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 /* New members MUST be added within the struct_group() macro below. */
31 struct_group_tagged(posix_acl_hdr, hdr,
32 refcount_t a_refcount;
33 unsigned int a_count;
34 struct rcu_head a_rcu;
35 );
36 struct posix_acl_entry a_entries[] __counted_by(a_count);
37 };
38 static_assert(offsetof(struct posix_acl, a_entries) == sizeof(struct posix_acl_hdr),
39 "struct member likely outside of struct_group_tagged()");
40
41 #define FOREACH_ACL_ENTRY(pa, acl, pe) \
42 for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
43
44
45 /*
46 * Duplicate an ACL handle.
47 */
48 static inline struct posix_acl *
posix_acl_dup(struct posix_acl * acl)49 posix_acl_dup(struct posix_acl *acl)
50 {
51 if (acl)
52 refcount_inc(&acl->a_refcount);
53 return acl;
54 }
55
56 /*
57 * Free an ACL handle.
58 */
59 static inline void
posix_acl_release(struct posix_acl * acl)60 posix_acl_release(struct posix_acl *acl)
61 {
62 if (acl && refcount_dec_and_test(&acl->a_refcount))
63 kfree_rcu(acl, a_rcu);
64 }
65
66
67 /* posix_acl.c */
68
69 extern void posix_acl_init(struct posix_acl *, int);
70 extern struct posix_acl *posix_acl_alloc(unsigned int count, gfp_t flags);
71 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
72 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
73 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
74 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
75
76 extern struct posix_acl *get_posix_acl(struct inode *, int);
77 int set_posix_acl(struct mnt_idmap *, struct dentry *, int,
78 struct posix_acl *);
79
80 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
81 struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags);
82
83 #ifdef CONFIG_FS_POSIX_ACL
84 int posix_acl_chmod(struct mnt_idmap *, struct dentry *, umode_t);
85 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
86 struct posix_acl **);
87 int posix_acl_update_mode(struct mnt_idmap *, struct inode *, umode_t *,
88 struct posix_acl **);
89
90 int simple_set_acl(struct mnt_idmap *, struct dentry *,
91 struct posix_acl *, int);
92 extern int simple_acl_create(struct inode *, struct inode *);
93
94 struct posix_acl *get_cached_acl(struct inode *inode, int type);
95 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
96 void forget_cached_acl(struct inode *inode, int type);
97 void forget_all_cached_acls(struct inode *inode);
98 int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
99 int posix_acl_permission(struct mnt_idmap *, struct inode *,
100 const struct posix_acl *, int);
101
cache_no_acl(struct inode * inode)102 static inline void cache_no_acl(struct inode *inode)
103 {
104 inode->i_acl = NULL;
105 inode->i_default_acl = NULL;
106 }
107
108 int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
109 const char *acl_name, struct posix_acl *kacl);
110 struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
111 struct dentry *dentry, const char *acl_name);
112 int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
113 const char *acl_name);
114 int posix_acl_listxattr(struct inode *inode, char **buffer,
115 ssize_t *remaining_size);
116 #else
posix_acl_chmod(struct mnt_idmap * idmap,struct dentry * dentry,umode_t mode)117 static inline int posix_acl_chmod(struct mnt_idmap *idmap,
118 struct dentry *dentry, umode_t mode)
119 {
120 return 0;
121 }
122
123 #define simple_set_acl NULL
124
simple_acl_create(struct inode * dir,struct inode * inode)125 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
126 {
127 return 0;
128 }
cache_no_acl(struct inode * inode)129 static inline void cache_no_acl(struct inode *inode)
130 {
131 }
132
posix_acl_create(struct inode * inode,umode_t * mode,struct posix_acl ** default_acl,struct posix_acl ** acl)133 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
134 struct posix_acl **default_acl, struct posix_acl **acl)
135 {
136 *default_acl = *acl = NULL;
137 return 0;
138 }
139
forget_all_cached_acls(struct inode * inode)140 static inline void forget_all_cached_acls(struct inode *inode)
141 {
142 }
143
vfs_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * name,struct posix_acl * acl)144 static inline int vfs_set_acl(struct mnt_idmap *idmap,
145 struct dentry *dentry, const char *name,
146 struct posix_acl *acl)
147 {
148 return -EOPNOTSUPP;
149 }
150
vfs_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)151 static inline struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
152 struct dentry *dentry,
153 const char *acl_name)
154 {
155 return ERR_PTR(-EOPNOTSUPP);
156 }
157
vfs_remove_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)158 static inline int vfs_remove_acl(struct mnt_idmap *idmap,
159 struct dentry *dentry, const char *acl_name)
160 {
161 return -EOPNOTSUPP;
162 }
posix_acl_listxattr(struct inode * inode,char ** buffer,ssize_t * remaining_size)163 static inline int posix_acl_listxattr(struct inode *inode, char **buffer,
164 ssize_t *remaining_size)
165 {
166 return 0;
167 }
168 #endif /* CONFIG_FS_POSIX_ACL */
169
170 struct posix_acl *get_inode_acl(struct inode *inode, int type);
171
172 #endif /* __LINUX_POSIX_ACL_H */
173