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 <linux/mm.h> |
19 | #include <linux/user_namespace.h> |
20 | #include <uapi/linux/xattr.h> |
21 | |
22 | struct inode; |
23 | struct dentry; |
24 | |
25 | static inline bool is_posix_acl_xattr(const char *name) |
26 | { |
27 | return (strcmp(name, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || |
28 | (strcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0); |
29 | } |
30 | |
31 | /* |
32 | * struct xattr_handler: When @name is set, match attributes with exactly that |
33 | * name. When @prefix is set instead, match attributes with that prefix and |
34 | * with a non-empty suffix. |
35 | */ |
36 | struct xattr_handler { |
37 | const char *name; |
38 | const char *prefix; |
39 | int flags; /* fs private flags */ |
40 | bool (*list)(struct dentry *dentry); |
41 | int (*get)(const struct xattr_handler *, struct dentry *dentry, |
42 | struct inode *inode, const char *name, void *buffer, |
43 | size_t size); |
44 | int (*set)(const struct xattr_handler *, |
45 | struct mnt_idmap *idmap, struct dentry *dentry, |
46 | struct inode *inode, const char *name, const void *buffer, |
47 | size_t size, int flags); |
48 | }; |
49 | |
50 | /** |
51 | * xattr_handler_can_list - check whether xattr can be listed |
52 | * @handler: handler for this type of xattr |
53 | * @dentry: dentry whose inode xattr to list |
54 | * |
55 | * Determine whether the xattr associated with @dentry can be listed given |
56 | * @handler. |
57 | * |
58 | * Return: true if xattr can be listed, false if not. |
59 | */ |
60 | static inline bool xattr_handler_can_list(const struct xattr_handler *handler, |
61 | struct dentry *dentry) |
62 | { |
63 | return handler && (!handler->list || handler->list(dentry)); |
64 | } |
65 | |
66 | const char *xattr_full_name(const struct xattr_handler *, const char *); |
67 | |
68 | struct xattr { |
69 | const char *name; |
70 | void *value; |
71 | size_t value_len; |
72 | }; |
73 | |
74 | ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); |
75 | ssize_t vfs_getxattr(struct mnt_idmap *, struct dentry *, const char *, |
76 | void *, size_t); |
77 | ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); |
78 | int __vfs_setxattr(struct mnt_idmap *, struct dentry *, struct inode *, |
79 | const char *, const void *, size_t, int); |
80 | int __vfs_setxattr_noperm(struct mnt_idmap *, struct dentry *, |
81 | const char *, const void *, size_t, int); |
82 | int __vfs_setxattr_locked(struct mnt_idmap *, struct dentry *, |
83 | const char *, const void *, size_t, int, |
84 | struct inode **); |
85 | int vfs_setxattr(struct mnt_idmap *, struct dentry *, const char *, |
86 | const void *, size_t, int); |
87 | int __vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *); |
88 | int __vfs_removexattr_locked(struct mnt_idmap *, struct dentry *, |
89 | const char *, struct inode **); |
90 | int vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *); |
91 | |
92 | ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size); |
93 | int vfs_getxattr_alloc(struct mnt_idmap *idmap, |
94 | struct dentry *dentry, const char *name, |
95 | char **xattr_value, size_t size, gfp_t flags); |
96 | |
97 | int xattr_supports_user_prefix(struct inode *inode); |
98 | |
99 | static inline const char *xattr_prefix(const struct xattr_handler *handler) |
100 | { |
101 | return handler->prefix ?: handler->name; |
102 | } |
103 | |
104 | struct simple_xattrs { |
105 | struct rb_root rb_root; |
106 | rwlock_t lock; |
107 | }; |
108 | |
109 | struct simple_xattr { |
110 | struct rb_node rb_node; |
111 | char *name; |
112 | size_t size; |
113 | char value[]; |
114 | }; |
115 | |
116 | void simple_xattrs_init(struct simple_xattrs *xattrs); |
117 | void simple_xattrs_free(struct simple_xattrs *xattrs, size_t *freed_space); |
118 | size_t simple_xattr_space(const char *name, size_t size); |
119 | struct simple_xattr *simple_xattr_alloc(const void *value, size_t size); |
120 | void simple_xattr_free(struct simple_xattr *xattr); |
121 | int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, |
122 | void *buffer, size_t size); |
123 | struct simple_xattr *simple_xattr_set(struct simple_xattrs *xattrs, |
124 | const char *name, const void *value, |
125 | size_t size, int flags); |
126 | ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, |
127 | char *buffer, size_t size); |
128 | void simple_xattr_add(struct simple_xattrs *xattrs, |
129 | struct simple_xattr *new_xattr); |
130 | int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name); |
131 | |
132 | #endif /* _LINUX_XATTR_H */ |
133 | |