Bumped version to 0.5.1

Add MacOS build to workflow

.github/workflows/build-gnutls.yml

@@ -0,0 +1,40 @@
+name: Build and test with GnuTLS
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+jobs:
+  build-ubuntu:
+    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 -j2)
+    - name: test
+      run: ./build/tests
+  build-macos:
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: install packages
+      run: brew install gnutls nettle
+    - name: submodules
+      run: git submodule update --init --recursive
+    - name: cmake
+      run: cmake -B build -DUSE_JUICE=1 -DUSE_GNUTLS=1
+      env:
+# hack to bypass EPERM issue on sendto()
+        CFLAGS: -DJUICE_ENABLE_ADDRS_LOCALHOST
+    - name: make
+      run: (cd build; make -j2)
+    - 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-ubuntu:
+    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 -j2)
+    - name: test
+      run: ./build/tests
+

.github/workflows/build-openssl.yml

@@ -0,0 +1,42 @@
+name: Build and test with OpenSSL
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+jobs:
+  build-ubuntu:
+    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 -j2)
+    - name: test
+      run: ./build/tests
+  build-macos:
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: install packages
+      run: brew reinstall openssl@1.1
+    - name: submodules
+      run: git submodule update --init --recursive
+    - name: cmake
+      run: cmake -B build -DUSE_JUICE=1 -DUSE_GNUTLS=0
+      env:
+        OPENSSL_ROOT_DIR: /usr/local/opt/openssl
+        OPENSSL_LIBRARIES: /usr/local/opt/openssl/lib
+# hack to bypass EPERM issue on sendto()
+        CFLAGS: -DJUICE_ENABLE_ADDRS_LOCALHOST
+    - name: make
+      run: (cd build; make -j2)
+    - name: test
+      run: ./build/tests

.github/workflows/build.yml

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

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 3.7)
 project (libdatachannel
 	DESCRIPTION "WebRTC DataChannels Library"
-	VERSION 0.4.9
+	VERSION 0.5.1
 	LANGUAGES CXX)
 
 option(USE_GNUTLS "Use GnuTLS instead of OpenSSL" OFF)
@@ -18,8 +18,8 @@ set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
 
 if(WIN32)
 	add_definitions(-DWIN32_LEAN_AND_MEAN)
-	if (MSYS OR MINGW)
+	if (MSVC)
-		add_definitions(-DSCTP_STDINT_INCLUDE=<stdint.h>)
+		add_definitions(-DNOMINMAX)
 	endif()
 endif()
 
@@ -71,10 +71,15 @@ set(TESTS_ANSWERER_SOURCES
     ${CMAKE_CURRENT_SOURCE_DIR}/test/p2p/answerer.cpp
 )
 
-set(THREADS_PREFER_PTHREAD_FLAG ON)
+set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
+set(THREADS_PREFER_PTHREAD_FLAG TRUE)
 find_package(Threads REQUIRED)
 
 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()
 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)
@@ -88,10 +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_include_directories(datachannel PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/deps/plog/include)
+target_link_libraries(datachannel PUBLIC Threads::Threads)
-target_link_libraries(datachannel Threads::Threads Usrsctp::UsrsctpStatic)
+target_link_libraries(datachannel PRIVATE Usrsctp::UsrsctpStatic)
 
 add_library(datachannel-static STATIC EXCLUDE_FROM_ALL ${LIBDATACHANNEL_SOURCES})
 set_target_properties(datachannel-static PROPERTIES
@@ -99,14 +105,15 @@ 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_include_directories(datachannel-static PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/deps/plog/include)
+target_link_libraries(datachannel-static PUBLIC Threads::Threads)
-target_link_libraries(datachannel-static Threads::Threads Usrsctp::UsrsctpStatic)
+target_link_libraries(datachannel-static PRIVATE Usrsctp::UsrsctpStatic)
 
 if(WIN32)
-	target_link_libraries(datachannel "wsock32" "ws2_32") # winsock2
+	target_link_libraries(datachannel PRIVATE wsock32 ws2_32) # winsock2
-	target_link_libraries(datachannel-static "wsock32" "ws2_32") # winsock2
+	target_link_libraries(datachannel-static PRIVATE wsock32 ws2_32) # winsock2
 endif()
 
 if (USE_GNUTLS)
@@ -120,29 +127,29 @@ 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 LibJuice::LibJuiceStatic)
+	target_link_libraries(datachannel PRIVATE LibJuice::LibJuiceStatic)
 	target_compile_definitions(datachannel-static PRIVATE USE_JUICE=1)
-	target_link_libraries(datachannel-static LibJuice::LibJuiceStatic)
+	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 LibNice::LibNice)
+	target_link_libraries(datachannel PRIVATE LibNice::LibNice)
 	target_compile_definitions(datachannel-static PRIVATE USE_JUICE=0)
-	target_link_libraries(datachannel-static LibNice::LibNice)
+	target_link_libraries(datachannel-static PRIVATE LibNice::LibNice)
 endif()
 
 add_library(LibDataChannel::LibDataChannel ALIAS datachannel)

Jamfile

@@ -1,3 +1,5 @@
+import feature : feature ;
+
 project libdatachannel ;
 path-constant CWD : . ;
 
@@ -5,21 +7,26 @@ lib libdatachannel
 	: # sources
 	[ glob ./src/*.cpp ]
 	: # requirements
+	<cxxstd>17
 	<include>./include/rtc
-	<define>USE_GNUTLS=0
 	<define>USE_JUICE=1
-	<cxxflags>"`pkg-config --cflags openssl`"
 	<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`"
 	;
 
+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
@@ -57,9 +64,21 @@ actions make_libusrsctp
 }
 
 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 USE_NETTLE=0)
+	(cd $(CWD)/deps/libjuice && make $(MAKEOPTS))
     cp $(CWD)/deps/libjuice/libjuice.a $(<)
 }
 

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/include.hpp

@@ -68,7 +68,7 @@ public:
 
 	synchronized_callback &operator=(std::function<void(P...)> func) {
 		std::lock_guard lock(mutex);
-		callback = func;
+		callback = std::move(func);
 		return *this;
 	}
 
@@ -78,7 +78,10 @@ public:
 			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/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

@@ -31,6 +31,7 @@
 
 #include <atomic>
 #include <functional>
+#include <future>
 #include <list>
 #include <mutex>
 #include <shared_mutex>
@@ -44,6 +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 {
@@ -126,7 +130,7 @@ private:
 	void resetCallbacks();
 
 	const Configuration mConfig;
-	const std::shared_ptr<Certificate> mCertificate;
+	const future_certificate_ptr mCertificate;
 
 	std::optional<Description> mLocalDescription, mRemoteDescription;
 	mutable std::recursive_mutex mLocalDescriptionMutex, mRemoteDescriptionMutex;

include/rtc/rtc.h

@@ -114,6 +114,9 @@ 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

src/candidate.cpp

@@ -60,12 +60,19 @@ bool Candidate::resolve(ResolveMode mode) {
 	if (mIsResolved)
 		return true;
 
+	PLOG_VERBOSE << "Resolving candidate (mode="
+				 << (mode == ResolveMode::Simple ? "simple" : "lookup")
+				 << "): " << mCandidate;
+
 	// See RFC 8445 for format
-	std::stringstream ss(mCandidate);
+	std::istringstream iss(mCandidate);
 	int component{0}, priority{0};
 	string foundation, transport, node, service, typ_, type;
-	if (ss >> foundation >> component >> transport >> priority &&
+	if (iss >> foundation >> component >> transport >> priority &&
-	    ss >> node >> service >> typ_ >> type && typ_ == "typ") {
+	    iss >> node >> service >> typ_ >> type && typ_ == "typ") {
+
+		string left;
+		std::getline(iss, left);
 
 		// Try to resolve the node
 		struct addrinfo hints = {};
@@ -94,15 +101,13 @@ bool Candidate::resolve(ResolveMode mode) {
 					if (getnameinfo(p->ai_addr, p->ai_addrlen, nodebuffer, MAX_NUMERICNODE_LEN,
 					                servbuffer, MAX_NUMERICSERV_LEN,
 					                NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
-						string left;
-						std::getline(ss, left);
 						const char sp{' '};
-						ss.clear();
+						std::ostringstream oss;
-						ss << foundation << sp << component << sp << transport << sp << priority;
+						oss << foundation << sp << component << sp << transport << sp << priority;
-						ss << sp << nodebuffer << sp << servbuffer << sp << "typ" << sp << type;
+						oss << sp << nodebuffer << sp << servbuffer << sp << "typ" << sp << type;
-						if (!left.empty())
+						oss << left;
-							ss << left;
+						mCandidate = oss.str();
-						mCandidate = ss.str();
+						PLOG_VERBOSE << "Resolved candidate: " << mCandidate;
 						return mIsResolved = true;
 					}
 				}

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) {
+namespace {
-	static std::unordered_map<string, shared_ptr<Certificate>> cache;
-	static std::mutex cacheMutex;
-
-	std::lock_guard lock(cacheMutex);
-	if (auto it = cache.find(commonName); it != cache.end())
-		return it->second;
 
+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);
+	return std::make_shared<Certificate>(*crt, *privkey);
-	cache.emplace(std::make_pair(commonName, certificate));
-	return certificate;
 }
 
+} // namespace
+
 } // namespace rtc
 
 #else
@@ -236,15 +231,9 @@ string make_fingerprint(X509 *x509) {
 	return oss.str();
 }
 
+namespace {
 
-shared_ptr<Certificate> make_certificate(const string &commonName) {
+certificate_ptr make_certificate_impl(string commonName) {
-	static std::unordered_map<string, shared_ptr<Certificate>> cache;
-	static std::mutex cacheMutex;
-
-	std::lock_guard lock(cacheMutex);
-	if (auto it = cache.find(commonName); it != cache.end())
-		return it->second;
-
 	shared_ptr<X509> x509(X509_new(), X509_free);
 	shared_ptr<EVP_PKEY> pkey(EVP_PKEY_new(), EVP_PKEY_free);
 
@@ -265,7 +254,8 @@ shared_ptr<Certificate> make_certificate(const string &commonName) {
 		throw std::runtime_error("Unable to generate key pair");
 
 	const size_t serialSize = 16;
-	const auto *commonNameBytes = reinterpret_cast<const unsigned char *>(commonName.c_str());
+	auto *commonNameBytes =
+	    reinterpret_cast<unsigned char *>(const_cast<char *>(commonName.c_str()));
 
 	if (!X509_gmtime_adj(X509_get_notBefore(x509.get()), 3600 * -1) ||
 	    !X509_gmtime_adj(X509_get_notAfter(x509.get()), 3600 * 24 * 365) ||
@@ -281,12 +271,54 @@ 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);
+	return std::make_shared<Certificate>(x509, pkey);
-	cache.emplace(std::make_pair(commonName, certificate));
-	return certificate;
 }
 
+} // 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/datachannel.cpp

@@ -93,19 +93,20 @@ string DataChannel::protocol() const { return mProtocol; }
 Reliability DataChannel::reliability() const { return *mReliability; }
 
 void DataChannel::close() {
+	mIsClosed = true;
 	if (mIsOpen.exchange(false))
 		if (auto transport = mSctpTransport.lock())
-			transport->reset(mStream);
+			transport->close(mStream);
-	mIsClosed = true;
-	mSctpTransport.reset();
 
+	mSctpTransport.reset();
 	resetCallbacks();
 }
 
 void DataChannel::remoteClose() {
-	mIsOpen = false;
 	if (!mIsClosed.exchange(true))
 		triggerClosed();
+
+	mIsOpen = false;
 	mSctpTransport.reset();
 }
 
@@ -139,6 +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;
 		}
 	}
 

src/dtlstransport.cpp

@@ -63,9 +63,8 @@ void DtlsTransport::Cleanup() {
 	// Nothing to do
 }
 
-DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certificate> certificate,
+DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, certificate_ptr certificate,
-                             verifier_callback verifierCallback,
+                             verifier_callback verifierCallback, state_callback stateChangeCallback)
-                             state_callback stateChangeCallback)
     : Transport(lower), mCertificate(certificate), mState(State::Disconnected),
       mVerifierCallback(std::move(verifierCallback)),
       mStateChangeCallback(std::move(stateChangeCallback)) {
@@ -100,6 +99,7 @@ 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() {
@@ -116,9 +116,7 @@ bool DtlsTransport::stop() {
 
 	PLOG_DEBUG << "Stopping DTLS recv thread";
 	mIncomingQueue.stop();
-	gnutls_bye(mSession, GNUTLS_SHUT_RDWR);
 	mRecvThread.join();
-	onRecv(nullptr);
 	return true;
 }
 
@@ -217,6 +215,8 @@ void DtlsTransport::runRecvLoop() {
 		PLOG_ERROR << "DTLS recv: " << e.what();
 	}
 
+	gnutls_bye(mSession, GNUTLS_SHUT_RDWR);
+
 	PLOG_INFO << "DTLS disconnected";
 	changeState(State::Disconnected);
 	recv(nullptr);
@@ -410,6 +410,7 @@ 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() {
@@ -427,7 +428,6 @@ bool DtlsTransport::stop() {
 	mIncomingQueue.stop();
 	mRecvThread.join();
 	SSL_shutdown(mSsl);
-	onRecv(nullptr);
 	return true;
 }
 

src/dtlstransport.hpp

@@ -51,7 +51,7 @@ public:
 	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();
 
@@ -65,7 +65,7 @@ private:
 	void changeState(State state);
 	void runRecvLoop();
 
-	const std::shared_ptr<Certificate> mCertificate;
+	const certificate_ptr mCertificate;
 
 	Queue<message_ptr> mIncomingQueue;
 	std::atomic<State> mState;

src/icetransport.cpp

@@ -103,7 +103,6 @@ IceTransport::IceTransport(const Configuration &config, Description::Role role,
 IceTransport::~IceTransport() { stop(); }
 
 bool IceTransport::stop() {
-	onRecv(nullptr);
 	return Transport::stop();
 }
 
@@ -169,15 +168,6 @@ bool IceTransport::send(message_ptr message) {
 	return outgoing(message);
 }
 
-void IceTransport::incoming(message_ptr message) {
-	PLOG_VERBOSE << "Incoming size=" << message->size();
-	recv(message);
-}
-
-void IceTransport::incoming(const byte *data, int size) {
-	incoming(make_message(data, data + size));
-}
-
 bool IceTransport::outgoing(message_ptr message) {
 	return juice_send(mAgent.get(), reinterpret_cast<const char *>(message->data()),
 	                  message->size()) >= 0;
@@ -234,7 +224,9 @@ void IceTransport::RecvCallback(juice_agent_t *agent, const char *data, size_t s
                                 void *user_ptr) {
 	auto iceTransport = static_cast<rtc::IceTransport *>(user_ptr);
 	try {
-		iceTransport->incoming(reinterpret_cast<const byte *>(data), size);
+		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();
 	}
@@ -455,6 +447,9 @@ bool IceTransport::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;
@@ -541,15 +536,6 @@ bool IceTransport::send(message_ptr message) {
 	return outgoing(message);
 }
 
-void IceTransport::incoming(message_ptr message) {
-	PLOG_VERBOSE << "Incoming size=" << message->size();
-	recv(message);
-}
-
-void IceTransport::incoming(const byte *data, int size) {
-	incoming(make_message(data, data + size));
-}
-
 bool IceTransport::outgoing(message_ptr message) {
 	return nice_agent_send(mNiceAgent.get(), mStreamId, 1, message->size(),
 	                       reinterpret_cast<const char *>(message->data())) >= 0;
@@ -637,7 +623,9 @@ 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) {
 		PLOG_WARNING << e.what();
 	}
@@ -700,14 +688,14 @@ bool IceTransport::getSelectedCandidatePair(CandidateInfo *localInfo, CandidateI
 
 const CandidateType IceTransport::NiceTypeToCandidateType(NiceCandidateType type) {
 	switch (type) {
-	case NiceCandidateType::NICE_CANDIDATE_TYPE_HOST:
-		return CandidateType::Host;
 	case NiceCandidateType::NICE_CANDIDATE_TYPE_PEER_REFLEXIVE:
 		return CandidateType::PeerReflexive;
 	case NiceCandidateType::NICE_CANDIDATE_TYPE_RELAYED:
 		return CandidateType::Relayed;
 	case NiceCandidateType::NICE_CANDIDATE_TYPE_SERVER_REFLEXIVE:
 		return CandidateType::ServerReflexive;
+	default:
+		return CandidateType::Host;
 	}
 }
 
@@ -720,7 +708,7 @@ IceTransport::NiceTransportTypeToCandidateTransportType(NiceCandidateTransport t
 		return CandidateTransportType::TcpPassive;
 	case NiceCandidateTransport::NICE_CANDIDATE_TRANSPORT_TCP_SO:
 		return CandidateTransportType::TcpSo;
-	case NiceCandidateTransport::NICE_CANDIDATE_TRANSPORT_UDP:
+	default:
 		return CandidateTransportType::Udp;
 	}
 }

src/icetransport.hpp

@@ -85,8 +85,6 @@ public:
 	bool send(message_ptr message) override; // false if dropped
 
 private:
-	void incoming(message_ptr message) override;
-	void incoming(const byte *data, int size);
 	bool outgoing(message_ptr message) override;
 
 	void changeState(State state);

src/init.cpp

@@ -18,6 +18,7 @@
 
 #include "init.hpp"
 
+#include "certificate.hpp"
 #include "dtlstransport.hpp"
 #include "sctptransport.hpp"
 
@@ -74,6 +75,7 @@ Init::Init() {
 }
 
 Init::~Init() {
+	CleanupCertificateCache();
 	DtlsTransport::Cleanup();
 	SctpTransport::Cleanup();
 

src/peerconnection.cpp

@@ -53,7 +53,8 @@ auto weak_bind_verifier(F &&f, T *t, Args &&... _args) {
 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() { close(); }
 
@@ -268,9 +269,10 @@ shared_ptr<DtlsTransport> PeerConnection::initDtlsTransport() {
 		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, mCertificate, weak_bind_verifier(&PeerConnection::checkFingerprint, this, _1),
+		    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)
@@ -421,8 +423,8 @@ void PeerConnection::forwardMessage(message_ptr message) {
 			                          weak_ptr<DataChannel>{channel}));
 			mDataChannels.insert(std::make_pair(message->stream, channel));
 		} else {
-			// Invalid, close the DataChannel by resetting the stream
+			// Invalid, close the DataChannel
-			sctpTransport->reset(message->stream);
+			sctpTransport->close(message->stream);
 			return;
 		}
 	}
@@ -512,9 +514,11 @@ void PeerConnection::processLocalDescription(Description description) {
 	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);
 

src/rtc.cpp

@@ -450,3 +450,5 @@ int rtcReceiveMessage(int dc, char *buffer, int *size) {
 		    *message);
 	});
 }
+
+void rtcCleanup() { rtc::Cleanup(); }

src/sctptransport.cpp

@@ -21,6 +21,7 @@
 #include <chrono>
 #include <exception>
 #include <iostream>
+#include <thread>
 #include <vector>
 
 #ifdef USE_JUICE
@@ -62,7 +63,10 @@ void SctpTransport::Init() {
 	usrsctp_sysctl_set_sctp_heartbeat_interval_default(10 * 1000); // ms
 }
 
-void SctpTransport::Cleanup() { 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,
                              message_callback recvCallback, amount_callback bufferedAmountCallback,
@@ -163,13 +167,16 @@ 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() {
 	stop();
 
-	usrsctp_close(mSock);
+	if (mSock)
+		usrsctp_close(mSock);
+
 	usrsctp_deregister_address(this);
 }
 
@@ -187,6 +194,9 @@ bool SctpTransport::stop() {
 }
 
 void SctpTransport::connect() {
+	if (!mSock)
+		return;
+
 	PLOG_DEBUG << "SCTP connect";
 	changeState(State::Connecting);
 
@@ -210,12 +220,19 @@ void SctpTransport::connect() {
 }
 
 void SctpTransport::shutdown() {
+	if (!mSock)
+		return;
+
 	PLOG_DEBUG << "SCTP shutdown";
 
-	if (usrsctp_shutdown(mSock, SHUT_RDWR)) {
+	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();
@@ -237,31 +254,15 @@ bool SctpTransport::send(message_ptr message) {
 	return false;
 }
 
+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::reset(unsigned int stream) {
-	PLOG_DEBUG << "SCTP resetting stream " << stream;
-
-	std::unique_lock lock(mWriteMutex);
-	mWritten = false;
-	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);
-	if (usrsctp_setsockopt(mSock, IPPROTO_SCTP, SCTP_RESET_STREAMS, &srs, len) == 0) {
-		mWrittenCondition.wait_for(lock, 1000ms,
-		                           [&]() { return mWritten || mState != State::Connected; });
-	} else {
-		PLOG_WARNING << "SCTP reset stream " << stream << " failed, errno=" << errno;
-	}
-}
-
 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
@@ -301,16 +302,9 @@ bool SctpTransport::trySendQueue() {
 
 bool SctpTransport::trySendMessage(message_ptr message) {
 	// Requires mSendMutex to be locked
-	if (mState != State::Connected)
+	if (!mSock || mState != State::Connected)
 		return false;
 
-	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();
-
 	uint32_t ppid;
 	switch (message->type) {
 	case Message::String:
@@ -319,11 +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
@@ -388,6 +395,33 @@ void SctpTransport::updateBufferedAmount(uint16_t streamId, long delta) {
 	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();
@@ -564,7 +598,7 @@ void SctpTransport::processNotification(const union sctp_notification *notify, s
 		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 (flags & SCTP_STREAM_RESET_INCOMING_SSN) {
@@ -593,15 +627,17 @@ size_t SctpTransport::bytesSent() { return mBytesSent; }
 
 size_t SctpTransport::bytesReceived() { return mBytesReceived; }
 
-std::optional<std::chrono::milliseconds> SctpTransport::rtt() {
+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)) {
-	if (usrsctp_getsockopt(this->mSock, IPPROTO_SCTP, SCTP_STATUS, &status, &len)) {
 		PLOG_WARNING << "Could not read SCTP_STATUS";
-		return std::nullopt;
+		return nullopt;
 	}
-	return std::chrono::milliseconds(status.sstat_primary.spinfo_srtt);
+	return milliseconds(status.sstat_primary.spinfo_srtt);
 }
 
 int SctpTransport::RecvCallback(struct socket *sock, union sctp_sockstore addr, void *data,

src/sctptransport.hpp

@@ -51,8 +51,8 @@ public:
 
 	bool stop() override;
 	bool send(message_ptr message) override; // false if buffered
+	void close(unsigned int stream);
 	void flush();
-	void reset(unsigned int stream);
 
 	// Stats
 	void clearStats();
@@ -81,6 +81,7 @@ private:
 	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,
@@ -99,9 +100,9 @@ private:
 	std::map<uint16_t, size_t> mBufferedAmount;
 	amount_callback mBufferedAmountCallback;
 
-	std::recursive_mutex mWriteMutex;
+	std::mutex mWriteMutex;
-	std::condition_variable_any mWrittenCondition;
+	std::condition_variable mWrittenCondition;
-	bool mWritten = false;
+	std::atomic<bool> mWritten = false; // written outside lock
 	bool mWrittenOnce = false;
 
 	state_callback mStateChangeCallback;

src/transport.hpp

@@ -32,26 +32,30 @@ using namespace std::placeholders;
 
 class Transport {
 public:
-	Transport(std::shared_ptr<Transport> lower = nullptr) : mLower(std::move(lower)) {
+	Transport(std::shared_ptr<Transport> lower = nullptr) : mLower(std::move(lower)) {}
+	virtual ~Transport() {
+		stop();
 		if (mLower)
-			mLower->onRecv(std::bind(&Transport::incoming, this, _1));
+			mLower->onRecv(nullptr); // doing it on stop could cause a deadlock
 	}
-	virtual ~Transport() { stop(); }
 
 	virtual bool stop() {
-		if (mLower)
-			mLower->onRecv(nullptr);
 		return !mShutdown.exchange(true);
 	}
 
-	virtual bool send(message_ptr message) = 0;
+	void registerIncoming() {
+		if (mLower)
+			mLower->onRecv(std::bind(&Transport::incoming, this, _1));
+	}
 
 	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); }
 
-	virtual void incoming(message_ptr message) = 0;
+	virtual void incoming(message_ptr message) { recv(message); }
 	virtual bool outgoing(message_ptr message) {
 		if (mLower)
 			return mLower->send(message);

test/capi.cpp

@@ -23,9 +23,12 @@
 #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
-using namespace std;
 
 typedef struct {
 	rtcState state;
@@ -196,6 +199,10 @@ int test_capi_main() {
 	deletePeer(peer2);
 	sleep(1);
 
+	// You may call rtcCleanup() when finished to free static resources
+	rtcCleanup();
+	sleep(1);
+
 	printf("Success\n");
 	return 0;
 

test/connectivity.cpp

@@ -140,5 +140,9 @@ void test_connectivity() {
 	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/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;
+
+}