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Move more functions from PeerConnection to SdpOfferAnswer

Browse Source 
These are functions that are called only from SdpOfferAnswer,
or that logically belong in the SdpOfferAnswer class.

Bug: webrtc:11995
Change-Id: I92136ee84e20e50957814c21b041ca152a2acca4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/186268
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32271}
This commit is contained in:
Harald Alvestrand
2020-10-01 10:23:33 +00:00
committed by Commit Bot
parent a0ad0bbf8f
commit c06e374a55
4 changed files with 717 additions and 697 deletions
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635
pc/peer_connection.cc
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@ -149,30 +149,6 @@ bool CanAddLocalMediaStream(webrtc::StreamCollectionInterface* current_streams,
return true;
}
// Add options to |[audio/video]_media_description_options| from |senders|.
void AddPlanBRtpSenderOptions(
const std::vector<rtc::scoped_refptr<
RtpSenderProxyWithInternal<RtpSenderInternal>>>& senders,
cricket::MediaDescriptionOptions* audio_media_description_options,
cricket::MediaDescriptionOptions* video_media_description_options,
int num_sim_layers) {
for (const auto& sender : senders) {
if (sender->media_type() == cricket::MEDIA_TYPE_AUDIO) {
if (audio_media_description_options) {
audio_media_description_options->AddAudioSender(
sender->id(), sender->internal()->stream_ids());
}
} else {
RTC_DCHECK(sender->media_type() == cricket::MEDIA_TYPE_VIDEO);
if (video_media_description_options) {
video_media_description_options->AddVideoSender(
sender->id(), sender->internal()->stream_ids(), {},
SimulcastLayerList(), num_sim_layers);
}
}
}
}
// Add options to |session_options| from |rtp_data_channels|.
void AddRtpDataChannelOptions(
const std::map<std::string, rtc::scoped_refptr<RtpDataChannel>>&
@ -445,17 +421,6 @@ std::string GenerateRtcpCname() {
return cname;
}
// From |rtc_options|, fill parts of |session_options| shared by all generated
// m= sectionss (in other words, nothing that involves a map/array).
void ExtractSharedMediaSessionOptions(
const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options,
cricket::MediaSessionOptions* session_options) {
session_options->vad_enabled = rtc_options.voice_activity_detection;
session_options->bundle_enabled = rtc_options.use_rtp_mux;
session_options->raw_packetization_for_video =
rtc_options.raw_packetization_for_video;
}
PeerConnection::PeerConnection(PeerConnectionFactory* factory,
std::unique_ptr<RtcEventLog> event_log,
std::unique_ptr<Call> call)
@ -1348,6 +1313,7 @@ std::vector<rtc::scoped_refptr<RtpSenderInterface>> PeerConnection::GetSenders()
std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
PeerConnection::GetSendersInternal() const {
RTC_DCHECK_RUN_ON(signaling_thread());
std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
all_senders;
for (const auto& transceiver : transceivers_.List()) {
@ -1698,9 +1664,11 @@ void PeerConnection::RemoveStoppedTransceivers() {
continue;
}
const ContentInfo* local_content =
FindMediaSectionForTransceiver(transceiver, local_description());
sdp_handler_.FindMediaSectionForTransceiver(transceiver,
local_description());
const ContentInfo* remote_content =
FindMediaSectionForTransceiver(transceiver, remote_description());
sdp_handler_.FindMediaSectionForTransceiver(transceiver,
remote_description());
if ((local_content && local_content->rejected) ||
(remote_content && remote_content->rejected)) {
RTC_LOG(LS_INFO) << "Dissociating transceiver"
@ -1721,64 +1689,6 @@ void PeerConnection::RemoveStoppedTransceivers() {
}
}
// The SDP parser used to populate these values by default for the 'content
// name' if an a=mid line was absent.
static absl::string_view GetDefaultMidForPlanB(cricket::MediaType media_type) {
switch (media_type) {
case cricket::MEDIA_TYPE_AUDIO:
return cricket::CN_AUDIO;
case cricket::MEDIA_TYPE_VIDEO:
return cricket::CN_VIDEO;
case cricket::MEDIA_TYPE_DATA:
return cricket::CN_DATA;
}
RTC_NOTREACHED();
return "";
}
void PeerConnection::FillInMissingRemoteMids(
cricket::SessionDescription* new_remote_description) {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(new_remote_description);
const cricket::ContentInfos no_infos;
const cricket::ContentInfos& local_contents =
(local_description() ? local_description()->description()->contents()
: no_infos);
const cricket::ContentInfos& remote_contents =
(remote_description() ? remote_description()->description()->contents()
: no_infos);
for (size_t i = 0; i < new_remote_description->contents().size(); ++i) {
cricket::ContentInfo& content = new_remote_description->contents()[i];
if (!content.name.empty()) {
continue;
}
std::string new_mid;
absl::string_view source_explanation;
if (IsUnifiedPlan()) {
if (i < local_contents.size()) {
new_mid = local_contents[i].name;
source_explanation = "from the matching local media section";
} else if (i < remote_contents.size()) {
new_mid = remote_contents[i].name;
source_explanation = "from the matching previous remote media section";
} else {
new_mid = mid_generator_();
source_explanation = "generated just now";
}
} else {
new_mid = std::string(
GetDefaultMidForPlanB(content.media_description()->type()));
source_explanation = "to match pre-existing behavior";
}
RTC_DCHECK(!new_mid.empty());
content.name = new_mid;
new_remote_description->transport_infos()[i].content_name = new_mid;
RTC_LOG(LS_INFO) << "SetRemoteDescription: Remote media section at i=" << i
<< " is missing an a=mid line. Filling in the value '"
<< new_mid << "' " << source_explanation << ".";
}
}
void PeerConnection::SetRemoteDescription(
SetSessionDescriptionObserver* observer,
SessionDescriptionInterface* desc_ptr) {
@ -1839,48 +1749,6 @@ PeerConnection::GetTransceiverByMLineIndex(size_t mline_index) const {
return transceivers_.FindByMLineIndex(mline_index);
}
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
PeerConnection::FindAvailableTransceiverToReceive(
cricket::MediaType media_type) const {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(IsUnifiedPlan());
// From JSEP section 5.10 (Applying a Remote Description):
// If the m= section is sendrecv or recvonly, and there are RtpTransceivers of
// the same type that were added to the PeerConnection by addTrack and are not
// associated with any m= section and are not stopped, find the first such
// RtpTransceiver.
for (auto transceiver : transceivers_.List()) {
if (transceiver->media_type() == media_type &&
transceiver->internal()->created_by_addtrack() && !transceiver->mid() &&
!transceiver->stopped()) {
return transceiver;
}
}
return nullptr;
}
const cricket::ContentInfo* PeerConnection::FindMediaSectionForTransceiver(
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
transceiver,
const SessionDescriptionInterface* sdesc) const {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(transceiver);
RTC_DCHECK(sdesc);
if (IsUnifiedPlan()) {
if (!transceiver->internal()->mid()) {
// This transceiver is not associated with a media section yet.
return nullptr;
}
return sdesc->description()->GetContentByName(
*transceiver->internal()->mid());
} else {
// Plan B only allows at most one audio and one video section, so use the
// first media section of that type.
return cricket::GetFirstMediaContent(sdesc->description()->contents(),
transceiver->media_type());
}
}
PeerConnectionInterface::RTCConfiguration PeerConnection::GetConfiguration() {
RTC_DCHECK_RUN_ON(signaling_thread());
return configuration_;
@ -2687,465 +2555,6 @@ void PeerConnection::PostCreateSessionDescriptionFailure(
MSG_CREATE_SESSIONDESCRIPTION_FAILED, msg);
}
void PeerConnection::GetOptionsForOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
RTC_DCHECK_RUN_ON(signaling_thread());
ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
if (IsUnifiedPlan()) {
GetOptionsForUnifiedPlanOffer(offer_answer_options, session_options);
} else {
GetOptionsForPlanBOffer(offer_answer_options, session_options);
}
// Intentionally unset the data channel type for RTP data channel with the
// second condition. Otherwise the RTP data channels would be successfully
// negotiated by default and the unit tests in WebRtcDataBrowserTest will fail
// when building with chromium. We want to leave RTP data channels broken, so
// people won't try to use them.
if (data_channel_controller_.HasRtpDataChannels() ||
data_channel_type() != cricket::DCT_RTP) {
session_options->data_channel_type = data_channel_type();
}
// Apply ICE restart flag and renomination flag.
bool ice_restart =
offer_answer_options.ice_restart || sdp_handler_.HasNewIceCredentials();
for (auto& options : session_options->media_description_options) {
options.transport_options.ice_restart = ice_restart;
options.transport_options.enable_ice_renomination =
configuration_.enable_ice_renomination;
}
session_options->rtcp_cname = rtcp_cname_;
session_options->crypto_options = GetCryptoOptions();
session_options->pooled_ice_credentials =
network_thread()->Invoke<std::vector<cricket::IceParameters>>(
RTC_FROM_HERE,
rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
port_allocator_.get()));
session_options->offer_extmap_allow_mixed =
configuration_.offer_extmap_allow_mixed;
// Allow fallback for using obsolete SCTP syntax.
// Note that the default in |session_options| is true, while
// the default in |options| is false.
session_options->use_obsolete_sctp_sdp =
offer_answer_options.use_obsolete_sctp_sdp;
}
void PeerConnection::GetOptionsForPlanBOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Figure out transceiver directional preferences.
bool send_audio = !GetAudioTransceiver()->internal()->senders().empty();
bool send_video = !GetVideoTransceiver()->internal()->senders().empty();
// By default, generate sendrecv/recvonly m= sections.
bool recv_audio = true;
bool recv_video = true;
// By default, only offer a new m= section if we have media to send with it.
bool offer_new_audio_description = send_audio;
bool offer_new_video_description = send_video;
bool offer_new_data_description = data_channel_controller_.HasDataChannels();
// The "offer_to_receive_X" options allow those defaults to be overridden.
if (offer_answer_options.offer_to_receive_audio !=
RTCOfferAnswerOptions::kUndefined) {
recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
offer_new_audio_description =
offer_new_audio_description ||
(offer_answer_options.offer_to_receive_audio > 0);
}
if (offer_answer_options.offer_to_receive_video !=
RTCOfferAnswerOptions::kUndefined) {
recv_video = (offer_answer_options.offer_to_receive_video > 0);
offer_new_video_description =
offer_new_video_description ||
(offer_answer_options.offer_to_receive_video > 0);
}
absl::optional<size_t> audio_index;
absl::optional<size_t> video_index;
absl::optional<size_t> data_index;
// If a current description exists, generate m= sections in the same order,
// using the first audio/video/data section that appears and rejecting
// extraneous ones.
if (local_description()) {
GenerateMediaDescriptionOptions(
local_description(),
RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
RtpTransceiverDirectionFromSendRecv(send_video, recv_video),
&audio_index, &video_index, &data_index, session_options);
}
// Add audio/video/data m= sections to the end if needed.
if (!audio_index && offer_new_audio_description) {
cricket::MediaDescriptionOptions options(
cricket::MEDIA_TYPE_AUDIO, cricket::CN_AUDIO,
RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio), false);
options.header_extensions =
channel_manager()->GetSupportedAudioRtpHeaderExtensions();
session_options->media_description_options.push_back(options);
audio_index = session_options->media_description_options.size() - 1;
}
if (!video_index && offer_new_video_description) {
cricket::MediaDescriptionOptions options(
cricket::MEDIA_TYPE_VIDEO, cricket::CN_VIDEO,
RtpTransceiverDirectionFromSendRecv(send_video, recv_video), false);
options.header_extensions =
channel_manager()->GetSupportedVideoRtpHeaderExtensions();
session_options->media_description_options.push_back(options);
video_index = session_options->media_description_options.size() - 1;
}
if (!data_index && offer_new_data_description) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForActiveData(cricket::CN_DATA));
data_index = session_options->media_description_options.size() - 1;
}
cricket::MediaDescriptionOptions* audio_media_description_options =
!audio_index ? nullptr
: &session_options->media_description_options[*audio_index];
cricket::MediaDescriptionOptions* video_media_description_options =
!video_index ? nullptr
: &session_options->media_description_options[*video_index];
AddPlanBRtpSenderOptions(GetSendersInternal(),
audio_media_description_options,
video_media_description_options,
offer_answer_options.num_simulcast_layers);
}
static cricket::MediaDescriptionOptions
GetMediaDescriptionOptionsForTransceiver(
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
transceiver,
const std::string& mid,
bool is_create_offer) {
// NOTE: a stopping transceiver should be treated as a stopped one in
// createOffer as specified in
// https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
bool stopped =
is_create_offer ? transceiver->stopping() : transceiver->stopped();
cricket::MediaDescriptionOptions media_description_options(
transceiver->media_type(), mid, transceiver->direction(), stopped);
media_description_options.codec_preferences =
transceiver->codec_preferences();
media_description_options.header_extensions =
transceiver->HeaderExtensionsToOffer();
// This behavior is specified in JSEP. The gist is that:
// 1. The MSID is included if the RtpTransceiver's direction is sendonly or
// sendrecv.
// 2. If the MSID is included, then it must be included in any subsequent
// offer/answer exactly the same until the RtpTransceiver is stopped.
if (stopped || (!RtpTransceiverDirectionHasSend(transceiver->direction()) &&
!transceiver->internal()->has_ever_been_used_to_send())) {
return media_description_options;
}
cricket::SenderOptions sender_options;
sender_options.track_id = transceiver->sender()->id();
sender_options.stream_ids = transceiver->sender()->stream_ids();
// The following sets up RIDs and Simulcast.
// RIDs are included if Simulcast is requested or if any RID was specified.
RtpParameters send_parameters =
transceiver->internal()->sender_internal()->GetParametersInternal();
bool has_rids = std::any_of(send_parameters.encodings.begin(),
send_parameters.encodings.end(),
[](const RtpEncodingParameters& encoding) {
return !encoding.rid.empty();
});
std::vector<RidDescription> send_rids;
SimulcastLayerList send_layers;
for (const RtpEncodingParameters& encoding : send_parameters.encodings) {
if (encoding.rid.empty()) {
continue;
}
send_rids.push_back(RidDescription(encoding.rid, RidDirection::kSend));
send_layers.AddLayer(SimulcastLayer(encoding.rid, !encoding.active));
}
if (has_rids) {
sender_options.rids = send_rids;
}
sender_options.simulcast_layers = send_layers;
// When RIDs are configured, we must set num_sim_layers to 0 to.
// Otherwise, num_sim_layers must be 1 because either there is no
// simulcast, or simulcast is acheived by munging the SDP.
sender_options.num_sim_layers = has_rids ? 0 : 1;
media_description_options.sender_options.push_back(sender_options);
return media_description_options;
}
// Returns the ContentInfo at mline index |i|, or null if none exists.
static const ContentInfo* GetContentByIndex(
const SessionDescriptionInterface* sdesc,
size_t i) {
if (!sdesc) {
return nullptr;
}
const ContentInfos& contents = sdesc->description()->contents();
return (i < contents.size() ? &contents[i] : nullptr);
}
void PeerConnection::GetOptionsForUnifiedPlanOffer(
const RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Rules for generating an offer are dictated by JSEP sections 5.2.1 (Initial
// Offers) and 5.2.2 (Subsequent Offers).
RTC_DCHECK_EQ(session_options->media_description_options.size(), 0);
const ContentInfos no_infos;
const ContentInfos& local_contents =
(local_description() ? local_description()->description()->contents()
: no_infos);
const ContentInfos& remote_contents =
(remote_description() ? remote_description()->description()->contents()
: no_infos);
// The mline indices that can be recycled. New transceivers should reuse these
// slots first.
std::queue<size_t> recycleable_mline_indices;
// First, go through each media section that exists in either the local or
// remote description and generate a media section in this offer for the
// associated transceiver. If a media section can be recycled, generate a
// default, rejected media section here that can be later overwritten.
for (size_t i = 0;
i < std::max(local_contents.size(), remote_contents.size()); ++i) {
// Either |local_content| or |remote_content| is non-null.
const ContentInfo* local_content =
(i < local_contents.size() ? &local_contents[i] : nullptr);
const ContentInfo* current_local_content =
GetContentByIndex(current_local_description(), i);
const ContentInfo* remote_content =
(i < remote_contents.size() ? &remote_contents[i] : nullptr);
const ContentInfo* current_remote_content =
GetContentByIndex(current_remote_description(), i);
bool had_been_rejected =
(current_local_content && current_local_content->rejected) ||
(current_remote_content && current_remote_content->rejected);
const std::string& mid =
(local_content ? local_content->name : remote_content->name);
cricket::MediaType media_type =
(local_content ? local_content->media_description()->type()
: remote_content->media_description()->type());
if (media_type == cricket::MEDIA_TYPE_AUDIO ||
media_type == cricket::MEDIA_TYPE_VIDEO) {
// A media section is considered eligible for recycling if it is marked as
// rejected in either the current local or current remote description.
auto transceiver = GetAssociatedTransceiver(mid);
if (!transceiver) {
// No associated transceiver. The media section has been stopped.
recycleable_mline_indices.push(i);
session_options->media_description_options.push_back(
cricket::MediaDescriptionOptions(media_type, mid,
RtpTransceiverDirection::kInactive,
/*stopped=*/true));
} else {
// NOTE: a stopping transceiver should be treated as a stopped one in
// createOffer as specified in
// https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
if (had_been_rejected && transceiver->stopping()) {
session_options->media_description_options.push_back(
cricket::MediaDescriptionOptions(
transceiver->media_type(), mid,
RtpTransceiverDirection::kInactive,
/*stopped=*/true));
recycleable_mline_indices.push(i);
} else {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForTransceiver(
transceiver, mid,
/*is_create_offer=*/true));
// CreateOffer shouldn't really cause any state changes in
// PeerConnection, but we need a way to match new transceivers to new
// media sections in SetLocalDescription and JSEP specifies this is
// done by recording the index of the media section generated for the
// transceiver in the offer.
transceiver->internal()->set_mline_index(i);
}
}
} else {
RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
if (had_been_rejected) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForRejectedData(mid));
} else {
RTC_CHECK(GetDataMid());
if (mid == *GetDataMid()) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForActiveData(mid));
} else {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForRejectedData(mid));
}
}
}
}
// Next, look for transceivers that are newly added (that is, are not stopped
// and not associated). Reuse media sections marked as recyclable first,
// otherwise append to the end of the offer. New media sections should be
// added in the order they were added to the PeerConnection.
for (const auto& transceiver : transceivers_.List()) {
if (transceiver->mid() || transceiver->stopping()) {
continue;
}
size_t mline_index;
if (!recycleable_mline_indices.empty()) {
mline_index = recycleable_mline_indices.front();
recycleable_mline_indices.pop();
session_options->media_description_options[mline_index] =
GetMediaDescriptionOptionsForTransceiver(
transceiver, mid_generator_(), /*is_create_offer=*/true);
} else {
mline_index = session_options->media_description_options.size();
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForTransceiver(
transceiver, mid_generator_(), /*is_create_offer=*/true));
}
// See comment above for why CreateOffer changes the transceiver's state.
transceiver->internal()->set_mline_index(mline_index);
}
// Lastly, add a m-section if we have local data channels and an m section
// does not already exist.
if (!GetDataMid() && data_channel_controller_.HasDataChannels()) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForActiveData(mid_generator_()));
}
}
void PeerConnection::GetOptionsForAnswer(
const RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
RTC_DCHECK_RUN_ON(signaling_thread());
ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
if (IsUnifiedPlan()) {
GetOptionsForUnifiedPlanAnswer(offer_answer_options, session_options);
} else {
GetOptionsForPlanBAnswer(offer_answer_options, session_options);
}
// Intentionally unset the data channel type for RTP data channel. Otherwise
// the RTP data channels would be successfully negotiated by default and the
// unit tests in WebRtcDataBrowserTest will fail when building with chromium.
// We want to leave RTP data channels broken, so people won't try to use them.
if (data_channel_controller_.HasRtpDataChannels() ||
data_channel_type() != cricket::DCT_RTP) {
session_options->data_channel_type = data_channel_type();
}
// Apply ICE renomination flag.
for (auto& options : session_options->media_description_options) {
options.transport_options.enable_ice_renomination =
configuration_.enable_ice_renomination;
}
session_options->rtcp_cname = rtcp_cname_;
session_options->crypto_options = GetCryptoOptions();
session_options->pooled_ice_credentials =
network_thread()->Invoke<std::vector<cricket::IceParameters>>(
RTC_FROM_HERE,
rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
port_allocator_.get()));
}
void PeerConnection::GetOptionsForPlanBAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Figure out transceiver directional preferences.
bool send_audio = !GetAudioTransceiver()->internal()->senders().empty();
bool send_video = !GetVideoTransceiver()->internal()->senders().empty();
// By default, generate sendrecv/recvonly m= sections. The direction is also
// restricted by the direction in the offer.
bool recv_audio = true;
bool recv_video = true;
// The "offer_to_receive_X" options allow those defaults to be overridden.
if (offer_answer_options.offer_to_receive_audio !=
RTCOfferAnswerOptions::kUndefined) {
recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
}
if (offer_answer_options.offer_to_receive_video !=
RTCOfferAnswerOptions::kUndefined) {
recv_video = (offer_answer_options.offer_to_receive_video > 0);
}
absl::optional<size_t> audio_index;
absl::optional<size_t> video_index;
absl::optional<size_t> data_index;
// Generate m= sections that match those in the offer.
// Note that mediasession.cc will handle intersection our preferred
// direction with the offered direction.
GenerateMediaDescriptionOptions(
remote_description(),
RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
RtpTransceiverDirectionFromSendRecv(send_video, recv_video), &audio_index,
&video_index, &data_index, session_options);
cricket::MediaDescriptionOptions* audio_media_description_options =
!audio_index ? nullptr
: &session_options->media_description_options[*audio_index];
cricket::MediaDescriptionOptions* video_media_description_options =
!video_index ? nullptr
: &session_options->media_description_options[*video_index];
AddPlanBRtpSenderOptions(GetSendersInternal(),
audio_media_description_options,
video_media_description_options,
offer_answer_options.num_simulcast_layers);
}
void PeerConnection::GetOptionsForUnifiedPlanAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Rules for generating an answer are dictated by JSEP sections 5.3.1 (Initial
// Answers) and 5.3.2 (Subsequent Answers).
RTC_DCHECK(remote_description());
RTC_DCHECK(remote_description()->GetType() == SdpType::kOffer);
for (const ContentInfo& content :
remote_description()->description()->contents()) {
cricket::MediaType media_type = content.media_description()->type();
if (media_type == cricket::MEDIA_TYPE_AUDIO ||
media_type == cricket::MEDIA_TYPE_VIDEO) {
auto transceiver = GetAssociatedTransceiver(content.name);
if (transceiver) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForTransceiver(
transceiver, content.name,
/*is_create_offer=*/false));
} else {
// This should only happen with rejected transceivers.
RTC_DCHECK(content.rejected);
session_options->media_description_options.push_back(
cricket::MediaDescriptionOptions(media_type, content.name,
RtpTransceiverDirection::kInactive,
/*stopped=*/true));
}
} else {
RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
// Reject all data sections if data channels are disabled.
// Reject a data section if it has already been rejected.
// Reject all data sections except for the first one.
if (data_channel_type() == cricket::DCT_NONE || content.rejected ||
content.name != *GetDataMid()) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForRejectedData(content.name));
} else {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForActiveData(content.name));
}
}
}
}
void PeerConnection::GenerateMediaDescriptionOptions(
const SessionDescriptionInterface* session_desc,
@ -3155,6 +2564,7 @@ void PeerConnection::GenerateMediaDescriptionOptions(
absl::optional<size_t>* video_index,
absl::optional<size_t>* data_index,
cricket::MediaSessionOptions* session_options) {
RTC_DCHECK_RUN_ON(signaling_thread());
for (const cricket::ContentInfo& content :
session_desc->description()->contents()) {
if (IsAudioContent(&content)) {
@ -3209,6 +2619,7 @@ void PeerConnection::GenerateMediaDescriptionOptions(
cricket::MediaDescriptionOptions
PeerConnection::GetMediaDescriptionOptionsForActiveData(
const std::string& mid) const {
RTC_DCHECK_RUN_ON(signaling_thread());
// Direction for data sections is meaningless, but legacy endpoints might
// expect sendrecv.
cricket::MediaDescriptionOptions options(cricket::MEDIA_TYPE_DATA, mid,
@ -3222,6 +2633,7 @@ PeerConnection::GetMediaDescriptionOptionsForActiveData(
cricket::MediaDescriptionOptions
PeerConnection::GetMediaDescriptionOptionsForRejectedData(
const std::string& mid) const {
RTC_DCHECK_RUN_ON(signaling_thread());
cricket::MediaDescriptionOptions options(cricket::MEDIA_TYPE_DATA, mid,
RtpTransceiverDirection::kInactive,
/*stopped=*/true);
@ -3511,6 +2923,7 @@ void PeerConnection::OnSctpDataChannelClosed(DataChannelInterface* channel) {
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
PeerConnection::GetAudioTransceiver() const {
RTC_DCHECK_RUN_ON(signaling_thread());
// This method only works with Plan B SDP, where there is a single
// audio/video transceiver.
RTC_DCHECK(!IsUnifiedPlan());
@ -3525,6 +2938,7 @@ PeerConnection::GetAudioTransceiver() const {
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
PeerConnection::GetVideoTransceiver() const {
RTC_DCHECK_RUN_ON(signaling_thread());
// This method only works with Plan B SDP, where there is a single
// audio/video transceiver.
RTC_DCHECK(!IsUnifiedPlan());
@ -3839,7 +3253,7 @@ void PeerConnection::UpdatePayloadTypeDemuxingState(
for (const auto& transceiver : transceivers_.List()) {
cricket::ChannelInterface* channel = transceiver->internal()->channel();
const ContentInfo* content =
FindMediaSectionForTransceiver(transceiver, sdesc);
sdp_handler_.FindMediaSectionForTransceiver(transceiver, sdesc);
if (!channel || !content) {
continue;
}
@ -3888,7 +3302,7 @@ RTCError PeerConnection::PushdownMediaDescription(
// Push down the new SDP media section for each audio/video transceiver.
for (const auto& transceiver : transceivers_.List()) {
const ContentInfo* content_info =
FindMediaSectionForTransceiver(transceiver, sdesc);
sdp_handler_.FindMediaSectionForTransceiver(transceiver, sdesc);
cricket::ChannelInterface* channel = transceiver->internal()->channel();
if (!channel || !content_info || content_info->rejected) {
continue;
@ -4596,30 +4010,6 @@ bool PeerConnection::HasRtcpMuxEnabled(const cricket::ContentInfo* content) {
return content->media_description()->rtcp_mux();
}
bool PeerConnection::ExpectSetLocalDescription(SdpType type) {
PeerConnectionInterface::SignalingState state = signaling_state();
if (type == SdpType::kOffer) {
return (state == PeerConnectionInterface::kStable) ||
(state == PeerConnectionInterface::kHaveLocalOffer);
} else {
RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
return (state == PeerConnectionInterface::kHaveRemoteOffer) ||
(state == PeerConnectionInterface::kHaveLocalPrAnswer);
}
}
bool PeerConnection::ExpectSetRemoteDescription(SdpType type) {
PeerConnectionInterface::SignalingState state = signaling_state();
if (type == SdpType::kOffer) {
return (state == PeerConnectionInterface::kStable) ||
(state == PeerConnectionInterface::kHaveRemoteOffer);
} else {
RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
return (state == PeerConnectionInterface::kHaveLocalOffer) ||
(state == PeerConnectionInterface::kHaveRemotePrAnswer);
}
}
const char* PeerConnection::SessionErrorToString(SessionError error) const {
switch (error) {
case SessionError::kNone:
@ -5068,6 +4458,7 @@ PeerConnectionObserver* PeerConnection::Observer() const {
}
CryptoOptions PeerConnection::GetCryptoOptions() {
RTC_DCHECK_RUN_ON(signaling_thread());
// TODO(bugs.webrtc.org/9891) - Remove PeerConnectionFactory::CryptoOptions
// after it has been removed.
return configuration_.crypto_options.has_value()

71
pc/peer_connection.h
View File

@ -412,15 +412,15 @@ class PeerConnection : public PeerConnectionInternal,
RTC_RUN_ON(signaling_thread());
std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
GetSendersInternal() const RTC_RUN_ON(signaling_thread());
GetSendersInternal() const;
std::vector<
rtc::scoped_refptr<RtpReceiverProxyWithInternal<RtpReceiverInternal>>>
GetReceiversInternal() const RTC_RUN_ON(signaling_thread());
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
GetAudioTransceiver() const RTC_RUN_ON(signaling_thread());
GetAudioTransceiver() const;
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
GetVideoTransceiver() const RTC_RUN_ON(signaling_thread());
GetVideoTransceiver() const;
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
GetFirstAudioTransceiver() const RTC_RUN_ON(signaling_thread());
@ -560,20 +560,6 @@ class PeerConnection : public PeerConnectionInternal,
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
GetTransceiverByMLineIndex(size_t mline_index) const;
// Returns an RtpTransciever, if available, that can be used to receive the
// given media type according to JSEP rules.
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
FindAvailableTransceiverToReceive(cricket::MediaType media_type) const;
// Returns the media section in the given session description that is
// associated with the RtpTransceiver. Returns null if none found or this
// RtpTransceiver is not associated. Logic varies depending on the
// SdpSemantics specified in the configuration.
const cricket::ContentInfo* FindMediaSectionForTransceiver(
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
transceiver,
const SessionDescriptionInterface* sdesc) const;
// Runs the algorithm **process the removal of a remote track** specified in
// the WebRTC specification.
// This method will update the following lists:
@ -595,21 +581,6 @@ class PeerConnection : public PeerConnectionInternal,
void OnNegotiationNeeded();
// Returns a MediaSessionOptions struct with options decided by |options|,
// the local MediaStreams and DataChannels.
void GetOptionsForOffer(const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options);
void GetOptionsForPlanBOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
void GetOptionsForUnifiedPlanOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
RTCError HandleLegacyOfferOptions(const RTCOfferAnswerOptions& options);
void RemoveRecvDirectionFromReceivingTransceiversOfType(
@ -620,21 +591,6 @@ class PeerConnection : public PeerConnectionInternal,
GetReceivingTransceiversOfType(cricket::MediaType media_type)
RTC_RUN_ON(signaling_thread());
// Returns a MediaSessionOptions struct with options decided by
// |constraints|, the local MediaStreams and DataChannels.
void GetOptionsForAnswer(const RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options);
void GetOptionsForPlanBAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
void GetOptionsForUnifiedPlanAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
// Generates MediaDescriptionOptions for the |session_opts| based on existing
// local description or remote description.
void GenerateMediaDescriptionOptions(
@ -644,18 +600,17 @@ class PeerConnection : public PeerConnectionInternal,
absl::optional<size_t>* audio_index,
absl::optional<size_t>* video_index,
absl::optional<size_t>* data_index,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
cricket::MediaSessionOptions* session_options);
// Generates the active MediaDescriptionOptions for the local data channel
// given the specified MID.
cricket::MediaDescriptionOptions GetMediaDescriptionOptionsForActiveData(
const std::string& mid) const RTC_RUN_ON(signaling_thread());
const std::string& mid) const;
// Generates the rejected MediaDescriptionOptions for the local data channel
// given the specified MID.
cricket::MediaDescriptionOptions GetMediaDescriptionOptionsForRejectedData(
const std::string& mid) const RTC_RUN_ON(signaling_thread());
const std::string& mid) const;
// Returns the MID for the data section associated with either the
// RtpDataChannel or SCTP data channel, if it has been set. If no data
@ -732,12 +687,6 @@ class PeerConnection : public PeerConnectionInternal,
return configuration_.sdp_semantics == SdpSemantics::kUnifiedPlan;
}
// The offer/answer machinery assumes the media section MID is present and
// unique. To support legacy end points that do not supply a=mid lines, this
// method will modify the session description to add MIDs generated according
// to the SDP semantics.
void FillInMissingRemoteMids(cricket::SessionDescription* remote_description);
// Return the RtpSender with the given track attached.
rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>
FindSenderForTrack(MediaStreamTrackInterface* track) const
@ -893,12 +842,6 @@ class PeerConnection : public PeerConnectionInternal,
bool ValidateBundleSettings(const cricket::SessionDescription* desc);
bool HasRtcpMuxEnabled(const cricket::ContentInfo* content);
// Check if a call to SetLocalDescription is acceptable with a session
// description of the given type.
bool ExpectSetLocalDescription(SdpType type);
// Check if a call to SetRemoteDescription is acceptable with a session
// description of the given type.
bool ExpectSetRemoteDescription(SdpType type);
// Verifies a=setup attribute as per RFC 5763.
bool ValidateDtlsSetupAttribute(const cricket::SessionDescription* desc,
SdpType type);
@ -1004,7 +947,7 @@ class PeerConnection : public PeerConnectionInternal,
// Returns the CryptoOptions for this PeerConnection. This will always
// return the RTCConfiguration.crypto_options if set and will only default
// back to the PeerConnectionFactory settings if nothing was set.
CryptoOptions GetCryptoOptions() RTC_RUN_ON(signaling_thread());
CryptoOptions GetCryptoOptions();
// Returns rtp transport, result can not be nullptr.
RtpTransportInternal* GetRtpTransport(const std::string& mid)

650
pc/sdp_offer_answer.cc
View File

@ -10,6 +10,9 @@
#include "pc/sdp_offer_answer.h"
#include <algorithm>
#include <queue>
#include "api/media_stream_proxy.h"
#include "api/uma_metrics.h"
#include "pc/media_stream.h"
@ -40,6 +43,9 @@ namespace webrtc {
namespace {
typedef webrtc::PeerConnectionInterface::RTCOfferAnswerOptions
RTCOfferAnswerOptions;
// Error messages
const char kInvalidSdp[] = "Invalid session description.";
const char kInvalidCandidates[] = "Description contains invalid candidates.";
@ -494,6 +500,132 @@ static RTCError DisableSimulcastInSender(
return sender->DisableEncodingLayers(disabled_layers);
}
// The SDP parser used to populate these values by default for the 'content
// name' if an a=mid line was absent.
static absl::string_view GetDefaultMidForPlanB(cricket::MediaType media_type) {
switch (media_type) {
case cricket::MEDIA_TYPE_AUDIO:
return cricket::CN_AUDIO;
case cricket::MEDIA_TYPE_VIDEO:
return cricket::CN_VIDEO;
case cricket::MEDIA_TYPE_DATA:
return cricket::CN_DATA;
}
RTC_NOTREACHED();
return "";
}
// Add options to |[audio/video]_media_description_options| from |senders|.
void AddPlanBRtpSenderOptions(
const std::vector<rtc::scoped_refptr<
RtpSenderProxyWithInternal<RtpSenderInternal>>>& senders,
cricket::MediaDescriptionOptions* audio_media_description_options,
cricket::MediaDescriptionOptions* video_media_description_options,
int num_sim_layers) {
for (const auto& sender : senders) {
if (sender->media_type() == cricket::MEDIA_TYPE_AUDIO) {
if (audio_media_description_options) {
audio_media_description_options->AddAudioSender(
sender->id(), sender->internal()->stream_ids());
}
} else {
RTC_DCHECK(sender->media_type() == cricket::MEDIA_TYPE_VIDEO);
if (video_media_description_options) {
video_media_description_options->AddVideoSender(
sender->id(), sender->internal()->stream_ids(), {},
SimulcastLayerList(), num_sim_layers);
}
}
}
}
static cricket::MediaDescriptionOptions
GetMediaDescriptionOptionsForTransceiver(
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
transceiver,
const std::string& mid,
bool is_create_offer) {
// NOTE: a stopping transceiver should be treated as a stopped one in
// createOffer as specified in
// https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
bool stopped =
is_create_offer ? transceiver->stopping() : transceiver->stopped();
cricket::MediaDescriptionOptions media_description_options(
transceiver->media_type(), mid, transceiver->direction(), stopped);
media_description_options.codec_preferences =
transceiver->codec_preferences();
media_description_options.header_extensions =
transceiver->HeaderExtensionsToOffer();
// This behavior is specified in JSEP. The gist is that:
// 1. The MSID is included if the RtpTransceiver's direction is sendonly or
// sendrecv.
// 2. If the MSID is included, then it must be included in any subsequent
// offer/answer exactly the same until the RtpTransceiver is stopped.
if (stopped || (!RtpTransceiverDirectionHasSend(transceiver->direction()) &&
!transceiver->internal()->has_ever_been_used_to_send())) {
return media_description_options;
}
cricket::SenderOptions sender_options;
sender_options.track_id = transceiver->sender()->id();
sender_options.stream_ids = transceiver->sender()->stream_ids();
// The following sets up RIDs and Simulcast.
// RIDs are included if Simulcast is requested or if any RID was specified.
RtpParameters send_parameters =
transceiver->internal()->sender_internal()->GetParametersInternal();
bool has_rids = std::any_of(send_parameters.encodings.begin(),
send_parameters.encodings.end(),
[](const RtpEncodingParameters& encoding) {
return !encoding.rid.empty();
});
std::vector<RidDescription> send_rids;
SimulcastLayerList send_layers;
for (const RtpEncodingParameters& encoding : send_parameters.encodings) {
if (encoding.rid.empty()) {
continue;
}
send_rids.push_back(RidDescription(encoding.rid, RidDirection::kSend));
send_layers.AddLayer(SimulcastLayer(encoding.rid, !encoding.active));
}
if (has_rids) {
sender_options.rids = send_rids;
}
sender_options.simulcast_layers = send_layers;
// When RIDs are configured, we must set num_sim_layers to 0 to.
// Otherwise, num_sim_layers must be 1 because either there is no
// simulcast, or simulcast is acheived by munging the SDP.
sender_options.num_sim_layers = has_rids ? 0 : 1;
media_description_options.sender_options.push_back(sender_options);
return media_description_options;
}
// Returns the ContentInfo at mline index |i|, or null if none exists.
static const ContentInfo* GetContentByIndex(
const SessionDescriptionInterface* sdesc,
size_t i) {
if (!sdesc) {
return nullptr;
}
const ContentInfos& contents = sdesc->description()->contents();
return (i < contents.size() ? &contents[i] : nullptr);
}
// From |rtc_options|, fill parts of |session_options| shared by all generated
// m= sectionss (in other words, nothing that involves a map/array).
void ExtractSharedMediaSessionOptions(
const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options,
cricket::MediaSessionOptions* session_options) {
session_options->vad_enabled = rtc_options.voice_activity_detection;
session_options->bundle_enabled = rtc_options.use_rtp_mux;
session_options->raw_packetization_for_video =
rtc_options.raw_packetization_for_video;
}
} // namespace
// Used by parameterless SetLocalDescription() to create an offer or answer.
@ -964,7 +1096,7 @@ RTCError SdpOfferAnswerHandler::ApplyLocalDescription(
}
const ContentInfo* content =
pc_->FindMediaSectionForTransceiver(transceiver, local_description());
FindMediaSectionForTransceiver(transceiver, local_description());
if (!content) {
continue;
}
@ -1041,7 +1173,7 @@ RTCError SdpOfferAnswerHandler::ApplyLocalDescription(
continue;
}
const ContentInfo* content =
pc_->FindMediaSectionForTransceiver(transceiver, local_description());
FindMediaSectionForTransceiver(transceiver, local_description());
if (!content) {
continue;
}
@ -1316,8 +1448,8 @@ RTCError SdpOfferAnswerHandler::ApplyRemoteDescription(
std::vector<rtc::scoped_refptr<MediaStreamInterface>> added_streams;
std::vector<rtc::scoped_refptr<MediaStreamInterface>> removed_streams;
for (const auto& transceiver : pc_->transceivers_.List()) {
const ContentInfo* content = pc_->FindMediaSectionForTransceiver(
transceiver, remote_description());
const ContentInfo* content =
FindMediaSectionForTransceiver(transceiver, remote_description());
if (!content) {
continue;
}
@ -1668,7 +1800,7 @@ void SdpOfferAnswerHandler::DoCreateOffer(
}
cricket::MediaSessionOptions session_options;
pc_->GetOptionsForOffer(options, &session_options);
GetOptionsForOffer(options, &session_options);
webrtc_session_desc_factory_->CreateOffer(observer, options, session_options);
}
@ -1753,7 +1885,7 @@ void SdpOfferAnswerHandler::DoCreateAnswer(
}
cricket::MediaSessionOptions session_options;
pc_->GetOptionsForAnswer(options, &session_options);
GetOptionsForAnswer(options, &session_options);
webrtc_session_desc_factory_->CreateAnswer(observer, session_options);
}
@ -1808,7 +1940,7 @@ void SdpOfferAnswerHandler::DoSetRemoteDescription(
// Handle remote descriptions missing a=mid lines for interop with legacy end
// points.
pc_->FillInMissingRemoteMids(desc->description());
FillInMissingRemoteMids(desc->description());
RTCError error = ValidateSessionDescription(desc.get(), cricket::CS_REMOTE);
if (!error.ok()) {
@ -2539,9 +2671,8 @@ RTCError SdpOfferAnswerHandler::ValidateSessionDescription(
}
SdpType type = sdesc->GetType();
if ((source == cricket::CS_LOCAL && !pc_->ExpectSetLocalDescription(type)) ||
(source == cricket::CS_REMOTE &&
!pc_->ExpectSetRemoteDescription(type))) {
if ((source == cricket::CS_LOCAL && !ExpectSetLocalDescription(type)) ||
(source == cricket::CS_REMOTE && !ExpectSetRemoteDescription(type))) {
LOG_AND_RETURN_ERROR(
RTCErrorType::INVALID_STATE,
"Called in wrong state: " + GetSignalingStateString(signaling_state()));
@ -2759,7 +2890,7 @@ SdpOfferAnswerHandler::AssociateTransceiver(
if (!transceiver &&
RtpTransceiverDirectionHasRecv(media_desc->direction()) &&
!media_desc->HasSimulcast()) {
transceiver = pc_->FindAvailableTransceiverToReceive(media_desc->type());
transceiver = FindAvailableTransceiverToReceive(media_desc->type());
}
// If no RtpTransceiver was found in the previous step, create one with a
// recvonly direction.
@ -2918,4 +3049,501 @@ RTCError SdpOfferAnswerHandler::UpdateDataChannel(
return RTCError::OK();
}
bool SdpOfferAnswerHandler::ExpectSetLocalDescription(SdpType type) {
PeerConnectionInterface::SignalingState state = signaling_state();
if (type == SdpType::kOffer) {
return (state == PeerConnectionInterface::kStable) ||
(state == PeerConnectionInterface::kHaveLocalOffer);
} else {
RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
return (state == PeerConnectionInterface::kHaveRemoteOffer) ||
(state == PeerConnectionInterface::kHaveLocalPrAnswer);
}
}
bool SdpOfferAnswerHandler::ExpectSetRemoteDescription(SdpType type) {
PeerConnectionInterface::SignalingState state = signaling_state();
if (type == SdpType::kOffer) {
return (state == PeerConnectionInterface::kStable) ||
(state == PeerConnectionInterface::kHaveRemoteOffer);
} else {
RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
return (state == PeerConnectionInterface::kHaveLocalOffer) ||
(state == PeerConnectionInterface::kHaveRemotePrAnswer);
}
}
void SdpOfferAnswerHandler::FillInMissingRemoteMids(
cricket::SessionDescription* new_remote_description) {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(new_remote_description);
const cricket::ContentInfos no_infos;
const cricket::ContentInfos& local_contents =
(local_description() ? local_description()->description()->contents()
: no_infos);
const cricket::ContentInfos& remote_contents =
(remote_description() ? remote_description()->description()->contents()
: no_infos);
for (size_t i = 0; i < new_remote_description->contents().size(); ++i) {
cricket::ContentInfo& content = new_remote_description->contents()[i];
if (!content.name.empty()) {
continue;
}
std::string new_mid;
absl::string_view source_explanation;
if (IsUnifiedPlan()) {
if (i < local_contents.size()) {
new_mid = local_contents[i].name;
source_explanation = "from the matching local media section";
} else if (i < remote_contents.size()) {
new_mid = remote_contents[i].name;
source_explanation = "from the matching previous remote media section";
} else {
new_mid = pc_->mid_generator()->GenerateString();
source_explanation = "generated just now";
}
} else {
new_mid = std::string(
GetDefaultMidForPlanB(content.media_description()->type()));
source_explanation = "to match pre-existing behavior";
}
RTC_DCHECK(!new_mid.empty());
content.name = new_mid;
new_remote_description->transport_infos()[i].content_name = new_mid;
RTC_LOG(LS_INFO) << "SetRemoteDescription: Remote media section at i=" << i
<< " is missing an a=mid line. Filling in the value '"
<< new_mid << "' " << source_explanation << ".";
}
}
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
SdpOfferAnswerHandler::FindAvailableTransceiverToReceive(
cricket::MediaType media_type) const {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(IsUnifiedPlan());
// From JSEP section 5.10 (Applying a Remote Description):
// If the m= section is sendrecv or recvonly, and there are RtpTransceivers of
// the same type that were added to the PeerConnection by addTrack and are not
// associated with any m= section and are not stopped, find the first such
// RtpTransceiver.
for (auto transceiver : pc_->transceivers_.List()) {
if (transceiver->media_type() == media_type &&
transceiver->internal()->created_by_addtrack() && !transceiver->mid() &&
!transceiver->stopped()) {
return transceiver;
}
}
return nullptr;
}
const cricket::ContentInfo*
SdpOfferAnswerHandler::FindMediaSectionForTransceiver(
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
transceiver,
const SessionDescriptionInterface* sdesc) const {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(transceiver);
RTC_DCHECK(sdesc);
if (IsUnifiedPlan()) {
if (!transceiver->internal()->mid()) {
// This transceiver is not associated with a media section yet.
return nullptr;
}
return sdesc->description()->GetContentByName(
*transceiver->internal()->mid());
} else {
// Plan B only allows at most one audio and one video section, so use the
// first media section of that type.
return cricket::GetFirstMediaContent(sdesc->description()->contents(),
transceiver->media_type());
}
}
void SdpOfferAnswerHandler::GetOptionsForOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
RTC_DCHECK_RUN_ON(signaling_thread());
ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
if (IsUnifiedPlan()) {
GetOptionsForUnifiedPlanOffer(offer_answer_options, session_options);
} else {
GetOptionsForPlanBOffer(offer_answer_options, session_options);
}
// Intentionally unset the data channel type for RTP data channel with the
// second condition. Otherwise the RTP data channels would be successfully
// negotiated by default and the unit tests in WebRtcDataBrowserTest will fail
// when building with chromium. We want to leave RTP data channels broken, so
// people won't try to use them.
if (pc_->data_channel_controller()->HasRtpDataChannels() ||
pc_->data_channel_type() != cricket::DCT_RTP) {
session_options->data_channel_type = pc_->data_channel_type();
}
// Apply ICE restart flag and renomination flag.
bool ice_restart = offer_answer_options.ice_restart || HasNewIceCredentials();
for (auto& options : session_options->media_description_options) {
options.transport_options.ice_restart = ice_restart;
options.transport_options.enable_ice_renomination =
pc_->configuration()->enable_ice_renomination;
}
session_options->rtcp_cname = pc_->rtcp_cname_;
session_options->crypto_options = pc_->GetCryptoOptions();
session_options->pooled_ice_credentials =
pc_->network_thread()->Invoke<std::vector<cricket::IceParameters>>(
RTC_FROM_HERE,
rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
pc_->port_allocator_.get()));
session_options->offer_extmap_allow_mixed =
pc_->configuration()->offer_extmap_allow_mixed;
// Allow fallback for using obsolete SCTP syntax.
// Note that the default in |session_options| is true, while
// the default in |options| is false.
session_options->use_obsolete_sctp_sdp =
offer_answer_options.use_obsolete_sctp_sdp;
}
void SdpOfferAnswerHandler::GetOptionsForPlanBOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Figure out transceiver directional preferences.
bool send_audio = !pc_->GetAudioTransceiver()->internal()->senders().empty();
bool send_video = !pc_->GetVideoTransceiver()->internal()->senders().empty();
// By default, generate sendrecv/recvonly m= sections.
bool recv_audio = true;
bool recv_video = true;
// By default, only offer a new m= section if we have media to send with it.
bool offer_new_audio_description = send_audio;
bool offer_new_video_description = send_video;
bool offer_new_data_description =
pc_->data_channel_controller()->HasDataChannels();
// The "offer_to_receive_X" options allow those defaults to be overridden.
if (offer_answer_options.offer_to_receive_audio !=
PeerConnectionInterface::RTCOfferAnswerOptions::kUndefined) {
recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
offer_new_audio_description =
offer_new_audio_description ||
(offer_answer_options.offer_to_receive_audio > 0);
}
if (offer_answer_options.offer_to_receive_video !=
RTCOfferAnswerOptions::kUndefined) {
recv_video = (offer_answer_options.offer_to_receive_video > 0);
offer_new_video_description =
offer_new_video_description ||
(offer_answer_options.offer_to_receive_video > 0);
}
absl::optional<size_t> audio_index;
absl::optional<size_t> video_index;
absl::optional<size_t> data_index;
// If a current description exists, generate m= sections in the same order,
// using the first audio/video/data section that appears and rejecting
// extraneous ones.
if (local_description()) {
pc_->GenerateMediaDescriptionOptions(
local_description(),
RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
RtpTransceiverDirectionFromSendRecv(send_video, recv_video),
&audio_index, &video_index, &data_index, session_options);
}
// Add audio/video/data m= sections to the end if needed.
if (!audio_index && offer_new_audio_description) {
cricket::MediaDescriptionOptions options(
cricket::MEDIA_TYPE_AUDIO, cricket::CN_AUDIO,
RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio), false);
options.header_extensions =
pc_->channel_manager()->GetSupportedAudioRtpHeaderExtensions();
session_options->media_description_options.push_back(options);
audio_index = session_options->media_description_options.size() - 1;
}
if (!video_index && offer_new_video_description) {
cricket::MediaDescriptionOptions options(
cricket::MEDIA_TYPE_VIDEO, cricket::CN_VIDEO,
RtpTransceiverDirectionFromSendRecv(send_video, recv_video), false);
options.header_extensions =
pc_->channel_manager()->GetSupportedVideoRtpHeaderExtensions();
session_options->media_description_options.push_back(options);
video_index = session_options->media_description_options.size() - 1;
}
if (!data_index && offer_new_data_description) {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForActiveData(cricket::CN_DATA));
data_index = session_options->media_description_options.size() - 1;
}
cricket::MediaDescriptionOptions* audio_media_description_options =
!audio_index ? nullptr
: &session_options->media_description_options[*audio_index];
cricket::MediaDescriptionOptions* video_media_description_options =
!video_index ? nullptr
: &session_options->media_description_options[*video_index];
AddPlanBRtpSenderOptions(pc_->GetSendersInternal(),
audio_media_description_options,
video_media_description_options,
offer_answer_options.num_simulcast_layers);
}
void SdpOfferAnswerHandler::GetOptionsForUnifiedPlanOffer(
const RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Rules for generating an offer are dictated by JSEP sections 5.2.1 (Initial
// Offers) and 5.2.2 (Subsequent Offers).
RTC_DCHECK_EQ(session_options->media_description_options.size(), 0);
const ContentInfos no_infos;
const ContentInfos& local_contents =
(local_description() ? local_description()->description()->contents()
: no_infos);
const ContentInfos& remote_contents =
(remote_description() ? remote_description()->description()->contents()
: no_infos);
// The mline indices that can be recycled. New transceivers should reuse these
// slots first.
std::queue<size_t> recycleable_mline_indices;
// First, go through each media section that exists in either the local or
// remote description and generate a media section in this offer for the
// associated transceiver. If a media section can be recycled, generate a
// default, rejected media section here that can be later overwritten.
for (size_t i = 0;
i < std::max(local_contents.size(), remote_contents.size()); ++i) {
// Either |local_content| or |remote_content| is non-null.
const ContentInfo* local_content =
(i < local_contents.size() ? &local_contents[i] : nullptr);
const ContentInfo* current_local_content =
GetContentByIndex(current_local_description(), i);
const ContentInfo* remote_content =
(i < remote_contents.size() ? &remote_contents[i] : nullptr);
const ContentInfo* current_remote_content =
GetContentByIndex(current_remote_description(), i);
bool had_been_rejected =
(current_local_content && current_local_content->rejected) ||
(current_remote_content && current_remote_content->rejected);
const std::string& mid =
(local_content ? local_content->name : remote_content->name);
cricket::MediaType media_type =
(local_content ? local_content->media_description()->type()
: remote_content->media_description()->type());
if (media_type == cricket::MEDIA_TYPE_AUDIO ||
media_type == cricket::MEDIA_TYPE_VIDEO) {
// A media section is considered eligible for recycling if it is marked as
// rejected in either the current local or current remote description.
auto transceiver = pc_->GetAssociatedTransceiver(mid);
if (!transceiver) {
// No associated transceiver. The media section has been stopped.
recycleable_mline_indices.push(i);
session_options->media_description_options.push_back(
cricket::MediaDescriptionOptions(media_type, mid,
RtpTransceiverDirection::kInactive,
/*stopped=*/true));
} else {
// NOTE: a stopping transceiver should be treated as a stopped one in
// createOffer as specified in
// https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
if (had_been_rejected && transceiver->stopping()) {
session_options->media_description_options.push_back(
cricket::MediaDescriptionOptions(
transceiver->media_type(), mid,
RtpTransceiverDirection::kInactive,
/*stopped=*/true));
recycleable_mline_indices.push(i);
} else {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForTransceiver(
transceiver, mid,
/*is_create_offer=*/true));
// CreateOffer shouldn't really cause any state changes in
// PeerConnection, but we need a way to match new transceivers to new
// media sections in SetLocalDescription and JSEP specifies this is
// done by recording the index of the media section generated for the
// transceiver in the offer.
transceiver->internal()->set_mline_index(i);
}
}
} else {
RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
if (had_been_rejected) {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForRejectedData(mid));
} else {
RTC_CHECK(pc_->GetDataMid());
if (mid == *(pc_->GetDataMid())) {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForActiveData(mid));
} else {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForRejectedData(mid));
}
}
}
}
// Next, look for transceivers that are newly added (that is, are not stopped
// and not associated). Reuse media sections marked as recyclable first,
// otherwise append to the end of the offer. New media sections should be
// added in the order they were added to the PeerConnection.
for (const auto& transceiver : pc_->transceivers_.List()) {
if (transceiver->mid() || transceiver->stopping()) {
continue;
}
size_t mline_index;
if (!recycleable_mline_indices.empty()) {
mline_index = recycleable_mline_indices.front();
recycleable_mline_indices.pop();
session_options->media_description_options[mline_index] =
GetMediaDescriptionOptionsForTransceiver(
transceiver, pc_->mid_generator()->GenerateString(),
/*is_create_offer=*/true);
} else {
mline_index = session_options->media_description_options.size();
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForTransceiver(
transceiver, pc_->mid_generator()->GenerateString(),
/*is_create_offer=*/true));
}
// See comment above for why CreateOffer changes the transceiver's state.
transceiver->internal()->set_mline_index(mline_index);
}
// Lastly, add a m-section if we have local data channels and an m section
// does not already exist.
if (!pc_->GetDataMid() && pc_->data_channel_controller()->HasDataChannels()) {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForActiveData(
pc_->mid_generator()->GenerateString()));
}
}
void SdpOfferAnswerHandler::GetOptionsForAnswer(
const RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
RTC_DCHECK_RUN_ON(signaling_thread());
ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
if (IsUnifiedPlan()) {
GetOptionsForUnifiedPlanAnswer(offer_answer_options, session_options);
} else {
GetOptionsForPlanBAnswer(offer_answer_options, session_options);
}
// Intentionally unset the data channel type for RTP data channel. Otherwise
// the RTP data channels would be successfully negotiated by default and the
// unit tests in WebRtcDataBrowserTest will fail when building with chromium.
// We want to leave RTP data channels broken, so people won't try to use them.
if (pc_->data_channel_controller()->HasRtpDataChannels() ||
pc_->data_channel_type() != cricket::DCT_RTP) {
session_options->data_channel_type = pc_->data_channel_type();
}
// Apply ICE renomination flag.
for (auto& options : session_options->media_description_options) {
options.transport_options.enable_ice_renomination =
pc_->configuration()->enable_ice_renomination;
}
session_options->rtcp_cname = pc_->rtcp_cname_;
session_options->crypto_options = pc_->GetCryptoOptions();
session_options->pooled_ice_credentials =
pc_->network_thread()->Invoke<std::vector<cricket::IceParameters>>(
RTC_FROM_HERE,
rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
pc_->port_allocator_.get()));
}
void SdpOfferAnswerHandler::GetOptionsForPlanBAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Figure out transceiver directional preferences.
bool send_audio = !pc_->GetAudioTransceiver()->internal()->senders().empty();
bool send_video = !pc_->GetVideoTransceiver()->internal()->senders().empty();
// By default, generate sendrecv/recvonly m= sections. The direction is also
// restricted by the direction in the offer.
bool recv_audio = true;
bool recv_video = true;
// The "offer_to_receive_X" options allow those defaults to be overridden.
if (offer_answer_options.offer_to_receive_audio !=
RTCOfferAnswerOptions::kUndefined) {
recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
}
if (offer_answer_options.offer_to_receive_video !=
RTCOfferAnswerOptions::kUndefined) {
recv_video = (offer_answer_options.offer_to_receive_video > 0);
}
absl::optional<size_t> audio_index;
absl::optional<size_t> video_index;
absl::optional<size_t> data_index;
// Generate m= sections that match those in the offer.
// Note that mediasession.cc will handle intersection our preferred
// direction with the offered direction.
pc_->GenerateMediaDescriptionOptions(
remote_description(),
RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
RtpTransceiverDirectionFromSendRecv(send_video, recv_video), &audio_index,
&video_index, &data_index, session_options);
cricket::MediaDescriptionOptions* audio_media_description_options =
!audio_index ? nullptr
: &session_options->media_description_options[*audio_index];
cricket::MediaDescriptionOptions* video_media_description_options =
!video_index ? nullptr
: &session_options->media_description_options[*video_index];
AddPlanBRtpSenderOptions(pc_->GetSendersInternal(),
audio_media_description_options,
video_media_description_options,
offer_answer_options.num_simulcast_layers);
}
void SdpOfferAnswerHandler::GetOptionsForUnifiedPlanAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
cricket::MediaSessionOptions* session_options) {
// Rules for generating an answer are dictated by JSEP sections 5.3.1 (Initial
// Answers) and 5.3.2 (Subsequent Answers).
RTC_DCHECK(remote_description());
RTC_DCHECK(remote_description()->GetType() == SdpType::kOffer);
for (const ContentInfo& content :
remote_description()->description()->contents()) {
cricket::MediaType media_type = content.media_description()->type();
if (media_type == cricket::MEDIA_TYPE_AUDIO ||
media_type == cricket::MEDIA_TYPE_VIDEO) {
auto transceiver = pc_->GetAssociatedTransceiver(content.name);
if (transceiver) {
session_options->media_description_options.push_back(
GetMediaDescriptionOptionsForTransceiver(
transceiver, content.name,
/*is_create_offer=*/false));
} else {
// This should only happen with rejected transceivers.
RTC_DCHECK(content.rejected);
session_options->media_description_options.push_back(
cricket::MediaDescriptionOptions(media_type, content.name,
RtpTransceiverDirection::kInactive,
/*stopped=*/true));
}
} else {
RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
// Reject all data sections if data channels are disabled.
// Reject a data section if it has already been rejected.
// Reject all data sections except for the first one.
if (pc_->data_channel_type() == cricket::DCT_NONE || content.rejected ||
content.name != *(pc_->GetDataMid())) {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForRejectedData(content.name));
} else {
session_options->media_description_options.push_back(
pc_->GetMediaDescriptionOptionsForActiveData(content.name));
}
}
}
}
} // namespace webrtc

58
pc/sdp_offer_answer.h
View File

@ -131,6 +131,15 @@ class SdpOfferAnswerHandler {
bool IceRestartPending(const std::string& content_name) const;
void UpdateNegotiationNeeded();
// Returns the media section in the given session description that is
// associated with the RtpTransceiver. Returns null if none found or this
// RtpTransceiver is not associated. Logic varies depending on the
// SdpSemantics specified in the configuration.
const cricket::ContentInfo* FindMediaSectionForTransceiver(
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
transceiver,
const SessionDescriptionInterface* sdesc) const;
private:
class ImplicitCreateSessionDescriptionObserver;
friend class ImplicitCreateSessionDescriptionObserver;
@ -253,6 +262,55 @@ class SdpOfferAnswerHandler {
const cricket::ContentInfo& content,
const cricket::ContentGroup* bundle_group)
RTC_RUN_ON(signaling_thread());
// Check if a call to SetLocalDescription is acceptable with a session
// description of the given type.
bool ExpectSetLocalDescription(SdpType type);
// Check if a call to SetRemoteDescription is acceptable with a session
// description of the given type.
bool ExpectSetRemoteDescription(SdpType type);
// The offer/answer machinery assumes the media section MID is present and
// unique. To support legacy end points that do not supply a=mid lines, this
// method will modify the session description to add MIDs generated according
// to the SDP semantics.
void FillInMissingRemoteMids(cricket::SessionDescription* remote_description);
// Returns an RtpTransciever, if available, that can be used to receive the
// given media type according to JSEP rules.
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
FindAvailableTransceiverToReceive(cricket::MediaType media_type) const;
// Returns a MediaSessionOptions struct with options decided by |options|,
// the local MediaStreams and DataChannels.
void GetOptionsForOffer(const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options);
void GetOptionsForPlanBOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
void GetOptionsForUnifiedPlanOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
// Returns a MediaSessionOptions struct with options decided by
// |constraints|, the local MediaStreams and DataChannels.
void GetOptionsForAnswer(const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options);
void GetOptionsForPlanBAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
void GetOptionsForUnifiedPlanAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions&
offer_answer_options,
cricket::MediaSessionOptions* session_options)
RTC_RUN_ON(signaling_thread());
// ===================================================================