1 /* user-type.h: User-defined key type 2 * 3 * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #ifndef _KEYS_USER_TYPE_H 13 #define _KEYS_USER_TYPE_H 14 15 #include <linux/key.h> 16 #include <linux/rcupdate.h> 17 18 /*****************************************************************************/ 19 /* 20 * the payload for a key of type "user" 21 * - once filled in and attached to a key: 22 * - the payload struct is invariant may not be changed, only replaced 23 * - the payload must be read with RCU procedures or with the key semaphore 24 * held 25 * - the payload may only be replaced with the key semaphore write-locked 26 * - the key's data length is the size of the actual data, not including the 27 * payload wrapper 28 */ 29 struct user_key_payload { 30 struct rcu_head rcu; /* RCU destructor */ 31 unsigned short datalen; /* length of this data */ 32 char data[0]; /* actual data */ 33 }; 34 35 extern struct key_type key_type_user; 36 37 extern int user_instantiate(struct key *key, const void *data, size_t datalen); 38 extern int user_update(struct key *key, const void *data, size_t datalen); 39 extern int user_match(const struct key *key, const void *criterion); 40 extern void user_destroy(struct key *key); 41 extern void user_describe(const struct key *user, struct seq_file *m); 42 extern long user_read(const struct key *key, 43 char __user *buffer, size_t buflen); 44 45 46 #endif /* _KEYS_USER_TYPE_H */ 47