fix(web): fence routes to the current session (#2522)

* fix(web): publish routable sessions before connect events
* fix(web): fence routes to the current session

easytier-web/src/client_manager/mod.rs

@@ -5,7 +5,7 @@ pub mod storage;
 
 use std::sync::{
     Arc,
-    atomic::{AtomicU32, Ordering},
+    atomic::{AtomicU32, AtomicU64, Ordering},
 };
 use std::time::Duration;
 
@@ -62,6 +62,7 @@ pub struct ClientManager {
     tasks: JoinSet<()>,
 
     listeners_cnt: Arc<AtomicU32>,
+    next_session_epoch: Arc<AtomicU64>,
 
     client_sessions: Arc<DashMap<url::Url, Arc<Session>>>,
     storage: Storage,
@@ -94,6 +95,7 @@ impl ClientManager {
             tasks,
 
             listeners_cnt: Arc::new(AtomicU32::new(0)),
+            next_session_epoch: Arc::new(AtomicU64::new(0)),
 
             client_sessions,
             storage: Storage::new(db),
@@ -115,6 +117,7 @@ impl ClientManager {
         let sessions = self.client_sessions.clone();
         let storage = self.storage.weak_ref();
         let listeners_cnt = self.listeners_cnt.clone();
+        let next_session_epoch = self.next_session_epoch.clone();
         let geoip_db = self.geoip_db.clone();
         let heartbeat_min_response_delay = self.heartbeat_min_response_delay;
         let feature_flags = self.feature_flags.clone();
@@ -148,9 +151,12 @@ impl ClientManager {
                     heartbeat_min_response_delay,
                     feature_flags.clone(),
                     webhook_config.clone(),
+                    next_session_epoch.fetch_add(1, Ordering::Relaxed) + 1,
                 );
                 session.serve(tunnel).await;
-                sessions.insert(client_url, Arc::new(session));
+                let session = Arc::new(session);
+                sessions.insert(client_url, session.clone());
+                session.mark_route_ready();
             }
             listeners_cnt.fetch_sub(1, Ordering::Relaxed);
         });
@@ -427,6 +433,9 @@ mod tests {
         validate_count: Arc<AtomicUsize>,
         block_second_validate: Arc<AtomicBool>,
         allow_second_validate: Arc<AtomicBool>,
+        connected_count: Arc<AtomicUsize>,
+        block_connected: Arc<AtomicBool>,
+        allow_connected: Arc<AtomicBool>,
     }
 
     impl TestWebhookState {
@@ -438,6 +447,9 @@ mod tests {
                 validate_count: Arc::new(AtomicUsize::new(0)),
                 block_second_validate: Arc::new(AtomicBool::new(false)),
                 allow_second_validate: Arc::new(AtomicBool::new(true)),
+                connected_count: Arc::new(AtomicUsize::new(0)),
+                block_connected: Arc::new(AtomicBool::new(false)),
+                allow_connected: Arc::new(AtomicBool::new(true)),
             }
         }
 
@@ -450,6 +462,13 @@ mod tests {
             state
         }
 
+        fn with_blocked_connected(validate_responses: impl IntoIterator<Item = bool>) -> Self {
+            let state = Self::new(validate_responses);
+            state.block_connected.store(true, Ordering::Release);
+            state.allow_connected.store(false, Ordering::Release);
+            state
+        }
+
         fn allow_second_validate(&self) {
             self.allow_second_validate.store(true, Ordering::Release);
         }
@@ -457,6 +476,14 @@ mod tests {
         fn validate_count(&self) -> usize {
             self.validate_count.load(Ordering::Acquire)
         }
+
+        fn allow_connected(&self) {
+            self.allow_connected.store(true, Ordering::Release);
+        }
+
+        fn connected_count(&self) -> usize {
+            self.connected_count.load(Ordering::Acquire)
+        }
     }
 
     async fn validate_token_handler(
@@ -489,6 +516,18 @@ mod tests {
         Json(json!({}))
     }
 
+    async fn node_connected_handler(
+        State(state): State<TestWebhookState>,
+    ) -> Json<serde_json::Value> {
+        state.connected_count.fetch_add(1, Ordering::AcqRel);
+        while state.block_connected.load(Ordering::Acquire)
+            && !state.allow_connected.load(Ordering::Acquire)
+        {
+            tokio::time::sleep(Duration::from_millis(20)).await;
+        }
+        Json(json!({}))
+    }
+
     async fn test_webhook_config() -> (
         crate::webhook::SharedWebhookConfig,
         tokio::task::JoinHandle<()>,
@@ -507,7 +546,7 @@ mod tests {
     ) {
         let app = Router::new()
             .route("/validate-token", post(validate_token_handler))
-            .route("/webhook/node-connected", post(webhook_ack_handler))
+            .route("/webhook/node-connected", post(node_connected_handler))
             .route("/webhook/node-disconnected", post(webhook_ack_handler))
             .with_state(state.clone());
         let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
@@ -541,6 +580,42 @@ mod tests {
             .unwrap()
     }
 
+    #[tokio::test]
+    async fn connected_webhook_observes_a_routable_current_session() {
+        let webhook_state = TestWebhookState::with_blocked_connected([true]);
+        let (webhook_config, webhook_server, webhook_state) =
+            test_webhook_config_with_state(webhook_state).await;
+        let mut mgr = ClientManager::new(
+            Db::memory_db().await,
+            None,
+            Duration::ZERO,
+            Arc::new(FeatureFlags::default()),
+            webhook_config,
+        );
+        let config_server_addr = add_random_udp_listener(&mut mgr).await;
+        let machine_id = uuid::Uuid::new_v4();
+        let _client = start_web_client_for_test(
+            config_server_addr,
+            machine_id,
+            Arc::new(native_instance_manager()),
+        )
+        .await;
+
+        wait_for_condition(
+            || async { webhook_state.connected_count() == 1 },
+            Duration::from_secs(12),
+        )
+        .await;
+        let user_id = wait_for_validated_user(&mgr, machine_id).await;
+        let session = mgr
+            .get_session_by_machine_id(user_id, &machine_id)
+            .expect("connected target must already resolve to a session");
+        assert!(session.is_running());
+
+        webhook_state.allow_connected();
+        webhook_server.abort();
+    }
+
     async fn wait_for_validated_user(mgr: &ClientManager, machine_id: uuid::Uuid) -> i32 {
         tokio::time::timeout(Duration::from_secs(12), async {
             loop {

easytier-web/src/client_manager/session.rs

@@ -67,6 +67,7 @@ pub struct SessionData {
     webhook_connected_binding_version: Option<u64>,
     webhook_validation_dirty: bool,
     webhook_validation_notify: Arc<Notify>,
+    session_epoch: u64,
 }
 
 impl SessionData {
@@ -96,6 +97,7 @@ impl SessionData {
             webhook_connected_binding_version: None,
             webhook_validation_dirty: false,
             webhook_validation_notify: Arc::new(Notify::new()),
+            session_epoch: 0,
         }
     }
 
@@ -252,7 +254,7 @@ impl Drop for SessionData {
         if let Ok(storage) = Storage::try_from(self.storage.clone())
             && let Some(token) = self.storage_token.as_ref()
         {
-            storage.remove_client(token);
+            storage.remove_session_client(token, self.session_epoch);
 
             // Notify the webhook receiver when a node disconnects.
             if self.webhook_config.is_enabled()
@@ -426,7 +428,12 @@ impl SessionRpcService {
             let authorized = data.auth_state.is_authorized();
             if let Some(storage_token) = data.storage_token.clone() {
                 let report_time = Self::heartbeat_report_timestamp(&runtime_req);
-                storage.update_client(storage_token, report_time, authorized);
+                storage.update_session_client(
+                    storage_token,
+                    report_time,
+                    authorized,
+                    data.session_epoch,
+                );
             }
             let runtime_notify = (authorized && data.storage_token.is_some())
                 .then(|| (data.notifier.clone(), runtime_req));
@@ -498,7 +505,7 @@ impl SessionRpcService {
             }
         };
 
-        let (storage_token, notifier, runtime_req) = {
+        let (storage_token, notifier, runtime_req, session_epoch) = {
             let mut data = self.data.write().await;
             let is_new_storage_token = data.storage_token.is_none();
             let runtime_req = Self::store_latest_heartbeat_req(&mut data, req.clone());
@@ -519,11 +526,16 @@ impl SessionRpcService {
                 tracing::error!("Heartbeat succeeded before session token was initialized");
                 return Ok(HeartbeatResponse {});
             };
-            (storage_token, data.notifier.clone(), runtime_req)
+            (
+                storage_token,
+                data.notifier.clone(),
+                runtime_req,
+                data.session_epoch,
+            )
         };
 
         let report_time = Self::heartbeat_report_timestamp(&runtime_req);
-        storage.update_client(storage_token, report_time, true);
+        storage.update_session_client(storage_token, report_time, true, session_epoch);
         let _ = notifier.send(runtime_req);
         Ok(HeartbeatResponse {})
     }
@@ -575,6 +587,7 @@ pub struct Session {
 
     webhook_validation_task: Option<AbortOnDropHandle<()>>,
     config_reconcile_task: Option<AbortOnDropHandle<()>>,
+    route_ready: Arc<Notify>,
 }
 
 impl Debug for Session {
@@ -594,9 +607,11 @@ impl Session {
         heartbeat_min_response_delay: Duration,
         feature_flags: Arc<FeatureFlags>,
         webhook_config: SharedWebhookConfig,
+        session_epoch: u64,
     ) -> Self {
-        let session_data =
+        let mut session_data =
             SessionData::new(storage, client_url, location, feature_flags, webhook_config);
+        session_data.session_epoch = session_epoch;
         let data = Arc::new(RwLock::new(session_data));
 
         let rpc_mgr =
@@ -615,6 +630,7 @@ impl Session {
             data,
             webhook_validation_task: None,
             config_reconcile_task: None,
+            route_ready: Arc::new(Notify::new()),
         }
     }
 
@@ -623,10 +639,13 @@ impl Session {
 
         let data = self.data.read().await;
         if data.webhook_config.is_enabled() {
+            let route_ready = self.route_ready.clone();
+            let session_data = Arc::downgrade(&self.data);
             self.webhook_validation_task
-                .replace(AbortOnDropHandle::new(tokio::spawn(
+                .replace(AbortOnDropHandle::new(tokio::spawn(async move {
-                    webhook_validation::run_worker(Arc::downgrade(&self.data)),
+                    route_ready.notified().await;
-                )));
+                    webhook_validation::run_worker(session_data).await;
+                })));
         }
         self.config_reconcile_task
             .replace(AbortOnDropHandle::new(tokio::spawn(
@@ -640,6 +659,10 @@ impl Session {
             )));
     }
 
+    pub fn mark_route_ready(&self) {
+        self.route_ready.notify_one();
+    }
+
     pub fn is_running(&self) -> bool {
         self.rpc_mgr.is_running()
     }
@@ -796,6 +819,8 @@ mod tests {
     struct ValidateWebhookTestState {
         received: Arc<Mutex<Option<oneshot::Sender<()>>>>,
         release: Arc<Notify>,
+        connected_received: Arc<Mutex<Option<oneshot::Sender<()>>>>,
+        connected_release: Option<Arc<Notify>>,
     }
 
     async fn valid_validate_token_handler(
@@ -813,11 +838,25 @@ mod tests {
         }))
     }
 
+    async fn node_connected_handler(
+        State(state): State<ValidateWebhookTestState>,
+    ) -> Json<serde_json::Value> {
+        if let Some(sender) = state.connected_received.lock().await.take() {
+            let _ = sender.send(());
+        }
+        if let Some(release) = state.connected_release {
+            release.notified().await;
+        }
+
+        Json(json!({}))
+    }
+
     async fn test_webhook_config(
         state: ValidateWebhookTestState,
     ) -> (SharedWebhookConfig, tokio::task::JoinHandle<()>) {
         let app = Router::new()
             .route("/validate-token", post(valid_validate_token_handler))
+            .route("/webhook/node-connected", post(node_connected_handler))
             .with_state(state);
         let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
         let addr = listener.local_addr().unwrap();
@@ -907,10 +946,14 @@ mod tests {
         let req = heartbeat_request("token", machine_id);
         let storage = Storage::new(crate::db::Db::memory_db().await);
         let (received_tx, received_rx) = oneshot::channel();
+        let (connected_tx, connected_rx) = oneshot::channel();
         let release = Arc::new(Notify::new());
+        let connected_release = Arc::new(Notify::new());
         let (webhook_config, server) = test_webhook_config(ValidateWebhookTestState {
             received: Arc::new(Mutex::new(Some(received_tx))),
             release: release.clone(),
+            connected_received: Arc::new(Mutex::new(Some(connected_tx))),
+            connected_release: Some(connected_release.clone()),
         })
         .await;
         let mut session = SessionData::new(
@@ -938,6 +981,18 @@ mod tests {
         ));
         received_rx.await.unwrap();
         release.notify_waiters();
+        connected_rx.await.unwrap();
+        let user_id = storage
+            .db()
+            .get_user_id_by_token("token")
+            .await
+            .unwrap()
+            .unwrap();
+        assert_eq!(
+            storage.get_client_url_by_machine_id(user_id, &machine_id),
+            Some(url::Url::parse("http://127.0.0.1").unwrap())
+        );
+        connected_release.notify_waiters();
         validation.await.unwrap().unwrap();
         server.abort();
 
@@ -970,6 +1025,8 @@ mod tests {
         let (webhook_config, server) = test_webhook_config(ValidateWebhookTestState {
             received: Arc::new(Mutex::new(Some(received_tx))),
             release,
+            connected_received: Arc::new(Mutex::new(None)),
+            connected_release: None,
         })
         .await;
         let mut data = SessionData::new(

easytier-web/src/client_manager/session/webhook_validation.rs

@@ -228,7 +228,7 @@ pub(super) async fn apply_rejected(
     let Some(session_data) = session_data.upgrade() else {
         return;
     };
-    let (storage_token, disconnect_notification) = {
+    let (storage_token, disconnect_notification, session_epoch) = {
         let mut data = session_data.write().await;
         if !data.req.as_ref().is_some_and(|req| {
             SessionRpcService::heartbeat_matches_identity(
@@ -258,13 +258,13 @@ pub(super) async fn apply_rejected(
                     binding_version,
                 })
         });
-        (storage_token, disconnect_notification)
+        (storage_token, disconnect_notification, data.session_epoch)
     };
     if let Some(storage_token) = storage_token {
         let report_time = SessionRpcService::heartbeat_report_timestamp(&input.req);
         input
             .storage
-            .update_client(storage_token, report_time, false);
+            .update_session_client(storage_token, report_time, false, session_epoch);
     }
     if disconnect_notification.is_some() {
         wait_webhook_connection_transition(
@@ -290,7 +290,14 @@ pub(super) async fn apply_success(
     let Some(session_data) = session_data.upgrade() else {
         return;
     };
-    let (storage_token, notifier, disconnect_notification, connect_notification, runtime_req) = {
+    let (
+        storage_token,
+        notifier,
+        disconnect_notification,
+        connect_notification,
+        runtime_req,
+        session_epoch,
+    ) = {
         let mut data = session_data.write().await;
         let Some(runtime_req) = data.req.clone() else {
             return;
@@ -367,9 +374,15 @@ pub(super) async fn apply_success(
             disconnect_notification,
             connect_notification,
             runtime_req,
+            data.session_epoch,
         )
     };
 
+    let report_time = SessionRpcService::heartbeat_report_timestamp(&runtime_req);
+    input
+        .storage
+        .update_session_client(storage_token, report_time, true, session_epoch);
+
     if disconnect_notification.is_some() || connect_notification.is_some() {
         wait_webhook_connection_transition(
             Arc::downgrade(&session_data),
@@ -379,10 +392,6 @@ pub(super) async fn apply_success(
         .await;
     }
 
-    let report_time = SessionRpcService::heartbeat_report_timestamp(&runtime_req);
-    input
-        .storage
-        .update_client(storage_token, report_time, true);
     let _ = notifier.send(runtime_req);
 }
 

easytier-web/src/client_manager/storage.rs

@@ -18,6 +18,7 @@ struct ClientInfo {
     storage_token: StorageToken,
     report_time: i64,
     authorized: bool,
+    session_epoch: u64,
 }
 
 #[derive(Debug)]
@@ -46,10 +47,15 @@ impl Storage {
         }))
     }
 
-    fn remove_client_info_map(map: &DashMap<uuid::Uuid, ClientInfo>, stoken: &StorageToken) {
+    fn remove_client_info_map(
+        map: &DashMap<uuid::Uuid, ClientInfo>,
+        stoken: &StorageToken,
+        session_epoch: u64,
+    ) {
         map.remove_if(&stoken.machine_id, |_, v| {
             v.storage_token.client_url == stoken.client_url
                 && v.storage_token.user_id == stoken.user_id
+                && v.session_epoch == session_epoch
         });
     }
 
@@ -59,7 +65,9 @@ impl Storage {
                 let same_client = e.storage_token.client_url
                     == client_info.storage_token.client_url
                     && e.storage_token.user_id == client_info.storage_token.user_id;
-                let should_replace = if (same_client && e.authorized != client_info.authorized)
+                let should_replace = if e.session_epoch != client_info.session_epoch {
+                    e.session_epoch < client_info.session_epoch
+                } else if (same_client && e.authorized != client_info.authorized)
                     || (!e.authorized && client_info.authorized)
                 {
                     true
@@ -79,22 +87,38 @@ impl Storage {
             .or_insert(client_info.clone());
     }
 
+    #[cfg(test)]
     pub fn update_client(&self, stoken: StorageToken, report_time: i64, authorized: bool) {
+        self.update_session_client(stoken, report_time, authorized, 0);
+    }
+
+    pub(super) fn update_session_client(
+        &self,
+        stoken: StorageToken,
+        report_time: i64,
+        authorized: bool,
+        session_epoch: u64,
+    ) {
         let inner = self.0.user_clients_map.entry(stoken.user_id).or_default();
 
         let client_info = ClientInfo {
             storage_token: stoken.clone(),
             report_time,
             authorized,
+            session_epoch,
         };
         Self::update_client_info_map(&inner, &client_info);
     }
 
     pub fn remove_client(&self, stoken: &StorageToken) {
+        self.remove_session_client(stoken, 0);
+    }
+
+    pub(super) fn remove_session_client(&self, stoken: &StorageToken, session_epoch: u64) {
         self.0
             .user_clients_map
             .remove_if(&stoken.user_id, |_, set| {
-                Self::remove_client_info_map(set, stoken);
+                Self::remove_client_info_map(set, stoken, session_epoch);
                 set.is_empty()
             });
     }
@@ -238,6 +262,31 @@ mod tests {
         assert_eq!(storage.get_client_url_by_machine_id(2, &machine_id), None);
     }
 
+    #[tokio::test]
+    async fn newer_session_epoch_owns_route_until_it_is_removed() {
+        let storage = Storage::new(Db::memory_db().await);
+        let machine_id = uuid::Uuid::new_v4();
+        let old = make_storage_token(1, machine_id, "tcp://127.0.0.1:1001");
+        let current = make_storage_token(1, machine_id, "tcp://127.0.0.1:1002");
+
+        storage.update_session_client(old.clone(), 20, true, 1);
+        storage.update_session_client(current.clone(), 20, true, 2);
+        storage.update_session_client(old.clone(), 30, true, 1);
+
+        assert_eq!(
+            storage.get_client_url_by_machine_id(1, &machine_id),
+            Some(current.client_url.clone())
+        );
+
+        storage.remove_session_client(&old, 1);
+        assert_eq!(
+            storage.get_client_url_by_machine_id(1, &machine_id),
+            Some(current.client_url.clone())
+        );
+        storage.remove_session_client(&current, 2);
+        assert_eq!(storage.get_client_url_by_machine_id(1, &machine_id), None);
+    }
+
     #[tokio::test]
     async fn list_clients_returns_current_storage_tokens() {
         let storage = Storage::new(Db::memory_db().await);