Carriers Auto-negotiation Aggressiveness

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

src/config/load/strict_keys.rs

@@ -264,6 +264,7 @@ const WEB_CONFIG_KEYS: &[&str] = &[
     "carrier",
     "carriers",
     "carrier_learning",
+    "carrier_negotiation_aggressiveness",
     "debug",
     "limits",
     "timeouts",
@@ -278,10 +279,14 @@ const WEB_LIMITS_CONFIG_KEYS: &[&str] = &[
     "max_frames_per_body",
     "max_http_connections",
     "max_http_handlers",
+    "max_lane_open_waits_per_session",
+    "pending_bytes_per_lane",
+    "pending_items_per_lane",
     "websocket_bytes_global",
     "websocket_admission_watermark_pct",
     "websocket_eviction_watermark_pct",
     "websocket_http_connection_reserve",
+    "max_websocket_evictions_in_flight",
     "max_carrier_learning_entries",
     "max_body_readers",
     "max_body_bytes_global",
@@ -332,7 +337,12 @@ const WEB_TIMEOUTS_CONFIG_KEYS: &[&str] = &[
     "header_secs",
     "body_secs",
     "stream_handshake_secs",
+    "stream_first_byte_secs",
     "long_poll_secs",
+    "lane_open_wait_secs",
+    "carrier_health_secs",
+    "websocket_upgrade_secs",
+    "websocket_open_secs",
     "websocket_write_secs",
     "websocket_backpressure_secs",
     "websocket_eviction_secs",

src/config/load/validate_web.rs

@@ -72,9 +72,9 @@ pub(super) fn validate(config: &mut ProxyConfig) -> Result<()> {
     validate_limits(&config.web.limits)?;
     debug::validate(&config.web.debug, &config.web.limits)?;
     let carriers = negotiation::validate(&config.web)?;
-    if carriers.contains(&WebCarrier::HttpsLanes) && config.web.limits.max_http_handlers < 2 {
+    if carriers.contains(&WebCarrier::HttpsLanes) && config.web.limits.max_http_handlers < 4 {
         return config_error(
-            "WEB https-lanes candidates require web.limits.max_http_handlers >= 2",
+            "WEB https-lanes candidates require web.limits.max_http_handlers >= 4",
         );
     }
     timeouts::validate(&config.web.timeouts)?;
@@ -162,6 +162,16 @@ fn validate_limits(limits: &WebLimitsConfig) -> Result<()> {
     let positive = [
         ("max_http_connections", limits.max_http_connections),
         ("max_http_handlers", limits.max_http_handlers),
+        (
+            "max_lane_open_waits_per_session",
+            limits.max_lane_open_waits_per_session,
+        ),
+        ("pending_bytes_per_lane", limits.pending_bytes_per_lane),
+        ("pending_items_per_lane", limits.pending_items_per_lane),
+        (
+            "max_websocket_evictions_in_flight",
+            limits.max_websocket_evictions_in_flight,
+        ),
         (
             "max_carrier_learning_entries",
             limits.max_carrier_learning_entries,
@@ -240,6 +250,8 @@ fn validate_limits(limits: &WebLimitsConfig) -> Result<()> {
         || limits.max_body_readers > limits.max_http_handlers
         || limits.pending_bytes_per_session > limits.pending_bytes_global
         || limits.pending_items_per_session > limits.pending_items_global
+        || limits.pending_bytes_per_lane > limits.pending_bytes_per_session
+        || limits.pending_items_per_lane > limits.pending_items_per_session
         || limits.control_bytes_per_session > limits.control_bytes_global
         || limits.control_bytes_per_session > limits.pending_bytes_per_session
         || limits.control_bytes_global > limits.pending_bytes_global

src/config/load/validate_web/negotiation.rs

@@ -14,6 +14,14 @@ pub(super) fn validate(config: &WebConfig) -> Result<Vec<WebCarrier>> {
         }
     }
     let candidates = config.carrier_candidates();
+    if config.carrier_negotiation_enabled()
+        && config.carrier_learning
+        && config.limits.max_carrier_learning_entries < 3
+    {
+        return config_error(
+            "web.limits.max_carrier_learning_entries must be >= 3 when carrier learning is enabled",
+        );
+    }
     if candidates.len() > WebCarrier::ALL.len() {
         return config_error(
             "web.carriers and the web.carrier fallback must contain at most four carriers",

src/config/load/validate_web/timeouts.rs

@@ -6,7 +6,12 @@ pub(super) fn validate(timeouts: &WebTimeoutsConfig) -> Result<()> {
         ("header_secs", timeouts.header_secs),
         ("body_secs", timeouts.body_secs),
         ("stream_handshake_secs", timeouts.stream_handshake_secs),
+        ("stream_first_byte_secs", timeouts.stream_first_byte_secs),
         ("long_poll_secs", timeouts.long_poll_secs),
+        ("lane_open_wait_secs", timeouts.lane_open_wait_secs),
+        ("carrier_health_secs", timeouts.carrier_health_secs),
+        ("websocket_upgrade_secs", timeouts.websocket_upgrade_secs),
+        ("websocket_open_secs", timeouts.websocket_open_secs),
         ("websocket_write_secs", timeouts.websocket_write_secs),
         (
             "websocket_backpressure_secs",

src/config/types.rs

@@ -53,8 +53,8 @@ pub use server::{
 };
 #[allow(unused_imports)]
 pub use web::{
-    WebConfig, WebDecoyConfig, WebLimitsConfig, WebProfileConfig, WebSecretMode, WebTimeoutsConfig,
+    WebCarrierNegotiationAggressiveness, WebConfig, WebDecoyConfig, WebLimitsConfig,
-    WebVhostConfig,
+    WebProfileConfig, WebSecretMode, WebTimeoutsConfig, WebVhostConfig,
 };
 #[allow(unused_imports)]
 pub use web_carrier::{WebCarrier, WebCarriers};

src/config/types/web.rs

@@ -98,6 +98,15 @@ pub struct WebLimitsConfig {
     /// Process-wide concurrently executing HTTP handler ceiling.
     #[serde(default = "default_web_max_http_handlers")]
     pub max_http_handlers: usize,
+    /// Per-session ceiling for downlink polls waiting for a lane OPEN.
+    #[serde(default = "default_web_max_lane_open_waits_per_session")]
+    pub max_lane_open_waits_per_session: usize,
+    /// Queued and in-flight downlink bytes allowed for one independent lane.
+    #[serde(default = "default_web_pending_bytes_per_lane")]
+    pub pending_bytes_per_lane: usize,
+    /// Queued and in-flight downlink items allowed for one independent lane.
+    #[serde(default = "default_web_pending_items_per_lane")]
+    pub pending_items_per_lane: usize,
     /// Process-wide transient WebSocket byte sub-budget inside pending bytes.
     #[serde(default = "default_web_websocket_bytes_global")]
     pub websocket_bytes_global: usize,
@@ -110,6 +119,9 @@ pub struct WebLimitsConfig {
     /// Accepted HTTP connections that WebSocket upgrades must leave available.
     #[serde(default = "default_web_websocket_http_connection_reserve")]
     pub websocket_http_connection_reserve: usize,
+    /// Concurrent pressure-eviction claims allowed process-wide.
+    #[serde(default = "default_web_max_websocket_evictions_in_flight")]
+    pub max_websocket_evictions_in_flight: usize,
     /// Process-wide bounded carrier-learning evidence entry ceiling.
     #[serde(default = "default_web_max_carrier_learning_entries")]
     pub max_carrier_learning_entries: usize,
@@ -215,10 +227,15 @@ impl Default for WebLimitsConfig {
             max_frames_per_body: default_web_max_frames_per_body(),
             max_http_connections: default_web_max_http_connections(),
             max_http_handlers: default_web_max_http_handlers(),
+            max_lane_open_waits_per_session: default_web_max_lane_open_waits_per_session(),
+            pending_bytes_per_lane: default_web_pending_bytes_per_lane(),
+            pending_items_per_lane: default_web_pending_items_per_lane(),
             websocket_bytes_global: default_web_websocket_bytes_global(),
             websocket_admission_watermark_pct: default_web_websocket_admission_watermark_pct(),
             websocket_eviction_watermark_pct: default_web_websocket_eviction_watermark_pct(),
             websocket_http_connection_reserve: default_web_websocket_http_connection_reserve(),
+            max_websocket_evictions_in_flight:
+                default_web_max_websocket_evictions_in_flight(),
             max_carrier_learning_entries: default_web_max_carrier_learning_entries(),
             max_body_readers: default_web_max_body_readers(),
             max_body_bytes_global: default_web_max_body_bytes_global(),
@@ -266,9 +283,24 @@ pub struct WebTimeoutsConfig {
     /// Deadline from the first inner byte through MTProxy authentication.
     #[serde(default = "default_web_stream_handshake_timeout_secs")]
     pub stream_handshake_secs: u64,
+    /// Absolute deadline for receiving the first inner MTProxy byte.
+    #[serde(default = "default_web_stream_first_byte_secs")]
+    pub stream_first_byte_secs: u64,
     /// Maximum wait for one empty downlink long poll.
     #[serde(default = "default_web_long_poll_timeout_secs")]
     pub long_poll_secs: u64,
+    /// Grace for a canonical downlink poll that races its lane OPEN.
+    #[serde(default = "default_web_lane_open_wait_secs")]
+    pub lane_open_wait_secs: u64,
+    /// Post-commit observation interval required before learning succeeds.
+    #[serde(default = "default_web_carrier_health_secs")]
+    pub carrier_health_secs: u64,
+    /// Maximum wait for Hyper to transfer an accepted WebSocket upgrade.
+    #[serde(default = "default_web_websocket_upgrade_secs")]
+    pub websocket_upgrade_secs: u64,
+    /// Absolute deadline for the first carrier binary message after upgrade.
+    #[serde(default = "default_web_websocket_open_secs")]
+    pub websocket_open_secs: u64,
     /// Maximum wait for one WebSocket write to complete.
     #[serde(default = "default_web_websocket_write_secs")]
     pub websocket_write_secs: u64,
@@ -307,7 +339,12 @@ impl Default for WebTimeoutsConfig {
             header_secs: default_web_header_timeout_secs(),
             body_secs: default_web_body_timeout_secs(),
             stream_handshake_secs: default_web_stream_handshake_timeout_secs(),
+            stream_first_byte_secs: default_web_stream_first_byte_secs(),
             long_poll_secs: default_web_long_poll_timeout_secs(),
+            lane_open_wait_secs: default_web_lane_open_wait_secs(),
+            carrier_health_secs: default_web_carrier_health_secs(),
+            websocket_upgrade_secs: default_web_websocket_upgrade_secs(),
+            websocket_open_secs: default_web_websocket_open_secs(),
             websocket_write_secs: default_web_websocket_write_secs(),
             websocket_backpressure_secs: default_web_websocket_backpressure_secs(),
             websocket_eviction_secs: default_web_websocket_eviction_secs(),
@@ -323,6 +360,19 @@ impl Default for WebTimeoutsConfig {
     }
 }
 
+/// Sensitivity of process-local carrier-learning evidence.
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum WebCarrierNegotiationAggressiveness {
+    /// Require broad evidence and never rank by client IP.
+    #[default]
+    Conservative,
+    /// Use moderate User-Agent, client-IP, and profile thresholds.
+    Balanced,
+    /// React to the first bounded evidence sample.
+    Aggressive,
+}
+
 /// WEB ingress, carrier, fallback, and lifecycle configuration.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct WebConfig {
@@ -338,6 +388,9 @@ pub struct WebConfig {
     /// Enables bounded process-local carrier learning for automatic sessions.
     #[serde(default = "default_web_carrier_learning")]
     pub carrier_learning: bool,
+    /// Controls the evidence thresholds used by automatic carrier ranking.
+    #[serde(default)]
+    pub carrier_negotiation_aggressiveness: WebCarrierNegotiationAggressiveness,
     /// Hard process and protocol limits.
     #[serde(default)]
     pub limits: WebLimitsConfig,
@@ -381,6 +434,8 @@ impl Default for WebConfig {
             carrier: WebCarrier::default(),
             carriers: WebCarriers::default(),
             carrier_learning: default_web_carrier_learning(),
+            carrier_negotiation_aggressiveness:
+                WebCarrierNegotiationAggressiveness::default(),
             limits: WebLimitsConfig::default(),
             debug: WebDebugConfig::default(),
             timeouts: WebTimeoutsConfig::default(),

src/config/types/web/defaults.rs

@@ -41,10 +41,14 @@ usize_default!(default_web_carrier_batch_bytes, 2 * 1024 * 1024);
 usize_default!(default_web_max_frames_per_body, 4096);
 usize_default!(default_web_max_http_connections, 1024);
 usize_default!(default_web_max_http_handlers, 512);
+usize_default!(default_web_max_lane_open_waits_per_session, 16);
+usize_default!(default_web_pending_bytes_per_lane, 8 * 1024 * 1024);
+usize_default!(default_web_pending_items_per_lane, 1024);
 usize_default!(default_web_websocket_bytes_global, 256 * 1024 * 1024);
 u8_default!(default_web_websocket_admission_watermark_pct, 75);
 u8_default!(default_web_websocket_eviction_watermark_pct, 90);
 usize_default!(default_web_websocket_http_connection_reserve, 64);
+usize_default!(default_web_max_websocket_evictions_in_flight, 8);
 usize_default!(default_web_max_carrier_learning_entries, 4096);
 usize_default!(default_web_max_body_readers, 32);
 usize_default!(default_web_max_body_bytes_global, 64 * 1024 * 1024);
@@ -79,7 +83,12 @@ u32_default!(default_web_new_streams_burst, 512);
 u64_default!(default_web_header_timeout_secs, 10);
 u64_default!(default_web_body_timeout_secs, 30);
 u64_default!(default_web_stream_handshake_timeout_secs, 10);
+u64_default!(default_web_stream_first_byte_secs, 30);
 u64_default!(default_web_long_poll_timeout_secs, 25);
+u64_default!(default_web_lane_open_wait_secs, 2);
+u64_default!(default_web_carrier_health_secs, 30);
+u64_default!(default_web_websocket_upgrade_secs, 5);
+u64_default!(default_web_websocket_open_secs, 15);
 u64_default!(default_web_websocket_write_secs, 30);
 u64_default!(default_web_websocket_backpressure_secs, 30);
 u64_default!(default_web_websocket_eviction_secs, 1);

src/web/session.rs

@@ -46,7 +46,14 @@ struct InboundChunk {
     offset: usize,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) struct StreamIdentity {
+    pub(crate) id: u32,
+    pub(crate) instance: u64,
+}
+
 struct StreamState {
+    instance: u64,
     inbound: VecDeque<InboundChunk>,
     receive_window: u32,
     send_credit: u64,
@@ -73,6 +80,7 @@ struct DownBatch {
 }
 
 struct CarrierLane {
+    instance: u64,
     pending_frames: VecDeque<QueuedFrame>,
     pending_windows: HashMap<u32, usize>,
     unacked: Option<DownBatch>,
@@ -85,8 +93,9 @@ struct CarrierLane {
 }
 
 impl CarrierLane {
-    fn new() -> Self {
+    fn new(instance: u64) -> Self {
         Self {
+            instance,
             pending_frames: VecDeque::new(),
             pending_windows: HashMap::new(),
             unacked: None,
@@ -102,6 +111,8 @@ impl CarrierLane {
 
 struct SessionState {
     streams: HashMap<u32, StreamState>,
+    closing_streams: HashMap<u32, u64>,
+    next_stream_instance: u64,
     active_peer_ports: HashSet<u16>,
     closed_streams: HashSet<u32>,
     closed_order: VecDeque<u32>,
@@ -113,6 +124,7 @@ struct SessionState {
     last_up_sequence: u64,
     last_up_digest: TokenHash,
     carrier_lanes: HashMap<u32, CarrierLane>,
+    next_lane_instance: u64,
     websocket_lane_reservations: HashMap<u32, u16>,
     pending_bytes: usize,
     pending_items: usize,
@@ -183,8 +195,10 @@ impl WebSession {
         timeouts: WebTimeoutsConfig,
     ) -> Arc<Self> {
         let mut carrier_lanes = HashMap::new();
+        let mut next_lane_instance = 1;
         if selected_carrier == WebCarrier::HttpsLanes {
-            carrier_lanes.insert(0, CarrierLane::new());
+            carrier_lanes.insert(0, CarrierLane::new(next_lane_instance));
+            next_lane_instance += 1;
         }
         Arc::new(Self {
             manager,
@@ -201,6 +215,8 @@ impl WebSession {
             timeouts,
             state: Mutex::new(SessionState {
                 streams: HashMap::new(),
+                closing_streams: HashMap::new(),
+                next_stream_instance: 1,
                 active_peer_ports: HashSet::new(),
                 closed_streams: HashSet::new(),
                 closed_order: VecDeque::new(),
@@ -212,6 +228,7 @@ impl WebSession {
                 last_up_sequence: 0,
                 last_up_digest: [0; 32],
                 carrier_lanes,
+                next_lane_instance,
                 websocket_lane_reservations: HashMap::new(),
                 pending_bytes: 0,
                 pending_items: 0,
@@ -329,17 +346,21 @@ impl WebSession {
     /// Polls client-to-server bytes and returns consumed flow-control credit.
     pub(super) fn poll_read(
         &self,
-        stream_id: u32,
+        stream: StreamIdentity,
         cx: &mut Context<'_>,
         output: &mut ReadBuf<'_>,
     ) -> Poll<io::Result<()>> {
         let mut state = self.state.lock();
         let (count, finished) = {
-            let Some(stream) = state.streams.get_mut(&stream_id) else {
+            let Some(stream_state) = state
+                .streams
+                .get_mut(&stream.id)
+                .filter(|state| state.instance == stream.instance)
+            else {
                 return Poll::Ready(Ok(()));
             };
-            let Some(chunk) = stream.inbound.front_mut() else {
+            let Some(chunk) = stream_state.inbound.front_mut() else {
-                stream.read_waker = Some(cx.waker().clone());
+                stream_state.read_waker = Some(cx.waker().clone());
                 return Poll::Pending;
             };
             let available = &chunk.bytes[chunk.offset..];
@@ -348,14 +369,14 @@ impl WebSession {
             chunk.offset += count;
             let finished = chunk.offset == chunk.bytes.len();
             if finished {
-                stream.inbound.pop_front();
+                stream_state.inbound.pop_front();
             }
-            stream.receive_window = stream.receive_window.saturating_add(count as u32);
+            stream_state.receive_window = stream_state.receive_window.saturating_add(count as u32);
             (count, finished)
         };
         let overhead = if finished { QUEUE_ITEM_COST } else { 0 };
         self.release_locked(&mut state, count + overhead, usize::from(finished), false);
-        if !self.queue_window_locked(&mut state, stream_id, count as u32) {
+        if !self.queue_window_locked(&mut state, stream.id, count as u32) {
             drop(state);
             self.close();
             return Poll::Ready(Err(io::Error::other(
@@ -368,7 +389,7 @@ impl WebSession {
     /// Polls server-to-client writes against stream credit and bounded queues.
     pub(super) fn poll_write(
         &self,
-        stream_id: u32,
+        stream: StreamIdentity,
         cx: &mut Context<'_>,
         input: &[u8],
     ) -> Poll<io::Result<usize>> {
@@ -376,7 +397,11 @@ impl WebSession {
             return Poll::Ready(Ok(0));
         }
         let mut state = self.state.lock();
-        let Some(stream) = state.streams.get_mut(&stream_id) else {
+        let Some(stream_state) = state
+            .streams
+            .get_mut(&stream.id)
+            .filter(|state| state.instance == stream.instance)
+        else {
             return Poll::Ready(Err(io::Error::new(
                 io::ErrorKind::BrokenPipe,
                 "WEB logical stream is closed",
@@ -386,24 +411,32 @@ impl WebSession {
             .len()
             .min(frame::DATA_CHUNK_BYTES)
             .min(self.limits.max_frame_payload_bytes)
-            .min(stream.send_credit as usize);
+            .min(stream_state.send_credit as usize);
         if count == 0 {
-            stream.write_waker = Some(cx.waker().clone());
+            stream_state.write_waker = Some(cx.waker().clone());
             return Poll::Pending;
         }
-        if !self.queue_data_locked(&mut state, stream_id, &input[..count]) {
+        if !self.queue_data_locked(&mut state, stream.id, &input[..count]) {
-            if let Some(stream) = state.streams.get_mut(&stream_id) {
+            if let Some(stream_state) = state
-                stream.write_waker = Some(cx.waker().clone());
+                .streams
+                .get_mut(&stream.id)
+                .filter(|state| state.instance == stream.instance)
+            {
+                stream_state.write_waker = Some(cx.waker().clone());
             }
             return Poll::Pending;
         }
-        let Some(stream) = state.streams.get_mut(&stream_id) else {
+        let Some(stream_state) = state
+            .streams
+            .get_mut(&stream.id)
+            .filter(|state| state.instance == stream.instance)
+        else {
             return Poll::Ready(Err(io::Error::new(
                 io::ErrorKind::BrokenPipe,
                 "WEB logical stream is closed",
             )));
         };
-        stream.send_credit -= count as u64;
+        stream_state.send_credit -= count as u64;
         state.last_activity = Instant::now();
         drop(state);
         if self.carrier().is_multiplexed() {

src/web/session/backend.rs

@@ -7,7 +7,7 @@ use crate::proxy::shared_state::ConntrackClosePolicy;
 use crate::web::frame::FrameType;
 use crate::web::stream::WebLogicalStream;
 
-use super::{WebSession, inbound_queue_cost};
+use super::{StreamIdentity, WebSession, inbound_queue_cost};
 
 #[cfg(test)]
 #[path = "backend_tests.rs"]
@@ -17,61 +17,64 @@ impl WebSession {
     /// Starts one owned inner handshake and relay task for an admitted stream.
     pub(super) fn spawn_stream(
         self: &Arc<Self>,
-        stream_id: u32,
+        completion: StreamCompletion,
-        peer_port: u16,
         retain_reservation_on_reject: bool,
     ) -> bool {
+        let stream = completion.stream;
+        let peer_port = completion.peer_port;
         let Some(manager) = self.manager.upgrade() else {
-            self.stream_rejected_before_spawn(stream_id, peer_port, retain_reservation_on_reject);
+            completion
+                .retain_rejected
+                .store(retain_reservation_on_reject, Ordering::Release);
+            drop(completion);
             return false;
         };
         let generation = manager.active_generation();
         if !*generation.admission_rx.borrow() {
             self.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::StreamRejected,
-                Some(stream_id),
+                Some(stream.id),
                 Some("admission_closed"),
             );
-            self.stream_rejected_before_spawn(stream_id, peer_port, retain_reservation_on_reject);
+            completion
+                .retain_rejected
+                .store(retain_reservation_on_reject, Ordering::Release);
+            drop(completion);
             return false;
         }
         let Ok(connection_permit) = generation.max_connections.clone().try_acquire_owned() else {
             manager.record_stream_rejected();
             self.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::StreamRejected,
-                Some(stream_id),
+                Some(stream.id),
                 Some("connection_limit"),
             );
-            self.stream_rejected_before_spawn(stream_id, peer_port, retain_reservation_on_reject);
+            completion
+                .retain_rejected
+                .store(retain_reservation_on_reject, Ordering::Release);
+            drop(completion);
             return false;
         };
         let deps = generation.client_runtime_deps();
         let replay_checker = Arc::clone(&generation.replay_checker);
         let session = Arc::clone(self);
         let cancel = self.cancel.clone();
-        let retain_rejected = Arc::new(AtomicBool::new(false));
+        let retain_rejected = Arc::clone(&completion.retain_rejected);
-        self.tasks_live.fetch_add(1, Ordering::AcqRel);
-        let completion = StreamCompletion {
-            session: Arc::clone(&session),
-            stream_id,
-            peer_port,
-            retain_rejected: Arc::clone(&retain_rejected),
-        };
         let future = async move {
             let _connection_permit = connection_permit;
             let _completion = completion;
             session.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::StreamAdmitted,
-                Some(stream_id),
+                Some(stream.id),
                 None,
             );
-            let stream = WebLogicalStream::new(Arc::clone(&session), stream_id);
+            let logical_stream = WebLogicalStream::new(Arc::clone(&session), stream);
             tokio::select! {
                 _ = cancel.cancelled() => {}
                 _ = run_stream(
                     Arc::clone(&session),
-                    stream_id,
                     stream,
+                    logical_stream,
                     deps,
                     replay_checker,
                     peer_port,
@@ -82,7 +85,7 @@ impl WebSession {
             retain_rejected.store(retain_reservation_on_reject, Ordering::Release);
             self.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::StreamRejected,
-                Some(stream_id),
+                Some(stream.id),
                 Some("generation_closed"),
             );
             drop(future);
@@ -93,21 +96,28 @@ impl WebSession {
 
     fn stream_rejected_before_spawn(
         &self,
-        stream_id: u32,
+        stream: StreamIdentity,
         peer_port: u16,
         retain_reservation: bool,
     ) {
         if !retain_reservation {
-            self.stream_finished(stream_id, peer_port);
+            self.stream_finished(stream, peer_port);
             return;
         }
         let queued = {
             let mut state = self.state.lock();
-            state.streams.remove(&stream_id).map(|stream| {
+            state
-                let (bytes, items) = inbound_queue_cost(&stream.inbound);
+                .streams
+                .get(&stream.id)
+                .filter(|state| state.instance == stream.instance)
+                .is_some()
+                .then(|| state.streams.remove(&stream.id))
+                .flatten()
+                .map(|stream_state| {
+                let (bytes, items) = inbound_queue_cost(&stream_state.inbound);
                 self.release_locked(&mut state, bytes, items, false);
-                self.remember_closed_locked(&mut state, stream_id);
+                self.remember_closed_locked(&mut state, stream.id);
-                self.queue_control_locked(&mut state, FrameType::Close, stream_id, &[])
+                self.queue_control_locked(&mut state, FrameType::Close, stream.id, &[])
             })
         };
         if queued.is_some_and(|queued| !queued) {
@@ -115,16 +125,24 @@ impl WebSession {
         }
     }
 
-    fn stream_finished(&self, stream_id: u32, peer_port: u16) {
+    fn stream_finished(&self, stream: StreamIdentity, peer_port: u16) {
         let (queued, reserved) = {
             let mut state = self.state.lock();
             let reserved = state.active_peer_ports.remove(&peer_port);
-            let queued = state.streams.remove(&stream_id).map(|stream| {
+            let current = state
-                let (bytes, items) = inbound_queue_cost(&stream.inbound);
+                .streams
+                .get(&stream.id)
+                .is_some_and(|state| state.instance == stream.instance);
+            let queued = current.then(|| state.streams.remove(&stream.id)).flatten().map(|stream_state| {
+                let (bytes, items) = inbound_queue_cost(&stream_state.inbound);
                 self.release_locked(&mut state, bytes, items, false);
-                self.remember_closed_locked(&mut state, stream_id);
+                self.remember_closed_locked(&mut state, stream.id);
-                self.queue_control_locked(&mut state, FrameType::Close, stream_id, &[])
+                self.queue_control_locked(&mut state, FrameType::Close, stream.id, &[])
             });
+            if state.closing_streams.get(&stream.id) == Some(&stream.instance) {
+                state.closing_streams.remove(&stream.id);
+                self.remember_closed_locked(&mut state, stream.id);
+            }
             (queued, reserved)
         };
         if reserved && let Some(manager) = self.manager.upgrade() {
@@ -146,25 +164,41 @@ impl WebSession {
     }
 }
 
-struct StreamCompletion {
+pub(super) struct StreamCompletion {
     session: Arc<WebSession>,
-    stream_id: u32,
+    pub(super) stream: StreamIdentity,
-    peer_port: u16,
+    pub(super) peer_port: u16,
     retain_rejected: Arc<AtomicBool>,
 }
 
+impl WebSession {
+    pub(super) fn own_stream_task(
+        self: &Arc<Self>,
+        stream: StreamIdentity,
+        peer_port: u16,
+    ) -> StreamCompletion {
+        self.tasks_live.fetch_add(1, Ordering::AcqRel);
+        StreamCompletion {
+            session: Arc::clone(self),
+            stream,
+            peer_port,
+            retain_rejected: Arc::new(AtomicBool::new(false)),
+        }
+    }
+}
+
 impl Drop for StreamCompletion {
     fn drop(&mut self) {
         self.session.trace_lifecycle(
             crate::web::trace::TraceLifecycleEvent::StreamClosed,
-            Some(self.stream_id),
+            Some(self.stream.id),
             None,
         );
         if self.retain_rejected.load(Ordering::Acquire) {
             self.session
-                .stream_rejected_before_spawn(self.stream_id, self.peer_port, true);
+                .stream_rejected_before_spawn(self.stream, self.peer_port, true);
         } else {
-            self.session.stream_finished(self.stream_id, self.peer_port);
+            self.session.stream_finished(self.stream, self.peer_port);
         }
         if self.session.tasks_live.fetch_sub(1, Ordering::AcqRel) == 1 {
             self.session.tasks_done.notify_waiters();
@@ -174,7 +208,7 @@ impl Drop for StreamCompletion {
 
 async fn run_stream(
     session: Arc<WebSession>,
-    stream_id: u32,
+    stream_identity: StreamIdentity,
     stream: WebLogicalStream,
     deps: crate::proxy::authenticated::ClientRuntimeDeps,
     replay_checker: Arc<crate::stats::ReplayChecker>,
@@ -191,13 +225,27 @@ async fn run_stream(
     let peer = std::net::SocketAddr::new(session.client_ip, peer_port);
     deps.stats.increment_connects_all();
 
-    // A carrier may publish OPEN before the local MTProto socket writes its
+    // Silent OPEN ownership has a separate absolute deadline so it cannot
-    // first byte. Session and stream quotas bound this idle phase without
+    // consume stream and tuple quotas indefinitely before handshake admission.
-    // consuming the process-wide active-handshake budget.
+    let first_byte = tokio::time::timeout(
-    if reader.read_exact(&mut handshake[..1]).await.is_err() {
+        Duration::from_secs(session.timeouts.stream_first_byte_secs),
+        reader.read_exact(&mut handshake[..1]),
+    )
+    .await;
+    if first_byte.is_err() {
+        session.trace_lifecycle(
+            crate::web::trace::TraceLifecycleEvent::HandshakeTimeout,
+            Some(stream_identity.id),
+            Some("first_byte_timeout"),
+        );
+        deps.stats
+            .increment_connects_bad_with_class("web_mtproto_first_byte_timeout");
+        return;
+    }
+    if first_byte.is_ok_and(|result| result.is_err()) {
         session.trace_lifecycle(
             crate::web::trace::TraceLifecycleEvent::HandshakeIo,
-            Some(stream_id),
+            Some(stream_identity.id),
             Some("first_byte_io"),
         );
         deps.stats
@@ -206,7 +254,7 @@ async fn run_stream(
     }
     session.trace_lifecycle(
         crate::web::trace::TraceLifecycleEvent::StreamFirstByte,
-        Some(stream_id),
+        Some(stream_identity.id),
         None,
     );
     let Some(manager) = session.manager.upgrade() else {
@@ -215,7 +263,7 @@ async fn run_stream(
     let Some(handshake_permit) = manager.try_stream_handshake() else {
         session.trace_lifecycle(
             crate::web::trace::TraceLifecycleEvent::StreamRejected,
-            Some(stream_id),
+            Some(stream_identity.id),
             Some("handshake_limit"),
         );
         return;
@@ -246,7 +294,7 @@ async fn run_stream(
         Err(_) => {
             session.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::HandshakeTimeout,
-                Some(stream_id),
+                Some(stream_identity.id),
                 Some("timeout"),
             );
             deps.stats
@@ -258,7 +306,7 @@ async fn run_stream(
         Ok(Err(_)) => {
             session.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::HandshakeIo,
-                Some(stream_id),
+                Some(stream_identity.id),
                 Some("io"),
             );
             deps.stats
@@ -268,7 +316,7 @@ async fn run_stream(
         Ok(Ok(crate::error::HandshakeResult::Success((reader, writer, success)))) => {
             session.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::HandshakeSucceeded,
-                Some(stream_id),
+                Some(stream_identity.id),
                 None,
             );
             (reader, writer, success)
@@ -276,7 +324,7 @@ async fn run_stream(
         Ok(Ok(_)) => {
             session.trace_lifecycle(
                 crate::web::trace::TraceLifecycleEvent::HandshakeRejected,
-                Some(stream_id),
+                Some(stream_identity.id),
                 Some("bad_client"),
             );
             deps.stats
@@ -286,7 +334,7 @@ async fn run_stream(
     };
     session.trace_lifecycle(
         crate::web::trace::TraceLifecycleEvent::RelayStarted,
-        Some(stream_id),
+        Some(stream_identity.id),
         None,
     );
     let relay_result = run_authenticated(
@@ -301,7 +349,7 @@ async fn run_stream(
     .await;
     session.trace_lifecycle(
         crate::web::trace::TraceLifecycleEvent::RelayEnded,
-        Some(stream_id),
+        Some(stream_identity.id),
         Some(if relay_result.is_ok() {
             "completed"
         } else {

src/web/stream.rs

@@ -7,21 +7,21 @@ use std::task::{Context, Poll};
 use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
 use tokio::sync::futures::OwnedNotified;
 
-use crate::web::session::WebSession;
+use crate::web::session::{StreamIdentity, WebSession};
 
 /// Async byte stream that maps one WEB stream identifier onto carrier frames.
 pub(crate) struct WebLogicalStream {
     session: Arc<WebSession>,
-    stream_id: u32,
+    stream: StreamIdentity,
     budget_wait: Option<Pin<Box<OwnedNotified>>>,
 }
 
 impl WebLogicalStream {
     /// Binds a virtual byte stream to one live carrier stream identifier.
-    pub(crate) fn new(session: Arc<WebSession>, stream_id: u32) -> Self {
+    pub(crate) fn new(session: Arc<WebSession>, stream: StreamIdentity) -> Self {
         Self {
             session,
-            stream_id,
+            stream,
             budget_wait: None,
         }
     }
@@ -33,7 +33,7 @@ impl AsyncRead for WebLogicalStream {
         cx: &mut Context<'_>,
         output: &mut ReadBuf<'_>,
     ) -> Poll<io::Result<()>> {
-        self.session.poll_read(self.stream_id, cx, output)
+        self.session.poll_read(self.stream, cx, output)
     }
 }
 
@@ -43,7 +43,7 @@ impl AsyncWrite for WebLogicalStream {
         cx: &mut Context<'_>,
         input: &[u8],
     ) -> Poll<io::Result<usize>> {
-        let result = self.session.poll_write(self.stream_id, cx, input);
+        let result = self.session.poll_write(self.stream, cx, input);
         if !result.is_pending() {
             self.budget_wait = None;
             return result;
@@ -64,7 +64,7 @@ impl AsyncWrite for WebLogicalStream {
             }
             self.budget_wait = None;
         }
-        match self.session.poll_write(self.stream_id, cx, input) {
+        match self.session.poll_write(self.stream, cx, input) {
             Poll::Ready(result) => {
                 self.budget_wait = None;
                 Poll::Ready(result)