[fix] Manage bookkeeping for incoming requests to the underlying sock…

…ets behind reverse proxied websocket events. Only use the appropriate variables in the closure scope of the `upgrade` event from this bookkeeping

lib/node-http-proxy.js

@@ -530,24 +530,30 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, head, options
  }
  }
 
- function onUpgrade(reverseProxy) {
+ function onUpgrade(out, reverseProxy) {
+ if (!out) {
+ reverseProxy.end();
+ socket.end();
+ return;
+ }
+
  var listeners = {};
 
  // We're now connected to the server, so lets change server socket
  reverseProxy.on('data', listeners._r_data = function(data) {
  // Pass data to client
- if (socket.writable) {
+ if (out.incoming.socket.writable) {
  try {
- socket.write(data);
+ out.incoming.socket.write(data);
  } 
  catch (e) {
- socket.end();
+ out.incoming.socket.end();
  reverseProxy.end();
  }
  }
  });
 
- socket.on('data', listeners._data = function(data) {
+ out.incoming.socket.on('data', listeners._data = function(data) {
  // Pass data from client to server
  try {
  reverseProxy.write(data);
@@ -562,13 +568,13 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, head, options
  function detach() {
  reverseProxy.removeListener('close', listeners._r_close);
  reverseProxy.removeListener('data', listeners._r_data);
- socket.removeListener('data', listeners._data);
- socket.removeListener('close', listeners._close);
+ out.incoming.socket.removeListener('data', listeners._data);
+ out.incoming.socket.removeListener('close', listeners._close);
  }
 
  // Hook disconnections
  reverseProxy.on('end', listeners._r_close = function() {
- socket.end();
+ out.incoming.socket.end();
  detach();
  });
 
@@ -592,27 +598,47 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, head, options
  outgoing = {
  host: options.host,
  port: options.port,
- agent: agent,
  method: 'GET',
  path: req.url,
- headers: req.headers
+ headers: req.headers,
  };
 
  // Make the outgoing WebSocket request
- var request = http.request(outgoing, function () { });
-
- // Not disconnect on update
- agent.on('upgrade', function(request, remoteSocket, head) {
- // Prepare socket
- _socket(remoteSocket, true);
+ var request = agent.appendMessage(outgoing);
 
- // Emit event
- onUpgrade(remoteSocket);
- });
+ //
+ // Here we set the incoming `req`, `socket` and `head` data to the outgoing
+ // request so that we can reuse this data later on in the closure scope
+ // available to the `upgrade` event. This bookkeeping is not tracked anywhere 
+ // in nodejs core and is **very** specific to proxying WebSockets.
+ //
+ request.agent = agent;
+ request.incoming = {
+ request: req,
+ socket: socket,
+ head: head
+ };
+
+ //
+ // If the agent for this particular `host` and `port` combination
+ // is not already listening for the `upgrade` event, then do so once.
+ // This will force us not to disconnect. 
+ //
+ // In addition, it's important to note the closure scope here. Since
+ // there is no mapping of the 
+ //
+ if (!agent._events || agent._events['upgrade'].length === 0) {
+ agent.on('upgrade', function (out, remoteSocket, head) {
+ // Prepare socket
+ _socket(remoteSocket, true);
+
+ // Emit event
+ onUpgrade(remoteSocket._httpMessage, remoteSocket);
+ });
+ }
 
- var handshake;
  if (typeof request.socket !== 'undefined') {
- request.socket.on('data', handshake = function(data) {
+ request.socket.on('data', function handshake (data) {
  // Handshaking
 
  // Ok, kind of harmfull part of code