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_begin(struct key *keyring,
  91                            const struct key_type *type,
  92                            const char *description,
  93                            struct keyring_list **_prealloc);
  94extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  95extern void __key_link(struct key *keyring, struct key *key,
  96                       struct keyring_list **_prealloc);
  97extern void __key_link_end(struct key *keyring,
  98                           struct key_type *type,
  99                           struct keyring_list *prealloc);
 100
 101extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 102                                      const struct key_type *type,
 103                                      const char *description,
 104                                      key_perm_t perm);
 105
 106extern struct key *keyring_search_instkey(struct key *keyring,
 107                                          key_serial_t target_id);
 108
 109typedef int (*key_match_func_t)(const struct key *, const void *);
 110
 111extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 112                                    const struct cred *cred,
 113                                    struct key_type *type,
 114                                    const void *description,
 115                                    key_match_func_t match);
 116
 117extern key_ref_t search_process_keyrings(struct key_type *type,
 118                                         const void *description,
 119                                         key_match_func_t match,
 120                                         const struct cred *cred);
 121
 122extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 123
 124extern int install_user_keyrings(void);
 125extern int install_thread_keyring_to_cred(struct cred *);
 126extern int install_process_keyring_to_cred(struct cred *);
 127extern int install_session_keyring_to_cred(struct cred *, struct key *);
 128
 129extern struct key *request_key_and_link(struct key_type *type,
 130                                        const char *description,
 131                                        const void *callout_info,
 132                                        size_t callout_len,
 133                                        void *aux,
 134                                        struct key *dest_keyring,
 135                                        unsigned long flags);
 136
 137extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 138                                 key_perm_t perm);
 139#define KEY_LOOKUP_CREATE       0x01
 140#define KEY_LOOKUP_PARTIAL      0x02
 141#define KEY_LOOKUP_FOR_UNLINK   0x04
 142
 143extern long join_session_keyring(const char *name);
 144
 145extern unsigned key_gc_delay;
 146extern void keyring_gc(struct key *keyring, time_t limit);
 147extern void key_schedule_gc(time_t expiry_at);
 148
 149/*
 150 * check to see whether permission is granted to use a key in the desired way
 151 */
 152extern int key_task_permission(const key_ref_t key_ref,
 153                               const struct cred *cred,
 154                               key_perm_t perm);
 155
 156static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 157{
 158        return key_task_permission(key_ref, current_cred(), perm);
 159}
 160
 161/* required permissions */
 162#define KEY_VIEW        0x01    /* require permission to view attributes */
 163#define KEY_READ        0x02    /* require permission to read content */
 164#define KEY_WRITE       0x04    /* require permission to update / modify */
 165#define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 166#define KEY_LINK        0x10    /* require permission to link */
 167#define KEY_SETATTR     0x20    /* require permission to change attributes */
 168#define KEY_ALL         0x3f    /* all the above permissions */
 169
 170/*
 171 * request_key authorisation
 172 */
 173struct request_key_auth {
 174        struct key              *target_key;
 175        struct key              *dest_keyring;
 176        const struct cred       *cred;
 177        void                    *callout_info;
 178        size_t                  callout_len;
 179        pid_t                   pid;
 180};
 181
 182extern struct key_type key_type_request_key_auth;
 183extern struct key *request_key_auth_new(struct key *target,
 184                                        const void *callout_info,
 185                                        size_t callout_len,
 186                                        struct key *dest_keyring);
 187
 188extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 189
 190/*
 191 * keyctl functions
 192 */
 193extern long keyctl_get_keyring_ID(key_serial_t, int);
 194extern long keyctl_join_session_keyring(const char __user *);
 195extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 196extern long keyctl_revoke_key(key_serial_t);
 197extern long keyctl_keyring_clear(key_serial_t);
 198extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 199extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 200extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 201extern long keyctl_keyring_search(key_serial_t, const char __user *,
 202                                  const char __user *, key_serial_t);
 203extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 204extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 205extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 206extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 207                                   size_t, key_serial_t);
 208extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 209extern long keyctl_set_reqkey_keyring(int);
 210extern long keyctl_set_timeout(key_serial_t, unsigned);
 211extern long keyctl_assume_authority(key_serial_t);
 212extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 213                                size_t buflen);
 214extern long keyctl_session_to_parent(void);
 215
 216/*
 217 * debugging key validation
 218 */
 219#ifdef KEY_DEBUGGING
 220extern void __key_check(const struct key *);
 221
 222static inline void key_check(const struct key *key)
 223{
 224        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 225                __key_check(key);
 226}
 227
 228#else
 229
 230#define key_check(key) do {} while(0)
 231
 232#endif
 233
 234#endif /* _INTERNAL_H */
 235