cosmopolitan/libc/sock/setsockopt.c

79 lines
3.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/nt/winsock.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"
#include "libc/sysv/consts/so.h"
#include "libc/sysv/errfuns.h"
static bool setsockopt_polyfill(int *optname) {
if (errno == ENOPROTOOPT && *optname == SO_REUSEPORT /* RHEL5 */) {
*optname = SO_REUSEADDR; /* close enough */
return true; /* fudges errno */
}
return false;
}
static textwindows int setsockopt$nt(struct Fd *fd, int level, int optname,
const void *optval, uint32_t optlen) {
if (__setsockopt$nt(fd->handle, level, optname, optval, optlen) != -1) {
return 0;
} else {
return __winsockerr();
}
}
/**
* Modifies socket settings.
*
* This function is the ultimate rabbit hole. Basic usage:
*
* int yes = 1;
* setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));
*
* @param level can be SOL_SOCKET, SOL_IP, SOL_TCP, etc.
* @param optname can be SO_{REUSE{PORT,ADDR},KEEPALIVE,etc.} etc.
* @return 0 on success, or -1 w/ errno
* @error ENOPROTOOPT for unknown (level,optname)
* @see libc/sysv/consts.sh for tuning catalogue
* @see getsockopt()
*/
int setsockopt(int fd, int level, int optname, const void *optval,
uint32_t optlen) {
if (!optval) return efault();
if (!level || !optname) return enoprotoopt(); /* our sysvconsts definition */
if (optname == -1) return 0; /* our sysvconsts definition */
if (!IsWindows()) {
do {
if (setsockopt$sysv(fd, level, optname, optval, optlen) != -1) {
return 0;
}
} while (setsockopt_polyfill(&optname));
return -1;
} else if (__isfdkind(fd, kFdSocket)) {
return setsockopt$nt(&g_fds.p[fd], level, optname, optval, optlen);
} else {
return ebadf();
}
}