summaryrefslogtreecommitdiffstats
path: root/net/mac80211/key.c
blob: 3e51dd7d98b34aad114e6b927beae8e4ecdde9fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007-2008	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/if_ether.h>
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "debugfs_key.h"
#include "aes_ccm.h"
#include "aes_cmac.h"


/**
 * DOC: Key handling basics
 *
 * Key handling in mac80211 is done based on per-interface (sub_if_data)
 * keys and per-station keys. Since each station belongs to an interface,
 * each station key also belongs to that interface.
 *
 * Hardware acceleration is done on a best-effort basis for algorithms
 * that are implemented in software,  for each key the hardware is asked
 * to enable that key for offloading but if it cannot do that the key is
 * simply kept for software encryption (unless it is for an algorithm
 * that isn't implemented in software).
 * There is currently no way of knowing whether a key is handled in SW
 * or HW except by looking into debugfs.
 *
 * All key management is internally protected by a mutex. Within all
 * other parts of mac80211, key references are, just as STA structure
 * references, protected by RCU. Note, however, that some things are
 * unprotected, namely the key->sta dereferences within the hardware
 * acceleration functions. This means that sta_info_destroy() must
 * remove the key which waits for an RCU grace period.
 */

static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

static void assert_key_lock(struct ieee80211_local *local)
{
	lockdep_assert_held(&local->key_mtx);
}

static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
{
	/*
	 * When this count is zero, SKB resizing for allocating tailroom
	 * for IV or MMIC is skipped. But, this check has created two race
	 * cases in xmit path while transiting from zero count to one:
	 *
	 * 1. SKB resize was skipped because no key was added but just before
	 * the xmit key is added and SW encryption kicks off.
	 *
	 * 2. SKB resize was skipped because all the keys were hw planted but
	 * just before xmit one of the key is deleted and SW encryption kicks
	 * off.
	 *
	 * In both the above case SW encryption will find not enough space for
	 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
	 *
	 * Solution has been explained at
	 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
	 */

	if (!sdata->crypto_tx_tailroom_needed_cnt++) {
		/*
		 * Flush all XMIT packets currently using HW encryption or no
		 * encryption at all if the count transition is from 0 -> 1.
		 */
		synchronize_net();
	}
}

static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
{
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	int ret;

	might_sleep();

	if (key->flags & KEY_FLAG_TAINTED)
		return -EINVAL;

	if (!key->local->ops->set_key)
		goto out_unsupported;

	assert_key_lock(key->local);

	sta = key->sta;

	/*
	 * If this is a per-STA GTK, check if it
	 * is supported; if not, return.
	 */
	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
	    !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
		goto out_unsupported;

	if (sta && !sta->uploaded)
		goto out_unsupported;

	sdata = key->sdata;
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
		/*
		 * The driver doesn't know anything about VLAN interfaces.
		 * Hence, don't send GTKs for VLAN interfaces to the driver.
		 */
		if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
			goto out_unsupported;
	}

	ret = drv_set_key(key->local, SET_KEY, sdata,
			  sta ? &sta->sta : NULL, &key->conf);

	if (!ret) {
		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;

		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
			sdata->crypto_tx_tailroom_needed_cnt--;

		WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
			(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));

		return 0;
	}

	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
		sdata_err(sdata,
			  "failed to set key (%d, %pM) to hardware (%d)\n",
			  key->conf.keyidx,
			  sta ? sta->sta.addr : bcast_addr, ret);

 out_unsupported:
	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
	case WLAN_CIPHER_SUITE_TKIP:
	case WLAN_CIPHER_SUITE_CCMP:
	case WLAN_CIPHER_SUITE_AES_CMAC:
		/* all of these we can do in software */
		return 0;
	default:
		return -EINVAL;
	}
}

static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
{
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	int ret;

	might_sleep();

	if (!key || !key->local->ops->set_key)
		return;

	assert_key_lock(key->local);

	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
		return;

	sta = key->sta;
	sdata = key->sdata;

	if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
	      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
	      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
		increment_tailroom_need_count(sdata);

	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
			  sta ? &sta->sta : NULL, &key->conf);

	if (ret)
		sdata_err(sdata,
			  "failed to remove key (%d, %pM) from hardware (%d)\n",
			  key->conf.keyidx,
			  sta ? sta->sta.addr : bcast_addr, ret);

	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
}

static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
					int idx, bool uni, bool multi)
{
	struct ieee80211_key *key = NULL;

	assert_key_lock(sdata->local);

	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	if (uni) {
		rcu_assign_pointer(sdata->default_unicast_key, key);
		drv_set_default_unicast_key(sdata->local, sdata, idx);
	}

	if (multi)
		rcu_assign_pointer(sdata->default_multicast_key, key);

	ieee80211_debugfs_key_update_default(sdata);
}

void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
			       bool uni, bool multi)
{
	mutex_lock(&sdata->local->key_mtx);
	__ieee80211_set_default_key(sdata, idx, uni, multi);
	mutex_unlock(&sdata->local->key_mtx);
}

static void
__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
{
	struct ieee80211_key *key = NULL;

	assert_key_lock(sdata->local);

	if (idx >= NUM_DEFAULT_KEYS &&
	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	rcu_assign_pointer(sdata->default_mgmt_key, key);

	ieee80211_debugfs_key_update_default(sdata);
}

void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
				    int idx)
{
	mutex_lock(&sdata->local->key_mtx);
	__ieee80211_set_default_mgmt_key(sdata, idx);
	mutex_unlock(&sdata->local->key_mtx);
}


static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
				  struct sta_info *sta,
				  bool pairwise,
				  struct ieee80211_key *old,
				  struct ieee80211_key *new)
{
	int idx;
	bool defunikey, defmultikey, defmgmtkey;

	if (new)
		list_add_tail(&new->list, &sdata->key_list);

	if (sta && pairwise) {
		rcu_assign_pointer(sta->ptk, new);
	} else if (sta) {
		if (old)
			idx = old->conf.keyidx;
		else
			idx = new->conf.keyidx;
		rcu_assign_pointer(sta->gtk[idx], new);
	} else {
		WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);

		if (old)
			idx = old->conf.keyidx;
		else
			idx = new->conf.keyidx;

		defunikey = old &&
			old == key_mtx_dereference(sdata->local,
						sdata->default_unicast_key);
		defmultikey = old &&
			old == key_mtx_dereference(sdata->local,
						sdata->default_multicast_key);
		defmgmtkey = old &&
			old == key_mtx_dereference(sdata->local,
						sdata->default_mgmt_key);

		if (defunikey && !new)
			__ieee80211_set_default_key(sdata, -1, true, false);
		if (defmultikey && !new)
			__ieee80211_set_default_key(sdata, -1, false, true);
		if (defmgmtkey && !new)
			__ieee80211_set_default_mgmt_key(sdata, -1);

		rcu_assign_pointer(sdata->keys[idx], new);
		if (defunikey && new)
			__ieee80211_set_default_key(sdata, new->conf.keyidx,
						    true, false);
		if (defmultikey && new)
			__ieee80211_set_default_key(sdata, new->conf.keyidx,
						    false, true);
		if (defmgmtkey && new)
			__ieee80211_set_default_mgmt_key(sdata,
							 new->conf.keyidx);
	}

	if (old)
		list_del(&old->list);
}

struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
					  const u8 *key_data,
					  size_t seq_len, const u8 *seq)
{
	struct ieee80211_key *key;
	int i, j, err;

	BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);

	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
	if (!key)
		return ERR_PTR(-ENOMEM);

	/*
	 * Default to software encryption; we'll later upload the
	 * key to the hardware if possible.
	 */
	key->conf.flags = 0;
	key->flags = 0;

	key->conf.cipher = cipher;
	key->conf.keyidx = idx;
	key->conf.keylen = key_len;
	switch (cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
		key->conf.iv_len = IEEE80211_WEP_IV_LEN;
		key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
		break;
	case WLAN_CIPHER_SUITE_TKIP:
		key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
		key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
		if (seq) {
			for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
				key->u.tkip.rx[i].iv32 =
					get_unaligned_le32(&seq[2]);
				key->u.tkip.rx[i].iv16 =
					get_unaligned_le16(seq);
			}
		}
		spin_lock_init(&key->u.tkip.txlock);
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
		key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
		if (seq) {
			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
				for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
					key->u.ccmp.rx_pn[i][j] =
						seq[IEEE80211_CCMP_PN_LEN - j - 1];
		}
		/*
		 * Initialize AES key state here as an optimization so that
		 * it does not need to be initialized for every packet.
		 */
		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
		if (IS_ERR(key->u.ccmp.tfm)) {
			err = PTR_ERR(key->u.ccmp.tfm);
			kfree(key);
			return ERR_PTR(err);
		}
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		key->conf.iv_len = 0;
		key->conf.icv_len = sizeof(struct ieee80211_mmie);
		if (seq)
			for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
				key->u.aes_cmac.rx_pn[j] =
					seq[IEEE80211_CMAC_PN_LEN - j - 1];
		/*
		 * Initialize AES key state here as an optimization so that
		 * it does not need to be initialized for every packet.
		 */
		key->u.aes_cmac.tfm =
			ieee80211_aes_cmac_key_setup(key_data);
		if (IS_ERR(key->u.aes_cmac.tfm)) {
			err = PTR_ERR(key->u.aes_cmac.tfm);
			kfree(key);
			return ERR_PTR(err);
		}
		break;
	}
	memcpy(key->conf.key, key_data, key_len);
	INIT_LIST_HEAD(&key->list);

	return key;
}

static void ieee80211_key_free_common(struct ieee80211_key *key)
{
	if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
		ieee80211_aes_key_free(key->u.ccmp.tfm);
	if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
		ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
	kfree(key);
}

static void __ieee80211_key_destroy(struct ieee80211_key *key,
				    bool delay_tailroom)
{
	if (key->local)
		ieee80211_key_disable_hw_accel(key);

	if (key->local) {
		struct ieee80211_sub_if_data *sdata = key->sdata;

		ieee80211_debugfs_key_remove(key);

		if (delay_tailroom) {
			/* see ieee80211_delayed_tailroom_dec */
			sdata->crypto_tx_tailroom_pending_dec++;
			schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
					      HZ/2);
		} else {
			sdata->crypto_tx_tailroom_needed_cnt--;
		}
	}

	ieee80211_key_free_common(key);
}

static void ieee80211_key_destroy(struct ieee80211_key *key,
				  bool delay_tailroom)
{
	if (!key)
		return;

	/*
	 * Synchronize so the TX path can no longer be using
	 * this key before we free/remove it.
	 */
	synchronize_net();

	__ieee80211_key_destroy(key, delay_tailroom);
}

void ieee80211_key_free_unused(struct ieee80211_key *key)
{
	WARN_ON(key->sdata || key->local);
	ieee80211_key_free_common(key);
}

int ieee80211_key_link(struct ieee80211_key *key,
		       struct ieee80211_sub_if_data *sdata,
		       struct sta_info *sta)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_key *old_key;
	int idx, ret;
	bool pairwise;

	BUG_ON(!sdata);
	BUG_ON(!key);

	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
	idx = key->conf.keyidx;
	key->local = sdata->local;
	key->sdata = sdata;
	key->sta = sta;

	mutex_lock(&sdata->local->key_mtx);

	if (sta && pairwise)
		old_key = key_mtx_dereference(sdata->local, sta->ptk);
	else if (sta)
		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
	else
		old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	increment_tailroom_need_count(sdata);

	ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
	ieee80211_key_destroy(old_key, true);

	ieee80211_debugfs_key_add(key);

	if (!local->wowlan) {
		ret = ieee80211_key_enable_hw_accel(key);
		if (ret)
			ieee80211_key_free(key, true);
	} else {
		ret = 0;
	}

	mutex_unlock(&sdata->local->key_mtx);

	return ret;
}

void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
{
	if (!key)
		return;

	/*
	 * Replace key with nothingness if it was ever used.
	 */
	if (key->sdata)
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
	ieee80211_key_destroy(key, delay_tailroom);
}

void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_key *key;

	ASSERT_RTNL();

	if (WARN_ON(!ieee80211_sdata_running(sdata)))
		return;

	mutex_lock(&sdata->local->key_mtx);

	sdata->crypto_tx_tailroom_needed_cnt = 0;

	list_for_each_entry(key, &sdata->key_list, list) {
		increment_tailroom_need_count(sdata);
		ieee80211_key_enable_hw_accel(key);
	}

	mutex_unlock(&sdata->local->key_mtx);
}

void ieee80211_iter_keys(struct ieee80211_hw *hw,
			 struct ieee80211_vif *vif,
			 void (*iter)(struct ieee80211_hw *hw,
				      struct ieee80211_vif *vif,
				      struct ieee80211_sta *sta,
				      struct ieee80211_key_conf *key,
				      void *data),
			 void *iter_data)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_key *key, *tmp;
	struct ieee80211_sub_if_data *sdata;

	ASSERT_RTNL();

	mutex_lock(&local->key_mtx);
	if (vif) {
		sdata = vif_to_sdata(vif);
		list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
			iter(hw, &sdata->vif,
			     key->sta ? &key->sta->sta : NULL,
			     &key->conf, iter_data);
	} else {
		list_for_each_entry(sdata, &local->interfaces, list)
			list_for_each_entry_safe(key, tmp,
						 &sdata->key_list, list)
				iter(hw, &sdata->vif,
				     key->sta ? &key->sta->sta : NULL,
				     &key->conf, iter_data);
	}
	mutex_unlock(&local->key_mtx);
}
EXPORT_SYMBOL(ieee80211_iter_keys);

void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_key *key, *tmp;
	LIST_HEAD(keys);

	cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);

	mutex_lock(&sdata->local->key_mtx);

	sdata->crypto_tx_tailroom_needed_cnt -=
		sdata->crypto_tx_tailroom_pending_dec;
	sdata->crypto_tx_tailroom_pending_dec = 0;

	ieee80211_debugfs_key_remove_mgmt_default(sdata);

	list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
		list_add_tail(&key->list, &keys);
	}

	ieee80211_debugfs_key_update_default(sdata);

	if (!list_empty(&keys)) {
		synchronize_net();
		list_for_each_entry_safe(key, tmp, &keys, list)
			__ieee80211_key_destroy(key, false);
	}

	WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
		     sdata->crypto_tx_tailroom_pending_dec);

	mutex_unlock(&sdata->local->key_mtx);
}

void ieee80211_free_sta_keys(struct ieee80211_local *local,
			     struct sta_info *sta)
{
	struct ieee80211_key *key, *tmp;
	LIST_HEAD(keys);
	int i;

	mutex_lock(&local->key_mtx);
	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
		key = key_mtx_dereference(local, sta->gtk[i]);
		if (!key)
			continue;
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
		list_add(&key->list, &keys);
	}

	key = key_mtx_dereference(local, sta->ptk);
	if (key) {
		ieee80211_key_replace(key->sdata, key->sta,
				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
				key, NULL);
		list_add(&key->list, &keys);
	}

	/*
	 * NB: the station code relies on this being
	 * done even if there aren't any keys
	 */
	synchronize_net();

	list_for_each_entry_safe(key, tmp, &keys, list)
		__ieee80211_key_destroy(key, true);

	mutex_unlock(&local->key_mtx);
}

void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
{
	struct ieee80211_sub_if_data *sdata;

	sdata = container_of(wk, struct ieee80211_sub_if_data,
			     dec_tailroom_needed_wk.work);

	/*
	 * The reason for the delayed tailroom needed decrementing is to
	 * make roaming faster: during roaming, all keys are first deleted
	 * and then new keys are installed. The first new key causes the
	 * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
	 * the cost of synchronize_net() (which can be slow). Avoid this
	 * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
	 * key removal for a while, so if we roam the value is larger than
	 * zero and no 0->1 transition happens.
	 *
	 * The cost is that if the AP switching was from an AP with keys
	 * to one without, we still allocate tailroom while it would no
	 * longer be needed. However, in the typical (fast) roaming case
	 * within an ESS this usually won't happen.
	 */

	mutex_lock(&sdata->local->key_mtx);
	sdata->crypto_tx_tailroom_needed_cnt -=
		sdata->crypto_tx_tailroom_pending_dec;
	sdata->crypto_tx_tailroom_pending_dec = 0;
	mutex_unlock(&sdata->local->key_mtx);
}

void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
				const u8 *replay_ctr, gfp_t gfp)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);

	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);

void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
			      struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	u64 pn64;

	if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
		return;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		seq->tkip.iv32 = key->u.tkip.tx.iv32;
		seq->tkip.iv16 = key->u.tkip.tx.iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		pn64 = atomic64_read(&key->u.ccmp.tx_pn);
		seq->ccmp.pn[5] = pn64;
		seq->ccmp.pn[4] = pn64 >> 8;
		seq->ccmp.pn[3] = pn64 >> 16;
		seq->ccmp.pn[2] = pn64 >> 24;
		seq->ccmp.pn[1] = pn64 >> 32;
		seq->ccmp.pn[0] = pn64 >> 40;
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
		seq->ccmp.pn[5] = pn64;
		seq->ccmp.pn[4] = pn64 >> 8;
		seq->ccmp.pn[3] = pn64 >> 16;
		seq->ccmp.pn[2] = pn64 >> 24;
		seq->ccmp.pn[1] = pn64 >> 32;
		seq->ccmp.pn[0] = pn64 >> 40;
		break;
	default:
		WARN_ON(1);
	}
}
EXPORT_SYMBOL(ieee80211_get_key_tx_seq);

void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
			      int tid, struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	const u8 *pn;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
			return;
		seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
		seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
			return;
		if (tid < 0)
			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
		else
			pn = key->u.ccmp.rx_pn[tid];
		memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		if (WARN_ON(tid != 0))
			return;
		pn = key->u.aes_cmac.rx_pn;
		memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
		break;
	}
}
EXPORT_SYMBOL(ieee80211_get_key_rx_seq);

void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
			      struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	u64 pn64;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		key->u.tkip.tx.iv32 = seq->tkip.iv32;
		key->u.tkip.tx.iv16 = seq->tkip.iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		pn64 = (u64)seq->ccmp.pn[5] |
		       ((u64)seq->ccmp.pn[4] << 8) |
		       ((u64)seq->ccmp.pn[3] << 16) |
		       ((u64)seq->ccmp.pn[2] << 24) |
		       ((u64)seq->ccmp.pn[1] << 32) |
		       ((u64)seq->ccmp.pn[0] << 40);
		atomic64_set(&key->u.ccmp.tx_pn, pn64);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		pn64 = (u64)seq->aes_cmac.pn[5] |
		       ((u64)seq->aes_cmac.pn[4] << 8) |
		       ((u64)seq->aes_cmac.pn[3] << 16) |
		       ((u64)seq->aes_cmac.pn[2] << 24) |
		       ((u64)seq->aes_cmac.pn[1] << 32) |
		       ((u64)seq->aes_cmac.pn[0] << 40);
		atomic64_set(&key->u.aes_cmac.tx_pn, pn64);
		break;
	default:
		WARN_ON(1);
		break;
	}
}
EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);

void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
			      int tid, struct ieee80211_key_seq *seq)
{
	struct ieee80211_key *key;
	u8 *pn;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
			return;
		key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
		key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
			return;
		if (tid < 0)
			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
		else
			pn = key->u.ccmp.rx_pn[tid];
		memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		if (WARN_ON(tid != 0))
			return;
		pn = key->u.aes_cmac.rx_pn;
		memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
		break;
	default:
		WARN_ON(1);
		break;
	}
}
EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);

void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
{
	struct ieee80211_key *key;

	key = container_of(keyconf, struct ieee80211_key, conf);

	assert_key_lock(key->local);

	/*
	 * if key was uploaded, we assume the driver will/has remove(d)
	 * it, so adjust bookkeeping accordingly
	 */
	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
		key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;

		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
		      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
			increment_tailroom_need_count(key->sdata);
	}

	ieee80211_key_free(key, false);
}
EXPORT_SYMBOL_GPL(ieee80211_remove_key);

struct ieee80211_key_conf *
ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
			struct ieee80211_key_conf *keyconf)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_key *key;
	int err;

	if (WARN_ON(!local->wowlan))
		return ERR_PTR(-EINVAL);

	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
		return ERR_PTR(-EINVAL);

	key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
				  keyconf->keylen, keyconf->key,
				  0, NULL);
	if (IS_ERR(key))
		return ERR_CAST(key);

	if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
		key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;

	err = ieee80211_key_link(key, sdata, NULL);
	if (err)
		return ERR_PTR(err);

	return &key->conf;
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);
OpenPOWER on IntegriCloud