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/*
* 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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