client.js
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'use strict';
var crypto = require('crypto'),
url = require('url'),
util = require('util'),
HttpParser = require('../http_parser'),
Base = require('./base'),
Hybi = require('./hybi'),
Proxy = require('./proxy');
var Client = function(_url, options) {
this.version = 'hybi-13';
Hybi.call(this, null, _url, options);
this.readyState = -1;
this._key = Client.generateKey();
this._accept = Hybi.generateAccept(this._key);
this._http = new HttpParser('response');
var uri = url.parse(this.url),
auth = uri.auth && new Buffer(uri.auth, 'utf8').toString('base64');
if (this.VALID_PROTOCOLS.indexOf(uri.protocol) < 0)
throw new Error(this.url + ' is not a valid WebSocket URL');
this._pathname = (uri.pathname || '/') + (uri.search || '');
this._headers.set('Host', uri.host);
this._headers.set('Upgrade', 'websocket');
this._headers.set('Connection', 'Upgrade');
this._headers.set('Sec-WebSocket-Key', this._key);
this._headers.set('Sec-WebSocket-Version', '13');
if (this._protocols.length > 0)
this._headers.set('Sec-WebSocket-Protocol', this._protocols.join(', '));
if (auth)
this._headers.set('Authorization', 'Basic ' + auth);
};
util.inherits(Client, Hybi);
Client.generateKey = function() {
return crypto.randomBytes(16).toString('base64');
};
var instance = {
VALID_PROTOCOLS: ['ws:', 'wss:'],
proxy: function(origin, options) {
return new Proxy(this, origin, options);
},
start: function() {
if (this.readyState !== -1) return false;
this._write(this._handshakeRequest());
this.readyState = 0;
return true;
},
parse: function(chunk) {
if (this.readyState === 3) return;
if (this.readyState > 0) return Hybi.prototype.parse.call(this, chunk);
this._http.parse(chunk);
if (!this._http.isComplete()) return;
this._validateHandshake();
if (this.readyState === 3) return;
this._open();
this.parse(this._http.body);
},
_handshakeRequest: function() {
var extensions = this._extensions.generateOffer();
if (extensions)
this._headers.set('Sec-WebSocket-Extensions', extensions);
var start = 'GET ' + this._pathname + ' HTTP/1.1',
headers = [start, this._headers.toString(), ''];
return new Buffer(headers.join('\r\n'), 'utf8');
},
_failHandshake: function(message) {
message = 'Error during WebSocket handshake: ' + message;
this.readyState = 3;
this.emit('error', new Error(message));
this.emit('close', new Base.CloseEvent(this.ERRORS.protocol_error, message));
},
_validateHandshake: function() {
this.statusCode = this._http.statusCode;
this.headers = this._http.headers;
if (this._http.error)
return this._failHandshake(this._http.error.message);
if (this._http.statusCode !== 101)
return this._failHandshake('Unexpected response code: ' + this._http.statusCode);
var headers = this._http.headers,
upgrade = headers['upgrade'] || '',
connection = headers['connection'] || '',
accept = headers['sec-websocket-accept'] || '',
protocol = headers['sec-websocket-protocol'] || '';
if (upgrade === '')
return this._failHandshake("'Upgrade' header is missing");
if (upgrade.toLowerCase() !== 'websocket')
return this._failHandshake("'Upgrade' header value is not 'WebSocket'");
if (connection === '')
return this._failHandshake("'Connection' header is missing");
if (connection.toLowerCase() !== 'upgrade')
return this._failHandshake("'Connection' header value is not 'Upgrade'");
if (accept !== this._accept)
return this._failHandshake('Sec-WebSocket-Accept mismatch');
this.protocol = null;
if (protocol !== '') {
if (this._protocols.indexOf(protocol) < 0)
return this._failHandshake('Sec-WebSocket-Protocol mismatch');
else
this.protocol = protocol;
}
try {
this._extensions.activate(this.headers['sec-websocket-extensions']);
} catch (e) {
return this._failHandshake(e.message);
}
}
};
for (var key in instance)
Client.prototype[key] = instance[key];
module.exports = Client;