diff options
Diffstat (limited to 'dom/media/webrtc/jsep/JsepSessionImpl.cpp')
| -rw-r--r-- | dom/media/webrtc/jsep/JsepSessionImpl.cpp | 2473 |
1 files changed, 2473 insertions, 0 deletions
diff --git a/dom/media/webrtc/jsep/JsepSessionImpl.cpp b/dom/media/webrtc/jsep/JsepSessionImpl.cpp new file mode 100644 index 0000000000..50def6eb6c --- /dev/null +++ b/dom/media/webrtc/jsep/JsepSessionImpl.cpp @@ -0,0 +1,2473 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "jsep/JsepSessionImpl.h" + +#include <stdlib.h> + +#include <bitset> +#include <iterator> +#include <set> +#include <string> +#include <utility> + +#include "transport/logging.h" +#include "mozilla/Preferences.h" +#include "mozilla/Telemetry.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/net/DataChannelProtocol.h" +#include "nsDebug.h" +#include "nspr.h" +#include "nss.h" +#include "pk11pub.h" + +#include "api/rtp_parameters.h" + +#include "jsep/JsepTrack.h" +#include "jsep/JsepTransport.h" +#include "sdp/HybridSdpParser.h" +#include "sdp/SipccSdp.h" + +namespace mozilla { + +MOZ_MTLOG_MODULE("jsep") + +#define JSEP_SET_ERROR(error) \ + do { \ + std::ostringstream os; \ + os << error; \ + mLastError = os.str(); \ + MOZ_MTLOG(ML_ERROR, "[" << mName << "]: " << mLastError); \ + } while (0); + +static std::bitset<128> GetForbiddenSdpPayloadTypes() { + std::bitset<128> forbidden(0); + forbidden[1] = true; + forbidden[2] = true; + forbidden[19] = true; + for (uint16_t i = 64; i < 96; ++i) { + forbidden[i] = true; + } + return forbidden; +} + +static std::string GetRandomHex(size_t words) { + std::ostringstream os; + + for (size_t i = 0; i < words; ++i) { + uint32_t rand; + SECStatus rv = PK11_GenerateRandom(reinterpret_cast<unsigned char*>(&rand), + sizeof(rand)); + if (rv != SECSuccess) { + MOZ_CRASH(); + return ""; + } + + os << std::hex << std::setfill('0') << std::setw(8) << rand; + } + return os.str(); +} + +JsepSessionImpl::JsepSessionImpl(const JsepSessionImpl& aOrig) + : JsepSession(aOrig), + JsepSessionCopyableStuff(aOrig), + mUuidGen(aOrig.mUuidGen->Clone()), + mGeneratedOffer(aOrig.mGeneratedOffer ? aOrig.mGeneratedOffer->Clone() + : nullptr), + mGeneratedAnswer(aOrig.mGeneratedAnswer ? aOrig.mGeneratedAnswer->Clone() + : nullptr), + mCurrentLocalDescription(aOrig.mCurrentLocalDescription + ? aOrig.mCurrentLocalDescription->Clone() + : nullptr), + mCurrentRemoteDescription(aOrig.mCurrentRemoteDescription + ? aOrig.mCurrentRemoteDescription->Clone() + : nullptr), + mPendingLocalDescription(aOrig.mPendingLocalDescription + ? aOrig.mPendingLocalDescription->Clone() + : nullptr), + mPendingRemoteDescription(aOrig.mPendingRemoteDescription + ? aOrig.mPendingRemoteDescription->Clone() + : nullptr), + mSdpHelper(&mLastError), + mParser(new HybridSdpParser()) { + for (const auto& codec : aOrig.mSupportedCodecs) { + mSupportedCodecs.emplace_back(codec->Clone()); + } +} + +nsresult JsepSessionImpl::Init() { + mLastError.clear(); + + MOZ_ASSERT(!mSessionId, "Init called more than once"); + + nsresult rv = SetupIds(); + NS_ENSURE_SUCCESS(rv, rv); + + mEncodeTrackId = + Preferences::GetBool("media.peerconnection.sdp.encode_track_id", true); + + mIceUfrag = GetRandomHex(1); + mIcePwd = GetRandomHex(4); + return NS_OK; +} + +static void GetIceCredentials( + const Sdp& aSdp, + std::set<std::pair<std::string, std::string>>* aCredentials) { + for (size_t i = 0; i < aSdp.GetMediaSectionCount(); ++i) { + const SdpAttributeList& attrs = aSdp.GetMediaSection(i).GetAttributeList(); + if (attrs.HasAttribute(SdpAttribute::kIceUfragAttribute) && + attrs.HasAttribute(SdpAttribute::kIcePwdAttribute)) { + aCredentials->insert( + std::make_pair(attrs.GetIceUfrag(), attrs.GetIcePwd())); + } + } +} + +std::set<std::pair<std::string, std::string>> +JsepSessionImpl::GetLocalIceCredentials() const { + std::set<std::pair<std::string, std::string>> result; + if (mCurrentLocalDescription) { + GetIceCredentials(*mCurrentLocalDescription, &result); + } + if (mPendingLocalDescription) { + GetIceCredentials(*mPendingLocalDescription, &result); + } + return result; +} + +void JsepSessionImpl::AddTransceiver(const JsepTransceiver& aTransceiver) { + mLastError.clear(); + MOZ_MTLOG(ML_DEBUG, + "[" << mName << "]: Adding transceiver " << aTransceiver.GetUuid()); +#ifdef DEBUG + if (aTransceiver.GetMediaType() == SdpMediaSection::kApplication) { + // Make sure we don't add more than one DataChannel transceiver + for (const auto& transceiver : mTransceivers) { + MOZ_ASSERT(transceiver.GetMediaType() != SdpMediaSection::kApplication); + } + } +#endif + mTransceivers.push_back(aTransceiver); + InitTransceiver(mTransceivers.back()); +} + +void JsepSessionImpl::InitTransceiver(JsepTransceiver& aTransceiver) { + mLastError.clear(); + + if (aTransceiver.GetMediaType() != SdpMediaSection::kApplication) { + // Make sure we have an ssrc. Might already be set. + aTransceiver.mSendTrack.EnsureSsrcs(mSsrcGenerator, 1U); + aTransceiver.mSendTrack.SetCNAME(mCNAME); + + // Make sure we have identifiers for send track, just in case. + // (man I hate this) + if (mEncodeTrackId) { + aTransceiver.mSendTrack.SetTrackId(aTransceiver.GetUuid()); + } + } else { + // Datachannel transceivers should always be sendrecv. Just set it instead + // of asserting. + aTransceiver.mJsDirection = SdpDirectionAttribute::kSendrecv; + } + + aTransceiver.mSendTrack.PopulateCodecs(mSupportedCodecs); + aTransceiver.mRecvTrack.PopulateCodecs(mSupportedCodecs); + // We do not set mLevel yet, we do that either on createOffer, or setRemote +} + +nsresult JsepSessionImpl::SetBundlePolicy(JsepBundlePolicy policy) { + mLastError.clear(); + + if (mBundlePolicy == policy) { + return NS_OK; + } + + if (mCurrentLocalDescription) { + JSEP_SET_ERROR( + "Changing the bundle policy is only supported before the " + "first SetLocalDescription."); + return NS_ERROR_UNEXPECTED; + } + + mBundlePolicy = policy; + return NS_OK; +} + +nsresult JsepSessionImpl::AddDtlsFingerprint( + const nsACString& algorithm, const std::vector<uint8_t>& value) { + mLastError.clear(); + JsepDtlsFingerprint fp; + + fp.mAlgorithm = algorithm; + fp.mValue = value; + + mDtlsFingerprints.push_back(fp); + + return NS_OK; +} + +nsresult JsepSessionImpl::AddRtpExtension( + JsepMediaType mediaType, const std::string& extensionName, + SdpDirectionAttribute::Direction direction) { + mLastError.clear(); + + for (auto& ext : mRtpExtensions) { + if (ext.mExtmap.direction == direction && + ext.mExtmap.extensionname == extensionName) { + if (ext.mMediaType != mediaType) { + ext.mMediaType = JsepMediaType::kAudioVideo; + } + return NS_OK; + } + } + + uint16_t freeEntry = GetNeverUsedExtmapEntry(); + + if (freeEntry == 0) { + return NS_ERROR_FAILURE; + } + + JsepExtmapMediaType extMediaType = { + mediaType, + {freeEntry, direction, + // do we want to specify direction? + direction != SdpDirectionAttribute::kSendrecv, extensionName, ""}}; + + mRtpExtensions.push_back(extMediaType); + return NS_OK; +} + +nsresult JsepSessionImpl::AddAudioRtpExtension( + const std::string& extensionName, + SdpDirectionAttribute::Direction direction) { + return AddRtpExtension(JsepMediaType::kAudio, extensionName, direction); +} + +nsresult JsepSessionImpl::AddVideoRtpExtension( + const std::string& extensionName, + SdpDirectionAttribute::Direction direction) { + return AddRtpExtension(JsepMediaType::kVideo, extensionName, direction); +} + +nsresult JsepSessionImpl::AddAudioVideoRtpExtension( + const std::string& extensionName, + SdpDirectionAttribute::Direction direction) { + return AddRtpExtension(JsepMediaType::kAudioVideo, extensionName, direction); +} + +nsresult JsepSessionImpl::CreateOfferMsection(const JsepOfferOptions& options, + JsepTransceiver& transceiver, + Sdp* local) { + SdpMediaSection::Protocol protocol( + SdpHelper::GetProtocolForMediaType(transceiver.GetMediaType())); + + const Sdp* answer(GetAnswer()); + const SdpMediaSection* lastAnswerMsection = nullptr; + + if (answer && + (local->GetMediaSectionCount() < answer->GetMediaSectionCount())) { + lastAnswerMsection = + &answer->GetMediaSection(local->GetMediaSectionCount()); + // Use the protocol the answer used, even if it is not what we would have + // used. + protocol = lastAnswerMsection->GetProtocol(); + } + + SdpMediaSection* msection = &local->AddMediaSection( + transceiver.GetMediaType(), transceiver.mJsDirection, 0, protocol, + sdp::kIPv4, "0.0.0.0"); + + // Some of this stuff (eg; mid) sticks around even if disabled + if (lastAnswerMsection) { + MOZ_ASSERT(lastAnswerMsection->GetMediaType() == + transceiver.GetMediaType()); + nsresult rv = mSdpHelper.CopyStickyParams(*lastAnswerMsection, msection); + NS_ENSURE_SUCCESS(rv, rv); + } + + if (transceiver.IsStopping() || transceiver.IsStopped()) { + SdpHelper::DisableMsection(local, msection); + return NS_OK; + } + + msection->SetPort(9); + + // We don't do this in AddTransportAttributes because that is also used for + // making answers, and we don't want to unconditionally set rtcp-mux or + // rtcp-rsize there. + if (mSdpHelper.HasRtcp(msection->GetProtocol())) { + // Set RTCP-MUX. + msection->GetAttributeList().SetAttribute( + new SdpFlagAttribute(SdpAttribute::kRtcpMuxAttribute)); + // Set RTCP-RSIZE + if (msection->GetMediaType() == SdpMediaSection::MediaType::kVideo && + Preferences::GetBool("media.navigator.video.offer_rtcp_rsize", false)) { + msection->GetAttributeList().SetAttribute( + new SdpFlagAttribute(SdpAttribute::kRtcpRsizeAttribute)); + } + } + + nsresult rv = AddTransportAttributes(msection, SdpSetupAttribute::kActpass); + NS_ENSURE_SUCCESS(rv, rv); + + transceiver.mSendTrack.AddToOffer(mSsrcGenerator, msection); + transceiver.mRecvTrack.AddToOffer(mSsrcGenerator, msection); + + AddExtmap(msection); + + std::string mid; + // We do not set the mid on the transceiver, that happens when a description + // is set. + if (transceiver.IsAssociated()) { + mid = transceiver.GetMid(); + } else { + mid = GetNewMid(); + } + + msection->GetAttributeList().SetAttribute( + new SdpStringAttribute(SdpAttribute::kMidAttribute, mid)); + + return NS_OK; +} + +void JsepSessionImpl::SetupBundle(Sdp* sdp) const { + std::vector<std::string> mids; + std::set<SdpMediaSection::MediaType> observedTypes; + + // This has the effect of changing the bundle level if the first m-section + // goes from disabled to enabled. This is kinda inefficient. + + for (size_t i = 0; i < sdp->GetMediaSectionCount(); ++i) { + auto& attrs = sdp->GetMediaSection(i).GetAttributeList(); + if ((sdp->GetMediaSection(i).GetPort() != 0) && + attrs.HasAttribute(SdpAttribute::kMidAttribute)) { + bool useBundleOnly = false; + switch (mBundlePolicy) { + case kBundleMaxCompat: + // We don't use bundle-only for max-compat + break; + case kBundleBalanced: + // balanced means we use bundle-only on everything but the first + // m-section of a given type + if (observedTypes.count(sdp->GetMediaSection(i).GetMediaType())) { + useBundleOnly = true; + } + observedTypes.insert(sdp->GetMediaSection(i).GetMediaType()); + break; + case kBundleMaxBundle: + // max-bundle means we use bundle-only on everything but the first + // m-section + useBundleOnly = !mids.empty(); + break; + } + + if (useBundleOnly) { + attrs.SetAttribute( + new SdpFlagAttribute(SdpAttribute::kBundleOnlyAttribute)); + // Set port to 0 for sections with bundle-only attribute. (mjf) + sdp->GetMediaSection(i).SetPort(0); + } + + mids.push_back(attrs.GetMid()); + } + } + + if (!mids.empty()) { + UniquePtr<SdpGroupAttributeList> groupAttr(new SdpGroupAttributeList); + groupAttr->PushEntry(SdpGroupAttributeList::kBundle, mids); + sdp->GetAttributeList().SetAttribute(groupAttr.release()); + } +} + +JsepSession::Result JsepSessionImpl::CreateOffer( + const JsepOfferOptions& options, std::string* offer) { + mLastError.clear(); + + if (mState != kJsepStateStable && mState != kJsepStateHaveLocalOffer) { + JSEP_SET_ERROR("Cannot create offer in state " << GetStateStr(mState)); + // Spec doesn't seem to say this is an error. It probably should. + return dom::PCError::InvalidStateError; + } + + // This is one of those places where CreateOffer sets some state. + SetIceRestarting(options.mIceRestart.isSome() && *(options.mIceRestart)); + + UniquePtr<Sdp> sdp; + + // Make the basic SDP that is common to offer/answer. + nsresult rv = CreateGenericSDP(&sdp); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + for (size_t level = 0; + Maybe<JsepTransceiver> transceiver = GetTransceiverForLocal(level); + ++level) { + rv = CreateOfferMsection(options, *transceiver, sdp.get()); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + SetTransceiver(*transceiver); + } + + SetupBundle(sdp.get()); + + if (mCurrentLocalDescription && GetAnswer()) { + rv = CopyPreviousTransportParams(*GetAnswer(), *mCurrentLocalDescription, + *sdp, sdp.get()); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + } + + *offer = sdp->ToString(); + mGeneratedOffer = std::move(sdp); + ++mSessionVersion; + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: CreateOffer \nSDP=\n" << *offer); + + return Result(); +} + +std::string JsepSessionImpl::GetLocalDescription( + JsepDescriptionPendingOrCurrent type) const { + std::ostringstream os; + mozilla::Sdp* sdp = GetParsedLocalDescription(type); + if (sdp) { + sdp->Serialize(os); + } + return os.str(); +} + +std::string JsepSessionImpl::GetRemoteDescription( + JsepDescriptionPendingOrCurrent type) const { + std::ostringstream os; + mozilla::Sdp* sdp = GetParsedRemoteDescription(type); + if (sdp) { + sdp->Serialize(os); + } + return os.str(); +} + +void JsepSessionImpl::AddExtmap(SdpMediaSection* msection) { + auto extensions = GetRtpExtensions(*msection); + + if (!extensions.empty()) { + SdpExtmapAttributeList* extmap = new SdpExtmapAttributeList; + extmap->mExtmaps = extensions; + msection->GetAttributeList().SetAttribute(extmap); + } +} + +std::vector<SdpExtmapAttributeList::Extmap> JsepSessionImpl::GetRtpExtensions( + const SdpMediaSection& msection) { + std::vector<SdpExtmapAttributeList::Extmap> result; + JsepMediaType mediaType = JsepMediaType::kNone; + switch (msection.GetMediaType()) { + case SdpMediaSection::kAudio: + mediaType = JsepMediaType::kAudio; + break; + case SdpMediaSection::kVideo: + mediaType = JsepMediaType::kVideo; + if (msection.GetAttributeList().HasAttribute( + SdpAttribute::kRidAttribute)) { + // We need RID support + // TODO: Would it be worth checking that the direction is sane? + AddVideoRtpExtension(webrtc::RtpExtension::kRidUri, + SdpDirectionAttribute::kSendonly); + + if (mRtxIsAllowed && + Preferences::GetBool("media.peerconnection.video.use_rtx", false)) { + AddVideoRtpExtension(webrtc::RtpExtension::kRepairedRidUri, + SdpDirectionAttribute::kSendonly); + } + } + break; + default:; + } + if (mediaType != JsepMediaType::kNone) { + for (auto ext = mRtpExtensions.begin(); ext != mRtpExtensions.end(); + ++ext) { + if (ext->mMediaType == mediaType || + ext->mMediaType == JsepMediaType::kAudioVideo) { + result.push_back(ext->mExtmap); + } + } + } + return result; +} + +std::string JsepSessionImpl::GetNewMid() { + std::string mid; + + do { + std::ostringstream osMid; + osMid << mMidCounter++; + mid = osMid.str(); + } while (mUsedMids.count(mid)); + + mUsedMids.insert(mid); + return mid; +} + +void JsepSessionImpl::AddCommonExtmaps(const SdpMediaSection& remoteMsection, + SdpMediaSection* msection) { + auto negotiatedRtpExtensions = GetRtpExtensions(*msection); + mSdpHelper.NegotiateAndAddExtmaps(remoteMsection, negotiatedRtpExtensions, + msection); +} + +uint16_t JsepSessionImpl::GetNeverUsedExtmapEntry() { + uint16_t result = 1; + + // Walk the set in order, and return the first "hole" we find + for (const auto used : mExtmapEntriesEverUsed) { + if (result != used) { + MOZ_ASSERT(result < used); + break; + } + + // RFC 5285 says entries >= 4096 are used in offers to force the answerer + // to pick, so we do not want to actually use these + if (used == 4095) { + JSEP_SET_ERROR( + "Too many rtp extensions have been added. " + "That's 4095. Who _does_ that?"); + return 0; + } + + result = used + 1; + } + + mExtmapEntriesEverUsed.insert(result); + return result; +} + +JsepSession::Result JsepSessionImpl::CreateAnswer( + const JsepAnswerOptions& options, std::string* answer) { + mLastError.clear(); + + if (mState != kJsepStateHaveRemoteOffer) { + JSEP_SET_ERROR("Cannot create answer in state " << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + + UniquePtr<Sdp> sdp; + + // Make the basic SDP that is common to offer/answer. + nsresult rv = CreateGenericSDP(&sdp); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + const Sdp& offer = *mPendingRemoteDescription; + + // Copy the bundle groups into our answer + UniquePtr<SdpGroupAttributeList> groupAttr(new SdpGroupAttributeList); + mSdpHelper.GetBundleGroups(offer, &groupAttr->mGroups); + sdp->GetAttributeList().SetAttribute(groupAttr.release()); + + for (size_t i = 0; i < offer.GetMediaSectionCount(); ++i) { + // The transceivers are already in place, due to setRemote + Maybe<JsepTransceiver> transceiver(GetTransceiverForLevel(i)); + if (!transceiver) { + JSEP_SET_ERROR("No transceiver for level " << i); + MOZ_ASSERT(false); + return dom::PCError::OperationError; + } + rv = CreateAnswerMsection(options, *transceiver, offer.GetMediaSection(i), + sdp.get()); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + SetTransceiver(*transceiver); + } + + // Ensure that each bundle-group starts with a mid that has a transport, in + // case we've disabled what the offerer wanted to use. If the group doesn't + // contain anything that has a transport, remove it. + groupAttr.reset(new SdpGroupAttributeList); + std::vector<SdpGroupAttributeList::Group> bundleGroups; + mSdpHelper.GetBundleGroups(*sdp, &bundleGroups); + for (auto& group : bundleGroups) { + for (auto& mid : group.tags) { + const SdpMediaSection* msection = + mSdpHelper.FindMsectionByMid(offer, mid); + + if (msection && !msection->GetAttributeList().HasAttribute( + SdpAttribute::kBundleOnlyAttribute)) { + std::swap(group.tags[0], mid); + groupAttr->mGroups.push_back(group); + break; + } + } + } + sdp->GetAttributeList().SetAttribute(groupAttr.release()); + + if (mCurrentLocalDescription) { + // per discussion with bwc, 3rd parm here should be offer, not *sdp. (mjf) + rv = CopyPreviousTransportParams(*GetAnswer(), *mCurrentRemoteDescription, + offer, sdp.get()); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + } + + *answer = sdp->ToString(); + mGeneratedAnswer = std::move(sdp); + ++mSessionVersion; + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: CreateAnswer \nSDP=\n" << *answer); + + return Result(); +} + +nsresult JsepSessionImpl::CreateAnswerMsection( + const JsepAnswerOptions& options, JsepTransceiver& transceiver, + const SdpMediaSection& remoteMsection, Sdp* sdp) { + MOZ_ASSERT(transceiver.GetMediaType() == remoteMsection.GetMediaType()); + SdpDirectionAttribute::Direction direction = + reverse(remoteMsection.GetDirection()) & transceiver.mJsDirection; + SdpMediaSection& msection = + sdp->AddMediaSection(remoteMsection.GetMediaType(), direction, 9, + remoteMsection.GetProtocol(), sdp::kIPv4, "0.0.0.0"); + + nsresult rv = mSdpHelper.CopyStickyParams(remoteMsection, &msection); + NS_ENSURE_SUCCESS(rv, rv); + + if (mSdpHelper.MsectionIsDisabled(remoteMsection)) { + SdpHelper::DisableMsection(sdp, &msection); + return NS_OK; + } + + MOZ_ASSERT(transceiver.IsAssociated()); + if (msection.GetAttributeList().GetMid().empty()) { + msection.GetAttributeList().SetAttribute(new SdpStringAttribute( + SdpAttribute::kMidAttribute, transceiver.GetMid())); + } + + MOZ_ASSERT(transceiver.GetMid() == msection.GetAttributeList().GetMid()); + + SdpSetupAttribute::Role role; + if (transceiver.mTransport.mDtls && !IsIceRestarting()) { + role = (transceiver.mTransport.mDtls->mRole == + JsepDtlsTransport::kJsepDtlsClient) + ? SdpSetupAttribute::kActive + : SdpSetupAttribute::kPassive; + } else { + rv = DetermineAnswererSetupRole(remoteMsection, &role); + NS_ENSURE_SUCCESS(rv, rv); + } + + rv = AddTransportAttributes(&msection, role); + NS_ENSURE_SUCCESS(rv, rv); + + transceiver.mSendTrack.AddToAnswer(remoteMsection, mSsrcGenerator, &msection); + transceiver.mRecvTrack.AddToAnswer(remoteMsection, mSsrcGenerator, &msection); + + // Add extmap attributes. This logic will probably be moved to the track, + // since it can be specified on a per-sender basis in JS. + // We will need some validation to ensure that the ids are identical for + // RTP streams that are bundled together, though (bug 1406529). + AddCommonExtmaps(remoteMsection, &msection); + + if (msection.GetFormats().empty()) { + // Could not negotiate anything. Disable m-section. + SdpHelper::DisableMsection(sdp, &msection); + } + + return NS_OK; +} + +nsresult JsepSessionImpl::DetermineAnswererSetupRole( + const SdpMediaSection& remoteMsection, SdpSetupAttribute::Role* rolep) { + // Determine the role. + // RFC 5763 says: + // + // The endpoint MUST use the setup attribute defined in [RFC4145]. + // The endpoint that is the offerer MUST use the setup attribute + // value of setup:actpass and be prepared to receive a client_hello + // before it receives the answer. The answerer MUST use either a + // setup attribute value of setup:active or setup:passive. Note that + // if the answerer uses setup:passive, then the DTLS handshake will + // not begin until the answerer is received, which adds additional + // latency. setup:active allows the answer and the DTLS handshake to + // occur in parallel. Thus, setup:active is RECOMMENDED. Whichever + // party is active MUST initiate a DTLS handshake by sending a + // ClientHello over each flow (host/port quartet). + // + // We default to assuming that the offerer is passive and we are active. + SdpSetupAttribute::Role role = SdpSetupAttribute::kActive; + + if (remoteMsection.GetAttributeList().HasAttribute( + SdpAttribute::kSetupAttribute)) { + switch (remoteMsection.GetAttributeList().GetSetup().mRole) { + case SdpSetupAttribute::kActive: + role = SdpSetupAttribute::kPassive; + break; + case SdpSetupAttribute::kPassive: + case SdpSetupAttribute::kActpass: + role = SdpSetupAttribute::kActive; + break; + case SdpSetupAttribute::kHoldconn: + // This should have been caught by ParseSdp + MOZ_ASSERT(false); + JSEP_SET_ERROR( + "The other side used an illegal setup attribute" + " (\"holdconn\")."); + return NS_ERROR_INVALID_ARG; + } + } + + *rolep = role; + return NS_OK; +} + +JsepSession::Result JsepSessionImpl::SetLocalDescription( + JsepSdpType type, const std::string& constSdp) { + mLastError.clear(); + std::string sdp = constSdp; + + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: SetLocalDescription type=" << type + << "\nSDP=\n" + << sdp); + + switch (type) { + case kJsepSdpOffer: + if (!mGeneratedOffer) { + JSEP_SET_ERROR( + "Cannot set local offer when createOffer has not been called."); + return dom::PCError::InvalidModificationError; + } + if (sdp.empty()) { + sdp = mGeneratedOffer->ToString(); + } + if (mState == kJsepStateHaveLocalOffer) { + // Rollback previous offer before applying the new one. + SetLocalDescription(kJsepSdpRollback, ""); + MOZ_ASSERT(mState == kJsepStateStable); + } + break; + case kJsepSdpAnswer: + case kJsepSdpPranswer: + if (!mGeneratedAnswer) { + JSEP_SET_ERROR( + "Cannot set local answer when createAnswer has not been called."); + return dom::PCError::InvalidModificationError; + } + if (sdp.empty()) { + sdp = mGeneratedAnswer->ToString(); + } + break; + case kJsepSdpRollback: + if (mState != kJsepStateHaveLocalOffer) { + JSEP_SET_ERROR("Cannot rollback local description in " + << GetStateStr(mState)); + // Currently, spec allows this in any state except stable, and + // sRD(rollback) and sLD(rollback) do exactly the same thing. + return dom::PCError::InvalidStateError; + } + + mPendingLocalDescription.reset(); + SetState(kJsepStateStable); + RollbackLocalOffer(); + return Result(); + } + + switch (mState) { + case kJsepStateStable: + if (type != kJsepSdpOffer) { + JSEP_SET_ERROR("Cannot set local answer in state " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + break; + case kJsepStateHaveRemoteOffer: + if (type != kJsepSdpAnswer && type != kJsepSdpPranswer) { + JSEP_SET_ERROR("Cannot set local offer in state " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + break; + default: + JSEP_SET_ERROR("Cannot set local offer or answer in state " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + + UniquePtr<Sdp> parsed; + nsresult rv = ParseSdp(sdp, &parsed); + // Needs to be RTCError with sdp-syntax-error + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + // Check that content hasn't done anything unsupported with the SDP + rv = ValidateLocalDescription(*parsed, type); + NS_ENSURE_SUCCESS(rv, dom::PCError::InvalidModificationError); + + switch (type) { + case kJsepSdpOffer: + rv = ValidateOffer(*parsed); + break; + case kJsepSdpAnswer: + case kJsepSdpPranswer: + rv = ValidateAnswer(*mPendingRemoteDescription, *parsed); + break; + case kJsepSdpRollback: + MOZ_CRASH(); // Handled above + } + NS_ENSURE_SUCCESS(rv, dom::PCError::InvalidAccessError); + + if (type == kJsepSdpOffer) { + // Save in case we need to rollback + mOldTransceivers = mTransceivers; + } + + SdpHelper::BundledMids bundledMids; + rv = mSdpHelper.GetBundledMids(*parsed, &bundledMids); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + SdpHelper::BundledMids remoteBundledMids; + if (type != kJsepSdpOffer) { + rv = mSdpHelper.GetBundledMids(*mPendingRemoteDescription, + &remoteBundledMids); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + } + + for (size_t i = 0; i < parsed->GetMediaSectionCount(); ++i) { + Maybe<JsepTransceiver> transceiver(GetTransceiverForLevel(i)); + if (!transceiver) { + MOZ_ASSERT(false); + JSEP_SET_ERROR("No transceiver for level " << i); + return dom::PCError::OperationError; + } + + const auto& msection = parsed->GetMediaSection(i); + transceiver->Associate(msection.GetAttributeList().GetMid()); + transceiver->mRecvTrack.RecvTrackSetLocal(msection); + + if (mSdpHelper.MsectionIsDisabled(msection)) { + transceiver->mTransport.Close(); + SetTransceiver(*transceiver); + continue; + } + + bool hasOwnTransport = mSdpHelper.OwnsTransport( + msection, bundledMids, + (type == kJsepSdpOffer) ? sdp::kOffer : sdp::kAnswer); + if (type != kJsepSdpOffer) { + const auto& remoteMsection = + mPendingRemoteDescription->GetMediaSection(i); + // Don't allow the answer to override what the offer allowed for + hasOwnTransport &= mSdpHelper.OwnsTransport( + remoteMsection, remoteBundledMids, sdp::kOffer); + } + + if (hasOwnTransport) { + EnsureHasOwnTransport(parsed->GetMediaSection(i), *transceiver); + } + + if (type == kJsepSdpOffer) { + if (!hasOwnTransport) { + auto it = bundledMids.find(transceiver->GetMid()); + if (it != bundledMids.end()) { + transceiver->SetBundleLevel(it->second->GetLevel()); + } + } + } else { + auto it = remoteBundledMids.find(transceiver->GetMid()); + if (it != remoteBundledMids.end()) { + transceiver->SetBundleLevel(it->second->GetLevel()); + } + } + SetTransceiver(*transceiver); + } + + CopyBundleTransports(); + + switch (type) { + case kJsepSdpOffer: + rv = SetLocalDescriptionOffer(std::move(parsed)); + break; + case kJsepSdpAnswer: + case kJsepSdpPranswer: + rv = SetLocalDescriptionAnswer(type, std::move(parsed)); + break; + case kJsepSdpRollback: + MOZ_CRASH(); // Handled above + } + + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + return Result(); +} + +nsresult JsepSessionImpl::SetLocalDescriptionOffer(UniquePtr<Sdp> offer) { + MOZ_ASSERT(mState == kJsepStateStable); + mPendingLocalDescription = std::move(offer); + mIsPendingOfferer = Some(true); + SetState(kJsepStateHaveLocalOffer); + return NS_OK; +} + +nsresult JsepSessionImpl::SetLocalDescriptionAnswer(JsepSdpType type, + UniquePtr<Sdp> answer) { + MOZ_ASSERT(mState == kJsepStateHaveRemoteOffer); + mPendingLocalDescription = std::move(answer); + + nsresult rv = HandleNegotiatedSession(mPendingLocalDescription, + mPendingRemoteDescription); + NS_ENSURE_SUCCESS(rv, rv); + + mCurrentRemoteDescription = std::move(mPendingRemoteDescription); + mCurrentLocalDescription = std::move(mPendingLocalDescription); + MOZ_ASSERT(mIsPendingOfferer.isSome() && !*mIsPendingOfferer); + mIsPendingOfferer.reset(); + mIsCurrentOfferer = Some(false); + + SetState(kJsepStateStable); + return NS_OK; +} + +JsepSession::Result JsepSessionImpl::SetRemoteDescription( + JsepSdpType type, const std::string& sdp) { + mLastError.clear(); + + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: SetRemoteDescription type=" << type + << "\nSDP=\n" + << sdp); + + if (mState == kJsepStateHaveRemoteOffer && type == kJsepSdpOffer) { + // Rollback previous offer before applying the new one. + SetRemoteDescription(kJsepSdpRollback, ""); + MOZ_ASSERT(mState == kJsepStateStable); + } + + if (type == kJsepSdpRollback) { + if (mState != kJsepStateHaveRemoteOffer) { + JSEP_SET_ERROR("Cannot rollback remote description in " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + + mPendingRemoteDescription.reset(); + SetState(kJsepStateStable); + RollbackRemoteOffer(); + + return Result(); + } + + switch (mState) { + case kJsepStateStable: + if (type != kJsepSdpOffer) { + JSEP_SET_ERROR("Cannot set remote answer in state " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + break; + case kJsepStateHaveLocalOffer: + case kJsepStateHaveRemotePranswer: + if (type != kJsepSdpAnswer && type != kJsepSdpPranswer) { + JSEP_SET_ERROR("Cannot set remote offer in state " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + break; + default: + JSEP_SET_ERROR("Cannot set remote offer or answer in current state " + << GetStateStr(mState)); + return dom::PCError::InvalidStateError; + } + + // Parse. + UniquePtr<Sdp> parsed; + nsresult rv = ParseSdp(sdp, &parsed); + // Needs to be RTCError with sdp-syntax-error + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + rv = ValidateRemoteDescription(*parsed); + NS_ENSURE_SUCCESS(rv, dom::PCError::InvalidAccessError); + + switch (type) { + case kJsepSdpOffer: + rv = ValidateOffer(*parsed); + break; + case kJsepSdpAnswer: + case kJsepSdpPranswer: + rv = ValidateAnswer(*mPendingLocalDescription, *parsed); + break; + case kJsepSdpRollback: + MOZ_CRASH(); // Handled above + } + NS_ENSURE_SUCCESS(rv, dom::PCError::InvalidAccessError); + + bool iceLite = + parsed->GetAttributeList().HasAttribute(SdpAttribute::kIceLiteAttribute); + + // check for mismatch ufrag/pwd indicating ice restart + // can't just check the first one because it might be disabled + bool iceRestarting = false; + if (mCurrentRemoteDescription.get()) { + for (size_t i = 0; !iceRestarting && + i < mCurrentRemoteDescription->GetMediaSectionCount(); + ++i) { + const SdpMediaSection& newMsection = parsed->GetMediaSection(i); + const SdpMediaSection& oldMsection = + mCurrentRemoteDescription->GetMediaSection(i); + + if (mSdpHelper.MsectionIsDisabled(newMsection) || + mSdpHelper.MsectionIsDisabled(oldMsection)) { + continue; + } + + iceRestarting = mSdpHelper.IceCredentialsDiffer(newMsection, oldMsection); + } + } + + std::vector<std::string> iceOptions; + if (parsed->GetAttributeList().HasAttribute( + SdpAttribute::kIceOptionsAttribute)) { + iceOptions = parsed->GetAttributeList().GetIceOptions().mValues; + } + + if (type == kJsepSdpOffer) { + // Save in case we need to rollback. + mOldTransceivers = mTransceivers; + for (auto& transceiver : mTransceivers) { + if (!transceiver.IsNegotiated()) { + // We chose a level for this transceiver, but never negotiated it. + // Discard this state. + transceiver.ClearLevel(); + } + } + } + + // TODO(bug 1095780): Note that we create remote tracks even when + // They contain only codecs we can't negotiate or other craziness. + rv = UpdateTransceiversFromRemoteDescription(*parsed); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + for (size_t i = 0; i < parsed->GetMediaSectionCount(); ++i) { + MOZ_ASSERT(GetTransceiverForLevel(i)); + } + + switch (type) { + case kJsepSdpOffer: + rv = SetRemoteDescriptionOffer(std::move(parsed)); + break; + case kJsepSdpAnswer: + case kJsepSdpPranswer: + rv = SetRemoteDescriptionAnswer(type, std::move(parsed)); + break; + case kJsepSdpRollback: + MOZ_CRASH(); // Handled above + } + + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + + mRemoteIsIceLite = iceLite; + mIceOptions = iceOptions; + SetIceRestarting(iceRestarting); + return Result(); +} + +nsresult JsepSessionImpl::HandleNegotiatedSession( + const UniquePtr<Sdp>& local, const UniquePtr<Sdp>& remote) { + // local ufrag/pwd has been negotiated; we will never go back to the old ones + mOldIceUfrag.clear(); + mOldIcePwd.clear(); + + bool remoteIceLite = + remote->GetAttributeList().HasAttribute(SdpAttribute::kIceLiteAttribute); + + mIceControlling = remoteIceLite || *mIsPendingOfferer; + + const Sdp& answer = *mIsPendingOfferer ? *remote : *local; + + SdpHelper::BundledMids bundledMids; + nsresult rv = mSdpHelper.GetBundledMids(answer, &bundledMids); + NS_ENSURE_SUCCESS(rv, rv); + + // First, set the bundle level on the transceivers + for (auto& [mid, transportOwner] : bundledMids) { + Maybe<JsepTransceiver> bundledTransceiver = GetTransceiverForMid(mid); + if (!bundledTransceiver) { + JSEP_SET_ERROR("No transceiver for bundled mid " << mid); + return NS_ERROR_INVALID_ARG; + } + bundledTransceiver->SetBundleLevel(transportOwner->GetLevel()); + SetTransceiver(*bundledTransceiver); + } + + // Now walk through the m-sections, perform negotiation, and update the + // transceivers. + for (size_t i = 0; i < local->GetMediaSectionCount(); ++i) { + Maybe<JsepTransceiver> transceiver(GetTransceiverForLevel(i)); + if (!transceiver) { + MOZ_ASSERT(false); + JSEP_SET_ERROR("No transceiver for level " << i); + return NS_ERROR_FAILURE; + } + + if (mSdpHelper.MsectionIsDisabled(local->GetMediaSection(i))) { + transceiver->SetRemoved(); + } + + // Skip disabled m-sections. + if (answer.GetMediaSection(i).GetPort() == 0) { + transceiver->mTransport.Close(); + transceiver->SetStopped(); + transceiver->Disassociate(); + transceiver->ClearBundleLevel(); + transceiver->mSendTrack.SetActive(false); + transceiver->mRecvTrack.SetActive(false); + transceiver->SetCanRecycleMyMsection(); + SetTransceiver(*transceiver); + // Do not clear mLevel yet! That will happen on the next negotiation. + continue; + } + + rv = MakeNegotiatedTransceiver(remote->GetMediaSection(i), + local->GetMediaSection(i), *transceiver); + NS_ENSURE_SUCCESS(rv, rv); + SetTransceiver(*transceiver); + } + + CopyBundleTransports(); + + std::vector<JsepTrack*> remoteTracks; + for (auto& transceiver : mTransceivers) { + remoteTracks.push_back(&transceiver.mRecvTrack); + } + JsepTrack::SetUniquePayloadTypes(remoteTracks); + + mNegotiations++; + + mGeneratedAnswer.reset(); + mGeneratedOffer.reset(); + + return NS_OK; +} + +nsresult JsepSessionImpl::MakeNegotiatedTransceiver( + const SdpMediaSection& remote, const SdpMediaSection& local, + JsepTransceiver& transceiver) { + const SdpMediaSection& answer = *mIsPendingOfferer ? remote : local; + + bool sending = false; + bool receiving = false; + + // We do not pay any attention to whether the transceiver is stopped here, + // because that is only a signal to the JSEP engine to _attempt_ to reject + // the corresponding m-section the next time we're the offerer. + if (*mIsPendingOfferer) { + receiving = answer.IsSending(); + sending = answer.IsReceiving(); + } else { + sending = answer.IsSending(); + receiving = answer.IsReceiving(); + } + + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: Negotiated m= line" + << " index=" << local.GetLevel() << " type=" + << local.GetMediaType() << " sending=" << sending + << " receiving=" << receiving); + + transceiver.SetNegotiated(); + + // Ensure that this is finalized in case we need to copy it below + nsresult rv = + FinalizeTransport(remote.GetAttributeList(), answer.GetAttributeList(), + &transceiver.mTransport); + NS_ENSURE_SUCCESS(rv, rv); + + transceiver.mSendTrack.SetActive(sending); + rv = transceiver.mSendTrack.Negotiate(answer, remote, local); + if (NS_FAILED(rv)) { + JSEP_SET_ERROR("Answer had no codecs in common with offer in m-section " + << local.GetLevel()); + return rv; + } + + JsepTrack& recvTrack = transceiver.mRecvTrack; + recvTrack.SetActive(receiving); + rv = recvTrack.Negotiate(answer, remote, local); + if (NS_FAILED(rv)) { + JSEP_SET_ERROR("Answer had no codecs in common with offer in m-section " + << local.GetLevel()); + return rv; + } + + if (transceiver.HasBundleLevel() && recvTrack.GetSsrcs().empty() && + recvTrack.GetMediaType() != SdpMediaSection::kApplication) { + // TODO(bug 1105005): Once we have urn:ietf:params:rtp-hdrext:sdes:mid + // support, we should only fire this warning if that extension was not + // negotiated. + MOZ_MTLOG(ML_ERROR, "[" << mName + << "]: Bundled m-section has no ssrc " + "attributes. This may cause media packets to be " + "dropped."); + } + + if (transceiver.mTransport.mComponents == 2) { + // RTCP MUX or not. + // TODO(bug 1095743): verify that the PTs are consistent with mux. + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: RTCP-MUX is off"); + } + + if (answer.GetAttributeList().HasAttribute(SdpAttribute::kExtmapAttribute)) { + const auto extmaps = answer.GetAttributeList().GetExtmap().mExtmaps; + for (const auto& negotiatedExtension : extmaps) { + if (negotiatedExtension.entry == 0) { + MOZ_ASSERT(false, "This should have been caught sooner"); + continue; + } + + mExtmapEntriesEverNegotiated[negotiatedExtension.entry] = + negotiatedExtension.extensionname; + + for (auto& originalExtension : mRtpExtensions) { + if (negotiatedExtension.extensionname == + originalExtension.mExtmap.extensionname) { + // Update extmap to match what was negotiated + originalExtension.mExtmap.entry = negotiatedExtension.entry; + mExtmapEntriesEverUsed.insert(negotiatedExtension.entry); + } else if (originalExtension.mExtmap.entry == + negotiatedExtension.entry) { + // If this extmap entry was claimed for a different extension, update + // it to a new value so we don't end up with a duplicate. + originalExtension.mExtmap.entry = GetNeverUsedExtmapEntry(); + } + } + } + } + + return NS_OK; +} + +void JsepSessionImpl::EnsureHasOwnTransport(const SdpMediaSection& msection, + JsepTransceiver& transceiver) { + JsepTransport& transport = transceiver.mTransport; + + if (!transceiver.HasOwnTransport()) { + // Transceiver didn't own this transport last time, it won't now either + transport.Close(); + } + + transport.mLocalUfrag = msection.GetAttributeList().GetIceUfrag(); + transport.mLocalPwd = msection.GetAttributeList().GetIcePwd(); + + transceiver.ClearBundleLevel(); + + if (!transport.mComponents) { + if (mSdpHelper.HasRtcp(msection.GetProtocol())) { + transport.mComponents = 2; + } else { + transport.mComponents = 1; + } + } + + if (transport.mTransportId.empty()) { + // TODO: Once we use different ICE ufrag/pass for each m-section, we can + // use that here. + std::ostringstream os; + os << "transport_" << mTransportIdCounter++; + transport.mTransportId = os.str(); + } +} + +void JsepSessionImpl::CopyBundleTransports() { + for (auto& transceiver : mTransceivers) { + if (transceiver.HasBundleLevel()) { + MOZ_MTLOG(ML_DEBUG, + "[" << mName << "] Transceiver " << transceiver.GetLevel() + << " is in a bundle; transceiver " + << transceiver.BundleLevel() << " owns the transport."); + Maybe<const JsepTransceiver> transportOwner = + GetTransceiverForLevel(transceiver.BundleLevel()); + MOZ_ASSERT(transportOwner); + if (transportOwner) { + transceiver.mTransport = transportOwner->mTransport; + } + } else if (transceiver.HasLevel()) { + MOZ_MTLOG(ML_DEBUG, "[" << mName << "] Transceiver " + << transceiver.GetLevel() + << " is not necessarily in a bundle."); + } + if (transceiver.HasLevel()) { + MOZ_MTLOG(ML_DEBUG, + "[" << mName << "] Transceiver " << transceiver.GetLevel() + << " transport-id: " << transceiver.mTransport.mTransportId + << " components: " << transceiver.mTransport.mComponents); + } + } +} + +nsresult JsepSessionImpl::FinalizeTransport(const SdpAttributeList& remote, + const SdpAttributeList& answer, + JsepTransport* transport) const { + if (!transport->mComponents) { + return NS_OK; + } + + if (!transport->mIce || transport->mIce->mUfrag != remote.GetIceUfrag() || + transport->mIce->mPwd != remote.GetIcePwd()) { + UniquePtr<JsepIceTransport> ice = MakeUnique<JsepIceTransport>(); + transport->mDtls = nullptr; + + // We do sanity-checking for these in ParseSdp + ice->mUfrag = remote.GetIceUfrag(); + ice->mPwd = remote.GetIcePwd(); + transport->mIce = std::move(ice); + } + + if (remote.HasAttribute(SdpAttribute::kCandidateAttribute)) { + transport->mIce->mCandidates = remote.GetCandidate(); + } + + if (!transport->mDtls) { + // RFC 5763 says: + // + // The endpoint MUST use the setup attribute defined in [RFC4145]. + // The endpoint that is the offerer MUST use the setup attribute + // value of setup:actpass and be prepared to receive a client_hello + // before it receives the answer. The answerer MUST use either a + // setup attribute value of setup:active or setup:passive. Note that + // if the answerer uses setup:passive, then the DTLS handshake will + // not begin until the answerer is received, which adds additional + // latency. setup:active allows the answer and the DTLS handshake to + // occur in parallel. Thus, setup:active is RECOMMENDED. Whichever + // party is active MUST initiate a DTLS handshake by sending a + // ClientHello over each flow (host/port quartet). + UniquePtr<JsepDtlsTransport> dtls = MakeUnique<JsepDtlsTransport>(); + dtls->mFingerprints = remote.GetFingerprint(); + if (!answer.HasAttribute(mozilla::SdpAttribute::kSetupAttribute)) { + dtls->mRole = *mIsPendingOfferer ? JsepDtlsTransport::kJsepDtlsServer + : JsepDtlsTransport::kJsepDtlsClient; + } else { + if (*mIsPendingOfferer) { + dtls->mRole = (answer.GetSetup().mRole == SdpSetupAttribute::kActive) + ? JsepDtlsTransport::kJsepDtlsServer + : JsepDtlsTransport::kJsepDtlsClient; + } else { + dtls->mRole = (answer.GetSetup().mRole == SdpSetupAttribute::kActive) + ? JsepDtlsTransport::kJsepDtlsClient + : JsepDtlsTransport::kJsepDtlsServer; + } + } + + transport->mDtls = std::move(dtls); + } + + if (answer.HasAttribute(SdpAttribute::kRtcpMuxAttribute)) { + transport->mComponents = 1; + } + + return NS_OK; +} + +nsresult JsepSessionImpl::AddTransportAttributes( + SdpMediaSection* msection, SdpSetupAttribute::Role dtlsRole) { + if (mIceUfrag.empty() || mIcePwd.empty()) { + JSEP_SET_ERROR("Missing ICE ufrag or password"); + return NS_ERROR_FAILURE; + } + + SdpAttributeList& attrList = msection->GetAttributeList(); + attrList.SetAttribute( + new SdpStringAttribute(SdpAttribute::kIceUfragAttribute, mIceUfrag)); + attrList.SetAttribute( + new SdpStringAttribute(SdpAttribute::kIcePwdAttribute, mIcePwd)); + + msection->GetAttributeList().SetAttribute(new SdpSetupAttribute(dtlsRole)); + + return NS_OK; +} + +nsresult JsepSessionImpl::CopyPreviousTransportParams( + const Sdp& oldAnswer, const Sdp& offerersPreviousSdp, const Sdp& newOffer, + Sdp* newLocal) { + for (size_t i = 0; i < oldAnswer.GetMediaSectionCount(); ++i) { + if (!mSdpHelper.MsectionIsDisabled(newLocal->GetMediaSection(i)) && + mSdpHelper.AreOldTransportParamsValid(oldAnswer, offerersPreviousSdp, + newOffer, i)) { + // If newLocal is an offer, this will be the number of components we used + // last time, and if it is an answer, this will be the number of + // components we've decided we're using now. + Maybe<const JsepTransceiver> transceiver(GetTransceiverForLevel(i)); + if (!transceiver) { + MOZ_ASSERT(false); + JSEP_SET_ERROR("No transceiver for level " << i); + return NS_ERROR_FAILURE; + } + size_t numComponents = transceiver->mTransport.mComponents; + nsresult rv = mSdpHelper.CopyTransportParams( + numComponents, mCurrentLocalDescription->GetMediaSection(i), + &newLocal->GetMediaSection(i)); + NS_ENSURE_SUCCESS(rv, rv); + } + } + + return NS_OK; +} + +nsresult JsepSessionImpl::ParseSdp(const std::string& sdp, + UniquePtr<Sdp>* parsedp) { + auto results = mParser->Parse(sdp); + auto parsed = std::move(results->Sdp()); + mLastSdpParsingErrors = results->Errors(); + if (!parsed) { + std::string error = results->ParserName() + " Failed to parse SDP: "; + mSdpHelper.AppendSdpParseErrors(mLastSdpParsingErrors, &error); + JSEP_SET_ERROR(error); + return NS_ERROR_INVALID_ARG; + } + // Verify that the JSEP rules for all SDP are followed + for (size_t i = 0; i < parsed->GetMediaSectionCount(); ++i) { + if (mSdpHelper.MsectionIsDisabled(parsed->GetMediaSection(i))) { + // Disabled, let this stuff slide. + continue; + } + + const SdpMediaSection& msection(parsed->GetMediaSection(i)); + auto& mediaAttrs = msection.GetAttributeList(); + + if (mediaAttrs.HasAttribute(SdpAttribute::kMidAttribute) && + mediaAttrs.GetMid().length() > 16) { + JSEP_SET_ERROR( + "Invalid description, mid length greater than 16 " + "unsupported until 2-byte rtp header extensions are " + "supported in webrtc.org"); + return NS_ERROR_INVALID_ARG; + } + + if (mediaAttrs.HasAttribute(SdpAttribute::kExtmapAttribute)) { + std::set<uint16_t> extIds; + for (const auto& ext : mediaAttrs.GetExtmap().mExtmaps) { + uint16_t id = ext.entry; + + if (id < 1 || id > 14) { + JSEP_SET_ERROR("Description contains invalid extension id " + << id << " on level " << i + << " which is unsupported until 2-byte rtp" + " header extensions are supported in webrtc.org"); + return NS_ERROR_INVALID_ARG; + } + + if (extIds.find(id) != extIds.end()) { + JSEP_SET_ERROR("Description contains duplicate extension id " + << id << " on level " << i); + return NS_ERROR_INVALID_ARG; + } + extIds.insert(id); + } + } + + static const std::bitset<128> forbidden = GetForbiddenSdpPayloadTypes(); + if (msection.GetMediaType() == SdpMediaSection::kAudio || + msection.GetMediaType() == SdpMediaSection::kVideo) { + // Sanity-check that payload type can work with RTP + for (const std::string& fmt : msection.GetFormats()) { + uint16_t payloadType; + if (!SdpHelper::GetPtAsInt(fmt, &payloadType)) { + JSEP_SET_ERROR("Payload type \"" + << fmt << "\" is not a 16-bit unsigned int at level " + << i); + return NS_ERROR_INVALID_ARG; + } + if (payloadType > 127) { + JSEP_SET_ERROR("audio/video payload type \"" + << fmt << "\" is too large at level " << i); + return NS_ERROR_INVALID_ARG; + } + if (forbidden.test(payloadType)) { + JSEP_SET_ERROR("Illegal audio/video payload type \"" + << fmt << "\" at level " << i); + return NS_ERROR_INVALID_ARG; + } + } + } + } + + *parsedp = std::move(parsed); + return NS_OK; +} + +nsresult JsepSessionImpl::SetRemoteDescriptionOffer(UniquePtr<Sdp> offer) { + MOZ_ASSERT(mState == kJsepStateStable); + + mPendingRemoteDescription = std::move(offer); + mIsPendingOfferer = Some(false); + + SetState(kJsepStateHaveRemoteOffer); + return NS_OK; +} + +nsresult JsepSessionImpl::SetRemoteDescriptionAnswer(JsepSdpType type, + UniquePtr<Sdp> answer) { + MOZ_ASSERT(mState == kJsepStateHaveLocalOffer || + mState == kJsepStateHaveRemotePranswer); + + mPendingRemoteDescription = std::move(answer); + + nsresult rv = HandleNegotiatedSession(mPendingLocalDescription, + mPendingRemoteDescription); + NS_ENSURE_SUCCESS(rv, rv); + + mCurrentRemoteDescription = std::move(mPendingRemoteDescription); + mCurrentLocalDescription = std::move(mPendingLocalDescription); + MOZ_ASSERT(mIsPendingOfferer.isSome() && *mIsPendingOfferer); + mIsPendingOfferer.reset(); + mIsCurrentOfferer = Some(true); + + SetState(kJsepStateStable); + return NS_OK; +} + +Maybe<JsepTransceiver> JsepSessionImpl::GetTransceiverForLevel( + size_t level) const { + return FindTransceiver([level](const JsepTransceiver& transceiver) { + return transceiver.HasLevel() && (transceiver.GetLevel() == level); + }); +} + +Maybe<JsepTransceiver> JsepSessionImpl::GetTransceiverForMid( + const std::string& mid) const { + return FindTransceiver([mid](const JsepTransceiver& transceiver) { + return transceiver.IsAssociated() && (transceiver.GetMid() == mid); + }); +} + +Maybe<JsepTransceiver> JsepSessionImpl::GetTransceiverForLocal(size_t level) { + if (Maybe<JsepTransceiver> transceiver = GetTransceiverForLevel(level)) { + if (transceiver->CanRecycleMyMsection() && + transceiver->GetMediaType() != SdpMediaSection::kApplication) { + // Attempt to recycle. If this fails, the old transceiver stays put. + transceiver->Disassociate(); + Maybe<JsepTransceiver> newTransceiver = + FindUnassociatedTransceiver(transceiver->GetMediaType(), false); + if (newTransceiver) { + newTransceiver->SetLevel(level); + transceiver->ClearLevel(); + transceiver->mSendTrack.ClearRids(); + SetTransceiver(*newTransceiver); + SetTransceiver(*transceiver); + return newTransceiver; + } + } + + SetTransceiver(*transceiver); + return transceiver; + } + + // There is no transceiver for |level| right now. + + // Look for an RTP transceiver (spec requires us to give the lower levels to + // new RTP transceivers) + for (auto& transceiver : mTransceivers) { + if (transceiver.GetMediaType() != SdpMediaSection::kApplication && + transceiver.IsFreeToUse()) { + transceiver.SetLevel(level); + return Some(transceiver); + } + } + + // Ok, look for a datachannel + for (auto& transceiver : mTransceivers) { + if (transceiver.IsFreeToUse()) { + transceiver.SetLevel(level); + return Some(transceiver); + } + } + + return Nothing(); +} + +Maybe<JsepTransceiver> JsepSessionImpl::GetTransceiverForRemote( + const SdpMediaSection& msection) { + size_t level = msection.GetLevel(); + Maybe<JsepTransceiver> transceiver = GetTransceiverForLevel(level); + if (transceiver) { + if (!transceiver->CanRecycleMyMsection()) { + return transceiver; + } + transceiver->Disassociate(); + transceiver->ClearLevel(); + transceiver->mSendTrack.ClearRids(); + SetTransceiver(*transceiver); + } + + // No transceiver for |level| + transceiver = FindUnassociatedTransceiver(msection.GetMediaType(), true); + if (transceiver) { + transceiver->SetLevel(level); + SetTransceiver(*transceiver); + return transceiver; + } + + // Make a new transceiver + JsepTransceiver newTransceiver(msection.GetMediaType(), *mUuidGen, + SdpDirectionAttribute::kRecvonly); + newTransceiver.SetLevel(level); + newTransceiver.SetOnlyExistsBecauseOfSetRemote(true); + AddTransceiver(newTransceiver); + return Some(mTransceivers.back()); +} + +Maybe<JsepTransceiver> JsepSessionImpl::GetTransceiverWithTransport( + const std::string& transportId) const { + for (const auto& transceiver : mTransceivers) { + if (transceiver.HasOwnTransport() && + (transceiver.mTransport.mTransportId == transportId)) { + MOZ_ASSERT(transceiver.HasLevel(), + "Transceiver has a transport, but no level!"); + return Some(transceiver); + } + } + + return Nothing(); +} + +nsresult JsepSessionImpl::UpdateTransceiversFromRemoteDescription( + const Sdp& remote) { + // Iterate over the sdp, updating remote tracks as we go + for (size_t i = 0; i < remote.GetMediaSectionCount(); ++i) { + const SdpMediaSection& msection = remote.GetMediaSection(i); + + Maybe<JsepTransceiver> transceiver(GetTransceiverForRemote(msection)); + if (!transceiver) { + return NS_ERROR_FAILURE; + } + + if (!mSdpHelper.MsectionIsDisabled(msection)) { + if (msection.GetAttributeList().HasAttribute( + SdpAttribute::kMidAttribute)) { + transceiver->Associate(msection.GetAttributeList().GetMid()); + } + if (!transceiver->IsAssociated()) { + transceiver->Associate(GetNewMid()); + } else { + mUsedMids.insert(transceiver->GetMid()); + } + } else { + // We do not disassociate here, that happens when negotiation completes + // These things cannot be rolled back. + transceiver->mTransport.Close(); + transceiver->SetStopped(); + SetTransceiver(*transceiver); + continue; + } + + if (msection.GetMediaType() == SdpMediaSection::MediaType::kApplication) { + SetTransceiver(*transceiver); + continue; + } + + transceiver->mSendTrack.SendTrackSetRemote(mSsrcGenerator, msection); + + // Interop workaround for endpoints that don't support msid. + // Ensures that there is a default stream id set, provided the remote is + // sending. + // TODO(bug 1426005): Remove this, or at least move it to JsepTrack. + transceiver->mRecvTrack.UpdateStreamIds({mDefaultRemoteStreamId}); + + // This will process a=msid if present, or clear the stream ids if the + // msection is not sending. If the msection is sending, and there are no + // a=msid, the previously set default will stay. + transceiver->mRecvTrack.RecvTrackSetRemote(remote, msection); + SetTransceiver(*transceiver); + } + + return NS_OK; +} + +Maybe<JsepTransceiver> JsepSessionImpl::FindUnassociatedTransceiver( + SdpMediaSection::MediaType type, bool magic) { + // Look through transceivers that are not mapped to an m-section + for (auto& transceiver : mTransceivers) { + if (type == SdpMediaSection::kApplication && + type == transceiver.GetMediaType()) { + transceiver.RestartDatachannelTransceiver(); + return Some(transceiver); + } + if (transceiver.IsFreeToUse() && + (!magic || transceiver.HasAddTrackMagic()) && + (transceiver.GetMediaType() == type)) { + return Some(transceiver); + } + } + + return Nothing(); +} + +void JsepSessionImpl::RollbackLocalOffer() { + for (size_t i = 0; i < mTransceivers.size(); ++i) { + auto& transceiver = mTransceivers[i]; + if (mOldTransceivers.size() > i) { + transceiver.Rollback(mOldTransceivers[i], false); + mOldTransceivers[i] = transceiver; + continue; + } + + JsepTransceiver temp(transceiver.GetMediaType(), *mUuidGen); + InitTransceiver(temp); + transceiver.Rollback(temp, false); + mOldTransceivers.push_back(transceiver); + } + + mTransceivers = std::move(mOldTransceivers); +} + +void JsepSessionImpl::RollbackRemoteOffer() { + for (size_t i = 0; i < mTransceivers.size(); ++i) { + auto& transceiver = mTransceivers[i]; + if (mOldTransceivers.size() > i) { + // Some stuff cannot be rolled back. Save this information. + transceiver.Rollback(mOldTransceivers[i], true); + mOldTransceivers[i] = transceiver; + continue; + } + + if (transceiver.HasLevel()) { + // New transceiver, that was either created by the remote offer, or + // attached to the remote offer. + // We rollback even for transceivers we will remove, just to ensure we end + // up at the starting state. + JsepTransceiver temp(transceiver.GetMediaType(), *mUuidGen); + InitTransceiver(temp); + transceiver.Rollback(temp, true); + + if (transceiver.OnlyExistsBecauseOfSetRemote()) { + transceiver.SetStopped(); + transceiver.Disassociate(); + transceiver.SetRemoved(); + } else { + // Oof. This hangs around because of addTrack. Make it magic! + transceiver.SetAddTrackMagic(); + } + } // else, _we_ added this and it is not attached to the remote offer yet + + mOldTransceivers.push_back(transceiver); + } + + mTransceivers = std::move(mOldTransceivers); +} + +nsresult JsepSessionImpl::ValidateLocalDescription(const Sdp& description, + JsepSdpType type) { + Sdp* generated = nullptr; + // TODO(bug 1095226): Better checking. + if (type == kJsepSdpOffer) { + generated = mGeneratedOffer.get(); + } else { + generated = mGeneratedAnswer.get(); + } + + if (!generated) { + JSEP_SET_ERROR( + "Calling SetLocal without first calling CreateOffer/Answer" + " is not supported."); + return NS_ERROR_UNEXPECTED; + } + + if (description.GetMediaSectionCount() != generated->GetMediaSectionCount()) { + JSEP_SET_ERROR("Changing the number of m-sections is not allowed"); + return NS_ERROR_INVALID_ARG; + } + + for (size_t i = 0; i < description.GetMediaSectionCount(); ++i) { + auto& origMsection = generated->GetMediaSection(i); + auto& finalMsection = description.GetMediaSection(i); + if (origMsection.GetMediaType() != finalMsection.GetMediaType()) { + JSEP_SET_ERROR("Changing the media-type of m-sections is not allowed"); + return NS_ERROR_INVALID_ARG; + } + + // These will be present in reoffer + if (!mCurrentLocalDescription) { + if (finalMsection.GetAttributeList().HasAttribute( + SdpAttribute::kCandidateAttribute)) { + JSEP_SET_ERROR("Adding your own candidate attributes is not supported"); + return NS_ERROR_INVALID_ARG; + } + + if (finalMsection.GetAttributeList().HasAttribute( + SdpAttribute::kEndOfCandidatesAttribute)) { + JSEP_SET_ERROR("Why are you trying to set a=end-of-candidates?"); + return NS_ERROR_INVALID_ARG; + } + } + + if (mSdpHelper.MsectionIsDisabled(finalMsection)) { + continue; + } + + if (!finalMsection.GetAttributeList().HasAttribute( + SdpAttribute::kMidAttribute)) { + JSEP_SET_ERROR("Local descriptions must have a=mid attributes."); + return NS_ERROR_INVALID_ARG; + } + + if (finalMsection.GetAttributeList().GetMid() != + origMsection.GetAttributeList().GetMid()) { + JSEP_SET_ERROR("Changing the mid of m-sections is not allowed."); + return NS_ERROR_INVALID_ARG; + } + + // TODO(bug 1095218): Check msid + // TODO(bug 1095226): Check ice-ufrag and ice-pwd + // TODO(bug 1095226): Check fingerprints + // TODO(bug 1095226): Check payload types (at least ensure that payload + // types we don't actually support weren't added) + // TODO(bug 1095226): Check ice-options? + } + + if (description.GetAttributeList().HasAttribute( + SdpAttribute::kIceLiteAttribute)) { + JSEP_SET_ERROR("Running ICE in lite mode is unsupported"); + return NS_ERROR_INVALID_ARG; + } + + return NS_OK; +} + +nsresult JsepSessionImpl::ValidateRemoteDescription(const Sdp& description) { + if (!mCurrentLocalDescription) { + // Initial offer; nothing to validate besides the stuff in ParseSdp + return NS_OK; + } + + if (mCurrentLocalDescription->GetMediaSectionCount() > + description.GetMediaSectionCount()) { + JSEP_SET_ERROR( + "New remote description has fewer m-sections than the " + "previous remote description."); + return NS_ERROR_INVALID_ARG; + } + + for (size_t i = 0; i < description.GetMediaSectionCount(); ++i) { + const SdpAttributeList& attrs = + description.GetMediaSection(i).GetAttributeList(); + + if (attrs.HasAttribute(SdpAttribute::kExtmapAttribute)) { + for (const auto& ext : attrs.GetExtmap().mExtmaps) { + if (mExtmapEntriesEverNegotiated.count(ext.entry) && + mExtmapEntriesEverNegotiated[ext.entry] != ext.extensionname) { + JSEP_SET_ERROR( + "Remote description attempted to remap RTP extension id " + << ext.entry << " from " + << mExtmapEntriesEverNegotiated[ext.entry] << " to " + << ext.extensionname); + return NS_ERROR_INVALID_ARG; + } + } + } + } + + if (!mCurrentRemoteDescription) { + // No further checking for initial answers + return NS_OK; + } + + // These are solely to check that bundle is valid + SdpHelper::BundledMids bundledMids; + nsresult rv = GetNegotiatedBundledMids(&bundledMids); + NS_ENSURE_SUCCESS(rv, rv); + + SdpHelper::BundledMids newBundledMids; + rv = mSdpHelper.GetBundledMids(description, &newBundledMids); + NS_ENSURE_SUCCESS(rv, rv); + + // check for partial ice restart, which is not supported + Maybe<bool> iceCredsDiffer; + for (size_t i = 0; i < mCurrentRemoteDescription->GetMediaSectionCount(); + ++i) { + const SdpMediaSection& newMsection = description.GetMediaSection(i); + const SdpMediaSection& oldMsection = + mCurrentRemoteDescription->GetMediaSection(i); + + if (mSdpHelper.MsectionIsDisabled(newMsection) || + mSdpHelper.MsectionIsDisabled(oldMsection)) { + continue; + } + + if (oldMsection.GetMediaType() != newMsection.GetMediaType()) { + JSEP_SET_ERROR("Remote description changes the media type of m-line " + << i); + return NS_ERROR_INVALID_ARG; + } + + bool differ = mSdpHelper.IceCredentialsDiffer(newMsection, oldMsection); + + if (mIsPendingOfferer.isSome() && *mIsPendingOfferer && differ && + !IsIceRestarting()) { + JSEP_SET_ERROR( + "Remote description indicates ICE restart but offer did not " + "request ICE restart (new remote description changes either " + "the ice-ufrag or ice-pwd)"); + return NS_ERROR_INVALID_ARG; + } + + // Detect whether all the creds are the same or all are different + if (!iceCredsDiffer.isSome()) { + // for the first msection capture whether creds are different or same + iceCredsDiffer = mozilla::Some(differ); + } else if (iceCredsDiffer.isSome() && *iceCredsDiffer != differ) { + // subsequent msections must match the first sections + JSEP_SET_ERROR( + "Partial ICE restart is unsupported at this time " + "(new remote description changes either the ice-ufrag " + "or ice-pwd on fewer than all msections)"); + return NS_ERROR_INVALID_ARG; + } + } + + return NS_OK; +} + +nsresult JsepSessionImpl::ValidateOffer(const Sdp& offer) { + return mSdpHelper.ValidateTransportAttributes(offer, sdp::kOffer); +} + +nsresult JsepSessionImpl::ValidateAnswer(const Sdp& offer, const Sdp& answer) { + if (offer.GetMediaSectionCount() != answer.GetMediaSectionCount()) { + JSEP_SET_ERROR("Offer and answer have different number of m-lines " + << "(" << offer.GetMediaSectionCount() << " vs " + << answer.GetMediaSectionCount() << ")"); + return NS_ERROR_INVALID_ARG; + } + + nsresult rv = mSdpHelper.ValidateTransportAttributes(answer, sdp::kAnswer); + NS_ENSURE_SUCCESS(rv, rv); + + for (size_t i = 0; i < offer.GetMediaSectionCount(); ++i) { + const SdpMediaSection& offerMsection = offer.GetMediaSection(i); + const SdpMediaSection& answerMsection = answer.GetMediaSection(i); + + if (offerMsection.GetMediaType() != answerMsection.GetMediaType()) { + JSEP_SET_ERROR("Answer and offer have different media types at m-line " + << i); + return NS_ERROR_INVALID_ARG; + } + + if (mSdpHelper.MsectionIsDisabled(answerMsection)) { + continue; + } + + if (mSdpHelper.MsectionIsDisabled(offerMsection)) { + JSEP_SET_ERROR( + "Answer tried to enable an m-section that was disabled in the offer"); + return NS_ERROR_INVALID_ARG; + } + + if (!offerMsection.IsSending() && answerMsection.IsReceiving()) { + JSEP_SET_ERROR("Answer tried to set recv when offer did not set send"); + return NS_ERROR_INVALID_ARG; + } + + if (!offerMsection.IsReceiving() && answerMsection.IsSending()) { + JSEP_SET_ERROR("Answer tried to set send when offer did not set recv"); + return NS_ERROR_INVALID_ARG; + } + + const SdpAttributeList& answerAttrs(answerMsection.GetAttributeList()); + const SdpAttributeList& offerAttrs(offerMsection.GetAttributeList()); + if (answerAttrs.HasAttribute(SdpAttribute::kMidAttribute) && + offerAttrs.HasAttribute(SdpAttribute::kMidAttribute) && + offerAttrs.GetMid() != answerAttrs.GetMid()) { + JSEP_SET_ERROR("Answer changes mid for level, was \'" + << offerMsection.GetAttributeList().GetMid() + << "\', now \'" + << answerMsection.GetAttributeList().GetMid() << "\'"); + return NS_ERROR_INVALID_ARG; + } + + // Sanity check extmap + if (answerAttrs.HasAttribute(SdpAttribute::kExtmapAttribute)) { + if (!offerAttrs.HasAttribute(SdpAttribute::kExtmapAttribute)) { + JSEP_SET_ERROR("Answer adds extmap attributes to level " << i); + return NS_ERROR_INVALID_ARG; + } + + for (const auto& ansExt : answerAttrs.GetExtmap().mExtmaps) { + bool found = false; + for (const auto& offExt : offerAttrs.GetExtmap().mExtmaps) { + if (ansExt.extensionname == offExt.extensionname) { + if ((ansExt.direction & reverse(offExt.direction)) != + ansExt.direction) { + // FIXME we do not return an error here, because Chrome up to + // version 57 is actually tripping over this if they are the + // answerer. See bug 1355010 for details. + MOZ_MTLOG(ML_WARNING, + "[" << mName + << "]: Answer has inconsistent" + " direction on extmap attribute at level " + << i << " (" << ansExt.extensionname + << "). Offer had " << offExt.direction + << ", answer had " << ansExt.direction << "."); + // return NS_ERROR_INVALID_ARG; + } + + if (offExt.entry < 4096 && (offExt.entry != ansExt.entry)) { + JSEP_SET_ERROR("Answer changed id for extmap attribute at level " + << i << " (" << offExt.extensionname << ") from " + << offExt.entry << " to " << ansExt.entry << "."); + return NS_ERROR_INVALID_ARG; + } + + if (ansExt.entry >= 4096) { + JSEP_SET_ERROR("Answer used an invalid id (" + << ansExt.entry + << ") for extmap attribute at level " << i << " (" + << ansExt.extensionname << ")."); + return NS_ERROR_INVALID_ARG; + } + + found = true; + break; + } + } + + if (!found) { + JSEP_SET_ERROR("Answer has extmap " + << ansExt.extensionname + << " at " + "level " + << i << " that was not present in offer."); + return NS_ERROR_INVALID_ARG; + } + } + } + } + + return NS_OK; +} + +nsresult JsepSessionImpl::CreateGenericSDP(UniquePtr<Sdp>* sdpp) { + // draft-ietf-rtcweb-jsep-08 Section 5.2.1: + // o The second SDP line MUST be an "o=" line, as specified in + // [RFC4566], Section 5.2. The value of the <username> field SHOULD + // be "-". The value of the <sess-id> field SHOULD be a + // cryptographically random number. To ensure uniqueness, this + // number SHOULD be at least 64 bits long. The value of the <sess- + // version> field SHOULD be zero. The value of the <nettype> + // <addrtype> <unicast-address> tuple SHOULD be set to a non- + // meaningful address, such as IN IP4 0.0.0.0, to prevent leaking the + // local address in this field. As mentioned in [RFC4566], the + // entire o= line needs to be unique, but selecting a random number + // for <sess-id> is sufficient to accomplish this. + // + // Historical note: we used to report the actual version number here, after + // "SDPARTA-", but that becomes a problem starting with version 100, since + // some services parse 100 as "10" and give us legacy/broken behavior. So + // we're freezing the version number at 99.0 in this string. + auto origin = SdpOrigin("mozilla...THIS_IS_SDPARTA-99.0", mSessionId, + mSessionVersion, sdp::kIPv4, "0.0.0.0"); + + UniquePtr<Sdp> sdp = MakeUnique<SipccSdp>(origin); + + if (mDtlsFingerprints.empty()) { + JSEP_SET_ERROR("Missing DTLS fingerprint"); + return NS_ERROR_FAILURE; + } + + UniquePtr<SdpFingerprintAttributeList> fpl = + MakeUnique<SdpFingerprintAttributeList>(); + for (auto& dtlsFingerprint : mDtlsFingerprints) { + fpl->PushEntry(dtlsFingerprint.mAlgorithm, dtlsFingerprint.mValue); + } + sdp->GetAttributeList().SetAttribute(fpl.release()); + + auto* iceOpts = new SdpOptionsAttribute(SdpAttribute::kIceOptionsAttribute); + iceOpts->PushEntry("trickle"); + sdp->GetAttributeList().SetAttribute(iceOpts); + + // This assumes content doesn't add a bunch of msid attributes with a + // different semantic in mind. + std::vector<std::string> msids; + msids.push_back("*"); + mSdpHelper.SetupMsidSemantic(msids, sdp.get()); + + *sdpp = std::move(sdp); + return NS_OK; +} + +nsresult JsepSessionImpl::SetupIds() { + SECStatus rv = PK11_GenerateRandom( + reinterpret_cast<unsigned char*>(&mSessionId), sizeof(mSessionId)); + // RFC 3264 says that session-ids MUST be representable as a _signed_ + // 64 bit number, meaning the MSB cannot be set. + mSessionId = mSessionId >> 1; + if (rv != SECSuccess) { + JSEP_SET_ERROR("Failed to generate session id: " << rv); + return NS_ERROR_FAILURE; + } + + if (!mUuidGen->Generate(&mDefaultRemoteStreamId)) { + JSEP_SET_ERROR("Failed to generate default uuid for streams"); + return NS_ERROR_FAILURE; + } + + if (!mUuidGen->Generate(&mCNAME)) { + JSEP_SET_ERROR("Failed to generate CNAME"); + return NS_ERROR_FAILURE; + } + + return NS_OK; +} + +void JsepSessionImpl::SetDefaultCodecs( + const std::vector<UniquePtr<JsepCodecDescription>>& aPreferredCodecs) { + mSupportedCodecs.clear(); + + for (const auto& codec : aPreferredCodecs) { + mSupportedCodecs.emplace_back(codec->Clone()); + } +} + +void JsepSessionImpl::SetState(JsepSignalingState state) { + if (state == mState) return; + + MOZ_MTLOG(ML_NOTICE, "[" << mName << "]: " << GetStateStr(mState) << " -> " + << GetStateStr(state)); + mState = state; +} + +JsepSession::Result JsepSessionImpl::AddRemoteIceCandidate( + const std::string& candidate, const std::string& mid, + const Maybe<uint16_t>& level, const std::string& ufrag, + std::string* transportId) { + mLastError.clear(); + if (!mCurrentRemoteDescription && !mPendingRemoteDescription) { + JSEP_SET_ERROR("Cannot add ICE candidate when there is no remote SDP"); + return dom::PCError::InvalidStateError; + } + + if (mid.empty() && !level.isSome() && candidate.empty()) { + // Set end-of-candidates on SDP + if (mCurrentRemoteDescription) { + nsresult rv = mSdpHelper.SetIceGatheringComplete( + mCurrentRemoteDescription.get(), ufrag); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + } + + if (mPendingRemoteDescription) { + // If we had an error when adding the candidate to the current + // description, we stomp them here. This is deliberate. + nsresult rv = mSdpHelper.SetIceGatheringComplete( + mPendingRemoteDescription.get(), ufrag); + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + } + return Result(); + } + + Maybe<JsepTransceiver> transceiver; + if (!mid.empty()) { + transceiver = GetTransceiverForMid(mid); + } else if (level.isSome()) { + transceiver = GetTransceiverForLevel(level.value()); + } + + if (!transceiver) { + JSEP_SET_ERROR("Cannot set ICE candidate for level=" + << level << " mid=" << mid << ": No such transceiver."); + return dom::PCError::OperationError; + } + + if (level.isSome() && transceiver->GetLevel() != level.value()) { + MOZ_MTLOG(ML_WARNING, "Mismatch between mid and level - \"" + << mid << "\" is not the mid for level " + << level); + } + + *transportId = transceiver->mTransport.mTransportId; + nsresult rv = NS_ERROR_UNEXPECTED; + if (mCurrentRemoteDescription) { + rv = + mSdpHelper.AddCandidateToSdp(mCurrentRemoteDescription.get(), candidate, + transceiver->GetLevel(), ufrag); + } + + if (mPendingRemoteDescription) { + // If we had an error when adding the candidate to the current description, + // we stomp them here. This is deliberate. + rv = + mSdpHelper.AddCandidateToSdp(mPendingRemoteDescription.get(), candidate, + transceiver->GetLevel(), ufrag); + } + + NS_ENSURE_SUCCESS(rv, dom::PCError::OperationError); + return Result(); +} + +nsresult JsepSessionImpl::AddLocalIceCandidate(const std::string& candidate, + const std::string& transportId, + const std::string& ufrag, + uint16_t* level, + std::string* mid, + bool* skipped) { + mLastError.clear(); + *skipped = true; + if (!mCurrentLocalDescription && !mPendingLocalDescription) { + JSEP_SET_ERROR("Cannot add ICE candidate when there is no local SDP"); + return NS_ERROR_UNEXPECTED; + } + + Maybe<const JsepTransceiver> transceiver = + GetTransceiverWithTransport(transportId); + if (!transceiver || !transceiver->IsAssociated()) { + // mainly here to make some testing less complicated, but also just in case + return NS_OK; + } + + *level = transceiver->GetLevel(); + *mid = transceiver->GetMid(); + + nsresult rv = NS_ERROR_INVALID_ARG; + if (mCurrentLocalDescription) { + rv = mSdpHelper.AddCandidateToSdp(mCurrentLocalDescription.get(), candidate, + *level, ufrag); + } + + if (mPendingLocalDescription) { + // If we had an error when adding the candidate to the current description, + // we stomp them here. This is deliberate. + rv = mSdpHelper.AddCandidateToSdp(mPendingLocalDescription.get(), candidate, + *level, ufrag); + } + + *skipped = false; + return rv; +} + +nsresult JsepSessionImpl::UpdateDefaultCandidate( + const std::string& defaultCandidateAddr, uint16_t defaultCandidatePort, + const std::string& defaultRtcpCandidateAddr, + uint16_t defaultRtcpCandidatePort, const std::string& transportId) { + mLastError.clear(); + + mozilla::Sdp* sdp = + GetParsedLocalDescription(kJsepDescriptionPendingOrCurrent); + + if (!sdp) { + JSEP_SET_ERROR("Cannot add ICE candidate in state " << GetStateStr(mState)); + return NS_ERROR_UNEXPECTED; + } + + for (const auto& transceiver : mTransceivers) { + // We set the default address for bundled m-sections, but not candidate + // attributes. Ugh. + if (transceiver.mTransport.mTransportId == transportId) { + MOZ_ASSERT(transceiver.HasLevel(), + "Transceiver has a transport, but no level! " + "This should never happen."); + std::string defaultRtcpCandidateAddrCopy(defaultRtcpCandidateAddr); + if (mState == kJsepStateStable) { + if (transceiver.mTransport.mComponents == 1) { + // We know we're doing rtcp-mux by now. Don't create an rtcp attr. + defaultRtcpCandidateAddrCopy = ""; + defaultRtcpCandidatePort = 0; + } + } + + size_t level = transceiver.GetLevel(); + if (level >= sdp->GetMediaSectionCount()) { + MOZ_ASSERT(false, "Transceiver's level is too large!"); + JSEP_SET_ERROR("Transceiver's level is too large!"); + return NS_ERROR_FAILURE; + } + + auto& msection = sdp->GetMediaSection(level); + + // Do not add default candidate to a bundle-only m-section, sinice that + // might confuse endpoints that do not support bundle-only. + if (!msection.GetAttributeList().HasAttribute( + SdpAttribute::kBundleOnlyAttribute)) { + mSdpHelper.SetDefaultAddresses( + defaultCandidateAddr, defaultCandidatePort, + defaultRtcpCandidateAddrCopy, defaultRtcpCandidatePort, &msection); + } + } + } + + return NS_OK; +} + +nsresult JsepSessionImpl::GetNegotiatedBundledMids( + SdpHelper::BundledMids* bundledMids) { + const Sdp* answerSdp = GetAnswer(); + + if (!answerSdp) { + return NS_OK; + } + + return mSdpHelper.GetBundledMids(*answerSdp, bundledMids); +} + +mozilla::Sdp* JsepSessionImpl::GetParsedLocalDescription( + JsepDescriptionPendingOrCurrent type) const { + if (type == kJsepDescriptionPending) { + return mPendingLocalDescription.get(); + } else if (mPendingLocalDescription && + type == kJsepDescriptionPendingOrCurrent) { + return mPendingLocalDescription.get(); + } + return mCurrentLocalDescription.get(); +} + +mozilla::Sdp* JsepSessionImpl::GetParsedRemoteDescription( + JsepDescriptionPendingOrCurrent type) const { + if (type == kJsepDescriptionPending) { + return mPendingRemoteDescription.get(); + } else if (mPendingRemoteDescription && + type == kJsepDescriptionPendingOrCurrent) { + return mPendingRemoteDescription.get(); + } + return mCurrentRemoteDescription.get(); +} + +const Sdp* JsepSessionImpl::GetAnswer() const { + return (mIsCurrentOfferer.isSome() && *mIsCurrentOfferer) + ? mCurrentRemoteDescription.get() + : mCurrentLocalDescription.get(); +} + +void JsepSessionImpl::SetIceRestarting(bool restarting) { + if (restarting) { + // not restarting -> restarting + if (!IsIceRestarting()) { + // We don't set this more than once, so the old ufrag/pwd is preserved + // even if we CreateOffer({iceRestart:true}) multiple times in a row. + mOldIceUfrag = mIceUfrag; + mOldIcePwd = mIcePwd; + } + mIceUfrag = GetRandomHex(1); + mIcePwd = GetRandomHex(4); + } else if (IsIceRestarting()) { + // restarting -> not restarting, restore old ufrag/pwd + mIceUfrag = mOldIceUfrag; + mIcePwd = mOldIcePwd; + mOldIceUfrag.clear(); + mOldIcePwd.clear(); + } +} + +nsresult JsepSessionImpl::Close() { + mLastError.clear(); + SetState(kJsepStateClosed); + return NS_OK; +} + +const std::string JsepSessionImpl::GetLastError() const { return mLastError; } + +const std::vector<std::pair<size_t, std::string>>& +JsepSessionImpl::GetLastSdpParsingErrors() const { + return mLastSdpParsingErrors; +} + +bool JsepSessionImpl::CheckNegotiationNeeded() const { + MOZ_ASSERT(mState == kJsepStateStable); + + for (const auto& transceiver : mTransceivers) { + if (transceiver.IsStopped()) { + // Nothing to do with this + continue; + } + + if (transceiver.IsStopping()) { + MOZ_MTLOG(ML_DEBUG, "[" << mName + << "]: Negotiation needed because of " + "transceiver we need to stop"); + return true; + } + + if (!transceiver.IsAssociated()) { + MOZ_MTLOG(ML_DEBUG, "[" << mName + << "]: Negotiation needed because of " + "transceiver we need to associate."); + return true; + } + + MOZ_ASSERT(transceiver.IsAssociated() && !transceiver.IsStopping() && + !transceiver.IsStopped()); + + if (!mCurrentLocalDescription || !mCurrentRemoteDescription) { + MOZ_CRASH( + "Transceivers should not be associated if we're in stable " + "before the first negotiation."); + continue; + } + + if (!transceiver.HasLevel()) { + MOZ_CRASH("Associated transceivers should always have a level."); + continue; + } + + if (transceiver.GetMediaType() == SdpMediaSection::kApplication) { + continue; + } + + size_t level = transceiver.GetLevel(); + if (NS_WARN_IF(mCurrentLocalDescription->GetMediaSectionCount() <= level) || + NS_WARN_IF(mCurrentRemoteDescription->GetMediaSectionCount() <= + level)) { + MOZ_ASSERT(false); + continue; + } + + const SdpMediaSection& local = + mCurrentLocalDescription->GetMediaSection(level); + const SdpMediaSection& remote = + mCurrentRemoteDescription->GetMediaSection(level); + + if (transceiver.mJsDirection & sdp::kSend) { + std::vector<std::string> sdpMsids; + if (local.GetAttributeList().HasAttribute(SdpAttribute::kMsidAttribute)) { + for (const auto& msidAttr : local.GetAttributeList().GetMsid().mMsids) { + if (msidAttr.identifier != "-") { + sdpMsids.push_back(msidAttr.identifier); + } + } + } + std::sort(sdpMsids.begin(), sdpMsids.end()); + + std::vector<std::string> jsepMsids; + for (const auto& jsepMsid : transceiver.mSendTrack.GetStreamIds()) { + jsepMsids.push_back(jsepMsid); + } + std::sort(jsepMsids.begin(), jsepMsids.end()); + + if (!std::equal(sdpMsids.begin(), sdpMsids.end(), jsepMsids.begin(), + jsepMsids.end())) { + MOZ_MTLOG(ML_DEBUG, + "[" << mName + << "]: Negotiation needed because transceiver " + "is sending, and the local SDP has different " + "msids than the send track"); + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: SDP msids = ["); + for (const auto& msid : sdpMsids) { + MOZ_MTLOG(ML_DEBUG, msid << ", "); + } + MOZ_MTLOG(ML_DEBUG, "]"); + MOZ_MTLOG(ML_DEBUG, "[" << mName << "]: JSEP msids = ["); + for (const auto& msid : jsepMsids) { + MOZ_MTLOG(ML_DEBUG, msid << ", "); + } + MOZ_MTLOG(ML_DEBUG, "]"); + return true; + } + } + + if (mIsCurrentOfferer.isSome() && *mIsCurrentOfferer) { + if ((local.GetDirection() != transceiver.mJsDirection) && + reverse(remote.GetDirection()) != transceiver.mJsDirection) { + MOZ_MTLOG(ML_DEBUG, "[" << mName + << "]: Negotiation needed because " + "the direction on our offer, and the remote " + "answer, does not " + "match the direction on a transceiver."); + return true; + } + } else if (local.GetDirection() != + (transceiver.mJsDirection & reverse(remote.GetDirection()))) { + MOZ_MTLOG( + ML_DEBUG, + "[" << mName + << "]: Negotiation needed because " + "the direction on our answer doesn't match the direction on a " + "transceiver, even though the remote offer would have allowed " + "it."); + return true; + } + } + + return false; +} + +} // namespace mozilla |