Revert "Merge pull request webrtc#346 from webrtc/dtlsLoopback"

This reverts commit bb8f949, reversing
changes made to 9336635.

src/app_engine/apprtc.py

@@ -256,6 +256,8 @@ def get_room_parameters(request, room_id, client_id, is_initiator):
 
   debug = request.get('debug')
   if debug == 'loopback':
+    # Set dtls to false as DTLS does not work for loopback.
+    dtls = 'false'
     include_loopback_js = '<script src="/js/loopback.js"></script>'
   else:
     include_loopback_js = ''
@@ -386,6 +388,8 @@ def add_client_to_room(request, room_id, client_id, is_loopback):
     if occupancy == 0:
       is_initiator = True
       room.add_client(client_id, Client(is_initiator))
+      if is_loopback:
+        room.add_client(constants.LOOPBACK_CLIENT_ID, Client(False))
     else:
       is_initiator = False
       other_client = room.get_other_client(client_id)
@@ -406,7 +410,7 @@ def add_client_to_room(request, room_id, client_id, is_loopback):
     else:
       retries = retries + 1
   return {'error': error, 'is_initiator': is_initiator,
-          'messages': messages, 'room_state': str(room), 'client_id': client_id}
+          'messages': messages, 'room_state': str(room)}
 
 def remove_client_from_room(host, room_id, client_id):
   key = get_memcache_key_for_room(host, room_id)
@@ -527,18 +531,8 @@ def write_room_parameters(self, room_id, client_id, messages, is_initiator):
     self.write_response('SUCCESS', params, messages)
 
   def post(self, room_id):
+    client_id = generate_random(8)
     is_loopback = self.request.get('debug') == 'loopback'
-    if is_loopback:
-      client_id = constants.LOOPBACK_CLIENT_ID
-      memcache_client = memcache.Client()
-      room = memcache_client.gets(
-        get_memcache_key_for_room(self.request.host_url, room_id))
-      if room is not None:
-        if room.has_client(client_id):
-          client_id = constants.LOOPBACK_CLIENT_ID_2
-    else:
-      client_id = generate_random(8)
-
     result = add_client_to_room(self.request, room_id, client_id, is_loopback)
     if result['error'] is not None:
       logging.info('Error adding client to room: ' + result['error'] + \
@@ -547,7 +541,7 @@ def post(self, room_id):
       return
 
     self.write_room_parameters(
-        room_id, result['client_id'], result['messages'], result['is_initiator'])
+        room_id, client_id, result['messages'], result['is_initiator'])
     logging.info('User ' + client_id + ' joined room ' + room_id)
     logging.info('Room ' + room_id + ' has state ' + result['room_state'])
 

src/app_engine/constants.py

@@ -9,9 +9,7 @@
 ROOM_MEMCACHE_EXPIRATION_SEC = 60 * 60 * 24
 MEMCACHE_RETRY_LIMIT = 100
 
-# Client ID's for the loopback peerconnections.
 LOOPBACK_CLIENT_ID = 'LOOPBACK_CLIENT_ID'
-LOOPBACK_CLIENT_ID_2 = 'LOOPBACK_CLIENT_ID_2'
 
 # TODO: Remove once clients support ICE_SERVER.
 TURN_BASE_URL = 'https://computeengineondemand.appspot.com'

src/web_app/js/appcontroller.js

@@ -252,7 +252,6 @@ AppController.prototype.hangup_ = function() {
   // Reset key and mouse event handlers.
   document.onkeypress = null;
   window.onmousemove = null;
-  this.remoteVideo_.srcObject = null;
 };
 
 AppController.prototype.onRemoteHangup_ = function() {
@@ -375,8 +374,6 @@ AppController.prototype.transitionToWaiting_ = function() {
 AppController.prototype.transitionToDone_ = function() {
   // Stop waiting for remote video.
   this.remoteVideo_.oncanplay = undefined;
-  // Rotate back the video div for rejoin and new room situations.
-  this.deactivate_(this.videosDiv_);
   this.deactivate_(this.localVideo_);
   this.deactivate_(this.remoteVideo_);
   this.deactivate_(this.miniVideo_);

src/web_app/js/call.js

@@ -15,9 +15,8 @@
 /* exported Call */
 
 'use strict';
-// doNotRequestMediaAndIceServers should be set to true if getUserMedia and Ice
-// servers should not be request.
-var Call = function(params, doNotRequestMediaAndIceServers) {
+
+var Call = function(params) {
   this.params_ = params;
   this.roomServer_ = params.roomServer || '';
 
@@ -43,11 +42,7 @@ var Call = function(params, doNotRequestMediaAndIceServers) {
 
   this.getMediaPromise_ = null;
   this.getIceServersPromise_ = null;
-  // Only request ICE servers and getUserMedia for p2p calls and the 1st
-  // loopback peerConnection.
-  if (!doNotRequestMediaAndIceServers) {
-    this.requestMediaAndIceServers_();
-  }
+  this.requestMediaAndIceServers_();
 };
 
 Call.prototype.requestMediaAndIceServers_ = function() {
@@ -61,6 +56,9 @@ Call.prototype.isInitiator = function() {
 
 Call.prototype.start = function(roomId) {
   this.connectToRoom_(roomId);
+  if (this.params_.isLoopback) {
+    setupLoopback(this.params_.wssUrl, roomId);
+  }
 };
 
 Call.prototype.queueCleanupMessages_ = function() {
@@ -156,32 +154,32 @@ Call.prototype.hangup = function(async) {
   var steps = [];
   steps.push({
     step: function() {
-      // Send POST request to /leave.
-      var path = this.getLeaveUrl_();
-      return sendUrlRequest('POST', path, async);
-    }.bind(this),
+        // Send POST request to /leave.
+        var path = this.getLeaveUrl_();
+        return sendUrlRequest('POST', path, async);
+      }.bind(this),
     errorString: 'Error sending /leave:'
   });
   steps.push({
     step: function() {
-      // Send bye to the other client.
-      this.channel_.send(JSON.stringify({type: 'bye'}));
-    }.bind(this),
+        // Send bye to the other client.
+        this.channel_.send(JSON.stringify({type: 'bye'}));
+      }.bind(this),
     errorString: 'Error sending bye:'
   });
   steps.push({
     step: function() {
-      // Close signaling channel.
-      return this.channel_.close(async);
-    }.bind(this),
+        // Close signaling channel.
+        return this.channel_.close(async);
+      }.bind(this),
     errorString: 'Error closing signaling channel:'
   });
   steps.push({
     step: function() {
-      this.params_.previousRoomId = this.params_.roomId;
-      this.params_.roomId = null;
-      this.params_.clientId = null;
-    }.bind(this),
+        this.params_.previousRoomId = this.params_.roomId;
+        this.params_.roomId = null;
+        this.params_.clientId = null;
+      }.bind(this),
     errorString: 'Error setting params:'
   });
 
@@ -234,6 +232,7 @@ Call.prototype.onRemoteHangup = function() {
     this.pcClient_.close();
     this.pcClient_ = null;
   }
+
   this.startSignaling_();
 };
 
@@ -323,6 +322,7 @@ Call.prototype.connectToRoom_ = function(roomId) {
   // already registered with GAE.
   Promise.all([channelPromise, joinPromise]).then(function() {
     this.channel_.register(this.params_.roomId, this.params_.clientId);
+
     // We only start signaling after we have registered the signaling channel
     // and have media and TURN. Since we send candidates as soon as the peer
     // connection generates them we need to wait for the signaling channel to be
@@ -492,9 +492,6 @@ Call.prototype.startSignaling_ = function() {
     } else {
       this.pcClient_.startAsCallee(this.params_.messages);
     }
-    if (this.params_.isLoopback && this.params_.isInitiator) {
-      setupLoopback(this.params_);
-    }
     this.maybeReportGetUserMediaErrors_();
   }.bind(this))
   .catch(function(e) {

src/web_app/js/loopback.js

@@ -1,5 +1,5 @@
 /*
- *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *  Copyright (c) 2014 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
@@ -12,65 +12,74 @@
 
 'use strict';
 
-function setupLoopback(params) {
-  trace('Setting up loopback peerConnection client.');
-  // Reuse the parameters from peerConnection 1 by creating a new object and
-  // modify it to what's needed for peerConnection 2.
-  var params_ = JSON.parse(JSON.stringify(params));
-  params_.clientId = 'LOOPBACK_CLIENT_ID_2';
-  params_.isInitiator = false;
-  params_.mediaConstraints.audio = false;
-  params_.mediaConstraints.video = false;
-  // For loopback calls we reuse the parameters from peerConnection 1 hence it
-  // does not need to request ICE servers and also we do not need gUM since the
-  // remote stream is cloned and used as a local stream for peerConnection 2.
-  var call = new Call(params_, true);
-
-  // Dereference the call object so the peerConnection can be garbage collected.
-  function deleteCall() {
-    call = null;
+// We handle the loopback case by making a second connection to the WSS so that
+// we receive the same messages that we send out. When receiving an offer we
+// convert that offer into an answer message. When receiving candidates we
+// echo back the candidate. Answer is ignored because we should never receive
+// one while in loopback. Bye is ignored because there is no work to do.
+var loopbackWebSocket = null;
+var LOOPBACK_CLIENT_ID = 'loopback_client_id';
+function setupLoopback(wssUrl, roomId) {
+  if (loopbackWebSocket) {
+    loopbackWebSocket.close();
   }
+  trace('Setting up loopback WebSocket.');
+  // TODO(tkchin): merge duplicate code once SignalingChannel abstraction
+  // exists.
+  loopbackWebSocket = new WebSocket(wssUrl);
 
-  // Hangup peerconnection 2 properly since the UI only controls
-  // peerconnection 1.
-  call.onremotehangup = function() {
-    this.hangup(true);
-    this.startTime = null;
-    if (this.pcClient_) {
-      this.pcClient_.close();
-      this.pcClient_ = null;
-    }
-    deleteCall();
-  }.bind(call);
+  var sendLoopbackMessage = function(message) {
+    var msgString = JSON.stringify({
+      cmd: 'send',
+      msg: JSON.stringify(message)
+    });
+    loopbackWebSocket.send(msgString);
+  };
 
-  // Add the remote stream from peerConnection 1 as a local stream for
-  // peerConnection 2 (loopback) before sending an answer to avoid renegotiation
-  // since peerConnection 2 does not have a access to the stream until
-  // peerConnection 1 has added it.
-  call.onremotestreamadded = function(event) {
-    if (this.params_.clientId === 'LOOPBACK_CLIENT_ID_2') {
-      // Since this fired once per track we need to make sure it will only add
-      // the stream once.
-      if (this.pcClient_.loopBackStream === null) {
-        // 2nd peerConnection should not be the initiator.
-        if (!this.params_.isInitiator_) {
-          this.pcClient_.loopBackStream = event.clone();
-          // Disable audio tracks on the remote tracks of the remote stream
-          // otherwise it will be played back by the Chrome mixer as well.
-          event.getAudioTracks()[0].enabled = false;
-          this.pcClient_.pc_.addStream(this.pcClient_.loopBackStream);
-          this.pcClient_.doAnswer_();
-        }
-      }
-    }
-  }.bind(call);
+  loopbackWebSocket.onopen = function() {
+    trace('Loopback WebSocket opened.');
+    var registerMessage = {
+      cmd: 'register',
+      roomid: roomId,
+      clientid: LOOPBACK_CLIENT_ID
+    };
+    loopbackWebSocket.send(JSON.stringify(registerMessage));
+  };
 
-  // Make sure to shutdown peerConnection 2 properly when a user
-  // closes the tab.
-  window.onbeforeunload = function() {
-    call.hangup.bind(call, false);
+  loopbackWebSocket.onmessage = function(event) {
+    var wssMessage;
+    var message;
+    try {
+      wssMessage = JSON.parse(event.data);
+      message = JSON.parse(wssMessage.msg);
+    } catch (e) {
+      trace('Error parsing JSON: ' + event.data);
+      return;
+    }
+    if (wssMessage.error) {
+      trace('WSS error: ' + wssMessage.error);
+      return;
+    }
+    if (message.type === 'offer') {
+      var loopbackAnswer = wssMessage.msg;
+      loopbackAnswer = loopbackAnswer.replace('"offer"', '"answer"');
+      loopbackAnswer =
+          loopbackAnswer.replace('a=ice-options:google-ice\\r\\n', '');
+      // As of Chrome M51, an additional crypto method has been added when
+      // using SDES. This works in a P2P due to the negotiation phase removes
+      // this line but for loopback where we reuse the offer, that is skipped
+      // and remains in the answer and breaks the call.
+      // https://bugs.chromium.org/p/chromium/issues/detail?id=616263
+      loopbackAnswer = loopbackAnswer
+          .replace(/a=crypto:0 AES_CM_128_HMAC_SHA1_32\sinline:.{44}/, '');
+      sendLoopbackMessage(JSON.parse(loopbackAnswer));
+    } else if (message.type === 'candidate') {
+      sendLoopbackMessage(message);
+    }
   };
 
-  // Start peerConnection 2.
-  call.start(params_.roomId);
+  loopbackWebSocket.onclose = function(event) {
+    trace('Loopback WebSocket closed with code:' + event.code + ' reason:' +
+          event.reason);
+  };
 }