datachannel, refactor: add patch for WebRTC Direct.

datachannel/include/rtc/peerconnection.hpp

@@ -35,6 +35,11 @@ struct RTC_CPP_EXPORT DataChannelInit {
 	string protocol = "";
 };
 
+struct RTC_CPP_EXPORT LocalDescriptionInit {
+    optional<string> iceUfrag;
+    optional<string> icePwd;
+};
+
 class RTC_CPP_EXPORT PeerConnection final : CheshireCat<impl::PeerConnection> {
 public:
 	enum class State : int {
@@ -90,7 +95,7 @@ class RTC_CPP_EXPORT PeerConnection final : CheshireCat<impl::PeerConnection> {
 	uint16_t maxDataChannelId() const;
 	bool getSelectedCandidatePair(Candidate *local, Candidate *remote);
 
-	void setLocalDescription(Description::Type type = Description::Type::Unspec);
+	void setLocalDescription(Description::Type type = Description::Type::Unspec, LocalDescriptionInit init = {});
 	void setRemoteDescription(Description description);
 	void addRemoteCandidate(Candidate candidate);
 
@@ -112,6 +117,7 @@ class RTC_CPP_EXPORT PeerConnection final : CheshireCat<impl::PeerConnection> {
 	void onSignalingStateChange(std::function<void(SignalingState state)> callback);
 
 	void resetCallbacks();
+	CertificateFingerprint remoteFingerprint();
 
 	// Stats
 	void clearStats();

datachannel/src/impl/icetransport.cpp

@@ -161,6 +161,10 @@ IceTransport::IceTransport(const Configuration &config, candidate_callback candi
 	}
 }
 
+void IceTransport::setIceAttributes([[maybe_unused]] string uFrag, [[maybe_unused]] string pwd) {
+	PLOG_WARNING << "Setting custom ICE attributes is not supported with libnice, please use libjuice";
+}
+
 IceTransport::~IceTransport() {
 	PLOG_DEBUG << "Destroying ICE transport";
 	mAgent.reset();
@@ -608,6 +612,12 @@ IceTransport::IceTransport(const Configuration &config, candidate_callback candi
 	                       RecvCallback, this);
 }
 
+void IceTransport::setIceAttributes(string uFrag, string pwd) {
+	if (juice_set_local_ice_attributes(mAgent.get(), uFrag.c_str(), pwd.c_str()) < 0) {
+		throw std::invalid_argument("Invalid ICE attributes");
+	}
+}
+
 IceTransport::~IceTransport() {
 	PLOG_DEBUG << "Destroying ICE transport";
 	nice_agent_attach_recv(mNiceAgent.get(), mStreamId, 1, g_main_loop_get_context(MainLoop.get()),

datachannel/src/impl/icetransport.hpp

@@ -51,6 +51,7 @@ class IceTransport : public Transport {
 	void setRemoteDescription(const Description &description);
 	bool addRemoteCandidate(const Candidate &candidate);
 	void gatherLocalCandidates(string mid);
+	void setIceAttributes(string uFrag, string pwd);
 
 	optional<string> getLocalAddress() const;
 	optional<string> getRemoteAddress() const;

datachannel/src/impl/peerconnection.cpp

@@ -224,6 +224,8 @@ shared_ptr<DtlsTransport> PeerConnection::initDtlsTransport() {
 			fingerprintAlgorithm = remote->fingerprint()->algorithm;
 		}
 
+		mRemoteFingerprintAlgorithm = fingerprintAlgorithm;
+
 		auto lower = std::atomic_load(&mIceTransport);
 		if (!lower)
 			throw std::logic_error("No underlying ICE transport for DTLS transport");
@@ -434,19 +436,16 @@ bool PeerConnection::checkFingerprint(const std::string &fingerprint) {
 	if (!mRemoteDescription || !mRemoteDescription->fingerprint())
 		return false;
 
-	if (config.disableFingerprintVerification) {
-		CertificateFingerprint fp;
-
-		fp.algorithm = mRemoteDescription->fingerprint()->algorithm;
-		fp.value = fingerprint;
-		mRemoteDescription->setFingerprint(fp);
-
+  if (config.disableFingerprintVerification) {
+		PLOG_VERBOSE << "Skipping fingerprint validation";
+		mRemoteFingerprint = fingerprint;
 		return true;
 	}
 
 	auto expectedFingerprint = mRemoteDescription->fingerprint()->value;
-	if (expectedFingerprint  == fingerprint) {
+	if (expectedFingerprint == fingerprint) {
 		PLOG_VERBOSE << "Valid fingerprint \"" << fingerprint << "\"";
+		mRemoteFingerprint = fingerprint;
 		return true;
 	}
 
@@ -1298,6 +1297,13 @@ void PeerConnection::resetCallbacks() {
 	trackCallback = nullptr;
 }
 
+CertificateFingerprint PeerConnection::remoteFingerprint() {
+	if (mRemoteFingerprint)
+		return {CertificateFingerprint{mRemoteFingerprintAlgorithm, *mRemoteFingerprint}};
+	else
+		return {};
+}
+
 void PeerConnection::updateTrackSsrcCache(const Description &description) {
 	std::unique_lock lock(mTracksMutex); // for safely writing to mTracksBySsrc
 

datachannel/src/impl/peerconnection.hpp

@@ -98,6 +98,7 @@ struct PeerConnection : std::enable_shared_from_this<PeerConnection> {
 	bool changeSignalingState(SignalingState newState);
 
 	void resetCallbacks();
+	CertificateFingerprint remoteFingerprint();
 
 	// Helper method for asynchronous callback invocation
 	template <typename... Args> void trigger(synchronized_callback<Args...> *cb, Args... args) {
@@ -157,6 +158,9 @@ struct PeerConnection : std::enable_shared_from_this<PeerConnection> {
 
 	Queue<shared_ptr<DataChannel>> mPendingDataChannels;
 	Queue<shared_ptr<Track>> mPendingTracks;
+
+	CertificateFingerprint::Algorithm mRemoteFingerprintAlgorithm = CertificateFingerprint::Algorithm::Sha256;
+	optional<string> mRemoteFingerprint;
 };
 
 } // namespace rtc::impl

datachannel/src/peerconnection.cpp

@@ -76,7 +76,7 @@ bool PeerConnection::hasMedia() const {
 	return local && local->hasAudioOrVideo();
 }
 
-void PeerConnection::setLocalDescription(Description::Type type) {
+void PeerConnection::setLocalDescription(Description::Type type, LocalDescriptionInit init) {
 	std::unique_lock signalingLock(impl()->signalingMutex);
 	PLOG_VERBOSE << "Setting local description, type=" << Description::typeToString(type);
 
@@ -140,6 +140,11 @@ void PeerConnection::setLocalDescription(Description::Type type) {
 	if (!iceTransport)
 		return; // closed
 
+	if (init.iceUfrag && init.icePwd) {
+		PLOG_DEBUG << "Using custom ICE attributes, ufrag=\"" << init.iceUfrag.value() << "\", pwd=\"" << init.icePwd.value() << "\"";
+		iceTransport->setIceAttributes(init.iceUfrag.value(), init.icePwd.value());
+	}
+
 	Description local = iceTransport->getLocalDescription(type);
 	impl()->processLocalDescription(std::move(local));
 
@@ -354,6 +359,10 @@ optional<std::chrono::milliseconds> PeerConnection::rtt() {
 	return sctpTransport ? sctpTransport->rtt() : nullopt;
 }
 
+CertificateFingerprint PeerConnection::remoteFingerprint() {
+	return impl()->remoteFingerprint();
+}
+
 std::ostream &operator<<(std::ostream &out, PeerConnection::State state) {
 	using State = PeerConnection::State;
 	const char *str;