cosmopolitan/libc/sock/recvfrom.c
Justine Tunney 933411ba99 Improve synchronization
- Fix bugs in kDos2Errno definition
- malloc() should now be thread safe
- Fix bug in rollup.com header generator
- Fix open(O_APPEND) on the New Technology
- Fix select() on the New Technology and test it
- Work towards refactoring i/o for thread safety
- Socket reads and writes on NT now poll for signals
- Work towards i/o completion ports on the New Technology
- Make read() and write() intermittently check for signals
- Blinkenlights keyboard i/o so much better on NT w/ poll()
- You can now poll() files and sockets at the same time on NT
- Fix bug in appendr() that manifests with dlmalloc footers off
2022-04-15 15:31:55 -07:00

80 lines
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 │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/internal.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/struct/iovec.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.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
* @restartable (unless SO_RCVTIMEO)
*/
ssize_t recvfrom(int fd, void *buf, size_t size, uint32_t flags,
void *opt_out_srcaddr, uint32_t *opt_inout_srcaddrsize) {
ssize_t rc, got;
if (IsAsan() &&
(!__asan_is_valid(buf, size) ||
(opt_out_srcaddr &&
!__asan_is_valid(opt_out_srcaddr, *opt_inout_srcaddrsize)))) {
rc = efault();
} else if (!IsWindows()) {
got = sys_recvfrom(fd, buf, size, flags, opt_out_srcaddr,
opt_inout_srcaddrsize);
if (opt_out_srcaddr && IsBsd() && got != -1) {
sockaddr2linux(opt_out_srcaddr);
}
rc = got;
} else if (__isfdopen(fd)) {
if (__isfdkind(fd, kFdSocket)) {
rc = sys_recvfrom_nt(&g_fds.p[fd], (struct iovec[]){{buf, size}}, 1,
flags, opt_out_srcaddr, opt_inout_srcaddrsize);
} else if (__isfdkind(fd, kFdFile) && !opt_out_srcaddr) { /* socketpair */
if (flags) {
rc = einval();
} else {
rc = sys_read_nt(&g_fds.p[fd], (struct iovec[]){{buf, size}}, 1, -1);
}
} else {
rc = enotsock();
}
} else {
rc = ebadf();
}
STRACE("recvfrom(%d, [%#.*hhs%s], %'zu, %#x) → %'ld% lm", fd,
MAX(0, MIN(40, rc)), buf, rc > 40 ? "..." : "", size, flags, rc);
return rc;
}