David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 1 | /* Basic authentication token and access key management |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame^] | 3 | * Copyright (C) 2004-2008 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 */ |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 37 | DEFINE_MUTEX(key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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); |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 107 | mutex_init(&candidate->cons_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | * assign a key the next unique serial number |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 143 | * - these are assigned randomly to avoid security issues through covert |
| 144 | * channel problems |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | */ |
| 146 | static inline void key_alloc_serial(struct key *key) |
| 147 | { |
| 148 | struct rb_node *parent, **p; |
| 149 | struct key *xkey; |
| 150 | |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 151 | /* 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] | 152 | * serial number tree */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 153 | do { |
| 154 | get_random_bytes(&key->serial, sizeof(key->serial)); |
| 155 | |
| 156 | key->serial >>= 1; /* negative numbers are not permitted */ |
| 157 | } while (key->serial < 3); |
| 158 | |
| 159 | spin_lock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 161 | attempt_insertion: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | parent = NULL; |
| 163 | p = &key_serial_tree.rb_node; |
| 164 | |
| 165 | while (*p) { |
| 166 | parent = *p; |
| 167 | xkey = rb_entry(parent, struct key, serial_node); |
| 168 | |
| 169 | if (key->serial < xkey->serial) |
| 170 | p = &(*p)->rb_left; |
| 171 | else if (key->serial > xkey->serial) |
| 172 | p = &(*p)->rb_right; |
| 173 | else |
| 174 | goto serial_exists; |
| 175 | } |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 176 | |
| 177 | /* we've found a suitable hole - arrange for this key to occupy it */ |
| 178 | rb_link_node(&key->serial_node, parent, p); |
| 179 | rb_insert_color(&key->serial_node, &key_serial_tree); |
| 180 | |
| 181 | spin_unlock(&key_serial_lock); |
| 182 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | |
| 184 | /* we found a key with the proposed serial number - walk the tree from |
| 185 | * that point looking for the next unused serial number */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 186 | serial_exists: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | for (;;) { |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 188 | key->serial++; |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 189 | if (key->serial < 3) { |
| 190 | key->serial = 3; |
| 191 | goto attempt_insertion; |
| 192 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | |
| 194 | parent = rb_next(parent); |
| 195 | if (!parent) |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 196 | goto attempt_insertion; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | |
| 198 | xkey = rb_entry(parent, struct key, serial_node); |
| 199 | if (key->serial < xkey->serial) |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 200 | goto attempt_insertion; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | } |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | } /* end key_alloc_serial() */ |
| 204 | |
| 205 | /*****************************************************************************/ |
| 206 | /* |
| 207 | * allocate a key of the specified type |
| 208 | * - update the user's quota to reflect the existence of the key |
David Howells | 8d9067b | 2006-01-06 00:11:24 -0800 | [diff] [blame] | 209 | * - called from a key-type operation with key_types_sem read-locked by |
| 210 | * key_create_or_update() |
| 211 | * - this prevents unregistration of the key type |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | * - upon return the key is as yet uninstantiated; the caller needs to either |
| 213 | * instantiate the key or discard it before returning |
| 214 | */ |
| 215 | struct key *key_alloc(struct key_type *type, const char *desc, |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 216 | uid_t uid, gid_t gid, struct task_struct *ctx, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 217 | key_perm_t perm, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | { |
| 219 | struct key_user *user = NULL; |
| 220 | struct key *key; |
| 221 | size_t desclen, quotalen; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 222 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
| 224 | key = ERR_PTR(-EINVAL); |
| 225 | if (!desc || !*desc) |
| 226 | goto error; |
| 227 | |
| 228 | desclen = strlen(desc) + 1; |
| 229 | quotalen = desclen + type->def_datalen; |
| 230 | |
| 231 | /* get hold of the key tracking for this user */ |
| 232 | user = key_user_lookup(uid); |
| 233 | if (!user) |
| 234 | goto no_memory_1; |
| 235 | |
| 236 | /* check that the user's quota permits allocation of another key and |
| 237 | * its description */ |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 238 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | spin_lock(&user->lock); |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 240 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
| 241 | if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || |
| 242 | user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES |
| 243 | ) |
| 244 | goto no_quota; |
| 245 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | |
| 247 | user->qnkeys++; |
| 248 | user->qnbytes += quotalen; |
| 249 | spin_unlock(&user->lock); |
| 250 | } |
| 251 | |
| 252 | /* allocate and initialise the key and its description */ |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 253 | key = kmem_cache_alloc(key_jar, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | if (!key) |
| 255 | goto no_memory_2; |
| 256 | |
| 257 | if (desc) { |
Eric Sesterhenn | 48ad504 | 2006-12-06 20:33:47 -0800 | [diff] [blame] | 258 | key->description = kmemdup(desc, desclen, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | if (!key->description) |
| 260 | goto no_memory_3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | } |
| 262 | |
| 263 | atomic_set(&key->usage, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | init_rwsem(&key->sem); |
| 265 | key->type = type; |
| 266 | key->user = user; |
| 267 | key->quotalen = quotalen; |
| 268 | key->datalen = type->def_datalen; |
| 269 | key->uid = uid; |
| 270 | key->gid = gid; |
| 271 | key->perm = perm; |
| 272 | key->flags = 0; |
| 273 | key->expiry = 0; |
| 274 | key->payload.data = NULL; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 275 | key->security = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 277 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 278 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
| 280 | memset(&key->type_data, 0, sizeof(key->type_data)); |
| 281 | |
| 282 | #ifdef KEY_DEBUGGING |
| 283 | key->magic = KEY_DEBUG_MAGIC; |
| 284 | #endif |
| 285 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 286 | /* let the security module know about the key */ |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 287 | ret = security_key_alloc(key, ctx, flags); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 288 | if (ret < 0) |
| 289 | goto security_error; |
| 290 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | /* publish the key by giving it a serial number */ |
| 292 | atomic_inc(&user->nkeys); |
| 293 | key_alloc_serial(key); |
| 294 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 295 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | return key; |
| 297 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 298 | security_error: |
| 299 | kfree(key->description); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | kmem_cache_free(key_jar, key); |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 301 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | spin_lock(&user->lock); |
| 303 | user->qnkeys--; |
| 304 | user->qnbytes -= quotalen; |
| 305 | spin_unlock(&user->lock); |
| 306 | } |
| 307 | key_user_put(user); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 308 | key = ERR_PTR(ret); |
| 309 | goto error; |
| 310 | |
| 311 | no_memory_3: |
| 312 | kmem_cache_free(key_jar, key); |
| 313 | no_memory_2: |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 314 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 315 | spin_lock(&user->lock); |
| 316 | user->qnkeys--; |
| 317 | user->qnbytes -= quotalen; |
| 318 | spin_unlock(&user->lock); |
| 319 | } |
| 320 | key_user_put(user); |
| 321 | no_memory_1: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | key = ERR_PTR(-ENOMEM); |
| 323 | goto error; |
| 324 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 325 | no_quota: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | spin_unlock(&user->lock); |
| 327 | key_user_put(user); |
| 328 | key = ERR_PTR(-EDQUOT); |
| 329 | goto error; |
| 330 | |
| 331 | } /* end key_alloc() */ |
| 332 | |
| 333 | EXPORT_SYMBOL(key_alloc); |
| 334 | |
| 335 | /*****************************************************************************/ |
| 336 | /* |
| 337 | * reserve an amount of quota for the key's payload |
| 338 | */ |
| 339 | int key_payload_reserve(struct key *key, size_t datalen) |
| 340 | { |
| 341 | int delta = (int) datalen - key->datalen; |
| 342 | int ret = 0; |
| 343 | |
| 344 | key_check(key); |
| 345 | |
| 346 | /* contemplate the quota adjustment */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 347 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | spin_lock(&key->user->lock); |
| 349 | |
| 350 | if (delta > 0 && |
| 351 | key->user->qnbytes + delta > KEYQUOTA_MAX_BYTES |
| 352 | ) { |
| 353 | ret = -EDQUOT; |
| 354 | } |
| 355 | else { |
| 356 | key->user->qnbytes += delta; |
| 357 | key->quotalen += delta; |
| 358 | } |
| 359 | spin_unlock(&key->user->lock); |
| 360 | } |
| 361 | |
| 362 | /* change the recorded data length if that didn't generate an error */ |
| 363 | if (ret == 0) |
| 364 | key->datalen = datalen; |
| 365 | |
| 366 | return ret; |
| 367 | |
| 368 | } /* end key_payload_reserve() */ |
| 369 | |
| 370 | EXPORT_SYMBOL(key_payload_reserve); |
| 371 | |
| 372 | /*****************************************************************************/ |
| 373 | /* |
| 374 | * instantiate a key and link it into the target keyring atomically |
| 375 | * - called with the target keyring's semaphore writelocked |
| 376 | */ |
| 377 | static int __key_instantiate_and_link(struct key *key, |
| 378 | const void *data, |
| 379 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 380 | struct key *keyring, |
| 381 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | { |
| 383 | int ret, awaken; |
| 384 | |
| 385 | key_check(key); |
| 386 | key_check(keyring); |
| 387 | |
| 388 | awaken = 0; |
| 389 | ret = -EBUSY; |
| 390 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 391 | mutex_lock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | |
| 393 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 394 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | /* instantiate the key */ |
| 396 | ret = key->type->instantiate(key, data, datalen); |
| 397 | |
| 398 | if (ret == 0) { |
| 399 | /* mark the key as being instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 401 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 403 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | |
| 406 | /* and link it into the destination keyring */ |
| 407 | if (keyring) |
| 408 | ret = __key_link(keyring, key); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 409 | |
| 410 | /* disable the authorisation key */ |
| 411 | if (instkey) |
| 412 | key_revoke(instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | } |
| 414 | } |
| 415 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 416 | mutex_unlock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
| 418 | /* wake up anyone waiting for a key to be constructed */ |
| 419 | if (awaken) |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 420 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | |
| 422 | return ret; |
| 423 | |
| 424 | } /* end __key_instantiate_and_link() */ |
| 425 | |
| 426 | /*****************************************************************************/ |
| 427 | /* |
| 428 | * instantiate a key and link it into the target keyring atomically |
| 429 | */ |
| 430 | int key_instantiate_and_link(struct key *key, |
| 431 | const void *data, |
| 432 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 433 | struct key *keyring, |
| 434 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | { |
| 436 | int ret; |
| 437 | |
| 438 | if (keyring) |
| 439 | down_write(&keyring->sem); |
| 440 | |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 441 | ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | |
| 443 | if (keyring) |
| 444 | up_write(&keyring->sem); |
| 445 | |
| 446 | return ret; |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 447 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | } /* end key_instantiate_and_link() */ |
| 449 | |
| 450 | EXPORT_SYMBOL(key_instantiate_and_link); |
| 451 | |
| 452 | /*****************************************************************************/ |
| 453 | /* |
| 454 | * negatively instantiate a key and link it into the target keyring atomically |
| 455 | */ |
| 456 | int key_negate_and_link(struct key *key, |
| 457 | unsigned timeout, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 458 | struct key *keyring, |
| 459 | struct key *instkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | { |
| 461 | struct timespec now; |
| 462 | int ret, awaken; |
| 463 | |
| 464 | key_check(key); |
| 465 | key_check(keyring); |
| 466 | |
| 467 | awaken = 0; |
| 468 | ret = -EBUSY; |
| 469 | |
| 470 | if (keyring) |
| 471 | down_write(&keyring->sem); |
| 472 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 473 | mutex_lock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | |
| 475 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 476 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | /* mark the key as being negatively instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 479 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
| 480 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | now = current_kernel_time(); |
| 482 | key->expiry = now.tv_sec + timeout; |
| 483 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 484 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | ret = 0; |
| 488 | |
| 489 | /* and link it into the destination keyring */ |
| 490 | if (keyring) |
| 491 | ret = __key_link(keyring, key); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 492 | |
| 493 | /* disable the authorisation key */ |
| 494 | if (instkey) |
| 495 | key_revoke(instkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | } |
| 497 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 498 | mutex_unlock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | |
| 500 | if (keyring) |
| 501 | up_write(&keyring->sem); |
| 502 | |
| 503 | /* wake up anyone waiting for a key to be constructed */ |
| 504 | if (awaken) |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 505 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | |
| 507 | return ret; |
| 508 | |
| 509 | } /* end key_negate_and_link() */ |
| 510 | |
| 511 | EXPORT_SYMBOL(key_negate_and_link); |
| 512 | |
| 513 | /*****************************************************************************/ |
| 514 | /* |
| 515 | * do cleaning up in process context so that we don't have to disable |
| 516 | * interrupts all over the place |
| 517 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 518 | static void key_cleanup(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | { |
| 520 | struct rb_node *_n; |
| 521 | struct key *key; |
| 522 | |
| 523 | go_again: |
| 524 | /* look for a dead key in the tree */ |
| 525 | spin_lock(&key_serial_lock); |
| 526 | |
| 527 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 528 | key = rb_entry(_n, struct key, serial_node); |
| 529 | |
| 530 | if (atomic_read(&key->usage) == 0) |
| 531 | goto found_dead_key; |
| 532 | } |
| 533 | |
| 534 | spin_unlock(&key_serial_lock); |
| 535 | return; |
| 536 | |
| 537 | found_dead_key: |
| 538 | /* we found a dead key - once we've removed it from the tree, we can |
| 539 | * drop the lock */ |
| 540 | rb_erase(&key->serial_node, &key_serial_tree); |
| 541 | spin_unlock(&key_serial_lock); |
| 542 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 543 | key_check(key); |
| 544 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 545 | security_key_free(key); |
| 546 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | /* deal with the user's key tracking and quota */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 548 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | spin_lock(&key->user->lock); |
| 550 | key->user->qnkeys--; |
| 551 | key->user->qnbytes -= key->quotalen; |
| 552 | spin_unlock(&key->user->lock); |
| 553 | } |
| 554 | |
| 555 | atomic_dec(&key->user->nkeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 556 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | atomic_dec(&key->user->nikeys); |
| 558 | |
| 559 | key_user_put(key->user); |
| 560 | |
| 561 | /* now throw away the key memory */ |
| 562 | if (key->type->destroy) |
| 563 | key->type->destroy(key); |
| 564 | |
| 565 | kfree(key->description); |
| 566 | |
| 567 | #ifdef KEY_DEBUGGING |
| 568 | key->magic = KEY_DEBUG_MAGIC_X; |
| 569 | #endif |
| 570 | kmem_cache_free(key_jar, key); |
| 571 | |
| 572 | /* there may, of course, be more than one key to destroy */ |
| 573 | goto go_again; |
| 574 | |
| 575 | } /* end key_cleanup() */ |
| 576 | |
| 577 | /*****************************************************************************/ |
| 578 | /* |
| 579 | * dispose of a reference to a key |
| 580 | * - when all the references are gone, we schedule the cleanup task to come and |
| 581 | * pull it out of the tree in definite process context |
| 582 | */ |
| 583 | void key_put(struct key *key) |
| 584 | { |
| 585 | if (key) { |
| 586 | key_check(key); |
| 587 | |
| 588 | if (atomic_dec_and_test(&key->usage)) |
| 589 | schedule_work(&key_cleanup_task); |
| 590 | } |
| 591 | |
| 592 | } /* end key_put() */ |
| 593 | |
| 594 | EXPORT_SYMBOL(key_put); |
| 595 | |
| 596 | /*****************************************************************************/ |
| 597 | /* |
| 598 | * find a key by its serial number |
| 599 | */ |
| 600 | struct key *key_lookup(key_serial_t id) |
| 601 | { |
| 602 | struct rb_node *n; |
| 603 | struct key *key; |
| 604 | |
| 605 | spin_lock(&key_serial_lock); |
| 606 | |
| 607 | /* search the tree for the specified key */ |
| 608 | n = key_serial_tree.rb_node; |
| 609 | while (n) { |
| 610 | key = rb_entry(n, struct key, serial_node); |
| 611 | |
| 612 | if (id < key->serial) |
| 613 | n = n->rb_left; |
| 614 | else if (id > key->serial) |
| 615 | n = n->rb_right; |
| 616 | else |
| 617 | goto found; |
| 618 | } |
| 619 | |
| 620 | not_found: |
| 621 | key = ERR_PTR(-ENOKEY); |
| 622 | goto error; |
| 623 | |
| 624 | found: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 625 | /* pretend it doesn't exist if it's dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | if (atomic_read(&key->usage) == 0 || |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 627 | test_bit(KEY_FLAG_DEAD, &key->flags) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 628 | key->type == &key_type_dead) |
| 629 | goto not_found; |
| 630 | |
| 631 | /* this races with key_put(), but that doesn't matter since key_put() |
| 632 | * doesn't actually change the key |
| 633 | */ |
| 634 | atomic_inc(&key->usage); |
| 635 | |
| 636 | error: |
| 637 | spin_unlock(&key_serial_lock); |
| 638 | return key; |
| 639 | |
| 640 | } /* end key_lookup() */ |
| 641 | |
| 642 | /*****************************************************************************/ |
| 643 | /* |
| 644 | * find and lock the specified key type against removal |
| 645 | * - we return with the sem readlocked |
| 646 | */ |
| 647 | struct key_type *key_type_lookup(const char *type) |
| 648 | { |
| 649 | struct key_type *ktype; |
| 650 | |
| 651 | down_read(&key_types_sem); |
| 652 | |
| 653 | /* look up the key type to see if it's one of the registered kernel |
| 654 | * types */ |
| 655 | list_for_each_entry(ktype, &key_types_list, link) { |
| 656 | if (strcmp(ktype->name, type) == 0) |
| 657 | goto found_kernel_type; |
| 658 | } |
| 659 | |
| 660 | up_read(&key_types_sem); |
| 661 | ktype = ERR_PTR(-ENOKEY); |
| 662 | |
| 663 | found_kernel_type: |
| 664 | return ktype; |
| 665 | |
| 666 | } /* end key_type_lookup() */ |
| 667 | |
| 668 | /*****************************************************************************/ |
| 669 | /* |
| 670 | * unlock a key type |
| 671 | */ |
| 672 | void key_type_put(struct key_type *ktype) |
| 673 | { |
| 674 | up_read(&key_types_sem); |
| 675 | |
| 676 | } /* end key_type_put() */ |
| 677 | |
| 678 | /*****************************************************************************/ |
| 679 | /* |
| 680 | * attempt to update an existing key |
| 681 | * - the key has an incremented refcount |
| 682 | * - we need to put the key if we get an error |
| 683 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 684 | static inline key_ref_t __key_update(key_ref_t key_ref, |
| 685 | const void *payload, size_t plen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 687 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | int ret; |
| 689 | |
| 690 | /* need write permission on the key to update it */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 691 | ret = key_permission(key_ref, KEY_WRITE); |
| 692 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | goto error; |
| 694 | |
| 695 | ret = -EEXIST; |
| 696 | if (!key->type->update) |
| 697 | goto error; |
| 698 | |
| 699 | down_write(&key->sem); |
| 700 | |
| 701 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 702 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 704 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | |
| 706 | up_write(&key->sem); |
| 707 | |
| 708 | if (ret < 0) |
| 709 | goto error; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 710 | out: |
| 711 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 713 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 715 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 716 | goto out; |
| 717 | |
| 718 | } /* end __key_update() */ |
| 719 | |
| 720 | /*****************************************************************************/ |
| 721 | /* |
| 722 | * search the specified keyring for a key of the same description; if one is |
| 723 | * found, update it, otherwise add a new one |
| 724 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 725 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
| 726 | const char *type, |
| 727 | const char *description, |
| 728 | const void *payload, |
| 729 | size_t plen, |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 730 | key_perm_t perm, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 731 | unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | { |
| 733 | struct key_type *ktype; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 734 | struct key *keyring, *key = NULL; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 735 | key_ref_t key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | int ret; |
| 737 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | /* look up the key type to see if it's one of the registered kernel |
| 739 | * types */ |
| 740 | ktype = key_type_lookup(type); |
| 741 | if (IS_ERR(ktype)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 742 | key_ref = ERR_PTR(-ENODEV); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | goto error; |
| 744 | } |
| 745 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 746 | key_ref = ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | if (!ktype->match || !ktype->instantiate) |
| 748 | goto error_2; |
| 749 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 750 | keyring = key_ref_to_ptr(keyring_ref); |
| 751 | |
| 752 | key_check(keyring); |
| 753 | |
David Howells | c3a9d65 | 2006-04-10 15:15:21 +0100 | [diff] [blame] | 754 | key_ref = ERR_PTR(-ENOTDIR); |
| 755 | if (keyring->type != &key_type_keyring) |
| 756 | goto error_2; |
| 757 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 758 | down_write(&keyring->sem); |
| 759 | |
| 760 | /* if we're going to allocate a new key, we're going to have |
| 761 | * to modify the keyring */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 762 | ret = key_permission(keyring_ref, KEY_WRITE); |
| 763 | if (ret < 0) { |
| 764 | key_ref = ERR_PTR(ret); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 765 | goto error_3; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 766 | } |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 767 | |
David Howells | 1d9b7d9 | 2006-03-25 03:06:52 -0800 | [diff] [blame] | 768 | /* if it's possible to update this type of key, search for an existing |
| 769 | * key of the same type and description in the destination keyring and |
| 770 | * update that instead if possible |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | */ |
David Howells | 1d9b7d9 | 2006-03-25 03:06:52 -0800 | [diff] [blame] | 772 | if (ktype->update) { |
| 773 | key_ref = __keyring_search_one(keyring_ref, ktype, description, |
| 774 | 0); |
| 775 | if (!IS_ERR(key_ref)) |
| 776 | goto found_matching_key; |
| 777 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 779 | /* if the client doesn't provide, decide on the permissions we want */ |
| 780 | if (perm == KEY_PERM_UNDEF) { |
| 781 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; |
| 782 | 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] | 783 | |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 784 | if (ktype->read) |
| 785 | perm |= KEY_POS_READ | KEY_USR_READ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 787 | if (ktype == &key_type_keyring || ktype->update) |
| 788 | perm |= KEY_USR_WRITE; |
| 789 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | |
| 791 | /* allocate a new key */ |
| 792 | key = key_alloc(ktype, description, current->fsuid, current->fsgid, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 793 | current, perm, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | if (IS_ERR(key)) { |
David Howells | e231c2e | 2008-02-07 00:15:26 -0800 | [diff] [blame] | 795 | key_ref = ERR_CAST(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | goto error_3; |
| 797 | } |
| 798 | |
| 799 | /* instantiate it and link it into the target keyring */ |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 800 | ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | if (ret < 0) { |
| 802 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 803 | key_ref = ERR_PTR(ret); |
| 804 | goto error_3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | } |
| 806 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 807 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
| 808 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | error_3: |
| 810 | up_write(&keyring->sem); |
| 811 | error_2: |
| 812 | key_type_put(ktype); |
| 813 | error: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 814 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | |
| 816 | found_matching_key: |
| 817 | /* we found a matching key, so we're going to try to update it |
| 818 | * - we can drop the locks first as we have the key pinned |
| 819 | */ |
| 820 | up_write(&keyring->sem); |
| 821 | key_type_put(ktype); |
| 822 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 823 | key_ref = __key_update(key_ref, payload, plen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | goto error; |
| 825 | |
| 826 | } /* end key_create_or_update() */ |
| 827 | |
| 828 | EXPORT_SYMBOL(key_create_or_update); |
| 829 | |
| 830 | /*****************************************************************************/ |
| 831 | /* |
| 832 | * update a key |
| 833 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 834 | 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] | 835 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 836 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | int ret; |
| 838 | |
| 839 | key_check(key); |
| 840 | |
| 841 | /* the key must be writable */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 842 | ret = key_permission(key_ref, KEY_WRITE); |
| 843 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | goto error; |
| 845 | |
| 846 | /* attempt to update it if supported */ |
| 847 | ret = -EOPNOTSUPP; |
| 848 | if (key->type->update) { |
| 849 | down_write(&key->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 851 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 852 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 854 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | |
| 856 | up_write(&key->sem); |
| 857 | } |
| 858 | |
| 859 | error: |
| 860 | return ret; |
| 861 | |
| 862 | } /* end key_update() */ |
| 863 | |
| 864 | EXPORT_SYMBOL(key_update); |
| 865 | |
| 866 | /*****************************************************************************/ |
| 867 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | * revoke a key |
| 869 | */ |
| 870 | void key_revoke(struct key *key) |
| 871 | { |
| 872 | key_check(key); |
| 873 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 874 | /* make sure no one's trying to change or use the key when we mark it |
| 875 | * - we tell lockdep that we might nest because we might be revoking an |
| 876 | * authorisation key whilst holding the sem on a key we've just |
| 877 | * instantiated |
| 878 | */ |
| 879 | down_write_nested(&key->sem, 1); |
| 880 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && |
| 881 | key->type->revoke) |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 882 | key->type->revoke(key); |
| 883 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | up_write(&key->sem); |
| 885 | |
| 886 | } /* end key_revoke() */ |
| 887 | |
| 888 | EXPORT_SYMBOL(key_revoke); |
| 889 | |
| 890 | /*****************************************************************************/ |
| 891 | /* |
| 892 | * register a type of key |
| 893 | */ |
| 894 | int register_key_type(struct key_type *ktype) |
| 895 | { |
| 896 | struct key_type *p; |
| 897 | int ret; |
| 898 | |
| 899 | ret = -EEXIST; |
| 900 | down_write(&key_types_sem); |
| 901 | |
| 902 | /* disallow key types with the same name */ |
| 903 | list_for_each_entry(p, &key_types_list, link) { |
| 904 | if (strcmp(p->name, ktype->name) == 0) |
| 905 | goto out; |
| 906 | } |
| 907 | |
| 908 | /* store the type */ |
| 909 | list_add(&ktype->link, &key_types_list); |
| 910 | ret = 0; |
| 911 | |
| 912 | out: |
| 913 | up_write(&key_types_sem); |
| 914 | return ret; |
| 915 | |
| 916 | } /* end register_key_type() */ |
| 917 | |
| 918 | EXPORT_SYMBOL(register_key_type); |
| 919 | |
| 920 | /*****************************************************************************/ |
| 921 | /* |
| 922 | * unregister a type of key |
| 923 | */ |
| 924 | void unregister_key_type(struct key_type *ktype) |
| 925 | { |
| 926 | struct rb_node *_n; |
| 927 | struct key *key; |
| 928 | |
| 929 | down_write(&key_types_sem); |
| 930 | |
| 931 | /* withdraw the key type */ |
| 932 | list_del_init(&ktype->link); |
| 933 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 934 | /* mark all the keys of this type dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | spin_lock(&key_serial_lock); |
| 936 | |
| 937 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 938 | key = rb_entry(_n, struct key, serial_node); |
| 939 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 940 | if (key->type == ktype) |
| 941 | key->type = &key_type_dead; |
| 942 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 944 | spin_unlock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 946 | /* make sure everyone revalidates their keys */ |
Paul E. McKenney | b2b1866 | 2005-06-25 14:55:38 -0700 | [diff] [blame] | 947 | synchronize_rcu(); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 948 | |
| 949 | /* we should now be able to destroy the payloads of all the keys of |
| 950 | * this type with impunity */ |
| 951 | spin_lock(&key_serial_lock); |
| 952 | |
| 953 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 954 | key = rb_entry(_n, struct key, serial_node); |
| 955 | |
| 956 | if (key->type == ktype) { |
| 957 | if (ktype->destroy) |
| 958 | ktype->destroy(key); |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 959 | memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 960 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 961 | } |
| 962 | |
| 963 | spin_unlock(&key_serial_lock); |
| 964 | up_write(&key_types_sem); |
| 965 | |
| 966 | } /* end unregister_key_type() */ |
| 967 | |
| 968 | EXPORT_SYMBOL(unregister_key_type); |
| 969 | |
| 970 | /*****************************************************************************/ |
| 971 | /* |
| 972 | * initialise the key management stuff |
| 973 | */ |
| 974 | void __init key_init(void) |
| 975 | { |
| 976 | /* allocate a slab in which we can store keys */ |
| 977 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 978 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | |
| 980 | /* add the special key types */ |
| 981 | list_add_tail(&key_type_keyring.link, &key_types_list); |
| 982 | list_add_tail(&key_type_dead.link, &key_types_list); |
| 983 | list_add_tail(&key_type_user.link, &key_types_list); |
| 984 | |
| 985 | /* record the root user tracking */ |
| 986 | rb_link_node(&root_key_user.node, |
| 987 | NULL, |
| 988 | &key_user_tree.rb_node); |
| 989 | |
| 990 | rb_insert_color(&root_key_user.node, |
| 991 | &key_user_tree); |
| 992 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | } /* end key_init() */ |