1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 File: linux/posix_acl_xattr.h
4
5 Extended attribute system call representation of Access Control Lists.
6
7 Copyright (C) 2000 by Andreas Gruenbacher <a.gruenbacher@computer.org>
8 Copyright (C) 2002 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
9 */
10#ifndef _POSIX_ACL_XATTR_H
11#define _POSIX_ACL_XATTR_H
12
13#include <uapi/linux/xattr.h>
14#include <uapi/linux/posix_acl_xattr.h>
15#include <linux/posix_acl.h>
16
17static inline size_t
18posix_acl_xattr_size(int count)
19{
20 return (sizeof(struct posix_acl_xattr_header) +
21 (count * sizeof(struct posix_acl_xattr_entry)));
22}
23
24static inline int
25posix_acl_xattr_count(size_t size)
26{
27 if (size < sizeof(struct posix_acl_xattr_header))
28 return -1;
29 size -= sizeof(struct posix_acl_xattr_header);
30 if (size % sizeof(struct posix_acl_xattr_entry))
31 return -1;
32 return size / sizeof(struct posix_acl_xattr_entry);
33}
34
35#ifdef CONFIG_FS_POSIX_ACL
36struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
37 const void *value, size_t size);
38#else
39static inline struct posix_acl *
40posix_acl_from_xattr(struct user_namespace *user_ns, const void *value,
41 size_t size)
42{
43 return ERR_PTR(-EOPNOTSUPP);
44}
45#endif
46
47int posix_acl_to_xattr(struct user_namespace *user_ns,
48 const struct posix_acl *acl, void *buffer, size_t size);
49static inline const char *posix_acl_xattr_name(int type)
50{
51 switch (type) {
52 case ACL_TYPE_ACCESS:
53 return XATTR_NAME_POSIX_ACL_ACCESS;
54 case ACL_TYPE_DEFAULT:
55 return XATTR_NAME_POSIX_ACL_DEFAULT;
56 }
57
58 return "";
59}
60
61static inline int posix_acl_type(const char *name)
62{
63 if (strcmp(name, XATTR_NAME_POSIX_ACL_ACCESS) == 0)
64 return ACL_TYPE_ACCESS;
65 else if (strcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)
66 return ACL_TYPE_DEFAULT;
67
68 return -1;
69}
70
71/* These are legacy handlers. Don't use them for new code. */
72extern const struct xattr_handler nop_posix_acl_access;
73extern const struct xattr_handler nop_posix_acl_default;
74
75#endif /* _POSIX_ACL_XATTR_H */
76