Merge pull request #718 from astronaut808/fix/me-downstream-retry

Improve ME downstream retries for queued fairness backlog

Cargo.lock

@@ -2780,7 +2780,7 @@ checksum = "7b2093cf4c8eb1e67749a6762251bc9cd836b6fc171623bd0a9d324d37af2417"
 
 [[package]]
 name = "telemt"
-version = "3.4.1"
+version = "3.4.3"
 dependencies = [
  "aes",
  "anyhow",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "telemt"
-version = "3.4.1"
+version = "3.4.3"
 edition = "2024"
 
 [features]

Dockerfile

@@ -77,6 +77,34 @@ COPY config.toml /app/config.toml
 
 EXPOSE 443 9090 9091
 
+HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 CMD ["/app/telemt", "healthcheck", "/app/config.toml", "--mode", "liveness"]
+
+ENTRYPOINT ["/app/telemt"]
+CMD ["config.toml"]
+
+# ==========================
+# Production Netfilter Profile
+# ==========================
+FROM debian:12-slim AS prod-netfilter
+
+RUN set -eux; \
+    apt-get update; \
+    apt-get install -y --no-install-recommends \
+        ca-certificates \
+        conntrack \
+        nftables \
+        iptables; \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY --from=minimal /telemt /app/telemt
+COPY config.toml /app/config.toml
+
+EXPOSE 443 9090 9091
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 CMD ["/app/telemt", "healthcheck", "/app/config.toml", "--mode", "liveness"]
+
 ENTRYPOINT ["/app/telemt"]
 CMD ["config.toml"]
 
@@ -94,5 +122,7 @@ USER nonroot:nonroot
 
 EXPOSE 443 9090 9091
 
+HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 CMD ["/app/telemt", "healthcheck", "/app/config.toml", "--mode", "liveness"]
+
 ENTRYPOINT ["/app/telemt"]
 CMD ["config.toml"]

docker-compose.host-netfilter.yml

@@ -0,0 +1,10 @@
+services:
+  telemt:
+    build:
+      context: .
+      target: prod-netfilter
+    network_mode: host
+    ports: []
+    cap_add:
+      - NET_BIND_SERVICE
+      - NET_ADMIN

docker-compose.netfilter.yml

@@ -0,0 +1,8 @@
+services:
+  telemt:
+    build:
+      context: .
+      target: prod-netfilter
+    cap_add:
+      - NET_BIND_SERVICE
+      - NET_ADMIN

docker-compose.yml

@@ -1,7 +1,9 @@
 services:
   telemt:
     image: ghcr.io/telemt/telemt:latest
-    build: .
+    build:
+      context: .
+      target: prod
     container_name: telemt
     restart: unless-stopped
     ports:
@@ -16,13 +18,18 @@ services:
       - /etc/telemt:rw,mode=1777,size=4m
     environment:
       - RUST_LOG=info
+    healthcheck:
+      test: [ "CMD", "/app/telemt", "healthcheck", "/etc/telemt/config.toml", "--mode", "liveness" ]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 20s
     # Uncomment this line if you want to use host network for IPv6, but bridge is default and usually better
     # network_mode: host
     cap_drop:
       - ALL
     cap_add:
       - NET_BIND_SERVICE
-      - NET_ADMIN
     read_only: true
     security_opt:
       - no-new-privileges:true

docs/Config_params/CONFIG_PARAMS.en.md

@@ -255,13 +255,22 @@ This document lists all configuration keys accepted by `config.toml`.
     ```
 ## proxy_secret_path
   - **Constraints / validation**: `String`. When omitted, the default path is `"proxy-secret"`. Empty values are accepted by TOML/serde but will likely fail at runtime (invalid file path).
-  - **Description**: Path to Telegram infrastructure `proxy-secret` cache file used by ME handshake/RPC auth. Telemt always tries a fresh download from `https://core.telegram.org/getProxySecret` first, caches it to this path on success, and falls back to reading the cached file (any age) on download failure.
+  - **Description**: Path to Telegram infrastructure `proxy-secret` cache file used by ME handshake/RPC auth. Telemt always tries a fresh download from `https://core.telegram.org/getProxySecret` first (unless `proxy_secret_url` is set) , caches it to this path on success, and falls back to reading the cached file (any age) on download failure.
   - **Example**:
 
     ```toml
     [general]
     proxy_secret_path = "proxy-secret"
     ```
+## proxy_secret_url
+  - **Constraints / validation**: `String`. When omitted, the `"https://core.telegram.org/getProxySecret"` is used.
+  - **Description**: Optional URL to obtain `proxy-secret` file used by ME handshake/RPC auth. Telemt always tries a fresh download from this URL first (with fallback to `https://core.telegram.org/getProxySecret` if absent). 
+  - **Example**:
+
+    ```toml
+    [general]
+    proxy_secret_url = "https://core.telegram.org/getProxySecret"
+    ```
 ## proxy_config_v4_cache_path
   - **Constraints / validation**: `String`. When set, must not be empty/whitespace-only.
   - **Description**: Optional disk cache path for raw `getProxyConfig` (IPv4) snapshot. At startup Telemt tries to fetch a fresh snapshot first; on fetch failure or empty snapshot it falls back to this cache file when present and non-empty.
@@ -271,6 +280,15 @@ This document lists all configuration keys accepted by `config.toml`.
     [general]
     proxy_config_v4_cache_path = "cache/proxy-config-v4.txt"
     ```
+## proxy_config_v4_url
+- **Constraints / validation**: `String`. When omitted, the `"https://core.telegram.org/getProxyConfig"` is used.
+- **Description**: Optional URL to obtain raw `getProxyConfig` (IPv4). Telemt always tries a fresh download from this URL first (with fallback to `https://core.telegram.org/getProxyConfig` if absent).
+- **Example**:
+
+  ```toml
+  [general]
+  proxy_config_v4_url = "https://core.telegram.org/getProxyConfig"
+  ```
 ## proxy_config_v6_cache_path
   - **Constraints / validation**: `String`. When set, must not be empty/whitespace-only.
   - **Description**: Optional disk cache path for raw `getProxyConfigV6` (IPv6) snapshot. At startup Telemt tries to fetch a fresh snapshot first; on fetch failure or empty snapshot it falls back to this cache file when present and non-empty.
@@ -280,6 +298,15 @@ This document lists all configuration keys accepted by `config.toml`.
     [general]
     proxy_config_v6_cache_path = "cache/proxy-config-v6.txt"
     ```
+## proxy_config_v6_url
+- **Constraints / validation**: `String`. When omitted, the `"https://core.telegram.org/getProxyConfigV6"` is used.
+- **Description**: Optional URL to obtain raw `getProxyConfigV6` (IPv6). Telemt always tries a fresh download from this URL first (with fallback to `https://core.telegram.org/getProxyConfigV6` if absent).
+- **Example**:
+
+  ```toml
+  [general]
+  proxy_config_v6_url = "https://core.telegram.org/getProxyConfigV6"
+  ```
 ## ad_tag
   - **Constraints / validation**: `String` (optional). When set, must be exactly 32 hex characters; invalid values are disabled during config load.
   - **Description**: Global fallback sponsored-channel `ad_tag` (used when user has no override in `access.user_ad_tags`). An all-zero tag is accepted but has no effect (and is warned about) until replaced with a real tag from `@MTProxybot`.

docs/Config_params/CONFIG_PARAMS.ru.md

@@ -255,13 +255,22 @@
     ```
 ## proxy_secret_path
   - **Ограничения / валидация**: `String`. Если этот параметр не указан, используется путь по умолчанию — «proxy-secret». Пустые значения принимаются TOML/serde, но во время выполнения произойдет ошибка (invalid file path).
-  - **Описание**: Путь к файлу кэша `proxy-secret` инфраструктуры Telegram, используемому ME-handshake/аутентификацией RPC. Telemt всегда сначала пытается выполнить новую загрузку с https://core.telegram.org/getProxySecret, в случае успеха кэширует ее по этому пути и возвращается к чтению кэшированного файла в случае сбоя загрузки.
+  - **Описание**: Путь к файлу кэша `proxy-secret` инфраструктуры Telegram, используемому ME-handshake/аутентификацией RPC. Telemt всегда сначала пытается выполнить новую загрузку с https://core.telegram.org/getProxySecret (если не установлен `proxy_secret_url`), в случае успеха кэширует ее по этому пути и возвращается к чтению кэшированного файла в случае сбоя загрузки.
   - **Пример**:
 
     ```toml
     [general]
     proxy_secret_path = "proxy-secret"
     ```
+## proxy_secret_url
+  - **Ограничения / валидация**: `String`. Если не указан, используется `"https://core.telegram.org/getProxySecret"`.
+  - **Описание**: Необязательный URL для получения файла `proxy-secret` используемого ME-handshake/аутентификацией RPC. Telemt всегда сначала пытается выполнить новую загрузку с этого URL (если не задан, используется https://core.telegram.org/getProxySecret).
+  - **Пример**:
+
+    ```toml
+    [general]
+    proxy_secret_url = "https://core.telegram.org/getProxySecret"
+    ```
 ## proxy_config_v4_cache_path
   - **Ограничения / валидация**: `String`. Если используется, значение не должно быть пустым или содержать только пробелы.
   - **Описание**: Необязательный путь к кэшу для необработанного (raw) снимка getProxyConfig (IPv4). При запуске Telemt сначала пытается получить свежий снимок; в случае сбоя выборки или пустого снимка он возвращается к этому файлу кэша, если он присутствует и не пуст.
@@ -271,6 +280,15 @@
     [general]
     proxy_config_v4_cache_path = "cache/proxy-config-v4.txt"
     ```
+## proxy_config_v4_url
+  - **Ограничения / валидация**: `String`. Если не указан, используется `"https://core.telegram.org/getProxyConfig"`.
+  - **Описание**: Необязательный URL для получения `getProxyConfig` (IPv4). Telemt при всегда пытается выполнить новую загрузку с этого URL (и если не задан, использует `https://core.telegram.org/getProxyConfig`).
+  - **Example**:
+  
+    ```toml
+    [general]
+    proxy_config_v4_url = "https://core.telegram.org/getProxyConfig"
+    ```
 ## proxy_config_v6_cache_path
   - **Ограничения / валидация**: `String`. Если используется, значение не должно быть пустым или содержать только пробелы.
   - **Описание**: Необязательный путь к кэшу для необработанного (raw) снимка getProxyConfigV6 (IPv6). При запуске Telemt сначала пытается получить свежий снимок; в случае сбоя выборки или пустого снимка он возвращается к этому файлу кэша, если он присутствует и не пуст.
@@ -280,6 +298,15 @@
     [general]
     proxy_config_v6_cache_path = "cache/proxy-config-v6.txt"
     ```
+## proxy_config_v6_url
+- **Ограничения / валидация**: `String`. Если не указан, используется `"https://core.telegram.org/getProxyConfigV6"`.
+- **Описание**: Необязательный URL для получения `getProxyConfigV6` (IPv6). Telemt при всегда пытается выполнить новую загрузку с этого URL (и если не задан, использует `https://core.telegram.org/getProxyConfigV6`).
+- **Example**:
+
+  ```toml
+  [general]
+  proxy_config_v6_url = "https://core.telegram.org/getProxyConfigV6"
+  ```
 ## ad_tag
   - **Ограничения / валидация**: `String` (необязательный параметр). Если используется, значение должно быть ровно 32 символа в шестнадцатеричной системе; недопустимые значения отключаются во время загрузки конфигурации.
   - **Описание**: Глобальный резервный спонсируемый канал `ad_tag` (используется, когда у пользователя нет переопределения в `access.user_ad_tags`). Тег со всеми нулями принимается, но не имеет никакого эффекта, пока не будет заменен реальным тегом от `@MTProxybot`.

src/api/mod.rs

@@ -41,8 +41,8 @@ use config_store::{current_revision, load_config_from_disk, parse_if_match};
 use events::ApiEventStore;
 use http_utils::{error_response, read_json, read_optional_json, success_response};
 use model::{
-    ApiFailure, CreateUserRequest, DeleteUserResponse, HealthData, PatchUserRequest,
-    RotateSecretRequest, SummaryData, UserActiveIps,
+    ApiFailure, CreateUserRequest, DeleteUserResponse, HealthData, HealthReadyData,
+    PatchUserRequest, RotateSecretRequest, SummaryData, UserActiveIps,
 };
 use runtime_edge::{
     EdgeConnectionsCacheEntry, build_runtime_connections_summary_data,
@@ -275,6 +275,33 @@ async fn handle(
                 };
                 Ok(success_response(StatusCode::OK, data, revision))
             }
+            ("GET", "/v1/health/ready") => {
+                let revision = current_revision(&shared.config_path).await?;
+                let admission_open = shared.runtime_state.admission_open.load(Ordering::Relaxed);
+                let upstream_health = shared.upstream_manager.api_health_summary().await;
+                let ready = admission_open && upstream_health.healthy_total > 0;
+                let reason = if ready {
+                    None
+                } else if !admission_open {
+                    Some("admission_closed")
+                } else {
+                    Some("no_healthy_upstreams")
+                };
+                let data = HealthReadyData {
+                    ready,
+                    status: if ready { "ready" } else { "not_ready" },
+                    reason,
+                    admission_open,
+                    healthy_upstreams: upstream_health.healthy_total,
+                    total_upstreams: upstream_health.configured_total,
+                };
+                let status_code = if ready {
+                    StatusCode::OK
+                } else {
+                    StatusCode::SERVICE_UNAVAILABLE
+                };
+                Ok(success_response(status_code, data, revision))
+            }
             ("GET", "/v1/system/info") => {
                 let revision = current_revision(&shared.config_path).await?;
                 let data = build_system_info_data(shared.as_ref(), cfg.as_ref(), &revision);

src/api/model.rs

@@ -60,6 +60,17 @@ pub(super) struct HealthData {
     pub(super) read_only: bool,
 }
 
+#[derive(Serialize)]
+pub(super) struct HealthReadyData {
+    pub(super) ready: bool,
+    pub(super) status: &'static str,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) reason: Option<&'static str>,
+    pub(super) admission_open: bool,
+    pub(super) healthy_upstreams: usize,
+    pub(super) total_upstreams: usize,
+}
+
 #[derive(Serialize)]
 pub(super) struct SummaryData {
     pub(super) uptime_seconds: f64,

src/cli.rs

@@ -6,12 +6,15 @@
 //! - `reload [--pid-file PATH]` - Reload configuration (SIGHUP)
 //! - `status [--pid-file PATH]` - Check daemon status
 //! - `run [OPTIONS] [config.toml]` - Run in foreground (default behavior)
+//! - `healthcheck [OPTIONS] [config.toml]` - Run control-plane health probe
 
 use rand::RngExt;
 use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
+use crate::healthcheck::{self, HealthcheckMode};
+
 #[cfg(unix)]
 use crate::daemon::{self, DEFAULT_PID_FILE, DaemonOptions};
 
@@ -28,6 +31,8 @@ pub enum Subcommand {
     Reload,
     /// Check daemon status (`status` subcommand).
     Status,
+    /// Run health probe and exit with status code.
+    Healthcheck,
     /// Fire-and-forget setup (`--init`).
     Init,
 }
@@ -38,6 +43,8 @@ pub struct ParsedCommand {
     pub subcommand: Subcommand,
     pub pid_file: PathBuf,
     pub config_path: String,
+    pub healthcheck_mode: HealthcheckMode,
+    pub healthcheck_mode_invalid: Option<String>,
     #[cfg(unix)]
     pub daemon_opts: DaemonOptions,
     pub init_opts: Option<InitOptions>,
@@ -52,6 +59,8 @@ impl Default for ParsedCommand {
             #[cfg(not(unix))]
             pid_file: PathBuf::from("/var/run/telemt.pid"),
             config_path: "config.toml".to_string(),
+            healthcheck_mode: HealthcheckMode::Liveness,
+            healthcheck_mode_invalid: None,
             #[cfg(unix)]
             daemon_opts: DaemonOptions::default(),
             init_opts: None,
@@ -91,6 +100,9 @@ pub fn parse_command(args: &[String]) -> ParsedCommand {
             "status" => {
                 cmd.subcommand = Subcommand::Status;
             }
+            "healthcheck" => {
+                cmd.subcommand = Subcommand::Healthcheck;
+            }
             "run" => {
                 cmd.subcommand = Subcommand::Run;
                 #[cfg(unix)]
@@ -113,7 +125,35 @@ pub fn parse_command(args: &[String]) -> ParsedCommand {
     while i < args.len() {
         match args[i].as_str() {
             // Skip subcommand names
-            "start" | "stop" | "reload" | "status" | "run" => {}
+            "start" | "stop" | "reload" | "status" | "run" | "healthcheck" => {}
+            "--mode" => {
+                i += 1;
+                if i < args.len() {
+                    match HealthcheckMode::from_cli_arg(&args[i]) {
+                        Some(mode) => {
+                            cmd.healthcheck_mode = mode;
+                            cmd.healthcheck_mode_invalid = None;
+                        }
+                        None => {
+                            cmd.healthcheck_mode_invalid = Some(args[i].clone());
+                        }
+                    }
+                } else {
+                    cmd.healthcheck_mode_invalid = Some(String::new());
+                }
+            }
+            s if s.starts_with("--mode=") => {
+                let raw = s.trim_start_matches("--mode=");
+                match HealthcheckMode::from_cli_arg(raw) {
+                    Some(mode) => {
+                        cmd.healthcheck_mode = mode;
+                        cmd.healthcheck_mode_invalid = None;
+                    }
+                    None => {
+                        cmd.healthcheck_mode_invalid = Some(raw.to_string());
+                    }
+                }
+            }
             // PID file option (for stop/reload/status)
             "--pid-file" => {
                 i += 1;
@@ -152,6 +192,20 @@ pub fn execute_subcommand(cmd: &ParsedCommand) -> Option<i32> {
         Subcommand::Stop => Some(cmd_stop(&cmd.pid_file)),
         Subcommand::Reload => Some(cmd_reload(&cmd.pid_file)),
         Subcommand::Status => Some(cmd_status(&cmd.pid_file)),
+        Subcommand::Healthcheck => {
+            if let Some(invalid_mode) = cmd.healthcheck_mode_invalid.as_ref() {
+                if invalid_mode.is_empty() {
+                    eprintln!("[telemt] Missing value for --mode (supported: liveness, ready)");
+                } else {
+                    eprintln!(
+                        "[telemt] Invalid --mode value '{invalid_mode}' (supported: liveness, ready)"
+                    );
+                }
+                Some(2)
+            } else {
+                Some(healthcheck::run(&cmd.config_path, cmd.healthcheck_mode))
+            }
+        }
         Subcommand::Init => {
             if let Some(opts) = cmd.init_opts.clone() {
                 match run_init(opts) {
@@ -177,6 +231,20 @@ pub fn execute_subcommand(cmd: &ParsedCommand) -> Option<i32> {
             eprintln!("[telemt] Subcommand not supported on this platform");
             Some(1)
         }
+        Subcommand::Healthcheck => {
+            if let Some(invalid_mode) = cmd.healthcheck_mode_invalid.as_ref() {
+                if invalid_mode.is_empty() {
+                    eprintln!("[telemt] Missing value for --mode (supported: liveness, ready)");
+                } else {
+                    eprintln!(
+                        "[telemt] Invalid --mode value '{invalid_mode}' (supported: liveness, ready)"
+                    );
+                }
+                Some(2)
+            } else {
+                Some(healthcheck::run(&cmd.config_path, cmd.healthcheck_mode))
+            }
+        }
         Subcommand::Init => {
             if let Some(opts) = cmd.init_opts.clone() {
                 match run_init(opts) {

src/config/load.rs

@@ -343,6 +343,10 @@ impl ProxyConfig {
         let network_table = parsed_toml
             .get("network")
             .and_then(|value| value.as_table());
+        let server_table = parsed_toml.get("server").and_then(|value| value.as_table());
+        let conntrack_control_table = server_table
+            .and_then(|table| table.get("conntrack_control"))
+            .and_then(|value| value.as_table());
         let update_every_is_explicit = general_table
             .map(|table| table.contains_key("update_every"))
             .unwrap_or(false);
@@ -372,10 +376,17 @@ impl ProxyConfig {
         let stun_servers_is_explicit = network_table
             .map(|table| table.contains_key("stun_servers"))
             .unwrap_or(false);
+        let inline_conntrack_control_is_explicit = conntrack_control_table
+            .map(|table| table.contains_key("inline_conntrack_control"))
+            .unwrap_or(false);
 
         let mut config: ProxyConfig = parsed_toml
             .try_into()
             .map_err(|e| ProxyError::Config(e.to_string()))?;
+        config
+            .server
+            .conntrack_control
+            .inline_conntrack_control_explicit = inline_conntrack_control_is_explicit;
 
         if !update_every_is_explicit && (legacy_secret_is_explicit || legacy_config_is_explicit) {
             config.general.update_every = None;
@@ -1881,6 +1892,43 @@ mod tests {
         );
     }
 
+    #[test]
+    fn conntrack_inline_explicit_flag_is_false_when_omitted() {
+        let cfg = load_config_from_temp_toml(
+            r#"
+            [general]
+            [network]
+            [server]
+            [server.conntrack_control]
+            [access]
+            "#,
+        );
+        assert!(
+            !cfg.server
+                .conntrack_control
+                .inline_conntrack_control_explicit
+        );
+    }
+
+    #[test]
+    fn conntrack_inline_explicit_flag_is_true_when_present() {
+        let cfg = load_config_from_temp_toml(
+            r#"
+            [general]
+            [network]
+            [server]
+            [server.conntrack_control]
+            inline_conntrack_control = true
+            [access]
+            "#,
+        );
+        assert!(
+            cfg.server
+                .conntrack_control
+                .inline_conntrack_control_explicit
+        );
+    }
+
     #[test]
     fn unknown_sni_action_parses_and_defaults_to_drop() {
         let cfg_default: ProxyConfig = toml::from_str(

src/config/types.rs

@@ -392,14 +392,26 @@ pub struct GeneralConfig {
     #[serde(default = "default_proxy_secret_path")]
     pub proxy_secret_path: Option<String>,
 
+    /// Optional custom URL for infrastructure secret (https://core.telegram.org/getProxySecret if absent).
+    #[serde(default)]
+    pub proxy_secret_url: Option<String>,
+
     /// Optional path to cache raw getProxyConfig (IPv4) snapshot for startup fallback.
     #[serde(default = "default_proxy_config_v4_cache_path")]
     pub proxy_config_v4_cache_path: Option<String>,
 
+    /// Optional custom URL for getProxyConfig (https://core.telegram.org/getProxyConfig if absent).
+    #[serde(default)]
+    pub proxy_config_v4_url: Option<String>,
+
     /// Optional path to cache raw getProxyConfigV6 snapshot for startup fallback.
     #[serde(default = "default_proxy_config_v6_cache_path")]
     pub proxy_config_v6_cache_path: Option<String>,
 
+    /// Optional custom URL for getProxyConfigV6 (https://core.telegram.org/getProxyConfigV6 if absent).
+    #[serde(default)]
+    pub proxy_config_v6_url: Option<String>,
+
     /// Global ad_tag (32 hex chars from @MTProxybot). Fallback when user has no per-user tag in access.user_ad_tags.
     #[serde(default)]
     pub ad_tag: Option<String>,
@@ -960,8 +972,11 @@ impl Default for GeneralConfig {
             use_middle_proxy: default_true(),
             ad_tag: None,
             proxy_secret_path: default_proxy_secret_path(),
+            proxy_secret_url: None,
             proxy_config_v4_cache_path: default_proxy_config_v4_cache_path(),
+            proxy_config_v4_url: None,
             proxy_config_v6_cache_path: default_proxy_config_v6_cache_path(),
+            proxy_config_v6_url: None,
             middle_proxy_nat_ip: None,
             middle_proxy_nat_probe: default_true(),
             middle_proxy_nat_stun: default_middle_proxy_nat_stun(),
@@ -1329,6 +1344,10 @@ pub struct ConntrackControlConfig {
     #[serde(default = "default_conntrack_control_enabled")]
     pub inline_conntrack_control: bool,
 
+    /// Tracks whether inline_conntrack_control was explicitly set in config.
+    #[serde(skip)]
+    pub inline_conntrack_control_explicit: bool,
+
     /// Conntrack mode for listener ingress traffic.
     #[serde(default)]
     pub mode: ConntrackMode,
@@ -1363,6 +1382,7 @@ impl Default for ConntrackControlConfig {
     fn default() -> Self {
         Self {
             inline_conntrack_control: default_conntrack_control_enabled(),
+            inline_conntrack_control_explicit: false,
             mode: ConntrackMode::default(),
             backend: ConntrackBackend::default(),
             profile: ConntrackPressureProfile::default(),

src/conntrack_control.rs

@@ -24,6 +24,13 @@ enum NetfilterBackend {
     Iptables,
 }
 
+#[derive(Clone, Copy)]
+struct ConntrackRuntimeSupport {
+    netfilter_backend: Option<NetfilterBackend>,
+    has_cap_net_admin: bool,
+    has_conntrack_binary: bool,
+}
+
 #[derive(Clone, Copy)]
 struct PressureSample {
     conn_pct: Option<u8>,
@@ -56,11 +63,8 @@ pub(crate) fn spawn_conntrack_controller(
     shared: Arc<ProxySharedState>,
 ) {
     if !cfg!(target_os = "linux") {
-        let enabled = config_rx
-            .borrow()
-            .server
-            .conntrack_control
-            .inline_conntrack_control;
+        let cfg = config_rx.borrow();
+        let enabled = cfg.server.conntrack_control.inline_conntrack_control;
         stats.set_conntrack_control_enabled(enabled);
         stats.set_conntrack_control_available(false);
         stats.set_conntrack_pressure_active(false);
@@ -68,9 +72,14 @@ pub(crate) fn spawn_conntrack_controller(
         stats.set_conntrack_rule_apply_ok(false);
         shared.disable_conntrack_close_sender();
         shared.set_conntrack_pressure_active(false);
-        if enabled {
+        if enabled
+            && cfg
+                .server
+                .conntrack_control
+                .inline_conntrack_control_explicit
+        {
             warn!(
-                "conntrack control is configured but unsupported on this OS; disabling runtime worker"
+                "conntrack control explicitly enabled but unsupported on this OS; disabling runtime worker"
             );
         }
         return;
@@ -92,16 +101,17 @@ async fn run_conntrack_controller(
     let mut cfg = config_rx.borrow().clone();
     let mut pressure_state = PressureState::new(stats.as_ref());
     let mut delete_budget_tokens = cfg.server.conntrack_control.delete_budget_per_sec;
-    let mut backend = pick_backend(cfg.server.conntrack_control.backend);
+    let mut runtime_support = probe_runtime_support(cfg.server.conntrack_control.backend);
+    let mut effective_enabled = effective_conntrack_enabled(&cfg, runtime_support);
 
     apply_runtime_state(
         stats.as_ref(),
         shared.as_ref(),
         &cfg,
-        backend.is_some(),
+        runtime_support,
         false,
     );
-    reconcile_rules(&cfg, backend, stats.as_ref()).await;
+    reconcile_rules(&cfg, runtime_support, stats.as_ref()).await;
 
     loop {
         tokio::select! {
@@ -110,17 +120,18 @@ async fn run_conntrack_controller(
                     break;
                 }
                 cfg = config_rx.borrow_and_update().clone();
-                backend = pick_backend(cfg.server.conntrack_control.backend);
+                runtime_support = probe_runtime_support(cfg.server.conntrack_control.backend);
+                effective_enabled = effective_conntrack_enabled(&cfg, runtime_support);
                 delete_budget_tokens = cfg.server.conntrack_control.delete_budget_per_sec;
-                apply_runtime_state(stats.as_ref(), shared.as_ref(), &cfg, backend.is_some(), pressure_state.active);
-                reconcile_rules(&cfg, backend, stats.as_ref()).await;
+                apply_runtime_state(stats.as_ref(), shared.as_ref(), &cfg, runtime_support, pressure_state.active);
+                reconcile_rules(&cfg, runtime_support, stats.as_ref()).await;
             }
             event = close_rx.recv() => {
                 let Some(event) = event else {
                     break;
                 };
                 stats.set_conntrack_event_queue_depth(close_rx.len() as u64);
-                if !cfg.server.conntrack_control.inline_conntrack_control {
+                if !effective_enabled {
                     continue;
                 }
                 if !pressure_state.active {
@@ -156,6 +167,7 @@ async fn run_conntrack_controller(
                     stats.as_ref(),
                     shared.as_ref(),
                     &cfg,
+                    effective_enabled,
                     &sample,
                     &mut pressure_state,
                 );
@@ -175,20 +187,30 @@ fn apply_runtime_state(
     stats: &Stats,
     shared: &ProxySharedState,
     cfg: &ProxyConfig,
-    backend_available: bool,
+    runtime_support: ConntrackRuntimeSupport,
     pressure_active: bool,
 ) {
     let enabled = cfg.server.conntrack_control.inline_conntrack_control;
-    let available = enabled && backend_available && has_cap_net_admin();
-    if enabled && !available {
+    let available = effective_conntrack_enabled(cfg, runtime_support);
+    if enabled
+        && !available
+        && cfg
+            .server
+            .conntrack_control
+            .inline_conntrack_control_explicit
+    {
         warn!(
-            "conntrack control enabled but unavailable (missing CAP_NET_ADMIN or backend binaries)"
+            has_cap_net_admin = runtime_support.has_cap_net_admin,
+            backend_available = runtime_support.netfilter_backend.is_some(),
+            conntrack_binary_available = runtime_support.has_conntrack_binary,
+            configured_backend = ?cfg.server.conntrack_control.backend,
+            "conntrack control explicitly enabled but unavailable; disabling runtime features"
         );
     }
     stats.set_conntrack_control_enabled(enabled);
     stats.set_conntrack_control_available(available);
-    shared.set_conntrack_pressure_active(enabled && pressure_active);
-    stats.set_conntrack_pressure_active(enabled && pressure_active);
+    shared.set_conntrack_pressure_active(available && pressure_active);
+    stats.set_conntrack_pressure_active(available && pressure_active);
 }
 
 fn collect_pressure_sample(
@@ -228,10 +250,11 @@ fn update_pressure_state(
     stats: &Stats,
     shared: &ProxySharedState,
     cfg: &ProxyConfig,
+    effective_enabled: bool,
     sample: &PressureSample,
     state: &mut PressureState,
 ) {
-    if !cfg.server.conntrack_control.inline_conntrack_control {
+    if !effective_enabled {
         if state.active {
             state.active = false;
             state.low_streak = 0;
@@ -285,22 +308,26 @@ fn update_pressure_state(
     state.low_streak = 0;
 }
 
-async fn reconcile_rules(cfg: &ProxyConfig, backend: Option<NetfilterBackend>, stats: &Stats) {
+async fn reconcile_rules(
+    cfg: &ProxyConfig,
+    runtime_support: ConntrackRuntimeSupport,
+    stats: &Stats,
+) {
     if !cfg.server.conntrack_control.inline_conntrack_control {
         clear_notrack_rules_all_backends().await;
         stats.set_conntrack_rule_apply_ok(true);
         return;
     }
 
-    if !has_cap_net_admin() {
+    if !effective_conntrack_enabled(cfg, runtime_support) {
+        clear_notrack_rules_all_backends().await;
         stats.set_conntrack_rule_apply_ok(false);
         return;
     }
 
-    let Some(backend) = backend else {
-        stats.set_conntrack_rule_apply_ok(false);
-        return;
-    };
+    let backend = runtime_support
+        .netfilter_backend
+        .expect("netfilter backend must be available for effective conntrack control");
 
     let apply_result = match backend {
         NetfilterBackend::Nftables => apply_nft_rules(cfg).await,
@@ -315,6 +342,24 @@ async fn reconcile_rules(cfg: &ProxyConfig, backend: Option<NetfilterBackend>, s
     }
 }
 
+fn probe_runtime_support(configured_backend: ConntrackBackend) -> ConntrackRuntimeSupport {
+    ConntrackRuntimeSupport {
+        netfilter_backend: pick_backend(configured_backend),
+        has_cap_net_admin: has_cap_net_admin(),
+        has_conntrack_binary: command_exists("conntrack"),
+    }
+}
+
+fn effective_conntrack_enabled(
+    cfg: &ProxyConfig,
+    runtime_support: ConntrackRuntimeSupport,
+) -> bool {
+    cfg.server.conntrack_control.inline_conntrack_control
+        && runtime_support.has_cap_net_admin
+        && runtime_support.netfilter_backend.is_some()
+        && runtime_support.has_conntrack_binary
+}
+
 fn pick_backend(configured: ConntrackBackend) -> Option<NetfilterBackend> {
     match configured {
         ConntrackBackend::Auto => {
@@ -710,7 +755,7 @@ mod tests {
             me_queue_pressure_delta: 0,
         };
 
-        update_pressure_state(&stats, shared.as_ref(), &cfg, &sample, &mut state);
+        update_pressure_state(&stats, shared.as_ref(), &cfg, true, &sample, &mut state);
 
         assert!(state.active);
         assert!(shared.conntrack_pressure_active());
@@ -731,7 +776,14 @@ mod tests {
             accept_timeout_delta: 0,
             me_queue_pressure_delta: 0,
         };
-        update_pressure_state(&stats, shared.as_ref(), &cfg, &high_sample, &mut state);
+        update_pressure_state(
+            &stats,
+            shared.as_ref(),
+            &cfg,
+            true,
+            &high_sample,
+            &mut state,
+        );
         assert!(state.active);
 
         let low_sample = PressureSample {
@@ -740,11 +792,11 @@ mod tests {
             accept_timeout_delta: 0,
             me_queue_pressure_delta: 0,
         };
-        update_pressure_state(&stats, shared.as_ref(), &cfg, &low_sample, &mut state);
+        update_pressure_state(&stats, shared.as_ref(), &cfg, true, &low_sample, &mut state);
         assert!(state.active);
-        update_pressure_state(&stats, shared.as_ref(), &cfg, &low_sample, &mut state);
+        update_pressure_state(&stats, shared.as_ref(), &cfg, true, &low_sample, &mut state);
         assert!(state.active);
-        update_pressure_state(&stats, shared.as_ref(), &cfg, &low_sample, &mut state);
+        update_pressure_state(&stats, shared.as_ref(), &cfg, true, &low_sample, &mut state);
 
         assert!(!state.active);
         assert!(!shared.conntrack_pressure_active());
@@ -765,7 +817,7 @@ mod tests {
             me_queue_pressure_delta: 10,
         };
 
-        update_pressure_state(&stats, shared.as_ref(), &cfg, &sample, &mut state);
+        update_pressure_state(&stats, shared.as_ref(), &cfg, false, &sample, &mut state);
 
         assert!(!state.active);
         assert!(!shared.conntrack_pressure_active());

src/healthcheck.rs

@@ -0,0 +1,211 @@
+use std::io::{Read, Write};
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, TcpStream};
+use std::time::Duration;
+
+use serde_json::Value;
+
+use crate::config::ProxyConfig;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum HealthcheckMode {
+    Liveness,
+    Ready,
+}
+
+impl HealthcheckMode {
+    pub(crate) fn from_cli_arg(value: &str) -> Option<Self> {
+        match value {
+            "liveness" => Some(Self::Liveness),
+            "ready" => Some(Self::Ready),
+            _ => None,
+        }
+    }
+
+    fn request_path(self) -> &'static str {
+        match self {
+            Self::Liveness => "/v1/health",
+            Self::Ready => "/v1/health/ready",
+        }
+    }
+}
+
+pub(crate) fn run(config_path: &str, mode: HealthcheckMode) -> i32 {
+    match run_inner(config_path, mode) {
+        Ok(()) => 0,
+        Err(error) => {
+            eprintln!("[telemt] healthcheck failed: {error}");
+            1
+        }
+    }
+}
+
+fn run_inner(config_path: &str, mode: HealthcheckMode) -> Result<(), String> {
+    let config =
+        ProxyConfig::load(config_path).map_err(|error| format!("config load failed: {error}"))?;
+    let api_cfg = &config.server.api;
+    if !api_cfg.enabled {
+        return Ok(());
+    }
+
+    let listen: SocketAddr = api_cfg
+        .listen
+        .parse()
+        .map_err(|_| format!("invalid API listen address: {}", api_cfg.listen))?;
+    if listen.port() == 0 {
+        return Err("API listen port is 0".to_string());
+    }
+    let target = probe_target(listen);
+
+    let mut stream = TcpStream::connect_timeout(&target, Duration::from_secs(2))
+        .map_err(|error| format!("connect {target} failed: {error}"))?;
+    stream
+        .set_read_timeout(Some(Duration::from_secs(2)))
+        .map_err(|error| format!("set read timeout failed: {error}"))?;
+    stream
+        .set_write_timeout(Some(Duration::from_secs(2)))
+        .map_err(|error| format!("set write timeout failed: {error}"))?;
+
+    let request = build_request(target, mode.request_path(), &api_cfg.auth_header);
+    stream
+        .write_all(request.as_bytes())
+        .map_err(|error| format!("request write failed: {error}"))?;
+    stream
+        .flush()
+        .map_err(|error| format!("request flush failed: {error}"))?;
+
+    let mut raw_response = Vec::new();
+    stream
+        .read_to_end(&mut raw_response)
+        .map_err(|error| format!("response read failed: {error}"))?;
+    let response =
+        String::from_utf8(raw_response).map_err(|_| "response is not valid UTF-8".to_string())?;
+
+    let (status_code, body) = split_response(&response)?;
+    if status_code != 200 {
+        return Err(format!("HTTP status {status_code}"));
+    }
+
+    validate_payload(mode, body)?;
+    Ok(())
+}
+
+fn probe_target(listen: SocketAddr) -> SocketAddr {
+    match listen {
+        SocketAddr::V4(addr) => {
+            let ip = if addr.ip().is_unspecified() {
+                Ipv4Addr::LOCALHOST
+            } else {
+                *addr.ip()
+            };
+            SocketAddr::from((ip, addr.port()))
+        }
+        SocketAddr::V6(addr) => {
+            let ip = if addr.ip().is_unspecified() {
+                Ipv6Addr::LOCALHOST
+            } else {
+                *addr.ip()
+            };
+            SocketAddr::from((ip, addr.port()))
+        }
+    }
+}
+
+fn build_request(target: SocketAddr, path: &str, auth_header: &str) -> String {
+    let mut request = format!(
+        "GET {path} HTTP/1.1\r\nHost: {}\r\nConnection: close\r\n",
+        target
+    );
+    if !auth_header.is_empty() {
+        request.push_str("Authorization: ");
+        request.push_str(auth_header);
+        request.push_str("\r\n");
+    }
+    request.push_str("\r\n");
+    request
+}
+
+fn split_response(response: &str) -> Result<(u16, &str), String> {
+    let header_end = response
+        .find("\r\n\r\n")
+        .ok_or_else(|| "invalid HTTP response headers".to_string())?;
+    let header = &response[..header_end];
+    let body = &response[header_end + 4..];
+    let status_line = header
+        .lines()
+        .next()
+        .ok_or_else(|| "missing HTTP status line".to_string())?;
+    let status_code = parse_status_code(status_line)?;
+    Ok((status_code, body))
+}
+
+fn parse_status_code(status_line: &str) -> Result<u16, String> {
+    let mut parts = status_line.split_whitespace();
+    let version = parts
+        .next()
+        .ok_or_else(|| "missing HTTP version".to_string())?;
+    if !version.starts_with("HTTP/") {
+        return Err(format!("invalid HTTP status line: {status_line}"));
+    }
+    let code = parts
+        .next()
+        .ok_or_else(|| "missing HTTP status code".to_string())?;
+    code.parse::<u16>()
+        .map_err(|_| format!("invalid HTTP status code: {code}"))
+}
+
+fn validate_payload(mode: HealthcheckMode, body: &str) -> Result<(), String> {
+    let payload: Value =
+        serde_json::from_str(body).map_err(|_| "response body is not valid JSON".to_string())?;
+    if payload.get("ok").and_then(Value::as_bool) != Some(true) {
+        return Err("response JSON has ok=false".to_string());
+    }
+
+    let data = payload
+        .get("data")
+        .ok_or_else(|| "response JSON has no data field".to_string())?;
+    match mode {
+        HealthcheckMode::Liveness => {
+            if data.get("status").and_then(Value::as_str) != Some("ok") {
+                return Err("liveness status is not ok".to_string());
+            }
+        }
+        HealthcheckMode::Ready => {
+            if data.get("ready").and_then(Value::as_bool) != Some(true) {
+                return Err("readiness flag is false".to_string());
+            }
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{HealthcheckMode, parse_status_code, split_response, validate_payload};
+
+    #[test]
+    fn parse_status_code_reads_http_200() {
+        let status = parse_status_code("HTTP/1.1 200 OK").expect("must parse status");
+        assert_eq!(status, 200);
+    }
+
+    #[test]
+    fn split_response_extracts_status_and_body() {
+        let response = "HTTP/1.1 200 OK\r\nContent-Type: application/json\r\n\r\n{\"ok\":true}";
+        let (status, body) = split_response(response).expect("must split response");
+        assert_eq!(status, 200);
+        assert_eq!(body, "{\"ok\":true}");
+    }
+
+    #[test]
+    fn validate_payload_accepts_liveness_contract() {
+        let body = "{\"ok\":true,\"data\":{\"status\":\"ok\"}}";
+        validate_payload(HealthcheckMode::Liveness, body).expect("liveness payload must pass");
+    }
+
+    #[test]
+    fn validate_payload_rejects_not_ready() {
+        let body = "{\"ok\":true,\"data\":{\"ready\":false}}";
+        let result = validate_payload(HealthcheckMode::Ready, body);
+        assert!(result.is_err());
+    }
+}

src/maestro/me_startup.rs

@@ -66,6 +66,7 @@ pub(crate) async fn initialize_me_pool(
         match crate::transport::middle_proxy::fetch_proxy_secret_with_upstream(
             proxy_secret_path,
             config.general.proxy_secret_len_max,
+            config.general.proxy_secret_url.as_deref(),
             Some(upstream_manager.clone()),
         )
         .await
@@ -126,7 +127,11 @@ pub(crate) async fn initialize_me_pool(
                 .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_PROXY_CONFIG_V4)
                 .await;
             let cfg_v4 = load_startup_proxy_config_snapshot(
-                "https://core.telegram.org/getProxyConfig",
+                config
+                    .general
+                    .proxy_config_v4_url
+                    .as_deref()
+                    .unwrap_or("https://core.telegram.org/getProxyConfig"),
                 config.general.proxy_config_v4_cache_path.as_deref(),
                 me2dc_fallback,
                 "getProxyConfig",
@@ -158,7 +163,11 @@ pub(crate) async fn initialize_me_pool(
                 .set_me_status(StartupMeStatus::Initializing, COMPONENT_ME_PROXY_CONFIG_V6)
                 .await;
             let cfg_v6 = load_startup_proxy_config_snapshot(
-                "https://core.telegram.org/getProxyConfigV6",
+                config
+                    .general
+                    .proxy_config_v6_url
+                    .as_deref()
+                    .unwrap_or("https://core.telegram.org/getProxyConfigV6"),
                 config.general.proxy_config_v6_cache_path.as_deref(),
                 me2dc_fallback,
                 "getProxyConfigV6",

src/main.rs

@@ -8,6 +8,7 @@ mod crypto;
 #[cfg(unix)]
 mod daemon;
 mod error;
+mod healthcheck;
 mod ip_tracker;
 #[cfg(test)]
 #[path = "tests/ip_tracker_encapsulation_adversarial_tests.rs"]

src/tls_front/emulator.rs

@@ -66,9 +66,19 @@ fn ensure_payload_capacity(mut sizes: Vec<usize>, payload_len: usize) -> Vec<usi
 fn emulated_app_data_sizes(cached: &CachedTlsData) -> Vec<usize> {
     match cached.behavior_profile.source {
         TlsProfileSource::Raw | TlsProfileSource::Merged => {
-            if !cached.behavior_profile.app_data_record_sizes.is_empty() {
-                return cached.behavior_profile.app_data_record_sizes.clone();
-            }
+            return cached
+                .app_data_records_sizes
+                .first()
+                .copied()
+                .or_else(|| {
+                    cached
+                        .behavior_profile
+                        .app_data_record_sizes
+                        .first()
+                        .copied()
+                })
+                .map(|size| vec![size])
+                .unwrap_or_else(|| vec![cached.total_app_data_len.max(1024)]);
         }
         TlsProfileSource::Default | TlsProfileSource::Rustls => {}
     }
@@ -80,8 +90,8 @@ fn emulated_app_data_sizes(cached: &CachedTlsData) -> Vec<usize> {
     sizes
 }
 
-fn emulated_change_cipher_spec_count(cached: &CachedTlsData) -> usize {
-    usize::from(cached.behavior_profile.change_cipher_spec_count.max(1))
+fn emulated_change_cipher_spec_count(_cached: &CachedTlsData) -> usize {
+    1
 }
 
 fn emulated_ticket_record_sizes(
@@ -89,19 +99,20 @@ fn emulated_ticket_record_sizes(
     new_session_tickets: u8,
     rng: &SecureRandom,
 ) -> Vec<usize> {
-    let mut sizes = match cached.behavior_profile.source {
-        TlsProfileSource::Raw | TlsProfileSource::Merged => {
-            cached.behavior_profile.ticket_record_sizes.clone()
+    let target_count = usize::from(new_session_tickets.min(MAX_TICKET_RECORDS as u8));
+    if target_count == 0 {
+        return Vec::new();
     }
-        TlsProfileSource::Default | TlsProfileSource::Rustls => Vec::new(),
+
+    let profiled_sizes = match cached.behavior_profile.source {
+        TlsProfileSource::Raw | TlsProfileSource::Merged => {
+            cached.behavior_profile.ticket_record_sizes.as_slice()
+        }
+        TlsProfileSource::Default | TlsProfileSource::Rustls => &[],
     };
 
-    let target_count = sizes
-        .len()
-        .max(usize::from(
-            new_session_tickets.min(MAX_TICKET_RECORDS as u8),
-        ))
-        .min(MAX_TICKET_RECORDS);
+    let mut sizes = Vec::with_capacity(target_count);
+    sizes.extend(profiled_sizes.iter().copied().take(target_count));
 
     while sizes.len() < target_count {
         sizes.push(rng.range(48) + 48);
@@ -242,7 +253,18 @@ pub fn build_emulated_server_hello(
     }
 
     // --- ApplicationData (fake encrypted records) ---
-    let mut sizes = jitter_and_clamp_sizes(&emulated_app_data_sizes(cached), rng);
+    let mut sizes = {
+        let base_sizes = emulated_app_data_sizes(cached);
+        match cached.behavior_profile.source {
+            TlsProfileSource::Raw | TlsProfileSource::Merged => base_sizes
+                .into_iter()
+                .map(|size| size.clamp(MIN_APP_DATA, MAX_APP_DATA))
+                .collect(),
+            TlsProfileSource::Default | TlsProfileSource::Rustls => {
+                jitter_and_clamp_sizes(&base_sizes, rng)
+            }
+        }
+    };
     let compact_payload = cached
         .cert_info
         .as_ref()
@@ -508,7 +530,7 @@ mod tests {
     }
 
     #[test]
-    fn test_build_emulated_server_hello_replays_tail_records_for_profiled_tls() {
+    fn test_build_emulated_server_hello_ignores_tail_records_for_profiled_tls() {
         let mut cached = make_cached(None);
         cached.app_data_records_sizes = vec![27, 3905, 537, 69];
         cached.total_app_data_len = 4538;
@@ -530,19 +552,11 @@ mod tests {
 
         let hello_len = u16::from_be_bytes([response[3], response[4]]) as usize;
         let ccs_start = 5 + hello_len;
-        let mut pos = ccs_start + 6;
-        let mut app_lengths = Vec::new();
-        while pos + 5 <= response.len() {
-            assert_eq!(response[pos], TLS_RECORD_APPLICATION);
-            let record_len = u16::from_be_bytes([response[pos + 3], response[pos + 4]]) as usize;
-            app_lengths.push(record_len);
-            pos += 5 + record_len;
-        }
-
-        assert_eq!(app_lengths.len(), 4);
-        assert_eq!(app_lengths[0], 64);
-        assert_eq!(app_lengths[3], 69);
-        assert!(app_lengths[1] >= 64);
-        assert!(app_lengths[2] >= 64);
+        let app_start = ccs_start + 6;
+        let app_len =
+            u16::from_be_bytes([response[app_start + 3], response[app_start + 4]]) as usize;
+        assert_eq!(response[app_start], TLS_RECORD_APPLICATION);
+        assert_eq!(app_len, 64);
+        assert_eq!(app_start + 5 + app_len, response.len());
     }
 }

src/tls_front/tests/emulator_profile_fidelity_security_tests.rs

@@ -52,7 +52,7 @@ fn record_lengths_by_type(response: &[u8], wanted_type: u8) -> Vec<usize> {
 }
 
 #[test]
-fn emulated_server_hello_replays_profile_change_cipher_spec_count() {
+fn emulated_server_hello_keeps_single_change_cipher_spec_for_client_compatibility() {
     let cached = make_cached();
     let rng = SecureRandom::new();
 
@@ -69,12 +69,12 @@ fn emulated_server_hello_replays_profile_change_cipher_spec_count() {
 
     assert_eq!(response[0], TLS_RECORD_HANDSHAKE);
     let ccs_records = record_lengths_by_type(&response, TLS_RECORD_CHANGE_CIPHER);
-    assert_eq!(ccs_records.len(), 2);
+    assert_eq!(ccs_records.len(), 1);
     assert!(ccs_records.iter().all(|len| *len == 1));
 }
 
 #[test]
-fn emulated_server_hello_replays_profile_ticket_tail_lengths() {
+fn emulated_server_hello_does_not_emit_profile_ticket_tail_when_disabled() {
     let cached = make_cached();
     let rng = SecureRandom::new();
 
@@ -90,6 +90,25 @@ fn emulated_server_hello_replays_profile_ticket_tail_lengths() {
     );
 
     let app_records = record_lengths_by_type(&response, TLS_RECORD_APPLICATION);
-    assert!(app_records.len() >= 4);
-    assert_eq!(&app_records[app_records.len() - 2..], &[220, 180]);
+    assert_eq!(app_records, vec![1200]);
+}
+
+#[test]
+fn emulated_server_hello_uses_profile_ticket_lengths_when_enabled() {
+    let cached = make_cached();
+    let rng = SecureRandom::new();
+
+    let response = build_emulated_server_hello(
+        b"secret",
+        &[0x91; 32],
+        &[0x92; 16],
+        &cached,
+        false,
+        &rng,
+        None,
+        2,
+    );
+
+    let app_records = record_lengths_by_type(&response, TLS_RECORD_APPLICATION);
+    assert_eq!(app_records, vec![1200, 220, 180]);
 }

src/transport/middle_proxy/config_updater.rs

@@ -321,7 +321,14 @@ async fn run_update_cycle(
     let mut maps_changed = false;
 
     let mut ready_v4: Option<(ProxyConfigData, u64)> = None;
-    let cfg_v4 = retry_fetch("https://core.telegram.org/getProxyConfig", upstream.clone()).await;
+    let cfg_v4 = retry_fetch(
+        cfg.general
+            .proxy_config_v4_url
+            .as_deref()
+            .unwrap_or("https://core.telegram.org/getProxyConfig"),
+        upstream.clone(),
+    )
+    .await;
     if let Some(cfg_v4) = cfg_v4
         && snapshot_passes_guards(cfg, &cfg_v4, "getProxyConfig")
     {
@@ -346,7 +353,10 @@ async fn run_update_cycle(
 
     let mut ready_v6: Option<(ProxyConfigData, u64)> = None;
     let cfg_v6 = retry_fetch(
-        "https://core.telegram.org/getProxyConfigV6",
+        cfg.general
+            .proxy_config_v6_url
+            .as_deref()
+            .unwrap_or("https://core.telegram.org/getProxyConfigV6"),
         upstream.clone(),
     )
     .await;
@@ -430,6 +440,7 @@ async fn run_update_cycle(
         match download_proxy_secret_with_max_len_via_upstream(
             cfg.general.proxy_secret_len_max,
             upstream,
+            cfg.general.proxy_secret_url.as_deref(),
         )
         .await
         {

src/transport/middle_proxy/fairness/mod.rs

@@ -7,7 +7,6 @@ mod model;
 mod pressure;
 mod scheduler;
 
-#[cfg(test)]
 pub(crate) use model::PressureState;
 pub(crate) use model::{AdmissionDecision, DispatchAction, DispatchFeedback, SchedulerDecision};
 pub(crate) use scheduler::{WorkerFairnessConfig, WorkerFairnessSnapshot, WorkerFairnessState};

src/transport/middle_proxy/fairness/model.rs

@@ -77,11 +77,12 @@ pub(crate) struct FlowFairnessState {
     pub(crate) standing_state: StandingQueueState,
     pub(crate) scheduler_state: FlowSchedulerState,
     pub(crate) bucket_id: usize,
+    pub(crate) weight_quanta: u8,
     pub(crate) in_active_ring: bool,
 }
 
 impl FlowFairnessState {
-    pub(crate) fn new(flow_id: u64, worker_id: u16, bucket_id: usize) -> Self {
+    pub(crate) fn new(flow_id: u64, worker_id: u16, bucket_id: usize, weight_quanta: u8) -> Self {
         Self {
             _flow_id: flow_id,
             _worker_id: worker_id,
@@ -97,6 +98,7 @@ impl FlowFairnessState {
             standing_state: StandingQueueState::Transient,
             scheduler_state: FlowSchedulerState::Idle,
             bucket_id,
+            weight_quanta: weight_quanta.max(1),
             in_active_ring: false,
         }
     }

src/transport/middle_proxy/fairness/pressure.rs

@@ -146,59 +146,55 @@ impl PressureEvaluator {
             ((signals.standing_flows.saturating_mul(100)) / signals.active_flows).min(100) as u8
         };
 
-        let mut pressure_score = 0u8;
+        let mut pressured = false;
+        let mut saturated = false;
 
+        let queue_saturated_pct = cfg.queue_ratio_shedding_pct.min(cfg.queue_ratio_saturated_pct);
         if queue_ratio_pct >= cfg.queue_ratio_pressured_pct {
-            pressure_score = pressure_score.max(1);
+            pressured = true;
         }
-        if queue_ratio_pct >= cfg.queue_ratio_shedding_pct {
-            pressure_score = pressure_score.max(2);
-        }
-        if queue_ratio_pct >= cfg.queue_ratio_saturated_pct {
-            pressure_score = pressure_score.max(3);
+        if queue_ratio_pct >= queue_saturated_pct {
+            saturated = true;
         }
 
+        let standing_saturated_pct = cfg
+            .standing_ratio_shedding_pct
+            .min(cfg.standing_ratio_saturated_pct);
         if standing_ratio_pct >= cfg.standing_ratio_pressured_pct {
-            pressure_score = pressure_score.max(1);
+            pressured = true;
         }
-        if standing_ratio_pct >= cfg.standing_ratio_shedding_pct {
-            pressure_score = pressure_score.max(2);
-        }
-        if standing_ratio_pct >= cfg.standing_ratio_saturated_pct {
-            pressure_score = pressure_score.max(3);
+        if standing_ratio_pct >= standing_saturated_pct {
+            saturated = true;
         }
 
+        let rejects_saturated = cfg.rejects_shedding.min(cfg.rejects_saturated);
         if self.admission_rejects_window >= cfg.rejects_pressured {
-            pressure_score = pressure_score.max(1);
+            pressured = true;
         }
-        if self.admission_rejects_window >= cfg.rejects_shedding {
-            pressure_score = pressure_score.max(2);
-        }
-        if self.admission_rejects_window >= cfg.rejects_saturated {
-            pressure_score = pressure_score.max(3);
+        if self.admission_rejects_window >= rejects_saturated {
+            saturated = true;
         }
 
+        let stalls_saturated = cfg.stalls_shedding.min(cfg.stalls_saturated);
         if self.route_stalls_window >= cfg.stalls_pressured {
-            pressure_score = pressure_score.max(1);
+            pressured = true;
         }
-        if self.route_stalls_window >= cfg.stalls_shedding {
-            pressure_score = pressure_score.max(2);
-        }
-        if self.route_stalls_window >= cfg.stalls_saturated {
-            pressure_score = pressure_score.max(3);
+        if self.route_stalls_window >= stalls_saturated {
+            saturated = true;
         }
 
         if signals.backpressured_flows > signals.active_flows.saturating_div(2)
             && signals.active_flows > 0
         {
-            pressure_score = pressure_score.max(2);
+            pressured = true;
         }
 
-        match pressure_score {
-            0 => PressureState::Normal,
-            1 => PressureState::Pressured,
-            2 => PressureState::Shedding,
-            _ => PressureState::Saturated,
+        if saturated {
+            PressureState::Saturated
+        } else if pressured {
+            PressureState::Pressured
+        } else {
+            PressureState::Normal
         }
     }
 

src/transport/middle_proxy/fairness/scheduler.rs

@@ -1,7 +1,8 @@
-use std::collections::{HashMap, VecDeque};
+use std::collections::{HashMap, HashSet, VecDeque};
 use std::time::{Duration, Instant};
 
 use bytes::Bytes;
+use crate::protocol::constants::RPC_FLAG_QUICKACK;
 
 use super::model::{
     AdmissionDecision, DispatchAction, DispatchCandidate, DispatchFeedback, FlowFairnessState,
@@ -26,6 +27,8 @@ pub(crate) struct WorkerFairnessConfig {
     pub(crate) max_consecutive_stalls_before_close: u8,
     pub(crate) soft_bucket_count: usize,
     pub(crate) soft_bucket_share_pct: u8,
+    pub(crate) default_flow_weight: u8,
+    pub(crate) quickack_flow_weight: u8,
     pub(crate) pressure: PressureConfig,
 }
 
@@ -46,6 +49,8 @@ impl Default for WorkerFairnessConfig {
             max_consecutive_stalls_before_close: 16,
             soft_bucket_count: 64,
             soft_bucket_share_pct: 25,
+            default_flow_weight: 1,
+            quickack_flow_weight: 4,
             pressure: PressureConfig::default(),
         }
     }
@@ -57,9 +62,9 @@ struct FlowEntry {
 }
 
 impl FlowEntry {
-    fn new(flow_id: u64, worker_id: u16, bucket_id: usize) -> Self {
+    fn new(flow_id: u64, worker_id: u16, bucket_id: usize, weight_quanta: u8) -> Self {
         Self {
-            fairness: FlowFairnessState::new(flow_id, worker_id, bucket_id),
+            fairness: FlowFairnessState::new(flow_id, worker_id, bucket_id, weight_quanta),
             queue: VecDeque::new(),
         }
     }
@@ -86,6 +91,7 @@ pub(crate) struct WorkerFairnessState {
     pressure: PressureEvaluator,
     flows: HashMap<u64, FlowEntry>,
     active_ring: VecDeque<u64>,
+    active_ring_members: HashSet<u64>,
     total_queued_bytes: u64,
     bucket_queued_bytes: Vec<u64>,
     bucket_active_flows: Vec<usize>,
@@ -108,6 +114,7 @@ impl WorkerFairnessState {
             pressure: PressureEvaluator::new(now),
             flows: HashMap::new(),
             active_ring: VecDeque::new(),
+            active_ring_members: HashSet::new(),
             total_queued_bytes: 0,
             bucket_queued_bytes: vec![0; bucket_count],
             bucket_active_flows: vec![0; bucket_count],
@@ -184,6 +191,7 @@ impl WorkerFairnessState {
         }
 
         let bucket_id = self.bucket_for(conn_id);
+        let frame_weight = Self::weight_for_flags(&self.config, flags);
         let bucket_cap = self
             .config
             .max_total_queued_bytes
@@ -205,12 +213,13 @@ impl WorkerFairnessState {
                 self.bucket_active_flows[bucket_id].saturating_add(1);
             self.flows.insert(
                 conn_id,
-                FlowEntry::new(conn_id, self.config.worker_id, bucket_id),
+                FlowEntry::new(conn_id, self.config.worker_id, bucket_id, frame_weight),
             );
             self.flows
                 .get_mut(&conn_id)
                 .expect("flow inserted must be retrievable")
         };
+        entry.fairness.weight_quanta = entry.fairness.weight_quanta.max(frame_weight);
 
         if entry.fairness.pending_bytes.saturating_add(frame_bytes)
             > self.config.max_flow_queued_bytes
@@ -242,11 +251,24 @@ impl WorkerFairnessState {
         self.bucket_queued_bytes[bucket_id] =
             self.bucket_queued_bytes[bucket_id].saturating_add(frame_bytes);
 
+        let mut enqueue_active = false;
         if !entry.fairness.in_active_ring {
             entry.fairness.in_active_ring = true;
-            self.active_ring.push_back(conn_id);
+            enqueue_active = true;
         }
 
+        let pressure_state = self.pressure.state();
+        let (before_membership, after_membership) = {
+            let before = Self::flow_membership(&entry.fairness);
+            Self::classify_flow(&self.config, pressure_state, now, &mut entry.fairness);
+            let after = Self::flow_membership(&entry.fairness);
+            (before, after)
+        };
+        if enqueue_active {
+            self.enqueue_active_conn(conn_id);
+        }
+        self.apply_flow_membership_delta(before_membership, after_membership);
+
         self.evaluate_pressure(now, true);
         AdmissionDecision::Admit
     }
@@ -260,32 +282,44 @@ impl WorkerFairnessState {
             let Some(conn_id) = self.active_ring.pop_front() else {
                 break;
             };
+            if !self.active_ring_members.remove(&conn_id) {
+                continue;
+            }
 
             let mut candidate = None;
             let mut requeue_active = false;
             let mut drained_bytes = 0u64;
             let mut bucket_id = 0usize;
+            let mut should_continue = false;
+            let mut enqueue_active = false;
+            let mut membership_delta = None;
             let pressure_state = self.pressure.state();
 
             if let Some(flow) = self.flows.get_mut(&conn_id) {
                 bucket_id = flow.fairness.bucket_id;
+                flow.fairness.in_active_ring = false;
+                let before_membership = Self::flow_membership(&flow.fairness);
 
                 if flow.queue.is_empty() {
                     flow.fairness.in_active_ring = false;
                     flow.fairness.scheduler_state = FlowSchedulerState::Idle;
                     flow.fairness.pending_bytes = 0;
+                    flow.fairness.deficit_bytes = 0;
                     flow.fairness.queue_started_at = None;
-                    continue;
-                }
-
+                    should_continue = true;
+                } else {
                     Self::classify_flow(&self.config, pressure_state, now, &mut flow.fairness);
 
-                let quantum =
-                    Self::effective_quantum_bytes(&self.config, pressure_state, &flow.fairness);
+                    let quantum = Self::effective_quantum_bytes(
+                        &self.config,
+                        pressure_state,
+                        &flow.fairness,
+                    );
                     flow.fairness.deficit_bytes = flow
                         .fairness
                         .deficit_bytes
                         .saturating_add(i64::from(quantum));
+                    Self::clamp_deficit_bytes(&self.config, &mut flow.fairness);
                     self.deficit_grants = self.deficit_grants.saturating_add(1);
 
                     let front_len = flow.queue.front().map_or(0, |front| front.queued_bytes());
@@ -294,6 +328,8 @@ impl WorkerFairnessState {
                             flow.fairness.consecutive_skips.saturating_add(1);
                         self.deficit_skips = self.deficit_skips.saturating_add(1);
                         requeue_active = true;
+                        flow.fairness.in_active_ring = true;
+                        enqueue_active = true;
                     } else if let Some(frame) = flow.queue.pop_front() {
                         drained_bytes = frame.queued_bytes();
                         flow.fairness.pending_bytes =
@@ -302,6 +338,7 @@ impl WorkerFairnessState {
                             .fairness
                             .deficit_bytes
                             .saturating_sub(drained_bytes as i64);
+                        Self::clamp_deficit_bytes(&self.config, &mut flow.fairness);
                         flow.fairness.consecutive_skips = 0;
                         flow.fairness.queue_started_at =
                             flow.queue.front().map(|front| front.enqueued_at);
@@ -309,6 +346,10 @@ impl WorkerFairnessState {
                         if !requeue_active {
                             flow.fairness.scheduler_state = FlowSchedulerState::Idle;
                             flow.fairness.in_active_ring = false;
+                            flow.fairness.deficit_bytes = 0;
+                        } else {
+                            flow.fairness.in_active_ring = true;
+                            enqueue_active = true;
                         }
                         candidate = Some(DispatchCandidate {
                             pressure_state,
@@ -318,17 +359,25 @@ impl WorkerFairnessState {
                     }
                 }
 
+                membership_delta = Some((before_membership, Self::flow_membership(&flow.fairness)));
+            }
+
+            if let Some((before_membership, after_membership)) = membership_delta {
+                self.apply_flow_membership_delta(before_membership, after_membership);
+            }
+
+            if should_continue {
+                continue;
+            }
+
             if drained_bytes > 0 {
                 self.total_queued_bytes = self.total_queued_bytes.saturating_sub(drained_bytes);
                 self.bucket_queued_bytes[bucket_id] =
                     self.bucket_queued_bytes[bucket_id].saturating_sub(drained_bytes);
             }
 
-            if requeue_active {
-                if let Some(flow) = self.flows.get_mut(&conn_id) {
-                    flow.fairness.in_active_ring = true;
-                }
-                self.active_ring.push_back(conn_id);
+            if requeue_active && enqueue_active {
+                self.enqueue_active_conn(conn_id);
             }
 
             if let Some(candidate) = candidate {
@@ -348,7 +397,9 @@ impl WorkerFairnessState {
     ) -> DispatchAction {
         match feedback {
             DispatchFeedback::Routed => {
+                let mut membership_delta = None;
                 if let Some(flow) = self.flows.get_mut(&conn_id) {
+                    let before_membership = Self::flow_membership(&flow.fairness);
                     flow.fairness.last_drain_at = Some(now);
                     flow.fairness.recent_drain_bytes = flow
                         .fairness
@@ -358,6 +409,17 @@ impl WorkerFairnessState {
                     if flow.fairness.scheduler_state != FlowSchedulerState::Idle {
                         flow.fairness.scheduler_state = FlowSchedulerState::Active;
                     }
+                    Self::classify_flow(
+                        &self.config,
+                        self.pressure.state(),
+                        now,
+                        &mut flow.fairness,
+                    );
+                    membership_delta =
+                        Some((before_membership, Self::flow_membership(&flow.fairness)));
+                }
+                if let Some((before_membership, after_membership)) = membership_delta {
+                    self.apply_flow_membership_delta(before_membership, after_membership);
                 }
                 self.evaluate_pressure(now, false);
                 DispatchAction::Continue
@@ -365,17 +427,20 @@ impl WorkerFairnessState {
             DispatchFeedback::QueueFull => {
                 self.pressure.note_route_stall(now, &self.config.pressure);
                 self.downstream_stalls = self.downstream_stalls.saturating_add(1);
+                let state = self.pressure.state();
                 let Some(flow) = self.flows.get_mut(&conn_id) else {
                     self.evaluate_pressure(now, true);
                     return DispatchAction::Continue;
                 };
+                let (before_membership, after_membership, should_close_flow, enqueue_active) = {
+                    let before_membership = Self::flow_membership(&flow.fairness);
+                    let mut enqueue_active = false;
 
                     flow.fairness.consecutive_stalls =
                         flow.fairness.consecutive_stalls.saturating_add(1);
                     flow.fairness.scheduler_state = FlowSchedulerState::Backpressured;
                     flow.fairness.pressure_class = FlowPressureClass::Backpressured;
 
-                let state = self.pressure.state();
                     let should_shed_frame = matches!(state, PressureState::Saturated)
                         || (matches!(state, PressureState::Shedding)
                             && flow.fairness.standing_state == StandingQueueState::Standing
@@ -392,20 +457,35 @@ impl WorkerFairnessState {
                             flow.fairness.pending_bytes.saturating_add(frame_bytes);
                         flow.fairness.queue_started_at =
                             flow.queue.front().map(|front| front.enqueued_at);
-                    self.total_queued_bytes = self.total_queued_bytes.saturating_add(frame_bytes);
-                    self.bucket_queued_bytes[flow.fairness.bucket_id] = self.bucket_queued_bytes
-                        [flow.fairness.bucket_id]
+                        self.total_queued_bytes =
+                            self.total_queued_bytes.saturating_add(frame_bytes);
+                        self.bucket_queued_bytes[flow.fairness.bucket_id] = self
+                            .bucket_queued_bytes[flow.fairness.bucket_id]
                             .saturating_add(frame_bytes);
                         if !flow.fairness.in_active_ring {
                             flow.fairness.in_active_ring = true;
-                        self.active_ring.push_back(conn_id);
+                            enqueue_active = true;
                         }
                     }
 
-                if flow.fairness.consecutive_stalls
+                    Self::classify_flow(&self.config, state, now, &mut flow.fairness);
+                    let after_membership = Self::flow_membership(&flow.fairness);
+                    let should_close_flow = flow.fairness.consecutive_stalls
                         >= self.config.max_consecutive_stalls_before_close
-                    && self.pressure.state() == PressureState::Saturated
-                {
+                        && self.pressure.state() == PressureState::Saturated;
+                    (
+                        before_membership,
+                        after_membership,
+                        should_close_flow,
+                        enqueue_active,
+                    )
+                };
+                if enqueue_active {
+                    self.enqueue_active_conn(conn_id);
+                }
+                self.apply_flow_membership_delta(before_membership, after_membership);
+
+                if should_close_flow {
                     self.remove_flow(conn_id);
                     self.evaluate_pressure(now, true);
                     return DispatchAction::CloseFlow;
@@ -426,6 +506,15 @@ impl WorkerFairnessState {
         let Some(entry) = self.flows.remove(&conn_id) else {
             return;
         };
+        self.active_ring_members.remove(&conn_id);
+        self.active_ring.retain(|queued_conn_id| *queued_conn_id != conn_id);
+        let (was_standing, was_backpressured) = Self::flow_membership(&entry.fairness);
+        if was_standing {
+            self.standing_flow_count = self.standing_flow_count.saturating_sub(1);
+        }
+        if was_backpressured {
+            self.backpressured_flow_count = self.backpressured_flow_count.saturating_sub(1);
+        }
 
         self.bucket_active_flows[entry.fairness.bucket_id] =
             self.bucket_active_flows[entry.fairness.bucket_id].saturating_sub(1);
@@ -440,27 +529,6 @@ impl WorkerFairnessState {
     }
 
     fn evaluate_pressure(&mut self, now: Instant, force: bool) {
-        let mut standing = 0usize;
-        let mut backpressured = 0usize;
-
-        for flow in self.flows.values_mut() {
-            Self::classify_flow(&self.config, self.pressure.state(), now, &mut flow.fairness);
-            if flow.fairness.standing_state == StandingQueueState::Standing {
-                standing = standing.saturating_add(1);
-            }
-            if matches!(
-                flow.fairness.scheduler_state,
-                FlowSchedulerState::Backpressured
-                    | FlowSchedulerState::Penalized
-                    | FlowSchedulerState::SheddingCandidate
-            ) {
-                backpressured = backpressured.saturating_add(1);
-            }
-        }
-
-        self.standing_flow_count = standing;
-        self.backpressured_flow_count = backpressured;
-
         let _ = self.pressure.maybe_evaluate(
             now,
             &self.config.pressure,
@@ -468,8 +536,8 @@ impl WorkerFairnessState {
             PressureSignals {
                 active_flows: self.flows.len(),
                 total_queued_bytes: self.total_queued_bytes,
-                standing_flows: standing,
-                backpressured_flows: backpressured,
+                standing_flows: self.standing_flow_count,
+                backpressured_flows: self.backpressured_flow_count,
             },
             force,
         );
@@ -481,12 +549,39 @@ impl WorkerFairnessState {
         now: Instant,
         fairness: &mut FlowFairnessState,
     ) {
-        if fairness.pending_bytes == 0 {
-            fairness.pressure_class = FlowPressureClass::Healthy;
-            fairness.standing_state = StandingQueueState::Transient;
-            fairness.scheduler_state = FlowSchedulerState::Idle;
+        let (pressure_class, standing_state, scheduler_state, standing) =
+            Self::derive_flow_classification(config, pressure_state, now, fairness);
+        fairness.pressure_class = pressure_class;
+        fairness.standing_state = standing_state;
+        fairness.scheduler_state = scheduler_state;
+        if scheduler_state == FlowSchedulerState::Idle {
+            fairness.deficit_bytes = 0;
+        }
+        if standing {
+            fairness.penalty_score = fairness.penalty_score.saturating_add(1);
+        } else {
             fairness.penalty_score = fairness.penalty_score.saturating_sub(1);
-            return;
+        }
+    }
+
+    fn derive_flow_classification(
+        config: &WorkerFairnessConfig,
+        pressure_state: PressureState,
+        now: Instant,
+        fairness: &FlowFairnessState,
+    ) -> (
+        FlowPressureClass,
+        StandingQueueState,
+        FlowSchedulerState,
+        bool,
+    ) {
+        if fairness.pending_bytes == 0 {
+            return (
+                FlowPressureClass::Healthy,
+                StandingQueueState::Transient,
+                FlowSchedulerState::Idle,
+                false,
+            );
         }
 
         let queue_age = fairness
@@ -503,29 +598,165 @@ impl WorkerFairnessState {
             && (fairness.consecutive_stalls >= config.standing_stall_threshold || drain_stalled);
 
         if standing {
-            fairness.standing_state = StandingQueueState::Standing;
-            fairness.pressure_class = FlowPressureClass::Standing;
-            fairness.penalty_score = fairness.penalty_score.saturating_add(1);
-            fairness.scheduler_state = if pressure_state >= PressureState::Shedding {
+            let scheduler_state = if pressure_state >= PressureState::Shedding {
                 FlowSchedulerState::SheddingCandidate
             } else {
                 FlowSchedulerState::Penalized
             };
-            return;
+            return (
+                FlowPressureClass::Standing,
+                StandingQueueState::Standing,
+                scheduler_state,
+                true,
+            );
         }
 
-        fairness.standing_state = StandingQueueState::Transient;
         if fairness.consecutive_stalls > 0 {
-            fairness.pressure_class = FlowPressureClass::Backpressured;
-            fairness.scheduler_state = FlowSchedulerState::Backpressured;
-        } else if fairness.pending_bytes >= config.standing_queue_min_backlog_bytes {
-            fairness.pressure_class = FlowPressureClass::Bursty;
-            fairness.scheduler_state = FlowSchedulerState::Active;
-        } else {
-            fairness.pressure_class = FlowPressureClass::Healthy;
-            fairness.scheduler_state = FlowSchedulerState::Active;
+            return (
+                FlowPressureClass::Backpressured,
+                StandingQueueState::Transient,
+                FlowSchedulerState::Backpressured,
+                false,
+            );
         }
-        fairness.penalty_score = fairness.penalty_score.saturating_sub(1);
+
+        if fairness.pending_bytes >= config.standing_queue_min_backlog_bytes {
+            return (
+                FlowPressureClass::Bursty,
+                StandingQueueState::Transient,
+                FlowSchedulerState::Active,
+                false,
+            );
+        }
+
+        (
+            FlowPressureClass::Healthy,
+            StandingQueueState::Transient,
+            FlowSchedulerState::Active,
+            false,
+        )
+    }
+
+    #[inline]
+    fn flow_membership(fairness: &FlowFairnessState) -> (bool, bool) {
+        (
+            fairness.standing_state == StandingQueueState::Standing,
+            Self::scheduler_state_is_backpressured(fairness.scheduler_state),
+        )
+    }
+
+    #[inline]
+    fn scheduler_state_is_backpressured(state: FlowSchedulerState) -> bool {
+        matches!(
+            state,
+            FlowSchedulerState::Backpressured
+                | FlowSchedulerState::Penalized
+                | FlowSchedulerState::SheddingCandidate
+        )
+    }
+
+    fn apply_flow_membership_delta(
+        &mut self,
+        before_membership: (bool, bool),
+        after_membership: (bool, bool),
+    ) {
+        if before_membership.0 != after_membership.0 {
+            if after_membership.0 {
+                self.standing_flow_count = self.standing_flow_count.saturating_add(1);
+            } else {
+                self.standing_flow_count = self.standing_flow_count.saturating_sub(1);
+            }
+        }
+        if before_membership.1 != after_membership.1 {
+            if after_membership.1 {
+                self.backpressured_flow_count = self.backpressured_flow_count.saturating_add(1);
+            } else {
+                self.backpressured_flow_count = self.backpressured_flow_count.saturating_sub(1);
+            }
+        }
+    }
+
+    #[inline]
+    fn clamp_deficit_bytes(config: &WorkerFairnessConfig, fairness: &mut FlowFairnessState) {
+        let max_deficit = config.max_flow_queued_bytes.min(i64::MAX as u64) as i64;
+        fairness.deficit_bytes = fairness.deficit_bytes.clamp(0, max_deficit);
+    }
+
+    #[inline]
+    fn enqueue_active_conn(&mut self, conn_id: u64) {
+        if self.active_ring_members.insert(conn_id) {
+            self.active_ring.push_back(conn_id);
+        }
+    }
+
+    #[inline]
+    fn weight_for_flags(config: &WorkerFairnessConfig, flags: u32) -> u8 {
+        if (flags & RPC_FLAG_QUICKACK) != 0 {
+            return config.quickack_flow_weight.max(1);
+        }
+        config.default_flow_weight.max(1)
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_recompute_flow_counters(&self, now: Instant) -> (usize, usize) {
+        let pressure_state = self.pressure.state();
+        let mut standing = 0usize;
+        let mut backpressured = 0usize;
+        for flow in self.flows.values() {
+            let (_, standing_state, scheduler_state, _) =
+                Self::derive_flow_classification(&self.config, pressure_state, now, &flow.fairness);
+            if standing_state == StandingQueueState::Standing {
+                standing = standing.saturating_add(1);
+            }
+            if Self::scheduler_state_is_backpressured(scheduler_state) {
+                backpressured = backpressured.saturating_add(1);
+            }
+        }
+        (standing, backpressured)
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_check_active_ring_consistency(&self) -> bool {
+        if self.active_ring.len() != self.active_ring_members.len() {
+            return false;
+        }
+
+        let mut seen = HashSet::with_capacity(self.active_ring.len());
+        for conn_id in self.active_ring.iter().copied() {
+            if !seen.insert(conn_id) {
+                return false;
+            }
+            if !self.active_ring_members.contains(&conn_id) {
+                return false;
+            }
+            let Some(flow) = self.flows.get(&conn_id) else {
+                return false;
+            };
+            if !flow.fairness.in_active_ring || flow.queue.is_empty() {
+                return false;
+            }
+        }
+
+        for (conn_id, flow) in self.flows.iter() {
+            let in_ring = self.active_ring_members.contains(conn_id);
+            if flow.fairness.in_active_ring != in_ring {
+                return false;
+            }
+            if in_ring && flow.queue.is_empty() {
+                return false;
+            }
+        }
+
+        true
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_max_deficit_bytes(&self) -> i64 {
+        self.flows
+            .values()
+            .map(|entry| entry.fairness.deficit_bytes)
+            .max()
+            .unwrap_or(0)
     }
 
     fn effective_quantum_bytes(
@@ -542,12 +773,14 @@ impl WorkerFairnessState {
             return config.penalized_quantum_bytes.max(1);
         }
 
-        match pressure_state {
+        let base_quantum = match pressure_state {
             PressureState::Normal => config.base_quantum_bytes.max(1),
             PressureState::Pressured => config.pressured_quantum_bytes.max(1),
             PressureState::Shedding => config.pressured_quantum_bytes.max(1),
             PressureState::Saturated => config.penalized_quantum_bytes.max(1),
-        }
+        };
+        let weighted_quantum = base_quantum.saturating_mul(fairness.weight_quanta.max(1) as u32);
+        weighted_quantum.max(1)
     }
 
     fn bucket_for(&self, conn_id: u64) -> usize {

src/transport/middle_proxy/reader.rs

@@ -4,7 +4,7 @@ use std::collections::HashMap;
 use std::io::ErrorKind;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, AtomicU32, AtomicU64, Ordering};
-use std::time::Instant;
+use std::time::{Duration, Instant};
 
 use bytes::{Bytes, BytesMut};
 use tokio::io::AsyncReadExt;
@@ -21,8 +21,8 @@ use crate::stats::Stats;
 
 use super::codec::{RpcChecksumMode, WriterCommand, rpc_crc};
 use super::fairness::{
-    AdmissionDecision, DispatchAction, DispatchFeedback, SchedulerDecision, WorkerFairnessConfig,
-    WorkerFairnessSnapshot, WorkerFairnessState,
+    AdmissionDecision, DispatchAction, DispatchFeedback, PressureState, SchedulerDecision,
+    WorkerFairnessConfig, WorkerFairnessSnapshot, WorkerFairnessState,
 };
 use super::registry::RouteResult;
 use super::{ConnRegistry, MeResponse};
@@ -45,10 +45,22 @@ fn is_data_route_queue_full(result: RouteResult) -> bool {
     )
 }
 
-fn should_close_on_queue_full_streak(streak: u8) -> bool {
+fn should_close_on_queue_full_streak(streak: u8, pressure_state: PressureState) -> bool {
+    if pressure_state < PressureState::Shedding {
+        return false;
+    }
+
     streak >= DATA_ROUTE_QUEUE_FULL_STARVATION_THRESHOLD
 }
 
+fn should_schedule_fairness_retry(snapshot: &WorkerFairnessSnapshot) -> bool {
+    snapshot.total_queued_bytes > 0
+}
+
+fn fairness_retry_delay(route_wait_ms: u64) -> Duration {
+    Duration::from_millis(route_wait_ms.max(1))
+}
+
 async fn route_data_with_retry(
     reg: &ConnRegistry,
     conn_id: u64,
@@ -157,7 +169,7 @@ async fn drain_fairness_scheduler(
             break;
         };
         let cid = candidate.frame.conn_id;
-        let _pressure_state = candidate.pressure_state;
+        let pressure_state = candidate.pressure_state;
         let _flow_class = candidate.flow_class;
         let routed = route_data_with_retry(
             reg,
@@ -176,7 +188,7 @@ async fn drain_fairness_scheduler(
         if is_data_route_queue_full(routed) {
             let streak = data_route_queue_full_streak.entry(cid).or_insert(0);
             *streak = streak.saturating_add(1);
-            if should_close_on_queue_full_streak(*streak) {
+            if should_close_on_queue_full_streak(*streak, pressure_state) {
                 fairness.remove_flow(cid);
                 data_route_queue_full_streak.remove(&cid);
                 reg.unregister(cid).await;
@@ -231,10 +243,33 @@ pub(crate) async fn reader_loop(
     let mut fairness_snapshot = fairness.snapshot();
     loop {
         let mut tmp = [0u8; 65_536];
+        let backlog_retry_enabled = should_schedule_fairness_retry(&fairness_snapshot);
+        let backlog_retry_delay =
+            fairness_retry_delay(reader_route_data_wait_ms.load(Ordering::Relaxed));
+        let mut retry_only = false;
         let n = tokio::select! {
             res = rd.read(&mut tmp) => res.map_err(ProxyError::Io)?,
+            _ = tokio::time::sleep(backlog_retry_delay), if backlog_retry_enabled => {
+                retry_only = true;
+                0usize
+            },
             _ = cancel.cancelled() => return Ok(()),
         };
+        if retry_only {
+            let route_wait_ms = reader_route_data_wait_ms.load(Ordering::Relaxed);
+            drain_fairness_scheduler(
+                &mut fairness,
+                reg.as_ref(),
+                &tx,
+                &mut data_route_queue_full_streak,
+                route_wait_ms,
+                stats.as_ref(),
+            )
+            .await;
+            let current_snapshot = fairness.snapshot();
+            apply_fairness_metrics_delta(stats.as_ref(), &mut fairness_snapshot, current_snapshot);
+            continue;
+        }
         if n == 0 {
             stats.increment_me_reader_eof_total();
             return Err(ProxyError::Io(std::io::Error::new(
@@ -317,12 +352,9 @@ pub(crate) async fn reader_loop(
                     stats.increment_me_route_drop_queue_full_high();
                     let streak = data_route_queue_full_streak.entry(cid).or_insert(0);
                     *streak = streak.saturating_add(1);
-                    if should_close_on_queue_full_streak(*streak)
-                        || matches!(
-                            admission,
-                            AdmissionDecision::RejectSaturated
-                                | AdmissionDecision::RejectStandingFlow
-                        )
+                    let pressure_state = fairness.pressure_state();
+                    if should_close_on_queue_full_streak(*streak, pressure_state)
+                        || matches!(admission, AdmissionDecision::RejectSaturated)
                     {
                         fairness.remove_flow(cid);
                         data_route_queue_full_streak.remove(&cid);
@@ -445,14 +477,18 @@ pub(crate) async fn reader_loop(
 
 #[cfg(test)]
 mod tests {
+    use std::time::Duration;
+
     use bytes::Bytes;
 
+    use super::PressureState;
     use crate::transport::middle_proxy::ConnRegistry;
 
     use super::{
-        MeResponse, RouteResult, is_data_route_queue_full, route_data_with_retry,
-        should_close_on_queue_full_streak, should_close_on_route_result_for_ack,
-        should_close_on_route_result_for_data,
+        MeResponse, RouteResult, WorkerFairnessSnapshot, fairness_retry_delay,
+        is_data_route_queue_full, route_data_with_retry, should_close_on_queue_full_streak,
+        should_close_on_route_result_for_ack, should_close_on_route_result_for_data,
+        should_schedule_fairness_retry,
     };
 
     #[test]
@@ -475,10 +511,29 @@ mod tests {
         assert!(is_data_route_queue_full(RouteResult::QueueFullBase));
         assert!(is_data_route_queue_full(RouteResult::QueueFullHigh));
         assert!(!is_data_route_queue_full(RouteResult::NoConn));
-        assert!(!should_close_on_queue_full_streak(1));
-        assert!(!should_close_on_queue_full_streak(2));
-        assert!(should_close_on_queue_full_streak(3));
-        assert!(should_close_on_queue_full_streak(u8::MAX));
+        assert!(!should_close_on_queue_full_streak(1, PressureState::Normal));
+        assert!(!should_close_on_queue_full_streak(2, PressureState::Pressured));
+        assert!(!should_close_on_queue_full_streak(3, PressureState::Pressured));
+        assert!(should_close_on_queue_full_streak(3, PressureState::Shedding));
+        assert!(should_close_on_queue_full_streak(
+            u8::MAX,
+            PressureState::Saturated
+        ));
+    }
+
+    #[test]
+    fn fairness_retry_is_scheduled_only_when_queue_has_pending_bytes() {
+        let mut snapshot = WorkerFairnessSnapshot::default();
+        assert!(!should_schedule_fairness_retry(&snapshot));
+
+        snapshot.total_queued_bytes = 1;
+        assert!(should_schedule_fairness_retry(&snapshot));
+    }
+
+    #[test]
+    fn fairness_retry_delay_never_drops_below_one_millisecond() {
+        assert_eq!(fairness_retry_delay(0), Duration::from_millis(1));
+        assert_eq!(fairness_retry_delay(2), Duration::from_millis(2));
     }
 
     #[test]

src/transport/middle_proxy/secret.rs

@@ -37,20 +37,26 @@ pub(super) fn validate_proxy_secret_len(data_len: usize, max_len: usize) -> Resu
 
 /// Fetch Telegram proxy-secret binary.
 #[allow(dead_code)]
-pub async fn fetch_proxy_secret(cache_path: Option<&str>, max_len: usize) -> Result<Vec<u8>> {
-    fetch_proxy_secret_with_upstream(cache_path, max_len, None).await
+pub async fn fetch_proxy_secret(
+    cache_path: Option<&str>,
+    max_len: usize,
+    proxy_secret_url: Option<&str>,
+) -> Result<Vec<u8>> {
+    fetch_proxy_secret_with_upstream(cache_path, max_len, proxy_secret_url, None).await
 }
 
 /// Fetch Telegram proxy-secret binary, optionally through upstream routing.
 pub async fn fetch_proxy_secret_with_upstream(
     cache_path: Option<&str>,
     max_len: usize,
+    proxy_secret_url: Option<&str>,
     upstream: Option<Arc<UpstreamManager>>,
 ) -> Result<Vec<u8>> {
     let cache = cache_path.unwrap_or("proxy-secret");
 
     // 1) Try fresh download first.
-    match download_proxy_secret_with_max_len_via_upstream(max_len, upstream).await {
+    match download_proxy_secret_with_max_len_via_upstream(max_len, upstream, proxy_secret_url).await
+    {
         Ok(data) => {
             if let Err(e) = tokio::fs::write(cache, &data).await {
                 warn!(error = %e, "Failed to cache proxy-secret (non-fatal)");
@@ -91,14 +97,19 @@ pub async fn fetch_proxy_secret_with_upstream(
 
 #[allow(dead_code)]
 pub async fn download_proxy_secret_with_max_len(max_len: usize) -> Result<Vec<u8>> {
-    download_proxy_secret_with_max_len_via_upstream(max_len, None).await
+    download_proxy_secret_with_max_len_via_upstream(max_len, None, None).await
 }
 
 pub async fn download_proxy_secret_with_max_len_via_upstream(
     max_len: usize,
     upstream: Option<Arc<UpstreamManager>>,
+    proxy_secret_url: Option<&str>,
 ) -> Result<Vec<u8>> {
-    let resp = https_get("https://core.telegram.org/getProxySecret", upstream).await?;
+    let resp = https_get(
+        proxy_secret_url.unwrap_or("https://core.telegram.org/getProxySecret"),
+        upstream,
+    )
+    .await?;
 
     if !(200..=299).contains(&resp.status) {
         return Err(ProxyError::Proxy(format!(

src/transport/middle_proxy/tests/fairness_security_tests.rs

@@ -2,6 +2,7 @@ use std::time::{Duration, Instant};
 
 use bytes::Bytes;
 
+use crate::protocol::constants::RPC_FLAG_QUICKACK;
 use crate::transport::middle_proxy::fairness::{
     AdmissionDecision, DispatchAction, DispatchFeedback, PressureState, SchedulerDecision,
     WorkerFairnessConfig, WorkerFairnessState,
@@ -114,6 +115,62 @@ fn fairness_keeps_fast_flow_progress_under_slow_neighbor() {
     assert!(snapshot.total_queued_bytes <= 64 * 1024);
 }
 
+#[test]
+fn fairness_prioritizes_quickack_flow_when_weights_enabled() {
+    let mut now = Instant::now();
+    let mut fairness = WorkerFairnessState::new(
+        WorkerFairnessConfig {
+            max_total_queued_bytes: 256 * 1024,
+            max_flow_queued_bytes: 64 * 1024,
+            base_quantum_bytes: 8 * 1024,
+            pressured_quantum_bytes: 8 * 1024,
+            penalized_quantum_bytes: 8 * 1024,
+            default_flow_weight: 1,
+            quickack_flow_weight: 4,
+            ..WorkerFairnessConfig::default()
+        },
+        now,
+    );
+
+    for _ in 0..8 {
+        assert_eq!(
+            fairness.enqueue_data(10, RPC_FLAG_QUICKACK, enqueue_payload(16 * 1024), now),
+            AdmissionDecision::Admit
+        );
+        assert_eq!(
+            fairness.enqueue_data(20, 0, enqueue_payload(16 * 1024), now),
+            AdmissionDecision::Admit
+        );
+    }
+
+    let mut quickack_dispatched = 0u64;
+    let mut bulk_dispatched = 0u64;
+    for _ in 0..64 {
+        now += Duration::from_millis(1);
+        let SchedulerDecision::Dispatch(candidate) = fairness.next_decision(now) else {
+            break;
+        };
+
+        if candidate.frame.conn_id == 10 {
+            quickack_dispatched = quickack_dispatched.saturating_add(1);
+        } else if candidate.frame.conn_id == 20 {
+            bulk_dispatched = bulk_dispatched.saturating_add(1);
+        }
+
+        let _ = fairness.apply_dispatch_feedback(
+            candidate.frame.conn_id,
+            candidate,
+            DispatchFeedback::Routed,
+            now,
+        );
+    }
+
+    assert!(
+        quickack_dispatched > bulk_dispatched,
+        "quickack flow must receive higher dispatch rate with larger weight"
+    );
+}
+
 #[test]
 fn fairness_pressure_hysteresis_prevents_instant_flapping() {
     let mut now = Instant::now();
@@ -180,6 +237,12 @@ fn fairness_randomized_sequence_preserves_memory_bounds() {
         }
 
         let snapshot = fairness.snapshot();
+        let (standing_recomputed, backpressured_recomputed) =
+            fairness.debug_recompute_flow_counters(now);
         assert!(snapshot.total_queued_bytes <= 32 * 1024);
+        assert_eq!(snapshot.standing_flows, standing_recomputed);
+        assert_eq!(snapshot.backpressured_flows, backpressured_recomputed);
+        assert!(fairness.debug_check_active_ring_consistency());
+        assert!(fairness.debug_max_deficit_bytes() <= 4 * 1024);
     }
 }

src/transport/upstream.rs

@@ -279,6 +279,12 @@ pub struct UpstreamApiSummarySnapshot {
     pub shadowsocks_total: usize,
 }
 
+#[derive(Debug, Clone, Copy, Default)]
+pub struct UpstreamApiHealthSummary {
+    pub configured_total: usize,
+    pub healthy_total: usize,
+}
+
 #[derive(Debug, Clone)]
 pub struct UpstreamApiSnapshot {
     pub summary: UpstreamApiSummarySnapshot,
@@ -444,6 +450,20 @@ impl UpstreamManager {
         Some(UpstreamApiSnapshot { summary, upstreams })
     }
 
+    pub async fn api_health_summary(&self) -> UpstreamApiHealthSummary {
+        let guard = self.upstreams.read().await;
+        let mut summary = UpstreamApiHealthSummary {
+            configured_total: guard.len(),
+            healthy_total: 0,
+        };
+        for upstream in guard.iter() {
+            if upstream.healthy {
+                summary.healthy_total += 1;
+            }
+        }
+        summary
+    }
+
     fn describe_upstream(upstream_type: &UpstreamType) -> (UpstreamRouteKind, String) {
         match upstream_type {
             UpstreamType::Direct { .. } => (UpstreamRouteKind::Direct, "direct".to_string()),