cosmopolitan/libc/sock/recvfrom.c
Justine Tunney 3e4fd4b0ad Add epoll and do more release readiness changes
This change also pays off some of the remaining technical debt with
stdio, file descriptors, and memory managemnt polyfills.
2020-11-28 12:01:51 -08:00

60 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();
}
}