js • Lines: 470/*
* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree.
*/
/* eslint-env node */
'use strict';
import SDPUtils from 'sdp';
import * as utils from './utils';
export function shimRTCIceCandidate(window) {
// foundation is arbitrarily chosen as an indicator for full support for
// https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
if (!window.RTCIceCandidate || (window.RTCIceCandidate && 'foundation' in
window.RTCIceCandidate.prototype)) {
return;
}
const NativeRTCIceCandidate = window.RTCIceCandidate;
window.RTCIceCandidate = function RTCIceCandidate(args) {
// Remove the a= which shouldn't be part of the candidate string.
if (typeof args === 'object' && args.candidate &&
args.candidate.indexOf('a=') === 0) {
args = JSON.parse(JSON.stringify(args));
args.candidate = args.candidate.substring(2);
}
if (args.candidate && args.candidate.length) {
// Augment the native candidate with the parsed fields.
const nativeCandidate = new NativeRTCIceCandidate(args);
const parsedCandidate = SDPUtils.parseCandidate(args.candidate);
for (const key in parsedCandidate) {
if (!(key in nativeCandidate)) {
Object.defineProperty(nativeCandidate, key,
{value: parsedCandidate[key]});
}
}
// Override serializer to not serialize the extra attributes.
nativeCandidate.toJSON = function toJSON() {
return {
candidate: nativeCandidate.candidate,
sdpMid: nativeCandidate.sdpMid,
sdpMLineIndex: nativeCandidate.sdpMLineIndex,
usernameFragment: nativeCandidate.usernameFragment,
};
};
return nativeCandidate;
}
return new NativeRTCIceCandidate(args);
};
window.RTCIceCandidate.prototype = NativeRTCIceCandidate.prototype;
// Hook up the augmented candidate in onicecandidate and
// addEventListener('icecandidate', ...)
utils.wrapPeerConnectionEvent(window, 'icecandidate', e => {
if (e.candidate) {
Object.defineProperty(e, 'candidate', {
value: new window.RTCIceCandidate(e.candidate),
writable: 'false'
});
}
return e;
});
}
export function shimRTCIceCandidateRelayProtocol(window) {
if (!window.RTCIceCandidate || (window.RTCIceCandidate && 'relayProtocol' in
window.RTCIceCandidate.prototype)) {
return;
}
// Hook up the augmented candidate in onicecandidate and
// addEventListener('icecandidate', ...)
utils.wrapPeerConnectionEvent(window, 'icecandidate', e => {
if (e.candidate) {
const parsedCandidate = SDPUtils.parseCandidate(e.candidate.candidate);
if (parsedCandidate.type === 'relay') {
// This is a libwebrtc-specific mapping of local type preference
// to relayProtocol.
e.candidate.relayProtocol = {
0: 'tls',
1: 'tcp',
2: 'udp',
}[parsedCandidate.priority >> 24];
}
}
return e;
});
}
export function shimMaxMessageSize(window, browserDetails) {
if (!window.RTCPeerConnection) {
return;
}
if (!('sctp' in window.RTCPeerConnection.prototype)) {
Object.defineProperty(window.RTCPeerConnection.prototype, 'sctp', {
get() {
return typeof this._sctp === 'undefined' ? null : this._sctp;
}
});
}
const sctpInDescription = function(description) {
if (!description || !description.sdp) {
return false;
}
const sections = SDPUtils.splitSections(description.sdp);
sections.shift();
return sections.some(mediaSection => {
const mLine = SDPUtils.parseMLine(mediaSection);
return mLine && mLine.kind === 'application'
&& mLine.protocol.indexOf('SCTP') !== -1;
});
};
const getRemoteFirefoxVersion = function(description) {
// TODO: Is there a better solution for detecting Firefox?
const match = description.sdp.match(/mozilla...THIS_IS_SDPARTA-(\d+)/);
if (match === null || match.length < 2) {
return -1;
}
const version = parseInt(match[1], 10);
// Test for NaN (yes, this is ugly)
return version !== version ? -1 : version;
};
const getCanSendMaxMessageSize = function(remoteIsFirefox) {
// Every implementation we know can send at least 64 KiB.
// Note: Although Chrome is technically able to send up to 256 KiB, the
// data does not reach the other peer reliably.
// See: https://bugs.chromium.org/p/webrtc/issues/detail?id=8419
let canSendMaxMessageSize = 65536;
if (browserDetails.browser === 'firefox') {
if (browserDetails.version < 57) {
if (remoteIsFirefox === -1) {
// FF < 57 will send in 16 KiB chunks using the deprecated PPID
// fragmentation.
canSendMaxMessageSize = 16384;
} else {
// However, other FF (and RAWRTC) can reassemble PPID-fragmented
// messages. Thus, supporting ~2 GiB when sending.
canSendMaxMessageSize = 2147483637;
}
} else if (browserDetails.version < 60) {
// Currently, all FF >= 57 will reset the remote maximum message size
// to the default value when a data channel is created at a later
// stage. :(
// See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
canSendMaxMessageSize =
browserDetails.version === 57 ? 65535 : 65536;
} else {
// FF >= 60 supports sending ~2 GiB
canSendMaxMessageSize = 2147483637;
}
}
return canSendMaxMessageSize;
};
const getMaxMessageSize = function(description, remoteIsFirefox) {
// Note: 65536 bytes is the default value from the SDP spec. Also,
// every implementation we know supports receiving 65536 bytes.
let maxMessageSize = 65536;
// FF 57 has a slightly incorrect default remote max message size, so
// we need to adjust it here to avoid a failure when sending.
// See: https://bugzilla.mozilla.org/show_bug.cgi?id=1425697
if (browserDetails.browser === 'firefox'
&& browserDetails.version === 57) {
maxMessageSize = 65535;
}
const match = SDPUtils.matchPrefix(description.sdp,
'a=max-message-size:');
if (match.length > 0) {
maxMessageSize = parseInt(match[0].substring(19), 10);
} else if (browserDetails.browser === 'firefox' &&
remoteIsFirefox !== -1) {
// If the maximum message size is not present in the remote SDP and
// both local and remote are Firefox, the remote peer can receive
// ~2 GiB.
maxMessageSize = 2147483637;
}
return maxMessageSize;
};
const origSetRemoteDescription =
window.RTCPeerConnection.prototype.setRemoteDescription;
window.RTCPeerConnection.prototype.setRemoteDescription =
function setRemoteDescription() {
this._sctp = null;
// Chrome decided to not expose .sctp in plan-b mode.
// As usual, adapter.js has to do an 'ugly worakaround'
// to cover up the mess.
if (browserDetails.browser === 'chrome' && browserDetails.version >= 76) {
const {sdpSemantics} = this.getConfiguration();
if (sdpSemantics === 'plan-b') {
Object.defineProperty(this, 'sctp', {
get() {
return typeof this._sctp === 'undefined' ? null : this._sctp;
},
enumerable: true,
configurable: true,
});
}
}
if (sctpInDescription(arguments[0])) {
// Check if the remote is FF.
const isFirefox = getRemoteFirefoxVersion(arguments[0]);
// Get the maximum message size the local peer is capable of sending
const canSendMMS = getCanSendMaxMessageSize(isFirefox);
// Get the maximum message size of the remote peer.
const remoteMMS = getMaxMessageSize(arguments[0], isFirefox);
// Determine final maximum message size
let maxMessageSize;
if (canSendMMS === 0 && remoteMMS === 0) {
maxMessageSize = Number.POSITIVE_INFINITY;
} else if (canSendMMS === 0 || remoteMMS === 0) {
maxMessageSize = Math.max(canSendMMS, remoteMMS);
} else {
maxMessageSize = Math.min(canSendMMS, remoteMMS);
}
// Create a dummy RTCSctpTransport object and the 'maxMessageSize'
// attribute.
const sctp = {};
Object.defineProperty(sctp, 'maxMessageSize', {
get() {
return maxMessageSize;
}
});
this._sctp = sctp;
}
return origSetRemoteDescription.apply(this, arguments);
};
}
export function shimSendThrowTypeError(window, browserDetails) {
if (!(window.RTCPeerConnection &&
'createDataChannel' in window.RTCPeerConnection.prototype)) {
return;
}
if (browserDetails.browser === 'chrome' && browserDetails.version > 149) {
// Fixed by https://issues.chromium.org/issues/490588131
return;
}
// Note: Although Firefox >= 57 has a native implementation, the maximum
// message size can be reset for all data channels at a later stage.
// See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
if (browserDetails.browser === 'firefox' && browserDetails.version > 60) {
return;
}
function wrapDcSend(dc, pc) {
const origDataChannelSend = dc.send;
dc.send = function send() {
const data = arguments[0];
const length = data.length || data.size || data.byteLength;
if (dc.readyState === 'open' &&
pc.sctp && length > pc.sctp.maxMessageSize) {
throw new TypeError('Message too large (can send a maximum of ' +
pc.sctp.maxMessageSize + ' bytes)');
}
return origDataChannelSend.apply(dc, arguments);
};
}
const origCreateDataChannel =
window.RTCPeerConnection.prototype.createDataChannel;
window.RTCPeerConnection.prototype.createDataChannel =
function createDataChannel() {
const dataChannel = origCreateDataChannel.apply(this, arguments);
wrapDcSend(dataChannel, this);
return dataChannel;
};
utils.wrapPeerConnectionEvent(window, 'datachannel', e => {
wrapDcSend(e.channel, e.target);
return e;
});
}
/* shims RTCConnectionState by pretending it is the same as iceConnectionState.
* See https://bugs.chromium.org/p/webrtc/issues/detail?id=6145#c12
* for why this is a valid hack in Chrome. In Firefox it is slightly incorrect
* since DTLS failures would be hidden. See
* https://bugzilla.mozilla.org/show_bug.cgi?id=1265827
* for the Firefox tracking bug.
*/
export function shimConnectionState(window) {
if (!window.RTCPeerConnection ||
'connectionState' in window.RTCPeerConnection.prototype) {
return;
}
const proto = window.RTCPeerConnection.prototype;
Object.defineProperty(proto, 'connectionState', {
get() {
return {
completed: 'connected',
checking: 'connecting'
}[this.iceConnectionState] || this.iceConnectionState;
},
enumerable: true,
configurable: true
});
Object.defineProperty(proto, 'onconnectionstatechange', {
get() {
return this._onconnectionstatechange || null;
},
set(cb) {
if (this._onconnectionstatechange) {
this.removeEventListener('connectionstatechange',
this._onconnectionstatechange);
delete this._onconnectionstatechange;
}
if (cb) {
this.addEventListener('connectionstatechange',
this._onconnectionstatechange = cb);
}
},
enumerable: true,
configurable: true
});
['setLocalDescription', 'setRemoteDescription'].forEach((method) => {
const origMethod = proto[method];
proto[method] = function() {
if (!this._connectionstatechangepoly) {
this._connectionstatechangepoly = e => {
const pc = e.target;
if (pc._lastConnectionState !== pc.connectionState) {
pc._lastConnectionState = pc.connectionState;
const newEvent = new Event('connectionstatechange', e);
pc.dispatchEvent(newEvent);
}
return e;
};
this.addEventListener('iceconnectionstatechange',
this._connectionstatechangepoly);
}
return origMethod.apply(this, arguments);
};
});
}
export function removeExtmapAllowMixed(window, browserDetails) {
/* remove a=extmap-allow-mixed for webrtc.org < M71 */
if (!window.RTCPeerConnection) {
return;
}
if (browserDetails.browser === 'chrome' && browserDetails.version >= 71) {
return;
}
if (browserDetails.browser === 'safari' &&
browserDetails._safariVersion >= 13.1) {
return;
}
const nativeSRD = window.RTCPeerConnection.prototype.setRemoteDescription;
window.RTCPeerConnection.prototype.setRemoteDescription =
function setRemoteDescription(desc) {
if (desc && desc.sdp && desc.sdp.indexOf('\na=extmap-allow-mixed') !== -1) {
const sdp = desc.sdp.split('\n').filter((line) => {
return line.trim() !== 'a=extmap-allow-mixed';
}).join('\n');
// Safari enforces read-only-ness of RTCSessionDescription fields.
if (window.RTCSessionDescription &&
desc instanceof window.RTCSessionDescription) {
arguments[0] = new window.RTCSessionDescription({
type: desc.type,
sdp,
});
} else {
desc.sdp = sdp;
}
}
return nativeSRD.apply(this, arguments);
};
}
export function shimAddIceCandidateNullOrEmpty(window, browserDetails) {
// Support for addIceCandidate(null or undefined)
// as well as addIceCandidate({candidate: "", ...})
// https://bugs.chromium.org/p/chromium/issues/detail?id=978582
// Note: must be called before other polyfills which change the signature.
if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
return;
}
const nativeAddIceCandidate =
window.RTCPeerConnection.prototype.addIceCandidate;
if (!nativeAddIceCandidate || nativeAddIceCandidate.length === 0) {
return;
}
window.RTCPeerConnection.prototype.addIceCandidate =
function addIceCandidate() {
if (!arguments[0]) {
if (arguments[1]) {
arguments[1].apply(null);
}
return Promise.resolve();
}
// Firefox 68+ emits and processes {candidate: "", ...}, ignore
// in older versions.
// Native support for ignoring exists for Chrome M77+.
// Safari ignores as well, exact version unknown but works in the same
// version that also ignores addIceCandidate(null).
if (((browserDetails.browser === 'chrome' && browserDetails.version < 78)
|| (browserDetails.browser === 'firefox'
&& browserDetails.version < 68)
|| (browserDetails.browser === 'safari'))
&& arguments[0] && arguments[0].candidate === '') {
return Promise.resolve();
}
return nativeAddIceCandidate.apply(this, arguments);
};
}
// Note: Make sure to call this ahead of APIs that modify
// setLocalDescription.length
export function shimParameterlessSetLocalDescription(window, browserDetails) {
if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
return;
}
const nativeSetLocalDescription =
window.RTCPeerConnection.prototype.setLocalDescription;
if (!nativeSetLocalDescription || nativeSetLocalDescription.length === 0) {
return;
}
window.RTCPeerConnection.prototype.setLocalDescription =
function setLocalDescription() {
let desc = arguments[0] || {};
if (typeof desc !== 'object' || (desc.type && desc.sdp)) {
return nativeSetLocalDescription.apply(this, arguments);
}
// The remaining steps should technically happen when SLD comes off the
// RTCPeerConnection's operations chain (not ahead of going on it), but
// this is too difficult to shim. Instead, this shim only covers the
// common case where the operations chain is empty. This is imperfect, but
// should cover many cases. Rationale: Even if we can't reduce the glare
// window to zero on imperfect implementations, there's value in tapping
// into the perfect negotiation pattern that several browsers support.
desc = {type: desc.type, sdp: desc.sdp};
if (!desc.type) {
switch (this.signalingState) {
case 'stable':
case 'have-local-offer':
case 'have-remote-pranswer':
desc.type = 'offer';
break;
default:
desc.type = 'answer';
break;
}
}
if (desc.sdp || (desc.type !== 'offer' && desc.type !== 'answer')) {
return nativeSetLocalDescription.apply(this, [desc]);
}
const func = desc.type === 'offer' ? this.createOffer : this.createAnswer;
return func.apply(this)
.then(d => nativeSetLocalDescription.apply(this, [d]));
};
}