::{debug, info, warn};
 use std::time::SystemTime;
 use httpdate;
 
 use crate::error::{ProxyError, Result};
 
+pub const PROXY_SECRET_MIN_LEN: usize = 32;
+
+pub(super) fn validate_proxy_secret_len(data_len: usize, max_len: usize) -> Result<()> {
+    if max_len < PROXY_SECRET_MIN_LEN {
+        return Err(ProxyError::Proxy(format!(
+            "proxy-secret max length is invalid: {} bytes (must be >= {})",
+            max_len,
+            PROXY_SECRET_MIN_LEN
+        )));
+    }
+
+    if data_len < PROXY_SECRET_MIN_LEN {
+        return Err(ProxyError::Proxy(format!(
+            "proxy-secret too short: {} bytes (need >= {})",
+            data_len,
+            PROXY_SECRET_MIN_LEN
+        )));
+    }
+
+    if data_len > max_len {
+        return Err(ProxyError::Proxy(format!(
+            "proxy-secret too long: {} bytes (limit = {})",
+            data_len,
+            max_len
+        )));
+    }
+
+    Ok(())
+}
+
 /// Fetch Telegram proxy-secret binary.
-pub async fn fetch_proxy_secret(cache_path: Option<&str>) -> Result<Vec<u8>> {
+pub async fn fetch_proxy_secret(cache_path: Option<&str>, max_len: usize) -> Result<Vec<u8>> {
     let cache = cache_path.unwrap_or("proxy-secret");
 
     // 1) Try fresh download first.
-    match download_proxy_secret().await {
+    match download_proxy_secret_with_max_len(max_len).await {
         Ok(data) => {
             if let Err(e) = tokio::fs::write(cache, &data).await {
                 warn!(error = %e, "Failed to cache proxy-secret (non-fatal)");
@@ -26,9 +54,9 @@ pub async fn fetch_proxy_secret(cache_path: Option<&str>) -> Result<Vec<u8>> {
         }
     }
 
-    // 2) Fallback to cache/file regardless of age; require len>=32.
+    // 2) Fallback to cache/file regardless of age; require len in bounds.
     match tokio::fs::read(cache).await {
-        Ok(data) if data.len() >= 32 => {
+        Ok(data) if validate_proxy_secret_len(data.len(), max_len).is_ok() => {
             let age_hours = tokio::fs::metadata(cache)
                 .await
                 .ok()
@@ -43,17 +71,14 @@ pub async fn fetch_proxy_secret(cache_path: Option<&str>) -> Result<Vec<u8>> {
             );
             Ok(data)
         }
-        Ok(data) => Err(ProxyError::Proxy(format!(
-            "Cached proxy-secret too short: {} bytes (need >= 32)",
-            data.len()
-        ))),
+        Ok(data) => validate_proxy_secret_len(data.len(), max_len).map(|_| data),
         Err(e) => Err(ProxyError::Proxy(format!(
             "Failed to read proxy-secret cache after download failure: {e}"
         ))),
     }
 }
 
-pub async fn download_proxy_secret() -> Result<Vec<u8>> {
+pub async fn download_proxy_secret_with_max_len(max_len: usize) -> Result<Vec<u8>> {
     let resp = reqwest::get("https://core.telegram.org/getProxySecret")
         .await
         .map_err(|e| ProxyError::Proxy(format!("Failed to download proxy-secret: {e}")))?;
@@ -65,20 +90,18 @@ pub async fn download_proxy_secret() -> Result<Vec<u8>> {
         )));
     }
 
-    if let Some(date) = resp.headers().get(reqwest::header::DATE) {
-        if let Ok(date_str) = date.to_str() {
-            if let Ok(server_time) = httpdate::parse_http_date(date_str) {
-                if let Ok(skew) = SystemTime::now().duration_since(server_time).or_else(|e| {
-                    server_time.duration_since(SystemTime::now()).map_err(|_| e)
-                }) {
-                    let skew_secs = skew.as_secs();
-                    if skew_secs > 60 {
-                        warn!(skew_secs, "Time skew >60s detected from proxy-secret Date header");
-                    } else if skew_secs > 30 {
-                        warn!(skew_secs, "Time skew >30s detected from proxy-secret Date header");
-                    }
-                }
-            }
+    if let Some(date) = resp.headers().get(reqwest::header::DATE)
+        && let Ok(date_str) = date.to_str()
+        && let Ok(server_time) = httpdate::parse_http_date(date_str)
+        && let Ok(skew) = SystemTime::now().duration_since(server_time).or_else(|e| {
+            server_time.duration_since(SystemTime::now()).map_err(|_| e)
+        })
+    {
+        let skew_secs = skew.as_secs();
+        if skew_secs > 60 {
+            warn!(skew_secs, "Time skew >60s detected from proxy-secret Date header");
+        } else if skew_secs > 30 {
+            warn!(skew_secs, "Time skew >30s detected from proxy-secret Date header");
         }
     }
 
@@ -88,12 +111,7 @@ pub async fn download_proxy_secret() -> Result<Vec<u8>> {
         .map_err(|e| ProxyError::Proxy(format!("Read proxy-secret body: {e}")))?
         .to_vec();
 
-    if data.len() < 32 {
-        return Err(ProxyError::Proxy(format!(
-            "proxy-secret too short: {} bytes (need >= 32)",
-            data.len()
-        )));
-    }
+    validate_proxy_secret_len(data.len(), max_len)?;
 
     info!(len = data.len(), "Downloaded proxy-secret OK");
     Ok(data)

src/transport/middle_proxy/send.rs

@@ -62,6 +62,8 @@ impl MePool {
             let mut writers_snapshot = {
                 let ws = self.writers.read().await;
                 if ws.is_empty() {
+                    // Create waiter before recovery attempts so notify_one permits are not missed.
+                    let waiter = self.writer_available.notified();
                     drop(ws);
                     for family in self.family_order() {
                         let map = match family {
@@ -72,13 +74,19 @@ impl MePool {
                             for (ip, port) in addrs {
                                 let addr = SocketAddr::new(*ip, *port);
                                 if self.connect_one(addr, self.rng.as_ref()).await.is_ok() {
-                                    self.writer_available.notify_waiters();
+                                    self.writer_available.notify_one();
                                     break;
                                 }
                             }
                         }
                     }
-                    if tokio::time::timeout(Duration::from_secs(3), self.writer_available.notified()).await.is_err() {
+                    if !self.writers.read().await.is_empty() {
+                        continue;
+                    }
+                    if tokio::time::timeout(Duration::from_secs(3), waiter).await.is_err() {
+                        if !self.writers.read().await.is_empty() {
+                            continue;
+                        }
                         return Err(ProxyError::Proxy("All ME connections dead (waited 3s)".into()));
                     }
                     continue;
@@ -126,8 +134,8 @@ impl MePool {
             candidate_indices.sort_by_key(|idx| {
                 let w = &writers_snapshot[*idx];
                 let degraded = w.degraded.load(Ordering::Relaxed);
-                let draining = w.draining.load(Ordering::Relaxed);
-                (draining as usize, degraded as usize)
+                let stale = (w.generation < self.current_generation()) as usize;
+                (stale, degraded as usize)
             });
 
             let start = self.rr.fetch_add(1, Ordering::Relaxed) as usize % candidate_indices.len();
@@ -135,13 +143,23 @@ impl MePool {
             for offset in 0..candidate_indices.len() {
                 let idx = candidate_indices[(start + offset) % candidate_indices.len()];
                 let w = &writers_snapshot[idx];
-                if w.draining.load(Ordering::Relaxed) {
+                if !self.writer_accepts_new_binding(w) {
                     continue;
                 }
                 if w.tx.send(WriterCommand::Data(payload.clone())).await.is_ok() {
                     self.registry
                         .bind_writer(conn_id, w.id, w.tx.clone(), meta.clone())
                         .await;
+                    if w.generation < self.current_generation() {
+                        self.stats.increment_pool_stale_pick_total();
+                        debug!(
+                            conn_id,
+                            writer_id = w.id,
+                            writer_generation = w.generation,
+                            current_generation = self.current_generation(),
+                            "Selected stale ME writer for fallback bind"
+                        );
+                    }
                     return Ok(());
                 } else {
                     warn!(writer_id = w.id, "ME writer channel closed");
@@ -151,7 +169,7 @@ impl MePool {
             }
 
             let w = writers_snapshot[candidate_indices[start]].clone();
-            if w.draining.load(Ordering::Relaxed) {
+            if !self.writer_accepts_new_binding(&w) {
                 continue;
             }
             match w.tx.send(WriterCommand::Data(payload.clone())).await {
@@ -159,6 +177,9 @@ impl MePool {
                     self.registry
                         .bind_writer(conn_id, w.id, w.tx.clone(), meta.clone())
                         .await;
+                    if w.generation < self.current_generation() {
+                        self.stats.increment_pool_stale_pick_total();
+                    }
                     return Ok(());
                 }
                 Err(_) => {
@@ -221,10 +242,10 @@ impl MePool {
             }
             if preferred.is_empty() {
                 let def = self.default_dc.load(Ordering::Relaxed);
-                if def != 0 {
-                    if let Some(v) = map_guard.get(&def) {
-                        preferred.extend(v.iter().map(|(ip, port)| SocketAddr::new(*ip, *port)));
-                    }
+                if def != 0
+                    && let Some(v) = map_guard.get(&def)
+                {
+                    preferred.extend(v.iter().map(|(ip, port)| SocketAddr::new(*ip, *port)));
                 }
             }
 
@@ -237,22 +258,22 @@ impl MePool {
 
         if preferred.is_empty() {
             return (0..writers.len())
-                .filter(|i| !writers[*i].draining.load(Ordering::Relaxed))
+                .filter(|i| self.writer_accepts_new_binding(&writers[*i]))
                 .collect();
         }
 
         let mut out = Vec::new();
         for (idx, w) in writers.iter().enumerate() {
-            if w.draining.load(Ordering::Relaxed) {
+            if !self.writer_accepts_new_binding(w) {
                 continue;
             }
-            if preferred.iter().any(|p| *p == w.addr) {
+            if preferred.contains(&w.addr) {
                 out.push(idx);
             }
         }
         if out.is_empty() {
             return (0..writers.len())
-                .filter(|i| !writers[*i].draining.load(Ordering::Relaxed))
+                .filter(|i| self.writer_accepts_new_binding(&writers[*i]))
                 .collect();
         }
         out

src/transport/mod.rs

@@ -6,9 +6,13 @@ pub mod socket;
 pub mod socks;
 pub mod upstream;
 
+#[allow(unused_imports)]
 pub use pool::ConnectionPool;
+#[allow(unused_imports)]
 pub use proxy_protocol::{ProxyProtocolInfo, parse_proxy_protocol};
 pub use socket::*;
+#[allow(unused_imports)]
 pub use socks::*;
+#[allow(unused_imports)]
 pub use upstream::{DcPingResult, StartupPingResult, UpstreamManager};
 pub mod middle_proxy;

src/transport/pool.rs

@@ -1,5 +1,7 @@
 //! Connection Pool
 
+#![allow(dead_code)]
+
 use std::collections::HashMap;
 use std::net::SocketAddr;
 use std::sync::Arc;
@@ -8,7 +10,7 @@ use tokio::net::TcpStream;
 use tokio::sync::Mutex;
 use tokio::time::timeout;
 use parking_lot::RwLock;
-use tracing::{debug, warn};
+use tracing::debug;
 use crate::error::{ProxyError, Result};
 use super::socket::configure_tcp_socket;
 

src/transport/proxy_protocol.rs

@@ -28,6 +28,7 @@ mod address_family {
 
 /// Information extracted from PROXY protocol header
 #[derive(Debug, Clone)]
+#[allow(dead_code)]
 pub struct ProxyProtocolInfo {
     /// Source (client) address
     pub src_addr: SocketAddr,
@@ -37,6 +38,7 @@ pub struct ProxyProtocolInfo {
     pub version: u8,
 }
 
+#[allow(dead_code)]
 impl ProxyProtocolInfo {
     /// Create info with just source address
     pub fn new(src_addr: SocketAddr) -> Self {
@@ -231,12 +233,14 @@ async fn parse_v2<R: AsyncRead + Unpin>(
 }
 
 /// Builder for PROXY protocol v1 header
+#[allow(dead_code)]
 pub struct ProxyProtocolV1Builder {
     family: &'static str,
     src_addr: Option<SocketAddr>,
     dst_addr: Option<SocketAddr>,
 }
 
+#[allow(dead_code)]
 impl ProxyProtocolV1Builder {
     pub fn new() -> Self {
         Self {
@@ -284,11 +288,13 @@ impl Default for ProxyProtocolV1Builder {
 }
 
 /// Builder for PROXY protocol v2 header
+#[allow(dead_code)]
 pub struct ProxyProtocolV2Builder {
     src: Option<SocketAddr>,
     dst: Option<SocketAddr>,
 }
 
+#[allow(dead_code)]
 impl ProxyProtocolV2Builder {
     pub fn new() -> Self {
         Self { src: None, dst: None }

src/transport/socket.rs

@@ -1,5 +1,7 @@
 //! TCP Socket Configuration
 
+use std::collections::HashSet;
+use std::fs;
 use std::io::Result;
 use std::net::{SocketAddr, IpAddr};
 use std::time::Duration;
@@ -8,6 +10,7 @@ use socket2::{Socket, TcpKeepalive, Domain, Type, Protocol};
 use tracing::debug;
 
 /// Configure TCP socket with recommended settings for proxy use
+#[allow(dead_code)]
 pub fn configure_tcp_socket(
     stream: &TcpStream,
     keepalive: bool,
@@ -80,6 +83,7 @@ pub fn configure_client_socket(
 }
 
 /// Set socket to send RST on close (for masking)
+#[allow(dead_code)]
 pub fn set_linger_zero(stream: &TcpStream) -> Result<()> {
     let socket = socket2::SockRef::from(stream);
     socket.set_linger(Some(Duration::ZERO))?;
@@ -87,6 +91,7 @@ pub fn set_linger_zero(stream: &TcpStream) -> Result<()> {
 }
 
 /// Create a new TCP socket for outgoing connections
+#[allow(dead_code)]
 pub fn create_outgoing_socket(addr: SocketAddr) -> Result<Socket> {
     create_outgoing_socket_bound(addr, None)
 }
@@ -118,6 +123,7 @@ pub fn create_outgoing_socket_bound(addr: SocketAddr, bind_addr: Option<IpAddr>)
 
 
 /// Get local address of a socket
+#[allow(dead_code)]
 pub fn get_local_addr(stream: &TcpStream) -> Option<SocketAddr> {
     stream.local_addr().ok()
 }
@@ -130,17 +136,17 @@ pub fn resolve_interface_ip(name: &str, want_ipv6: bool) -> Option<IpAddr> {
 
     if let Ok(addrs) = getifaddrs() {
         for iface in addrs {
-            if iface.interface_name == name {
-                if let Some(address) = iface.address {
-                    if let Some(v4) = address.as_sockaddr_in() {
-                        if !want_ipv6 {
-                            return Some(IpAddr::V4(v4.ip()));
-                        }
-                    } else if let Some(v6) = address.as_sockaddr_in6() {
-                        if want_ipv6 {
-                            return Some(IpAddr::V6(v6.ip().clone()));
-                        }
+            if iface.interface_name == name
+                && let Some(address) = iface.address
+            {
+                if let Some(v4) = address.as_sockaddr_in() {
+                    if !want_ipv6 {
+                        return Some(IpAddr::V4(v4.ip()));
                     }
+                } else if let Some(v6) = address.as_sockaddr_in6()
+                    && want_ipv6
+                {
+                    return Some(IpAddr::V6(v6.ip()));
                 }
             }
         }
@@ -155,11 +161,13 @@ pub fn resolve_interface_ip(_name: &str, _want_ipv6: bool) -> Option<IpAddr> {
 }
 
 /// Get peer address of a socket
+#[allow(dead_code)]
 pub fn get_peer_addr(stream: &TcpStream) -> Option<SocketAddr> {
     stream.peer_addr().ok()
 }
 
 /// Check if address is IPv6
+#[allow(dead_code)]
 pub fn is_ipv6(addr: &SocketAddr) -> bool {
     addr.is_ipv6()
 }
@@ -234,6 +242,133 @@ pub fn create_listener(addr: SocketAddr, options: &ListenOptions) -> Result<Sock
     Ok(socket)
 }
 
+/// Best-effort process list for listeners occupying the same local TCP port.
+#[derive(Debug, Clone)]
+pub struct ListenerProcessInfo {
+    pub pid: u32,
+    pub process: String,
+}
+
+/// Find processes currently listening on the local TCP port of `addr`.
+/// Returns an empty list when unsupported or when no owners can be resolved.
+pub fn find_listener_processes(addr: SocketAddr) -> Vec<ListenerProcessInfo> {
+    #[cfg(target_os = "linux")]
+    {
+        find_listener_processes_linux(addr)
+    }
+    #[cfg(not(target_os = "linux"))]
+    {
+        let _ = addr;
+        Vec::new()
+    }
+}
+
+#[cfg(target_os = "linux")]
+fn find_listener_processes_linux(addr: SocketAddr) -> Vec<ListenerProcessInfo> {
+    let inodes = listening_inodes_for_port(addr);
+    if inodes.is_empty() {
+        return Vec::new();
+    }
+
+    let mut out = Vec::new();
+
+    let proc_entries = match fs::read_dir("/proc") {
+        Ok(entries) => entries,
+        Err(_) => return out,
+    };
+
+    for entry in proc_entries.flatten() {
+        let pid = match entry.file_name().to_string_lossy().parse::<u32>() {
+            Ok(pid) => pid,
+            Err(_) => continue,
+        };
+
+        let fd_dir = entry.path().join("fd");
+        let fd_entries = match fs::read_dir(fd_dir) {
+            Ok(entries) => entries,
+            Err(_) => continue,
+        };
+
+        let mut matched = false;
+        for fd in fd_entries.flatten() {
+            let link_target = match fs::read_link(fd.path()) {
+                Ok(link) => link,
+                Err(_) => continue,
+            };
+
+            let link_str = link_target.to_string_lossy();
+            let Some(rest) = link_str.strip_prefix("socket:[") else {
+                continue;
+            };
+            let Some(inode_str) = rest.strip_suffix(']') else {
+                continue;
+            };
+            let Ok(inode) = inode_str.parse::<u64>() else {
+                continue;
+            };
+
+            if inodes.contains(&inode) {
+                matched = true;
+                break;
+            }
+        }
+
+        if matched {
+            let process = fs::read_to_string(entry.path().join("comm"))
+                .ok()
+                .map(|s| s.trim().to_string())
+                .filter(|s| !s.is_empty())
+                .unwrap_or_else(|| "unknown".to_string());
+            out.push(ListenerProcessInfo { pid, process });
+        }
+    }
+
+    out.sort_by_key(|p| p.pid);
+    out.dedup_by_key(|p| p.pid);
+    out
+}
+
+#[cfg(target_os = "linux")]
+fn listening_inodes_for_port(addr: SocketAddr) -> HashSet<u64> {
+    let path = match addr {
+        SocketAddr::V4(_) => "/proc/net/tcp",
+        SocketAddr::V6(_) => "/proc/net/tcp6",
+    };
+
+    let mut inodes = HashSet::new();
+    let Ok(data) = fs::read_to_string(path) else {
+        return inodes;
+    };
+
+    for line in data.lines().skip(1) {
+        let cols: Vec<&str> = line.split_whitespace().collect();
+        if cols.len() < 10 {
+            continue;
+        }
+
+        // LISTEN state in /proc/net/tcp*
+        if cols[3] != "0A" {
+            continue;
+        }
+
+        let Some(port_hex) = cols[1].split(':').nth(1) else {
+            continue;
+        };
+        let Ok(port) = u16::from_str_radix(port_hex, 16) else {
+            continue;
+        };
+        if port != addr.port() {
+            continue;
+        }
+
+        if let Ok(inode) = cols[9].parse::<u64>() {
+            inodes.insert(inode);
+        }
+    }
+
+    inodes
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/transport/socks.rs

@@ -1,7 +1,7 @@
 //! SOCKS4/5 Client Implementation
 
 use std::net::{IpAddr, SocketAddr};
-use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpStream;
 use crate::error::{ProxyError, Result};
 
@@ -27,11 +27,11 @@ pub async fn connect_socks4(
     buf.extend_from_slice(user);
     buf.push(0); // NULL
     
-    stream.write_all(&buf).await.map_err(|e| ProxyError::Io(e))?;
+    stream.write_all(&buf).await.map_err(ProxyError::Io)?;
     
     // Response: VN (1) | CD (1) | DSTPORT (2) | DSTIP (4)
     let mut resp = [0u8; 8];
-    stream.read_exact(&mut resp).await.map_err(|e| ProxyError::Io(e))?;
+    stream.read_exact(&mut resp).await.map_err(ProxyError::Io)?;
     
     if resp[1] != 90 {
         return Err(ProxyError::Proxy(format!("SOCKS4 request rejected: code {}", resp[1])));
@@ -56,10 +56,10 @@ pub async fn connect_socks5(
     let mut buf = vec![5u8, methods.len() as u8];
     buf.extend_from_slice(&methods);
     
-    stream.write_all(&buf).await.map_err(|e| ProxyError::Io(e))?;
+    stream.write_all(&buf).await.map_err(ProxyError::Io)?;
     
     let mut resp = [0u8; 2];
-    stream.read_exact(&mut resp).await.map_err(|e| ProxyError::Io(e))?;
+    stream.read_exact(&mut resp).await.map_err(ProxyError::Io)?;
     
     if resp[0] != 5 {
         return Err(ProxyError::Proxy("Invalid SOCKS5 version".to_string()));
@@ -80,10 +80,10 @@ pub async fn connect_socks5(
                 auth_buf.push(p_bytes.len() as u8);
                 auth_buf.extend_from_slice(p_bytes);
                 
-                stream.write_all(&auth_buf).await.map_err(|e| ProxyError::Io(e))?;
+                stream.write_all(&auth_buf).await.map_err(ProxyError::Io)?;
                 
                 let mut auth_resp = [0u8; 2];
-                stream.read_exact(&mut auth_resp).await.map_err(|e| ProxyError::Io(e))?;
+                stream.read_exact(&mut auth_resp).await.map_err(ProxyError::Io)?;
                 
                 if auth_resp[1] != 0 {
                     return Err(ProxyError::Proxy("SOCKS5 authentication failed".to_string()));
@@ -112,11 +112,11 @@ pub async fn connect_socks5(
     
     req.extend_from_slice(&target.port().to_be_bytes());
     
-    stream.write_all(&req).await.map_err(|e| ProxyError::Io(e))?;
+    stream.write_all(&req).await.map_err(ProxyError::Io)?;
     
     // Response
     let mut head = [0u8; 4];
-    stream.read_exact(&mut head).await.map_err(|e| ProxyError::Io(e))?;
+    stream.read_exact(&mut head).await.map_err(ProxyError::Io)?;
     
     if head[1] != 0 {
         return Err(ProxyError::Proxy(format!("SOCKS5 request failed: code {}", head[1])));
@@ -126,17 +126,17 @@ pub async fn connect_socks5(
     match head[3] {
         1 => { // IPv4
             let mut addr = [0u8; 4 + 2];
-            stream.read_exact(&mut addr).await.map_err(|e| ProxyError::Io(e))?;
+            stream.read_exact(&mut addr).await.map_err(ProxyError::Io)?;
         },
         3 => { // Domain
             let mut len = [0u8; 1];
-            stream.read_exact(&mut len).await.map_err(|e| ProxyError::Io(e))?;
+            stream.read_exact(&mut len).await.map_err(ProxyError::Io)?;
             let mut addr = vec![0u8; len[0] as usize + 2];
-            stream.read_exact(&mut addr).await.map_err(|e| ProxyError::Io(e))?;
+            stream.read_exact(&mut addr).await.map_err(ProxyError::Io)?;
         },
         4 => { // IPv6
             let mut addr = [0u8; 16 + 2];
-            stream.read_exact(&mut addr).await.map_err(|e| ProxyError::Io(e))?;
+            stream.read_exact(&mut addr).await.map_err(ProxyError::Io)?;
         },
         _ => return Err(ProxyError::Proxy("Invalid address type in SOCKS5 response".to_string())),
     }

src/transport/upstream.rs

@@ -1,7 +1,9 @@
 //! Upstream Management with per-DC latency-weighted selection
-//! 
+//!
 //! IPv6/IPv4 connectivity checks with configurable preference.
 
+#![allow(deprecated)]
+
 use std::collections::HashMap;
 use std::net::{SocketAddr, IpAddr};
 use std::sync::Arc;
@@ -24,6 +26,8 @@ const NUM_DCS: usize = 5;
 
 /// Timeout for individual DC ping attempt
 const DC_PING_TIMEOUT_SECS: u64 = 5;
+/// Timeout for direct TG DC TCP connect readiness.
+const DIRECT_CONNECT_TIMEOUT_SECS: u64 = 10;
 
 // ============= RTT Tracking =============
 
@@ -53,9 +57,10 @@ impl LatencyEma {
 // ============= Per-DC IP Preference Tracking =============
 
 /// Tracks which IP version works for each DC
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub enum IpPreference {
     /// Not yet tested
+    #[default]
     Unknown,
     /// IPv6 works
     PreferV6,
@@ -67,12 +72,6 @@ pub enum IpPreference {
     Unavailable,
 }
 
-impl Default for IpPreference {
-    fn default() -> Self {
-        Self::Unknown
-    }
-}
-
 // ============= Upstream State =============
 
 #[derive(Debug)]
@@ -108,7 +107,7 @@ impl UpstreamState {
         if abs_dc == 0 {
             return None;
         }
-        if abs_dc >= 1 && abs_dc <= NUM_DCS {
+        if (1..=NUM_DCS).contains(&abs_dc) {
             Some(abs_dc - 1)
         } else {
             // Unknown DC → default cluster (DC 2, index 1)
@@ -118,10 +117,10 @@ impl UpstreamState {
 
     /// Get latency for a specific DC, falling back to average across all known DCs
     fn effective_latency(&self, dc_idx: Option<i16>) -> Option<f64> {
-        if let Some(di) = dc_idx.and_then(Self::dc_array_idx) {
-            if let Some(ms) = self.dc_latency[di].get() {
-                return Some(ms);
-            }
+        if let Some(di) = dc_idx.and_then(Self::dc_array_idx)
+            && let Some(ms) = self.dc_latency[di].get()
+        {
+            return Some(ms);
         }
 
         let (sum, count) = self.dc_latency.iter()
@@ -375,7 +374,16 @@ impl UpstreamManager {
                 let std_stream: std::net::TcpStream = socket.into();
                 let stream = TcpStream::from_std(std_stream)?;
 
-                stream.writable().await?;
+                let connect_timeout = Duration::from_secs(DIRECT_CONNECT_TIMEOUT_SECS);
+                match tokio::time::timeout(connect_timeout, stream.writable()).await {
+                    Ok(Ok(())) => {}
+                    Ok(Err(e)) => return Err(ProxyError::Io(e)),
+                    Err(_) => {
+                        return Err(ProxyError::ConnectionTimeout {
+                            addr: target.to_string(),
+                        });
+                    }
+                }
                 if let Some(e) = stream.take_error()? {
                     return Err(ProxyError::Io(e));
                 }
@@ -383,67 +391,128 @@ impl UpstreamManager {
                 Ok(stream)
             },
             UpstreamType::Socks4 { address, interface, user_id } => {
-                let proxy_addr: SocketAddr = address.parse()
-                    .map_err(|_| ProxyError::Config("Invalid SOCKS4 address".to_string()))?;
+                let connect_timeout = Duration::from_secs(DIRECT_CONNECT_TIMEOUT_SECS);
+                // Try to parse as SocketAddr first (IP:port), otherwise treat as hostname:port
+                let mut stream = if let Ok(proxy_addr) = address.parse::<SocketAddr>() {
+                    // IP:port format - use socket with optional interface binding
+                    let bind_ip = Self::resolve_bind_address(
+                        interface,
+                        &None,
+                        proxy_addr,
+                        bind_rr.as_deref(),
+                    );
 
-                let bind_ip = Self::resolve_bind_address(
-                    interface,
-                    &None,
-                    proxy_addr,
-                    bind_rr.as_deref(),
-                );
+                    let socket = create_outgoing_socket_bound(proxy_addr, bind_ip)?;
 
-                let socket = create_outgoing_socket_bound(proxy_addr, bind_ip)?;
+                    socket.set_nonblocking(true)?;
+                    match socket.connect(&proxy_addr.into()) {
+                        Ok(()) => {},
+                        Err(err) if err.raw_os_error() == Some(libc::EINPROGRESS) || err.kind() == std::io::ErrorKind::WouldBlock => {},
+                        Err(err) => return Err(ProxyError::Io(err)),
+                    }
 
-                socket.set_nonblocking(true)?;
-                match socket.connect(&proxy_addr.into()) {
-                    Ok(()) => {},
-                    Err(err) if err.raw_os_error() == Some(libc::EINPROGRESS) || err.kind() == std::io::ErrorKind::WouldBlock => {},
-                    Err(err) => return Err(ProxyError::Io(err)),
-                }
+                    let std_stream: std::net::TcpStream = socket.into();
+                    let stream = TcpStream::from_std(std_stream)?;
 
-                let std_stream: std::net::TcpStream = socket.into();
-                let mut stream = TcpStream::from_std(std_stream)?;
+                    match tokio::time::timeout(connect_timeout, stream.writable()).await {
+                        Ok(Ok(())) => {}
+                        Ok(Err(e)) => return Err(ProxyError::Io(e)),
+                        Err(_) => {
+                            return Err(ProxyError::ConnectionTimeout {
+                                addr: proxy_addr.to_string(),
+                            });
+                        }
+                    }
+                    if let Some(e) = stream.take_error()? {
+                        return Err(ProxyError::Io(e));
+                    }
+                    stream
+                } else {
+                    // Hostname:port format - use tokio DNS resolution
+                    // Note: interface binding is not supported for hostnames
+                    if interface.is_some() {
+                        warn!("SOCKS4 interface binding is not supported for hostname addresses, ignoring");
+                    }
+                    match tokio::time::timeout(connect_timeout, TcpStream::connect(address)).await {
+                        Ok(Ok(stream)) => stream,
+                        Ok(Err(e)) => return Err(ProxyError::Io(e)),
+                        Err(_) => {
+                            return Err(ProxyError::ConnectionTimeout {
+                                addr: address.clone(),
+                            });
+                        }
+                    }
+                };
 
-                stream.writable().await?;
-                if let Some(e) = stream.take_error()? {
-                    return Err(ProxyError::Io(e));
-                }
                 // replace socks user_id with config.selected_scope, if set
                 let scope: Option<&str> = Some(config.selected_scope.as_str())
                     .filter(|s| !s.is_empty());
                 let _user_id: Option<&str> = scope.or(user_id.as_deref());
 
-                connect_socks4(&mut stream, target, _user_id).await?;
+                match tokio::time::timeout(connect_timeout, connect_socks4(&mut stream, target, _user_id)).await {
+                    Ok(Ok(())) => {}
+                    Ok(Err(e)) => return Err(e),
+                    Err(_) => {
+                        return Err(ProxyError::ConnectionTimeout {
+                            addr: target.to_string(),
+                        });
+                    }
+                }
                 Ok(stream)
             },
             UpstreamType::Socks5 { address, interface, username, password } => {
-                let proxy_addr: SocketAddr = address.parse()
-                    .map_err(|_| ProxyError::Config("Invalid SOCKS5 address".to_string()))?;
+                let connect_timeout = Duration::from_secs(DIRECT_CONNECT_TIMEOUT_SECS);
+                // Try to parse as SocketAddr first (IP:port), otherwise treat as hostname:port
+                let mut stream = if let Ok(proxy_addr) = address.parse::<SocketAddr>() {
+                    // IP:port format - use socket with optional interface binding
+                    let bind_ip = Self::resolve_bind_address(
+                        interface,
+                        &None,
+                        proxy_addr,
+                        bind_rr.as_deref(),
+                    );
 
-                let bind_ip = Self::resolve_bind_address(
-                    interface,
-                    &None,
-                    proxy_addr,
-                    bind_rr.as_deref(),
-                );
+                    let socket = create_outgoing_socket_bound(proxy_addr, bind_ip)?;
 
-                let socket = create_outgoing_socket_bound(proxy_addr, bind_ip)?;
+                    socket.set_nonblocking(true)?;
+                    match socket.connect(&proxy_addr.into()) {
+                        Ok(()) => {},
+                        Err(err) if err.raw_os_error() == Some(libc::EINPROGRESS) || err.kind() == std::io::ErrorKind::WouldBlock => {},
+                        Err(err) => return Err(ProxyError::Io(err)),
+                    }
 
-                socket.set_nonblocking(true)?;
-                match socket.connect(&proxy_addr.into()) {
-                    Ok(()) => {},
-                    Err(err) if err.raw_os_error() == Some(libc::EINPROGRESS) || err.kind() == std::io::ErrorKind::WouldBlock => {},
-                    Err(err) => return Err(ProxyError::Io(err)),
-                }
+                    let std_stream: std::net::TcpStream = socket.into();
+                    let stream = TcpStream::from_std(std_stream)?;
 
-                let std_stream: std::net::TcpStream = socket.into();
-                let mut stream = TcpStream::from_std(std_stream)?;
-
-                stream.writable().await?;
-                if let Some(e) = stream.take_error()? {
-                    return Err(ProxyError::Io(e));
-                }
+                    match tokio::time::timeout(connect_timeout, stream.writable()).await {
+                        Ok(Ok(())) => {}
+                        Ok(Err(e)) => return Err(ProxyError::Io(e)),
+                        Err(_) => {
+                            return Err(ProxyError::ConnectionTimeout {
+                                addr: proxy_addr.to_string(),
+                            });
+                        }
+                    }
+                    if let Some(e) = stream.take_error()? {
+                        return Err(ProxyError::Io(e));
+                    }
+                    stream
+                } else {
+                    // Hostname:port format - use tokio DNS resolution
+                    // Note: interface binding is not supported for hostnames
+                    if interface.is_some() {
+                        warn!("SOCKS5 interface binding is not supported for hostname addresses, ignoring");
+                    }
+                    match tokio::time::timeout(connect_timeout, TcpStream::connect(address)).await {
+                        Ok(Ok(stream)) => stream,
+                        Ok(Err(e)) => return Err(ProxyError::Io(e)),
+                        Err(_) => {
+                            return Err(ProxyError::ConnectionTimeout {
+                                addr: address.clone(),
+                            });
+                        }
+                    }
+                };
 
                 debug!(config = ?config, "Socks5 connection");
                 // replace socks user:pass with config.selected_scope, if set
@@ -452,7 +521,20 @@ impl UpstreamManager {
                 let _username: Option<&str> = scope.or(username.as_deref());
                 let _password: Option<&str> = scope.or(password.as_deref());
 
-                connect_socks5(&mut stream, target, _username, _password).await?;
+                match tokio::time::timeout(
+                    connect_timeout,
+                    connect_socks5(&mut stream, target, _username, _password),
+                )
+                .await
+                {
+                    Ok(Ok(())) => {}
+                    Ok(Err(e)) => return Err(e),
+                    Err(_) => {
+                        return Err(ProxyError::ConnectionTimeout {
+                            addr: target.to_string(),
+                        });
+                    }
+                }
                 Ok(stream)
             },
         }
@@ -464,7 +546,7 @@ impl UpstreamManager {
     /// Tests BOTH IPv6 and IPv4, returns separate results for each.
     pub async fn ping_all_dcs(
         &self,
-        prefer_ipv6: bool,
+        _prefer_ipv6: bool,
         dc_overrides: &HashMap<String, Vec<String>>,
         ipv4_enabled: bool,
         ipv6_enabled: bool,
@@ -495,7 +577,7 @@ impl UpstreamManager {
 
                     let result = tokio::time::timeout(
                         Duration::from_secs(DC_PING_TIMEOUT_SECS),
-                        self.ping_single_dc(&upstream_config, Some(bind_rr.clone()), addr_v6)
+                        self.ping_single_dc(upstream_config, Some(bind_rr.clone()), addr_v6)
                     ).await;
 
                     let ping_result = match result {
@@ -546,7 +628,7 @@ impl UpstreamManager {
 
                     let result = tokio::time::timeout(
                         Duration::from_secs(DC_PING_TIMEOUT_SECS),
-                        self.ping_single_dc(&upstream_config, Some(bind_rr.clone()), addr_v4)
+                        self.ping_single_dc(upstream_config, Some(bind_rr.clone()), addr_v4)
                     ).await;
 
                     let ping_result = match result {
@@ -609,7 +691,7 @@ impl UpstreamManager {
                             }
                             let result = tokio::time::timeout(
                                 Duration::from_secs(DC_PING_TIMEOUT_SECS),
-                                self.ping_single_dc(&upstream_config, Some(bind_rr.clone()), addr)
+                                self.ping_single_dc(upstream_config, Some(bind_rr.clone()), addr)
                             ).await;
 
                             let ping_result = match result {
@@ -822,6 +904,7 @@ impl UpstreamManager {
     }
 
     /// Get the preferred IP for a DC (for use by other components)
+    #[allow(dead_code)]
     pub async fn get_dc_ip_preference(&self, dc_idx: i16) -> Option<IpPreference> {
         let guard = self.upstreams.read().await;
         if guard.is_empty() {
@@ -833,6 +916,7 @@ impl UpstreamManager {
     }
 
     /// Get preferred DC address based on config preference
+    #[allow(dead_code)]
     pub async fn get_dc_addr(&self, dc_idx: i16, prefer_ipv6: bool) -> Option<SocketAddr> {
         let arr_idx = UpstreamState::dc_array_idx(dc_idx)?;
 

src/util/ip.rs

@@ -1,22 +1,24 @@
 //! IP Addr Detect
 
-use std::net::{IpAddr, SocketAddr, UdpSocket};
+use std::net::{IpAddr, UdpSocket};
 use std::time::Duration;
 use tracing::{debug, warn};
 
 /// Detected IP addresses
 #[derive(Debug, Clone, Default)]
+#[allow(dead_code)]
 pub struct IpInfo {
     pub ipv4: Option<IpAddr>,
     pub ipv6: Option<IpAddr>,
 }
 
+#[allow(dead_code)]
 impl IpInfo {
     /// Check if any IP is detected
     pub fn has_any(&self) -> bool {
         self.ipv4.is_some() || self.ipv6.is_some()
     }
-    
+
     /// Get preferred IP (IPv6 if available and preferred)
     pub fn preferred(&self, prefer_ipv6: bool) -> Option<IpAddr> {
         if prefer_ipv6 {
@@ -28,12 +30,14 @@ impl IpInfo {
 }
 
 /// URLs for IP detection
+#[allow(dead_code)]
 const IPV4_URLS: &[&str] = &[
     "http://v4.ident.me/",
     "http://ipv4.icanhazip.com/",
     "http://api.ipify.org/",
 ];
 
+#[allow(dead_code)]
 const IPV6_URLS: &[&str] = &[
     "http://v6.ident.me/",
     "http://ipv6.icanhazip.com/",
@@ -42,12 +46,14 @@ const IPV6_URLS: &[&str] = &[
 
 /// Detect local IP address by connecting to a public DNS
 /// This does not actually send any packets
+#[allow(dead_code)]
 fn get_local_ip(target: &str) -> Option<IpAddr> {
     let socket = UdpSocket::bind("0.0.0.0:0").ok()?;
     socket.connect(target).ok()?;
     socket.local_addr().ok().map(|addr| addr.ip())
 }
 
+#[allow(dead_code)]
 fn get_local_ipv6(target: &str) -> Option<IpAddr> {
     let socket = UdpSocket::bind("[::]:0").ok()?;
     socket.connect(target).ok()?;
@@ -55,59 +61,62 @@ fn get_local_ipv6(target: &str) -> Option<IpAddr> {
 }
 
 /// Detect public IP addresses
+#[allow(dead_code)]
 pub async fn detect_ip() -> IpInfo {
     let mut info = IpInfo::default();
 
     // Try to get local interface IP first (default gateway interface)
     // We connect to Google DNS to find out which interface is used for routing
-    if let Some(ip) = get_local_ip("8.8.8.8:80") {
-        if ip.is_ipv4() && !ip.is_loopback() {
-             info.ipv4 = Some(ip);
-             debug!(ip = %ip, "Detected local IPv4 address via routing");
-        }
+    if let Some(ip) = get_local_ip("8.8.8.8:80")
+        && ip.is_ipv4()
+        && !ip.is_loopback()
+    {
+        info.ipv4 = Some(ip);
+        debug!(ip = %ip, "Detected local IPv4 address via routing");
     }
 
-    if let Some(ip) = get_local_ipv6("[2001:4860:4860::8888]:80") {
-        if ip.is_ipv6() && !ip.is_loopback() {
-            info.ipv6 = Some(ip);
-            debug!(ip = %ip, "Detected local IPv6 address via routing");
-        }
+    if let Some(ip) = get_local_ipv6("[2001:4860:4860::8888]:80")
+        && ip.is_ipv6()
+        && !ip.is_loopback()
+    {
+        info.ipv6 = Some(ip);
+        debug!(ip = %ip, "Detected local IPv6 address via routing");
     }
-    
-    // If local detection failed or returned private IP (and we want public), 
+
+    // If local detection failed or returned private IP (and we want public),
     // or just as a fallback/verification, we might want to check external services.
-    // However, the requirement is: "if IP for listening is not set... it should be IP from interface... 
+    // However, the requirement is: "if IP for listening is not set... it should be IP from interface...
     // if impossible - request external resources".
-    
+
     // So if we found a local IP, we might be good. But often servers are behind NAT.
     // If the local IP is private, we probably want the public IP for the tg:// link.
     // Let's check if the detected IPs are private.
-    
-    let need_external_v4 = info.ipv4.map_or(true, |ip| is_private_ip(ip));
-    let need_external_v6 = info.ipv6.map_or(true, |ip| is_private_ip(ip));
+
+    let need_external_v4 = info.ipv4.is_none_or(is_private_ip);
+    let need_external_v6 = info.ipv6.is_none_or(is_private_ip);
 
     if need_external_v4 {
         debug!("Local IPv4 is private or missing, checking external services...");
         for url in IPV4_URLS {
-            if let Some(ip) = fetch_ip(url).await {
-                if ip.is_ipv4() {
-                    info.ipv4 = Some(ip);
-                    debug!(ip = %ip, "Detected public IPv4 address");
-                    break;
-                }
+            if let Some(ip) = fetch_ip(url).await
+                && ip.is_ipv4()
+            {
+                info.ipv4 = Some(ip);
+                debug!(ip = %ip, "Detected public IPv4 address");
+                break;
             }
         }
     }
-    
+
     if need_external_v6 {
         debug!("Local IPv6 is private or missing, checking external services...");
         for url in IPV6_URLS {
-            if let Some(ip) = fetch_ip(url).await {
-                if ip.is_ipv6() {
-                    info.ipv6 = Some(ip);
-                    debug!(ip = %ip, "Detected public IPv6 address");
-                    break;
-                }
+            if let Some(ip) = fetch_ip(url).await
+                && ip.is_ipv6()
+            {
+                info.ipv6 = Some(ip);
+                debug!(ip = %ip, "Detected public IPv6 address");
+                break;
             }
         }
     }
@@ -119,6 +128,7 @@ pub async fn detect_ip() -> IpInfo {
     info
 }
 
+#[allow(dead_code)]
 fn is_private_ip(ip: IpAddr) -> bool {
     match ip {
         IpAddr::V4(ipv4) => {
@@ -131,19 +141,21 @@ fn is_private_ip(ip: IpAddr) -> bool {
 }
 
 /// Fetch IP from URL
+#[allow(dead_code)]
 async fn fetch_ip(url: &str) -> Option<IpAddr> {
     let client = reqwest::Client::builder()
         .timeout(Duration::from_secs(5))
         .build()
         .ok()?;
-    
+
     let response = client.get(url).send().await.ok()?;
     let text = response.text().await.ok()?;
-    
+
     text.trim().parse().ok()
 }
 
 /// Synchronous IP detection (for startup)
+#[allow(dead_code)]
 pub fn detect_ip_sync() -> IpInfo {
     tokio::runtime::Handle::current().block_on(detect_ip())
 }

src/util/mod.rs

@@ -3,5 +3,7 @@
 pub mod ip;
 pub mod time;
 
+#[allow(unused_imports)]
 pub use ip::*;
+#[allow(unused_imports)]
 pub use time::*;

src/util/time.rs

@@ -4,11 +4,14 @@ use std::time::Duration;
 use chrono::{DateTime, Utc};
 use tracing::{debug, warn, error};
 
+#[allow(dead_code)]
 const TIME_SYNC_URL: &str = "https://core.telegram.org/getProxySecret";
+#[allow(dead_code)]
 const MAX_TIME_SKEW_SECS: i64 = 30;
 
 /// Time sync result
 #[derive(Debug, Clone)]
+#[allow(dead_code)]
 pub struct TimeSyncResult {
     pub server_time: DateTime<Utc>,
     pub local_time: DateTime<Utc>,
@@ -17,6 +20,7 @@ pub struct TimeSyncResult {
 }
 
 /// Check time synchronization with Telegram servers
+#[allow(dead_code)]
 pub async fn check_time_sync() -> Option<TimeSyncResult> {
     let client = reqwest::Client::builder()
         .timeout(Duration::from_secs(10))
@@ -60,17 +64,18 @@ pub async fn check_time_sync() -> Option<TimeSyncResult> {
 }
 
 /// Background time sync task
+#[allow(dead_code)]
 pub async fn time_sync_task(check_interval: Duration) -> ! {
     loop {
-        if let Some(result) = check_time_sync().await {
-            if result.is_skewed {
-                error!(
-                    "System clock is off by {} seconds. Please sync your clock.",
-                    result.skew_secs
-                );
-            }
+        if let Some(result) = check_time_sync().await
+            && result.is_skewed
+        {
+            error!(
+                "System clock is off by {} seconds. Please sync your clock.",
+                result.skew_secs
+            );
         }
-        
+
         tokio::time::sleep(check_interval).await;
     }
 }

tools/tlsearch.py

@@ -0,0 +1,396 @@
+#!/usr/bin/env python3
+"""
+TLS Profile Inspector
+
+Usage:
+  python3 tools/tlsearch.py
+  python3 tools/tlsearch.py tlsfront
+  python3 tools/tlsearch.py tlsfront/petrovich.ru.json
+  python3 tools/tlsearch.py tlsfront --only-current
+"""
+
+from __future__ import annotations
+
+import argparse
+import datetime as dt
+import json
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any, Iterable
+
+
+TLS_VERSIONS = {
+    0x0301: "TLS 1.0",
+    0x0302: "TLS 1.1",
+    0x0303: "TLS 1.2",
+    0x0304: "TLS 1.3",
+}
+
+EXT_NAMES = {
+    0: "server_name",
+    5: "status_request",
+    10: "supported_groups",
+    11: "ec_point_formats",
+    13: "signature_algorithms",
+    16: "alpn",
+    18: "signed_certificate_timestamp",
+    21: "padding",
+    23: "extended_master_secret",
+    35: "session_ticket",
+    43: "supported_versions",
+    45: "psk_key_exchange_modes",
+    51: "key_share",
+}
+
+CIPHER_NAMES = {
+    0x1301: "TLS_AES_128_GCM_SHA256",
+    0x1302: "TLS_AES_256_GCM_SHA384",
+    0x1303: "TLS_CHACHA20_POLY1305_SHA256",
+    0x1304: "TLS_AES_128_CCM_SHA256",
+    0x1305: "TLS_AES_128_CCM_8_SHA256",
+    0x009C: "TLS_RSA_WITH_AES_128_GCM_SHA256",
+    0x009D: "TLS_RSA_WITH_AES_256_GCM_SHA384",
+    0xC02F: "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+    0xC030: "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
+    0xCCA8: "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256",
+    0xCCA9: "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256",
+}
+
+NAMED_GROUPS = {
+    0x001D: "x25519",
+    0x0017: "secp256r1",
+    0x0018: "secp384r1",
+    0x0019: "secp521r1",
+    0x0100: "ffdhe2048",
+    0x0101: "ffdhe3072",
+    0x0102: "ffdhe4096",
+}
+
+
+@dataclass
+class ProfileRecognition:
+    schema: str
+    mode: str
+    has_cert_info: bool
+    has_full_cert_payload: bool
+    cert_message_len: int
+    cert_chain_count: int
+    cert_chain_total_len: int
+    issues: list[str]
+
+
+def to_hex(data: Iterable[int]) -> str:
+    return "".join(f"{b:02x}" for b in data)
+
+
+def read_u16be(data: list[int], off: int = 0) -> int:
+    return (data[off] << 8) | data[off + 1]
+
+
+def normalize_u8_list(value: Any) -> list[int]:
+    if not isinstance(value, list):
+        return []
+    out: list[int] = []
+    for item in value:
+        if isinstance(item, int) and 0 <= item <= 0xFF:
+            out.append(item)
+        else:
+            return []
+    return out
+
+
+def as_dict(value: Any) -> dict[str, Any]:
+    return value if isinstance(value, dict) else {}
+
+
+def as_int(value: Any, default: int = 0) -> int:
+    return value if isinstance(value, int) else default
+
+
+def decode_version_pair(v: list[int]) -> str:
+    if len(v) != 2:
+        return f"invalid({v})"
+    ver = read_u16be(v)
+    return f"0x{ver:04x} ({TLS_VERSIONS.get(ver, 'unknown')})"
+
+
+def decode_cipher_suite(v: list[int]) -> str:
+    if len(v) != 2:
+        return f"invalid({v})"
+    cs = read_u16be(v)
+    name = CIPHER_NAMES.get(cs, "unknown")
+    return f"0x{cs:04x} ({name})"
+
+
+def decode_supported_versions(data: list[int]) -> str:
+    if len(data) == 2:
+        ver = read_u16be(data)
+        return f"selected=0x{ver:04x} ({TLS_VERSIONS.get(ver, 'unknown')})"
+    if not data:
+        return "empty"
+    if len(data) < 3:
+        return f"raw={to_hex(data)}"
+    vec_len = data[0]
+    versions: list[str] = []
+    for i in range(1, min(1 + vec_len, len(data)), 2):
+        if i + 1 >= len(data):
+            break
+        ver = read_u16be(data, i)
+        versions.append(f"0x{ver:04x}({TLS_VERSIONS.get(ver, 'unknown')})")
+    return "offered=[" + ", ".join(versions) + "]"
+
+
+def decode_key_share(data: list[int]) -> str:
+    if len(data) < 4:
+        return f"raw={to_hex(data)}"
+    group = read_u16be(data, 0)
+    key_len = read_u16be(data, 2)
+    key_hex = to_hex(data[4 : 4 + min(key_len, len(data) - 4)])
+    gname = NAMED_GROUPS.get(group, "unknown_group")
+    return f"group=0x{group:04x}({gname}), key_len={key_len}, key={key_hex}"
+
+
+def decode_alpn(data: list[int]) -> str:
+    if len(data) < 3:
+        return f"raw={to_hex(data)}"
+    total = read_u16be(data, 0)
+    pos = 2
+    vals: list[str] = []
+    limit = min(len(data), 2 + total)
+    while pos < limit:
+        ln = data[pos]
+        pos += 1
+        if pos + ln > limit:
+            break
+        raw = bytes(data[pos : pos + ln])
+        pos += ln
+        try:
+            vals.append(raw.decode("ascii"))
+        except UnicodeDecodeError:
+            vals.append(raw.hex())
+    return "protocols=[" + ", ".join(vals) + "]"
+
+
+def decode_extension(ext_type: int, data: list[int]) -> str:
+    if ext_type == 43:
+        return decode_supported_versions(data)
+    if ext_type == 51:
+        return decode_key_share(data)
+    if ext_type == 16:
+        return decode_alpn(data)
+    return f"raw={to_hex(data)}"
+
+
+def ts_to_iso(ts: Any) -> str:
+    if not isinstance(ts, int):
+        return "-"
+    return dt.datetime.fromtimestamp(ts, tz=dt.timezone.utc).isoformat()
+
+
+def recognize_profile(obj: dict[str, Any]) -> ProfileRecognition:
+    issues: list[str] = []
+
+    sh = as_dict(obj.get("server_hello_template"))
+    if not sh:
+        issues.append("missing server_hello_template")
+
+    version = normalize_u8_list(sh.get("version"))
+    if version and len(version) != 2:
+        issues.append("server_hello_template.version must have 2 bytes")
+
+    app_sizes = obj.get("app_data_records_sizes")
+    if not isinstance(app_sizes, list) or not app_sizes:
+        issues.append("missing app_data_records_sizes")
+    elif any((not isinstance(v, int) or v <= 0) for v in app_sizes):
+        issues.append("app_data_records_sizes contains invalid values")
+
+    if not isinstance(obj.get("total_app_data_len"), int):
+        issues.append("missing total_app_data_len")
+
+    cert_info = as_dict(obj.get("cert_info"))
+    has_cert_info = bool(
+        cert_info.get("subject_cn")
+        or cert_info.get("issuer_cn")
+        or cert_info.get("san_names")
+        or isinstance(cert_info.get("not_before_unix"), int)
+        or isinstance(cert_info.get("not_after_unix"), int)
+    )
+
+    cert_payload = as_dict(obj.get("cert_payload"))
+    cert_message_len = 0
+    cert_chain_count = 0
+    cert_chain_total_len = 0
+    has_full_cert_payload = False
+
+    if cert_payload:
+        cert_msg = normalize_u8_list(cert_payload.get("certificate_message"))
+        if not cert_msg:
+            issues.append("cert_payload.certificate_message is missing or invalid")
+        else:
+            cert_message_len = len(cert_msg)
+
+        chain_raw = cert_payload.get("cert_chain_der")
+        if not isinstance(chain_raw, list):
+            issues.append("cert_payload.cert_chain_der is missing or invalid")
+        else:
+            for entry in chain_raw:
+                cert = normalize_u8_list(entry)
+                if cert:
+                    cert_chain_count += 1
+                    cert_chain_total_len += len(cert)
+                else:
+                    issues.append("cert_payload.cert_chain_der has invalid certificate entry")
+                    break
+
+        has_full_cert_payload = cert_message_len > 0 and cert_chain_count > 0
+    elif obj.get("cert_payload") is not None:
+        issues.append("cert_payload is not an object")
+
+    if has_full_cert_payload:
+        schema = "current"
+        mode = "full-cert-payload"
+    elif has_cert_info:
+        schema = "current-compact"
+        mode = "compact-cert-info"
+    else:
+        schema = "legacy"
+        mode = "random-fallback"
+
+    if issues:
+        schema = f"{schema}+issues"
+
+    return ProfileRecognition(
+        schema=schema,
+        mode=mode,
+        has_cert_info=has_cert_info,
+        has_full_cert_payload=has_full_cert_payload,
+        cert_message_len=cert_message_len,
+        cert_chain_count=cert_chain_count,
+        cert_chain_total_len=cert_chain_total_len,
+        issues=issues,
+    )
+
+
+def decode_profile(path: Path) -> tuple[str, ProfileRecognition]:
+    obj: dict[str, Any] = json.loads(path.read_text(encoding="utf-8"))
+    recognition = recognize_profile(obj)
+
+    sh = as_dict(obj.get("server_hello_template"))
+    version = normalize_u8_list(sh.get("version"))
+    cipher = normalize_u8_list(sh.get("cipher_suite"))
+    random_bytes = normalize_u8_list(sh.get("random"))
+    session_id = normalize_u8_list(sh.get("session_id"))
+
+    lines: list[str] = []
+    lines.append(f"[{path.name}]")
+    lines.append(f"  domain: {obj.get('domain', '-')}")
+    lines.append(f"  profile.schema: {recognition.schema}")
+    lines.append(f"  profile.mode: {recognition.mode}")
+    lines.append(f"  profile.has_full_cert_payload: {recognition.has_full_cert_payload}")
+    lines.append(f"  profile.has_cert_info: {recognition.has_cert_info}")
+    if recognition.has_full_cert_payload:
+        lines.append(f"  profile.cert_message_len: {recognition.cert_message_len}")
+        lines.append(f"  profile.cert_chain_count: {recognition.cert_chain_count}")
+        lines.append(f"  profile.cert_chain_total_len: {recognition.cert_chain_total_len}")
+    if recognition.issues:
+        lines.append("  profile.issues:")
+        for issue in recognition.issues:
+            lines.append(f"    - {issue}")
+
+    lines.append(f"  tls.version: {decode_version_pair(version)}")
+    lines.append(f"  tls.cipher: {decode_cipher_suite(cipher)}")
+    lines.append(f"  tls.compression: {sh.get('compression', '-')}")
+    lines.append(f"  tls.random: {to_hex(random_bytes)}")
+    lines.append(f"  tls.session_id_len: {len(session_id)}")
+    if session_id:
+        lines.append(f"  tls.session_id: {to_hex(session_id)}")
+
+    app_sizes = obj.get("app_data_records_sizes", [])
+    if isinstance(app_sizes, list):
+        lines.append("  app_data_records_sizes: " + ", ".join(str(v) for v in app_sizes))
+    else:
+        lines.append("  app_data_records_sizes: -")
+    lines.append(f"  total_app_data_len: {obj.get('total_app_data_len', '-')}")
+
+    cert = as_dict(obj.get("cert_info"))
+    if cert:
+        lines.append("  cert_info:")
+        lines.append(f"    subject_cn: {cert.get('subject_cn') or '-'}")
+        lines.append(f"    issuer_cn: {cert.get('issuer_cn') or '-'}")
+        lines.append(f"    not_before: {ts_to_iso(cert.get('not_before_unix'))}")
+        lines.append(f"    not_after:  {ts_to_iso(cert.get('not_after_unix'))}")
+        sans = cert.get("san_names")
+        if isinstance(sans, list) and sans:
+            lines.append("    san_names: " + ", ".join(str(v) for v in sans))
+        else:
+            lines.append("    san_names: -")
+    else:
+        lines.append("  cert_info: -")
+
+    exts = sh.get("extensions", [])
+    if not isinstance(exts, list):
+        exts = []
+    lines.append(f"  extensions[{len(exts)}]:")
+    for ext in exts:
+        ext_obj = as_dict(ext)
+        ext_type = as_int(ext_obj.get("ext_type"), -1)
+        data = normalize_u8_list(ext_obj.get("data"))
+        name = EXT_NAMES.get(ext_type, "unknown")
+        decoded = decode_extension(ext_type, data)
+        lines.append(f"    - type={ext_type} ({name}), len={len(data)}: {decoded}")
+
+    lines.append("")
+    return ("\n".join(lines), recognition)
+
+
+def collect_files(input_path: Path) -> list[Path]:
+    if input_path.is_file():
+        return [input_path]
+    return sorted(p for p in input_path.glob("*.json") if p.is_file())
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(
+        description="Decode TLS profile JSON files and recognize current schema."
+    )
+    parser.add_argument(
+        "path",
+        nargs="?",
+        default="tlsfront",
+        help="Path to tlsfront directory or a single JSON file.",
+    )
+    parser.add_argument(
+        "--only-current",
+        action="store_true",
+        help="Show only profiles recognized as current/full-cert-payload.",
+    )
+    args = parser.parse_args()
+
+    base = Path(args.path)
+    if not base.exists():
+        print(f"Path not found: {base}")
+        return 1
+
+    files = collect_files(base)
+    if not files:
+        print(f"No JSON files found in: {base}")
+        return 1
+
+    printed = 0
+    for path in files:
+        try:
+            rendered, recognition = decode_profile(path)
+            if args.only_current and recognition.schema != "current":
+                continue
+            print(rendered, end="")
+            printed += 1
+        except Exception as e:  # noqa: BLE001
+            print(f"[{path.name}] decode error: {e}\n")
+
+    if args.only_current and printed == 0:
+        print("No current profiles found.")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

tools/zbx_telemt_template.yaml

@@ -0,0 +1,276 @@
+zabbix_export:
+  version: '7.0'
+  template_groups:
+    - uuid: 43d0fe04c7094000829b0d28c6e3470c
+      name: 'Custom Templates'
+  templates:
+    - uuid: f2a694213c3d49d88cc03bffb111429e
+      template: Telemt
+      name: Telemt
+      description: |
+        A simple template using Prometheus metrics.
+        Set the {$TELEMT_URL} macro with the metrics URL
+      groups:
+        - name: 'Custom Templates'
+      items:
+        - uuid: fb95391c7f894e3eb6984b92885813a2
+          name: 'Connections bad total'
+          type: DEPENDENT
+          key: telemt.conn_bad_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_connections_bad_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Server connections'
+        - uuid: f36c9632394a4af3853583857ca8dbf1
+          name: 'Connections total'
+          type: DEPENDENT
+          key: telemt.conn_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_connections_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Server connections'
+        - uuid: 1618272cf68e44509425f5fab029db7b
+          name: 'Handshake timeouts total'
+          type: DEPENDENT
+          key: telemt.handshake_timeouts_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_handshake_timeouts_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Server connections'
+        - uuid: fb95391c7f894e3eb6984b92885813d2
+          name: 'ME keepalive send failures'
+          type: DEPENDENT
+          key: telemt.me_keepalive_failed_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_me_keepalive_failed_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Middle-End connections'
+        - uuid: fb95391c7f894e3eb6984b92885813c2
+          name: 'ME keepalive frames sent'
+          type: DEPENDENT
+          key: telemt.me_keepalive_sent_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_me_keepalive_sent_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Middle-End connections'
+        - uuid: fb95391c7f894e3eb6984b92885811a2
+          name: 'ME reconnect attempts'
+          type: DEPENDENT
+          key: telemt.me_reconnect_attempts_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_me_reconnect_attempts_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Middle-End connections'
+        - uuid: fb95391c7f894e3eb6984b92885812a2
+          name: 'ME reconnect successes'
+          type: DEPENDENT
+          key: telemt.me_reconnect_success_total
+          delay: '0'
+          trends: '0'
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_me_reconnect_success_total
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Middle-End connections'
+        - uuid: 991b1858e3f94b3098ff0f84859efc41
+          name: 'Prometheus metrics'
+          type: HTTP_AGENT
+          key: telemt.prom_metrics
+          value_type: TEXT
+          trends: '0'
+          url: '{$TELEMT_URL}'
+        - uuid: fb95391c7f894e3eb6984b92885813b2
+          name: 'Telemt Uptime'
+          type: DEPENDENT
+          key: telemt.uptime
+          delay: '0'
+          trends: '0'
+          units: s
+          preprocessing:
+            - type: PROMETHEUS_PATTERN
+              parameters:
+                - telemt_uptime_seconds
+                - value
+                - ''
+          master_item:
+            key: telemt.prom_metrics
+          tags:
+            - tag: Application
+              value: 'Server connections'
+      discovery_rules:
+        - uuid: 22727585c14049fbb0863c15dd68634c
+          name: 'Get users'
+          type: DEPENDENT
+          key: telemt.users
+          delay: '0'
+          item_prototypes:
+            - uuid: 137e371a47714a21b5c0c89d535dd717
+              name: 'Active connections by {#TELEMT_USER}'
+              type: DEPENDENT
+              key: 'telemt.active_conn_[{#TELEMT_USER}]'
+              delay: '0'
+              preprocessing:
+                - type: PROMETHEUS_PATTERN
+                  parameters:
+                    - 'telemt_user_connections_current{user="{#TELEMT_USER}"}'
+                    - value
+                    - ''
+              master_item:
+                key: telemt.prom_metrics
+              tags:
+                - tag: Application
+                  value: 'Users connections'
+            - uuid: 3ccce91ab5d54b4d972280c7b7bda910
+              name: 'Messages received from {#TELEMT_USER}'
+              type: DEPENDENT
+              key: 'telemt.msgs_from_[{#TELEMT_USER}]'
+              delay: '0'
+              preprocessing:
+                - type: PROMETHEUS_PATTERN
+                  parameters:
+                    - 'telemt_user_msgs_from_client{user="{#TELEMT_USER}"}'
+                    - value
+                    - ''
+              master_item:
+                key: telemt.prom_metrics
+              tags:
+                - tag: Application
+                  value: 'Users connections'
+            - uuid: e539126215f2419bbfd0d8099aabe1cb
+              name: 'Messages sent to {#TELEMT_USER}'
+              type: DEPENDENT
+              key: 'telemt.msgs_to_[{#TELEMT_USER}]'
+              delay: '0'
+              preprocessing:
+                - type: PROMETHEUS_PATTERN
+                  parameters:
+                    - 'telemt_user_msgs_to_client{user="{#TELEMT_USER}"}'
+                    - value
+                    - ''
+              master_item:
+                key: telemt.prom_metrics
+              tags:
+                - tag: Application
+                  value: 'Users connections'
+            - uuid: 810a8f6346a44ae7bd79a357dbfe2b3c
+              name: 'Bytes received from {#TELEMT_USER}'
+              type: DEPENDENT
+              key: 'telemt.octets_from_[{#TELEMT_USER}]'
+              delay: '0'
+              units: B
+              preprocessing:
+                - type: PROMETHEUS_PATTERN
+                  parameters:
+                    - 'telemt_user_octets_from_client{user="{#TELEMT_USER}"}'
+                    - value
+                    - ''
+              master_item:
+                key: telemt.prom_metrics
+              tags:
+                - tag: Application
+                  value: 'Users connections'
+            - uuid: d0cc3b4d618b4f0d97f8127b51f872c8
+              name: 'Bytes sent to {#TELEMT_USER}'
+              type: DEPENDENT
+              key: 'telemt.octets_to_[{#TELEMT_USER}]'
+              delay: '0'
+              units: B
+              preprocessing:
+                - type: PROMETHEUS_PATTERN
+                  parameters:
+                    - 'telemt_user_octets_to_client{user="{#TELEMT_USER}"}'
+                    - value
+                    - ''
+              master_item:
+                key: telemt.prom_metrics
+              tags:
+                - tag: Application
+                  value: 'Users connections'
+            - uuid: e9735aef967b4af28ed59f6c76ad493d
+              name: 'Total connections by {#TELEMT_USER}'
+              type: DEPENDENT
+              key: 'telemt.total_conn_[{#TELEMT_USER}]'
+              delay: '0'
+              preprocessing:
+                - type: PROMETHEUS_PATTERN
+                  parameters:
+                    - 'telemt_user_connections_total{user="{#TELEMT_USER}"}'
+                    - value
+                    - ''
+              master_item:
+                key: telemt.prom_metrics
+              tags:
+                - tag: Application
+                  value: 'Users connections'
+          master_item:
+            key: telemt.prom_metrics
+          lld_macro_paths:
+            - lld_macro: '{#TELEMT_USER}'
+              path: '$.labels[''user'']'
+          preprocessing:
+            - type: PROMETHEUS_TO_JSON
+              parameters:
+                - ''
+      tags:
+        - tag: target
+          value: Telemt