1 /* Basic authentication token and access key management
3 * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/poison.h>
15 #include <linux/sched.h>
16 #include <linux/slab.h>
17 #include <linux/security.h>
18 #include <linux/workqueue.h>
19 #include <linux/random.h>
20 #include <linux/err.h>
23 struct kmem_cache
*key_jar
;
24 struct rb_root key_serial_tree
; /* tree of keys indexed by serial */
25 DEFINE_SPINLOCK(key_serial_lock
);
27 struct rb_root key_user_tree
; /* tree of quota records indexed by UID */
28 DEFINE_SPINLOCK(key_user_lock
);
30 unsigned int key_quota_root_maxkeys
= 200; /* root's key count quota */
31 unsigned int key_quota_root_maxbytes
= 20000; /* root's key space quota */
32 unsigned int key_quota_maxkeys
= 200; /* general key count quota */
33 unsigned int key_quota_maxbytes
= 20000; /* general key space quota */
35 static LIST_HEAD(key_types_list
);
36 static DECLARE_RWSEM(key_types_sem
);
38 /* We serialise key instantiation and link */
39 DEFINE_MUTEX(key_construction_mutex
);
42 void __key_check(const struct key
*key
)
44 printk("__key_check: key %p {%08x} should be {%08x}\n",
45 key
, key
->magic
, KEY_DEBUG_MAGIC
);
51 * Get the key quota record for a user, allocating a new record if one doesn't
54 struct key_user
*key_user_lookup(kuid_t uid
)
56 struct key_user
*candidate
= NULL
, *user
;
57 struct rb_node
*parent
= NULL
;
61 p
= &key_user_tree
.rb_node
;
62 spin_lock(&key_user_lock
);
64 /* search the tree for a user record with a matching UID */
67 user
= rb_entry(parent
, struct key_user
, node
);
69 if (uid_lt(uid
, user
->uid
))
71 else if (uid_gt(uid
, user
->uid
))
77 /* if we get here, we failed to find a match in the tree */
79 /* allocate a candidate user record if we don't already have
81 spin_unlock(&key_user_lock
);
84 candidate
= kmalloc(sizeof(struct key_user
), GFP_KERNEL
);
85 if (unlikely(!candidate
))
88 /* the allocation may have scheduled, so we need to repeat the
89 * search lest someone else added the record whilst we were
94 /* if we get here, then the user record still hadn't appeared on the
95 * second pass - so we use the candidate record */
96 atomic_set(&candidate
->usage
, 1);
97 atomic_set(&candidate
->nkeys
, 0);
98 atomic_set(&candidate
->nikeys
, 0);
100 candidate
->qnkeys
= 0;
101 candidate
->qnbytes
= 0;
102 spin_lock_init(&candidate
->lock
);
103 mutex_init(&candidate
->cons_lock
);
105 rb_link_node(&candidate
->node
, parent
, p
);
106 rb_insert_color(&candidate
->node
, &key_user_tree
);
107 spin_unlock(&key_user_lock
);
111 /* okay - we found a user record for this UID */
113 atomic_inc(&user
->usage
);
114 spin_unlock(&key_user_lock
);
121 * Dispose of a user structure
123 void key_user_put(struct key_user
*user
)
125 if (atomic_dec_and_lock(&user
->usage
, &key_user_lock
)) {
126 rb_erase(&user
->node
, &key_user_tree
);
127 spin_unlock(&key_user_lock
);
134 * Allocate a serial number for a key. These are assigned randomly to avoid
135 * security issues through covert channel problems.
137 static inline void key_alloc_serial(struct key
*key
)
139 struct rb_node
*parent
, **p
;
142 /* propose a random serial number and look for a hole for it in the
143 * serial number tree */
145 get_random_bytes(&key
->serial
, sizeof(key
->serial
));
147 key
->serial
>>= 1; /* negative numbers are not permitted */
148 } while (key
->serial
< 3);
150 spin_lock(&key_serial_lock
);
154 p
= &key_serial_tree
.rb_node
;
158 xkey
= rb_entry(parent
, struct key
, serial_node
);
160 if (key
->serial
< xkey
->serial
)
162 else if (key
->serial
> xkey
->serial
)
168 /* we've found a suitable hole - arrange for this key to occupy it */
169 rb_link_node(&key
->serial_node
, parent
, p
);
170 rb_insert_color(&key
->serial_node
, &key_serial_tree
);
172 spin_unlock(&key_serial_lock
);
175 /* we found a key with the proposed serial number - walk the tree from
176 * that point looking for the next unused serial number */
180 if (key
->serial
< 3) {
182 goto attempt_insertion
;
185 parent
= rb_next(parent
);
187 goto attempt_insertion
;
189 xkey
= rb_entry(parent
, struct key
, serial_node
);
190 if (key
->serial
< xkey
->serial
)
191 goto attempt_insertion
;
196 * key_alloc - Allocate a key of the specified type.
197 * @type: The type of key to allocate.
198 * @desc: The key description to allow the key to be searched out.
199 * @uid: The owner of the new key.
200 * @gid: The group ID for the new key's group permissions.
201 * @cred: The credentials specifying UID namespace.
202 * @perm: The permissions mask of the new key.
203 * @flags: Flags specifying quota properties.
205 * Allocate a key of the specified type with the attributes given. The key is
206 * returned in an uninstantiated state and the caller needs to instantiate the
207 * key before returning.
209 * The user's key count quota is updated to reflect the creation of the key and
210 * the user's key data quota has the default for the key type reserved. The
211 * instantiation function should amend this as necessary. If insufficient
212 * quota is available, -EDQUOT will be returned.
214 * The LSM security modules can prevent a key being created, in which case
215 * -EACCES will be returned.
217 * Returns a pointer to the new key if successful and an error code otherwise.
219 * Note that the caller needs to ensure the key type isn't uninstantiated.
220 * Internally this can be done by locking key_types_sem. Externally, this can
221 * be done by either never unregistering the key type, or making sure
222 * key_alloc() calls don't race with module unloading.
224 struct key
*key_alloc(struct key_type
*type
, const char *desc
,
225 kuid_t uid
, kgid_t gid
, const struct cred
*cred
,
226 key_perm_t perm
, unsigned long flags
)
228 struct key_user
*user
= NULL
;
230 size_t desclen
, quotalen
;
233 key
= ERR_PTR(-EINVAL
);
237 if (type
->vet_description
) {
238 ret
= type
->vet_description(desc
);
245 desclen
= strlen(desc
) + 1;
246 quotalen
= desclen
+ type
->def_datalen
;
248 /* get hold of the key tracking for this user */
249 user
= key_user_lookup(uid
);
253 /* check that the user's quota permits allocation of another key and
255 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
)) {
256 unsigned maxkeys
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
257 key_quota_root_maxkeys
: key_quota_maxkeys
;
258 unsigned maxbytes
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
259 key_quota_root_maxbytes
: key_quota_maxbytes
;
261 spin_lock(&user
->lock
);
262 if (!(flags
& KEY_ALLOC_QUOTA_OVERRUN
)) {
263 if (user
->qnkeys
+ 1 >= maxkeys
||
264 user
->qnbytes
+ quotalen
>= maxbytes
||
265 user
->qnbytes
+ quotalen
< user
->qnbytes
)
270 user
->qnbytes
+= quotalen
;
271 spin_unlock(&user
->lock
);
274 /* allocate and initialise the key and its description */
275 key
= kmem_cache_alloc(key_jar
, GFP_KERNEL
);
280 key
->description
= kmemdup(desc
, desclen
, GFP_KERNEL
);
281 if (!key
->description
)
285 atomic_set(&key
->usage
, 1);
286 init_rwsem(&key
->sem
);
287 lockdep_set_class(&key
->sem
, &type
->lock_class
);
290 key
->quotalen
= quotalen
;
291 key
->datalen
= type
->def_datalen
;
297 key
->payload
.data
= NULL
;
298 key
->security
= NULL
;
300 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
))
301 key
->flags
|= 1 << KEY_FLAG_IN_QUOTA
;
303 memset(&key
->type_data
, 0, sizeof(key
->type_data
));
306 key
->magic
= KEY_DEBUG_MAGIC
;
309 /* let the security module know about the key */
310 ret
= security_key_alloc(key
, cred
, flags
);
314 /* publish the key by giving it a serial number */
315 atomic_inc(&user
->nkeys
);
316 key_alloc_serial(key
);
322 kfree(key
->description
);
323 kmem_cache_free(key_jar
, key
);
324 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
)) {
325 spin_lock(&user
->lock
);
327 user
->qnbytes
-= quotalen
;
328 spin_unlock(&user
->lock
);
335 kmem_cache_free(key_jar
, key
);
337 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
)) {
338 spin_lock(&user
->lock
);
340 user
->qnbytes
-= quotalen
;
341 spin_unlock(&user
->lock
);
345 key
= ERR_PTR(-ENOMEM
);
349 spin_unlock(&user
->lock
);
351 key
= ERR_PTR(-EDQUOT
);
354 EXPORT_SYMBOL(key_alloc
);
357 * key_payload_reserve - Adjust data quota reservation for the key's payload
358 * @key: The key to make the reservation for.
359 * @datalen: The amount of data payload the caller now wants.
361 * Adjust the amount of the owning user's key data quota that a key reserves.
362 * If the amount is increased, then -EDQUOT may be returned if there isn't
363 * enough free quota available.
365 * If successful, 0 is returned.
367 int key_payload_reserve(struct key
*key
, size_t datalen
)
369 int delta
= (int)datalen
- key
->datalen
;
374 /* contemplate the quota adjustment */
375 if (delta
!= 0 && test_bit(KEY_FLAG_IN_QUOTA
, &key
->flags
)) {
376 unsigned maxbytes
= uid_eq(key
->user
->uid
, GLOBAL_ROOT_UID
) ?
377 key_quota_root_maxbytes
: key_quota_maxbytes
;
379 spin_lock(&key
->user
->lock
);
382 (key
->user
->qnbytes
+ delta
>= maxbytes
||
383 key
->user
->qnbytes
+ delta
< key
->user
->qnbytes
)) {
387 key
->user
->qnbytes
+= delta
;
388 key
->quotalen
+= delta
;
390 spin_unlock(&key
->user
->lock
);
393 /* change the recorded data length if that didn't generate an error */
395 key
->datalen
= datalen
;
399 EXPORT_SYMBOL(key_payload_reserve
);
402 * Instantiate a key and link it into the target keyring atomically. Must be
403 * called with the target keyring's semaphore writelocked. The target key's
404 * semaphore need not be locked as instantiation is serialised by
405 * key_construction_mutex.
407 static int __key_instantiate_and_link(struct key
*key
,
412 unsigned long *_prealloc
)
422 mutex_lock(&key_construction_mutex
);
424 /* can't instantiate twice */
425 if (!test_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
)) {
426 /* instantiate the key */
427 ret
= key
->type
->instantiate(key
, data
, datalen
);
430 /* mark the key as being instantiated */
431 atomic_inc(&key
->user
->nikeys
);
432 set_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
);
434 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT
, &key
->flags
))
437 /* and link it into the destination keyring */
439 __key_link(keyring
, key
, _prealloc
);
441 /* disable the authorisation key */
447 mutex_unlock(&key_construction_mutex
);
449 /* wake up anyone waiting for a key to be constructed */
451 wake_up_bit(&key
->flags
, KEY_FLAG_USER_CONSTRUCT
);
457 * key_instantiate_and_link - Instantiate a key and link it into the keyring.
458 * @key: The key to instantiate.
459 * @data: The data to use to instantiate the keyring.
460 * @datalen: The length of @data.
461 * @keyring: Keyring to create a link in on success (or NULL).
462 * @authkey: The authorisation token permitting instantiation.
464 * Instantiate a key that's in the uninstantiated state using the provided data
465 * and, if successful, link it in to the destination keyring if one is
468 * If successful, 0 is returned, the authorisation token is revoked and anyone
469 * waiting for the key is woken up. If the key was already instantiated,
470 * -EBUSY will be returned.
472 int key_instantiate_and_link(struct key
*key
,
478 unsigned long prealloc
;
482 ret
= __key_link_begin(keyring
, key
->type
, key
->description
,
488 ret
= __key_instantiate_and_link(key
, data
, datalen
, keyring
, authkey
,
492 __key_link_end(keyring
, key
->type
, prealloc
);
497 EXPORT_SYMBOL(key_instantiate_and_link
);
500 * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
501 * @key: The key to instantiate.
502 * @timeout: The timeout on the negative key.
503 * @error: The error to return when the key is hit.
504 * @keyring: Keyring to create a link in on success (or NULL).
505 * @authkey: The authorisation token permitting instantiation.
507 * Negatively instantiate a key that's in the uninstantiated state and, if
508 * successful, set its timeout and stored error and link it in to the
509 * destination keyring if one is supplied. The key and any links to the key
510 * will be automatically garbage collected after the timeout expires.
512 * Negative keys are used to rate limit repeated request_key() calls by causing
513 * them to return the stored error code (typically ENOKEY) until the negative
516 * If successful, 0 is returned, the authorisation token is revoked and anyone
517 * waiting for the key is woken up. If the key was already instantiated,
518 * -EBUSY will be returned.
520 int key_reject_and_link(struct key
*key
,
526 unsigned long prealloc
;
528 int ret
, awaken
, link_ret
= 0;
537 link_ret
= __key_link_begin(keyring
, key
->type
,
538 key
->description
, &prealloc
);
540 mutex_lock(&key_construction_mutex
);
542 /* can't instantiate twice */
543 if (!test_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
)) {
544 /* mark the key as being negatively instantiated */
545 atomic_inc(&key
->user
->nikeys
);
546 set_bit(KEY_FLAG_NEGATIVE
, &key
->flags
);
547 set_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
);
548 key
->type_data
.reject_error
= -error
;
549 now
= current_kernel_time();
550 key
->expiry
= now
.tv_sec
+ timeout
;
551 key_schedule_gc(key
->expiry
+ key_gc_delay
);
553 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT
, &key
->flags
))
558 /* and link it into the destination keyring */
559 if (keyring
&& link_ret
== 0)
560 __key_link(keyring
, key
, &prealloc
);
562 /* disable the authorisation key */
567 mutex_unlock(&key_construction_mutex
);
570 __key_link_end(keyring
, key
->type
, prealloc
);
572 /* wake up anyone waiting for a key to be constructed */
574 wake_up_bit(&key
->flags
, KEY_FLAG_USER_CONSTRUCT
);
576 return ret
== 0 ? link_ret
: ret
;
578 EXPORT_SYMBOL(key_reject_and_link
);
581 * key_put - Discard a reference to a key.
582 * @key: The key to discard a reference from.
584 * Discard a reference to a key, and when all the references are gone, we
585 * schedule the cleanup task to come and pull it out of the tree in process
586 * context at some later time.
588 void key_put(struct key
*key
)
593 if (atomic_dec_and_test(&key
->usage
))
594 queue_work(system_nrt_wq
, &key_gc_work
);
597 EXPORT_SYMBOL(key_put
);
600 * Find a key by its serial number.
602 struct key
*key_lookup(key_serial_t id
)
607 spin_lock(&key_serial_lock
);
609 /* search the tree for the specified key */
610 n
= key_serial_tree
.rb_node
;
612 key
= rb_entry(n
, struct key
, serial_node
);
614 if (id
< key
->serial
)
616 else if (id
> key
->serial
)
623 key
= ERR_PTR(-ENOKEY
);
627 /* pretend it doesn't exist if it is awaiting deletion */
628 if (atomic_read(&key
->usage
) == 0)
631 /* this races with key_put(), but that doesn't matter since key_put()
632 * doesn't actually change the key
634 atomic_inc(&key
->usage
);
637 spin_unlock(&key_serial_lock
);
642 * Find and lock the specified key type against removal.
644 * We return with the sem read-locked if successful. If the type wasn't
645 * available -ENOKEY is returned instead.
647 struct key_type
*key_type_lookup(const char *type
)
649 struct key_type
*ktype
;
651 down_read(&key_types_sem
);
653 /* look up the key type to see if it's one of the registered kernel
655 list_for_each_entry(ktype
, &key_types_list
, link
) {
656 if (strcmp(ktype
->name
, type
) == 0)
657 goto found_kernel_type
;
660 up_read(&key_types_sem
);
661 ktype
= ERR_PTR(-ENOKEY
);
667 void key_set_timeout(struct key
*key
, unsigned timeout
)
672 /* make the changes with the locks held to prevent races */
673 down_write(&key
->sem
);
676 now
= current_kernel_time();
677 expiry
= now
.tv_sec
+ timeout
;
680 key
->expiry
= expiry
;
681 key_schedule_gc(key
->expiry
+ key_gc_delay
);
685 EXPORT_SYMBOL_GPL(key_set_timeout
);
688 * Unlock a key type locked by key_type_lookup().
690 void key_type_put(struct key_type
*ktype
)
692 up_read(&key_types_sem
);
696 * Attempt to update an existing key.
698 * The key is given to us with an incremented refcount that we need to discard
699 * if we get an error.
701 static inline key_ref_t
__key_update(key_ref_t key_ref
,
702 const void *payload
, size_t plen
)
704 struct key
*key
= key_ref_to_ptr(key_ref
);
707 /* need write permission on the key to update it */
708 ret
= key_permission(key_ref
, KEY_WRITE
);
713 if (!key
->type
->update
)
716 down_write(&key
->sem
);
718 ret
= key
->type
->update(key
, payload
, plen
);
720 /* updating a negative key instantiates it */
721 clear_bit(KEY_FLAG_NEGATIVE
, &key
->flags
);
732 key_ref
= ERR_PTR(ret
);
737 * key_create_or_update - Update or create and instantiate a key.
738 * @keyring_ref: A pointer to the destination keyring with possession flag.
739 * @type: The type of key.
740 * @description: The searchable description for the key.
741 * @payload: The data to use to instantiate or update the key.
742 * @plen: The length of @payload.
743 * @perm: The permissions mask for a new key.
744 * @flags: The quota flags for a new key.
746 * Search the destination keyring for a key of the same description and if one
747 * is found, update it, otherwise create and instantiate a new one and create a
748 * link to it from that keyring.
750 * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
753 * Returns a pointer to the new key if successful, -ENODEV if the key type
754 * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
755 * caller isn't permitted to modify the keyring or the LSM did not permit
756 * creation of the key.
758 * On success, the possession flag from the keyring ref will be tacked on to
759 * the key ref before it is returned.
761 key_ref_t
key_create_or_update(key_ref_t keyring_ref
,
763 const char *description
,
769 unsigned long prealloc
;
770 const struct cred
*cred
= current_cred();
771 struct key_type
*ktype
;
772 struct key
*keyring
, *key
= NULL
;
776 /* look up the key type to see if it's one of the registered kernel
778 ktype
= key_type_lookup(type
);
780 key_ref
= ERR_PTR(-ENODEV
);
784 key_ref
= ERR_PTR(-EINVAL
);
785 if (!ktype
->match
|| !ktype
->instantiate
)
788 keyring
= key_ref_to_ptr(keyring_ref
);
792 key_ref
= ERR_PTR(-ENOTDIR
);
793 if (keyring
->type
!= &key_type_keyring
)
796 ret
= __key_link_begin(keyring
, ktype
, description
, &prealloc
);
800 /* if we're going to allocate a new key, we're going to have
801 * to modify the keyring */
802 ret
= key_permission(keyring_ref
, KEY_WRITE
);
804 key_ref
= ERR_PTR(ret
);
808 /* if it's possible to update this type of key, search for an existing
809 * key of the same type and description in the destination keyring and
810 * update that instead if possible
813 key_ref
= __keyring_search_one(keyring_ref
, ktype
, description
,
815 if (!IS_ERR(key_ref
))
816 goto found_matching_key
;
819 /* if the client doesn't provide, decide on the permissions we want */
820 if (perm
== KEY_PERM_UNDEF
) {
821 perm
= KEY_POS_VIEW
| KEY_POS_SEARCH
| KEY_POS_LINK
| KEY_POS_SETATTR
;
822 perm
|= KEY_USR_VIEW
| KEY_USR_SEARCH
| KEY_USR_LINK
| KEY_USR_SETATTR
;
825 perm
|= KEY_POS_READ
| KEY_USR_READ
;
827 if (ktype
== &key_type_keyring
|| ktype
->update
)
828 perm
|= KEY_USR_WRITE
;
831 /* allocate a new key */
832 key
= key_alloc(ktype
, description
, cred
->fsuid
, cred
->fsgid
, cred
,
835 key_ref
= ERR_CAST(key
);
839 /* instantiate it and link it into the target keyring */
840 ret
= __key_instantiate_and_link(key
, payload
, plen
, keyring
, NULL
,
844 key_ref
= ERR_PTR(ret
);
848 key_ref
= make_key_ref(key
, is_key_possessed(keyring_ref
));
851 __key_link_end(keyring
, ktype
, prealloc
);
858 /* we found a matching key, so we're going to try to update it
859 * - we can drop the locks first as we have the key pinned
861 __key_link_end(keyring
, ktype
, prealloc
);
864 key_ref
= __key_update(key_ref
, payload
, plen
);
867 EXPORT_SYMBOL(key_create_or_update
);
870 * key_update - Update a key's contents.
871 * @key_ref: The pointer (plus possession flag) to the key.
872 * @payload: The data to be used to update the key.
873 * @plen: The length of @payload.
875 * Attempt to update the contents of a key with the given payload data. The
876 * caller must be granted Write permission on the key. Negative keys can be
877 * instantiated by this method.
879 * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
880 * type does not support updating. The key type may return other errors.
882 int key_update(key_ref_t key_ref
, const void *payload
, size_t plen
)
884 struct key
*key
= key_ref_to_ptr(key_ref
);
889 /* the key must be writable */
890 ret
= key_permission(key_ref
, KEY_WRITE
);
894 /* attempt to update it if supported */
896 if (key
->type
->update
) {
897 down_write(&key
->sem
);
899 ret
= key
->type
->update(key
, payload
, plen
);
901 /* updating a negative key instantiates it */
902 clear_bit(KEY_FLAG_NEGATIVE
, &key
->flags
);
910 EXPORT_SYMBOL(key_update
);
913 * key_revoke - Revoke a key.
914 * @key: The key to be revoked.
916 * Mark a key as being revoked and ask the type to free up its resources. The
917 * revocation timeout is set and the key and all its links will be
918 * automatically garbage collected after key_gc_delay amount of time if they
919 * are not manually dealt with first.
921 void key_revoke(struct key
*key
)
928 /* make sure no one's trying to change or use the key when we mark it
929 * - we tell lockdep that we might nest because we might be revoking an
930 * authorisation key whilst holding the sem on a key we've just
933 down_write_nested(&key
->sem
, 1);
934 if (!test_and_set_bit(KEY_FLAG_REVOKED
, &key
->flags
) &&
936 key
->type
->revoke(key
);
938 /* set the death time to no more than the expiry time */
939 now
= current_kernel_time();
941 if (key
->revoked_at
== 0 || key
->revoked_at
> time
) {
942 key
->revoked_at
= time
;
943 key_schedule_gc(key
->revoked_at
+ key_gc_delay
);
948 EXPORT_SYMBOL(key_revoke
);
951 * key_invalidate - Invalidate a key.
952 * @key: The key to be invalidated.
954 * Mark a key as being invalidated and have it cleaned up immediately. The key
955 * is ignored by all searches and other operations from this point.
957 void key_invalidate(struct key
*key
)
959 kenter("%d", key_serial(key
));
963 if (!test_bit(KEY_FLAG_INVALIDATED
, &key
->flags
)) {
964 down_write_nested(&key
->sem
, 1);
965 if (!test_and_set_bit(KEY_FLAG_INVALIDATED
, &key
->flags
))
966 key_schedule_gc_links();
970 EXPORT_SYMBOL(key_invalidate
);
973 * register_key_type - Register a type of key.
974 * @ktype: The new key type.
976 * Register a new key type.
978 * Returns 0 on success or -EEXIST if a type of this name already exists.
980 int register_key_type(struct key_type
*ktype
)
985 memset(&ktype
->lock_class
, 0, sizeof(ktype
->lock_class
));
988 down_write(&key_types_sem
);
990 /* disallow key types with the same name */
991 list_for_each_entry(p
, &key_types_list
, link
) {
992 if (strcmp(p
->name
, ktype
->name
) == 0)
997 list_add(&ktype
->link
, &key_types_list
);
999 pr_notice("Key type %s registered\n", ktype
->name
);
1003 up_write(&key_types_sem
);
1006 EXPORT_SYMBOL(register_key_type
);
1009 * unregister_key_type - Unregister a type of key.
1010 * @ktype: The key type.
1012 * Unregister a key type and mark all the extant keys of this type as dead.
1013 * Those keys of this type are then destroyed to get rid of their payloads and
1014 * they and their links will be garbage collected as soon as possible.
1016 void unregister_key_type(struct key_type
*ktype
)
1018 down_write(&key_types_sem
);
1019 list_del_init(&ktype
->link
);
1020 downgrade_write(&key_types_sem
);
1021 key_gc_keytype(ktype
);
1022 pr_notice("Key type %s unregistered\n", ktype
->name
);
1023 up_read(&key_types_sem
);
1025 EXPORT_SYMBOL(unregister_key_type
);
1028 * Initialise the key management state.
1030 void __init
key_init(void)
1032 /* allocate a slab in which we can store keys */
1033 key_jar
= kmem_cache_create("key_jar", sizeof(struct key
),
1034 0, SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
1036 /* add the special key types */
1037 list_add_tail(&key_type_keyring
.link
, &key_types_list
);
1038 list_add_tail(&key_type_dead
.link
, &key_types_list
);
1039 list_add_tail(&key_type_user
.link
, &key_types_list
);
1040 list_add_tail(&key_type_logon
.link
, &key_types_list
);
1042 /* record the root user tracking */
1043 rb_link_node(&root_key_user
.node
,
1045 &key_user_tree
.rb_node
);
1047 rb_insert_color(&root_key_user
.node
,
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