1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Author: Aleksa Sarai <cyphar@cyphar.com>
4 * Copyright (C) 2018-2019 SUSE LLC.
5 */
6
7 #ifndef __RESOLVEAT_H__
8 #define __RESOLVEAT_H__
9
10 #define _GNU_SOURCE
11 #include <stdint.h>
12 #include <stdbool.h>
13 #include <errno.h>
14 #include <linux/types.h>
15 #include "../kselftest.h"
16
17 #define ARRAY_LEN(X) (sizeof (X) / sizeof (*(X)))
18 #define BUILD_BUG_ON(e) ((void)(sizeof(struct { int:(-!!(e)); })))
19
20 #ifndef SYS_openat2
21 #ifndef __NR_openat2
22 #define __NR_openat2 437
23 #endif /* __NR_openat2 */
24 #define SYS_openat2 __NR_openat2
25 #endif /* SYS_openat2 */
26
27 /*
28 * Arguments for how openat2(2) should open the target path. If @resolve is
29 * zero, then openat2(2) operates very similarly to openat(2).
30 *
31 * However, unlike openat(2), unknown bits in @flags result in -EINVAL rather
32 * than being silently ignored. @mode must be zero unless one of {O_CREAT,
33 * O_TMPFILE} are set.
34 *
35 * @flags: O_* flags.
36 * @mode: O_CREAT/O_TMPFILE file mode.
37 * @resolve: RESOLVE_* flags.
38 */
39 struct open_how {
40 __u64 flags;
41 __u64 mode;
42 __u64 resolve;
43 };
44
45 #define OPEN_HOW_SIZE_VER0 24 /* sizeof first published struct */
46 #define OPEN_HOW_SIZE_LATEST OPEN_HOW_SIZE_VER0
47
48 bool needs_openat2(const struct open_how *how);
49
50 #ifndef RESOLVE_IN_ROOT
51 /* how->resolve flags for openat2(2). */
52 #define RESOLVE_NO_XDEV 0x01 /* Block mount-point crossings
53 (includes bind-mounts). */
54 #define RESOLVE_NO_MAGICLINKS 0x02 /* Block traversal through procfs-style
55 "magic-links". */
56 #define RESOLVE_NO_SYMLINKS 0x04 /* Block traversal through all symlinks
57 (implies OEXT_NO_MAGICLINKS) */
58 #define RESOLVE_BENEATH 0x08 /* Block "lexical" trickery like
59 "..", symlinks, and absolute
60 paths which escape the dirfd. */
61 #define RESOLVE_IN_ROOT 0x10 /* Make all jumps to "/" and ".."
62 be scoped inside the dirfd
63 (similar to chroot(2)). */
64 #endif /* RESOLVE_IN_ROOT */
65
66 #define E_func(func, ...) \
67 do { \
68 errno = 0; \
69 if (func(__VA_ARGS__) < 0) \
70 ksft_exit_fail_msg("%s:%d %s failed - errno:%d\n", \
71 __FILE__, __LINE__, #func, errno); \
72 } while (0)
73
74 #define E_asprintf(...) E_func(asprintf, __VA_ARGS__)
75 #define E_chmod(...) E_func(chmod, __VA_ARGS__)
76 #define E_dup2(...) E_func(dup2, __VA_ARGS__)
77 #define E_fchdir(...) E_func(fchdir, __VA_ARGS__)
78 #define E_fstatat(...) E_func(fstatat, __VA_ARGS__)
79 #define E_kill(...) E_func(kill, __VA_ARGS__)
80 #define E_mkdirat(...) E_func(mkdirat, __VA_ARGS__)
81 #define E_mount(...) E_func(mount, __VA_ARGS__)
82 #define E_prctl(...) E_func(prctl, __VA_ARGS__)
83 #define E_readlink(...) E_func(readlink, __VA_ARGS__)
84 #define E_setresuid(...) E_func(setresuid, __VA_ARGS__)
85 #define E_symlinkat(...) E_func(symlinkat, __VA_ARGS__)
86 #define E_touchat(...) E_func(touchat, __VA_ARGS__)
87 #define E_unshare(...) E_func(unshare, __VA_ARGS__)
88
89 #define E_assert(expr, msg, ...) \
90 do { \
91 if (!(expr)) \
92 ksft_exit_fail_msg("ASSERT(%s:%d) failed (%s): " msg "\n", \
93 __FILE__, __LINE__, #expr, ##__VA_ARGS__); \
94 } while (0)
95
96 int raw_openat2(int dfd, const char *path, void *how, size_t size);
97 int sys_openat2(int dfd, const char *path, struct open_how *how);
98 int sys_openat(int dfd, const char *path, struct open_how *how);
99 int sys_renameat2(int olddirfd, const char *oldpath,
100 int newdirfd, const char *newpath, unsigned int flags);
101
102 int touchat(int dfd, const char *path);
103 char *fdreadlink(int fd);
104 bool fdequal(int fd, int dfd, const char *path);
105
106 extern bool openat2_supported;
107
108 #endif /* __RESOLVEAT_H__ */
109
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