1/*
2  File: linux/posix_acl.h
3
4  (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
5*/
6
7
8#ifndef __LINUX_POSIX_ACL_H
9#define __LINUX_POSIX_ACL_H
10
11#include <linux/bug.h>
12#include <linux/slab.h>
13#include <linux/rcupdate.h>
14
15#define ACL_UNDEFINED_ID	(-1)
16
17/* a_type field in acl_user_posix_entry_t */
18#define ACL_TYPE_ACCESS		(0x8000)
19#define ACL_TYPE_DEFAULT	(0x4000)
20
21/* e_tag entry in struct posix_acl_entry */
22#define ACL_USER_OBJ		(0x01)
23#define ACL_USER		(0x02)
24#define ACL_GROUP_OBJ		(0x04)
25#define ACL_GROUP		(0x08)
26#define ACL_MASK		(0x10)
27#define ACL_OTHER		(0x20)
28
29/* permissions in the e_perm field */
30#define ACL_READ		(0x04)
31#define ACL_WRITE		(0x02)
32#define ACL_EXECUTE		(0x01)
33//#define ACL_ADD		(0x08)
34//#define ACL_DELETE		(0x10)
35
36struct posix_acl_entry {
37	short			e_tag;
38	unsigned short		e_perm;
39	union {
40		kuid_t		e_uid;
41		kgid_t		e_gid;
42	};
43};
44
45struct posix_acl {
46	union {
47		atomic_t		a_refcount;
48		struct rcu_head		a_rcu;
49	};
50	unsigned int		a_count;
51	struct posix_acl_entry	a_entries[0];
52};
53
54#define FOREACH_ACL_ENTRY(pa, acl, pe) \
55	for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
56
57
58/*
59 * Duplicate an ACL handle.
60 */
61static inline struct posix_acl *
62posix_acl_dup(struct posix_acl *acl)
63{
64	if (acl)
65		atomic_inc(&acl->a_refcount);
66	return acl;
67}
68
69/*
70 * Free an ACL handle.
71 */
72static inline void
73posix_acl_release(struct posix_acl *acl)
74{
75	if (acl && atomic_dec_and_test(&acl->a_refcount))
76		kfree_rcu(acl, a_rcu);
77}
78
79
80/* posix_acl.c */
81
82extern void posix_acl_init(struct posix_acl *, int);
83extern struct posix_acl *posix_acl_alloc(int, gfp_t);
84extern int posix_acl_valid(const struct posix_acl *);
85extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
86extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
87extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
88extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
89extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
90
91extern struct posix_acl *get_posix_acl(struct inode *, int);
92extern int set_posix_acl(struct inode *, int, struct posix_acl *);
93
94#ifdef CONFIG_FS_POSIX_ACL
95extern int posix_acl_chmod(struct inode *, umode_t);
96extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
97		struct posix_acl **);
98
99extern int simple_set_acl(struct inode *, struct posix_acl *, int);
100extern int simple_acl_create(struct inode *, struct inode *);
101
102struct posix_acl **acl_by_type(struct inode *inode, int type);
103struct posix_acl *get_cached_acl(struct inode *inode, int type);
104struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
105void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
106void forget_cached_acl(struct inode *inode, int type);
107void forget_all_cached_acls(struct inode *inode);
108
109static inline void cache_no_acl(struct inode *inode)
110{
111	inode->i_acl = NULL;
112	inode->i_default_acl = NULL;
113}
114#else
115static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
116{
117	return 0;
118}
119
120#define simple_set_acl		NULL
121
122static inline int simple_acl_create(struct inode *dir, struct inode *inode)
123{
124	return 0;
125}
126static inline void cache_no_acl(struct inode *inode)
127{
128}
129
130static inline int posix_acl_create(struct inode *inode, umode_t *mode,
131		struct posix_acl **default_acl, struct posix_acl **acl)
132{
133	*default_acl = *acl = NULL;
134	return 0;
135}
136
137static inline void forget_all_cached_acls(struct inode *inode)
138{
139}
140#endif /* CONFIG_FS_POSIX_ACL */
141
142struct posix_acl *get_acl(struct inode *inode, int type);
143
144#endif  /* __LINUX_POSIX_ACL_H */
145