cosmopolitan/libc/sock/send.c
Justine Tunney 3f0bcdc3ef
Improve cancellations, randomness, and time
- Exhaustively document cancellation points
- Rename SIGCANCEL to SIGTHR just like BSDs
- Further improve POSIX thread cancellations
- Ensure asynchronous cancellations work correctly
- Elevate the quality of getrandom() and getentropy()
- Make futexes cancel correctly on OpenBSD 6.x and 7.x
- Add reboot.com and shutdown.com to examples directory
- Remove underscore prefix from awesome timespec_*() APIs
- Create assertions that help verify our cancellation points
- Remove bad timespec APIs (cmp generalizes eq/ne/gt/gte/lt/lte)
2022-11-05 23:45:32 -07:00

73 lines
3.5 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/cp.internal.h"
#include "libc/calls/internal.h"
#include "libc/calls/struct/iovec.h"
#include "libc/calls/struct/iovec.internal.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/macros.internal.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"
#include "libc/sysv/errfuns.h"
/**
* Sends data to network socket.
*
* @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.
* @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.
* @cancellationpoint
* @asyncsignalsafe
* @restartable (unless SO_RCVTIMEO)
*/
ssize_t send(int fd, const void *buf, size_t size, int flags) {
ssize_t rc;
BEGIN_CANCELLATION_POINT;
if (IsAsan() && !__asan_is_valid(buf, size)) {
rc = efault();
} else if (!IsWindows()) {
rc = sys_sendto(fd, buf, size, flags, 0, 0);
} else if (__isfdopen(fd)) {
if (__isfdkind(fd, kFdSocket)) {
rc = sys_send_nt(fd, (struct iovec[]){{buf, size}}, 1, flags);
} else if (__isfdkind(fd, kFdFile)) {
if (flags) {
rc = einval();
} else {
rc = sys_write_nt(fd, (struct iovec[]){{buf, size}}, 1, -1);
}
} else {
rc = enotsock();
}
} else {
rc = ebadf();
}
END_CANCELLATION_POINT;
DATATRACE("send(%d, %#.*hhs%s, %'zu, %#x) → %'ld% lm", fd,
MAX(0, MIN(40, rc)), buf, rc > 40 ? "..." : "", size, flags, rc);
return rc;
}