ME Soft Reinit tuning

Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>

src/config/defaults.rs

@@ -182,6 +182,26 @@ pub(crate) fn default_update_every_secs() -> u64 {
     30 * 60
 }
 
+pub(crate) fn default_me_config_stable_snapshots() -> u8 {
+    2
+}
+
+pub(crate) fn default_me_config_apply_cooldown_secs() -> u64 {
+    300
+}
+
+pub(crate) fn default_proxy_secret_stable_snapshots() -> u8 {
+    2
+}
+
+pub(crate) fn default_proxy_secret_rotate_runtime() -> bool {
+    true
+}
+
+pub(crate) fn default_proxy_secret_len_max() -> usize {
+    256
+}
+
 pub(crate) fn default_me_reinit_drain_timeout_secs() -> u64 {
     120
 }

src/config/load.rs

@@ -147,6 +147,24 @@ impl ProxyConfig {
             }
         }
 
+        if config.general.me_config_stable_snapshots == 0 {
+            return Err(ProxyError::Config(
+                "general.me_config_stable_snapshots must be > 0".to_string(),
+            ));
+        }
+
+        if config.general.proxy_secret_stable_snapshots == 0 {
+            return Err(ProxyError::Config(
+                "general.proxy_secret_stable_snapshots must be > 0".to_string(),
+            ));
+        }
+
+        if !(32..=4096).contains(&config.general.proxy_secret_len_max) {
+            return Err(ProxyError::Config(
+                "general.proxy_secret_len_max must be within [32, 4096]".to_string(),
+            ));
+        }
+
         if !(0.0..=1.0).contains(&config.general.me_pool_min_fresh_ratio) {
             return Err(ProxyError::Config(
                 "general.me_pool_min_fresh_ratio must be within [0.0, 1.0]".to_string(),
@@ -462,6 +480,66 @@ mod tests {
         let _ = std::fs::remove_file(path);
     }
 
+    #[test]
+    fn me_config_stable_snapshots_zero_is_rejected() {
+        let toml = r#"
+            [general]
+            me_config_stable_snapshots = 0
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_me_config_stable_snapshots_zero_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.me_config_stable_snapshots must be > 0"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn proxy_secret_stable_snapshots_zero_is_rejected() {
+        let toml = r#"
+            [general]
+            proxy_secret_stable_snapshots = 0
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_proxy_secret_stable_snapshots_zero_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.proxy_secret_stable_snapshots must be > 0"));
+        let _ = std::fs::remove_file(path);
+    }
+
+    #[test]
+    fn proxy_secret_len_max_out_of_range_is_rejected() {
+        let toml = r#"
+            [general]
+            proxy_secret_len_max = 16
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+        "#;
+        let dir = std::env::temp_dir();
+        let path = dir.join("telemt_proxy_secret_len_max_out_of_range_test.toml");
+        std::fs::write(&path, toml).unwrap();
+        let err = ProxyConfig::load(&path).unwrap_err().to_string();
+        assert!(err.contains("general.proxy_secret_len_max must be within [32, 4096]"));
+        let _ = std::fs::remove_file(path);
+    }
+
     #[test]
     fn me_pool_min_fresh_ratio_out_of_range_is_rejected() {
         let toml = r#"

src/config/types.rs

@@ -267,6 +267,26 @@ pub struct GeneralConfig {
     #[serde(default)]
     pub update_every: Option<u64>,
 
+    /// Number of identical getProxyConfig snapshots required before applying ME map updates.
+    #[serde(default = "default_me_config_stable_snapshots")]
+    pub me_config_stable_snapshots: u8,
+
+    /// Cooldown in seconds between applied ME map updates.
+    #[serde(default = "default_me_config_apply_cooldown_secs")]
+    pub me_config_apply_cooldown_secs: u64,
+
+    /// Number of identical getProxySecret snapshots required before runtime secret rotation.
+    #[serde(default = "default_proxy_secret_stable_snapshots")]
+    pub proxy_secret_stable_snapshots: u8,
+
+    /// Enable runtime proxy-secret rotation from getProxySecret.
+    #[serde(default = "default_proxy_secret_rotate_runtime")]
+    pub proxy_secret_rotate_runtime: bool,
+
+    /// Maximum allowed proxy-secret length in bytes for startup and runtime refresh.
+    #[serde(default = "default_proxy_secret_len_max")]
+    pub proxy_secret_len_max: usize,
+
     /// Drain-TTL in seconds for stale ME writers after endpoint map changes.
     /// During TTL, stale writers may be used only as fallback for new bindings.
     #[serde(default = "default_me_pool_drain_ttl_secs")]
@@ -346,6 +366,11 @@ impl Default for GeneralConfig {
             hardswap: default_hardswap(),
             fast_mode_min_tls_record: default_fast_mode_min_tls_record(),
             update_every: Some(default_update_every_secs()),
+            me_config_stable_snapshots: default_me_config_stable_snapshots(),
+            me_config_apply_cooldown_secs: default_me_config_apply_cooldown_secs(),
+            proxy_secret_stable_snapshots: default_proxy_secret_stable_snapshots(),
+            proxy_secret_rotate_runtime: default_proxy_secret_rotate_runtime(),
+            proxy_secret_len_max: default_proxy_secret_len_max(),
             me_pool_drain_ttl_secs: default_me_pool_drain_ttl_secs(),
             me_pool_min_fresh_ratio: default_me_pool_min_fresh_ratio(),
             me_reinit_drain_timeout_secs: default_me_reinit_drain_timeout_secs(),

src/main.rs

@@ -298,25 +298,30 @@ async fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
         // proxy-secret is from: https://core.telegram.org/getProxySecret
         // =============================================================
         let proxy_secret_path = config.general.proxy_secret_path.as_deref();
-match crate::transport::middle_proxy::fetch_proxy_secret(proxy_secret_path).await {
-    Ok(proxy_secret) => {
-        info!(
-            secret_len = proxy_secret.len(),
-            key_sig = format_args!(
-                "0x{:08x}",
-                if proxy_secret.len() >= 4 {
-                    u32::from_le_bytes([
-                        proxy_secret[0],
-                        proxy_secret[1],
-                        proxy_secret[2],
-                        proxy_secret[3],
-                    ])
-                } else {
-                    0
-                }
-            ),
-            "Proxy-secret loaded"
-        );
+        match crate::transport::middle_proxy::fetch_proxy_secret(
+            proxy_secret_path,
+            config.general.proxy_secret_len_max,
+        )
+        .await
+        {
+            Ok(proxy_secret) => {
+                info!(
+                    secret_len = proxy_secret.len(),
+                    key_sig = format_args!(
+                        "0x{:08x}",
+                        if proxy_secret.len() >= 4 {
+                            u32::from_le_bytes([
+                                proxy_secret[0],
+                                proxy_secret[1],
+                                proxy_secret[2],
+                                proxy_secret[3],
+                            ])
+                        } else {
+                            0
+                        }
+                    ),
+                    "Proxy-secret loaded"
+                );
 
                 // Load ME config (v4/v6) + default DC
                 let mut cfg_v4 = fetch_proxy_config(

src/transport/middle_proxy/config_updater.rs

@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::hash::{DefaultHasher, Hash, Hasher};
 use std::net::IpAddr;
 use std::sync::Arc;
 use std::time::Duration;
@@ -11,7 +12,7 @@ use crate::config::ProxyConfig;
 use crate::error::Result;
 
 use super::MePool;
-use super::secret::download_proxy_secret;
+use super::secret::download_proxy_secret_with_max_len;
 use crate::crypto::SecureRandom;
 use std::time::SystemTime;
 
@@ -39,6 +40,92 @@ pub struct ProxyConfigData {
     pub default_dc: Option<i32>,
 }
 
+#[derive(Debug, Default)]
+struct StableSnapshot {
+    candidate_hash: Option<u64>,
+    candidate_hits: u8,
+    applied_hash: Option<u64>,
+}
+
+impl StableSnapshot {
+    fn observe(&mut self, hash: u64) -> u8 {
+        if self.candidate_hash == Some(hash) {
+            self.candidate_hits = self.candidate_hits.saturating_add(1);
+        } else {
+            self.candidate_hash = Some(hash);
+            self.candidate_hits = 1;
+        }
+        self.candidate_hits
+    }
+
+    fn is_applied(&self, hash: u64) -> bool {
+        self.applied_hash == Some(hash)
+    }
+
+    fn mark_applied(&mut self, hash: u64) {
+        self.applied_hash = Some(hash);
+    }
+}
+
+#[derive(Debug, Default)]
+struct UpdaterState {
+    config_v4: StableSnapshot,
+    config_v6: StableSnapshot,
+    secret: StableSnapshot,
+    last_map_apply_at: Option<tokio::time::Instant>,
+}
+
+fn hash_proxy_config(cfg: &ProxyConfigData) -> u64 {
+    let mut hasher = DefaultHasher::new();
+    cfg.default_dc.hash(&mut hasher);
+
+    let mut by_dc: Vec<(i32, Vec<(IpAddr, u16)>)> =
+        cfg.map.iter().map(|(dc, addrs)| (*dc, addrs.clone())).collect();
+    by_dc.sort_by_key(|(dc, _)| *dc);
+    for (dc, mut addrs) in by_dc {
+        dc.hash(&mut hasher);
+        addrs.sort_unstable();
+        for (ip, port) in addrs {
+            ip.hash(&mut hasher);
+            port.hash(&mut hasher);
+        }
+    }
+
+    hasher.finish()
+}
+
+fn hash_secret(secret: &[u8]) -> u64 {
+    let mut hasher = DefaultHasher::new();
+    secret.hash(&mut hasher);
+    hasher.finish()
+}
+
+fn map_apply_cooldown_ready(
+    last_applied: Option<tokio::time::Instant>,
+    cooldown: Duration,
+) -> bool {
+    if cooldown.is_zero() {
+        return true;
+    }
+    match last_applied {
+        Some(ts) => ts.elapsed() >= cooldown,
+        None => true,
+    }
+}
+
+fn map_apply_cooldown_remaining_secs(
+    last_applied: tokio::time::Instant,
+    cooldown: Duration,
+) -> u64 {
+    if cooldown.is_zero() {
+        return 0;
+    }
+    cooldown
+        .checked_sub(last_applied.elapsed())
+        .map(|d| d.as_secs())
+        .unwrap_or(0)
+}
+
 fn parse_host_port(s: &str) -> Option<(IpAddr, u16)> {
     if let Some(bracket_end) = s.rfind(']')
         && s.starts_with('[')
@@ -130,7 +217,12 @@ pub async fn fetch_proxy_config(url: &str) -> Result<ProxyConfigData> {
     Ok(ProxyConfigData { map, default_dc })
 }
 
-async fn run_update_cycle(pool: &Arc<MePool>, rng: &Arc<SecureRandom>, cfg: &ProxyConfig) {
+async fn run_update_cycle(
+    pool: &Arc<MePool>,
+    rng: &Arc<SecureRandom>,
+    cfg: &ProxyConfig,
+    state: &mut UpdaterState,
+) {
     pool.update_runtime_reinit_policy(
         cfg.general.hardswap,
         cfg.general.me_pool_drain_ttl_secs,
@@ -138,33 +230,93 @@ async fn run_update_cycle(pool: &Arc<MePool>, rng: &Arc<SecureRandom>, cfg: &Pro
         cfg.general.me_pool_min_fresh_ratio,
     );
 
+    let required_cfg_snapshots = cfg.general.me_config_stable_snapshots.max(1);
+    let required_secret_snapshots = cfg.general.proxy_secret_stable_snapshots.max(1);
+    let apply_cooldown = Duration::from_secs(cfg.general.me_config_apply_cooldown_secs);
     let mut maps_changed = false;
 
-    // Update proxy config v4
+    let mut ready_v4: Option<(ProxyConfigData, u64)> = None;
     let cfg_v4 = retry_fetch("https://core.telegram.org/getProxyConfig").await;
     if let Some(cfg_v4) = cfg_v4 {
-        let changed = pool.update_proxy_maps(cfg_v4.map.clone(), None).await;
-        if let Some(dc) = cfg_v4.default_dc {
-            pool.default_dc
-                .store(dc, std::sync::atomic::Ordering::Relaxed);
-        }
-        if changed {
-            maps_changed = true;
-            info!("ME config updated (v4)");
+        let cfg_v4_hash = hash_proxy_config(&cfg_v4);
+        let stable_hits = state.config_v4.observe(cfg_v4_hash);
+        if stable_hits < required_cfg_snapshots {
+            debug!(
+                stable_hits,
+                required_cfg_snapshots,
+                snapshot = format_args!("0x{cfg_v4_hash:016x}"),
+                "ME config v4 candidate observed"
+            );
+        } else if state.config_v4.is_applied(cfg_v4_hash) {
+            debug!(
+                snapshot = format_args!("0x{cfg_v4_hash:016x}"),
+                "ME config v4 stable snapshot already applied"
+            );
         } else {
-            debug!("ME config v4 unchanged");
+            ready_v4 = Some((cfg_v4, cfg_v4_hash));
         }
     }
 
-    // Update proxy config v6 (optional)
+    let mut ready_v6: Option<(ProxyConfigData, u64)> = None;
     let cfg_v6 = retry_fetch("https://core.telegram.org/getProxyConfigV6").await;
     if let Some(cfg_v6) = cfg_v6 {
-        let changed = pool.update_proxy_maps(HashMap::new(), Some(cfg_v6.map)).await;
-        if changed {
-            maps_changed = true;
-            info!("ME config updated (v6)");
+        let cfg_v6_hash = hash_proxy_config(&cfg_v6);
+        let stable_hits = state.config_v6.observe(cfg_v6_hash);
+        if stable_hits < required_cfg_snapshots {
+            debug!(
+                stable_hits,
+                required_cfg_snapshots,
+                snapshot = format_args!("0x{cfg_v6_hash:016x}"),
+                "ME config v6 candidate observed"
+            );
+        } else if state.config_v6.is_applied(cfg_v6_hash) {
+            debug!(
+                snapshot = format_args!("0x{cfg_v6_hash:016x}"),
+                "ME config v6 stable snapshot already applied"
+            );
         } else {
-            debug!("ME config v6 unchanged");
+            ready_v6 = Some((cfg_v6, cfg_v6_hash));
+        }
+    }
+
+    if ready_v4.is_some() || ready_v6.is_some() {
+        if map_apply_cooldown_ready(state.last_map_apply_at, apply_cooldown) {
+            let update_v4 = ready_v4
+                .as_ref()
+                .map(|(snapshot, _)| snapshot.map.clone())
+                .unwrap_or_default();
+            let update_v6 = ready_v6
+                .as_ref()
+                .map(|(snapshot, _)| snapshot.map.clone());
+
+            let changed = pool.update_proxy_maps(update_v4, update_v6).await;
+
+            if let Some((snapshot, hash)) = ready_v4 {
+                if let Some(dc) = snapshot.default_dc {
+                    pool.default_dc
+                        .store(dc, std::sync::atomic::Ordering::Relaxed);
+                }
+                state.config_v4.mark_applied(hash);
+            }
+
+            if let Some((_snapshot, hash)) = ready_v6 {
+                state.config_v6.mark_applied(hash);
+            }
+
+            state.last_map_apply_at = Some(tokio::time::Instant::now());
+
+            if changed {
+                maps_changed = true;
+                info!("ME config update applied after stable-gate");
+            } else {
+                debug!("ME config stable-gate applied with no map delta");
+            }
+        } else if let Some(last) = state.last_map_apply_at {
+            let wait_secs = map_apply_cooldown_remaining_secs(last, apply_cooldown);
+            debug!(
+                wait_secs,
+                "ME config stable snapshot deferred by cooldown"
+            );
         }
     }
 
@@ -175,14 +327,37 @@ async fn run_update_cycle(pool: &Arc<MePool>, rng: &Arc<SecureRandom>, cfg: &Pro
 
     pool.reset_stun_state();
 
-    // Update proxy-secret
-    match download_proxy_secret().await {
-        Ok(secret) => {
-            if pool.update_secret(secret).await {
-                info!("proxy-secret updated and pool reconnect scheduled");
+    if cfg.general.proxy_secret_rotate_runtime {
+        match download_proxy_secret_with_max_len(cfg.general.proxy_secret_len_max).await {
+            Ok(secret) => {
+                let secret_hash = hash_secret(&secret);
+                let stable_hits = state.secret.observe(secret_hash);
+                if stable_hits < required_secret_snapshots {
+                    debug!(
+                        stable_hits,
+                        required_secret_snapshots,
+                        snapshot = format_args!("0x{secret_hash:016x}"),
+                        "proxy-secret candidate observed"
+                    );
+                } else if state.secret.is_applied(secret_hash) {
+                    debug!(
+                        snapshot = format_args!("0x{secret_hash:016x}"),
+                        "proxy-secret stable snapshot already applied"
+                    );
+                } else {
+                    let rotated = pool.update_secret(secret).await;
+                    state.secret.mark_applied(secret_hash);
+                    if rotated {
+                        info!("proxy-secret rotated after stable-gate");
+                    } else {
+                        debug!("proxy-secret stable snapshot confirmed as unchanged");
+                    }
+                }
             }
+            Err(e) => warn!(error = %e, "proxy-secret update failed"),
         }
-        Err(e) => warn!(error = %e, "proxy-secret update failed"),
+    } else {
+        debug!("proxy-secret runtime rotation disabled by config");
     }
 }
 
@@ -191,6 +366,7 @@ pub async fn me_config_updater(
     rng: Arc<SecureRandom>,
     mut config_rx: watch::Receiver<Arc<ProxyConfig>>,
 ) {
+    let mut state = UpdaterState::default();
     let mut update_every_secs = config_rx
         .borrow()
         .general
@@ -207,7 +383,7 @@ pub async fn me_config_updater(
         tokio::select! {
             _ = &mut sleep => {
                 let cfg = config_rx.borrow().clone();
-                run_update_cycle(&pool, &rng, cfg.as_ref()).await;
+                run_update_cycle(&pool, &rng, cfg.as_ref(), &mut state).await;
                 let refreshed_secs = cfg.general.effective_update_every_secs().max(1);
                 if refreshed_secs != update_every_secs {
                     info!(
@@ -245,7 +421,7 @@ pub async fn me_config_updater(
                     );
                     update_every_secs = new_secs;
                     update_every = Duration::from_secs(update_every_secs);
-                    run_update_cycle(&pool, &rng, cfg.as_ref()).await;
+                    run_update_cycle(&pool, &rng, cfg.as_ref(), &mut state).await;
                     next_tick = tokio::time::Instant::now() + update_every;
                 } else {
                     info!(

src/transport/middle_proxy/secret.rs

@@ -4,12 +4,42 @@ use httpdate;
 
 use crate::error::{ProxyError, Result};
 
+pub const PROXY_SECRET_MIN_LEN: usize = 32;
+
+pub(super) fn validate_proxy_secret_len(data_len: usize, max_len: usize) -> Result<()> {
+    if max_len < PROXY_SECRET_MIN_LEN {
+        return Err(ProxyError::Proxy(format!(
+            "proxy-secret max length is invalid: {} bytes (must be >= {})",
+            max_len,
+            PROXY_SECRET_MIN_LEN
+        )));
+    }
+
+    if data_len < PROXY_SECRET_MIN_LEN {
+        return Err(ProxyError::Proxy(format!(
+            "proxy-secret too short: {} bytes (need >= {})",
+            data_len,
+            PROXY_SECRET_MIN_LEN
+        )));
+    }
+
+    if data_len > max_len {
+        return Err(ProxyError::Proxy(format!(
+            "proxy-secret too long: {} bytes (limit = {})",
+            data_len,
+            max_len
+        )));
+    }
+
+    Ok(())
+}
+
 /// Fetch Telegram proxy-secret binary.
-pub async fn fetch_proxy_secret(cache_path: Option<&str>) -> Result<Vec<u8>> {
+pub async fn fetch_proxy_secret(cache_path: Option<&str>, max_len: usize) -> Result<Vec<u8>> {
     let cache = cache_path.unwrap_or("proxy-secret");
 
     // 1) Try fresh download first.
-    match download_proxy_secret().await {
+    match download_proxy_secret_with_max_len(max_len).await {
         Ok(data) => {
             if let Err(e) = tokio::fs::write(cache, &data).await {
                 warn!(error = %e, "Failed to cache proxy-secret (non-fatal)");
@@ -24,9 +54,9 @@ pub async fn fetch_proxy_secret(cache_path: Option<&str>) -> Result<Vec<u8>> {
         }
     }
 
-    // 2) Fallback to cache/file regardless of age; require len>=32.
+    // 2) Fallback to cache/file regardless of age; require len in bounds.
     match tokio::fs::read(cache).await {
-        Ok(data) if data.len() >= 32 => {
+        Ok(data) if validate_proxy_secret_len(data.len(), max_len).is_ok() => {
             let age_hours = tokio::fs::metadata(cache)
                 .await
                 .ok()
@@ -41,17 +71,14 @@ pub async fn fetch_proxy_secret(cache_path: Option<&str>) -> Result<Vec<u8>> {
             );
             Ok(data)
         }
-        Ok(data) => Err(ProxyError::Proxy(format!(
-            "Cached proxy-secret too short: {} bytes (need >= 32)",
-            data.len()
-        ))),
+        Ok(data) => validate_proxy_secret_len(data.len(), max_len).map(|_| data),
         Err(e) => Err(ProxyError::Proxy(format!(
             "Failed to read proxy-secret cache after download failure: {e}"
         ))),
     }
 }
 
-pub async fn download_proxy_secret() -> Result<Vec<u8>> {
+pub async fn download_proxy_secret_with_max_len(max_len: usize) -> Result<Vec<u8>> {
     let resp = reqwest::get("https://core.telegram.org/getProxySecret")
         .await
         .map_err(|e| ProxyError::Proxy(format!("Failed to download proxy-secret: {e}")))?;
@@ -84,12 +111,7 @@ pub async fn download_proxy_secret() -> Result<Vec<u8>> {
         .map_err(|e| ProxyError::Proxy(format!("Read proxy-secret body: {e}")))?
         .to_vec();
 
-    if data.len() < 32 {
-        return Err(ProxyError::Proxy(format!(
-            "proxy-secret too short: {} bytes (need >= 32)",
-            data.len()
-        )));
-    }
+    validate_proxy_secret_len(data.len(), max_len)?;
 
     info!(len = data.len(), "Downloaded proxy-secret OK");
     Ok(data)