LXR linux/security/keys/internal.h

   1/* internal.h: authentication token and access key management internal defs
   2 *
   3 * Copyright (C) 2003-5, 2007 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 _INTERNAL_H
  13#define _INTERNAL_H
  14
  15#include <linux/sched.h>
  16#include <linux/key-type.h>
  17
  18static inline __attribute__((format(printf, 1, 2)))
  19void no_printk(const char *fmt, ...)
  20{
  21}
  22
  23#ifdef __KDEBUG
  24#define kenter(FMT, ...) \
  25        printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  26#define kleave(FMT, ...) \
  27        printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  28#define kdebug(FMT, ...) \
  29        printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  30#else
  31#define kenter(FMT, ...) \
  32        no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  33#define kleave(FMT, ...) \
  34        no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  35#define kdebug(FMT, ...) \
  36        no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  37#endif
  38
  39extern struct key_type key_type_user;
  40
  41/*****************************************************************************/
  42/*
  43 * keep track of keys for a user
  44 * - this needs to be separate to user_struct to avoid a refcount-loop
  45 *   (user_struct pins some keyrings which pin this struct)
  46 * - this also keeps track of keys under request from userspace for this UID
  47 */
  48struct key_user {
  49        struct rb_node          node;
  50        struct mutex            cons_lock;      /* construction initiation lock */
  51        spinlock_t              lock;
  52        atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  53        atomic_t                nkeys;          /* number of keys */
  54        atomic_t                nikeys;         /* number of instantiated keys */
  55        uid_t                   uid;
  56        struct user_namespace   *user_ns;
  57        int                     qnkeys;         /* number of keys allocated to this user */
  58        int                     qnbytes;        /* number of bytes allocated to this user */
  59};
  60
  61extern struct rb_root   key_user_tree;
  62extern spinlock_t       key_user_lock;
  63extern struct key_user  root_key_user;
  64
  65extern struct key_user *key_user_lookup(uid_t uid,
  66                                        struct user_namespace *user_ns);
  67extern void key_user_put(struct key_user *user);
  68
  69/*
  70 * key quota limits
  71 * - root has its own separate limits to everyone else
  72 */
  73extern unsigned key_quota_root_maxkeys;
  74extern unsigned key_quota_root_maxbytes;
  75extern unsigned key_quota_maxkeys;
  76extern unsigned key_quota_maxbytes;
  77
  78#define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  79
  80
  81extern struct rb_root key_serial_tree;
  82extern spinlock_t key_serial_lock;
  83extern struct mutex key_construction_mutex;
  84extern wait_queue_head_t request_key_conswq;
  85
  86
  87extern struct key_type *key_type_lookup(const char *type);
  88extern void key_type_put(struct key_type *ktype);
  89
  90extern int __key_link(struct key *keyring, struct key *key);
  91
  92extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
  93                                      const struct key_type *type,
  94                                      const char *description,
  95                                      key_perm_t perm);
  96
  97extern struct key *keyring_search_instkey(struct key *keyring,
  98                                          key_serial_t target_id);
  99
 100typedef int (*key_match_func_t)(const struct key *, const void *);
 101
 102extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 103                                    const struct cred *cred,
 104                                    struct key_type *type,
 105                                    const void *description,
 106                                    key_match_func_t match);
 107
 108extern key_ref_t search_process_keyrings(struct key_type *type,
 109                                         const void *description,
 110                                         key_match_func_t match,
 111                                         const struct cred *cred);
 112
 113extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 114
 115extern int install_user_keyrings(void);
 116extern int install_thread_keyring_to_cred(struct cred *);
 117extern int install_process_keyring_to_cred(struct cred *);
 118
 119extern struct key *request_key_and_link(struct key_type *type,
 120                                        const char *description,
 121                                        const void *callout_info,
 122                                        size_t callout_len,
 123                                        void *aux,
 124                                        struct key *dest_keyring,
 125                                        unsigned long flags);
 126
 127extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
 128                                 key_perm_t perm);
 129
 130extern long join_session_keyring(const char *name);
 131
 132/*
 133 * check to see whether permission is granted to use a key in the desired way
 134 */
 135extern int key_task_permission(const key_ref_t key_ref,
 136                               const struct cred *cred,
 137                               key_perm_t perm);
 138
 139static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 140{
 141        return key_task_permission(key_ref, current_cred(), perm);
 142}
 143
 144/* required permissions */
 145#define KEY_VIEW        0x01    /* require permission to view attributes */
 146#define KEY_READ        0x02    /* require permission to read content */
 147#define KEY_WRITE       0x04    /* require permission to update / modify */
 148#define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 149#define KEY_LINK        0x10    /* require permission to link */
 150#define KEY_SETATTR     0x20    /* require permission to change attributes */
 151#define KEY_ALL         0x3f    /* all the above permissions */
 152
 153/*
 154 * request_key authorisation
 155 */
 156struct request_key_auth {
 157        struct key              *target_key;
 158        struct key              *dest_keyring;
 159        const struct cred       *cred;
 160        void                    *callout_info;
 161        size_t                  callout_len;
 162        pid_t                   pid;
 163};
 164
 165extern struct key_type key_type_request_key_auth;
 166extern struct key *request_key_auth_new(struct key *target,
 167                                        const void *callout_info,
 168                                        size_t callout_len,
 169                                        struct key *dest_keyring);
 170
 171extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 172
 173/*
 174 * keyctl functions
 175 */
 176extern long keyctl_get_keyring_ID(key_serial_t, int);
 177extern long keyctl_join_session_keyring(const char __user *);
 178extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 179extern long keyctl_revoke_key(key_serial_t);
 180extern long keyctl_keyring_clear(key_serial_t);
 181extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 182extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 183extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 184extern long keyctl_keyring_search(key_serial_t, const char __user *,
 185                                  const char __user *, key_serial_t);
 186extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 187extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 188extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 189extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 190                                   size_t, key_serial_t);
 191extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 192extern long keyctl_set_reqkey_keyring(int);
 193extern long keyctl_set_timeout(key_serial_t, unsigned);
 194extern long keyctl_assume_authority(key_serial_t);
 195extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 196                                size_t buflen);
 197
 198/*
 199 * debugging key validation
 200 */
 201#ifdef KEY_DEBUGGING
 202extern void __key_check(const struct key *);
 203
 204static inline void key_check(const struct key *key)
 205{
 206        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 207                __key_check(key);
 208}
 209
 210#else
 211
 212#define key_check(key) do {} while(0)
 213
 214#endif
 215
 216#endif /* _INTERNAL_H */
 217