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1 /*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
5 * Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/if_ether.h>
13 #include <linux/etherdevice.h>
14 #include <linux/list.h>
15 #include <linux/rcupdate.h>
16 #include <linux/rtnetlink.h>
17 #include <linux/slab.h>
18 #include <linux/export.h>
19 #include <net/mac80211.h>
20 #include <asm/unaligned.h>
21 #include "ieee80211_i.h"
22 #include "driver-ops.h"
23 #include "debugfs_key.h"
24 #include "aes_ccm.h"
25 #include "aes_cmac.h"
26
27
28 /**
29 * DOC: Key handling basics
30 *
31 * Key handling in mac80211 is done based on per-interface (sub_if_data)
32 * keys and per-station keys. Since each station belongs to an interface,
33 * each station key also belongs to that interface.
34 *
35 * Hardware acceleration is done on a best-effort basis for algorithms
36 * that are implemented in software, for each key the hardware is asked
37 * to enable that key for offloading but if it cannot do that the key is
38 * simply kept for software encryption (unless it is for an algorithm
39 * that isn't implemented in software).
40 * There is currently no way of knowing whether a key is handled in SW
41 * or HW except by looking into debugfs.
42 *
43 * All key management is internally protected by a mutex. Within all
44 * other parts of mac80211, key references are, just as STA structure
45 * references, protected by RCU. Note, however, that some things are
46 * unprotected, namely the key->sta dereferences within the hardware
47 * acceleration functions. This means that sta_info_destroy() must
48 * remove the key which waits for an RCU grace period.
49 */
50
51 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
52
53 static void assert_key_lock(struct ieee80211_local *local)
54 {
55 lockdep_assert_held(&local->key_mtx);
56 }
57
58 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
59 {
60 /*
61 * When this count is zero, SKB resizing for allocating tailroom
62 * for IV or MMIC is skipped. But, this check has created two race
63 * cases in xmit path while transiting from zero count to one:
64 *
65 * 1. SKB resize was skipped because no key was added but just before
66 * the xmit key is added and SW encryption kicks off.
67 *
68 * 2. SKB resize was skipped because all the keys were hw planted but
69 * just before xmit one of the key is deleted and SW encryption kicks
70 * off.
71 *
72 * In both the above case SW encryption will find not enough space for
73 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
74 *
75 * Solution has been explained at
76 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
77 */
78
79 if (!sdata->crypto_tx_tailroom_needed_cnt++) {
80 /*
81 * Flush all XMIT packets currently using HW encryption or no
82 * encryption at all if the count transition is from 0 -> 1.
83 */
84 synchronize_net();
85 }
86 }
87
88 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
89 {
90 struct ieee80211_sub_if_data *sdata;
91 struct sta_info *sta;
92 int ret;
93
94 might_sleep();
95
96 if (key->flags & KEY_FLAG_TAINTED)
97 return -EINVAL;
98
99 if (!key->local->ops->set_key)
100 goto out_unsupported;
101
102 assert_key_lock(key->local);
103
104 sta = key->sta;
105
106 /*
107 * If this is a per-STA GTK, check if it
108 * is supported; if not, return.
109 */
110 if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
111 !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
112 goto out_unsupported;
113
114 if (sta && !sta->uploaded)
115 goto out_unsupported;
116
117 sdata = key->sdata;
118 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
119 /*
120 * The driver doesn't know anything about VLAN interfaces.
121 * Hence, don't send GTKs for VLAN interfaces to the driver.
122 */
123 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
124 goto out_unsupported;
125 }
126
127 ret = drv_set_key(key->local, SET_KEY, sdata,
128 sta ? &sta->sta : NULL, &key->conf);
129
130 if (!ret) {
131 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
132
133 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
134 (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
135 (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
136 sdata->crypto_tx_tailroom_needed_cnt--;
137
138 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
139 (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
140
141 return 0;
142 }
143
144 if (ret != -ENOSPC && ret != -EOPNOTSUPP)
145 sdata_err(sdata,
146 "failed to set key (%d, %pM) to hardware (%d)\n",
147 key->conf.keyidx,
148 sta ? sta->sta.addr : bcast_addr, ret);
149
150 out_unsupported:
151 switch (key->conf.cipher) {
152 case WLAN_CIPHER_SUITE_WEP40:
153 case WLAN_CIPHER_SUITE_WEP104:
154 case WLAN_CIPHER_SUITE_TKIP:
155 case WLAN_CIPHER_SUITE_CCMP:
156 case WLAN_CIPHER_SUITE_AES_CMAC:
157 /* all of these we can do in software */
158 return 0;
159 default:
160 return -EINVAL;
161 }
162 }
163
164 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
165 {
166 struct ieee80211_sub_if_data *sdata;
167 struct sta_info *sta;
168 int ret;
169
170 might_sleep();
171
172 if (!key || !key->local->ops->set_key)
173 return;
174
175 assert_key_lock(key->local);
176
177 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
178 return;
179
180 sta = key->sta;
181 sdata = key->sdata;
182
183 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
184 (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
185 (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
186 increment_tailroom_need_count(sdata);
187
188 ret = drv_set_key(key->local, DISABLE_KEY, sdata,
189 sta ? &sta->sta : NULL, &key->conf);
190
191 if (ret)
192 sdata_err(sdata,
193 "failed to remove key (%d, %pM) from hardware (%d)\n",
194 key->conf.keyidx,
195 sta ? sta->sta.addr : bcast_addr, ret);
196
197 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
198 }
199
200 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
201 int idx, bool uni, bool multi)
202 {
203 struct ieee80211_key *key = NULL;
204
205 assert_key_lock(sdata->local);
206
207 if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
208 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
209
210 if (uni) {
211 rcu_assign_pointer(sdata->default_unicast_key, key);
212 drv_set_default_unicast_key(sdata->local, sdata, idx);
213 }
214
215 if (multi)
216 rcu_assign_pointer(sdata->default_multicast_key, key);
217
218 ieee80211_debugfs_key_update_default(sdata);
219 }
220
221 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
222 bool uni, bool multi)
223 {
224 mutex_lock(&sdata->local->key_mtx);
225 __ieee80211_set_default_key(sdata, idx, uni, multi);
226 mutex_unlock(&sdata->local->key_mtx);
227 }
228
229 static void
230 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
231 {
232 struct ieee80211_key *key = NULL;
233
234 assert_key_lock(sdata->local);
235
236 if (idx >= NUM_DEFAULT_KEYS &&
237 idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
238 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
239
240 rcu_assign_pointer(sdata->default_mgmt_key, key);
241
242 ieee80211_debugfs_key_update_default(sdata);
243 }
244
245 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
246 int idx)
247 {
248 mutex_lock(&sdata->local->key_mtx);
249 __ieee80211_set_default_mgmt_key(sdata, idx);
250 mutex_unlock(&sdata->local->key_mtx);
251 }
252
253
254 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
255 struct sta_info *sta,
256 bool pairwise,
257 struct ieee80211_key *old,
258 struct ieee80211_key *new)
259 {
260 int idx;
261 bool defunikey, defmultikey, defmgmtkey;
262
263 /* caller must provide at least one old/new */
264 if (WARN_ON(!new && !old))
265 return;
266
267 if (new)
268 list_add_tail(&new->list, &sdata->key_list);
269
270 WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
271
272 if (old)
273 idx = old->conf.keyidx;
274 else
275 idx = new->conf.keyidx;
276
277 if (sta) {
278 if (pairwise) {
279 rcu_assign_pointer(sta->ptk[idx], new);
280 sta->ptk_idx = idx;
281 } else {
282 rcu_assign_pointer(sta->gtk[idx], new);
283 sta->gtk_idx = idx;
284 }
285 } else {
286 defunikey = old &&
287 old == key_mtx_dereference(sdata->local,
288 sdata->default_unicast_key);
289 defmultikey = old &&
290 old == key_mtx_dereference(sdata->local,
291 sdata->default_multicast_key);
292 defmgmtkey = old &&
293 old == key_mtx_dereference(sdata->local,
294 sdata->default_mgmt_key);
295
296 if (defunikey && !new)
297 __ieee80211_set_default_key(sdata, -1, true, false);
298 if (defmultikey && !new)
299 __ieee80211_set_default_key(sdata, -1, false, true);
300 if (defmgmtkey && !new)
301 __ieee80211_set_default_mgmt_key(sdata, -1);
302
303 rcu_assign_pointer(sdata->keys[idx], new);
304 if (defunikey && new)
305 __ieee80211_set_default_key(sdata, new->conf.keyidx,
306 true, false);
307 if (defmultikey && new)
308 __ieee80211_set_default_key(sdata, new->conf.keyidx,
309 false, true);
310 if (defmgmtkey && new)
311 __ieee80211_set_default_mgmt_key(sdata,
312 new->conf.keyidx);
313 }
314
315 if (old)
316 list_del(&old->list);
317 }
318
319 struct ieee80211_key *
320 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
321 const u8 *key_data,
322 size_t seq_len, const u8 *seq,
323 const struct ieee80211_cipher_scheme *cs)
324 {
325 struct ieee80211_key *key;
326 int i, j, err;
327
328 BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
329
330 key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
331 if (!key)
332 return ERR_PTR(-ENOMEM);
333
334 /*
335 * Default to software encryption; we'll later upload the
336 * key to the hardware if possible.
337 */
338 key->conf.flags = 0;
339 key->flags = 0;
340
341 key->conf.cipher = cipher;
342 key->conf.keyidx = idx;
343 key->conf.keylen = key_len;
344 switch (cipher) {
345 case WLAN_CIPHER_SUITE_WEP40:
346 case WLAN_CIPHER_SUITE_WEP104:
347 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
348 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
349 break;
350 case WLAN_CIPHER_SUITE_TKIP:
351 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
352 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
353 if (seq) {
354 for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
355 key->u.tkip.rx[i].iv32 =
356 get_unaligned_le32(&seq[2]);
357 key->u.tkip.rx[i].iv16 =
358 get_unaligned_le16(seq);
359 }
360 }
361 spin_lock_init(&key->u.tkip.txlock);
362 break;
363 case WLAN_CIPHER_SUITE_CCMP:
364 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
365 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
366 if (seq) {
367 for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
368 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
369 key->u.ccmp.rx_pn[i][j] =
370 seq[IEEE80211_CCMP_PN_LEN - j - 1];
371 }
372 /*
373 * Initialize AES key state here as an optimization so that
374 * it does not need to be initialized for every packet.
375 */
376 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
377 if (IS_ERR(key->u.ccmp.tfm)) {
378 err = PTR_ERR(key->u.ccmp.tfm);
379 kfree(key);
380 return ERR_PTR(err);
381 }
382 break;
383 case WLAN_CIPHER_SUITE_AES_CMAC:
384 key->conf.iv_len = 0;
385 key->conf.icv_len = sizeof(struct ieee80211_mmie);
386 if (seq)
387 for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
388 key->u.aes_cmac.rx_pn[j] =
389 seq[IEEE80211_CMAC_PN_LEN - j - 1];
390 /*
391 * Initialize AES key state here as an optimization so that
392 * it does not need to be initialized for every packet.
393 */
394 key->u.aes_cmac.tfm =
395 ieee80211_aes_cmac_key_setup(key_data);
396 if (IS_ERR(key->u.aes_cmac.tfm)) {
397 err = PTR_ERR(key->u.aes_cmac.tfm);
398 kfree(key);
399 return ERR_PTR(err);
400 }
401 break;
402 default:
403 if (cs) {
404 size_t len = (seq_len > MAX_PN_LEN) ?
405 MAX_PN_LEN : seq_len;
406
407 key->conf.iv_len = cs->hdr_len;
408 key->conf.icv_len = cs->mic_len;
409 for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
410 for (j = 0; j < len; j++)
411 key->u.gen.rx_pn[i][j] =
412 seq[len - j - 1];
413 }
414 }
415 memcpy(key->conf.key, key_data, key_len);
416 INIT_LIST_HEAD(&key->list);
417
418 return key;
419 }
420
421 static void ieee80211_key_free_common(struct ieee80211_key *key)
422 {
423 if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
424 ieee80211_aes_key_free(key->u.ccmp.tfm);
425 if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
426 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
427 kfree(key);
428 }
429
430 static void __ieee80211_key_destroy(struct ieee80211_key *key,
431 bool delay_tailroom)
432 {
433 if (key->local)
434 ieee80211_key_disable_hw_accel(key);
435
436 if (key->local) {
437 struct ieee80211_sub_if_data *sdata = key->sdata;
438
439 ieee80211_debugfs_key_remove(key);
440
441 if (delay_tailroom) {
442 /* see ieee80211_delayed_tailroom_dec */
443 sdata->crypto_tx_tailroom_pending_dec++;
444 schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
445 HZ/2);
446 } else {
447 sdata->crypto_tx_tailroom_needed_cnt--;
448 }
449 }
450
451 ieee80211_key_free_common(key);
452 }
453
454 static void ieee80211_key_destroy(struct ieee80211_key *key,
455 bool delay_tailroom)
456 {
457 if (!key)
458 return;
459
460 /*
461 * Synchronize so the TX path can no longer be using
462 * this key before we free/remove it.
463 */
464 synchronize_net();
465
466 __ieee80211_key_destroy(key, delay_tailroom);
467 }
468
469 void ieee80211_key_free_unused(struct ieee80211_key *key)
470 {
471 WARN_ON(key->sdata || key->local);
472 ieee80211_key_free_common(key);
473 }
474
475 int ieee80211_key_link(struct ieee80211_key *key,
476 struct ieee80211_sub_if_data *sdata,
477 struct sta_info *sta)
478 {
479 struct ieee80211_local *local = sdata->local;
480 struct ieee80211_key *old_key;
481 int idx, ret;
482 bool pairwise;
483
484 BUG_ON(!sdata);
485 BUG_ON(!key);
486
487 pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
488 idx = key->conf.keyidx;
489 key->local = sdata->local;
490 key->sdata = sdata;
491 key->sta = sta;
492
493 mutex_lock(&sdata->local->key_mtx);
494
495 if (sta && pairwise)
496 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
497 else if (sta)
498 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
499 else
500 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
501
502 increment_tailroom_need_count(sdata);
503
504 ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
505 ieee80211_key_destroy(old_key, true);
506
507 ieee80211_debugfs_key_add(key);
508
509 if (!local->wowlan) {
510 ret = ieee80211_key_enable_hw_accel(key);
511 if (ret)
512 ieee80211_key_free(key, true);
513 } else {
514 ret = 0;
515 }
516
517 mutex_unlock(&sdata->local->key_mtx);
518
519 return ret;
520 }
521
522 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
523 {
524 if (!key)
525 return;
526
527 /*
528 * Replace key with nothingness if it was ever used.
529 */
530 if (key->sdata)
531 ieee80211_key_replace(key->sdata, key->sta,
532 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
533 key, NULL);
534 ieee80211_key_destroy(key, delay_tailroom);
535 }
536
537 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
538 {
539 struct ieee80211_key *key;
540
541 ASSERT_RTNL();
542
543 if (WARN_ON(!ieee80211_sdata_running(sdata)))
544 return;
545
546 mutex_lock(&sdata->local->key_mtx);
547
548 sdata->crypto_tx_tailroom_needed_cnt = 0;
549
550 list_for_each_entry(key, &sdata->key_list, list) {
551 increment_tailroom_need_count(sdata);
552 ieee80211_key_enable_hw_accel(key);
553 }
554
555 mutex_unlock(&sdata->local->key_mtx);
556 }
557
558 void ieee80211_iter_keys(struct ieee80211_hw *hw,
559 struct ieee80211_vif *vif,
560 void (*iter)(struct ieee80211_hw *hw,
561 struct ieee80211_vif *vif,
562 struct ieee80211_sta *sta,
563 struct ieee80211_key_conf *key,
564 void *data),
565 void *iter_data)
566 {
567 struct ieee80211_local *local = hw_to_local(hw);
568 struct ieee80211_key *key, *tmp;
569 struct ieee80211_sub_if_data *sdata;
570
571 ASSERT_RTNL();
572
573 mutex_lock(&local->key_mtx);
574 if (vif) {
575 sdata = vif_to_sdata(vif);
576 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
577 iter(hw, &sdata->vif,
578 key->sta ? &key->sta->sta : NULL,
579 &key->conf, iter_data);
580 } else {
581 list_for_each_entry(sdata, &local->interfaces, list)
582 list_for_each_entry_safe(key, tmp,
583 &sdata->key_list, list)
584 iter(hw, &sdata->vif,
585 key->sta ? &key->sta->sta : NULL,
586 &key->conf, iter_data);
587 }
588 mutex_unlock(&local->key_mtx);
589 }
590 EXPORT_SYMBOL(ieee80211_iter_keys);
591
592 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
593 {
594 struct ieee80211_key *key, *tmp;
595 LIST_HEAD(keys);
596
597 cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
598
599 mutex_lock(&sdata->local->key_mtx);
600
601 sdata->crypto_tx_tailroom_needed_cnt -=
602 sdata->crypto_tx_tailroom_pending_dec;
603 sdata->crypto_tx_tailroom_pending_dec = 0;
604
605 ieee80211_debugfs_key_remove_mgmt_default(sdata);
606
607 list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
608 ieee80211_key_replace(key->sdata, key->sta,
609 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
610 key, NULL);
611 list_add_tail(&key->list, &keys);
612 }
613
614 ieee80211_debugfs_key_update_default(sdata);
615
616 if (!list_empty(&keys)) {
617 synchronize_net();
618 list_for_each_entry_safe(key, tmp, &keys, list)
619 __ieee80211_key_destroy(key, false);
620 }
621
622 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
623 sdata->crypto_tx_tailroom_pending_dec);
624
625 mutex_unlock(&sdata->local->key_mtx);
626 }
627
628 void ieee80211_free_sta_keys(struct ieee80211_local *local,
629 struct sta_info *sta)
630 {
631 struct ieee80211_key *key;
632 int i;
633
634 mutex_lock(&local->key_mtx);
635 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
636 key = key_mtx_dereference(local, sta->gtk[i]);
637 if (!key)
638 continue;
639 ieee80211_key_replace(key->sdata, key->sta,
640 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
641 key, NULL);
642 __ieee80211_key_destroy(key, true);
643 }
644
645 for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
646 key = key_mtx_dereference(local, sta->ptk[i]);
647 if (!key)
648 continue;
649 ieee80211_key_replace(key->sdata, key->sta,
650 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
651 key, NULL);
652 __ieee80211_key_destroy(key, true);
653 }
654
655 mutex_unlock(&local->key_mtx);
656 }
657
658 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
659 {
660 struct ieee80211_sub_if_data *sdata;
661
662 sdata = container_of(wk, struct ieee80211_sub_if_data,
663 dec_tailroom_needed_wk.work);
664
665 /*
666 * The reason for the delayed tailroom needed decrementing is to
667 * make roaming faster: during roaming, all keys are first deleted
668 * and then new keys are installed. The first new key causes the
669 * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
670 * the cost of synchronize_net() (which can be slow). Avoid this
671 * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
672 * key removal for a while, so if we roam the value is larger than
673 * zero and no 0->1 transition happens.
674 *
675 * The cost is that if the AP switching was from an AP with keys
676 * to one without, we still allocate tailroom while it would no
677 * longer be needed. However, in the typical (fast) roaming case
678 * within an ESS this usually won't happen.
679 */
680
681 mutex_lock(&sdata->local->key_mtx);
682 sdata->crypto_tx_tailroom_needed_cnt -=
683 sdata->crypto_tx_tailroom_pending_dec;
684 sdata->crypto_tx_tailroom_pending_dec = 0;
685 mutex_unlock(&sdata->local->key_mtx);
686 }
687
688 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
689 const u8 *replay_ctr, gfp_t gfp)
690 {
691 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
692
693 trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
694
695 cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
696 }
697 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
698
699 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
700 struct ieee80211_key_seq *seq)
701 {
702 struct ieee80211_key *key;
703 u64 pn64;
704
705 if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
706 return;
707
708 key = container_of(keyconf, struct ieee80211_key, conf);
709
710 switch (key->conf.cipher) {
711 case WLAN_CIPHER_SUITE_TKIP:
712 seq->tkip.iv32 = key->u.tkip.tx.iv32;
713 seq->tkip.iv16 = key->u.tkip.tx.iv16;
714 break;
715 case WLAN_CIPHER_SUITE_CCMP:
716 pn64 = atomic64_read(&key->u.ccmp.tx_pn);
717 seq->ccmp.pn[5] = pn64;
718 seq->ccmp.pn[4] = pn64 >> 8;
719 seq->ccmp.pn[3] = pn64 >> 16;
720 seq->ccmp.pn[2] = pn64 >> 24;
721 seq->ccmp.pn[1] = pn64 >> 32;
722 seq->ccmp.pn[0] = pn64 >> 40;
723 break;
724 case WLAN_CIPHER_SUITE_AES_CMAC:
725 pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
726 seq->ccmp.pn[5] = pn64;
727 seq->ccmp.pn[4] = pn64 >> 8;
728 seq->ccmp.pn[3] = pn64 >> 16;
729 seq->ccmp.pn[2] = pn64 >> 24;
730 seq->ccmp.pn[1] = pn64 >> 32;
731 seq->ccmp.pn[0] = pn64 >> 40;
732 break;
733 default:
734 WARN_ON(1);
735 }
736 }
737 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
738
739 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
740 int tid, struct ieee80211_key_seq *seq)
741 {
742 struct ieee80211_key *key;
743 const u8 *pn;
744
745 key = container_of(keyconf, struct ieee80211_key, conf);
746
747 switch (key->conf.cipher) {
748 case WLAN_CIPHER_SUITE_TKIP:
749 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
750 return;
751 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
752 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
753 break;
754 case WLAN_CIPHER_SUITE_CCMP:
755 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
756 return;
757 if (tid < 0)
758 pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
759 else
760 pn = key->u.ccmp.rx_pn[tid];
761 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
762 break;
763 case WLAN_CIPHER_SUITE_AES_CMAC:
764 if (WARN_ON(tid != 0))
765 return;
766 pn = key->u.aes_cmac.rx_pn;
767 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
768 break;
769 }
770 }
771 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
772
773 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
774 struct ieee80211_key_seq *seq)
775 {
776 struct ieee80211_key *key;
777 u64 pn64;
778
779 key = container_of(keyconf, struct ieee80211_key, conf);
780
781 switch (key->conf.cipher) {
782 case WLAN_CIPHER_SUITE_TKIP:
783 key->u.tkip.tx.iv32 = seq->tkip.iv32;
784 key->u.tkip.tx.iv16 = seq->tkip.iv16;
785 break;
786 case WLAN_CIPHER_SUITE_CCMP:
787 pn64 = (u64)seq->ccmp.pn[5] |
788 ((u64)seq->ccmp.pn[4] << 8) |
789 ((u64)seq->ccmp.pn[3] << 16) |
790 ((u64)seq->ccmp.pn[2] << 24) |
791 ((u64)seq->ccmp.pn[1] << 32) |
792 ((u64)seq->ccmp.pn[0] << 40);
793 atomic64_set(&key->u.ccmp.tx_pn, pn64);
794 break;
795 case WLAN_CIPHER_SUITE_AES_CMAC:
796 pn64 = (u64)seq->aes_cmac.pn[5] |
797 ((u64)seq->aes_cmac.pn[4] << 8) |
798 ((u64)seq->aes_cmac.pn[3] << 16) |
799 ((u64)seq->aes_cmac.pn[2] << 24) |
800 ((u64)seq->aes_cmac.pn[1] << 32) |
801 ((u64)seq->aes_cmac.pn[0] << 40);
802 atomic64_set(&key->u.aes_cmac.tx_pn, pn64);
803 break;
804 default:
805 WARN_ON(1);
806 break;
807 }
808 }
809 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
810
811 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
812 int tid, struct ieee80211_key_seq *seq)
813 {
814 struct ieee80211_key *key;
815 u8 *pn;
816
817 key = container_of(keyconf, struct ieee80211_key, conf);
818
819 switch (key->conf.cipher) {
820 case WLAN_CIPHER_SUITE_TKIP:
821 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
822 return;
823 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
824 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
825 break;
826 case WLAN_CIPHER_SUITE_CCMP:
827 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
828 return;
829 if (tid < 0)
830 pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
831 else
832 pn = key->u.ccmp.rx_pn[tid];
833 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
834 break;
835 case WLAN_CIPHER_SUITE_AES_CMAC:
836 if (WARN_ON(tid != 0))
837 return;
838 pn = key->u.aes_cmac.rx_pn;
839 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
840 break;
841 default:
842 WARN_ON(1);
843 break;
844 }
845 }
846 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
847
848 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
849 {
850 struct ieee80211_key *key;
851
852 key = container_of(keyconf, struct ieee80211_key, conf);
853
854 assert_key_lock(key->local);
855
856 /*
857 * if key was uploaded, we assume the driver will/has remove(d)
858 * it, so adjust bookkeeping accordingly
859 */
860 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
861 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
862
863 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
864 (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
865 (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
866 increment_tailroom_need_count(key->sdata);
867 }
868
869 ieee80211_key_free(key, false);
870 }
871 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
872
873 struct ieee80211_key_conf *
874 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
875 struct ieee80211_key_conf *keyconf)
876 {
877 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
878 struct ieee80211_local *local = sdata->local;
879 struct ieee80211_key *key;
880 int err;
881
882 if (WARN_ON(!local->wowlan))
883 return ERR_PTR(-EINVAL);
884
885 if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
886 return ERR_PTR(-EINVAL);
887
888 key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
889 keyconf->keylen, keyconf->key,
890 0, NULL, NULL);
891 if (IS_ERR(key))
892 return ERR_CAST(key);
893
894 if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
895 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
896
897 err = ieee80211_key_link(key, sdata, NULL);
898 if (err)
899 return ERR_PTR(err);
900
901 return &key->conf;
902 }
903 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);