1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17#include <linux/err.h>
18#include <linux/bug.h>
19#include <linux/completion.h>
20#include <linux/ieee802154.h>
21#include <crypto/aead.h>
22#include <crypto/skcipher.h>
23
24#include "ieee802154_i.h"
25#include "llsec.h"
26
27static void llsec_key_put(struct mac802154_llsec_key *key);
28static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
29 const struct ieee802154_llsec_key_id *b);
30
31static void llsec_dev_free(struct mac802154_llsec_device *dev);
32
33void mac802154_llsec_init(struct mac802154_llsec *sec)
34{
35 memset(sec, 0, sizeof(*sec));
36
37 memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN);
38
39 INIT_LIST_HEAD(&sec->table.security_levels);
40 INIT_LIST_HEAD(&sec->table.devices);
41 INIT_LIST_HEAD(&sec->table.keys);
42 hash_init(sec->devices_short);
43 hash_init(sec->devices_hw);
44 rwlock_init(&sec->lock);
45}
46
47void mac802154_llsec_destroy(struct mac802154_llsec *sec)
48{
49 struct ieee802154_llsec_seclevel *sl, *sn;
50 struct ieee802154_llsec_device *dev, *dn;
51 struct ieee802154_llsec_key_entry *key, *kn;
52
53 list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) {
54 struct mac802154_llsec_seclevel *msl;
55
56 msl = container_of(sl, struct mac802154_llsec_seclevel, level);
57 list_del(&sl->list);
58 kzfree(msl);
59 }
60
61 list_for_each_entry_safe(dev, dn, &sec->table.devices, list) {
62 struct mac802154_llsec_device *mdev;
63
64 mdev = container_of(dev, struct mac802154_llsec_device, dev);
65 list_del(&dev->list);
66 llsec_dev_free(mdev);
67 }
68
69 list_for_each_entry_safe(key, kn, &sec->table.keys, list) {
70 struct mac802154_llsec_key *mkey;
71
72 mkey = container_of(key->key, struct mac802154_llsec_key, key);
73 list_del(&key->list);
74 llsec_key_put(mkey);
75 kzfree(key);
76 }
77}
78
79int mac802154_llsec_get_params(struct mac802154_llsec *sec,
80 struct ieee802154_llsec_params *params)
81{
82 read_lock_bh(&sec->lock);
83 *params = sec->params;
84 read_unlock_bh(&sec->lock);
85
86 return 0;
87}
88
89int mac802154_llsec_set_params(struct mac802154_llsec *sec,
90 const struct ieee802154_llsec_params *params,
91 int changed)
92{
93 write_lock_bh(&sec->lock);
94
95 if (changed & IEEE802154_LLSEC_PARAM_ENABLED)
96 sec->params.enabled = params->enabled;
97 if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER)
98 sec->params.frame_counter = params->frame_counter;
99 if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL)
100 sec->params.out_level = params->out_level;
101 if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY)
102 sec->params.out_key = params->out_key;
103 if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE)
104 sec->params.default_key_source = params->default_key_source;
105 if (changed & IEEE802154_LLSEC_PARAM_PAN_ID)
106 sec->params.pan_id = params->pan_id;
107 if (changed & IEEE802154_LLSEC_PARAM_HWADDR)
108 sec->params.hwaddr = params->hwaddr;
109 if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR)
110 sec->params.coord_hwaddr = params->coord_hwaddr;
111 if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR)
112 sec->params.coord_shortaddr = params->coord_shortaddr;
113
114 write_unlock_bh(&sec->lock);
115
116 return 0;
117}
118
119static struct mac802154_llsec_key*
120llsec_key_alloc(const struct ieee802154_llsec_key *template)
121{
122 const int authsizes[3] = { 4, 8, 16 };
123 struct mac802154_llsec_key *key;
124 int i;
125
126 key = kzalloc(sizeof(*key), GFP_KERNEL);
127 if (!key)
128 return NULL;
129
130 kref_init(&key->ref);
131 key->key = *template;
132
133 BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm));
134
135 for (i = 0; i < ARRAY_SIZE(key->tfm); i++) {
136 key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0,
137 CRYPTO_ALG_ASYNC);
138 if (IS_ERR(key->tfm[i]))
139 goto err_tfm;
140 if (crypto_aead_setkey(key->tfm[i], template->key,
141 IEEE802154_LLSEC_KEY_SIZE))
142 goto err_tfm;
143 if (crypto_aead_setauthsize(key->tfm[i], authsizes[i]))
144 goto err_tfm;
145 }
146
147 key->tfm0 = crypto_alloc_skcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC);
148 if (IS_ERR(key->tfm0))
149 goto err_tfm;
150
151 if (crypto_skcipher_setkey(key->tfm0, template->key,
152 IEEE802154_LLSEC_KEY_SIZE))
153 goto err_tfm0;
154
155 return key;
156
157err_tfm0:
158 crypto_free_skcipher(key->tfm0);
159err_tfm:
160 for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
161 if (key->tfm[i])
162 crypto_free_aead(key->tfm[i]);
163
164 kzfree(key);
165 return NULL;
166}
167
168static void llsec_key_release(struct kref *ref)
169{
170 struct mac802154_llsec_key *key;
171 int i;
172
173 key = container_of(ref, struct mac802154_llsec_key, ref);
174
175 for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
176 crypto_free_aead(key->tfm[i]);
177
178 crypto_free_skcipher(key->tfm0);
179 kzfree(key);
180}
181
182static struct mac802154_llsec_key*
183llsec_key_get(struct mac802154_llsec_key *key)
184{
185 kref_get(&key->ref);
186 return key;
187}
188
189static void llsec_key_put(struct mac802154_llsec_key *key)
190{
191 kref_put(&key->ref, llsec_key_release);
192}
193
194static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
195 const struct ieee802154_llsec_key_id *b)
196{
197 if (a->mode != b->mode)
198 return false;
199
200 if (a->mode == IEEE802154_SCF_KEY_IMPLICIT)
201 return ieee802154_addr_equal(&a->device_addr, &b->device_addr);
202
203 if (a->id != b->id)
204 return false;
205
206 switch (a->mode) {
207 case IEEE802154_SCF_KEY_INDEX:
208 return true;
209 case IEEE802154_SCF_KEY_SHORT_INDEX:
210 return a->short_source == b->short_source;
211 case IEEE802154_SCF_KEY_HW_INDEX:
212 return a->extended_source == b->extended_source;
213 }
214
215 return false;
216}
217
218int mac802154_llsec_key_add(struct mac802154_llsec *sec,
219 const struct ieee802154_llsec_key_id *id,
220 const struct ieee802154_llsec_key *key)
221{
222 struct mac802154_llsec_key *mkey = NULL;
223 struct ieee802154_llsec_key_entry *pos, *new;
224
225 if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) &&
226 key->cmd_frame_ids)
227 return -EINVAL;
228
229 list_for_each_entry(pos, &sec->table.keys, list) {
230 if (llsec_key_id_equal(&pos->id, id))
231 return -EEXIST;
232
233 if (memcmp(pos->key->key, key->key,
234 IEEE802154_LLSEC_KEY_SIZE))
235 continue;
236
237 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
238
239
240
241
242
243 if (pos->key->frame_types != key->frame_types ||
244 pos->key->cmd_frame_ids != key->cmd_frame_ids)
245 return -EEXIST;
246
247 break;
248 }
249
250 new = kzalloc(sizeof(*new), GFP_KERNEL);
251 if (!new)
252 return -ENOMEM;
253
254 if (!mkey)
255 mkey = llsec_key_alloc(key);
256 else
257 mkey = llsec_key_get(mkey);
258
259 if (!mkey)
260 goto fail;
261
262 new->id = *id;
263 new->key = &mkey->key;
264
265 list_add_rcu(&new->list, &sec->table.keys);
266
267 return 0;
268
269fail:
270 kzfree(new);
271 return -ENOMEM;
272}
273
274int mac802154_llsec_key_del(struct mac802154_llsec *sec,
275 const struct ieee802154_llsec_key_id *key)
276{
277 struct ieee802154_llsec_key_entry *pos;
278
279 list_for_each_entry(pos, &sec->table.keys, list) {
280 struct mac802154_llsec_key *mkey;
281
282 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
283
284 if (llsec_key_id_equal(&pos->id, key)) {
285 list_del_rcu(&pos->list);
286 llsec_key_put(mkey);
287 return 0;
288 }
289 }
290
291 return -ENOENT;
292}
293
294static bool llsec_dev_use_shortaddr(__le16 short_addr)
295{
296 return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) &&
297 short_addr != cpu_to_le16(0xffff);
298}
299
300static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id)
301{
302 return ((__force u16)short_addr) << 16 | (__force u16)pan_id;
303}
304
305static u64 llsec_dev_hash_long(__le64 hwaddr)
306{
307 return (__force u64)hwaddr;
308}
309
310static struct mac802154_llsec_device*
311llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr,
312 __le16 pan_id)
313{
314 struct mac802154_llsec_device *dev;
315 u32 key = llsec_dev_hash_short(short_addr, pan_id);
316
317 hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) {
318 if (dev->dev.short_addr == short_addr &&
319 dev->dev.pan_id == pan_id)
320 return dev;
321 }
322
323 return NULL;
324}
325
326static struct mac802154_llsec_device*
327llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr)
328{
329 struct mac802154_llsec_device *dev;
330 u64 key = llsec_dev_hash_long(hwaddr);
331
332 hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) {
333 if (dev->dev.hwaddr == hwaddr)
334 return dev;
335 }
336
337 return NULL;
338}
339
340static void llsec_dev_free(struct mac802154_llsec_device *dev)
341{
342 struct ieee802154_llsec_device_key *pos, *pn;
343 struct mac802154_llsec_device_key *devkey;
344
345 list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) {
346 devkey = container_of(pos, struct mac802154_llsec_device_key,
347 devkey);
348
349 list_del(&pos->list);
350 kzfree(devkey);
351 }
352
353 kzfree(dev);
354}
355
356int mac802154_llsec_dev_add(struct mac802154_llsec *sec,
357 const struct ieee802154_llsec_device *dev)
358{
359 struct mac802154_llsec_device *entry;
360 u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id);
361 u64 hwkey = llsec_dev_hash_long(dev->hwaddr);
362
363 BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN);
364
365 if ((llsec_dev_use_shortaddr(dev->short_addr) &&
366 llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) ||
367 llsec_dev_find_long(sec, dev->hwaddr))
368 return -EEXIST;
369
370 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
371 if (!entry)
372 return -ENOMEM;
373
374 entry->dev = *dev;
375 spin_lock_init(&entry->lock);
376 INIT_LIST_HEAD(&entry->dev.keys);
377
378 if (llsec_dev_use_shortaddr(dev->short_addr))
379 hash_add_rcu(sec->devices_short, &entry->bucket_s, skey);
380 else
381 INIT_HLIST_NODE(&entry->bucket_s);
382
383 hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey);
384 list_add_tail_rcu(&entry->dev.list, &sec->table.devices);
385
386 return 0;
387}
388
389static void llsec_dev_free_rcu(struct rcu_head *rcu)
390{
391 llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu));
392}
393
394int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr)
395{
396 struct mac802154_llsec_device *pos;
397
398 pos = llsec_dev_find_long(sec, device_addr);
399 if (!pos)
400 return -ENOENT;
401
402 hash_del_rcu(&pos->bucket_s);
403 hash_del_rcu(&pos->bucket_hw);
404 list_del_rcu(&pos->dev.list);
405 call_rcu(&pos->rcu, llsec_dev_free_rcu);
406
407 return 0;
408}
409
410static struct mac802154_llsec_device_key*
411llsec_devkey_find(struct mac802154_llsec_device *dev,
412 const struct ieee802154_llsec_key_id *key)
413{
414 struct ieee802154_llsec_device_key *devkey;
415
416 list_for_each_entry_rcu(devkey, &dev->dev.keys, list) {
417 if (!llsec_key_id_equal(key, &devkey->key_id))
418 continue;
419
420 return container_of(devkey, struct mac802154_llsec_device_key,
421 devkey);
422 }
423
424 return NULL;
425}
426
427int mac802154_llsec_devkey_add(struct mac802154_llsec *sec,
428 __le64 dev_addr,
429 const struct ieee802154_llsec_device_key *key)
430{
431 struct mac802154_llsec_device *dev;
432 struct mac802154_llsec_device_key *devkey;
433
434 dev = llsec_dev_find_long(sec, dev_addr);
435
436 if (!dev)
437 return -ENOENT;
438
439 if (llsec_devkey_find(dev, &key->key_id))
440 return -EEXIST;
441
442 devkey = kmalloc(sizeof(*devkey), GFP_KERNEL);
443 if (!devkey)
444 return -ENOMEM;
445
446 devkey->devkey = *key;
447 list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys);
448 return 0;
449}
450
451int mac802154_llsec_devkey_del(struct mac802154_llsec *sec,
452 __le64 dev_addr,
453 const struct ieee802154_llsec_device_key *key)
454{
455 struct mac802154_llsec_device *dev;
456 struct mac802154_llsec_device_key *devkey;
457
458 dev = llsec_dev_find_long(sec, dev_addr);
459
460 if (!dev)
461 return -ENOENT;
462
463 devkey = llsec_devkey_find(dev, &key->key_id);
464 if (!devkey)
465 return -ENOENT;
466
467 list_del_rcu(&devkey->devkey.list);
468 kfree_rcu(devkey, rcu);
469 return 0;
470}
471
472static struct mac802154_llsec_seclevel*
473llsec_find_seclevel(const struct mac802154_llsec *sec,
474 const struct ieee802154_llsec_seclevel *sl)
475{
476 struct ieee802154_llsec_seclevel *pos;
477
478 list_for_each_entry(pos, &sec->table.security_levels, list) {
479 if (pos->frame_type != sl->frame_type ||
480 (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD &&
481 pos->cmd_frame_id != sl->cmd_frame_id) ||
482 pos->device_override != sl->device_override ||
483 pos->sec_levels != sl->sec_levels)
484 continue;
485
486 return container_of(pos, struct mac802154_llsec_seclevel,
487 level);
488 }
489
490 return NULL;
491}
492
493int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec,
494 const struct ieee802154_llsec_seclevel *sl)
495{
496 struct mac802154_llsec_seclevel *entry;
497
498 if (llsec_find_seclevel(sec, sl))
499 return -EEXIST;
500
501 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
502 if (!entry)
503 return -ENOMEM;
504
505 entry->level = *sl;
506
507 list_add_tail_rcu(&entry->level.list, &sec->table.security_levels);
508
509 return 0;
510}
511
512int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec,
513 const struct ieee802154_llsec_seclevel *sl)
514{
515 struct mac802154_llsec_seclevel *pos;
516
517 pos = llsec_find_seclevel(sec, sl);
518 if (!pos)
519 return -ENOENT;
520
521 list_del_rcu(&pos->level.list);
522 kfree_rcu(pos, rcu);
523
524 return 0;
525}
526
527static int llsec_recover_addr(struct mac802154_llsec *sec,
528 struct ieee802154_addr *addr)
529{
530 __le16 caddr = sec->params.coord_shortaddr;
531
532 addr->pan_id = sec->params.pan_id;
533
534 if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) {
535 return -EINVAL;
536 } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) {
537 addr->extended_addr = sec->params.coord_hwaddr;
538 addr->mode = IEEE802154_ADDR_LONG;
539 } else {
540 addr->short_addr = sec->params.coord_shortaddr;
541 addr->mode = IEEE802154_ADDR_SHORT;
542 }
543
544 return 0;
545}
546
547static struct mac802154_llsec_key*
548llsec_lookup_key(struct mac802154_llsec *sec,
549 const struct ieee802154_hdr *hdr,
550 const struct ieee802154_addr *addr,
551 struct ieee802154_llsec_key_id *key_id)
552{
553 struct ieee802154_addr devaddr = *addr;
554 u8 key_id_mode = hdr->sec.key_id_mode;
555 struct ieee802154_llsec_key_entry *key_entry;
556 struct mac802154_llsec_key *key;
557
558 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT &&
559 devaddr.mode == IEEE802154_ADDR_NONE) {
560 if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) {
561 devaddr.extended_addr = sec->params.coord_hwaddr;
562 devaddr.mode = IEEE802154_ADDR_LONG;
563 } else if (llsec_recover_addr(sec, &devaddr) < 0) {
564 return NULL;
565 }
566 }
567
568 list_for_each_entry_rcu(key_entry, &sec->table.keys, list) {
569 const struct ieee802154_llsec_key_id *id = &key_entry->id;
570
571 if (!(key_entry->key->frame_types & BIT(hdr->fc.type)))
572 continue;
573
574 if (id->mode != key_id_mode)
575 continue;
576
577 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) {
578 if (ieee802154_addr_equal(&devaddr, &id->device_addr))
579 goto found;
580 } else {
581 if (id->id != hdr->sec.key_id)
582 continue;
583
584 if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) ||
585 (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX &&
586 id->short_source == hdr->sec.short_src) ||
587 (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX &&
588 id->extended_source == hdr->sec.extended_src))
589 goto found;
590 }
591 }
592
593 return NULL;
594
595found:
596 key = container_of(key_entry->key, struct mac802154_llsec_key, key);
597 if (key_id)
598 *key_id = key_entry->id;
599 return llsec_key_get(key);
600}
601
602static void llsec_geniv(u8 iv[16], __le64 addr,
603 const struct ieee802154_sechdr *sec)
604{
605 __be64 addr_bytes = (__force __be64) swab64((__force u64) addr);
606 __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter);
607
608 iv[0] = 1;
609 memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes));
610 memcpy(iv + 9, &frame_counter, sizeof(frame_counter));
611 iv[13] = sec->level;
612 iv[14] = 0;
613 iv[15] = 1;
614}
615
616static int
617llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
618 const struct ieee802154_hdr *hdr,
619 struct mac802154_llsec_key *key)
620{
621 u8 iv[16];
622 struct scatterlist src;
623 SKCIPHER_REQUEST_ON_STACK(req, key->tfm0);
624 int err;
625
626 llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
627 sg_init_one(&src, skb->data, skb->len);
628 skcipher_request_set_tfm(req, key->tfm0);
629 skcipher_request_set_callback(req, 0, NULL, NULL);
630 skcipher_request_set_crypt(req, &src, &src, skb->len, iv);
631 err = crypto_skcipher_encrypt(req);
632 skcipher_request_zero(req);
633 return err;
634}
635
636static struct crypto_aead*
637llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen)
638{
639 int i;
640
641 for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
642 if (crypto_aead_authsize(key->tfm[i]) == authlen)
643 return key->tfm[i];
644
645 BUG();
646}
647
648static int
649llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
650 const struct ieee802154_hdr *hdr,
651 struct mac802154_llsec_key *key)
652{
653 u8 iv[16];
654 unsigned char *data;
655 int authlen, assoclen, datalen, rc;
656 struct scatterlist sg;
657 struct aead_request *req;
658
659 authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
660 llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
661
662 req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
663 if (!req)
664 return -ENOMEM;
665
666 assoclen = skb->mac_len;
667
668 data = skb_mac_header(skb) + skb->mac_len;
669 datalen = skb_tail_pointer(skb) - data;
670
671 skb_put(skb, authlen);
672
673 sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen + authlen);
674
675 if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) {
676 assoclen += datalen;
677 datalen = 0;
678 }
679
680 aead_request_set_callback(req, 0, NULL, NULL);
681 aead_request_set_crypt(req, &sg, &sg, datalen, iv);
682 aead_request_set_ad(req, assoclen);
683
684 rc = crypto_aead_encrypt(req);
685
686 kzfree(req);
687
688 return rc;
689}
690
691static int llsec_do_encrypt(struct sk_buff *skb,
692 const struct mac802154_llsec *sec,
693 const struct ieee802154_hdr *hdr,
694 struct mac802154_llsec_key *key)
695{
696 if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
697 return llsec_do_encrypt_unauth(skb, sec, hdr, key);
698 else
699 return llsec_do_encrypt_auth(skb, sec, hdr, key);
700}
701
702int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
703{
704 struct ieee802154_hdr hdr;
705 int rc, authlen, hlen;
706 struct mac802154_llsec_key *key;
707 u32 frame_ctr;
708
709 hlen = ieee802154_hdr_pull(skb, &hdr);
710
711 if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA)
712 return -EINVAL;
713
714 if (!hdr.fc.security_enabled || hdr.sec.level == 0) {
715 skb_push(skb, hlen);
716 return 0;
717 }
718
719 authlen = ieee802154_sechdr_authtag_len(&hdr.sec);
720
721 if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)
722 return -EMSGSIZE;
723
724 rcu_read_lock();
725
726 read_lock_bh(&sec->lock);
727
728 if (!sec->params.enabled) {
729 rc = -EINVAL;
730 goto fail_read;
731 }
732
733 key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL);
734 if (!key) {
735 rc = -ENOKEY;
736 goto fail_read;
737 }
738
739 read_unlock_bh(&sec->lock);
740
741 write_lock_bh(&sec->lock);
742
743 frame_ctr = be32_to_cpu(sec->params.frame_counter);
744 hdr.sec.frame_counter = cpu_to_le32(frame_ctr);
745 if (frame_ctr == 0xFFFFFFFF) {
746 write_unlock_bh(&sec->lock);
747 llsec_key_put(key);
748 rc = -EOVERFLOW;
749 goto fail;
750 }
751
752 sec->params.frame_counter = cpu_to_be32(frame_ctr + 1);
753
754 write_unlock_bh(&sec->lock);
755
756 rcu_read_unlock();
757
758 skb->mac_len = ieee802154_hdr_push(skb, &hdr);
759 skb_reset_mac_header(skb);
760
761 rc = llsec_do_encrypt(skb, sec, &hdr, key);
762 llsec_key_put(key);
763
764 return rc;
765
766fail_read:
767 read_unlock_bh(&sec->lock);
768fail:
769 rcu_read_unlock();
770 return rc;
771}
772
773static struct mac802154_llsec_device*
774llsec_lookup_dev(struct mac802154_llsec *sec,
775 const struct ieee802154_addr *addr)
776{
777 struct ieee802154_addr devaddr = *addr;
778 struct mac802154_llsec_device *dev = NULL;
779
780 if (devaddr.mode == IEEE802154_ADDR_NONE &&
781 llsec_recover_addr(sec, &devaddr) < 0)
782 return NULL;
783
784 if (devaddr.mode == IEEE802154_ADDR_SHORT) {
785 u32 key = llsec_dev_hash_short(devaddr.short_addr,
786 devaddr.pan_id);
787
788 hash_for_each_possible_rcu(sec->devices_short, dev,
789 bucket_s, key) {
790 if (dev->dev.pan_id == devaddr.pan_id &&
791 dev->dev.short_addr == devaddr.short_addr)
792 return dev;
793 }
794 } else {
795 u64 key = llsec_dev_hash_long(devaddr.extended_addr);
796
797 hash_for_each_possible_rcu(sec->devices_hw, dev,
798 bucket_hw, key) {
799 if (dev->dev.hwaddr == devaddr.extended_addr)
800 return dev;
801 }
802 }
803
804 return NULL;
805}
806
807static int
808llsec_lookup_seclevel(const struct mac802154_llsec *sec,
809 u8 frame_type, u8 cmd_frame_id,
810 struct ieee802154_llsec_seclevel *rlevel)
811{
812 struct ieee802154_llsec_seclevel *level;
813
814 list_for_each_entry_rcu(level, &sec->table.security_levels, list) {
815 if (level->frame_type == frame_type &&
816 (frame_type != IEEE802154_FC_TYPE_MAC_CMD ||
817 level->cmd_frame_id == cmd_frame_id)) {
818 *rlevel = *level;
819 return 0;
820 }
821 }
822
823 return -EINVAL;
824}
825
826static int
827llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
828 const struct ieee802154_hdr *hdr,
829 struct mac802154_llsec_key *key, __le64 dev_addr)
830{
831 u8 iv[16];
832 unsigned char *data;
833 int datalen;
834 struct scatterlist src;
835 SKCIPHER_REQUEST_ON_STACK(req, key->tfm0);
836 int err;
837
838 llsec_geniv(iv, dev_addr, &hdr->sec);
839 data = skb_mac_header(skb) + skb->mac_len;
840 datalen = skb_tail_pointer(skb) - data;
841
842 sg_init_one(&src, data, datalen);
843
844 skcipher_request_set_tfm(req, key->tfm0);
845 skcipher_request_set_callback(req, 0, NULL, NULL);
846 skcipher_request_set_crypt(req, &src, &src, datalen, iv);
847
848 err = crypto_skcipher_decrypt(req);
849 skcipher_request_zero(req);
850 return err;
851}
852
853static int
854llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
855 const struct ieee802154_hdr *hdr,
856 struct mac802154_llsec_key *key, __le64 dev_addr)
857{
858 u8 iv[16];
859 unsigned char *data;
860 int authlen, datalen, assoclen, rc;
861 struct scatterlist sg;
862 struct aead_request *req;
863
864 authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
865 llsec_geniv(iv, dev_addr, &hdr->sec);
866
867 req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
868 if (!req)
869 return -ENOMEM;
870
871 assoclen = skb->mac_len;
872
873 data = skb_mac_header(skb) + skb->mac_len;
874 datalen = skb_tail_pointer(skb) - data;
875
876 sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen);
877
878 if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) {
879 assoclen += datalen - authlen;
880 datalen = authlen;
881 }
882
883 aead_request_set_callback(req, 0, NULL, NULL);
884 aead_request_set_crypt(req, &sg, &sg, datalen, iv);
885 aead_request_set_ad(req, assoclen);
886
887 rc = crypto_aead_decrypt(req);
888
889 kzfree(req);
890 skb_trim(skb, skb->len - authlen);
891
892 return rc;
893}
894
895static int
896llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec,
897 const struct ieee802154_hdr *hdr,
898 struct mac802154_llsec_key *key, __le64 dev_addr)
899{
900 if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
901 return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr);
902 else
903 return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr);
904}
905
906static int
907llsec_update_devkey_record(struct mac802154_llsec_device *dev,
908 const struct ieee802154_llsec_key_id *in_key)
909{
910 struct mac802154_llsec_device_key *devkey;
911
912 devkey = llsec_devkey_find(dev, in_key);
913
914 if (!devkey) {
915 struct mac802154_llsec_device_key *next;
916
917 next = kzalloc(sizeof(*devkey), GFP_ATOMIC);
918 if (!next)
919 return -ENOMEM;
920
921 next->devkey.key_id = *in_key;
922
923 spin_lock_bh(&dev->lock);
924
925 devkey = llsec_devkey_find(dev, in_key);
926 if (!devkey)
927 list_add_rcu(&next->devkey.list, &dev->dev.keys);
928 else
929 kzfree(next);
930
931 spin_unlock_bh(&dev->lock);
932 }
933
934 return 0;
935}
936
937static int
938llsec_update_devkey_info(struct mac802154_llsec_device *dev,
939 const struct ieee802154_llsec_key_id *in_key,
940 u32 frame_counter)
941{
942 struct mac802154_llsec_device_key *devkey = NULL;
943
944 if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) {
945 devkey = llsec_devkey_find(dev, in_key);
946 if (!devkey)
947 return -ENOENT;
948 }
949
950 if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) {
951 int rc = llsec_update_devkey_record(dev, in_key);
952
953 if (rc < 0)
954 return rc;
955 }
956
957 spin_lock_bh(&dev->lock);
958
959 if ((!devkey && frame_counter < dev->dev.frame_counter) ||
960 (devkey && frame_counter < devkey->devkey.frame_counter)) {
961 spin_unlock_bh(&dev->lock);
962 return -EINVAL;
963 }
964
965 if (devkey)
966 devkey->devkey.frame_counter = frame_counter + 1;
967 else
968 dev->dev.frame_counter = frame_counter + 1;
969
970 spin_unlock_bh(&dev->lock);
971
972 return 0;
973}
974
975int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
976{
977 struct ieee802154_hdr hdr;
978 struct mac802154_llsec_key *key;
979 struct ieee802154_llsec_key_id key_id;
980 struct mac802154_llsec_device *dev;
981 struct ieee802154_llsec_seclevel seclevel;
982 int err;
983 __le64 dev_addr;
984 u32 frame_ctr;
985
986 if (ieee802154_hdr_peek(skb, &hdr) < 0)
987 return -EINVAL;
988 if (!hdr.fc.security_enabled)
989 return 0;
990 if (hdr.fc.version == 0)
991 return -EINVAL;
992
993 read_lock_bh(&sec->lock);
994 if (!sec->params.enabled) {
995 read_unlock_bh(&sec->lock);
996 return -EINVAL;
997 }
998 read_unlock_bh(&sec->lock);
999
1000 rcu_read_lock();
1001
1002 key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id);
1003 if (!key) {
1004 err = -ENOKEY;
1005 goto fail;
1006 }
1007
1008 dev = llsec_lookup_dev(sec, &hdr.source);
1009 if (!dev) {
1010 err = -EINVAL;
1011 goto fail_dev;
1012 }
1013
1014 if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) {
1015 err = -EINVAL;
1016 goto fail_dev;
1017 }
1018
1019 if (!(seclevel.sec_levels & BIT(hdr.sec.level)) &&
1020 (hdr.sec.level == 0 && seclevel.device_override &&
1021 !dev->dev.seclevel_exempt)) {
1022 err = -EINVAL;
1023 goto fail_dev;
1024 }
1025
1026 frame_ctr = le32_to_cpu(hdr.sec.frame_counter);
1027
1028 if (frame_ctr == 0xffffffff) {
1029 err = -EOVERFLOW;
1030 goto fail_dev;
1031 }
1032
1033 err = llsec_update_devkey_info(dev, &key_id, frame_ctr);
1034 if (err)
1035 goto fail_dev;
1036
1037 dev_addr = dev->dev.hwaddr;
1038
1039 rcu_read_unlock();
1040
1041 err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr);
1042 llsec_key_put(key);
1043 return err;
1044
1045fail_dev:
1046 llsec_key_put(key);
1047fail:
1048 rcu_read_unlock();
1049 return err;
1050}
1051
