1 /* Test for access to file, relative to open directory. Linux version.
2 Copyright (C) 2006-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
21 #include <sys/types.h>
27 __faccessat (int fd
, const char *file
, int mode
, int flag
)
29 int ret
= INLINE_SYSCALL_CALL (faccessat2
, fd
, file
, mode
, flag
);
30 #if __ASSUME_FACCESSAT2
33 if (ret
== 0 || errno
!= ENOSYS
)
36 if (flag
& ~(AT_SYMLINK_NOFOLLOW
| AT_EACCESS
))
37 return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL
);
39 if ((flag
== 0 || ((flag
& ~AT_EACCESS
) == 0 && ! __libc_enable_secure
)))
40 return INLINE_SYSCALL (faccessat
, 3, fd
, file
, mode
);
42 struct __stat64_t64 stats
;
43 if (__fstatat64_time64 (fd
, file
, &stats
, flag
& AT_SYMLINK_NOFOLLOW
))
46 mode
&= (X_OK
| W_OK
| R_OK
); /* Clear any bogus bits. */
47 # if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH
48 # error Oops, portability assumptions incorrect.
52 return 0; /* The file exists. */
54 uid_t uid
= (flag
& AT_EACCESS
) ? __geteuid () : __getuid ();
56 /* The super-user can read and write any file, and execute any file
57 that anyone can execute. */
58 if (uid
== 0 && ((mode
& X_OK
) == 0
59 || (stats
.st_mode
& (S_IXUSR
| S_IXGRP
| S_IXOTH
))))
62 int granted
= (uid
== stats
.st_uid
63 ? (unsigned int) (stats
.st_mode
& (mode
<< 6)) >> 6
64 : (stats
.st_gid
== ((flag
& AT_EACCESS
)
65 ? __getegid () : __getgid ())
66 || __group_member (stats
.st_gid
))
67 ? (unsigned int) (stats
.st_mode
& (mode
<< 3)) >> 3
68 : (stats
.st_mode
& mode
));
73 return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES
);
74 #endif /* !__ASSUME_FACCESSAT2 */
76 weak_alias (__faccessat
, faccessat
)