1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 File: linux/xattr.h
4
5 Extended attributes handling.
6
7 Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
8 Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
9 Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
10*/
11#ifndef _LINUX_XATTR_H
12#define _LINUX_XATTR_H
13
14
15#include <linux/slab.h>
16#include <linux/types.h>
17#include <linux/spinlock.h>
18#include <uapi/linux/xattr.h>
19
20struct inode;
21struct dentry;
22
23/*
24 * struct xattr_handler: When @name is set, match attributes with exactly that
25 * name. When @prefix is set instead, match attributes with that prefix and
26 * with a non-empty suffix.
27 */
28struct xattr_handler {
29 const char *name;
30 const char *prefix;
31 int flags; /* fs private flags */
32 bool (*list)(struct dentry *dentry);
33 int (*get)(const struct xattr_handler *, struct dentry *dentry,
34 struct inode *inode, const char *name, void *buffer,
35 size_t size);
36 int (*set)(const struct xattr_handler *, struct dentry *dentry,
37 struct inode *inode, const char *name, const void *buffer,
38 size_t size, int flags);
39};
40
41const char *xattr_full_name(const struct xattr_handler *, const char *);
42
43struct xattr {
44 const char *name;
45 void *value;
46 size_t value_len;
47};
48
49ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t);
50ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
51ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
52int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int);
53int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
54int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
55int __vfs_removexattr(struct dentry *, const char *);
56int vfs_removexattr(struct dentry *, const char *);
57
58ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
59ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
60 char **xattr_value, size_t size, gfp_t flags);
61
62static inline const char *xattr_prefix(const struct xattr_handler *handler)
63{
64 return handler->prefix ?: handler->name;
65}
66
67struct simple_xattrs {
68 struct list_head head;
69 spinlock_t lock;
70};
71
72struct simple_xattr {
73 struct list_head list;
74 char *name;
75 size_t size;
76 char value[0];
77};
78
79/*
80 * initialize the simple_xattrs structure
81 */
82static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
83{
84 INIT_LIST_HEAD(&xattrs->head);
85 spin_lock_init(&xattrs->lock);
86}
87
88/*
89 * free all the xattrs
90 */
91static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
92{
93 struct simple_xattr *xattr, *node;
94
95 list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
96 kfree(xattr->name);
97 kfree(xattr);
98 }
99}
100
101struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
102int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
103 void *buffer, size_t size);
104int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
105 const void *value, size_t size, int flags);
106ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
107 size_t size);
108void simple_xattr_list_add(struct simple_xattrs *xattrs,
109 struct simple_xattr *new_xattr);
110
111#endif /* _LINUX_XATTR_H */
112