cosmopolitan/libc/calls/write.c

94 lines
4.7 KiB
C
Raw Normal View History

2020-06-15 14:18:57 +00:00
/*-*- 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
2020-12-28 01:18:44 +00:00
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.
2020-06-15 14:18:57 +00:00
2020-12-28 01:18:44 +00:00
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.
2020-06-15 14:18:57 +00:00
*/
#include "libc/calls/cp.internal.h"
2021-10-15 02:36:49 +00:00
#include "libc/calls/internal.h"
2020-06-15 14:18:57 +00:00
#include "libc/calls/struct/iovec.h"
#include "libc/calls/struct/iovec.internal.h"
2022-05-23 22:06:11 +00:00
#include "libc/calls/syscall-sysv.internal.h"
2021-10-15 02:36:49 +00:00
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/runtime/zipos.internal.h"
#include "libc/sock/sock.h"
2021-10-15 02:36:49 +00:00
#include "libc/sysv/errfuns.h"
2020-06-15 14:18:57 +00:00
/**
* Writes data to file descriptor.
*
* This function changes the current file position. For documentation
* on file position behaviors and gotchas, see the lseek() function.
2022-10-07 10:41:50 +00:00
* This function may be used on socket file descriptors, including on
* Windows.
*
2022-10-05 06:32:16 +00:00
* @param fd is open file descriptor
2020-06-15 14:18:57 +00:00
* @param buf is copied from, cf. copy_file_range(), sendfile(), etc.
* @return [1..size] bytes on success, or -1 w/ errno; noting zero is
* impossible unless size was passed as zero to do an error check
2022-10-05 06:32:16 +00:00
* @raise EBADF if `fd` is negative or not an open file descriptor
* @raise EBADF if `fd` wasn't opened with `O_WRONLY` or `O_RDWR`
* @raise EPIPE if `fd` is a pipe whose other reader end was closed,
* after the `SIGPIPE` signal was delivered, blocked, or ignored
* @raise EFBIG if `RLIMIT_FSIZE` soft limit was exceeded, after the
* `SIGXFSZ` signal was either delivered, blocked, or ignored
* @raise EFAULT if `size` is nonzero and `buf` points to bad memory
* @raise EPERM if pledge() is in play without the stdio promise
* @raise ENOSPC if device containing `fd` is full
* @raise EIO if low-level i/o error happened
* @raise EINTR if signal was delivered instead
* @raise ECANCELED if thread was cancelled in masked mode
2022-10-05 06:32:16 +00:00
* @raise EAGAIN if `O_NONBLOCK` is in play and write needs to block
* @raise ENOBUFS if kernel lacked internal resources; which FreeBSD
* and XNU say could happen with sockets, and OpenBSD documents it
* as a general possibility; whereas other system don't specify it
* @raise ENXIO is specified only by POSIX and XNU when a request is
* made of a nonexistent device or outside device capabilities
* @cancellationpoint
2020-06-15 14:18:57 +00:00
* @asyncsignalsafe
* @restartable
* @vforksafe
2020-06-15 14:18:57 +00:00
*/
ssize_t write(int fd, const void *buf, size_t size) {
ssize_t rc;
BEGIN_CANCELLATION_POINT;
2021-10-15 02:36:49 +00:00
if (fd >= 0) {
2022-10-05 06:32:16 +00:00
if ((!buf && size) || (IsAsan() && !__asan_is_valid(buf, size))) {
rc = efault();
} else if (__isfdkind(fd, kFdZip)) {
rc = ebadf();
2021-10-15 02:36:49 +00:00
} else if (!IsWindows() && !IsMetal()) {
rc = sys_write(fd, buf, size);
2021-10-15 02:36:49 +00:00
} else if (fd >= g_fds.n) {
rc = ebadf();
2021-10-15 02:36:49 +00:00
} else if (IsMetal()) {
rc = sys_writev_metal(g_fds.p + fd, &(struct iovec){buf, size}, 1);
2021-10-15 02:36:49 +00:00
} else {
rc = sys_writev_nt(fd, &(struct iovec){buf, size}, 1);
2021-10-15 02:36:49 +00:00
}
} else {
2022-10-05 06:32:16 +00:00
rc = ebadf();
2021-10-15 02:36:49 +00:00
}
END_CANCELLATION_POINT;
DATATRACE("write(%d, %#.*hhs%s, %'zu) → %'zd% m", fd, MAX(0, MIN(40, rc)),
buf, rc > 40 ? "..." : "", size, rc);
return rc;
2020-06-15 14:18:57 +00:00
}