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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
Andreas Gruenbacher97d79292015-12-02 14:44:35 +010012#include <uapi/linux/xattr.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/posix_acl.h>
14
Linus Torvalds1da177e2005-04-16 15:20:36 -070015/* Supported ACL a_version fields */
16#define POSIX_ACL_XATTR_VERSION 0x0002
17
Linus Torvalds1da177e2005-04-16 15:20:36 -070018/* An undefined entry e_id value */
19#define ACL_UNDEFINED_ID (-1)
20
21typedef struct {
Christoph Hellwigf9fd27a2005-06-23 00:10:19 -070022 __le16 e_tag;
23 __le16 e_perm;
24 __le32 e_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025} posix_acl_xattr_entry;
26
27typedef struct {
Christoph Hellwigf9fd27a2005-06-23 00:10:19 -070028 __le32 a_version;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 posix_acl_xattr_entry a_entries[0];
30} posix_acl_xattr_header;
31
32
33static inline size_t
34posix_acl_xattr_size(int count)
35{
36 return (sizeof(posix_acl_xattr_header) +
37 (count * sizeof(posix_acl_xattr_entry)));
38}
39
40static inline int
41posix_acl_xattr_count(size_t size)
42{
43 if (size < sizeof(posix_acl_xattr_header))
44 return -1;
45 size -= sizeof(posix_acl_xattr_header);
46 if (size % sizeof(posix_acl_xattr_entry))
47 return -1;
48 return size / sizeof(posix_acl_xattr_entry);
49}
50
Eric W. Biederman2f6f0652012-02-07 18:52:57 -080051#ifdef CONFIG_FS_POSIX_ACL
52void posix_acl_fix_xattr_from_user(void *value, size_t size);
53void posix_acl_fix_xattr_to_user(void *value, size_t size);
54#else
55static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
56{
57}
58static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
59{
60}
61#endif
62
Eric W. Biederman5f3a4a22012-09-10 20:17:44 -070063struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
64 const void *value, size_t size);
65int posix_acl_to_xattr(struct user_namespace *user_ns,
66 const struct posix_acl *acl, void *buffer, size_t size);
Christoph Hellwig9a59f452005-06-23 00:10:19 -070067
Christoph Hellwig2aeccbe2013-12-20 05:16:40 -080068extern const struct xattr_handler posix_acl_access_xattr_handler;
69extern const struct xattr_handler posix_acl_default_xattr_handler;
70
Linus Torvalds1da177e2005-04-16 15:20:36 -070071#endif /* _POSIX_ACL_XATTR_H */