From af2c727b416c941bf64228048ce83da0bea540d1 Mon Sep 17 00:00:00 2001
From: Roman Shtylman <shtylman@gmail.com>
Date: Wed, 6 Nov 2013 23:06:59 -0500
Subject: [PATCH] fix upstream client disconnect handling

When upstream client disconnects, kill any waiting connections. This is
needed to inform the browser that the upstream connection is no longer
available and to close the socket so a new one will be created for new
requests.
---
 server.js | 44 +++++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/server.js b/server.js
index c59cf37..8ae0d9e 100644
--- a/server.js
+++ b/server.js
@@ -51,13 +51,29 @@ function maybe_bounce(req, res, bounce) {
 
     ++stats.requests;
 
-    res.on('close', function() {
+    res.once('close', function() {
         --stats.requests;
     });
 
     // get client port
     client.next_socket(function(socket, done) {
-        var stream = bounce(socket); //, { headers: { connection: 'close' } });
+        // happens when client upstream is disconnected
+        // we gracefully inform the user and kill their conn
+        // without this, the browser will leave some connections open
+        // and try to use them again for new requests
+        // we cannot have this as we need bouncy to assign the requests again
+        if (!socket) {
+            res.statusCode = 504;
+            res.end();
+            req.connection.destroy();
+            return;
+        }
+
+        var stream = bounce(socket, { headers: { connection: 'close' } });
+
+        stream.on('error', function(err) {
+            socket.destroy();
+        });
 
         // return the socket to the client pool
         stream.once('end', function() {
@@ -122,6 +138,7 @@ module.exports = function(opt) {
 
     app.use('/css/widgets.css', makeup(__dirname + '/static/css/widgets.css'));
     app.use(express.static(__dirname + '/static'));
+
     app.use(app.router);
 
     app.get('/', function(req, res, next) {
@@ -143,9 +160,17 @@ module.exports = function(opt) {
         });
     });
 
+    app.get('/', function(req, res, next) {
+        return res.render('index');
+    });
+
     app.get('/:req_id', function(req, res, next) {
         var req_id = req.param('req_id');
 
+        if (! /[a-z]{4}/.test(req_id)) {
+            return next();
+        }
+
         debug('making new client with id %s', req_id);
         new_client(req_id, opt, function(err, info) {
             if (err) {
@@ -160,8 +185,9 @@ module.exports = function(opt) {
 
     });
 
-    app.get('/', function(req, res, next) {
-        return res.render('index');
+    var app_port = 0;
+    var app_server = app.listen(app_port, function() {
+        app_port = app_server.address().port;
     });
 
     // connected engine.io sockets for stats updates
@@ -173,7 +199,7 @@ module.exports = function(opt) {
         });
     }, 1000);
 
-    var eio_server = new engine.Server();
+    var eio_server = engine.attach(app_server);
     eio_server.on('connection', function (socket) {
 
         eio_sockets.push(socket);
@@ -189,14 +215,6 @@ module.exports = function(opt) {
         });
     });
 
-    app.use('/engine.io', function(req, res, next) {
-        eio_server.handleRequest(req, res);
-    });
-
-    var app_port = 0;
-    var app_server = app.listen(app_port, function() {
-        app_port = app_server.address().port;
-    });
 
     var server = bouncy(function(req, res, bounce) {
         debug('request %s', req.url);