spdlog/details/tcp_client-windows.h

0001 // Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
0002 // Distributed under the MIT License (http://opensource.org/licenses/MIT)
0003
0004 #pragma once
0005
0006 #define WIN32_LEAN_AND_MEAN
0007 // tcp client helper
0008 #include <spdlog/common.h>
0009 #include <spdlog/details/os.h>
0010
0011 #include <stdio.h>
0012 #include <stdlib.h>
0013 #include <string>
0014 #include <windows.h>
0015 #include <winsock2.h>
0016 #include <ws2tcpip.h>
0017
0018 #pragma comment(lib, "Ws2_32.lib")
0019 #pragma comment(lib, "Mswsock.lib")
0020 #pragma comment(lib, "AdvApi32.lib")
0021
0022 namespace spdlog {
0023 namespace details {
0024 class tcp_client {
0025     SOCKET socket_ = INVALID_SOCKET;
0026
0027     static void init_winsock_() {
0028         WSADATA wsaData;
0029         auto rv = WSAStartup(MAKEWORD(2, 2), &wsaData);
0030         if (rv != 0) {
0031             throw_winsock_error_("WSAStartup failed", ::WSAGetLastError());
0032         }
0033     }
0034
0035     static void throw_winsock_error_(const std::string &msg, int last_error) {
0036         char buf[512];
0037         ::FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL,
0038                          last_error, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), buf,
0039                          (sizeof(buf) / sizeof(char)), NULL);
0040
0041         throw_spdlog_ex(fmt_lib::format("tcp_sink - {}: {}", msg, buf));
0042     }
0043
0044 public:
0045     tcp_client() { init_winsock_(); }
0046
0047     ~tcp_client() {
0048         close();
0049         ::WSACleanup();
0050     }
0051
0052     bool is_connected() const { return socket_ != INVALID_SOCKET; }
0053
0054     void close() {
0055         ::closesocket(socket_);
0056         socket_ = INVALID_SOCKET;
0057     }
0058
0059     SOCKET fd() const { return socket_; }
0060
0061     // try to connect or throw on failure
0062     void connect(const std::string &host, int port) {
0063         if (is_connected()) {
0064             close();
0065         }
0066         struct addrinfo hints {};
0067         ZeroMemory(&hints, sizeof(hints));
0068
0069         hints.ai_family = AF_UNSPEC;      // To work with IPv4, IPv6, and so on
0070         hints.ai_socktype = SOCK_STREAM;  // TCP
0071         hints.ai_flags = AI_NUMERICSERV;  // port passed as as numeric value
0072         hints.ai_protocol = 0;
0073
0074         auto port_str = std::to_string(port);
0075         struct addrinfo *addrinfo_result;
0076         auto rv = ::getaddrinfo(host.c_str(), port_str.c_str(), &hints, &addrinfo_result);
0077         int last_error = 0;
0078         if (rv != 0) {
0079             last_error = ::WSAGetLastError();
0080             WSACleanup();
0081             throw_winsock_error_("getaddrinfo failed", last_error);
0082         }
0083
0084         // Try each address until we successfully connect(2).
0085
0086         for (auto *rp = addrinfo_result; rp != nullptr; rp = rp->ai_next) {
0087             socket_ = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
0088             if (socket_ == INVALID_SOCKET) {
0089                 last_error = ::WSAGetLastError();
0090                 WSACleanup();
0091                 continue;
0092             }
0093             if (::connect(socket_, rp->ai_addr, (int)rp->ai_addrlen) == 0) {
0094                 break;
0095             } else {
0096                 last_error = ::WSAGetLastError();
0097                 close();
0098             }
0099         }
0100         ::freeaddrinfo(addrinfo_result);
0101         if (socket_ == INVALID_SOCKET) {
0102             WSACleanup();
0103             throw_winsock_error_("connect failed", last_error);
0104         }
0105
0106         // set TCP_NODELAY
0107         int enable_flag = 1;
0108         ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<char *>(&enable_flag),
0109                      sizeof(enable_flag));
0110     }
0111
0112     // Send exactly n_bytes of the given data.
0113     // On error close the connection and throw.
0114     void send(const char *data, size_t n_bytes) {
0115         size_t bytes_sent = 0;
0116         while (bytes_sent < n_bytes) {
0117             const int send_flags = 0;
0118             auto write_result =
0119                 ::send(socket_, data + bytes_sent, (int)(n_bytes - bytes_sent), send_flags);
0120             if (write_result == SOCKET_ERROR) {
0121                 int last_error = ::WSAGetLastError();
0122                 close();
0123                 throw_winsock_error_("send failed", last_error);
0124             }
0125
0126             if (write_result == 0)  // (probably should not happen but in any case..)
0127             {
0128                 break;
0129             }
0130             bytes_sent += static_cast<size_t>(write_result);
0131         }
0132     }
0133 };
0134 }  // namespace details
0135 }  // namespace spdlog