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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 File: linux/posix_acl_xattr.h
3
4 Extended attribute system call representation of Access Control Lists.
5
6 Copyright (C) 2000 by Andreas Gruenbacher <a.gruenbacher@computer.org>
7 Copyright (C) 2002 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
8 */
9#ifndef _POSIX_ACL_XATTR_H
10#define _POSIX_ACL_XATTR_H
11
12#include <linux/posix_acl.h>
13
14/* Extended attribute names */
15#define POSIX_ACL_XATTR_ACCESS "system.posix_acl_access"
16#define POSIX_ACL_XATTR_DEFAULT "system.posix_acl_default"
17
18/* Supported ACL a_version fields */
19#define POSIX_ACL_XATTR_VERSION 0x0002
20
21
22/* An undefined entry e_id value */
23#define ACL_UNDEFINED_ID (-1)
24
25typedef struct {
Christoph Hellwigf9fd27a2005-06-23 00:10:19 -070026 __le16 e_tag;
27 __le16 e_perm;
28 __le32 e_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029} posix_acl_xattr_entry;
30
31typedef struct {
Christoph Hellwigf9fd27a2005-06-23 00:10:19 -070032 __le32 a_version;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 posix_acl_xattr_entry a_entries[0];
34} posix_acl_xattr_header;
35
36
37static inline size_t
38posix_acl_xattr_size(int count)
39{
40 return (sizeof(posix_acl_xattr_header) +
41 (count * sizeof(posix_acl_xattr_entry)));
42}
43
44static inline int
45posix_acl_xattr_count(size_t size)
46{
47 if (size < sizeof(posix_acl_xattr_header))
48 return -1;
49 size -= sizeof(posix_acl_xattr_header);
50 if (size % sizeof(posix_acl_xattr_entry))
51 return -1;
52 return size / sizeof(posix_acl_xattr_entry);
53}
54
Eric W. Biederman2f6f0652012-02-07 18:52:57 -080055#ifdef CONFIG_FS_POSIX_ACL
56void posix_acl_fix_xattr_from_user(void *value, size_t size);
57void posix_acl_fix_xattr_to_user(void *value, size_t size);
58#else
59static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
60{
61}
62static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
63{
64}
65#endif
66
Eric W. Biederman5f3a4a22012-09-10 20:17:44 -070067struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
68 const void *value, size_t size);
69int posix_acl_to_xattr(struct user_namespace *user_ns,
70 const struct posix_acl *acl, void *buffer, size_t size);
Christoph Hellwig9a59f452005-06-23 00:10:19 -070071
Christoph Hellwig2aeccbe2013-12-20 05:16:40 -080072extern const struct xattr_handler posix_acl_access_xattr_handler;
73extern const struct xattr_handler posix_acl_default_xattr_handler;
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075#endif /* _POSIX_ACL_XATTR_H */