Fixed signaling state callback in C API test

Send RTCP with the same DSCP as RTP

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.7)
 project(libdatachannel
-	VERSION 0.10.1
+	VERSION 0.10.3
 	LANGUAGES CXX)
 set(PROJECT_DESCRIPTION "WebRTC Data Channels Library")
 
@@ -36,7 +36,7 @@ set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
 
 if(WIN32)
 	add_definitions(-DWIN32_LEAN_AND_MEAN)
-	if (MSVC)
+	if(MSVC)
 		add_definitions(-DNOMINMAX)
 		add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 		add_definitions(-D_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING)
@@ -163,8 +163,8 @@ target_link_libraries(datachannel-static PUBLIC Threads::Threads plog::plog)
 target_link_libraries(datachannel-static PRIVATE Usrsctp::Usrsctp)
 
 if(WIN32)
-	target_link_libraries(datachannel PRIVATE ws2_32) # winsock2
+	target_link_libraries(datachannel PUBLIC ws2_32) # winsock2
-	target_link_libraries(datachannel-static PRIVATE ws2_32) # winsock2
+	target_link_libraries(datachannel-static PUBLIC ws2_32) # winsock2
 endif()
 
 if(NO_MEDIA)
@@ -272,11 +272,7 @@ if(NOT NO_TESTS)
 		set_target_properties(datachannel-tests PROPERTIES OUTPUT_NAME tests)
 	endif()
 	target_include_directories(datachannel-tests PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
-	if(WIN32)
+	target_link_libraries(datachannel-tests datachannel)
-		target_link_libraries(datachannel-tests datachannel-static) # DLL exports only the C API
-	else()
-		target_link_libraries(datachannel-tests datachannel)
-	endif()
 
 	# Benchmark
 	add_executable(datachannel-benchmark test/benchmark.cpp)
@@ -288,11 +284,7 @@ if(NOT NO_TESTS)
 	endif()
 	target_compile_definitions(datachannel-benchmark PRIVATE BENCHMARK_MAIN=1)
 	target_include_directories(datachannel-benchmark PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
-	if(WIN32)
+	target_link_libraries(datachannel-benchmark datachannel)
-		target_link_libraries(datachannel-benchmark datachannel-static) # DLL exports only the C API
-	else()
-		target_link_libraries(datachannel-benchmark datachannel)
-	endif()
 endif()
 
 # Examples

README.md

@@ -27,8 +27,9 @@ Features:
 - Full IPv6 support
 - Trickle ICE ([draft-ietf-ice-trickle-21](https://tools.ietf.org/html/draft-ietf-ice-trickle-21))
 - JSEP compatible ([draft-ietf-rtcweb-jsep-26](https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-26))
-- SRTP and SRTCP key derivation from DTLS ([RFC5764](https://tools.ietf.org/html/rfc5764))
 - Multicast DNS candidates ([draft-ietf-rtcweb-mdns-ice-candidates-04](https://tools.ietf.org/html/draft-ietf-rtcweb-mdns-ice-candidates-04))
+- SRTP and SRTCP key derivation from DTLS ([RFC5764](https://tools.ietf.org/html/rfc5764))
+- Differentiated Services QoS ([draft-ietf-tsvwg-rtcweb-qos-18](https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18))
 - TURN relaying ([RFC5766](https://tools.ietf.org/html/rfc5766)) with [libnice](https://github.com/libnice/libnice) as ICE backend
 
 Note only SDP BUNDLE mode is supported for media multiplexing ([draft-ietf-mmusic-sdp-bundle-negotiation-54](https://tools.ietf.org/html/draft-ietf-mmusic-sdp-bundle-negotiation-54)). The behavior is equivalent to the JSEP bundle-only policy: the library always negociates one unique network component, where SRTP media streams are multiplexed with SRTCP control packets ([RFC5761](https://tools.ietf.org/html/rfc5761)) and SCTP/DTLS data traffic ([RFC5764](https://tools.ietf.org/html/rfc5764)).

examples/client/CMakeLists.txt

@@ -9,14 +9,9 @@ target_compile_definitions(datachannel-client PUBLIC STATIC_GETOPT)
 else()
 add_executable(datachannel-client main.cpp parse_cl.cpp parse_cl.h)
 endif()
+
 set_target_properties(datachannel-client PROPERTIES
 	CXX_STANDARD 17
 	OUTPUT_NAME client)
-
-if(WIN32)
-	target_link_libraries(datachannel-client datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-client datachannel)
-endif()
 target_link_libraries(datachannel-client datachannel nlohmann_json)
 

examples/copy-paste/CMakeLists.txt

@@ -4,19 +4,11 @@ add_executable(datachannel-copy-paste-offerer offerer.cpp)
 set_target_properties(datachannel-copy-paste-offerer PROPERTIES
 	CXX_STANDARD 17
 	OUTPUT_NAME offerer)
-if(WIN32)
+target_link_libraries(datachannel-copy-paste-offerer datachannel)
-	target_link_libraries(datachannel-copy-paste-offerer datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-copy-paste-offerer datachannel)
-endif()
 
 add_executable(datachannel-copy-paste-answerer answerer.cpp)
 set_target_properties(datachannel-copy-paste-answerer PROPERTIES
 	CXX_STANDARD 17
 	OUTPUT_NAME answerer)
-if(WIN32)
+target_link_libraries(datachannel-copy-paste-answerer datachannel)
-	target_link_libraries(datachannel-copy-paste-answerer datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-copy-paste-answerer datachannel)
-endif()
 

examples/media/CMakeLists.txt

@@ -4,11 +4,5 @@ add_executable(datachannel-media main.cpp)
 set_target_properties(datachannel-media PROPERTIES
         CXX_STANDARD 17
         OUTPUT_NAME media)
+target_link_libraries(datachannel-media datachannel nlohmann_json)
 
-if(WIN32)
-    target_link_libraries(datachannel-media datachannel-static) # DLL exports only the C API
-else()
-    target_link_libraries(datachannel-media datachannel)
-endif()
-
-target_link_libraries(datachannel-media datachannel nlohmann_json)

examples/sfu-media/CMakeLists.txt

@@ -4,12 +4,5 @@ add_executable(datachannel-sfu-media main.cpp)
 set_target_properties(datachannel-sfu-media PROPERTIES
 		CXX_STANDARD 17
 		OUTPUT_NAME sfu-media)
-
-if(WIN32)
-	target_link_libraries(datachannel-sfu-media datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-sfu-media datachannel)
-endif()
-
 target_link_libraries(datachannel-sfu-media datachannel nlohmann_json)
 

include/rtc/candidate.hpp

@@ -25,7 +25,7 @@
 
 namespace rtc {
 
-class Candidate {
+class RTC_CPP_EXPORT Candidate {
 public:
 	enum class Family { Unresolved, Ipv4, Ipv6 };
 	enum class Type { Unknown, Host, ServerReflexive, PeerReflexive, Relayed };
@@ -40,35 +40,44 @@ public:
 	enum class ResolveMode { Simple, Lookup };
 	bool resolve(ResolveMode mode = ResolveMode::Simple);
 
+	Type type() const;
+	TransportType transportType() const;
+	uint32_t priority() const;
 	string candidate() const;
 	string mid() const;
 	operator string() const;
 
+	bool operator==(const Candidate &other) const;
+	bool operator!=(const Candidate &other) const;
+
 	bool isResolved() const;
 	Family family() const;
-	Type type() const;
-	TransportType transportType() const;
 	std::optional<string> address() const;
 	std::optional<uint16_t> port() const;
-	std::optional<uint32_t> priority() const;
 
 private:
-	string mCandidate;
+	void parse(string candidate);
+
+	string mFoundation;
+	uint32_t mComponent, mPriority;
+	string mTypeString, mTransportString;
+	Type mType;
+	TransportType mTransportType;
+	string mNode, mService;
+	string mTail;
+
 	std::optional<string> mMid;
 
 	// Extracted on resolution
 	Family mFamily;
-	Type mType;
-	TransportType mTransportType;
 	string mAddress;
 	uint16_t mPort;
-	uint32_t mPriority;
 };
 
 } // namespace rtc
 
-std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate);
-std::ostream &operator<<(std::ostream &out, const rtc::Candidate::Type &type);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Candidate::Type &type);
-std::ostream &operator<<(std::ostream &out, const rtc::Candidate::TransportType &transportType);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Candidate::TransportType &transportType);
 
 #endif

include/rtc/channel.hpp

@@ -28,7 +28,7 @@
 
 namespace rtc {
 
-class Channel {
+class RTC_CPP_EXPORT Channel {
 public:
 	Channel() = default;
 	virtual ~Channel() = default;

include/rtc/configuration.hpp

@@ -26,7 +26,7 @@
 
 namespace rtc {
 
-struct IceServer {
+struct RTC_CPP_EXPORT IceServer {
 	enum class Type { Stun, Turn };
 	enum class RelayType { TurnUdp, TurnTcp, TurnTls };
 
@@ -51,7 +51,7 @@ struct IceServer {
 	RelayType relayType;
 };
 
-struct ProxyServer {
+struct RTC_CPP_EXPORT ProxyServer {
 	enum class Type { None = 0, Socks5, Http, Last = Http };
 
 	ProxyServer(Type type_, string ip_, uint16_t port_, string username_ = "",
@@ -64,7 +64,7 @@ struct ProxyServer {
 	string password;
 };
 
-struct Configuration {
+struct RTC_CPP_EXPORT Configuration {
 	std::vector<IceServer> iceServers;
 	std::optional<ProxyServer> proxyServer;
 	bool enableIceTcp = false;

include/rtc/datachannel.hpp

@@ -36,7 +36,7 @@ namespace rtc {
 class SctpTransport;
 class PeerConnection;
 
-class DataChannel : public std::enable_shared_from_this<DataChannel>, public Channel {
+class RTC_CPP_EXPORT DataChannel : public std::enable_shared_from_this<DataChannel>, public Channel {
 public:
 	DataChannel(std::weak_ptr<PeerConnection> pc, uint16_t stream, string label, string protocol,
 	            Reliability reliability);
@@ -87,7 +87,7 @@ private:
 	friend class PeerConnection;
 };
 
-class NegociatedDataChannel final : public DataChannel {
+class RTC_CPP_EXPORT NegociatedDataChannel final : public DataChannel {
 public:
 	NegociatedDataChannel(std::weak_ptr<PeerConnection> pc, uint16_t stream, string label,
 	                      string protocol, Reliability reliability);

include/rtc/description.hpp

@@ -32,7 +32,7 @@
 
 namespace rtc {
 
-class Description {
+class RTC_CPP_EXPORT Description {
 public:
 	enum class Type { Unspec, Offer, Answer, Pranswer, Rollback };
 	enum class Role { ActPass, Passive, Active };
@@ -53,6 +53,7 @@ public:
 	void hintType(Type type);
 	void setFingerprint(string fingerprint);
 
+	bool hasCandidate(const Candidate &candidate) const;
 	void addCandidate(Candidate candidate);
 	void addCandidates(std::vector<Candidate> candidates);
 	void endCandidates();
@@ -62,7 +63,7 @@ public:
 	string generateSdp(string_view eol) const;
 	string generateApplicationSdp(string_view eol) const;
 
-	class Entry {
+	class RTC_CPP_EXPORT Entry {
 	public:
 		virtual ~Entry() = default;
 
@@ -94,7 +95,7 @@ public:
 		Direction mDirection;
 	};
 
-	struct Application : public Entry {
+	struct RTC_CPP_EXPORT Application : public Entry {
 	public:
 		Application(string mid = "data");
 		virtual ~Application() = default;
@@ -119,7 +120,7 @@ public:
 	};
 
 	// Media (non-data)
-	class Media : public Entry {
+	class RTC_CPP_EXPORT Media : public Entry {
 	public:
 		Media(const string &sdp);
 		Media(const string &mline, string mid, Direction dir = Direction::SendOnly);
@@ -182,7 +183,7 @@ public:
 		void addRTPMap(const RTPMap &map);
 	};
 
-	class Audio : public Media {
+	class RTC_CPP_EXPORT Audio : public Media {
 	public:
 		Audio(string mid = "audio", Direction dir = Direction::SendOnly);
 
@@ -190,7 +191,7 @@ public:
 		void addOpusCodec(int payloadType);
 	};
 
-	class Video : public Media {
+	class RTC_CPP_EXPORT Video : public Media {
 	public:
 		Video(string mid = "video", Direction dir = Direction::SendOnly);
 
@@ -244,8 +245,8 @@ private:
 
 } // namespace rtc
 
-std::ostream &operator<<(std::ostream &out, const rtc::Description &description);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Description &description);
-std::ostream &operator<<(std::ostream &out, rtc::Description::Type type);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::Description::Type type);
-std::ostream &operator<<(std::ostream &out, rtc::Description::Role role);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::Description::Role role);
 
 #endif

include/rtc/include.hpp

@@ -28,9 +28,15 @@
 #endif
 
 #ifdef _WIN32
+#define RTC_CPP_EXPORT __declspec(dllexport)
 #ifndef _WIN32_WINNT
 #define _WIN32_WINNT 0x0602 // Windows 8
 #endif
+#ifdef _MSC_VER
+#pragma warning(disable:4251) // disable "X needs to have dll-interface..."
+#endif
+#else
+#define RTC_CPP_EXPORT
 #endif
 
 #include "log.hpp"

include/rtc/init.hpp

@@ -27,7 +27,7 @@ namespace rtc {
 
 using init_token = std::shared_ptr<void>;
 
-class Init {
+class RTC_CPP_EXPORT Init {
 public:
 	static init_token Token();
 	static void Preload();

include/rtc/log.hpp

@@ -35,6 +35,8 @@
 #pragma warning(pop)
 #endif
 
+#include "include.hpp"
+
 namespace rtc {
 
 enum class LogLevel { // Don't change, it must match plog severity
@@ -47,8 +49,8 @@ enum class LogLevel { // Don't change, it must match plog severity
 	Verbose = 6
 };
 
-void InitLogger(LogLevel level);
+RTC_CPP_EXPORT void InitLogger(LogLevel level);
-void InitLogger(plog::Severity severity, plog::IAppender *appender = nullptr);
+RTC_CPP_EXPORT void InitLogger(plog::Severity severity, plog::IAppender *appender = nullptr);
 } // namespace rtc
 
 #endif

include/rtc/message.hpp

@@ -29,7 +29,7 @@
 
 namespace rtc {
 
-struct Message : binary {
+struct RTC_CPP_EXPORT Message : binary {
 	enum Type { Binary, String, Control, Reset };
 
 	Message(const Message &message) = default;
@@ -42,7 +42,8 @@ struct Message : binary {
 	Message(binary &&data, Type type_ = Binary) : binary(std::move(data)), type(type_) {}
 
 	Type type;
-	unsigned int stream = 0;
+	unsigned int stream = 0; // Stream id (SCTP stream or SSRC)
+	unsigned int dscp = 0;   // Differentiated Services Code Point
 	std::shared_ptr<Reliability> reliability;
 };
 

include/rtc/peerconnection.hpp

@@ -50,14 +50,14 @@ class SctpTransport;
 using certificate_ptr = std::shared_ptr<Certificate>;
 using future_certificate_ptr = std::shared_future<certificate_ptr>;
 
-struct DataChannelInit {
+struct RTC_CPP_EXPORT DataChannelInit {
 	Reliability reliability = {};
 	bool negotiated = false;
 	std::optional<uint16_t> id = nullopt;
 	string protocol = "";
 };
 
-class PeerConnection final : public std::enable_shared_from_this<PeerConnection> {
+class RTC_CPP_EXPORT PeerConnection final : public std::enable_shared_from_this<PeerConnection> {
 public:
 	enum class State : int {
 		New = RTC_NEW,
@@ -203,8 +203,8 @@ private:
 
 } // namespace rtc
 
-std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::State state);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::State state);
-std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::GatheringState state);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::GatheringState state);
-std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::SignalingState state);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::SignalingState state);
 
 #endif

include/rtc/rtcp.hpp

@@ -29,7 +29,7 @@
 
 namespace rtc {
 
-class RtcpHandler {
+class RTC_CPP_EXPORT RtcpHandler {
 protected:
 	/**
 	 * Use this callback when trying to send custom data (such as RTCP) to the client.
@@ -64,7 +64,7 @@ public:
 class Track;
 
 // An RtcpSession can be plugged into a Track to handle the whole RTCP session
-class RtcpReceivingSession : public RtcpHandler {
+class RTC_CPP_EXPORT RtcpReceivingSession : public RtcpHandler {
 public:
 	rtc::message_ptr incoming(rtc::message_ptr ptr) override;
 	rtc::message_ptr outgoing(rtc::message_ptr ptr) override;

include/rtc/rtp.hpp

@@ -20,7 +20,7 @@
 #ifndef RTC_RTP_HPP
 #define RTC_RTP_HPP
 
-#include <rtc/log.hpp>
+#include "log.hpp"
 
 #include <cmath>
 
@@ -75,19 +75,15 @@ public:
 	inline void setPayloadType(uint8_t newPayloadType) {
 		_payloadType = (_payloadType & 0b10000000u) | (0b01111111u & newPayloadType);
 	}
-	inline void setSsrc(uint32_t ssrc) { _ssrc = htonl(ssrc); }
+	inline void setSsrc(uint32_t in_ssrc) { _ssrc = htonl(in_ssrc); }
 
 	void setTimestamp(uint32_t i) { _timestamp = htonl(i); }
 
 	void log() {
-		PLOG_VERBOSE  << "RTP V: " << (int) version()
+		PLOG_VERBOSE << "RTP V: " << (int)version() << " P: " << (padding() ? "P" : " ")
-		            << " P: " << (padding() ? "P" : " ")
+		             << " X: " << (extension() ? "X" : " ") << " CC: " << (int)csrcCount()
-		            << " X: " << (extension() ? "X" : " ")
+		             << " M: " << (marker() ? "M" : " ") << " PT: " << (int)payloadType()
-		            << " CC: "  << (int) csrcCount()
+		             << " SEQNO: " << seqNumber() << " TS: " << timestamp();
-		            << " M: " << (marker() ? "M" : " ")
-		            << " PT: " << (int) payloadType()
-		            << " SEQNO: " << seqNumber()
-		            << " TS: " << timestamp();
 	}
 };
 
@@ -103,13 +99,13 @@ private:
 	uint32_t _delaySinceLastReport;
 
 public:
-	inline void preparePacket(SSRC ssrc, [[maybe_unused]] unsigned int packetsLost,
+	inline void preparePacket(SSRC in_ssrc, [[maybe_unused]] unsigned int packetsLost,
 	                          [[maybe_unused]] unsigned int totalPackets, uint16_t highestSeqNo,
 	                          uint16_t seqNoCycles, uint32_t jitter, uint64_t lastSR_NTP,
 	                          uint64_t lastSR_DELAY) {
 		setSeqNo(highestSeqNo, seqNoCycles);
 		setJitter(jitter);
-		setSSRC(ssrc);
+		setSSRC(in_ssrc);
 
 		// Middle 32 bits of NTP Timestamp
 		//		  this->lastReport = lastSR_NTP >> 16u;
@@ -120,7 +116,7 @@ public:
 		//		  this->delaySinceLastReport = lastSR_DELAY;
 	}
 
-	inline void setSSRC(SSRC ssrc) { this->ssrc = htonl(ssrc); }
+	inline void setSSRC(SSRC in_ssrc) { this->ssrc = htonl(in_ssrc); }
 	inline SSRC getSSRC() const { return ntohl(ssrc); }
 
 	inline void setPacketsLost([[maybe_unused]] unsigned int packetsLost,
@@ -199,9 +195,9 @@ public:
 
 	inline void log() const {
 		PLOG_VERBOSE << "RTCP header: "
-		          << "version=" << unsigned(version()) << ", padding=" << padding()
+		             << "version=" << unsigned(version()) << ", padding=" << padding()
-		          << ", reportCount=" << unsigned(reportCount())
+		             << ", reportCount=" << unsigned(reportCount())
-		          << ", payloadType=" << unsigned(payloadType()) << ", length=" << length();
+		             << ", payloadType=" << unsigned(payloadType()) << ", length=" << length();
 	}
 };
 
@@ -337,7 +333,7 @@ struct RTCP_REMB {
 		return sizeof(uint32_t) * (1 + header.header.length());
 	}
 
-	void preparePacket(SSRC senderSSRC, unsigned int numSSRC, unsigned int bitrate) {
+	void preparePacket(SSRC senderSSRC, unsigned int numSSRC, unsigned int in_bitrate) {
 
 		// Report Count becomes the format here.
 		header.header.prepareHeader(206, 15, 0);
@@ -352,21 +348,21 @@ struct RTCP_REMB {
 		id[2] = 'M';
 		id[3] = 'B';
 
-		setBitrate(numSSRC, bitrate);
+		setBitrate(numSSRC, in_bitrate);
 	}
 
-	void setBitrate(unsigned int numSSRC, unsigned int bitrate) {
+	void setBitrate(unsigned int numSSRC, unsigned int in_bitrate) {
 		unsigned int exp = 0;
-		while (bitrate > pow(2, 18) - 1) {
+		while (in_bitrate > pow(2, 18) - 1) {
 			exp++;
-			bitrate /= 2;
+			in_bitrate /= 2;
 		}
 
 		// "length" in packet is one less than the number of 32 bit words in the packet.
 		header.header.setLength(
 		    uint16_t((offsetof(RTCP_REMB, ssrc) / sizeof(uint32_t)) - 1 + numSSRC));
 
-		this->bitrate = htonl((numSSRC << (32u - 8u)) | (exp << (32u - 8u - 6u)) | bitrate);
+		this->bitrate = htonl((numSSRC << (32u - 8u)) | (exp << (32u - 8u - 6u)) | in_bitrate);
 	}
 
 	void setSsrc(int iterator, SSRC newSssrc) { ssrc[iterator] = htonl(newSssrc); }
@@ -428,7 +424,7 @@ public:
 
 public:
 	void preparePacket(SSRC ssrc, unsigned int discreteSeqNoCount) {
-		header.header.prepareHeader(205, 1, 2 + discreteSeqNoCount);
+		header.header.prepareHeader(205, 1, 2 + uint16_t(discreteSeqNoCount));
 		header.setMediaSourceSSRC(ssrc);
 		header.setPacketSenderSSRC(ssrc);
 	}

include/rtc/track.hpp

@@ -35,7 +35,7 @@ namespace rtc {
 class DtlsSrtpTransport;
 #endif
 
-class Track final : public std::enable_shared_from_this<Track>, public Channel {
+class RTC_CPP_EXPORT Track final : public std::enable_shared_from_this<Track>, public Channel {
 public:
 	Track(Description::Media description);
 	~Track() = default;
@@ -70,8 +70,8 @@ private:
 	std::weak_ptr<DtlsSrtpTransport> mDtlsSrtpTransport;
 #endif
 
-	bool outgoing(message_ptr message);
 	void incoming(message_ptr message);
+	bool outgoing(message_ptr message);
 
 	Description::Media mMediaDescription;
 	std::atomic<bool> mIsClosed = false;

include/rtc/websocket.hpp

@@ -38,7 +38,7 @@ class TcpTransport;
 class TlsTransport;
 class WsTransport;
 
-class WebSocket final : public Channel, public std::enable_shared_from_this<WebSocket> {
+class RTC_CPP_EXPORT WebSocket final : public Channel, public std::enable_shared_from_this<WebSocket> {
 public:
 	enum class State : int {
 		Connecting = 0,

src/candidate.cpp

@@ -20,6 +20,7 @@
 
 #include <algorithm>
 #include <array>
+#include <cctype>
 #include <sstream>
 #include <unordered_map>
 
@@ -39,39 +40,44 @@ using std::string;
 
 namespace {
 
-inline bool hasprefix(const string &str, const string &prefix) {
+inline bool match_prefix(const string &str, const string &prefix) {
 	return str.size() >= prefix.size() &&
 	       std::mismatch(prefix.begin(), prefix.end(), str.begin()).first == prefix.end();
 }
 
+inline void trim_begin(string &str) {
+	str.erase(str.begin(),
+	          std::find_if(str.begin(), str.end(), [](char c) { return !std::isspace(c); }));
+}
+
+inline void trim_end(string &str) {
+	str.erase(
+	    std::find_if(str.rbegin(), str.rend(), [](char c) { return !std::isspace(c); }).base(),
+	    str.end());
+}
+
 } // namespace
 
 namespace rtc {
 
 Candidate::Candidate()
-    : mFamily(Family::Unresolved), mType(Type::Unknown), mTransportType(TransportType::Unknown),
+    : mFoundation("none"), mComponent(0), mPriority(0), mTypeString("unknown"),
-      mPort(0), mPriority(0) {}
+      mTransportString("unknown"), mType(Type::Unknown), mTransportType(TransportType::Unknown),
+      mNode("0.0.0.0"), mService("9"), mFamily(Family::Unresolved), mPort(0) {}
 
 Candidate::Candidate(string candidate) : Candidate() {
-	const std::array prefixes{"a=", "candidate:"};
+	if (!candidate.empty())
-	for (const string &prefix : prefixes)
+		parse(std::move(candidate));
-		if (hasprefix(candidate, prefix))
-			candidate.erase(0, prefix.size());
-
-	mCandidate = std::move(candidate);
 }
 
-Candidate::Candidate(string candidate, string mid) : Candidate(std::move(candidate)) {
+Candidate::Candidate(string candidate, string mid) : Candidate() {
+	if (!candidate.empty())
+		parse(std::move(candidate));
 	if (!mid.empty())
 		mMid.emplace(std::move(mid));
 }
 
-void Candidate::hintMid(string mid) {
+void Candidate::parse(string candidate) {
-	if (!mMid)
-		mMid.emplace(std::move(mid));
-}
-
-bool Candidate::resolve(ResolveMode mode) {
 	using TypeMap_t = std::unordered_map<string, Type>;
 	using TcpTypeMap_t = std::unordered_map<string, TransportType>;
 
@@ -84,99 +90,122 @@ bool Candidate::resolve(ResolveMode mode) {
 	                                        {"passive", TransportType::TcpPassive},
 	                                        {"so", TransportType::TcpSo}};
 
-	if (mFamily != Family::Unresolved)
+	const std::array prefixes{"a=", "candidate:"};
-		return true;
+	for (const string &prefix : prefixes)
+		if (match_prefix(candidate, prefix))
+			candidate.erase(0, prefix.size());
 
-	if (mCandidate.empty())
+	PLOG_VERBOSE << "Parsing candidate: " << candidate;
-		throw std::logic_error("Candidate is empty");
-
-	PLOG_VERBOSE << "Resolving candidate (mode="
-	             << (mode == ResolveMode::Simple ? "simple" : "lookup") << "): " << mCandidate;
 
 	// See RFC 8445 for format
-	std::istringstream iss(mCandidate);
+	std::istringstream iss(candidate);
-	int component{0}, priority{0};
+	string transport, typ_, type;
-	string foundation, transport, node, service, typ_, type;
+	if (!(iss >> mFoundation >> mComponent >> mTransportString >> mPriority &&
-	if (iss >> foundation >> component >> transport >> priority &&
+	      iss >> mNode >> mService >> typ_ >> mTypeString && typ_ == "typ"))
-	    iss >> node >> service >> typ_ >> type && typ_ == "typ") {
+		throw std::invalid_argument("Invalid candidate format");
 
-		string left;
+	std::getline(iss, mTail);
-		std::getline(iss, left);
+	trim_begin(mTail);
+	trim_end(mTail);
 
-		if (auto it = TypeMap.find(type); it != TypeMap.end())
+	if (auto it = TypeMap.find(type); it != TypeMap.end())
-			mType = it->second;
+		mType = it->second;
-		else
+	else
-			mType = Type::Unknown;
+		mType = Type::Unknown;
 
-		if (transport == "UDP" || transport == "udp") {
+	if (transport == "UDP" || transport == "udp") {
-			mTransportType = TransportType::Udp;
+		mTransportType = TransportType::Udp;
-		} else if (transport == "TCP" || transport == "tcp") {
+	} else if (transport == "TCP" || transport == "tcp") {
-			std::istringstream iss(left);
+		// Peek tail to find TCP type
-			string tcptype_, tcptype;
+		std::istringstream iss(mTail);
-			if (iss >> tcptype_ >> tcptype && tcptype_ == "tcptype") {
+		string tcptype_, tcptype;
-				if (auto it = TcpTypeMap.find(tcptype); it != TcpTypeMap.end())
+		if (iss >> tcptype_ >> tcptype && tcptype_ == "tcptype") {
-					mTransportType = it->second;
+			if (auto it = TcpTypeMap.find(tcptype); it != TcpTypeMap.end())
-				else
+				mTransportType = it->second;
-					mTransportType = TransportType::TcpUnknown;
+			else
-
-			} else {
 				mTransportType = TransportType::TcpUnknown;
-			}
+
 		} else {
-			mTransportType = TransportType::Unknown;
+			mTransportType = TransportType::TcpUnknown;
 		}
+	} else {
+		mTransportType = TransportType::Unknown;
+	}
+}
 
-		// Try to resolve the node
+void Candidate::hintMid(string mid) {
-		struct addrinfo hints = {};
+	if (!mMid)
-		hints.ai_family = AF_UNSPEC;
+		mMid.emplace(std::move(mid));
-		hints.ai_flags = AI_ADDRCONFIG;
+}
-		if (mTransportType == TransportType::Udp) {
-			hints.ai_socktype = SOCK_DGRAM;
-			hints.ai_protocol = IPPROTO_UDP;
-		} else if (mTransportType != TransportType::Unknown) {
-			hints.ai_socktype = SOCK_STREAM;
-			hints.ai_protocol = IPPROTO_TCP;
-		}
 
-		if (mode == ResolveMode::Simple)
+bool Candidate::resolve(ResolveMode mode) {
-			hints.ai_flags |= AI_NUMERICHOST;
+	PLOG_VERBOSE << "Resolving candidate (mode="
+	             << (mode == ResolveMode::Simple ? "simple" : "lookup") << "): " << mNode << ' '
+	             << mService;
 
-		struct addrinfo *result = nullptr;
+	// Try to resolve the node and service
-		if (getaddrinfo(node.c_str(), service.c_str(), &hints, &result) == 0) {
+	struct addrinfo hints = {};
-			for (auto p = result; p; p = p->ai_next) {
+	hints.ai_family = AF_UNSPEC;
-				if (p->ai_family == AF_INET || p->ai_family == AF_INET6) {
+	hints.ai_flags = AI_ADDRCONFIG;
-					// Rewrite the candidate
+	if (mTransportType == TransportType::Udp) {
-					char nodebuffer[MAX_NUMERICNODE_LEN];
+		hints.ai_socktype = SOCK_DGRAM;
-					char servbuffer[MAX_NUMERICSERV_LEN];
+		hints.ai_protocol = IPPROTO_UDP;
-					if (getnameinfo(p->ai_addr, socklen_t(p->ai_addrlen), nodebuffer,
+	} else if (mTransportType != TransportType::Unknown) {
-					                MAX_NUMERICNODE_LEN, servbuffer, MAX_NUMERICSERV_LEN,
+		hints.ai_socktype = SOCK_STREAM;
-					                NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
+		hints.ai_protocol = IPPROTO_TCP;
+	}
 
-						mAddress = nodebuffer;
+	if (mode == ResolveMode::Simple)
-						mPort = uint16_t(std::stoul(servbuffer));
+		hints.ai_flags |= AI_NUMERICHOST;
-						mFamily = p->ai_family == AF_INET6 ? Family::Ipv6 : Family::Ipv4;
 
-						const char sp{' '};
+	struct addrinfo *result = nullptr;
-						std::ostringstream oss;
+	if (getaddrinfo(mNode.c_str(), mService.c_str(), &hints, &result) == 0) {
-						oss << foundation << sp << component << sp << transport << sp << priority;
+		for (auto p = result; p; p = p->ai_next) {
-						oss << sp << nodebuffer << sp << servbuffer << sp << "typ" << sp << type;
+			if (p->ai_family == AF_INET || p->ai_family == AF_INET6) {
-						oss << left;
+				char nodebuffer[MAX_NUMERICNODE_LEN];
-						mCandidate = oss.str();
+				char servbuffer[MAX_NUMERICSERV_LEN];
+				if (getnameinfo(p->ai_addr, socklen_t(p->ai_addrlen), nodebuffer,
+				                MAX_NUMERICNODE_LEN, servbuffer, MAX_NUMERICSERV_LEN,
+				                NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
 
-						PLOG_VERBOSE << "Resolved candidate: " << mCandidate;
+					mAddress = nodebuffer;
-						break;
+					mPort = uint16_t(std::stoul(servbuffer));
-					}
+					mFamily = p->ai_family == AF_INET6 ? Family::Ipv6 : Family::Ipv4;
+					PLOG_VERBOSE << "Resolved candidate: " << mAddress << ' ' << mPort;
+					break;
 				}
 			}
-
-			freeaddrinfo(result);
 		}
+
+		freeaddrinfo(result);
 	}
 
 	return mFamily != Family::Unresolved;
 }
 
-string Candidate::candidate() const { return "candidate:" + mCandidate; }
+Candidate::Type Candidate::type() const { return mType; }
+
+Candidate::TransportType Candidate::transportType() const { return mTransportType; }
+
+uint32_t Candidate::priority() const { return mPriority; }
+
+string Candidate::candidate() const {
+	const char sp{' '};
+	std::ostringstream oss;
+	oss << "candidate:";
+	oss << mFoundation << sp << mComponent << sp << mTransportString << sp << mPriority << sp;
+	if (isResolved())
+		oss << mAddress << sp << mPort;
+	else
+		oss << mNode << sp << mService;
+
+	oss << sp << "typ" << sp << mTypeString;
+
+	if (!mTail.empty())
+		oss << sp << mTail;
+
+	return oss.str();
+}
 
 string Candidate::mid() const { return mMid.value_or("0"); }
 
@@ -186,14 +215,18 @@ Candidate::operator string() const {
 	return line.str();
 }
 
+bool Candidate::operator==(const Candidate &other) const {
+	return mFoundation == other.mFoundation;
+}
+
+bool Candidate::operator!=(const Candidate &other) const {
+	return mFoundation != other.mFoundation;
+}
+
 bool Candidate::isResolved() const { return mFamily != Family::Unresolved; }
 
 Candidate::Family Candidate::family() const { return mFamily; }
 
-Candidate::Type Candidate::type() const { return mType; }
-
-Candidate::TransportType Candidate::transportType() const { return mTransportType; }
-
 std::optional<string> Candidate::address() const {
 	return isResolved() ? std::make_optional(mAddress) : nullopt;
 }
@@ -202,10 +235,6 @@ std::optional<uint16_t> Candidate::port() const {
 	return isResolved() ? std::make_optional(mPort) : nullopt;
 }
 
-std::optional<uint32_t> Candidate::priority() const {
-	return isResolved() ? std::make_optional(mPriority) : nullopt;
-}
-
 } // namespace rtc
 
 std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate) {
@@ -217,11 +246,11 @@ std::ostream &operator<<(std::ostream &out, const rtc::Candidate::Type &type) {
 	case rtc::Candidate::Type::Host:
 		return out << "host";
 	case rtc::Candidate::Type::PeerReflexive:
-		return out << "peer_reflexive";
+		return out << "prflx";
 	case rtc::Candidate::Type::ServerReflexive:
-		return out << "server_reflexive";
+		return out << "srflx";
 	case rtc::Candidate::Type::Relayed:
-		return out << "relayed";
+		return out << "relay";
 	default:
 		return out << "unknown";
 	}

src/datachannel.cpp

@@ -306,7 +306,7 @@ void NegociatedDataChannel::processOpenMessage(message_ptr message) {
 	mLabel.assign(end, open.labelLength);
 	mProtocol.assign(end + open.labelLength, open.protocolLength);
 
-	mReliability->unordered = (open.reliabilityParameter & 0x80) != 0;
+	mReliability->unordered = (open.channelType & 0x80) != 0;
 	switch (open.channelType & 0x7F) {
 	case CHANNEL_PARTIAL_RELIABLE_REXMIT:
 		mReliability->type = Reliability::Type::Rexmit;

src/description.cpp

@@ -171,16 +171,27 @@ void Description::setFingerprint(string fingerprint) {
 	mFingerprint.emplace(std::move(fingerprint));
 }
 
+bool Description::hasCandidate(const Candidate &candidate) const {
+	for (const Candidate &other : mCandidates)
+		if (candidate == other)
+			return true;
+
+	return false;
+}
+
 void Description::addCandidate(Candidate candidate) {
 	candidate.hintMid(bundleMid());
+
+	for (const Candidate &other : mCandidates)
+		if (candidate == other)
+			return;
+
 	mCandidates.emplace_back(std::move(candidate));
 }
 
 void Description::addCandidates(std::vector<Candidate> candidates) {
-	for (Candidate candidate : candidates) {
+	for (Candidate candidate : candidates)
-		candidate.hintMid(bundleMid());
+		addCandidate(std::move(candidate));
-		mCandidates.emplace_back(std::move(candidate));
-	}
 }
 
 void Description::endCandidates() { mEnded = true; }

src/dtlssrtptransport.cpp

@@ -141,7 +141,14 @@ bool DtlsSrtpTransport::sendMedia(message_ptr message) {
 	}
 
 	message->resize(size);
-	return outgoing(message);
+
+	if (message->dscp == 0) { // Track might override the value
+		// Set recommended medium-priority DSCP value
+		// See https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18
+		message->dscp = 36; // AF42: Assured Forwarding class 4, medium drop probability
+	}
+
+	return Transport::outgoing(message); // bypass DTLS DSCP marking
 }
 
 void DtlsSrtpTransport::incoming(message_ptr message) {

src/dtlstransport.cpp

@@ -53,7 +53,7 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, certificate_ptr cer
                              verifier_callback verifierCallback, state_callback stateChangeCallback)
     : Transport(lower, std::move(stateChangeCallback)), mCertificate(certificate),
       mVerifierCallback(std::move(verifierCallback)),
-      mIsClient(lower->role() == Description::Role::Active) {
+      mIsClient(lower->role() == Description::Role::Active), mCurrentDscp(0) {
 
 	PLOG_DEBUG << "Initializing DTLS transport (GnuTLS)";
 
@@ -122,6 +122,7 @@ bool DtlsTransport::send(message_ptr message) {
 
 	PLOG_VERBOSE << "Send size=" << message->size();
 
+	mCurrentDscp = message->dscp;
 	ssize_t ret;
 	do {
 		ret = gnutls_record_send(mSession, message->data(), message->size());
@@ -143,6 +144,13 @@ void DtlsTransport::incoming(message_ptr message) {
 	mIncomingQueue.push(message);
 }
 
+bool DtlsTransport::outgoing(message_ptr message) {
+	if (message->dscp == 0)
+		message->dscp = mCurrentDscp;
+
+	return Transport::outgoing(std::move(message));
+}
+
 void DtlsTransport::postHandshake() {
 	// Dummy
 }
@@ -309,7 +317,7 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
                              verifier_callback verifierCallback, state_callback stateChangeCallback)
     : Transport(lower, std::move(stateChangeCallback)), mCertificate(certificate),
       mVerifierCallback(std::move(verifierCallback)),
-      mIsClient(lower->role() == Description::Role::Active) {
+      mIsClient(lower->role() == Description::Role::Active), mCurrentDscp(0) {
 	PLOG_DEBUG << "Initializing DTLS transport (OpenSSL)";
 
 	try {
@@ -405,6 +413,7 @@ bool DtlsTransport::send(message_ptr message) {
 
 	PLOG_VERBOSE << "Send size=" << message->size();
 
+	mCurrentDscp = message->dscp;
 	int ret = SSL_write(mSsl, message->data(), int(message->size()));
 	return openssl::check(mSsl, ret);
 }
@@ -419,6 +428,13 @@ void DtlsTransport::incoming(message_ptr message) {
 	mIncomingQueue.push(message);
 }
 
+bool DtlsTransport::outgoing(message_ptr message) {
+	if (message->dscp == 0)
+		message->dscp = mCurrentDscp;
+
+	return Transport::outgoing(std::move(message));
+}
+
 void DtlsTransport::postHandshake() {
 	// Dummy
 }

src/dtlstransport.hpp

@@ -53,6 +53,7 @@ public:
 
 protected:
 	virtual void incoming(message_ptr message) override;
+	virtual bool outgoing(message_ptr message) override;
 	virtual void postHandshake();
 	void runRecvLoop();
 
@@ -62,6 +63,7 @@ protected:
 
 	Queue<message_ptr> mIncomingQueue;
 	std::thread mRecvThread;
+	std::atomic<unsigned int> mCurrentDscp;
 
 #if USE_GNUTLS
 	gnutls_session_t mSession;

src/icetransport.cpp

@@ -222,8 +222,10 @@ bool IceTransport::send(message_ptr message) {
 }
 
 bool IceTransport::outgoing(message_ptr message) {
-	return juice_send(mAgent.get(), reinterpret_cast<const char *>(message->data()),
+	// Explicit Congestion Notification takes the least-significant 2 bits of the DS field
-	                  message->size()) >= 0;
+	int ds = int(message->dscp << 2);
+	return juice_send_diffserv(mAgent.get(), reinterpret_cast<const char *>(message->data()),
+	                           message->size(), ds) >= 0;
 }
 
 void IceTransport::changeGatheringState(GatheringState state) {
@@ -330,7 +332,7 @@ IceTransport::IceTransport(const Configuration &config, candidate_callback candi
       mMid("0"), mGatheringState(GatheringState::New),
       mCandidateCallback(std::move(candidateCallback)),
       mGatheringStateChangeCallback(std::move(gatheringStateChangeCallback)),
-      mNiceAgent(nullptr, nullptr), mMainLoop(nullptr, nullptr) {
+      mNiceAgent(nullptr, nullptr), mMainLoop(nullptr, nullptr), mOutgoingDscp(0) {
 
 	PLOG_DEBUG << "Initializing ICE transport (libnice)";
 
@@ -564,12 +566,14 @@ bool IceTransport::addRemoteCandidate(const Candidate &candidate) {
 		return false;
 
 	// Warning: the candidate string must start with "a=candidate:" and it must not end with a
-	// newline, else libnice will reject it.
+	// newline or whitespace, else libnice will reject it.
 	string sdp(candidate);
 	NiceCandidate *cand =
 	    nice_agent_parse_remote_candidate_sdp(mNiceAgent.get(), mStreamId, sdp.c_str());
-	if (!cand)
+	if (!cand) {
+		PLOG_WARNING << "Rejected ICE candidate: " << sdp;
 		return false;
+	}
 
 	GSList *list = g_slist_append(nullptr, cand);
 	int ret = nice_agent_set_remote_candidates(mNiceAgent.get(), mStreamId, 1, list);
@@ -615,6 +619,13 @@ bool IceTransport::send(message_ptr message) {
 }
 
 bool IceTransport::outgoing(message_ptr message) {
+	std::lock_guard lock(mOutgoingMutex);
+	if (mOutgoingDscp != message->dscp) {
+		mOutgoingDscp = message->dscp;
+		// Explicit Congestion Notification takes the least-significant 2 bits of the DS field
+		int ds = int(message->dscp << 2);
+		nice_agent_set_stream_tos(mNiceAgent.get(), mStreamId, ds); // ToS is the legacy name for DS
+	}
 	return nice_agent_send(mNiceAgent.get(), mStreamId, 1, message->size(),
 	                       reinterpret_cast<const char *>(message->data())) >= 0;
 }

src/icetransport.hpp

@@ -35,6 +35,7 @@
 #include <atomic>
 #include <chrono>
 #include <thread>
+#include <mutex>
 
 namespace rtc {
 
@@ -99,6 +100,8 @@ private:
 	std::unique_ptr<GMainLoop, void (*)(GMainLoop *)> mMainLoop;
 	std::thread mMainLoopThread;
 	guint mTimeoutId = 0;
+	std::mutex mOutgoingMutex;
+	unsigned int mOutgoingDscp;
 
 	static string AddressToString(const NiceAddress &addr);
 

src/peerconnection.cpp

@@ -266,10 +266,6 @@ void PeerConnection::setRemoteDescription(Description description) {
 	// Candidates will be added at the end, extract them for now
 	auto remoteCandidates = description.extractCandidates();
 	auto type = description.type();
-
-	auto iceTransport = initIceTransport();
-
-	iceTransport->setRemoteDescription(description);
 	processRemoteDescription(std::move(description));
 
 	changeSignalingState(newSignalingState);
@@ -279,8 +275,9 @@ void PeerConnection::setRemoteDescription(Description description) {
 		setLocalDescription(Description::Type::Answer);
 	} else {
 		// This is an answer
+		auto iceTransport = std::atomic_load(&mIceTransport);
 		auto sctpTransport = std::atomic_load(&mSctpTransport);
-		if (!sctpTransport && iceTransport->role() == Description::Role::Active) {
+		if (!sctpTransport && iceTransport && iceTransport->role() == Description::Role::Active) {
 			// Since we assumed passive role during DataChannel creation, we need to shift the
 			// stream numbers by one to shift them from odd to even.
 			std::unique_lock lock(mDataChannelsMutex); // we are going to swap the container
@@ -372,7 +369,7 @@ void PeerConnection::onSignalingStateChange(std::function<void(SignalingState st
 std::shared_ptr<Track> PeerConnection::addTrack(Description::Media description) {
 #if !RTC_ENABLE_MEDIA
 	if (mTracks.empty()) {
-		PLOG_WARNING << "Tracks will be inative (not compiled with SRTP support)";
+		PLOG_WARNING << "Tracks will be inative (not compiled with media support)";
 	}
 #endif
 
@@ -506,7 +503,7 @@ shared_ptr<DtlsTransport> PeerConnection::initDtlsTransport() {
 			    lower, certificate, verifierCallback,
 			    std::bind(&PeerConnection::forwardMedia, this, _1), stateChangeCallback);
 #else
-			PLOG_WARNING << "Ignoring media support (not compiled with SRTP support)";
+			PLOG_WARNING << "Ignoring media support (not compiled with media support)";
 #endif
 		}
 
@@ -875,7 +872,7 @@ void PeerConnection::incomingTrack(Description::Media description) {
 	std::unique_lock lock(mTracksMutex); // we are going to emplace
 #if !RTC_ENABLE_MEDIA
 	if (mTracks.empty()) {
-		PLOG_WARNING << "Tracks will be inative (not compiled with SRTP support)";
+		PLOG_WARNING << "Tracks will be inative (not compiled with media support)";
 	}
 #endif
 	if (mTracks.find(description.mid()) == mTracks.end()) {
@@ -1079,7 +1076,7 @@ void PeerConnection::processLocalCandidate(Candidate candidate) {
 	if (!mLocalDescription)
 		throw std::logic_error("Got a local candidate without local description");
 
-	candidate.resolve(Candidate::ResolveMode::Simple); // for proper SDP generation later
+	candidate.resolve(Candidate::ResolveMode::Simple);
 	mLocalDescription->addCandidate(candidate);
 
 	PLOG_VERBOSE << "Issuing local candidate: " << candidate;
@@ -1095,10 +1092,13 @@ void PeerConnection::processRemoteDescription(Description description) {
 		if (mRemoteDescription)
 			existingCandidates = mRemoteDescription->extractCandidates();
 
-		mRemoteDescription.emplace(std::move(description));
+		mRemoteDescription.emplace(description);
 		mRemoteDescription->addCandidates(std::move(existingCandidates));
 	}
 
+	auto iceTransport = initIceTransport();
+	iceTransport->setRemoteDescription(std::move(description));
+
 	if (description.hasApplication()) {
 		auto dtlsTransport = std::atomic_load(&mDtlsTransport);
 		auto sctpTransport = std::atomic_load(&mSctpTransport);
@@ -1109,28 +1109,40 @@ void PeerConnection::processRemoteDescription(Description description) {
 }
 
 void PeerConnection::processRemoteCandidate(Candidate candidate) {
-	std::lock_guard lock(mRemoteDescriptionMutex);
 	auto iceTransport = std::atomic_load(&mIceTransport);
-	if (!mRemoteDescription || !iceTransport)
+	{
-		throw std::logic_error("Got a remote candidate without remote description");
+		// Set as remote candidate
+		std::lock_guard lock(mRemoteDescriptionMutex);
+		if (!mRemoteDescription)
+			throw std::logic_error("Got a remote candidate without remote description");
 
-	candidate.hintMid(mRemoteDescription->bundleMid());
+		if (!iceTransport)
+			throw std::logic_error("Got a remote candidate without ICE transport");
 
-	if (candidate.resolve(Candidate::ResolveMode::Simple)) {
+		candidate.hintMid(mRemoteDescription->bundleMid());
-		iceTransport->addRemoteCandidate(candidate);
+
-	} else {
+		if (mRemoteDescription->hasCandidate(candidate))
-		// OK, we might need a lookup, do it asynchronously
+			return; // already in description, ignore
-		// We don't use the thread pool because we have no control on the timeout
+
-		weak_ptr<IceTransport> weakIceTransport{iceTransport};
+		candidate.resolve(Candidate::ResolveMode::Simple);
-		std::thread t([weakIceTransport, candidate]() mutable {
+		mRemoteDescription->addCandidate(candidate);
-			if (candidate.resolve(Candidate::ResolveMode::Lookup))
-				if (auto iceTransport = weakIceTransport.lock())
-					iceTransport->addRemoteCandidate(candidate);
-		});
-		t.detach();
 	}
 
-	mRemoteDescription->addCandidate(std::move(candidate));
+	if (candidate.isResolved()) {
+		iceTransport->addRemoteCandidate(std::move(candidate));
+	} else {
+		// We might need a lookup, do it asynchronously
+		// We don't use the thread pool because we have no control on the timeout
+		if (auto iceTransport = std::atomic_load(&mIceTransport)) {
+			weak_ptr<IceTransport> weakIceTransport{iceTransport};
+			std::thread t([weakIceTransport, candidate = std::move(candidate)]() mutable {
+				if (candidate.resolve(Candidate::ResolveMode::Lookup))
+					if (auto iceTransport = weakIceTransport.lock())
+						iceTransport->addRemoteCandidate(std::move(candidate));
+			});
+			t.detach();
+		}
+	}
 }
 
 void PeerConnection::triggerDataChannel(weak_ptr<DataChannel> weakDataChannel) {

src/sctptransport.cpp

@@ -88,7 +88,7 @@ void SctpTransport::Cleanup() {
 SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
                              message_callback recvCallback, amount_callback bufferedAmountCallback,
                              state_callback stateChangeCallback)
-    : Transport(lower, std::move(stateChangeCallback)), mPort(port),
+    : Transport(lower, std::move(stateChangeCallback)), mPort(port), mPendingRecvCount(0),
       mSendQueue(0, message_size_func), mBufferedAmountCallback(std::move(bufferedAmountCallback)) {
 	onRecv(recvCallback);
 
@@ -325,8 +325,16 @@ void SctpTransport::incoming(message_ptr message) {
 	usrsctp_conninput(this, message->data(), message->size(), 0);
 }
 
+bool SctpTransport::outgoing(message_ptr message) {
+	// Set recommended medium-priority DSCP value
+	// See https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18
+	message->dscp = 10; // AF11: Assured Forwarding class 1, low drop probability
+	return Transport::outgoing(std::move(message));
+}
+
 void SctpTransport::doRecv() {
 	std::lock_guard lock(mRecvMutex);
+	--mPendingRecvCount;
 	try {
 		while (true) {
 			const size_t bufferSize = 65536;
@@ -532,15 +540,17 @@ bool SctpTransport::safeFlush() {
 }
 
 void SctpTransport::handleUpcall() {
-	if(!mSock)
+	if (!mSock)
 		return;
 
 	PLOG_VERBOSE << "Handle upcall";
 
 	int events = usrsctp_get_events(mSock);
 
-	if (events & SCTP_EVENT_READ)
+	if (events & SCTP_EVENT_READ && mPendingRecvCount == 0) {
+		++mPendingRecvCount;
 		mProcessor.enqueue(&SctpTransport::doRecv, this);
+	}
 
 	if (events & SCTP_EVENT_WRITE)
 		mProcessor.enqueue(&SctpTransport::safeFlush, this);
@@ -551,6 +561,7 @@ int SctpTransport::handleWrite(byte *data, size_t len, uint8_t /*tos*/, uint8_t
 		std::unique_lock lock(mWriteMutex);
 		PLOG_VERBOSE << "Handle write, len=" << len;
 
+		auto message = make_message(data, data + len);
 		if (!outgoing(make_message(data, data + len)))
 			return -1;
 

src/sctptransport.hpp

@@ -77,6 +77,7 @@ private:
 	void shutdown();
 	void close();
 	void incoming(message_ptr message) override;
+	bool outgoing(message_ptr message) override;
 
 	void doRecv();
 	bool trySendQueue();
@@ -95,6 +96,7 @@ private:
 	struct socket *mSock;
 
 	Processor mProcessor;
+	std::atomic<int> mPendingRecvCount;
 	std::mutex mRecvMutex, mSendMutex;
 	Queue<message_ptr> mSendQueue;
 	std::map<uint16_t, size_t> mBufferedAmount;

src/track.cpp

@@ -45,12 +45,30 @@ void Track::close() {
 	setRtcpHandler(nullptr);
 }
 
-bool Track::send(message_variant data) { return outgoing(make_message(std::move(data))); }
+bool Track::send(message_variant data) {
+	if (mIsClosed)
+		throw std::runtime_error("Track is closed");
 
-bool Track::send(const byte *data, size_t size) {
+	auto direction = mMediaDescription.direction();
-	return outgoing(std::make_shared<Message>(data, data + size, Message::Binary));
+	if ((direction == Description::Direction::RecvOnly ||
+	     direction == Description::Direction::Inactive)) {
+		PLOG_WARNING << "Track media direction does not allow transmission, dropping";
+		return false;
+	}
+
+	auto message = make_message(std::move(data));
+
+	if (mRtcpHandler) {
+		message = mRtcpHandler->outgoing(message);
+		if (!message)
+			return false;
+	}
+
+	return outgoing(std::move(message));
 }
 
+bool Track::send(const byte *data, size_t size) { return send(binary(data, data + size)); }
+
 std::optional<message_variant> Track::receive() {
 	if (auto next = mRecvQueue.tryPop())
 		return to_variant(std::move(**next));
@@ -88,50 +106,10 @@ void Track::open(shared_ptr<DtlsSrtpTransport> transport) {
 }
 #endif
 
-bool Track::outgoing(message_ptr message) {
-
-	if (mRtcpHandler) {
-		message = mRtcpHandler->outgoing(message);
-		if (!message)
-			return false;
-	}
-
-	auto direction = mMediaDescription.direction();
-	if ((direction == Description::Direction::RecvOnly ||
-	     direction == Description::Direction::Inactive) &&
-	    message->type != Message::Control) {
-		PLOG_WARNING << "Track media direction does not allow transmission, dropping";
-		return false;
-	}
-
-	if (mIsClosed)
-		throw std::runtime_error("Track is closed");
-
-	if (message->size() > maxMessageSize())
-		throw std::runtime_error("Message size exceeds limit");
-
-#if RTC_ENABLE_MEDIA
-	auto transport = mDtlsSrtpTransport.lock();
-	if (!transport)
-		throw std::runtime_error("Track transport is not open");
-
-	return transport->sendMedia(message);
-#else
-	PLOG_WARNING << "Ignoring track send (not compiled with SRTP support)";
-	return false;
-#endif
-}
-
 void Track::incoming(message_ptr message) {
 	if (!message)
 		return;
 
-	if (mRtcpHandler) {
-		message = mRtcpHandler->incoming(message);
-		if (!message)
-			return;
-	}
-
 	auto direction = mMediaDescription.direction();
 	if ((direction == Description::Direction::SendOnly ||
 	     direction == Description::Direction::Inactive) &&
@@ -140,30 +118,46 @@ void Track::incoming(message_ptr message) {
 		return;
 	}
 
+	if (mRtcpHandler) {
+		message = mRtcpHandler->incoming(message);
+		if (!message)
+			return;
+	}
+
 	// Tail drop if queue is full
-	if (mRecvQueue.full())
+	if (mRecvQueue.full()) {
+		PLOG_WARNING << "Track incoming queue is full, dropping";
 		return;
+	}
 
 	mRecvQueue.push(message);
 	triggerAvailable(mRecvQueue.size());
 }
 
+bool Track::outgoing([[maybe_unused]] message_ptr message) {
+#if RTC_ENABLE_MEDIA
+	auto transport = mDtlsSrtpTransport.lock();
+	if (!transport)
+		throw std::runtime_error("Track transport is not open");
+
+	// Set recommended medium-priority DSCP value
+	// See https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18
+	if (mMediaDescription.type() == "audio")
+		message->dscp = 46; // EF: Expedited Forwarding
+	else
+		message->dscp = 36; // AF42: Assured Forwarding class 4, medium drop probability
+
+	return transport->sendMedia(message);
+#else
+	PLOG_WARNING << "Ignoring track send (not compiled with media support)";
+	return false;
+#endif
+}
+
 void Track::setRtcpHandler(std::shared_ptr<RtcpHandler> handler) {
 	mRtcpHandler = std::move(handler);
-	if (mRtcpHandler) {
+	if (mRtcpHandler)
-		mRtcpHandler->onOutgoing([&]([[maybe_unused]] const rtc::message_ptr &message) {
+		mRtcpHandler->onOutgoing(std::bind(&Track::outgoing, this, std::placeholders::_1));
-#if RTC_ENABLE_MEDIA
-			auto transport = mDtlsSrtpTransport.lock();
-			if (!transport)
-				throw std::runtime_error("Track transport is not open");
-
-			return transport->sendMedia(message);
-#else
-			PLOG_WARNING << "Ignoring track send (not compiled with SRTP support)";
-			return false;
-#endif
-		});
-	}
 }
 
 bool Track::requestKeyframe() {

src/transport.hpp

@@ -28,8 +28,6 @@
 
 namespace rtc {
 
-using namespace std::placeholders;
-
 class Transport {
 public:
 	enum class State { Disconnected, Connecting, Connected, Completed, Failed };
@@ -57,7 +55,7 @@ public:
 	void registerIncoming() {
 		if (mLower) {
 			PLOG_VERBOSE << "Registering incoming callback";
-			mLower->onRecv(std::bind(&Transport::incoming, this, _1));
+			mLower->onRecv(std::bind(&Transport::incoming, this, std::placeholders::_1));
 		}
 	}
 

src/websocket.cpp

@@ -36,6 +36,7 @@
 namespace rtc {
 
 using std::shared_ptr;
+using namespace std::placeholders;
 
 WebSocket::WebSocket(std::optional<Configuration> config)
     : mConfig(config ? std::move(*config) : Configuration()),

test/capi_connectivity.cpp

@@ -100,14 +100,48 @@ static void RTC_API messageCallback(int id, const char *message, int size, void
 
 static void RTC_API dataChannelCallback(int pc, int dc, void *ptr) {
 	Peer *peer = (Peer *)ptr;
-	peer->dc = dc;
+
-	peer->connected = true;
+	char label[256];
+	if (rtcGetDataChannelLabel(dc, label, 256) < 0) {
+		fprintf(stderr, "rtcGetDataChannelLabel failed\n");
+		return;
+	}
+
+	char protocol[256];
+	if (rtcGetDataChannelProtocol(dc, protocol, 256) < 0) {
+		fprintf(stderr, "rtcGetDataChannelProtocol failed\n");
+		return;
+	}
+
+	rtcReliability reliability;
+	if (rtcGetDataChannelReliability(dc, &reliability) < 0) {
+		fprintf(stderr, "rtcGetDataChannelReliability failed\n");
+		return;
+	}
+
+	printf("DataChannel %d: Received with label \"%s\" and protocol \"%s\"\n",
+	       peer == peer1 ? 1 : 2, label, protocol);
+
+	if (strcmp(label, "test") != 0) {
+		fprintf(stderr, "Wrong DataChannel label\n");
+		return;
+	}
+
+	if (strcmp(protocol, "protocol") != 0) {
+		fprintf(stderr, "Wrong DataChannel protocol\n");
+		return;
+	}
+
+	if (reliability.unordered == false) {
+		fprintf(stderr, "Wrong DataChannel reliability\n");
+		return;
+	}
+
 	rtcSetClosedCallback(dc, closedCallback);
 	rtcSetMessageCallback(dc, messageCallback);
 
-	char buffer[256];
+	peer->dc = dc;
-	if (rtcGetDataChannelLabel(dc, buffer, 256) >= 0)
+	peer->connected = true;
-		printf("DataChannel %d: Received with label \"%s\"\n", peer == peer1 ? 1 : 2, buffer);
 
 	const char *message = peer == peer1 ? "Hello from 1" : "Hello from 2";
 	rtcSendMessage(peer->dc, message, -1); // negative size indicates a null-terminated string
@@ -127,6 +161,7 @@ static Peer *createPeer(const rtcConfiguration *config) {
 	rtcSetLocalCandidateCallback(peer->pc, candidateCallback);
 	rtcSetStateChangeCallback(peer->pc, stateChangeCallback);
 	rtcSetGatheringStateChangeCallback(peer->pc, gatheringStateCallback);
+	rtcSetSignalingStateChangeCallback(peer->pc, signalingStateCallback);
 
 	return peer;
 }
@@ -173,7 +208,12 @@ int test_capi_connectivity_main() {
 		goto error;
 
 	// Peer 1: Create data channel
-	peer1->dc = rtcCreateDataChannel(peer1->pc, "test");
+	rtcDataChannelInit init;
+	memset(&init, 0, sizeof(init));
+	init.protocol = "protocol";
+	init.reliability.unordered = true;
+
+	peer1->dc = rtcCreateDataChannelEx(peer1->pc, "test", &init);
 	rtcSetOpenCallback(peer1->dc, openCallback);
 	rtcSetClosedCallback(peer1->dc, closedCallback);
 	rtcSetMessageCallback(peer1->dc, messageCallback);