1/* provide a replacement openat function
2   Copyright (C) 2004-2006, 2008-2010 Free Software Foundation, Inc.
3
4   This program is free software: you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 3 of the License, or
7   (at your option) any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
16
17/* written by Jim Meyering */
18
19#ifndef _GL_HEADER_OPENAT
20#define _GL_HEADER_OPENAT
21
22#include <fcntl.h>
23
24#include <sys/types.h>
25#include <sys/stat.h>
26#include <dirent.h>
27#include <unistd.h>
28#include <stdbool.h>
29
30#ifndef __attribute__
31# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
32#  define __attribute__(x) /* empty */
33# endif
34#endif
35
36#ifndef ATTRIBUTE_NORETURN
37# define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
38#endif
39
40#if !HAVE_OPENAT
41
42int openat_permissive (int fd, char const *file, int flags, mode_t mode,
43                       int *cwd_errno);
44bool openat_needs_fchdir (void);
45
46#else
47
48# define openat_permissive(Fd, File, Flags, Mode, Cwd_errno) \
49    openat (Fd, File, Flags, Mode)
50# define openat_needs_fchdir() false
51
52#endif
53
54void openat_restore_fail (int) ATTRIBUTE_NORETURN;
55void openat_save_fail (int) ATTRIBUTE_NORETURN;
56
57/* Using these function names makes application code
58   slightly more readable than it would be with
59   fchownat (..., 0) or fchownat (..., AT_SYMLINK_NOFOLLOW).  */
60static inline int
61chownat (int fd, char const *file, uid_t owner, gid_t group)
62{
63  return fchownat (fd, file, owner, group, 0);
64}
65
66static inline int
67lchownat (int fd, char const *file, uid_t owner, gid_t group)
68{
69  return fchownat (fd, file, owner, group, AT_SYMLINK_NOFOLLOW);
70}
71
72static inline int
73chmodat (int fd, char const *file, mode_t mode)
74{
75  return fchmodat (fd, file, mode, 0);
76}
77
78static inline int
79lchmodat (int fd, char const *file, mode_t mode)
80{
81  return fchmodat (fd, file, mode, AT_SYMLINK_NOFOLLOW);
82}
83
84static inline int
85statat (int fd, char const *name, struct stat *st)
86{
87  return fstatat (fd, name, st, 0);
88}
89
90static inline int
91lstatat (int fd, char const *name, struct stat *st)
92{
93  return fstatat (fd, name, st, AT_SYMLINK_NOFOLLOW);
94}
95
96#if GNULIB_FACCESSAT
97/* For now, there are no wrappers named laccessat or leuidaccessat,
98   since gnulib doesn't support faccessat(,AT_SYMLINK_NOFOLLOW) and
99   since access rights on symlinks are of limited utility.  */
100
101static inline int
102accessat (int fd, char const *file, int mode)
103{
104  return faccessat (fd, file, mode, 0);
105}
106
107static inline int
108euidaccessat (int fd, char const *file, int mode)
109{
110  return faccessat (fd, file, mode, AT_EACCESS);
111}
112#endif
113
114#endif /* _GL_HEADER_OPENAT */
115