mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
1837dc2e85
- Introduce path module to redbean - Fix glitch with linenoise printing extra line on eof - Introduce closefrom() and close_range() system calls - Make file descriptor closing more secure in pledge.com
60 lines
2.9 KiB
C
60 lines
2.9 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 2022 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/calls.h"
|
|
#include "libc/calls/strace.internal.h"
|
|
#include "libc/calls/syscall-sysv.internal.h"
|
|
#include "libc/errno.h"
|
|
#include "libc/limits.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
|
|
/**
|
|
* Closes extra file descriptors, e.g.
|
|
*
|
|
* // close all non-stdio file descriptors
|
|
* if (closefrom(3) == -1) {
|
|
* for (int i = 3; i < 256; ++i) {
|
|
* close(i);
|
|
* }
|
|
* }
|
|
*
|
|
* @return 0 on success, or -1 w/ errno
|
|
* @error ENOSYS if not Linux 5.9+ / FreeBSD / OpenBSD
|
|
* @error EBADF on OpenBSD if `first` is greater than highest fd
|
|
* @error EINVAL if flags are bad or first is greater than last
|
|
* @error EMFILE if a weird race condition happens on Linux
|
|
* @error EINTR possibly on OpenBSD
|
|
* @error ENOMEM on Linux maybe
|
|
* @note supported on Linux 5.9+, FreeBSD 8+, and OpenBSD
|
|
*/
|
|
int closefrom(int first) {
|
|
int rc, err;
|
|
if (first >= 0) {
|
|
err = errno;
|
|
if ((rc = sys_close_range(first, -1, 0)) == -1) {
|
|
if (errno == ENOSYS) {
|
|
errno = err;
|
|
rc = sys_closefrom(first);
|
|
}
|
|
}
|
|
} else {
|
|
rc = ebadf();
|
|
}
|
|
STRACE("closefrom(%d) → %d% m", first, rc);
|
|
return rc;
|
|
}
|