projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| d15b99ac | 1 | /* Test for access to file, relative to open directory. Linux version. |
| 2b778ceb | 2 | Copyright (C) 2006-2021 Free Software Foundation, Inc. |
| d15b99ac RM |
3 | This file is part of the GNU C Library. |
| 4 | ||
| 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. | |
| 9 | ||
| 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. | |
| 14 | ||
| 15 | You should have received a copy of the GNU Lesser General Public | |
| 59ba27a6 | 16 | License along with the GNU C Library; if not, see |
| 5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
| d15b99ac | 18 | |
| d15b99ac | 19 | #include <fcntl.h> |
| d15b99ac RM |
20 | #include <unistd.h> |
| 21 | #include <sys/types.h> | |
| 01bd6251 | 22 | #include <sys/stat.h> |
| d15b99ac RM |
23 | #include <sysdep.h> |
| 24 | ||
| 7c65e900 | 25 | |
| d15b99ac | 26 | int |
| bd2260a2 | 27 | faccessat (int fd, const char *file, int mode, int flag) |
| d15b99ac | 28 | { |
| 3d3ab573 FW |
29 | int ret = INLINE_SYSCALL_CALL (faccessat2, fd, file, mode, flag); |
| 30 | #if __ASSUME_FACCESSAT2 | |
| 31 | return ret; | |
| 32 | #else | |
| 33 | if (ret == 0 || errno != ENOSYS) | |
| 34 | return ret; | |
| 35 | ||
| d15b99ac | 36 | if (flag & ~(AT_SYMLINK_NOFOLLOW | AT_EACCESS)) |
| 2caca60d | 37 | return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); |
| d15b99ac | 38 | |
| 809fdf0d | 39 | if ((flag == 0 || ((flag & ~AT_EACCESS) == 0 && ! __libc_enable_secure))) |
| e5dee2c8 | 40 | return INLINE_SYSCALL (faccessat, 3, fd, file, mode); |
| d15b99ac RM |
41 | |
| 42 | struct stat64 stats; | |
| 04986243 | 43 | if (__fstatat64 (fd, file, &stats, flag & AT_SYMLINK_NOFOLLOW)) |
| d15b99ac RM |
44 | return -1; |
| 45 | ||
| 46 | mode &= (X_OK | W_OK | R_OK); /* Clear any bogus bits. */ | |
| 3d3ab573 FW |
47 | # if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH |
| 48 | # error Oops, portability assumptions incorrect. | |
| 49 | # endif | |
| d15b99ac RM |
50 | |
| 51 | if (mode == F_OK) | |
| 52 | return 0; /* The file exists. */ | |
| 53 | ||
| 54 | uid_t uid = (flag & AT_EACCESS) ? __geteuid () : __getuid (); | |
| 55 | ||
| 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)))) | |
| 60 | return 0; | |
| 61 | ||
| 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)); | |
| 69 | ||
| 70 | if (granted == mode) | |
| 71 | return 0; | |
| 72 | ||
| 2caca60d | 73 | return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES); |
| 3d3ab573 | 74 | #endif /* !__ASSUME_FACCESSAT2 */ |
| d15b99ac | 75 | } |