1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* user-type.h: User-defined key type
3 *
4 * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #ifndef _KEYS_USER_TYPE_H
9 #define _KEYS_USER_TYPE_H
10
11 #include <linux/key.h>
12 #include <linux/rcupdate.h>
13
14 #ifdef CONFIG_KEYS
15
16 /*****************************************************************************/
17 /*
18 * the payload for a key of type "user" or "logon"
19 * - once filled in and attached to a key:
20 * - the payload struct is invariant may not be changed, only replaced
21 * - the payload must be read with RCU procedures or with the key semaphore
22 * held
23 * - the payload may only be replaced with the key semaphore write-locked
24 * - the key's data length is the size of the actual data, not including the
25 * payload wrapper
26 */
27 struct user_key_payload {
28 struct rcu_head rcu; /* RCU destructor */
29 unsigned short datalen; /* length of this data */
30 char data[] __aligned(__alignof__(u64)); /* actual data */
31 };
32
33 extern struct key_type key_type_user;
34 extern struct key_type key_type_logon;
35
36 struct key_preparsed_payload;
37
38 extern int user_preparse(struct key_preparsed_payload *prep);
39 extern void user_free_preparse(struct key_preparsed_payload *prep);
40 extern int user_update(struct key *key, struct key_preparsed_payload *prep);
41 extern void user_revoke(struct key *key);
42 extern void user_destroy(struct key *key);
43 extern void user_describe(const struct key *user, struct seq_file *m);
44 extern long user_read(const struct key *key, char *buffer, size_t buflen);
45
46 static inline const struct user_key_payload *user_key_payload_rcu(const struct key *key)
47 {
48 return (struct user_key_payload *)dereference_key_rcu(key);
49 }
50
51 static inline struct user_key_payload *user_key_payload_locked(const struct key *key)
52 {
53 return (struct user_key_payload *)dereference_key_locked((struct key *)key);
54 }
55
56 #endif /* CONFIG_KEYS */
57
58 #endif /* _KEYS_USER_TYPE_H */
59
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