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
36 struct 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
45 struct 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 */
61 static inline struct posix_acl *
posix_acl_dup(struct posix_acl * acl)62 posix_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 */
72 static inline void
posix_acl_release(struct posix_acl * acl)73 posix_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
82 extern void posix_acl_init(struct posix_acl *, int);
83 extern struct posix_acl *posix_acl_alloc(int, gfp_t);
84 extern int posix_acl_valid(const struct posix_acl *);
85 extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
86 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
87 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
88 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
89 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
90
91 extern struct posix_acl *get_posix_acl(struct inode *, int);
92 extern int set_posix_acl(struct inode *, int, struct posix_acl *);
93
94 #ifdef CONFIG_FS_POSIX_ACL
95 extern int posix_acl_chmod(struct inode *, umode_t);
96 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
97 struct posix_acl **);
98 extern int posix_acl_update_mode(struct inode *, umode_t *, struct posix_acl **);
99
100 extern int simple_set_acl(struct inode *, struct posix_acl *, int);
101 extern int simple_acl_create(struct inode *, struct inode *);
102
103 struct posix_acl **acl_by_type(struct inode *inode, int type);
104 struct posix_acl *get_cached_acl(struct inode *inode, int type);
105 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
106 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
107 void forget_cached_acl(struct inode *inode, int type);
108 void forget_all_cached_acls(struct inode *inode);
109
cache_no_acl(struct inode * inode)110 static inline void cache_no_acl(struct inode *inode)
111 {
112 inode->i_acl = NULL;
113 inode->i_default_acl = NULL;
114 }
115 #else
posix_acl_chmod(struct inode * inode,umode_t mode)116 static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
117 {
118 return 0;
119 }
120
121 #define simple_set_acl NULL
122
simple_acl_create(struct inode * dir,struct inode * inode)123 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
124 {
125 return 0;
126 }
cache_no_acl(struct inode * inode)127 static inline void cache_no_acl(struct inode *inode)
128 {
129 }
130
posix_acl_create(struct inode * inode,umode_t * mode,struct posix_acl ** default_acl,struct posix_acl ** acl)131 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
132 struct posix_acl **default_acl, struct posix_acl **acl)
133 {
134 *default_acl = *acl = NULL;
135 return 0;
136 }
137
forget_all_cached_acls(struct inode * inode)138 static inline void forget_all_cached_acls(struct inode *inode)
139 {
140 }
141 #endif /* CONFIG_FS_POSIX_ACL */
142
143 struct posix_acl *get_acl(struct inode *inode, int type);
144
145 #endif /* __LINUX_POSIX_ACL_H */
146