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_SHORT_INDEX:
 211                 return a->short_source == b->short_source;
 212         case IEEE802154_SCF_KEY_HW_INDEX:
 213                 return a->extended_source == b->extended_source;
 214         }
 215
 216         return false;
 217 }
 218
 219 int mac802154_llsec_key_add(struct mac802154_llsec *sec,
 220                             const struct ieee802154_llsec_key_id *id,
 221                             const struct ieee802154_llsec_key *key)
 222 {
 223         struct mac802154_llsec_key *mkey = NULL;
 224         struct ieee802154_llsec_key_entry *pos, *new;
 225
 226         if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) &&
 227             key->cmd_frame_ids)
 228                 return -EINVAL;
 229
 230         list_for_each_entry(pos, &sec->table.keys, list) {
 231                 if (llsec_key_id_equal(&pos->id, id))
 232                         return -EEXIST;
 233
 234                 if (memcmp(pos->key->key, key->key,
 235                            IEEE802154_LLSEC_KEY_SIZE))
 236                         continue;
 237
 238                 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
 239
 240                 /* Don't allow multiple instances of the same AES key to have
 241                  * different allowed frame types/command frame ids, as this is
 242                  * not possible in the 802.15.4 PIB.
 243                  */
 244                 if (pos->key->frame_types != key->frame_types ||
 245                     pos->key->cmd_frame_ids != key->cmd_frame_ids)
 246                         return -EEXIST;
 247
 248                 break;
 249         }
 250
 251         new = kzalloc(sizeof(*new), GFP_KERNEL);
 252         if (!new)
 253                 return -ENOMEM;
 254
 255         if (!mkey)
 256                 mkey = llsec_key_alloc(key);
 257         else
 258                 mkey = llsec_key_get(mkey);
 259
 260         if (!mkey)
 261                 goto fail;
 262
 263         new->id = *id;
 264         new->key = &mkey->key;
 265
 266         list_add_rcu(&new->list, &sec->table.keys);
 267
 268         return 0;
 269
 270 fail:
 271         kfree(new);
 272         return -ENOMEM;
 273 }
 274
 275 int mac802154_llsec_key_del(struct mac802154_llsec *sec,
 276                             const struct ieee802154_llsec_key_id *key)
 277 {
 278         struct ieee802154_llsec_key_entry *pos;
 279
 280         list_for_each_entry(pos, &sec->table.keys, list) {
 281                 struct mac802154_llsec_key *mkey;
 282
 283                 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
 284
 285                 if (llsec_key_id_equal(&pos->id, key)) {
 286                         llsec_key_put(mkey);
 287                         return 0;
 288                 }
 289         }
 290
 291         return -ENOENT;
 292 }
 293
 294
 295
 296 static bool llsec_dev_use_shortaddr(__le16 short_addr)
 297 {
 298         return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) &&
 299                 short_addr != cpu_to_le16(0xffff);
 300 }
 301
 302 static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id)
 303 {
 304         return ((__force u16) short_addr) << 16 | (__force u16) pan_id;
 305 }
 306
 307 static u64 llsec_dev_hash_long(__le64 hwaddr)
 308 {
 309         return (__force u64) hwaddr;
 310 }
 311
 312 static struct mac802154_llsec_device*
 313 llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr,
 314                      __le16 pan_id)
 315 {
 316         struct mac802154_llsec_device *dev;
 317         u32 key = llsec_dev_hash_short(short_addr, pan_id);
 318
 319         hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) {
 320                 if (dev->dev.short_addr == short_addr &&
 321                     dev->dev.pan_id == pan_id)
 322                         return dev;
 323         }
 324
 325         return NULL;
 326 }
 327
 328 static struct mac802154_llsec_device*
 329 llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr)
 330 {
 331         struct mac802154_llsec_device *dev;
 332         u64 key = llsec_dev_hash_long(hwaddr);
 333
 334         hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) {
 335                 if (dev->dev.hwaddr == hwaddr)
 336                         return dev;
 337         }
 338
 339         return NULL;
 340 }
 341
 342 static void llsec_dev_free(struct mac802154_llsec_device *dev)
 343 {
 344         struct ieee802154_llsec_device_key *pos, *pn;
 345         struct mac802154_llsec_device_key *devkey;
 346
 347         list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) {
 348                 devkey = container_of(pos, struct mac802154_llsec_device_key,
 349                                       devkey);
 350
 351                 list_del(&pos->list);
 352                 kfree(devkey);
 353         }
 354
 355         kfree(dev);
 356 }
 357
 358 int mac802154_llsec_dev_add(struct mac802154_llsec *sec,
 359                             const struct ieee802154_llsec_device *dev)
 360 {
 361         struct mac802154_llsec_device *entry;
 362         u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id);
 363         u64 hwkey = llsec_dev_hash_long(dev->hwaddr);
 364
 365         BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN);
 366
 367         if ((llsec_dev_use_shortaddr(dev->short_addr) &&
 368              llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) ||
 369              llsec_dev_find_long(sec, dev->hwaddr))
 370                 return -EEXIST;
 371
 372         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 373         if (!entry)
 374                 return -ENOMEM;
 375
 376         entry->dev = *dev;
 377         spin_lock_init(&entry->lock);
 378         INIT_LIST_HEAD(&entry->dev.keys);
 379
 380         if (llsec_dev_use_shortaddr(dev->short_addr))
 381                 hash_add_rcu(sec->devices_short, &entry->bucket_s, skey);
 382         else
 383                 INIT_HLIST_NODE(&entry->bucket_s);
 384
 385         hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey);
 386         list_add_tail_rcu(&entry->dev.list, &sec->table.devices);
 387
 388         return 0;
 389 }
 390
 391 static void llsec_dev_free_rcu(struct rcu_head *rcu)
 392 {
 393         llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu));
 394 }
 395
 396 int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr)
 397 {
 398         struct mac802154_llsec_device *pos;
 399
 400         pos = llsec_dev_find_long(sec, device_addr);
 401         if (!pos)
 402                 return -ENOENT;
 403
 404         hash_del_rcu(&pos->bucket_s);
 405         hash_del_rcu(&pos->bucket_hw);
 406         call_rcu(&pos->rcu, llsec_dev_free_rcu);
 407
 408         return 0;
 409 }
 410
 411
 412
 413 static struct mac802154_llsec_device_key*
 414 llsec_devkey_find(struct mac802154_llsec_device *dev,
 415                   const struct ieee802154_llsec_key_id *key)
 416 {
 417         struct ieee802154_llsec_device_key *devkey;
 418
 419         list_for_each_entry_rcu(devkey, &dev->dev.keys, list) {
 420                 if (!llsec_key_id_equal(key, &devkey->key_id))
 421                         continue;
 422
 423                 return container_of(devkey, struct mac802154_llsec_device_key,
 424                                     devkey);
 425         }
 426
 427         return NULL;
 428 }
 429
 430 int mac802154_llsec_devkey_add(struct mac802154_llsec *sec,
 431                                __le64 dev_addr,
 432                                const struct ieee802154_llsec_device_key *key)
 433 {
 434         struct mac802154_llsec_device *dev;
 435         struct mac802154_llsec_device_key *devkey;
 436
 437         dev = llsec_dev_find_long(sec, dev_addr);
 438
 439         if (!dev)
 440                 return -ENOENT;
 441
 442         if (llsec_devkey_find(dev, &key->key_id))
 443                 return -EEXIST;
 444
 445         devkey = kmalloc(sizeof(*devkey), GFP_KERNEL);
 446         if (!devkey)
 447                 return -ENOMEM;
 448
 449         devkey->devkey = *key;
 450         list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys);
 451         return 0;
 452 }
 453
 454 int mac802154_llsec_devkey_del(struct mac802154_llsec *sec,
 455                                __le64 dev_addr,
 456                                const struct ieee802154_llsec_device_key *key)
 457 {
 458         struct mac802154_llsec_device *dev;
 459         struct mac802154_llsec_device_key *devkey;
 460
 461         dev = llsec_dev_find_long(sec, dev_addr);
 462
 463         if (!dev)
 464                 return -ENOENT;
 465
 466         devkey = llsec_devkey_find(dev, &key->key_id);
 467         if (!devkey)
 468                 return -ENOENT;
 469
 470         list_del_rcu(&devkey->devkey.list);
 471         kfree_rcu(devkey, rcu);
 472         return 0;
 473 }
 474
 475
 476
 477 static struct mac802154_llsec_seclevel*
 478 llsec_find_seclevel(const struct mac802154_llsec *sec,
 479                     const struct ieee802154_llsec_seclevel *sl)
 480 {
 481         struct ieee802154_llsec_seclevel *pos;
 482
 483         list_for_each_entry(pos, &sec->table.security_levels, list) {
 484                 if (pos->frame_type != sl->frame_type ||
 485                     (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD &&
 486                      pos->cmd_frame_id != sl->cmd_frame_id) ||
 487                     pos->device_override != sl->device_override ||
 488                     pos->sec_levels != sl->sec_levels)
 489                         continue;
 490
 491                 return container_of(pos, struct mac802154_llsec_seclevel,
 492                                     level);
 493         }
 494
 495         return NULL;
 496 }
 497
 498 int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec,
 499                                  const struct ieee802154_llsec_seclevel *sl)
 500 {
 501         struct mac802154_llsec_seclevel *entry;
 502
 503         if (llsec_find_seclevel(sec, sl))
 504                 return -EEXIST;
 505
 506         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 507         if (!entry)
 508                 return -ENOMEM;
 509
 510         entry->level = *sl;
 511
 512         list_add_tail_rcu(&entry->level.list, &sec->table.security_levels);
 513
 514         return 0;
 515 }
 516
 517 int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec,
 518                                  const struct ieee802154_llsec_seclevel *sl)
 519 {
 520         struct mac802154_llsec_seclevel *pos;
 521
 522         pos = llsec_find_seclevel(sec, sl);
 523         if (!pos)
 524                 return -ENOENT;
 525
 526         list_del_rcu(&pos->level.list);
 527         kfree_rcu(pos, rcu);
 528
 529         return 0;
 530 }
 531
 532
 533
 534 static int llsec_recover_addr(struct mac802154_llsec *sec,
 535                               struct ieee802154_addr *addr)
 536 {
 537         __le16 caddr = sec->params.coord_shortaddr;
 538         addr->pan_id = sec->params.pan_id;
 539
 540         if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) {
 541                 return -EINVAL;
 542         } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) {
 543                 addr->extended_addr = sec->params.coord_hwaddr;
 544                 addr->mode = IEEE802154_ADDR_LONG;
 545         } else {
 546                 addr->short_addr = sec->params.coord_shortaddr;
 547                 addr->mode = IEEE802154_ADDR_SHORT;
 548         }
 549
 550         return 0;
 551 }
 552
 553 static struct mac802154_llsec_key*
 554 llsec_lookup_key(struct mac802154_llsec *sec,
 555                  const struct ieee802154_hdr *hdr,
 556                  const struct ieee802154_addr *addr,
 557                  struct ieee802154_llsec_key_id *key_id)
 558 {
 559         struct ieee802154_addr devaddr = *addr;
 560         u8 key_id_mode = hdr->sec.key_id_mode;
 561         struct ieee802154_llsec_key_entry *key_entry;
 562         struct mac802154_llsec_key *key;
 563
 564         if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT &&
 565             devaddr.mode == IEEE802154_ADDR_NONE) {
 566                 if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) {
 567                         devaddr.extended_addr = sec->params.coord_hwaddr;
 568                         devaddr.mode = IEEE802154_ADDR_LONG;
 569                 } else if (llsec_recover_addr(sec, &devaddr) < 0) {
 570                         return NULL;
 571                 }
 572         }
 573
 574         list_for_each_entry_rcu(key_entry, &sec->table.keys, list) {
 575                 const struct ieee802154_llsec_key_id *id = &key_entry->id;
 576
 577                 if (!(key_entry->key->frame_types & BIT(hdr->fc.type)))
 578                         continue;
 579
 580                 if (id->mode != key_id_mode)
 581                         continue;
 582
 583                 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) {
 584                         if (ieee802154_addr_equal(&devaddr, &id->device_addr))
 585                                 goto found;
 586                 } else {
 587                         if (id->id != hdr->sec.key_id)
 588                                 continue;
 589
 590                         if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) ||
 591                             (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX &&
 592                              id->short_source == hdr->sec.short_src) ||
 593                             (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX &&
 594                              id->extended_source == hdr->sec.extended_src))
 595                                 goto found;
 596                 }
 597         }
 598
 599         return NULL;
 600
 601 found:
 602         key = container_of(key_entry->key, struct mac802154_llsec_key, key);
 603         if (key_id)
 604                 *key_id = key_entry->id;
 605         return llsec_key_get(key);
 606 }
 607
 608
 609 static void llsec_geniv(u8 iv[16], __le64 addr,
 610                         const struct ieee802154_sechdr *sec)
 611 {
 612         __be64 addr_bytes = (__force __be64) swab64((__force u64) addr);
 613         __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter);
 614
 615         iv[0] = 1; /* L' = L - 1 = 1 */
 616         memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes));
 617         memcpy(iv + 9, &frame_counter, sizeof(frame_counter));
 618         iv[13] = sec->level;
 619         iv[14] = 0;
 620         iv[15] = 1;
 621 }
 622
 623 static int
 624 llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 625                         const struct ieee802154_hdr *hdr,
 626                         struct mac802154_llsec_key *key)
 627 {
 628         u8 iv[16];
 629         struct scatterlist src;
 630         struct blkcipher_desc req = {
 631                 .tfm = key->tfm0,
 632                 .info = iv,
 633                 .flags = 0,
 634         };
 635
 636         llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
 637         sg_init_one(&src, skb->data, skb->len);
 638         return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len);
 639 }
 640
 641 static struct crypto_aead*
 642 llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen)
 643 {
 644         int i;
 645
 646         for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
 647                 if (crypto_aead_authsize(key->tfm[i]) == authlen)
 648                         return key->tfm[i];
 649
 650         BUG();
 651 }
 652
 653 static int
 654 llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 655                       const struct ieee802154_hdr *hdr,
 656                       struct mac802154_llsec_key *key)
 657 {
 658         u8 iv[16];
 659         unsigned char *data;
 660         int authlen, assoclen, datalen, rc;
 661         struct scatterlist src, assoc[2], dst[2];
 662         struct aead_request *req;
 663
 664         authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
 665         llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
 666
 667         req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
 668         if (!req)
 669                 return -ENOMEM;
 670
 671         sg_init_table(assoc, 2);
 672         sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
 673         assoclen = skb->mac_len;
 674
 675         data = skb_mac_header(skb) + skb->mac_len;
 676         datalen = skb_tail_pointer(skb) - data;
 677
 678         if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
 679                 sg_set_buf(&assoc[1], data, 0);
 680         } else {
 681                 sg_set_buf(&assoc[1], data, datalen);
 682                 assoclen += datalen;
 683                 datalen = 0;
 684         }
 685
 686         sg_init_one(&src, data, datalen);
 687
 688         sg_init_table(dst, 2);
 689         sg_set_buf(&dst[0], data, datalen);
 690         sg_set_buf(&dst[1], skb_put(skb, authlen), authlen);
 691
 692         aead_request_set_callback(req, 0, NULL, NULL);
 693         aead_request_set_assoc(req, assoc, assoclen);
 694         aead_request_set_crypt(req, &src, dst, datalen, iv);
 695
 696         rc = crypto_aead_encrypt(req);
 697
 698         kfree(req);
 699
 700         return rc;
 701 }
 702
 703 static int llsec_do_encrypt(struct sk_buff *skb,
 704                             const struct mac802154_llsec *sec,
 705                             const struct ieee802154_hdr *hdr,
 706                             struct mac802154_llsec_key *key)
 707 {
 708         if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
 709                 return llsec_do_encrypt_unauth(skb, sec, hdr, key);
 710         else
 711                 return llsec_do_encrypt_auth(skb, sec, hdr, key);
 712 }
 713
 714 int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
 715 {
 716         struct ieee802154_hdr hdr;
 717         int rc, authlen, hlen;
 718         struct mac802154_llsec_key *key;
 719         u32 frame_ctr;
 720
 721         hlen = ieee802154_hdr_pull(skb, &hdr);
 722
 723         if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA)
 724                 return -EINVAL;
 725
 726         if (!hdr.fc.security_enabled || hdr.sec.level == 0) {
 727                 skb_push(skb, hlen);
 728                 return 0;
 729         }
 730
 731         authlen = ieee802154_sechdr_authtag_len(&hdr.sec);
 732
 733         if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)
 734                 return -EMSGSIZE;
 735
 736         rcu_read_lock();
 737
 738         read_lock_bh(&sec->lock);
 739
 740         if (!sec->params.enabled) {
 741                 rc = -EINVAL;
 742                 goto fail_read;
 743         }
 744
 745         key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL);
 746         if (!key) {
 747                 rc = -ENOKEY;
 748                 goto fail_read;
 749         }
 750
 751         read_unlock_bh(&sec->lock);
 752
 753         write_lock_bh(&sec->lock);
 754
 755         frame_ctr = be32_to_cpu(sec->params.frame_counter);
 756         hdr.sec.frame_counter = cpu_to_le32(frame_ctr);
 757         if (frame_ctr == 0xFFFFFFFF) {
 758                 write_unlock_bh(&sec->lock);
 759                 llsec_key_put(key);
 760                 rc = -EOVERFLOW;
 761                 goto fail;
 762         }
 763
 764         sec->params.frame_counter = cpu_to_be32(frame_ctr + 1);
 765
 766         write_unlock_bh(&sec->lock);
 767
 768         rcu_read_unlock();
 769
 770         skb->mac_len = ieee802154_hdr_push(skb, &hdr);
 771         skb_reset_mac_header(skb);
 772
 773         rc = llsec_do_encrypt(skb, sec, &hdr, key);
 774         llsec_key_put(key);
 775
 776         return rc < 0 ? rc : 0;
 777
 778 fail_read:
 779         read_unlock(&sec->lock);
 780 fail:
 781         rcu_read_unlock();
 782         return rc;
 783 }
 784
 785
 786
 787 static struct mac802154_llsec_device*
 788 llsec_lookup_dev(struct mac802154_llsec *sec,
 789                  const struct ieee802154_addr *addr)
 790 {
 791         struct ieee802154_addr devaddr = *addr;
 792         struct mac802154_llsec_device *dev = NULL;
 793
 794         if (devaddr.mode == IEEE802154_ADDR_NONE &&
 795             llsec_recover_addr(sec, &devaddr) < 0)
 796                 return NULL;
 797
 798         if (devaddr.mode == IEEE802154_ADDR_SHORT) {
 799                 u32 key = llsec_dev_hash_short(devaddr.short_addr,
 800                                                devaddr.pan_id);
 801
 802                 hash_for_each_possible_rcu(sec->devices_short, dev,
 803                                            bucket_s, key) {
 804                         if (dev->dev.pan_id == devaddr.pan_id &&
 805                             dev->dev.short_addr == devaddr.short_addr)
 806                                 return dev;
 807                 }
 808         } else {
 809                 u64 key = llsec_dev_hash_long(devaddr.extended_addr);
 810
 811                 hash_for_each_possible_rcu(sec->devices_hw, dev,
 812                                            bucket_hw, key) {
 813                         if (dev->dev.hwaddr == devaddr.extended_addr)
 814                                 return dev;
 815                 }
 816         }
 817
 818         return NULL;
 819 }
 820
 821 static int
 822 llsec_lookup_seclevel(const struct mac802154_llsec *sec,
 823                       u8 frame_type, u8 cmd_frame_id,
 824                       struct ieee802154_llsec_seclevel *rlevel)
 825 {
 826         struct ieee802154_llsec_seclevel *level;
 827
 828         list_for_each_entry_rcu(level, &sec->table.security_levels, list) {
 829                 if (level->frame_type == frame_type &&
 830                     (frame_type != IEEE802154_FC_TYPE_MAC_CMD ||
 831                      level->cmd_frame_id == cmd_frame_id)) {
 832                         *rlevel = *level;
 833                         return 0;
 834                 }
 835         }
 836
 837         return -EINVAL;
 838 }
 839
 840 static int
 841 llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 842                         const struct ieee802154_hdr *hdr,
 843                         struct mac802154_llsec_key *key, __le64 dev_addr)
 844 {
 845         u8 iv[16];
 846         unsigned char *data;
 847         int datalen;
 848         struct scatterlist src;
 849         struct blkcipher_desc req = {
 850                 .tfm = key->tfm0,
 851                 .info = iv,
 852                 .flags = 0,
 853         };
 854
 855         llsec_geniv(iv, dev_addr, &hdr->sec);
 856         data = skb_mac_header(skb) + skb->mac_len;
 857         datalen = skb_tail_pointer(skb) - data;
 858
 859         sg_init_one(&src, data, datalen);
 860
 861         return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen);
 862 }
 863
 864 static int
 865 llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
 866                       const struct ieee802154_hdr *hdr,
 867                       struct mac802154_llsec_key *key, __le64 dev_addr)
 868 {
 869         u8 iv[16];
 870         unsigned char *data;
 871         int authlen, datalen, assoclen, rc;
 872         struct scatterlist src, assoc[2];
 873         struct aead_request *req;
 874
 875         authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
 876         llsec_geniv(iv, dev_addr, &hdr->sec);
 877
 878         req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
 879         if (!req)
 880                 return -ENOMEM;
 881
 882         sg_init_table(assoc, 2);
 883         sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
 884         assoclen = skb->mac_len;
 885
 886         data = skb_mac_header(skb) + skb->mac_len;
 887         datalen = skb_tail_pointer(skb) - data;
 888
 889         if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
 890                 sg_set_buf(&assoc[1], data, 0);
 891         } else {
 892                 sg_set_buf(&assoc[1], data, datalen - authlen);
 893                 assoclen += datalen - authlen;
 894                 data += datalen - authlen;
 895                 datalen = authlen;
 896         }
 897
 898         sg_init_one(&src, data, datalen);
 899
 900         aead_request_set_callback(req, 0, NULL, NULL);
 901         aead_request_set_assoc(req, assoc, assoclen);
 902         aead_request_set_crypt(req, &src, &src, datalen, iv);
 903
 904         rc = crypto_aead_decrypt(req);
 905
 906         kfree(req);
 907         skb_trim(skb, skb->len - authlen);
 908
 909         return rc;
 910 }
 911
 912 static int
 913 llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec,
 914                  const struct ieee802154_hdr *hdr,
 915                  struct mac802154_llsec_key *key, __le64 dev_addr)
 916 {
 917         if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
 918                 return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr);
 919         else
 920                 return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr);
 921 }
 922
 923 static int
 924 llsec_update_devkey_record(struct mac802154_llsec_device *dev,
 925                            const struct ieee802154_llsec_key_id *in_key)
 926 {
 927         struct mac802154_llsec_device_key *devkey;
 928
 929         devkey = llsec_devkey_find(dev, in_key);
 930
 931         if (!devkey) {
 932                 struct mac802154_llsec_device_key *next;
 933
 934                 next = kzalloc(sizeof(*devkey), GFP_ATOMIC);
 935                 if (!next)
 936                         return -ENOMEM;
 937
 938                 next->devkey.key_id = *in_key;
 939
 940                 spin_lock_bh(&dev->lock);
 941
 942                 devkey = llsec_devkey_find(dev, in_key);
 943                 if (!devkey)
 944                         list_add_rcu(&next->devkey.list, &dev->dev.keys);
 945                 else
 946                         kfree(next);
 947
 948                 spin_unlock_bh(&dev->lock);
 949         }
 950
 951         return 0;
 952 }
 953
 954 static int
 955 llsec_update_devkey_info(struct mac802154_llsec_device *dev,
 956                          const struct ieee802154_llsec_key_id *in_key,
 957                          u32 frame_counter)
 958 {
 959         struct mac802154_llsec_device_key *devkey = NULL;
 960
 961         if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) {
 962                 devkey = llsec_devkey_find(dev, in_key);
 963                 if (!devkey)
 964                         return -ENOENT;
 965         }
 966
 967         if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) {
 968                 int rc = llsec_update_devkey_record(dev, in_key);
 969
 970                 if (rc < 0)
 971                         return rc;
 972         }
 973
 974         spin_lock_bh(&dev->lock);
 975
 976         if ((!devkey && frame_counter < dev->dev.frame_counter) ||
 977             (devkey && frame_counter < devkey->devkey.frame_counter)) {
 978                 spin_unlock_bh(&dev->lock);
 979                 return -EINVAL;
 980         }
 981
 982         if (devkey)
 983                 devkey->devkey.frame_counter = frame_counter + 1;
 984         else
 985                 dev->dev.frame_counter = frame_counter + 1;
 986
 987         spin_unlock_bh(&dev->lock);
 988
 989         return 0;
 990 }
 991
 992 int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
 993 {
 994         struct ieee802154_hdr hdr;
 995         struct mac802154_llsec_key *key;
 996         struct ieee802154_llsec_key_id key_id;
 997         struct mac802154_llsec_device *dev;
 998         struct ieee802154_llsec_seclevel seclevel;
 999         int err;
1000         __le64 dev_addr;
1001         u32 frame_ctr;
1002
1003         if (ieee802154_hdr_peek(skb, &hdr) < 0)
1004                 return -EINVAL;
1005         if (!hdr.fc.security_enabled)
1006                 return 0;
1007         if (hdr.fc.version == 0)
1008                 return -EINVAL;
1009
1010         read_lock_bh(&sec->lock);
1011         if (!sec->params.enabled) {
1012                 read_unlock_bh(&sec->lock);
1013                 return -EINVAL;
1014         }
1015         read_unlock_bh(&sec->lock);
1016
1017         rcu_read_lock();
1018
1019         key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id);
1020         if (!key) {
1021                 err = -ENOKEY;
1022                 goto fail;
1023         }
1024
1025         dev = llsec_lookup_dev(sec, &hdr.source);
1026         if (!dev) {
1027                 err = -EINVAL;
1028                 goto fail_dev;
1029         }
1030
1031         if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) {
1032                 err = -EINVAL;
1033                 goto fail_dev;
1034         }
1035
1036         if (!(seclevel.sec_levels & BIT(hdr.sec.level)) &&
1037             (hdr.sec.level == 0 && seclevel.device_override &&
1038              !dev->dev.seclevel_exempt)) {
1039                 err = -EINVAL;
1040                 goto fail_dev;
1041         }
1042
1043         frame_ctr = le32_to_cpu(hdr.sec.frame_counter);
1044
1045         if (frame_ctr == 0xffffffff) {
1046                 err = -EOVERFLOW;
1047                 goto fail_dev;
1048         }
1049
1050         err = llsec_update_devkey_info(dev, &key_id, frame_ctr);
1051         if (err)
1052                 goto fail_dev;
1053
1054         dev_addr = dev->dev.hwaddr;
1055
1056         rcu_read_unlock();
1057
1058         err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr);
1059         llsec_key_put(key);
1060         return err;
1061
1062 fail_dev:
1063         llsec_key_put(key);
1064 fail:
1065         rcu_read_unlock();
1066         return err;
1067 }