Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* key.c: basic authentication token and access key management |
| 2 | * |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/slab.h> |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 16 | #include <linux/security.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/workqueue.h> |
| 18 | #include <linux/err.h> |
| 19 | #include "internal.h" |
| 20 | |
| 21 | static kmem_cache_t *key_jar; |
| 22 | static key_serial_t key_serial_next = 3; |
| 23 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
| 24 | DEFINE_SPINLOCK(key_serial_lock); |
| 25 | |
| 26 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ |
| 27 | DEFINE_SPINLOCK(key_user_lock); |
| 28 | |
| 29 | static LIST_HEAD(key_types_list); |
| 30 | static DECLARE_RWSEM(key_types_sem); |
| 31 | |
| 32 | static void key_cleanup(void *data); |
| 33 | static DECLARE_WORK(key_cleanup_task, key_cleanup, NULL); |
| 34 | |
| 35 | /* we serialise key instantiation and link */ |
| 36 | DECLARE_RWSEM(key_construction_sem); |
| 37 | |
| 38 | /* any key who's type gets unegistered will be re-typed to this */ |
| 39 | struct key_type key_type_dead = { |
| 40 | .name = "dead", |
| 41 | }; |
| 42 | |
| 43 | #ifdef KEY_DEBUGGING |
| 44 | void __key_check(const struct key *key) |
| 45 | { |
| 46 | printk("__key_check: key %p {%08x} should be {%08x}\n", |
| 47 | key, key->magic, KEY_DEBUG_MAGIC); |
| 48 | BUG(); |
| 49 | } |
| 50 | #endif |
| 51 | |
| 52 | /*****************************************************************************/ |
| 53 | /* |
| 54 | * get the key quota record for a user, allocating a new record if one doesn't |
| 55 | * already exist |
| 56 | */ |
| 57 | struct key_user *key_user_lookup(uid_t uid) |
| 58 | { |
| 59 | struct key_user *candidate = NULL, *user; |
| 60 | struct rb_node *parent = NULL; |
| 61 | struct rb_node **p; |
| 62 | |
| 63 | try_again: |
| 64 | p = &key_user_tree.rb_node; |
| 65 | spin_lock(&key_user_lock); |
| 66 | |
| 67 | /* search the tree for a user record with a matching UID */ |
| 68 | while (*p) { |
| 69 | parent = *p; |
| 70 | user = rb_entry(parent, struct key_user, node); |
| 71 | |
| 72 | if (uid < user->uid) |
| 73 | p = &(*p)->rb_left; |
| 74 | else if (uid > user->uid) |
| 75 | p = &(*p)->rb_right; |
| 76 | else |
| 77 | goto found; |
| 78 | } |
| 79 | |
| 80 | /* if we get here, we failed to find a match in the tree */ |
| 81 | if (!candidate) { |
| 82 | /* allocate a candidate user record if we don't already have |
| 83 | * one */ |
| 84 | spin_unlock(&key_user_lock); |
| 85 | |
| 86 | user = NULL; |
| 87 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); |
| 88 | if (unlikely(!candidate)) |
| 89 | goto out; |
| 90 | |
| 91 | /* the allocation may have scheduled, so we need to repeat the |
| 92 | * search lest someone else added the record whilst we were |
| 93 | * asleep */ |
| 94 | goto try_again; |
| 95 | } |
| 96 | |
| 97 | /* if we get here, then the user record still hadn't appeared on the |
| 98 | * second pass - so we use the candidate record */ |
| 99 | atomic_set(&candidate->usage, 1); |
| 100 | atomic_set(&candidate->nkeys, 0); |
| 101 | atomic_set(&candidate->nikeys, 0); |
| 102 | candidate->uid = uid; |
| 103 | candidate->qnkeys = 0; |
| 104 | candidate->qnbytes = 0; |
| 105 | spin_lock_init(&candidate->lock); |
| 106 | INIT_LIST_HEAD(&candidate->consq); |
| 107 | |
| 108 | rb_link_node(&candidate->node, parent, p); |
| 109 | rb_insert_color(&candidate->node, &key_user_tree); |
| 110 | spin_unlock(&key_user_lock); |
| 111 | user = candidate; |
| 112 | goto out; |
| 113 | |
| 114 | /* okay - we found a user record for this UID */ |
| 115 | found: |
| 116 | atomic_inc(&user->usage); |
| 117 | spin_unlock(&key_user_lock); |
| 118 | if (candidate) |
| 119 | kfree(candidate); |
| 120 | out: |
| 121 | return user; |
| 122 | |
| 123 | } /* end key_user_lookup() */ |
| 124 | |
| 125 | /*****************************************************************************/ |
| 126 | /* |
| 127 | * dispose of a user structure |
| 128 | */ |
| 129 | void key_user_put(struct key_user *user) |
| 130 | { |
| 131 | if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { |
| 132 | rb_erase(&user->node, &key_user_tree); |
| 133 | spin_unlock(&key_user_lock); |
| 134 | |
| 135 | kfree(user); |
| 136 | } |
| 137 | |
| 138 | } /* end key_user_put() */ |
| 139 | |
| 140 | /*****************************************************************************/ |
| 141 | /* |
| 142 | * insert a key with a fixed serial number |
| 143 | */ |
| 144 | static void __init __key_insert_serial(struct key *key) |
| 145 | { |
| 146 | struct rb_node *parent, **p; |
| 147 | struct key *xkey; |
| 148 | |
| 149 | parent = NULL; |
| 150 | p = &key_serial_tree.rb_node; |
| 151 | |
| 152 | while (*p) { |
| 153 | parent = *p; |
| 154 | xkey = rb_entry(parent, struct key, serial_node); |
| 155 | |
| 156 | if (key->serial < xkey->serial) |
| 157 | p = &(*p)->rb_left; |
| 158 | else if (key->serial > xkey->serial) |
| 159 | p = &(*p)->rb_right; |
| 160 | else |
| 161 | BUG(); |
| 162 | } |
| 163 | |
| 164 | /* we've found a suitable hole - arrange for this key to occupy it */ |
| 165 | rb_link_node(&key->serial_node, parent, p); |
| 166 | rb_insert_color(&key->serial_node, &key_serial_tree); |
| 167 | |
| 168 | } /* end __key_insert_serial() */ |
| 169 | |
| 170 | /*****************************************************************************/ |
| 171 | /* |
| 172 | * assign a key the next unique serial number |
| 173 | * - we work through all the serial numbers between 2 and 2^31-1 in turn and |
| 174 | * then wrap |
| 175 | */ |
| 176 | static inline void key_alloc_serial(struct key *key) |
| 177 | { |
| 178 | struct rb_node *parent, **p; |
| 179 | struct key *xkey; |
| 180 | |
| 181 | spin_lock(&key_serial_lock); |
| 182 | |
| 183 | /* propose a likely serial number and look for a hole for it in the |
| 184 | * serial number tree */ |
| 185 | key->serial = key_serial_next; |
| 186 | if (key->serial < 3) |
| 187 | key->serial = 3; |
| 188 | key_serial_next = key->serial + 1; |
| 189 | |
| 190 | parent = NULL; |
| 191 | p = &key_serial_tree.rb_node; |
| 192 | |
| 193 | while (*p) { |
| 194 | parent = *p; |
| 195 | xkey = rb_entry(parent, struct key, serial_node); |
| 196 | |
| 197 | if (key->serial < xkey->serial) |
| 198 | p = &(*p)->rb_left; |
| 199 | else if (key->serial > xkey->serial) |
| 200 | p = &(*p)->rb_right; |
| 201 | else |
| 202 | goto serial_exists; |
| 203 | } |
| 204 | goto insert_here; |
| 205 | |
| 206 | /* we found a key with the proposed serial number - walk the tree from |
| 207 | * that point looking for the next unused serial number */ |
| 208 | serial_exists: |
| 209 | for (;;) { |
| 210 | key->serial = key_serial_next; |
| 211 | if (key->serial < 2) |
| 212 | key->serial = 2; |
| 213 | key_serial_next = key->serial + 1; |
| 214 | |
| 215 | if (!parent->rb_parent) |
| 216 | p = &key_serial_tree.rb_node; |
| 217 | else if (parent->rb_parent->rb_left == parent) |
| 218 | p = &parent->rb_parent->rb_left; |
| 219 | else |
| 220 | p = &parent->rb_parent->rb_right; |
| 221 | |
| 222 | parent = rb_next(parent); |
| 223 | if (!parent) |
| 224 | break; |
| 225 | |
| 226 | xkey = rb_entry(parent, struct key, serial_node); |
| 227 | if (key->serial < xkey->serial) |
| 228 | goto insert_here; |
| 229 | } |
| 230 | |
| 231 | /* we've found a suitable hole - arrange for this key to occupy it */ |
| 232 | insert_here: |
| 233 | rb_link_node(&key->serial_node, parent, p); |
| 234 | rb_insert_color(&key->serial_node, &key_serial_tree); |
| 235 | |
| 236 | spin_unlock(&key_serial_lock); |
| 237 | |
| 238 | } /* end key_alloc_serial() */ |
| 239 | |
| 240 | /*****************************************************************************/ |
| 241 | /* |
| 242 | * allocate a key of the specified type |
| 243 | * - update the user's quota to reflect the existence of the key |
| 244 | * - called from a key-type operation with key_types_sem read-locked by either |
| 245 | * key_create_or_update() or by key_duplicate(); this prevents unregistration |
| 246 | * of the key type |
| 247 | * - upon return the key is as yet uninstantiated; the caller needs to either |
| 248 | * instantiate the key or discard it before returning |
| 249 | */ |
| 250 | struct key *key_alloc(struct key_type *type, const char *desc, |
| 251 | uid_t uid, gid_t gid, key_perm_t perm, |
| 252 | int not_in_quota) |
| 253 | { |
| 254 | struct key_user *user = NULL; |
| 255 | struct key *key; |
| 256 | size_t desclen, quotalen; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 257 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | |
| 259 | key = ERR_PTR(-EINVAL); |
| 260 | if (!desc || !*desc) |
| 261 | goto error; |
| 262 | |
| 263 | desclen = strlen(desc) + 1; |
| 264 | quotalen = desclen + type->def_datalen; |
| 265 | |
| 266 | /* get hold of the key tracking for this user */ |
| 267 | user = key_user_lookup(uid); |
| 268 | if (!user) |
| 269 | goto no_memory_1; |
| 270 | |
| 271 | /* check that the user's quota permits allocation of another key and |
| 272 | * its description */ |
| 273 | if (!not_in_quota) { |
| 274 | spin_lock(&user->lock); |
| 275 | if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS && |
| 276 | user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES |
| 277 | ) |
| 278 | goto no_quota; |
| 279 | |
| 280 | user->qnkeys++; |
| 281 | user->qnbytes += quotalen; |
| 282 | spin_unlock(&user->lock); |
| 283 | } |
| 284 | |
| 285 | /* allocate and initialise the key and its description */ |
| 286 | key = kmem_cache_alloc(key_jar, SLAB_KERNEL); |
| 287 | if (!key) |
| 288 | goto no_memory_2; |
| 289 | |
| 290 | if (desc) { |
| 291 | key->description = kmalloc(desclen, GFP_KERNEL); |
| 292 | if (!key->description) |
| 293 | goto no_memory_3; |
| 294 | |
| 295 | memcpy(key->description, desc, desclen); |
| 296 | } |
| 297 | |
| 298 | atomic_set(&key->usage, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | init_rwsem(&key->sem); |
| 300 | key->type = type; |
| 301 | key->user = user; |
| 302 | key->quotalen = quotalen; |
| 303 | key->datalen = type->def_datalen; |
| 304 | key->uid = uid; |
| 305 | key->gid = gid; |
| 306 | key->perm = perm; |
| 307 | key->flags = 0; |
| 308 | key->expiry = 0; |
| 309 | key->payload.data = NULL; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 310 | key->security = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | |
| 312 | if (!not_in_quota) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 313 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | |
| 315 | memset(&key->type_data, 0, sizeof(key->type_data)); |
| 316 | |
| 317 | #ifdef KEY_DEBUGGING |
| 318 | key->magic = KEY_DEBUG_MAGIC; |
| 319 | #endif |
| 320 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 321 | /* let the security module know about the key */ |
| 322 | ret = security_key_alloc(key); |
| 323 | if (ret < 0) |
| 324 | goto security_error; |
| 325 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | /* publish the key by giving it a serial number */ |
| 327 | atomic_inc(&user->nkeys); |
| 328 | key_alloc_serial(key); |
| 329 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 330 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | return key; |
| 332 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 333 | security_error: |
| 334 | kfree(key->description); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | kmem_cache_free(key_jar, key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | if (!not_in_quota) { |
| 337 | spin_lock(&user->lock); |
| 338 | user->qnkeys--; |
| 339 | user->qnbytes -= quotalen; |
| 340 | spin_unlock(&user->lock); |
| 341 | } |
| 342 | key_user_put(user); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 343 | key = ERR_PTR(ret); |
| 344 | goto error; |
| 345 | |
| 346 | no_memory_3: |
| 347 | kmem_cache_free(key_jar, key); |
| 348 | no_memory_2: |
| 349 | if (!not_in_quota) { |
| 350 | spin_lock(&user->lock); |
| 351 | user->qnkeys--; |
| 352 | user->qnbytes -= quotalen; |
| 353 | spin_unlock(&user->lock); |
| 354 | } |
| 355 | key_user_put(user); |
| 356 | no_memory_1: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | key = ERR_PTR(-ENOMEM); |
| 358 | goto error; |
| 359 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 360 | no_quota: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | spin_unlock(&user->lock); |
| 362 | key_user_put(user); |
| 363 | key = ERR_PTR(-EDQUOT); |
| 364 | goto error; |
| 365 | |
| 366 | } /* end key_alloc() */ |
| 367 | |
| 368 | EXPORT_SYMBOL(key_alloc); |
| 369 | |
| 370 | /*****************************************************************************/ |
| 371 | /* |
| 372 | * reserve an amount of quota for the key's payload |
| 373 | */ |
| 374 | int key_payload_reserve(struct key *key, size_t datalen) |
| 375 | { |
| 376 | int delta = (int) datalen - key->datalen; |
| 377 | int ret = 0; |
| 378 | |
| 379 | key_check(key); |
| 380 | |
| 381 | /* contemplate the quota adjustment */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 382 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | spin_lock(&key->user->lock); |
| 384 | |
| 385 | if (delta > 0 && |
| 386 | key->user->qnbytes + delta > KEYQUOTA_MAX_BYTES |
| 387 | ) { |
| 388 | ret = -EDQUOT; |
| 389 | } |
| 390 | else { |
| 391 | key->user->qnbytes += delta; |
| 392 | key->quotalen += delta; |
| 393 | } |
| 394 | spin_unlock(&key->user->lock); |
| 395 | } |
| 396 | |
| 397 | /* change the recorded data length if that didn't generate an error */ |
| 398 | if (ret == 0) |
| 399 | key->datalen = datalen; |
| 400 | |
| 401 | return ret; |
| 402 | |
| 403 | } /* end key_payload_reserve() */ |
| 404 | |
| 405 | EXPORT_SYMBOL(key_payload_reserve); |
| 406 | |
| 407 | /*****************************************************************************/ |
| 408 | /* |
| 409 | * instantiate a key and link it into the target keyring atomically |
| 410 | * - called with the target keyring's semaphore writelocked |
| 411 | */ |
| 412 | static int __key_instantiate_and_link(struct key *key, |
| 413 | const void *data, |
| 414 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 415 | struct key *keyring, |
| 416 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | { |
| 418 | int ret, awaken; |
| 419 | |
| 420 | key_check(key); |
| 421 | key_check(keyring); |
| 422 | |
| 423 | awaken = 0; |
| 424 | ret = -EBUSY; |
| 425 | |
| 426 | down_write(&key_construction_sem); |
| 427 | |
| 428 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 429 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | /* instantiate the key */ |
| 431 | ret = key->type->instantiate(key, data, datalen); |
| 432 | |
| 433 | if (ret == 0) { |
| 434 | /* mark the key as being instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 436 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 438 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | |
| 441 | /* and link it into the destination keyring */ |
| 442 | if (keyring) |
| 443 | ret = __key_link(keyring, key); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 444 | |
| 445 | /* disable the authorisation key */ |
| 446 | if (instkey) |
| 447 | key_revoke(instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | } |
| 449 | } |
| 450 | |
| 451 | up_write(&key_construction_sem); |
| 452 | |
| 453 | /* wake up anyone waiting for a key to be constructed */ |
| 454 | if (awaken) |
| 455 | wake_up_all(&request_key_conswq); |
| 456 | |
| 457 | return ret; |
| 458 | |
| 459 | } /* end __key_instantiate_and_link() */ |
| 460 | |
| 461 | /*****************************************************************************/ |
| 462 | /* |
| 463 | * instantiate a key and link it into the target keyring atomically |
| 464 | */ |
| 465 | int key_instantiate_and_link(struct key *key, |
| 466 | const void *data, |
| 467 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 468 | struct key *keyring, |
| 469 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | { |
| 471 | int ret; |
| 472 | |
| 473 | if (keyring) |
| 474 | down_write(&keyring->sem); |
| 475 | |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 476 | ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | |
| 478 | if (keyring) |
| 479 | up_write(&keyring->sem); |
| 480 | |
| 481 | return ret; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 482 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | } /* end key_instantiate_and_link() */ |
| 484 | |
| 485 | EXPORT_SYMBOL(key_instantiate_and_link); |
| 486 | |
| 487 | /*****************************************************************************/ |
| 488 | /* |
| 489 | * negatively instantiate a key and link it into the target keyring atomically |
| 490 | */ |
| 491 | int key_negate_and_link(struct key *key, |
| 492 | unsigned timeout, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 493 | struct key *keyring, |
| 494 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | { |
| 496 | struct timespec now; |
| 497 | int ret, awaken; |
| 498 | |
| 499 | key_check(key); |
| 500 | key_check(keyring); |
| 501 | |
| 502 | awaken = 0; |
| 503 | ret = -EBUSY; |
| 504 | |
| 505 | if (keyring) |
| 506 | down_write(&keyring->sem); |
| 507 | |
| 508 | down_write(&key_construction_sem); |
| 509 | |
| 510 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 511 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | /* mark the key as being negatively instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 514 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
| 515 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | now = current_kernel_time(); |
| 517 | key->expiry = now.tv_sec + timeout; |
| 518 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 519 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | ret = 0; |
| 523 | |
| 524 | /* and link it into the destination keyring */ |
| 525 | if (keyring) |
| 526 | ret = __key_link(keyring, key); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 527 | |
| 528 | /* disable the authorisation key */ |
| 529 | if (instkey) |
| 530 | key_revoke(instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | } |
| 532 | |
| 533 | up_write(&key_construction_sem); |
| 534 | |
| 535 | if (keyring) |
| 536 | up_write(&keyring->sem); |
| 537 | |
| 538 | /* wake up anyone waiting for a key to be constructed */ |
| 539 | if (awaken) |
| 540 | wake_up_all(&request_key_conswq); |
| 541 | |
| 542 | return ret; |
| 543 | |
| 544 | } /* end key_negate_and_link() */ |
| 545 | |
| 546 | EXPORT_SYMBOL(key_negate_and_link); |
| 547 | |
| 548 | /*****************************************************************************/ |
| 549 | /* |
| 550 | * do cleaning up in process context so that we don't have to disable |
| 551 | * interrupts all over the place |
| 552 | */ |
| 553 | static void key_cleanup(void *data) |
| 554 | { |
| 555 | struct rb_node *_n; |
| 556 | struct key *key; |
| 557 | |
| 558 | go_again: |
| 559 | /* look for a dead key in the tree */ |
| 560 | spin_lock(&key_serial_lock); |
| 561 | |
| 562 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 563 | key = rb_entry(_n, struct key, serial_node); |
| 564 | |
| 565 | if (atomic_read(&key->usage) == 0) |
| 566 | goto found_dead_key; |
| 567 | } |
| 568 | |
| 569 | spin_unlock(&key_serial_lock); |
| 570 | return; |
| 571 | |
| 572 | found_dead_key: |
| 573 | /* we found a dead key - once we've removed it from the tree, we can |
| 574 | * drop the lock */ |
| 575 | rb_erase(&key->serial_node, &key_serial_tree); |
| 576 | spin_unlock(&key_serial_lock); |
| 577 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 578 | key_check(key); |
| 579 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 580 | security_key_free(key); |
| 581 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | /* deal with the user's key tracking and quota */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 583 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | spin_lock(&key->user->lock); |
| 585 | key->user->qnkeys--; |
| 586 | key->user->qnbytes -= key->quotalen; |
| 587 | spin_unlock(&key->user->lock); |
| 588 | } |
| 589 | |
| 590 | atomic_dec(&key->user->nkeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 591 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | atomic_dec(&key->user->nikeys); |
| 593 | |
| 594 | key_user_put(key->user); |
| 595 | |
| 596 | /* now throw away the key memory */ |
| 597 | if (key->type->destroy) |
| 598 | key->type->destroy(key); |
| 599 | |
| 600 | kfree(key->description); |
| 601 | |
| 602 | #ifdef KEY_DEBUGGING |
| 603 | key->magic = KEY_DEBUG_MAGIC_X; |
| 604 | #endif |
| 605 | kmem_cache_free(key_jar, key); |
| 606 | |
| 607 | /* there may, of course, be more than one key to destroy */ |
| 608 | goto go_again; |
| 609 | |
| 610 | } /* end key_cleanup() */ |
| 611 | |
| 612 | /*****************************************************************************/ |
| 613 | /* |
| 614 | * dispose of a reference to a key |
| 615 | * - when all the references are gone, we schedule the cleanup task to come and |
| 616 | * pull it out of the tree in definite process context |
| 617 | */ |
| 618 | void key_put(struct key *key) |
| 619 | { |
| 620 | if (key) { |
| 621 | key_check(key); |
| 622 | |
| 623 | if (atomic_dec_and_test(&key->usage)) |
| 624 | schedule_work(&key_cleanup_task); |
| 625 | } |
| 626 | |
| 627 | } /* end key_put() */ |
| 628 | |
| 629 | EXPORT_SYMBOL(key_put); |
| 630 | |
| 631 | /*****************************************************************************/ |
| 632 | /* |
| 633 | * find a key by its serial number |
| 634 | */ |
| 635 | struct key *key_lookup(key_serial_t id) |
| 636 | { |
| 637 | struct rb_node *n; |
| 638 | struct key *key; |
| 639 | |
| 640 | spin_lock(&key_serial_lock); |
| 641 | |
| 642 | /* search the tree for the specified key */ |
| 643 | n = key_serial_tree.rb_node; |
| 644 | while (n) { |
| 645 | key = rb_entry(n, struct key, serial_node); |
| 646 | |
| 647 | if (id < key->serial) |
| 648 | n = n->rb_left; |
| 649 | else if (id > key->serial) |
| 650 | n = n->rb_right; |
| 651 | else |
| 652 | goto found; |
| 653 | } |
| 654 | |
| 655 | not_found: |
| 656 | key = ERR_PTR(-ENOKEY); |
| 657 | goto error; |
| 658 | |
| 659 | found: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 660 | /* pretend it doesn't exist if it's dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | if (atomic_read(&key->usage) == 0 || |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 662 | test_bit(KEY_FLAG_DEAD, &key->flags) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | key->type == &key_type_dead) |
| 664 | goto not_found; |
| 665 | |
| 666 | /* this races with key_put(), but that doesn't matter since key_put() |
| 667 | * doesn't actually change the key |
| 668 | */ |
| 669 | atomic_inc(&key->usage); |
| 670 | |
| 671 | error: |
| 672 | spin_unlock(&key_serial_lock); |
| 673 | return key; |
| 674 | |
| 675 | } /* end key_lookup() */ |
| 676 | |
| 677 | /*****************************************************************************/ |
| 678 | /* |
| 679 | * find and lock the specified key type against removal |
| 680 | * - we return with the sem readlocked |
| 681 | */ |
| 682 | struct key_type *key_type_lookup(const char *type) |
| 683 | { |
| 684 | struct key_type *ktype; |
| 685 | |
| 686 | down_read(&key_types_sem); |
| 687 | |
| 688 | /* look up the key type to see if it's one of the registered kernel |
| 689 | * types */ |
| 690 | list_for_each_entry(ktype, &key_types_list, link) { |
| 691 | if (strcmp(ktype->name, type) == 0) |
| 692 | goto found_kernel_type; |
| 693 | } |
| 694 | |
| 695 | up_read(&key_types_sem); |
| 696 | ktype = ERR_PTR(-ENOKEY); |
| 697 | |
| 698 | found_kernel_type: |
| 699 | return ktype; |
| 700 | |
| 701 | } /* end key_type_lookup() */ |
| 702 | |
| 703 | /*****************************************************************************/ |
| 704 | /* |
| 705 | * unlock a key type |
| 706 | */ |
| 707 | void key_type_put(struct key_type *ktype) |
| 708 | { |
| 709 | up_read(&key_types_sem); |
| 710 | |
| 711 | } /* end key_type_put() */ |
| 712 | |
| 713 | /*****************************************************************************/ |
| 714 | /* |
| 715 | * attempt to update an existing key |
| 716 | * - the key has an incremented refcount |
| 717 | * - we need to put the key if we get an error |
| 718 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 719 | static inline key_ref_t __key_update(key_ref_t key_ref, |
| 720 | const void *payload, size_t plen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 722 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | int ret; |
| 724 | |
| 725 | /* need write permission on the key to update it */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 726 | ret = key_permission(key_ref, KEY_WRITE); |
| 727 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | goto error; |
| 729 | |
| 730 | ret = -EEXIST; |
| 731 | if (!key->type->update) |
| 732 | goto error; |
| 733 | |
| 734 | down_write(&key->sem); |
| 735 | |
| 736 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 737 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 739 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
| 741 | up_write(&key->sem); |
| 742 | |
| 743 | if (ret < 0) |
| 744 | goto error; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 745 | out: |
| 746 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 748 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 750 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | goto out; |
| 752 | |
| 753 | } /* end __key_update() */ |
| 754 | |
| 755 | /*****************************************************************************/ |
| 756 | /* |
| 757 | * search the specified keyring for a key of the same description; if one is |
| 758 | * found, update it, otherwise add a new one |
| 759 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 760 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
| 761 | const char *type, |
| 762 | const char *description, |
| 763 | const void *payload, |
| 764 | size_t plen, |
| 765 | int not_in_quota) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | { |
| 767 | struct key_type *ktype; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 768 | struct key *keyring, *key = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | key_perm_t perm; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 770 | key_ref_t key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | int ret; |
| 772 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | /* look up the key type to see if it's one of the registered kernel |
| 774 | * types */ |
| 775 | ktype = key_type_lookup(type); |
| 776 | if (IS_ERR(ktype)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 777 | key_ref = ERR_PTR(-ENODEV); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | goto error; |
| 779 | } |
| 780 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 781 | key_ref = ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | if (!ktype->match || !ktype->instantiate) |
| 783 | goto error_2; |
| 784 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 785 | keyring = key_ref_to_ptr(keyring_ref); |
| 786 | |
| 787 | key_check(keyring); |
| 788 | |
| 789 | down_write(&keyring->sem); |
| 790 | |
| 791 | /* if we're going to allocate a new key, we're going to have |
| 792 | * to modify the keyring */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 793 | ret = key_permission(keyring_ref, KEY_WRITE); |
| 794 | if (ret < 0) { |
| 795 | key_ref = ERR_PTR(ret); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 796 | goto error_3; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 797 | } |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 798 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | /* search for an existing key of the same type and description in the |
| 800 | * destination keyring |
| 801 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 802 | key_ref = __keyring_search_one(keyring_ref, ktype, description, 0); |
| 803 | if (!IS_ERR(key_ref)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | goto found_matching_key; |
| 805 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | /* decide on the permissions we want */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 807 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; |
| 808 | perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | |
| 810 | if (ktype->read) |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 811 | perm |= KEY_POS_READ | KEY_USR_READ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | |
| 813 | if (ktype == &key_type_keyring || ktype->update) |
| 814 | perm |= KEY_USR_WRITE; |
| 815 | |
| 816 | /* allocate a new key */ |
| 817 | key = key_alloc(ktype, description, current->fsuid, current->fsgid, |
| 818 | perm, not_in_quota); |
| 819 | if (IS_ERR(key)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 820 | key_ref = ERR_PTR(PTR_ERR(key)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 821 | goto error_3; |
| 822 | } |
| 823 | |
| 824 | /* instantiate it and link it into the target keyring */ |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 825 | ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | if (ret < 0) { |
| 827 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 828 | key_ref = ERR_PTR(ret); |
| 829 | goto error_3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | } |
| 831 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 832 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
| 833 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | error_3: |
| 835 | up_write(&keyring->sem); |
| 836 | error_2: |
| 837 | key_type_put(ktype); |
| 838 | error: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 839 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | |
| 841 | found_matching_key: |
| 842 | /* we found a matching key, so we're going to try to update it |
| 843 | * - we can drop the locks first as we have the key pinned |
| 844 | */ |
| 845 | up_write(&keyring->sem); |
| 846 | key_type_put(ktype); |
| 847 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 848 | key_ref = __key_update(key_ref, payload, plen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | goto error; |
| 850 | |
| 851 | } /* end key_create_or_update() */ |
| 852 | |
| 853 | EXPORT_SYMBOL(key_create_or_update); |
| 854 | |
| 855 | /*****************************************************************************/ |
| 856 | /* |
| 857 | * update a key |
| 858 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 859 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 861 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | int ret; |
| 863 | |
| 864 | key_check(key); |
| 865 | |
| 866 | /* the key must be writable */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 867 | ret = key_permission(key_ref, KEY_WRITE); |
| 868 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | goto error; |
| 870 | |
| 871 | /* attempt to update it if supported */ |
| 872 | ret = -EOPNOTSUPP; |
| 873 | if (key->type->update) { |
| 874 | down_write(&key->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 875 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame^] | 876 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 877 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 879 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | |
| 881 | up_write(&key->sem); |
| 882 | } |
| 883 | |
| 884 | error: |
| 885 | return ret; |
| 886 | |
| 887 | } /* end key_update() */ |
| 888 | |
| 889 | EXPORT_SYMBOL(key_update); |
| 890 | |
| 891 | /*****************************************************************************/ |
| 892 | /* |
| 893 | * duplicate a key, potentially with a revised description |
| 894 | * - must be supported by the keytype (keyrings for instance can be duplicated) |
| 895 | */ |
| 896 | struct key *key_duplicate(struct key *source, const char *desc) |
| 897 | { |
| 898 | struct key *key; |
| 899 | int ret; |
| 900 | |
| 901 | key_check(source); |
| 902 | |
| 903 | if (!desc) |
| 904 | desc = source->description; |
| 905 | |
| 906 | down_read(&key_types_sem); |
| 907 | |
| 908 | ret = -EINVAL; |
| 909 | if (!source->type->duplicate) |
| 910 | goto error; |
| 911 | |
| 912 | /* allocate and instantiate a key */ |
| 913 | key = key_alloc(source->type, desc, current->fsuid, current->fsgid, |
| 914 | source->perm, 0); |
| 915 | if (IS_ERR(key)) |
| 916 | goto error_k; |
| 917 | |
| 918 | down_read(&source->sem); |
| 919 | ret = key->type->duplicate(key, source); |
| 920 | up_read(&source->sem); |
| 921 | if (ret < 0) |
| 922 | goto error2; |
| 923 | |
| 924 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 925 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | |
| 927 | error_k: |
| 928 | up_read(&key_types_sem); |
| 929 | out: |
| 930 | return key; |
| 931 | |
| 932 | error2: |
| 933 | key_put(key); |
| 934 | error: |
| 935 | up_read(&key_types_sem); |
| 936 | key = ERR_PTR(ret); |
| 937 | goto out; |
| 938 | |
| 939 | } /* end key_duplicate() */ |
| 940 | |
| 941 | /*****************************************************************************/ |
| 942 | /* |
| 943 | * revoke a key |
| 944 | */ |
| 945 | void key_revoke(struct key *key) |
| 946 | { |
| 947 | key_check(key); |
| 948 | |
| 949 | /* make sure no one's trying to change or use the key when we mark |
| 950 | * it */ |
| 951 | down_write(&key->sem); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 952 | set_bit(KEY_FLAG_REVOKED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | up_write(&key->sem); |
| 954 | |
| 955 | } /* end key_revoke() */ |
| 956 | |
| 957 | EXPORT_SYMBOL(key_revoke); |
| 958 | |
| 959 | /*****************************************************************************/ |
| 960 | /* |
| 961 | * register a type of key |
| 962 | */ |
| 963 | int register_key_type(struct key_type *ktype) |
| 964 | { |
| 965 | struct key_type *p; |
| 966 | int ret; |
| 967 | |
| 968 | ret = -EEXIST; |
| 969 | down_write(&key_types_sem); |
| 970 | |
| 971 | /* disallow key types with the same name */ |
| 972 | list_for_each_entry(p, &key_types_list, link) { |
| 973 | if (strcmp(p->name, ktype->name) == 0) |
| 974 | goto out; |
| 975 | } |
| 976 | |
| 977 | /* store the type */ |
| 978 | list_add(&ktype->link, &key_types_list); |
| 979 | ret = 0; |
| 980 | |
| 981 | out: |
| 982 | up_write(&key_types_sem); |
| 983 | return ret; |
| 984 | |
| 985 | } /* end register_key_type() */ |
| 986 | |
| 987 | EXPORT_SYMBOL(register_key_type); |
| 988 | |
| 989 | /*****************************************************************************/ |
| 990 | /* |
| 991 | * unregister a type of key |
| 992 | */ |
| 993 | void unregister_key_type(struct key_type *ktype) |
| 994 | { |
| 995 | struct rb_node *_n; |
| 996 | struct key *key; |
| 997 | |
| 998 | down_write(&key_types_sem); |
| 999 | |
| 1000 | /* withdraw the key type */ |
| 1001 | list_del_init(&ktype->link); |
| 1002 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1003 | /* mark all the keys of this type dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | spin_lock(&key_serial_lock); |
| 1005 | |
| 1006 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 1007 | key = rb_entry(_n, struct key, serial_node); |
| 1008 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1009 | if (key->type == ktype) |
| 1010 | key->type = &key_type_dead; |
| 1011 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1013 | spin_unlock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1015 | /* make sure everyone revalidates their keys */ |
Paul E. McKenney | b2b1866 | 2005-06-25 14:55:38 -0700 | [diff] [blame] | 1016 | synchronize_rcu(); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1017 | |
| 1018 | /* we should now be able to destroy the payloads of all the keys of |
| 1019 | * this type with impunity */ |
| 1020 | spin_lock(&key_serial_lock); |
| 1021 | |
| 1022 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 1023 | key = rb_entry(_n, struct key, serial_node); |
| 1024 | |
| 1025 | if (key->type == ktype) { |
| 1026 | if (ktype->destroy) |
| 1027 | ktype->destroy(key); |
| 1028 | memset(&key->payload, 0xbd, sizeof(key->payload)); |
| 1029 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | } |
| 1031 | |
| 1032 | spin_unlock(&key_serial_lock); |
| 1033 | up_write(&key_types_sem); |
| 1034 | |
| 1035 | } /* end unregister_key_type() */ |
| 1036 | |
| 1037 | EXPORT_SYMBOL(unregister_key_type); |
| 1038 | |
| 1039 | /*****************************************************************************/ |
| 1040 | /* |
| 1041 | * initialise the key management stuff |
| 1042 | */ |
| 1043 | void __init key_init(void) |
| 1044 | { |
| 1045 | /* allocate a slab in which we can store keys */ |
| 1046 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), |
| 1047 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL); |
| 1048 | |
| 1049 | /* add the special key types */ |
| 1050 | list_add_tail(&key_type_keyring.link, &key_types_list); |
| 1051 | list_add_tail(&key_type_dead.link, &key_types_list); |
| 1052 | list_add_tail(&key_type_user.link, &key_types_list); |
| 1053 | |
| 1054 | /* record the root user tracking */ |
| 1055 | rb_link_node(&root_key_user.node, |
| 1056 | NULL, |
| 1057 | &key_user_tree.rb_node); |
| 1058 | |
| 1059 | rb_insert_color(&root_key_user.node, |
| 1060 | &key_user_tree); |
| 1061 | |
| 1062 | /* record root's user standard keyrings */ |
| 1063 | key_check(&root_user_keyring); |
| 1064 | key_check(&root_session_keyring); |
| 1065 | |
| 1066 | __key_insert_serial(&root_user_keyring); |
| 1067 | __key_insert_serial(&root_session_keyring); |
| 1068 | |
| 1069 | keyring_publish_name(&root_user_keyring); |
| 1070 | keyring_publish_name(&root_session_keyring); |
| 1071 | |
| 1072 | /* link the two root keyrings together */ |
| 1073 | key_link(&root_session_keyring, &root_user_keyring); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1074 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | } /* end key_init() */ |