/* user-type.h: User-defined key type * * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _KEYS_USER_TYPE_H#define _KEYS_USER_TYPE_H #include <linux/key.h>#include <linux/rcupdate.h> /*****************************************************************************//* * the payload for a key of type "user" * - once filled in and attached to a key: *   - the payload struct is invariant may not be changed, only replaced *   - the payload must be read with RCU procedures or with the key semaphore *     held *   - the payload may only be replaced with the key semaphore write-locked * - the key's data length is the size of the actual data, not including the *   payload wrapper */struct user_key_payload {	struct rcu_head	rcu;		/* RCU destructor */	unsigned short	datalen;	/* length of this data */	char		data[0];	/* actual data */}; extern struct key_type key_type_user; extern int user_instantiate(struct key *key, const void *data, size_t datalen);extern int user_update(struct key *key, const void *data, size_t datalen);extern int user_match(const struct key *key, const void *criterion);extern void user_destroy(struct key *key);extern void user_describe(const struct key *user, struct seq_file *m);extern long user_read(const struct key *key,		      char __user *buffer, size_t buflen);  #endif /* _KEYS_USER_TYPE_H */