cosmopolitan/libc/sock/sendto.c

68 lines
3.8 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/calls/struct/iovec.h"
#include "libc/dce.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
/**
* Sends data over network.
*
* This function blocks unless MSG_DONTWAIT is passed. In that case, the
* non-error EWOULDBLOCK might be returned. It basically means we didn't
* wait around to learn an amount of bytes were written that we know in
* advance are guaranteed to be atomic.
*
* @param fd is the file descriptor returned by socket()
* @param buf is the data to send, which we'll copy if necessary
* @param size is the byte-length of buf
* @param flags MSG_OOB, MSG_DONTROUTE, MSG_PARTIAL, MSG_NOSIGNAL, etc.
* @param opt_addr is a binary ip:port destination override, which is
* mandatory for UDP if connect() wasn't called
* @param addrsize is the byte-length of addr's true polymorphic form
* @return number of bytes transmitted, or -1 w/ errno
* @error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable),
* EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.
* @asyncsignalsafe
*/
ssize_t sendto(int fd, const void *buf, size_t size, uint32_t flags,
const void *opt_addr, uint32_t addrsize) {
static_assert(sizeof(struct sockaddr_in) == sizeof(struct sockaddr_in$bsd));
if (!IsWindows()) {
if (!IsBsd() || !opt_addr) {
return sendto$sysv(fd, buf, size, flags, opt_addr, addrsize);
} else {
struct sockaddr_in$bsd addr2;
if (addrsize != sizeof(addr2)) return einval();
memcpy(&addr2, opt_addr, sizeof(struct sockaddr_in));
sockaddr2bsd(&addr2);
return sendto$sysv(fd, buf, size, flags, &addr2, addrsize);
}
} else if (__isfdkind(fd, kFdSocket)) {
return sendto$nt(&g_fds.p[fd], (struct iovec[]){{buf, size}}, 1, flags,
opt_addr, addrsize);
} else {
return ebadf();
}
}