--- /dev/null
+'use strict';
+
+const EventEmitter = require('events');
+const crypto = require('crypto');
+const http = require('http');
+const url = require('url');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const extension = require('./extension');
+const constants = require('./constants');
+const WebSocket = require('./websocket');
+
+/**
+ * Class representing a WebSocket server.
+ *
+ * @extends EventEmitter
+ */
+class WebSocketServer extends EventEmitter {
+ /**
+ * Create a `WebSocketServer` instance.
+ *
+ * @param {Object} options Configuration options
+ * @param {String} options.host The hostname where to bind the server
+ * @param {Number} options.port The port where to bind the server
+ * @param {http.Server} options.server A pre-created HTTP/S server to use
+ * @param {Function} options.verifyClient An hook to reject connections
+ * @param {Function} options.handleProtocols An hook to handle protocols
+ * @param {String} options.path Accept only connections matching this path
+ * @param {Boolean} options.noServer Enable no server mode
+ * @param {Boolean} options.clientTracking Specifies whether or not to track clients
+ * @param {(Boolean|Object)} options.perMessageDeflate Enable/disable permessage-deflate
+ * @param {Number} options.maxPayload The maximum allowed message size
+ * @param {Function} callback A listener for the `listening` event
+ */
+ constructor (options, callback) {
+ super();
+
+ options = Object.assign({
+ maxPayload: 100 * 1024 * 1024,
+ perMessageDeflate: false,
+ handleProtocols: null,
+ clientTracking: true,
+ verifyClient: null,
+ noServer: false,
+ backlog: null, // use default (511 as implemented in net.js)
+ server: null,
+ host: null,
+ path: null,
+ port: null
+ }, options);
+
+ if (options.port == null && !options.server && !options.noServer) {
+ throw new TypeError(
+ 'One of the "port", "server", or "noServer" options must be specified'
+ );
+ }
+
+ if (options.port != null) {
+ this._server = http.createServer((req, res) => {
+ const body = http.STATUS_CODES[426];
+
+ res.writeHead(426, {
+ 'Content-Length': body.length,
+ 'Content-Type': 'text/plain'
+ });
+ res.end(body);
+ });
+ this._server.listen(options.port, options.host, options.backlog, callback);
+ } else if (options.server) {
+ this._server = options.server;
+ }
+
+ if (this._server) {
+ this._removeListeners = addListeners(this._server, {
+ listening: this.emit.bind(this, 'listening'),
+ error: this.emit.bind(this, 'error'),
+ upgrade: (req, socket, head) => {
+ this.handleUpgrade(req, socket, head, (ws) => {
+ this.emit('connection', ws, req);
+ });
+ }
+ });
+ }
+
+ if (options.perMessageDeflate === true) options.perMessageDeflate = {};
+ if (options.clientTracking) this.clients = new Set();
+ this.options = options;
+ }
+
+ /**
+ * Returns the bound address, the address family name, and port of the server
+ * as reported by the operating system if listening on an IP socket.
+ * If the server is listening on a pipe or UNIX domain socket, the name is
+ * returned as a string.
+ *
+ * @return {(Object|String|null)} The address of the server
+ * @public
+ */
+ address () {
+ if (this.options.noServer) {
+ throw new Error('The server is operating in "noServer" mode');
+ }
+
+ if (!this._server) return null;
+ return this._server.address();
+ }
+
+ /**
+ * Close the server.
+ *
+ * @param {Function} cb Callback
+ * @public
+ */
+ close (cb) {
+ //
+ // Terminate all associated clients.
+ //
+ if (this.clients) {
+ for (const client of this.clients) client.terminate();
+ }
+
+ const server = this._server;
+
+ if (server) {
+ this._removeListeners();
+ this._removeListeners = this._server = null;
+
+ //
+ // Close the http server if it was internally created.
+ //
+ if (this.options.port != null) return server.close(cb);
+ }
+
+ if (cb) cb();
+ }
+
+ /**
+ * See if a given request should be handled by this server instance.
+ *
+ * @param {http.IncomingMessage} req Request object to inspect
+ * @return {Boolean} `true` if the request is valid, else `false`
+ * @public
+ */
+ shouldHandle (req) {
+ if (this.options.path && url.parse(req.url).pathname !== this.options.path) {
+ return false;
+ }
+
+ return true;
+ }
+
+ /**
+ * Handle a HTTP Upgrade request.
+ *
+ * @param {http.IncomingMessage} req The request object
+ * @param {net.Socket} socket The network socket between the server and client
+ * @param {Buffer} head The first packet of the upgraded stream
+ * @param {Function} cb Callback
+ * @public
+ */
+ handleUpgrade (req, socket, head, cb) {
+ socket.on('error', socketOnError);
+
+ const version = +req.headers['sec-websocket-version'];
+ const extensions = {};
+
+ if (
+ req.method !== 'GET' || req.headers.upgrade.toLowerCase() !== 'websocket' ||
+ !req.headers['sec-websocket-key'] || (version !== 8 && version !== 13) ||
+ !this.shouldHandle(req)
+ ) {
+ return abortHandshake(socket, 400);
+ }
+
+ if (this.options.perMessageDeflate) {
+ const perMessageDeflate = new PerMessageDeflate(
+ this.options.perMessageDeflate,
+ true,
+ this.options.maxPayload
+ );
+
+ try {
+ const offers = extension.parse(
+ req.headers['sec-websocket-extensions']
+ );
+
+ if (offers[PerMessageDeflate.extensionName]) {
+ perMessageDeflate.accept(offers[PerMessageDeflate.extensionName]);
+ extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
+ }
+ } catch (err) {
+ return abortHandshake(socket, 400);
+ }
+ }
+
+ //
+ // Optionally call external client verification handler.
+ //
+ if (this.options.verifyClient) {
+ const info = {
+ origin: req.headers[`${version === 8 ? 'sec-websocket-origin' : 'origin'}`],
+ secure: !!(req.connection.authorized || req.connection.encrypted),
+ req
+ };
+
+ if (this.options.verifyClient.length === 2) {
+ this.options.verifyClient(info, (verified, code, message, headers) => {
+ if (!verified) {
+ return abortHandshake(socket, code || 401, message, headers);
+ }
+
+ this.completeUpgrade(extensions, req, socket, head, cb);
+ });
+ return;
+ }
+
+ if (!this.options.verifyClient(info)) return abortHandshake(socket, 401);
+ }
+
+ this.completeUpgrade(extensions, req, socket, head, cb);
+ }
+
+ /**
+ * Upgrade the connection to WebSocket.
+ *
+ * @param {Object} extensions The accepted extensions
+ * @param {http.IncomingMessage} req The request object
+ * @param {net.Socket} socket The network socket between the server and client
+ * @param {Buffer} head The first packet of the upgraded stream
+ * @param {Function} cb Callback
+ * @private
+ */
+ completeUpgrade (extensions, req, socket, head, cb) {
+ //
+ // Destroy the socket if the client has already sent a FIN packet.
+ //
+ if (!socket.readable || !socket.writable) return socket.destroy();
+
+ const key = crypto.createHash('sha1')
+ .update(req.headers['sec-websocket-key'] + constants.GUID, 'binary')
+ .digest('base64');
+
+ const headers = [
+ 'HTTP/1.1 101 Switching Protocols',
+ 'Upgrade: websocket',
+ 'Connection: Upgrade',
+ `Sec-WebSocket-Accept: ${key}`
+ ];
+
+ const ws = new WebSocket(null);
+ var protocol = req.headers['sec-websocket-protocol'];
+
+ if (protocol) {
+ protocol = protocol.trim().split(/ *, */);
+
+ //
+ // Optionally call external protocol selection handler.
+ //
+ if (this.options.handleProtocols) {
+ protocol = this.options.handleProtocols(protocol, req);
+ } else {
+ protocol = protocol[0];
+ }
+
+ if (protocol) {
+ headers.push(`Sec-WebSocket-Protocol: ${protocol}`);
+ ws.protocol = protocol;
+ }
+ }
+
+ if (extensions[PerMessageDeflate.extensionName]) {
+ const params = extensions[PerMessageDeflate.extensionName].params;
+ const value = extension.format({
+ [PerMessageDeflate.extensionName]: [params]
+ });
+ headers.push(`Sec-WebSocket-Extensions: ${value}`);
+ ws._extensions = extensions;
+ }
+
+ //
+ // Allow external modification/inspection of handshake headers.
+ //
+ this.emit('headers', headers, req);
+
+ socket.write(headers.concat('\r\n').join('\r\n'));
+ socket.removeListener('error', socketOnError);
+
+ ws.setSocket(socket, head, this.options.maxPayload);
+
+ if (this.clients) {
+ this.clients.add(ws);
+ ws.on('close', () => this.clients.delete(ws));
+ }
+
+ cb(ws);
+ }
+}
+
+module.exports = WebSocketServer;
+
+/**
+ * Add event listeners on an `EventEmitter` using a map of <event, listener>
+ * pairs.
+ *
+ * @param {EventEmitter} server The event emitter
+ * @param {Object.<String, Function>} map The listeners to add
+ * @return {Function} A function that will remove the added listeners when called
+ * @private
+ */
+function addListeners (server, map) {
+ for (const event of Object.keys(map)) server.on(event, map[event]);
+
+ return function removeListeners () {
+ for (const event of Object.keys(map)) {
+ server.removeListener(event, map[event]);
+ }
+ };
+}
+
+/**
+ * Handle premature socket errors.
+ *
+ * @private
+ */
+function socketOnError () {
+ this.destroy();
+}
+
+/**
+ * Close the connection when preconditions are not fulfilled.
+ *
+ * @param {net.Socket} socket The socket of the upgrade request
+ * @param {Number} code The HTTP response status code
+ * @param {String} [message] The HTTP response body
+ * @param {Object} [headers] Additional HTTP response headers
+ * @private
+ */
+function abortHandshake (socket, code, message, headers) {
+ if (socket.writable) {
+ message = message || http.STATUS_CODES[code];
+ headers = Object.assign({
+ 'Connection': 'close',
+ 'Content-type': 'text/html',
+ 'Content-Length': Buffer.byteLength(message)
+ }, headers);
+
+ socket.write(
+ `HTTP/1.1 ${code} ${http.STATUS_CODES[code]}\r\n` +
+ Object.keys(headers).map(h => `${h}: ${headers[h]}`).join('\r\n') +
+ '\r\n\r\n' +
+ message
+ );
+ }
+
+ socket.removeListener('error', socketOnError);
+ socket.destroy();
+}
projects / VSoRC / .git / blobdiff