/* 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_revoke(struct key *key);

  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 */