Bumped version to 0.5.0

Asynchronous certificate generation

.github/workflows/build-gnutls.yml

@@ -0,0 +1,24 @@
+name: Build and test with GnuTLS
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+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
+

.github/workflows/build-nice.yml

@@ -0,0 +1,24 @@
+name: Build and test with libnice
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: install packages
+      run: sudo apt update && sudo apt install libgnutls28-dev libnice-dev
+    - name: submodules
+      run: git submodule update --init --recursive
+    - name: cmake
+      run: cmake -B build -DUSE_JUICE=0 -DUSE_GNUTLS=1
+    - name: make
+      run: (cd build; make)
+    - name: test
+      run: ./build/tests
+

.github/workflows/build-openssl.yml

@@ -0,0 +1,24 @@
+name: Build and test with OpenSSL
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: install packages
+      run: sudo apt update && sudo apt install libssl-dev
+    - name: submodules
+      run: git submodule update --init --recursive
+    - name: cmake
+      run: cmake -B build -DUSE_JUICE=1 -DUSE_GNUTLS=0
+    - name: make
+      run: (cd build; make)
+    - name: test
+      run: ./build/tests
+

.gitmodules

@@ -1,3 +1,9 @@
+[submodule "deps/plog"]
+	path = deps/plog
+	url = https://github.com/SergiusTheBest/plog
 [submodule "usrsctp"]
-	path = usrsctp
+	path = deps/usrsctp
 	url = https://github.com/sctplab/usrsctp.git
+[submodule "deps/libjuice"]
+	path = deps/libjuice
+	url = https://github.com/paullouisageneau/libjuice

CMakeLists.txt

@@ -1,52 +1,91 @@
 cmake_minimum_required (VERSION 3.7)
 project (libdatachannel
-	DESCRIPTION "WebRTC Data Channels Library"
-	VERSION 0.2.1
+	DESCRIPTION "WebRTC DataChannels Library"
+	VERSION 0.5.0
 	LANGUAGES CXX)
 
+option(USE_GNUTLS "Use GnuTLS instead of OpenSSL" OFF)
+option(USE_JUICE "Use libjuice instead of libnice" OFF)
+
+if(USE_GNUTLS)
+	option(USE_NETTLE "Use Nettle instead of OpenSSL in libjuice" ON)
+else()
+	option(USE_NETTLE "Use Nettle instead of OpenSSL in libjuice" OFF)
+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 (MSVC)
+		add_definitions(-DNOMINMAX)
+	endif()
+endif()
+
 set(LIBDATACHANNEL_SOURCES
-	candidate.cpp
-	certificate.cpp
-	channel.cpp
-	configuration.cpp
-	datachannel.cpp
-	description.cpp
-	dtlstransport.cpp
-	icetransport.cpp
-	peerconnection.cpp
-	rtc.cpp
-	sctptransport.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/candidate.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/certificate.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/channel.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/configuration.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/src/datachannel.cpp
+	${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
-    main.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/main.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/connectivity.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/capi.cpp
 )
 
-list(TRANSFORM LIBDATACHANNEL_SOURCES PREPEND ${CMAKE_CURRENT_SOURCE_DIR}/src/)
-list(TRANSFORM TESTS_SOURCES PREPEND ${CMAKE_CURRENT_SOURCE_DIR}/test/)
+set(TESTS_OFFERER_SOURCES
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/p2p/offerer.cpp
+)
 
-# Hack because usrsctp uses CMAKE_SOURCE_DIR instead of CMAKE_CURRENT_SOURCE_DIR
-set(CMAKE_REQUIRED_FLAGS "-I${CMAKE_CURRENT_SOURCE_DIR}/usrsctp/usrsctplib")
+set(TESTS_ANSWERER_SOURCES
+    ${CMAKE_CURRENT_SOURCE_DIR}/test/p2p/answerer.cpp
+)
 
-add_subdirectory(usrsctp EXCLUDE_FROM_ALL)
+set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
+set(THREADS_PREFER_PTHREAD_FLAG TRUE)
+find_package(Threads REQUIRED)
 
-# Set include directory and custom options to make usrsctp compile with recent g++
-target_include_directories(usrsctp-static PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/usrsctp/usrsctplib)
-
-if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  # using regular Clang or AppleClang: Needed since they don't have -Wno-error=format-truncation
-  target_compile_options(usrsctp-static PRIVATE -Wno-error=address-of-packed-member)
-else()
-  # all other compilers
-  target_compile_options(usrsctp-static PRIVATE -Wno-error=address-of-packed-member -Wno-error=format-truncation)
+add_subdirectory(deps/usrsctp EXCLUDE_FROM_ALL)
+if (MSYS OR MINGW)
+	target_compile_definitions(usrsctp PUBLIC -DSCTP_STDINT_INCLUDE=<stdint.h>)
+	target_compile_definitions(usrsctp-static PUBLIC -DSCTP_STDINT_INCLUDE=<stdint.h>)
 endif()
-
-option(USE_GNUTLS "Use GnuTLS instead of OpenSSL" OFF)
-
-find_package(LibNice REQUIRED)
+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)
 
 add_library(datachannel SHARED ${LIBDATACHANNEL_SOURCES})
 set_target_properties(datachannel PROPERTIES
@@ -54,9 +93,11 @@ set_target_properties(datachannel PROPERTIES
 	CXX_STANDARD 17)
 
 target_include_directories(datachannel PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_include_directories(datachannel PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/deps/plog/include)
 target_include_directories(datachannel PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include/rtc)
 target_include_directories(datachannel PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
-target_link_libraries(datachannel usrsctp-static LibNice::LibNice)
+target_link_libraries(datachannel PUBLIC Threads::Threads)
+target_link_libraries(datachannel PRIVATE Usrsctp::UsrsctpStatic)
 
 add_library(datachannel-static STATIC EXCLUDE_FROM_ALL ${LIBDATACHANNEL_SOURCES})
 set_target_properties(datachannel-static PROPERTIES
@@ -64,9 +105,16 @@ set_target_properties(datachannel-static PROPERTIES
 	CXX_STANDARD 17)
 
 target_include_directories(datachannel-static PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_include_directories(datachannel-static PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/deps/plog/include)
 target_include_directories(datachannel-static PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include/rtc)
 target_include_directories(datachannel-static PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
-target_link_libraries(datachannel-static usrsctp-static LibNice::LibNice)
+target_link_libraries(datachannel-static PUBLIC Threads::Threads)
+target_link_libraries(datachannel-static PRIVATE Usrsctp::UsrsctpStatic)
+
+if(WIN32)
+	target_link_libraries(datachannel PRIVATE wsock32 ws2_32) # winsock2
+	target_link_libraries(datachannel-static PRIVATE wsock32 ws2_32) # winsock2
+endif()
 
 if (USE_GNUTLS)
 	find_package(GnuTLS REQUIRED)
@@ -79,24 +127,59 @@ if (USE_GNUTLS)
 			IMPORTED_LOCATION "${GNUTLS_LIBRARIES}")
 	endif()
 	target_compile_definitions(datachannel PRIVATE USE_GNUTLS=1)
-	target_link_libraries(datachannel GnuTLS::GnuTLS)
+	target_link_libraries(datachannel PRIVATE GnuTLS::GnuTLS)
 	target_compile_definitions(datachannel-static PRIVATE USE_GNUTLS=1)
-	target_link_libraries(datachannel-static GnuTLS::GnuTLS)
+	target_link_libraries(datachannel-static PRIVATE GnuTLS::GnuTLS)
 else()
 	find_package(OpenSSL REQUIRED)
 	target_compile_definitions(datachannel PRIVATE USE_GNUTLS=0)
-	target_link_libraries(datachannel OpenSSL::SSL)
+	target_link_libraries(datachannel PRIVATE OpenSSL::SSL)
 	target_compile_definitions(datachannel-static PRIVATE USE_GNUTLS=0)
-	target_link_libraries(datachannel-static OpenSSL::SSL)
+	target_link_libraries(datachannel-static PRIVATE OpenSSL::SSL)
+endif()
+
+if (USE_JUICE)
+	add_subdirectory(deps/libjuice EXCLUDE_FROM_ALL)
+	target_compile_definitions(datachannel PRIVATE USE_JUICE=1)
+	target_link_libraries(datachannel PRIVATE LibJuice::LibJuiceStatic)
+	target_compile_definitions(datachannel-static PRIVATE USE_JUICE=1)
+	target_link_libraries(datachannel-static PRIVATE LibJuice::LibJuiceStatic)
+else()
+	find_package(LibNice REQUIRED)
+	target_compile_definitions(datachannel PRIVATE USE_JUICE=0)
+	target_link_libraries(datachannel PRIVATE LibNice::LibNice)
+	target_compile_definitions(datachannel-static PRIVATE USE_JUICE=0)
+	target_link_libraries(datachannel-static PRIVATE LibNice::LibNice)
 endif()
 
 add_library(LibDataChannel::LibDataChannel ALIAS datachannel)
 add_library(LibDataChannel::LibDataChannelStatic ALIAS datachannel-static)
 
-add_executable(tests ${TESTS_SOURCES})
-set_target_properties(tests PROPERTIES
+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
 	VERSION ${PROJECT_VERSION}
 	CXX_STANDARD 17)
+set_target_properties(datachannel-tests PROPERTIES OUTPUT_NAME tests)
+target_include_directories(datachannel-tests PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
+target_link_libraries(datachannel-tests datachannel)
 
-target_link_libraries(tests datachannel)
+# P2P Test: offerer
+add_executable(datachannel-offerer ${TESTS_OFFERER_SOURCES})
+set_target_properties(datachannel-offerer PROPERTIES
+	VERSION ${PROJECT_VERSION}
+	CXX_STANDARD 17)
+set_target_properties(datachannel-offerer PROPERTIES OUTPUT_NAME offerer)
+target_link_libraries(datachannel-offerer datachannel)
+
+# P2P Test: answerer
+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 answerer)
+target_link_libraries(datachannel-answerer datachannel)
 

Jamfile

@@ -1,3 +1,5 @@
+import feature : feature ;
+
 project libdatachannel ;
 path-constant CWD : . ;
 
@@ -5,34 +7,78 @@ lib libdatachannel
 	: # sources
 	[ glob ./src/*.cpp ]
 	: # requirements
+	<cxxstd>17
 	<include>./include/rtc
-	<define>USE_GNUTLS=0
-	<cxxflags>"`pkg-config --cflags openssl glib-2.0 gobject-2.0 nice`"
+	<define>USE_JUICE=1
 	<library>/libdatachannel//usrsctp
+	<library>/libdatachannel//juice
+	<library>/libdatachannel//plog
 	: # default build
 	<link>static
 	: # usage requirements
 	<include>./include
+	<library>/libdatachannel//plog
 	<cxxflags>-pthread
-	<linkflags>"`pkg-config --libs openssl glib-2.0 gobject-2.0 nice`"
 	;
 
+feature crypto : openssl gnutls : composite propagated ;
+feature.compose <crypto>openssl
+    : <define>USE_GNUTLS=0 ;
+feature.compose <crypto>gnutls
+    : <define>USE_GNUTLS=1 ;
+
+alias plog
+    : # no sources
+    : # no build requirements
+    : # no default build
+    : # usage requirements
+    <include>./deps/plog/include
+    ;
+
 alias usrsctp
     : # no sources
     : # no build requirements
     : # no default build
     : # usage requirements
-    <include>./usrsctp/usrsctplib
+    <include>./deps/usrsctp/usrsctplib
 	<library>libusrsctp.a
     ;
 
+alias juice
+    : # no sources
+    : # no build requirements
+    : # no default build
+    : # usage requirements
+    <include>./deps/libjuice/include
+	<library>libjuice.a
+    ;
+
 make libusrsctp.a : : @make_libusrsctp ;
 actions make_libusrsctp
 {
-	(cd $(CWD)/usrsctp && \
+	(cd $(CWD)/deps/usrsctp && \
 		./bootstrap && \
 		./configure --enable-static --disable-debug CFLAGS="-fPIC -Wno-address-of-packed-member" && \
 		make)
-    cp $(CWD)/usrsctp/usrsctplib/.libs/libusrsctp.a $(<)
+    cp $(CWD)/deps/usrsctp/usrsctplib/.libs/libusrsctp.a $(<)
+}
+
+make libjuice.a : : @make_libjuice ;
+
+rule make_libjuice ( targets * : sources * : properties * )
+{
+	if <crypto>gnutls in $(properties)
+	{
+		MAKEOPTS on $(targets) = "USE_NETTLE=1" ;
+	}
+	else
+	{
+		MAKEOPTS on $(targets) = "USE_NETTLE=0" ;
+	}
+}
+actions make_libjuice
+{
+	(cd $(CWD)/deps/libjuice && make $(MAKEOPTS))
+    cp $(CWD)/deps/libjuice/libjuice.a $(<)
 }
 

Makefile

@@ -4,45 +4,67 @@ NAME=libdatachannel
 CXX=$(CROSS)g++
 AR=$(CROSS)ar
 RM=rm -f
-CPPFLAGS=-O2 -pthread -fPIC -Wall -Wno-address-of-packed-member
 CXXFLAGS=-std=c++17
+CPPFLAGS=-O2 -pthread -fPIC -Wall
 LDFLAGS=-pthread
-LIBS=glib-2.0 gobject-2.0 nice
-USRSCTP_DIR=usrsctp
+LIBS=
+LOCALLIBS=libusrsctp.a
+USRSCTP_DIR=deps/usrsctp
+JUICE_DIR=deps/libjuice
+PLOG_DIR=deps/plog
+
+INCLUDES=-Iinclude/rtc -I$(PLOG_DIR)/include -I$(USRSCTP_DIR)/usrsctplib
+LDLIBS=
 
 USE_GNUTLS ?= 0
-ifeq ($(USE_GNUTLS), 1)
-        CPPFLAGS+= -DUSE_GNUTLS=1
-        LIBS+= gnutls
+ifneq ($(USE_GNUTLS), 0)
+        CPPFLAGS+=-DUSE_GNUTLS=1
+        LIBS+=gnutls
 else
-        CPPFLAGS+= -DUSE_GNUTLS=0
-        LIBS+= openssl
+        CPPFLAGS+=-DUSE_GNUTLS=0
+        LIBS+=openssl
 endif
 
-LDLIBS= $(shell pkg-config --libs $(LIBS))
-INCLUDES=-Iinclude/rtc -I$(USRSCTP_DIR)/usrsctplib $(shell pkg-config --cflags $(LIBS))
+USE_JUICE ?= 0
+ifneq ($(USE_JUICE), 0)
+        CPPFLAGS+=-DUSE_JUICE=1
+        INCLUDES+=-I$(JUICE_DIR)/include
+        LOCALLIBS+=libjuice.a
+ifneq ($(USE_GNUTLS), 0)
+        LIBS+=nettle
+endif
+else
+        CPPFLAGS+=-DUSE_JUICE=0
+        LIBS+=glib-2.0 gobject-2.0 nice
+endif
+
+INCLUDES+=$(shell pkg-config --cflags $(LIBS))
+LDLIBS+=$(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
 	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(INCLUDES) -MMD -MP -o $@ -c $<
 
 test/%.o: test/%.cpp
-	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -Iinclude -MMD -MP -o $@ -c $<
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(INCLUDES) -Iinclude -Isrc -MMD -MP -o $@ -c $<
 
 -include $(subst .cpp,.d,$(SRCS))
 
 $(NAME).a: $(OBJS)
 	$(AR) crf $@ $(OBJS)
 
-$(NAME).so: libusrsctp.a $(OBJS)
-	$(CXX) $(LDFLAGS) -shared -o $@ $(OBJS) $(LDLIBS) libusrsctp.a
+$(NAME).so: $(LOCALLIBS) $(OBJS)
+	$(CXX) $(LDFLAGS) -shared -o $@ $(OBJS) $(LDLIBS)
 
-tests: $(NAME).a test/main.o
-	$(CXX) $(LDFLAGS) -o $@ test/main.o $(LDLIBS) $(NAME).a libusrsctp.a
+tests: $(NAME).a $(TEST_OBJS)
+	$(CXX) $(LDFLAGS) -o $@ $(TEST_OBJS) $(NAME).a $(LDLIBS)
 
 clean:
 	-$(RM) include/rtc/*.d *.d
@@ -53,16 +75,26 @@ dist-clean: clean
 	-$(RM) $(NAME).a
 	-$(RM) $(NAME).so
 	-$(RM) libusrsctp.a
+	-$(RM) libjuice.a
 	-$(RM) tests
 	-$(RM) include/*~
 	-$(RM) src/*~
 	-$(RM) test/*~
 	-cd $(USRSCTP_DIR) && make clean
+	-cd $(JUICE_DIR) && make 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 .
 
+libjuice.a:
+ifneq ($(USE_GNUTLS), 0)
+	cd $(JUICE_DIR) && make USE_NETTLE=1
+else
+	cd $(JUICE_DIR) && make USE_NETTLE=0
+endif
+	cp $(JUICE_DIR)/libjuice.a .
+

README.md

@@ -1,33 +1,46 @@
 # 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.
 
+The connectivity can be provided through my ad-hoc ICE library [libjuice](https://github.com/paullouisageneau/libjuice) as submodule or through [libnice](https://github.com/libnice/libnice). The security layer can be provided through [GnuTLS](https://www.gnutls.org/) or [OpenSSL](https://www.openssl.org/).
+
 Licensed under LGPLv2, see [LICENSE](https://github.com/paullouisageneau/libdatachannel/blob/master/LICENSE).
 
 ## Compatibility
 
-The library aims at fully implementing SCTP DataChannels ([draft-ietf-rtcweb-data-channel-13](https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-13)) over DTLS/UDP ([RFC7350](https://tools.ietf.org/html/rfc7350) and [RFC8261](https://tools.ietf.org/html/rfc8261)) and has been tested to be compatible with Firefox and Chromium. It supports IPv6 and Multicast DNS candidates resolution ([draft-ietf-rtcweb-mdns-ice-candidates-03](https://tools.ietf.org/html/draft-ietf-rtcweb-mdns-ice-candidates-03)) provided the operating system also supports it.
+The library aims at fully implementing WebRTC SCTP DataChannels ([draft-ietf-rtcweb-data-channel-13](https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-13)) over DTLS/UDP ([RFC7350](https://tools.ietf.org/html/rfc7350) and [RFC8261](https://tools.ietf.org/html/rfc8261)) with ICE ([RFC8445](https://tools.ietf.org/html/rfc8445)). It has been tested to be compatible with Firefox and Chromium. It supports IPv6 and Multicast DNS candidates resolution ([draft-ietf-rtcweb-mdns-ice-candidates-03](https://tools.ietf.org/html/draft-ietf-rtcweb-mdns-ice-candidates-03)) provided the operating system also supports it.
 
 ## Dependencies
 
-- libnice: https://github.com/libnice/libnice
 - GnuTLS: https://www.gnutls.org/ or OpenSSL: https://www.openssl.org/
 
+Optional:
+- libnice: https://nice.freedesktop.org/ (substituable with libjuice)
+
 Submodules:
 - usrsctp: https://github.com/sctplab/usrsctp
+- libjuice: https://github.com/paullouisageneau/libjuice
 
 ## Building
+### Building with CMake (preferred)
 
 ```bash
 $ git submodule update --init --recursive
 $ mkdir build
 $ cd build
-$ cmake -DUSE_GNUTLS=1 ..
+$ cmake -DUSE_JUICE=1 -DUSE_GNUTLS=1 ..
 $ make
 ```
 
+### Building directly with Make
+
+```bash
+$ git submodule update --init --recursive
+$ make USE_JUICE=1 USE_GNUTLS=1
+```
+
 ## Example
 
 In the following example, note the callbacks are called in another thread.
@@ -66,11 +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;
 });
 
@@ -101,5 +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.
 

cmake/Modules/FindLibNice.cmake

@@ -10,7 +10,7 @@ if (NOT TARGET LibNice::LibNice)
             HINTS ${PC_LIBNICE_LIBDIR} ${PC_LIBNICE_LIBRARY_DIRS})
 
     include(FindPackageHandleStandardArgs)
-    find_package_handle_standard_args(Libnice DEFAULT_MSG
+    find_package_handle_standard_args(LibNice DEFAULT_MSG
             LIBNICE_LIBRARY LIBNICE_INCLUDE_DIR)
     mark_as_advanced(LIBNICE_INCLUDE_DIR LIBNICE_LIBRARY)
 

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 availableAmount() const; // total size available to receive
+	virtual size_t maxMessageSize() const; // max message size in a call to send
 	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

@@ -27,16 +27,47 @@
 namespace rtc {
 
 struct IceServer {
-	IceServer(const string &host_);
-	IceServer(const string &hostname_, uint16_t port_);
-	IceServer(const string &hostname_, const string &service_);
+	enum class Type { Stun, Turn };
+	enum class RelayType { TurnUdp, TurnTcp, TurnTls };
+
+	// Any type
+	IceServer(const string &url);
+
+	// STUN
+	IceServer(string hostname_, uint16_t port_);
+	IceServer(string hostname_, string service_);
+
+	// TURN
+	IceServer(string hostname_, uint16_t port, string username_, string password_,
+	          RelayType relayType_ = RelayType::TurnUdp);
+	IceServer(string hostname_, string service_, string username_, string password_,
+	          RelayType relayType_ = RelayType::TurnUdp);
 
 	string hostname;
 	string service;
+	Type type;
+	string username;
+	string password;
+	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

@@ -36,43 +36,42 @@ namespace rtc {
 class SctpTransport;
 class PeerConnection;
 
-class DataChannel : public Channel {
+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 open(std::shared_ptr<SctpTransport> sctpTransport);
+	void remoteClose();
+	void open(std::shared_ptr<SctpTransport> transport);
 	bool outgoing(mutable_message_ptr message);
 	void incoming(message_ptr message);
 	void processOpenMessage(message_ptr message);
 
-	std::shared_ptr<PeerConnection> mPeerConnection;
-	std::shared_ptr<SctpTransport> mSctpTransport;
+	const std::weak_ptr<PeerConnection> mPeerConnection;
+	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;
@@ -45,7 +46,9 @@ public:
 	std::optional<string> fingerprint() const;
 	std::optional<uint16_t> sctpPort() const;
 	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);
@@ -56,6 +59,8 @@ public:
 
 	operator string() const;
 
+	string generateSdp(const string &eol) const;
+
 private:
 	Type mType;
 	Role mRole;

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>
@@ -48,27 +56,32 @@ 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
 
+
 template <class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
 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) {
-		std::lock_guard<std::recursive_mutex> lock(mutex);
-		callback = func;
+		std::lock_guard lock(mutex);
+		callback = std::move(func);
 		return *this;
 	}
 
 	void operator()(P... args) const {
-		std::lock_guard<std::recursive_mutex> lock(mutex);
+		std::lock_guard lock(mutex);
 		if (callback)
 			callback(args...);
 	}
 
-	operator bool() const { return callback ? true : false; }
+	operator bool() const {
+		std::lock_guard lock(mutex);
+		return callback ? true : false;
+	}
 
 private:
 	std::function<void(P...)> callback;

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/message.hpp

@@ -28,9 +28,9 @@
 namespace rtc {
 
 struct Message : binary {
-	enum Type { Binary, String, Control };
+	enum Type { Binary, String, Control, Reset };
 
-	Message(size_t size) : binary(size), type(Binary) {}
+	Message(size_t size, Type type_ = Binary) : binary(size), type(type_) {}
 
 	template <typename Iterator>
 	Message(Iterator begin_, Iterator end_, Type type_ = Binary)
@@ -46,7 +46,7 @@ using mutable_message_ptr = std::shared_ptr<Message>;
 using message_callback = std::function<void(message_ptr message)>;
 
 constexpr auto message_size_func = [](const message_ptr &m) -> size_t {
-	return m->type != Message::Control ? m->size() : 0;
+	return m->type == Message::Binary || m->type == Message::String ? m->size() : 0;
 };
 
 template <typename Iterator>
@@ -59,6 +59,15 @@ message_ptr make_message(Iterator begin, Iterator end, Message::Type type = Mess
 	return message;
 }
 
+inline message_ptr make_message(size_t size, Message::Type type = Message::Binary,
+                                unsigned int stream = 0,
+                                std::shared_ptr<Reliability> reliability = nullptr) {
+	auto message = std::make_shared<Message>(size, type);
+	message->stream = stream;
+	message->reliability = reliability;
+	return message;
+}
+
 } // namespace rtc
 
 #endif

include/rtc/peerconnection.hpp

@@ -24,13 +24,17 @@
 #include "datachannel.hpp"
 #include "description.hpp"
 #include "include.hpp"
+#include "init.hpp"
 #include "message.hpp"
 #include "reliability.hpp"
 #include "rtc.hpp"
 
 #include <atomic>
 #include <functional>
+#include <future>
 #include <list>
+#include <mutex>
+#include <shared_mutex>
 #include <thread>
 #include <unordered_map>
 
@@ -41,6 +45,9 @@ class IceTransport;
 class DtlsTransport;
 class SctpTransport;
 
+using certificate_ptr = std::shared_ptr<Certificate>;
+using future_certificate_ptr = std::shared_future<certificate_ptr>;
+
 class PeerConnection : public std::enable_shared_from_this<PeerConnection> {
 public:
 	enum class State : int {
@@ -55,13 +62,15 @@ public:
 	enum class GatheringState : int {
 		New = RTC_GATHERING_NEW,
 		InProgress = RTC_GATHERING_INPROGRESS,
-		Complete = RTC_GATHERING_COMPLETE,
+		Complete = RTC_GATHERING_COMPLETE
 	};
 
 	PeerConnection(void);
 	PeerConnection(const Configuration &config);
 	~PeerConnection();
 
+	void close();
+
 	const Configuration *config() const;
 	State state() const;
 	GatheringState gatheringState() const;
@@ -82,35 +91,56 @@ public:
 	void onStateChange(std::function<void(State state)> callback);
 	void onGatheringStateChange(std::function<void(GatheringState state)> callback);
 
-private:
-	void initIceTransport(Description::Role role);
-	void initDtlsTransport();
-	void initSctpTransport();
+	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();
+	void remoteCloseDataChannels();
 
 	void processLocalDescription(Description description);
 	void processLocalCandidate(Candidate candidate);
 	void triggerDataChannel(std::weak_ptr<DataChannel> weakDataChannel);
-	void changeState(State state);
-	void changeGatheringState(GatheringState state);
+	bool changeState(State state);
+	bool changeGatheringState(GatheringState state);
+
+	void resetCallbacks();
 
 	const Configuration mConfig;
-	const std::shared_ptr<Certificate> mCertificate;
+	const future_certificate_ptr mCertificate;
 
-	std::optional<Description> mLocalDescription;
-	std::optional<Description> mRemoteDescription;
+	std::optional<Description> mLocalDescription, mRemoteDescription;
+	mutable std::recursive_mutex mLocalDescriptionMutex, mRemoteDescriptionMutex;
 
 	std::shared_ptr<IceTransport> mIceTransport;
 	std::shared_ptr<DtlsTransport> mDtlsTransport;
 	std::shared_ptr<SctpTransport> mSctpTransport;
 
 	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();
-	void wait(const std::chrono::milliseconds &duration);
+	bool wait(const std::optional<std::chrono::milliseconds> &duration = nullopt);
 
 private:
 	const size_t mLimit;
@@ -67,31 +65,29 @@ Queue<T>::Queue(size_t limit, amount_function func) : mLimit(limit), mAmount(0)
 template <typename T> Queue<T>::~Queue() { stop(); }
 
 template <typename T> void Queue<T>::stop() {
-	std::lock_guard<std::mutex> lock(mMutex);
+	std::lock_guard lock(mMutex);
 	mStopping = true;
 	mPopCondition.notify_all();
 	mPushCondition.notify_all();
 }
 
 template <typename T> bool Queue<T>::empty() const {
-	std::lock_guard<std::mutex> lock(mMutex);
+	std::lock_guard lock(mMutex);
 	return mQueue.empty();
 }
 
 template <typename T> size_t Queue<T>::size() const {
-	std::lock_guard<std::mutex> lock(mMutex);
+	std::lock_guard lock(mMutex);
 	return mQueue.size();
 }
 
 template <typename T> size_t Queue<T>::amount() const {
-	std::lock_guard<std::mutex> lock(mMutex);
+	std::lock_guard lock(mMutex);
 	return mAmount;
 }
 
-template <typename T> void Queue<T>::push(const T &element) { push(T{element}); }
-
-template <typename T> void Queue<T>::push(T &&element) {
-	std::unique_lock<std::mutex> lock(mMutex);
+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) {
 		mAmount += mAmountFunction(element);
@@ -101,7 +97,7 @@ template <typename T> void Queue<T>::push(T &&element) {
 }
 
 template <typename T> std::optional<T> Queue<T>::pop() {
-	std::unique_lock<std::mutex> lock(mMutex);
+	std::unique_lock lock(mMutex);
 	mPopCondition.wait(lock, [this]() { return !mQueue.empty() || mStopping; });
 	if (!mQueue.empty()) {
 		mAmount -= mAmountFunction(mQueue.front());
@@ -114,7 +110,7 @@ template <typename T> std::optional<T> Queue<T>::pop() {
 }
 
 template <typename T> std::optional<T> Queue<T>::peek() {
-	std::unique_lock<std::mutex> lock(mMutex);
+	std::unique_lock lock(mMutex);
 	if (!mQueue.empty()) {
 		return std::optional<T>{mQueue.front()};
 	} else {
@@ -122,14 +118,14 @@ template <typename T> std::optional<T> Queue<T>::peek() {
 	}
 }
 
-template <typename T> void Queue<T>::wait() {
-	std::unique_lock<std::mutex> lock(mMutex);
-	mPopCondition.wait(lock, [this]() { return !mQueue.empty() || mStopping; });
-}
-
-template <typename T> void Queue<T>::wait(const std::chrono::milliseconds &duration) {
-	std::unique_lock<std::mutex> lock(mMutex);
-	mPopCondition.wait_for(lock, duration, [this]() { return !mQueue.empty() || mStopping; });
+template <typename T>
+bool Queue<T>::wait(const std::optional<std::chrono::milliseconds> &duration) {
+	std::unique_lock lock(mMutex);
+	if (duration)
+		mPopCondition.wait_for(lock, *duration, [this]() { return !mQueue.empty() || mStopping; });
+	else
+		mPopCondition.wait(lock, [this]() { return !mQueue.empty() || mStopping; });
+	return !mStopping;
 }
 
 } // namespace rtc

include/rtc/rtc.h

@@ -23,7 +23,9 @@
 extern "C" {
 #endif
 
-// libdatachannel rtc C API
+#include <stdint.h>
+
+// libdatachannel C API
 
 typedef enum {
 	RTC_NEW = 0,
@@ -32,39 +34,91 @@ typedef enum {
 	RTC_DISCONNECTED = 3,
 	RTC_FAILED = 4,
 	RTC_CLOSED = 5
-} rtc_state_t;
+} rtcState;
 
 typedef enum {
 	RTC_GATHERING_NEW = 0,
 	RTC_GATHERING_INPROGRESS = 1,
 	RTC_GATHERING_COMPLETE = 2
-} rtc_gathering_state_t;
+} rtcGatheringState;
 
-int rtcCreatePeerConnection(const char **iceServers, int iceServersCount);
-void rtcDeletePeerConnection(int pc);
-int rtcCreateDataChannel(int pc, const char *label);
-void rtcDeleteDataChannel(int dc);
-void rtcSetDataChannelCallback(int pc, void (*dataChannelCallback)(int, void *));
-void rtcSetLocalDescriptionCallback(int pc, void (*descriptionCallback)(const char *, const char *,
-                                                                        void *));
-void rtcSetLocalCandidateCallback(int pc,
-                                  void (*candidateCallback)(const char *, const char *, void *));
-void rtcSetStateChangeCallback(int pc, void (*stateCallback)(rtc_state_t state, void *));
-void rtcSetGatheringStateChangeCallback(int pc,
-                                         void (*gatheringStateCallback)(rtc_gathering_state_t state,
-                                                                        void *));
-void rtcSetRemoteDescription(int pc, const char *sdp, const char *type);
-void rtcAddRemoteCandidate(int pc, const char *candidate, const char *mid);
-int rtcGetDataChannelLabel(int dc, char *data, int size);
-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);
+// Don't change, it must match plog severity
+typedef enum {
+	RTC_LOG_NONE = 0,
+	RTC_LOG_FATAL = 1,
+	RTC_LOG_ERROR = 2,
+	RTC_LOG_WARNING = 3,
+	RTC_LOG_INFO = 4,
+	RTC_LOG_DEBUG = 5,
+	RTC_LOG_VERBOSE = 6
+} rtcLogLevel;
+
+typedef struct {
+	const char **iceServers;
+	int iceServersCount;
+	uint16_t portRangeBegin;
+	uint16_t portRangeEnd;
+} rtcConfiguration;
+
+typedef void (*dataChannelCallbackFunc)(int dc, void *ptr);
+typedef void (*descriptionCallbackFunc)(const char *sdp, const char *type, void *ptr);
+typedef void (*candidateCallbackFunc)(const char *cand, const char *mid, void *ptr);
+typedef void (*stateChangeCallbackFunc)(rtcState state, void *ptr);
+typedef void (*gatheringStateCallbackFunc)(rtcGatheringState state, void *ptr);
+typedef void (*openCallbackFunc)(void *ptr);
+typedef void (*closedCallbackFunc)(void *ptr);
+typedef void (*errorCallbackFunc)(const char *error, void *ptr);
+typedef void (*messageCallbackFunc)(const char *message, int size, void *ptr);
+typedef void (*bufferedAmountLowCallbackFunc)(void *ptr);
+typedef void (*availableCallbackFunc)(void *ptr);
+
+// Log
+void rtcInitLogger(rtcLogLevel level);
+
+// User pointer
 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);
+
+// Cleanup
+void rtcCleanup();
+
 #ifdef __cplusplus
 } // extern "C"
 #endif
 
 #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;
@@ -54,7 +60,7 @@ bool Candidate::resolve(ResolveMode mode) {
 	if (mIsResolved)
 		return true;
 
-	// See RFC 5245 for format
+	// See RFC 8445 for format
 	std::stringstream ss(mCandidate);
 	int component{0}, priority{0};
 	string foundation, transport, node, service, typ_, type;
@@ -70,6 +76,11 @@ bool Candidate::resolve(ResolveMode mode) {
 			hints.ai_protocol = IPPROTO_UDP;
 		}
 
+		if (transport == "TCP" || transport == "tcp") {
+			hints.ai_socktype = SOCK_STREAM;
+			hints.ai_protocol = IPPROTO_TCP;
+		}
+
 		if (mode == ResolveMode::Simple)
 			hints.ai_flags |= AI_NUMERICHOST;
 
@@ -121,3 +132,32 @@ 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

@@ -141,14 +141,9 @@ string make_fingerprint(gnutls_x509_crt_t crt) {
 	return oss.str();
 }
 
-shared_ptr<Certificate> make_certificate(const string &commonName) {
-	static std::unordered_map<string, shared_ptr<Certificate>> cache;
-	static std::mutex cacheMutex;
-
-	std::lock_guard<std::mutex> lock(cacheMutex);
-	if (auto it = cache.find(commonName); it != cache.end())
-		return it->second;
+namespace {
 
+certificate_ptr make_certificate_impl(string commonName) {
 	std::unique_ptr<gnutls_x509_crt_t, decltype(&delete_crt)> crt(create_crt(), delete_crt);
 	std::unique_ptr<gnutls_x509_privkey_t, decltype(&delete_privkey)> privkey(create_privkey(),
 	                                                                          delete_privkey);
@@ -174,11 +169,11 @@ shared_ptr<Certificate> make_certificate(const string &commonName) {
 	check_gnutls(gnutls_x509_crt_sign2(*crt, *crt, *privkey, GNUTLS_DIG_SHA256, 0),
 	             "Unable to auto-sign certificate");
 
-	auto certificate = std::make_shared<Certificate>(*crt, *privkey);
-	cache.emplace(std::make_pair(commonName, certificate));
-	return certificate;
+	return std::make_shared<Certificate>(*crt, *privkey);
 }
 
+} // namespace
+
 } // namespace rtc
 
 #else
@@ -236,22 +231,9 @@ string make_fingerprint(X509 *x509) {
 	return oss.str();
 }
 
+namespace {
 
-shared_ptr<Certificate> make_certificate(const string &commonName) {
-	static std::unordered_map<string, shared_ptr<Certificate>> cache;
-	static std::mutex cacheMutex;
-
-	std::lock_guard<std::mutex> lock(cacheMutex);
-	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();
-	}
-
+certificate_ptr make_certificate_impl(string commonName) {
 	shared_ptr<X509> x509(X509_new(), X509_free);
 	shared_ptr<EVP_PKEY> pkey(EVP_PKEY_new(), EVP_PKEY_free);
 
@@ -288,12 +270,54 @@ shared_ptr<Certificate> make_certificate(const string &commonName) {
 	if (!X509_sign(x509.get(), pkey.get(), EVP_sha256()))
 		throw std::runtime_error("Unable to auto-sign certificate");
 
-	auto certificate = std::make_shared<Certificate>(x509, pkey);
-	cache.emplace(std::make_pair(commonName, certificate));
-	return certificate;
+	return std::make_shared<Certificate>(x509, pkey);
 }
 
+} // namespace
+
 } // namespace rtc
 
 #endif
 
+// Common for GnuTLS and OpenSSL
+
+namespace rtc {
+
+namespace {
+
+// Helper function roughly equivalent to std::async with policy std::launch::async
+// since std::async might be unreliable on some platforms (e.g. Mingw32 on Windows)
+template <class F, class... Args>
+std::future<std::result_of_t<std::decay_t<F>(std::decay_t<Args>...)>> thread_call(F &&f,
+                                                                                  Args &&... args) {
+	using R = std::result_of_t<std::decay_t<F>(std::decay_t<Args>...)>;
+	std::packaged_task<R()> task(std::bind(f, std::forward<Args>(args)...));
+	std::future<R> future = task.get_future();
+	std::thread t(std::move(task));
+	t.detach();
+	return future;
+}
+
+static std::unordered_map<string, future_certificate_ptr> CertificateCache;
+static std::mutex CertificateCacheMutex;
+
+} // namespace
+
+future_certificate_ptr make_certificate(string commonName) {
+	std::lock_guard lock(CertificateCacheMutex);
+
+	if (auto it = CertificateCache.find(commonName); it != CertificateCache.end())
+		return it->second;
+
+	auto future = thread_call(make_certificate_impl, commonName);
+	auto shared = future.share();
+	CertificateCache.emplace(std::move(commonName), shared);
+	return shared;
+}
+
+void CleanupCertificateCache() {
+	std::lock_guard lock(CertificateCacheMutex);
+	CertificateCache.clear();
+}
+
+} // namespace rtc

src/certificate.hpp

@@ -21,6 +21,7 @@
 
 #include "include.hpp"
 
+#include <future>
 #include <tuple>
 
 #if USE_GNUTLS
@@ -62,7 +63,12 @@ string make_fingerprint(gnutls_x509_crt_t crt);
 string make_fingerprint(X509 *x509);
 #endif
 
-std::shared_ptr<Certificate> make_certificate(const string &commonName);
+using certificate_ptr = std::shared_ptr<Certificate>;
+using future_certificate_ptr = std::shared_future<certificate_ptr>;
+
+future_certificate_ptr make_certificate(string commonName); // cached
+
+void CleanupCertificateCache();
 
 } // namespace rtc
 

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

@@ -18,22 +18,74 @@
 
 #include "configuration.hpp"
 
+#include <regex>
+
 namespace rtc {
 
-using std::to_string;
+IceServer::IceServer(const string &url) {
+	// Modified regex from RFC 3986, see https://tools.ietf.org/html/rfc3986#appendix-B
+	static const char *rs =
+	    R"(^(([^:.@/?#]+):)?(/{0,2}((([^:@]*)(:([^@]*))?)@)?(([^:/?#]*)(:([^/?#]*))?))?([^?#]*)(\?([^#]*))?(#(.*))?)";
+	static const std::regex r(rs, std::regex::extended);
 
-IceServer::IceServer(const string &host) {
-	if(size_t pos = host.rfind(':'); pos != string::npos) {
-		hostname = host.substr(0, pos);
-		service = host.substr(pos + 1);
-	} else {
-		hostname = host;
-		service = "3478"; // STUN UDP port
+	std::smatch m;
+	if (!std::regex_match(url, m, r) || m[10].length() == 0)
+		throw std::invalid_argument("Invalid ICE server URL: " + url);
+
+	std::vector<std::optional<string>> opt(m.size());
+	std::transform(m.begin(), m.end(), opt.begin(), [](const auto &sm) {
+		return sm.length() > 0 ? std::make_optional(string(sm)) : nullopt;
+	});
+
+	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") {
+		type = Type::Turn;
+		relayType = RelayType::TurnTls;
+	} else
+		throw std::invalid_argument("Unknown ICE server protocol: " + scheme);
+
+	if (auto &query = opt[15]) {
+		if (query->find("transport=udp") != string::npos)
+			relayType = RelayType::TurnUdp;
+		if (query->find("transport=tcp") != string::npos)
+			relayType = RelayType::TurnTcp;
+		if (query->find("transport=tls") != string::npos)
+			relayType = RelayType::TurnTls;
 	}
+
+	username = opt[6].value_or("");
+	password = opt[8].value_or("");
+	hostname = opt[10].value();
+	service = opt[12].value_or(relayType == RelayType::TurnTls ? "5349" : "3478");
+
+	while (!hostname.empty() && hostname.front() == '[')
+		hostname.erase(hostname.begin());
+	while (!hostname.empty() && hostname.back() == ']')
+		hostname.pop_back();
 }
 
-IceServer::IceServer(const string &hostname_, uint16_t port_) : IceServer(hostname_, to_string(port_)) {}
+IceServer::IceServer(string hostname_, uint16_t port_)
+    : IceServer(std::move(hostname_), std::to_string(port_)) {}
 
-IceServer::IceServer(const string &hostname_, const string &service_) : hostname(hostname_), service(service_) {}
+IceServer::IceServer(string hostname_, string service_)
+    : hostname(std::move(hostname_)), service(std::move(service_)), type(Type::Stun) {}
+
+IceServer::IceServer(string hostname_, uint16_t port_, string username_, string password_,
+                     RelayType relayType_)
+    : IceServer(hostname_, std::to_string(port_), std::move(username_), std::move(password_),
+                relayType_) {}
+
+IceServer::IceServer(string hostname_, string service_, string username_, string password_,
+                     RelayType relayType_)
+    : 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
@@ -60,31 +67,47 @@ 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) {}
 
-DataChannel::~DataChannel() { close(); }
+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() {
-	mIsOpen = false;
-	if (!mIsClosed.exchange(true)) {
-		if (mSctpTransport)
-			mSctpTransport->reset(mStream);
-	}
+	mIsClosed = true;
+	if (mIsOpen.exchange(false))
+		if (auto transport = mSctpTransport.lock())
+			transport->close(mStream);
 
-	// Reset mSctpTransport first so SctpTransport is never alive without PeerConnection
 	mSctpTransport.reset();
-	mPeerConnection.reset();
+	resetCallbacks();
+}
+
+void DataChannel::remoteClose() {
+	if (!mIsClosed.exchange(true))
+		triggerClosed();
+
+	mIsOpen = false;
+	mSctpTransport.reset();
 }
 
 bool DataChannel::send(const std::variant<binary, string> &data) {
@@ -108,12 +131,8 @@ std::optional<std::variant<binary, string>> DataChannel::receive() {
 		switch (message->type) {
 		case Message::Control: {
 			auto raw = reinterpret_cast<const uint8_t *>(message->data());
-			if (raw[0] == MESSAGE_CLOSE) {
-				if (mIsOpen) {
-					close();
-					triggerClosed();
-				}
-			}
+			if (raw[0] == MESSAGE_CLOSE)
+				remoteClose();
 			break;
 		}
 		case Message::String:
@@ -121,6 +140,9 @@ std::optional<std::variant<binary, string>> DataChannel::receive() {
 			    string(reinterpret_cast<const char *>(message->data()), message->size()));
 		case Message::Binary:
 			return std::make_optional(std::move(*message));
+		default:
+			// Ignore
+			break;
 		}
 	}
 
@@ -131,27 +153,20 @@ 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 maxMessageSize = description->maxMessageSize())
-			return *maxMessageSize > 0 ? *maxMessageSize : LOCAL_MAX_MESSAGE_SIZE;
+	if (auto pc = mPeerConnection.lock())
+		if (auto description = pc->remoteDescription())
+			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; }
-
-string DataChannel::protocol() const { return mProtocol; }
-
-Reliability DataChannel::reliability() const { return *mReliability; }
-
-void DataChannel::open(shared_ptr<SctpTransport> sctpTransport) {
-	mSctpTransport = sctpTransport;
+void DataChannel::open(shared_ptr<SctpTransport> transport) {
+	mSctpTransport = transport;
 
 	uint8_t channelType = static_cast<uint8_t>(mReliability->type);
 	if (mReliability->unordered)
@@ -178,20 +193,24 @@ 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 +249,10 @@ 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 +289,7 @@ 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) {
-	if (mType == Type::Answer && mRole == Role::ActPass)
-		mRole = Role::Passive; // ActPass is illegal for an answer, so default to passive
+    : mType(Type::Unspec), mRole(role), mMid("0"), mIceUfrag(""), mIcePwd(""), mTrickle(true) {
+	hintType(type);
 
 	auto seed = std::chrono::system_clock::now().time_since_epoch().count();
 	std::default_random_engine generator(seed);
@@ -107,6 +108,16 @@ std::optional<uint16_t> Description::sctpPort() const { return mSctpPort; }
 
 std::optional<size_t> Description::maxMessageSize() const { return mMaxMessageSize; }
 
+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));
 }
@@ -128,37 +139,39 @@ std::vector<Candidate> Description::extractCandidates() {
 	return result;
 }
 
-Description::operator string() const {
+Description::operator string() const { return generateSdp("\r\n"); }
+
+string Description::generateSdp(const string &eol) const {
 	if (!mFingerprint)
-		throw std::logic_error("Fingerprint must be set to generate a SDP");
+		throw std::logic_error("Fingerprint must be set to generate an SDP string");
 
 	std::ostringstream sdp;
-	sdp << "v=0\n";
-	sdp << "o=- " << mSessionId << " 0 IN IP4 127.0.0.1\n";
-	sdp << "s=-\n";
-	sdp << "t=0 0\n";
-	sdp << "a=group:BUNDLE 0\n";
-	sdp << "m=application 9 UDP/DTLS/SCTP webrtc-datachannel\n";
-	sdp << "c=IN IP4 0.0.0.0\n";
-	sdp << "a=ice-ufrag:" << mIceUfrag << "\n";
-	sdp << "a=ice-pwd:" << mIcePwd << "\n";
+	sdp << "v=0" << eol;
+	sdp << "o=- " << mSessionId << " 0 IN IP4 127.0.0.1" << eol;
+	sdp << "s=-" << eol;
+	sdp << "t=0 0" << eol;
+	sdp << "a=group:BUNDLE 0" << eol;
+	sdp << "m=application 9 UDP/DTLS/SCTP webrtc-datachannel" << eol;
+	sdp << "c=IN IP4 0.0.0.0" << eol;
+	sdp << "a=ice-ufrag:" << mIceUfrag << eol;
+	sdp << "a=ice-pwd:" << mIcePwd << eol;
 	if (mTrickle)
-		sdp << "a=ice-options:trickle\n";
-	sdp << "a=mid:" << mMid << "\n";
-	sdp << "a=setup:" << roleToString(mRole) << "\n";
-	sdp << "a=dtls-id:1\n";
+		sdp << "a=ice-options:trickle" << eol;
+	sdp << "a=mid:" << mMid << eol;
+	sdp << "a=setup:" << roleToString(mRole) << eol;
+	sdp << "a=dtls-id:1" << eol;
 	if (mFingerprint)
-		sdp << "a=fingerprint:sha-256 " << *mFingerprint << "\n";
+		sdp << "a=fingerprint:sha-256 " << *mFingerprint << eol;
 	if (mSctpPort)
-		sdp << "a=sctp-port:" << *mSctpPort << "\n";
+		sdp << "a=sctp-port:" << *mSctpPort << eol;
 	if (mMaxMessageSize)
-		sdp << "a=max-message-size:" << *mMaxMessageSize << "\n";
+		sdp << "a=max-message-size:" << *mMaxMessageSize << eol;
 	for (const auto &candidate : mCandidates) {
-		sdp << string(candidate) << "\n";
+		sdp << string(candidate) << eol;
 	}
 
 	if (!mTrickle)
-		sdp << "a=end-of-candidates\n";
+		sdp << "a=end-of-candidates" << eol;
 
 	return sdp.str();
 }

src/dtlstransport.cpp

@@ -18,12 +18,16 @@
 
 #include "dtlstransport.hpp"
 #include "icetransport.hpp"
+#include "message.hpp"
 
 #include <cassert>
+#include <chrono>
 #include <cstring>
 #include <exception>
 #include <iostream>
 
+using namespace std::chrono;
+
 using std::shared_ptr;
 using std::string;
 using std::unique_ptr;
@@ -37,8 +41,11 @@ namespace {
 
 static bool check_gnutls(int ret, const string &message = "GnuTLS error") {
 	if (ret < 0) {
-		if (!gnutls_error_is_fatal(ret))
+		if (!gnutls_error_is_fatal(ret)) {
+			PLOG_INFO << gnutls_strerror(ret);
 			return false;
+		}
+		PLOG_ERROR << message << ": " << gnutls_strerror(ret);
 		throw std::runtime_error(message + ": " + gnutls_strerror(ret));
 	}
 	return true;
@@ -48,13 +55,21 @@ static bool check_gnutls(int ret, const string &message = "GnuTLS error") {
 
 namespace rtc {
 
-DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certificate> certificate,
-                             verifier_callback verifierCallback,
-                             state_callback stateChangeCallback)
+void DtlsTransport::Init() {
+	// Nothing to do
+}
+
+void DtlsTransport::Cleanup() {
+	// Nothing to do
+}
+
+DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, certificate_ptr certificate,
+                             verifier_callback verifierCallback, state_callback stateChangeCallback)
     : Transport(lower), mCertificate(certificate), mState(State::Disconnected),
       mVerifierCallback(std::move(verifierCallback)),
       mStateChangeCallback(std::move(stateChangeCallback)) {
-	gnutls_certificate_set_verify_function(mCertificate->credentials(), CertificateCallback);
+
+	PLOG_DEBUG << "Initializing DTLS transport (GnuTLS)";
 
 	bool active = lower->role() == Description::Role::Active;
 	unsigned int flags = GNUTLS_DATAGRAM | (active ? GNUTLS_CLIENT : GNUTLS_SERVER);
@@ -63,17 +78,19 @@ 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, 400, 60000);
-	gnutls_handshake_set_timeout(mSession, 60000);
+	gnutls_dtls_set_timeouts(mSession,
+	                         1000,   // 1s retransmission timeout recommended by RFC 6347
+	                         30000); // 30s total timeout
+	gnutls_handshake_set_timeout(mSession, 30000);
 
 	gnutls_session_set_ptr(mSession, this);
 	gnutls_transport_set_ptr(mSession, this);
@@ -82,24 +99,33 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
 	gnutls_transport_set_pull_timeout_function(mSession, TimeoutCallback);
 
 	mRecvThread = std::thread(&DtlsTransport::runRecvLoop, this);
+	registerIncoming();
 }
 
 DtlsTransport::~DtlsTransport() {
-	resetLower();
+	stop();
 
-	mIncomingQueue.stop();
-	mRecvThread.join();
-
-	gnutls_bye(mSession, GNUTLS_SHUT_RDWR);
 	gnutls_deinit(mSession);
 }
 
 DtlsTransport::State DtlsTransport::state() const { return mState; }
 
+bool DtlsTransport::stop() {
+	if (!Transport::stop())
+		return false;
+
+	PLOG_DEBUG << "Stopping DTLS recv thread";
+	mIncomingQueue.stop();
+	mRecvThread.join();
+	return true;
+}
+
 bool DtlsTransport::send(message_ptr message) {
 	if (!message || mState != State::Connected)
 		return false;
 
+	PLOG_VERBOSE << "Send size=" << message->size();
+
 	ssize_t ret;
 	do {
 		ret = gnutls_record_send(mSession, message->data(), message->size());
@@ -111,7 +137,15 @@ bool DtlsTransport::send(message_ptr message) {
 	return check_gnutls(ret);
 }
 
-void DtlsTransport::incoming(message_ptr message) { mIncomingQueue.push(message); }
+void DtlsTransport::incoming(message_ptr message) {
+	if (!message) {
+		mIncomingQueue.stop();
+		return;
+	}
+
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	mIncomingQueue.push(message);
+}
 
 void DtlsTransport::changeState(State state) {
 	if (mState.exchange(state) != state)
@@ -124,6 +158,7 @@ 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 {
@@ -140,13 +175,14 @@ void DtlsTransport::runRecvLoop() {
 		gnutls_dtls_set_mtu(mSession, maxMtu + 1);
 
 	} catch (const std::exception &e) {
-		std::cerr << "DTLS handshake: " << e.what() << std::endl;
+		PLOG_ERROR << "DTLS handshake: " << e.what();
 		changeState(State::Failed);
 		return;
 	}
 
 	// Receive loop
 	try {
+		PLOG_INFO << "DTLS handshake done";
 		changeState(State::Connected);
 
 		const size_t bufferSize = maxMtu;
@@ -159,12 +195,15 @@ void DtlsTransport::runRecvLoop() {
 			} while (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN);
 
 			// Consider premature termination as remote closing
-			if (ret == GNUTLS_E_PREMATURE_TERMINATION)
+			if (ret == GNUTLS_E_PREMATURE_TERMINATION) {
+				PLOG_DEBUG << "DTLS connection terminated";
 				break;
+			}
 
 			if (check_gnutls(ret)) {
 				if (ret == 0) {
 					// Closed
+					PLOG_DEBUG << "DTLS connection cleanly closed";
 					break;
 				}
 				auto *b = reinterpret_cast<byte *>(buffer);
@@ -173,9 +212,12 @@ void DtlsTransport::runRecvLoop() {
 		}
 
 	} catch (const std::exception &e) {
-		std::cerr << "DTLS recv: " << e.what() << std::endl;
+		PLOG_ERROR << "DTLS recv: " << e.what();
 	}
 
+	gnutls_bye(mSession, GNUTLS_SHUT_RDWR);
+
+	PLOG_INFO << "DTLS disconnected";
 	changeState(State::Disconnected);
 	recv(nullptr);
 }
@@ -220,32 +262,28 @@ ssize_t DtlsTransport::WriteCallback(gnutls_transport_ptr_t ptr, const void *dat
 
 ssize_t DtlsTransport::ReadCallback(gnutls_transport_ptr_t ptr, void *data, size_t maxlen) {
 	DtlsTransport *t = static_cast<DtlsTransport *>(ptr);
-	auto next = t->mIncomingQueue.pop();
-	auto message = next ? *next : nullptr;
-	if (!message) {
-		// Closed
+	if (auto next = t->mIncomingQueue.pop()) {
+		auto message = *next;
+		ssize_t len = std::min(maxlen, message->size());
+		std::memcpy(data, message->data(), len);
 		gnutls_transport_set_errno(t->mSession, 0);
-		return 0;
+		return len;
 	}
-
-	ssize_t len = std::min(maxlen, message->size());
-	std::memcpy(data, message->data(), len);
+	// Closed
 	gnutls_transport_set_errno(t->mSession, 0);
-	return len;
+	return 0;
 }
 
 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(std::chrono::milliseconds(ms));
-	else
-		t->mIncomingQueue.wait();
+	t->mIncomingQueue.wait(ms != GNUTLS_INDEFINITE_TIMEOUT ? std::make_optional(milliseconds(ms))
+	                                                       : nullopt);
 	return !t->mIncomingQueue.empty() ? 1 : 0;
 }
 
 } // namespace rtc
 
-#else
+#else // USE_GNUTLS==0
 
 #include <openssl/bio.h>
 #include <openssl/ec.h>
@@ -266,8 +304,10 @@ string openssl_error_string(unsigned long err) {
 bool check_openssl(int success, const string &message = "OpenSSL error") {
 	if (success)
 		return true;
-	else
-		throw std::runtime_error(message + ": " + openssl_error_string(ERR_get_error()));
+
+	string str = openssl_error_string(ERR_get_error());
+	PLOG_ERROR << message << ": " << str;
+	throw std::runtime_error(message + ": " + str);
 }
 
 bool check_openssl_ret(SSL *ssl, int ret, const string &message = "OpenSSL error") {
@@ -275,35 +315,53 @@ bool check_openssl_ret(SSL *ssl, int ret, const string &message = "OpenSSL error
 		return true;
 
 	unsigned long err = SSL_get_error(ssl, ret);
-	if (err == SSL_ERROR_NONE || err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE)
+	if (err == SSL_ERROR_NONE || err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
 		return true;
-	else if (err == SSL_ERROR_ZERO_RETURN)
+	}
+	if (err == SSL_ERROR_ZERO_RETURN) {
+		PLOG_DEBUG << "DTLS connection cleanly closed";
 		return false;
-	else
-		throw std::runtime_error(message + ": " + openssl_error_string(err));
+	}
+	string str = openssl_error_string(err);
+	PLOG_ERROR << str;
+	throw std::runtime_error(message + ": " + str);
 }
 
 } // namespace
 
 namespace rtc {
 
+BIO_METHOD *DtlsTransport::BioMethods = NULL;
 int DtlsTransport::TransportExIndex = -1;
 std::mutex DtlsTransport::GlobalMutex;
 
-void DtlsTransport::GlobalInit() {
-	std::lock_guard<std::mutex> lock(GlobalMutex);
+void DtlsTransport::Init() {
+	std::lock_guard lock(GlobalMutex);
+	if (!BioMethods) {
+		BioMethods = BIO_meth_new(BIO_TYPE_BIO, "DTLS writer");
+		if (!BioMethods)
+			throw std::runtime_error("Unable to BIO methods for DTLS writer");
+		BIO_meth_set_create(BioMethods, BioMethodNew);
+		BIO_meth_set_destroy(BioMethods, BioMethodFree);
+		BIO_meth_set_write(BioMethods, BioMethodWrite);
+		BIO_meth_set_ctrl(BioMethods, BioMethodCtrl);
+	}
 	if (TransportExIndex < 0) {
 		TransportExIndex = SSL_get_ex_new_index(0, NULL, NULL, NULL, NULL);
 	}
 }
 
+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),
       mVerifierCallback(std::move(verifierCallback)),
       mStateChangeCallback(std::move(stateChangeCallback)) {
 
-	GlobalInit();
+	PLOG_DEBUG << "Initializing DTLS transport (OpenSSL)";
 
 	if (!(mCtx = SSL_CTX_new(DTLS_method())))
 		throw std::runtime_error("Unable to create SSL context");
@@ -314,7 +372,7 @@ 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
-	SSL_CTX_set_options(mCtx, SSL_OP_NO_SSLv3 | SSL_OP_NO_COMPRESSION);
+	SSL_CTX_set_options(mCtx, SSL_OP_NO_SSLv3 | SSL_OP_NO_COMPRESSION | SSL_OP_NO_QUERY_MTU);
 	SSL_CTX_set_min_proto_version(mCtx, DTLS1_VERSION);
 	SSL_CTX_set_read_ahead(mCtx, 1);
 	SSL_CTX_set_quiet_shutdown(mCtx, 1);
@@ -330,21 +388,20 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
 	check_openssl(SSL_CTX_check_private_key(mCtx), "SSL local private key check failed");
 
 	if (!(mSsl = SSL_new(mCtx)))
-	    throw std::runtime_error("Unable to create SSL instance");
+		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);
 	else
 		SSL_set_accept_state(mSsl);
 
-    if (!(mInBio = BIO_new(BIO_s_mem())) || !(mOutBio = BIO_new(BIO_s_mem())))
-	    throw std::runtime_error("Unable to create BIO");
+	if (!(mInBio = BIO_new(BIO_s_mem())) || !(mOutBio = BIO_new(BioMethods)))
+		throw std::runtime_error("Unable to create BIO");
 
 	BIO_set_mem_eof_return(mInBio, BIO_EOF);
-	BIO_set_mem_eof_return(mOutBio, BIO_EOF);
+	BIO_set_data(mOutBio, this);
 	SSL_set_bio(mSsl, mInBio, mOutBio);
 
 	auto ecdh = unique_ptr<EC_KEY, decltype(&EC_KEY_free)>(
@@ -353,43 +410,50 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
 	SSL_set_tmp_ecdh(mSsl, ecdh.get());
 
 	mRecvThread = std::thread(&DtlsTransport::runRecvLoop, this);
+	registerIncoming();
 }
 
 DtlsTransport::~DtlsTransport() {
-	resetLower();
+	stop();
 
-	mIncomingQueue.stop();
-	mRecvThread.join();
-
-	SSL_shutdown(mSsl);
 	SSL_free(mSsl);
 	SSL_CTX_free(mCtx);
 }
 
+bool DtlsTransport::stop() {
+	if (!Transport::stop())
+		return false;
+
+	PLOG_DEBUG << "Stopping DTLS recv thread";
+	mIncomingQueue.stop();
+	mRecvThread.join();
+	SSL_shutdown(mSsl);
+	return true;
+}
+
 DtlsTransport::State DtlsTransport::state() const { return mState; }
 
 bool DtlsTransport::send(message_ptr message) {
-	const size_t bufferSize = 4096;
-	byte buffer[bufferSize];
-
 	if (!message || mState != State::Connected)
 		return false;
 
+	PLOG_VERBOSE << "Send size=" << message->size();
+
 	int ret = SSL_write(mSsl, message->data(), message->size());
-	if (!check_openssl_ret(mSsl, ret)) {
+	if (!check_openssl_ret(mSsl, ret))
 		return false;
-	}
-
-	while (BIO_ctrl_pending(mOutBio) > 0) {
-		int ret = BIO_read(mOutBio, buffer, bufferSize);
-		if (check_openssl_ret(mSsl, ret) && ret > 0)
-			outgoing(make_message(buffer, buffer + ret));
-	}
-
 	return true;
 }
 
-void DtlsTransport::incoming(message_ptr message) { mIncomingQueue.push(message); }
+void DtlsTransport::incoming(message_ptr message) {
+	if (!message) {
+		mIncomingQueue.stop();
+		return;
+	}
+
+	PLOG_VERBOSE << "Incoming size=" << message->size();
+	mIncomingQueue.push(message);
+}
 
 void DtlsTransport::changeState(State state) {
 	if (mState.exchange(state) != state)
@@ -397,53 +461,85 @@ void DtlsTransport::changeState(State state) {
 }
 
 void DtlsTransport::runRecvLoop() {
-	const size_t bufferSize = 4096;
-	byte buffer[bufferSize];
-
+	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);
-		while (BIO_ctrl_pending(mOutBio) > 0) {
-			int ret = BIO_read(mOutBio, buffer, bufferSize);
-			if (check_openssl_ret(mSsl, ret) && ret > 0)
-				outgoing(make_message(buffer, buffer + ret));
-		}
+		// Initiate the handshake
+		int ret = SSL_do_handshake(mSsl);
+		check_openssl_ret(mSsl, ret, "Handshake failed");
 
-		while (auto next = mIncomingQueue.pop()) {
-			auto message = *next;
-			BIO_write(mInBio, message->data(), message->size());
-			int ret = SSL_read(mSsl, buffer, bufferSize);
-			if (!check_openssl_ret(mSsl, ret))
-				break;
+		const size_t bufferSize = maxMtu;
+		byte buffer[bufferSize];
+		while (true) {
+			// Process pending messages
+			while (!mIncomingQueue.empty()) {
+				auto message = *mIncomingQueue.pop();
+				BIO_write(mInBio, message->data(), message->size());
 
-			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 (unsigned long err = ERR_get_error())
-					throw std::runtime_error("handshake failed: " + openssl_error_string(err));
+					if (SSL_is_init_finished(mSsl)) {
+						// RFC 8261: DTLS MUST support sending messages larger than the current path
+						// MTU See https://tools.ietf.org/html/rfc8261#section-5
+						SSL_set_mtu(mSsl, maxMtu + 1);
 
-				while (BIO_ctrl_pending(mOutBio) > 0) {
-					ret = BIO_read(mOutBio, buffer, bufferSize);
-					if (check_openssl_ret(mSsl, ret) && ret > 0)
-						outgoing(make_message(buffer, buffer + ret));
+						PLOG_INFO << "DTLS handshake done";
+						changeState(State::Connected);
+					}
+				} else {
+					int ret = SSL_read(mSsl, buffer, bufferSize);
+					if (!check_openssl_ret(mSsl, ret))
+						break;
+					if (ret > 0)
+						recv(make_message(buffer, buffer + ret));
 				}
-
-				if (SSL_is_init_finished(mSsl))
-					changeState(State::Connected);
 			}
 
-			if (decrypted)
-				recv(decrypted);
+			// No more messages pending, retransmit and rearm timeout if connecting
+			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) {
-		std::cerr << "DTLS recv: " << e.what() << std::endl;
+		PLOG_ERROR << "DTLS recv: " << e.what();
 	}
 
 	if (mState == State::Connected) {
+		PLOG_INFO << "DTLS disconnected";
 		changeState(State::Disconnected);
 		recv(nullptr);
 	} else {
+		PLOG_ERROR << "DTLS handshake failed";
 		changeState(State::Failed);
 	}
 }
@@ -465,12 +561,53 @@ void DtlsTransport::InfoCallback(const SSL *ssl, int where, int ret) {
 	    static_cast<DtlsTransport *>(SSL_get_ex_data(ssl, DtlsTransport::TransportExIndex));
 
 	if (where & SSL_CB_ALERT) {
-		if (ret != 256) // Close Notify
-			std::cerr << "DTLS alert: " << SSL_alert_desc_string_long(ret) << std::endl;
+		if (ret != 256) { // Close Notify
+			PLOG_ERROR << "DTLS alert: " << SSL_alert_desc_string_long(ret);
+		}
 		t->mIncomingQueue.stop(); // Close the connection
 	}
 }
 
+int DtlsTransport::BioMethodNew(BIO *bio) {
+	BIO_set_init(bio, 1);
+	BIO_set_data(bio, NULL);
+	BIO_set_shutdown(bio, 0);
+	return 1;
+}
+
+int DtlsTransport::BioMethodFree(BIO *bio) {
+	if (!bio)
+		return 0;
+	BIO_set_data(bio, NULL);
+	return 1;
+}
+
+int DtlsTransport::BioMethodWrite(BIO *bio, const char *in, int inl) {
+	if (inl <= 0)
+		return inl;
+	auto transport = reinterpret_cast<DtlsTransport *>(BIO_get_data(bio));
+	if (!transport)
+		return -1;
+	auto b = reinterpret_cast<const byte *>(in);
+	transport->outgoing(make_message(b, b + inl));
+	return inl; // can't fail
+}
+
+long DtlsTransport::BioMethodCtrl(BIO *bio, int cmd, long num, void *ptr) {
+	switch (cmd) {
+	case BIO_CTRL_FLUSH:
+		return 1;
+	case BIO_CTRL_DGRAM_QUERY_MTU:
+		return 0; // SSL_OP_NO_QUERY_MTU must be set
+	case BIO_CTRL_WPENDING:
+	case BIO_CTRL_PENDING:
+		return 0;
+	default:
+		break;
+	}
+	return 0;
+}
+
 } // namespace rtc
 
 #endif

src/dtlstransport.hpp

@@ -43,25 +43,29 @@ 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)>;
 	using state_callback = std::function<void(State state)>;
 
-	DtlsTransport(std::shared_ptr<IceTransport> lower, std::shared_ptr<Certificate> certificate,
+	DtlsTransport(std::shared_ptr<IceTransport> lower, certificate_ptr certificate,
 	              verifier_callback verifierCallback, state_callback stateChangeCallback);
 	~DtlsTransport();
 
 	State state() const;
 
-	bool send(message_ptr message); // false if dropped
+	bool stop() override;
+	bool send(message_ptr message) override; // false if dropped
 
 private:
-	void incoming(message_ptr message);
+	void incoming(message_ptr message) override;
 	void changeState(State state);
 	void runRecvLoop();
 
-	const std::shared_ptr<Certificate> mCertificate;
+	const certificate_ptr mCertificate;
 
 	Queue<message_ptr> mIncomingQueue;
 	std::atomic<State> mState;
@@ -82,12 +86,17 @@ private:
 	SSL *mSsl;
 	BIO *mInBio, *mOutBio;
 
+	static BIO_METHOD *BioMethods;
 	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);
+
+	static int BioMethodNew(BIO *bio);
+	static int BioMethodFree(BIO *bio);
+	static int BioMethodWrite(BIO *bio, const char *in, int inl);
+	static long BioMethodCtrl(BIO *bio, int cmd, long num, void *ptr);
 #endif
 };
 

src/icetransport.cpp

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2019 Paul-Louis Ageneau
+ * 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
@@ -17,40 +17,271 @@
  */
 
 #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 <chrono>
 #include <iostream>
 #include <random>
 #include <sstream>
 
-namespace rtc {
+#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;
 using std::weak_ptr;
 
+#if USE_JUICE
+
+namespace rtc {
+
 IceTransport::IceTransport(const Configuration &config, Description::Role role,
-                           candidate_callback candidateCallback,
-                           state_callback stateChangeCallback,
+                           candidate_callback candidateCallback, state_callback stateChangeCallback,
                            gathering_state_callback gatheringStateChangeCallback)
     : mRole(role), mMid("0"), mState(State::Disconnected), mGatheringState(GatheringState::New),
-      mNiceAgent(nullptr, nullptr), mMainLoop(nullptr, nullptr),
       mCandidateCallback(std::move(candidateCallback)),
       mStateChangeCallback(std::move(stateChangeCallback)),
-      mGatheringStateChangeCallback(std::move(gatheringStateChangeCallback)) {
+      mGatheringStateChangeCallback(std::move(gatheringStateChangeCallback)),
+      mAgent(nullptr, nullptr) {
 
-	auto logLevelFlags = GLogLevelFlags(G_LOG_LEVEL_MASK | G_LOG_FLAG_FATAL | G_LOG_FLAG_RECURSION);
-	g_log_set_handler(nullptr, logLevelFlags, LogCallback, this);
-	nice_debug_enable(false);
+	PLOG_DEBUG << "Initializing ICE transport (libjuice)";
+	if (config.enableIceTcp) {
+		PLOG_WARNING << "ICE-TCP is not supported with libjuice";
+	}
+	juice_set_log_handler(IceTransport::LogCallback);
+	juice_set_log_level(JUICE_LOG_LEVEL_VERBOSE);
+
+	juice_config_t jconfig = {};
+	jconfig.cb_state_changed = IceTransport::StateChangeCallback;
+	jconfig.cb_candidate = IceTransport::CandidateCallback;
+	jconfig.cb_gathering_done = IceTransport::GatheringDoneCallback;
+	jconfig.cb_recv = IceTransport::RecvCallback;
+	jconfig.user_ptr = this;
+
+	// Randomize servers order
+	std::vector<IceServer> servers = config.iceServers;
+	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 (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())
+				server.service = "3478"; // STUN UDP port
+			PLOG_DEBUG << "Using STUN server \"" << server.hostname << ":" << server.service
+			           << "\"";
+			mStunHostname = server.hostname;
+			mStunService = server.service;
+			jconfig.stun_server_host = mStunHostname.c_str();
+			jconfig.stun_server_port = std::stoul(mStunService);
+		}
+	}
+
+	// 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);
+	if (!mAgent)
+		throw std::runtime_error("Failed to create the ICE agent");
+}
+
+IceTransport::~IceTransport() { stop(); }
+
+bool IceTransport::stop() {
+	return Transport::stop();
+}
+
+Description::Role IceTransport::role() const { return mRole; }
+
+IceTransport::State IceTransport::state() const { return mState; }
+
+Description IceTransport::getLocalDescription(Description::Type type) const {
+	char sdp[JUICE_MAX_SDP_STRING_LEN];
+	if (juice_get_local_description(mAgent.get(), sdp, JUICE_MAX_SDP_STRING_LEN) < 0)
+		throw std::runtime_error("Failed to generate local SDP");
+
+	return Description(string(sdp), type, mRole);
+}
+
+void IceTransport::setRemoteDescription(const Description &description) {
+	mRole = description.role() == Description::Role::Active ? Description::Role::Passive
+	                                                        : Description::Role::Active;
+	mMid = description.mid();
+	if (juice_set_remote_description(mAgent.get(), string(description).c_str()) < 0)
+		throw std::runtime_error("Failed to parse remote SDP");
+}
+
+bool IceTransport::addRemoteCandidate(const Candidate &candidate) {
+	// Don't try to pass unresolved candidates for more safety
+	if (!candidate.isResolved())
+		return false;
+
+	return juice_add_remote_candidate(mAgent.get(), string(candidate).c_str()) >= 0;
+}
+
+void IceTransport::gatherLocalCandidates() {
+	// Change state now as candidates calls can be synchronous
+	changeGatheringState(GatheringState::InProgress);
+
+	if (juice_gather_candidates(mAgent.get()) < 0) {
+		throw std::runtime_error("Failed to gather local ICE candidates");
+	}
+}
+
+std::optional<string> IceTransport::getLocalAddress() const {
+	char str[JUICE_MAX_ADDRESS_STRING_LEN];
+	if (juice_get_selected_addresses(mAgent.get(), str, JUICE_MAX_ADDRESS_STRING_LEN, NULL, 0) ==
+	    0) {
+		return std::make_optional(string(str));
+	}
+	return nullopt;
+}
+std::optional<string> IceTransport::getRemoteAddress() const {
+	char str[JUICE_MAX_ADDRESS_STRING_LEN];
+	if (juice_get_selected_addresses(mAgent.get(), NULL, 0, str, JUICE_MAX_ADDRESS_STRING_LEN) ==
+	    0) {
+		return std::make_optional(string(str));
+	}
+	return nullopt;
+}
+
+bool IceTransport::send(message_ptr message) {
+	if (!message || (mState != State::Connected && mState != State::Completed))
+		return false;
+
+	PLOG_VERBOSE << "Send size=" << message->size();
+	return outgoing(message);
+}
+
+bool IceTransport::outgoing(message_ptr message) {
+	return juice_send(mAgent.get(), reinterpret_cast<const char *>(message->data()),
+	                  message->size()) >= 0;
+}
+
+void IceTransport::changeState(State state) {
+	if (mState.exchange(state) != state)
+		mStateChangeCallback(mState);
+}
+
+void IceTransport::changeGatheringState(GatheringState state) {
+	if (mGatheringState.exchange(state) != state)
+		mGatheringStateChangeCallback(mGatheringState);
+}
+
+void IceTransport::processStateChange(unsigned int state) {
+	changeState(static_cast<State>(state));
+}
+
+void IceTransport::processCandidate(const string &candidate) {
+	mCandidateCallback(Candidate(candidate, mMid));
+}
+
+void IceTransport::processGatheringDone() { changeGatheringState(GatheringState::Complete); }
+
+void IceTransport::StateChangeCallback(juice_agent_t *agent, juice_state_t state, void *user_ptr) {
+	auto iceTransport = static_cast<rtc::IceTransport *>(user_ptr);
+	try {
+		iceTransport->processStateChange(static_cast<unsigned int>(state));
+	} catch (const std::exception &e) {
+		PLOG_WARNING << e.what();
+	}
+}
+
+void IceTransport::CandidateCallback(juice_agent_t *agent, const char *sdp, void *user_ptr) {
+	auto iceTransport = static_cast<rtc::IceTransport *>(user_ptr);
+	try {
+		iceTransport->processCandidate(sdp);
+	} catch (const std::exception &e) {
+		PLOG_WARNING << e.what();
+	}
+}
+
+void IceTransport::GatheringDoneCallback(juice_agent_t *agent, void *user_ptr) {
+	auto iceTransport = static_cast<rtc::IceTransport *>(user_ptr);
+	try {
+		iceTransport->processGatheringDone();
+	} catch (const std::exception &e) {
+		PLOG_WARNING << e.what();
+	}
+}
+
+void IceTransport::RecvCallback(juice_agent_t *agent, const char *data, size_t size,
+                                void *user_ptr) {
+	auto iceTransport = static_cast<rtc::IceTransport *>(user_ptr);
+	try {
+		PLOG_VERBOSE << "Incoming size=" << size;
+		auto b = reinterpret_cast<const byte *>(data);
+		iceTransport->incoming(make_message(b, b + size));
+	} catch (const std::exception &e) {
+		PLOG_WARNING << e.what();
+	}
+}
+
+void IceTransport::LogCallback(juice_log_level_t level, const char *message) {
+	plog::Severity severity;
+	switch (level) {
+	case JUICE_LOG_LEVEL_FATAL:
+		severity = plog::fatal;
+		break;
+	case JUICE_LOG_LEVEL_ERROR:
+		severity = plog::error;
+		break;
+	case JUICE_LOG_LEVEL_WARN:
+		severity = plog::warning;
+		break;
+	case JUICE_LOG_LEVEL_INFO:
+		severity = plog::info;
+		break;
+	default:
+		severity = plog::verbose; // libjuice debug as verbose
+		break;
+	}
+	PLOG(severity) << "juice: " << message;
+}
+
+} // namespace rtc
+
+#else // USE_JUICE == 0
+
+namespace rtc {
+
+IceTransport::IceTransport(const Configuration &config, Description::Role role,
+                           candidate_callback candidateCallback, state_callback stateChangeCallback,
+                           gathering_state_callback gatheringStateChangeCallback)
+    : mRole(role), mMid("0"), mState(State::Disconnected), mGatheringState(GatheringState::New),
+      mCandidateCallback(std::move(candidateCallback)),
+      mStateChangeCallback(std::move(stateChangeCallback)),
+      mGatheringStateChangeCallback(std::move(gatheringStateChangeCallback)),
+      mNiceAgent(nullptr, nullptr), mMainLoop(nullptr, nullptr) {
+
+	PLOG_DEBUG << "Initializing ICE transport (libnice)";
+
+	g_log_set_handler("libnice", G_LOG_LEVEL_MASK, LogCallback, this);
+
+	IF_PLOG(plog::verbose) {
+		nice_debug_enable(false); // do not output STUN debug messages
+	}
 
 	mMainLoop = decltype(mMainLoop)(g_main_loop_new(nullptr, FALSE), g_main_loop_unref);
 	if (!mMainLoop)
 		std::runtime_error("Failed to create the main loop");
 
+	// RFC 5245 was obsoleted by RFC 8445 but this should be OK.
 	mNiceAgent = decltype(mNiceAgent)(
 	    nice_agent_new(g_main_loop_get_context(mMainLoop.get()), NICE_COMPATIBILITY_RFC5245),
 	    g_object_unref);
@@ -60,23 +291,50 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 
 	mMainLoopThread = std::thread(g_main_loop_run, mMainLoop.get());
 
-	g_object_set(G_OBJECT(mNiceAgent.get()), "controlling-mode", TRUE, nullptr);
+	mStreamId = nice_agent_add_stream(mNiceAgent.get(), 1);
+	if (!mStreamId)
+		throw std::runtime_error("Failed to add a stream");
+
+	g_object_set(G_OBJECT(mNiceAgent.get()), "controlling-mode", TRUE, nullptr); // decided later
 	g_object_set(G_OBJECT(mNiceAgent.get()), "ice-udp", TRUE, nullptr);
-	g_object_set(G_OBJECT(mNiceAgent.get()), "ice-tcp", FALSE, nullptr);
-	g_object_set(G_OBJECT(mNiceAgent.get()), "stun-initial-timeout", 200, nullptr);
+	g_object_set(G_OBJECT(mNiceAgent.get()), "ice-tcp", config.enableIceTcp ? TRUE : FALSE,
+	             nullptr);
+
+	// RFC 8445: Agents MUST NOT use an RTO value smaller than 500 ms.
+	g_object_set(G_OBJECT(mNiceAgent.get()), "stun-initial-timeout", 500, nullptr);
 	g_object_set(G_OBJECT(mNiceAgent.get()), "stun-max-retransmissions", 3, nullptr);
-	g_object_set(G_OBJECT(mNiceAgent.get()), "stun-pacing-timer", 20, nullptr);
+
+	// RFC 8445: ICE agents SHOULD use a default Ta value, 50 ms, but MAY use another value based on
+	// the characteristics of the associated data.
+	g_object_set(G_OBJECT(mNiceAgent.get()), "stun-pacing-timer", 25, nullptr);
+
 	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();
 	std::shuffle(servers.begin(), servers.end(), std::default_random_engine(seed));
 
+	// Add one STUN server
 	bool success = false;
 	for (auto &server : servers) {
 		if (server.hostname.empty())
 			continue;
+		if (server.type != IceServer::Type::Stun)
+			continue;
 		if (server.service.empty())
 			server.service = "3478"; // STUN UDP port
 
@@ -94,9 +352,10 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 				char nodebuffer[MAX_NUMERICNODE_LEN];
 				char servbuffer[MAX_NUMERICSERV_LEN];
 				if (getnameinfo(p->ai_addr, p->ai_addrlen, nodebuffer, MAX_NUMERICNODE_LEN,
-
 				                servbuffer, MAX_NUMERICNODE_LEN,
 				                NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
+					PLOG_DEBUG << "Using STUN server \"" << server.hostname << ":" << server.service
+					           << "\"";
 					g_object_set(G_OBJECT(mNiceAgent.get()), "stun-server", nodebuffer, nullptr);
 					g_object_set(G_OBJECT(mNiceAgent.get()), "stun-server-port",
 					             std::stoul(servbuffer), nullptr);
@@ -111,6 +370,56 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 			break;
 	}
 
+	// Add TURN servers
+	for (auto &server : servers) {
+		if (server.hostname.empty())
+			continue;
+		if (server.type != IceServer::Type::Turn)
+			continue;
+		if (server.service.empty())
+			server.service = server.relayType == IceServer::RelayType::TurnTls ? "5349" : "3478";
+
+		struct addrinfo hints = {};
+		hints.ai_family = AF_UNSPEC;
+		hints.ai_socktype =
+		    server.relayType == IceServer::RelayType::TurnUdp ? SOCK_DGRAM : SOCK_STREAM;
+		hints.ai_protocol =
+		    server.relayType == IceServer::RelayType::TurnUdp ? IPPROTO_UDP : IPPROTO_TCP;
+		hints.ai_flags = AI_ADDRCONFIG;
+		struct addrinfo *result = nullptr;
+		if (getaddrinfo(server.hostname.c_str(), server.service.c_str(), &hints, &result) != 0)
+			continue;
+
+		for (auto p = result; p; p = p->ai_next) {
+			if (p->ai_family == AF_INET || p->ai_family == AF_INET6) {
+				char nodebuffer[MAX_NUMERICNODE_LEN];
+				char servbuffer[MAX_NUMERICSERV_LEN];
+				if (getnameinfo(p->ai_addr, p->ai_addrlen, nodebuffer, MAX_NUMERICNODE_LEN,
+				                servbuffer, MAX_NUMERICNODE_LEN,
+				                NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
+
+					NiceRelayType niceRelayType;
+					switch (server.relayType) {
+					case IceServer::RelayType::TurnTcp:
+						niceRelayType = NICE_RELAY_TYPE_TURN_TCP;
+						break;
+					case IceServer::RelayType::TurnTls:
+						niceRelayType = NICE_RELAY_TYPE_TURN_TLS;
+						break;
+					default:
+						niceRelayType = NICE_RELAY_TYPE_TURN_UDP;
+						break;
+					}
+					nice_agent_set_relay_info(mNiceAgent.get(), mStreamId, 1, nodebuffer,
+					                          std::stoul(servbuffer), server.username.c_str(),
+					                          server.password.c_str(), niceRelayType);
+				}
+			}
+		}
+
+		freeaddrinfo(result);
+	}
+
 	g_signal_connect(G_OBJECT(mNiceAgent.get()), "component-state-changed",
 	                 G_CALLBACK(StateChangeCallback), this);
 	g_signal_connect(G_OBJECT(mNiceAgent.get()), "new-candidate-full",
@@ -118,10 +427,6 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 	g_signal_connect(G_OBJECT(mNiceAgent.get()), "candidate-gathering-done",
 	                 G_CALLBACK(GatheringDoneCallback), this);
 
-	mStreamId = nice_agent_add_stream(mNiceAgent.get(), 1);
-	if (!mStreamId)
-		throw std::runtime_error("Failed to add a stream");
-
 	nice_agent_set_stream_name(mNiceAgent.get(), mStreamId, "application");
 	nice_agent_set_port_range(mNiceAgent.get(), mStreamId, 1, config.portRangeBegin,
 	                          config.portRangeEnd);
@@ -130,9 +435,24 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 	                       RecvCallback, this);
 }
 
-IceTransport::~IceTransport() {
+IceTransport::~IceTransport() { stop(); }
+
+bool IceTransport::stop() {
+	if (mTimeoutId) {
+		g_source_remove(mTimeoutId);
+		mTimeoutId = 0;
+	}
+
+	if (!Transport::stop())
+		return false;
+
+	PLOG_DEBUG << "Stopping ICE thread";
+	nice_agent_attach_recv(mNiceAgent.get(), mStreamId, 1, g_main_loop_get_context(mMainLoop.get()),
+	                       NULL, NULL);
+	nice_agent_remove_stream(mNiceAgent.get(), mStreamId);
 	g_main_loop_quit(mMainLoop.get());
 	mMainLoopThread.join();
+	return true;
 }
 
 Description::Role IceTransport::role() const { return mRole; }
@@ -140,8 +460,8 @@ Description::Role IceTransport::role() const { return mRole; }
 IceTransport::State IceTransport::state() const { return mState; }
 
 Description IceTransport::getLocalDescription(Description::Type type) const {
-	// RFC 5245: The agent that generated the offer which started the ICE processing MUST take the
-	// controlling role, and the other MUST take the controlled role.
+	// RFC 8445: The initiating agent that started the ICE processing MUST take the controlling
+	// role, and the other MUST take the controlled role.
 	g_object_set(G_OBJECT(mNiceAgent.get()), "controlling-mode",
 	             type == Description::Type::Offer ? TRUE : FALSE, nullptr);
 
@@ -154,14 +474,15 @@ void IceTransport::setRemoteDescription(const Description &description) {
 	mRole = description.role() == Description::Role::Active ? Description::Role::Passive
 	                                                        : Description::Role::Active;
 	mMid = description.mid();
+	mTrickleTimeout = description.trickleEnabled() ? 30s : 0s;
 
-	if (nice_agent_parse_remote_sdp(mNiceAgent.get(), string(description).c_str()) < 0)
+	// Warning: libnice expects "\n" as end of line
+	if (nice_agent_parse_remote_sdp(mNiceAgent.get(), description.generateSdp("\n").c_str()) < 0)
 		throw std::runtime_error("Failed to parse remote SDP");
 }
 
 bool IceTransport::addRemoteCandidate(const Candidate &candidate) {
 	// Don't try to pass unresolved candidates to libnice for more safety
-
 	if (!candidate.isResolved())
 		return false;
 
@@ -197,6 +518,7 @@ std::optional<string> IceTransport::getLocalAddress() const {
 	}
 	return nullopt;
 }
+
 std::optional<string> IceTransport::getRemoteAddress() const {
 	NiceCandidate *local = nullptr;
 	NiceCandidate *remote = nullptr;
@@ -207,22 +529,16 @@ std::optional<string> IceTransport::getRemoteAddress() const {
 }
 
 bool IceTransport::send(message_ptr message) {
-	if (!message || !mStreamId)
+	if (!message || (mState != State::Connected && mState != State::Completed))
 		return false;
 
-	outgoing(message);
-	return true;
+	PLOG_VERBOSE << "Send size=" << message->size();
+	return outgoing(message);
 }
 
-void IceTransport::incoming(message_ptr message) { recv(message); }
-
-void IceTransport::incoming(const byte *data, int size) {
-	incoming(make_message(data, data + size));
-}
-
-void IceTransport::outgoing(message_ptr message) {
-	nice_agent_send(mNiceAgent.get(), mStreamId, 1, message->size(),
-	                reinterpret_cast<const char *>(message->data()));
+bool IceTransport::outgoing(message_ptr message) {
+	return nice_agent_send(mNiceAgent.get(), mStreamId, 1, message->size(),
+	                       reinterpret_cast<const char *>(message->data())) >= 0;
 }
 
 void IceTransport::changeState(State state) {
@@ -231,8 +547,14 @@ void IceTransport::changeState(State state) {
 }
 
 void IceTransport::changeGatheringState(GatheringState state) {
-	mGatheringState = state;
-	mGatheringStateChangeCallback(mGatheringState);
+	if (mGatheringState.exchange(state) != state)
+		mGatheringStateChangeCallback(mGatheringState);
+}
+
+void IceTransport::processTimeout() {
+	PLOG_WARNING << "ICE timeout";
+	mTimeoutId = 0;
+	changeState(State::Failed);
 }
 
 void IceTransport::processCandidate(const string &candidate) {
@@ -241,9 +563,20 @@ void IceTransport::processCandidate(const string &candidate) {
 
 void IceTransport::processGatheringDone() { changeGatheringState(GatheringState::Complete); }
 
-void IceTransport::processStateChange(uint32_t state) {
-	if (state != NICE_COMPONENT_STATE_GATHERING)
-		changeState(static_cast<State>(state));
+void IceTransport::processStateChange(unsigned int state) {
+	if (state == NICE_COMPONENT_STATE_FAILED && mTrickleTimeout.count() > 0) {
+		if (mTimeoutId)
+			g_source_remove(mTimeoutId);
+		mTimeoutId = g_timeout_add(mTrickleTimeout.count() /* ms */, TimeoutCallback, this);
+		return;
+	}
+
+	if (state == NICE_COMPONENT_STATE_CONNECTED && mTimeoutId) {
+		g_source_remove(mTimeoutId);
+		mTimeoutId = 0;
+	}
+
+	changeState(static_cast<State>(state));
 }
 
 string IceTransport::AddressToString(const NiceAddress &addr) {
@@ -262,7 +595,7 @@ void IceTransport::CandidateCallback(NiceAgent *agent, NiceCandidate *candidate,
 	try {
 		iceTransport->processCandidate(cand);
 	} catch (const std::exception &e) {
-		std::cerr << "ICE candidate: " << e.what() << std::endl;
+		PLOG_WARNING << e.what();
 	}
 	g_free(cand);
 }
@@ -272,17 +605,17 @@ void IceTransport::GatheringDoneCallback(NiceAgent *agent, guint streamId, gpoin
 	try {
 		iceTransport->processGatheringDone();
 	} catch (const std::exception &e) {
-		std::cerr << "ICE gathering done: " << e.what() << std::endl;
+		PLOG_WARNING << e.what();
 	}
 }
 
 void IceTransport::StateChangeCallback(NiceAgent *agent, guint streamId, guint componentId,
-                                        guint state, gpointer userData) {
+                                       guint state, gpointer userData) {
 	auto iceTransport = static_cast<rtc::IceTransport *>(userData);
 	try {
 		iceTransport->processStateChange(state);
 	} catch (const std::exception &e) {
-		std::cerr << "ICE change state: " << e.what() << std::endl;
+		PLOG_WARNING << e.what();
 	}
 }
 
@@ -290,15 +623,96 @@ void IceTransport::RecvCallback(NiceAgent *agent, guint streamId, guint componen
                                 gchar *buf, gpointer userData) {
 	auto iceTransport = static_cast<rtc::IceTransport *>(userData);
 	try {
-		iceTransport->incoming(reinterpret_cast<byte *>(buf), len);
+		PLOG_VERBOSE << "Incoming size=" << len;
+		auto b = reinterpret_cast<byte *>(buf);
+		iceTransport->incoming(make_message(b, b + len));
 	} catch (const std::exception &e) {
-		std::cerr << "ICE incoming: " << e.what() << std::endl;
+		PLOG_WARNING << e.what();
 	}
 }
 
+gboolean IceTransport::TimeoutCallback(gpointer userData) {
+	auto iceTransport = static_cast<rtc::IceTransport *>(userData);
+	try {
+		iceTransport->processTimeout();
+	} catch (const std::exception &e) {
+		PLOG_WARNING << e.what();
+	}
+	return FALSE;
+}
+
 void IceTransport::LogCallback(const gchar *logDomain, GLogLevelFlags logLevel,
                                const gchar *message, gpointer userData) {
-	std::cout << message << std::endl;
+	plog::Severity severity;
+	unsigned int flags = logLevel & G_LOG_LEVEL_MASK;
+	if (flags & G_LOG_LEVEL_ERROR)
+		severity = plog::fatal;
+	else if (flags & G_LOG_LEVEL_CRITICAL)
+		severity = plog::error;
+	else if (flags & G_LOG_LEVEL_WARNING)
+		severity = plog::warning;
+	else if (flags & G_LOG_LEVEL_MESSAGE)
+		severity = plog::info;
+	else if (flags & G_LOG_LEVEL_INFO)
+		severity = plog::info;
+	else
+		severity = plog::verbose; // libnice debug as verbose
+
+	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_PEER_REFLEXIVE:
+		return CandidateType::PeerReflexive;
+	case NiceCandidateType::NICE_CANDIDATE_TYPE_RELAYED:
+		return CandidateType::Relayed;
+	case NiceCandidateType::NICE_CANDIDATE_TYPE_SERVER_REFLEXIVE:
+		return CandidateType::ServerReflexive;
+	default:
+		return CandidateType::Host;
+	}
+}
+
+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;
+	default:
+		return CandidateTransportType::Udp;
+	}
 }
 
 } // namespace rtc
+
+#endif

src/icetransport.hpp

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2019 Paul-Louis Ageneau
+ * 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
@@ -26,25 +26,39 @@
 #include "peerconnection.hpp"
 #include "transport.hpp"
 
-extern "C" {
+#if USE_JUICE
+#include <juice/juice.h>
+#else
 #include <nice/agent.h>
-}
+#endif
 
 #include <atomic>
+#include <chrono>
 #include <thread>
 
 namespace rtc {
 
 class IceTransport : public Transport {
 public:
-	enum class State : uint32_t {
+#if USE_JUICE
+	enum class State : unsigned int{
+	    Disconnected = JUICE_STATE_DISCONNECTED,
+	    Connecting = JUICE_STATE_CONNECTING,
+	    Connected = JUICE_STATE_CONNECTED,
+	    Completed = JUICE_STATE_COMPLETED,
+	    Failed = JUICE_STATE_FAILED,
+	};
+#else
+	enum class State : unsigned int {
 		Disconnected = NICE_COMPONENT_STATE_DISCONNECTED,
 		Connecting = NICE_COMPONENT_STATE_CONNECTING,
 		Connected = NICE_COMPONENT_STATE_CONNECTED,
 		Completed = NICE_COMPONENT_STATE_READY,
-		Failed = NICE_COMPONENT_STATE_FAILED
+		Failed = NICE_COMPONENT_STATE_FAILED,
 	};
 
+	bool getSelectedCandidatePair(CandidateInfo *local, CandidateInfo *remote);
+#endif
 	enum class GatheringState { New = 0, InProgress = 1, Complete = 2 };
 
 	using candidate_callback = std::function<void(const Candidate &candidate)>;
@@ -67,44 +81,61 @@ public:
 	std::optional<string> getLocalAddress() const;
 	std::optional<string> getRemoteAddress() const;
 
-	bool send(message_ptr message); // false if dropped
+	bool stop() override;
+	bool send(message_ptr message) override; // false if dropped
 
 private:
-	void incoming(message_ptr message);
-	void incoming(const byte *data, int size);
-	void outgoing(message_ptr message);
+	bool outgoing(message_ptr message) override;
 
 	void changeState(State state);
 	void changeGatheringState(GatheringState state);
 
+	void processStateChange(unsigned int state);
 	void processCandidate(const string &candidate);
 	void processGatheringDone();
-	void processStateChange(uint32_t state);
+	void processTimeout();
 
 	Description::Role mRole;
 	string mMid;
+	std::chrono::milliseconds mTrickleTimeout;
 	std::atomic<State> mState;
 	std::atomic<GatheringState> mGatheringState;
 
-	uint32_t mStreamId = 0;
-	std::unique_ptr<NiceAgent, void (*)(gpointer)> mNiceAgent;
-	std::unique_ptr<GMainLoop, void (*)(GMainLoop *)> mMainLoop;
-	std::thread mMainLoopThread;
-
 	candidate_callback mCandidateCallback;
 	state_callback mStateChangeCallback;
 	gathering_state_callback mGatheringStateChangeCallback;
 
+#if USE_JUICE
+	std::unique_ptr<juice_agent_t, void (*)(juice_agent_t *)> mAgent;
+	string mStunHostname;
+	string mStunService;
+
+	static void StateChangeCallback(juice_agent_t *agent, juice_state_t state, void *user_ptr);
+	static void CandidateCallback(juice_agent_t *agent, const char *sdp, void *user_ptr);
+	static void GatheringDoneCallback(juice_agent_t *agent, void *user_ptr);
+	static void RecvCallback(juice_agent_t *agent, const char *data, size_t size, void *user_ptr);
+	static void LogCallback(juice_log_level_t level, const char *message);
+#else
+	uint32_t mStreamId = 0;
+	std::unique_ptr<NiceAgent, void (*)(gpointer)> mNiceAgent;
+	std::unique_ptr<GMainLoop, void (*)(GMainLoop *)> mMainLoop;
+	std::thread mMainLoopThread;
+	guint mTimeoutId = 0;
+
 	static string AddressToString(const NiceAddress &addr);
 
 	static void CandidateCallback(NiceAgent *agent, NiceCandidate *candidate, gpointer userData);
 	static void GatheringDoneCallback(NiceAgent *agent, guint streamId, gpointer userData);
 	static void StateChangeCallback(NiceAgent *agent, guint streamId, guint componentId,
-	                                 guint state, gpointer userData);
+	                                guint state, gpointer userData);
 	static void RecvCallback(NiceAgent *agent, guint stream_id, guint component_id, guint len,
 	                         gchar *buf, gpointer userData);
+	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
 };
 
 } // namespace rtc

src/init.cpp

@@ -0,0 +1,88 @@
+/**
+ * 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 "certificate.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() {
+	CleanupCertificateCache();
+	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

@@ -20,9 +20,11 @@
 #include "certificate.hpp"
 #include "dtlstransport.hpp"
 #include "icetransport.hpp"
+#include "include.hpp"
 #include "sctptransport.hpp"
 
 #include <iostream>
+#include <thread>
 
 namespace rtc {
 
@@ -31,15 +33,34 @@ 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) {}
+    : mConfig(config), mCertificate(make_certificate("libdatachannel")), mState(State::New),
+      mGatheringState(GatheringState::New) {}
 
-PeerConnection::~PeerConnection() {
-	mSctpTransport.reset();
-	mDtlsTransport.reset();
-	mIceTransport.reset();
+PeerConnection::~PeerConnection() { close(); }
+
+void PeerConnection::close() {
+	closeDataChannels();
+	closeTransports();
 }
 
 const Configuration *PeerConnection::config() const { return &mConfig; }
@@ -48,34 +69,49 @@ PeerConnection::State PeerConnection::state() const { return mState; }
 
 PeerConnection::GatheringState PeerConnection::gatheringState() const { return mGatheringState; }
 
-std::optional<Description> PeerConnection::localDescription() const { return mLocalDescription; }
+std::optional<Description> PeerConnection::localDescription() const {
+	std::lock_guard lock(mLocalDescriptionMutex);
+	return mLocalDescription;
+}
 
-std::optional<Description> PeerConnection::remoteDescription() const { return mRemoteDescription; }
+std::optional<Description> PeerConnection::remoteDescription() const {
+	std::lock_guard lock(mRemoteDescriptionMutex);
+	return mRemoteDescription;
+}
 
 void PeerConnection::setRemoteDescription(Description description) {
+	description.hintType(localDescription() ? Description::Type::Answer : Description::Type::Offer);
 	auto remoteCandidates = description.extractCandidates();
+
+	std::lock_guard lock(mRemoteDescriptionMutex);
 	mRemoteDescription.emplace(std::move(description));
 
-	if (!mIceTransport)
-		initIceTransport(Description::Role::ActPass);
+	auto iceTransport = std::atomic_load(&mIceTransport);
+	if (!iceTransport)
+		iceTransport = initIceTransport(Description::Role::ActPass);
 
-	mIceTransport->setRemoteDescription(*mRemoteDescription);
+	iceTransport->setRemoteDescription(*mRemoteDescription);
 
 	if (mRemoteDescription->type() == Description::Type::Offer) {
 		// This is an offer and we are the answerer.
-		processLocalDescription(mIceTransport->getLocalDescription(Description::Type::Answer));
-		mIceTransport->gatherLocalCandidates();
+		processLocalDescription(iceTransport->getLocalDescription(Description::Type::Answer));
+		iceTransport->gatherLocalCandidates();
 	} else {
 		// This is an answer and we are the offerer.
-		if (!mSctpTransport && mIceTransport->role() == Description::Role::Active) {
+		auto sctpTransport = std::atomic_load(&mSctpTransport);
+		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);
 		}
 	}
@@ -85,16 +121,19 @@ void PeerConnection::setRemoteDescription(Description description) {
 }
 
 void PeerConnection::addRemoteCandidate(Candidate candidate) {
-	if (!mRemoteDescription || !mIceTransport)
+	std::lock_guard lock(mRemoteDescriptionMutex);
+
+	auto iceTransport = std::atomic_load(&mIceTransport);
+	if (!mRemoteDescription || !iceTransport)
 		throw std::logic_error("Remote candidate set without remote description");
 
 	mRemoteDescription->addCandidate(candidate);
 
 	if (candidate.resolve(Candidate::ResolveMode::Simple)) {
-		mIceTransport->addRemoteCandidate(candidate);
+		iceTransport->addRemoteCandidate(candidate);
 	} else {
 		// OK, we might need a lookup, do it asynchronously
-		weak_ptr<IceTransport> weakIceTransport{mIceTransport};
+		weak_ptr<IceTransport> weakIceTransport{iceTransport};
 		std::thread t([weakIceTransport, candidate]() mutable {
 			if (candidate.resolve(Candidate::ResolveMode::Lookup))
 				if (auto iceTransport = weakIceTransport.lock())
@@ -105,11 +144,13 @@ void PeerConnection::addRemoteCandidate(Candidate candidate) {
 }
 
 std::optional<string> PeerConnection::localAddress() const {
-	return mIceTransport ? mIceTransport->getLocalAddress() : nullopt;
+	auto iceTransport = std::atomic_load(&mIceTransport);
+	return iceTransport ? iceTransport->getLocalAddress() : nullopt;
 }
 
 std::optional<string> PeerConnection::remoteAddress() const {
-	return mIceTransport ? mIceTransport->getRemoteAddress() : nullopt;
+	auto iceTransport = std::atomic_load(&mIceTransport);
+	return iceTransport ? iceTransport->getRemoteAddress() : nullopt;
 }
 
 shared_ptr<DataChannel> PeerConnection::createDataChannel(const string &label,
@@ -119,31 +160,22 @@ shared_ptr<DataChannel> PeerConnection::createDataChannel(const string &label,
 	// setup:passive. [...] Thus, setup:active is RECOMMENDED.
 	// See https://tools.ietf.org/html/rfc5763#section-5
 	// Therefore, we assume passive role when we are the offerer.
-	auto role = mIceTransport ? mIceTransport->role() : Description::Role::Passive;
+	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
-	// 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 = emplaceDataChannel(role, label, protocol, reliability);
 
-	auto channel =
-	    std::make_shared<DataChannel>(shared_from_this(), stream, label, protocol, reliability);
-	mDataChannels.insert(std::make_pair(stream, channel));
-
-	if (!mIceTransport) {
+	if (!iceTransport) {
 		// RFC 5763: The endpoint that is the offerer MUST use the setup attribute value of
 		// setup:actpass.
 		// See https://tools.ietf.org/html/rfc5763#section-5
-		initIceTransport(Description::Role::ActPass);
-		processLocalDescription(mIceTransport->getLocalDescription(Description::Type::Offer));
-		mIceTransport->gatherLocalCandidates();
-	} else if (mSctpTransport && mSctpTransport->state() == SctpTransport::State::Connected) {
-		channel->open(mSctpTransport);
+		iceTransport = initIceTransport(Description::Role::ActPass);
+		processLocalDescription(iceTransport->getLocalDescription(Description::Type::Offer));
+		iceTransport->gatherLocalCandidates();
+	} else {
+		if (auto transport = std::atomic_load(&mSctpTransport))
+			if (transport->state() == SctpTransport::State::Connected)
+				channel->open(transport);
 	}
 	return channel;
 }
@@ -170,85 +202,196 @@ void PeerConnection::onGatheringStateChange(std::function<void(GatheringState st
 	mGatheringStateChangeCallback = callback;
 }
 
-void PeerConnection::initIceTransport(Description::Role role) {
-	mIceTransport = std::make_shared<IceTransport>(
-	    mConfig, role, std::bind(&PeerConnection::processLocalCandidate, this, _1),
-	    [this](IceTransport::State state) {
-		    switch (state) {
-		    case IceTransport::State::Connecting:
-			    changeState(State::Connecting);
-			    break;
-		    case IceTransport::State::Failed:
-			    changeState(State::Failed);
-			    break;
-		    case IceTransport::State::Connected:
-			    initDtlsTransport();
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    },
-	    [this](IceTransport::GatheringState state) {
-		    switch (state) {
-		    case IceTransport::GatheringState::InProgress:
-			    changeGatheringState(GatheringState::InProgress);
-			    break;
-		    case IceTransport::GatheringState::Complete:
-			    if (mLocalDescription)
-				    mLocalDescription->endCandidates();
-			    changeGatheringState(GatheringState::Complete);
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    });
+shared_ptr<IceTransport> PeerConnection::initIceTransport(Description::Role role) {
+	try {
+		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;
+
+	} catch (const std::exception &e) {
+		PLOG_ERROR << e.what();
+		changeState(State::Failed);
+		throw std::runtime_error("ICE transport initialization failed");
+	}
 }
 
-void PeerConnection::initDtlsTransport() {
-	mDtlsTransport = std::make_shared<DtlsTransport>(
-	    mIceTransport, mCertificate, std::bind(&PeerConnection::checkFingerprint, this, _1),
-	    [this](DtlsTransport::State state) {
-		    switch (state) {
-		    case DtlsTransport::State::Connected:
-			    initSctpTransport();
-			    break;
-		    case DtlsTransport::State::Failed:
-			    changeState(State::Failed);
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    });
+shared_ptr<DtlsTransport> PeerConnection::initDtlsTransport() {
+	try {
+		if (auto transport = std::atomic_load(&mDtlsTransport))
+			return transport;
+
+		auto certificate = mCertificate.get();
+		auto lower = std::atomic_load(&mIceTransport);
+		auto transport = std::make_shared<DtlsTransport>(
+		    lower, certificate, 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;
+
+	} catch (const std::exception &e) {
+		PLOG_ERROR << e.what();
+		changeState(State::Failed);
+		throw std::runtime_error("DTLS transport initialization failed");
+	}
 }
 
-void PeerConnection::initSctpTransport() {
-	uint16_t sctpPort = mRemoteDescription->sctpPort().value_or(DEFAULT_SCTP_PORT);
-	mSctpTransport = std::make_shared<SctpTransport>(
-	    mDtlsTransport, sctpPort, std::bind(&PeerConnection::forwardMessage, this, _1),
-	    std::bind(&PeerConnection::forwardBufferedAmount, this, _1, _2),
-	    [this](SctpTransport::State state) {
-		    switch (state) {
-		    case SctpTransport::State::Connected:
-			    changeState(State::Connected);
-			    openDataChannels();
-			    break;
-		    case SctpTransport::State::Failed:
-			    changeState(State::Failed);
-			    break;
-		    case SctpTransport::State::Disconnected:
-			    changeState(State::Disconnected);
-			    break;
-		    default:
-			    // Ignore
-			    break;
-		    }
-	    });
+shared_ptr<SctpTransport> PeerConnection::initSctpTransport() {
+	try {
+		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;
+
+	} catch (const std::exception &e) {
+		PLOG_ERROR << e.what();
+		changeState(State::Failed);
+		throw std::runtime_error("SCTP transport initialization failed");
+	}
+}
+
+void PeerConnection::closeTransports() {
+	// Change state to sink state Closed to block init methods
+	changeState(State::Closed);
+
+	// Reset callbacks now that state is changed
+	resetCallbacks();
+
+	// Pass the references to a thread, allowing to terminate a transport from its own thread
+	auto sctp = std::atomic_exchange(&mSctpTransport, decltype(mSctpTransport)(nullptr));
+	auto dtls = std::atomic_exchange(&mDtlsTransport, decltype(mDtlsTransport)(nullptr));
+	auto ice = std::atomic_exchange(&mIceTransport, decltype(mIceTransport)(nullptr));
+	if (sctp || dtls || ice) {
+		std::thread t([sctp, dtls, ice]() mutable {
+			if (sctp)
+				sctp->stop();
+			if (dtls)
+				dtls->stop();
+			if (ice)
+				ice->stop();
+
+			sctp.reset();
+			dtls.reset();
+			ice.reset();
+		});
+		t.detach();
+	}
+}
+
+void PeerConnection::endLocalCandidates() {
+	std::lock_guard lock(mLocalDescriptionMutex);
+	if (mLocalDescription)
+		mLocalDescription->endCandidates();
 }
 
 bool PeerConnection::checkFingerprint(const std::string &fingerprint) const {
+	std::lock_guard lock(mRemoteDescriptionMutex);
 	if (auto expectedFingerprint =
 	        mRemoteDescription ? mRemoteDescription->fingerprint() : nullopt) {
 		return *expectedFingerprint == fingerprint;
@@ -257,36 +400,31 @@ bool PeerConnection::checkFingerprint(const std::string &fingerprint) const {
 }
 
 void PeerConnection::forwardMessage(message_ptr message) {
-	if (!mIceTransport || !mSctpTransport)
-		throw std::logic_error("Got a DataChannel message without transport");
-
 	if (!message) {
-		closeDataChannels();
+		remoteCloseDataChannels();
 		return;
 	}
 
-	shared_ptr<DataChannel> channel;
-	if (auto it = mDataChannels.find(message->stream); it != mDataChannels.end()) {
-		channel = it->second.lock();
-		if (!channel || channel->isClosed()) {
-			mDataChannels.erase(it);
-			channel = nullptr;
-		}
-	}
+	auto channel = findDataChannel(message->stream);
+
+	auto iceTransport = std::atomic_load(&mIceTransport);
+	auto sctpTransport = std::atomic_load(&mSctpTransport);
+	if (!iceTransport || !sctpTransport)
+		return;
 
 	if (!channel) {
 		const byte dataChannelOpenMessage{0x03};
-		unsigned int remoteParity = (mIceTransport->role() == Description::Role::Active) ? 1 : 0;
+		unsigned int remoteParity = (iceTransport->role() == Description::Role::Active) ? 1 : 0;
 		if (message->type == Message::Control && *message->data() == dataChannelOpenMessage &&
 		    message->stream % 2 == remoteParity) {
 			channel =
-			    std::make_shared<DataChannel>(shared_from_this(), mSctpTransport, message->stream);
-			channel->onOpen(std::bind(&PeerConnection::triggerDataChannel, this,
+			    std::make_shared<DataChannel>(shared_from_this(), sctpTransport, message->stream);
+			channel->onOpen(weak_bind(&PeerConnection::triggerDataChannel, this,
 			                          weak_ptr<DataChannel>{channel}));
 			mDataChannels.insert(std::make_pair(message->stream, channel));
 		} else {
-			// Invalid, close the DataChannel by resetting the stream
-			mSctpTransport->reset(message->stream);
+			// Invalid, close the DataChannel
+			sctpTransport->close(message->stream);
 			return;
 		}
 	}
@@ -295,46 +433,92 @@ void PeerConnection::forwardMessage(message_ptr message) {
 }
 
 void PeerConnection::forwardBufferedAmount(uint16_t stream, size_t amount) {
-	shared_ptr<DataChannel> channel;
-	if (auto it = mDataChannels.find(stream); it != mDataChannels.end()) {
-		channel = it->second.lock();
-		if (!channel || channel->isClosed()) {
-			mDataChannels.erase(it);
-			channel = nullptr;
-		}
-	}
-
-	if (channel)
+	if (auto channel = findDataChannel(stream))
 		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();
-	while (it != mDataChannels.end()) {
-		auto channel = it->second.lock();
-		if (!channel || channel->isClosed()) {
-			it = mDataChannels.erase(it);
-			continue;
+	// Iterate
+	{
+		std::shared_lock lock(mDataChannelsMutex); // read-only
+		auto it = mDataChannels.begin();
+		while (it != mDataChannels.end()) {
+			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;
 	}
 }
 
 void PeerConnection::openDataChannels() {
-	iterateDataChannels([this](shared_ptr<DataChannel> channel) { channel->open(mSctpTransport); });
+	if (auto transport = std::atomic_load(&mSctpTransport))
+		iterateDataChannels([&](shared_ptr<DataChannel> channel) { channel->open(transport); });
 }
 
 void PeerConnection::closeDataChannels() {
-	iterateDataChannels([](shared_ptr<DataChannel> channel) { channel->close(); });
+	iterateDataChannels([&](shared_ptr<DataChannel> channel) { channel->close(); });
+}
+
+void PeerConnection::remoteCloseDataChannels() {
+	iterateDataChannels([&](shared_ptr<DataChannel> channel) { channel->remoteClose(); });
 }
 
 void PeerConnection::processLocalDescription(Description description) {
-	auto remoteSctpPort = mRemoteDescription ? mRemoteDescription->sctpPort() : nullopt;
+	std::optional<uint16_t> remoteSctpPort;
+	if (auto remote = remoteDescription())
+		remoteSctpPort = remote->sctpPort();
 
+	auto certificate = mCertificate.get(); // wait for certificate if not ready
+
+	std::lock_guard lock(mLocalDescriptionMutex);
 	mLocalDescription.emplace(std::move(description));
-	mLocalDescription->setFingerprint(mCertificate->fingerprint());
+	mLocalDescription->setFingerprint(certificate->fingerprint());
 	mLocalDescription->setSctpPort(remoteSctpPort.value_or(DEFAULT_SCTP_PORT));
 	mLocalDescription->setMaxMessageSize(LOCAL_MAX_MESSAGE_SIZE);
 
@@ -342,6 +526,7 @@ void PeerConnection::processLocalDescription(Description description) {
 }
 
 void PeerConnection::processLocalCandidate(Candidate candidate) {
+	std::lock_guard lock(mLocalDescriptionMutex);
 	if (!mLocalDescription)
 		throw std::logic_error("Got a local candidate without local description");
 
@@ -358,14 +543,72 @@ void PeerConnection::triggerDataChannel(weak_ptr<DataChannel> weakDataChannel) {
 	mDataChannelCallback(dataChannel);
 }
 
-void PeerConnection::changeState(State state) {
-	if (mState.exchange(state) != state)
-		mStateChangeCallback(state);
+bool PeerConnection::changeState(State state) {
+	State current;
+	do {
+		current = mState.load();
+		if (current == state)
+			return true;
+		if (current == State::Closed)
+			return false;
+
+	} while (!mState.compare_exchange_weak(current, 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
@@ -389,6 +632,9 @@ std::ostream &operator<<(std::ostream &out, const rtc::PeerConnection::State &st
 	case State::Failed:
 		str = "failed";
 		break;
+	case State::Closed:
+		str = "closed";
+		break;
 	default:
 		str = "unknown";
 		break;
@@ -415,4 +661,3 @@ std::ostream &operator<<(std::ostream &out, const rtc::PeerConnection::Gathering
 	}
 	return out << str;
 }
-

src/rtc.cpp

@@ -17,196 +17,438 @@
  */
 
 #include "datachannel.hpp"
+#include "include.hpp"
 #include "peerconnection.hpp"
 
 #include <rtc.h>
 
+#include <exception>
+#include <mutex>
 #include <unordered_map>
+#include <utility>
 
 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
-
-int rtcCreatePeerConnection(const char **iceServers, int iceServersCount) {
-	Configuration config;
-	for (int i = 0; i < iceServersCount; ++i) {
-		config.iceServers.emplace_back(IceServer(string(iceServers[i])));
-	}
-	int pc = ++lastId;
-	peerConnectionMap.emplace(std::make_pair(pc, std::make_shared<PeerConnection>(config)));
-	return pc;
-}
-
-void rtcDeletePeerConnection(int pc) { peerConnectionMap.erase(pc); }
-
-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));
-	return dc;
-}
-
-void rtcDeleteDataChannel(int dc) { dataChannelMap.erase(dc); }
-
-void rtcSetDataChannelCallback(int pc, void (*dataChannelCallback)(int, void *)) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
-
-	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 *,
-                                                                        void *)) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
-
-	it->second->onLocalDescription([pc, descriptionCallback](const Description &description) {
-		descriptionCallback(string(description).c_str(), description.typeString().c_str(),
-		                    getUserPointer(pc));
-	});
-}
-
-void rtcSetLocalCandidateCallback(int pc,
-                                  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) {
-		candidateCallback(candidate.candidate().c_str(), candidate.mid().c_str(),
-		                  getUserPointer(pc));
-	});
-}
-
-void rtcSetStateChangeCallback(int pc, void (*stateCallback)(rtc_state_t state, void *)) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
-
-	it->second->onStateChange([pc, stateCallback](PeerConnection::State state) {
-		stateCallback(static_cast<rtc_state_t>(state), getUserPointer(pc));
-	});
-}
-
-void rtcSetGatheringStateChangeCallback(int pc,
-                                         void (*gatheringStateCallback)(rtc_gathering_state_t state,
-                                                                        void *)) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
-
-	it->second->onGatheringStateChange(
-	    [pc, gatheringStateCallback](PeerConnection::GatheringState state) {
-		    gatheringStateCallback(static_cast<rtc_gathering_state_t>(state), getUserPointer(pc));
-	    });
-}
-
-void rtcSetRemoteDescription(int pc, const char *sdp, const char *type) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
-
-	it->second->setRemoteDescription(Description(string(sdp), type ? string(type) : ""));
-}
-
-void rtcAddRemoteCandidate(int pc, const char *candidate, const char *mid) {
-	auto it = peerConnectionMap.find(pc);
-	if (it == peerConnectionMap.end())
-		return;
-
-	it->second->addRemoteCandidate(Candidate(string(candidate), mid ? string(mid) : ""));
-}
-
-int rtcGetDataChannelLabel(int dc, char *buffer, int size) {
-	auto it = dataChannelMap.find(dc);
-	if (it == dataChannelMap.end())
-		return 0;
-
-	if (!size)
-		return 0;
-
-	string label = it->second->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 *)) {
-	auto it = dataChannelMap.find(dc);
-	if (it == dataChannelMap.end())
-		return;
-
-	it->second->onOpen([dc, openCallback]() { openCallback(getUserPointer(dc)); });
-}
-
-void rtcSetErrorCallback(int dc, void (*errorCallback)(const char *, void *)) {
-	auto it = dataChannelMap.find(dc);
-	if (it == dataChannelMap.end())
-		return;
-
-	it->second->onError([dc, errorCallback](const string &error) {
-		errorCallback(error.c_str(), getUserPointer(dc));
-	});
-}
-
-void rtcSetMessageCallback(int dc, void (*messageCallback)(const char *, int, void *)) {
-	auto it = dataChannelMap.find(dc);
-	if (it == dataChannelMap.end())
-		return;
-
-	it->second->onMessage(
-	    [dc, messageCallback](const binary &b) {
-		    messageCallback(reinterpret_cast<const char *>(b.data()), b.size(), getUserPointer(dc));
-	    },
-	    [dc, messageCallback](const string &s) {
-		    messageCallback(s.c_str(), -1, getUserPointer(dc));
-	    });
-}
-
-int rtcSendMessage(int dc, const char *data, int size) {
-	auto it = dataChannelMap.find(dc);
-	if (it == dataChannelMap.end())
-		return 0;
-
-	if (size >= 0) {
-		auto b = reinterpret_cast<const byte *>(data);
-		it->second->send(b, size);
-		return size;
-	} else {
-		string s(data);
-		it->second->send(s);
-		return s.size();
-	}
-}
-
-void rtcSetUserPointer(int i, void *ptr) {
+void setUserPointer(int i, void *ptr) {
+	std::lock_guard lock(mutex);
 	if (ptr)
 		userPointerMap.insert(std::make_pair(i, ptr));
 	else
 		userPointerMap.erase(i);
 }
 
+shared_ptr<PeerConnection> getPeerConnection(int id) {
+	std::lock_guard lock(mutex);
+	auto it = peerConnectionMap.find(id);
+	return it != peerConnectionMap.end() ? it->second : nullptr;
+}
+
+shared_ptr<DataChannel> getDataChannel(int id) {
+	std::lock_guard lock(mutex);
+	auto it = dataChannelMap.find(id);
+	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, ptr));
+	return pc;
+}
+
+int emplaceDataChannel(shared_ptr<DataChannel> ptr) {
+	std::lock_guard lock(mutex);
+	int dc = ++lastId;
+	dataChannelMap.emplace(std::make_pair(dc, ptr));
+	return dc;
+}
+
+bool erasePeerConnection(int pc) {
+	std::lock_guard lock(mutex);
+	if (peerConnectionMap.erase(pc) == 0)
+		return false;
+	userPointerMap.erase(pc);
+	return true;
+}
+
+bool eraseDataChannel(int dc) {
+	std::lock_guard lock(mutex);
+	if (dataChannelMap.erase(dc) == 0)
+		return false;
+	userPointerMap.erase(dc);
+	return true;
+}
+
+} // namespace
+
+void rtcInitLogger(rtcLogLevel level) { InitLogger(static_cast<LogLevel>(level)); }
+
+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));
+}
+
+int rtcDeletePeerConnection(int pc) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	peerConnection->onDataChannel(nullptr);
+	peerConnection->onLocalDescription(nullptr);
+	peerConnection->onLocalCandidate(nullptr);
+	peerConnection->onStateChange(nullptr);
+	peerConnection->onGatheringStateChange(nullptr);
+
+	erasePeerConnection(pc);
+	return 0;
+}
+
+int rtcCreateDataChannel(int pc, const char *label) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	int dc = emplaceDataChannel(peerConnection->createDataChannel(string(label)));
+	void *ptr = getUserPointer(pc);
+	rtcSetUserPointer(dc, ptr);
+	return dc;
+}
+
+int rtcDeleteDataChannel(int dc) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	dataChannel->onOpen(nullptr);
+	dataChannel->onClosed(nullptr);
+	dataChannel->onError(nullptr);
+	dataChannel->onMessage(nullptr);
+	dataChannel->onBufferedAmountLow(nullptr);
+	dataChannel->onAvailable(nullptr);
+
+	eraseDataChannel(dc);
+	return 0;
+}
+
+int rtcSetDataChannelCallback(int pc, dataChannelCallbackFunc cb) {
+	auto peerConnection = getPeerConnection(pc);
+	if (!peerConnection)
+		return -1;
+
+	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 dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (!size)
+		return 0;
+
+	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;
+}
+
+int rtcSetOpenCallback(int dc, openCallbackFunc 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 rtcSetClosedCallback(int dc, closedCallbackFunc cb) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (cb)
+		dataChannel->onClosed([dc, cb]() { cb(getUserPointer(dc)); });
+	else
+		dataChannel->onClosed(nullptr);
+	return 0;
+}
+
+int rtcSetErrorCallback(int dc, errorCallbackFunc cb) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (cb)
+		dataChannel->onError(
+		    [dc, cb](const string &error) { cb(error.c_str(), getUserPointer(dc)); });
+	else
+		dataChannel->onError(nullptr);
+	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 dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	if (size >= 0) {
+		auto b = reinterpret_cast<const byte *>(data);
+		CATCH(dataChannel->send(b, size));
+		return size;
+	} else {
+		string s(data);
+		CATCH(dataChannel->send(s));
+		return s.size();
+	}
+}
+
+int rtcGetBufferedAmount(int dc) {
+	auto dataChannel = getDataChannel(dc);
+	if (!dataChannel)
+		return -1;
+
+	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);
+	});
+}
+
+void rtcCleanup() { rtc::Cleanup(); }

src/sctptransport.cpp

@@ -21,30 +21,51 @@
 #include <chrono>
 #include <exception>
 #include <iostream>
+#include <thread>
 #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;
 
 using std::shared_ptr;
 
 namespace rtc {
 
-std::mutex SctpTransport::GlobalMutex;
-int SctpTransport::InstancesCount = 0;
-
-void SctpTransport::GlobalInit() {
-	std::unique_lock<std::mutex> lock(GlobalMutex);
-	if (InstancesCount++ == 0) {
-		usrsctp_init(0, &SctpTransport::WriteCallback, nullptr);
-		usrsctp_sysctl_set_sctp_ecn_enable(0);
-	}
+void SctpTransport::Init() {
+	usrsctp_init(0, &SctpTransport::WriteCallback, nullptr);
+	usrsctp_sysctl_set_sctp_ecn_enable(0);
+	usrsctp_sysctl_set_sctp_init_rtx_max_default(5);
+	usrsctp_sysctl_set_sctp_path_rtx_max_default(5);
+	usrsctp_sysctl_set_sctp_assoc_rtx_max_default(5);              // single path
+	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() {
-	std::unique_lock<std::mutex> lock(GlobalMutex);
-	if (--InstancesCount == 0) {
-		usrsctp_finish();
-	}
+void SctpTransport::Cleanup() {
+	while (usrsctp_finish() != 0)
+		std::this_thread::sleep_for(100ms);
 }
 
 SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
@@ -55,7 +76,7 @@ SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
       mStateChangeCallback(std::move(stateChangeCallback)), mState(State::Disconnected) {
 	onRecv(recvCallback);
 
-	GlobalInit();
+	PLOG_DEBUG << "Initializing SCTP transport";
 
 	usrsctp_register_address(this);
 	mSock = usrsctp_socket(AF_CONN, SOCK_STREAM, IPPROTO_SCTP, &SctpTransport::RecvCallback,
@@ -105,12 +126,11 @@ SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
 		                         std::to_string(errno));
 
 	struct sctp_paddrparams spp = {};
-#ifdef __linux__
-	// Linux UDP does path MTU discovery by default (setting DF and returning EMSGSIZE).
-	// It should be safe to enable discovery for SCTP.
+#if USE_PMTUD
+	// Enabled SCTP path MTU discovery
 	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
@@ -128,6 +148,14 @@ 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
@@ -139,32 +167,37 @@ SctpTransport::SctpTransport(std::shared_ptr<Transport> lower, uint16_t port,
 		throw std::runtime_error("Could not set SCTP send buffer size, errno=" +
 		                         std::to_string(errno));
 
+	registerIncoming();
 	connect();
 }
 
 SctpTransport::~SctpTransport() {
-	resetLower();
-	onRecv(nullptr); // unset recv callback
+	stop();
 
-	mSendQueue.stop();
-
-	// Unblock incoming
-	if (!mConnectDataSent) {
-		std::unique_lock<std::mutex> lock(mConnectMutex);
-		mConnectDataSent = true;
-		mConnectCondition.notify_all();
-	}
-
-	if (mSock) {
-		usrsctp_shutdown(mSock, SHUT_RDWR);
+	if (mSock)
 		usrsctp_close(mSock);
-	}
 
 	usrsctp_deregister_address(this);
-	GlobalCleanup();
+}
+
+SctpTransport::State SctpTransport::state() const { return mState; }
+
+bool SctpTransport::stop() {
+	if (!Transport::stop())
+		return false;
+
+	mSendQueue.stop();
+	safeFlush();
+	shutdown();
+	onRecv(nullptr);
+	return true;
 }
 
 void SctpTransport::connect() {
+	if (!mSock)
+		return;
+
+	PLOG_DEBUG << "SCTP connect";
 	changeState(State::Connecting);
 
 	struct sockaddr_conn sconn = {};
@@ -186,14 +219,32 @@ void SctpTransport::connect() {
 		throw std::runtime_error("Connection attempt failed, errno=" + std::to_string(errno));
 }
 
-SctpTransport::State SctpTransport::state() const { return mState; }
+void SctpTransport::shutdown() {
+	if (!mSock)
+		return;
+
+	PLOG_DEBUG << "SCTP shutdown";
+
+	if (usrsctp_shutdown(mSock, SHUT_RDWR) != 0 && errno != ENOTCONN) {
+		PLOG_WARNING << "SCTP shutdown failed, errno=" << errno;
+	}
+
+	// close() abort the connection when linger is disabled, call it now
+	usrsctp_close(mSock);
+	mSock = nullptr;
+
+	PLOG_INFO << "SCTP disconnected";
+	changeState(State::Disconnected);
+	mWrittenCondition.notify_all();
+}
 
 bool SctpTransport::send(message_ptr message) {
-	std::lock_guard<std::mutex> lock(mSendMutex);
-
+	std::lock_guard lock(mSendMutex);
 	if (!message)
 		return mSendQueue.empty();
 
+	PLOG_VERBOSE << "Send size=" << message->size();
+
 	// If nothing is pending, try to send directly
 	if (mSendQueue.empty() && trySendMessage(message))
 		return true;
@@ -203,32 +254,32 @@ bool SctpTransport::send(message_ptr message) {
 	return false;
 }
 
-void SctpTransport::reset(unsigned int stream) {
-	using srs_t = struct sctp_reset_streams;
-	const size_t len = sizeof(srs_t) + sizeof(uint16_t);
-	byte buffer[len] = {};
-	srs_t &srs = *reinterpret_cast<srs_t *>(buffer);
-	srs.srs_flags = SCTP_STREAM_RESET_OUTGOING;
-	srs.srs_number_streams = 1;
-	srs.srs_stream_list[0] = uint16_t(stream);
-	usrsctp_setsockopt(mSock, IPPROTO_SCTP, SCTP_RESET_STREAMS, &srs, len);
+void SctpTransport::close(unsigned int stream) {
+	send(make_message(0, Message::Reset, uint16_t(stream)));
+}
+
+void SctpTransport::flush() {
+	std::lock_guard lock(mSendMutex);
+	trySendQueue();
 }
 
 void SctpTransport::incoming(message_ptr message) {
+	// There could be a race condition here where we receive the remote INIT before the local one is
+	// sent, which would result in the connection being aborted. Therefore, we need to wait for data
+	// to be sent on our side (i.e. the local INIT) before proceeding.
+	{
+		std::unique_lock lock(mWriteMutex);
+		mWrittenCondition.wait(lock, [&]() { return mWrittenOnce || mState != State::Connected; });
+	}
+
 	if (!message) {
+		PLOG_INFO << "SCTP disconnected";
 		changeState(State::Disconnected);
 		recv(nullptr);
 		return;
 	}
 
-	// There could be a race condition here where we receive the remote INIT before the local one is
-	// sent, which would result in the connection being aborted. Therefore, we need to wait for data
-	// to be sent on our side (i.e. the local INIT) before proceeding.
-	if (!mConnectDataSent) {
-		std::unique_lock<std::mutex> lock(mConnectMutex);
-		mConnectCondition.wait(lock, [this]() -> bool { return mConnectDataSent; });
-	}
-
+	PLOG_VERBOSE << "Incoming size=" << message->size();
 	usrsctp_conninput(this, message->data(), message->size(), 0);
 }
 
@@ -251,11 +302,8 @@ bool SctpTransport::trySendQueue() {
 
 bool SctpTransport::trySendMessage(message_ptr message) {
 	// Requires mSendMutex to be locked
-	//
-	// TODO: Implement SCTP ndata specification draft when supported everywhere
-	// See https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-08
-
-	const Reliability reliability = message->reliability ? *message->reliability : Reliability();
+	if (!mSock || mState != State::Connected)
+		return false;
 
 	uint32_t ppid;
 	switch (message->type) {
@@ -265,11 +313,24 @@ bool SctpTransport::trySendMessage(message_ptr message) {
 	case Message::Binary:
 		ppid = !message->empty() ? PPID_BINARY : PPID_BINARY_EMPTY;
 		break;
-	default:
+	case Message::Control:
 		ppid = PPID_CONTROL;
 		break;
+	case Message::Reset:
+		sendReset(message->stream);
+		return true;
+	default:
+		// Ignore
+		return true;
 	}
 
+	PLOG_VERBOSE << "SCTP try send size=" << message->size();
+
+	// TODO: Implement SCTP ndata specification draft when supported everywhere
+	// See https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-08
+
+	const Reliability reliability = message->reliability ? *message->reliability : Reliability();
+
 	struct sctp_sendv_spa spa = {};
 
 	// set sndinfo
@@ -283,7 +344,6 @@ bool SctpTransport::trySendMessage(message_ptr message) {
 	if (reliability.unordered)
 		spa.sendv_sndinfo.snd_flags |= SCTP_UNORDERED;
 
-	using std::chrono::milliseconds;
 	switch (reliability.type) {
 	case Reliability::TYPE_PARTIAL_RELIABLE_REXMIT:
 		spa.sendv_flags |= SCTP_SEND_PRINFO_VALID;
@@ -309,38 +369,86 @@ bool SctpTransport::trySendMessage(message_ptr message) {
 		ret = usrsctp_sendv(mSock, &zero, 1, nullptr, 0, &spa, sizeof(spa), SCTP_SENDV_SPA, 0);
 	}
 
-	if (ret >= 0)
+	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
+	} else {
+		PLOG_ERROR << "SCTP sending failed, errno=" << errno;
 		throw std::runtime_error("Sending failed, errno=" + std::to_string(errno));
+	}
 }
 
 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;
-	amount = size_t(std::max(long(amount) + delta, long(0)));
+	size_t amount = size_t(std::max(long(it->second) + delta, long(0)));
 	if (amount == 0)
 		mBufferedAmount.erase(it);
+	else
+		it->second = amount;
+
 	mBufferedAmountCallback(streamId, amount);
 }
 
+void SctpTransport::sendReset(uint16_t streamId) {
+	// Requires mSendMutex to be locked
+	if (!mSock || state() != State::Connected)
+		return;
+
+	PLOG_DEBUG << "SCTP resetting stream " << streamId;
+
+	using srs_t = struct sctp_reset_streams;
+	const size_t len = sizeof(srs_t) + sizeof(uint16_t);
+	byte buffer[len] = {};
+	srs_t &srs = *reinterpret_cast<srs_t *>(buffer);
+	srs.srs_flags = SCTP_STREAM_RESET_OUTGOING;
+	srs.srs_number_streams = 1;
+	srs.srs_stream_list[0] = streamId;
+
+	mWritten = false;
+	if (usrsctp_setsockopt(mSock, IPPROTO_SCTP, SCTP_RESET_STREAMS, &srs, len) == 0) {
+		std::unique_lock lock(mWriteMutex); // locking before setsockopt might deadlock usrsctp...
+		mWrittenCondition.wait_for(lock, 1000ms,
+		                           [&]() { return mWritten || mState != State::Connected; });
+	} else if (errno == EINVAL) {
+		PLOG_VERBOSE << "SCTP stream " << streamId << " already reset";
+	} else {
+		PLOG_WARNING << "SCTP reset stream " << streamId << " failed, errno=" << errno;
+	}
+}
+
+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 {
-		if (!data) {
-			recv(nullptr);
-			return 0;
-		}
+		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
@@ -348,44 +456,42 @@ 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) {
-		std::cerr << "SCTP recv: " << e.what() << std::endl;
+		PLOG_ERROR << "SCTP recv: " << e.what();
 		return -1;
 	}
 	return 0; // success
 }
 
 int SctpTransport::handleSend(size_t free) {
-	try {
-		std::lock_guard<std::mutex> lock(mSendMutex);
-		trySendQueue();
-	} catch (const std::exception &e) {
-		std::cerr << "SCTP send: " << e.what() << std::endl;
-		return -1;
-	}
-	return 0; // success
+	PLOG_VERBOSE << "Handle send, free=" << free;
+	return safeFlush() ? 0 : -1;
 }
 
 int SctpTransport::handleWrite(byte *data, size_t len, uint8_t tos, uint8_t set_df) {
 	try {
-		outgoing(make_message(data, data + len));
+		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();
 
-		if (!mConnectDataSent) {
-			std::unique_lock<std::mutex> lock(mConnectMutex);
-			mConnectDataSent = true;
-			mConnectCondition.notify_all();
-		}
 	} catch (const std::exception &e) {
-		std::cerr << "SCTP write: " << e.what() << std::endl;
+		PLOG_ERROR << "SCTP write: " << e.what();
 		return -1;
 	}
 	return 0; // success
 }
 
 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.
@@ -400,9 +506,11 @@ 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();
@@ -422,9 +530,11 @@ 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();
@@ -440,48 +550,58 @@ void SctpTransport::processData(const byte *data, size_t len, uint16_t sid, Payl
 
 	default:
 		// Unknown
-		std::cerr << "Unknown PPID: " << uint32_t(ppid) << std::endl;
+		PLOG_WARNING << "Unknown PPID: " << uint32_t(ppid);
 		return;
 	}
 }
 
 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;
-		std::unique_lock<std::mutex> lock(mConnectMutex);
 		if (assoc_change.sac_state == SCTP_COMM_UP) {
+			PLOG_INFO << "SCTP connected";
 			changeState(State::Connected);
 		} else {
 			if (mState == State::Connecting) {
-				std::cerr << "SCTP connection failed" << std::endl;
+				PLOG_ERROR << "SCTP connection failed";
 				changeState(State::Failed);
 			} else {
+				PLOG_INFO << "SCTP disconnected";
 				changeState(State::Disconnected);
 			}
+			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<std::mutex> lock(mSendMutex);
-		trySendQueue();
+		safeFlush();
+		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);
+		const uint16_t flags = reset_event.strreset_flags;
 
-		if (reset_event.strreset_flags & SCTP_STREAM_RESET_INCOMING_SSN) {
+		if (flags & SCTP_STREAM_RESET_OUTGOING_SSN) {
 			for (int i = 0; i < count; ++i) {
 				uint16_t streamId = reset_event.strreset_stream_list[i];
-				reset(streamId);
+				close(streamId);
 			}
 		}
-
-		if (reset_event.strreset_flags & SCTP_STREAM_RESET_OUTGOING_SSN) {
+		if (flags & SCTP_STREAM_RESET_INCOMING_SSN) {
 			const byte dataChannelCloseMessage{0x04};
 			for (int i = 0; i < count; ++i) {
 				uint16_t streamId = reset_event.strreset_stream_list[i];
@@ -498,6 +618,28 @@ 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<milliseconds> SctpTransport::rtt() {
+	if (!mSock || state() != State::Connected)
+		return nullopt;
+
+	struct sctp_status status = {};
+	socklen_t len = sizeof(status);
+	if (usrsctp_getsockopt(mSock, IPPROTO_SCTP, SCTP_STATUS, &status, &len)) {
+		PLOG_WARNING << "Could not read SCTP_STATUS";
+		return nullopt;
+	}
+	return 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

@@ -28,10 +28,6 @@
 #include <functional>
 #include <map>
 #include <mutex>
-#include <thread>
-
-#include <sys/socket.h>
-#include <sys/types.h>
 
 #include "usrsctp.h"
 
@@ -39,6 +35,9 @@ 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)>;
@@ -50,8 +49,16 @@ public:
 
 	State state() const;
 
-	bool send(message_ptr message); // false if buffered
-	void reset(unsigned int stream);
+	bool stop() override;
+	bool send(message_ptr message) override; // false if buffered
+	void close(unsigned int stream);
+	void flush();
+
+	// 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
@@ -67,12 +74,15 @@ private:
 	};
 
 	void connect();
-	void incoming(message_ptr message);
+	void shutdown();
+	void incoming(message_ptr message) override;
 	void changeState(State state);
 
 	bool trySendQueue();
 	bool trySendMessage(message_ptr message);
 	void updateBufferedAmount(uint16_t streamId, long delta);
+	void sendReset(uint16_t streamId);
+	bool safeFlush();
 
 	int handleRecv(struct socket *sock, union sctp_sockstore addr, const byte *data, size_t len,
 	               struct sctp_rcvinfo recv_info, int flags);
@@ -90,26 +100,23 @@ private:
 	std::map<uint16_t, size_t> mBufferedAmount;
 	amount_callback mBufferedAmountCallback;
 
-	std::mutex mConnectMutex;
-	std::condition_variable mConnectCondition;
-	std::atomic<bool> mConnectDataSent = false;
-	std::atomic<bool> mStopping = false;
+	std::mutex mWriteMutex;
+	std::condition_variable mWrittenCondition;
+	std::atomic<bool> mWritten = false; // written outside lock
+	bool mWrittenOnce = 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

@@ -32,31 +32,41 @@ using namespace std::placeholders;
 
 class Transport {
 public:
-	Transport(std::shared_ptr<Transport> lower = nullptr) : mLower(std::move(lower)) {
-		if (auto lower = std::atomic_load(&mLower))
-			lower->onRecv(std::bind(&Transport::incoming, this, _1));
+	Transport(std::shared_ptr<Transport> lower = nullptr) : mLower(std::move(lower)) {}
+	virtual ~Transport() {
+		stop();
+		if (mLower)
+			mLower->onRecv(nullptr); // doing it on stop could cause a deadlock
+	}
+
+	virtual bool stop() {
+		return !mShutdown.exchange(true);
+	}
+
+	void registerIncoming() {
+		if (mLower)
+			mLower->onRecv(std::bind(&Transport::incoming, this, _1));
 	}
-	virtual ~Transport() { resetLower(); }
 
-	virtual bool send(message_ptr message) = 0;
 	void onRecv(message_callback callback) { mRecvCallback = std::move(callback); }
 
+	virtual bool send(message_ptr message) { return outgoing(message); }
+
 protected:
 	void recv(message_ptr message) { mRecvCallback(message); }
-	void resetLower() {
-		if (auto lower = std::atomic_exchange(&mLower, std::shared_ptr<Transport>(nullptr)))
-			lower->onRecv(nullptr);
-	}
 
-	virtual void incoming(message_ptr message) = 0;
-	virtual void outgoing(message_ptr message) {
-		if (auto lower = std::atomic_load(&mLower))
-			lower->send(message);
+	virtual void incoming(message_ptr message) { recv(message); }
+	virtual bool outgoing(message_ptr message) {
+		if (mLower)
+			return mLower->send(message);
+		else
+			return false;
 	}
 
 private:
 	std::shared_ptr<Transport> mLower;
 	synchronized_callback<message_ptr> mRecvCallback;
+	std::atomic<bool> mShutdown = false;
 };
 
 } // namespace rtc

test/capi.cpp

@@ -0,0 +1,220 @@
+/**
+ * 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>
+
+#ifdef _WIN32
+#include <windows.h>
+static void sleep(unsigned int secs) { Sleep(secs * 1000); }
+#else
+#include <unistd.h> // for sleep
+#endif
+
+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);
+
+	// You may call rtcCleanup() when finished to free static resources
+	rtcCleanup();
+	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 +1,148 @@
+/**
+ * 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);
+
+	// You may call rtc::Cleanup() when finished to free static resources
+	rtc::Cleanup();
+	this_thread::sleep_for(1s);
+
+	cout << "Success" << endl;
+}

test/main.cpp

@@ -16,100 +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) {
-	rtc::Configuration config;
-	// config.iceServers.emplace_back("stun.l.google.com:19302");
-
-	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 (dc1->isOpen() && dc2->isOpen()) {
-		dc1->close();
-		dc2->close();
-
-		cout << "Success" << endl;
-		return 0;
-	} else {
-		cout << "Failure" << endl;
-		return 1;
+	try {
+		std::cout << "*** Running connectivity test..." << std::endl;
+		test_connectivity();
+		std::cout << "*** Finished connectivity test" << std::endl;
+	} catch (const exception &e) {
+		std::cerr << "Connectivity test failed: " << e.what() << 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/README.md

@@ -0,0 +1,9 @@
+* Execute ```offerer``` app in console
+* Execute ```answerer``` app in another console
+* Copy "Local Description" from ```offerer```
+* Enter 1 to ```answerer```
+* Paste copied description, press enter
+* Redo same procedure for ```answerer```
+* Redo same procedure for candidates
+* Wait for "DataChannel open" message
+* Send message from one peer to another

test/p2p/answerer.cpp

@@ -0,0 +1,159 @@
+/**
+ * Copyright (c) 2019 Paul-Louis Ageneau, Murat Dogan
+ *
+ * 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; }
+
+int main(int argc, char **argv) {
+	InitLogger(LogLevel::Warning);
+
+	Configuration config;
+	// config.iceServers.emplace_back("stun.l.google.com:19302");
+
+	auto pc = std::make_shared<PeerConnection>(config);
+
+	pc->onLocalDescription([](const Description &description) {
+		cout << "Local Description (Paste this to the other peer):" << endl;
+		cout << string(description) << endl;
+	});
+
+	pc->onLocalCandidate([](const Candidate &candidate) {
+		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; });
+	pc->onGatheringStateChange([](PeerConnection::GatheringState state) {
+		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;
+		dc = _dc;
+
+		dc->onClosed([&]() { cout << "[DataChannel closed: " << dc->label() << "]" << endl; });
+
+		dc->onMessage([](const variant<binary, string> &message) {
+			if (holds_alternative<string>(message)) {
+				cout << "[Received message: " << get<string>(message) << "]" << endl;
+			}
+		});
+	});
+
+	bool exit = false;
+	while (!exit) {
+		cout << endl
+		     << "**********************************************************************************"
+		        "*****"
+		     << endl
+		     << "* 0: Exit /"
+		     << " 1: Enter remote description /"
+		     << " 2: Enter remote candidate /"
+		     << " 3: Send message /"
+		     << " 4: Print Connection Info *" << endl
+		     << "[Command]: ";
+
+		int command = -1;
+		cin >> command;
+		cin.ignore();
+
+		switch (command) {
+		case 0: {
+			exit = true;
+			break;
+		}
+		case 1: {
+			// Parse Description
+			cout << "[Description]: ";
+			string sdp, line;
+			while (getline(cin, line) && !line.empty()) {
+				sdp += line;
+				sdp += "\r\n";
+			}
+			std::cout << sdp;
+			pc->setRemoteDescription(sdp);
+			break;
+		}
+		case 2: {
+			// Parse Candidate
+			cout << "[Candidate]: ";
+			string candidate;
+			getline(cin, candidate);
+			pc->addRemoteCandidate(candidate);
+			break;
+		}
+		case 3: {
+			// Send Message
+			if (!dc || !dc->isOpen()) {
+				cout << "** Channel is not Open ** ";
+				break;
+			}
+			cout << "[Message]: ";
+			string message;
+			getline(cin, message);
+			dc->send(message);
+			break;
+		}
+		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)
+		dc->close();
+	if (pc)
+		pc->close();
+}

test/p2p/offerer.cpp

@@ -0,0 +1,159 @@
+/**
+ * Copyright (c) 2019 Paul-Louis Ageneau, Murat Dogan
+ *
+ * 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; }
+
+int main(int argc, char **argv) {
+	InitLogger(LogLevel::Warning);
+
+	Configuration config;
+	// config.iceServers.emplace_back("stun.l.google.com:19302");
+
+	auto pc = std::make_shared<PeerConnection>(config);
+
+	pc->onLocalDescription([](const Description &description) {
+		cout << "Local Description (Paste this to the other peer):" << endl;
+		cout << string(description) << endl;
+	});
+
+	pc->onLocalCandidate([](const Candidate &candidate) {
+		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; });
+
+	pc->onGatheringStateChange([](PeerConnection::GatheringState state) {
+		cout << "[Gathering State: " << state << "]" << endl;
+	});
+
+	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->onMessage([](const variant<binary, string> &message) {
+		if (holds_alternative<string>(message)) {
+			cout << "[Received: " << get<string>(message) << "]" << endl;
+		}
+	});
+
+	this_thread::sleep_for(1s);
+
+	bool exit = false;
+	while (!exit) {
+		cout << endl
+		     << "**********************************************************************************"
+		        "*****"
+		     << endl
+		     << "* 0: Exit /"
+		     << " 1: Enter remote description /"
+		     << " 2: Enter remote candidate /"
+		     << " 3: Send message /"
+		     << " 4: Print Connection Info *" << endl
+		     << "[Command]: ";
+
+		int command = -1;
+		cin >> command;
+		cin.ignore();
+
+		switch (command) {
+		case 0: {
+			exit = true;
+			break;
+		}
+		case 1: {
+			// Parse Description
+			cout << "[Description]: ";
+			string sdp, line;
+			while (getline(cin, line) && !line.empty()) {
+				sdp += line;
+				sdp += "\r\n";
+			}
+			pc->setRemoteDescription(sdp);
+			break;
+		}
+		case 2: {
+			// Parse Candidate
+			cout << "[Candidate]: ";
+			string candidate;
+			getline(cin, candidate);
+			pc->addRemoteCandidate(candidate);
+			break;
+		}
+		case 3: {
+			// Send Message
+			if (!dc->isOpen()) {
+				cout << "** Channel is not Open ** ";
+				break;
+			}
+			cout << "[Message]: ";
+			string message;
+			getline(cin, message);
+			dc->send(message);
+			break;
+		}
+		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)
+		dc->close();
+	if (pc)
+		pc->close();
+}

test/p2p_c_version/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.5.1)
+project(offerer C)
+
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_FLAGS "-Wall -g -O2")
+
+add_executable(offerer offerer.c)
+target_link_libraries(offerer  datachannel)
+
+add_executable(answerer answerer.c)
+target_link_libraries(answerer  datachannel)

test/p2p_c_version/answerer.c

@@ -0,0 +1,326 @@
+/**
+ * Copyright (c) 2020 Paul-Louis Ageneau
+ * Copyright (c) 2020 Stevedan Ogochukwu Omodolor
+ *
+ * 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 <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h> // for sleep
+#include <ctype.h>
+
+typedef struct {
+        rtcState state;
+        rtcGatheringState gatheringState;
+        int pc;
+        int dc;
+        bool connected;
+} Peer;
+
+Peer *peer = NULL;
+
+static void dataChannelCallback(int dc, void *ptr);
+
+static void descriptionCallback(const char *sdp, const char *type, void *ptr);
+
+static void candidateCallback(const char *cand, const char *mid, void *ptr);
+
+static void stateChangeCallback(rtcState state, void *ptr);
+
+static void gatheringStateCallback(rtcGatheringState state, void *ptr);
+
+static void closedCallback(void *ptr);
+
+static void messageCallback(const char *message, int size, void *ptr);
+
+static void deletePeer(Peer *peer);
+
+int all_space(const char *str);
+char* state_print(rtcState state);
+char* rtcGatheringState_print(rtcState state);
+
+int main(int argc, char **argv) {
+        rtcInitLogger(RTC_LOG_DEBUG);
+
+        // Create peer
+        rtcConfiguration config;
+        memset(&config, 0, sizeof(config));
+
+        Peer *peer = (Peer *)malloc(sizeof(Peer));
+        if (!peer) {
+
+                printf("Error allocating memory for peer\n");
+                deletePeer(peer);
+
+        }
+        memset(peer, 0, sizeof(Peer));
+
+        printf("Peer created\n");
+
+        // Create peer connection
+        peer->pc = rtcCreatePeerConnection(&config);
+
+        rtcSetUserPointer(peer->pc, peer);
+        rtcSetLocalDescriptionCallback(peer->pc, descriptionCallback);
+        rtcSetLocalCandidateCallback(peer->pc, candidateCallback);
+        rtcSetStateChangeCallback(peer->pc, stateChangeCallback);
+        rtcSetGatheringStateChangeCallback(peer->pc, gatheringStateCallback);
+
+        rtcSetUserPointer(peer->dc, NULL);
+        rtcSetDataChannelCallback(peer->pc, dataChannelCallback);
+
+
+
+
+        bool exit = false;
+
+        while (!exit) {
+
+                printf("\n");
+                printf("***************************************************************************************\n");
+
+                // << endl
+                printf("* 0: Exit /"
+                       " 1: Enter remote description /"
+                       " 2: Enter remote candidate /"
+                       " 3: Send message /"
+                       " 4: Print Connection Info *\n"
+                       "[Command]: ");
+
+                int command = -1;
+                int c;
+                // int check_scan
+                if (scanf("%d", &command)) {
+
+                }else {
+                        break;
+                }
+                while ((c = getchar()) != '\n' && c != EOF) { }
+
+                fflush(stdin);
+                switch (command) {
+                case 0: {
+                        exit = true;
+                        break;
+                }
+                case 1: {
+                        // Parse Description
+                        printf("[Description]: ");
+
+
+                        char *line = NULL;
+                        size_t len = 0;
+                        size_t read = 0;
+                        char *sdp = (char*) malloc(sizeof(char));
+                        while ((read = getline(&line, &len, stdin)) != -1 && !all_space(line)) {
+                                sdp = (char*) realloc (sdp,(strlen(sdp)+1) +strlen(line)+1);
+                                strcat(sdp, line);
+
+                        }
+                        printf("%s\n",sdp);
+                        rtcSetRemoteDescription(peer->pc, sdp, "offer");
+                        free(sdp);
+                        free(line);
+                        break;
+
+                }
+                case 2: {
+                        // Parse Candidate
+                        printf("[Candidate]: ");
+                        char* candidate = NULL;
+                        size_t candidate_size = 0;
+
+                        if(getline(&candidate, &candidate_size, stdin)) {
+                                rtcAddRemoteCandidate(peer->pc, candidate, "0");
+                                free(candidate);
+
+                        }else {
+                                printf("Error reading line\n");
+                                break;
+                        }
+
+                        break;
+                }
+                case 3: {
+                        // Send Message
+                        if(!peer->connected) {
+                                printf("** Channel is not Open **");
+                                break;
+                        }
+                        printf("[Message]: ");
+                        char* message = NULL;
+                        size_t message_size = 0;
+
+                        if(getline(&message, &message_size, stdin)) {
+                                rtcSendMessage(peer->dc, message, -1);
+                                free(message);
+                        }else {
+                                printf("Error reading line\n");
+                                break;
+                        }
+                        break;
+                }
+                case 4: {
+                        // Connection Info
+                        if(!peer->connected) {
+                                printf("** Channel is not Open **");
+                                break;
+                        }
+                        char buffer[256];
+                        if (rtcGetLocalAddress(peer->pc, buffer, 256) >= 0)
+                                printf("Local address 1:  %s\n", buffer);
+                        if (rtcGetRemoteAddress(peer->pc, buffer, 256) >= 0)
+                                printf("Remote address 1: %s\n", buffer);
+
+                        else
+                                printf("Could not get Candidate Pair Info\n");
+                        break;
+                }
+                default: {
+                        printf("** Invalid Command **");
+                        break;
+                }
+                }
+        }
+
+
+        deletePeer(peer);
+        return 0;
+}
+
+
+static void descriptionCallback(const char *sdp, const char *type, void *ptr) {
+        // Peer *peer = (Peer *)ptr;
+        printf("Description %s:\n%s\n", "answerer", sdp);
+}
+
+static void candidateCallback(const char *cand, const char *mid, void *ptr) {
+        // Peer *peer = (Peer *)ptr;
+        printf("Candidate %s: %s\n", "answerer", cand);
+
+}
+
+static void stateChangeCallback(rtcState state, void *ptr) {
+        Peer *peer = (Peer *)ptr;
+        peer->state = state;
+        printf("State %s: %s\n", "answerer", state_print(state));
+}
+
+static void gatheringStateCallback(rtcGatheringState state, void *ptr) {
+        Peer *peer = (Peer *)ptr;
+        peer->gatheringState = state;
+        printf("Gathering state %s: %s\n", "answerer", rtcGatheringState_print(state));
+}
+
+
+
+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 %s: %s\n", "answerer", message);
+        } else {
+                printf("Message %s: [binary of size %d]\n", "answerer", size);
+        }
+}
+static void deletePeer(Peer *peer) {
+        if (peer) {
+                if (peer->dc)
+                        rtcDeleteDataChannel(peer->dc);
+                if (peer->pc)
+                        rtcDeletePeerConnection(peer->pc);
+                free(peer);
+        }
+}
+
+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 %s: Received with label \"%s\"\n", "answerer", buffer);
+
+
+}
+int all_space(const char *str) {
+        while (*str) {
+                if (!isspace(*str++)) {
+                        return 0;
+                }
+        }
+        return 1;
+}
+
+char* state_print(rtcState state) {
+        char *str = NULL;
+        switch (state) {
+        case RTC_NEW:
+                str = "RTC_NEW";
+                break;
+        case RTC_CONNECTING:
+                str = "RTC_CONNECTING";
+                break;
+        case RTC_CONNECTED:
+                str = "RTC_CONNECTED";
+                break;
+        case RTC_DISCONNECTED:
+                str = "RTC_DISCONNECTED";
+                break;
+        case RTC_FAILED:
+                str = "RTC_FAILED";
+                break;
+        case RTC_CLOSED:
+                str = "RTC_CLOSED";
+                break;
+        default:
+                break;
+        }
+
+        return str;
+
+}
+
+char* rtcGatheringState_print(rtcState state) {
+        char* str = NULL;
+        switch (state) {
+        case RTC_GATHERING_NEW:
+                str = "RTC_GATHERING_NEW";
+                break;
+        case RTC_GATHERING_INPROGRESS:
+                str = "RTC_GATHERING_INPROGRESS";
+                break;
+        case RTC_GATHERING_COMPLETE:
+                str = "RTC_GATHERING_COMPLETE";
+                break;
+        default:
+                break;
+        }
+
+        return str;
+
+}

test/p2p_c_version/offerer.c

@@ -0,0 +1,334 @@
+/**
+ * Copyright (c) 2020 Paul-Louis Ageneau
+ * Copyright (c) 2020 Stevedan Ogochukwu Omodolor
+ *
+ * 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 <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h> // for sleep
+#include <ctype.h>
+
+char* state_print(rtcState state);
+char* rtcGatheringState_print(rtcState state);
+
+typedef struct {
+        rtcState state;
+        rtcGatheringState gatheringState;
+        int pc;
+        int dc;
+        bool connected;
+} Peer;
+
+Peer *peer = NULL;
+
+static void descriptionCallback(const char *sdp, const char *type, void *ptr);
+
+static void candidateCallback(const char *cand, const char *mid, void *ptr);
+
+static void stateChangeCallback(rtcState state, void *ptr);
+
+static void gatheringStateCallback(rtcGatheringState state, void *ptr);
+
+static void openCallback(void *ptr);
+
+static void closedCallback(void *ptr);
+
+static void messageCallback(const char *message, int size, void *ptr);
+
+static void deletePeer(Peer *peer);
+
+int all_space(const char *str);
+
+int main(int argc, char **argv){
+        rtcInitLogger(RTC_LOG_DEBUG);
+
+        // Create peer
+        rtcConfiguration config;
+        memset(&config, 0, sizeof(config));
+
+        Peer *peer = (Peer *)malloc(sizeof(Peer));
+        if (!peer) {
+
+                printf("Error allocating memory for peer\n");
+                deletePeer(peer);
+
+        }
+        memset(peer, 0, sizeof(Peer));
+
+        printf("Peer created\n");
+
+        // Create peer connection
+        peer->pc = rtcCreatePeerConnection(&config);
+        rtcSetUserPointer(peer->pc, peer);
+        rtcSetLocalDescriptionCallback(peer->pc, descriptionCallback);
+        rtcSetLocalCandidateCallback(peer->pc, candidateCallback);
+        rtcSetStateChangeCallback(peer->pc, stateChangeCallback);
+        rtcSetGatheringStateChangeCallback(peer->pc, gatheringStateCallback);
+
+        // Since this is the offere, we will create a datachannel
+        peer->dc = rtcCreateDataChannel(peer->pc, "test");
+
+        rtcSetOpenCallback(peer->dc, openCallback);
+
+
+        rtcSetClosedCallback(peer->dc, closedCallback);
+
+        rtcSetMessageCallback(peer->dc, messageCallback);
+
+
+        sleep(1);
+
+        bool exit = false;
+
+        while (!exit) {
+
+                printf("\n");
+                printf("***************************************************************************************\n");
+
+                // << endl
+                printf("* 0: Exit /"
+                       " 1: Enter remote description /"
+                       " 2: Enter remote candidate /"
+                       " 3: Send message /"
+                       " 4: Print Connection Info *\n"
+                       "[Command]: ");
+
+                int command = -1;
+                int c;
+                if (scanf("%d", &command)) {
+
+                }else {
+                        break;
+                }
+                while ((c = getchar()) != '\n' && c != EOF) { }
+                fflush(stdin);
+
+                switch (command) {
+                case 0: {
+                        exit = true;
+                        break;
+                }
+                case 1: {
+                        // Parse Description
+                        printf("[Description]: ");
+
+
+                        char *line = NULL;
+                        size_t len = 0;
+                        size_t read = 0;
+                        char *sdp = (char*) malloc(sizeof(char));
+                        while ((read = getline(&line, &len, stdin)) != -1 && !all_space(line)) {
+                                sdp = (char*) realloc (sdp,(strlen(sdp)+1) +strlen(line)+1);
+                                strcat(sdp, line);
+
+                        }
+                        printf("%s\n",sdp);
+                        rtcSetRemoteDescription(peer->pc, sdp, "answer");
+                        free(sdp);
+                        free(line);
+                        break;
+
+                }
+                case 2: {
+                        // Parse Candidate
+                        printf("[Candidate]: ");
+                        char* candidate = NULL;
+                        size_t candidate_size = 0;
+                        if(getline(&candidate, &candidate_size, stdin)) {
+                                rtcAddRemoteCandidate(peer->pc, candidate, "0");
+                                free(candidate);
+
+                        }else {
+                                printf("Error reading line\n");
+                                break;
+                        }
+
+
+                        break;
+                }
+                case 3: {
+                        // Send Message
+                        if(!peer->connected) {
+                                printf("** Channel is not Open **");
+                                break;
+                        }
+                        printf("[Message]: ");
+                        char* message = NULL;
+                        size_t message_size = 0;
+                        if(getline(&message, &message_size, stdin)) {
+                                rtcSendMessage(peer->dc, message, -1);
+                                free(message);
+                        }else {
+                                printf("Error reading line\n");
+                                break;
+                        }
+
+                        break;
+                }
+                case 4: {
+                        // Connection Info
+                        if(!peer->connected) {
+                                printf("** Channel is not Open **");
+                                break;
+                        }
+                        char buffer[256];
+                        if (rtcGetLocalAddress(peer->pc, buffer, 256) >= 0)
+                                printf("Local address 1:  %s\n", buffer);
+                        if (rtcGetRemoteAddress(peer->pc, buffer, 256) >= 0)
+                                printf("Remote address 1: %s\n", buffer);
+
+                        else
+                                printf("Could not get Candidate Pair Info\n");
+                        break;
+                }
+                default: {
+                        printf("** Invalid Command **");
+                        break;
+                }
+                }
+        }
+
+        deletePeer(peer);
+        return 0;
+}
+
+
+
+
+
+
+static void descriptionCallback(const char *sdp, const char *type, void *ptr) {
+        // Peer *peer = (Peer *)ptr;
+        printf("Description %s:\n%s\n", "offerer", sdp);
+}
+
+static void candidateCallback(const char *cand, const char *mid, void *ptr) {
+        // Peer *peer = (Peer *)ptr;
+        printf("Candidate %s: %s\n", "offerer", cand);
+
+}
+
+static void stateChangeCallback(rtcState state, void *ptr) {
+        Peer *peer = (Peer *)ptr;
+        peer->state = state;
+        printf("State %s: %s\n", "offerer", state_print(state));
+}
+
+static void gatheringStateCallback(rtcGatheringState state, void *ptr) {
+        Peer *peer = (Peer *)ptr;
+        peer->gatheringState = state;
+        printf("Gathering state %s: %s\n", "offerer", rtcGatheringState_print(state));
+}
+
+
+static void openCallback(void *ptr) {
+        Peer *peer = (Peer *)ptr;
+        peer->connected = true;
+        char buffer[256];
+        if (rtcGetDataChannelLabel(peer->dc, buffer, 256) >= 0)
+                printf("DataChannel %s: Received with label \"%s\"\n","offerer", buffer);
+
+
+}
+
+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 %s: %s\n", "offerer", message);
+        } else {
+                printf("Message %s: [binary of size %d]\n", "offerer", size);
+        }
+}
+static void deletePeer(Peer *peer) {
+        if (peer) {
+                if (peer->dc)
+                        rtcDeleteDataChannel(peer->dc);
+                if (peer->pc)
+                        rtcDeletePeerConnection(peer->pc);
+                free(peer);
+        }
+}
+
+
+int all_space(const char *str) {
+        while (*str) {
+                if (!isspace(*str++)) {
+                        return 0;
+                }
+        }
+        return 1;
+}
+
+char* state_print(rtcState state) {
+        char *str = NULL;
+        switch (state) {
+        case RTC_NEW:
+                str = "RTC_NEW";
+                break;
+        case RTC_CONNECTING:
+                str = "RTC_CONNECTING";
+                break;
+        case RTC_CONNECTED:
+                str = "RTC_CONNECTED";
+                break;
+        case RTC_DISCONNECTED:
+                str = "RTC_DISCONNECTED";
+                break;
+        case RTC_FAILED:
+                str = "RTC_FAILED";
+                break;
+        case RTC_CLOSED:
+                str = "RTC_CLOSED";
+                break;
+        default:
+                break;
+        }
+
+        return str;
+
+}
+
+char* rtcGatheringState_print(rtcState state) {
+        char* str = NULL;
+        switch (state) {
+        case RTC_GATHERING_NEW:
+                str = "RTC_GATHERING_NEW";
+                break;
+        case RTC_GATHERING_INPROGRESS:
+                str = "RTC_GATHERING_INPROGRESS";
+                break;
+        case RTC_GATHERING_COMPLETE:
+                str = "RTC_GATHERING_COMPLETE";
+                break;
+        default:
+                break;
+        }
+
+        return str;
+
+}