cosmopolitan/libc/sock/recvfrom.c

61 lines
3.4 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/nt/winsock.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"
#include "libc/sysv/errfuns.h"
/**
* Receives data from network.
*
* This function blocks unless MSG_DONTWAIT is passed.
*
* @param fd is the file descriptor returned by socket()
* @param buf is where received network data gets copied
* @param size is the byte capacity of buf
* @param flags can have MSG_{WAITALL,DONTROUTE,PEEK,OOB}, etc.
* @param opt_out_srcaddr receives the binary ip:port of the data's origin
* @param opt_inout_srcaddrsize is srcaddr capacity which gets updated
* @return number of bytes received, 0 on remote close, or -1 w/ errno
* @error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable),
* EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.
* @asyncsignalsafe
*/
ssize_t recvfrom(int fd, void *buf, size_t size, uint32_t flags,
void *opt_out_srcaddr, uint32_t *opt_inout_srcaddrsize) {
ssize_t got;
if (!IsWindows()) {
got = recvfrom$sysv(fd, buf, size, flags, opt_out_srcaddr,
opt_inout_srcaddrsize);
if (opt_out_srcaddr && IsBsd() && got != -1) {
sockaddr2linux(opt_out_srcaddr);
}
return got;
} else if (__isfdkind(fd, kFdSocket)) {
return recvfrom$nt(&g_fds.p[fd], (struct iovec[]){{buf, size}}, 1, flags,
opt_out_srcaddr, opt_inout_srcaddrsize);
} else {
return ebadf();
}
}