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	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 */
43static inline struct posix_acl *
44posix_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 */
54static inline void
55posix_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
64extern void posix_acl_init(struct posix_acl *, int);
65extern struct posix_acl *posix_acl_alloc(int, gfp_t);
66extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
67extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
68extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
69extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
70
71extern struct posix_acl *get_posix_acl(struct inode *, int);
72int set_posix_acl(struct mnt_idmap *, struct dentry *, int,
73		  struct posix_acl *);
74
75struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
76struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags);
77
78#ifdef CONFIG_FS_POSIX_ACL
79int posix_acl_chmod(struct mnt_idmap *, struct dentry *, umode_t);
80extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
81		struct posix_acl **);
82int posix_acl_update_mode(struct mnt_idmap *, struct inode *, umode_t *,
83			  struct posix_acl **);
84
85int simple_set_acl(struct mnt_idmap *, struct dentry *,
86		   struct posix_acl *, int);
87extern int simple_acl_create(struct inode *, struct inode *);
88
89struct posix_acl *get_cached_acl(struct inode *inode, int type);
90void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
91void forget_cached_acl(struct inode *inode, int type);
92void forget_all_cached_acls(struct inode *inode);
93int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
94int posix_acl_permission(struct mnt_idmap *, struct inode *,
95			 const struct posix_acl *, int);
96
97static inline void cache_no_acl(struct inode *inode)
98{
99	inode->i_acl = NULL;
100	inode->i_default_acl = NULL;
101}
102
103int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
104		const char *acl_name, struct posix_acl *kacl);
105struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
106			      struct dentry *dentry, const char *acl_name);
107int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
108		   const char *acl_name);
109int posix_acl_listxattr(struct inode *inode, char **buffer,
110			ssize_t *remaining_size);
111#else
112static 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
120static inline int simple_acl_create(struct inode *dir, struct inode *inode)
121{
122	return 0;
123}
124static inline void cache_no_acl(struct inode *inode)
125{
126}
127
128static 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
135static inline void forget_all_cached_acls(struct inode *inode)
136{
137}
138
139static 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
146static 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
153static inline int vfs_remove_acl(struct mnt_idmap *idmap,
154				 struct dentry *dentry, const char *acl_name)
155{
156	return -EOPNOTSUPP;
157}
158static 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
165struct posix_acl *get_inode_acl(struct inode *inode, int type);
166
167#endif  /* __LINUX_POSIX_ACL_H */
168