[fix] Add `x-forward-*` headers for WebSocket requests. Closes #74

lib/node-http-proxy/http-proxy.js

@@ -351,6 +351,20 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, head, buffer)
     //
     return socket.destroy();
   }
+  
+  //
+  // Add common proxy headers to the request so that they can
+  // be availible to the proxy target server:
+  //
+  // * `x-forwarded-for`: IP Address of the original request
+  // * `x-forwarded-proto`: Protocol of the original request
+  // * `x-forwarded-port`: Port of the original request.
+  //
+  if (this.enable.xforward && req.connection && req.connection.socket) {
+    req.headers['x-forwarded-for']   = req.connection.remoteAddress || req.connection.socket.remoteAddress;
+    req.headers['x-forwarded-port']  = req.connection.remotePort || req.connection.socket.remotePort;
+    req.headers['x-forwarded-proto'] = req.connection.pair ? 'https' : 'http';
+  }
 
   //
   // Helper function for setting appropriate socket values: