net/mac802154/llsec.c

   1 /*
   2  * Copyright (C) 2014 Fraunhofer ITWM
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * Written by:
  14  * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/bug.h>
  19 #include <linux/completion.h>
  20 #include <net/ieee802154.h>
  21 #include <crypto/algapi.h>
  22
  23 #include "mac802154.h"
  24 #include "llsec.h"
  25
  26 static void llsec_key_put(struct mac802154_llsec_key *key);
  27 static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
  28                                const struct ieee802154_llsec_key_id *b);
  29
  30 static void llsec_dev_free(struct mac802154_llsec_device *dev);
  31
  32 void mac802154_llsec_init(struct mac802154_llsec *sec)
  33 {
  34         memset(sec, 0, sizeof(*sec));
  35
  36         memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN);
  37
  38         INIT_LIST_HEAD(&sec->table.security_levels);
  39         INIT_LIST_HEAD(&sec->table.devices);
  40         INIT_LIST_HEAD(&sec->table.keys);
  41         hash_init(sec->devices_short);
  42         hash_init(sec->devices_hw);
  43         rwlock_init(&sec->lock);
  44 }
  45
  46 void mac802154_llsec_destroy(struct mac802154_llsec *sec)
  47 {
  48         struct ieee802154_llsec_seclevel *sl, *sn;
  49         struct ieee802154_llsec_device *dev, *dn;
  50         struct ieee802154_llsec_key_entry *key, *kn;
  51
  52         list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) {
  53                 struct mac802154_llsec_seclevel *msl;
  54
  55                 msl = container_of(sl, struct mac802154_llsec_seclevel, level);
  56                 list_del(&sl->list);
  57                 kfree(msl);
  58         }
  59
  60         list_for_each_entry_safe(dev, dn, &sec->table.devices, list) {
  61                 struct mac802154_llsec_device *mdev;
  62
  63                 mdev = container_of(dev, struct mac802154_llsec_device, dev);
  64                 list_del(&dev->list);
  65                 llsec_dev_free(mdev);
  66         }
  67
  68         list_for_each_entry_safe(key, kn, &sec->table.keys, list) {
  69                 struct mac802154_llsec_key *mkey;
  70
  71                 mkey = container_of(key->key, struct mac802154_llsec_key, key);
  72                 list_del(&key->list);
  73                 llsec_key_put(mkey);
  74                 kfree(key);
  75         }
  76 }
  77
  78
  79
  80 int mac802154_llsec_get_params(struct mac802154_llsec *sec,
  81                                struct ieee802154_llsec_params *params)
  82 {
  83         read_lock_bh(&sec->lock);
  84         *params = sec->params;
  85         read_unlock_bh(&sec->lock);
  86
  87         return 0;
  88 }
  89
  90 int mac802154_llsec_set_params(struct mac802154_llsec *sec,
  91                                const struct ieee802154_llsec_params *params,
  92                                int changed)
  93 {
  94         write_lock_bh(&sec->lock);
  95
  96         if (changed & IEEE802154_LLSEC_PARAM_ENABLED)
  97                 sec->params.enabled = params->enabled;
  98         if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER)
  99                 sec->params.frame_counter = params->frame_counter;
 100         if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL)
 101                 sec->params.out_level = params->out_level;
 102         if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY)
 103                 sec->params.out_key = params->out_key;
 104         if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE)
 105                 sec->params.default_key_source = params->default_key_source;
 106         if (changed & IEEE802154_LLSEC_PARAM_PAN_ID)
 107                 sec->params.pan_id = params->pan_id;
 108         if (changed & IEEE802154_LLSEC_PARAM_HWADDR)
 109                 sec->params.hwaddr = params->hwaddr;
 110         if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR)
 111                 sec->params.coord_hwaddr = params->coord_hwaddr;
 112         if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR)
 113                 sec->params.coord_shortaddr = params->coord_shortaddr;
 114
 115         write_unlock_bh(&sec->lock);
 116
 117         return 0;
 118 }
 119
 120
 121
 122 static struct mac802154_llsec_key*
 123 llsec_key_alloc(const struct ieee802154_llsec_key *template)
 124 {
 125         const int authsizes[3] = { 4, 8, 16 };
 126         struct mac802154_llsec_key *key;
 127         int i;
 128
 129         key = kzalloc(sizeof(*key), GFP_KERNEL);
 130         if (!key)
 131                 return NULL;
 132
 133         kref_init(&key->ref);
 134         key->key = *template;
 135
 136         BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm));
 137
 138         for (i = 0; i < ARRAY_SIZE(key->tfm); i++) {
 139                 key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0,
 140                                                 CRYPTO_ALG_ASYNC);
 141                 if (!key->tfm[i])
 142                         goto err_tfm;
 143                 if (crypto_aead_setkey(key->tfm[i], template->key,
 144                                        IEEE802154_LLSEC_KEY_SIZE))
 145                         goto err_tfm;
 146                 if (crypto_aead_setauthsize(key->tfm[i], authsizes[i]))
 147                         goto err_tfm;
 148         }
 149
 150         key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC);
 151         if (!key->tfm0)
 152                 goto err_tfm;
 153
 154         if (crypto_blkcipher_setkey(key->tfm0, template->key,
 155                                     IEEE802154_LLSEC_KEY_SIZE))
 156                 goto err_tfm0;
 157
 158         return key;
 159
 160 err_tfm0:
 161         crypto_free_blkcipher(key->tfm0);
 162 err_tfm:
 163         for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
 164                 if (key->tfm[i])
 165                         crypto_free_aead(key->tfm[i]);
 166
 167         kfree(key);
 168         return NULL;
 169 }
 170
 171 static void llsec_key_release(struct kref *ref)
 172 {
 173         struct mac802154_llsec_key *key;
 174         int i;
 175
 176         key = container_of(ref, struct mac802154_llsec_key, ref);
 177
 178         for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
 179                 crypto_free_aead(key->tfm[i]);
 180
 181         crypto_free_blkcipher(key->tfm0);
 182         kfree(key);
 183 }
 184
 185 static struct mac802154_llsec_key*
 186 llsec_key_get(struct mac802154_llsec_key *key)
 187 {
 188         kref_get(&key->ref);
 189         return key;
 190 }
 191
 192 static void llsec_key_put(struct mac802154_llsec_key *key)
 193 {
 194         kref_put(&key->ref, llsec_key_release);
 195 }
 196
 197 static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
 198                                const struct ieee802154_llsec_key_id *b)
 199 {
 200         if (a->mode != b->mode)
 201                 return false;
 202
 203         if (a->mode == IEEE802154_SCF_KEY_IMPLICIT)
 204                 return ieee802154_addr_equal(&a->device_addr, &b->device_addr);
 205
 206         if (a->id != b->id)
 207                 return false;
 208
 209         switch (a->mode) {
 210         case IEEE802154_SCF_KEY_INDEX:
 211                 return true;
 212         case IEEE802154_SCF_KEY_SHORT_INDEX:
 213                 return a->short_source == b->short_source;
 214         case IEEE802154_SCF_KEY_HW_INDEX:
 215                 return a->extended_source == b->extended_source;
 216         }
 217
 218         return false;
 219 }
 220
 221 int mac802154_llsec_key_add(struct mac802154_llsec *sec,
 222                             const struct ieee802154_llsec_key_id *id,
 223                             const struct ieee802154_llsec_key *key)
 224 {
 225         struct mac802154_llsec_key *mkey = NULL;
 226         struct ieee802154_llsec_key_entry *pos, *new;
 227
 228         if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) &&
 229             key->cmd_frame_ids)
 230                 return -EINVAL;
 231
 232         list_for_each_entry(pos, &sec->table.keys, list) {
 233                 if (llsec_key_id_equal(&pos->id, id))
 234                         return -EEXIST;
 235
 236                 if (memcmp(pos->key->key, key->key,
 237                            IEEE802154_LLSEC_KEY_SIZE))
 238                         continue;
 239
 240                 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
 241
 242                 /* Don't allow multiple instances of the same AES key to have
 243                  * different allowed frame types/command frame ids, as this is
 244                  * not possible in the 802.15.4 PIB.
 245                  */
 246                 if (pos->key->frame_types != key->frame_types ||
 247                     pos->key->cmd_frame_ids != key->cmd_frame_ids)
 248                         return -EEXIST;
 249
 250                 break;
 251         }
 252
 253         new = kzalloc(sizeof(*new), GFP_KERNEL);
 254         if (!new)
 255                 return -ENOMEM;
 256
 257         if (!mkey)
 258                 mkey = llsec_key_alloc(key);
 259         else
 260                 mkey = llsec_key_get(mkey);
 261
 262         if (!mkey)
 263                 goto fail;
 264
 265         new->id = *id;
 266         new->key = &mkey->key;
 267
 268         list_add_rcu(&new->list, &sec->table.keys);
 269
 270         return 0;
 271
 272 fail:
 273         kfree(new);
 274         return -ENOMEM;
 275 }
 276
 277 int mac802154_llsec_key_del(struct mac802154_llsec *sec,
 278                             const struct ieee802154_llsec_key_id *key)
 279 {
 280         struct ieee802154_llsec_key_entry *pos;
 281
 282         list_for_each_entry(pos, &sec->table.keys, list) {
 283                 struct mac802154_llsec_key *mkey;
 284
 285                 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
 286
 287                 if (llsec_key_id_equal(&pos->id, key)) {
 288                         list_del_rcu(&pos->list);
 289                         llsec_key_put(mkey);
 290                         return 0;
 291                 }
 292         }
 293
 294         return -ENOENT;
 295 }
 296
 297
 298
 299 static bool llsec_dev_use_shortaddr(__le16 short_addr)
 300 {
 301         return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) &&
 302                 short_addr != cpu_to_le16(0xffff);
 303 }
 304
 305 static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id)
 306 {
 307         return ((__force u16) short_addr) << 16 | (__force u16) pan_id;
 308 }
 309
 310 static u64 llsec_dev_hash_long(__le64 hwaddr)
 311 {
 312         return (__force u64) hwaddr;
 313 }
 314
 315 static struct mac802154_llsec_device*
 316 llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr,
 317                      __le16 pan_id)
 318 {
 319         struct mac802154_llsec_device *dev;
 320         u32 key = llsec_dev_hash_short(short_addr, pan_id);
 321
 322         hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) {
 323                 if (dev->dev.short_addr == short_addr &&
 324                     dev->dev.pan_id == pan_id)
 325                         return dev;
 326         }
 327
 328         return NULL;
 329 }
 330
 331 static struct mac802154_llsec_device*
 332 llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr)
 333 {
 334         struct mac802154_llsec_device *dev;
 335         u64 key = llsec_dev_hash_long(hwaddr);
 336
 337         hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) {
 338                 if (dev->dev.hwaddr == hwaddr)
 339                         return dev;
 340         }
 341
 342         return NULL;
 343 }
 344
 345 static void llsec_dev_free(struct mac802154_llsec_device *dev)
 346 {
 347         struct ieee802154_llsec_device_key *pos, *pn;
 348         struct mac802154_llsec_device_key *devkey;
 349
 350         list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) {
 351                 devkey = container_of(pos, struct mac802154_llsec_device_key,
 352                                       devkey);
 353
 354                 list_del(&pos->list);
 355                 kfree(devkey);
 356         }
 357
 358         kfree(dev);
 359 }
 360
 361 int mac802154_llsec_dev_add(struct mac802154_llsec *sec,
 362                             const struct ieee802154_llsec_device *dev)
 363 {
 364         struct mac802154_llsec_device *entry;
 365         u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id);
 366         u64 hwkey = llsec_dev_hash_long(dev->hwaddr);
 367
 368         BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN);
 369
 370         if ((llsec_dev_use_shortaddr(dev->short_addr) &&
 371              llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) ||
 372              llsec_dev_find_long(sec, dev->hwaddr))
 373                 return -EEXIST;
 374
 375         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 376         if (!entry)
 377                 return -ENOMEM;
 378
 379         entry->dev = *dev;
 380         spin_lock_init(&entry->lock);
 381         INIT_LIST_HEAD(&entry->dev.keys);
 382
 383         if (llsec_dev_use_shortaddr(dev->short_addr))
 384                 hash_add_rcu(sec->devices_short, &entry->bucket_s, skey);
 385         else
 386                 INIT_HLIST_NODE(&entry->bucket_s);
 387
 388         hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey);
 389         list_add_tail_rcu(&entry->dev.list, &sec->table.devices);
 390
 391         return 0;
 392 }
 393
 394 static void llsec_dev_free_rcu(struct rcu_head *rcu)
 395 {
 396         llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu));
 397 }
 398
 399 int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr)
 400 {
 401         struct mac802154_llsec_device *pos;
 402
 403         pos = llsec_dev_find_long(sec, device_addr);
 404         if (!pos)
 405                 return -ENOENT;
 406
 407         hash_del_rcu(&pos->bucket_s);
 408         hash_del_rcu(&pos->bucket_hw);
 409         call_rcu(&pos->rcu, llsec_dev_free_rcu);
 410
 411         return 0;
 412 }
 413
 414
 415
 416 static struct mac802154_llsec_device_key*
 417 llsec_devkey_find(struct mac802154_llsec_device *dev,
 418                   const struct ieee802154_llsec_key_id *key)
 419 {
 420         struct ieee802154_llsec_device_key *devkey;
 421
 422         list_for_each_entry_rcu(devkey, &dev->dev.keys, list) {
 423                 if (!llsec_key_id_equal(key, &devkey->key_id))
 424                         continue;
 425
 426                 return container_of(devkey, struct mac802154_llsec_device_key,
 427                                     devkey);
 428         }
 429
 430         return NULL;
 431 }
 432
 433 int mac802154_llsec_devkey_add(struct mac802154_llsec *sec,
 434                                __le64 dev_addr,
 435                                const struct ieee802154_llsec_device_key *key)
 436 {
 437         struct mac802154_llsec_device *dev;
 438         struct mac802154_llsec_device_key *devkey;
 439
 440         dev = llsec_dev_find_long(sec, dev_addr);
 441
 442         if (!dev)
 443                 return -ENOENT;
 444
 445         if (llsec_devkey_find(dev, &key->key_id))
 446                 return -EEXIST;
 447
 448         devkey = kmalloc(sizeof(*devkey), GFP_KERNEL);
 449         if (!devkey)
 450                 return -ENOMEM;
 451
 452         devkey->devkey = *key;
 453         list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys);
 454         return 0;
 455 }
 456
 457 int mac802154_llsec_devkey_del(struct mac802154_llsec *sec,
 458                                __le64 dev_addr,
 459                                const struct ieee802154_llsec_device_key *key)
 460 {
 461         struct mac802154_llsec_device *dev;
 462         struct mac802154_llsec_device_key *devkey;
 463
 464         dev = llsec_dev_find_long(sec, dev_addr);
 465
 466         if (!dev)
 467                 return -ENOENT;
 468
 469         devkey = llsec_devkey_find(dev, &key->key_id);
 470         if (!devkey)
 471                 return -ENOENT;
 472
 473         list_del_rcu(&devkey->devkey.list);
 474         kfree_rcu(devkey, rcu);
 475         return 0;
 476 }
 477
 478
 479
 480 static struct mac802154_llsec_seclevel*
 481 llsec_find_seclevel(const struct mac802154_llsec *sec,
 482                     const struct ieee802154_llsec_seclevel *sl)
 483 {
 484         struct ieee802154_llsec_seclevel *pos;
 485
 486         list_for_each_entry(pos, &sec->table.security_levels, list) {
 487                 if (pos->frame_type != sl->frame_type ||
 488                     (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD &&
 489                      pos->cmd_frame_id != sl->cmd_frame_id) ||
 490                     pos->device_override != sl->device_override ||
 491                     pos->sec_levels != sl->sec_levels)
 492                         continue;
 493
 494                 return container_of(pos, struct mac802154_llsec_seclevel,
 495                                     level);
 496         }
 497
 498         return NULL;
 499 }
 500
 501 int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec,
 502                                  const struct ieee802154_llsec_seclevel *sl)
 503 {
 504         struct mac802154_llsec_seclevel *entry;
 505
 506         if (llsec_find_seclevel(sec, sl))
 507                 return -EEXIST;
 508
 509         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 510         if (!entry)
 511                 return -ENOMEM;
 512
 513         entry->level = *sl;
 514
 515         list_add_tail_rcu(&entry->level.list, &sec->table.security_levels);
 516
 517         return 0;
 518 }
 519
 520 int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec,
 521                                  const struct ieee802154_llsec_seclevel *sl)
 522 {
 523         struct mac802154_llsec_seclevel *pos;
 524
 525         pos = llsec_find_seclevel(sec, sl);
 526         if (!pos)
 527                 return -ENOENT;
 528
 529         list_del_rcu(&pos->level.list);
 530         kfree_rcu(pos, rcu);
 531
 532         return 0;
 533 }
 534
 535
 536
 537 static int llsec_recover_addr(struct mac802154_llsec *sec,
 538                               struct ieee802154_addr *addr)
 539 {
 540         __le16 caddr = sec->params.coord_shortaddr;
 541         addr->pan_id = sec->params.pan_id;
 542
 543         if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) {
 544                 return -EINVAL;
 545         } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) {
 546                 addr->extended_addr = sec->params.coord_hwaddr;
 547                 addr->mode = IEEE802154_ADDR_LONG;
 548         } else {
 549                 addr->short_addr = sec->params.coord_shortaddr;
 550                 addr->mode = IEEE802154_ADDR_SHORT;
 551         }
 552
 553         return 0;
 554 }
 555
 556 static struct mac802154_llsec_key*
 557 llsec_lookup_key(struct mac802154_llsec *sec,
 558                  const struct ieee802154_hdr *hdr,
 559                  const struct ieee802154_addr *addr,
 560                  struct ieee802154_llsec_key_id *key_id)
 561 {
 562         struct ieee802154_addr devaddr = *addr;
 563         u8 key_id_mode = hdr->sec.key_id_mode;
 564         struct ieee802154_llsec_key_entry *key_entry;
 565         struct mac802154_llsec_key *key;
 566
 567         if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT &&
 568             devaddr.mode == IEEE802154_ADDR_NONE) {
 569                 if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) {
 570                         devaddr.extended_addr = sec->params.coord_hwaddr;
 571                         devaddr.mode = IEEE802154_ADDR_LONG;
 572                 } else if (llsec_recover_addr(sec, &devaddr) < 0) {
 573                         return NULL;
 574                 }
 575         }
 576
 577         list_for_each_entry_rcu(key_entry, &sec->table.keys, list) {
 578                 const struct ieee802154_llsec_key_id *id = &key_entry->id;
 579
 580                 if (!(key_entry->key->frame_types & BIT(hdr->fc.type)))
 581                         continue;
 582
 583                 if (id->mode != key_id_mode)
 584                         continue;
 585
 586                 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) {
 587                         if (ieee802154_addr_equal(&devaddr, &id->device_addr))
 588                                 goto found;
 589                 } else {
 590                         if (id->id != hdr->sec.key_id)
 591                                 continue;
 592
 593                         if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) ||
 594                             (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX &&
 595                              id->short_source == hdr->sec.short_src) ||
 596                             (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX &&
 597                              id->extended_source == hdr->sec.extended_src))
 598                                 goto found;
 599                 }
 600         }
 601
 602         return NULL;
 603
 604 found:
 605         key = container_of(key_entry->key, struct mac802154_llsec_key, key);
 606         if (key_id)
 607                 *key_id = key_entry->id;
 608         return llsec_key_get(key);
 609 }
 610
 611
 612 static void llsec_geniv(u8 iv[16], __le64 addr,
 613                         const struct ieee802154_sechdr *sec)
 614 {
 615         __be64 addr_bytes = (__force __be64) swab64((__force u64) addr);
 616         __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter);
 617
 618         iv[0] = 1; /* L' = L - 1 = 1 */
 619         memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes));
 620         memcpy(iv + 9, &frame_counter, sizeof(frame_counter));
 621         iv[13] = sec->level;
 622         iv[14] = 0;
 623         iv[15] = 1;
 624 }
 625
 626 static int
 627 llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 628                         const struct ieee802154_hdr *hdr,
 629                         struct mac802154_llsec_key *key)
 630 {
 631         u8 iv[16];
 632         struct scatterlist src;
 633         struct blkcipher_desc req = {
 634                 .tfm = key->tfm0,
 635                 .info = iv,
 636                 .flags = 0,
 637         };
 638
 639         llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
 640         sg_init_one(&src, skb->data, skb->len);
 641         return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len);
 642 }
 643
 644 static struct crypto_aead*
 645 llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen)
 646 {
 647         int i;
 648
 649         for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
 650                 if (crypto_aead_authsize(key->tfm[i]) == authlen)
 651                         return key->tfm[i];
 652
 653         BUG();
 654 }
 655
 656 static int
 657 llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 658                       const struct ieee802154_hdr *hdr,
 659                       struct mac802154_llsec_key *key)
 660 {
 661         u8 iv[16];
 662         unsigned char *data;
 663         int authlen, assoclen, datalen, rc;
 664         struct scatterlist src, assoc[2], dst[2];
 665         struct aead_request *req;
 666
 667         authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
 668         llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
 669
 670         req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
 671         if (!req)
 672                 return -ENOMEM;
 673
 674         sg_init_table(assoc, 2);
 675         sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
 676         assoclen = skb->mac_len;
 677
 678         data = skb_mac_header(skb) + skb->mac_len;
 679         datalen = skb_tail_pointer(skb) - data;
 680
 681         if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
 682                 sg_set_buf(&assoc[1], data, 0);
 683         } else {
 684                 sg_set_buf(&assoc[1], data, datalen);
 685                 assoclen += datalen;
 686                 datalen = 0;
 687         }
 688
 689         sg_init_one(&src, data, datalen);
 690
 691         sg_init_table(dst, 2);
 692         sg_set_buf(&dst[0], data, datalen);
 693         sg_set_buf(&dst[1], skb_put(skb, authlen), authlen);
 694
 695         aead_request_set_callback(req, 0, NULL, NULL);
 696         aead_request_set_assoc(req, assoc, assoclen);
 697         aead_request_set_crypt(req, &src, dst, datalen, iv);
 698
 699         rc = crypto_aead_encrypt(req);
 700
 701         kfree(req);
 702
 703         return rc;
 704 }
 705
 706 static int llsec_do_encrypt(struct sk_buff *skb,
 707                             const struct mac802154_llsec *sec,
 708                             const struct ieee802154_hdr *hdr,
 709                             struct mac802154_llsec_key *key)
 710 {
 711         if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
 712                 return llsec_do_encrypt_unauth(skb, sec, hdr, key);
 713         else
 714                 return llsec_do_encrypt_auth(skb, sec, hdr, key);
 715 }
 716
 717 int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
 718 {
 719         struct ieee802154_hdr hdr;
 720         int rc, authlen, hlen;
 721         struct mac802154_llsec_key *key;
 722         u32 frame_ctr;
 723
 724         hlen = ieee802154_hdr_pull(skb, &hdr);
 725
 726         if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA)
 727                 return -EINVAL;
 728
 729         if (!hdr.fc.security_enabled || hdr.sec.level == 0) {
 730                 skb_push(skb, hlen);
 731                 return 0;
 732         }
 733
 734         authlen = ieee802154_sechdr_authtag_len(&hdr.sec);
 735
 736         if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)
 737                 return -EMSGSIZE;
 738
 739         rcu_read_lock();
 740
 741         read_lock_bh(&sec->lock);
 742
 743         if (!sec->params.enabled) {
 744                 rc = -EINVAL;
 745                 goto fail_read;
 746         }
 747
 748         key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL);
 749         if (!key) {
 750                 rc = -ENOKEY;
 751                 goto fail_read;
 752         }
 753
 754         read_unlock_bh(&sec->lock);
 755
 756         write_lock_bh(&sec->lock);
 757
 758         frame_ctr = be32_to_cpu(sec->params.frame_counter);
 759         hdr.sec.frame_counter = cpu_to_le32(frame_ctr);
 760         if (frame_ctr == 0xFFFFFFFF) {
 761                 write_unlock_bh(&sec->lock);
 762                 llsec_key_put(key);
 763                 rc = -EOVERFLOW;
 764                 goto fail;
 765         }
 766
 767         sec->params.frame_counter = cpu_to_be32(frame_ctr + 1);
 768
 769         write_unlock_bh(&sec->lock);
 770
 771         rcu_read_unlock();
 772
 773         skb->mac_len = ieee802154_hdr_push(skb, &hdr);
 774         skb_reset_mac_header(skb);
 775
 776         rc = llsec_do_encrypt(skb, sec, &hdr, key);
 777         llsec_key_put(key);
 778
 779         return rc;
 780
 781 fail_read:
 782         read_unlock_bh(&sec->lock);
 783 fail:
 784         rcu_read_unlock();
 785         return rc;
 786 }
 787
 788
 789
 790 static struct mac802154_llsec_device*
 791 llsec_lookup_dev(struct mac802154_llsec *sec,
 792                  const struct ieee802154_addr *addr)
 793 {
 794         struct ieee802154_addr devaddr = *addr;
 795         struct mac802154_llsec_device *dev = NULL;
 796
 797         if (devaddr.mode == IEEE802154_ADDR_NONE &&
 798             llsec_recover_addr(sec, &devaddr) < 0)
 799                 return NULL;
 800
 801         if (devaddr.mode == IEEE802154_ADDR_SHORT) {
 802                 u32 key = llsec_dev_hash_short(devaddr.short_addr,
 803                                                devaddr.pan_id);
 804
 805                 hash_for_each_possible_rcu(sec->devices_short, dev,
 806                                            bucket_s, key) {
 807                         if (dev->dev.pan_id == devaddr.pan_id &&
 808                             dev->dev.short_addr == devaddr.short_addr)
 809                                 return dev;
 810                 }
 811         } else {
 812                 u64 key = llsec_dev_hash_long(devaddr.extended_addr);
 813
 814                 hash_for_each_possible_rcu(sec->devices_hw, dev,
 815                                            bucket_hw, key) {
 816                         if (dev->dev.hwaddr == devaddr.extended_addr)
 817                                 return dev;
 818                 }
 819         }
 820
 821         return NULL;
 822 }
 823
 824 static int
 825 llsec_lookup_seclevel(const struct mac802154_llsec *sec,
 826                       u8 frame_type, u8 cmd_frame_id,
 827                       struct ieee802154_llsec_seclevel *rlevel)
 828 {
 829         struct ieee802154_llsec_seclevel *level;
 830
 831         list_for_each_entry_rcu(level, &sec->table.security_levels, list) {
 832                 if (level->frame_type == frame_type &&
 833                     (frame_type != IEEE802154_FC_TYPE_MAC_CMD ||
 834                      level->cmd_frame_id == cmd_frame_id)) {
 835                         *rlevel = *level;
 836                         return 0;
 837                 }
 838         }
 839
 840         return -EINVAL;
 841 }
 842
 843 static int
 844 llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 845                         const struct ieee802154_hdr *hdr,
 846                         struct mac802154_llsec_key *key, __le64 dev_addr)
 847 {
 848         u8 iv[16];
 849         unsigned char *data;
 850         int datalen;
 851         struct scatterlist src;
 852         struct blkcipher_desc req = {
 853                 .tfm = key->tfm0,
 854                 .info = iv,
 855                 .flags = 0,
 856         };
 857
 858         llsec_geniv(iv, dev_addr, &hdr->sec);
 859         data = skb_mac_header(skb) + skb->mac_len;
 860         datalen = skb_tail_pointer(skb) - data;
 861
 862         sg_init_one(&src, data, datalen);
 863
 864         return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen);
 865 }
 866
 867 static int
 868 llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 869                       const struct ieee802154_hdr *hdr,
 870                       struct mac802154_llsec_key *key, __le64 dev_addr)
 871 {
 872         u8 iv[16];
 873         unsigned char *data;
 874         int authlen, datalen, assoclen, rc;
 875         struct scatterlist src, assoc[2];
 876         struct aead_request *req;
 877
 878         authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
 879         llsec_geniv(iv, dev_addr, &hdr->sec);
 880
 881         req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
 882         if (!req)
 883                 return -ENOMEM;
 884
 885         sg_init_table(assoc, 2);
 886         sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
 887         assoclen = skb->mac_len;
 888
 889         data = skb_mac_header(skb) + skb->mac_len;
 890         datalen = skb_tail_pointer(skb) - data;
 891
 892         if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
 893                 sg_set_buf(&assoc[1], data, 0);
 894         } else {
 895                 sg_set_buf(&assoc[1], data, datalen - authlen);
 896                 assoclen += datalen - authlen;
 897                 data += datalen - authlen;
 898                 datalen = authlen;
 899         }
 900
 901         sg_init_one(&src, data, datalen);
 902
 903         aead_request_set_callback(req, 0, NULL, NULL);
 904         aead_request_set_assoc(req, assoc, assoclen);
 905         aead_request_set_crypt(req, &src, &src, datalen, iv);
 906
 907         rc = crypto_aead_decrypt(req);
 908
 909         kfree(req);
 910         skb_trim(skb, skb->len - authlen);
 911
 912         return rc;
 913 }
 914
 915 static int
 916 llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec,
 917                  const struct ieee802154_hdr *hdr,
 918                  struct mac802154_llsec_key *key, __le64 dev_addr)
 919 {
 920         if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
 921                 return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr);
 922         else
 923                 return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr);
 924 }
 925
 926 static int
 927 llsec_update_devkey_record(struct mac802154_llsec_device *dev,
 928                            const struct ieee802154_llsec_key_id *in_key)
 929 {
 930         struct mac802154_llsec_device_key *devkey;
 931
 932         devkey = llsec_devkey_find(dev, in_key);
 933
 934         if (!devkey) {
 935                 struct mac802154_llsec_device_key *next;
 936
 937                 next = kzalloc(sizeof(*devkey), GFP_ATOMIC);
 938                 if (!next)
 939                         return -ENOMEM;
 940
 941                 next->devkey.key_id = *in_key;
 942
 943                 spin_lock_bh(&dev->lock);
 944
 945                 devkey = llsec_devkey_find(dev, in_key);
 946                 if (!devkey)
 947                         list_add_rcu(&next->devkey.list, &dev->dev.keys);
 948                 else
 949                         kfree(next);
 950
 951                 spin_unlock_bh(&dev->lock);
 952         }
 953
 954         return 0;
 955 }
 956
 957 static int
 958 llsec_update_devkey_info(struct mac802154_llsec_device *dev,
 959                          const struct ieee802154_llsec_key_id *in_key,
 960                          u32 frame_counter)
 961 {
 962         struct mac802154_llsec_device_key *devkey = NULL;
 963
 964         if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) {
 965                 devkey = llsec_devkey_find(dev, in_key);
 966                 if (!devkey)
 967                         return -ENOENT;
 968         }
 969
 970         if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) {
 971                 int rc = llsec_update_devkey_record(dev, in_key);
 972
 973                 if (rc < 0)
 974                         return rc;
 975         }
 976
 977         spin_lock_bh(&dev->lock);
 978
 979         if ((!devkey && frame_counter < dev->dev.frame_counter) ||
 980             (devkey && frame_counter < devkey->devkey.frame_counter)) {
 981                 spin_unlock_bh(&dev->lock);
 982                 return -EINVAL;
 983         }
 984
 985         if (devkey)
 986                 devkey->devkey.frame_counter = frame_counter + 1;
 987         else
 988                 dev->dev.frame_counter = frame_counter + 1;
 989
 990         spin_unlock_bh(&dev->lock);
 991
 992         return 0;
 993 }
 994
 995 int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
 996 {
 997         struct ieee802154_hdr hdr;
 998         struct mac802154_llsec_key *key;
 999         struct ieee802154_llsec_key_id key_id;
1000         struct mac802154_llsec_device *dev;
1001         struct ieee802154_llsec_seclevel seclevel;
1002         int err;
1003         __le64 dev_addr;
1004         u32 frame_ctr;
1005
1006         if (ieee802154_hdr_peek(skb, &hdr) < 0)
1007                 return -EINVAL;
1008         if (!hdr.fc.security_enabled)
1009                 return 0;
1010         if (hdr.fc.version == 0)
1011                 return -EINVAL;
1012
1013         read_lock_bh(&sec->lock);
1014         if (!sec->params.enabled) {
1015                 read_unlock_bh(&sec->lock);
1016                 return -EINVAL;
1017         }
1018         read_unlock_bh(&sec->lock);
1019
1020         rcu_read_lock();
1021
1022         key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id);
1023         if (!key) {
1024                 err = -ENOKEY;
1025                 goto fail;
1026         }
1027
1028         dev = llsec_lookup_dev(sec, &hdr.source);
1029         if (!dev) {
1030                 err = -EINVAL;
1031                 goto fail_dev;
1032         }
1033
1034         if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) {
1035                 err = -EINVAL;
1036                 goto fail_dev;
1037         }
1038
1039         if (!(seclevel.sec_levels & BIT(hdr.sec.level)) &&
1040             (hdr.sec.level == 0 && seclevel.device_override &&
1041              !dev->dev.seclevel_exempt)) {
1042                 err = -EINVAL;
1043                 goto fail_dev;
1044         }
1045
1046         frame_ctr = le32_to_cpu(hdr.sec.frame_counter);
1047
1048         if (frame_ctr == 0xffffffff) {
1049                 err = -EOVERFLOW;
1050                 goto fail_dev;
1051         }
1052
1053         err = llsec_update_devkey_info(dev, &key_id, frame_ctr);
1054         if (err)
1055                 goto fail_dev;
1056
1057         dev_addr = dev->dev.hwaddr;
1058
1059         rcu_read_unlock();
1060
1061         err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr);
1062         llsec_key_put(key);
1063         return err;
1064
1065 fail_dev:
1066         llsec_key_put(key);
1067 fail:
1068         rcu_read_unlock();
1069         return err;
1070 }