blob: 929736e8c6f4c41b05183b4018597651bf2e067d [file] [log] [blame]
/*
* Copyright 2020 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "pc/sdp_offer_answer.h"
#include <algorithm>
#include <iterator>
#include <map>
#include <queue>
#include <type_traits>
#include <utility>
#include "absl/algorithm/container.h"
#include "absl/memory/memory.h"
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "api/crypto/crypto_options.h"
#include "api/dtls_transport_interface.h"
#include "api/rtp_parameters.h"
#include "api/rtp_receiver_interface.h"
#include "api/rtp_sender_interface.h"
#include "api/video/builtin_video_bitrate_allocator_factory.h"
#include "media/base/codec.h"
#include "media/base/media_engine.h"
#include "media/base/rid_description.h"
#include "p2p/base/ice_transport_internal.h"
#include "p2p/base/p2p_constants.h"
#include "p2p/base/p2p_transport_channel.h"
#include "p2p/base/port.h"
#include "p2p/base/transport_description.h"
#include "p2p/base/transport_description_factory.h"
#include "p2p/base/transport_info.h"
#include "pc/data_channel_utils.h"
#include "pc/dtls_transport.h"
#include "pc/media_stream.h"
#include "pc/media_stream_proxy.h"
#include "pc/peer_connection.h"
#include "pc/peer_connection_message_handler.h"
#include "pc/rtp_media_utils.h"
#include "pc/rtp_sender.h"
#include "pc/rtp_transport_internal.h"
#include "pc/simulcast_description.h"
#include "pc/stats_collector.h"
#include "pc/usage_pattern.h"
#include "pc/webrtc_session_description_factory.h"
#include "rtc_base/helpers.h"
#include "rtc_base/location.h"
#include "rtc_base/logging.h"
#include "rtc_base/ref_counted_object.h"
#include "rtc_base/rtc_certificate.h"
#include "rtc_base/ssl_stream_adapter.h"
#include "rtc_base/string_encode.h"
#include "rtc_base/strings/string_builder.h"
#include "rtc_base/third_party/sigslot/sigslot.h"
#include "rtc_base/trace_event.h"
#include "system_wrappers/include/field_trial.h"
#include "system_wrappers/include/metrics.h"
using cricket::ContentInfo;
using cricket::ContentInfos;
using cricket::MediaContentDescription;
using cricket::MediaProtocolType;
using cricket::RidDescription;
using cricket::RidDirection;
using cricket::SessionDescription;
using cricket::SimulcastDescription;
using cricket::SimulcastLayer;
using cricket::SimulcastLayerList;
using cricket::StreamParams;
using cricket::TransportInfo;
using cricket::LOCAL_PORT_TYPE;
using cricket::PRFLX_PORT_TYPE;
using cricket::RELAY_PORT_TYPE;
using cricket::STUN_PORT_TYPE;
namespace webrtc {
namespace {
typedef webrtc::PeerConnectionInterface::RTCOfferAnswerOptions
RTCOfferAnswerOptions;
constexpr const char* kAlwaysAllowPayloadTypeDemuxingFieldTrialName =
"WebRTC-AlwaysAllowPayloadTypeDemuxing";
// Error messages
const char kInvalidSdp[] = "Invalid session description.";
const char kInvalidCandidates[] = "Description contains invalid candidates.";
const char kBundleWithoutRtcpMux[] =
"rtcp-mux must be enabled when BUNDLE "
"is enabled.";
const char kMlineMismatchInAnswer[] =
"The order of m-lines in answer doesn't match order in offer. Rejecting "
"answer.";
const char kMlineMismatchInSubsequentOffer[] =
"The order of m-lines in subsequent offer doesn't match order from "
"previous offer/answer.";
const char kSdpWithoutIceUfragPwd[] =
"Called with SDP without ice-ufrag and ice-pwd.";
const char kSdpWithoutDtlsFingerprint[] =
"Called with SDP without DTLS fingerprint.";
const char kSdpWithoutSdesCrypto[] = "Called with SDP without SDES crypto.";
const char kSessionError[] = "Session error code: ";
const char kSessionErrorDesc[] = "Session error description: ";
// UMA metric names.
const char kSimulcastVersionApplyLocalDescription[] =
"WebRTC.PeerConnection.Simulcast.ApplyLocalDescription";
const char kSimulcastVersionApplyRemoteDescription[] =
"WebRTC.PeerConnection.Simulcast.ApplyRemoteDescription";
const char kSimulcastDisabled[] = "WebRTC.PeerConnection.Simulcast.Disabled";
// The length of RTCP CNAMEs.
static const int kRtcpCnameLength = 16;
const char kDefaultStreamId[] = "default";
// NOTE: Duplicated in peer_connection.cc:
static const char kDefaultAudioSenderId[] = "defaulta0";
static const char kDefaultVideoSenderId[] = "defaultv0";
void NoteAddIceCandidateResult(int result) {
RTC_HISTOGRAM_ENUMERATION("WebRTC.PeerConnection.AddIceCandidate", result,
kAddIceCandidateMax);
}
void NoteKeyProtocolAndMedia(KeyExchangeProtocolType protocol_type,
cricket::MediaType media_type) {
// Array of structs needed to map {KeyExchangeProtocolType,
// cricket::MediaType} to KeyExchangeProtocolMedia without using std::map in
// order to avoid -Wglobal-constructors and -Wexit-time-destructors.
static constexpr struct {
KeyExchangeProtocolType protocol_type;
cricket::MediaType media_type;
KeyExchangeProtocolMedia protocol_media;
} kEnumCounterKeyProtocolMediaMap[] = {
{kEnumCounterKeyProtocolDtls, cricket::MEDIA_TYPE_AUDIO,
kEnumCounterKeyProtocolMediaTypeDtlsAudio},
{kEnumCounterKeyProtocolDtls, cricket::MEDIA_TYPE_VIDEO,
kEnumCounterKeyProtocolMediaTypeDtlsVideo},
{kEnumCounterKeyProtocolDtls, cricket::MEDIA_TYPE_DATA,
kEnumCounterKeyProtocolMediaTypeDtlsData},
{kEnumCounterKeyProtocolSdes, cricket::MEDIA_TYPE_AUDIO,
kEnumCounterKeyProtocolMediaTypeSdesAudio},
{kEnumCounterKeyProtocolSdes, cricket::MEDIA_TYPE_VIDEO,
kEnumCounterKeyProtocolMediaTypeSdesVideo},
{kEnumCounterKeyProtocolSdes, cricket::MEDIA_TYPE_DATA,
kEnumCounterKeyProtocolMediaTypeSdesData},
};
RTC_HISTOGRAM_ENUMERATION("WebRTC.PeerConnection.KeyProtocol", protocol_type,
kEnumCounterKeyProtocolMax);
for (const auto& i : kEnumCounterKeyProtocolMediaMap) {
if (i.protocol_type == protocol_type && i.media_type == media_type) {
RTC_HISTOGRAM_ENUMERATION("WebRTC.PeerConnection.KeyProtocolByMedia",
i.protocol_media,
kEnumCounterKeyProtocolMediaTypeMax);
}
}
}
std::map<std::string, const cricket::ContentGroup*> GetBundleGroupsByMid(
const SessionDescription* desc) {
std::vector<const cricket::ContentGroup*> bundle_groups =
desc->GetGroupsByName(cricket::GROUP_TYPE_BUNDLE);
std::map<std::string, const cricket::ContentGroup*> bundle_groups_by_mid;
for (const cricket::ContentGroup* bundle_group : bundle_groups) {
for (const std::string& content_name : bundle_group->content_names()) {
bundle_groups_by_mid[content_name] = bundle_group;
}
}
return bundle_groups_by_mid;
}
// Returns true if |new_desc| requests an ICE restart (i.e., new ufrag/pwd).
bool CheckForRemoteIceRestart(const SessionDescriptionInterface* old_desc,
const SessionDescriptionInterface* new_desc,
const std::string& content_name) {
if (!old_desc) {
return false;
}
const SessionDescription* new_sd = new_desc->description();
const SessionDescription* old_sd = old_desc->description();
const ContentInfo* cinfo = new_sd->GetContentByName(content_name);
if (!cinfo || cinfo->rejected) {
return false;
}
// If the content isn't rejected, check if ufrag and password has changed.
const cricket::TransportDescription* new_transport_desc =
new_sd->GetTransportDescriptionByName(content_name);
const cricket::TransportDescription* old_transport_desc =
old_sd->GetTransportDescriptionByName(content_name);
if (!new_transport_desc || !old_transport_desc) {
// No transport description exists. This is not an ICE restart.
return false;
}
if (cricket::IceCredentialsChanged(
old_transport_desc->ice_ufrag, old_transport_desc->ice_pwd,
new_transport_desc->ice_ufrag, new_transport_desc->ice_pwd)) {
RTC_LOG(LS_INFO) << "Remote peer requests ICE restart for " << content_name
<< ".";
return true;
}
return false;
}
// Generates a string error message for SetLocalDescription/SetRemoteDescription
// from an RTCError.
std::string GetSetDescriptionErrorMessage(cricket::ContentSource source,
SdpType type,
const RTCError& error) {
rtc::StringBuilder oss;
oss << "Failed to set " << (source == cricket::CS_LOCAL ? "local" : "remote")
<< " " << SdpTypeToString(type) << " sdp: " << error.message();
return oss.Release();
}
std::string GetStreamIdsString(rtc::ArrayView<const std::string> stream_ids) {
std::string output = "streams=[";
const char* separator = "";
for (const auto& stream_id : stream_ids) {
output.append(separator).append(stream_id);
separator = ", ";
}
output.append("]");
return output;
}
void ReportSimulcastApiVersion(const char* name,
const SessionDescription& session) {
bool has_legacy = false;
bool has_spec_compliant = false;
for (const ContentInfo& content : session.contents()) {
if (!content.media_description()) {
continue;
}
has_spec_compliant |= content.media_description()->HasSimulcast();
for (const StreamParams& sp : content.media_description()->streams()) {
has_legacy |= sp.has_ssrc_group(cricket::kSimSsrcGroupSemantics);
}
}
if (has_legacy) {
RTC_HISTOGRAM_ENUMERATION(name, kSimulcastApiVersionLegacy,
kSimulcastApiVersionMax);
}
if (has_spec_compliant) {
RTC_HISTOGRAM_ENUMERATION(name, kSimulcastApiVersionSpecCompliant,
kSimulcastApiVersionMax);
}
if (!has_legacy && !has_spec_compliant) {
RTC_HISTOGRAM_ENUMERATION(name, kSimulcastApiVersionNone,
kSimulcastApiVersionMax);
}
}
const ContentInfo* FindTransceiverMSection(
RtpTransceiver* transceiver,
const SessionDescriptionInterface* session_description) {
return transceiver->mid()
? session_description->description()->GetContentByName(
*transceiver->mid())
: nullptr;
}
// If the direction is "recvonly" or "inactive", treat the description
// as containing no streams.
// See: https://code.google.com/p/webrtc/issues/detail?id=5054
std::vector<cricket::StreamParams> GetActiveStreams(
const cricket::MediaContentDescription* desc) {
return RtpTransceiverDirectionHasSend(desc->direction())
? desc->streams()
: std::vector<cricket::StreamParams>();
}
// Logic to decide if an m= section can be recycled. This means that the new
// m= section is not rejected, but the old local or remote m= section is
// rejected. |old_content_one| and |old_content_two| refer to the m= section
// of the old remote and old local descriptions in no particular order.
// We need to check both the old local and remote because either
// could be the most current from the latest negotation.
bool IsMediaSectionBeingRecycled(SdpType type,
const ContentInfo& content,
const ContentInfo* old_content_one,
const ContentInfo* old_content_two) {
return type == SdpType::kOffer && !content.rejected &&
((old_content_one && old_content_one->rejected) ||
(old_content_two && old_content_two->rejected));
}
// Verify that the order of media sections in |new_desc| matches
// |current_desc|. The number of m= sections in |new_desc| should be no
// less than |current_desc|. In the case of checking an answer's
// |new_desc|, the |current_desc| is the last offer that was set as the
// local or remote. In the case of checking an offer's |new_desc| we
// check against the local and remote descriptions stored from the last
// negotiation, because either of these could be the most up to date for
// possible rejected m sections. These are the |current_desc| and
// |secondary_current_desc|.
bool MediaSectionsInSameOrder(const SessionDescription& current_desc,
const SessionDescription* secondary_current_desc,
const SessionDescription& new_desc,
const SdpType type) {
if (current_desc.contents().size() > new_desc.contents().size()) {
return false;
}
for (size_t i = 0; i < current_desc.contents().size(); ++i) {
const cricket::ContentInfo* secondary_content_info = nullptr;
if (secondary_current_desc &&
i < secondary_current_desc->contents().size()) {
secondary_content_info = &secondary_current_desc->contents()[i];
}
if (IsMediaSectionBeingRecycled(type, new_desc.contents()[i],
&current_desc.contents()[i],
secondary_content_info)) {
// For new offer descriptions, if the media section can be recycled, it's
// valid for the MID and media type to change.
continue;
}
if (new_desc.contents()[i].name != current_desc.contents()[i].name) {
return false;
}
const MediaContentDescription* new_desc_mdesc =
new_desc.contents()[i].media_description();
const MediaContentDescription* current_desc_mdesc =
current_desc.contents()[i].media_description();
if (new_desc_mdesc->type() != current_desc_mdesc->type()) {
return false;
}
}
return true;
}
bool MediaSectionsHaveSameCount(const SessionDescription& desc1,
const SessionDescription& desc2) {
return desc1.contents().size() == desc2.contents().size();
}
// Checks that each non-rejected content has SDES crypto keys or a DTLS
// fingerprint, unless it's in a BUNDLE group, in which case only the
// BUNDLE-tag section (first media section/description in the BUNDLE group)
// needs a ufrag and pwd. Mismatches, such as replying with a DTLS fingerprint
// to SDES keys, will be caught in JsepTransport negotiation, and backstopped
// by Channel's |srtp_required| check.
RTCError VerifyCrypto(const SessionDescription* desc,
bool dtls_enabled,
const std::map<std::string, const cricket::ContentGroup*>&
bundle_groups_by_mid) {
for (const cricket::ContentInfo& content_info : desc->contents()) {
if (content_info.rejected) {
continue;
}
// Note what media is used with each crypto protocol, for all sections.
NoteKeyProtocolAndMedia(dtls_enabled ? webrtc::kEnumCounterKeyProtocolDtls
: webrtc::kEnumCounterKeyProtocolSdes,
content_info.media_description()->type());
const std::string& mid = content_info.name;
auto it = bundle_groups_by_mid.find(mid);
const cricket::ContentGroup* bundle =
it != bundle_groups_by_mid.end() ? it->second : nullptr;
if (bundle && mid != *(bundle->FirstContentName())) {
// This isn't the first media section in the BUNDLE group, so it's not
// required to have crypto attributes, since only the crypto attributes
// from the first section actually get used.
continue;
}
// If the content isn't rejected or bundled into another m= section, crypto
// must be present.
const MediaContentDescription* media = content_info.media_description();
const TransportInfo* tinfo = desc->GetTransportInfoByName(mid);
if (!media || !tinfo) {
// Something is not right.
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER, kInvalidSdp);
}
if (dtls_enabled) {
if (!tinfo->description.identity_fingerprint) {
RTC_LOG(LS_WARNING)
<< "Session description must have DTLS fingerprint if "
"DTLS enabled.";
return RTCError(RTCErrorType::INVALID_PARAMETER,
kSdpWithoutDtlsFingerprint);
}
} else {
if (media->cryptos().empty()) {
RTC_LOG(LS_WARNING)
<< "Session description must have SDES when DTLS disabled.";
return RTCError(RTCErrorType::INVALID_PARAMETER, kSdpWithoutSdesCrypto);
}
}
}
return RTCError::OK();
}
// Checks that each non-rejected content has ice-ufrag and ice-pwd set, unless
// it's in a BUNDLE group, in which case only the BUNDLE-tag section (first
// media section/description in the BUNDLE group) needs a ufrag and pwd.
bool VerifyIceUfragPwdPresent(
const SessionDescription* desc,
const std::map<std::string, const cricket::ContentGroup*>&
bundle_groups_by_mid) {
for (const cricket::ContentInfo& content_info : desc->contents()) {
if (content_info.rejected) {
continue;
}
const std::string& mid = content_info.name;
auto it = bundle_groups_by_mid.find(mid);
const cricket::ContentGroup* bundle =
it != bundle_groups_by_mid.end() ? it->second : nullptr;
if (bundle && mid != *(bundle->FirstContentName())) {
// This isn't the first media section in the BUNDLE group, so it's not
// required to have ufrag/password, since only the ufrag/password from
// the first section actually get used.
continue;
}
// If the content isn't rejected or bundled into another m= section,
// ice-ufrag and ice-pwd must be present.
const TransportInfo* tinfo = desc->GetTransportInfoByName(mid);
if (!tinfo) {
// Something is not right.
RTC_LOG(LS_ERROR) << kInvalidSdp;
return false;
}
if (tinfo->description.ice_ufrag.empty() ||
tinfo->description.ice_pwd.empty()) {
RTC_LOG(LS_ERROR) << "Session description must have ice ufrag and pwd.";
return false;
}
}
return true;
}
RTCError ValidateMids(const cricket::SessionDescription& description) {
std::set<std::string> mids;
for (const cricket::ContentInfo& content : description.contents()) {
if (content.name.empty()) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"A media section is missing a MID attribute.");
}
if (!mids.insert(content.name).second) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"Duplicate a=mid value '" + content.name + "'.");
}
}
return RTCError::OK();
}
bool IsValidOfferToReceiveMedia(int value) {
typedef PeerConnectionInterface::RTCOfferAnswerOptions Options;
return (value >= Options::kUndefined) &&
(value <= Options::kMaxOfferToReceiveMedia);
}
bool ValidateOfferAnswerOptions(
const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options) {
return IsValidOfferToReceiveMedia(rtc_options.offer_to_receive_audio) &&
IsValidOfferToReceiveMedia(rtc_options.offer_to_receive_video);
}
// Map internal signaling state name to spec name:
// https://w3c.github.io/webrtc-pc/#rtcsignalingstate-enum
std::string GetSignalingStateString(
PeerConnectionInterface::SignalingState state) {
switch (state) {
case PeerConnectionInterface::kStable:
return "stable";
case PeerConnectionInterface::kHaveLocalOffer:
return "have-local-offer";
case PeerConnectionInterface::kHaveLocalPrAnswer:
return "have-local-pranswer";
case PeerConnectionInterface::kHaveRemoteOffer:
return "have-remote-offer";
case PeerConnectionInterface::kHaveRemotePrAnswer:
return "have-remote-pranswer";
case PeerConnectionInterface::kClosed:
return "closed";
}
RTC_NOTREACHED();
return "";
}
// This method will extract any send encodings that were sent by the remote
// connection. This is currently only relevant for Simulcast scenario (where
// the number of layers may be communicated by the server).
std::vector<RtpEncodingParameters> GetSendEncodingsFromRemoteDescription(
const MediaContentDescription& desc) {
if (!desc.HasSimulcast()) {
return {};
}
std::vector<RtpEncodingParameters> result;
const SimulcastDescription& simulcast = desc.simulcast_description();
// This is a remote description, the parameters we are after should appear
// as receive streams.
for (const auto& alternatives : simulcast.receive_layers()) {
RTC_DCHECK(!alternatives.empty());
// There is currently no way to specify or choose from alternatives.
// We will always use the first alternative, which is the most preferred.
const SimulcastLayer& layer = alternatives[0];
RtpEncodingParameters parameters;
parameters.rid = layer.rid;
parameters.active = !layer.is_paused;
result.push_back(parameters);
}
return result;
}
RTCError UpdateSimulcastLayerStatusInSender(
const std::vector<SimulcastLayer>& layers,
rtc::scoped_refptr<RtpSenderInternal> sender) {
RTC_DCHECK(sender);
RtpParameters parameters = sender->GetParametersInternal();
std::vector<std::string> disabled_layers;
// The simulcast envelope cannot be changed, only the status of the streams.
// So we will iterate over the send encodings rather than the layers.
for (RtpEncodingParameters& encoding : parameters.encodings) {
auto iter = std::find_if(layers.begin(), layers.end(),
[&encoding](const SimulcastLayer& layer) {
return layer.rid == encoding.rid;
});
// A layer that cannot be found may have been removed by the remote party.
if (iter == layers.end()) {
disabled_layers.push_back(encoding.rid);
continue;
}
encoding.active = !iter->is_paused;
}
RTCError result = sender->SetParametersInternal(parameters);
if (result.ok()) {
result = sender->DisableEncodingLayers(disabled_layers);
}
return result;
}
bool SimulcastIsRejected(const ContentInfo* local_content,
const MediaContentDescription& answer_media_desc,
bool enable_encrypted_rtp_header_extensions) {
bool simulcast_offered = local_content &&
local_content->media_description() &&
local_content->media_description()->HasSimulcast();
bool simulcast_answered = answer_media_desc.HasSimulcast();
bool rids_supported = RtpExtension::FindHeaderExtensionByUri(
answer_media_desc.rtp_header_extensions(), RtpExtension::kRidUri,
enable_encrypted_rtp_header_extensions
? RtpExtension::Filter::kPreferEncryptedExtension
: RtpExtension::Filter::kDiscardEncryptedExtension);
return simulcast_offered && (!simulcast_answered || !rids_supported);
}
RTCError DisableSimulcastInSender(
rtc::scoped_refptr<RtpSenderInternal> sender) {
RTC_DCHECK(sender);
RtpParameters parameters = sender->GetParametersInternal();
if (parameters.encodings.size() <= 1) {
return RTCError::OK();
}
std::vector<std::string> disabled_layers;
std::transform(
parameters.encodings.begin() + 1, parameters.encodings.end(),
std::back_inserter(disabled_layers),
[](const RtpEncodingParameters& encoding) { return encoding.rid; });
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.
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;
case cricket::MEDIA_TYPE_UNSUPPORTED:
return "not supported";
}
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);
}
}
}
}
cricket::MediaDescriptionOptions GetMediaDescriptionOptionsForTransceiver(
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->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->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.
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;
}
// Generate a RTCP CNAME when a PeerConnection is created.
std::string GenerateRtcpCname() {
std::string cname;
if (!rtc::CreateRandomString(kRtcpCnameLength, &cname)) {
RTC_LOG(LS_ERROR) << "Failed to generate CNAME.";
RTC_NOTREACHED();
}
return cname;
}
// Check if we can send |new_stream| on a PeerConnection.
bool CanAddLocalMediaStream(webrtc::StreamCollectionInterface* current_streams,
webrtc::MediaStreamInterface* new_stream) {
if (!new_stream || !current_streams) {
return false;
}
if (current_streams->find(new_stream->id()) != nullptr) {
RTC_LOG(LS_ERROR) << "MediaStream with ID " << new_stream->id()
<< " is already added.";
return false;
}
return true;
}
rtc::scoped_refptr<webrtc::DtlsTransport> LookupDtlsTransportByMid(
rtc::Thread* network_thread,
JsepTransportController* controller,
const std::string& mid) {
// TODO(tommi): Can we post this (and associated operations where this
// function is called) to the network thread and avoid this Invoke?
// We might be able to simplify a few things if we set the transport on
// the network thread and then update the implementation to check that
// the set_ and relevant get methods are always called on the network
// thread (we'll need to update proxy maps).
return network_thread->Invoke<rtc::scoped_refptr<webrtc::DtlsTransport>>(
RTC_FROM_HERE,
[controller, &mid] { return controller->LookupDtlsTransportByMid(mid); });
}
bool ContentHasHeaderExtension(const cricket::ContentInfo& content_info,
absl::string_view header_extension_uri) {
for (const RtpExtension& rtp_header_extension :
content_info.media_description()->rtp_header_extensions()) {
if (rtp_header_extension.uri == header_extension_uri) {
return true;
}
}
return false;
}
} // namespace
// Used by parameterless SetLocalDescription() to create an offer or answer.
// Upon completion of creating the session description, SetLocalDescription() is
// invoked with the result.
class SdpOfferAnswerHandler::ImplicitCreateSessionDescriptionObserver
: public CreateSessionDescriptionObserver {
public:
ImplicitCreateSessionDescriptionObserver(
rtc::WeakPtr<SdpOfferAnswerHandler> sdp_handler,
rtc::scoped_refptr<SetLocalDescriptionObserverInterface>
set_local_description_observer)
: sdp_handler_(std::move(sdp_handler)),
set_local_description_observer_(
std::move(set_local_description_observer)) {}
~ImplicitCreateSessionDescriptionObserver() override {
RTC_DCHECK(was_called_);
}
void SetOperationCompleteCallback(
std::function<void()> operation_complete_callback) {
operation_complete_callback_ = std::move(operation_complete_callback);
}
bool was_called() const { return was_called_; }
void OnSuccess(SessionDescriptionInterface* desc_ptr) override {
RTC_DCHECK(!was_called_);
std::unique_ptr<SessionDescriptionInterface> desc(desc_ptr);
was_called_ = true;
// Abort early if |pc_| is no longer valid.
if (!sdp_handler_) {
operation_complete_callback_();
return;
}
// DoSetLocalDescription() is a synchronous operation that invokes
// |set_local_description_observer_| with the result.
sdp_handler_->DoSetLocalDescription(
std::move(desc), std::move(set_local_description_observer_));
operation_complete_callback_();
}
void OnFailure(RTCError error) override {
RTC_DCHECK(!was_called_);
was_called_ = true;
set_local_description_observer_->OnSetLocalDescriptionComplete(RTCError(
error.type(), std::string("SetLocalDescription failed to create "
"session description - ") +
error.message()));
operation_complete_callback_();
}
private:
bool was_called_ = false;
rtc::WeakPtr<SdpOfferAnswerHandler> sdp_handler_;
rtc::scoped_refptr<SetLocalDescriptionObserverInterface>
set_local_description_observer_;
std::function<void()> operation_complete_callback_;
};
// Wraps a CreateSessionDescriptionObserver and an OperationsChain operation
// complete callback. When the observer is invoked, the wrapped observer is
// invoked followed by invoking the completion callback.
class CreateSessionDescriptionObserverOperationWrapper
: public CreateSessionDescriptionObserver {
public:
CreateSessionDescriptionObserverOperationWrapper(
rtc::scoped_refptr<CreateSessionDescriptionObserver> observer,
std::function<void()> operation_complete_callback)
: observer_(std::move(observer)),
operation_complete_callback_(std::move(operation_complete_callback)) {
RTC_DCHECK(observer_);
}
~CreateSessionDescriptionObserverOperationWrapper() override {
#if RTC_DCHECK_IS_ON
RTC_DCHECK(was_called_);
#endif
}
void OnSuccess(SessionDescriptionInterface* desc) override {
#if RTC_DCHECK_IS_ON
RTC_DCHECK(!was_called_);
was_called_ = true;
#endif // RTC_DCHECK_IS_ON
// Completing the operation before invoking the observer allows the observer
// to execute SetLocalDescription() without delay.
operation_complete_callback_();
observer_->OnSuccess(desc);
}
void OnFailure(RTCError error) override {
#if RTC_DCHECK_IS_ON
RTC_DCHECK(!was_called_);
was_called_ = true;
#endif // RTC_DCHECK_IS_ON
operation_complete_callback_();
observer_->OnFailure(std::move(error));
}
private:
#if RTC_DCHECK_IS_ON
bool was_called_ = false;
#endif // RTC_DCHECK_IS_ON
rtc::scoped_refptr<CreateSessionDescriptionObserver> observer_;
std::function<void()> operation_complete_callback_;
};
// Wrapper for SetSessionDescriptionObserver that invokes the success or failure
// callback in a posted message handled by the peer connection. This introduces
// a delay that prevents recursive API calls by the observer, but this also
// means that the PeerConnection can be modified before the observer sees the
// result of the operation. This is ill-advised for synchronizing states.
//
// Implements both the SetLocalDescriptionObserverInterface and the
// SetRemoteDescriptionObserverInterface.
class SdpOfferAnswerHandler::SetSessionDescriptionObserverAdapter
: public SetLocalDescriptionObserverInterface,
public SetRemoteDescriptionObserverInterface {
public:
SetSessionDescriptionObserverAdapter(
rtc::WeakPtr<SdpOfferAnswerHandler> handler,
rtc::scoped_refptr<SetSessionDescriptionObserver> inner_observer)
: handler_(std::move(handler)),
inner_observer_(std::move(inner_observer)) {}
// SetLocalDescriptionObserverInterface implementation.
void OnSetLocalDescriptionComplete(RTCError error) override {
OnSetDescriptionComplete(std::move(error));
}
// SetRemoteDescriptionObserverInterface implementation.
void OnSetRemoteDescriptionComplete(RTCError error) override {
OnSetDescriptionComplete(std::move(error));
}
private:
void OnSetDescriptionComplete(RTCError error) {
if (!handler_)
return;
if (error.ok()) {
handler_->pc_->message_handler()->PostSetSessionDescriptionSuccess(
inner_observer_);
} else {
handler_->pc_->message_handler()->PostSetSessionDescriptionFailure(
inner_observer_, std::move(error));
}
}
rtc::WeakPtr<SdpOfferAnswerHandler> handler_;
rtc::scoped_refptr<SetSessionDescriptionObserver> inner_observer_;
};
class SdpOfferAnswerHandler::LocalIceCredentialsToReplace {
public:
// Sets the ICE credentials that need restarting to the ICE credentials of
// the current and pending descriptions.
void SetIceCredentialsFromLocalDescriptions(
const SessionDescriptionInterface* current_local_description,
const SessionDescriptionInterface* pending_local_description) {
ice_credentials_.clear();
if (current_local_description) {
AppendIceCredentialsFromSessionDescription(*current_local_description);
}
if (pending_local_description) {
AppendIceCredentialsFromSessionDescription(*pending_local_description);
}
}
void ClearIceCredentials() { ice_credentials_.clear(); }
// Returns true if we have ICE credentials that need restarting.
bool HasIceCredentials() const { return !ice_credentials_.empty(); }
// Returns true if |local_description| shares no ICE credentials with the
// ICE credentials that need restarting.
bool SatisfiesIceRestart(
const SessionDescriptionInterface& local_description) const {
for (const auto& transport_info :
local_description.description()->transport_infos()) {
if (ice_credentials_.find(std::make_pair(
transport_info.description.ice_ufrag,
transport_info.description.ice_pwd)) != ice_credentials_.end()) {
return false;
}
}
return true;
}
private:
void AppendIceCredentialsFromSessionDescription(
const SessionDescriptionInterface& desc) {
for (const auto& transport_info : desc.description()->transport_infos()) {
ice_credentials_.insert(
std::make_pair(transport_info.description.ice_ufrag,
transport_info.description.ice_pwd));
}
}
std::set<std::pair<std::string, std::string>> ice_credentials_;
};
SdpOfferAnswerHandler::SdpOfferAnswerHandler(PeerConnection* pc)
: pc_(pc),
local_streams_(StreamCollection::Create()),
remote_streams_(StreamCollection::Create()),
operations_chain_(rtc::OperationsChain::Create()),
rtcp_cname_(GenerateRtcpCname()),
local_ice_credentials_to_replace_(new LocalIceCredentialsToReplace()),
weak_ptr_factory_(this) {
operations_chain_->SetOnChainEmptyCallback(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr()]() {
if (!this_weak_ptr)
return;
this_weak_ptr->OnOperationsChainEmpty();
});
}
SdpOfferAnswerHandler::~SdpOfferAnswerHandler() {}
// Static
std::unique_ptr<SdpOfferAnswerHandler> SdpOfferAnswerHandler::Create(
PeerConnection* pc,
const PeerConnectionInterface::RTCConfiguration& configuration,
PeerConnectionDependencies& dependencies) {
auto handler = absl::WrapUnique(new SdpOfferAnswerHandler(pc));
handler->Initialize(configuration, dependencies);
return handler;
}
void SdpOfferAnswerHandler::Initialize(
const PeerConnectionInterface::RTCConfiguration& configuration,
PeerConnectionDependencies& dependencies) {
RTC_DCHECK_RUN_ON(signaling_thread());
video_options_.screencast_min_bitrate_kbps =
configuration.screencast_min_bitrate;
audio_options_.combined_audio_video_bwe =
configuration.combined_audio_video_bwe;
audio_options_.audio_jitter_buffer_max_packets =
configuration.audio_jitter_buffer_max_packets;
audio_options_.audio_jitter_buffer_fast_accelerate =
configuration.audio_jitter_buffer_fast_accelerate;
audio_options_.audio_jitter_buffer_min_delay_ms =
configuration.audio_jitter_buffer_min_delay_ms;
audio_options_.audio_jitter_buffer_enable_rtx_handling =
configuration.audio_jitter_buffer_enable_rtx_handling;
// Obtain a certificate from RTCConfiguration if any were provided (optional).
rtc::scoped_refptr<rtc::RTCCertificate> certificate;
if (!configuration.certificates.empty()) {
// TODO(hbos,torbjorng): Decide on certificate-selection strategy instead of
// just picking the first one. The decision should be made based on the DTLS
// handshake. The DTLS negotiations need to know about all certificates.
certificate = configuration.certificates[0];
}
webrtc_session_desc_factory_ =
std::make_unique<WebRtcSessionDescriptionFactory>(
signaling_thread(), channel_manager(), this, pc_->session_id(),
pc_->dtls_enabled(), std::move(dependencies.cert_generator),
certificate, &ssrc_generator_,
[this](const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) {
transport_controller()->SetLocalCertificate(certificate);
});
if (pc_->options()->disable_encryption) {
webrtc_session_desc_factory_->SetSdesPolicy(cricket::SEC_DISABLED);
}
webrtc_session_desc_factory_->set_enable_encrypted_rtp_header_extensions(
pc_->GetCryptoOptions().srtp.enable_encrypted_rtp_header_extensions);
webrtc_session_desc_factory_->set_is_unified_plan(IsUnifiedPlan());
if (dependencies.video_bitrate_allocator_factory) {
video_bitrate_allocator_factory_ =
std::move(dependencies.video_bitrate_allocator_factory);
} else {
video_bitrate_allocator_factory_ =
CreateBuiltinVideoBitrateAllocatorFactory();
}
}
// ==================================================================
// Access to pc_ variables
cricket::ChannelManager* SdpOfferAnswerHandler::channel_manager() const {
return pc_->channel_manager();
}
TransceiverList* SdpOfferAnswerHandler::transceivers() {
if (!pc_->rtp_manager()) {
return nullptr;
}
return pc_->rtp_manager()->transceivers();
}
const TransceiverList* SdpOfferAnswerHandler::transceivers() const {
if (!pc_->rtp_manager()) {
return nullptr;
}
return pc_->rtp_manager()->transceivers();
}
JsepTransportController* SdpOfferAnswerHandler::transport_controller() {
return pc_->transport_controller();
}
const JsepTransportController* SdpOfferAnswerHandler::transport_controller()
const {
return pc_->transport_controller();
}
DataChannelController* SdpOfferAnswerHandler::data_channel_controller() {
return pc_->data_channel_controller();
}
const DataChannelController* SdpOfferAnswerHandler::data_channel_controller()
const {
return pc_->data_channel_controller();
}
cricket::PortAllocator* SdpOfferAnswerHandler::port_allocator() {
return pc_->port_allocator();
}
const cricket::PortAllocator* SdpOfferAnswerHandler::port_allocator() const {
return pc_->port_allocator();
}
RtpTransmissionManager* SdpOfferAnswerHandler::rtp_manager() {
return pc_->rtp_manager();
}
const RtpTransmissionManager* SdpOfferAnswerHandler::rtp_manager() const {
return pc_->rtp_manager();
}
// ===================================================================
void SdpOfferAnswerHandler::PrepareForShutdown() {
RTC_DCHECK_RUN_ON(signaling_thread());
weak_ptr_factory_.InvalidateWeakPtrs();
}
void SdpOfferAnswerHandler::Close() {
ChangeSignalingState(PeerConnectionInterface::kClosed);
}
void SdpOfferAnswerHandler::RestartIce() {
RTC_DCHECK_RUN_ON(signaling_thread());
local_ice_credentials_to_replace_->SetIceCredentialsFromLocalDescriptions(
current_local_description(), pending_local_description());
UpdateNegotiationNeeded();
}
rtc::Thread* SdpOfferAnswerHandler::signaling_thread() const {
return pc_->signaling_thread();
}
void SdpOfferAnswerHandler::CreateOffer(
CreateSessionDescriptionObserver* observer,
const PeerConnectionInterface::RTCOfferAnswerOptions& options) {
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(),
observer_refptr =
rtc::scoped_refptr<CreateSessionDescriptionObserver>(observer),
options](std::function<void()> operations_chain_callback) {
// Abort early if |this_weak_ptr| is no longer valid.
if (!this_weak_ptr) {
observer_refptr->OnFailure(
RTCError(RTCErrorType::INTERNAL_ERROR,
"CreateOffer failed because the session was shut down"));
operations_chain_callback();
return;
}
// The operation completes asynchronously when the wrapper is invoked.
rtc::scoped_refptr<CreateSessionDescriptionObserverOperationWrapper>
observer_wrapper(new rtc::RefCountedObject<
CreateSessionDescriptionObserverOperationWrapper>(
std::move(observer_refptr),
std::move(operations_chain_callback)));
this_weak_ptr->DoCreateOffer(options, observer_wrapper);
});
}
void SdpOfferAnswerHandler::SetLocalDescription(
SetSessionDescriptionObserver* observer,
SessionDescriptionInterface* desc_ptr) {
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(),
observer_refptr =
rtc::scoped_refptr<SetSessionDescriptionObserver>(observer),
desc = std::unique_ptr<SessionDescriptionInterface>(desc_ptr)](
std::function<void()> operations_chain_callback) mutable {
// Abort early if |this_weak_ptr| is no longer valid.
if (!this_weak_ptr) {
// For consistency with SetSessionDescriptionObserverAdapter whose
// posted messages doesn't get processed when the PC is destroyed, we
// do not inform |observer_refptr| that the operation failed.
operations_chain_callback();
return;
}
// SetSessionDescriptionObserverAdapter takes care of making sure the
// |observer_refptr| is invoked in a posted message.
this_weak_ptr->DoSetLocalDescription(
std::move(desc),
rtc::scoped_refptr<SetLocalDescriptionObserverInterface>(
new rtc::RefCountedObject<SetSessionDescriptionObserverAdapter>(
this_weak_ptr, observer_refptr)));
// For backwards-compatability reasons, we declare the operation as
// completed here (rather than in a post), so that the operation chain
// is not blocked by this operation when the observer is invoked. This
// allows the observer to trigger subsequent offer/answer operations
// synchronously if the operation chain is now empty.
operations_chain_callback();
});
}
void SdpOfferAnswerHandler::SetLocalDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
rtc::scoped_refptr<SetLocalDescriptionObserverInterface> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(), observer,
desc = std::move(desc)](
std::function<void()> operations_chain_callback) mutable {
// Abort early if |this_weak_ptr| is no longer valid.
if (!this_weak_ptr) {
observer->OnSetLocalDescriptionComplete(RTCError(
RTCErrorType::INTERNAL_ERROR,
"SetLocalDescription failed because the session was shut down"));
operations_chain_callback();
return;
}
this_weak_ptr->DoSetLocalDescription(std::move(desc), observer);
// DoSetLocalDescription() is implemented as a synchronous operation.
// The |observer| will already have been informed that it completed, and
// we can mark this operation as complete without any loose ends.
operations_chain_callback();
});
}
void SdpOfferAnswerHandler::SetLocalDescription(
SetSessionDescriptionObserver* observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
SetLocalDescription(
new rtc::RefCountedObject<SetSessionDescriptionObserverAdapter>(
weak_ptr_factory_.GetWeakPtr(), observer));
}
void SdpOfferAnswerHandler::SetLocalDescription(
rtc::scoped_refptr<SetLocalDescriptionObserverInterface> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
// The |create_sdp_observer| handles performing DoSetLocalDescription() with
// the resulting description as well as completing the operation.
rtc::scoped_refptr<ImplicitCreateSessionDescriptionObserver>
create_sdp_observer(
new rtc::RefCountedObject<ImplicitCreateSessionDescriptionObserver>(
weak_ptr_factory_.GetWeakPtr(), observer));
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(),
create_sdp_observer](std::function<void()> operations_chain_callback) {
// The |create_sdp_observer| is responsible for completing the
// operation.
create_sdp_observer->SetOperationCompleteCallback(
std::move(operations_chain_callback));
// Abort early if |this_weak_ptr| is no longer valid. This triggers the
// same code path as if DoCreateOffer() or DoCreateAnswer() failed.
if (!this_weak_ptr) {
create_sdp_observer->OnFailure(RTCError(
RTCErrorType::INTERNAL_ERROR,
"SetLocalDescription failed because the session was shut down"));
return;
}
switch (this_weak_ptr->signaling_state()) {
case PeerConnectionInterface::kStable:
case PeerConnectionInterface::kHaveLocalOffer:
case PeerConnectionInterface::kHaveRemotePrAnswer:
// TODO(hbos): If [LastCreatedOffer] exists and still represents the
// current state of the system, use that instead of creating another
// offer.
this_weak_ptr->DoCreateOffer(
PeerConnectionInterface::RTCOfferAnswerOptions(),
create_sdp_observer);
break;
case PeerConnectionInterface::kHaveLocalPrAnswer:
case PeerConnectionInterface::kHaveRemoteOffer:
// TODO(hbos): If [LastCreatedAnswer] exists and still represents
// the current state of the system, use that instead of creating
// another answer.
this_weak_ptr->DoCreateAnswer(
PeerConnectionInterface::RTCOfferAnswerOptions(),
create_sdp_observer);
break;
case PeerConnectionInterface::kClosed:
create_sdp_observer->OnFailure(RTCError(
RTCErrorType::INVALID_STATE,
"SetLocalDescription called when PeerConnection is closed."));
break;
}
});
}
RTCError SdpOfferAnswerHandler::ApplyLocalDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
const std::map<std::string, const cricket::ContentGroup*>&
bundle_groups_by_mid) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::ApplyLocalDescription");
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(desc);
// Update stats here so that we have the most recent stats for tracks and
// streams that might be removed by updating the session description.
pc_->stats()->UpdateStats(PeerConnectionInterface::kStatsOutputLevelStandard);
// Take a reference to the old local description since it's used below to
// compare against the new local description. When setting the new local
// description, grab ownership of the replaced session description in case it
// is the same as |old_local_description|, to keep it alive for the duration
// of the method.
const SessionDescriptionInterface* old_local_description =
local_description();
std::unique_ptr<SessionDescriptionInterface> replaced_local_description;
SdpType type = desc->GetType();
if (type == SdpType::kAnswer) {
replaced_local_description = pending_local_description_
? std::move(pending_local_description_)
: std::move(current_local_description_);
current_local_description_ = std::move(desc);
pending_local_description_ = nullptr;
current_remote_description_ = std::move(pending_remote_description_);
} else {
replaced_local_description = std::move(pending_local_description_);
pending_local_description_ = std::move(desc);
}
// The session description to apply now must be accessed by
// |local_description()|.
RTC_DCHECK(local_description());
// Report statistics about any use of simulcast.
ReportSimulcastApiVersion(kSimulcastVersionApplyLocalDescription,
*local_description()->description());
if (!is_caller_) {
if (remote_description()) {
// Remote description was applied first, so this PC is the callee.
is_caller_ = false;
} else {
// Local description is applied first, so this PC is the caller.
is_caller_ = true;
}
}
RTCError error = PushdownTransportDescription(cricket::CS_LOCAL, type);
if (!error.ok()) {
return error;
}
if (IsUnifiedPlan()) {
RTCError error = UpdateTransceiversAndDataChannels(
cricket::CS_LOCAL, *local_description(), old_local_description,
remote_description(), bundle_groups_by_mid);
if (!error.ok()) {
return error;
}
std::vector<rtc::scoped_refptr<RtpTransceiverInterface>> remove_list;
std::vector<rtc::scoped_refptr<MediaStreamInterface>> removed_streams;
for (const auto& transceiver_ext : transceivers()->List()) {
auto transceiver = transceiver_ext->internal();
if (transceiver->stopped()) {
continue;
}
// 2.2.7.1.1.(6-9): Set sender and receiver's transport slots.
// Note that code paths that don't set MID won't be able to use
// information about DTLS transports.
if (transceiver->mid()) {
auto dtls_transport = LookupDtlsTransportByMid(
pc_->network_thread(), transport_controller(), *transceiver->mid());
transceiver->sender_internal()->set_transport(dtls_transport);
transceiver->receiver_internal()->set_transport(dtls_transport);
}
const ContentInfo* content =
FindMediaSectionForTransceiver(transceiver, local_description());
if (!content) {
continue;
}
const MediaContentDescription* media_desc = content->media_description();
// 2.2.7.1.6: If description is of type "answer" or "pranswer", then run
// the following steps:
if (type == SdpType::kPrAnswer || type == SdpType::kAnswer) {
// 2.2.7.1.6.1: If direction is "sendonly" or "inactive", and
// transceiver's [[FiredDirection]] slot is either "sendrecv" or
// "recvonly", process the removal of a remote track for the media
// description, given transceiver, removeList, and muteTracks.
if (!RtpTransceiverDirectionHasRecv(media_desc->direction()) &&
(transceiver->fired_direction() &&
RtpTransceiverDirectionHasRecv(*transceiver->fired_direction()))) {
ProcessRemovalOfRemoteTrack(transceiver_ext, &remove_list,
&removed_streams);
}
// 2.2.7.1.6.2: Set transceiver's [[CurrentDirection]] and
// [[FiredDirection]] slots to direction.
transceiver->set_current_direction(media_desc->direction());
transceiver->set_fired_direction(media_desc->direction());
}
}
auto observer = pc_->Observer();
for (const auto& transceiver : remove_list) {
observer->OnRemoveTrack(transceiver->receiver());
}
for (const auto& stream : removed_streams) {
observer->OnRemoveStream(stream);
}
} else {
// Media channels will be created only when offer is set. These may use new
// transports just created by PushdownTransportDescription.
if (type == SdpType::kOffer) {
// TODO(bugs.webrtc.org/4676) - Handle CreateChannel failure, as new local
// description is applied. Restore back to old description.
RTCError error = CreateChannels(*local_description()->description());
if (!error.ok()) {
return error;
}
}
// Remove unused channels if MediaContentDescription is rejected.
RemoveUnusedChannels(local_description()->description());
}
error = UpdateSessionState(type, cricket::CS_LOCAL,
local_description()->description(),
bundle_groups_by_mid);
if (!error.ok()) {
return error;
}
if (remote_description()) {
// Now that we have a local description, we can push down remote candidates.
UseCandidatesInSessionDescription(remote_description());
}
pending_ice_restarts_.clear();
if (session_error() != SessionError::kNone) {
LOG_AND_RETURN_ERROR(RTCErrorType::INTERNAL_ERROR, GetSessionErrorMsg());
}
// If setting the description decided our SSL role, allocate any necessary
// SCTP sids.
rtc::SSLRole role;
if (pc_->GetSctpSslRole(&role)) {
data_channel_controller()->AllocateSctpSids(role);
}
if (IsUnifiedPlan()) {
// We must use List and not ListInternal here because
// transceivers()->StableState() is indexed by the non-internal refptr.
for (const auto& transceiver_ext : transceivers()->List()) {
auto transceiver = transceiver_ext->internal();
if (transceiver->stopped()) {
continue;
}
const ContentInfo* content =
FindMediaSectionForTransceiver(transceiver, local_description());
if (!content) {
continue;
}
cricket::ChannelInterface* channel = transceiver->channel();
if (content->rejected || !channel || channel->local_streams().empty()) {
// 0 is a special value meaning "this sender has no associated send
// stream". Need to call this so the sender won't attempt to configure
// a no longer existing stream and run into DCHECKs in the lower
// layers.
transceiver->sender_internal()->SetSsrc(0);
} else {
// Get the StreamParams from the channel which could generate SSRCs.
const std::vector<StreamParams>& streams = channel->local_streams();
transceiver->sender_internal()->set_stream_ids(streams[0].stream_ids());
auto encodings = transceiver->sender_internal()->init_send_encodings();
transceiver->sender_internal()->SetSsrc(streams[0].first_ssrc());
if (!encodings.empty()) {
transceivers()
->StableState(transceiver_ext)
->SetInitSendEncodings(encodings);
}
}
}
} else {
// Plan B semantics.
// Update state and SSRC of local MediaStreams and DataChannels based on the
// local session description.
const cricket::ContentInfo* audio_content =
GetFirstAudioContent(local_description()->description());
if (audio_content) {
if (audio_content->rejected) {
RemoveSenders(cricket::MEDIA_TYPE_AUDIO);
} else {
const cricket::AudioContentDescription* audio_desc =
audio_content->media_description()->as_audio();
UpdateLocalSenders(audio_desc->streams(), audio_desc->type());
}
}
const cricket::ContentInfo* video_content =
GetFirstVideoContent(local_description()->description());
if (video_content) {
if (video_content->rejected) {
RemoveSenders(cricket::MEDIA_TYPE_VIDEO);
} else {
const cricket::VideoContentDescription* video_desc =
video_content->media_description()->as_video();
UpdateLocalSenders(video_desc->streams(), video_desc->type());
}
}
}
// This function does nothing with data content.
if (type == SdpType::kAnswer &&
local_ice_credentials_to_replace_->SatisfiesIceRestart(
*current_local_description_)) {
local_ice_credentials_to_replace_->ClearIceCredentials();
}
return RTCError::OK();
}
void SdpOfferAnswerHandler::SetRemoteDescription(
SetSessionDescriptionObserver* observer,
SessionDescriptionInterface* desc_ptr) {
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(),
observer_refptr =
rtc::scoped_refptr<SetSessionDescriptionObserver>(observer),
desc = std::unique_ptr<SessionDescriptionInterface>(desc_ptr)](
std::function<void()> operations_chain_callback) mutable {
// Abort early if |this_weak_ptr| is no longer valid.
if (!this_weak_ptr) {
// For consistency with SetSessionDescriptionObserverAdapter whose
// posted messages doesn't get processed when the PC is destroyed, we
// do not inform |observer_refptr| that the operation failed.
operations_chain_callback();
return;
}
// SetSessionDescriptionObserverAdapter takes care of making sure the
// |observer_refptr| is invoked in a posted message.
this_weak_ptr->DoSetRemoteDescription(
std::move(desc),
rtc::scoped_refptr<SetRemoteDescriptionObserverInterface>(
new rtc::RefCountedObject<SetSessionDescriptionObserverAdapter>(
this_weak_ptr, observer_refptr)));
// For backwards-compatability reasons, we declare the operation as
// completed here (rather than in a post), so that the operation chain
// is not blocked by this operation when the observer is invoked. This
// allows the observer to trigger subsequent offer/answer operations
// synchronously if the operation chain is now empty.
operations_chain_callback();
});
}
void SdpOfferAnswerHandler::SetRemoteDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
rtc::scoped_refptr<SetRemoteDescriptionObserverInterface> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(), observer,
desc = std::move(desc)](
std::function<void()> operations_chain_callback) mutable {
// Abort early if |this_weak_ptr| is no longer valid.
if (!this_weak_ptr) {
observer->OnSetRemoteDescriptionComplete(RTCError(
RTCErrorType::INTERNAL_ERROR,
"SetRemoteDescription failed because the session was shut down"));
operations_chain_callback();
return;
}
this_weak_ptr->DoSetRemoteDescription(std::move(desc),
std::move(observer));
// DoSetRemoteDescription() is implemented as a synchronous operation.
// The |observer| will already have been informed that it completed, and
// we can mark this operation as complete without any loose ends.
operations_chain_callback();
});
}
RTCError SdpOfferAnswerHandler::ApplyRemoteDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
const std::map<std::string, const cricket::ContentGroup*>&
bundle_groups_by_mid) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::ApplyRemoteDescription");
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(desc);
// Update stats here so that we have the most recent stats for tracks and
// streams that might be removed by updating the session description.
pc_->stats()->UpdateStats(PeerConnectionInterface::kStatsOutputLevelStandard);
// Take a reference to the old remote description since it's used below to
// compare against the new remote description. When setting the new remote
// description, grab ownership of the replaced session description in case it
// is the same as |old_remote_description|, to keep it alive for the duration
// of the method.
const SessionDescriptionInterface* old_remote_description =
remote_description();
std::unique_ptr<SessionDescriptionInterface> replaced_remote_description;
SdpType type = desc->GetType();
if (type == SdpType::kAnswer) {
replaced_remote_description = pending_remote_description_
? std::move(pending_remote_description_)
: std::move(current_remote_description_);
current_remote_description_ = std::move(desc);
pending_remote_description_ = nullptr;
current_local_description_ = std::move(pending_local_description_);
} else {
replaced_remote_description = std::move(pending_remote_description_);
pending_remote_description_ = std::move(desc);
}
// The session description to apply now must be accessed by
// |remote_description()|.
RTC_DCHECK(remote_description());
// Report statistics about any use of simulcast.
ReportSimulcastApiVersion(kSimulcastVersionApplyRemoteDescription,
*remote_description()->description());
RTCError error = PushdownTransportDescription(cricket::CS_REMOTE, type);
if (!error.ok()) {
return error;
}
// Transport and Media channels will be created only when offer is set.
if (IsUnifiedPlan()) {
RTCError error = UpdateTransceiversAndDataChannels(
cricket::CS_REMOTE, *remote_description(), local_description(),
old_remote_description, bundle_groups_by_mid);
if (!error.ok()) {
return error;
}
} else {
// Media channels will be created only when offer is set. These may use new
// transports just created by PushdownTransportDescription.
if (type == SdpType::kOffer) {
// TODO(mallinath) - Handle CreateChannel failure, as new local
// description is applied. Restore back to old description.
RTCError error = CreateChannels(*remote_description()->description());
if (!error.ok()) {
return error;
}
}
// Remove unused channels if MediaContentDescription is rejected.
RemoveUnusedChannels(remote_description()->description());
}
// NOTE: Candidates allocation will be initiated only when
// SetLocalDescription is called.
error = UpdateSessionState(type, cricket::CS_REMOTE,
remote_description()->description(),
bundle_groups_by_mid);
if (!error.ok()) {
return error;
}
if (local_description() &&
!UseCandidatesInSessionDescription(remote_description())) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER, kInvalidCandidates);
}
if (old_remote_description) {
for (const cricket::ContentInfo& content :
old_remote_description->description()->contents()) {
// Check if this new SessionDescription contains new ICE ufrag and
// password that indicates the remote peer requests an ICE restart.
// TODO(deadbeef): When we start storing both the current and pending
// remote description, this should reset pending_ice_restarts and compare
// against the current description.
if (CheckForRemoteIceRestart(old_remote_description, remote_description(),
content.name)) {
if (type == SdpType::kOffer) {
pending_ice_restarts_.insert(content.name);
}
} else {
// We retain all received candidates only if ICE is not restarted.
// When ICE is restarted, all previous candidates belong to an old
// generation and should not be kept.
// TODO(deadbeef): This goes against the W3C spec which says the remote
// description should only contain candidates from the last set remote
// description plus any candidates added since then. We should remove
// this once we're sure it won't break anything.
WebRtcSessionDescriptionFactory::CopyCandidatesFromSessionDescription(
old_remote_description, content.name, mutable_remote_description());
}
}
}
if (session_error() != SessionError::kNone) {
LOG_AND_RETURN_ERROR(RTCErrorType::INTERNAL_ERROR, GetSessionErrorMsg());
}
// Set the the ICE connection state to connecting since the connection may
// become writable with peer reflexive candidates before any remote candidate
// is signaled.
// TODO(pthatcher): This is a short-term solution for crbug/446908. A real fix
// is to have a new signal the indicates a change in checking state from the
// transport and expose a new checking() member from transport that can be
// read to determine the current checking state. The existing SignalConnecting
// actually means "gathering candidates", so cannot be be used here.
if (remote_description()->GetType() != SdpType::kOffer &&
remote_description()->number_of_mediasections() > 0u &&
pc_->ice_connection_state() ==
PeerConnectionInterface::kIceConnectionNew) {
pc_->SetIceConnectionState(PeerConnectionInterface::kIceConnectionChecking);
}
// If setting the description decided our SSL role, allocate any necessary
// SCTP sids.
rtc::SSLRole role;
if (pc_->GetSctpSslRole(&role)) {
data_channel_controller()->AllocateSctpSids(role);
}
if (IsUnifiedPlan()) {
std::vector<rtc::scoped_refptr<RtpTransceiverInterface>>
now_receiving_transceivers;
std::vector<rtc::scoped_refptr<RtpTransceiverInterface>> remove_list;
std::vector<rtc::scoped_refptr<MediaStreamInterface>> added_streams;
std::vector<rtc::scoped_refptr<MediaStreamInterface>> removed_streams;
for (const auto& transceiver_ext : transceivers()->List()) {
const auto transceiver = transceiver_ext->internal();
const ContentInfo* content =
FindMediaSectionForTransceiver(transceiver, remote_description());
if (!content) {
continue;
}
const MediaContentDescription* media_desc = content->media_description();
RtpTransceiverDirection local_direction =
RtpTransceiverDirectionReversed(media_desc->direction());
// Roughly the same as steps 2.2.8.6 of section 4.4.1.6 "Set the
// RTCSessionDescription: Set the associated remote streams given
// transceiver.[[Receiver]], msids, addList, and removeList".
// https://w3c.github.io/webrtc-pc/#set-the-rtcsessiondescription
if (RtpTransceiverDirectionHasRecv(local_direction)) {
std::vector<std::string> stream_ids;
if (!media_desc->streams().empty()) {
// The remote description has signaled the stream IDs.
stream_ids = media_desc->streams()[0].stream_ids();
}
transceivers()
->StableState(transceiver_ext)
->SetRemoteStreamIdsIfUnset(transceiver->receiver()->stream_ids());
RTC_LOG(LS_INFO) << "Processing the MSIDs for MID=" << content->name
<< " (" << GetStreamIdsString(stream_ids) << ").";
SetAssociatedRemoteStreams(transceiver->receiver_internal(), stream_ids,
&added_streams, &removed_streams);
// From the WebRTC specification, steps 2.2.8.5/6 of section 4.4.1.6
// "Set the RTCSessionDescription: If direction is sendrecv or recvonly,
// and transceiver's current direction is neither sendrecv nor recvonly,
// process the addition of a remote track for the media description.
if (!transceiver->fired_direction() ||
!RtpTransceiverDirectionHasRecv(*transceiver->fired_direction())) {
RTC_LOG(LS_INFO)
<< "Processing the addition of a remote track for MID="
<< content->name << ".";
now_receiving_transceivers.push_back(transceiver);
}
}
// 2.2.8.1.9: If direction is "sendonly" or "inactive", and transceiver's
// [[FiredDirection]] slot is either "sendrecv" or "recvonly", process the
// removal of a remote track for the media description, given transceiver,
// removeList, and muteTracks.
if (!RtpTransceiverDirectionHasRecv(local_direction) &&
(transceiver->fired_direction() &&
RtpTransceiverDirectionHasRecv(*transceiver->fired_direction()))) {
ProcessRemovalOfRemoteTrack(transceiver_ext, &remove_list,
&removed_streams);
}
// 2.2.8.1.10: Set transceiver's [[FiredDirection]] slot to direction.
transceiver->set_fired_direction(local_direction);
// 2.2.8.1.11: If description is of type "answer" or "pranswer", then run
// the following steps:
if (type == SdpType::kPrAnswer || type == SdpType::kAnswer) {
// 2.2.8.1.11.1: Set transceiver's [[CurrentDirection]] slot to
// direction.
transceiver->set_current_direction(local_direction);
// 2.2.8.1.11.[3-6]: Set the transport internal slots.
if (transceiver->mid()) {
auto dtls_transport = LookupDtlsTransportByMid(pc_->network_thread(),
transport_controller(),
*transceiver->mid());
transceiver->sender_internal()->set_transport(dtls_transport);
transceiver->receiver_internal()->set_transport(dtls_transport);
}
}
// 2.2.8.1.12: If the media description is rejected, and transceiver is
// not already stopped, stop the RTCRtpTransceiver transceiver.
if (content->rejected && !transceiver->stopped()) {
RTC_LOG(LS_INFO) << "Stopping transceiver for MID=" << content->name
<< " since the media section was rejected.";
transceiver->StopTransceiverProcedure();
}
if (!content->rejected &&
RtpTransceiverDirectionHasRecv(local_direction)) {
if (!media_desc->streams().empty() &&
media_desc->streams()[0].has_ssrcs()) {
uint32_t ssrc = media_desc->streams()[0].first_ssrc();
transceiver->receiver_internal()->SetupMediaChannel(ssrc);
} else {
transceiver->receiver_internal()->SetupUnsignaledMediaChannel();
}
}
}
// Once all processing has finished, fire off callbacks.
auto observer = pc_->Observer();
for (const auto& transceiver : now_receiving_transceivers) {
pc_->stats()->AddTrack(transceiver->receiver()->track());
observer->OnTrack(transceiver);
observer->OnAddTrack(transceiver->receiver(),
transceiver->receiver()->streams());
}
for (const auto& stream : added_streams) {
observer->OnAddStream(stream);
}
for (const auto& transceiver : remove_list) {
observer->OnRemoveTrack(transceiver->receiver());
}
for (const auto& stream : removed_streams) {
observer->OnRemoveStream(stream);
}
}
const cricket::ContentInfo* audio_content =
GetFirstAudioContent(remote_description()->description());
const cricket::ContentInfo* video_content =
GetFirstVideoContent(remote_description()->description());
const cricket::AudioContentDescription* audio_desc =
GetFirstAudioContentDescription(remote_description()->description());
const cricket::VideoContentDescription* video_desc =
GetFirstVideoContentDescription(remote_description()->description());
// Check if the descriptions include streams, just in case the peer supports
// MSID, but doesn't indicate so with "a=msid-semantic".
if (remote_description()->description()->msid_supported() ||
(audio_desc && !audio_desc->streams().empty()) ||
(video_desc && !video_desc->streams().empty())) {
remote_peer_supports_msid_ = true;
}
// We wait to signal new streams until we finish processing the description,
// since only at that point will new streams have all their tracks.
rtc::scoped_refptr<StreamCollection> new_streams(StreamCollection::Create());
if (!IsUnifiedPlan()) {
// TODO(steveanton): When removing RTP senders/receivers in response to a
// rejected media section, there is some cleanup logic that expects the
// voice/ video channel to still be set. But in this method the voice/video
// channel would have been destroyed by the SetRemoteDescription caller
// above so the cleanup that relies on them fails to run. The RemoveSenders
// calls should be moved to right before the DestroyChannel calls to fix
// this.
// Find all audio rtp streams and create corresponding remote AudioTracks
// and MediaStreams.
if (audio_content) {
if (audio_content->rejected) {
RemoveSenders(cricket::MEDIA_TYPE_AUDIO);
} else {
bool default_audio_track_needed =
!remote_peer_supports_msid_ &&
RtpTransceiverDirectionHasSend(audio_desc->direction());
UpdateRemoteSendersList(GetActiveStreams(audio_desc),
default_audio_track_needed, audio_desc->type(),
new_streams);
}
}
// Find all video rtp streams and create corresponding remote VideoTracks
// and MediaStreams.
if (video_content) {
if (video_content->rejected) {
RemoveSenders(cricket::MEDIA_TYPE_VIDEO);
} else {
bool default_video_track_needed =
!remote_peer_supports_msid_ &&
RtpTransceiverDirectionHasSend(video_desc->direction());
UpdateRemoteSendersList(GetActiveStreams(video_desc),
default_video_track_needed, video_desc->type(),
new_streams);
}
}
// Iterate new_streams and notify the observer about new MediaStreams.
auto observer = pc_->Observer();
for (size_t i = 0; i < new_streams->count(); ++i) {
MediaStreamInterface* new_stream = new_streams->at(i);
pc_->stats()->AddStream(new_stream);
observer->OnAddStream(
rtc::scoped_refptr<MediaStreamInterface>(new_stream));
}
UpdateEndedRemoteMediaStreams();
}
if (type == SdpType::kAnswer &&
local_ice_credentials_to_replace_->SatisfiesIceRestart(
*current_local_description_)) {
local_ice_credentials_to_replace_->ClearIceCredentials();
}
return RTCError::OK();
}
void SdpOfferAnswerHandler::DoSetLocalDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
rtc::scoped_refptr<SetLocalDescriptionObserverInterface> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::DoSetLocalDescription");
if (!observer) {
RTC_LOG(LS_ERROR) << "SetLocalDescription - observer is NULL.";
return;
}
if (!desc) {
observer->OnSetLocalDescriptionComplete(
RTCError(RTCErrorType::INTERNAL_ERROR, "SessionDescription is NULL."));
return;
}
// If a session error has occurred the PeerConnection is in a possibly
// inconsistent state so fail right away.
if (session_error() != SessionError::kNone) {
std::string error_message = GetSessionErrorMsg();
RTC_LOG(LS_ERROR) << "SetLocalDescription: " << error_message;
observer->OnSetLocalDescriptionComplete(
RTCError(RTCErrorType::INTERNAL_ERROR, std::move(error_message)));
return;
}
// For SLD we support only explicit rollback.
if (desc->GetType() == SdpType::kRollback) {
if (IsUnifiedPlan()) {
observer->OnSetLocalDescriptionComplete(Rollback(desc->GetType()));
} else {
observer->OnSetLocalDescriptionComplete(
RTCError(RTCErrorType::UNSUPPORTED_OPERATION,
"Rollback not supported in Plan B"));
}
return;
}
std::map<std::string, const cricket::ContentGroup*> bundle_groups_by_mid =
GetBundleGroupsByMid(desc->description());
RTCError error = ValidateSessionDescription(desc.get(), cricket::CS_LOCAL,
bundle_groups_by_mid);
if (!error.ok()) {
std::string error_message = GetSetDescriptionErrorMessage(
cricket::CS_LOCAL, desc->GetType(), error);
RTC_LOG(LS_ERROR) << error_message;
observer->OnSetLocalDescriptionComplete(
RTCError(RTCErrorType::INTERNAL_ERROR, std::move(error_message)));
return;
}
// Grab the description type before moving ownership to ApplyLocalDescription,
// which may destroy it before returning.
const SdpType type = desc->GetType();
error = ApplyLocalDescription(std::move(desc), bundle_groups_by_mid);
// |desc| may be destroyed at this point.
if (!error.ok()) {
// If ApplyLocalDescription fails, the PeerConnection could be in an
// inconsistent state, so act conservatively here and set the session error
// so that future calls to SetLocalDescription/SetRemoteDescription fail.
SetSessionError(SessionError::kContent, error.message());
std::string error_message =
GetSetDescriptionErrorMessage(cricket::CS_LOCAL, type, error);
RTC_LOG(LS_ERROR) << error_message;
observer->OnSetLocalDescriptionComplete(
RTCError(RTCErrorType::INTERNAL_ERROR, std::move(error_message)));
return;
}
RTC_DCHECK(local_description());
if (local_description()->GetType() == SdpType::kAnswer) {
RemoveStoppedTransceivers();
// TODO(deadbeef): We already had to hop to the network thread for
// MaybeStartGathering...
pc_->network_thread()->Invoke<void>(
RTC_FROM_HERE, [this] { port_allocator()->DiscardCandidatePool(); });
// Make UMA notes about what was agreed to.
ReportNegotiatedSdpSemantics(*local_description());
}
observer->OnSetLocalDescriptionComplete(RTCError::OK());
pc_->NoteUsageEvent(UsageEvent::SET_LOCAL_DESCRIPTION_SUCCEEDED);
// Check if negotiation is needed. We must do this after informing the
// observer that SetLocalDescription() has completed to ensure negotiation is
// not needed prior to the promise resolving.
if (IsUnifiedPlan()) {
bool was_negotiation_needed = is_negotiation_needed_;
UpdateNegotiationNeeded();
if (signaling_state() == PeerConnectionInterface::kStable &&
was_negotiation_needed && is_negotiation_needed_) {
// Legacy version.
pc_->Observer()->OnRenegotiationNeeded();
// Spec-compliant version; the event may get invalidated before firing.
GenerateNegotiationNeededEvent();
}
}
// MaybeStartGathering needs to be called after informing the observer so that
// we don't signal any candidates before signaling that SetLocalDescription
// completed.
transport_controller()->MaybeStartGathering();
}
void SdpOfferAnswerHandler::DoCreateOffer(
const PeerConnectionInterface::RTCOfferAnswerOptions& options,
rtc::scoped_refptr<CreateSessionDescriptionObserver> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::DoCreateOffer");
if (!observer) {
RTC_LOG(LS_ERROR) << "CreateOffer - observer is NULL.";
return;
}
if (pc_->IsClosed()) {
std::string error = "CreateOffer called when PeerConnection is closed.";
RTC_LOG(LS_ERROR) << error;
pc_->message_handler()->PostCreateSessionDescriptionFailure(
observer, RTCError(RTCErrorType::INVALID_STATE, std::move(error)));
return;
}
// If a session error has occurred the PeerConnection is in a possibly
// inconsistent state so fail right away.
if (session_error() != SessionError::kNone) {
std::string error_message = GetSessionErrorMsg();
RTC_LOG(LS_ERROR) << "CreateOffer: " << error_message;
pc_->message_handler()->PostCreateSessionDescriptionFailure(
observer,
RTCError(RTCErrorType::INTERNAL_ERROR, std::move(error_message)));
return;
}
if (!ValidateOfferAnswerOptions(options)) {
std::string error = "CreateOffer called with invalid options.";
RTC_LOG(LS_ERROR) << error;
pc_->message_handler()->PostCreateSessionDescriptionFailure(
observer, RTCError(RTCErrorType::INVALID_PARAMETER, std::move(error)));
return;
}
// Legacy handling for offer_to_receive_audio and offer_to_receive_video.
// Specified in WebRTC section 4.4.3.2 "Legacy configuration extensions".
if (IsUnifiedPlan()) {
RTCError error = HandleLegacyOfferOptions(options);
if (!error.ok()) {
pc_->message_handler()->PostCreateSessionDescriptionFailure(
observer, std::move(error));
return;
}
}
cricket::MediaSessionOptions session_options;
GetOptionsForOffer(options, &session_options);
webrtc_session_desc_factory_->CreateOffer(observer, options, session_options);
}
void SdpOfferAnswerHandler::CreateAnswer(
CreateSessionDescriptionObserver* observer,
const PeerConnectionInterface::RTCOfferAnswerOptions& options) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::CreateAnswer");
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(),
observer_refptr =
rtc::scoped_refptr<CreateSessionDescriptionObserver>(observer),
options](std::function<void()> operations_chain_callback) {
// Abort early if |this_weak_ptr| is no longer valid.
if (!this_weak_ptr) {
observer_refptr->OnFailure(RTCError(
RTCErrorType::INTERNAL_ERROR,
"CreateAnswer failed because the session was shut down"));
operations_chain_callback();
return;
}
// The operation completes asynchronously when the wrapper is invoked.
rtc::scoped_refptr<CreateSessionDescriptionObserverOperationWrapper>
observer_wrapper(new rtc::RefCountedObject<
CreateSessionDescriptionObserverOperationWrapper>(
std::move(observer_refptr),
std::move(operations_chain_callback)));
this_weak_ptr->DoCreateAnswer(options, observer_wrapper);
});
}
void SdpOfferAnswerHandler::DoCreateAnswer(
const PeerConnectionInterface::RTCOfferAnswerOptions& options,
rtc::scoped_refptr<CreateSessionDescriptionObserver> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::DoCreateAnswer");
if (!observer) {
RTC_LOG(LS_ERROR) << "CreateAnswer - observer is NULL.";
return;
}
// If a session error has occurred the PeerConnection is in a possibly
// inconsistent state so fail right away.
if (session_error() != SessionError::kNone) {
std::string error_message = GetSessionErrorMsg();
RTC_LOG(LS_ERROR) << "CreateAnswer: " << error_message;
pc_->message_handler()->PostCreateSessionDescriptionFailure(
observer,
RTCError(RTCErrorType::INTERNAL_ERROR, std::move(error_message)));
return;
}
if (!(signaling_state_ == PeerConnectionInterface::kHaveRemoteOffer ||
signaling_state_ == PeerConnectionInterface::kHaveLocalPrAnswer)) {
std::string error =
"PeerConnection cannot create an answer in a state other than "
"have-remote-offer or have-local-pranswer.";
RTC_LOG(LS_ERROR) << error;
pc_->message_handler()->PostCreateSessionDescriptionFailure(
observer, RTCError(RTCErrorType::INVALID_STATE, std::move(error)));
return;
}
// The remote description should be set if we're in the right state.
RTC_DCHECK(remote_description());
if (IsUnifiedPlan()) {
if (options.offer_to_receive_audio !=
PeerConnectionInterface::RTCOfferAnswerOptions::kUndefined) {
RTC_LOG(LS_WARNING) << "CreateAnswer: offer_to_receive_audio is not "
"supported with Unified Plan semantics. Use the "
"RtpTransceiver API instead.";
}
if (options.offer_to_receive_video !=
PeerConnectionInterface::RTCOfferAnswerOptions::kUndefined) {
RTC_LOG(LS_WARNING) << "CreateAnswer: offer_to_receive_video is not "
"supported with Unified Plan semantics. Use the "
"RtpTransceiver API instead.";
}
}
cricket::MediaSessionOptions session_options;
GetOptionsForAnswer(options, &session_options);
webrtc_session_desc_factory_->CreateAnswer(observer, session_options);
}
void SdpOfferAnswerHandler::DoSetRemoteDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
rtc::scoped_refptr<SetRemoteDescriptionObserverInterface> observer) {
RTC_DCHECK_RUN_ON(signaling_thread());
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::DoSetRemoteDescription");
if (!observer) {
RTC_LOG(LS_ERROR) << "SetRemoteDescription - observer is NULL.";
return;
}
if (!desc) {
observer->OnSetRemoteDescriptionComplete(RTCError(
RTCErrorType::INVALID_PARAMETER, "SessionDescription is NULL."));
return;
}
// If a session error has occurred the PeerConnection is in a possibly
// inconsistent state so fail right away.
if (session_error() != SessionError::kNone) {
std::string error_message = GetSessionErrorMsg();
RTC_LOG(LS_ERROR) << "SetRemoteDescription: " << error_message;
observer->OnSetRemoteDescriptionComplete(
RTCError(RTCErrorType::INTERNAL_ERROR, std::move(error_message)));
return;
}
if (IsUnifiedPlan()) {
if (pc_->configuration()->enable_implicit_rollback) {
if (desc->GetType() == SdpType::kOffer &&
signaling_state() == PeerConnectionInterface::kHaveLocalOffer) {
Rollback(desc->GetType());
}
}
// Explicit rollback.
if (desc->GetType() == SdpType::kRollback) {
observer->OnSetRemoteDescriptionComplete(Rollback(desc->GetType()));
return;
}
} else if (desc->GetType() == SdpType::kRollback) {
observer->OnSetRemoteDescriptionComplete(
RTCError(RTCErrorType::UNSUPPORTED_OPERATION,
"Rollback not supported in Plan B"));
return;
}
if (desc->GetType() == SdpType::kOffer ||
desc->GetType() == SdpType::kAnswer) {
// Report to UMA the format of the received offer or answer.
pc_->ReportSdpFormatReceived(*desc);
pc_->ReportSdpBundleUsage(*desc);
}
// Handle remote descriptions missing a=mid lines for interop with legacy end
// points.
FillInMissingRemoteMids(desc->description());
std::map<std::string, const cricket::ContentGroup*> bundle_groups_by_mid =
GetBundleGroupsByMid(desc->description());
RTCError error = ValidateSessionDescription(desc.get(), cricket::CS_REMOTE,
bundle_groups_by_mid);
if (!error.ok()) {
std::string error_message = GetSetDescriptionErrorMessage(
cricket::CS_REMOTE, desc->GetType(), error);
RTC_LOG(LS_ERROR) << error_message;
observer->OnSetRemoteDescriptionComplete(
RTCError(error.type(), std::move(error_message)));
return;
}
// Grab the description type before moving ownership to
// ApplyRemoteDescription, which may destroy it before returning.
const SdpType type = desc->GetType();
error = ApplyRemoteDescription(std::move(desc), bundle_groups_by_mid);
// |desc| may be destroyed at this point.
if (!error.ok()) {
// If ApplyRemoteDescription fails, the PeerConnection could be in an
// inconsistent state, so act conservatively here and set the session error
// so that future calls to SetLocalDescription/SetRemoteDescription fail.
SetSessionError(SessionError::kContent, error.message());
std::string error_message =
GetSetDescriptionErrorMessage(cricket::CS_REMOTE, type, error);
RTC_LOG(LS_ERROR) << error_message;
observer->OnSetRemoteDescriptionComplete(
RTCError(error.type(), std::move(error_message)));
return;
}
RTC_DCHECK(remote_description());
if (type == SdpType::kAnswer) {
RemoveStoppedTransceivers();
// TODO(deadbeef): We already had to hop to the network thread for
// MaybeStartGathering...
pc_->network_thread()->Invoke<void>(
RTC_FROM_HERE, [this] { port_allocator()->DiscardCandidatePool(); });
// Make UMA notes about what was agreed to.
ReportNegotiatedSdpSemantics(*remote_description());
}
observer->OnSetRemoteDescriptionComplete(RTCError::OK());
pc_->NoteUsageEvent(UsageEvent::SET_REMOTE_DESCRIPTION_SUCCEEDED);
// Check if negotiation is needed. We must do this after informing the
// observer that SetRemoteDescription() has completed to ensure negotiation is
// not needed prior to the promise resolving.
if (IsUnifiedPlan()) {
bool was_negotiation_needed = is_negotiation_needed_;
UpdateNegotiationNeeded();
if (signaling_state() == PeerConnectionInterface::kStable &&
was_negotiation_needed && is_negotiation_needed_) {
// Legacy version.
pc_->Observer()->OnRenegotiationNeeded();
// Spec-compliant version; the event may get invalidated before firing.
GenerateNegotiationNeededEvent();
}
}
}
void SdpOfferAnswerHandler::SetAssociatedRemoteStreams(
rtc::scoped_refptr<RtpReceiverInternal> receiver,
const std::vector<std::string>& stream_ids,
std::vector<rtc::scoped_refptr<MediaStreamInterface>>* added_streams,
std::vector<rtc::scoped_refptr<MediaStreamInterface>>* removed_streams) {
RTC_DCHECK_RUN_ON(signaling_thread());
std::vector<rtc::scoped_refptr<MediaStreamInterface>> media_streams;
for (const std::string& stream_id : stream_ids) {
rtc::scoped_refptr<MediaStreamInterface> stream =
remote_streams_->find(stream_id);
if (!stream) {
stream = MediaStreamProxy::Create(rtc::Thread::Current(),
MediaStream::Create(stream_id));
remote_streams_->AddStream(stream);
added_streams->push_back(stream);
}
media_streams.push_back(stream);
}
// Special case: "a=msid" missing, use random stream ID.
if (media_streams.empty() &&
!(remote_description()->description()->msid_signaling() &
cricket::kMsidSignalingMediaSection)) {
if (!missing_msid_default_stream_) {
missing_msid_default_stream_ = MediaStreamProxy::Create(
rtc::Thread::Current(), MediaStream::Create(rtc::CreateRandomUuid()));
added_streams->push_back(missing_msid_default_stream_);
}
media_streams.push_back(missing_msid_default_stream_);
}
std::vector<rtc::scoped_refptr<MediaStreamInterface>> previous_streams =
receiver->streams();
// SetStreams() will add/remove the receiver's track to/from the streams. This
// differs from the spec - the spec uses an "addList" and "removeList" to
// update the stream-track relationships in a later step. We do this earlier,
// changing the order of things, but the end-result is the same.
// TODO(hbos): When we remove remote_streams(), use set_stream_ids()
// instead. https://crbug.com/webrtc/9480
receiver->SetStreams(media_streams);
RemoveRemoteStreamsIfEmpty(previous_streams, removed_streams);
}
bool SdpOfferAnswerHandler::AddIceCandidate(
const IceCandidateInterface* ice_candidate) {
const AddIceCandidateResult result = AddIceCandidateInternal(ice_candidate);
NoteAddIceCandidateResult(result);
// If the return value is kAddIceCandidateFailNotReady, the candidate has been
// added, although not 'ready', but that's a success.
return result == kAddIceCandidateSuccess ||
result == kAddIceCandidateFailNotReady;
}
AddIceCandidateResult SdpOfferAnswerHandler::AddIceCandidateInternal(
const IceCandidateInterface* ice_candidate) {
RTC_DCHECK_RUN_ON(signaling_thread());
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::AddIceCandidate");
if (pc_->IsClosed()) {
RTC_LOG(LS_ERROR) << "AddIceCandidate: PeerConnection is closed.";
return kAddIceCandidateFailClosed;
}
if (!remote_description()) {
RTC_LOG(LS_ERROR) << "AddIceCandidate: ICE candidates can't be added "
"without any remote session description.";
return kAddIceCandidateFailNoRemoteDescription;
}
if (!ice_candidate) {
RTC_LOG(LS_ERROR) << "AddIceCandidate: Candidate is null.";
return kAddIceCandidateFailNullCandidate;
}
bool valid = false;
bool ready = ReadyToUseRemoteCandidate(ice_candidate, nullptr, &valid);
if (!valid) {
return kAddIceCandidateFailNotValid;
}
// Add this candidate to the remote session description.
if (!mutable_remote_description()->AddCandidate(ice_candidate)) {
RTC_LOG(LS_ERROR) << "AddIceCandidate: Candidate cannot be used.";
return kAddIceCandidateFailInAddition;
}
if (!ready) {
RTC_LOG(LS_INFO) << "AddIceCandidate: Not ready to use candidate.";
return kAddIceCandidateFailNotReady;
}
if (!UseCandidate(ice_candidate)) {
return kAddIceCandidateFailNotUsable;
}
pc_->NoteUsageEvent(UsageEvent::ADD_ICE_CANDIDATE_SUCCEEDED);
return kAddIceCandidateSuccess;
}
void SdpOfferAnswerHandler::AddIceCandidate(
std::unique_ptr<IceCandidateInterface> candidate,
std::function<void(RTCError)> callback) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::AddIceCandidate");
RTC_DCHECK_RUN_ON(signaling_thread());
// Chain this operation. If asynchronous operations are pending on the chain,
// this operation will be queued to be invoked, otherwise the contents of the
// lambda will execute immediately.
operations_chain_->ChainOperation(
[this_weak_ptr = weak_ptr_factory_.GetWeakPtr(),
candidate = std::move(candidate), callback = std::move(callback)](
std::function<void()> operations_chain_callback) {
auto result =
this_weak_ptr
? this_weak_ptr->AddIceCandidateInternal(candidate.get())
: kAddIceCandidateFailClosed;
NoteAddIceCandidateResult(result);
operations_chain_callback();
if (result == kAddIceCandidateFailClosed) {
callback(RTCError(
RTCErrorType::INVALID_STATE,
"AddIceCandidate failed because the session was shut down"));
} else if (result != kAddIceCandidateSuccess &&
result != kAddIceCandidateFailNotReady) {
// Fail with an error type and message consistent with Chromium.
// TODO(hbos): Fail with error types according to spec.
callback(RTCError(RTCErrorType::UNSUPPORTED_OPERATION,
"Error processing ICE candidate"));
} else {
callback(RTCError::OK());
}
});
}
bool SdpOfferAnswerHandler::RemoveIceCandidates(
const std::vector<cricket::Candidate>& candidates) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::RemoveIceCandidates");
RTC_DCHECK_RUN_ON(signaling_thread());
if (pc_->IsClosed()) {
RTC_LOG(LS_ERROR) << "RemoveIceCandidates: PeerConnection is closed.";
return false;
}
if (!remote_description()) {
RTC_LOG(LS_ERROR) << "RemoveIceCandidates: ICE candidates can't be removed "
"without any remote session description.";
return false;
}
if (candidates.empty()) {
RTC_LOG(LS_ERROR) << "RemoveIceCandidates: candidates are empty.";
return false;
}
size_t number_removed =
mutable_remote_description()->RemoveCandidates(candidates);
if (number_removed != candidates.size()) {
RTC_LOG(LS_ERROR)
<< "RemoveIceCandidates: Failed to remove candidates. Requested "
<< candidates.size() << " but only " << number_removed
<< " are removed.";
}
// Remove the candidates from the transport controller.
RTCError error = transport_controller()->RemoveRemoteCandidates(candidates);
if (!error.ok()) {
RTC_LOG(LS_ERROR)
<< "RemoveIceCandidates: Error when removing remote candidates: "
<< error.message();
}
return true;
}
void SdpOfferAnswerHandler::AddLocalIceCandidate(
const JsepIceCandidate* candidate) {
RTC_DCHECK_RUN_ON(signaling_thread());
if (local_description()) {
mutable_local_description()->AddCandidate(candidate);
}
}
void SdpOfferAnswerHandler::RemoveLocalIceCandidates(
const std::vector<cricket::Candidate>& candidates) {
RTC_DCHECK_RUN_ON(signaling_thread());
if (local_description()) {
mutable_local_description()->RemoveCandidates(candidates);
}
}
const SessionDescriptionInterface* SdpOfferAnswerHandler::local_description()
const {
RTC_DCHECK_RUN_ON(signaling_thread());
return pending_local_description_ ? pending_local_description_.get()
: current_local_description_.get();
}
const SessionDescriptionInterface* SdpOfferAnswerHandler::remote_description()
const {
RTC_DCHECK_RUN_ON(signaling_thread());
return pending_remote_description_ ? pending_remote_description_.get()
: current_remote_description_.get();
}
const SessionDescriptionInterface*
SdpOfferAnswerHandler::current_local_description() const {
RTC_DCHECK_RUN_ON(signaling_thread());
return current_local_description_.get();
}
const SessionDescriptionInterface*
SdpOfferAnswerHandler::current_remote_description() const {
RTC_DCHECK_RUN_ON(signaling_thread());
return current_remote_description_.get();
}
const SessionDescriptionInterface*
SdpOfferAnswerHandler::pending_local_description() const {
RTC_DCHECK_RUN_ON(signaling_thread());
return pending_local_description_.get();
}
const SessionDescriptionInterface*
SdpOfferAnswerHandler::pending_remote_description() const {
RTC_DCHECK_RUN_ON(signaling_thread());
return pending_remote_description_.get();
}
PeerConnectionInterface::SignalingState SdpOfferAnswerHandler::signaling_state()
const {
RTC_DCHECK_RUN_ON(signaling_thread());
return signaling_state_;
}
void SdpOfferAnswerHandler::ChangeSignalingState(
PeerConnectionInterface::SignalingState signaling_state) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::ChangeSignalingState");
RTC_DCHECK_RUN_ON(signaling_thread());
if (signaling_state_ == signaling_state) {
return;
}
RTC_LOG(LS_INFO) << "Session: " << pc_->session_id() << " Old state: "
<< GetSignalingStateString(signaling_state_)
<< " New state: "
<< GetSignalingStateString(signaling_state);
signaling_state_ = signaling_state;
pc_->Observer()->OnSignalingChange(signaling_state_);
}
RTCError SdpOfferAnswerHandler::UpdateSessionState(
SdpType type,
cricket::ContentSource source,
const cricket::SessionDescription* description,
const std::map<std::string, const cricket::ContentGroup*>&
bundle_groups_by_mid) {
RTC_DCHECK_RUN_ON(signaling_thread());
// If there's already a pending error then no state transition should happen.
// But all call-sites should be verifying this before calling us!
RTC_DCHECK(session_error() == SessionError::kNone);
// If this is answer-ish we're ready to let media flow.
if (type == SdpType::kPrAnswer || type == SdpType::kAnswer) {
EnableSending();
}
// Update the signaling state according to the specified state machine (see
// https://w3c.github.io/webrtc-pc/#rtcsignalingstate-enum).
if (type == SdpType::kOffer) {
ChangeSignalingState(source == cricket::CS_LOCAL
? PeerConnectionInterface::kHaveLocalOffer
: PeerConnectionInterface::kHaveRemoteOffer);
} else if (type == SdpType::kPrAnswer) {
ChangeSignalingState(source == cricket::CS_LOCAL
? PeerConnectionInterface::kHaveLocalPrAnswer
: PeerConnectionInterface::kHaveRemotePrAnswer);
} else {
RTC_DCHECK(type == SdpType::kAnswer);
ChangeSignalingState(PeerConnectionInterface::kStable);
transceivers()->DiscardStableStates();
}
// Update internal objects according to the session description's media
// descriptions.
return PushdownMediaDescription(type, source, bundle_groups_by_mid);
}
bool SdpOfferAnswerHandler::ShouldFireNegotiationNeededEvent(
uint32_t event_id) {
RTC_DCHECK_RUN_ON(signaling_thread());
// Plan B? Always fire to conform with useless legacy behavior.
if (!IsUnifiedPlan()) {
return true;
}
// The event ID has been invalidated. Either negotiation is no longer needed
// or a newer negotiation needed event has been generated.
if (event_id != negotiation_needed_event_id_) {
return false;
}
// The chain is no longer empty, update negotiation needed when it becomes
// empty. This should generate a newer negotiation needed event, making this
// one obsolete.
if (!operations_chain_->IsEmpty()) {
// Since we just suppressed an event that would have been fired, if
// negotiation is still needed by the time the chain becomes empty again, we
// must make sure to generate another event if negotiation is needed then.
// This happens when |is_negotiation_needed_| goes from false to true, so we
// set it to false until UpdateNegotiationNeeded() is called.
is_negotiation_needed_ = false;
update_negotiation_needed_on_empty_chain_ = true;
return false;
}
// We must not fire if the signaling state is no longer "stable". If
// negotiation is still needed when we return to "stable", a new negotiation
// needed event will be generated, so this one can safely be suppressed.
if (signaling_state_ != PeerConnectionInterface::kStable) {
return false;
}
// All checks have passed - please fire "negotiationneeded" now!
return true;
}
rtc::scoped_refptr<StreamCollectionInterface>
SdpOfferAnswerHandler::local_streams() {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_CHECK(!IsUnifiedPlan()) << "local_streams is not available with Unified "
"Plan SdpSemantics. Please use GetSenders "
"instead.";
return local_streams_;
}
rtc::scoped_refptr<StreamCollectionInterface>
SdpOfferAnswerHandler::remote_streams() {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_CHECK(!IsUnifiedPlan()) << "remote_streams is not available with Unified "
"Plan SdpSemantics. Please use GetReceivers "
"instead.";
return remote_streams_;
}
bool SdpOfferAnswerHandler::AddStream(MediaStreamInterface* local_stream) {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_CHECK(!IsUnifiedPlan()) << "AddStream is not available with Unified Plan "
"SdpSemantics. Please use AddTrack instead.";
if (pc_->IsClosed()) {
return false;
}
if (!CanAddLocalMediaStream(local_streams_, local_stream)) {
return false;
}
local_streams_->AddStream(local_stream);
MediaStreamObserver* observer = new MediaStreamObserver(local_stream);
observer->SignalAudioTrackAdded.connect(
this, &SdpOfferAnswerHandler::OnAudioTrackAdded);
observer->SignalAudioTrackRemoved.connect(
this, &SdpOfferAnswerHandler::OnAudioTrackRemoved);
observer->SignalVideoTrackAdded.connect(
this, &SdpOfferAnswerHandler::OnVideoTrackAdded);
observer->SignalVideoTrackRemoved.connect(
this, &SdpOfferAnswerHandler::OnVideoTrackRemoved);
stream_observers_.push_back(std::unique_ptr<MediaStreamObserver>(observer));
for (const auto& track : local_stream->GetAudioTracks()) {
rtp_manager()->AddAudioTrack(track.get(), local_stream);
}
for (const auto& track : local_stream->GetVideoTracks()) {
rtp_manager()->AddVideoTrack(track.get(), local_stream);
}
pc_->stats()->AddStream(local_stream);
UpdateNegotiationNeeded();
return true;
}
void SdpOfferAnswerHandler::RemoveStream(MediaStreamInterface* local_stream) {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_CHECK(!IsUnifiedPlan()) << "RemoveStream is not available with Unified "
"Plan SdpSemantics. Please use RemoveTrack "
"instead.";
TRACE_EVENT0("webrtc", "PeerConnection::RemoveStream");
if (!pc_->IsClosed()) {
for (const auto& track : local_stream->GetAudioTracks()) {
rtp_manager()->RemoveAudioTrack(track.get(), local_stream);
}
for (const auto& track : local_stream->GetVideoTracks()) {
rtp_manager()->RemoveVideoTrack(track.get(), local_stream);
}
}
local_streams_->RemoveStream(local_stream);
stream_observers_.erase(
std::remove_if(
stream_observers_.begin(), stream_observers_.end(),
[loca