Merge pull request #688 from agilethomas/hixie76_haproxy

Fix for #687 Hixie-76 doesn't work behind HAProxy

Author: 3rd-Eden

lib/WebSocketServer.js

@@ -369,8 +369,42 @@ function handleHixieUpgrade(req, socket, upgradeHead, cb) {
     var location = ((req.headers['x-forwarded-proto'] === 'https' || socket.encrypted) ? 'wss' : 'ws') + '://' + wshost + req.url
       , protocol = req.headers['sec-websocket-protocol'];
 
+    // build the response header and return a Buffer
+    var buildResponseHeader = function() {
+      var headers = [
+          'HTTP/1.1 101 Switching Protocols'
+        , 'Upgrade: WebSocket'
+        , 'Connection: Upgrade'
+        , 'Sec-WebSocket-Location: ' + location
+      ];
+      if (typeof protocol != 'undefined') headers.push('Sec-WebSocket-Protocol: ' + protocol);
+      if (typeof origin != 'undefined') headers.push('Sec-WebSocket-Origin: ' + origin);
+
+      return new Buffer(headers.concat('', '').join('\r\n'));
+    };
+
+    // send handshake response before receiving the nonce
+    var handshakeResponse = function() {
+
+      socket.setTimeout(0);
+      socket.setNoDelay(true);
+
+      var headerBuffer = buildResponseHeader();
+
+      try {
+        socket.write(headerBuffer, 'binary', function(err) {
+          // remove listener if there was an error
+          if (err) socket.removeListener('data', handler);
+          return;
+        });
+      } catch (e) {
+        try { socket.destroy(); } catch (e) {}
+        return;
+      };
+    };
+
     // handshake completion code to run once nonce has been successfully retrieved
-    var completeHandshake = function(nonce, rest) {
+    var completeHandshake = function(nonce, rest, headerBuffer) {
       // calculate key
       var k1 = req.headers['sec-websocket-key1']
         , k2 = req.headers['sec-websocket-key2']
@@ -392,20 +426,10 @@ function handleHixieUpgrade(req, socket, upgradeHead, cb) {
       });
       md5.update(nonce.toString('binary'));
 
-      var headers = [
-          'HTTP/1.1 101 Switching Protocols'
-        , 'Upgrade: WebSocket'
-        , 'Connection: Upgrade'
-        , 'Sec-WebSocket-Location: ' + location
-      ];
-      if (typeof protocol != 'undefined') headers.push('Sec-WebSocket-Protocol: ' + protocol);
-      if (typeof origin != 'undefined') headers.push('Sec-WebSocket-Origin: ' + origin);
-
       socket.setTimeout(0);
       socket.setNoDelay(true);
+
       try {
-        // merge header and hash buffer
-        var headerBuffer = new Buffer(headers.concat('', '').join('\r\n'));
         var hashBuffer = new Buffer(md5.digest('binary'), 'binary');
         var handshakeBuffer = new Buffer(headerBuffer.length + hashBuffer.length);
         headerBuffer.copy(handshakeBuffer, 0);
@@ -444,11 +468,10 @@ function handleHixieUpgrade(req, socket, upgradeHead, cb) {
     if (upgradeHead && upgradeHead.length >= nonceLength) {
       var nonce = upgradeHead.slice(0, nonceLength);
       var rest = upgradeHead.length > nonceLength ? upgradeHead.slice(nonceLength) : null;
-      completeHandshake.call(self, nonce, rest);
+      completeHandshake.call(self, nonce, rest, buildResponseHeader());
     }
     else {
-      // nonce not present in upgradeHead, so we must wait for enough data
-      // data to arrive before continuing
+      // nonce not present in upgradeHead
       var nonce = new Buffer(nonceLength);
       upgradeHead.copy(nonce, 0);
       var received = upgradeHead.length;
@@ -461,10 +484,17 @@ function handleHixieUpgrade(req, socket, upgradeHead, cb) {
         if (received == nonceLength) {
           socket.removeListener('data', handler);
           if (toRead < data.length) rest = data.slice(toRead);
-          completeHandshake.call(self, nonce, rest);
+
+          // complete the handshake but send empty buffer for headers since they have already been sent
+          completeHandshake.call(self, nonce, rest, new Buffer(0));
         }
       }
+
+      // handle additional data as we receive it
       socket.on('data', handler);
+
+      // send header response before we have the nonce to fix haproxy buffering
+      handshakeResponse();
     }
   }