LXR linux/include/keys/user-type.h

   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#ifdef CONFIG_KEYS
  19
  20/*****************************************************************************/
  21/*
  22 * the payload for a key of type "user" or "logon"
  23 * - once filled in and attached to a key:
  24 *   - the payload struct is invariant may not be changed, only replaced
  25 *   - the payload must be read with RCU procedures or with the key semaphore
  26 *     held
  27 *   - the payload may only be replaced with the key semaphore write-locked
  28 * - the key's data length is the size of the actual data, not including the
  29 *   payload wrapper
  30 */
  31struct user_key_payload {
  32        struct rcu_head rcu;            /* RCU destructor */
  33        unsigned short  datalen;        /* length of this data */
  34        char            data[0];        /* actual data */
  35};
  36
  37extern struct key_type key_type_user;
  38extern struct key_type key_type_logon;
  39
  40struct key_preparsed_payload;
  41
  42extern int user_preparse(struct key_preparsed_payload *prep);
  43extern void user_free_preparse(struct key_preparsed_payload *prep);
  44extern int user_update(struct key *key, struct key_preparsed_payload *prep);
  45extern void user_revoke(struct key *key);
  46extern void user_destroy(struct key *key);
  47extern void user_describe(const struct key *user, struct seq_file *m);
  48extern long user_read(const struct key *key,
  49                      char __user *buffer, size_t buflen);
  50
  51static inline const struct user_key_payload *user_key_payload(const struct key *key)
  52{
  53        return (struct user_key_payload *)rcu_dereference_key(key);
  54}
  55
  56#endif /* CONFIG_KEYS */
  57
  58#endif /* _KEYS_USER_TYPE_H */
  59