include/linux/key-ui.h

   1 /* key-ui.h: key userspace interface stuff for use by keyfs
   2  *
   3  * Copyright (C) 2004 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 _LINUX_KEY_UI_H
  13 #define _LINUX_KEY_UI_H
  14
  15 #include <linux/key.h>
  16
  17 /* the key tree */
  18 extern struct rb_root key_serial_tree;
  19 extern spinlock_t key_serial_lock;
  20
  21 /* required permissions */
  22 #define KEY_VIEW        0x01    /* require permission to view attributes */
  23 #define KEY_READ        0x02    /* require permission to read content */
  24 #define KEY_WRITE       0x04    /* require permission to update / modify */
  25 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
  26 #define KEY_LINK        0x10    /* require permission to link */
  27 #define KEY_ALL         0x1f    /* all the above permissions */
  28
  29 /*
  30  * the keyring payload contains a list of the keys to which the keyring is
  31  * subscribed
  32  */
  33 struct keyring_list {
  34         unsigned        maxkeys;        /* max keys this list can hold */
  35         unsigned        nkeys;          /* number of keys currently held */
  36         struct key      *keys[0];
  37 };
  38
  39
  40 /*
  41  * check to see whether permission is granted to use a key in the desired way
  42  */
  43 static inline int key_permission(const struct key *key, key_perm_t perm)
  44 {
  45         key_perm_t kperm;
  46
  47         if (key->uid == current->fsuid)
  48                 kperm = key->perm >> 16;
  49         else if (key->gid != -1 &&
  50                  key->perm & KEY_GRP_ALL &&
  51                  in_group_p(key->gid)
  52                  )
  53                 kperm = key->perm >> 8;
  54         else
  55                 kperm = key->perm;
  56
  57         kperm = kperm & perm & KEY_ALL;
  58
  59         return kperm == perm;
  60 }
  61
  62 /*
  63  * check to see whether permission is granted to use a key in at least one of
  64  * the desired ways
  65  */
  66 static inline int key_any_permission(const struct key *key, key_perm_t perm)
  67 {
  68         key_perm_t kperm;
  69
  70         if (key->uid == current->fsuid)
  71                 kperm = key->perm >> 16;
  72         else if (key->gid != -1 &&
  73                  key->perm & KEY_GRP_ALL &&
  74                  in_group_p(key->gid)
  75                  )
  76                 kperm = key->perm >> 8;
  77         else
  78                 kperm = key->perm;
  79
  80         kperm = kperm & perm & KEY_ALL;
  81
  82         return kperm != 0;
  83 }
  84
  85
  86 extern struct key *lookup_user_key(key_serial_t id, int create, int part,
  87                                    key_perm_t perm);
  88
  89 extern long join_session_keyring(const char *name);
  90
  91 extern struct key_type *key_type_lookup(const char *type);
  92 extern void key_type_put(struct key_type *ktype);
  93
  94 #define key_negative_timeout    60      /* default timeout on a negative key's existence */
  95
  96
  97 #endif /* _LINUX_KEY_UI_H */