diff --git a/include/spdlog/details/tcp_client-windows.h b/include/spdlog/details/tcp_client-windows.h index bf8f7b87..27fd715b 100644 --- a/include/spdlog/details/tcp_client-windows.h +++ b/include/spdlog/details/tcp_client-windows.h @@ -58,38 +58,54 @@ public: SOCKET fd() const { return socket_; } - // try to connect or throw on failure - void connect(const std::string &host, int port) { + // try to connect to syslog server + // throw connection timed out error if unable to connect within specified time + void connect(const std::string &host, int port, int timeout_secs) { + // if socket is already connected, close pre-existing connection to start new connection if (is_connected()) { close(); } + + // establish criteria of network connection struct addrinfo hints {}; ZeroMemory(&hints, sizeof(hints)); - - hints.ai_family = AF_UNSPEC; // To work with IPv4, IPv6, and so on - hints.ai_socktype = SOCK_STREAM; // TCP - hints.ai_flags = AI_NUMERICSERV; // port passed as as numeric value + hints.ai_family = AF_UNSPEC; // To work with address families IPv4, IPv6, and so on + hints.ai_socktype = SOCK_STREAM; // TCP will be used to establish a reliable connection hints.ai_protocol = 0; + // get address info of attempted connection, return 0 if successful auto port_str = std::to_string(port); struct addrinfo *addrinfo_result; auto rv = ::getaddrinfo(host.c_str(), port_str.c_str(), &hints, &addrinfo_result); int last_error = 0; + + // if there was an error getting address info if (rv != 0) { last_error = ::WSAGetLastError(); WSACleanup(); throw_winsock_error_("getaddrinfo failed", last_error); } - // Try each address until we successfully connect(2). - + // try each address until we successfully connect for (auto *rp = addrinfo_result; rp != nullptr; rp = rp->ai_next) { + // attempt to connect to current address, if unsuccessful move onto the next socket_ = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (socket_ == INVALID_SOCKET) { last_error = ::WSAGetLastError(); WSACleanup(); continue; } + + // set timeout for connection to user address, if no connection occurs within time limit move onto next address + struct timeval timeout_obj; // timeout_obj that will hold the timeout length + timeout_obj.tv_sec = timeout_secs; // set length of timeout in seconds based on passed-in parameter + timeout_obj.tv_usec = 0; // we are not using microseconds in this case + // server receive timeout (from user trying to connect) + setsockopt(socket_, SOL_SOCKET, SO_RCVTIMEO, (const char*)&timeout_obj, sizeof(timeout_obj)); + // server send timeout (to user trying to connect) + setsockopt(socket_, SOL_SOCKET, SO_SNDTIMEO, (const char*)&timeout_obj, sizeof(timeout_obj)); + + // try to connect to syslog server using current address, if successful break out of loop if (::connect(socket_, rp->ai_addr, (int)rp->ai_addrlen) == 0) { break; } else { @@ -97,13 +113,15 @@ public: close(); } } + + // free address info and throw connection failed error if no connection was made ::freeaddrinfo(addrinfo_result); if (socket_ == INVALID_SOCKET) { WSACleanup(); throw_winsock_error_("connect failed", last_error); } - // set TCP_NODELAY + // disable Nagle's algorithm to allow data packets to be sent immediately int enable_flag = 1; ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast(&enable_flag), sizeof(enable_flag));