From 9c1216eb637b61606d3ea4695144e0c65fc579f2 Mon Sep 17 00:00:00 2001
From: barisusakli <barisusakli@gmail.com>
Date: Wed, 19 Nov 2014 15:55:01 -0500
Subject: [PATCH] closes #2432

---
 src/middleware/middleware.js |  3 ++-
 src/middleware/ratelimit.js  | 35 +++++++++++++++++++++++++++++++++++
 src/socket.io/index.js       | 26 ++++++++++++++++----------
 3 files changed, 53 insertions(+), 11 deletions(-)
 create mode 100644 src/middleware/ratelimit.js

diff --git a/src/middleware/middleware.js b/src/middleware/middleware.js
index 89c954bccd..315d7cddf6 100644
--- a/src/middleware/middleware.js
+++ b/src/middleware/middleware.js
@@ -6,9 +6,11 @@ var app,
 	},
 	async = require('async'),
 	path = require('path'),
+	csrf = require('csurf'),
 	winston = require('winston'),
 	validator = require('validator'),
 	nconf = require('nconf'),
+
 	plugins = require('./../plugins'),
 	meta = require('./../meta'),
 	translator = require('./../../public/src/translator'),
@@ -18,7 +20,6 @@ var app,
 	topics = require('./../topics'),
 	messaging = require('../messaging'),
 	ensureLoggedIn = require('connect-ensure-login'),
-	csrf = require('csurf'),
 
 	controllers = {
 		api: require('./../controllers/api')
diff --git a/src/middleware/ratelimit.js b/src/middleware/ratelimit.js
new file mode 100644
index 0000000000..a468c97662
--- /dev/null
+++ b/src/middleware/ratelimit.js
@@ -0,0 +1,35 @@
+
+
+'use strict';
+var winston = require('winston');
+
+var ratelimit = {};
+
+var allowedCallsPerSecond = 10;
+
+
+ratelimit.isFlooding = function(socket) {
+	socket.callsPerSecond = socket.callsPerSecond || 0;
+	socket.elapsedTime = socket.elapsedTime || 0;
+	socket.lastCallTime = socket.lastCallTime || Date.now();
+
+	++socket.callsPerSecond;
+
+	var now = Date.now();
+	socket.elapsedTime += now - socket.lastCallTime;
+
+	if (socket.callsPerSecond > allowedCallsPerSecond && socket.elapsedTime < 1000) {
+		winston.warn('Flooding detected! Calls : ' + socket.callsPerSecond + ', Duration : ' + socket.elapsedTime);
+		return true;
+	}
+
+	if (socket.elapsedTime >= 1000) {
+		socket.elapsedTime = 0;
+		socket.callsPerSecond = 0;
+	}
+
+	socket.lastCallTime = now;
+	return false;
+};
+
+module.exports = ratelimit;
\ No newline at end of file
diff --git a/src/socket.io/index.js b/src/socket.io/index.js
index c58ce1dc95..b13b584ba3 100644
--- a/src/socket.io/index.js
+++ b/src/socket.io/index.js
@@ -15,6 +15,7 @@ var	SocketIO = require('socket.io'),
 	topics = require('../topics'),
 	logger = require('../logger'),
 	meta = require('../meta'),
+	ratelimit = require('../middleware/ratelimit'),
 
 	Sockets = {},
 	Namespaces = {};
@@ -195,16 +196,13 @@ Sockets.init = function(server) {
 		});
 
 		socket.on('*', function(payload, callback) {
-			function callMethod(method) {
-				method.call(null, socket, payload.args.length ? payload.args[0] : null, function(err, result) {
-					if (callback) {
-						callback(err?{message:err.message}:null, result);
-					}
-				});
+			if (!payload.name) {
+				return winston.warn('[socket.io] Empty method name');
 			}
 
-			if(!payload.name) {
-				return winston.warn('[socket.io] Empty method name');
+			if (ratelimit.isFlooding(socket)) {
+				winston.warn('[socket.io] Too many emits! Disconnecting ' + socket.uid);
+				return socket.disconnect();
 			}
 
 			var parts = payload.name.toString().split('.'),
@@ -226,15 +224,23 @@ Sockets.init = function(server) {
 
 			if (Namespaces[namespace].before) {
 				Namespaces[namespace].before(socket, payload.name, function() {
-					callMethod(methodToCall);
+					callMethod(methodToCall, socket, payload, callback);
 				});
 			} else {
-				callMethod(methodToCall);
+				callMethod(methodToCall, socket, payload, callback);
 			}
 		});
 	});
 };
 
+function callMethod(method, socket, payload, callback) {
+	method.call(null, socket, payload.args.length ? payload.args[0] : null, function(err, result) {
+		if (callback) {
+			callback(err ? {message: err.message} : null, result);
+		}
+	});
+}
+
 Sockets.logoutUser = function(uid) {
 	Sockets.getUserSockets(uid).forEach(function(socket) {
 		if (socket.handshake && socket.handshake.signedCookies && socket.handshake.signedCookies['express.sid']) {