[minor] Discard any data received after the close frame

Remove the `'data'` listener when the close frame is received.

Author: lpinca

lib/receiver.js

@@ -48,10 +48,11 @@ class Receiver {
     this._fragments = [];
 
     this._cleanupCallback = null;
+    this._isCleaningUp = false;
     this._hadError = false;
-    this._dead = false;
     this._loop = false;
 
+    this.add = this.add.bind(this);
     this.onmessage = null;
     this.onclose = null;
     this.onerror = null;
@@ -72,7 +73,7 @@ class Receiver {
   consume (n) {
     if (this._bufferedBytes < n) {
       this._loop = false;
-      if (this._dead) this.cleanup(this._cleanupCallback);
+      if (this._isCleaningUp) this.cleanup(this._cleanupCallback);
       return null;
     }
 
@@ -107,14 +108,12 @@ class Receiver {
   /**
    * Adds new data to the parser.
    *
-   * @param {Buffer} data A chunk of data
+   * @param {Buffer} chunk A chunk of data
    * @public
    */
-  add (data) {
-    if (this._dead) return;
-
-    this._bufferedBytes += data.length;
-    this._buffers.push(data);
+  add (chunk) {
+    this._bufferedBytes += chunk.length;
+    this._buffers.push(chunk);
     this.startLoop();
   }
 
@@ -532,10 +531,9 @@ class Receiver {
    * @public
    */
   cleanup (cb) {
-    this._dead = true;
-
     if (!this._hadError && (this._loop || this._state === INFLATING)) {
       this._cleanupCallback = cb;
+      this._isCleaningUp = true;
     } else {
       this._extensions = null;
       this._fragments = null;

lib/websocket.js

@@ -2,7 +2,6 @@
 
 const EventEmitter = require('events');
 const crypto = require('crypto');
-const Ultron = require('ultron');
 const https = require('https');
 const http = require('http');
 const url = require('url');
@@ -50,7 +49,6 @@ class WebSocket extends EventEmitter {
     this._receiver = null;
     this._sender = null;
     this._socket = null;
-    this._ultron = null;
 
     if (address !== null) {
       if (!protocols) {
@@ -123,18 +121,17 @@ class WebSocket extends EventEmitter {
     socket.setTimeout(0);
     socket.setNoDelay();
 
+    socket.on('close', this._finalize);
+    socket.on('error', this._finalize);
+    socket.on('end', this._finalize);
+
     this._receiver = new Receiver(this._extensions, maxPayload, this.binaryType);
     this._sender = new Sender(socket, this._extensions);
-    this._ultron = new Ultron(socket);
     this._socket = socket;
 
-    this._ultron.on('close', this._finalize);
-    this._ultron.on('error', this._finalize);
-    this._ultron.on('end', this._finalize);
-
     if (head.length > 0) socket.unshift(head);
 
-    this._ultron.on('data', (data) => this._receiver.add(data));
+    socket.on('data', this._receiver.add);
 
     this._receiver.onmessage = (data) => this.emit('message', data);
     this._receiver.onping = (data) => {
@@ -143,6 +140,11 @@ class WebSocket extends EventEmitter {
     };
     this._receiver.onpong = (data) => this.emit('pong', data);
     this._receiver.onclose = (code, reason) => {
+      //
+      // Discard any additional data that is received on the socket.
+      //
+      this._socket.removeListener('data', this._receiver.add);
+
       this._closeFrameReceived = true;
       this._closeMessage = reason;
       this._closeCode = code;
@@ -182,41 +184,32 @@ class WebSocket extends EventEmitter {
     this._finalized = true;
 
     if (typeof error === 'object') this.emit('error', error);
-    if (!this._socket) return this.emitClose();
+    if (!this._socket) {
+      this.readyState = WebSocket.CLOSED;
+      this.emit('close', this._closeCode, this._closeMessage);
+      return;
+    }
 
     clearTimeout(this._closeTimer);
-    this._closeTimer = null;
-
-    this._ultron.destroy();
-    this._ultron = null;
 
+    this._socket.removeListener('data', this._receiver.add);
+    this._socket.removeListener('close', this._finalize);
+    this._socket.removeListener('error', this._finalize);
+    this._socket.removeListener('end', this._finalize);
     this._socket.on('error', constants.NOOP);
 
     if (!error) this._socket.end();
     else this._socket.destroy();
 
-    this._socket = null;
-    this._sender = null;
+    this._receiver.cleanup(() => {
+      this.readyState = WebSocket.CLOSED;
 
-    this._receiver.cleanup(() => this.emitClose());
-    this._receiver = null;
-  }
-
-  /**
-   * Emit the `close` event.
-   *
-   * @private
-   */
-  emitClose () {
-    this.readyState = WebSocket.CLOSED;
-
-    this.emit('close', this._closeCode, this._closeMessage);
-
-    if (this._extensions[PerMessageDeflate.extensionName]) {
-      this._extensions[PerMessageDeflate.extensionName].cleanup();
-    }
+      if (this._extensions[PerMessageDeflate.extensionName]) {
+        this._extensions[PerMessageDeflate.extensionName].cleanup();
+      }
 
-    this.removeAllListeners();
+      this.emit('close', this._closeCode, this._closeMessage);
+    });
   }
 
   /**

test/receiver.test.js

@@ -443,19 +443,6 @@ describe('Receiver', function () {
     assert.deepStrictEqual(data, ['', 'Hello']);
   });
 
-  it('ignores data received after a close frame', function () {
-    const results = [];
-    const push = results.push.bind(results);
-    const p = new Receiver();
-
-    p.onclose = p.onmessage = push;
-
-    p.add(Buffer.from('8800', 'hex'));
-    p.add(Buffer.from('8100', 'hex'));
-
-    assert.deepStrictEqual(results, [1005, '']);
-  });
-
   it('raises an error when RSV1 is on and permessage-deflate is disabled', function (done) {
     const p = new Receiver();