Commit | Line | Data |
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76181c13 | 1 | /* Basic authentication token and access key management |
1da177e4 | 2 | * |
69664cf1 | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
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 | #include <linux/module.h> | |
13 | #include <linux/init.h> | |
a7807a32 | 14 | #include <linux/poison.h> |
1da177e4 LT |
15 | #include <linux/sched.h> |
16 | #include <linux/slab.h> | |
29db9190 | 17 | #include <linux/security.h> |
1da177e4 | 18 | #include <linux/workqueue.h> |
e51f6d34 | 19 | #include <linux/random.h> |
1da177e4 LT |
20 | #include <linux/err.h> |
21 | #include "internal.h" | |
22 | ||
8bc16dea | 23 | struct kmem_cache *key_jar; |
1da177e4 LT |
24 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
25 | DEFINE_SPINLOCK(key_serial_lock); | |
26 | ||
27 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ | |
28 | DEFINE_SPINLOCK(key_user_lock); | |
29 | ||
0b77f5bf DH |
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 */ | |
34 | ||
1da177e4 LT |
35 | static LIST_HEAD(key_types_list); |
36 | static DECLARE_RWSEM(key_types_sem); | |
37 | ||
973c9f4f | 38 | /* We serialise key instantiation and link */ |
76181c13 | 39 | DEFINE_MUTEX(key_construction_mutex); |
1da177e4 | 40 | |
1da177e4 LT |
41 | #ifdef KEY_DEBUGGING |
42 | void __key_check(const struct key *key) | |
43 | { | |
44 | printk("__key_check: key %p {%08x} should be {%08x}\n", | |
45 | key, key->magic, KEY_DEBUG_MAGIC); | |
46 | BUG(); | |
47 | } | |
48 | #endif | |
49 | ||
1da177e4 | 50 | /* |
973c9f4f DH |
51 | * Get the key quota record for a user, allocating a new record if one doesn't |
52 | * already exist. | |
1da177e4 | 53 | */ |
9a56c2db | 54 | struct key_user *key_user_lookup(kuid_t uid) |
1da177e4 LT |
55 | { |
56 | struct key_user *candidate = NULL, *user; | |
57 | struct rb_node *parent = NULL; | |
58 | struct rb_node **p; | |
59 | ||
973c9f4f | 60 | try_again: |
1da177e4 LT |
61 | p = &key_user_tree.rb_node; |
62 | spin_lock(&key_user_lock); | |
63 | ||
64 | /* search the tree for a user record with a matching UID */ | |
65 | while (*p) { | |
66 | parent = *p; | |
67 | user = rb_entry(parent, struct key_user, node); | |
68 | ||
9a56c2db | 69 | if (uid_lt(uid, user->uid)) |
1da177e4 | 70 | p = &(*p)->rb_left; |
9a56c2db | 71 | else if (uid_gt(uid, user->uid)) |
1d1e9756 | 72 | p = &(*p)->rb_right; |
1da177e4 LT |
73 | else |
74 | goto found; | |
75 | } | |
76 | ||
77 | /* if we get here, we failed to find a match in the tree */ | |
78 | if (!candidate) { | |
79 | /* allocate a candidate user record if we don't already have | |
80 | * one */ | |
81 | spin_unlock(&key_user_lock); | |
82 | ||
83 | user = NULL; | |
84 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); | |
85 | if (unlikely(!candidate)) | |
86 | goto out; | |
87 | ||
88 | /* the allocation may have scheduled, so we need to repeat the | |
89 | * search lest someone else added the record whilst we were | |
90 | * asleep */ | |
91 | goto try_again; | |
92 | } | |
93 | ||
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); | |
99 | candidate->uid = uid; | |
100 | candidate->qnkeys = 0; | |
101 | candidate->qnbytes = 0; | |
102 | spin_lock_init(&candidate->lock); | |
76181c13 | 103 | mutex_init(&candidate->cons_lock); |
1da177e4 LT |
104 | |
105 | rb_link_node(&candidate->node, parent, p); | |
106 | rb_insert_color(&candidate->node, &key_user_tree); | |
107 | spin_unlock(&key_user_lock); | |
108 | user = candidate; | |
109 | goto out; | |
110 | ||
111 | /* okay - we found a user record for this UID */ | |
973c9f4f | 112 | found: |
1da177e4 LT |
113 | atomic_inc(&user->usage); |
114 | spin_unlock(&key_user_lock); | |
a7f988ba | 115 | kfree(candidate); |
973c9f4f | 116 | out: |
1da177e4 | 117 | return user; |
a8b17ed0 | 118 | } |
1da177e4 | 119 | |
1da177e4 | 120 | /* |
973c9f4f | 121 | * Dispose of a user structure |
1da177e4 LT |
122 | */ |
123 | void key_user_put(struct key_user *user) | |
124 | { | |
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); | |
128 | ||
129 | kfree(user); | |
130 | } | |
a8b17ed0 | 131 | } |
1da177e4 | 132 | |
1da177e4 | 133 | /* |
973c9f4f DH |
134 | * Allocate a serial number for a key. These are assigned randomly to avoid |
135 | * security issues through covert channel problems. | |
1da177e4 LT |
136 | */ |
137 | static inline void key_alloc_serial(struct key *key) | |
138 | { | |
139 | struct rb_node *parent, **p; | |
140 | struct key *xkey; | |
141 | ||
e51f6d34 | 142 | /* propose a random serial number and look for a hole for it in the |
1da177e4 | 143 | * serial number tree */ |
e51f6d34 ML |
144 | do { |
145 | get_random_bytes(&key->serial, sizeof(key->serial)); | |
146 | ||
147 | key->serial >>= 1; /* negative numbers are not permitted */ | |
148 | } while (key->serial < 3); | |
149 | ||
150 | spin_lock(&key_serial_lock); | |
1da177e4 | 151 | |
9ad0830f | 152 | attempt_insertion: |
1da177e4 LT |
153 | parent = NULL; |
154 | p = &key_serial_tree.rb_node; | |
155 | ||
156 | while (*p) { | |
157 | parent = *p; | |
158 | xkey = rb_entry(parent, struct key, serial_node); | |
159 | ||
160 | if (key->serial < xkey->serial) | |
161 | p = &(*p)->rb_left; | |
162 | else if (key->serial > xkey->serial) | |
163 | p = &(*p)->rb_right; | |
164 | else | |
165 | goto serial_exists; | |
166 | } | |
9ad0830f DH |
167 | |
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); | |
171 | ||
172 | spin_unlock(&key_serial_lock); | |
173 | return; | |
1da177e4 LT |
174 | |
175 | /* we found a key with the proposed serial number - walk the tree from | |
176 | * that point looking for the next unused serial number */ | |
e51f6d34 | 177 | serial_exists: |
1da177e4 | 178 | for (;;) { |
e51f6d34 | 179 | key->serial++; |
9ad0830f DH |
180 | if (key->serial < 3) { |
181 | key->serial = 3; | |
182 | goto attempt_insertion; | |
183 | } | |
1da177e4 LT |
184 | |
185 | parent = rb_next(parent); | |
186 | if (!parent) | |
9ad0830f | 187 | goto attempt_insertion; |
1da177e4 LT |
188 | |
189 | xkey = rb_entry(parent, struct key, serial_node); | |
190 | if (key->serial < xkey->serial) | |
9ad0830f | 191 | goto attempt_insertion; |
1da177e4 | 192 | } |
a8b17ed0 | 193 | } |
1da177e4 | 194 | |
973c9f4f DH |
195 | /** |
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. | |
204 | * | |
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. | |
208 | * | |
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. | |
213 | * | |
214 | * The LSM security modules can prevent a key being created, in which case | |
215 | * -EACCES will be returned. | |
216 | * | |
217 | * Returns a pointer to the new key if successful and an error code otherwise. | |
218 | * | |
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. | |
1da177e4 LT |
223 | */ |
224 | struct key *key_alloc(struct key_type *type, const char *desc, | |
9a56c2db | 225 | kuid_t uid, kgid_t gid, const struct cred *cred, |
7e047ef5 | 226 | key_perm_t perm, unsigned long flags) |
1da177e4 LT |
227 | { |
228 | struct key_user *user = NULL; | |
229 | struct key *key; | |
230 | size_t desclen, quotalen; | |
29db9190 | 231 | int ret; |
1da177e4 LT |
232 | |
233 | key = ERR_PTR(-EINVAL); | |
234 | if (!desc || !*desc) | |
235 | goto error; | |
236 | ||
b9fffa38 DH |
237 | if (type->vet_description) { |
238 | ret = type->vet_description(desc); | |
239 | if (ret < 0) { | |
240 | key = ERR_PTR(ret); | |
241 | goto error; | |
242 | } | |
243 | } | |
244 | ||
1da177e4 LT |
245 | desclen = strlen(desc) + 1; |
246 | quotalen = desclen + type->def_datalen; | |
247 | ||
248 | /* get hold of the key tracking for this user */ | |
9a56c2db | 249 | user = key_user_lookup(uid); |
1da177e4 LT |
250 | if (!user) |
251 | goto no_memory_1; | |
252 | ||
253 | /* check that the user's quota permits allocation of another key and | |
254 | * its description */ | |
7e047ef5 | 255 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
9a56c2db | 256 | unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf | 257 | key_quota_root_maxkeys : key_quota_maxkeys; |
9a56c2db | 258 | unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
259 | key_quota_root_maxbytes : key_quota_maxbytes; |
260 | ||
1da177e4 | 261 | spin_lock(&user->lock); |
7e047ef5 | 262 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
0b77f5bf DH |
263 | if (user->qnkeys + 1 >= maxkeys || |
264 | user->qnbytes + quotalen >= maxbytes || | |
265 | user->qnbytes + quotalen < user->qnbytes) | |
7e047ef5 DH |
266 | goto no_quota; |
267 | } | |
1da177e4 LT |
268 | |
269 | user->qnkeys++; | |
270 | user->qnbytes += quotalen; | |
271 | spin_unlock(&user->lock); | |
272 | } | |
273 | ||
274 | /* allocate and initialise the key and its description */ | |
e94b1766 | 275 | key = kmem_cache_alloc(key_jar, GFP_KERNEL); |
1da177e4 LT |
276 | if (!key) |
277 | goto no_memory_2; | |
278 | ||
279 | if (desc) { | |
48ad504e | 280 | key->description = kmemdup(desc, desclen, GFP_KERNEL); |
1da177e4 LT |
281 | if (!key->description) |
282 | goto no_memory_3; | |
1da177e4 LT |
283 | } |
284 | ||
285 | atomic_set(&key->usage, 1); | |
1da177e4 | 286 | init_rwsem(&key->sem); |
7845bc39 | 287 | lockdep_set_class(&key->sem, &type->lock_class); |
1da177e4 LT |
288 | key->type = type; |
289 | key->user = user; | |
290 | key->quotalen = quotalen; | |
291 | key->datalen = type->def_datalen; | |
292 | key->uid = uid; | |
293 | key->gid = gid; | |
294 | key->perm = perm; | |
295 | key->flags = 0; | |
296 | key->expiry = 0; | |
297 | key->payload.data = NULL; | |
29db9190 | 298 | key->security = NULL; |
1da177e4 | 299 | |
7e047ef5 | 300 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
76d8aeab | 301 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
e8705c42 EB |
302 | if (flags & KEY_ALLOC_UID_KEYRING) |
303 | key->flags |= 1 << KEY_FLAG_UID_KEYRING; | |
1da177e4 LT |
304 | |
305 | memset(&key->type_data, 0, sizeof(key->type_data)); | |
306 | ||
307 | #ifdef KEY_DEBUGGING | |
308 | key->magic = KEY_DEBUG_MAGIC; | |
309 | #endif | |
310 | ||
29db9190 | 311 | /* let the security module know about the key */ |
d84f4f99 | 312 | ret = security_key_alloc(key, cred, flags); |
29db9190 DH |
313 | if (ret < 0) |
314 | goto security_error; | |
315 | ||
1da177e4 LT |
316 | /* publish the key by giving it a serial number */ |
317 | atomic_inc(&user->nkeys); | |
318 | key_alloc_serial(key); | |
319 | ||
29db9190 | 320 | error: |
1da177e4 LT |
321 | return key; |
322 | ||
29db9190 DH |
323 | security_error: |
324 | kfree(key->description); | |
1da177e4 | 325 | kmem_cache_free(key_jar, key); |
7e047ef5 | 326 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
1da177e4 LT |
327 | spin_lock(&user->lock); |
328 | user->qnkeys--; | |
329 | user->qnbytes -= quotalen; | |
330 | spin_unlock(&user->lock); | |
331 | } | |
332 | key_user_put(user); | |
29db9190 DH |
333 | key = ERR_PTR(ret); |
334 | goto error; | |
335 | ||
336 | no_memory_3: | |
337 | kmem_cache_free(key_jar, key); | |
338 | no_memory_2: | |
7e047ef5 | 339 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
29db9190 DH |
340 | spin_lock(&user->lock); |
341 | user->qnkeys--; | |
342 | user->qnbytes -= quotalen; | |
343 | spin_unlock(&user->lock); | |
344 | } | |
345 | key_user_put(user); | |
346 | no_memory_1: | |
1da177e4 LT |
347 | key = ERR_PTR(-ENOMEM); |
348 | goto error; | |
349 | ||
29db9190 | 350 | no_quota: |
1da177e4 LT |
351 | spin_unlock(&user->lock); |
352 | key_user_put(user); | |
353 | key = ERR_PTR(-EDQUOT); | |
354 | goto error; | |
a8b17ed0 | 355 | } |
1da177e4 LT |
356 | EXPORT_SYMBOL(key_alloc); |
357 | ||
973c9f4f DH |
358 | /** |
359 | * key_payload_reserve - Adjust data quota reservation for the key's payload | |
360 | * @key: The key to make the reservation for. | |
361 | * @datalen: The amount of data payload the caller now wants. | |
362 | * | |
363 | * Adjust the amount of the owning user's key data quota that a key reserves. | |
364 | * If the amount is increased, then -EDQUOT may be returned if there isn't | |
365 | * enough free quota available. | |
366 | * | |
367 | * If successful, 0 is returned. | |
1da177e4 LT |
368 | */ |
369 | int key_payload_reserve(struct key *key, size_t datalen) | |
370 | { | |
c5b60b5e | 371 | int delta = (int)datalen - key->datalen; |
1da177e4 LT |
372 | int ret = 0; |
373 | ||
374 | key_check(key); | |
375 | ||
376 | /* contemplate the quota adjustment */ | |
76d8aeab | 377 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
9a56c2db | 378 | unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
379 | key_quota_root_maxbytes : key_quota_maxbytes; |
380 | ||
1da177e4 LT |
381 | spin_lock(&key->user->lock); |
382 | ||
383 | if (delta > 0 && | |
0b77f5bf DH |
384 | (key->user->qnbytes + delta >= maxbytes || |
385 | key->user->qnbytes + delta < key->user->qnbytes)) { | |
1da177e4 LT |
386 | ret = -EDQUOT; |
387 | } | |
388 | else { | |
389 | key->user->qnbytes += delta; | |
390 | key->quotalen += delta; | |
391 | } | |
392 | spin_unlock(&key->user->lock); | |
393 | } | |
394 | ||
395 | /* change the recorded data length if that didn't generate an error */ | |
396 | if (ret == 0) | |
397 | key->datalen = datalen; | |
398 | ||
399 | return ret; | |
a8b17ed0 | 400 | } |
1da177e4 LT |
401 | EXPORT_SYMBOL(key_payload_reserve); |
402 | ||
1da177e4 | 403 | /* |
973c9f4f DH |
404 | * Instantiate a key and link it into the target keyring atomically. Must be |
405 | * called with the target keyring's semaphore writelocked. The target key's | |
406 | * semaphore need not be locked as instantiation is serialised by | |
407 | * key_construction_mutex. | |
1da177e4 LT |
408 | */ |
409 | static int __key_instantiate_and_link(struct key *key, | |
cf7f601c | 410 | struct key_preparsed_payload *prep, |
3e30148c | 411 | struct key *keyring, |
f70e2e06 | 412 | struct key *authkey, |
ceb73c12 | 413 | unsigned long *_prealloc) |
1da177e4 LT |
414 | { |
415 | int ret, awaken; | |
416 | ||
417 | key_check(key); | |
418 | key_check(keyring); | |
419 | ||
420 | awaken = 0; | |
421 | ret = -EBUSY; | |
422 | ||
76181c13 | 423 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
424 | |
425 | /* can't instantiate twice */ | |
76d8aeab | 426 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
1da177e4 | 427 | /* instantiate the key */ |
cf7f601c | 428 | ret = key->type->instantiate(key, prep); |
1da177e4 LT |
429 | |
430 | if (ret == 0) { | |
431 | /* mark the key as being instantiated */ | |
1da177e4 | 432 | atomic_inc(&key->user->nikeys); |
76d8aeab | 433 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
1da177e4 | 434 | |
76d8aeab | 435 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 436 | awaken = 1; |
1da177e4 LT |
437 | |
438 | /* and link it into the destination keyring */ | |
439 | if (keyring) | |
f70e2e06 | 440 | __key_link(keyring, key, _prealloc); |
3e30148c DH |
441 | |
442 | /* disable the authorisation key */ | |
d84f4f99 DH |
443 | if (authkey) |
444 | key_revoke(authkey); | |
1da177e4 LT |
445 | } |
446 | } | |
447 | ||
76181c13 | 448 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
449 | |
450 | /* wake up anyone waiting for a key to be constructed */ | |
451 | if (awaken) | |
76181c13 | 452 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 LT |
453 | |
454 | return ret; | |
a8b17ed0 | 455 | } |
1da177e4 | 456 | |
973c9f4f DH |
457 | /** |
458 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. | |
459 | * @key: The key to instantiate. | |
460 | * @data: The data to use to instantiate the keyring. | |
461 | * @datalen: The length of @data. | |
462 | * @keyring: Keyring to create a link in on success (or NULL). | |
463 | * @authkey: The authorisation token permitting instantiation. | |
464 | * | |
465 | * Instantiate a key that's in the uninstantiated state using the provided data | |
466 | * and, if successful, link it in to the destination keyring if one is | |
467 | * supplied. | |
468 | * | |
469 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
470 | * waiting for the key is woken up. If the key was already instantiated, | |
471 | * -EBUSY will be returned. | |
1da177e4 LT |
472 | */ |
473 | int key_instantiate_and_link(struct key *key, | |
474 | const void *data, | |
475 | size_t datalen, | |
3e30148c | 476 | struct key *keyring, |
d84f4f99 | 477 | struct key *authkey) |
1da177e4 | 478 | { |
cf7f601c | 479 | struct key_preparsed_payload prep; |
ceb73c12 | 480 | unsigned long prealloc; |
1da177e4 LT |
481 | int ret; |
482 | ||
cf7f601c DH |
483 | memset(&prep, 0, sizeof(prep)); |
484 | prep.data = data; | |
485 | prep.datalen = datalen; | |
486 | prep.quotalen = key->type->def_datalen; | |
487 | if (key->type->preparse) { | |
488 | ret = key->type->preparse(&prep); | |
489 | if (ret < 0) | |
490 | goto error; | |
491 | } | |
492 | ||
f70e2e06 DH |
493 | if (keyring) { |
494 | ret = __key_link_begin(keyring, key->type, key->description, | |
495 | &prealloc); | |
496 | if (ret < 0) | |
cf7f601c | 497 | goto error_free_preparse; |
f70e2e06 | 498 | } |
1da177e4 | 499 | |
cf7f601c | 500 | ret = __key_instantiate_and_link(key, &prep, keyring, authkey, |
f70e2e06 | 501 | &prealloc); |
1da177e4 LT |
502 | |
503 | if (keyring) | |
f70e2e06 | 504 | __key_link_end(keyring, key->type, prealloc); |
1da177e4 | 505 | |
cf7f601c DH |
506 | error_free_preparse: |
507 | if (key->type->preparse) | |
508 | key->type->free_preparse(&prep); | |
509 | error: | |
1da177e4 | 510 | return ret; |
a8b17ed0 | 511 | } |
1da177e4 LT |
512 | |
513 | EXPORT_SYMBOL(key_instantiate_and_link); | |
514 | ||
973c9f4f | 515 | /** |
fdd1b945 | 516 | * key_reject_and_link - Negatively instantiate a key and link it into the keyring. |
973c9f4f DH |
517 | * @key: The key to instantiate. |
518 | * @timeout: The timeout on the negative key. | |
fdd1b945 | 519 | * @error: The error to return when the key is hit. |
973c9f4f DH |
520 | * @keyring: Keyring to create a link in on success (or NULL). |
521 | * @authkey: The authorisation token permitting instantiation. | |
522 | * | |
523 | * Negatively instantiate a key that's in the uninstantiated state and, if | |
fdd1b945 DH |
524 | * successful, set its timeout and stored error and link it in to the |
525 | * destination keyring if one is supplied. The key and any links to the key | |
526 | * will be automatically garbage collected after the timeout expires. | |
973c9f4f DH |
527 | * |
528 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
fdd1b945 DH |
529 | * them to return the stored error code (typically ENOKEY) until the negative |
530 | * key expires. | |
973c9f4f DH |
531 | * |
532 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
533 | * waiting for the key is woken up. If the key was already instantiated, | |
534 | * -EBUSY will be returned. | |
1da177e4 | 535 | */ |
fdd1b945 | 536 | int key_reject_and_link(struct key *key, |
1da177e4 | 537 | unsigned timeout, |
fdd1b945 | 538 | unsigned error, |
3e30148c | 539 | struct key *keyring, |
d84f4f99 | 540 | struct key *authkey) |
1da177e4 | 541 | { |
ceb73c12 | 542 | unsigned long prealloc; |
1da177e4 | 543 | struct timespec now; |
f70e2e06 | 544 | int ret, awaken, link_ret = 0; |
1da177e4 LT |
545 | |
546 | key_check(key); | |
547 | key_check(keyring); | |
548 | ||
549 | awaken = 0; | |
550 | ret = -EBUSY; | |
551 | ||
552 | if (keyring) | |
f70e2e06 DH |
553 | link_ret = __key_link_begin(keyring, key->type, |
554 | key->description, &prealloc); | |
1da177e4 | 555 | |
76181c13 | 556 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
557 | |
558 | /* can't instantiate twice */ | |
76d8aeab | 559 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
1da177e4 | 560 | /* mark the key as being negatively instantiated */ |
1da177e4 | 561 | atomic_inc(&key->user->nikeys); |
76d8aeab DH |
562 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
563 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); | |
fdd1b945 | 564 | key->type_data.reject_error = -error; |
1da177e4 LT |
565 | now = current_kernel_time(); |
566 | key->expiry = now.tv_sec + timeout; | |
c08ef808 | 567 | key_schedule_gc(key->expiry + key_gc_delay); |
1da177e4 | 568 | |
76d8aeab | 569 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 570 | awaken = 1; |
1da177e4 | 571 | |
1da177e4 LT |
572 | ret = 0; |
573 | ||
574 | /* and link it into the destination keyring */ | |
f70e2e06 DH |
575 | if (keyring && link_ret == 0) |
576 | __key_link(keyring, key, &prealloc); | |
3e30148c DH |
577 | |
578 | /* disable the authorisation key */ | |
d84f4f99 DH |
579 | if (authkey) |
580 | key_revoke(authkey); | |
1da177e4 LT |
581 | } |
582 | ||
76181c13 | 583 | mutex_unlock(&key_construction_mutex); |
1da177e4 | 584 | |
273e07f9 | 585 | if (keyring && link_ret == 0) |
f70e2e06 | 586 | __key_link_end(keyring, key->type, prealloc); |
1da177e4 LT |
587 | |
588 | /* wake up anyone waiting for a key to be constructed */ | |
589 | if (awaken) | |
76181c13 | 590 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 | 591 | |
f70e2e06 | 592 | return ret == 0 ? link_ret : ret; |
a8b17ed0 | 593 | } |
fdd1b945 | 594 | EXPORT_SYMBOL(key_reject_and_link); |
1da177e4 | 595 | |
973c9f4f DH |
596 | /** |
597 | * key_put - Discard a reference to a key. | |
598 | * @key: The key to discard a reference from. | |
599 | * | |
600 | * Discard a reference to a key, and when all the references are gone, we | |
601 | * schedule the cleanup task to come and pull it out of the tree in process | |
602 | * context at some later time. | |
1da177e4 LT |
603 | */ |
604 | void key_put(struct key *key) | |
605 | { | |
606 | if (key) { | |
607 | key_check(key); | |
608 | ||
609 | if (atomic_dec_and_test(&key->usage)) | |
3b07e9ca | 610 | schedule_work(&key_gc_work); |
1da177e4 | 611 | } |
a8b17ed0 | 612 | } |
1da177e4 LT |
613 | EXPORT_SYMBOL(key_put); |
614 | ||
1da177e4 | 615 | /* |
973c9f4f | 616 | * Find a key by its serial number. |
1da177e4 LT |
617 | */ |
618 | struct key *key_lookup(key_serial_t id) | |
619 | { | |
620 | struct rb_node *n; | |
621 | struct key *key; | |
622 | ||
623 | spin_lock(&key_serial_lock); | |
624 | ||
625 | /* search the tree for the specified key */ | |
626 | n = key_serial_tree.rb_node; | |
627 | while (n) { | |
628 | key = rb_entry(n, struct key, serial_node); | |
629 | ||
630 | if (id < key->serial) | |
631 | n = n->rb_left; | |
632 | else if (id > key->serial) | |
633 | n = n->rb_right; | |
634 | else | |
635 | goto found; | |
636 | } | |
637 | ||
973c9f4f | 638 | not_found: |
1da177e4 LT |
639 | key = ERR_PTR(-ENOKEY); |
640 | goto error; | |
641 | ||
973c9f4f | 642 | found: |
5593122e DH |
643 | /* pretend it doesn't exist if it is awaiting deletion */ |
644 | if (atomic_read(&key->usage) == 0) | |
1da177e4 LT |
645 | goto not_found; |
646 | ||
647 | /* this races with key_put(), but that doesn't matter since key_put() | |
648 | * doesn't actually change the key | |
649 | */ | |
650 | atomic_inc(&key->usage); | |
651 | ||
973c9f4f | 652 | error: |
1da177e4 LT |
653 | spin_unlock(&key_serial_lock); |
654 | return key; | |
a8b17ed0 | 655 | } |
1da177e4 | 656 | |
1da177e4 | 657 | /* |
973c9f4f DH |
658 | * Find and lock the specified key type against removal. |
659 | * | |
660 | * We return with the sem read-locked if successful. If the type wasn't | |
661 | * available -ENOKEY is returned instead. | |
1da177e4 LT |
662 | */ |
663 | struct key_type *key_type_lookup(const char *type) | |
664 | { | |
665 | struct key_type *ktype; | |
666 | ||
667 | down_read(&key_types_sem); | |
668 | ||
669 | /* look up the key type to see if it's one of the registered kernel | |
670 | * types */ | |
671 | list_for_each_entry(ktype, &key_types_list, link) { | |
672 | if (strcmp(ktype->name, type) == 0) | |
673 | goto found_kernel_type; | |
674 | } | |
675 | ||
676 | up_read(&key_types_sem); | |
677 | ktype = ERR_PTR(-ENOKEY); | |
678 | ||
973c9f4f | 679 | found_kernel_type: |
1da177e4 | 680 | return ktype; |
a8b17ed0 | 681 | } |
1da177e4 | 682 | |
59e6b9c1 BS |
683 | void key_set_timeout(struct key *key, unsigned timeout) |
684 | { | |
685 | struct timespec now; | |
686 | time_t expiry = 0; | |
687 | ||
688 | /* make the changes with the locks held to prevent races */ | |
689 | down_write(&key->sem); | |
690 | ||
691 | if (timeout > 0) { | |
692 | now = current_kernel_time(); | |
693 | expiry = now.tv_sec + timeout; | |
694 | } | |
695 | ||
696 | key->expiry = expiry; | |
697 | key_schedule_gc(key->expiry + key_gc_delay); | |
698 | ||
699 | up_write(&key->sem); | |
700 | } | |
701 | EXPORT_SYMBOL_GPL(key_set_timeout); | |
702 | ||
1da177e4 | 703 | /* |
973c9f4f | 704 | * Unlock a key type locked by key_type_lookup(). |
1da177e4 LT |
705 | */ |
706 | void key_type_put(struct key_type *ktype) | |
707 | { | |
708 | up_read(&key_types_sem); | |
a8b17ed0 | 709 | } |
1da177e4 | 710 | |
1da177e4 | 711 | /* |
973c9f4f DH |
712 | * Attempt to update an existing key. |
713 | * | |
714 | * The key is given to us with an incremented refcount that we need to discard | |
715 | * if we get an error. | |
1da177e4 | 716 | */ |
664cceb0 | 717 | static inline key_ref_t __key_update(key_ref_t key_ref, |
cf7f601c | 718 | struct key_preparsed_payload *prep) |
1da177e4 | 719 | { |
664cceb0 | 720 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
721 | int ret; |
722 | ||
723 | /* need write permission on the key to update it */ | |
29db9190 DH |
724 | ret = key_permission(key_ref, KEY_WRITE); |
725 | if (ret < 0) | |
1da177e4 LT |
726 | goto error; |
727 | ||
728 | ret = -EEXIST; | |
729 | if (!key->type->update) | |
730 | goto error; | |
731 | ||
732 | down_write(&key->sem); | |
733 | ||
cf7f601c | 734 | ret = key->type->update(key, prep); |
76d8aeab | 735 | if (ret == 0) |
1da177e4 | 736 | /* updating a negative key instantiates it */ |
76d8aeab | 737 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
1da177e4 LT |
738 | |
739 | up_write(&key->sem); | |
740 | ||
741 | if (ret < 0) | |
742 | goto error; | |
664cceb0 DH |
743 | out: |
744 | return key_ref; | |
1da177e4 | 745 | |
664cceb0 | 746 | error: |
1da177e4 | 747 | key_put(key); |
664cceb0 | 748 | key_ref = ERR_PTR(ret); |
1da177e4 | 749 | goto out; |
a8b17ed0 | 750 | } |
1da177e4 | 751 | |
973c9f4f DH |
752 | /** |
753 | * key_create_or_update - Update or create and instantiate a key. | |
754 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
755 | * @type: The type of key. | |
756 | * @description: The searchable description for the key. | |
757 | * @payload: The data to use to instantiate or update the key. | |
758 | * @plen: The length of @payload. | |
759 | * @perm: The permissions mask for a new key. | |
760 | * @flags: The quota flags for a new key. | |
761 | * | |
762 | * Search the destination keyring for a key of the same description and if one | |
763 | * is found, update it, otherwise create and instantiate a new one and create a | |
764 | * link to it from that keyring. | |
765 | * | |
766 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
767 | * concocted. | |
768 | * | |
769 | * Returns a pointer to the new key if successful, -ENODEV if the key type | |
770 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the | |
771 | * caller isn't permitted to modify the keyring or the LSM did not permit | |
772 | * creation of the key. | |
773 | * | |
774 | * On success, the possession flag from the keyring ref will be tacked on to | |
775 | * the key ref before it is returned. | |
1da177e4 | 776 | */ |
664cceb0 DH |
777 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
778 | const char *type, | |
779 | const char *description, | |
780 | const void *payload, | |
781 | size_t plen, | |
6b79ccb5 | 782 | key_perm_t perm, |
7e047ef5 | 783 | unsigned long flags) |
1da177e4 | 784 | { |
ceb73c12 | 785 | unsigned long prealloc; |
cf7f601c | 786 | struct key_preparsed_payload prep; |
d84f4f99 | 787 | const struct cred *cred = current_cred(); |
1da177e4 | 788 | struct key_type *ktype; |
664cceb0 | 789 | struct key *keyring, *key = NULL; |
664cceb0 | 790 | key_ref_t key_ref; |
1da177e4 LT |
791 | int ret; |
792 | ||
1da177e4 LT |
793 | /* look up the key type to see if it's one of the registered kernel |
794 | * types */ | |
795 | ktype = key_type_lookup(type); | |
796 | if (IS_ERR(ktype)) { | |
664cceb0 | 797 | key_ref = ERR_PTR(-ENODEV); |
1da177e4 LT |
798 | goto error; |
799 | } | |
800 | ||
664cceb0 | 801 | key_ref = ERR_PTR(-EINVAL); |
cf7f601c DH |
802 | if (!ktype->match || !ktype->instantiate || |
803 | (!description && !ktype->preparse)) | |
804 | goto error_put_type; | |
1da177e4 | 805 | |
664cceb0 DH |
806 | keyring = key_ref_to_ptr(keyring_ref); |
807 | ||
808 | key_check(keyring); | |
809 | ||
c3a9d654 DH |
810 | key_ref = ERR_PTR(-ENOTDIR); |
811 | if (keyring->type != &key_type_keyring) | |
cf7f601c DH |
812 | goto error_put_type; |
813 | ||
814 | memset(&prep, 0, sizeof(prep)); | |
815 | prep.data = payload; | |
816 | prep.datalen = plen; | |
817 | prep.quotalen = ktype->def_datalen; | |
818 | if (ktype->preparse) { | |
819 | ret = ktype->preparse(&prep); | |
820 | if (ret < 0) { | |
821 | key_ref = ERR_PTR(ret); | |
822 | goto error_put_type; | |
823 | } | |
824 | if (!description) | |
825 | description = prep.description; | |
826 | key_ref = ERR_PTR(-EINVAL); | |
827 | if (!description) | |
828 | goto error_free_prep; | |
829 | } | |
c3a9d654 | 830 | |
f70e2e06 | 831 | ret = __key_link_begin(keyring, ktype, description, &prealloc); |
cf7f601c DH |
832 | if (ret < 0) { |
833 | key_ref = ERR_PTR(ret); | |
834 | goto error_free_prep; | |
835 | } | |
664cceb0 DH |
836 | |
837 | /* if we're going to allocate a new key, we're going to have | |
838 | * to modify the keyring */ | |
29db9190 DH |
839 | ret = key_permission(keyring_ref, KEY_WRITE); |
840 | if (ret < 0) { | |
841 | key_ref = ERR_PTR(ret); | |
cf7f601c | 842 | goto error_link_end; |
29db9190 | 843 | } |
664cceb0 | 844 | |
1d9b7d97 DH |
845 | /* if it's possible to update this type of key, search for an existing |
846 | * key of the same type and description in the destination keyring and | |
847 | * update that instead if possible | |
1da177e4 | 848 | */ |
1d9b7d97 DH |
849 | if (ktype->update) { |
850 | key_ref = __keyring_search_one(keyring_ref, ktype, description, | |
851 | 0); | |
852 | if (!IS_ERR(key_ref)) | |
853 | goto found_matching_key; | |
854 | } | |
1da177e4 | 855 | |
6b79ccb5 AR |
856 | /* if the client doesn't provide, decide on the permissions we want */ |
857 | if (perm == KEY_PERM_UNDEF) { | |
858 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; | |
96b5c8fe | 859 | perm |= KEY_USR_VIEW; |
1da177e4 | 860 | |
6b79ccb5 | 861 | if (ktype->read) |
96b5c8fe | 862 | perm |= KEY_POS_READ; |
1da177e4 | 863 | |
6b79ccb5 | 864 | if (ktype == &key_type_keyring || ktype->update) |
96b5c8fe | 865 | perm |= KEY_POS_WRITE; |
6b79ccb5 | 866 | } |
1da177e4 LT |
867 | |
868 | /* allocate a new key */ | |
d84f4f99 DH |
869 | key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred, |
870 | perm, flags); | |
1da177e4 | 871 | if (IS_ERR(key)) { |
e231c2ee | 872 | key_ref = ERR_CAST(key); |
cf7f601c | 873 | goto error_link_end; |
1da177e4 LT |
874 | } |
875 | ||
876 | /* instantiate it and link it into the target keyring */ | |
cf7f601c | 877 | ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &prealloc); |
1da177e4 LT |
878 | if (ret < 0) { |
879 | key_put(key); | |
664cceb0 | 880 | key_ref = ERR_PTR(ret); |
cf7f601c | 881 | goto error_link_end; |
1da177e4 LT |
882 | } |
883 | ||
664cceb0 DH |
884 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
885 | ||
cf7f601c | 886 | error_link_end: |
f70e2e06 | 887 | __key_link_end(keyring, ktype, prealloc); |
cf7f601c DH |
888 | error_free_prep: |
889 | if (ktype->preparse) | |
890 | ktype->free_preparse(&prep); | |
891 | error_put_type: | |
1da177e4 | 892 | key_type_put(ktype); |
cf7f601c | 893 | error: |
664cceb0 | 894 | return key_ref; |
1da177e4 LT |
895 | |
896 | found_matching_key: | |
897 | /* we found a matching key, so we're going to try to update it | |
898 | * - we can drop the locks first as we have the key pinned | |
899 | */ | |
f70e2e06 | 900 | __key_link_end(keyring, ktype, prealloc); |
1da177e4 | 901 | |
20d94bc9 DH |
902 | key = key_ref_to_ptr(key_ref); |
903 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) { | |
904 | ret = wait_for_key_construction(key, true); | |
905 | if (ret < 0) { | |
906 | key_ref_put(key_ref); | |
907 | key_ref = ERR_PTR(ret); | |
908 | goto error_free_prep; | |
909 | } | |
910 | } | |
911 | ||
cf7f601c DH |
912 | key_ref = __key_update(key_ref, &prep); |
913 | goto error_free_prep; | |
a8b17ed0 | 914 | } |
1da177e4 LT |
915 | EXPORT_SYMBOL(key_create_or_update); |
916 | ||
973c9f4f DH |
917 | /** |
918 | * key_update - Update a key's contents. | |
919 | * @key_ref: The pointer (plus possession flag) to the key. | |
920 | * @payload: The data to be used to update the key. | |
921 | * @plen: The length of @payload. | |
922 | * | |
923 | * Attempt to update the contents of a key with the given payload data. The | |
924 | * caller must be granted Write permission on the key. Negative keys can be | |
925 | * instantiated by this method. | |
926 | * | |
927 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key | |
928 | * type does not support updating. The key type may return other errors. | |
1da177e4 | 929 | */ |
664cceb0 | 930 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
1da177e4 | 931 | { |
cf7f601c | 932 | struct key_preparsed_payload prep; |
664cceb0 | 933 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
934 | int ret; |
935 | ||
936 | key_check(key); | |
937 | ||
938 | /* the key must be writable */ | |
29db9190 DH |
939 | ret = key_permission(key_ref, KEY_WRITE); |
940 | if (ret < 0) | |
1da177e4 LT |
941 | goto error; |
942 | ||
943 | /* attempt to update it if supported */ | |
944 | ret = -EOPNOTSUPP; | |
cf7f601c DH |
945 | if (!key->type->update) |
946 | goto error; | |
1da177e4 | 947 | |
cf7f601c DH |
948 | memset(&prep, 0, sizeof(prep)); |
949 | prep.data = payload; | |
950 | prep.datalen = plen; | |
951 | prep.quotalen = key->type->def_datalen; | |
952 | if (key->type->preparse) { | |
953 | ret = key->type->preparse(&prep); | |
954 | if (ret < 0) | |
955 | goto error; | |
1da177e4 LT |
956 | } |
957 | ||
cf7f601c DH |
958 | down_write(&key->sem); |
959 | ||
960 | ret = key->type->update(key, &prep); | |
961 | if (ret == 0) | |
962 | /* updating a negative key instantiates it */ | |
963 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); | |
964 | ||
965 | up_write(&key->sem); | |
966 | ||
967 | if (key->type->preparse) | |
968 | key->type->free_preparse(&prep); | |
969 | error: | |
1da177e4 | 970 | return ret; |
a8b17ed0 | 971 | } |
1da177e4 LT |
972 | EXPORT_SYMBOL(key_update); |
973 | ||
973c9f4f DH |
974 | /** |
975 | * key_revoke - Revoke a key. | |
976 | * @key: The key to be revoked. | |
977 | * | |
978 | * Mark a key as being revoked and ask the type to free up its resources. The | |
979 | * revocation timeout is set and the key and all its links will be | |
980 | * automatically garbage collected after key_gc_delay amount of time if they | |
981 | * are not manually dealt with first. | |
1da177e4 LT |
982 | */ |
983 | void key_revoke(struct key *key) | |
984 | { | |
5d135440 DH |
985 | struct timespec now; |
986 | time_t time; | |
987 | ||
1da177e4 LT |
988 | key_check(key); |
989 | ||
76181c13 DH |
990 | /* make sure no one's trying to change or use the key when we mark it |
991 | * - we tell lockdep that we might nest because we might be revoking an | |
992 | * authorisation key whilst holding the sem on a key we've just | |
993 | * instantiated | |
994 | */ | |
995 | down_write_nested(&key->sem, 1); | |
996 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && | |
997 | key->type->revoke) | |
04c567d9 DH |
998 | key->type->revoke(key); |
999 | ||
5d135440 DH |
1000 | /* set the death time to no more than the expiry time */ |
1001 | now = current_kernel_time(); | |
1002 | time = now.tv_sec; | |
1003 | if (key->revoked_at == 0 || key->revoked_at > time) { | |
1004 | key->revoked_at = time; | |
c08ef808 | 1005 | key_schedule_gc(key->revoked_at + key_gc_delay); |
5d135440 DH |
1006 | } |
1007 | ||
1da177e4 | 1008 | up_write(&key->sem); |
a8b17ed0 | 1009 | } |
1da177e4 LT |
1010 | EXPORT_SYMBOL(key_revoke); |
1011 | ||
fd75815f DH |
1012 | /** |
1013 | * key_invalidate - Invalidate a key. | |
1014 | * @key: The key to be invalidated. | |
1015 | * | |
1016 | * Mark a key as being invalidated and have it cleaned up immediately. The key | |
1017 | * is ignored by all searches and other operations from this point. | |
1018 | */ | |
1019 | void key_invalidate(struct key *key) | |
1020 | { | |
1021 | kenter("%d", key_serial(key)); | |
1022 | ||
1023 | key_check(key); | |
1024 | ||
1025 | if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { | |
1026 | down_write_nested(&key->sem, 1); | |
1027 | if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) | |
1028 | key_schedule_gc_links(); | |
1029 | up_write(&key->sem); | |
1030 | } | |
1031 | } | |
1032 | EXPORT_SYMBOL(key_invalidate); | |
1033 | ||
973c9f4f DH |
1034 | /** |
1035 | * register_key_type - Register a type of key. | |
1036 | * @ktype: The new key type. | |
1037 | * | |
1038 | * Register a new key type. | |
1039 | * | |
1040 | * Returns 0 on success or -EEXIST if a type of this name already exists. | |
1da177e4 LT |
1041 | */ |
1042 | int register_key_type(struct key_type *ktype) | |
1043 | { | |
1044 | struct key_type *p; | |
1045 | int ret; | |
1046 | ||
7845bc39 DH |
1047 | memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); |
1048 | ||
1da177e4 LT |
1049 | ret = -EEXIST; |
1050 | down_write(&key_types_sem); | |
1051 | ||
1052 | /* disallow key types with the same name */ | |
1053 | list_for_each_entry(p, &key_types_list, link) { | |
1054 | if (strcmp(p->name, ktype->name) == 0) | |
1055 | goto out; | |
1056 | } | |
1057 | ||
1058 | /* store the type */ | |
1059 | list_add(&ktype->link, &key_types_list); | |
1eb1bcf5 DH |
1060 | |
1061 | pr_notice("Key type %s registered\n", ktype->name); | |
1da177e4 LT |
1062 | ret = 0; |
1063 | ||
973c9f4f | 1064 | out: |
1da177e4 LT |
1065 | up_write(&key_types_sem); |
1066 | return ret; | |
a8b17ed0 | 1067 | } |
1da177e4 LT |
1068 | EXPORT_SYMBOL(register_key_type); |
1069 | ||
973c9f4f DH |
1070 | /** |
1071 | * unregister_key_type - Unregister a type of key. | |
1072 | * @ktype: The key type. | |
1073 | * | |
1074 | * Unregister a key type and mark all the extant keys of this type as dead. | |
1075 | * Those keys of this type are then destroyed to get rid of their payloads and | |
1076 | * they and their links will be garbage collected as soon as possible. | |
1da177e4 LT |
1077 | */ |
1078 | void unregister_key_type(struct key_type *ktype) | |
1079 | { | |
1da177e4 | 1080 | down_write(&key_types_sem); |
1da177e4 | 1081 | list_del_init(&ktype->link); |
0c061b57 DH |
1082 | downgrade_write(&key_types_sem); |
1083 | key_gc_keytype(ktype); | |
1eb1bcf5 | 1084 | pr_notice("Key type %s unregistered\n", ktype->name); |
0c061b57 | 1085 | up_read(&key_types_sem); |
a8b17ed0 | 1086 | } |
1da177e4 LT |
1087 | EXPORT_SYMBOL(unregister_key_type); |
1088 | ||
1da177e4 | 1089 | /* |
973c9f4f | 1090 | * Initialise the key management state. |
1da177e4 LT |
1091 | */ |
1092 | void __init key_init(void) | |
1093 | { | |
1094 | /* allocate a slab in which we can store keys */ | |
1095 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), | |
20c2df83 | 1096 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1097 | |
1098 | /* add the special key types */ | |
1099 | list_add_tail(&key_type_keyring.link, &key_types_list); | |
1100 | list_add_tail(&key_type_dead.link, &key_types_list); | |
1101 | list_add_tail(&key_type_user.link, &key_types_list); | |
9f6ed2ca | 1102 | list_add_tail(&key_type_logon.link, &key_types_list); |
1da177e4 LT |
1103 | |
1104 | /* record the root user tracking */ | |
1105 | rb_link_node(&root_key_user.node, | |
1106 | NULL, | |
1107 | &key_user_tree.rb_node); | |
1108 | ||
1109 | rb_insert_color(&root_key_user.node, | |
1110 | &key_user_tree); | |
a8b17ed0 | 1111 | } |