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webrtc / src / 136d3b0df3449c5dca4e321986543e27f858274c / . / pc / sdp_offer_answer.cc
blob: 04d1aff7898fdf9d33c2a88f03b04b8812b79854 [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 <cstddef>
#include <iterator>
#include <map>
#include <memory>
#include <queue>
#include <string>
#include <utility>
#include "absl/algorithm/container.h"
#include "absl/memory/memory.h"
#include "absl/strings/match.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/field_trials_view.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/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/channel_interface.h"
#include "pc/dtls_transport.h"
#include "pc/legacy_stats_collector.h"
#include "pc/media_stream.h"
#include "pc/media_stream_proxy.h"
#include "pc/peer_connection_internal.h"
#include "pc/peer_connection_message_handler.h"
#include "pc/rtp_media_utils.h"
#include "pc/rtp_receiver_proxy.h"
#include "pc/rtp_sender.h"
#include "pc/rtp_sender_proxy.h"
#include "pc/simulcast_description.h"
#include "pc/usage_pattern.h"
#include "pc/used_ids.h"
#include "pc/webrtc_session_description_factory.h"
#include "rtc_base/helpers.h"
#include "rtc_base/logging.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/trace_event.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 PeerConnectionInterface::RTCOfferAnswerOptions RTCOfferAnswerOptions;
// 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: ";
// The length of RTCP CNAMEs.
static const int kRtcpCnameLength = 16;
// The maximum length of the MID attribute.
static constexpr size_t kMidMaxSize = 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);
}
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: ";
RTC_DCHECK(!absl::StartsWith(error.message(), oss.str())) << error.message();
oss << 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;
}
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;
}
#if !defined(WEBRTC_FUCHSIA)
RTC_CHECK(dtls_enabled) << "SDES protocol is only allowed in Fuchsia";
#endif
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) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
kSdpWithoutDtlsFingerprint);
}
} else {
if (media->cryptos().empty()) {
LOG_AND_RETURN_ERROR(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 (content.name.size() > kMidMaxSize) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"The MID attribute exceeds the maximum supported "
"length of 16 characters.");
}
if (!mids.insert(content.name).second) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"Duplicate a=mid value '" + content.name + "'.");
}
}
return RTCError::OK();
}
RTCError FindDuplicateCodecParameters(
const RtpCodecParameters codec_parameters,
std::map<int, RtpCodecParameters>& payload_to_codec_parameters) {
auto existing_codec_parameters =
payload_to_codec_parameters.find(codec_parameters.payload_type);
if (existing_codec_parameters != payload_to_codec_parameters.end() &&
codec_parameters != existing_codec_parameters->second) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"A BUNDLE group contains a codec collision for "
"payload_type='" +
rtc::ToString(codec_parameters.payload_type) +
". All codecs must share the same type, "
"encoding name, clock rate and parameters.");
}
payload_to_codec_parameters.insert(
std::make_pair(codec_parameters.payload_type, codec_parameters));
return RTCError::OK();
}
RTCError ValidateBundledPayloadTypes(
const cricket::SessionDescription& description) {
// https://www.rfc-editor.org/rfc/rfc8843#name-payload-type-pt-value-reuse
// ... all codecs associated with the payload type number MUST share an
// identical codec configuration. This means that the codecs MUST share
// the same media type, encoding name, clock rate, and any parameter
// that can affect the codec configuration and packetization.
std::vector<const cricket::ContentGroup*> bundle_groups =
description.GetGroupsByName(cricket::GROUP_TYPE_BUNDLE);
for (const cricket::ContentGroup* bundle_group : bundle_groups) {
std::map<int, RtpCodecParameters> payload_to_codec_parameters;
for (const std::string& content_name : bundle_group->content_names()) {
const ContentInfo* content_description =
description.GetContentByName(content_name);
if (!content_description) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"A BUNDLE group contains a MID='" + content_name +
"' matching no m= section.");
}
const cricket::MediaContentDescription* media_description =
content_description->media_description();
RTC_DCHECK(media_description);
if (content_description->rejected || !media_description ||
!media_description->has_codecs()) {
continue;
}
const auto type = media_description->type();
if (type == cricket::MEDIA_TYPE_AUDIO ||
type == cricket::MEDIA_TYPE_VIDEO) {
for (const auto& c : media_description->codecs()) {
auto error = FindDuplicateCodecParameters(
c.ToCodecParameters(), payload_to_codec_parameters);
if (!error.ok()) {
return error;
}
}
}
}
}
return RTCError::OK();
}
RTCError FindDuplicateHeaderExtensionIds(
const RtpExtension extension,
std::map<int, RtpExtension>& id_to_extension) {
auto existing_extension = id_to_extension.find(extension.id);
if (existing_extension != id_to_extension.end() &&
!(extension.uri == existing_extension->second.uri &&
extension.encrypt == existing_extension->second.encrypt)) {
LOG_AND_RETURN_ERROR(
RTCErrorType::INVALID_PARAMETER,
"A BUNDLE group contains a codec collision for "
"header extension id=" +
rtc::ToString(extension.id) +
". The id must be the same across all bundled media descriptions");
}
id_to_extension.insert(std::make_pair(extension.id, extension));
return RTCError::OK();
}
RTCError ValidateBundledRtpHeaderExtensions(
const cricket::SessionDescription& description) {
// https://www.rfc-editor.org/rfc/rfc8843#name-rtp-header-extensions-consi
// ... the identifier used for a given extension MUST identify the same
// extension across all the bundled media descriptions.
std::vector<const cricket::ContentGroup*> bundle_groups =
description.GetGroupsByName(cricket::GROUP_TYPE_BUNDLE);
for (const cricket::ContentGroup* bundle_group : bundle_groups) {
std::map<int, RtpExtension> id_to_extension;
for (const std::string& content_name : bundle_group->content_names()) {
const ContentInfo* content_description =
description.GetContentByName(content_name);
if (!content_description) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"A BUNDLE group contains a MID='" + content_name +
"' matching no m= section.");
}
const cricket::MediaContentDescription* media_description =
content_description->media_description();
RTC_DCHECK(media_description);
if (content_description->rejected || !media_description ||
!media_description->has_codecs()) {
continue;
}
for (const auto& extension : media_description->rtp_header_extensions()) {
auto error =
FindDuplicateHeaderExtensionIds(extension, id_to_extension);
if (!error.ok()) {
return error;
}
}
}
}
return RTCError::OK();
}
RTCError ValidateRtpHeaderExtensionsForSpecSimulcast(
const cricket::SessionDescription& description) {
for (const ContentInfo& content : description.contents()) {
if (content.type != MediaProtocolType::kRtp || content.rejected) {
continue;
}
const auto media_description = content.media_description();
if (!media_description->HasSimulcast()) {
continue;
}
auto extensions = media_description->rtp_header_extensions();
auto it = absl::c_find_if(extensions, [](const RtpExtension& ext) {
return ext.uri == RtpExtension::kRidUri;
});
if (it == extensions.end()) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"The media section with MID='" + content.mid() +
"' negotiates simulcast but does not negotiate "
"the RID RTP header extension.");
}
}
return RTCError::OK();
}
RTCError ValidateSsrcGroups(const cricket::SessionDescription& description) {
for (const ContentInfo& content : description.contents()) {
if (content.type != MediaProtocolType::kRtp) {
continue;
}
for (const StreamParams& stream : content.media_description()->streams()) {
for (const cricket::SsrcGroup& group : stream.ssrc_groups) {
// Validate the number of SSRCs for standard SSRC group semantics such
// as FID and FEC-FR and the non-standard SIM group.
if ((group.semantics == cricket::kFidSsrcGroupSemantics &&
group.ssrcs.size() != 2) ||
(group.semantics == cricket::kFecFrSsrcGroupSemantics &&
group.ssrcs.size() != 2) ||
(group.semantics == cricket::kSimSsrcGroupSemantics &&
group.ssrcs.size() > kMaxSimulcastStreams)) {
LOG_AND_RETURN_ERROR(RTCErrorType::INVALID_PARAMETER,
"The media section with MID='" + content.mid() +
"' has a ssrc-group with semantics " +
group.semantics +
" and an unexpected number of SSRCs.");
}
}
}
}
return RTCError::OK();
}
RTCError ValidatePayloadTypes(const cricket::SessionDescription& description) {
for (const ContentInfo& content : description.contents()) {
if (content.type != MediaProtocolType::kRtp) {
continue;
}
const auto media_description = content.media_description();
RTC_DCHECK(media_description);
if (content.rejected || !media_description ||
!media_description->has_codecs()) {
continue;
}
const auto type = media_description->type();
if (type == cricket::MEDIA_TYPE_AUDIO) {
RTC_DCHECK(media_description->as_audio());
for (const auto& codec : media_description->as_audio()->codecs()) {
if (!cricket::UsedPayloadTypes::IsIdValid(
codec, media_description->rtcp_mux())) {
LOG_AND_RETURN_ERROR(
RTCErrorType::INVALID_PARAMETER,
"The media section with MID='" + content.mid() +
"' used an invalid payload type " + rtc::ToString(codec.id) +
" for codec '" + codec.name + ", rtcp-mux:" +
(media_description->rtcp_mux() ? "enabled" : "disabled"));
}
}
} else if (type == cricket::MEDIA_TYPE_VIDEO) {
RTC_DCHECK(media_description->as_video());
for (const auto& codec : media_description->as_video()->codecs()) {
if (!cricket::UsedPayloadTypes::IsIdValid(
codec, media_description->rtcp_mux())) {
LOG_AND_RETURN_ERROR(
RTCErrorType::INVALID_PARAMETER,
"The media section with MID='" + content.mid() +
"' used an invalid payload type " + rtc::ToString(codec.id) +
" for codec '" + codec.name + ", rtcp-mux:" +
(media_description->rtcp_mux() ? "enabled" : "disabled"));
}
}
}
}
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);
}
// 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->GetParametersInternalWithAllLayers();
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->SetParametersInternalWithAllLayers(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->GetParametersInternalWithAllLayers();
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_DCHECK_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->GetHeaderExtensionsToNegotiate();
// 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()->GetParametersInternalWithAllLayers();
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_DCHECK_NOTREACHED();
}
return cname;
}
// Check if we can send `new_stream` on a PeerConnection.
bool CanAddLocalMediaStream(StreamCollectionInterface* current_streams,
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<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 BlockingCall?
// 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->BlockingCall(
[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
void UpdateRtpHeaderExtensionPreferencesFromSdpMunging(
const cricket::SessionDescription* description,
TransceiverList* transceivers) {
// This integrates the RTP Header Extension Control API and local SDP munging
// for backward compability reasons. If something was enabled in the local
// description via SDP munging, consider it non-stopped in the API as well
// so that is shows up in subsequent offers/answers.
RTC_DCHECK(description);
RTC_DCHECK(transceivers);
for (const auto& content : description->contents()) {
auto transceiver = transceivers->FindByMid(content.name);
if (!transceiver) {
continue;
}
auto extension_capabilities = transceiver->GetHeaderExtensionsToNegotiate();
// Set the capability of every extension we see here to "sendrecv".
for (auto& ext : content.media_description()->rtp_header_extensions()) {
auto it = absl::c_find_if(extension_capabilities,
[&ext](const RtpHeaderExtensionCapability c) {
return ext.uri == c.uri;
});
if (it != extension_capabilities.end()) {
it->direction = RtpTransceiverDirection::kSendRecv;
}
}
transceiver->SetHeaderExtensionsToNegotiate(extension_capabilities);
}
}
// This class stores state related to a SetRemoteDescription operation, captures
// and reports potential errors that might occur and makes sure to notify the
// observer of the operation and the operations chain of completion.
class SdpOfferAnswerHandler::RemoteDescriptionOperation {
public:
RemoteDescriptionOperation(
SdpOfferAnswerHandler* handler,
std::unique_ptr<SessionDescriptionInterface> desc,
rtc::scoped_refptr<SetRemoteDescriptionObserverInterface> observer,
std::function<void()> operations_chain_callback)
: handler_(handler),
desc_(std::move(desc)),
observer_(std::move(observer)),
operations_chain_callback_(std::move(operations_chain_callback)),
unified_plan_(handler_->IsUnifiedPlan()) {
if (!desc_) {
type_ = static_cast<SdpType>(-1);
InvalidParam("SessionDescription is NULL.");
} else {
type_ = desc_->GetType();
}
}
~RemoteDescriptionOperation() {
RTC_DCHECK_RUN_ON(handler_->signaling_thread());
SignalCompletion();
operations_chain_callback_();
}
bool ok() const { return error_.ok(); }
// Notifies the observer that the operation is complete and releases the
// reference to the observer.
void SignalCompletion() {
if (!observer_)
return;
if (!error_.ok() && type_ != static_cast<SdpType>(-1)) {
std::string error_message =
GetSetDescriptionErrorMessage(cricket::CS_REMOTE, type_, error_);
RTC_LOG(LS_ERROR) << error_message;
error_.set_message(error_message);
}
observer_->OnSetRemoteDescriptionComplete(error_);
observer_ = nullptr; // Only fire the notification once.
}
// If a session error has occurred the PeerConnection is in a possibly
// inconsistent state so fail right away.
bool HaveSessionError() {
RTC_DCHECK(ok());
if (handler_->session_error() != SessionError::kNone)
InternalError(handler_->GetSessionErrorMsg());
return !ok();
}
// Returns true if the operation was a rollback operation. If this function
// returns true, the caller should consider the operation complete. Otherwise
// proceed to the next step.
bool MaybeRollback() {
RTC_DCHECK_RUN_ON(handler_->signaling_thread());
RTC_DCHECK(ok());
if (type_ != SdpType::kRollback) {
// Check if we can do an implicit rollback.
if (type_ == SdpType::kOffer && unified_plan_ &&
handler_->pc_->configuration()->enable_implicit_rollback &&
handler_->signaling_state() ==
PeerConnectionInterface::kHaveLocalOffer) {
handler_->Rollback(type_);
}
return false;
}
if (unified_plan_) {
error_ = handler_->Rollback(type_);
} else if (type_ == SdpType::kRollback) {
Unsupported("Rollback not supported in Plan B");
}
return true;
}
// Report to UMA the format of the received offer or answer.
void ReportOfferAnswerUma() {
RTC_DCHECK(ok());
if (type_ == SdpType::kOffer || type_ == SdpType::kAnswer) {
handler_->pc_->ReportSdpBundleUsage(*desc_.get());
}
}
// Checks if the session description for the operation is valid. If not, the
// function captures error information and returns false. Note that if the
// return value is false, the operation should be considered done.
bool IsDescriptionValid() {
RTC_DCHECK_RUN_ON(handler_->signaling_thread());
RTC_DCHECK(ok());
RTC_DCHECK(bundle_groups_by_mid_.empty()) << "Already called?";
bundle_groups_by_mid_ = GetBundleGroupsByMid(description());
error_ = handler_->ValidateSessionDescription(
desc_.get(), cricket::CS_REMOTE, bundle_groups_by_mid_);
return ok();
}
// Transfers ownership of the session description object over to `handler_`.
bool ReplaceRemoteDescriptionAndCheckError() {
RTC_DCHECK_RUN_ON(handler_->signaling_thread());
RTC_DCHECK(ok());
RTC_DCHECK(desc_);
RTC_DCHECK(!replaced_remote_description_);
#if RTC_DCHECK_IS_ON
const auto* existing_remote_description = handler_->remote_description();
#endif
error_ = handler_->ReplaceRemoteDescription(std::move(desc_), type_,
&replaced_remote_description_);
if (ok()) {
#if RTC_DCHECK_IS_ON
// Sanity check that our `old_remote_description()` method always returns
// the same value as `remote_description()` did before the call to
// ReplaceRemoteDescription.
RTC_DCHECK_EQ(existing_remote_description, old_remote_description());
#endif
} else {
SetAsSessionError();
}
return ok();
}
bool UpdateChannels() {
RTC_DCHECK(ok());
RTC_DCHECK(!desc_) << "ReplaceRemoteDescription hasn't been called";
const auto* remote_description = handler_->remote_description();
const cricket::SessionDescription* session_desc =
remote_description->description();
// Transport and Media channels will be created only when offer is set.
if (unified_plan_) {
error_ = handler_->UpdateTransceiversAndDataChannels(
cricket::CS_REMOTE, *remote_description,
handler_->local_description(), old_remote_description(),
bundle_groups_by_mid_);
} 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.
error_ = handler_->CreateChannels(*session_desc);
}
// Remove unused channels if MediaContentDescription is rejected.
handler_->RemoveUnusedChannels(session_desc);
}
return ok();
}
bool UpdateSessionState() {
RTC_DCHECK(ok());
error_ = handler_->UpdateSessionState(
type_, cricket::CS_REMOTE,
handler_->remote_description()->description(), bundle_groups_by_mid_);
if (!ok())
SetAsSessionError();
return ok();
}
bool UseCandidatesInRemoteDescription() {
RTC_DCHECK(ok());
if (handler_->local_description() &&
!handler_->UseCandidatesInRemoteDescription()) {
InvalidParam(kInvalidCandidates);
}
return ok();
}
// Convenience getter for desc_->GetType().
SdpType type() const { return type_; }
bool unified_plan() const { return unified_plan_; }
cricket::SessionDescription* description() { return desc_->description(); }
const SessionDescriptionInterface* old_remote_description() const {
RTC_DCHECK(!desc_) << "Called before replacing the remote description";
if (type_ == SdpType::kAnswer)
return replaced_remote_description_.get();
return replaced_remote_description_
? replaced_remote_description_.get()
: handler_->current_remote_description();
}
// Returns a reference to a cached map of bundle groups ordered by mid.
// Note that this will only be valid after a successful call to
// `IsDescriptionValid`.
const std::map<std::string, const cricket::ContentGroup*>&
bundle_groups_by_mid() const {
RTC_DCHECK(ok());
return bundle_groups_by_mid_;
}
private:
// Convenience methods for populating the embedded `error_` object.
void Unsupported(std::string message) {
SetError(RTCErrorType::UNSUPPORTED_OPERATION, std::move(message));
}
void InvalidParam(std::string message) {
SetError(RTCErrorType::INVALID_PARAMETER, std::move(message));
}
void InternalError(std::string message) {
SetError(RTCErrorType::INTERNAL_ERROR, std::move(message));
}
void SetError(RTCErrorType type, std::string message) {
RTC_DCHECK(ok()) << "Overwriting an existing error?";
error_ = RTCError(type, std::move(message));
}
// Called when the PeerConnection could be in an inconsistent state and we set
// the session error so that future calls to
// SetLocalDescription/SetRemoteDescription fail.
void SetAsSessionError() {
RTC_DCHECK(!ok());
handler_->SetSessionError(SessionError::kContent, error_.message());
}
SdpOfferAnswerHandler* const handler_;
std::unique_ptr<SessionDescriptionInterface> desc_;
// Keeps the replaced session description object alive while the operation
// is taking place since methods that depend on `old_remote_description()`
// for updating the state, need it.
std::unique_ptr<SessionDescriptionInterface> replaced_remote_description_;
rtc::scoped_refptr<SetRemoteDescriptionObserverInterface> observer_;
std::function<void()> operations_chain_callback_;
RTCError error_ = RTCError::OK();
std::map<std::string, const cricket::ContentGroup*> bundle_groups_by_mid_;
SdpType type_;
const bool unified_plan_;
};
// 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_.get());
} else {
handler_->pc_->message_handler()->PostSetSessionDescriptionFailure(
inner_observer_.get(), 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(PeerConnectionSdpMethods* pc,
ConnectionContext* context)
: pc_(pc),
context_(context),
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(
PeerConnectionSdpMethods* pc,
const PeerConnectionInterface::RTCConfiguration& configuration,
PeerConnectionDependencies& dependencies,
ConnectionContext* context) {
auto handler = absl::WrapUnique(new SdpOfferAnswerHandler(pc, context));
handler->Initialize(configuration, dependencies, context);
return handler;
}
void SdpOfferAnswerHandler::Initialize(
const PeerConnectionInterface::RTCConfiguration& configuration,
PeerConnectionDependencies& dependencies,
ConnectionContext* context) {
RTC_DCHECK_RUN_ON(signaling_thread());
// 100 kbps is used by default, but can be overriden by a non-standard
// RTCConfiguration value (not available on Web).
video_options_.screencast_min_bitrate_kbps =
configuration.screencast_min_bitrate.value_or(100);
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;
// 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>(
context, this, pc_->session_id(), pc_->dtls_enabled(),
std::move(dependencies.cert_generator), std::move(certificate),
[this](const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) {
RTC_DCHECK_RUN_ON(signaling_thread());
transport_controller_s()->SetLocalCertificate(certificate);
},
pc_->trials());
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::MediaEngineInterface* SdpOfferAnswerHandler::media_engine() const {
RTC_DCHECK(context_);
return context_->media_engine();
}
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_s() {
return pc_->transport_controller_s();
}
JsepTransportController* SdpOfferAnswerHandler::transport_controller_n() {
return pc_->transport_controller_n();
}
const JsepTransportController* SdpOfferAnswerHandler::transport_controller_s()
const {
return pc_->transport_controller_s();
}
const JsepTransportController* SdpOfferAnswerHandler::transport_controller_n()
const {
return pc_->transport_controller_n();
}
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 context_->signaling_thread();
}
rtc::Thread* SdpOfferAnswerHandler::network_thread() const {
return context_->network_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.
auto observer_wrapper = rtc::make_ref_counted<
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::make_ref_counted<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(
rtc::make_ref_counted<SetSessionDescriptionObserverAdapter>(
weak_ptr_factory_.GetWeakPtr(),
rtc::scoped_refptr<SetSessionDescriptionObserver>(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.
auto create_sdp_observer =
rtc::make_ref_counted<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);
// Invalidate the stats caches to make sure that they get
// updated the next time getStats() gets called, as updating the session
// description affects the stats.
pc_->ClearStatsCache();
// 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);
}
if (!initial_offerer_) {
initial_offerer_.emplace(type == SdpType::kOffer);
}
// The session description to apply now must be accessed by
// `local_description()`.
RTC_DCHECK(local_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()) {
error = UpdateTransceiversAndDataChannels(
cricket::CS_LOCAL, *local_description(), old_local_description,
remote_description(), bundle_groups_by_mid);
if (!error.ok()) {
RTC_LOG(LS_ERROR) << error.message() << " (" << SdpTypeToString(type)
<< ")";
return error;
}
if (ConfiguredForMedia()) {
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(
context_->network_thread(), transport_controller_s(),
*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.
error = CreateChannels(*local_description()->description());
if (!error.ok()) {
RTC_LOG(LS_ERROR) << error.message() << " (" << SdpTypeToString(type)
<< ")";
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()) {
RTC_LOG(LS_ERROR) << error.message() << " (" << SdpTypeToString(type)
<< ")";
return error;
}
// Now that we have a local description, we can push down remote candidates.
UseCandidatesInRemoteDescription();
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.
AllocateSctpSids();
// Validate SSRCs, we do not allow duplicates.
if (ConfiguredForMedia()) {
std::set<uint32_t> used_ssrcs;
for (const auto& content : local_description()->description()->contents()) {
for (const auto& stream : content.media_description()->streams()) {
for (uint32_t ssrc : stream.ssrcs) {
auto result = used_ssrcs.insert(ssrc);
if (!result.second) {
LOG_AND_RETURN_ERROR(
RTCErrorType::INVALID_PARAMETER,
"Duplicate ssrc " + rtc::ToString(ssrc) + " is not allowed");
}
}
}
}
}
if (IsUnifiedPlan()) {
if (ConfiguredForMedia()) {
// 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();
}
if (IsUnifiedPlan()) {
UpdateRtpHeaderExtensionPreferencesFromSdpMunging(
local_description()->description(), transceivers());
}
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::make_unique<RemoteDescriptionOperation>(
this_weak_ptr.get(), std::move(desc),
rtc::make_ref_counted<SetSessionDescriptionObserverAdapter>(
this_weak_ptr, observer_refptr),
std::move(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 {
if (!observer) {
RTC_DLOG(LS_ERROR) << "SetRemoteDescription - observer is NULL.";
operations_chain_callback();
return;
}
// 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::make_unique<RemoteDescriptionOperation>(
this_weak_ptr.get(), std::move(desc), std::move(observer),
std::move(operations_chain_callback)));
});
}
RTCError SdpOfferAnswerHandler::ReplaceRemoteDescription(
std::unique_ptr<SessionDescriptionInterface> desc,
SdpType sdp_type,
std::unique_ptr<SessionDescriptionInterface>* replaced_description) {
RTC_DCHECK(replaced_description);
if (sdp_type == SdpType::kAnswer) {
*replaced_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_description = std::move(pending_remote_description_);
pending_remote_description_ = std::move(desc);
}
// The session description to apply now must be accessed by
// `remote_description()`.
const cricket::SessionDescription* session_desc =
remote_description()->description();
// NOTE: This will perform a BlockingCall() to the network thread.
return transport_controller_s()->SetRemoteDescription(sdp_type, session_desc);
}
void SdpOfferAnswerHandler::ApplyRemoteDescription(
std::unique_ptr<RemoteDescriptionOperation> operation) {
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::ApplyRemoteDescription");
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(operation->description());
// Invalidate the stats caches to make sure that they get
// updated next time getStats() gets called, as updating the session
// description affects the stats.
pc_->ClearStatsCache();
if (!operation->ReplaceRemoteDescriptionAndCheckError())
return;
if (!operation->UpdateChannels())
return;
// NOTE: Candidates allocation will be initiated only when
// SetLocalDescription is called.
if (!operation->UpdateSessionState())
return;
if (!operation->UseCandidatesInRemoteDescription())
return;
if (operation->old_remote_description()) {
for (const cricket::ContentInfo& content :
operation->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(operation->old_remote_description(),
remote_description(), content.name)) {
if (operation->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(
operation->old_remote_description(), content.name,
mutable_remote_description());
}
}
}
if (operation->HaveSessionError())
return;
// 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_internal() ==
PeerConnectionInterface::kIceConnectionNew) {
pc_->SetIceConnectionState(PeerConnectionInterface::kIceConnectionChecking);
}
// If setting the description decided our SSL role, allocate any necessary
// SCTP sids.
AllocateSctpSids();
if (operation->unified_plan()) {
ApplyRemoteDescriptionUpdateTransceiverState(operation->type());
}
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;
}
if (!operation->unified_plan()) {
PlanBUpdateSendersAndReceivers(
GetFirstAudioContent(remote_description()->description()), audio_desc,
GetFirstVideoContent(remote_description()->description()), video_desc);
}
if (operation->type() == SdpType::kAnswer) {
if (local_ice_credentials_to_replace_->SatisfiesIceRestart(
*current_local_description_)) {
local_ice_credentials_to_replace_->ClearIceCredentials();
}
RemoveStoppedTransceivers();
}
// Consider the operation complete at this point.
operation->SignalCompletion();
SetRemoteDescriptionPostProcess(operation->type() == SdpType::kAnswer);
}
void SdpOfferAnswerHandler::ApplyRemoteDescriptionUpdateTransceiverState(
SdpType sdp_type) {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(IsUnifiedPlan());
if (!ConfiguredForMedia()) {
return;
}
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());
// Remember the previous remote streams if this is a remote offer. This
// makes it possible to rollback modifications to the streams.
if (sdp_type == SdpType::kOffer) {
transceivers()
->StableState(transceiver_ext)
->SetRemoteStreamIds(transceiver->receiver()->stream_ids());
}
// 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();
}
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 << ".";
// Since the transceiver is passed to the user in an
// OnTrack event, we must use the proxied transceiver.
now_receiving_transceivers.push_back(transceiver_ext);
}
}
// 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.
if (sdp_type == SdpType::kOffer) {
// Remember the previous fired direction if this is a remote offer. This
// makes it possible to rollback modifications to [[FiredDirection]],
// which is necessary for "ontrack" to fire in or after rollback.
transceivers()
->StableState(transceiver_ext)
->SetFiredDirection(transceiver->fired_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 (sdp_type == SdpType::kPrAnswer || sdp_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(
context_->network_thread(), transport_controller_s(),
*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_->legacy_stats()->AddTrack(transceiver->receiver()->track().get());
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);
}
}
void SdpOfferAnswerHandler::PlanBUpdateSendersAndReceivers(
const cricket::ContentInfo* audio_content,
const cricket::AudioContentDescription* audio_desc,
const cricket::ContentInfo* video_content,
const cricket::VideoContentDescription* video_desc) {
RTC_DCHECK_RUN_ON(signaling_thread());
RTC_DCHECK(!IsUnifiedPlan());
// 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());
// 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.get());
}
}
// 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.get());
}
}
// 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_->legacy_stats()->AddStream(new_stream);
observer->OnAddStream(rtc::scoped_refptr<MediaStreamInterface>(new_stream));
}
UpdateEndedRemoteMediaStreams();
}
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(error.type(), 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...
context_->network_thread()->BlockingCall(
[this] { port_allocator()->DiscardCandidatePool(); });
}
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_s()->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.get(),
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.get(),
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.get(),
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.get(), std::move(error));
return;
}
}
cricket::MediaSessionOptions session_options;
GetOptionsForOffer(options, &session_options);
webrtc_session_desc_factory_->CreateOffer(observer.get(), 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.
auto observer_wrapper = rtc::make_ref_counted<
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.get(),
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.get(),
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.get(), session_options);
}
void SdpOfferAnswerHandler::DoSetRemoteDescription(
std::unique_ptr<RemoteDescriptionOperation> operation) {
RTC_DCHECK_RUN_ON(signaling_thread());
TRACE_EVENT0("webrtc", "SdpOfferAnswerHandler::DoSetRemoteDescription");
if (!operation->ok())
return;
if (operation->HaveSessionError())
return;
if (operation->MaybeRollback())
return;
operation->ReportOfferAnswerUma();
// Handle remote descriptions missing a=mid lines for interop with legacy
// end points.
FillInMissingRemoteMids(operation->description());
if (!operation->IsDescriptionValid())
return;
ApplyRemoteDescription(std::move(operation));
}
// Called after a DoSetRemoteDescription operation completes.
void SdpOfferAnswerHandler::SetRemoteDescriptionPostProcess(bool was_answer) {
RTC_DCHECK(remote_description());
if (was_answer) {
// TODO(deadbeef): We already had to hop to the network thread for
// MaybeStartGathering...
context_->network_thread()->BlockingCall(
[this] { port_allocator()->DiscardCandidatePool(); });
}
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();
switch (result) {
case AddIceCandidateResult::kAddIceCandidateSuccess:
case AddIceCandidateResult::kAddIceCandidateFailNotReady:
// Success!
callback(RTCError::OK());
break;
case AddIceCandidateResult::kAddIceCandidateFailClosed:
// Note that the spec says to just abort without resolving the
// promise in this case, but this layer must return an RTCError.
callback(RTCError(
RTCErrorType::INVALID_STATE,
"AddIceCandidate failed because the session was shut down"));
break;
case AddIceCandidateResult::kAddIceCandidateFailNoRemoteDescription:
// Spec: "If remoteDescription is null return a promise rejected
// with a newly created InvalidStateError."
callback(RTCError(RTCErrorType::INVALID_STATE,
"The remote description was null"));
break;
case AddIceCandidateResult::kAddIceCandidateFailNullCandidate:
// TODO(https://crbug.com/935898): Handle end-of-candidates instead
// of treating null candidate as an error.
callback(RTCError(RTCErrorType::UNSUPPORTED_OPERATION,
"Error processing ICE candidate"));
break;
case AddIceCandidateResult::kAddIceCandidateFailNotValid:
case AddIceCandidateResult::kAddIceCandidateFailInAddition:
case AddIceCandidateResult::kAddIceCandidateFailNotUsable:
// Spec: "If candidate could not be successfully added [...] Reject
// p with a newly created OperationError and abort these steps."
// UNSUPPORTED_OPERATION maps to OperationError.
callback(RTCError(RTCErrorType::UNSUPPORTED_OPERATION,
"Error processing ICE candidate"));
break;
default:
RTC_DCHECK_NOTREACHED();
}
});
}
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_s()->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: "
<< PeerConnectionInterface::AsString(signaling_state_)
<< " New state: "
<< PeerConnectionInterface::AsString(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