Added .travis.yml

Manually handle OpenSSL handshake timeout

.github/workflows/build.yml

@@ -0,0 +1,21 @@
+name: Build and test
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v2
+    - name: install packages
+      run: sudo apt update && sudo apt install libgnutls28-dev nettle-dev
+    - name: submodules
+      run: git submodule update --init --recursive
+    - name: cmake
+      run: cmake -B build -DUSE_JUICE=1 -DUSE_GNUTLS=1
+    - name: make
+      run: (cd build; make)
+    - name: test
+      run: ./build/tests
+

.travis.yml

@@ -0,0 +1,4 @@
+os: osx
+osx_image: xcode11.3
+language: cpp
+script: cmake -B build -DUSE_JUICE=1 -DUSE_GNUTLS=1 && cd build && make && ./tests

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 3.7)
 project (libdatachannel
 	DESCRIPTION "WebRTC DataChannels Library"
-	VERSION 0.4.2
+	VERSION 0.4.9
 	LANGUAGES CXX)
 
 option(USE_GNUTLS "Use GnuTLS instead of OpenSSL" OFF)
@@ -16,6 +16,13 @@ endif()
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
 
+if(WIN32)
+	add_definitions(-DWIN32_LEAN_AND_MEAN)
+	if (MSYS OR MINGW)
+		add_definitions(-DSCTP_STDINT_INCLUDE=<stdint.h>)
+	endif()
+endif()
+
 set(LIBDATACHANNEL_SOURCES
 	${CMAKE_CURRENT_SOURCE_DIR}/src/candidate.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/certificate.cpp
@@ -25,13 +32,35 @@ set(LIBDATACHANNEL_SOURCES
 	${CMAKE_CURRENT_SOURCE_DIR}/src/description.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/dtlstransport.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/icetransport.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/init.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/log.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/peerconnection.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/rtc.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/src/sctptransport.cpp
 )
 
+set(LIBDATACHANNEL_HEADERS
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/candidate.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/channel.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/configuration.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/configuration.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/datachannel.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/description.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/include.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/init.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/log.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/message.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/peerconnection.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/queue.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/reliability.hpp
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/rtc.h
+	${CMAKE_CURRENT_SOURCE_DIR}/include/rtc/rtc.hpp
+)
+
 set(TESTS_SOURCES
     ${CMAKE_CURRENT_SOURCE_DIR}/test/main.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/connectivity.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/capi.cpp
 )
 
 set(TESTS_OFFERER_SOURCES
@@ -46,6 +75,10 @@ set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
 add_subdirectory(deps/usrsctp EXCLUDE_FROM_ALL)
+if (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
+    target_compile_options(usrsctp PRIVATE -Wno-error=format-truncation)
+	target_compile_options(usrsctp-static PRIVATE -Wno-error=format-truncation)
+endif()
 add_library(Usrsctp::Usrsctp ALIAS usrsctp)
 add_library(Usrsctp::UsrsctpStatic ALIAS usrsctp-static)
 
@@ -58,10 +91,7 @@ target_include_directories(datachannel PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/includ
 target_include_directories(datachannel PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include/rtc)
 target_include_directories(datachannel PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
 target_include_directories(datachannel PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/deps/plog/include)
-target_link_libraries(datachannel
+target_link_libraries(datachannel Threads::Threads Usrsctp::UsrsctpStatic)
-						Threads::Threads
-						Usrsctp::UsrsctpStatic
-						)
 
 add_library(datachannel-static STATIC EXCLUDE_FROM_ALL ${LIBDATACHANNEL_SOURCES})
 set_target_properties(datachannel-static PROPERTIES
@@ -72,10 +102,12 @@ target_include_directories(datachannel-static PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}
 target_include_directories(datachannel-static PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include/rtc)
 target_include_directories(datachannel-static PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
 target_include_directories(datachannel-static PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/deps/plog/include)
-target_link_libraries(datachannel-static
+target_link_libraries(datachannel-static Threads::Threads Usrsctp::UsrsctpStatic)
-						Threads::Threads
+
-						Usrsctp::UsrsctpStatic
+if(WIN32)
-						)
+	target_link_libraries(datachannel "wsock32" "ws2_32") # winsock2
+	target_link_libraries(datachannel-static "wsock32" "ws2_32") # winsock2
+endif()
 
 if (USE_GNUTLS)
 	find_package(GnuTLS REQUIRED)
@@ -116,6 +148,9 @@ endif()
 add_library(LibDataChannel::LibDataChannel ALIAS datachannel)
 add_library(LibDataChannel::LibDataChannelStatic ALIAS datachannel-static)
 
+install(TARGETS datachannel LIBRARY DESTINATION lib)
+install(FILES ${LIBDATACHANNEL_HEADERS} DESTINATION include/rtc)
+
 # Main Test
 add_executable(datachannel-tests ${TESTS_SOURCES})
 set_target_properties(datachannel-tests PROPERTIES
@@ -138,6 +173,6 @@ add_executable(datachannel-answerer ${TESTS_ANSWERER_SOURCES})
 set_target_properties(datachannel-answerer PROPERTIES
 	VERSION ${PROJECT_VERSION}
 	CXX_STANDARD 17)
-set_target_properties(datachannel-answerer PROPERTIES OUTPUT_NAME datachannel)
+set_target_properties(datachannel-answerer PROPERTIES OUTPUT_NAME answerer)
 target_link_libraries(datachannel-answerer datachannel)
 

Makefile

@@ -5,7 +5,7 @@ CXX=$(CROSS)g++
 AR=$(CROSS)ar
 RM=rm -f
 CXXFLAGS=-std=c++17
-CPPFLAGS=-O2 -pthread -fPIC -Wall -Wno-address-of-packed-member
+CPPFLAGS=-O2 -pthread -fPIC -Wall
 LDFLAGS=-pthread
 LIBS=
 LOCALLIBS=libusrsctp.a
@@ -44,6 +44,9 @@ LDLIBS+=$(LOCALLIBS) $(shell pkg-config --libs $(LIBS))
 SRCS=$(shell printf "%s " src/*.cpp)
 OBJS=$(subst .cpp,.o,$(SRCS))
 
+TEST_SRCS=$(shell printf "%s " test/*.cpp)
+TEST_OBJS=$(subst .cpp,.o,$(TEST_SRCS))
+
 all: $(NAME).a $(NAME).so tests
 
 src/%.o: src/%.cpp
@@ -60,8 +63,8 @@ $(NAME).a: $(OBJS)
 $(NAME).so: $(LOCALLIBS) $(OBJS)
 	$(CXX) $(LDFLAGS) -shared -o $@ $(OBJS) $(LDLIBS)
 
-tests: $(NAME).a test/main.o
+tests: $(NAME).a $(TEST_OBJS)
-	$(CXX) $(LDFLAGS) -o $@ test/main.o $(NAME).a $(LDLIBS)
+	$(CXX) $(LDFLAGS) -o $@ $(TEST_OBJS) $(NAME).a $(LDLIBS)
 
 clean:
 	-$(RM) include/rtc/*.d *.d
@@ -83,7 +86,7 @@ dist-clean: clean
 libusrsctp.a:
 	cd $(USRSCTP_DIR) && \
 		./bootstrap && \
-		./configure --enable-static --disable-debug CFLAGS="$(CPPFLAGS)" && \
+		./configure --enable-static --disable-debug CFLAGS="$(CPPFLAGS) -Wno-error=format-truncation" && \
 		make
 	cp $(USRSCTP_DIR)/usrsctplib/.libs/libusrsctp.a .
 

README.md

@@ -1,6 +1,6 @@
 # libdatachannel - C/C++ WebRTC DataChannels
 
-libdatachannel is a standalone implementation of WebRTC DataChannels in C++17 with C bindings. It enables direct connectivity between native applications and web browsers without the pain of importing the entire WebRTC stack. Its API is modelled as a simplified version of the JavaScript WebRTC API, in order to ease the design of cross-environment applications.
+libdatachannel is a standalone implementation of WebRTC DataChannels in C++17 with C bindings for POSIX platforms and Microsoft Windows. It enables direct connectivity between native applications and web browsers without the pain of importing the entire WebRTC stack. Its API is modelled as a simplified version of the JavaScript WebRTC API, in order to ease the design of cross-environment applications.
 
 This projet is originally inspired by [librtcdcpp](https://github.com/chadnickbok/librtcdcpp), however it is a complete rewrite from scratch, because the messy architecture of librtcdcpp made solving its implementation issues difficult.
 
@@ -79,11 +79,11 @@ MY_ON_RECV_CANDIDATE_FROM_REMOTE([pc](string candidate, string mid) {
 ### Observe the PeerConnection state
 
 ```cpp
-pc->onStateChanged([](PeerConnection::State state) {
+pc->onStateChange([](PeerConnection::State state) {
     cout << "State: " << state << endl;
 });
 
-pc->onGatheringStateChanged([](PeerConnection::GatheringState state) {
+pc->onGatheringStateChange([](PeerConnection::GatheringState state) {
     cout << "Gathering state: " << state << endl;
 });
 
@@ -114,5 +114,7 @@ pc->onDataChannel([&dc](shared_ptr<rtc::DataChannel> incoming) {
 
 ```
 
-See [test/main.cpp](https://github.com/paullouisageneau/libdatachannel/blob/master/test/main.cpp) for a complete local connection example.
+See [test/connectivity.cpp](https://github.com/paullouisageneau/libdatachannel/blob/master/test/connectivity.cpp) for a complete local connection example.
+
+See [test/cpai.cpp](https://github.com/paullouisageneau/libdatachannel/blob/master/test/capi.cpp) for a C API example.
 

include/rtc/candidate.hpp

@@ -25,6 +25,15 @@
 
 namespace rtc {
 
+enum class CandidateType { Host = 0, ServerReflexive, PeerReflexive, Relayed };
+enum class CandidateTransportType { Udp = 0, TcpActive, TcpPassive, TcpSo };
+struct CandidateInfo {
+	string address;
+	int port;
+	CandidateType type;
+	CandidateTransportType transportType;
+};
+
 class Candidate {
 public:
 	Candidate(string candidate, string mid = "");
@@ -46,6 +55,8 @@ private:
 } // namespace rtc
 
 std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate);
+std::ostream &operator<<(std::ostream &out, const rtc::CandidateType &type);
+std::ostream &operator<<(std::ostream &out, const rtc::CandidateTransportType &transportType);
 
 #endif
 

include/rtc/channel.hpp

@@ -31,12 +31,10 @@ class Channel {
 public:
 	virtual void close() = 0;
 	virtual bool send(const std::variant<binary, string> &data) = 0; // returns false if buffered
-	virtual std::optional<std::variant<binary, string>> receive() = 0; // only if onMessage unset
 
 	virtual bool isOpen() const = 0;
 	virtual bool isClosed() const = 0;
-
+	virtual size_t maxMessageSize() const; // max message size in a call to send
-	virtual size_t availableAmount() const; // total size available to receive
 	virtual size_t bufferedAmount() const; // total size buffered to send
 
 	void onOpen(std::function<void()> callback);
@@ -47,11 +45,14 @@ public:
 	void onMessage(std::function<void(const binary &data)> binaryCallback,
 	               std::function<void(const string &data)> stringCallback);
 
-	void onAvailable(std::function<void()> callback);
 	void onBufferedAmountLow(std::function<void()> callback);
-
 	void setBufferedAmountLowThreshold(size_t amount);
 
+	// Extended API
+	virtual std::optional<std::variant<binary, string>> receive() = 0; // only if onMessage unset
+	virtual size_t availableAmount() const; // total size available to receive
+	void onAvailable(std::function<void()> callback);
+
 protected:
 	virtual void triggerOpen();
 	virtual void triggerClosed();
@@ -59,6 +60,8 @@ protected:
 	virtual void triggerAvailable(size_t count);
 	virtual void triggerBufferedAmount(size_t amount);
 
+	void resetCallbacks();
+
 private:
 	synchronized_callback<> mOpenCallback;
 	synchronized_callback<> mClosedCallback;

include/rtc/configuration.hpp

@@ -51,8 +51,22 @@ struct IceServer {
 	RelayType relayType;
 };
 
+struct ProxyServer {
+	enum class Type { None = 0, Socks5, Http, Last = Http };
+
+	ProxyServer(Type type_, string ip_, uint16_t port_, string username_ = "",
+	            string password_ = "");
+
+	Type type;
+	string ip;
+	uint16_t port;
+	string username;
+	string password;
+};
+
 struct Configuration {
 	std::vector<IceServer> iceServers;
+	std::optional<ProxyServer> proxyServer;
 	bool enableIceTcp = false;
 	uint16_t portRangeBegin = 1024;
 	uint16_t portRangeEnd = 65535;

include/rtc/datachannel.hpp

@@ -38,42 +38,40 @@ class PeerConnection;
 
 class DataChannel : public std::enable_shared_from_this<DataChannel>, public Channel {
 public:
-	DataChannel(std::shared_ptr<PeerConnection> pc, unsigned int stream, string label,
+	DataChannel(std::weak_ptr<PeerConnection> pc, unsigned int stream, string label,
 	            string protocol, Reliability reliability);
-	DataChannel(std::shared_ptr<PeerConnection> pc, std::shared_ptr<SctpTransport> transport,
+	DataChannel(std::weak_ptr<PeerConnection> pc, std::weak_ptr<SctpTransport> transport,
 	            unsigned int stream);
 	~DataChannel();
 
-	void close(void) override;
-
-	bool send(const std::variant<binary, string> &data) override;
-	bool send(const byte *data, size_t size);
-
-	template <typename Buffer> bool sendBuffer(const Buffer &buf);
-	template <typename Iterator> bool sendBuffer(Iterator first, Iterator last);
-
-	std::optional<std::variant<binary, string>> receive() override;
-
-	bool isOpen(void) const override;
-	bool isClosed(void) const override;
-	size_t availableAmount() const override;
-
-	size_t maxMessageSize() const;  // maximum message size in a call to send or sendBuffer
-
 	unsigned int stream() const;
 	string label() const;
 	string protocol() const;
 	Reliability reliability() const;
 
+	void close(void) override;
+	bool send(const std::variant<binary, string> &data) override;
+	bool send(const byte *data, size_t size);
+	template <typename Buffer> bool sendBuffer(const Buffer &buf);
+	template <typename Iterator> bool sendBuffer(Iterator first, Iterator last);
+
+	bool isOpen(void) const override;
+	bool isClosed(void) const override;
+	size_t maxMessageSize() const override;
+
+	// Extended API
+	size_t availableAmount() const override;
+	std::optional<std::variant<binary, string>> receive() override;
+
 private:
 	void remoteClose();
-	void open(std::shared_ptr<SctpTransport> sctpTransport);
+	void open(std::shared_ptr<SctpTransport> transport);
 	bool outgoing(mutable_message_ptr message);
 	void incoming(message_ptr message);
 	void processOpenMessage(message_ptr message);
 
-	const std::shared_ptr<PeerConnection> mPeerConnection;
+	const std::weak_ptr<PeerConnection> mPeerConnection;
-	std::shared_ptr<SctpTransport> mSctpTransport;
+	std::weak_ptr<SctpTransport> mSctpTransport;
 
 	unsigned int mStream;
 	string mLabel;

include/rtc/description.hpp

@@ -35,6 +35,7 @@ public:
 	enum class Role { ActPass = 0, Passive = 1, Active = 2 };
 
 	Description(const string &sdp, const string &typeString = "");
+	Description(const string &sdp, Type type);
 	Description(const string &sdp, Type type, Role role);
 
 	Type type() const;
@@ -47,6 +48,7 @@ public:
 	std::optional<size_t> maxMessageSize() const;
 	bool trickleEnabled() const;
 
+	void hintType(Type type);
 	void setFingerprint(string fingerprint);
 	void setSctpPort(uint16_t port);
 	void setMaxMessageSize(size_t size);

include/rtc/include.hpp

@@ -19,6 +19,14 @@
 #ifndef RTC_INCLUDE_H
 #define RTC_INCLUDE_H
 
+#ifdef _WIN32
+#ifndef _WIN32_WINNT
+#define _WIN32_WINNT 0x0602
+#endif
+#endif
+
+#include "log.hpp"
+
 #include <cstddef>
 #include <functional>
 #include <memory>
@@ -27,9 +35,6 @@
 #include <string>
 #include <vector>
 
-#include "plog/Appenders/ColorConsoleAppender.h"
-#include "plog/Log.h"
-
 namespace rtc {
 
 using std::byte;
@@ -44,8 +49,6 @@ using std::uint32_t;
 using std::uint64_t;
 using std::uint8_t;
 
-// Constants
-
 const size_t MAX_NUMERICNODE_LEN = 48; // Max IPv6 string representation length
 const size_t MAX_NUMERICSERV_LEN = 6;  // Max port string representation length
 
@@ -53,29 +56,6 @@ const uint16_t DEFAULT_SCTP_PORT = 5000; // SCTP port to use by default
 const size_t DEFAULT_MAX_MESSAGE_SIZE = 65536;    // Remote max message size if not specified in SDP
 const size_t LOCAL_MAX_MESSAGE_SIZE = 256 * 1024; // Local max message size
 
-// Log
-
-enum class LogLevel { // Don't change, it must match plog severity
-	None = 0,
-	Fatal = 1,
-	Error = 2,
-	Warning = 3,
-	Info = 4,
-	Debug = 5,
-	Verbose = 6
-};
-
-inline void InitLogger(plog::Severity severity, plog::IAppender *appender = nullptr) {
-	static plog::ColorConsoleAppender<plog::TxtFormatter> consoleAppender;
-	if (!appender)
-		appender = &consoleAppender;
-	plog::init(severity, appender);
-	PLOG_DEBUG << "Logger initialized";
-}
-
-inline void InitLogger(LogLevel level) { InitLogger(static_cast<plog::Severity>(level)); }
-
-// Utils
 
 template <class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
 template <class... Ts> overloaded(Ts...)->overloaded<Ts...>;
@@ -83,6 +63,7 @@ template <class... Ts> overloaded(Ts...)->overloaded<Ts...>;
 template <typename... P> class synchronized_callback {
 public:
 	synchronized_callback() = default;
+	synchronized_callback(std::function<void(P...)> func) { *this = std::move(func); };
 	~synchronized_callback() { *this = nullptr; }
 
 	synchronized_callback &operator=(std::function<void(P...)> func) {

include/rtc/init.hpp

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2020 Paul-Louis Ageneau
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef RTC_INIT_H
+#define RTC_INIT_H
+
+#include "include.hpp"
+
+#include <mutex>
+
+namespace rtc {
+
+class Init;
+using init_token = std::shared_ptr<Init>;
+
+class Init {
+public:
+	static init_token Token();
+	static void Cleanup();
+
+	~Init();
+
+private:
+	Init();
+
+	static std::weak_ptr<Init> Weak;
+	static init_token Global;
+	static std::mutex Mutex;
+};
+
+inline void Cleanup() { Init::Cleanup(); }
+
+} // namespace rtc
+
+#endif

include/rtc/log.hpp

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) 2019 Paul-Louis Ageneau
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef RTC_LOG_H
+#define RTC_LOG_H
+
+#include "plog/Log.h"
+
+namespace rtc {
+
+enum class LogLevel { // Don't change, it must match plog severity
+	None = 0,
+	Fatal = 1,
+	Error = 2,
+	Warning = 3,
+	Info = 4,
+	Debug = 5,
+	Verbose = 6
+};
+
+void InitLogger(LogLevel level);
+void InitLogger(plog::Severity severity, plog::IAppender *appender = nullptr);
+}
+
+#endif

include/rtc/peerconnection.hpp

@@ -24,6 +24,7 @@
 #include "datachannel.hpp"
 #include "description.hpp"
 #include "include.hpp"
+#include "init.hpp"
 #include "message.hpp"
 #include "reliability.hpp"
 #include "rtc.hpp"
@@ -32,6 +33,7 @@
 #include <functional>
 #include <list>
 #include <mutex>
+#include <shared_mutex>
 #include <thread>
 #include <unordered_map>
 
@@ -50,14 +52,13 @@ public:
 		Connected = RTC_CONNECTED,
 		Disconnected = RTC_DISCONNECTED,
 		Failed = RTC_FAILED,
-		Closed = RTC_CLOSED,
+		Closed = RTC_CLOSED
-		Destroying = RTC_DESTROYING
 	};
 
 	enum class GatheringState : int {
 		New = RTC_GATHERING_NEW,
 		InProgress = RTC_GATHERING_INPROGRESS,
-		Complete = RTC_GATHERING_COMPLETE,
+		Complete = RTC_GATHERING_COMPLETE
 	};
 
 	PeerConnection(void);
@@ -86,15 +87,31 @@ public:
 	void onStateChange(std::function<void(State state)> callback);
 	void onGatheringStateChange(std::function<void(GatheringState state)> callback);
 
+	bool getSelectedCandidatePair(CandidateInfo *local, CandidateInfo *remote);
+
+	// Stats
+	void clearStats();
+	size_t bytesSent();
+	size_t bytesReceived();
+	std::optional<std::chrono::milliseconds> rtt();
+
 private:
+	init_token mInitToken = Init::Token();
+
 	std::shared_ptr<IceTransport> initIceTransport(Description::Role role);
 	std::shared_ptr<DtlsTransport> initDtlsTransport();
 	std::shared_ptr<SctpTransport> initSctpTransport();
+	void closeTransports();
 
 	void endLocalCandidates();
 	bool checkFingerprint(const std::string &fingerprint) const;
 	void forwardMessage(message_ptr message);
 	void forwardBufferedAmount(uint16_t stream, size_t amount);
+
+	std::shared_ptr<DataChannel> emplaceDataChannel(Description::Role role, const string &label,
+	                                                const string &protocol,
+	                                                const Reliability &reliability);
+	std::shared_ptr<DataChannel> findDataChannel(uint16_t stream);
 	void iterateDataChannels(std::function<void(std::shared_ptr<DataChannel> channel)> func);
 	void openDataChannels();
 	void closeDataChannels();
@@ -103,8 +120,10 @@ private:
 	void processLocalDescription(Description description);
 	void processLocalCandidate(Candidate candidate);
 	void triggerDataChannel(std::weak_ptr<DataChannel> weakDataChannel);
-	void changeState(State state);
+	bool changeState(State state);
-	void changeGatheringState(GatheringState state);
+	bool changeGatheringState(GatheringState state);
+
+	void resetCallbacks();
 
 	const Configuration mConfig;
 	const std::shared_ptr<Certificate> mCertificate;
@@ -115,9 +134,9 @@ private:
 	std::shared_ptr<IceTransport> mIceTransport;
 	std::shared_ptr<DtlsTransport> mDtlsTransport;
 	std::shared_ptr<SctpTransport> mSctpTransport;
-	std::recursive_mutex mInitMutex;
 
 	std::unordered_map<unsigned int, std::weak_ptr<DataChannel>> mDataChannels;
+	std::shared_mutex mDataChannelsMutex;
 
 	std::atomic<State> mState;
 	std::atomic<GatheringState> mGatheringState;

include/rtc/queue.hpp

@@ -41,12 +41,10 @@ public:
 	bool empty() const;
 	size_t size() const;   // elements
 	size_t amount() const; // amount
-	void push(const T &element);
+	void push(T element);
-	void push(T &&element);
 	std::optional<T> pop();
 	std::optional<T> peek();
-	void wait();
+	bool wait(const std::optional<std::chrono::milliseconds> &duration = nullopt);
-	void wait(const std::chrono::milliseconds &duration);
 
 private:
 	const size_t mLimit;
@@ -88,9 +86,7 @@ template <typename T> size_t Queue<T>::amount() const {
 	return mAmount;
 }
 
-template <typename T> void Queue<T>::push(const T &element) { push(T{element}); }
+template <typename T> void Queue<T>::push(T element) {
-
-template <typename T> void Queue<T>::push(T &&element) {
 	std::unique_lock lock(mMutex);
 	mPushCondition.wait(lock, [this]() { return !mLimit || mQueue.size() < mLimit || mStopping; });
 	if (!mStopping) {
@@ -122,14 +118,14 @@ template <typename T> std::optional<T> Queue<T>::peek() {
 	}
 }
 
-template <typename T> void Queue<T>::wait() {
+template <typename T>
+bool Queue<T>::wait(const std::optional<std::chrono::milliseconds> &duration) {
 	std::unique_lock lock(mMutex);
-	mPopCondition.wait(lock, [this]() { return !mQueue.empty() || mStopping; });
+	if (duration)
-}
+		mPopCondition.wait_for(lock, *duration, [this]() { return !mQueue.empty() || mStopping; });
-
+	else
-template <typename T> void Queue<T>::wait(const std::chrono::milliseconds &duration) {
+		mPopCondition.wait(lock, [this]() { return !mQueue.empty() || mStopping; });
-	std::unique_lock lock(mMutex);
+	return !mStopping;
-	mPopCondition.wait_for(lock, duration, [this]() { return !mQueue.empty() || mStopping; });
 }
 
 } // namespace rtc

include/rtc/rtc.h

@@ -23,6 +23,8 @@
 extern "C" {
 #endif
 
+#include <stdint.h>
+
 // libdatachannel C API
 
 typedef enum {
@@ -31,15 +33,14 @@ typedef enum {
 	RTC_CONNECTED = 2,
 	RTC_DISCONNECTED = 3,
 	RTC_FAILED = 4,
-	RTC_CLOSED = 5,
+	RTC_CLOSED = 5
-	RTC_DESTROYING = 6 // internal
+} rtcState;
-} rtc_state_t;
 
 typedef enum {
 	RTC_GATHERING_NEW = 0,
 	RTC_GATHERING_INPROGRESS = 1,
 	RTC_GATHERING_COMPLETE = 2
-} rtc_gathering_state_t;
+} rtcGatheringState;
 
 // Don't change, it must match plog severity
 typedef enum {
@@ -50,32 +51,69 @@ typedef enum {
 	RTC_LOG_INFO = 4,
 	RTC_LOG_DEBUG = 5,
 	RTC_LOG_VERBOSE = 6
-} rtc_log_level_t;
+} rtcLogLevel;
 
-void rtcInitLogger(rtc_log_level_t level);
+typedef struct {
+	const char **iceServers;
+	int iceServersCount;
+	uint16_t portRangeBegin;
+	uint16_t portRangeEnd;
+} rtcConfiguration;
 
-int rtcCreatePeerConnection(const char **iceServers, int iceServersCount);
+typedef void (*dataChannelCallbackFunc)(int dc, void *ptr);
-void rtcDeletePeerConnection(int pc);
+typedef void (*descriptionCallbackFunc)(const char *sdp, const char *type, void *ptr);
-int rtcCreateDataChannel(int pc, const char *label);
+typedef void (*candidateCallbackFunc)(const char *cand, const char *mid, void *ptr);
-void rtcDeleteDataChannel(int dc);
+typedef void (*stateChangeCallbackFunc)(rtcState state, void *ptr);
-void rtcSetDataChannelCallback(int pc, void (*dataChannelCallback)(int, void *));
+typedef void (*gatheringStateCallbackFunc)(rtcGatheringState state, void *ptr);
-void rtcSetLocalDescriptionCallback(int pc, void (*descriptionCallback)(const char *, const char *,
+typedef void (*openCallbackFunc)(void *ptr);
-                                                                        void *));
+typedef void (*closedCallbackFunc)(void *ptr);
-void rtcSetLocalCandidateCallback(int pc,
+typedef void (*errorCallbackFunc)(const char *error, void *ptr);
-                                  void (*candidateCallback)(const char *, const char *, void *));
+typedef void (*messageCallbackFunc)(const char *message, int size, void *ptr);
-void rtcSetStateChangeCallback(int pc, void (*stateCallback)(rtc_state_t state, void *));
+typedef void (*bufferedAmountLowCallbackFunc)(void *ptr);
-void rtcSetGatheringStateChangeCallback(int pc,
+typedef void (*availableCallbackFunc)(void *ptr);
-                                        void (*gatheringStateCallback)(rtc_gathering_state_t state,
+
-                                                                       void *));
+// Log
-void rtcSetRemoteDescription(int pc, const char *sdp, const char *type);
+void rtcInitLogger(rtcLogLevel level);
-void rtcAddRemoteCandidate(int pc, const char *candidate, const char *mid);
+
-int rtcGetDataChannelLabel(int dc, char *data, int size);
+// User pointer
-void rtcSetOpenCallback(int dc, void (*openCallback)(void *));
-void rtcSetErrorCallback(int dc, void (*errorCallback)(const char *, void *));
-void rtcSetMessageCallback(int dc, void (*messageCallback)(const char *, int, void *));
-int rtcSendMessage(int dc, const char *data, int size);
 void rtcSetUserPointer(int i, void *ptr);
 
+// PeerConnection
+int rtcCreatePeerConnection(const rtcConfiguration *config);
+int rtcDeletePeerConnection(int pc);
+
+int rtcSetDataChannelCallback(int pc, dataChannelCallbackFunc cb);
+int rtcSetLocalDescriptionCallback(int pc, descriptionCallbackFunc cb);
+int rtcSetLocalCandidateCallback(int pc, candidateCallbackFunc cb);
+int rtcSetStateChangeCallback(int pc, stateChangeCallbackFunc cb);
+int rtcSetGatheringStateChangeCallback(int pc, gatheringStateCallbackFunc cb);
+
+int rtcSetRemoteDescription(int pc, const char *sdp, const char *type);
+int rtcAddRemoteCandidate(int pc, const char *cand, const char *mid);
+
+int rtcGetLocalAddress(int pc, char *buffer, int size);
+int rtcGetRemoteAddress(int pc, char *buffer, int size);
+
+// DataChannel
+int rtcCreateDataChannel(int pc, const char *label);
+int rtcDeleteDataChannel(int dc);
+
+int rtcGetDataChannelLabel(int dc, char *buffer, int size);
+int rtcSetOpenCallback(int dc, openCallbackFunc cb);
+int rtcSetClosedCallback(int dc, closedCallbackFunc cb);
+int rtcSetErrorCallback(int dc, errorCallbackFunc cb);
+int rtcSetMessageCallback(int dc, messageCallbackFunc cb);
+int rtcSendMessage(int dc, const char *data, int size);
+
+int rtcGetBufferedAmount(int dc); // total size buffered to send
+int rtcSetBufferedAmountLowThreshold(int dc, int amount);
+int rtcSetBufferedAmountLowCallback(int dc, bufferedAmountLowCallbackFunc cb);
+
+// DataChannel extended API
+int rtcGetAvailableAmount(int dc); // total size available to receive
+int rtcSetAvailableCallback(int dc, availableCallbackFunc cb);
+int rtcReceiveMessage(int dc, char *buffer, int *size);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

include/rtc/rtc.hpp

@@ -17,6 +17,10 @@
  */
 
 // C++ API
+#include "include.hpp"
+#include "init.hpp" // for rtc::Cleanup()
+#include "log.hpp"
+//
 #include "datachannel.hpp"
 #include "peerconnection.hpp"
 

src/candidate.cpp

@@ -22,8 +22,14 @@
 #include <array>
 #include <sstream>
 
+#ifdef _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
 #include <netdb.h>
 #include <sys/socket.h>
+#endif
+
 #include <sys/types.h>
 
 using std::array;
@@ -125,3 +131,33 @@ Candidate::operator string() const {
 std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate) {
 	return out << std::string(candidate);
 }
+
+std::ostream &operator<<(std::ostream &out, const rtc::CandidateType &type) {
+	switch (type) {
+	case rtc::CandidateType::Host:
+		return out << "Host";
+	case rtc::CandidateType::PeerReflexive:
+		return out << "PeerReflexive";
+	case rtc::CandidateType::Relayed:
+		return out << "Relayed";
+	case rtc::CandidateType::ServerReflexive:
+		return out << "ServerReflexive";
+	default:
+		return out << "Unknown";
+	}
+}
+
+std::ostream &operator<<(std::ostream &out, const rtc::CandidateTransportType &transportType) {
+	switch (transportType) {
+	case rtc::CandidateTransportType::TcpActive:
+		return out << "TcpActive";
+	case rtc::CandidateTransportType::TcpPassive:
+		return out << "TcpPassive";
+	case rtc::CandidateTransportType::TcpSo:
+		return out << "TcpSo";
+	case rtc::CandidateTransportType::Udp:
+		return out << "Udp";
+	default:
+		return out << "Unknown";
+	}
+}

src/certificate.cpp

@@ -245,13 +245,6 @@ shared_ptr<Certificate> make_certificate(const string &commonName) {
 	if (auto it = cache.find(commonName); it != cache.end())
 		return it->second;
 
-	if (cache.empty()) {
-		// This is the first call to OpenSSL
-		OPENSSL_init_ssl(0, NULL);
-		SSL_load_error_strings();
-		ERR_load_crypto_strings();
-	}
-
 	shared_ptr<X509> x509(X509_new(), X509_free);
 	shared_ptr<EVP_PKEY> pkey(EVP_PKEY_new(), EVP_PKEY_free);
 

src/channel.cpp

@@ -18,10 +18,14 @@
 
 #include "channel.hpp"
 
-namespace {}
-
 namespace rtc {
 
+size_t Channel::maxMessageSize() const { return DEFAULT_MAX_MESSAGE_SIZE; }
+
+size_t Channel::bufferedAmount() const { return mBufferedAmount; }
+
+size_t Channel::availableAmount() const { return 0; }
+
 void Channel::onOpen(std::function<void()> callback) {
 	mOpenCallback = callback;
 }
@@ -49,20 +53,16 @@ void Channel::onMessage(std::function<void(const binary &data)> binaryCallback,
 	});
 }
 
-void Channel::onAvailable(std::function<void()> callback) {
-	mAvailableCallback = callback;
-}
-
 void Channel::onBufferedAmountLow(std::function<void()> callback) {
 	mBufferedAmountLowCallback = callback;
 }
 
-size_t Channel::availableAmount() const { return 0; }
-
-size_t Channel::bufferedAmount() const { return mBufferedAmount; }
-
 void Channel::setBufferedAmountLowThreshold(size_t amount) { mBufferedAmountLowThreshold = amount; }
 
+void Channel::onAvailable(std::function<void()> callback) {
+	mAvailableCallback = callback;
+}
+
 void Channel::triggerOpen() { mOpenCallback(); }
 
 void Channel::triggerClosed() { mClosedCallback(); }
@@ -88,5 +88,14 @@ void Channel::triggerBufferedAmount(size_t amount) {
 		mBufferedAmountLowCallback();
 }
 
+void Channel::resetCallbacks() {
+	mOpenCallback = nullptr;
+	mClosedCallback = nullptr;
+	mErrorCallback = nullptr;
+	mMessageCallback = nullptr;
+	mAvailableCallback = nullptr;
+	mBufferedAmountLowCallback = nullptr;
+}
+
 } // namespace rtc
 

src/configuration.cpp

@@ -38,16 +38,17 @@ IceServer::IceServer(const string &url) {
 	});
 
 	string scheme = opt[2].value_or("stun");
+	relayType = RelayType::TurnUdp;
 	if (scheme == "stun" || scheme == "STUN")
 		type = Type::Stun;
 	else if (scheme == "turn" || scheme == "TURN")
 		type = Type::Turn;
-	else if (scheme == "turns" || scheme == "TURNS")
+	else if (scheme == "turns" || scheme == "TURNS") {
 		type = Type::Turn;
-	else
+		relayType = RelayType::TurnTls;
+	} else
 		throw std::invalid_argument("Unknown ICE server protocol: " + scheme);
 
-	relayType = RelayType::TurnUdp;
 	if (auto &query = opt[15]) {
 		if (query->find("transport=udp") != string::npos)
 			relayType = RelayType::TurnUdp;
@@ -84,4 +85,7 @@ IceServer::IceServer(string hostname_, string service_, string username_, string
     : hostname(std::move(hostname_)), service(std::move(service_)), type(Type::Turn),
       username(std::move(username_)), password(std::move(password_)), relayType(relayType_) {}
 
+ProxyServer::ProxyServer(Type type_, string ip_, uint16_t port_, string username_, string password_)
+    : type(type_), ip(ip_), port(port_), username(username_), password(password_) {}
+
 } // namespace rtc

src/datachannel.cpp

@@ -21,9 +21,16 @@
 #include "peerconnection.hpp"
 #include "sctptransport.hpp"
 
+#ifdef _WIN32
+#include <winsock2.h>
+#else
+#include <arpa/inet.h>
+#endif
+
 namespace rtc {
 
 using std::shared_ptr;
+using std::weak_ptr;
 
 // Messages for the DataChannel establishment protocol
 // See https://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-09
@@ -60,16 +67,16 @@ struct CloseMessage {
 
 const size_t RECV_QUEUE_LIMIT = 1024 * 1024; // 1 MiB
 
-DataChannel::DataChannel(shared_ptr<PeerConnection> pc, unsigned int stream, string label,
+DataChannel::DataChannel(weak_ptr<PeerConnection> pc, unsigned int stream, string label,
                          string protocol, Reliability reliability)
-    : mPeerConnection(std::move(pc)), mStream(stream), mLabel(std::move(label)),
+    : mPeerConnection(pc), mStream(stream), mLabel(std::move(label)),
       mProtocol(std::move(protocol)),
       mReliability(std::make_shared<Reliability>(std::move(reliability))),
       mRecvQueue(RECV_QUEUE_LIMIT, message_size_func) {}
 
-DataChannel::DataChannel(shared_ptr<PeerConnection> pc, shared_ptr<SctpTransport> transport,
+DataChannel::DataChannel(weak_ptr<PeerConnection> pc, weak_ptr<SctpTransport> transport,
                          unsigned int stream)
-    : mPeerConnection(std::move(pc)), mSctpTransport(transport), mStream(stream),
+    : mPeerConnection(pc), mSctpTransport(transport), mStream(stream),
       mReliability(std::make_shared<Reliability>()),
       mRecvQueue(RECV_QUEUE_LIMIT, message_size_func) {}
 
@@ -77,11 +84,22 @@ DataChannel::~DataChannel() {
 	close();
 }
 
+unsigned int DataChannel::stream() const { return mStream; }
+
+string DataChannel::label() const { return mLabel; }
+
+string DataChannel::protocol() const { return mProtocol; }
+
+Reliability DataChannel::reliability() const { return *mReliability; }
+
 void DataChannel::close() {
-	if (mIsOpen.exchange(false) && mSctpTransport)
+	if (mIsOpen.exchange(false))
-		mSctpTransport->reset(mStream);
+		if (auto transport = mSctpTransport.lock())
+			transport->reset(mStream);
 	mIsClosed = true;
 	mSctpTransport.reset();
+
+	resetCallbacks();
 }
 
 void DataChannel::remoteClose() {
@@ -131,27 +149,20 @@ bool DataChannel::isOpen(void) const { return mIsOpen; }
 
 bool DataChannel::isClosed(void) const { return mIsClosed; }
 
-size_t DataChannel::availableAmount() const { return mRecvQueue.amount(); }
-
 size_t DataChannel::maxMessageSize() const {
 	size_t max = DEFAULT_MAX_MESSAGE_SIZE;
-	if (auto description = mPeerConnection->remoteDescription())
+	if (auto pc = mPeerConnection.lock())
-		if (auto maxMessageSize = description->maxMessageSize())
+		if (auto description = pc->remoteDescription())
-			return *maxMessageSize > 0 ? *maxMessageSize : LOCAL_MAX_MESSAGE_SIZE;
+			if (auto maxMessageSize = description->maxMessageSize())
+				return *maxMessageSize > 0 ? *maxMessageSize : LOCAL_MAX_MESSAGE_SIZE;
 
 	return std::min(max, LOCAL_MAX_MESSAGE_SIZE);
 }
 
-unsigned int DataChannel::stream() const { return mStream; }
+size_t DataChannel::availableAmount() const { return mRecvQueue.amount(); }
 
-string DataChannel::label() const { return mLabel; }
+void DataChannel::open(shared_ptr<SctpTransport> transport) {
-
+	mSctpTransport = transport;
-string DataChannel::protocol() const { return mProtocol; }
-
-Reliability DataChannel::reliability() const { return *mReliability; }
-
-void DataChannel::open(shared_ptr<SctpTransport> sctpTransport) {
-	mSctpTransport = sctpTransport;
 
 	uint8_t channelType = static_cast<uint8_t>(mReliability->type);
 	if (mReliability->unordered)
@@ -178,20 +189,24 @@ void DataChannel::open(shared_ptr<SctpTransport> sctpTransport) {
 	std::copy(mLabel.begin(), mLabel.end(), end);
 	std::copy(mProtocol.begin(), mProtocol.end(), end + mLabel.size());
 
-	mSctpTransport->send(make_message(buffer.begin(), buffer.end(), Message::Control, mStream));
+	transport->send(make_message(buffer.begin(), buffer.end(), Message::Control, mStream));
 }
 
 bool DataChannel::outgoing(mutable_message_ptr message) {
-	if (mIsClosed || !mSctpTransport)
+	if (mIsClosed)
 		throw std::runtime_error("DataChannel is closed");
 
 	if (message->size() > maxMessageSize())
 		throw std::runtime_error("Message size exceeds limit");
 
+	auto transport = mSctpTransport.lock();
+	if (!transport)
+		throw std::runtime_error("DataChannel has no transport");
+
 	// Before the ACK has been received on a DataChannel, all messages must be sent ordered
 	message->reliability = mIsOpen ? mReliability : nullptr;
 	message->stream = mStream;
-	return mSctpTransport->send(message);
+	return transport->send(message);
 }
 
 void DataChannel::incoming(message_ptr message) {
@@ -230,6 +245,10 @@ void DataChannel::incoming(message_ptr message) {
 }
 
 void DataChannel::processOpenMessage(message_ptr message) {
+	auto transport = mSctpTransport.lock();
+	if (!transport)
+		throw std::runtime_error("DataChannel has no transport");
+
 	if (message->size() < sizeof(OpenMessage))
 		throw std::invalid_argument("DataChannel open message too small");
 
@@ -266,7 +285,7 @@ void DataChannel::processOpenMessage(message_ptr message) {
 	auto &ack = *reinterpret_cast<AckMessage *>(buffer.data());
 	ack.type = MESSAGE_ACK;
 
-	mSctpTransport->send(make_message(buffer.begin(), buffer.end(), Message::Control, mStream));
+	transport->send(make_message(buffer.begin(), buffer.end(), Message::Control, mStream));
 
 	mIsOpen = true;
 	triggerOpen();

src/description.cpp

@@ -45,12 +45,13 @@ inline void trim_end(string &str) {
 namespace rtc {
 
 Description::Description(const string &sdp, const string &typeString)
-    : Description(sdp, stringToType(typeString), Description::Role::ActPass) {}
+    : Description(sdp, stringToType(typeString)) {}
+
+Description::Description(const string &sdp, Type type) : Description(sdp, type, Role::ActPass) {}
 
 Description::Description(const string &sdp, Type type, Role role)
-    : mType(type), mRole(role), mMid("0"), mIceUfrag("0"), mIcePwd("0"), mTrickle(true) {
+    : mType(Type::Unspec), mRole(role), mMid("0"), mIceUfrag(""), mIcePwd(""), mTrickle(true) {
-	if (mType == Type::Answer && mRole == Role::ActPass)
+	hintType(type);
-		mRole = Role::Passive; // ActPass is illegal for an answer, so default to passive
 
 	auto seed = std::chrono::system_clock::now().time_since_epoch().count();
 	std::default_random_engine generator(seed);
@@ -109,6 +110,14 @@ std::optional<size_t> Description::maxMessageSize() const { return mMaxMessageSi
 
 bool Description::trickleEnabled() const { return mTrickle; }
 
+void Description::hintType(Type type) {
+	if (mType == Type::Unspec) {
+		mType = type;
+		if (mType == Type::Answer && mRole == Role::ActPass)
+			mRole = Role::Passive; // ActPass is illegal for an answer, so default to passive
+	}
+}
+
 void Description::setFingerprint(string fingerprint) {
 	mFingerprint.emplace(std::move(fingerprint));
 }

src/dtlstransport.cpp

@@ -55,6 +55,14 @@ static bool check_gnutls(int ret, const string &message = "GnuTLS error") {
 
 namespace rtc {
 
+void DtlsTransport::Init() {
+	// Nothing to do
+}
+
+void DtlsTransport::Cleanup() {
+	// Nothing to do
+}
+
 DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certificate> certificate,
                              verifier_callback verifierCallback,
                              state_callback stateChangeCallback)
@@ -64,8 +72,6 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
 
 	PLOG_DEBUG << "Initializing DTLS transport (GnuTLS)";
 
-	gnutls_certificate_set_verify_function(mCertificate->credentials(), CertificateCallback);
-
 	bool active = lower->role() == Description::Role::Active;
 	unsigned int flags = GNUTLS_DATAGRAM | (active ? GNUTLS_CLIENT : GNUTLS_SERVER);
 	check_gnutls(gnutls_init(&mSession, flags));
@@ -73,17 +79,19 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
 	// RFC 8261: SCTP performs segmentation and reassembly based on the path MTU.
 	// Therefore, the DTLS layer MUST NOT use any compression algorithm.
 	// See https://tools.ietf.org/html/rfc8261#section-5
-	const char *priorities = "SECURE128:-VERS-SSL3.0:-ARCFOUR-128:-COMP-ALL";
+	const char *priorities = "SECURE128:-VERS-SSL3.0:-ARCFOUR-128:-COMP-ALL:+COMP-NULL";
 	const char *err_pos = NULL;
 	check_gnutls(gnutls_priority_set_direct(mSession, priorities, &err_pos),
 	             "Unable to set TLS priorities");
 
+	gnutls_certificate_set_verify_function(mCertificate->credentials(), CertificateCallback);
 	check_gnutls(
 	    gnutls_credentials_set(mSession, GNUTLS_CRD_CERTIFICATE, mCertificate->credentials()));
 
-	gnutls_dtls_set_mtu(mSession, 1280 - 40 - 8); // min MTU over UDP/IPv6 (only for handshake)
+	gnutls_dtls_set_timeouts(mSession,
-	gnutls_dtls_set_timeouts(mSession, 400, 60000);
+	                         1000,   // 1s retransmission timeout recommended by RFC 6347
-	gnutls_handshake_set_timeout(mSession, 60000);
+	                         30000); // 30s total timeout
+	gnutls_handshake_set_timeout(mSession, 30000);
 
 	gnutls_session_set_ptr(mSession, this);
 	gnutls_transport_set_ptr(mSession, this);
@@ -102,15 +110,16 @@ DtlsTransport::~DtlsTransport() {
 
 DtlsTransport::State DtlsTransport::state() const { return mState; }
 
-void DtlsTransport::stop() {
+bool DtlsTransport::stop() {
-	Transport::stop();
+	if (!Transport::stop())
+		return false;
 
-	if (mRecvThread.joinable()) {
+	PLOG_DEBUG << "Stopping DTLS recv thread";
-		PLOG_DEBUG << "Stopping DTLS recv thread";
+	mIncomingQueue.stop();
-		mIncomingQueue.stop();
+	gnutls_bye(mSession, GNUTLS_SHUT_RDWR);
-		gnutls_bye(mSession, GNUTLS_SHUT_RDWR);
+	mRecvThread.join();
-		mRecvThread.join();
+	onRecv(nullptr);
-	}
+	return true;
 }
 
 bool DtlsTransport::send(message_ptr message) {
@@ -131,10 +140,13 @@ bool DtlsTransport::send(message_ptr message) {
 }
 
 void DtlsTransport::incoming(message_ptr message) {
-	if (message)
+	if (!message) {
-		mIncomingQueue.push(message);
-	else
 		mIncomingQueue.stop();
+		return;
+	}
+
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	mIncomingQueue.push(message);
 }
 
 void DtlsTransport::changeState(State state) {
@@ -148,6 +160,7 @@ void DtlsTransport::runRecvLoop() {
 	// Handshake loop
 	try {
 		changeState(State::Connecting);
+		gnutls_dtls_set_mtu(mSession, 1280 - 40 - 8); // min MTU over UDP/IPv6
 
 		int ret;
 		do {
@@ -171,6 +184,7 @@ void DtlsTransport::runRecvLoop() {
 
 	// Receive loop
 	try {
+		PLOG_INFO << "DTLS handshake done";
 		changeState(State::Connected);
 
 		const size_t bufferSize = maxMtu;
@@ -262,10 +276,8 @@ ssize_t DtlsTransport::ReadCallback(gnutls_transport_ptr_t ptr, void *data, size
 
 int DtlsTransport::TimeoutCallback(gnutls_transport_ptr_t ptr, unsigned int ms) {
 	DtlsTransport *t = static_cast<DtlsTransport *>(ptr);
-	if (ms != GNUTLS_INDEFINITE_TIMEOUT)
+	t->mIncomingQueue.wait(ms != GNUTLS_INDEFINITE_TIMEOUT ? std::make_optional(milliseconds(ms))
-		t->mIncomingQueue.wait(milliseconds(ms));
+	                                                       : nullopt);
-	else
-		t->mIncomingQueue.wait();
 	return !t->mIncomingQueue.empty() ? 1 : 0;
 }
 
@@ -323,7 +335,7 @@ BIO_METHOD *DtlsTransport::BioMethods = NULL;
 int DtlsTransport::TransportExIndex = -1;
 std::mutex DtlsTransport::GlobalMutex;
 
-void DtlsTransport::GlobalInit() {
+void DtlsTransport::Init() {
 	std::lock_guard lock(GlobalMutex);
 	if (!BioMethods) {
 		BioMethods = BIO_meth_new(BIO_TYPE_BIO, "DTLS writer");
@@ -339,6 +351,10 @@ void DtlsTransport::GlobalInit() {
 	}
 }
 
+void DtlsTransport::Cleanup() {
+	// Nothing to do
+}
+
 DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certificate> certificate,
                              verifier_callback verifierCallback, state_callback stateChangeCallback)
     : Transport(lower), mCertificate(certificate), mState(State::Disconnected),
@@ -346,7 +362,6 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
       mStateChangeCallback(std::move(stateChangeCallback)) {
 
 	PLOG_DEBUG << "Initializing DTLS transport (OpenSSL)";
-	GlobalInit();
 
 	if (!(mCtx = SSL_CTX_new(DTLS_method())))
 		throw std::runtime_error("Unable to create SSL context");
@@ -376,7 +391,6 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
 		throw std::runtime_error("Unable to create SSL instance");
 
 	SSL_set_ex_data(mSsl, TransportExIndex, this);
-	SSL_set_mtu(mSsl, 1280 - 40 - 8); // min MTU over UDP/IPv6
 
 	if (lower->role() == Description::Role::Active)
 		SSL_set_connect_state(mSsl);
@@ -405,16 +419,16 @@ DtlsTransport::~DtlsTransport() {
 	SSL_CTX_free(mCtx);
 }
 
-void DtlsTransport::stop() {
+bool DtlsTransport::stop() {
-	Transport::stop();
+	if (!Transport::stop())
+		return false;
 
-	if (mRecvThread.joinable()) {
+	PLOG_DEBUG << "Stopping DTLS recv thread";
-		PLOG_DEBUG << "Stopping DTLS recv thread";
+	mIncomingQueue.stop();
-		mIncomingQueue.stop();
+	mRecvThread.join();
-		mRecvThread.join();
+	SSL_shutdown(mSsl);
-
+	onRecv(nullptr);
-		SSL_shutdown(mSsl);
+	return true;
-	}
 }
 
 DtlsTransport::State DtlsTransport::state() const { return mState; }
@@ -432,10 +446,13 @@ bool DtlsTransport::send(message_ptr message) {
 }
 
 void DtlsTransport::incoming(message_ptr message) {
-	if (message)
+	if (!message) {
-		mIncomingQueue.push(message);
-	else
 		mIncomingQueue.stop();
+		return;
+	}
+
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	mIncomingQueue.push(message);
 }
 
 void DtlsTransport::changeState(State state) {
@@ -447,35 +464,71 @@ void DtlsTransport::runRecvLoop() {
 	const size_t maxMtu = 4096;
 	try {
 		changeState(State::Connecting);
+		SSL_set_mtu(mSsl, 1280 - 40 - 8); // min MTU over UDP/IPv6
 
-		SSL_do_handshake(mSsl);
+		// Initiate the handshake
+		int ret = SSL_do_handshake(mSsl);
+		check_openssl_ret(mSsl, ret, "Handshake failed");
 
 		const size_t bufferSize = maxMtu;
 		byte buffer[bufferSize];
-		while (auto next = mIncomingQueue.pop()) {
+		while (true) {
-			auto message = *next;
+			// Process pending messages
-			BIO_write(mInBio, message->data(), message->size());
+			while (!mIncomingQueue.empty()) {
-			int ret = SSL_read(mSsl, buffer, bufferSize);
+				auto message = *mIncomingQueue.pop();
-			if (!check_openssl_ret(mSsl, ret))
+				BIO_write(mInBio, message->data(), message->size());
-				break;
 
-			auto decrypted = ret > 0 ? make_message(buffer, buffer + ret) : nullptr;
+				if (mState == State::Connecting) {
+					// Continue the handshake
+					int ret = SSL_do_handshake(mSsl);
+					if (!check_openssl_ret(mSsl, ret, "Handshake failed"))
+						break;
 
-			if (mState == State::Connecting) {
+					if (SSL_is_init_finished(mSsl)) {
-				if (unsigned long err = ERR_get_error())
+						// RFC 8261: DTLS MUST support sending messages larger than the current path
-					throw std::runtime_error("handshake failed: " + openssl_error_string(err));
+						// MTU See https://tools.ietf.org/html/rfc8261#section-5
+						SSL_set_mtu(mSsl, maxMtu + 1);
 
-				if (SSL_is_init_finished(mSsl)) {
+						PLOG_INFO << "DTLS handshake done";
-					changeState(State::Connected);
+						changeState(State::Connected);
-
+					}
-					// RFC 8261: DTLS MUST support sending messages larger than the current path MTU
+				} else {
-					// See https://tools.ietf.org/html/rfc8261#section-5
+					int ret = SSL_read(mSsl, buffer, bufferSize);
-					SSL_set_mtu(mSsl, maxMtu + 1);
+					if (!check_openssl_ret(mSsl, ret))
+						break;
+					if (ret > 0)
+						recv(make_message(buffer, buffer + ret));
 				}
 			}
 
-			if (decrypted)
+			// No more messages pending, retransmit and rearm timeout if connecting
-				recv(decrypted);
+			std::optional<milliseconds> duration;
+			if (mState == State::Connecting) {
+				// Warning: This function breaks the usual return value convention
+				int ret = DTLSv1_handle_timeout(mSsl);
+				if (ret < 0) {
+					throw std::runtime_error("Handshake timeout"); // write BIO can't fail
+				} else if (ret > 0) {
+					LOG_VERBOSE << "OpenSSL did DTLS retransmit";
+				}
+
+				struct timeval timeout = {};
+				if (mState == State::Connecting && DTLSv1_get_timeout(mSsl, &timeout)) {
+					duration = milliseconds(timeout.tv_sec * 1000 + timeout.tv_usec / 1000);
+					// Also handle handshake timeout manually because OpenSSL actually doesn't...
+					// OpenSSL backs off exponentially in base 2 starting from the recommended 1s
+					// so this allows for 5 retransmissions and fails after roughly 30s.
+					if (duration > 30s) {
+						throw std::runtime_error("Handshake timeout");
+					} else {
+						LOG_VERBOSE << "OpenSSL DTLS retransmit timeout is " << duration->count()
+						            << "ms";
+					}
+				}
+			}
+
+			if (!mIncomingQueue.wait(duration))
+				break; // queue is stopped
 		}
 	} catch (const std::exception &e) {
 		PLOG_ERROR << "DTLS recv: " << e.what();
@@ -486,7 +539,7 @@ void DtlsTransport::runRecvLoop() {
 		changeState(State::Disconnected);
 		recv(nullptr);
 	} else {
-		PLOG_INFO << "DTLS handshake failed";
+		PLOG_ERROR << "DTLS handshake failed";
 		changeState(State::Failed);
 	}
 }
@@ -536,7 +589,8 @@ int DtlsTransport::BioMethodWrite(BIO *bio, const char *in, int inl) {
 	if (!transport)
 		return -1;
 	auto b = reinterpret_cast<const byte *>(in);
-	return transport->outgoing(make_message(b, b + inl)) ? inl : 0;
+	transport->outgoing(make_message(b, b + inl));
+	return inl; // can't fail
 }
 
 long DtlsTransport::BioMethodCtrl(BIO *bio, int cmd, long num, void *ptr) {

src/dtlstransport.hpp

@@ -43,6 +43,9 @@ class IceTransport;
 
 class DtlsTransport : public Transport {
 public:
+	static void Init();
+	static void Cleanup();
+
 	enum class State { Disconnected, Connecting, Connected, Failed };
 
 	using verifier_callback = std::function<bool(const std::string &fingerprint)>;
@@ -54,7 +57,7 @@ public:
 
 	State state() const;
 
-	void stop() override;
+	bool stop() override;
 	bool send(message_ptr message) override; // false if dropped
 
 private:
@@ -87,7 +90,6 @@ private:
 	static int TransportExIndex;
 	static std::mutex GlobalMutex;
 
-	static void GlobalInit();
 	static int CertificateCallback(int preverify_ok, X509_STORE_CTX *ctx);
 	static void InfoCallback(const SSL *ssl, int where, int ret);
 

src/icetransport.cpp

@@ -18,16 +18,24 @@
 
 #include "icetransport.hpp"
 #include "configuration.hpp"
-
+#include "transport.hpp"
-#include <netdb.h>
-#include <netinet/in.h>
-#include <sys/socket.h>
-#include <sys/types.h>
 
 #include <iostream>
 #include <random>
 #include <sstream>
 
+#ifdef _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#endif
+
+#include <sys/types.h>
+
 using namespace std::chrono_literals;
 
 using std::shared_ptr;
@@ -65,7 +73,7 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 	unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
 	std::shuffle(servers.begin(), servers.end(), std::default_random_engine(seed));
 
-	// Pick a STUN server
+	// Pick a STUN server (TURN support is not implemented in libjuice yet)
 	for (auto &server : servers) {
 		if (!server.hostname.empty() && server.type == IceServer::Type::Stun) {
 			if (server.service.empty())
@@ -79,7 +87,12 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 		}
 	}
 
-	// TURN support is not implemented yet
+	// Port range
+	if (config.portRangeBegin > 1024 ||
+	    (config.portRangeEnd != 0 && config.portRangeEnd != 65535)) {
+		jconfig.local_port_range_begin = config.portRangeBegin;
+		jconfig.local_port_range_end = config.portRangeEnd;
+	}
 
 	// Create agent
 	mAgent = decltype(mAgent)(juice_create(&jconfig), juice_destroy);
@@ -89,8 +102,9 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 
 IceTransport::~IceTransport() { stop(); }
 
-void IceTransport::stop() {
+bool IceTransport::stop() {
-	// Nothing to do
+	onRecv(nullptr);
+	return Transport::stop();
 }
 
 Description::Role IceTransport::role() const { return mRole; }
@@ -109,9 +123,6 @@ void IceTransport::setRemoteDescription(const Description &description) {
 	mRole = description.role() == Description::Role::Active ? Description::Role::Passive
 	                                                        : Description::Role::Active;
 	mMid = description.mid();
-	// TODO
-	// mTrickleTimeout = description.trickleEnabled() ? 30s : 0s;
-
 	if (juice_set_remote_description(mAgent.get(), string(description).c_str()) < 0)
 		throw std::runtime_error("Failed to parse remote SDP");
 }
@@ -158,7 +169,10 @@ bool IceTransport::send(message_ptr message) {
 	return outgoing(message);
 }
 
-void IceTransport::incoming(message_ptr message) { recv(message); }
+void IceTransport::incoming(message_ptr message) {
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	recv(message);
+}
 
 void IceTransport::incoming(const byte *data, int size) {
 	incoming(make_message(data, data + size));
@@ -241,11 +255,8 @@ void IceTransport::LogCallback(juice_log_level_t level, const char *message) {
 	case JUICE_LOG_LEVEL_INFO:
 		severity = plog::info;
 		break;
-	case JUICE_LOG_LEVEL_DEBUG:
-		severity = plog::debug;
-		break;
 	default:
-		severity = plog::verbose;
+		severity = plog::verbose; // libjuice debug as verbose
 		break;
 	}
 	PLOG(severity) << "juice: " << message;
@@ -308,6 +319,18 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 	g_object_set(G_OBJECT(mNiceAgent.get()), "upnp", FALSE, nullptr);
 	g_object_set(G_OBJECT(mNiceAgent.get()), "upnp-timeout", 200, nullptr);
 
+	// Proxy
+	if (config.proxyServer.has_value()) {
+		ProxyServer proxyServer = config.proxyServer.value();
+		g_object_set(G_OBJECT(mNiceAgent.get()), "proxy-type", proxyServer.type, nullptr);
+		g_object_set(G_OBJECT(mNiceAgent.get()), "proxy-ip", proxyServer.ip.c_str(), nullptr);
+		g_object_set(G_OBJECT(mNiceAgent.get()), "proxy-port", proxyServer.port, nullptr);
+		g_object_set(G_OBJECT(mNiceAgent.get()), "proxy-username", proxyServer.username.c_str(),
+		             nullptr);
+		g_object_set(G_OBJECT(mNiceAgent.get()), "proxy-password", proxyServer.password.c_str(),
+		             nullptr);
+	}
+
 	// Randomize order
 	std::vector<IceServer> servers = config.iceServers;
 	unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
@@ -422,16 +445,19 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 
 IceTransport::~IceTransport() { stop(); }
 
-void IceTransport::stop() {
+bool IceTransport::stop() {
 	if (mTimeoutId) {
 		g_source_remove(mTimeoutId);
 		mTimeoutId = 0;
 	}
-	if (mMainLoopThread.joinable()) {
+
-		PLOG_DEBUG << "Stopping ICE thread";
+	if (!Transport::stop())
-		g_main_loop_quit(mMainLoop.get());
+		return false;
-		mMainLoopThread.join();
+
-	}
+	PLOG_DEBUG << "Stopping ICE thread";
+	g_main_loop_quit(mMainLoop.get());
+	mMainLoopThread.join();
+	return true;
 }
 
 Description::Role IceTransport::role() const { return mRole; }
@@ -515,7 +541,10 @@ bool IceTransport::send(message_ptr message) {
 	return outgoing(message);
 }
 
-void IceTransport::incoming(message_ptr message) { recv(message); }
+void IceTransport::incoming(message_ptr message) {
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	recv(message);
+}
 
 void IceTransport::incoming(const byte *data, int size) {
 	incoming(make_message(data, data + size));
@@ -644,6 +673,58 @@ void IceTransport::LogCallback(const gchar *logDomain, GLogLevelFlags logLevel,
 	PLOG(severity) << "nice: " << message;
 }
 
+bool IceTransport::getSelectedCandidatePair(CandidateInfo *localInfo, CandidateInfo *remoteInfo) {
+	NiceCandidate *local, *remote;
+	gboolean result = nice_agent_get_selected_pair(mNiceAgent.get(), mStreamId, 1, &local, &remote);
+
+	if (!result)
+		return false;
+
+	char ipaddr[INET6_ADDRSTRLEN];
+	nice_address_to_string(&local->addr, ipaddr);
+	localInfo->address = std::string(ipaddr);
+	localInfo->port = nice_address_get_port(&local->addr);
+	localInfo->type = IceTransport::NiceTypeToCandidateType(local->type);
+	localInfo->transportType =
+	    IceTransport::NiceTransportTypeToCandidateTransportType(local->transport);
+
+	nice_address_to_string(&remote->addr, ipaddr);
+	remoteInfo->address = std::string(ipaddr);
+	remoteInfo->port = nice_address_get_port(&remote->addr);
+	remoteInfo->type = IceTransport::NiceTypeToCandidateType(remote->type);
+	remoteInfo->transportType =
+	    IceTransport::NiceTransportTypeToCandidateTransportType(remote->transport);
+
+	return true;
+}
+
+const CandidateType IceTransport::NiceTypeToCandidateType(NiceCandidateType type) {
+	switch (type) {
+	case NiceCandidateType::NICE_CANDIDATE_TYPE_HOST:
+		return CandidateType::Host;
+	case NiceCandidateType::NICE_CANDIDATE_TYPE_PEER_REFLEXIVE:
+		return CandidateType::PeerReflexive;
+	case NiceCandidateType::NICE_CANDIDATE_TYPE_RELAYED:
+		return CandidateType::Relayed;
+	case NiceCandidateType::NICE_CANDIDATE_TYPE_SERVER_REFLEXIVE:
+		return CandidateType::ServerReflexive;
+	}
+}
+
+const CandidateTransportType
+IceTransport::NiceTransportTypeToCandidateTransportType(NiceCandidateTransport type) {
+	switch (type) {
+	case NiceCandidateTransport::NICE_CANDIDATE_TRANSPORT_TCP_ACTIVE:
+		return CandidateTransportType::TcpActive;
+	case NiceCandidateTransport::NICE_CANDIDATE_TRANSPORT_TCP_PASSIVE:
+		return CandidateTransportType::TcpPassive;
+	case NiceCandidateTransport::NICE_CANDIDATE_TRANSPORT_TCP_SO:
+		return CandidateTransportType::TcpSo;
+	case NiceCandidateTransport::NICE_CANDIDATE_TRANSPORT_UDP:
+		return CandidateTransportType::Udp;
+	}
+}
+
 } // namespace rtc
 
 #endif

src/icetransport.hpp

@@ -37,7 +37,7 @@
 #include <thread>
 
 namespace rtc {
-
+	
 class IceTransport : public Transport {
 public:
 #if USE_JUICE
@@ -56,6 +56,8 @@ public:
 		Completed = NICE_COMPONENT_STATE_READY,
 		Failed = NICE_COMPONENT_STATE_FAILED,
 	};
+
+	bool getSelectedCandidatePair(CandidateInfo *local, CandidateInfo *remote);
 #endif
 	enum class GatheringState { New = 0, InProgress = 1, Complete = 2 };
 
@@ -79,7 +81,7 @@ public:
 	std::optional<string> getLocalAddress() const;
 	std::optional<string> getRemoteAddress() const;
 
-	void stop() override;
+	bool stop() override;
 	bool send(message_ptr message) override; // false if dropped
 
 private:
@@ -133,6 +135,8 @@ private:
 	static gboolean TimeoutCallback(gpointer userData);
 	static void LogCallback(const gchar *log_domain, GLogLevelFlags log_level, const gchar *message,
 	                        gpointer user_data);
+	static const CandidateType NiceTypeToCandidateType(NiceCandidateType type);
+	static const CandidateTransportType NiceTransportTypeToCandidateTransportType(NiceCandidateTransport type);
 #endif
 };
 

src/init.cpp

@@ -0,0 +1,86 @@
+/**
+ * Copyright (c) 2020 Paul-Louis Ageneau
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "init.hpp"
+
+#include "dtlstransport.hpp"
+#include "sctptransport.hpp"
+
+#ifdef _WIN32
+#include <winsock2.h>
+#endif
+
+#if USE_GNUTLS
+// Nothing to do
+#else
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+#endif
+
+using std::shared_ptr;
+
+namespace rtc {
+
+std::weak_ptr<Init> Init::Weak;
+init_token Init::Global;
+std::mutex Init::Mutex;
+
+init_token Init::Token() {
+	std::lock_guard lock(Mutex);
+
+	if (!Global) {
+		if (auto token = Weak.lock())
+			Global = token;
+		else
+			Global = shared_ptr<Init>(new Init());
+	}
+	return Global;
+}
+
+void Init::Cleanup() { Global.reset(); }
+
+Init::Init() {
+#ifdef _WIN32
+	WSADATA wsaData;
+	if (WSAStartup(MAKEWORD(2, 2), &wsaData))
+		throw std::runtime_error("WSAStartup failed, error=" + std::to_string(WSAGetLastError()));
+#endif
+
+#if USE_GNUTLS
+		// Nothing to do
+#else
+	OPENSSL_init_ssl(0, NULL);
+	SSL_load_error_strings();
+	ERR_load_crypto_strings();
+#endif
+
+	DtlsTransport::Init();
+	SctpTransport::Init();
+}
+
+Init::~Init() {
+	DtlsTransport::Cleanup();
+	SctpTransport::Cleanup();
+
+#ifdef _WIN32
+	WSACleanup();
+#endif
+}
+
+} // namespace rtc
+

src/log.cpp

@@ -0,0 +1,42 @@
+/**
+ * Copyright (c) 2019-2020 Paul-Louis Ageneau
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "log.hpp"
+
+#include "plog/Appenders/ColorConsoleAppender.h"
+#include "plog/Log.h"
+#include "plog/Logger.h"
+
+namespace rtc {
+
+void InitLogger(LogLevel level) { InitLogger(static_cast<plog::Severity>(level)); }
+
+void InitLogger(plog::Severity severity, plog::IAppender *appender) {
+	static plog::ColorConsoleAppender<plog::TxtFormatter> consoleAppender;
+	static plog::Logger<0> *logger = nullptr;
+	if (!logger) {
+		logger = &plog::init(severity, appender ? appender : &consoleAppender);
+		PLOG_DEBUG << "Logger initialized";
+	} else {
+		logger->setMaxSeverity(severity);
+		if (appender)
+			logger->addAppender(appender);
+	}
+}
+}
+

src/peerconnection.cpp

@@ -24,6 +24,7 @@
 #include "sctptransport.hpp"
 
 #include <iostream>
+#include <thread>
 
 namespace rtc {
 
@@ -32,34 +33,33 @@ using namespace std::placeholders;
 using std::shared_ptr;
 using std::weak_ptr;
 
+template <typename F, typename T, typename... Args> auto weak_bind(F &&f, T *t, Args &&... _args) {
+	return [bound = std::bind(f, t, _args...), weak_this = t->weak_from_this()](auto &&... args) {
+		if (auto shared_this = weak_this.lock())
+			bound(args...);
+	};
+}
+
+template <typename F, typename T, typename... Args>
+auto weak_bind_verifier(F &&f, T *t, Args &&... _args) {
+	return [bound = std::bind(f, t, _args...), weak_this = t->weak_from_this()](auto &&... args) {
+		if (auto shared_this = weak_this.lock())
+			return bound(args...);
+		else
+			return false;
+	};
+}
+
 PeerConnection::PeerConnection() : PeerConnection(Configuration()) {}
 
 PeerConnection::PeerConnection(const Configuration &config)
     : mConfig(config), mCertificate(make_certificate("libdatachannel")), mState(State::New) {}
 
-PeerConnection::~PeerConnection() {
+PeerConnection::~PeerConnection() { close(); }
-	changeState(State::Destroying);
-	close();
-	mSctpTransport.reset();
-	mDtlsTransport.reset();
-	mIceTransport.reset();
-}
 
 void PeerConnection::close() {
-	// Close DataChannels
 	closeDataChannels();
-	mDataChannels.clear();
+	closeTransports();
-
-	// Close Transports
-	for (int i = 0; i < 2; ++i) { // Make sure a transport wasn't spawn behind our back
-		if (auto transport = std::atomic_load(&mSctpTransport))
-			transport->stop();
-		if (auto transport = std::atomic_load(&mDtlsTransport))
-			transport->stop();
-		if (auto transport = std::atomic_load(&mIceTransport))
-			transport->stop();
-	}
-	changeState(State::Closed);
 }
 
 const Configuration *PeerConnection::config() const { return &mConfig; }
@@ -79,9 +79,10 @@ std::optional<Description> PeerConnection::remoteDescription() const {
 }
 
 void PeerConnection::setRemoteDescription(Description description) {
-	std::lock_guard lock(mRemoteDescriptionMutex);
+	description.hintType(localDescription() ? Description::Type::Answer : Description::Type::Offer);
-
 	auto remoteCandidates = description.extractCandidates();
+
+	std::lock_guard lock(mRemoteDescriptionMutex);
 	mRemoteDescription.emplace(std::move(description));
 
 	auto iceTransport = std::atomic_load(&mIceTransport);
@@ -100,12 +101,16 @@ void PeerConnection::setRemoteDescription(Description description) {
 		if (!sctpTransport && 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
 			decltype(mDataChannels) newDataChannels;
-			iterateDataChannels([&](shared_ptr<DataChannel> channel) {
+			auto it = mDataChannels.begin();
+			while (it != mDataChannels.end()) {
+				auto channel = it->second.lock();
 				if (channel->stream() % 2 == 1)
 					channel->mStream -= 1;
 				newDataChannels.emplace(channel->stream(), channel);
-			});
+				++it;
+			}
 			std::swap(mDataChannels, newDataChannels);
 		}
 	}
@@ -157,19 +162,7 @@ shared_ptr<DataChannel> PeerConnection::createDataChannel(const string &label,
 	auto iceTransport = std::atomic_load(&mIceTransport);
 	auto role = iceTransport ? iceTransport->role() : Description::Role::Passive;
 
-	// The active side must use streams with even identifiers, whereas the passive side must use
+	auto channel = emplaceDataChannel(role, label, protocol, reliability);
-	// streams with odd identifiers.
-	// See https://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-09#section-6
-	unsigned int stream = (role == Description::Role::Active) ? 0 : 1;
-	while (mDataChannels.find(stream) != mDataChannels.end()) {
-		stream += 2;
-		if (stream >= 65535)
-			throw std::runtime_error("Too many DataChannels");
-	}
-
-	auto channel =
-	    std::make_shared<DataChannel>(shared_from_this(), stream, label, protocol, reliability);
-	mDataChannels.insert(std::make_pair(stream, channel));
 
 	if (!iceTransport) {
 		// RFC 5763: The endpoint that is the offerer MUST use the setup attribute value of
@@ -209,108 +202,184 @@ void PeerConnection::onGatheringStateChange(std::function<void(GatheringState st
 }
 
 shared_ptr<IceTransport> PeerConnection::initIceTransport(Description::Role role) {
-	std::lock_guard lock(mInitMutex);
+	try {
-	if (auto transport = std::atomic_load(&mIceTransport))
+		if (auto transport = std::atomic_load(&mIceTransport))
+			return transport;
+
+		auto transport = std::make_shared<IceTransport>(
+		    mConfig, role, weak_bind(&PeerConnection::processLocalCandidate, this, _1),
+		    [this, weak_this = weak_from_this()](IceTransport::State state) {
+			    auto shared_this = weak_this.lock();
+			    if (!shared_this)
+				    return;
+			    switch (state) {
+			    case IceTransport::State::Connecting:
+				    changeState(State::Connecting);
+				    break;
+			    case IceTransport::State::Failed:
+				    changeState(State::Failed);
+				    break;
+			    case IceTransport::State::Connected:
+				    initDtlsTransport();
+				    break;
+			    case IceTransport::State::Disconnected:
+				    changeState(State::Disconnected);
+				    break;
+			    default:
+				    // Ignore
+				    break;
+			    }
+		    },
+		    [this, weak_this = weak_from_this()](IceTransport::GatheringState state) {
+			    auto shared_this = weak_this.lock();
+			    if (!shared_this)
+				    return;
+			    switch (state) {
+			    case IceTransport::GatheringState::InProgress:
+				    changeGatheringState(GatheringState::InProgress);
+				    break;
+			    case IceTransport::GatheringState::Complete:
+				    endLocalCandidates();
+				    changeGatheringState(GatheringState::Complete);
+				    break;
+			    default:
+				    // Ignore
+				    break;
+			    }
+		    });
+
+		std::atomic_store(&mIceTransport, transport);
+		if (mState == State::Closed) {
+			mIceTransport.reset();
+			transport->stop();
+			throw std::runtime_error("Connection is closed");
+		}
 		return transport;
 
-	auto transport = std::make_shared<IceTransport>(
+	} catch (const std::exception &e) {
-	    mConfig, role, std::bind(&PeerConnection::processLocalCandidate, this, _1),
+		PLOG_ERROR << e.what();
-	    [this](IceTransport::State state) {
+		changeState(State::Failed);
-		    switch (state) {
+		throw std::runtime_error("ICE transport initialization failed");
-		    case IceTransport::State::Connecting:
+	}
-			    changeState(State::Connecting);
-			    break;
-		    case IceTransport::State::Failed:
-			    changeState(State::Failed);
-			    break;
-		    case IceTransport::State::Connected:
-			    initDtlsTransport();
-			    break;
-		    case IceTransport::State::Disconnected:
-			    changeState(State::Disconnected);
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    },
-	    [this](IceTransport::GatheringState state) {
-		    switch (state) {
-		    case IceTransport::GatheringState::InProgress:
-			    changeGatheringState(GatheringState::InProgress);
-			    break;
-		    case IceTransport::GatheringState::Complete:
-			    endLocalCandidates();
-			    changeGatheringState(GatheringState::Complete);
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    });
-	std::atomic_store(&mIceTransport, transport);
-	return transport;
 }
 
 shared_ptr<DtlsTransport> PeerConnection::initDtlsTransport() {
-	std::lock_guard lock(mInitMutex);
+	try {
-	if (auto transport = std::atomic_load(&mDtlsTransport))
+		if (auto transport = std::atomic_load(&mDtlsTransport))
+			return transport;
+
+		auto lower = std::atomic_load(&mIceTransport);
+		auto transport = std::make_shared<DtlsTransport>(
+		    lower, mCertificate, weak_bind_verifier(&PeerConnection::checkFingerprint, this, _1),
+		    [this, weak_this = weak_from_this()](DtlsTransport::State state) {
+			    auto shared_this = weak_this.lock();
+			    if (!shared_this)
+				    return;
+			    switch (state) {
+			    case DtlsTransport::State::Connected:
+				    initSctpTransport();
+				    break;
+			    case DtlsTransport::State::Failed:
+				    changeState(State::Failed);
+				    break;
+			    case DtlsTransport::State::Disconnected:
+				    changeState(State::Disconnected);
+				    break;
+			    default:
+				    // Ignore
+				    break;
+			    }
+		    });
+
+		std::atomic_store(&mDtlsTransport, transport);
+		if (mState == State::Closed) {
+			mDtlsTransport.reset();
+			transport->stop();
+			throw std::runtime_error("Connection is closed");
+		}
 		return transport;
 
-	auto lower = std::atomic_load(&mIceTransport);
+	} catch (const std::exception &e) {
-	auto transport = std::make_shared<DtlsTransport>(
+		PLOG_ERROR << e.what();
-	    lower, mCertificate, std::bind(&PeerConnection::checkFingerprint, this, _1),
+		changeState(State::Failed);
-	    [this](DtlsTransport::State state) {
+		throw std::runtime_error("DTLS transport initialization failed");
-		    switch (state) {
+	}
-		    case DtlsTransport::State::Connected:
-			    initSctpTransport();
-			    break;
-		    case DtlsTransport::State::Failed:
-			    changeState(State::Failed);
-			    break;
-		    case DtlsTransport::State::Disconnected:
-			    changeState(State::Disconnected);
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    });
-	std::atomic_store(&mDtlsTransport, transport);
-	return transport;
 }
 
 shared_ptr<SctpTransport> PeerConnection::initSctpTransport() {
-	std::lock_guard lock(mInitMutex);
+	try {
-	if (auto transport = std::atomic_load(&mSctpTransport))
+		if (auto transport = std::atomic_load(&mSctpTransport))
+			return transport;
+
+		uint16_t sctpPort = remoteDescription()->sctpPort().value_or(DEFAULT_SCTP_PORT);
+		auto lower = std::atomic_load(&mDtlsTransport);
+		auto transport = std::make_shared<SctpTransport>(
+		    lower, sctpPort, weak_bind(&PeerConnection::forwardMessage, this, _1),
+		    weak_bind(&PeerConnection::forwardBufferedAmount, this, _1, _2),
+		    [this, weak_this = weak_from_this()](SctpTransport::State state) {
+			    auto shared_this = weak_this.lock();
+			    if (!shared_this)
+				    return;
+			    switch (state) {
+			    case SctpTransport::State::Connected:
+				    changeState(State::Connected);
+				    openDataChannels();
+				    break;
+			    case SctpTransport::State::Failed:
+				    remoteCloseDataChannels();
+				    changeState(State::Failed);
+				    break;
+			    case SctpTransport::State::Disconnected:
+				    remoteCloseDataChannels();
+				    changeState(State::Disconnected);
+				    break;
+			    default:
+				    // Ignore
+				    break;
+			    }
+		    });
+
+		std::atomic_store(&mSctpTransport, transport);
+		if (mState == State::Closed) {
+			mSctpTransport.reset();
+			transport->stop();
+			throw std::runtime_error("Connection is closed");
+		}
 		return transport;
 
-	uint16_t sctpPort = remoteDescription()->sctpPort().value_or(DEFAULT_SCTP_PORT);
+	} catch (const std::exception &e) {
-	auto lower = std::atomic_load(&mDtlsTransport);
+		PLOG_ERROR << e.what();
-	auto transport = std::make_shared<SctpTransport>(
+		changeState(State::Failed);
-	    lower, sctpPort, std::bind(&PeerConnection::forwardMessage, this, _1),
+		throw std::runtime_error("SCTP transport initialization failed");
-	    std::bind(&PeerConnection::forwardBufferedAmount, this, _1, _2),
+	}
-	    [this](SctpTransport::State state) {
+}
-		    switch (state) {
+
-		    case SctpTransport::State::Connected:
+void PeerConnection::closeTransports() {
-			    changeState(State::Connected);
+	// Change state to sink state Closed to block init methods
-			    openDataChannels();
+	changeState(State::Closed);
-			    break;
+
-		    case SctpTransport::State::Failed:
+	// Reset callbacks now that state is changed
-			    remoteCloseDataChannels();
+	resetCallbacks();
-			    changeState(State::Failed);
+
-			    break;
+	// Pass the references to a thread, allowing to terminate a transport from its own thread
-		    case SctpTransport::State::Disconnected:
+	auto sctp = std::atomic_exchange(&mSctpTransport, decltype(mSctpTransport)(nullptr));
-			    remoteCloseDataChannels();
+	auto dtls = std::atomic_exchange(&mDtlsTransport, decltype(mDtlsTransport)(nullptr));
-			    changeState(State::Disconnected);
+	auto ice = std::atomic_exchange(&mIceTransport, decltype(mIceTransport)(nullptr));
-			    break;
+	if (sctp || dtls || ice) {
-		    default:
+		std::thread t([sctp, dtls, ice]() mutable {
-			    // Ignore
+			if (sctp)
-			    break;
+				sctp->stop();
-		    }
+			if (dtls)
-	    });
+				dtls->stop();
-	std::atomic_store(&mSctpTransport, transport);
+			if (ice)
-	return transport;
+				ice->stop();
+
+			sctp.reset();
+			dtls.reset();
+			ice.reset();
+		});
+		t.detach();
+	}
 }
 
 void PeerConnection::endLocalCandidates() {
@@ -334,14 +403,7 @@ void PeerConnection::forwardMessage(message_ptr message) {
 		return;
 	}
 
-	shared_ptr<DataChannel> channel;
+	auto channel = findDataChannel(message->stream);
-	if (auto it = mDataChannels.find(message->stream); it != mDataChannels.end()) {
-		channel = it->second.lock();
-		if (!channel || channel->isClosed()) {
-			mDataChannels.erase(it);
-			channel = nullptr;
-		}
-	}
 
 	auto iceTransport = std::atomic_load(&mIceTransport);
 	auto sctpTransport = std::atomic_load(&mSctpTransport);
@@ -355,7 +417,7 @@ void PeerConnection::forwardMessage(message_ptr message) {
 		    message->stream % 2 == remoteParity) {
 			channel =
 			    std::make_shared<DataChannel>(shared_from_this(), sctpTransport, message->stream);
-			channel->onOpen(std::bind(&PeerConnection::triggerDataChannel, this,
+			channel->onOpen(weak_bind(&PeerConnection::triggerDataChannel, this,
 			                          weak_ptr<DataChannel>{channel}));
 			mDataChannels.insert(std::make_pair(message->stream, channel));
 		} else {
@@ -369,30 +431,66 @@ void PeerConnection::forwardMessage(message_ptr message) {
 }
 
 void PeerConnection::forwardBufferedAmount(uint16_t stream, size_t amount) {
-	shared_ptr<DataChannel> channel;
+	if (auto channel = findDataChannel(stream))
-	if (auto it = mDataChannels.find(stream); it != mDataChannels.end()) {
-		channel = it->second.lock();
-		if (!channel || channel->isClosed()) {
-			mDataChannels.erase(it);
-			channel = nullptr;
-		}
-	}
-
-	if (channel)
 		channel->triggerBufferedAmount(amount);
 }
 
+shared_ptr<DataChannel> PeerConnection::emplaceDataChannel(Description::Role role,
+                                                           const string &label,
+                                                           const string &protocol,
+                                                           const Reliability &reliability) {
+	// The active side must use streams with even identifiers, whereas the passive side must use
+	// streams with odd identifiers.
+	// See https://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-09#section-6
+	std::unique_lock lock(mDataChannelsMutex); // we are going to emplace
+	unsigned int stream = (role == Description::Role::Active) ? 0 : 1;
+	while (mDataChannels.find(stream) != mDataChannels.end()) {
+		stream += 2;
+		if (stream >= 65535)
+			throw std::runtime_error("Too many DataChannels");
+	}
+	auto channel =
+	    std::make_shared<DataChannel>(shared_from_this(), stream, label, protocol, reliability);
+	mDataChannels.emplace(std::make_pair(stream, channel));
+	return channel;
+}
+
+shared_ptr<DataChannel> PeerConnection::findDataChannel(uint16_t stream) {
+	std::shared_lock lock(mDataChannelsMutex); // read-only
+	if (auto it = mDataChannels.find(stream); it != mDataChannels.end())
+		if (auto channel = it->second.lock())
+			return channel;
+
+	return nullptr;
+}
+
 void PeerConnection::iterateDataChannels(
     std::function<void(shared_ptr<DataChannel> channel)> func) {
-	auto it = mDataChannels.begin();
+	// Iterate
-	while (it != mDataChannels.end()) {
+	{
-		auto channel = it->second.lock();
+		std::shared_lock lock(mDataChannelsMutex); // read-only
-		if (!channel || channel->isClosed()) {
+		auto it = mDataChannels.begin();
-			it = mDataChannels.erase(it);
+		while (it != mDataChannels.end()) {
-			continue;
+			auto channel = it->second.lock();
+			if (channel && !channel->isClosed())
+				func(channel);
+
+			++it;
+		}
+	}
+
+	// Cleanup
+	{
+		std::unique_lock lock(mDataChannelsMutex); // we are going to erase
+		auto it = mDataChannels.begin();
+		while (it != mDataChannels.end()) {
+			if (!it->second.lock()) {
+				it = mDataChannels.erase(it);
+				continue;
+			}
+
+			++it;
 		}
-		func(channel);
-		++it;
 	}
 }
 
@@ -441,21 +539,72 @@ void PeerConnection::triggerDataChannel(weak_ptr<DataChannel> weakDataChannel) {
 	mDataChannelCallback(dataChannel);
 }
 
-void PeerConnection::changeState(State state) {
+bool PeerConnection::changeState(State state) {
 	State current;
 	do {
 		current = mState.load();
-		if (current == state || current == State::Destroying)
+		if (current == state)
-			return;
+			return true;
+		if (current == State::Closed)
+			return false;
+
 	} while (!mState.compare_exchange_weak(current, state));
 
-	if (state != State::Destroying)
+	mStateChangeCallback(state);
-		mStateChangeCallback(state);
+	return true;
 }
 
-void PeerConnection::changeGatheringState(GatheringState state) {
+bool PeerConnection::changeGatheringState(GatheringState state) {
 	if (mGatheringState.exchange(state) != state)
 		mGatheringStateChangeCallback(state);
+	return true;
+}
+
+void PeerConnection::resetCallbacks() {
+	// Unregister all callbacks
+	mDataChannelCallback = nullptr;
+	mLocalDescriptionCallback = nullptr;
+	mLocalCandidateCallback = nullptr;
+	mStateChangeCallback = nullptr;
+	mGatheringStateChangeCallback = nullptr;
+}
+
+bool PeerConnection::getSelectedCandidatePair(CandidateInfo *local, CandidateInfo *remote) {
+#if not USE_JUICE
+	auto iceTransport = std::atomic_load(&mIceTransport);
+	return iceTransport->getSelectedCandidatePair(local, remote);
+#else
+	PLOG_WARNING << "getSelectedCandidatePair is not implemented for libjuice";
+	return false;
+#endif
+}
+
+void PeerConnection::clearStats() {
+	auto sctpTransport = std::atomic_load(&mSctpTransport);
+	if (sctpTransport)
+		return sctpTransport->clearStats();
+}
+
+size_t PeerConnection::bytesSent() {
+	auto sctpTransport = std::atomic_load(&mSctpTransport);
+	if (sctpTransport)
+		return sctpTransport->bytesSent();
+	return 0;
+}
+
+size_t PeerConnection::bytesReceived() {
+	auto sctpTransport = std::atomic_load(&mSctpTransport);
+	if (sctpTransport)
+		return sctpTransport->bytesReceived();
+	return 0;
+}
+
+std::optional<std::chrono::milliseconds> PeerConnection::rtt() {
+	auto sctpTransport = std::atomic_load(&mSctpTransport);
+	if (sctpTransport)
+		return sctpTransport->rtt();
+	PLOG_WARNING << "Could not load sctpTransport";
+	return std::nullopt;
 }
 
 } // namespace rtc
@@ -482,9 +631,6 @@ std::ostream &operator<<(std::ostream &out, const rtc::PeerConnection::State &st
 	case State::Closed:
 		str = "closed";
 		break;
-	case State::Destroying:
-		str = "destroying";
-		break;
 	default:
 		str = "unknown";
 		break;
@@ -511,4 +657,3 @@ std::ostream &operator<<(std::ostream &out, const rtc::PeerConnection::Gathering
 	}
 	return out << str;
 }
-

src/rtc.cpp

@@ -22,195 +22,431 @@
 
 #include <rtc.h>
 
+#include <exception>
+#include <mutex>
 #include <unordered_map>
-
+#include <utility>
-#include <plog/Appenders/ColorConsoleAppender.h>
 
 using namespace rtc;
 using std::shared_ptr;
 using std::string;
 
+#define CATCH(statement)                                                                           \
+	try {                                                                                          \
+		statement;                                                                                 \
+	} catch (const std::exception &e) {                                                            \
+		PLOG_ERROR << e.what();                                                                    \
+		return -1;                                                                                 \
+	}
+
 namespace {
 
 std::unordered_map<int, shared_ptr<PeerConnection>> peerConnectionMap;
 std::unordered_map<int, shared_ptr<DataChannel>> dataChannelMap;
 std::unordered_map<int, void *> userPointerMap;
+std::mutex mutex;
 int lastId = 0;
 
 void *getUserPointer(int id) {
+	std::lock_guard lock(mutex);
 	auto it = userPointerMap.find(id);
 	return it != userPointerMap.end() ? it->second : nullptr;
 }
 
-} // namespace
+void setUserPointer(int i, void *ptr) {
+	std::lock_guard lock(mutex);
+	if (ptr)
+		userPointerMap.insert(std::make_pair(i, ptr));
+	else
+		userPointerMap.erase(i);
+}
 
-void rtcInitLogger(rtc_log_level_t level) { InitLogger(static_cast<LogLevel>(level)); }
+shared_ptr<PeerConnection> getPeerConnection(int id) {
+	std::lock_guard lock(mutex);
+	auto it = peerConnectionMap.find(id);
+	return it != peerConnectionMap.end() ? it->second : nullptr;
+}
 
-int rtcCreatePeerConnection(const char **iceServers, int iceServersCount) {
+shared_ptr<DataChannel> getDataChannel(int id) {
-	Configuration config;
+	std::lock_guard lock(mutex);
-	for (int i = 0; i < iceServersCount; ++i) {
+	auto it = dataChannelMap.find(id);
-		config.iceServers.emplace_back(IceServer(string(iceServers[i])));
+	return it != dataChannelMap.end() ? it->second : nullptr;
-	}
+}
+
+int emplacePeerConnection(shared_ptr<PeerConnection> ptr) {
+	std::lock_guard lock(mutex);
 	int pc = ++lastId;
-	peerConnectionMap.emplace(std::make_pair(pc, std::make_shared<PeerConnection>(config)));
+	peerConnectionMap.emplace(std::make_pair(pc, ptr));
 	return pc;
 }
 
-void rtcDeletePeerConnection(int pc) { peerConnectionMap.erase(pc); }
+int emplaceDataChannel(shared_ptr<DataChannel> ptr) {
-
+	std::lock_guard lock(mutex);
-int rtcCreateDataChannel(int pc, const char *label) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return 0;
-	auto dataChannel = it->second->createDataChannel(string(label));
 	int dc = ++lastId;
-	dataChannelMap.emplace(std::make_pair(dc, dataChannel));
+	dataChannelMap.emplace(std::make_pair(dc, ptr));
 	return dc;
 }
 
-void rtcDeleteDataChannel(int dc) { dataChannelMap.erase(dc); }
+bool erasePeerConnection(int pc) {
-
+	std::lock_guard lock(mutex);
-void rtcSetDataChannelCallback(int pc, void (*dataChannelCallback)(int, void *)) {
+	if (peerConnectionMap.erase(pc) == 0)
-	auto it = peerConnectionMap.find(pc);
+		return false;
-	if (it == peerConnectionMap.end())
+	userPointerMap.erase(pc);
-		return;
+	return true;
-
-	it->second->onDataChannel([pc, dataChannelCallback](std::shared_ptr<DataChannel> dataChannel) {
-		int dc = ++lastId;
-		dataChannelMap.emplace(std::make_pair(dc, dataChannel));
-		dataChannelCallback(dc, getUserPointer(pc));
-	});
 }
 
-void rtcSetLocalDescriptionCallback(int pc, void (*descriptionCallback)(const char *, const char *,
+bool eraseDataChannel(int dc) {
-                                                                        void *)) {
+	std::lock_guard lock(mutex);
-	auto it = peerConnectionMap.find(pc);
+	if (dataChannelMap.erase(dc) == 0)
-	if (it == peerConnectionMap.end())
+		return false;
-		return;
+	userPointerMap.erase(dc);
-
+	return true;
-	it->second->onLocalDescription([pc, descriptionCallback](const Description &description) {
-		descriptionCallback(string(description).c_str(), description.typeString().c_str(),
-		                    getUserPointer(pc));
-	});
 }
 
-void rtcSetLocalCandidateCallback(int pc,
+} // namespace
-                                  void (*candidateCallback)(const char *, const char *, void *)) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
 
-	it->second->onLocalCandidate([pc, candidateCallback](const Candidate &candidate) {
+void rtcInitLogger(rtcLogLevel level) { InitLogger(static_cast<LogLevel>(level)); }
-		candidateCallback(candidate.candidate().c_str(), candidate.mid().c_str(),
+
-		                  getUserPointer(pc));
+void rtcSetUserPointer(int i, void *ptr) { setUserPointer(i, ptr); }
-	});
+
+int rtcCreatePeerConnection(const rtcConfiguration *config) {
+	Configuration c;
+	for (int i = 0; i < config->iceServersCount; ++i)
+		c.iceServers.emplace_back(string(config->iceServers[i]));
+
+	if (config->portRangeBegin || config->portRangeEnd) {
+		c.portRangeBegin = config->portRangeBegin;
+		c.portRangeEnd = config->portRangeEnd;
+	}
+
+	return emplacePeerConnection(std::make_shared<PeerConnection>(c));
 }
 
-void rtcSetStateChangeCallback(int pc, void (*stateCallback)(rtc_state_t state, void *)) {
+int rtcDeletePeerConnection(int pc) {
-	auto it = peerConnectionMap.find(pc);
+	auto peerConnection = getPeerConnection(pc);
-	if (it == peerConnectionMap.end())
+	if (!peerConnection)
-		return;
+		return -1;
 
-	it->second->onStateChange([pc, stateCallback](PeerConnection::State state) {
+	peerConnection->onDataChannel(nullptr);
-		stateCallback(static_cast<rtc_state_t>(state), getUserPointer(pc));
+	peerConnection->onLocalDescription(nullptr);
-	});
+	peerConnection->onLocalCandidate(nullptr);
+	peerConnection->onStateChange(nullptr);
+	peerConnection->onGatheringStateChange(nullptr);
+
+	erasePeerConnection(pc);
+	return 0;
 }
 
-void rtcSetGatheringStateChangeCallback(int pc,
+int rtcCreateDataChannel(int pc, const char *label) {
-                                        void (*gatheringStateCallback)(rtc_gathering_state_t state,
+	auto peerConnection = getPeerConnection(pc);
-                                                                       void *)) {
+	if (!peerConnection)
-	auto it = peerConnectionMap.find(pc);
+		return -1;
-	if (it == peerConnectionMap.end())
-		return;
 
-	it->second->onGatheringStateChange(
+	int dc = emplaceDataChannel(peerConnection->createDataChannel(string(label)));
-	    [pc, gatheringStateCallback](PeerConnection::GatheringState state) {
+	void *ptr = getUserPointer(pc);
-		    gatheringStateCallback(static_cast<rtc_gathering_state_t>(state), getUserPointer(pc));
+	rtcSetUserPointer(dc, ptr);
-	    });
+	return dc;
 }
 
-void rtcSetRemoteDescription(int pc, const char *sdp, const char *type) {
+int rtcDeleteDataChannel(int dc) {
-	auto it = peerConnectionMap.find(pc);
+	auto dataChannel = getDataChannel(dc);
-	if (it == peerConnectionMap.end())
+	if (!dataChannel)
-		return;
+		return -1;
 
-	it->second->setRemoteDescription(Description(string(sdp), type ? string(type) : ""));
+	dataChannel->onOpen(nullptr);
+	dataChannel->onClosed(nullptr);
+	dataChannel->onError(nullptr);
+	dataChannel->onMessage(nullptr);
+	dataChannel->onBufferedAmountLow(nullptr);
+	dataChannel->onAvailable(nullptr);
+
+	eraseDataChannel(dc);
+	return 0;
 }
 
-void rtcAddRemoteCandidate(int pc, const char *candidate, const char *mid) {
+int rtcSetDataChannelCallback(int pc, dataChannelCallbackFunc cb) {
-	auto it = peerConnectionMap.find(pc);
+	auto peerConnection = getPeerConnection(pc);
-	if (it == peerConnectionMap.end())
+	if (!peerConnection)
-		return;
+		return -1;
 
-	it->second->addRemoteCandidate(Candidate(string(candidate), mid ? string(mid) : ""));
+	if (cb)
+		peerConnection->onDataChannel([pc, cb](std::shared_ptr<DataChannel> dataChannel) {
+			int dc = emplaceDataChannel(dataChannel);
+			void *ptr = getUserPointer(pc);
+			rtcSetUserPointer(dc, ptr);
+			cb(dc, ptr);
+		});
+	else
+		peerConnection->onDataChannel(nullptr);
+	return 0;
+}
+
+int rtcSetLocalDescriptionCallback(int pc, descriptionCallbackFunc cb) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	if (cb)
+		peerConnection->onLocalDescription([pc, cb](const Description &desc) {
+			cb(string(desc).c_str(), desc.typeString().c_str(), getUserPointer(pc));
+		});
+	else
+		peerConnection->onLocalDescription(nullptr);
+	return 0;
+}
+
+int rtcSetLocalCandidateCallback(int pc, candidateCallbackFunc cb) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	if (cb)
+		peerConnection->onLocalCandidate([pc, cb](const Candidate &cand) {
+			cb(cand.candidate().c_str(), cand.mid().c_str(), getUserPointer(pc));
+		});
+	else
+		peerConnection->onLocalCandidate(nullptr);
+	return 0;
+}
+
+int rtcSetStateChangeCallback(int pc, stateChangeCallbackFunc cb) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	if (cb)
+		peerConnection->onStateChange([pc, cb](PeerConnection::State state) {
+			cb(static_cast<rtcState>(state), getUserPointer(pc));
+		});
+	else
+		peerConnection->onStateChange(nullptr);
+	return 0;
+}
+
+int rtcSetGatheringStateChangeCallback(int pc, gatheringStateCallbackFunc cb) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	if (cb)
+		peerConnection->onGatheringStateChange([pc, cb](PeerConnection::GatheringState state) {
+			cb(static_cast<rtcGatheringState>(state), getUserPointer(pc));
+		});
+	else
+		peerConnection->onGatheringStateChange(nullptr);
+	return 0;
+}
+
+int rtcSetRemoteDescription(int pc, const char *sdp, const char *type) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	CATCH(peerConnection->setRemoteDescription({string(sdp), type ? string(type) : ""}));
+	return 0;
+}
+
+int rtcAddRemoteCandidate(int pc, const char *cand, const char *mid) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	CATCH(peerConnection->addRemoteCandidate({string(cand), mid ? string(mid) : ""}))
+	return 0;
+}
+
+int rtcGetLocalAddress(int pc, char *buffer, int size) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	if (auto addr = peerConnection->localAddress()) {
+		size = std::min(size_t(size - 1), addr->size());
+		std::copy(addr->data(), addr->data() + size, buffer);
+		buffer[size] = '\0';
+		return size + 1;
+	}
+	return -1;
+}
+
+int rtcGetRemoteAddress(int pc, char *buffer, int size) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	if (auto addr = peerConnection->remoteAddress()) {
+		size = std::min(size_t(size - 1), addr->size());
+		std::copy(addr->data(), addr->data() + size, buffer);
+		buffer[size] = '\0';
+		return size + 1;
+	}
+	return -1;
 }
 
 int rtcGetDataChannelLabel(int dc, char *buffer, int size) {
-	auto it = dataChannelMap.find(dc);
+	auto dataChannel = getDataChannel(dc);
-	if (it == dataChannelMap.end())
+	if (!dataChannel)
-		return 0;
+		return -1;
 
 	if (!size)
 		return 0;
 
-	string label = it->second->label();
+	string label = dataChannel->label();
 	size = std::min(size_t(size - 1), label.size());
 	std::copy(label.data(), label.data() + size, buffer);
 	buffer[size] = '\0';
 	return size + 1;
 }
 
-void rtcSetOpenCallback(int dc, void (*openCallback)(void *)) {
+int rtcSetOpenCallback(int dc, openCallbackFunc cb) {
-	auto it = dataChannelMap.find(dc);
+	auto dataChannel = getDataChannel(dc);
-	if (it == dataChannelMap.end())
+	if (!dataChannel)
-		return;
+		return -1;
 
-	it->second->onOpen([dc, openCallback]() { openCallback(getUserPointer(dc)); });
+	if (cb)
+		dataChannel->onOpen([dc, cb]() { cb(getUserPointer(dc)); });
+	else
+		dataChannel->onOpen(nullptr);
+	return 0;
 }
 
-void rtcSetErrorCallback(int dc, void (*errorCallback)(const char *, void *)) {
+int rtcSetClosedCallback(int dc, closedCallbackFunc cb) {
-	auto it = dataChannelMap.find(dc);
+	auto dataChannel = getDataChannel(dc);
-	if (it == dataChannelMap.end())
+	if (!dataChannel)
-		return;
+		return -1;
 
-	it->second->onError([dc, errorCallback](const string &error) {
+	if (cb)
-		errorCallback(error.c_str(), getUserPointer(dc));
+		dataChannel->onClosed([dc, cb]() { cb(getUserPointer(dc)); });
-	});
+	else
+		dataChannel->onClosed(nullptr);
+	return 0;
 }
 
-void rtcSetMessageCallback(int dc, void (*messageCallback)(const char *, int, void *)) {
+int rtcSetErrorCallback(int dc, errorCallbackFunc cb) {
-	auto it = dataChannelMap.find(dc);
+	auto dataChannel = getDataChannel(dc);
-	if (it == dataChannelMap.end())
+	if (!dataChannel)
-		return;
+		return -1;
 
-	it->second->onMessage(
+	if (cb)
-	    [dc, messageCallback](const binary &b) {
+		dataChannel->onError(
-		    messageCallback(reinterpret_cast<const char *>(b.data()), b.size(), getUserPointer(dc));
+		    [dc, cb](const string &error) { cb(error.c_str(), getUserPointer(dc)); });
-	    },
+	else
-	    [dc, messageCallback](const string &s) {
+		dataChannel->onError(nullptr);
-		    messageCallback(s.c_str(), -1, getUserPointer(dc));
+	return 0;
-	    });
+}
+
+int rtcSetMessageCallback(int dc, messageCallbackFunc cb) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (cb)
+		dataChannel->onMessage(
+		    [dc, cb](const binary &b) {
+			    cb(reinterpret_cast<const char *>(b.data()), b.size(), getUserPointer(dc));
+		    },
+		    [dc, cb](const string &s) { cb(s.c_str(), -1, getUserPointer(dc)); });
+	else
+		dataChannel->onMessage(nullptr);
+
+	return 0;
 }
 
 int rtcSendMessage(int dc, const char *data, int size) {
-	auto it = dataChannelMap.find(dc);
+	auto dataChannel = getDataChannel(dc);
-	if (it == dataChannelMap.end())
+	if (!dataChannel)
-		return 0;
+		return -1;
 
 	if (size >= 0) {
 		auto b = reinterpret_cast<const byte *>(data);
-		it->second->send(b, size);
+		CATCH(dataChannel->send(b, size));
 		return size;
 	} else {
 		string s(data);
-		it->second->send(s);
+		CATCH(dataChannel->send(s));
 		return s.size();
 	}
 }
 
-void rtcSetUserPointer(int i, void *ptr) {
+int rtcGetBufferedAmount(int dc) {
-	if (ptr)
+	auto dataChannel = getDataChannel(dc);
-		userPointerMap.insert(std::make_pair(i, ptr));
+	if (!dataChannel)
-	else
+		return -1;
-		userPointerMap.erase(i);
+
+	CATCH(return int(dataChannel->bufferedAmount()));
+}
+
+int rtcSetBufferedAmountLowThreshold(int dc, int amount) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	CATCH(dataChannel->setBufferedAmountLowThreshold(size_t(amount)));
+	return 0;
+}
+
+int rtcSetBufferedAmountLowCallback(int dc, bufferedAmountLowCallbackFunc cb) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (cb)
+		dataChannel->onBufferedAmountLow([dc, cb]() { cb(getUserPointer(dc)); });
+	else
+		dataChannel->onBufferedAmountLow(nullptr);
+	return 0;
+}
+
+int rtcGetAvailableAmount(int dc) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	CATCH(return int(dataChannel->availableAmount()));
+}
+
+int rtcSetAvailableCallback(int dc, availableCallbackFunc cb) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (cb)
+		dataChannel->onOpen([dc, cb]() { cb(getUserPointer(dc)); });
+	else
+		dataChannel->onOpen(nullptr);
+	return 0;
+}
+
+int rtcReceiveMessage(int dc, char *buffer, int *size) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (!size)
+		return -1;
+
+	CATCH({
+		auto message = dataChannel->receive();
+		if (!message)
+			return 0;
+
+		return std::visit( //
+		    overloaded{    //
+		               [&](const binary &b) {
+			               *size = std::min(*size, int(b.size()));
+			               auto data = reinterpret_cast<const char *>(b.data());
+			               std::copy(data, data + *size, buffer);
+			               return *size;
+		               },
+		               [&](const string &s) {
+			               int len = std::min(*size - 1, int(s.size()));
+			               if (len >= 0) {
+				               std::copy(s.data(), s.data() + len, buffer);
+				               buffer[len] = '\0';
+			               }
+			               *size = -(len + 1);
+			               return len + 1;
+		               }},
+		    *message);
+	});
 }

src/sctptransport.cpp

@@ -23,7 +23,24 @@
 #include <iostream>
 #include <vector>
 
-#include <arpa/inet.h>
+#ifdef USE_JUICE
+#ifndef __APPLE__
+// libjuice enables Linux path MTU discovery or sets the DF flag
+#define USE_PMTUD 1
+#else
+// Setting the DF flag is not available on Mac OS
+#define USE_PMTUD 0
+#endif
+#else
+#ifdef __linux__
+// Linux UDP does path MTU discovery by default (setting DF and returning EMSGSIZE)
+// It should be safe to enable discovery for SCTP.
+#define USE_PMTUD 1
+#else
+// Otherwise assume fragmentation
+#define USE_PMTUD 0
+#endif
+#endif
 
 using namespace std::chrono_literals;
 using namespace std::chrono;
@@ -32,31 +49,20 @@ using std::shared_ptr;
 
 namespace rtc {
 
-std::mutex SctpTransport::GlobalMutex;
+void SctpTransport::Init() {
-int SctpTransport::InstancesCount = 0;
+	usrsctp_init(0, &SctpTransport::WriteCallback, nullptr);
-
+	usrsctp_sysctl_set_sctp_ecn_enable(0);
-void SctpTransport::GlobalInit() {
+	usrsctp_sysctl_set_sctp_init_rtx_max_default(5);
-	std::lock_guard lock(GlobalMutex);
+	usrsctp_sysctl_set_sctp_path_rtx_max_default(5);
-	if (InstancesCount++ == 0) {
+	usrsctp_sysctl_set_sctp_assoc_rtx_max_default(5);              // single path
-		usrsctp_init(0, &SctpTransport::WriteCallback, nullptr);
+	usrsctp_sysctl_set_sctp_rto_min_default(1 * 1000);             // ms
-		usrsctp_sysctl_set_sctp_ecn_enable(0);
+	usrsctp_sysctl_set_sctp_rto_max_default(10 * 1000);            // ms
-		usrsctp_sysctl_set_sctp_init_rtx_max_default(5);
+	usrsctp_sysctl_set_sctp_rto_initial_default(1 * 1000);         // ms
-		usrsctp_sysctl_set_sctp_path_rtx_max_default(5);
+	usrsctp_sysctl_set_sctp_init_rto_max_default(10 * 1000);       // ms
-		usrsctp_sysctl_set_sctp_assoc_rtx_max_default(5);              // single path
+	usrsctp_sysctl_set_sctp_heartbeat_interval_default(10 * 1000); // ms
-		usrsctp_sysctl_set_sctp_rto_min_default(1 * 1000);             // ms
-		usrsctp_sysctl_set_sctp_rto_max_default(10 * 1000);            // ms
-		usrsctp_sysctl_set_sctp_rto_initial_default(1 * 1000);         // ms
-		usrsctp_sysctl_set_sctp_init_rto_max_default(10 * 1000);       // ms
-		usrsctp_sysctl_set_sctp_heartbeat_interval_default(10 * 1000); // ms
-	}
 }
 
-void SctpTransport::GlobalCleanup() {
+void SctpTransport::Cleanup() { usrsctp_finish(); }
-	std::lock_guard lock(GlobalMutex);
-	if (--InstancesCount == 0) {
-		usrsctp_finish();
-	}
-}
 
 SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
                              message_callback recvCallback, amount_callback bufferedAmountCallback,
@@ -67,7 +73,6 @@ SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
 	onRecv(recvCallback);
 
 	PLOG_DEBUG << "Initializing SCTP transport";
-	GlobalInit();
 
 	usrsctp_register_address(this);
 	mSock = usrsctp_socket(AF_CONN, SOCK_STREAM, IPPROTO_SCTP, &SctpTransport::RecvCallback,
@@ -117,12 +122,11 @@ SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
 		                         std::to_string(errno));
 
 	struct sctp_paddrparams spp = {};
-#ifdef __linux__
+#if USE_PMTUD
-	// Linux UDP does path MTU discovery by default (setting DF and returning EMSGSIZE).
+	// Enabled SCTP path MTU discovery
-	// It should be safe to enable discovery for SCTP.
 	spp.spp_flags = SPP_PMTUD_ENABLE;
 #else
-	// Otherwise, fall back to a safe MTU value.
+	// Fall back to a safe MTU value.
 	spp.spp_flags = SPP_PMTUD_DISABLE;
 	spp.spp_pathmtu = 1200; // Max safe value recommended by RFC 8261
 	                        // See https://tools.ietf.org/html/rfc8261#section-5
@@ -140,6 +144,14 @@ SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
 		throw std::runtime_error("Could not set socket option SCTP_INITMSG, errno=" +
 		                         std::to_string(errno));
 
+	// Prevent fragmented interleave of messages (i.e. level 0), see RFC 6458 8.1.20.
+	// Unless the user has set the fragmentation interleave level to 0, notifications
+	// may also be interleaved with partially delivered messages.
+	int level = 0;
+	if (usrsctp_setsockopt(mSock, IPPROTO_SCTP, SCTP_FRAGMENT_INTERLEAVE, &level, sizeof(level)))
+		throw std::runtime_error("Could not disable SCTP fragmented interleave, errno=" +
+		                         std::to_string(errno));
+
 	// The default send and receive window size of usrsctp is 256KiB, which is too small for
 	// realistic RTTs, therefore we increase it to 1MiB for better performance.
 	// See https://bugzilla.mozilla.org/show_bug.cgi?id=1051685
@@ -159,21 +171,19 @@ SctpTransport::~SctpTransport() {
 
 	usrsctp_close(mSock);
 	usrsctp_deregister_address(this);
-
-	GlobalCleanup();
 }
 
 SctpTransport::State SctpTransport::state() const { return mState; }
 
-void SctpTransport::stop() {
+bool SctpTransport::stop() {
-	Transport::stop();
+	if (!Transport::stop())
-	onRecv(nullptr);
+		return false;
 
-	if (!mShutdown.exchange(true)) {
+	mSendQueue.stop();
-		mSendQueue.stop();
+	safeFlush();
-		flush();
+	shutdown();
-		shutdown();
+	onRecv(nullptr);
-	}
+	return true;
 }
 
 void SctpTransport::connect() {
@@ -261,13 +271,15 @@ void SctpTransport::incoming(message_ptr message) {
 		mWrittenCondition.wait(lock, [&]() { return mWrittenOnce || mState != State::Connected; });
 	}
 
-	if (message) {
+	if (!message) {
-		usrsctp_conninput(this, message->data(), message->size(), 0);
-	} else {
 		PLOG_INFO << "SCTP disconnected";
 		changeState(State::Disconnected);
 		recv(nullptr);
+		return;
 	}
+
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	usrsctp_conninput(this, message->data(), message->size(), 0);
 }
 
 void SctpTransport::changeState(State state) {
@@ -352,8 +364,10 @@ bool SctpTransport::trySendMessage(message_ptr message) {
 
 	if (ret >= 0) {
 		PLOG_VERBOSE << "SCTP sent size=" << message->size();
+		if (message->type == Message::Type::Binary || message->type == Message::Type::String)
+			mBytesSent += message->size();
 		return true;
-	} else if (errno == EWOULDBLOCK && errno == EAGAIN) {
+	} else if (errno == EWOULDBLOCK || errno == EAGAIN) {
 		PLOG_VERBOSE << "SCTP sending not possible";
 		return false;
 	} else {
@@ -365,25 +379,42 @@ bool SctpTransport::trySendMessage(message_ptr message) {
 void SctpTransport::updateBufferedAmount(uint16_t streamId, long delta) {
 	// Requires mSendMutex to be locked
 	auto it = mBufferedAmount.insert(std::make_pair(streamId, 0)).first;
-	size_t amount = it->second;
+	size_t amount = size_t(std::max(long(it->second) + delta, long(0)));
-	amount = size_t(std::max(long(amount) + delta, long(0)));
 	if (amount == 0)
 		mBufferedAmount.erase(it);
+	else
+		it->second = amount;
+
 	mBufferedAmountCallback(streamId, amount);
 }
 
+bool SctpTransport::safeFlush() {
+	try {
+		flush();
+		return true;
+
+	} catch (const std::exception &e) {
+		PLOG_ERROR << "SCTP flush: " << e.what();
+		return false;
+	}
+}
+
 int SctpTransport::handleRecv(struct socket *sock, union sctp_sockstore addr, const byte *data,
                               size_t len, struct sctp_rcvinfo info, int flags) {
 	try {
+		PLOG_VERBOSE << "Handle recv, len=" << len;
 		if (!len)
 			return -1;
+
+		// This is valid because SCTP_FRAGMENT_INTERLEAVE is set to level 0
+		// so partial messages and notifications may not be interleaved.
 		if (flags & MSG_EOR) {
 			if (!mPartialRecv.empty()) {
 				mPartialRecv.insert(mPartialRecv.end(), data, data + len);
 				data = mPartialRecv.data();
 				len = mPartialRecv.size();
 			}
-			// Message is complete, process it
+			// Message/Notification is complete, process it
 			if (flags & MSG_NOTIFICATION)
 				processNotification(reinterpret_cast<const union sctp_notification *>(data), len);
 			else
@@ -391,7 +422,7 @@ int SctpTransport::handleRecv(struct socket *sock, union sctp_sockstore addr, co
 
 			mPartialRecv.clear();
 		} else {
-			// Message is not complete
+			// Message/Notification is not complete
 			mPartialRecv.insert(mPartialRecv.end(), data, data + len);
 		}
 	} catch (const std::exception &e) {
@@ -402,24 +433,21 @@ int SctpTransport::handleRecv(struct socket *sock, union sctp_sockstore addr, co
 }
 
 int SctpTransport::handleSend(size_t free) {
-	try {
+	PLOG_VERBOSE << "Handle send, free=" << free;
-		std::lock_guard lock(mSendMutex);
+	return safeFlush() ? 0 : -1;
-		trySendQueue();
-	} catch (const std::exception &e) {
-		PLOG_ERROR << "SCTP send: " << e.what();
-		return -1;
-	}
-	return 0; // success
 }
 
 int SctpTransport::handleWrite(byte *data, size_t len, uint8_t tos, uint8_t set_df) {
 	try {
+		PLOG_VERBOSE << "Handle write, len=" << len;
+
 		std::unique_lock lock(mWriteMutex);
 		if (!outgoing(make_message(data, data + len)))
 			return -1;
 		mWritten = true;
 		mWrittenOnce = true;
 		mWrittenCondition.notify_all();
+
 	} catch (const std::exception &e) {
 		PLOG_ERROR << "SCTP write: " << e.what();
 		return -1;
@@ -428,6 +456,8 @@ int SctpTransport::handleWrite(byte *data, size_t len, uint8_t tos, uint8_t set_
 }
 
 void SctpTransport::processData(const byte *data, size_t len, uint16_t sid, PayloadId ppid) {
+	PLOG_VERBOSE << "Process data, len=" << len;
+
 	// The usage of the PPIDs "WebRTC String Partial" and "WebRTC Binary Partial" is deprecated.
 	// See https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-13#section-6.6
 	// We handle them at reception for compatibility reasons but should never send them.
@@ -442,9 +472,11 @@ void SctpTransport::processData(const byte *data, size_t len, uint16_t sid, Payl
 
 	case PPID_STRING:
 		if (mPartialStringData.empty()) {
+			mBytesReceived += len;
 			recv(make_message(data, data + len, Message::String, sid));
 		} else {
 			mPartialStringData.insert(mPartialStringData.end(), data, data + len);
+			mBytesReceived += mPartialStringData.size();
 			recv(make_message(mPartialStringData.begin(), mPartialStringData.end(), Message::String,
 			                  sid));
 			mPartialStringData.clear();
@@ -464,9 +496,11 @@ void SctpTransport::processData(const byte *data, size_t len, uint16_t sid, Payl
 
 	case PPID_BINARY:
 		if (mPartialBinaryData.empty()) {
+			mBytesReceived += len;
 			recv(make_message(data, data + len, Message::Binary, sid));
 		} else {
 			mPartialBinaryData.insert(mPartialBinaryData.end(), data, data + len);
+			mBytesReceived += mPartialStringData.size();
 			recv(make_message(mPartialBinaryData.begin(), mPartialBinaryData.end(), Message::Binary,
 			                  sid));
 			mPartialBinaryData.clear();
@@ -488,10 +522,15 @@ void SctpTransport::processData(const byte *data, size_t len, uint16_t sid, Payl
 }
 
 void SctpTransport::processNotification(const union sctp_notification *notify, size_t len) {
-	if (len != size_t(notify->sn_header.sn_length))
+	if (len != size_t(notify->sn_header.sn_length)) {
+		PLOG_WARNING << "Invalid notification length";
 		return;
+	}
 
-	switch (notify->sn_header.sn_type) {
+	auto type = notify->sn_header.sn_type;
+	PLOG_VERBOSE << "Process notification, type=" << type;
+
+	switch (type) {
 	case SCTP_ASSOC_CHANGE: {
 		const struct sctp_assoc_change &assoc_change = notify->sn_assoc_change;
 		if (assoc_change.sac_state == SCTP_COMM_UP) {
@@ -507,13 +546,16 @@ void SctpTransport::processNotification(const union sctp_notification *notify, s
 			}
 			mWrittenCondition.notify_all();
 		}
+		break;
 	}
+
 	case SCTP_SENDER_DRY_EVENT: {
 		// It not should be necessary since the send callback should have been called already,
 		// but to be sure, let's try to send now.
-		std::lock_guard lock(mSendMutex);
+		safeFlush();
-		trySendQueue();
+		break;
 	}
+
 	case SCTP_STREAM_RESET_EVENT: {
 		const struct sctp_stream_reset_event &reset_event = notify->sn_strreset_event;
 		const int count = (reset_event.strreset_length - sizeof(reset_event)) / sizeof(uint16_t);
@@ -542,6 +584,26 @@ void SctpTransport::processNotification(const union sctp_notification *notify, s
 	}
 }
 
+void SctpTransport::clearStats() {
+	mBytesReceived = 0;
+	mBytesSent = 0;
+}
+
+size_t SctpTransport::bytesSent() { return mBytesSent; }
+
+size_t SctpTransport::bytesReceived() { return mBytesReceived; }
+
+std::optional<std::chrono::milliseconds> SctpTransport::rtt() {
+	struct sctp_status status = {};
+	socklen_t len = sizeof(status);
+
+	if (usrsctp_getsockopt(this->mSock, IPPROTO_SCTP, SCTP_STATUS, &status, &len)) {
+		PLOG_WARNING << "Could not read SCTP_STATUS";
+		return std::nullopt;
+	}
+	return std::chrono::milliseconds(status.sstat_primary.spinfo_srtt);
+}
+
 int SctpTransport::RecvCallback(struct socket *sock, union sctp_sockstore addr, void *data,
                                 size_t len, struct sctp_rcvinfo recv_info, int flags, void *ptr) {
 	int ret = static_cast<SctpTransport *>(ptr)->handleRecv(

src/sctptransport.hpp

@@ -29,15 +29,15 @@
 #include <map>
 #include <mutex>
 
-#include <sys/socket.h>
-#include <sys/types.h>
-
 #include "usrsctp.h"
 
 namespace rtc {
 
 class SctpTransport : public Transport {
 public:
+	static void Init();
+	static void Cleanup();
+
 	enum class State { Disconnected, Connecting, Connected, Failed };
 
 	using amount_callback = std::function<void(uint16_t streamId, size_t amount)>;
@@ -49,11 +49,17 @@ public:
 
 	State state() const;
 
-	void stop() override;
+	bool stop() override;
 	bool send(message_ptr message) override; // false if buffered
 	void flush();
 	void reset(unsigned int stream);
 
+	// Stats
+	void clearStats();
+	size_t bytesSent();
+	size_t bytesReceived();
+	std::optional<std::chrono::milliseconds> rtt();
+
 private:
 	// Order seems wrong but these are the actual values
 	// See https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-13#section-8
@@ -75,6 +81,7 @@ private:
 	bool trySendQueue();
 	bool trySendMessage(message_ptr message);
 	void updateBufferedAmount(uint16_t streamId, long delta);
+	bool safeFlush();
 
 	int handleRecv(struct socket *sock, union sctp_sockstore addr, const byte *data, size_t len,
 	               struct sctp_rcvinfo recv_info, int flags);
@@ -97,23 +104,18 @@ private:
 	bool mWritten = false;
 	bool mWrittenOnce = false;
 
-	std::atomic<bool> mShutdown = false;
-
 	state_callback mStateChangeCallback;
 	std::atomic<State> mState;
 
+	// Stats
+	std::atomic<size_t> mBytesSent = 0, mBytesReceived = 0;
+
 	binary mPartialRecv, mPartialStringData, mPartialBinaryData;
 
 	static int RecvCallback(struct socket *sock, union sctp_sockstore addr, void *data, size_t len,
 	                        struct sctp_rcvinfo recv_info, int flags, void *user_data);
 	static int SendCallback(struct socket *sock, uint32_t sb_free);
 	static int WriteCallback(void *sctp_ptr, void *data, size_t len, uint8_t tos, uint8_t set_df);
-
-	void GlobalInit();
-	void GlobalCleanup();
-
-	static std::mutex GlobalMutex;
-	static int InstancesCount;
 };
 
 } // namespace rtc

src/transport.hpp

@@ -38,9 +38,10 @@ public:
 	}
 	virtual ~Transport() { stop(); }
 
-	virtual void stop() {
+	virtual bool stop() {
 		if (mLower)
 			mLower->onRecv(nullptr);
+		return !mShutdown.exchange(true);
 	}
 
 	virtual bool send(message_ptr message) = 0;
@@ -61,6 +62,7 @@ protected:
 private:
 	std::shared_ptr<Transport> mLower;
 	synchronized_callback<message_ptr> mRecvCallback;
+	std::atomic<bool> mShutdown = false;
 };
 
 } // namespace rtc

test/capi.cpp

@@ -0,0 +1,213 @@
+/**
+ * Copyright (c) 2020 Paul-Louis Ageneau
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <rtc/rtc.h>
+
+#include <cstdbool>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+#include <unistd.h> // for sleep
+
+using namespace std;
+
+typedef struct {
+	rtcState state;
+	rtcGatheringState gatheringState;
+	int pc;
+	int dc;
+	bool connected;
+} Peer;
+
+Peer *peer1 = NULL;
+Peer *peer2 = NULL;
+
+static void descriptionCallback(const char *sdp, const char *type, void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	printf("Description %d:\n%s\n", peer == peer1 ? 1 : 2, sdp);
+	Peer *other = peer == peer1 ? peer2 : peer1;
+	rtcSetRemoteDescription(other->pc, sdp, type);
+}
+
+static void candidateCallback(const char *cand, const char *mid, void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	printf("Candidate %d: %s\n", peer == peer1 ? 1 : 2, cand);
+	Peer *other = peer == peer1 ? peer2 : peer1;
+	rtcAddRemoteCandidate(other->pc, cand, mid);
+}
+
+static void stateChangeCallback(rtcState state, void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	peer->state = state;
+	printf("State %d: %d\n", peer == peer1 ? 1 : 2, (int)state);
+}
+
+static void gatheringStateCallback(rtcGatheringState state, void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	peer->gatheringState = state;
+	printf("Gathering state %d: %d\n", peer == peer1 ? 1 : 2, (int)state);
+}
+
+static void openCallback(void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	peer->connected = true;
+	printf("DataChannel %d: Open\n", peer == peer1 ? 1 : 2);
+
+	const char *message = peer == peer1 ? "Hello from 1" : "Hello from 2";
+	rtcSendMessage(peer->dc, message, -1); // negative size indicates a null-terminated string
+}
+
+static void closedCallback(void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	peer->connected = false;
+}
+
+static void messageCallback(const char *message, int size, void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	if (size < 0) { // negative size indicates a null-terminated string
+		printf("Message %d: %s\n", peer == peer1 ? 1 : 2, message);
+	} else {
+		printf("Message %d: [binary of size %d]\n", peer == peer1 ? 1 : 2, size);
+	}
+}
+
+static void dataChannelCallback(int dc, void *ptr) {
+	Peer *peer = (Peer *)ptr;
+	peer->dc = dc;
+	peer->connected = true;
+	rtcSetClosedCallback(dc, closedCallback);
+	rtcSetMessageCallback(dc, messageCallback);
+
+	char buffer[256];
+	if (rtcGetDataChannelLabel(dc, buffer, 256) >= 0)
+		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
+}
+
+static Peer *createPeer(const rtcConfiguration *config) {
+	Peer *peer = (Peer *)malloc(sizeof(Peer));
+	if (!peer)
+		return nullptr;
+	memset(peer, 0, sizeof(Peer));
+
+	// Create peer connection
+	peer->pc = rtcCreatePeerConnection(config);
+	rtcSetUserPointer(peer->pc, peer);
+	rtcSetDataChannelCallback(peer->pc, dataChannelCallback);
+	rtcSetLocalDescriptionCallback(peer->pc, descriptionCallback);
+	rtcSetLocalCandidateCallback(peer->pc, candidateCallback);
+	rtcSetStateChangeCallback(peer->pc, stateChangeCallback);
+	rtcSetGatheringStateChangeCallback(peer->pc, gatheringStateCallback);
+
+	return peer;
+}
+
+static void deletePeer(Peer *peer) {
+	if (peer) {
+		if (peer->dc)
+			rtcDeleteDataChannel(peer->dc);
+		if (peer->pc)
+			rtcDeletePeerConnection(peer->pc);
+		free(peer);
+	}
+}
+
+int test_capi_main() {
+	int attempts;
+
+	rtcInitLogger(RTC_LOG_DEBUG);
+
+	// Create peer 1
+	rtcConfiguration config1;
+	memset(&config1, 0, sizeof(config1));
+	// STUN server example
+	// const char *iceServers[1] = {"stun:stun.l.google.com:19302"};
+	// config1.iceServers = iceServers;
+	// config1.iceServersCount = 1;
+
+	peer1 = createPeer(&config1);
+	if (!peer1)
+		goto error;
+
+	// Create peer 2
+	rtcConfiguration config2;
+	memset(&config2, 0, sizeof(config2));
+	// STUN server example
+	// config2.iceServers = iceServers;
+	// config2.iceServersCount = 1;
+	// Port range example
+	config2.portRangeBegin = 5000;
+	config2.portRangeEnd = 6000;
+
+	peer2 = createPeer(&config2);
+	if (!peer2)
+		goto error;
+
+	// Peer 1: Create data channel
+	peer1->dc = rtcCreateDataChannel(peer1->pc, "test");
+	rtcSetOpenCallback(peer1->dc, openCallback);
+	rtcSetClosedCallback(peer1->dc, closedCallback);
+	rtcSetMessageCallback(peer1->dc, messageCallback);
+
+	attempts = 10;
+	while (!peer2->connected && !peer1->connected && attempts--)
+		sleep(1);
+
+	if (peer1->state != RTC_CONNECTED || peer2->state != RTC_CONNECTED) {
+		fprintf(stderr, "PeerConnection is not connected\n");
+		goto error;
+	}
+
+	if (!peer1->connected || !peer2->connected) {
+		fprintf(stderr, "DataChannel is not connected\n");
+		goto error;
+	}
+
+	char buffer[256];
+	if (rtcGetLocalAddress(peer1->pc, buffer, 256) >= 0)
+		printf("Local address 1:  %s\n", buffer);
+	if (rtcGetRemoteAddress(peer1->pc, buffer, 256) >= 0)
+		printf("Remote address 1: %s\n", buffer);
+	if (rtcGetLocalAddress(peer2->pc, buffer, 256) >= 0)
+		printf("Local address 2:  %s\n", buffer);
+	if (rtcGetRemoteAddress(peer2->pc, buffer, 256) >= 0)
+		printf("Remote address 2: %s\n", buffer);
+
+	deletePeer(peer1);
+	sleep(1);
+	deletePeer(peer2);
+	sleep(1);
+
+	printf("Success\n");
+	return 0;
+
+error:
+	deletePeer(peer1);
+	deletePeer(peer2);
+	return -1;
+}
+
+#include <stdexcept>
+
+void test_capi() {
+	if (test_capi_main())
+		throw std::runtime_error("Connection failed");
+}

test/connectivity.cpp

@@ -0,0 +1,144 @@
+/**
+ * Copyright (c) 2019 Paul-Louis Ageneau
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "rtc/rtc.hpp"
+
+#include <chrono>
+#include <iostream>
+#include <memory>
+#include <thread>
+
+using namespace rtc;
+using namespace std;
+
+template <class T> weak_ptr<T> make_weak_ptr(shared_ptr<T> ptr) { return ptr; }
+
+void test_connectivity() {
+	InitLogger(LogLevel::Debug);
+
+	Configuration config1;
+	// STUN server example
+	// config1.iceServers.emplace_back("stun:stun.l.google.com:19302");
+
+	auto pc1 = std::make_shared<PeerConnection>(config1);
+
+	Configuration config2;
+	// STUN server example
+	// config2.iceServers.emplace_back("stun:stun.l.google.com:19302");
+	// Port range example
+	config2.portRangeBegin = 5000;
+	config2.portRangeEnd = 6000;
+
+	auto pc2 = std::make_shared<PeerConnection>(config2);
+
+	pc1->onLocalDescription([wpc2 = make_weak_ptr(pc2)](const Description &sdp) {
+		auto pc2 = wpc2.lock();
+		if (!pc2)
+			return;
+		cout << "Description 1: " << sdp << endl;
+		pc2->setRemoteDescription(sdp);
+	});
+
+	pc1->onLocalCandidate([wpc2 = make_weak_ptr(pc2)](const Candidate &candidate) {
+		auto pc2 = wpc2.lock();
+		if (!pc2)
+			return;
+		cout << "Candidate 1: " << candidate << endl;
+		pc2->addRemoteCandidate(candidate);
+	});
+
+	pc1->onStateChange([](PeerConnection::State state) { cout << "State 1: " << state << endl; });
+	pc1->onGatheringStateChange([](PeerConnection::GatheringState state) {
+		cout << "Gathering state 1: " << state << endl;
+	});
+
+	pc2->onLocalDescription([wpc1 = make_weak_ptr(pc1)](const Description &sdp) {
+		auto pc1 = wpc1.lock();
+		if (!pc1)
+			return;
+		cout << "Description 2: " << sdp << endl;
+		pc1->setRemoteDescription(sdp);
+	});
+
+	pc2->onLocalCandidate([wpc1 = make_weak_ptr(pc1)](const Candidate &candidate) {
+		auto pc1 = wpc1.lock();
+		if (!pc1)
+			return;
+		cout << "Candidate 2: " << candidate << endl;
+		pc1->addRemoteCandidate(candidate);
+	});
+
+	pc2->onStateChange([](PeerConnection::State state) { cout << "State 2: " << state << endl; });
+	pc2->onGatheringStateChange([](PeerConnection::GatheringState state) {
+		cout << "Gathering state 2: " << state << endl;
+	});
+
+	shared_ptr<DataChannel> dc2;
+	pc2->onDataChannel([&dc2](shared_ptr<DataChannel> dc) {
+		cout << "DataChannel 2: Received with label \"" << dc->label() << "\"" << endl;
+		dc2 = dc;
+		dc2->onMessage([](const variant<binary, string> &message) {
+			if (holds_alternative<string>(message)) {
+				cout << "Message 2: " << get<string>(message) << endl;
+			}
+		});
+		dc2->send("Hello from 2");
+	});
+
+	auto dc1 = pc1->createDataChannel("test");
+	dc1->onOpen([wdc1 = make_weak_ptr(dc1)]() {
+		auto dc1 = wdc1.lock();
+		if (!dc1)
+			return;
+		cout << "DataChannel 1: Open" << endl;
+		dc1->send("Hello from 1");
+	});
+	dc1->onMessage([](const variant<binary, string> &message) {
+		if (holds_alternative<string>(message)) {
+			cout << "Message 1: " << get<string>(message) << endl;
+		}
+	});
+
+	int attempts = 10;
+	while ((!dc2 || !dc2->isOpen() || !dc1->isOpen()) && attempts--)
+		this_thread::sleep_for(1s);
+
+	if (pc1->state() != PeerConnection::State::Connected &&
+	    pc2->state() != PeerConnection::State::Connected)
+		throw runtime_error("PeerConnection is not connected");
+
+	if (!dc1->isOpen() || !dc2->isOpen())
+		throw runtime_error("DataChannel is not open");
+
+	if (auto addr = pc1->localAddress())
+		cout << "Local address 1:  " << *addr << endl;
+	if (auto addr = pc1->remoteAddress())
+		cout << "Remote address 1: " << *addr << endl;
+	if (auto addr = pc2->localAddress())
+		cout << "Local address 2:  " << *addr << endl;
+	if (auto addr = pc2->remoteAddress())
+		cout << "Remote address 2: " << *addr << endl;
+
+	// Delay close of peer 2 to check closing works properly
+	pc1->close();
+	this_thread::sleep_for(1s);
+	pc2->close();
+	this_thread::sleep_for(1s);
+
+	cout << "Success" << endl;
+}

test/main.cpp

@@ -16,120 +16,29 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include "rtc/rtc.hpp"
-
-#include <chrono>
 #include <iostream>
-#include <memory>
-#include <thread>
 
-using namespace rtc;
 using namespace std;
 
-template <class T> weak_ptr<T> make_weak_ptr(shared_ptr<T> ptr) { return ptr; }
+void test_connectivity();
+void test_capi();
 
 int main(int argc, char **argv) {
-	InitLogger(LogLevel::Warning);
+	try {
-
+		std::cout << "*** Running connectivity test..." << std::endl;
-	Configuration config;
+		test_connectivity();
-	// config.iceServers.emplace_back("stun:stun.l.google.com:19302");
+		std::cout << "*** Finished connectivity test" << std::endl;
-	// config.enableIceTcp = true;
+	} catch (const exception &e) {
-
+		std::cerr << "Connectivity test failed: " << e.what() << endl;
-	// TURN server example
+		return -1;
-	// IceServer turnServer("TURN_SERVER_URL", "PORT_NO", "USERNAME", "PASSWORD",
-	//							IceServer::RelayType::TurnUdp);
-	// config.iceServers.push_back(turnServer);
-
-	auto pc1 = std::make_shared<PeerConnection>(config);
-	auto pc2 = std::make_shared<PeerConnection>(config);
-
-	pc1->onLocalDescription([wpc2 = make_weak_ptr(pc2)](const Description &sdp) {
-		auto pc2 = wpc2.lock();
-		if (!pc2)
-			return;
-		cout << "Description 1: " << sdp << endl;
-		pc2->setRemoteDescription(sdp);
-	});
-
-	pc1->onLocalCandidate([wpc2 = make_weak_ptr(pc2)](const Candidate &candidate) {
-		auto pc2 = wpc2.lock();
-		if (!pc2)
-			return;
-		cout << "Candidate 1: " << candidate << endl;
-		pc2->addRemoteCandidate(candidate);
-	});
-
-	pc1->onStateChange([](PeerConnection::State state) { cout << "State 1: " << state << endl; });
-	pc1->onGatheringStateChange([](PeerConnection::GatheringState state) {
-		cout << "Gathering state 1: " << state << endl;
-	});
-
-	pc2->onLocalDescription([wpc1 = make_weak_ptr(pc1)](const Description &sdp) {
-		auto pc1 = wpc1.lock();
-		if (!pc1)
-			return;
-		cout << "Description 2: " << sdp << endl;
-		pc1->setRemoteDescription(sdp);
-	});
-
-	pc2->onLocalCandidate([wpc1 = make_weak_ptr(pc1)](const Candidate &candidate) {
-		auto pc1 = wpc1.lock();
-		if (!pc1)
-			return;
-		cout << "Candidate 2: " << candidate << endl;
-		pc1->addRemoteCandidate(candidate);
-	});
-
-	pc2->onStateChange([](PeerConnection::State state) { cout << "State 2: " << state << endl; });
-	pc2->onGatheringStateChange([](PeerConnection::GatheringState state) {
-		cout << "Gathering state 2: " << state << endl;
-	});
-
-	shared_ptr<DataChannel> dc2;
-	pc2->onDataChannel([&dc2](shared_ptr<DataChannel> dc) {
-		cout << "Got a DataChannel with label: " << dc->label() << endl;
-		dc2 = dc;
-		dc2->onMessage([](const variant<binary, string> &message) {
-			if (holds_alternative<string>(message)) {
-				cout << "Received 2: " << get<string>(message) << endl;
-			}
-		});
-		dc2->send("Hello from 2");
-	});
-
-	auto dc1 = pc1->createDataChannel("test");
-	dc1->onOpen([wdc1 = make_weak_ptr(dc1)]() {
-		auto dc1 = wdc1.lock();
-		if (!dc1)
-			return;
-		cout << "DataChannel open: " << dc1->label() << endl;
-		dc1->send("Hello from 1");
-	});
-	dc1->onMessage([](const variant<binary, string> &message) {
-		if (holds_alternative<string>(message)) {
-			cout << "Received 1: " << get<string>(message) << endl;
-		}
-	});
-
-	this_thread::sleep_for(3s);
-
-	if (auto addr = pc1->localAddress())
-		cout << "Local address 1:  " << *addr << endl;
-	if (auto addr = pc1->remoteAddress())
-		cout << "Remote address 1: " << *addr << endl;
-	if (auto addr = pc2->localAddress())
-		cout << "Local address 2:  " << *addr << endl;
-	if (auto addr = pc2->remoteAddress())
-		cout << "Remote address 2: " << *addr << endl;
-
-	if (dc1->isOpen() && dc2->isOpen()) {
-		pc1->close();
-		pc2->close();
-
-		cout << "Success" << endl;
-		return 0;
-	} else {
-		cout << "Failure" << endl;
-		return 1;
 	}
+	try {
+		std::cout << "*** Running C API test..." << std::endl;
+		test_capi();
+		std::cout << "*** Finished C API test" << std::endl;
+	} catch (const exception &e) {
+		std::cerr << "C API test failed: " << e.what() << endl;
+		return -1;
+	}
+	return 0;
 }

test/p2p/answerer.cpp

@@ -21,6 +21,7 @@
 #include <chrono>
 #include <iostream>
 #include <memory>
+#include <thread>
 
 using namespace rtc;
 using namespace std;
@@ -32,41 +33,36 @@ int main(int argc, char **argv) {
 
 	Configuration config;
 	// config.iceServers.emplace_back("stun.l.google.com:19302");
-	// config.enableIceTcp = true;
-
-	// TURN Server example
-	// IceServer turnServer("TURN_SERVER_URL", "PORT_NO", "USERNAME", "PASSWORD",
-	//							IceServer::RelayType::TurnUdp);
-	// config.iceServers.push_back(turnServer);
 
 	auto pc = std::make_shared<PeerConnection>(config);
 
-	pc->onLocalDescription([](const Description &sdp) {
+	pc->onLocalDescription([](const Description &description) {
-		std::string s(sdp);
+		cout << "Local Description (Paste this to the other peer):" << endl;
-		std::replace(s.begin(), s.end(), '\n', static_cast<char>(94));
+		cout << string(description) << endl;
-		cout << "Local Description (Paste this to other peer):" << endl << s << endl << endl;
 	});
 
 	pc->onLocalCandidate([](const Candidate &candidate) {
-		cout << "Local Candidate (Paste this to other peer):" << endl << candidate << endl << endl;
+		cout << "Local Candidate (Paste this to the other peer after the local description):"
+		     << endl;
+		cout << string(candidate) << endl << endl;
 	});
 
 	pc->onStateChange(
-	    [](PeerConnection::State state) { cout << "[ State: " << state << " ]" << endl; });
+	    [](PeerConnection::State state) { cout << "[State: " << state << "]" << endl; });
 	pc->onGatheringStateChange([](PeerConnection::GatheringState state) {
-		cout << "[ Gathering State: " << state << " ]" << endl;
+		cout << "[Gathering State: " << state << "]" << endl;
 	});
 
 	shared_ptr<DataChannel> dc = nullptr;
 	pc->onDataChannel([&](shared_ptr<DataChannel> _dc) {
-		cout << "[ Got a DataChannel with label: " << _dc->label() << " ]" << endl;
+		cout << "[Got a DataChannel with label: " << _dc->label() << "]" << endl;
 		dc = _dc;
 
-		dc->onClosed([&]() { cout << "[ DataChannel closed: " << dc->label() << " ]" << endl; });
+		dc->onClosed([&]() { cout << "[DataChannel closed: " << dc->label() << "]" << endl; });
 
 		dc->onMessage([](const variant<binary, string> &message) {
 			if (holds_alternative<string>(message)) {
-				cout << "[ Received: " << get<string>(message) << " ]" << endl;
+				cout << "[Received message: " << get<string>(message) << "]" << endl;
 			}
 		});
 	});
@@ -74,67 +70,86 @@ int main(int argc, char **argv) {
 	bool exit = false;
 	while (!exit) {
 		cout << endl
+		     << "**********************************************************************************"
+		        "*****"
 		     << endl
-		     << "*************************************************************************" << endl
 		     << "* 0: Exit /"
-		     << " 1: Enter Description /"
+		     << " 1: Enter remote description /"
-		     << " 2: Enter Candidate /"
+		     << " 2: Enter remote candidate /"
-		     << " 3: Send Message *" << endl
+		     << " 3: Send message /"
-		     << " [Command]: ";
+		     << " 4: Print Connection Info *" << endl
+		     << "[Command]: ";
 
-		int command;
+		int command = -1;
-		std::string sdp, candidate, message;
-		const char *a;
-		std::unique_ptr<Candidate> candidatePtr;
-		std::unique_ptr<Description> descPtr;
 		cin >> command;
+		cin.ignore();
 
 		switch (command) {
-		case 0:
+		case 0: {
 			exit = true;
 			break;
-
+		}
-		case 1:
+		case 1: {
 			// Parse Description
-			cout << "[SDP]: ";
+			cout << "[Description]: ";
-			sdp = "";
+			string sdp, line;
-			while (sdp.length() == 0)
+			while (getline(cin, line) && !line.empty()) {
-				getline(cin, sdp);
+				sdp += line;
-
+				sdp += "\r\n";
-			std::replace(sdp.begin(), sdp.end(), static_cast<char>(94), '\n');
+			}
-			descPtr = std::make_unique<Description>(sdp, Description::Type::Offer,
+			std::cout << sdp;
-			                                        Description::Role::Passive);
+			pc->setRemoteDescription(sdp);
-			pc->setRemoteDescription(*descPtr);
 			break;
-
+		}
-		case 2:
+		case 2: {
 			// Parse Candidate
 			cout << "[Candidate]: ";
-			candidate = "";
+			string candidate;
-			while (candidate.length() == 0)
+			getline(cin, candidate);
-				getline(cin, candidate);
+			pc->addRemoteCandidate(candidate);
-
-			candidatePtr = std::make_unique<Candidate>(candidate);
-			pc->addRemoteCandidate(*candidatePtr);
 			break;
-
+		}
-		case 3:
+		case 3: {
 			// Send Message
 			if (!dc || !dc->isOpen()) {
 				cout << "** Channel is not Open ** ";
 				break;
 			}
 			cout << "[Message]: ";
-			message = "";
+			string message;
-			while (message.length() == 0)
+			getline(cin, message);
-				getline(cin, message);
 			dc->send(message);
 			break;
-
+		}
-		default:
+		case 4: {
+			// Connection Info
+			if (!dc || !dc->isOpen()) {
+				cout << "** Channel is not Open ** ";
+				break;
+			}
+			CandidateInfo local, remote;
+			std::optional<std::chrono::milliseconds> rtt = pc->rtt();
+			if (pc->getSelectedCandidatePair(&local, &remote)) {
+				cout << "Local: " << local.address << ":" << local.port << " " << local.type << " "
+				     << local.transportType << endl;
+				cout << "Remote: " << remote.address << ":" << remote.port << " " << remote.type
+				     << " " << remote.transportType << endl;
+				cout << "Bytes Sent:" << pc->bytesSent()
+				     << " / Bytes Received:" << pc->bytesReceived() << " / Round-Trip Time:";
+				if (rtt.has_value())
+					cout << rtt.value().count();
+				else
+					cout << "null";
+				cout << " ms";
+			} else
+				cout << "Could not get Candidate Pair Info" << endl;
+			break;
+		}
+		default: {
 			cout << "** Invalid Command ** ";
 			break;
 		}
+		}
 	}
 
 	if (dc)

test/p2p/offerer.cpp

@@ -21,6 +21,7 @@
 #include <chrono>
 #include <iostream>
 #include <memory>
+#include <thread>
 
 using namespace rtc;
 using namespace std;
@@ -32,106 +33,123 @@ int main(int argc, char **argv) {
 
 	Configuration config;
 	// config.iceServers.emplace_back("stun.l.google.com:19302");
-	// config.enableIceTcp = true;
-
-	// TURN server example
-	// IceServer turnServer("TURN_SERVER_URL", "PORT_NO", "USERNAME", "PASSWORD",
-	//							IceServer::RelayType::TurnUdp);
-	// config.iceServers.push_back(turnServer);
 
 	auto pc = std::make_shared<PeerConnection>(config);
 
-	pc->onLocalDescription([](const Description &sdp) {
+	pc->onLocalDescription([](const Description &description) {
-		std::string s(sdp);
+		cout << "Local Description (Paste this to the other peer):" << endl;
-		std::replace(s.begin(), s.end(), '\n', static_cast<char>(94));
+		cout << string(description) << endl;
-		cout << "Local Description (Paste this to other peer):" << endl << s << endl << endl;
 	});
 
 	pc->onLocalCandidate([](const Candidate &candidate) {
-		cout << "Local Candidate (Paste this to other peer):" << endl << candidate << endl << endl;
+		cout << "Local Candidate (Paste this to the other peer after the local description):"
+		     << endl;
+		cout << string(candidate) << endl << endl;
 	});
 
 	pc->onStateChange(
-	    [](PeerConnection::State state) { cout << "[ State: " << state << " ]" << endl; });
+	    [](PeerConnection::State state) { cout << "[State: " << state << "]" << endl; });
 
 	pc->onGatheringStateChange([](PeerConnection::GatheringState state) {
-		cout << "[ Gathering State: " << state << " ]" << endl;
+		cout << "[Gathering State: " << state << "]" << endl;
 	});
 
-	auto dc = pc->createDataChannel("test");
+	auto dc = pc->createDataChannel("test"); // this is the offerer, so create a data channel
-	dc->onOpen([&]() { cout << "[ DataChannel open: " << dc->label() << " ]" << endl; });
 
-	dc->onClosed([&]() { cout << "[ DataChannel closed: " << dc->label() << " ]" << endl; });
+	dc->onOpen([&]() { cout << "[DataChannel open: " << dc->label() << "]" << endl; });
+
+	dc->onClosed([&]() { cout << "[DataChannel closed: " << dc->label() << "]" << endl; });
 
 	dc->onMessage([](const variant<binary, string> &message) {
 		if (holds_alternative<string>(message)) {
-			cout << "[ Received: " << get<string>(message) << " ]" << endl;
+			cout << "[Received: " << get<string>(message) << "]" << endl;
 		}
 	});
 
+	this_thread::sleep_for(1s);
+
 	bool exit = false;
 	while (!exit) {
 		cout << endl
+		     << "**********************************************************************************"
+		        "*****"
 		     << endl
-		     << "*************************************************************************" << endl
 		     << "* 0: Exit /"
-		     << " 1: Enter Description /"
+		     << " 1: Enter remote description /"
-		     << " 2: Enter Candidate /"
+		     << " 2: Enter remote candidate /"
-		     << " 3: Send Message *" << endl
+		     << " 3: Send message /"
-		     << " [Command]: ";
+		     << " 4: Print Connection Info *" << endl
+		     << "[Command]: ";
 
-		int command;
+		int command = -1;
-		std::string sdp, candidate, message;
-		const char *a;
-		std::unique_ptr<Candidate> candidatePtr;
-		std::unique_ptr<Description> descPtr;
 		cin >> command;
+		cin.ignore();
 
 		switch (command) {
-		case 0:
+		case 0: {
 			exit = true;
 			break;
-
+		}
-		case 1:
+		case 1: {
 			// Parse Description
-			cout << "[SDP]: ";
+			cout << "[Description]: ";
-			sdp = "";
+			string sdp, line;
-			while (sdp.length() == 0)
+			while (getline(cin, line) && !line.empty()) {
-				getline(cin, sdp);
+				sdp += line;
-
+				sdp += "\r\n";
-			std::replace(sdp.begin(), sdp.end(), static_cast<char>(94), '\n');
+			}
-			descPtr = std::make_unique<Description>(sdp);
+			pc->setRemoteDescription(sdp);
-			pc->setRemoteDescription(*descPtr);
 			break;
-
+		}
-		case 2:
+		case 2: {
 			// Parse Candidate
 			cout << "[Candidate]: ";
-			candidate = "";
+			string candidate;
-			while (candidate.length() == 0)
+			getline(cin, candidate);
-				getline(cin, candidate);
+			pc->addRemoteCandidate(candidate);
-
-			candidatePtr = std::make_unique<Candidate>(candidate);
-			pc->addRemoteCandidate(*candidatePtr);
 			break;
-
+		}
-		case 3:
+		case 3: {
 			// Send Message
 			if (!dc->isOpen()) {
 				cout << "** Channel is not Open ** ";
 				break;
 			}
 			cout << "[Message]: ";
-			message = "";
+			string message;
-			while (message.length() == 0)
+			getline(cin, message);
-				getline(cin, message);
 			dc->send(message);
 			break;
-
+		}
-		default:
+		case 4: {
+			// Connection Info
+			if (!dc || !dc->isOpen()) {
+				cout << "** Channel is not Open ** ";
+				break;
+			}
+			CandidateInfo local, remote;
+			std::optional<std::chrono::milliseconds> rtt = pc->rtt();
+			if (pc->getSelectedCandidatePair(&local, &remote)) {
+				cout << "Local: " << local.address << ":" << local.port << " " << local.type << " "
+				     << local.transportType << endl;
+				cout << "Remote: " << remote.address << ":" << remote.port << " " << remote.type
+				     << " " << remote.transportType << endl;
+				cout << "Bytes Sent:" << pc->bytesSent()
+				     << " / Bytes Received:" << pc->bytesReceived() << " / Round-Trip Time:";
+				if (rtt.has_value())
+					cout << rtt.value().count();
+				else
+					cout << "null";
+				cout << " ms";
+			} else
+				cout << "Could not get Candidate Pair Info" << endl;
+			break;
+		}
+		default: {
 			cout << "** Invalid Command ** ";
 			break;
 		}
+		}
 	}
 
 	if (dc)