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Diffstat (limited to 'client/helloworld/net.c')
| -rw-r--r-- | client/helloworld/net.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/client/helloworld/net.c b/client/helloworld/net.c new file mode 100644 index 0000000..83192e0 --- /dev/null +++ b/client/helloworld/net.c @@ -0,0 +1,181 @@ +/* + * Created by yuuta on 7/22/22. + * + * A simple cross-platform (Unix and Windows) implementation of a socket client. + */ + +#include "net.h" + +#include <stdint.h> +#include <errno.h> +#include <stdio.h> +#include <string.h> + +#ifdef WIN32 +#include <windows.h> /* For DWORD */ +#include <winsock2.h> +#include <ws2tcpip.h> + +#define errno_sock WSAGetLastError() + +#else + +#include <sys/socket.h> +#include <netdb.h> +#include <unistd.h> +#include <sys/time.h> + +#define closesocket(socket) close(socket) +#define errno_sock errno + +#endif + +int net_connect(const char *host, + const uint16_t port, + SOCKET *sock) { + int r; + struct addrinfo *res; + char service[6]; + + snprintf(service, 6, "%u", port); + if ((r = getaddrinfo(host, service, NULL, &res))) { + return r; + } + + SOCKET fd; + if ((fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) <= 0) { + const int e = errno_sock; + freeaddrinfo(res); + return e; + } + if (connect(fd, res->ai_addr, res->ai_addrlen) < 0) { + const int e = errno_sock; + closesocket(fd); + freeaddrinfo(res); + return e; + } + freeaddrinfo(res); + *sock = fd; + return 0; +} + +int net_read(const SOCKET *sock, + void *buffer, + const size_t length, + size_t *read, + const unsigned int timeout) { + +#ifdef WIN32 + DWORD to = timeout * 1000; + if (setsockopt(*sock, SOL_SOCKET, SO_RCVTIMEO, (const char*)&to, sizeof to)) { +#else + struct timeval tv; + tv.tv_sec = timeout; + tv.tv_usec = 0; + if (setsockopt(*sock, SOL_SOCKET, SO_RCVTIMEO, (const char *) &tv, sizeof tv)) { +#endif + return errno_sock; + } + + int bytes; + if ((bytes = (int) recv(*sock, buffer, length, 0)) <= 0) { + if (bytes < 0) { + const int e = errno_sock; +#ifdef WIN32 + if (e == WSAETIMEDOUT) { +#else + if (e == EAGAIN) { +#endif + return NET_TIMEOUT; + } + return e; + } + return NET_CLOSED; + } + *read = bytes; + return 0; +} + +int net_send(const SOCKET *sock, + const void *buffer, + size_t len) { + size_t pos; + const uint8_t *ptr = buffer; + int retval; + + for (pos = 0U; pos < len; pos += retval) { + size_t n = len - pos; + retval = (int) send(*sock, &ptr[pos], (int) n, 0); + if (retval <= 0) { + return errno_sock; + } + } + return 0; +} + +int net_init(void) { +#ifdef WIN32 + int r; + WORD wVersionRequested; + WSADATA wsaData; + wVersionRequested = MAKEWORD(2, 2); + if ((r = WSAStartup(wVersionRequested, &wsaData))) { + fprintf(stderr, "WSAStartup failed with error: %d\n", r); + return r; + } + if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2) { + fprintf(stderr, "Could not find a usable version of Winsock.dll\n"); + WSACleanup(); + return 1; + } +#endif + return 0; +} + +void net_close(const SOCKET *sock) { + closesocket(*sock); +} + +#ifdef WIN32 +static __declspec( thread ) LPTSTR err_buf = NULL; +#else +static _Thread_local char err_buf[1024]; +#endif + +void net_free(void) { +#ifdef WIN32 + WSACleanup(); + if (err_buf) { + LocalFree(err_buf); + err_buf = NULL; + } +#endif +} + +char *net_strerror(int errnum) { +#ifdef WIN32 + if (err_buf) { + LocalFree(err_buf); + err_buf = NULL; + } + FormatMessage( + FORMAT_MESSAGE_FROM_SYSTEM | + FORMAT_MESSAGE_ALLOCATE_BUFFER | + FORMAT_MESSAGE_IGNORE_INSERTS, + NULL, + errnum, + MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), + (LPTSTR) &err_buf, + 0, + NULL); + if (!err_buf) { + return "Unknown error"; + } +#else + int r; + if ((r = strerror_r(errnum, err_buf, sizeof(err_buf) / sizeof(char)))) { + snprintf(err_buf, 1024, "%d (%d)", errnum, r); + } +#endif + return err_buf; +}
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