1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2 #pragma once
3
4 #include <linux/fs.h>
5 #include <stdbool.h>
6 #include <stddef.h>
7
8 #include "missing_fs.h"
9
10 /* The chattr() flags to apply when creating a new file *before* writing to it. In particular, flags such as
11 * FS_NOCOW_FL don't work if applied a-posteriori. All other flags are fine (or even necessary, think
12 * FS_IMMUTABLE_FL!) to apply after writing to the files. */
13 #define CHATTR_EARLY_FL \
14 (FS_NOATIME_FL | \
15 FS_COMPR_FL | \
16 FS_NOCOW_FL | \
17 FS_NOCOMP_FL | \
18 FS_PROJINHERIT_FL)
19
20 #define CHATTR_ALL_FL \
21 (FS_NOATIME_FL | \
22 FS_SYNC_FL | \
23 FS_DIRSYNC_FL | \
24 FS_APPEND_FL | \
25 FS_COMPR_FL | \
26 FS_NODUMP_FL | \
27 FS_EXTENT_FL | \
28 FS_IMMUTABLE_FL | \
29 FS_JOURNAL_DATA_FL | \
30 FS_SECRM_FL | \
31 FS_UNRM_FL | \
32 FS_NOTAIL_FL | \
33 FS_TOPDIR_FL | \
34 FS_NOCOW_FL | \
35 FS_PROJINHERIT_FL)
36
37 typedef enum ChattrApplyFlags {
38 CHATTR_FALLBACK_BITWISE = 1 << 0,
39 CHATTR_WARN_UNSUPPORTED_FLAGS = 1 << 1,
40 } ChattrApplyFlags;
41
42 int chattr_full(const char *path, int fd, unsigned value, unsigned mask, unsigned *ret_previous, unsigned *ret_final, ChattrApplyFlags flags);
43
chattr_fd(int fd,unsigned value,unsigned mask,unsigned * previous)44 static inline int chattr_fd(int fd, unsigned value, unsigned mask, unsigned *previous) {
45 return chattr_full(NULL, fd, value, mask, previous, NULL, 0);
46 }
chattr_path(const char * path,unsigned value,unsigned mask,unsigned * previous)47 static inline int chattr_path(const char *path, unsigned value, unsigned mask, unsigned *previous) {
48 return chattr_full(path, -1, value, mask, previous, NULL, 0);
49 }
50
51 int read_attr_fd(int fd, unsigned *ret);
52 int read_attr_path(const char *p, unsigned *ret);
53
54 /* Combination of chattr flags, that should be appropriate for secrets stored on disk: Secure Remove +
55 * Exclusion from Dumping + Synchronous Writing (i.e. not caching in memory) + In-Place Updating (i.e. not
56 * spurious copies). */
57 #define CHATTR_SECRET_FLAGS (FS_SECRM_FL|FS_NODUMP_FL|FS_SYNC_FL|FS_NOCOW_FL)
58
chattr_secret(int fd,ChattrApplyFlags flags)59 static inline int chattr_secret(int fd, ChattrApplyFlags flags) {
60 return chattr_full(NULL, fd, CHATTR_SECRET_FLAGS, CHATTR_SECRET_FLAGS, NULL, NULL, flags|CHATTR_FALLBACK_BITWISE);
61 }
62