glibc/sysdeps/unix/sysv/linux/faccessat.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

77 lines
2.5 KiB
C

/* Test for access to file, relative to open directory. Linux version.
Copyright (C) 2006-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sysdep.h>
int
__faccessat (int fd, const char *file, int mode, int flag)
{
int ret = INLINE_SYSCALL_CALL (faccessat2, fd, file, mode, flag);
#if __ASSUME_FACCESSAT2
return ret;
#else
if (ret == 0 || errno != ENOSYS)
return ret;
if (flag & ~(AT_SYMLINK_NOFOLLOW | AT_EACCESS))
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
if ((flag == 0 || ((flag & ~AT_EACCESS) == 0 && ! __libc_enable_secure)))
return INLINE_SYSCALL (faccessat, 3, fd, file, mode);
struct stat64 stats;
if (__fstatat64 (fd, file, &stats, flag & AT_SYMLINK_NOFOLLOW))
return -1;
mode &= (X_OK | W_OK | R_OK); /* Clear any bogus bits. */
# if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH
# error Oops, portability assumptions incorrect.
# endif
if (mode == F_OK)
return 0; /* The file exists. */
uid_t uid = (flag & AT_EACCESS) ? __geteuid () : __getuid ();
/* The super-user can read and write any file, and execute any file
that anyone can execute. */
if (uid == 0 && ((mode & X_OK) == 0
|| (stats.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))))
return 0;
int granted = (uid == stats.st_uid
? (unsigned int) (stats.st_mode & (mode << 6)) >> 6
: (stats.st_gid == ((flag & AT_EACCESS)
? __getegid () : __getgid ())
|| __group_member (stats.st_gid))
? (unsigned int) (stats.st_mode & (mode << 3)) >> 3
: (stats.st_mode & mode));
if (granted == mode)
return 0;
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES);
#endif /* !__ASSUME_FACCESSAT2 */
}
weak_alias (__faccessat, faccessat)