feat(smart-proxy): add socket-handler relay, fast-path port-only forwarding, metrics and bridge improvements, and various TS/Rust integration fixes

ts/proxies/smart-proxy/socket-handler-server.ts

@@ -15,6 +15,7 @@ export class SocketHandlerServer {
   private server: plugins.net.Server | null = null;
   private socketPath: string;
   private preprocessor: RoutePreprocessor;
+  private activeSockets = new Set<plugins.net.Socket>();
 
   constructor(preprocessor: RoutePreprocessor) {
     this.preprocessor = preprocessor;
@@ -41,6 +42,8 @@ export class SocketHandlerServer {
 
     return new Promise<void>((resolve, reject) => {
       this.server = plugins.net.createServer((socket) => {
+        this.activeSockets.add(socket);
+        socket.on('close', () => this.activeSockets.delete(socket));
         this.handleConnection(socket);
       });
 
@@ -61,6 +64,12 @@ export class SocketHandlerServer {
    * Stop the server and clean up.
    */
   public async stop(): Promise<void> {
+    // Destroy all active connections first
+    for (const socket of this.activeSockets) {
+      socket.destroy();
+    }
+    this.activeSockets.clear();
+
     if (this.server) {
       return new Promise<void>((resolve) => {
         this.server!.close(() => {
@@ -100,6 +109,7 @@ export class SocketHandlerServer {
 
       metadataParsed = true;
       socket.removeListener('data', onData);
+      socket.pause(); // Prevent data loss between handler removal and pipe setup
 
       const metadataJson = metadataBuffer.slice(0, newlineIndex);
       const remainingData = metadataBuffer.slice(newlineIndex + 1);
@@ -140,13 +150,6 @@ export class SocketHandlerServer {
       return;
     }
 
-    const handler = originalRoute.action.socketHandler;
-    if (!handler) {
-      logger.log('error', `Route ${routeKey} has no socketHandler`, { component: 'socket-handler-server' });
-      socket.destroy();
-      return;
-    }
-
     // Build route context
     const context: IRouteContext = {
       port: metadata.localPort || 0,
@@ -167,12 +170,110 @@ export class SocketHandlerServer {
       socket.unshift(Buffer.from(remainingData, 'utf8'));
     }
 
-    // Call the handler
-    try {
-      handler(socket, context);
-    } catch (err: any) {
-      logger.log('error', `Socket handler threw for route ${routeKey}: ${err.message}`, { component: 'socket-handler-server' });
-      socket.destroy();
+    const handler = originalRoute.action.socketHandler;
+    if (handler) {
+      // Route has an explicit socket handler callback
+      try {
+        const result = handler(socket, context);
+        // If the handler is async, wait for it to finish setup before resuming.
+        // This prevents data loss when async handlers need to do work before
+        // attaching their `data` listeners.
+        if (result && typeof (result as any).then === 'function') {
+          (result as any).then(() => {
+            socket.resume();
+          }).catch((err: any) => {
+            logger.log('error', `Async socket handler rejected for route ${routeKey}: ${err.message}`, { component: 'socket-handler-server' });
+            socket.destroy();
+          });
+        } else {
+          // Synchronous handler — listeners are already attached, safe to resume.
+          socket.resume();
+        }
+      } catch (err: any) {
+        logger.log('error', `Socket handler threw for route ${routeKey}: ${err.message}`, { component: 'socket-handler-server' });
+        socket.destroy();
+      }
+      return;
     }
+
+    // Route has dynamic host/port functions - resolve and forward
+    if (originalRoute.action.targets && originalRoute.action.targets.length > 0) {
+      this.forwardDynamicRoute(socket, originalRoute, context);
+      return;
+    }
+
+    logger.log('error', `Route ${routeKey} has no socketHandler and no targets`, { component: 'socket-handler-server' });
+    socket.destroy();
+  }
+
+  /**
+   * Forward a connection to a dynamically resolved target.
+   * Used for routes with function-based host/port that Rust cannot handle.
+   */
+  private forwardDynamicRoute(socket: plugins.net.Socket, route: IRouteConfig, context: IRouteContext): void {
+    const targets = route.action.targets!;
+    // Pick a target (round-robin would be ideal, but simple random for now)
+    const target = targets[Math.floor(Math.random() * targets.length)];
+
+    // Resolve host
+    let host: string;
+    if (typeof target.host === 'function') {
+      try {
+        const result = target.host(context);
+        host = Array.isArray(result) ? result[Math.floor(Math.random() * result.length)] : result;
+      } catch (err: any) {
+        logger.log('error', `Dynamic host function failed: ${err.message}`, { component: 'socket-handler-server' });
+        socket.destroy();
+        return;
+      }
+    } else if (typeof target.host === 'string') {
+      host = target.host;
+    } else if (Array.isArray(target.host)) {
+      host = target.host[Math.floor(Math.random() * target.host.length)];
+    } else {
+      host = 'localhost';
+    }
+
+    // Resolve port
+    let port: number;
+    if (typeof target.port === 'function') {
+      try {
+        port = target.port(context);
+      } catch (err: any) {
+        logger.log('error', `Dynamic port function failed: ${err.message}`, { component: 'socket-handler-server' });
+        socket.destroy();
+        return;
+      }
+    } else if (typeof target.port === 'number') {
+      port = target.port;
+    } else {
+      port = context.port;
+    }
+
+    logger.log('debug', `Dynamic forward: ${context.clientIp} -> ${host}:${port}`, { component: 'socket-handler-server' });
+
+    // Connect to the resolved target
+    const backend = plugins.net.connect(port, host, () => {
+      // Pipe bidirectionally
+      socket.pipe(backend);
+      backend.pipe(socket);
+    });
+
+    backend.on('error', (err) => {
+      logger.log('error', `Dynamic forward backend error: ${err.message}`, { component: 'socket-handler-server' });
+      socket.destroy();
+    });
+
+    socket.on('error', () => {
+      backend.destroy();
+    });
+
+    socket.on('close', () => {
+      backend.destroy();
+    });
+
+    backend.on('close', () => {
+      socket.destroy();
+    });
   }
 }