xref: /linux/include/linux/posix_acl.h (revision 84b9b44b) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3   File: linux/posix_acl.h
4 
5   (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
6 */
7 
8 
9 #ifndef __LINUX_POSIX_ACL_H
10 #define __LINUX_POSIX_ACL_H
11 
12 #include <linux/bug.h>
13 #include <linux/slab.h>
14 #include <linux/rcupdate.h>
15 #include <linux/refcount.h>
16 #include <uapi/linux/posix_acl.h>
17 
18 struct user_namespace;
19 
20 struct posix_acl_entry {
21 	short			e_tag;
22 	unsigned short		e_perm;
23 	union {
24 		kuid_t		e_uid;
25 		kgid_t		e_gid;
26 	};
27 };
28 
29 struct posix_acl {
30 	refcount_t		a_refcount;
31 	struct rcu_head		a_rcu;
32 	unsigned int		a_count;
33 	struct posix_acl_entry	a_entries[];
34 };
35 
36 #define FOREACH_ACL_ENTRY(pa, acl, pe) \
37 	for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
38 
39 
40 /*
41  * Duplicate an ACL handle.
42  */
43 static inline struct posix_acl *
44 posix_acl_dup(struct posix_acl *acl)
45 {
46 	if (acl)
47 		refcount_inc(&acl->a_refcount);
48 	return acl;
49 }
50 
51 /*
52  * Free an ACL handle.
53  */
54 static inline void
55 posix_acl_release(struct posix_acl *acl)
56 {
57 	if (acl && refcount_dec_and_test(&acl->a_refcount))
58 		kfree_rcu(acl, a_rcu);
59 }
60 
61 
62 /* posix_acl.c */
63 
64 extern void posix_acl_init(struct posix_acl *, int);
65 extern struct posix_acl *posix_acl_alloc(int, gfp_t);
66 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
67 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
68 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
69 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
70 
71 extern struct posix_acl *get_posix_acl(struct inode *, int);
72 int set_posix_acl(struct mnt_idmap *, struct dentry *, int,
73 		  struct posix_acl *);
74 
75 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
76 struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags);
77 
78 #ifdef CONFIG_FS_POSIX_ACL
79 int posix_acl_chmod(struct mnt_idmap *, struct dentry *, umode_t);
80 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
81 		struct posix_acl **);
82 int posix_acl_update_mode(struct mnt_idmap *, struct inode *, umode_t *,
83 			  struct posix_acl **);
84 
85 int simple_set_acl(struct mnt_idmap *, struct dentry *,
86 		   struct posix_acl *, int);
87 extern int simple_acl_create(struct inode *, struct inode *);
88 
89 struct posix_acl *get_cached_acl(struct inode *inode, int type);
90 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
91 void forget_cached_acl(struct inode *inode, int type);
92 void forget_all_cached_acls(struct inode *inode);
93 int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
94 int posix_acl_permission(struct mnt_idmap *, struct inode *,
95 			 const struct posix_acl *, int);
96 
97 static inline void cache_no_acl(struct inode *inode)
98 {
99 	inode->i_acl = NULL;
100 	inode->i_default_acl = NULL;
101 }
102 
103 int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
104 		const char *acl_name, struct posix_acl *kacl);
105 struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
106 			      struct dentry *dentry, const char *acl_name);
107 int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
108 		   const char *acl_name);
109 int posix_acl_listxattr(struct inode *inode, char **buffer,
110 			ssize_t *remaining_size);
111 #else
112 static inline int posix_acl_chmod(struct mnt_idmap *idmap,
113 				  struct dentry *dentry, umode_t mode)
114 {
115 	return 0;
116 }
117 
118 #define simple_set_acl		NULL
119 
120 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
121 {
122 	return 0;
123 }
124 static inline void cache_no_acl(struct inode *inode)
125 {
126 }
127 
128 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
129 		struct posix_acl **default_acl, struct posix_acl **acl)
130 {
131 	*default_acl = *acl = NULL;
132 	return 0;
133 }
134 
135 static inline void forget_all_cached_acls(struct inode *inode)
136 {
137 }
138 
139 static inline int vfs_set_acl(struct mnt_idmap *idmap,
140 			      struct dentry *dentry, const char *name,
141 			      struct posix_acl *acl)
142 {
143 	return -EOPNOTSUPP;
144 }
145 
146 static inline struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
147 					    struct dentry *dentry,
148 					    const char *acl_name)
149 {
150 	return ERR_PTR(-EOPNOTSUPP);
151 }
152 
153 static inline int vfs_remove_acl(struct mnt_idmap *idmap,
154 				 struct dentry *dentry, const char *acl_name)
155 {
156 	return -EOPNOTSUPP;
157 }
158 static inline int posix_acl_listxattr(struct inode *inode, char **buffer,
159 				      ssize_t *remaining_size)
160 {
161 	return 0;
162 }
163 #endif /* CONFIG_FS_POSIX_ACL */
164 
165 struct posix_acl *get_inode_acl(struct inode *inode, int type);
166 
167 #endif  /* __LINUX_POSIX_ACL_H */
168