/************************************************************************
* 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 util = require('util');
var utils = require('./utils');
var unit_lib = require('./build/Release/unit-http');
var EventEmitter = require('events').EventEmitter;
var WebSocketFrame = require('./websocket_frame');
var bufferAllocUnsafe = utils.bufferAllocUnsafe;
var bufferFromString = utils.bufferFromString;
// Connected, fully-open, ready to send and receive frames
const STATE_OPEN = 'open';
// Received a close frame from the remote peer
const STATE_PEER_REQUESTED_CLOSE = 'peer_requested_close';
// Sent close frame to remote peer. No further data can be sent.
const STATE_ENDING = 'ending';
// Connection is fully closed. No further data can be sent or received.
const STATE_CLOSED = 'closed';
var idCounter = 0;
function WebSocketConnection(socket, extensions, protocol, maskOutgoingPackets, config) {
this._debug = utils.BufferingLogger('websocket:connection', ++idCounter);
this._debug('constructor');
if (this._debug.enabled) {
instrumentSocketForDebugging(this, socket);
}
// Superclass Constructor
EventEmitter.call(this);
this._pingListenerCount = 0;
this.on('newListener', function(ev) {
if (ev === 'ping'){
this._pingListenerCount++;
}
}).on('removeListener', function(ev) {
if (ev === 'ping') {
this._pingListenerCount--;
}
});
this.config = config;
this.socket = socket;
this.protocol = protocol;
this.extensions = extensions;
this.remoteAddress = socket.remoteAddress;
this.closeReasonCode = -1;
this.closeDescription = null;
this.closeEventEmitted = false;
// We have to mask outgoing packets if we're acting as a WebSocket client.
this.maskOutgoingPackets = maskOutgoingPackets;
this.fragmentationSize = 0; // data received so far...
this.frameQueue = [];
// Various bits of connection state
this.connected = true;
this.state = STATE_OPEN;
this.waitingForCloseResponse = false;
// Received TCP FIN, socket's readable stream is finished.
this.receivedEnd = false;
this.closeTimeout = this.config.closeTimeout;
this.assembleFragments = this.config.assembleFragments;
this.maxReceivedMessageSize = this.config.maxReceivedMessageSize;
this.outputBufferFull = false;
this.inputPaused = false;
this._closeTimerHandler = this.handleCloseTimer.bind(this);
// Disable nagle algorithm?
this.socket.setNoDelay(this.config.disableNagleAlgorithm);
// Make sure there is no socket inactivity timeout
this.socket.setTimeout(0);
// The HTTP Client seems to subscribe to socket error events
// and re-dispatch them in such a way that doesn't make sense
// for users of our client, so we want to make sure nobody
// else is listening for error events on the socket besides us.
this.socket.removeAllListeners('error');
this._set_sock(this.socket);
}
WebSocketConnection.prototype._set_sock = unit_lib.websocket_set_sock;
WebSocketConnection.prototype._end = unit_lib.response_end;
WebSocketConnection.CLOSE_REASON_NORMAL = 1000;
WebSocketConnection.CLOSE_REASON_GOING_AWAY = 1001;
WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR = 1002;
WebSocketConnection.CLOSE_REASON_UNPROCESSABLE_INPUT = 1003;
WebSocketConnection.CLOSE_REASON_RESERVED = 1004; // Reserved value. Undefined meaning.
WebSocketConnection.CLOSE_REASON_NOT_PROVIDED = 1005; // Not to be used on the wire
WebSocketConnection.CLOSE_REASON_ABNORMAL = 1006; // Not to be used on the wire
WebSocketConnection.CLOSE_REASON_INVALID_DATA = 1007;
WebSocketConnection.CLOSE_REASON_POLICY_VIOLATION = 1008;
WebSocketConnection.CLOSE_REASON_MESSAGE_TOO_BIG = 1009;
WebSocketConnection.CLOSE_REASON_EXTENSION_REQUIRED = 1010;
WebSocketConnection.CLOSE_REASON_INTERNAL_SERVER_ERROR = 1011;
WebSocketConnection.CLOSE_REASON_TLS_HANDSHAKE_FAILED = 1015; // Not to be used on the wire
WebSocketConnection.CLOSE_DESCRIPTIONS = {
1000: 'Normal connection closure',
1001: 'Remote peer is going away',
1002: 'Protocol error',
1003: 'Unprocessable input',
1004: 'Reserved',
1005: 'Reason not provided',
1006: 'Abnormal closure, no further detail available',
1007: 'Invalid data received',
1008: 'Policy violation',
1009: 'Message too big',
1010: 'Extension requested by client is required',
1011: 'Internal Server Error',
1015: 'TLS Handshake Failed'
};
function validateCloseReason(code) {
if (code < 1000) {
// Status codes in the range 0-999 are not used
return false;
}
if (code >= 1000 && code <= 2999) {
// Codes from 1000 - 2999 are reserved for use by the protocol. Only
// a few codes are defined, all others are currently illegal.
return [1000, 1001, 1002, 1003, 1007, 1008, 1009, 1010, 1011, 1012, 1013, 1014].indexOf(code) !== -1;
}
if (code >= 3000 && code <= 3999) {
// Reserved for use by libraries, frameworks, and applications.
// Should be registered with IANA. Interpretation of these codes is
// undefined by the WebSocket protocol.
return true;
}
if (code >= 4000 && code <= 4999) {
// Reserved for private use. Interpretation of these codes is
// undefined by the WebSocket protocol.
return true;
}
if (code >= 5000) {
return false;
}
}
util.inherits(WebSocketConnection, EventEmitter);
WebSocketConnection.prototype._addSocketEventListeners = function() {
this.socket.on('error', this.handleSocketError.bind(this));
this.socket.on('end', this.handleSocketEnd.bind(this));
this.socket.on('close', this.handleSocketClose.bind(this));
};
WebSocketConnection.prototype.handleSocketError = function(error) {
this._debug('handleSocketError: %j', error);
if (this.state === STATE_CLOSED) {
// See https://github.com/theturtle32/WebSocket-Node/issues/288
this._debug(' --- Socket \'error\' after \'close\'');
return;
}
this.closeReasonCode = WebSocketConnection.CLOSE_REASON_ABNORMAL;
this.closeDescription = 'Socket Error: ' + error.syscall + ' ' + error.code;
this.connected = false;
this.state = STATE_CLOSED;
this.fragmentationSize = 0;
if (utils.eventEmitterListenerCount(this, 'error') > 0) {
this.emit('error', error);
}
this.socket.destroy(error);
this._debug.printOutput();
this._end();
};
WebSocketConnection.prototype.handleSocketEnd = function() {
this._debug('handleSocketEnd: received socket end. state = %s', this.state);
this.receivedEnd = true;
if (this.state === STATE_CLOSED) {
// When using the TLS module, sometimes the socket will emit 'end'
// after it emits 'close'. I don't think that's correct behavior,
// but we should deal with it gracefully by ignoring it.
this._debug(' --- Socket \'end\' after \'close\'');
return;
}
if (this.state !== STATE_PEER_REQUESTED_CLOSE &&
this.state !== STATE_ENDING) {
this._debug(' --- UNEXPECTED socket end.');
this.socket.end();
this._end();
}
};
WebSocketConnection.prototype.handleSocketClose = function(hadError) {
this._debug('handleSocketClose: received socket close');
this.socketHadError = hadError;
this.connected = false;
this.state = STATE_CLOSED;
// If closeReasonCode is still set to -1 at this point then we must
// not have received a close frame!!
if (this.closeReasonCode === -1) {
this.closeReasonCode = WebSocketConnection.CLOSE_REASON_ABNORMAL;
this.closeDescription = 'Connection dropped by remote peer.';
}
this.clearCloseTimer();
if (!this.closeEventEmitted) {
this.closeEventEmitted = true;
this._debug('-- Emitting WebSocketConnection close event');
this.emit('close', this.closeReasonCode, this.closeDescription);
}
};
WebSocketConnection.prototype.close = function(reasonCode, description) {
if (this.connected) {
this._debug('close: Initating clean WebSocket close sequence.');
if ('number' !== typeof reasonCode) {
reasonCode = WebSocketConnection.CLOSE_REASON_NORMAL;
}
if (!validateCloseReason(reasonCode)) {
throw new Error('Close code ' + reasonCode + ' is not valid.');
}
if ('string' !== typeof description) {
description = WebSocketConnection.CLOSE_DESCRIPTIONS[reasonCode];
}
this.closeReasonCode = reasonCode;
this.closeDescription = description;
this.setCloseTimer();
this.sendCloseFrame(this.closeReasonCode, this.closeDescription);
this.state = STATE_ENDING;
this.connected = false;
}
};
WebSocketConnection.prototype.drop = function(reasonCode, description, skipCloseFrame) {
this._debug('drop');
if (typeof(reasonCode) !== 'number') {
reasonCode = WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR;
}
if (typeof(description) !== 'string') {
// If no description is provided, try to look one up based on the
// specified reasonCode.
description = WebSocketConnection.CLOSE_DESCRIPTIONS[reasonCode];
}
this._debug('Forcefully dropping connection. skipCloseFrame: %s, code: %d, description: %s',
skipCloseFrame, reasonCode, description
);
this.closeReasonCode = reasonCode;
this.closeDescription = description;
this.frameQueue = [];
this.fragmentationSize = 0;
if (!skipCloseFrame) {
this.sendCloseFrame(reasonCode, description);
}
this.connected = false;
this.state = STATE_CLOSED;
this.clearCloseTimer();
if (!this.closeEventEmitted) {
this.closeEventEmitted = true;
this._debug('Emitting WebSocketConnection close event');
this.emit('close', this.closeReasonCode, this.closeDescription);
}
this._debug('Drop: destroying socket');
this.socket.destroy();
this._end();
};
WebSocketConnection.prototype.setCloseTimer = function() {
this._debug('setCloseTimer');
this.clearCloseTimer();
this._debug('Setting close timer');
this.waitingForCloseResponse = true;
this.closeTimer = setTimeout(this._closeTimerHandler, this.closeTimeout);
};
WebSocketConnection.prototype.clearCloseTimer = function() {
this._debug('clearCloseTimer');
if (this.closeTimer) {
this._debug('Clearing close timer');
clearTimeout(this.closeTimer);
this.waitingForCloseResponse = false;
this.closeTimer = null;
}
};
WebSocketConnection.prototype.handleCloseTimer = function() {
this._debug('handleCloseTimer');
this.closeTimer = null;
if (this.waitingForCloseResponse) {
this._debug('Close response not received from client. Forcing socket end.');
this.waitingForCloseResponse = false;
this.state = STATE_CLOSED;
this.socket.end();
this._end();
}
};
WebSocketConnection.prototype.processFrame = function(frame) {
if (!this.connected) {
return;
}
this._debug('processFrame');
this._debug(' -- frame: %s', frame);
// Any non-control opcode besides 0x00 (continuation) received in the
// middle of a fragmented message is illegal.
if (this.frameQueue.length !== 0 && (frame.opcode > 0x00 && frame.opcode < 0x08)) {
this.drop(WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR,
'Illegal frame opcode 0x' + frame.opcode.toString(16) + ' ' +
'received in middle of fragmented message.');
return;
}
switch(frame.opcode) {
case 0x02: // WebSocketFrame.BINARY_FRAME
this._debug('-- Binary Frame');
if (this.assembleFragments) {
if (frame.fin) {
// Complete single-frame message received
this._debug('---- Emitting \'message\' event');
this.emit('message', {
type: 'binary',
binaryData: frame.binaryPayload
});
}
else {
// beginning of a fragmented message
this.frameQueue.push(frame);
this.fragmentationSize = frame.length;
}
}
break;
case 0x01: // WebSocketFrame.TEXT_FRAME
this._debug('-- Text Frame');
if (this.assembleFragments) {
if (frame.fin) {
// Complete single-frame message received
this._debug('---- Emitting \'message\' event');
this.emit('message', {
type: 'utf8',
utf8Data: frame.binaryPayload.toString('utf8')
});
}
else {
// beginning of a fragmented message
this.frameQueue.push(frame);
this.fragmentationSize = frame.length;
}
}
break;
case 0x00: // WebSocketFrame.CONTINUATION
this._debug('-- Continuation Frame');
if (this.assembleFragments) {
if (this.frameQueue.length === 0) {
this.drop(WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR,
'Unexpected Continuation Frame');
return;
}
this.fragmentationSize += frame.length;
if (this.fragmentationSize > this.maxReceivedMessageSize) {
this.drop(WebSocketConnection.CLOSE_REASON_MESSAGE_TOO_BIG,
'Maximum message size exceeded.');
return;
}
this.frameQueue.push(frame);
if (frame.fin) {
// end of fragmented message, so we process the whole
// message now. We also have to decode the utf-8 data
// for text frames after combining all the fragments.
var bytesCopied = 0;
var binaryPayload = bufferAllocUnsafe(this.fragmentationSize);
var opcode = this.frameQueue[0].opcode;
this.frameQueue.forEach(function (currentFrame) {
currentFrame.binaryPayload.copy(binaryPayload, bytesCopied);
bytesCopied += currentFrame.binaryPayload.length;
});
this.frameQueue = [];
this.fragmentationSize = 0;
switch (opcode) {
case 0x02: // WebSocketOpcode.BINARY_FRAME
this.emit('message', {
type: 'binary',
binaryData: binaryPayload
});
break;
case 0x01: // WebSocketOpcode.TEXT_FRAME
this.emit('message', {
type: 'utf8',
utf8Data: binaryPayload.toString('utf8')
});
break;
default:
this.drop(WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR,
'Unexpected first opcode in fragmentation sequence: 0x' + opcode.toString(16));
return;
}
}
}
break;
case 0x09: // WebSocketFrame.PING
this._debug('-- Ping Frame');
if (this._pingListenerCount > 0) {
// logic to emit the ping frame: this is only done when a listener is known to exist
// Expose a function allowing the user to override the default ping() behavior
var cancelled = false;
var cancel = function() {
cancelled = true;
};
this.emit('ping', cancel, frame.binaryPayload);
// Only send a pong if the client did not indicate that he would like to cancel
if (!cancelled) {
this.pong(frame.binaryPayload);
}
}
else {
this.pong(frame.binaryPayload);
}
break;
case 0x0A: // WebSocketFrame.PONG
this._debug('-- Pong Frame');
this.emit('pong', frame.binaryPayload);
break;
case 0x08: // WebSocketFrame.CONNECTION_CLOSE
this._debug('-- Close Frame');
if (this.waitingForCloseResponse) {
// Got response to our request to close the connection.
// Close is complete, so we just hang up.
this._debug('---- Got close response from peer. Completing closing handshake.');
this.clearCloseTimer();
this.waitingForCloseResponse = false;
this.state = STATE_CLOSED;
this.socket.end();
this._end();
return;
}
this._debug('---- Closing handshake initiated by peer.');
// Got request from other party to close connection.
// Send back acknowledgement and then hang up.
this.state = STATE_PEER_REQUESTED_CLOSE;
var respondCloseReasonCode;
// Make sure the close reason provided is legal according to
// the protocol spec. Providing no close status is legal.
// WebSocketFrame sets closeStatus to -1 by default, so if it
// is still -1, then no status was provided.
if (frame.invalidCloseFrameLength) {
this.closeReasonCode = 1005; // 1005 = No reason provided.
respondCloseReasonCode = WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR;
}
else if (frame.closeStatus === -1 || validateCloseReason(frame.closeStatus)) {
this.closeReasonCode = frame.closeStatus;
respondCloseReasonCode = WebSocketConnection.CLOSE_REASON_NORMAL;
}
else {
this.closeReasonCode = frame.closeStatus;
respondCloseReasonCode = WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR;
}
// If there is a textual description in the close frame, extract it.
if (frame.binaryPayload.length > 1) {
this.closeDescription = frame.binaryPayload.toString('utf8');
}
else {
this.closeDescription = WebSocketConnection.CLOSE_DESCRIPTIONS[this.closeReasonCode];
}
this._debug(
'------ Remote peer %s - code: %d - %s - close frame payload length: %d',
this.remoteAddress, this.closeReasonCode,
this.closeDescription, frame.length
);
this._debug('------ responding to remote peer\'s close request.');
this.drop(respondCloseReasonCode, null);
this.connected = false;
break;
default:
this._debug('-- Unrecognized Opcode %d', frame.opcode);
this.drop(WebSocketConnection.CLOSE_REASON_PROTOCOL_ERROR,
'Unrecognized Opcode: 0x' + frame.opcode.toString(16));
break;
}
};
WebSocketConnection.prototype.send = function(data, cb) {
this._debug('send');
if (Buffer.isBuffer(data)) {
this.sendBytes(data, cb);
}
else if (typeof(data['toString']) === 'function') {
this.sendUTF(data, cb);
}
else {
throw new Error('Data provided must either be a Node Buffer or implement toString()');
}
};
WebSocketConnection.prototype.sendUTF = function(data, cb) {
data = bufferFromString(data.toString(), 'utf8');
this._debug('sendUTF: %d bytes', data.length);
var frame = new WebSocketFrame();
frame.opcode = 0x01; // WebSocketOpcode.TEXT_FRAME
frame.binaryPayload = data;
this.fragmentAndSend(frame, cb);
};
WebSocketConnection.prototype.sendBytes = function(data, cb) {
this._debug('sendBytes');
if (!Buffer.isBuffer(data)) {
throw new Error('You must pass a Node Buffer object to WebSocketConnection.prototype.sendBytes()');
}
var frame = new WebSocketFrame();
frame.opcode = 0x02; // WebSocketOpcode.BINARY_FRAME
frame.binaryPayload = data;
this.fragmentAndSend(frame, cb);
};
WebSocketConnection.prototype.ping = function(data) {
this._debug('ping');
var frame = new WebSocketFrame();
frame.opcode = 0x09; // WebSocketOpcode.PING
frame.fin = true;
if (data) {
if (!Buffer.isBuffer(data)) {
data = bufferFromString(data.toString(), 'utf8');
}
if (data.length > 125) {
this._debug('WebSocket: Data for ping is longer than 125 bytes. Truncating.');
data = data.slice(0,124);
}
frame.binaryPayload = data;
}
this.sendFrame(frame);
};
// Pong frames have to echo back the contents of the data portion of the
// ping frame exactly, byte for byte.
WebSocketConnection.prototype.pong = function(binaryPayload) {
this._debug('pong');
var frame = new WebSocketFrame();
frame.opcode = 0x0A; // WebSocketOpcode.PONG
if (Buffer.isBuffer(binaryPayload) && binaryPayload.length > 125) {
this._debug('WebSocket: Data for pong is longer than 125 bytes. Truncating.');
binaryPayload = binaryPayload.slice(0,124);
}
frame.binaryPayload = binaryPayload;
frame.fin = true;
this.sendFrame(frame);
};
WebSocketConnection.prototype.fragmentAndSend = function(frame, cb) {
this._debug('fragmentAndSend');
if (frame.opcode > 0x07) {
throw new Error('You cannot fragment control frames.');
}
var threshold = this.config.fragmentationThreshold;
var length = frame.binaryPayload.length;
// Send immediately if fragmentation is disabled or the message is not
// larger than the fragmentation threshold.
if (!this.config.fragmentOutgoingMessages || (frame.binaryPayload && length <= threshold)) {
frame.fin = true;
this.sendFrame(frame, cb);
return;
}
var numFragments = Math.ceil(length / threshold);
var sentFragments = 0;
var sentCallback = function fragmentSentCallback(err) {
if (err) {
if (typeof cb === 'function') {
// pass only the first error
cb(err);
cb = null;
}
return;
}
++sentFragments;
if ((sentFragments === numFragments) && (typeof cb === 'function')) {
cb();
}
};
for (var i=1; i <= numFragments; i++) {
var currentFrame = new WebSocketFrame();
// continuation opcode except for first frame.
currentFrame.opcode = (i === 1) ? frame.opcode : 0x00;
// fin set on last frame only
currentFrame.fin = (i === numFragments);
// length is likely to be shorter on the last fragment
var currentLength = (i === numFragments) ? length - (threshold * (i-1)) : threshold;
var sliceStart = threshold * (i-1);
// Slice the right portion of the original payload
currentFrame.binaryPayload = frame.binaryPayload.slice(sliceStart, sliceStart + currentLength);
this.sendFrame(currentFrame, sentCallback);
}
};
WebSocketConnection.prototype.sendCloseFrame = function(reasonCode, description, cb) {
if (typeof(reasonCode) !== 'number') {
reasonCode = WebSocketConnection.CLOSE_REASON_NORMAL;
}
this._debug('sendCloseFrame state: %s, reasonCode: %d, description: %s', this.state, reasonCode, description);
if (this.state !== STATE_OPEN && this.state !== STATE_PEER_REQUESTED_CLOSE) { return; }
var frame = new WebSocketFrame();
frame.fin = true;
frame.opcode = 0x08; // WebSocketOpcode.CONNECTION_CLOSE
frame.closeStatus = reasonCode;
if (typeof(description) === 'string') {
frame.binaryPayload = bufferFromString(description, 'utf8');
}
this.sendFrame(frame, cb);
this.socket.end();
};
WebSocketConnection.prototype._send_frame = unit_lib.websocket_send_frame;
WebSocketConnection.prototype.sendFrame = function(frame, cb) {
this._debug('sendFrame');
frame.mask = this.maskOutgoingPackets;
this._send_frame(frame);
if (typeof cb === 'function') {
cb();
}
var flushed = 0; // this.socket.write(frame.toBuffer(), cb);
this.outputBufferFull = !flushed;
return flushed;
};
module.exports = WebSocketConnection;
