Track pending ICE restarts independently for different media sections.

talk/app/webrtc/webrtcsessiondescriptionfactory.cc

 /*
  * libjingle
  * Copyright 2013 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 94 matching lines @@
 }
 
 void WebRtcIdentityRequestObserver::OnSuccess(
     rtc::scoped_ptr<rtc::SSLIdentity> identity) {
   SignalCertificateReady(rtc::RTCCertificate::Create(std::move(identity)));
 }
 
 // static
 void WebRtcSessionDescriptionFactory::CopyCandidatesFromSessionDescription(
     const SessionDescriptionInterface* source_desc,
+    cricket::MediaType media_type,
     SessionDescriptionInterface* dest_desc) {
-  if (!source_desc)
+  if (!source_desc) {
     return;
-  for (size_t m = 0; m < source_desc->number_of_mediasections() &&
-                     m < dest_desc->number_of_mediasections(); ++m) {
-    const IceCandidateCollection* source_candidates =
-        source_desc->candidates(m);
-    const IceCandidateCollection* dest_candidates = dest_desc->candidates(m);
-    for  (size_t n = 0; n < source_candidates->count(); ++n) {
-      const IceCandidateInterface* new_candidate = source_candidates->at(n);
-      if (!dest_candidates->HasCandidate(new_candidate))
-        dest_desc->AddCandidate(source_candidates->at(n));
-    }
+  }
+  const cricket::ContentInfos& contents =
+      source_desc->description()->contents();
+  const cricket::ContentInfo* cinfo =
+      GetFirstMediaContent(contents, media_type);
+  if (!cinfo) {
+    return;
+  }
+  size_t mediasection_index = static_cast<int>(cinfo - &contents[0]);
+  const IceCandidateCollection* source_candidates =
+      source_desc->candidates(mediasection_index);
+  const IceCandidateCollection* dest_candidates =
+      dest_desc->candidates(mediasection_index);
+  for (size_t n = 0; n < source_candidates->count(); ++n) {
+    const IceCandidateInterface* new_candidate = source_candidates->at(n);
+    if (!dest_candidates->HasCandidate(new_candidate))
+      dest_desc->AddCandidate(source_candidates->at(n));
   }
 }
 
 // Private constructor called by other constructors.
 WebRtcSessionDescriptionFactory::WebRtcSessionDescriptionFactory(
     rtc::Thread* signaling_thread,
     cricket::ChannelManager* channel_manager,
     rtc::scoped_ptr<DtlsIdentityStoreInterface> dtls_identity_store,
     const rtc::scoped_refptr<WebRtcIdentityRequestObserver>&
         identity_request_observer,
@@ skipping 246 matching lines @@
   ASSERT(session_version_ + 1 > session_version_);
   JsepSessionDescription* offer(new JsepSessionDescription(
       JsepSessionDescription::kOffer));
   if (!offer->Initialize(desc, session_id_,
                          rtc::ToString(session_version_++))) {
     delete offer;
     PostCreateSessionDescriptionFailed(request.observer,
                                        "Failed to initialize the offer.");
     return;
   }
-  if (session_->local_description() &&
-      !request.options.audio_transport_options.ice_restart &&
-      !request.options.video_transport_options.ice_restart &&
-      !request.options.data_transport_options.ice_restart) {
-    // Include all local ice candidates in the SessionDescription unless
-    // the an ice restart has been requested.
-    CopyCandidatesFromSessionDescription(session_->local_description(), offer);
+  if (session_->local_description()) {
+    // Include all local ICE candidates in the SessionDescription unless
+    // the remote peer has requested an ICE restart.
+    if (!request.options.audio_transport_options.ice_restart) {
+      CopyCandidatesFromSessionDescription(session_->local_description(),
+                                           cricket::MEDIA_TYPE_AUDIO, offer);
+    }
+    if (!request.options.video_transport_options.ice_restart) {
+      CopyCandidatesFromSessionDescription(session_->local_description(),
+                                           cricket::MEDIA_TYPE_VIDEO, offer);
+    }
+    if (!request.options.data_transport_options.ice_restart) {
+      CopyCandidatesFromSessionDescription(session_->local_description(),
+                                           cricket::MEDIA_TYPE_DATA, offer);
+    }
   }
   PostCreateSessionDescriptionSucceeded(request.observer, offer);
 }
 
 void WebRtcSessionDescriptionFactory::InternalCreateAnswer(
     CreateSessionDescriptionRequest request) {
   // According to http://tools.ietf.org/html/rfc5245#section-9.2.1.1
   // an answer should also contain new ice ufrag and password if an offer has
   // been received with new ufrag and password.
   request.options.audio_transport_options.ice_restart =
-      session_->IceRestartPending();
+      session_->AudioIceRestartPending();
   request.options.video_transport_options.ice_restart =
-      session_->IceRestartPending();
+      session_->VideoIceRestartPending();
   request.options.data_transport_options.ice_restart =
-      session_->IceRestartPending();
+      session_->DataIceRestartPending();
   // We should pass current ssl role to the transport description factory, if
   // there is already an existing ongoing session.
   rtc::SSLRole ssl_role;
   if (session_->GetSslRole(session_->voice_channel(), &ssl_role)) {
     request.options.audio_transport_options.prefer_passive_role =
         (rtc::SSL_SERVER == ssl_role);
   }
   if (session_->GetSslRole(session_->video_channel(), &ssl_role)) {
     request.options.video_transport_options.prefer_passive_role =
         (rtc::SSL_SERVER == ssl_role);
@@ skipping 20 matching lines @@
   ASSERT(session_version_ + 1 > session_version_);
   JsepSessionDescription* answer(new JsepSessionDescription(
       JsepSessionDescription::kAnswer));
   if (!answer->Initialize(desc, session_id_,
                           rtc::ToString(session_version_++))) {
     delete answer;
     PostCreateSessionDescriptionFailed(request.observer,
                                        "Failed to initialize the answer.");
     return;
   }
-  if (session_->local_description() &&
-      !request.options.audio_transport_options.ice_restart &&
-      !request.options.video_transport_options.ice_restart &&
-      !request.options.data_transport_options.ice_restart) {
-    // Include all local ice candidates in the SessionDescription unless
-    // the remote peer has requested an ice restart.
-    CopyCandidatesFromSessionDescription(session_->local_description(), answer);
+  if (session_->local_description()) {

[honghaiz3, 2016/02/10 01:01:48]

Does it make sense to write a method for this part to remove the code
duplication? This and the above one (starting at line 402) are pretty much
identical. 

[Taylor Brandstetter, 2016/02/10 21:18:32]

After refactoring, this section of code is smaller, so I think there's less
incentive to make a helper method.

+    // Include all local ICE candidates in the SessionDescription unless
+    // the remote peer has requested an ICE restart.
+    if (!request.options.audio_transport_options.ice_restart) {
+      CopyCandidatesFromSessionDescription(session_->local_description(),
+                                           cricket::MEDIA_TYPE_AUDIO, answer);
+    }
+    if (!request.options.video_transport_options.ice_restart) {
+      CopyCandidatesFromSessionDescription(session_->local_description(),
+                                           cricket::MEDIA_TYPE_VIDEO, answer);
+    }
+    if (!request.options.data_transport_options.ice_restart) {
+      CopyCandidatesFromSessionDescription(session_->local_description(),
+                                           cricket::MEDIA_TYPE_DATA, answer);
+    }
   }
-  session_->ResetIceRestartLatch();

[honghaiz3, 2016/02/10 01:01:48]

Is there a good reason to move this from here to SetLocalDescription?

[Taylor Brandstetter, 2016/02/10 21:18:32]

Yes. If the remote peer starts an ICE restart, createAnswer should continue to
generate new credentials until a new local description is set.

By resetting the latch here, if you called createAnswer twice, the second answer
would have the old credentials, which is wrong. That reminds me, I should have a
test for this.

   PostCreateSessionDescriptionSucceeded(request.observer, answer);
 }
 
 void WebRtcSessionDescriptionFactory::FailPendingRequests(
     const std::string& reason) {
   ASSERT(signaling_thread_->IsCurrent());
   while (!create_session_description_requests_.empty()) {
     const CreateSessionDescriptionRequest& request =
         create_session_description_requests_.front();
     PostCreateSessionDescriptionFailed(request.observer,
@@ skipping 43 matching lines @@
     if (create_session_description_requests_.front().type ==
         CreateSessionDescriptionRequest::kOffer) {
       InternalCreateOffer(create_session_description_requests_.front());
     } else {
       InternalCreateAnswer(create_session_description_requests_.front());
     }
     create_session_description_requests_.pop();
   }
 }
 }  // namespace webrtc