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 | ||
16feef43 DH |
245 | desclen = strlen(desc); |
246 | quotalen = desclen + 1 + type->def_datalen; | |
1da177e4 LT |
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 */ | |
2480f57f | 275 | key = kmem_cache_zalloc(key_jar, GFP_KERNEL); |
1da177e4 LT |
276 | if (!key) |
277 | goto no_memory_2; | |
278 | ||
279 | if (desc) { | |
16feef43 DH |
280 | key->index_key.desc_len = desclen; |
281 | key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); | |
1da177e4 LT |
282 | if (!key->description) |
283 | goto no_memory_3; | |
1da177e4 LT |
284 | } |
285 | ||
286 | atomic_set(&key->usage, 1); | |
1da177e4 | 287 | init_rwsem(&key->sem); |
7845bc39 | 288 | lockdep_set_class(&key->sem, &type->lock_class); |
16feef43 | 289 | key->index_key.type = type; |
1da177e4 LT |
290 | key->user = user; |
291 | key->quotalen = quotalen; | |
292 | key->datalen = type->def_datalen; | |
293 | key->uid = uid; | |
294 | key->gid = gid; | |
295 | key->perm = perm; | |
1da177e4 | 296 | |
7e047ef5 | 297 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
76d8aeab | 298 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
008643b8 DH |
299 | if (flags & KEY_ALLOC_TRUSTED) |
300 | key->flags |= 1 << KEY_FLAG_TRUSTED; | |
1da177e4 | 301 | |
1da177e4 LT |
302 | #ifdef KEY_DEBUGGING |
303 | key->magic = KEY_DEBUG_MAGIC; | |
304 | #endif | |
305 | ||
29db9190 | 306 | /* let the security module know about the key */ |
d84f4f99 | 307 | ret = security_key_alloc(key, cred, flags); |
29db9190 DH |
308 | if (ret < 0) |
309 | goto security_error; | |
310 | ||
1da177e4 LT |
311 | /* publish the key by giving it a serial number */ |
312 | atomic_inc(&user->nkeys); | |
313 | key_alloc_serial(key); | |
314 | ||
29db9190 | 315 | error: |
1da177e4 LT |
316 | return key; |
317 | ||
29db9190 DH |
318 | security_error: |
319 | kfree(key->description); | |
1da177e4 | 320 | kmem_cache_free(key_jar, key); |
7e047ef5 | 321 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
1da177e4 LT |
322 | spin_lock(&user->lock); |
323 | user->qnkeys--; | |
324 | user->qnbytes -= quotalen; | |
325 | spin_unlock(&user->lock); | |
326 | } | |
327 | key_user_put(user); | |
29db9190 DH |
328 | key = ERR_PTR(ret); |
329 | goto error; | |
330 | ||
331 | no_memory_3: | |
332 | kmem_cache_free(key_jar, key); | |
333 | no_memory_2: | |
7e047ef5 | 334 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
29db9190 DH |
335 | spin_lock(&user->lock); |
336 | user->qnkeys--; | |
337 | user->qnbytes -= quotalen; | |
338 | spin_unlock(&user->lock); | |
339 | } | |
340 | key_user_put(user); | |
341 | no_memory_1: | |
1da177e4 LT |
342 | key = ERR_PTR(-ENOMEM); |
343 | goto error; | |
344 | ||
29db9190 | 345 | no_quota: |
1da177e4 LT |
346 | spin_unlock(&user->lock); |
347 | key_user_put(user); | |
348 | key = ERR_PTR(-EDQUOT); | |
349 | goto error; | |
a8b17ed0 | 350 | } |
1da177e4 LT |
351 | EXPORT_SYMBOL(key_alloc); |
352 | ||
973c9f4f DH |
353 | /** |
354 | * key_payload_reserve - Adjust data quota reservation for the key's payload | |
355 | * @key: The key to make the reservation for. | |
356 | * @datalen: The amount of data payload the caller now wants. | |
357 | * | |
358 | * Adjust the amount of the owning user's key data quota that a key reserves. | |
359 | * If the amount is increased, then -EDQUOT may be returned if there isn't | |
360 | * enough free quota available. | |
361 | * | |
362 | * If successful, 0 is returned. | |
1da177e4 LT |
363 | */ |
364 | int key_payload_reserve(struct key *key, size_t datalen) | |
365 | { | |
c5b60b5e | 366 | int delta = (int)datalen - key->datalen; |
1da177e4 LT |
367 | int ret = 0; |
368 | ||
369 | key_check(key); | |
370 | ||
371 | /* contemplate the quota adjustment */ | |
76d8aeab | 372 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
9a56c2db | 373 | unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
374 | key_quota_root_maxbytes : key_quota_maxbytes; |
375 | ||
1da177e4 LT |
376 | spin_lock(&key->user->lock); |
377 | ||
378 | if (delta > 0 && | |
0b77f5bf DH |
379 | (key->user->qnbytes + delta >= maxbytes || |
380 | key->user->qnbytes + delta < key->user->qnbytes)) { | |
1da177e4 LT |
381 | ret = -EDQUOT; |
382 | } | |
383 | else { | |
384 | key->user->qnbytes += delta; | |
385 | key->quotalen += delta; | |
386 | } | |
387 | spin_unlock(&key->user->lock); | |
388 | } | |
389 | ||
390 | /* change the recorded data length if that didn't generate an error */ | |
391 | if (ret == 0) | |
392 | key->datalen = datalen; | |
393 | ||
394 | return ret; | |
a8b17ed0 | 395 | } |
1da177e4 LT |
396 | EXPORT_SYMBOL(key_payload_reserve); |
397 | ||
1da177e4 | 398 | /* |
973c9f4f DH |
399 | * Instantiate a key and link it into the target keyring atomically. Must be |
400 | * called with the target keyring's semaphore writelocked. The target key's | |
401 | * semaphore need not be locked as instantiation is serialised by | |
402 | * key_construction_mutex. | |
1da177e4 LT |
403 | */ |
404 | static int __key_instantiate_and_link(struct key *key, | |
cf7f601c | 405 | struct key_preparsed_payload *prep, |
3e30148c | 406 | struct key *keyring, |
f70e2e06 | 407 | struct key *authkey, |
b2a4df20 | 408 | struct assoc_array_edit **_edit) |
1da177e4 LT |
409 | { |
410 | int ret, awaken; | |
411 | ||
412 | key_check(key); | |
413 | key_check(keyring); | |
414 | ||
415 | awaken = 0; | |
416 | ret = -EBUSY; | |
417 | ||
76181c13 | 418 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
419 | |
420 | /* can't instantiate twice */ | |
76d8aeab | 421 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
1da177e4 | 422 | /* instantiate the key */ |
cf7f601c | 423 | ret = key->type->instantiate(key, prep); |
1da177e4 LT |
424 | |
425 | if (ret == 0) { | |
426 | /* mark the key as being instantiated */ | |
1da177e4 | 427 | atomic_inc(&key->user->nikeys); |
76d8aeab | 428 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
1da177e4 | 429 | |
76d8aeab | 430 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 431 | awaken = 1; |
1da177e4 LT |
432 | |
433 | /* and link it into the destination keyring */ | |
434 | if (keyring) | |
b2a4df20 | 435 | __key_link(key, _edit); |
3e30148c DH |
436 | |
437 | /* disable the authorisation key */ | |
d84f4f99 DH |
438 | if (authkey) |
439 | key_revoke(authkey); | |
1da177e4 LT |
440 | } |
441 | } | |
442 | ||
76181c13 | 443 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
444 | |
445 | /* wake up anyone waiting for a key to be constructed */ | |
446 | if (awaken) | |
76181c13 | 447 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 LT |
448 | |
449 | return ret; | |
a8b17ed0 | 450 | } |
1da177e4 | 451 | |
973c9f4f DH |
452 | /** |
453 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. | |
454 | * @key: The key to instantiate. | |
455 | * @data: The data to use to instantiate the keyring. | |
456 | * @datalen: The length of @data. | |
457 | * @keyring: Keyring to create a link in on success (or NULL). | |
458 | * @authkey: The authorisation token permitting instantiation. | |
459 | * | |
460 | * Instantiate a key that's in the uninstantiated state using the provided data | |
461 | * and, if successful, link it in to the destination keyring if one is | |
462 | * supplied. | |
463 | * | |
464 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
465 | * waiting for the key is woken up. If the key was already instantiated, | |
466 | * -EBUSY will be returned. | |
1da177e4 LT |
467 | */ |
468 | int key_instantiate_and_link(struct key *key, | |
469 | const void *data, | |
470 | size_t datalen, | |
3e30148c | 471 | struct key *keyring, |
d84f4f99 | 472 | struct key *authkey) |
1da177e4 | 473 | { |
cf7f601c | 474 | struct key_preparsed_payload prep; |
b2a4df20 | 475 | struct assoc_array_edit *edit; |
1da177e4 LT |
476 | int ret; |
477 | ||
cf7f601c DH |
478 | memset(&prep, 0, sizeof(prep)); |
479 | prep.data = data; | |
480 | prep.datalen = datalen; | |
481 | prep.quotalen = key->type->def_datalen; | |
482 | if (key->type->preparse) { | |
483 | ret = key->type->preparse(&prep); | |
484 | if (ret < 0) | |
485 | goto error; | |
486 | } | |
487 | ||
f70e2e06 | 488 | if (keyring) { |
b2a4df20 | 489 | ret = __key_link_begin(keyring, &key->index_key, &edit); |
f70e2e06 | 490 | if (ret < 0) |
cf7f601c | 491 | goto error_free_preparse; |
f70e2e06 | 492 | } |
1da177e4 | 493 | |
b2a4df20 | 494 | ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); |
1da177e4 LT |
495 | |
496 | if (keyring) | |
b2a4df20 | 497 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 | 498 | |
cf7f601c DH |
499 | error_free_preparse: |
500 | if (key->type->preparse) | |
501 | key->type->free_preparse(&prep); | |
502 | error: | |
1da177e4 | 503 | return ret; |
a8b17ed0 | 504 | } |
1da177e4 LT |
505 | |
506 | EXPORT_SYMBOL(key_instantiate_and_link); | |
507 | ||
973c9f4f | 508 | /** |
fdd1b945 | 509 | * key_reject_and_link - Negatively instantiate a key and link it into the keyring. |
973c9f4f DH |
510 | * @key: The key to instantiate. |
511 | * @timeout: The timeout on the negative key. | |
fdd1b945 | 512 | * @error: The error to return when the key is hit. |
973c9f4f DH |
513 | * @keyring: Keyring to create a link in on success (or NULL). |
514 | * @authkey: The authorisation token permitting instantiation. | |
515 | * | |
516 | * Negatively instantiate a key that's in the uninstantiated state and, if | |
fdd1b945 DH |
517 | * successful, set its timeout and stored error and link it in to the |
518 | * destination keyring if one is supplied. The key and any links to the key | |
519 | * will be automatically garbage collected after the timeout expires. | |
973c9f4f DH |
520 | * |
521 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
fdd1b945 DH |
522 | * them to return the stored error code (typically ENOKEY) until the negative |
523 | * key expires. | |
973c9f4f DH |
524 | * |
525 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
526 | * waiting for the key is woken up. If the key was already instantiated, | |
527 | * -EBUSY will be returned. | |
1da177e4 | 528 | */ |
fdd1b945 | 529 | int key_reject_and_link(struct key *key, |
1da177e4 | 530 | unsigned timeout, |
fdd1b945 | 531 | unsigned error, |
3e30148c | 532 | struct key *keyring, |
d84f4f99 | 533 | struct key *authkey) |
1da177e4 | 534 | { |
b2a4df20 | 535 | struct assoc_array_edit *edit; |
1da177e4 | 536 | struct timespec now; |
f70e2e06 | 537 | int ret, awaken, link_ret = 0; |
1da177e4 LT |
538 | |
539 | key_check(key); | |
540 | key_check(keyring); | |
541 | ||
542 | awaken = 0; | |
543 | ret = -EBUSY; | |
544 | ||
545 | if (keyring) | |
b2a4df20 | 546 | link_ret = __key_link_begin(keyring, &key->index_key, &edit); |
1da177e4 | 547 | |
76181c13 | 548 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
549 | |
550 | /* can't instantiate twice */ | |
76d8aeab | 551 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
1da177e4 | 552 | /* mark the key as being negatively instantiated */ |
1da177e4 | 553 | atomic_inc(&key->user->nikeys); |
74792b00 DH |
554 | key->type_data.reject_error = -error; |
555 | smp_wmb(); | |
76d8aeab DH |
556 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
557 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); | |
1da177e4 LT |
558 | now = current_kernel_time(); |
559 | key->expiry = now.tv_sec + timeout; | |
c08ef808 | 560 | key_schedule_gc(key->expiry + key_gc_delay); |
1da177e4 | 561 | |
76d8aeab | 562 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 563 | awaken = 1; |
1da177e4 | 564 | |
1da177e4 LT |
565 | ret = 0; |
566 | ||
567 | /* and link it into the destination keyring */ | |
f70e2e06 | 568 | if (keyring && link_ret == 0) |
b2a4df20 | 569 | __key_link(key, &edit); |
3e30148c DH |
570 | |
571 | /* disable the authorisation key */ | |
d84f4f99 DH |
572 | if (authkey) |
573 | key_revoke(authkey); | |
1da177e4 LT |
574 | } |
575 | ||
76181c13 | 576 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
577 | |
578 | if (keyring) | |
b2a4df20 | 579 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 LT |
580 | |
581 | /* wake up anyone waiting for a key to be constructed */ | |
582 | if (awaken) | |
76181c13 | 583 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 | 584 | |
f70e2e06 | 585 | return ret == 0 ? link_ret : ret; |
a8b17ed0 | 586 | } |
fdd1b945 | 587 | EXPORT_SYMBOL(key_reject_and_link); |
1da177e4 | 588 | |
973c9f4f DH |
589 | /** |
590 | * key_put - Discard a reference to a key. | |
591 | * @key: The key to discard a reference from. | |
592 | * | |
593 | * Discard a reference to a key, and when all the references are gone, we | |
594 | * schedule the cleanup task to come and pull it out of the tree in process | |
595 | * context at some later time. | |
1da177e4 LT |
596 | */ |
597 | void key_put(struct key *key) | |
598 | { | |
599 | if (key) { | |
600 | key_check(key); | |
601 | ||
602 | if (atomic_dec_and_test(&key->usage)) | |
3b07e9ca | 603 | schedule_work(&key_gc_work); |
1da177e4 | 604 | } |
a8b17ed0 | 605 | } |
1da177e4 LT |
606 | EXPORT_SYMBOL(key_put); |
607 | ||
1da177e4 | 608 | /* |
973c9f4f | 609 | * Find a key by its serial number. |
1da177e4 LT |
610 | */ |
611 | struct key *key_lookup(key_serial_t id) | |
612 | { | |
613 | struct rb_node *n; | |
614 | struct key *key; | |
615 | ||
616 | spin_lock(&key_serial_lock); | |
617 | ||
618 | /* search the tree for the specified key */ | |
619 | n = key_serial_tree.rb_node; | |
620 | while (n) { | |
621 | key = rb_entry(n, struct key, serial_node); | |
622 | ||
623 | if (id < key->serial) | |
624 | n = n->rb_left; | |
625 | else if (id > key->serial) | |
626 | n = n->rb_right; | |
627 | else | |
628 | goto found; | |
629 | } | |
630 | ||
973c9f4f | 631 | not_found: |
1da177e4 LT |
632 | key = ERR_PTR(-ENOKEY); |
633 | goto error; | |
634 | ||
973c9f4f | 635 | found: |
5593122e DH |
636 | /* pretend it doesn't exist if it is awaiting deletion */ |
637 | if (atomic_read(&key->usage) == 0) | |
1da177e4 LT |
638 | goto not_found; |
639 | ||
640 | /* this races with key_put(), but that doesn't matter since key_put() | |
641 | * doesn't actually change the key | |
642 | */ | |
ccc3e6d9 | 643 | __key_get(key); |
1da177e4 | 644 | |
973c9f4f | 645 | error: |
1da177e4 LT |
646 | spin_unlock(&key_serial_lock); |
647 | return key; | |
a8b17ed0 | 648 | } |
1da177e4 | 649 | |
1da177e4 | 650 | /* |
973c9f4f DH |
651 | * Find and lock the specified key type against removal. |
652 | * | |
653 | * We return with the sem read-locked if successful. If the type wasn't | |
654 | * available -ENOKEY is returned instead. | |
1da177e4 LT |
655 | */ |
656 | struct key_type *key_type_lookup(const char *type) | |
657 | { | |
658 | struct key_type *ktype; | |
659 | ||
660 | down_read(&key_types_sem); | |
661 | ||
662 | /* look up the key type to see if it's one of the registered kernel | |
663 | * types */ | |
664 | list_for_each_entry(ktype, &key_types_list, link) { | |
665 | if (strcmp(ktype->name, type) == 0) | |
666 | goto found_kernel_type; | |
667 | } | |
668 | ||
669 | up_read(&key_types_sem); | |
670 | ktype = ERR_PTR(-ENOKEY); | |
671 | ||
973c9f4f | 672 | found_kernel_type: |
1da177e4 | 673 | return ktype; |
a8b17ed0 | 674 | } |
1da177e4 | 675 | |
59e6b9c1 BS |
676 | void key_set_timeout(struct key *key, unsigned timeout) |
677 | { | |
678 | struct timespec now; | |
679 | time_t expiry = 0; | |
680 | ||
681 | /* make the changes with the locks held to prevent races */ | |
682 | down_write(&key->sem); | |
683 | ||
684 | if (timeout > 0) { | |
685 | now = current_kernel_time(); | |
686 | expiry = now.tv_sec + timeout; | |
687 | } | |
688 | ||
689 | key->expiry = expiry; | |
690 | key_schedule_gc(key->expiry + key_gc_delay); | |
691 | ||
692 | up_write(&key->sem); | |
693 | } | |
694 | EXPORT_SYMBOL_GPL(key_set_timeout); | |
695 | ||
1da177e4 | 696 | /* |
973c9f4f | 697 | * Unlock a key type locked by key_type_lookup(). |
1da177e4 LT |
698 | */ |
699 | void key_type_put(struct key_type *ktype) | |
700 | { | |
701 | up_read(&key_types_sem); | |
a8b17ed0 | 702 | } |
1da177e4 | 703 | |
1da177e4 | 704 | /* |
973c9f4f DH |
705 | * Attempt to update an existing key. |
706 | * | |
707 | * The key is given to us with an incremented refcount that we need to discard | |
708 | * if we get an error. | |
1da177e4 | 709 | */ |
664cceb0 | 710 | static inline key_ref_t __key_update(key_ref_t key_ref, |
cf7f601c | 711 | struct key_preparsed_payload *prep) |
1da177e4 | 712 | { |
664cceb0 | 713 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
714 | int ret; |
715 | ||
716 | /* need write permission on the key to update it */ | |
f5895943 | 717 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 718 | if (ret < 0) |
1da177e4 LT |
719 | goto error; |
720 | ||
721 | ret = -EEXIST; | |
722 | if (!key->type->update) | |
723 | goto error; | |
724 | ||
725 | down_write(&key->sem); | |
726 | ||
cf7f601c | 727 | ret = key->type->update(key, prep); |
76d8aeab | 728 | if (ret == 0) |
1da177e4 | 729 | /* updating a negative key instantiates it */ |
76d8aeab | 730 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
1da177e4 LT |
731 | |
732 | up_write(&key->sem); | |
733 | ||
734 | if (ret < 0) | |
735 | goto error; | |
664cceb0 DH |
736 | out: |
737 | return key_ref; | |
1da177e4 | 738 | |
664cceb0 | 739 | error: |
1da177e4 | 740 | key_put(key); |
664cceb0 | 741 | key_ref = ERR_PTR(ret); |
1da177e4 | 742 | goto out; |
a8b17ed0 | 743 | } |
1da177e4 | 744 | |
973c9f4f DH |
745 | /** |
746 | * key_create_or_update - Update or create and instantiate a key. | |
747 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
748 | * @type: The type of key. | |
749 | * @description: The searchable description for the key. | |
750 | * @payload: The data to use to instantiate or update the key. | |
751 | * @plen: The length of @payload. | |
752 | * @perm: The permissions mask for a new key. | |
753 | * @flags: The quota flags for a new key. | |
754 | * | |
755 | * Search the destination keyring for a key of the same description and if one | |
756 | * is found, update it, otherwise create and instantiate a new one and create a | |
757 | * link to it from that keyring. | |
758 | * | |
759 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
760 | * concocted. | |
761 | * | |
762 | * Returns a pointer to the new key if successful, -ENODEV if the key type | |
763 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the | |
764 | * caller isn't permitted to modify the keyring or the LSM did not permit | |
765 | * creation of the key. | |
766 | * | |
767 | * On success, the possession flag from the keyring ref will be tacked on to | |
768 | * the key ref before it is returned. | |
1da177e4 | 769 | */ |
664cceb0 DH |
770 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
771 | const char *type, | |
772 | const char *description, | |
773 | const void *payload, | |
774 | size_t plen, | |
6b79ccb5 | 775 | key_perm_t perm, |
7e047ef5 | 776 | unsigned long flags) |
1da177e4 | 777 | { |
16feef43 DH |
778 | struct keyring_index_key index_key = { |
779 | .description = description, | |
780 | }; | |
cf7f601c | 781 | struct key_preparsed_payload prep; |
b2a4df20 | 782 | struct assoc_array_edit *edit; |
d84f4f99 | 783 | const struct cred *cred = current_cred(); |
664cceb0 | 784 | struct key *keyring, *key = NULL; |
664cceb0 | 785 | key_ref_t key_ref; |
1da177e4 LT |
786 | int ret; |
787 | ||
1da177e4 LT |
788 | /* look up the key type to see if it's one of the registered kernel |
789 | * types */ | |
16feef43 DH |
790 | index_key.type = key_type_lookup(type); |
791 | if (IS_ERR(index_key.type)) { | |
664cceb0 | 792 | key_ref = ERR_PTR(-ENODEV); |
1da177e4 LT |
793 | goto error; |
794 | } | |
795 | ||
664cceb0 | 796 | key_ref = ERR_PTR(-EINVAL); |
16feef43 DH |
797 | if (!index_key.type->match || !index_key.type->instantiate || |
798 | (!index_key.description && !index_key.type->preparse)) | |
cf7f601c | 799 | goto error_put_type; |
1da177e4 | 800 | |
664cceb0 DH |
801 | keyring = key_ref_to_ptr(keyring_ref); |
802 | ||
803 | key_check(keyring); | |
804 | ||
c3a9d654 DH |
805 | key_ref = ERR_PTR(-ENOTDIR); |
806 | if (keyring->type != &key_type_keyring) | |
cf7f601c DH |
807 | goto error_put_type; |
808 | ||
809 | memset(&prep, 0, sizeof(prep)); | |
810 | prep.data = payload; | |
811 | prep.datalen = plen; | |
16feef43 | 812 | prep.quotalen = index_key.type->def_datalen; |
008643b8 | 813 | prep.trusted = flags & KEY_ALLOC_TRUSTED; |
16feef43 DH |
814 | if (index_key.type->preparse) { |
815 | ret = index_key.type->preparse(&prep); | |
cf7f601c DH |
816 | if (ret < 0) { |
817 | key_ref = ERR_PTR(ret); | |
818 | goto error_put_type; | |
819 | } | |
16feef43 DH |
820 | if (!index_key.description) |
821 | index_key.description = prep.description; | |
cf7f601c | 822 | key_ref = ERR_PTR(-EINVAL); |
16feef43 | 823 | if (!index_key.description) |
cf7f601c DH |
824 | goto error_free_prep; |
825 | } | |
16feef43 | 826 | index_key.desc_len = strlen(index_key.description); |
c3a9d654 | 827 | |
008643b8 DH |
828 | key_ref = ERR_PTR(-EPERM); |
829 | if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags)) | |
830 | goto error_free_prep; | |
831 | flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0; | |
832 | ||
b2a4df20 | 833 | ret = __key_link_begin(keyring, &index_key, &edit); |
cf7f601c DH |
834 | if (ret < 0) { |
835 | key_ref = ERR_PTR(ret); | |
836 | goto error_free_prep; | |
837 | } | |
664cceb0 DH |
838 | |
839 | /* if we're going to allocate a new key, we're going to have | |
840 | * to modify the keyring */ | |
f5895943 | 841 | ret = key_permission(keyring_ref, KEY_NEED_WRITE); |
29db9190 DH |
842 | if (ret < 0) { |
843 | key_ref = ERR_PTR(ret); | |
cf7f601c | 844 | goto error_link_end; |
29db9190 | 845 | } |
664cceb0 | 846 | |
1d9b7d97 DH |
847 | /* if it's possible to update this type of key, search for an existing |
848 | * key of the same type and description in the destination keyring and | |
849 | * update that instead if possible | |
1da177e4 | 850 | */ |
16feef43 | 851 | if (index_key.type->update) { |
b2a4df20 DH |
852 | key_ref = find_key_to_update(keyring_ref, &index_key); |
853 | if (key_ref) | |
1d9b7d97 DH |
854 | goto found_matching_key; |
855 | } | |
1da177e4 | 856 | |
6b79ccb5 AR |
857 | /* if the client doesn't provide, decide on the permissions we want */ |
858 | if (perm == KEY_PERM_UNDEF) { | |
859 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; | |
96b5c8fe | 860 | perm |= KEY_USR_VIEW; |
1da177e4 | 861 | |
16feef43 | 862 | if (index_key.type->read) |
96b5c8fe | 863 | perm |= KEY_POS_READ; |
1da177e4 | 864 | |
16feef43 DH |
865 | if (index_key.type == &key_type_keyring || |
866 | index_key.type->update) | |
96b5c8fe | 867 | perm |= KEY_POS_WRITE; |
6b79ccb5 | 868 | } |
1da177e4 LT |
869 | |
870 | /* allocate a new key */ | |
16feef43 DH |
871 | key = key_alloc(index_key.type, index_key.description, |
872 | cred->fsuid, cred->fsgid, cred, perm, flags); | |
1da177e4 | 873 | if (IS_ERR(key)) { |
e231c2ee | 874 | key_ref = ERR_CAST(key); |
cf7f601c | 875 | goto error_link_end; |
1da177e4 LT |
876 | } |
877 | ||
878 | /* instantiate it and link it into the target keyring */ | |
b2a4df20 | 879 | ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); |
1da177e4 LT |
880 | if (ret < 0) { |
881 | key_put(key); | |
664cceb0 | 882 | key_ref = ERR_PTR(ret); |
cf7f601c | 883 | goto error_link_end; |
1da177e4 LT |
884 | } |
885 | ||
664cceb0 DH |
886 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
887 | ||
cf7f601c | 888 | error_link_end: |
b2a4df20 | 889 | __key_link_end(keyring, &index_key, edit); |
cf7f601c | 890 | error_free_prep: |
16feef43 DH |
891 | if (index_key.type->preparse) |
892 | index_key.type->free_preparse(&prep); | |
cf7f601c | 893 | error_put_type: |
16feef43 | 894 | key_type_put(index_key.type); |
cf7f601c | 895 | error: |
664cceb0 | 896 | return key_ref; |
1da177e4 LT |
897 | |
898 | found_matching_key: | |
899 | /* we found a matching key, so we're going to try to update it | |
900 | * - we can drop the locks first as we have the key pinned | |
901 | */ | |
b2a4df20 | 902 | __key_link_end(keyring, &index_key, edit); |
1da177e4 | 903 | |
cf7f601c DH |
904 | key_ref = __key_update(key_ref, &prep); |
905 | goto error_free_prep; | |
a8b17ed0 | 906 | } |
1da177e4 LT |
907 | EXPORT_SYMBOL(key_create_or_update); |
908 | ||
973c9f4f DH |
909 | /** |
910 | * key_update - Update a key's contents. | |
911 | * @key_ref: The pointer (plus possession flag) to the key. | |
912 | * @payload: The data to be used to update the key. | |
913 | * @plen: The length of @payload. | |
914 | * | |
915 | * Attempt to update the contents of a key with the given payload data. The | |
916 | * caller must be granted Write permission on the key. Negative keys can be | |
917 | * instantiated by this method. | |
918 | * | |
919 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key | |
920 | * type does not support updating. The key type may return other errors. | |
1da177e4 | 921 | */ |
664cceb0 | 922 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
1da177e4 | 923 | { |
cf7f601c | 924 | struct key_preparsed_payload prep; |
664cceb0 | 925 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
926 | int ret; |
927 | ||
928 | key_check(key); | |
929 | ||
930 | /* the key must be writable */ | |
f5895943 | 931 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 932 | if (ret < 0) |
1da177e4 LT |
933 | goto error; |
934 | ||
935 | /* attempt to update it if supported */ | |
936 | ret = -EOPNOTSUPP; | |
cf7f601c DH |
937 | if (!key->type->update) |
938 | goto error; | |
1da177e4 | 939 | |
cf7f601c DH |
940 | memset(&prep, 0, sizeof(prep)); |
941 | prep.data = payload; | |
942 | prep.datalen = plen; | |
943 | prep.quotalen = key->type->def_datalen; | |
944 | if (key->type->preparse) { | |
945 | ret = key->type->preparse(&prep); | |
946 | if (ret < 0) | |
947 | goto error; | |
1da177e4 LT |
948 | } |
949 | ||
cf7f601c DH |
950 | down_write(&key->sem); |
951 | ||
952 | ret = key->type->update(key, &prep); | |
953 | if (ret == 0) | |
954 | /* updating a negative key instantiates it */ | |
955 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); | |
956 | ||
957 | up_write(&key->sem); | |
958 | ||
959 | if (key->type->preparse) | |
960 | key->type->free_preparse(&prep); | |
961 | error: | |
1da177e4 | 962 | return ret; |
a8b17ed0 | 963 | } |
1da177e4 LT |
964 | EXPORT_SYMBOL(key_update); |
965 | ||
973c9f4f DH |
966 | /** |
967 | * key_revoke - Revoke a key. | |
968 | * @key: The key to be revoked. | |
969 | * | |
970 | * Mark a key as being revoked and ask the type to free up its resources. The | |
971 | * revocation timeout is set and the key and all its links will be | |
972 | * automatically garbage collected after key_gc_delay amount of time if they | |
973 | * are not manually dealt with first. | |
1da177e4 LT |
974 | */ |
975 | void key_revoke(struct key *key) | |
976 | { | |
5d135440 DH |
977 | struct timespec now; |
978 | time_t time; | |
979 | ||
1da177e4 LT |
980 | key_check(key); |
981 | ||
76181c13 DH |
982 | /* make sure no one's trying to change or use the key when we mark it |
983 | * - we tell lockdep that we might nest because we might be revoking an | |
984 | * authorisation key whilst holding the sem on a key we've just | |
985 | * instantiated | |
986 | */ | |
987 | down_write_nested(&key->sem, 1); | |
988 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && | |
989 | key->type->revoke) | |
04c567d9 DH |
990 | key->type->revoke(key); |
991 | ||
5d135440 DH |
992 | /* set the death time to no more than the expiry time */ |
993 | now = current_kernel_time(); | |
994 | time = now.tv_sec; | |
995 | if (key->revoked_at == 0 || key->revoked_at > time) { | |
996 | key->revoked_at = time; | |
c08ef808 | 997 | key_schedule_gc(key->revoked_at + key_gc_delay); |
5d135440 DH |
998 | } |
999 | ||
1da177e4 | 1000 | up_write(&key->sem); |
a8b17ed0 | 1001 | } |
1da177e4 LT |
1002 | EXPORT_SYMBOL(key_revoke); |
1003 | ||
fd75815f DH |
1004 | /** |
1005 | * key_invalidate - Invalidate a key. | |
1006 | * @key: The key to be invalidated. | |
1007 | * | |
1008 | * Mark a key as being invalidated and have it cleaned up immediately. The key | |
1009 | * is ignored by all searches and other operations from this point. | |
1010 | */ | |
1011 | void key_invalidate(struct key *key) | |
1012 | { | |
1013 | kenter("%d", key_serial(key)); | |
1014 | ||
1015 | key_check(key); | |
1016 | ||
1017 | if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { | |
1018 | down_write_nested(&key->sem, 1); | |
1019 | if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) | |
1020 | key_schedule_gc_links(); | |
1021 | up_write(&key->sem); | |
1022 | } | |
1023 | } | |
1024 | EXPORT_SYMBOL(key_invalidate); | |
1025 | ||
973c9f4f DH |
1026 | /** |
1027 | * register_key_type - Register a type of key. | |
1028 | * @ktype: The new key type. | |
1029 | * | |
1030 | * Register a new key type. | |
1031 | * | |
1032 | * Returns 0 on success or -EEXIST if a type of this name already exists. | |
1da177e4 LT |
1033 | */ |
1034 | int register_key_type(struct key_type *ktype) | |
1035 | { | |
1036 | struct key_type *p; | |
1037 | int ret; | |
1038 | ||
7845bc39 DH |
1039 | memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); |
1040 | ||
1da177e4 LT |
1041 | ret = -EEXIST; |
1042 | down_write(&key_types_sem); | |
1043 | ||
1044 | /* disallow key types with the same name */ | |
1045 | list_for_each_entry(p, &key_types_list, link) { | |
1046 | if (strcmp(p->name, ktype->name) == 0) | |
1047 | goto out; | |
1048 | } | |
1049 | ||
1050 | /* store the type */ | |
1051 | list_add(&ktype->link, &key_types_list); | |
1eb1bcf5 DH |
1052 | |
1053 | pr_notice("Key type %s registered\n", ktype->name); | |
1da177e4 LT |
1054 | ret = 0; |
1055 | ||
973c9f4f | 1056 | out: |
1da177e4 LT |
1057 | up_write(&key_types_sem); |
1058 | return ret; | |
a8b17ed0 | 1059 | } |
1da177e4 LT |
1060 | EXPORT_SYMBOL(register_key_type); |
1061 | ||
973c9f4f DH |
1062 | /** |
1063 | * unregister_key_type - Unregister a type of key. | |
1064 | * @ktype: The key type. | |
1065 | * | |
1066 | * Unregister a key type and mark all the extant keys of this type as dead. | |
1067 | * Those keys of this type are then destroyed to get rid of their payloads and | |
1068 | * they and their links will be garbage collected as soon as possible. | |
1da177e4 LT |
1069 | */ |
1070 | void unregister_key_type(struct key_type *ktype) | |
1071 | { | |
1da177e4 | 1072 | down_write(&key_types_sem); |
1da177e4 | 1073 | list_del_init(&ktype->link); |
0c061b57 DH |
1074 | downgrade_write(&key_types_sem); |
1075 | key_gc_keytype(ktype); | |
1eb1bcf5 | 1076 | pr_notice("Key type %s unregistered\n", ktype->name); |
0c061b57 | 1077 | up_read(&key_types_sem); |
a8b17ed0 | 1078 | } |
1da177e4 LT |
1079 | EXPORT_SYMBOL(unregister_key_type); |
1080 | ||
1da177e4 | 1081 | /* |
973c9f4f | 1082 | * Initialise the key management state. |
1da177e4 LT |
1083 | */ |
1084 | void __init key_init(void) | |
1085 | { | |
1086 | /* allocate a slab in which we can store keys */ | |
1087 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), | |
20c2df83 | 1088 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1089 | |
1090 | /* add the special key types */ | |
1091 | list_add_tail(&key_type_keyring.link, &key_types_list); | |
1092 | list_add_tail(&key_type_dead.link, &key_types_list); | |
1093 | list_add_tail(&key_type_user.link, &key_types_list); | |
9f6ed2ca | 1094 | list_add_tail(&key_type_logon.link, &key_types_list); |
1da177e4 LT |
1095 | |
1096 | /* record the root user tracking */ | |
1097 | rb_link_node(&root_key_user.node, | |
1098 | NULL, | |
1099 | &key_user_tree.rb_node); | |
1100 | ||
1101 | rb_insert_color(&root_key_user.node, | |
1102 | &key_user_tree); | |
a8b17ed0 | 1103 | } |