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 user_key_payload_rcu(const struct key * key)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 user_key_payload_locked(const struct key * key)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