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
18struct user_namespace;
19
20struct 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
29struct 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};
38static_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 */
48static inline struct posix_acl *
49posix_acl_dup(struct posix_acl *acl)
50{
51 if (acl)
52 refcount_inc(r: &acl->a_refcount);
53 return acl;
54}
55
56/*
57 * Free an ACL handle.
58 */
59static inline void
60posix_acl_release(struct posix_acl *acl)
61{
62 if (acl && refcount_dec_and_test(r: &acl->a_refcount))
63 kfree_rcu(acl, a_rcu);
64}
65
66
67/* posix_acl.c */
68
69extern void posix_acl_init(struct posix_acl *, int);
70extern struct posix_acl *posix_acl_alloc(unsigned int count, gfp_t flags);
71extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
72extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
73extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
74extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
75
76extern struct posix_acl *get_posix_acl(struct inode *, int);
77int set_posix_acl(struct mnt_idmap *, struct dentry *, int,
78 struct posix_acl *);
79
80struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
81struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags);
82
83#ifdef CONFIG_FS_POSIX_ACL
84int posix_acl_chmod(struct mnt_idmap *, struct dentry *, umode_t);
85extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
86 struct posix_acl **);
87int posix_acl_update_mode(struct mnt_idmap *, struct inode *, umode_t *,
88 struct posix_acl **);
89
90int simple_set_acl(struct mnt_idmap *, struct dentry *,
91 struct posix_acl *, int);
92extern int simple_acl_create(struct inode *, struct inode *);
93
94struct posix_acl *get_cached_acl(struct inode *inode, int type);
95void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
96void forget_cached_acl(struct inode *inode, int type);
97void forget_all_cached_acls(struct inode *inode);
98int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
99int posix_acl_permission(struct mnt_idmap *, struct inode *,
100 const struct posix_acl *, int);
101
102static inline void cache_no_acl(struct inode *inode)
103{
104 inode->i_acl = NULL;
105 inode->i_default_acl = NULL;
106}
107
108int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
109 const char *acl_name, struct posix_acl *kacl);
110struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
111 struct dentry *dentry, const char *acl_name);
112int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
113 const char *acl_name);
114int posix_acl_listxattr(struct inode *inode, char **buffer,
115 ssize_t *remaining_size);
116#else
117static 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
125static inline int simple_acl_create(struct inode *dir, struct inode *inode)
126{
127 return 0;
128}
129static inline void cache_no_acl(struct inode *inode)
130{
131}
132
133static 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
140static inline void forget_all_cached_acls(struct inode *inode)
141{
142}
143
144static 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
151static 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
158static inline int vfs_remove_acl(struct mnt_idmap *idmap,
159 struct dentry *dentry, const char *acl_name)
160{
161 return -EOPNOTSUPP;
162}
163static 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
170struct posix_acl *get_inode_acl(struct inode *inode, int type);
171
172#endif /* __LINUX_POSIX_ACL_H */
173