|  | // Copyright 2021 The Dawn & Tint Authors | 
|  | // | 
|  | // Redistribution and use in source and binary forms, with or without | 
|  | // modification, are permitted provided that the following conditions are met: | 
|  | // | 
|  | // 1. Redistributions of source code must retain the above copyright notice, this | 
|  | //    list of conditions and the following disclaimer. | 
|  | // | 
|  | // 2. Redistributions in binary form must reproduce the above copyright notice, | 
|  | //    this list of conditions and the following disclaimer in the documentation | 
|  | //    and/or other materials provided with the distribution. | 
|  | // | 
|  | // 3. Neither the name of the copyright holder nor the names of its | 
|  | //    contributors may be used to endorse or promote products derived from | 
|  | //    this software without specific prior written permission. | 
|  | // | 
|  | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | 
|  | // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | 
|  | // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | 
|  | // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE | 
|  | // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | 
|  | // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | 
|  | // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | 
|  | // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | 
|  | // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 
|  | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
|  |  | 
|  | #include "src/tint/utils/socket.h" | 
|  |  | 
|  | #include "src/tint/utils/macros/compiler.h" | 
|  | #include "src/tint/utils/rwmutex.h" | 
|  |  | 
|  | #if TINT_BUILD_IS_WIN | 
|  | #include <winsock2.h> | 
|  | #include <ws2tcpip.h> | 
|  | #else | 
|  | #include <netdb.h> | 
|  | #include <netinet/in.h> | 
|  | #include <netinet/tcp.h> | 
|  | #include <sys/select.h> | 
|  | #include <sys/socket.h> | 
|  | #include <sys/time.h> | 
|  | #include <unistd.h> | 
|  | #include <cstdio> | 
|  | #endif | 
|  |  | 
|  | #if TINT_BUILD_IS_WIN | 
|  | #include <atomic> | 
|  | namespace { | 
|  | std::atomic<int> wsa_init_count = {0}; | 
|  | }  // anonymous namespace | 
|  | #else | 
|  | #include <fcntl.h> | 
|  | namespace { | 
|  | using SOCKET = int; | 
|  | }  // anonymous namespace | 
|  | #endif | 
|  |  | 
|  | namespace tint::socket { | 
|  | namespace { | 
|  | constexpr SOCKET InvalidSocket = static_cast<SOCKET>(-1); | 
|  | void Init() { | 
|  | #if TINT_BUILD_IS_WIN | 
|  | if (wsa_init_count++ == 0) { | 
|  | WSADATA winsock_data; | 
|  | (void)WSAStartup(MAKEWORD(2, 2), &winsock_data); | 
|  | } | 
|  | #endif | 
|  | } | 
|  |  | 
|  | void Term() { | 
|  | #if TINT_BUILD_IS_WIN | 
|  | if (--wsa_init_count == 0) { | 
|  | WSACleanup(); | 
|  | } | 
|  | #endif | 
|  | } | 
|  |  | 
|  | bool SetBlocking(SOCKET s, bool blocking) { | 
|  | #if TINT_BUILD_IS_WIN | 
|  | u_long mode = blocking ? 0 : 1; | 
|  | return ioctlsocket(s, FIONBIO, &mode) == NO_ERROR; | 
|  | #else | 
|  | auto arg = fcntl(s, F_GETFL, nullptr); | 
|  | if (arg < 0) { | 
|  | return false; | 
|  | } | 
|  | arg = blocking ? (arg & ~O_NONBLOCK) : (arg | O_NONBLOCK); | 
|  | return fcntl(s, F_SETFL, arg) >= 0; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | bool Errored(SOCKET s) { | 
|  | if (s == InvalidSocket) { | 
|  | return true; | 
|  | } | 
|  | char error = 0; | 
|  | socklen_t len = sizeof(error); | 
|  | getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &len); | 
|  | return error != 0; | 
|  | } | 
|  |  | 
|  | class Impl : public Socket { | 
|  | public: | 
|  | static std::shared_ptr<Impl> create(const char* address, const char* port) { | 
|  | Init(); | 
|  |  | 
|  | addrinfo hints = {}; | 
|  | hints.ai_family = AF_INET; | 
|  | hints.ai_socktype = SOCK_STREAM; | 
|  | hints.ai_protocol = IPPROTO_TCP; | 
|  | hints.ai_flags = AI_PASSIVE; | 
|  |  | 
|  | addrinfo* info = nullptr; | 
|  | auto err = getaddrinfo(address, port, &hints, &info); | 
|  | #if !TINT_BUILD_IS_WIN | 
|  | if (err) { | 
|  | printf("getaddrinfo(%s, %s) error: %s\n", address, port, gai_strerror(err)); | 
|  | } | 
|  | #else | 
|  | (void)err; | 
|  | #endif | 
|  |  | 
|  | if (info) { | 
|  | auto socket = ::socket(info->ai_family, info->ai_socktype, info->ai_protocol); | 
|  | auto out = std::make_shared<Impl>(info, socket); | 
|  | out->SetOptions(); | 
|  | return out; | 
|  | } | 
|  |  | 
|  | Term(); | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | explicit Impl(SOCKET socket) : info(nullptr), s(socket) {} | 
|  |  | 
|  | Impl(addrinfo* i, SOCKET socket) : info(i), s(socket) {} | 
|  |  | 
|  | ~Impl() override { | 
|  | if (info) { | 
|  | freeaddrinfo(info); | 
|  | } | 
|  | Close(); | 
|  | Term(); | 
|  | } | 
|  |  | 
|  | template <typename FUNCTION> | 
|  | void Lock(FUNCTION&& f) { | 
|  | RLock l(mutex); | 
|  | f(s, info); | 
|  | } | 
|  |  | 
|  | void SetOptions() { | 
|  | RLock l(mutex); | 
|  | if (s == InvalidSocket) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | int enable = 1; | 
|  |  | 
|  | #if !TINT_BUILD_IS_WIN | 
|  | // Prevent sockets lingering after process termination, causing | 
|  | // reconnection issues on the same port. | 
|  | setsockopt(s, SOL_SOCKET, SO_REUSEADDR, reinterpret_cast<char*>(&enable), sizeof(enable)); | 
|  |  | 
|  | struct { | 
|  | int l_onoff;  /* linger active */ | 
|  | int l_linger; /* how many seconds to linger for */ | 
|  | } linger = {false, 0}; | 
|  | setsockopt(s, SOL_SOCKET, SO_LINGER, reinterpret_cast<char*>(&linger), sizeof(linger)); | 
|  | #endif  // !TINT_BUILD_IS_WIN | 
|  |  | 
|  | // Enable TCP_NODELAY. | 
|  | setsockopt(s, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<char*>(&enable), sizeof(enable)); | 
|  | } | 
|  |  | 
|  | bool IsOpen() override { | 
|  | { | 
|  | RLock l(mutex); | 
|  | if ((s != InvalidSocket) && !Errored(s)) { | 
|  | return true; | 
|  | } | 
|  | } | 
|  | WLock lock(mutex); | 
|  | s = InvalidSocket; | 
|  | return false; | 
|  | } | 
|  |  | 
|  | void Close() override { | 
|  | { | 
|  | RLock l(mutex); | 
|  | if (s != InvalidSocket) { | 
|  | #if TINT_BUILD_IS_WIN | 
|  | closesocket(s); | 
|  | #else | 
|  | ::shutdown(s, SHUT_RDWR); | 
|  | #endif | 
|  | } | 
|  | } | 
|  |  | 
|  | WLock l(mutex); | 
|  | if (s != InvalidSocket) { | 
|  | #if !TINT_BUILD_IS_WIN | 
|  | ::close(s); | 
|  | #endif | 
|  | s = InvalidSocket; | 
|  | } | 
|  | } | 
|  |  | 
|  | size_t Read(void* buffer, size_t bytes) override { | 
|  | { | 
|  | RLock lock(mutex); | 
|  | if (s == InvalidSocket) { | 
|  | return 0; | 
|  | } | 
|  | auto len = recv(s, reinterpret_cast<char*>(buffer), bytes, 0); | 
|  | if (len > 0) { | 
|  | return static_cast<size_t>(len); | 
|  | } | 
|  | } | 
|  | // Socket closed or errored | 
|  | WLock lock(mutex); | 
|  | s = InvalidSocket; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | bool Write(const void* buffer, size_t bytes) override { | 
|  | RLock lock(mutex); | 
|  | if (s == InvalidSocket) { | 
|  | return false; | 
|  | } | 
|  | if (bytes == 0) { | 
|  | return true; | 
|  | } | 
|  | return ::send(s, reinterpret_cast<const char*>(buffer), bytes, 0) > 0; | 
|  | } | 
|  |  | 
|  | std::shared_ptr<Socket> Accept() override { | 
|  | std::shared_ptr<Impl> out; | 
|  | Lock([&](SOCKET socket, const addrinfo*) { | 
|  | if (socket != InvalidSocket) { | 
|  | Init(); | 
|  | if (auto sock = ::accept(socket, nullptr, nullptr); s >= 0) { | 
|  | out = std::make_shared<Impl>(sock); | 
|  | out->SetOptions(); | 
|  | } | 
|  | } | 
|  | }); | 
|  | return out; | 
|  | } | 
|  |  | 
|  | private: | 
|  | addrinfo* const info; | 
|  | SOCKET s = InvalidSocket; | 
|  | RWMutex mutex; | 
|  | }; | 
|  |  | 
|  | }  // anonymous namespace | 
|  |  | 
|  | Socket::~Socket() = default; | 
|  |  | 
|  | std::shared_ptr<Socket> Socket::Listen(const char* address, const char* port) { | 
|  | auto impl = Impl::create(address, port); | 
|  | if (!impl) { | 
|  | return nullptr; | 
|  | } | 
|  | impl->Lock([&](SOCKET socket, const addrinfo* info) { | 
|  | if (bind(socket, info->ai_addr, info->ai_addrlen) != 0) { | 
|  | impl.reset(); | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (listen(socket, 0) != 0) { | 
|  | impl.reset(); | 
|  | return; | 
|  | } | 
|  | }); | 
|  | return impl; | 
|  | } | 
|  |  | 
|  | std::shared_ptr<Socket> Socket::Connect(const char* address, | 
|  | const char* port, | 
|  | uint32_t timeout_ms) { | 
|  | auto impl = Impl::create(address, port); | 
|  | if (!impl) { | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | std::shared_ptr<Socket> out; | 
|  | impl->Lock([&](SOCKET socket, const addrinfo* info) { | 
|  | if (socket == InvalidSocket) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (timeout_ms == 0) { | 
|  | if (::connect(socket, info->ai_addr, info->ai_addrlen) == 0) { | 
|  | out = impl; | 
|  | } | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (!SetBlocking(socket, false)) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | auto res = ::connect(socket, info->ai_addr, info->ai_addrlen); | 
|  | if (res == 0) { | 
|  | if (SetBlocking(socket, true)) { | 
|  | out = impl; | 
|  | } | 
|  | } else { | 
|  | const auto timeout_us = timeout_ms * 1000; | 
|  |  | 
|  | // Note: These macros introduce identifiers that start with `__`. | 
|  | TINT_BEGIN_DISABLE_WARNING(RESERVED_IDENTIFIER); | 
|  | fd_set fdset; | 
|  | FD_ZERO(&fdset); | 
|  | FD_SET(socket, &fdset); | 
|  | TINT_END_DISABLE_WARNING(RESERVED_IDENTIFIER); | 
|  |  | 
|  | timeval tv; | 
|  | tv.tv_sec = timeout_us / 1000000; | 
|  | using USEC = decltype(tv.tv_usec); | 
|  | tv.tv_usec = static_cast<USEC>(timeout_us) - (static_cast<USEC>(tv.tv_sec) * 1000000); | 
|  | res = select(static_cast<int>(socket + 1), nullptr, &fdset, nullptr, &tv); | 
|  | if (res > 0 && !Errored(socket) && SetBlocking(socket, true)) { | 
|  | out = impl; | 
|  | } | 
|  | } | 
|  | }); | 
|  |  | 
|  | if (!out) { | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | return out->IsOpen() ? out : nullptr; | 
|  | } | 
|  |  | 
|  | }  // namespace tint::socket |