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 | 3dccff8 | 2006-03-25 03:06:51 -0800 | [diff] [blame] | 3 | * Copyright (C) 2004-6 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> |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 14 | #include <linux/poison.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/sched.h> |
| 16 | #include <linux/slab.h> |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 17 | #include <linux/security.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/workqueue.h> |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 19 | #include <linux/random.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/err.h> |
| 21 | #include "internal.h" |
| 22 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame^] | 23 | static struct kmem_cache *key_jar; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 30 | static LIST_HEAD(key_types_list); |
| 31 | static DECLARE_RWSEM(key_types_sem); |
| 32 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 33 | static void key_cleanup(struct work_struct *work); |
| 34 | static DECLARE_WORK(key_cleanup_task, key_cleanup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | /* we serialise key instantiation and link */ |
| 37 | DECLARE_RWSEM(key_construction_sem); |
| 38 | |
| 39 | /* any key who's type gets unegistered will be re-typed to this */ |
Adrian Bunk | 1ae8f40 | 2006-01-06 00:11:25 -0800 | [diff] [blame] | 40 | static struct key_type key_type_dead = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | .name = "dead", |
| 42 | }; |
| 43 | |
| 44 | #ifdef KEY_DEBUGGING |
| 45 | void __key_check(const struct key *key) |
| 46 | { |
| 47 | printk("__key_check: key %p {%08x} should be {%08x}\n", |
| 48 | key, key->magic, KEY_DEBUG_MAGIC); |
| 49 | BUG(); |
| 50 | } |
| 51 | #endif |
| 52 | |
| 53 | /*****************************************************************************/ |
| 54 | /* |
| 55 | * get the key quota record for a user, allocating a new record if one doesn't |
| 56 | * already exist |
| 57 | */ |
| 58 | struct key_user *key_user_lookup(uid_t uid) |
| 59 | { |
| 60 | struct key_user *candidate = NULL, *user; |
| 61 | struct rb_node *parent = NULL; |
| 62 | struct rb_node **p; |
| 63 | |
| 64 | try_again: |
| 65 | p = &key_user_tree.rb_node; |
| 66 | spin_lock(&key_user_lock); |
| 67 | |
| 68 | /* search the tree for a user record with a matching UID */ |
| 69 | while (*p) { |
| 70 | parent = *p; |
| 71 | user = rb_entry(parent, struct key_user, node); |
| 72 | |
| 73 | if (uid < user->uid) |
| 74 | p = &(*p)->rb_left; |
| 75 | else if (uid > user->uid) |
| 76 | p = &(*p)->rb_right; |
| 77 | else |
| 78 | goto found; |
| 79 | } |
| 80 | |
| 81 | /* if we get here, we failed to find a match in the tree */ |
| 82 | if (!candidate) { |
| 83 | /* allocate a candidate user record if we don't already have |
| 84 | * one */ |
| 85 | spin_unlock(&key_user_lock); |
| 86 | |
| 87 | user = NULL; |
| 88 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); |
| 89 | if (unlikely(!candidate)) |
| 90 | goto out; |
| 91 | |
| 92 | /* the allocation may have scheduled, so we need to repeat the |
| 93 | * search lest someone else added the record whilst we were |
| 94 | * asleep */ |
| 95 | goto try_again; |
| 96 | } |
| 97 | |
| 98 | /* if we get here, then the user record still hadn't appeared on the |
| 99 | * second pass - so we use the candidate record */ |
| 100 | atomic_set(&candidate->usage, 1); |
| 101 | atomic_set(&candidate->nkeys, 0); |
| 102 | atomic_set(&candidate->nikeys, 0); |
| 103 | candidate->uid = uid; |
| 104 | candidate->qnkeys = 0; |
| 105 | candidate->qnbytes = 0; |
| 106 | spin_lock_init(&candidate->lock); |
| 107 | INIT_LIST_HEAD(&candidate->consq); |
| 108 | |
| 109 | rb_link_node(&candidate->node, parent, p); |
| 110 | rb_insert_color(&candidate->node, &key_user_tree); |
| 111 | spin_unlock(&key_user_lock); |
| 112 | user = candidate; |
| 113 | goto out; |
| 114 | |
| 115 | /* okay - we found a user record for this UID */ |
| 116 | found: |
| 117 | atomic_inc(&user->usage); |
| 118 | spin_unlock(&key_user_lock); |
Jesper Juhl | a7f988b | 2005-11-07 01:01:35 -0800 | [diff] [blame] | 119 | kfree(candidate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 173 | * - these are assigned randomly to avoid security issues through covert |
| 174 | * channel problems |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | */ |
| 176 | static inline void key_alloc_serial(struct key *key) |
| 177 | { |
| 178 | struct rb_node *parent, **p; |
| 179 | struct key *xkey; |
| 180 | |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 181 | /* propose a random serial number and look for a hole for it in the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | * serial number tree */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 183 | do { |
| 184 | get_random_bytes(&key->serial, sizeof(key->serial)); |
| 185 | |
| 186 | key->serial >>= 1; /* negative numbers are not permitted */ |
| 187 | } while (key->serial < 3); |
| 188 | |
| 189 | spin_lock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | |
| 191 | parent = NULL; |
| 192 | p = &key_serial_tree.rb_node; |
| 193 | |
| 194 | while (*p) { |
| 195 | parent = *p; |
| 196 | xkey = rb_entry(parent, struct key, serial_node); |
| 197 | |
| 198 | if (key->serial < xkey->serial) |
| 199 | p = &(*p)->rb_left; |
| 200 | else if (key->serial > xkey->serial) |
| 201 | p = &(*p)->rb_right; |
| 202 | else |
| 203 | goto serial_exists; |
| 204 | } |
| 205 | goto insert_here; |
| 206 | |
| 207 | /* we found a key with the proposed serial number - walk the tree from |
| 208 | * that point looking for the next unused serial number */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 209 | serial_exists: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | for (;;) { |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 211 | key->serial++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | if (key->serial < 2) |
| 213 | key->serial = 2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | |
David Woodhouse | fed306f | 2006-04-21 13:16:49 +0100 | [diff] [blame] | 215 | if (!rb_parent(parent)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | p = &key_serial_tree.rb_node; |
David Woodhouse | fed306f | 2006-04-21 13:16:49 +0100 | [diff] [blame] | 217 | else if (rb_parent(parent)->rb_left == parent) |
| 218 | p = &(rb_parent(parent)->rb_left); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | else |
David Woodhouse | fed306f | 2006-04-21 13:16:49 +0100 | [diff] [blame] | 220 | p = &(rb_parent(parent)->rb_right); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 232 | insert_here: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
David Howells | 8d9067b | 2006-01-06 00:11:24 -0800 | [diff] [blame] | 244 | * - called from a key-type operation with key_types_sem read-locked by |
| 245 | * key_create_or_update() |
| 246 | * - this prevents unregistration of the key type |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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, |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 251 | uid_t uid, gid_t gid, struct task_struct *ctx, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 252 | key_perm_t perm, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 273 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | spin_lock(&user->lock); |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 275 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
| 276 | if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || |
| 277 | user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES |
| 278 | ) |
| 279 | goto no_quota; |
| 280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | |
| 282 | user->qnkeys++; |
| 283 | user->qnbytes += quotalen; |
| 284 | spin_unlock(&user->lock); |
| 285 | } |
| 286 | |
| 287 | /* allocate and initialise the key and its description */ |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 288 | key = kmem_cache_alloc(key_jar, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | if (!key) |
| 290 | goto no_memory_2; |
| 291 | |
| 292 | if (desc) { |
| 293 | key->description = kmalloc(desclen, GFP_KERNEL); |
| 294 | if (!key->description) |
| 295 | goto no_memory_3; |
| 296 | |
| 297 | memcpy(key->description, desc, desclen); |
| 298 | } |
| 299 | |
| 300 | atomic_set(&key->usage, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | init_rwsem(&key->sem); |
| 302 | key->type = type; |
| 303 | key->user = user; |
| 304 | key->quotalen = quotalen; |
| 305 | key->datalen = type->def_datalen; |
| 306 | key->uid = uid; |
| 307 | key->gid = gid; |
| 308 | key->perm = perm; |
| 309 | key->flags = 0; |
| 310 | key->expiry = 0; |
| 311 | key->payload.data = NULL; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 312 | key->security = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 314 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 315 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | |
| 317 | memset(&key->type_data, 0, sizeof(key->type_data)); |
| 318 | |
| 319 | #ifdef KEY_DEBUGGING |
| 320 | key->magic = KEY_DEBUG_MAGIC; |
| 321 | #endif |
| 322 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 323 | /* let the security module know about the key */ |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 324 | ret = security_key_alloc(key, ctx, flags); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 325 | if (ret < 0) |
| 326 | goto security_error; |
| 327 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | /* publish the key by giving it a serial number */ |
| 329 | atomic_inc(&user->nkeys); |
| 330 | key_alloc_serial(key); |
| 331 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 332 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | return key; |
| 334 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 335 | security_error: |
| 336 | kfree(key->description); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | kmem_cache_free(key_jar, key); |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 338 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | spin_lock(&user->lock); |
| 340 | user->qnkeys--; |
| 341 | user->qnbytes -= quotalen; |
| 342 | spin_unlock(&user->lock); |
| 343 | } |
| 344 | key_user_put(user); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 345 | key = ERR_PTR(ret); |
| 346 | goto error; |
| 347 | |
| 348 | no_memory_3: |
| 349 | kmem_cache_free(key_jar, key); |
| 350 | no_memory_2: |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 351 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 352 | spin_lock(&user->lock); |
| 353 | user->qnkeys--; |
| 354 | user->qnbytes -= quotalen; |
| 355 | spin_unlock(&user->lock); |
| 356 | } |
| 357 | key_user_put(user); |
| 358 | no_memory_1: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | key = ERR_PTR(-ENOMEM); |
| 360 | goto error; |
| 361 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 362 | no_quota: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | spin_unlock(&user->lock); |
| 364 | key_user_put(user); |
| 365 | key = ERR_PTR(-EDQUOT); |
| 366 | goto error; |
| 367 | |
| 368 | } /* end key_alloc() */ |
| 369 | |
| 370 | EXPORT_SYMBOL(key_alloc); |
| 371 | |
| 372 | /*****************************************************************************/ |
| 373 | /* |
| 374 | * reserve an amount of quota for the key's payload |
| 375 | */ |
| 376 | int key_payload_reserve(struct key *key, size_t datalen) |
| 377 | { |
| 378 | int delta = (int) datalen - key->datalen; |
| 379 | int ret = 0; |
| 380 | |
| 381 | key_check(key); |
| 382 | |
| 383 | /* contemplate the quota adjustment */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 384 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | spin_lock(&key->user->lock); |
| 386 | |
| 387 | if (delta > 0 && |
| 388 | key->user->qnbytes + delta > KEYQUOTA_MAX_BYTES |
| 389 | ) { |
| 390 | ret = -EDQUOT; |
| 391 | } |
| 392 | else { |
| 393 | key->user->qnbytes += delta; |
| 394 | key->quotalen += delta; |
| 395 | } |
| 396 | spin_unlock(&key->user->lock); |
| 397 | } |
| 398 | |
| 399 | /* change the recorded data length if that didn't generate an error */ |
| 400 | if (ret == 0) |
| 401 | key->datalen = datalen; |
| 402 | |
| 403 | return ret; |
| 404 | |
| 405 | } /* end key_payload_reserve() */ |
| 406 | |
| 407 | EXPORT_SYMBOL(key_payload_reserve); |
| 408 | |
| 409 | /*****************************************************************************/ |
| 410 | /* |
| 411 | * instantiate a key and link it into the target keyring atomically |
| 412 | * - called with the target keyring's semaphore writelocked |
| 413 | */ |
| 414 | static int __key_instantiate_and_link(struct key *key, |
| 415 | const void *data, |
| 416 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 417 | struct key *keyring, |
| 418 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | { |
| 420 | int ret, awaken; |
| 421 | |
| 422 | key_check(key); |
| 423 | key_check(keyring); |
| 424 | |
| 425 | awaken = 0; |
| 426 | ret = -EBUSY; |
| 427 | |
| 428 | down_write(&key_construction_sem); |
| 429 | |
| 430 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 431 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | /* instantiate the key */ |
| 433 | ret = key->type->instantiate(key, data, datalen); |
| 434 | |
| 435 | if (ret == 0) { |
| 436 | /* mark the key as being instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 438 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 440 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | |
| 443 | /* and link it into the destination keyring */ |
| 444 | if (keyring) |
| 445 | ret = __key_link(keyring, key); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 446 | |
| 447 | /* disable the authorisation key */ |
| 448 | if (instkey) |
| 449 | key_revoke(instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | } |
| 451 | } |
| 452 | |
| 453 | up_write(&key_construction_sem); |
| 454 | |
| 455 | /* wake up anyone waiting for a key to be constructed */ |
| 456 | if (awaken) |
| 457 | wake_up_all(&request_key_conswq); |
| 458 | |
| 459 | return ret; |
| 460 | |
| 461 | } /* end __key_instantiate_and_link() */ |
| 462 | |
| 463 | /*****************************************************************************/ |
| 464 | /* |
| 465 | * instantiate a key and link it into the target keyring atomically |
| 466 | */ |
| 467 | int key_instantiate_and_link(struct key *key, |
| 468 | const void *data, |
| 469 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 470 | struct key *keyring, |
| 471 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | { |
| 473 | int ret; |
| 474 | |
| 475 | if (keyring) |
| 476 | down_write(&keyring->sem); |
| 477 | |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 478 | ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | |
| 480 | if (keyring) |
| 481 | up_write(&keyring->sem); |
| 482 | |
| 483 | return ret; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 484 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | } /* end key_instantiate_and_link() */ |
| 486 | |
| 487 | EXPORT_SYMBOL(key_instantiate_and_link); |
| 488 | |
| 489 | /*****************************************************************************/ |
| 490 | /* |
| 491 | * negatively instantiate a key and link it into the target keyring atomically |
| 492 | */ |
| 493 | int key_negate_and_link(struct key *key, |
| 494 | unsigned timeout, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 495 | struct key *keyring, |
| 496 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | { |
| 498 | struct timespec now; |
| 499 | int ret, awaken; |
| 500 | |
| 501 | key_check(key); |
| 502 | key_check(keyring); |
| 503 | |
| 504 | awaken = 0; |
| 505 | ret = -EBUSY; |
| 506 | |
| 507 | if (keyring) |
| 508 | down_write(&keyring->sem); |
| 509 | |
| 510 | down_write(&key_construction_sem); |
| 511 | |
| 512 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 513 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | /* mark the key as being negatively instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 516 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
| 517 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | now = current_kernel_time(); |
| 519 | key->expiry = now.tv_sec + timeout; |
| 520 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 521 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | ret = 0; |
| 525 | |
| 526 | /* and link it into the destination keyring */ |
| 527 | if (keyring) |
| 528 | ret = __key_link(keyring, key); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 529 | |
| 530 | /* disable the authorisation key */ |
| 531 | if (instkey) |
| 532 | key_revoke(instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | } |
| 534 | |
| 535 | up_write(&key_construction_sem); |
| 536 | |
| 537 | if (keyring) |
| 538 | up_write(&keyring->sem); |
| 539 | |
| 540 | /* wake up anyone waiting for a key to be constructed */ |
| 541 | if (awaken) |
| 542 | wake_up_all(&request_key_conswq); |
| 543 | |
| 544 | return ret; |
| 545 | |
| 546 | } /* end key_negate_and_link() */ |
| 547 | |
| 548 | EXPORT_SYMBOL(key_negate_and_link); |
| 549 | |
| 550 | /*****************************************************************************/ |
| 551 | /* |
| 552 | * do cleaning up in process context so that we don't have to disable |
| 553 | * interrupts all over the place |
| 554 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 555 | static void key_cleanup(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | { |
| 557 | struct rb_node *_n; |
| 558 | struct key *key; |
| 559 | |
| 560 | go_again: |
| 561 | /* look for a dead key in the tree */ |
| 562 | spin_lock(&key_serial_lock); |
| 563 | |
| 564 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 565 | key = rb_entry(_n, struct key, serial_node); |
| 566 | |
| 567 | if (atomic_read(&key->usage) == 0) |
| 568 | goto found_dead_key; |
| 569 | } |
| 570 | |
| 571 | spin_unlock(&key_serial_lock); |
| 572 | return; |
| 573 | |
| 574 | found_dead_key: |
| 575 | /* we found a dead key - once we've removed it from the tree, we can |
| 576 | * drop the lock */ |
| 577 | rb_erase(&key->serial_node, &key_serial_tree); |
| 578 | spin_unlock(&key_serial_lock); |
| 579 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 580 | key_check(key); |
| 581 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 582 | security_key_free(key); |
| 583 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | /* deal with the user's key tracking and quota */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 585 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | spin_lock(&key->user->lock); |
| 587 | key->user->qnkeys--; |
| 588 | key->user->qnbytes -= key->quotalen; |
| 589 | spin_unlock(&key->user->lock); |
| 590 | } |
| 591 | |
| 592 | atomic_dec(&key->user->nkeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 593 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | atomic_dec(&key->user->nikeys); |
| 595 | |
| 596 | key_user_put(key->user); |
| 597 | |
| 598 | /* now throw away the key memory */ |
| 599 | if (key->type->destroy) |
| 600 | key->type->destroy(key); |
| 601 | |
| 602 | kfree(key->description); |
| 603 | |
| 604 | #ifdef KEY_DEBUGGING |
| 605 | key->magic = KEY_DEBUG_MAGIC_X; |
| 606 | #endif |
| 607 | kmem_cache_free(key_jar, key); |
| 608 | |
| 609 | /* there may, of course, be more than one key to destroy */ |
| 610 | goto go_again; |
| 611 | |
| 612 | } /* end key_cleanup() */ |
| 613 | |
| 614 | /*****************************************************************************/ |
| 615 | /* |
| 616 | * dispose of a reference to a key |
| 617 | * - when all the references are gone, we schedule the cleanup task to come and |
| 618 | * pull it out of the tree in definite process context |
| 619 | */ |
| 620 | void key_put(struct key *key) |
| 621 | { |
| 622 | if (key) { |
| 623 | key_check(key); |
| 624 | |
| 625 | if (atomic_dec_and_test(&key->usage)) |
| 626 | schedule_work(&key_cleanup_task); |
| 627 | } |
| 628 | |
| 629 | } /* end key_put() */ |
| 630 | |
| 631 | EXPORT_SYMBOL(key_put); |
| 632 | |
| 633 | /*****************************************************************************/ |
| 634 | /* |
| 635 | * find a key by its serial number |
| 636 | */ |
| 637 | struct key *key_lookup(key_serial_t id) |
| 638 | { |
| 639 | struct rb_node *n; |
| 640 | struct key *key; |
| 641 | |
| 642 | spin_lock(&key_serial_lock); |
| 643 | |
| 644 | /* search the tree for the specified key */ |
| 645 | n = key_serial_tree.rb_node; |
| 646 | while (n) { |
| 647 | key = rb_entry(n, struct key, serial_node); |
| 648 | |
| 649 | if (id < key->serial) |
| 650 | n = n->rb_left; |
| 651 | else if (id > key->serial) |
| 652 | n = n->rb_right; |
| 653 | else |
| 654 | goto found; |
| 655 | } |
| 656 | |
| 657 | not_found: |
| 658 | key = ERR_PTR(-ENOKEY); |
| 659 | goto error; |
| 660 | |
| 661 | found: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 662 | /* pretend it doesn't exist if it's dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | if (atomic_read(&key->usage) == 0 || |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 664 | test_bit(KEY_FLAG_DEAD, &key->flags) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | key->type == &key_type_dead) |
| 666 | goto not_found; |
| 667 | |
| 668 | /* this races with key_put(), but that doesn't matter since key_put() |
| 669 | * doesn't actually change the key |
| 670 | */ |
| 671 | atomic_inc(&key->usage); |
| 672 | |
| 673 | error: |
| 674 | spin_unlock(&key_serial_lock); |
| 675 | return key; |
| 676 | |
| 677 | } /* end key_lookup() */ |
| 678 | |
| 679 | /*****************************************************************************/ |
| 680 | /* |
| 681 | * find and lock the specified key type against removal |
| 682 | * - we return with the sem readlocked |
| 683 | */ |
| 684 | struct key_type *key_type_lookup(const char *type) |
| 685 | { |
| 686 | struct key_type *ktype; |
| 687 | |
| 688 | down_read(&key_types_sem); |
| 689 | |
| 690 | /* look up the key type to see if it's one of the registered kernel |
| 691 | * types */ |
| 692 | list_for_each_entry(ktype, &key_types_list, link) { |
| 693 | if (strcmp(ktype->name, type) == 0) |
| 694 | goto found_kernel_type; |
| 695 | } |
| 696 | |
| 697 | up_read(&key_types_sem); |
| 698 | ktype = ERR_PTR(-ENOKEY); |
| 699 | |
| 700 | found_kernel_type: |
| 701 | return ktype; |
| 702 | |
| 703 | } /* end key_type_lookup() */ |
| 704 | |
| 705 | /*****************************************************************************/ |
| 706 | /* |
| 707 | * unlock a key type |
| 708 | */ |
| 709 | void key_type_put(struct key_type *ktype) |
| 710 | { |
| 711 | up_read(&key_types_sem); |
| 712 | |
| 713 | } /* end key_type_put() */ |
| 714 | |
| 715 | /*****************************************************************************/ |
| 716 | /* |
| 717 | * attempt to update an existing key |
| 718 | * - the key has an incremented refcount |
| 719 | * - we need to put the key if we get an error |
| 720 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 721 | static inline key_ref_t __key_update(key_ref_t key_ref, |
| 722 | const void *payload, size_t plen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 724 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | int ret; |
| 726 | |
| 727 | /* need write permission on the key to update it */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 728 | ret = key_permission(key_ref, KEY_WRITE); |
| 729 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | goto error; |
| 731 | |
| 732 | ret = -EEXIST; |
| 733 | if (!key->type->update) |
| 734 | goto error; |
| 735 | |
| 736 | down_write(&key->sem); |
| 737 | |
| 738 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 739 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 741 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | |
| 743 | up_write(&key->sem); |
| 744 | |
| 745 | if (ret < 0) |
| 746 | goto error; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 747 | out: |
| 748 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 750 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 752 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | goto out; |
| 754 | |
| 755 | } /* end __key_update() */ |
| 756 | |
| 757 | /*****************************************************************************/ |
| 758 | /* |
| 759 | * search the specified keyring for a key of the same description; if one is |
| 760 | * found, update it, otherwise add a new one |
| 761 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 762 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
| 763 | const char *type, |
| 764 | const char *description, |
| 765 | const void *payload, |
| 766 | size_t plen, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 767 | unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | { |
| 769 | struct key_type *ktype; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 770 | struct key *keyring, *key = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | key_perm_t perm; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 772 | key_ref_t key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | int ret; |
| 774 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | /* look up the key type to see if it's one of the registered kernel |
| 776 | * types */ |
| 777 | ktype = key_type_lookup(type); |
| 778 | if (IS_ERR(ktype)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 779 | key_ref = ERR_PTR(-ENODEV); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | goto error; |
| 781 | } |
| 782 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 783 | key_ref = ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | if (!ktype->match || !ktype->instantiate) |
| 785 | goto error_2; |
| 786 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 787 | keyring = key_ref_to_ptr(keyring_ref); |
| 788 | |
| 789 | key_check(keyring); |
| 790 | |
David Howells | c3a9d65 | 2006-04-10 15:15:21 +0100 | [diff] [blame] | 791 | key_ref = ERR_PTR(-ENOTDIR); |
| 792 | if (keyring->type != &key_type_keyring) |
| 793 | goto error_2; |
| 794 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 795 | down_write(&keyring->sem); |
| 796 | |
| 797 | /* if we're going to allocate a new key, we're going to have |
| 798 | * to modify the keyring */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 799 | ret = key_permission(keyring_ref, KEY_WRITE); |
| 800 | if (ret < 0) { |
| 801 | key_ref = ERR_PTR(ret); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 802 | goto error_3; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 803 | } |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 804 | |
David Howells | 1d9b7d9 | 2006-03-25 03:06:52 -0800 | [diff] [blame] | 805 | /* if it's possible to update this type of key, search for an existing |
| 806 | * key of the same type and description in the destination keyring and |
| 807 | * update that instead if possible |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | */ |
David Howells | 1d9b7d9 | 2006-03-25 03:06:52 -0800 | [diff] [blame] | 809 | if (ktype->update) { |
| 810 | key_ref = __keyring_search_one(keyring_ref, ktype, description, |
| 811 | 0); |
| 812 | if (!IS_ERR(key_ref)) |
| 813 | goto found_matching_key; |
| 814 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 816 | /* decide on the permissions we want */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 817 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; |
| 818 | 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] | 819 | |
| 820 | if (ktype->read) |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 821 | perm |= KEY_POS_READ | KEY_USR_READ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | |
| 823 | if (ktype == &key_type_keyring || ktype->update) |
| 824 | perm |= KEY_USR_WRITE; |
| 825 | |
| 826 | /* allocate a new key */ |
| 827 | key = key_alloc(ktype, description, current->fsuid, current->fsgid, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 828 | current, perm, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | if (IS_ERR(key)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 830 | key_ref = ERR_PTR(PTR_ERR(key)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | goto error_3; |
| 832 | } |
| 833 | |
| 834 | /* instantiate it and link it into the target keyring */ |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 835 | ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | if (ret < 0) { |
| 837 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 838 | key_ref = ERR_PTR(ret); |
| 839 | goto error_3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | } |
| 841 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 842 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
| 843 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | error_3: |
| 845 | up_write(&keyring->sem); |
| 846 | error_2: |
| 847 | key_type_put(ktype); |
| 848 | error: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 849 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | |
| 851 | found_matching_key: |
| 852 | /* we found a matching key, so we're going to try to update it |
| 853 | * - we can drop the locks first as we have the key pinned |
| 854 | */ |
| 855 | up_write(&keyring->sem); |
| 856 | key_type_put(ktype); |
| 857 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 858 | key_ref = __key_update(key_ref, payload, plen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | goto error; |
| 860 | |
| 861 | } /* end key_create_or_update() */ |
| 862 | |
| 863 | EXPORT_SYMBOL(key_create_or_update); |
| 864 | |
| 865 | /*****************************************************************************/ |
| 866 | /* |
| 867 | * update a key |
| 868 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 869 | 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] | 870 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 871 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | int ret; |
| 873 | |
| 874 | key_check(key); |
| 875 | |
| 876 | /* the key must be writable */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 877 | ret = key_permission(key_ref, KEY_WRITE); |
| 878 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | goto error; |
| 880 | |
| 881 | /* attempt to update it if supported */ |
| 882 | ret = -EOPNOTSUPP; |
| 883 | if (key->type->update) { |
| 884 | down_write(&key->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 885 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 886 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 887 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 889 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | |
| 891 | up_write(&key->sem); |
| 892 | } |
| 893 | |
| 894 | error: |
| 895 | return ret; |
| 896 | |
| 897 | } /* end key_update() */ |
| 898 | |
| 899 | EXPORT_SYMBOL(key_update); |
| 900 | |
| 901 | /*****************************************************************************/ |
| 902 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | * revoke a key |
| 904 | */ |
| 905 | void key_revoke(struct key *key) |
| 906 | { |
| 907 | key_check(key); |
| 908 | |
| 909 | /* make sure no one's trying to change or use the key when we mark |
| 910 | * it */ |
| 911 | down_write(&key->sem); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 912 | set_bit(KEY_FLAG_REVOKED, &key->flags); |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 913 | |
| 914 | if (key->type->revoke) |
| 915 | key->type->revoke(key); |
| 916 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | up_write(&key->sem); |
| 918 | |
| 919 | } /* end key_revoke() */ |
| 920 | |
| 921 | EXPORT_SYMBOL(key_revoke); |
| 922 | |
| 923 | /*****************************************************************************/ |
| 924 | /* |
| 925 | * register a type of key |
| 926 | */ |
| 927 | int register_key_type(struct key_type *ktype) |
| 928 | { |
| 929 | struct key_type *p; |
| 930 | int ret; |
| 931 | |
| 932 | ret = -EEXIST; |
| 933 | down_write(&key_types_sem); |
| 934 | |
| 935 | /* disallow key types with the same name */ |
| 936 | list_for_each_entry(p, &key_types_list, link) { |
| 937 | if (strcmp(p->name, ktype->name) == 0) |
| 938 | goto out; |
| 939 | } |
| 940 | |
| 941 | /* store the type */ |
| 942 | list_add(&ktype->link, &key_types_list); |
| 943 | ret = 0; |
| 944 | |
| 945 | out: |
| 946 | up_write(&key_types_sem); |
| 947 | return ret; |
| 948 | |
| 949 | } /* end register_key_type() */ |
| 950 | |
| 951 | EXPORT_SYMBOL(register_key_type); |
| 952 | |
| 953 | /*****************************************************************************/ |
| 954 | /* |
| 955 | * unregister a type of key |
| 956 | */ |
| 957 | void unregister_key_type(struct key_type *ktype) |
| 958 | { |
| 959 | struct rb_node *_n; |
| 960 | struct key *key; |
| 961 | |
| 962 | down_write(&key_types_sem); |
| 963 | |
| 964 | /* withdraw the key type */ |
| 965 | list_del_init(&ktype->link); |
| 966 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 967 | /* mark all the keys of this type dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | spin_lock(&key_serial_lock); |
| 969 | |
| 970 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 971 | key = rb_entry(_n, struct key, serial_node); |
| 972 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 973 | if (key->type == ktype) |
| 974 | key->type = &key_type_dead; |
| 975 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 977 | spin_unlock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 979 | /* make sure everyone revalidates their keys */ |
Paul E. McKenney | b2b1866 | 2005-06-25 14:55:38 -0700 | [diff] [blame] | 980 | synchronize_rcu(); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 981 | |
| 982 | /* we should now be able to destroy the payloads of all the keys of |
| 983 | * this type with impunity */ |
| 984 | spin_lock(&key_serial_lock); |
| 985 | |
| 986 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 987 | key = rb_entry(_n, struct key, serial_node); |
| 988 | |
| 989 | if (key->type == ktype) { |
| 990 | if (ktype->destroy) |
| 991 | ktype->destroy(key); |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 992 | memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 993 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | } |
| 995 | |
| 996 | spin_unlock(&key_serial_lock); |
| 997 | up_write(&key_types_sem); |
| 998 | |
| 999 | } /* end unregister_key_type() */ |
| 1000 | |
| 1001 | EXPORT_SYMBOL(unregister_key_type); |
| 1002 | |
| 1003 | /*****************************************************************************/ |
| 1004 | /* |
| 1005 | * initialise the key management stuff |
| 1006 | */ |
| 1007 | void __init key_init(void) |
| 1008 | { |
| 1009 | /* allocate a slab in which we can store keys */ |
| 1010 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), |
| 1011 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL); |
| 1012 | |
| 1013 | /* add the special key types */ |
| 1014 | list_add_tail(&key_type_keyring.link, &key_types_list); |
| 1015 | list_add_tail(&key_type_dead.link, &key_types_list); |
| 1016 | list_add_tail(&key_type_user.link, &key_types_list); |
| 1017 | |
| 1018 | /* record the root user tracking */ |
| 1019 | rb_link_node(&root_key_user.node, |
| 1020 | NULL, |
| 1021 | &key_user_tree.rb_node); |
| 1022 | |
| 1023 | rb_insert_color(&root_key_user.node, |
| 1024 | &key_user_tree); |
| 1025 | |
| 1026 | /* record root's user standard keyrings */ |
| 1027 | key_check(&root_user_keyring); |
| 1028 | key_check(&root_session_keyring); |
| 1029 | |
| 1030 | __key_insert_serial(&root_user_keyring); |
| 1031 | __key_insert_serial(&root_session_keyring); |
| 1032 | |
| 1033 | keyring_publish_name(&root_user_keyring); |
| 1034 | keyring_publish_name(&root_session_keyring); |
| 1035 | |
| 1036 | /* link the two root keyrings together */ |
| 1037 | key_link(&root_session_keyring, &root_user_keyring); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1038 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | } /* end key_init() */ |