/************************************************************************ * Copyright 2010-2015 Brian McKelvey. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ***********************************************************************/ var extend = require('./utils').extend; var utils = require('./utils'); var util = require('util'); var EventEmitter = require('events').EventEmitter; var WebSocketRequest = require('./websocket_request'); var WebSocketServer = function WebSocketServer(config) { // Superclass Constructor EventEmitter.call(this); this._handlers = { upgrade: this.handleUpgrade.bind(this), requestAccepted: this.handleRequestAccepted.bind(this), requestResolved: this.handleRequestResolved.bind(this) }; this.connections = []; this.pendingRequests = []; if (config) { this.mount(config); } }; util.inherits(WebSocketServer, EventEmitter); WebSocketServer.prototype.mount = function(config) { this.config = { // The http server instance to attach to. Required. httpServer: null, // 64KiB max frame size. maxReceivedFrameSize: 0x10000, // 1MiB max message size, only applicable if // assembleFragments is true maxReceivedMessageSize: 0x100000, // Outgoing messages larger than fragmentationThreshold will be // split into multiple fragments. fragmentOutgoingMessages: true, // Outgoing frames are fragmented if they exceed this threshold. // Default is 16KiB fragmentationThreshold: 0x4000, // If true, fragmented messages will be automatically assembled // and the full message will be emitted via a 'message' event. // If false, each frame will be emitted via a 'frame' event and // the application will be responsible for aggregating multiple // fragmented frames. Single-frame messages will emit a 'message' // event in addition to the 'frame' event. // Most users will want to leave this set to 'true' assembleFragments: true, // If this is true, websocket connections will be accepted // regardless of the path and protocol specified by the client. // The protocol accepted will be the first that was requested // by the client. Clients from any origin will be accepted. // This should only be used in the simplest of cases. You should // probably leave this set to 'false' and inspect the request // object to make sure it's acceptable before accepting it. autoAcceptConnections: false, // Whether or not the X-Forwarded-For header should be respected. // It's important to set this to 'true' when accepting connections // from untrusted clients, as a malicious client could spoof its // IP address by simply setting this header. It's meant to be added // by a trusted proxy or other intermediary within your own // infrastructure. // See: http://en.wikipedia.org/wiki/X-Forwarded-For ignoreXForwardedFor: false, // The Nagle Algorithm makes more efficient use of network resources // by introducing a small delay before sending small packets so that // multiple messages can be batched together before going onto the // wire. This however comes at the cost of latency, so the default // is to disable it. If you don't need low latency and are streaming // lots of small messages, you can change this to 'false' disableNagleAlgorithm: true, // The number of milliseconds to wait after sending a close frame // for an acknowledgement to come back before giving up and just // closing the socket. closeTimeout: 5000 }; extend(this.config, config); if (this.config.httpServer) { if (!Array.isArray(this.config.httpServer)) { this.config.httpServer = [this.config.httpServer]; } var upgradeHandler = this._handlers.upgrade; this.config.httpServer.forEach(function(httpServer) { httpServer.on('upgrade', upgradeHandler); }); } else { throw new Error('You must specify an httpServer on which to mount the WebSocket server.'); } }; WebSocketServer.prototype.unmount = function() { var upgradeHandler = this._handlers.upgrade; this.config.httpServer.forEach(function(httpServer) { httpServer.removeListener('upgrade', upgradeHandler); }); }; WebSocketServer.prototype.closeAllConnections = function() { this.connections.forEach(function(connection) { connection.close(); }); this.pendingRequests.forEach(function(request) { process.nextTick(function() { request.reject(503); // HTTP 503 Service Unavailable }); }); }; WebSocketServer.prototype.broadcast = function(data) { if (Buffer.isBuffer(data)) { this.broadcastBytes(data); } else if (typeof(data.toString) === 'function') { this.broadcastUTF(data); } }; WebSocketServer.prototype.broadcastUTF = function(utfData) { this.connections.forEach(function(connection) { connection.sendUTF(utfData); }); }; WebSocketServer.prototype.broadcastBytes = function(binaryData) { this.connections.forEach(function(connection) { connection.sendBytes(binaryData); }); }; WebSocketServer.prototype.shutDown = function() { this.unmount(); this.closeAllConnections(); }; WebSocketServer.prototype.handleUpgrade = function(request, socket) { var wsRequest = new WebSocketRequest(socket, request, this.config); try { wsRequest.readHandshake(); } catch(e) { wsRequest.reject( e.httpCode ? e.httpCode : 400, e.message, e.headers ); return; } this.pendingRequests.push(wsRequest); wsRequest.once('requestAccepted', this._handlers.requestAccepted); wsRequest.once('requestResolved', this._handlers.requestResolved); if (!this.config.autoAcceptConnections && utils.eventEmitterListenerCount(this, 'request') > 0) { this.emit('request', wsRequest); } else if (this.config.autoAcceptConnections) { wsRequest.accept(wsRequest.requestedProtocols[0], wsRequest.origin); } else { wsRequest.reject(404, 'No handler is configured to accept the connection.'); } }; WebSocketServer.prototype.handleRequestAccepted = function(connection) { var self = this; connection.once('close', function(closeReason, description) { self.handleConnectionClose(connection, closeReason, description); }); this.connections.push(connection); this.emit('connect', connection); }; WebSocketServer.prototype.handleConnectionClose = function(connection, closeReason, description) { var index = this.connections.indexOf(connection); if (index !== -1) { this.connections.splice(index, 1); } this.emit('close', connection, closeReason, description); }; WebSocketServer.prototype.handleRequestResolved = function(request) { var index = this.pendingRequests.indexOf(request); if (index !== -1) { this.pendingRequests.splice(index, 1); } }; module.exports = WebSocketServer;