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[Unified Plan] Avoid offering two senders with the same ID

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This can happen with the following sequence of API calls:
1) AddTrack(track) + offer/answer
2) RemoveTrack(track's sender) + offer/answer
3) AddTrack(same track)

Since the first transceiver had already been used to send, it will
not get re-used by the second call to AddTrack. Another RtpSender
will be created with its ID = the track ID. But the code hits a
DCHECK when CreateOffer is later called since both m= sections will
offer the same track ID component of the MSID.

The fix implemented here is to randomly generate a sender ID if
there is already an RtpSender with the track's ID.

Bug: webrtc:8734
Change-Id: Ic2dda23d66e364e77ff7505e1c37e53105a17dae
Reviewed-on: https://webrtc-review.googlesource.com/84249
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23748}
This commit is contained in:
Steve Anton
2018-06-26 11:13:50 -07:00
committed by Commit Bot
parent 1bc9716078
commit 07563732f6
3 changed files with 81 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
pc/peerconnection.cc
View File

@ -1254,7 +1254,14 @@ PeerConnection::AddTrackUnifiedPlan(
: cricket::MEDIA_TYPE_VIDEO);
RTC_LOG(LS_INFO) << "Adding " << cricket::MediaTypeToString(media_type)
<< " transceiver in response to a call to AddTrack.";
auto sender = CreateSender(media_type, track->id(), track, stream_ids);
std::string sender_id = track->id();
// Avoid creating a sender with an existing ID by generating a random ID.
// This can happen if this is the second time AddTrack has created a sender
// for this track.
if (FindSenderById(sender_id)) {
sender_id = rtc::CreateRandomUuid();
}
auto sender = CreateSender(media_type, sender_id, track, stream_ids);
auto receiver = CreateReceiver(media_type, rtc::CreateRandomUuid());
transceiver = CreateAndAddTransceiver(sender, receiver);
transceiver->internal()->set_created_by_addtrack(true);
@ -1399,9 +1406,12 @@ PeerConnection::AddTransceiver(
RTC_LOG(LS_INFO) << "Adding " << cricket::MediaTypeToString(media_type)
<< " transceiver in response to a call to AddTransceiver.";
auto sender =
CreateSender(media_type, (track ? track->id() : rtc::CreateRandomUuid()),
track, init.stream_ids);
// Set the sender ID equal to the track ID if the track is specified unless
// that sender ID is already in use.
std::string sender_id =
(track && !FindSenderById(track->id()) ? track->id()
: rtc::CreateRandomUuid());
auto sender = CreateSender(media_type, sender_id, track, init.stream_ids);
auto receiver = CreateReceiver(media_type, rtc::CreateRandomUuid());
auto transceiver = CreateAndAddTransceiver(sender, receiver);
transceiver->internal()->set_direction(init.direction);
@ -1466,6 +1476,11 @@ PeerConnection::CreateAndAddTransceiver(
rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>> sender,
rtc::scoped_refptr<RtpReceiverProxyWithInternal<RtpReceiverInternal>>
receiver) {
// Ensure that the new sender does not have an ID that is already in use by
// another sender.
// Allow receiver IDs to conflict since those come from remote SDP (which
// could be invalid, but should not cause a crash).
RTC_DCHECK(!FindSenderById(sender->id()));
auto transceiver = RtpTransceiverProxyWithInternal<RtpTransceiver>::Create(
signaling_thread(), new RtpTransceiver(sender, receiver));
transceivers_.push_back(transceiver);