summaryrefslogtreecommitdiff
path: root/net/mac80211/mesh_plink.c
blob: 8cc8461b48a0a037dd129c2f0491093960d410f1 (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
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
/*
 * Copyright (c) 2008, 2009 open80211s Ltd.
 * Author:     Luis Carlos Cobo <luisca@cozybit.com>
 *
 * 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/gfp.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
#define mpl_dbg(fmt, args...)	printk(KERN_DEBUG fmt, ##args)
#else
#define mpl_dbg(fmt, args...)	do { (void)(0); } while (0)
#endif

#define PLINK_GET_LLID(p) (p + 2)
#define PLINK_GET_PLID(p) (p + 4)

#define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
				jiffies + HZ * t / 1000))

#define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
#define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
#define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
#define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
#define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)

/* We only need a valid sta if user configured a minimum rssi_threshold. */
#define rssi_threshold_check(sta, sdata) \
		(sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
		(sta && (s8) -ewma_read(&sta->avg_signal) > \
		sdata->u.mesh.mshcfg.rssi_threshold))

enum plink_event {
	PLINK_UNDEFINED,
	OPN_ACPT,
	OPN_RJCT,
	OPN_IGNR,
	CNF_ACPT,
	CNF_RJCT,
	CNF_IGNR,
	CLS_ACPT,
	CLS_IGNR
};

static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
		enum ieee80211_self_protected_actioncode action,
		u8 *da, __le16 llid, __le16 plid, __le16 reason);

static inline
void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
{
	atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
	mesh_accept_plinks_update(sdata);
}

static inline
void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
{
	atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
	mesh_accept_plinks_update(sdata);
}

/**
 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
 *
 * @sta: mesh peer link to restart
 *
 * Locking: this function must be called holding sta->lock
 */
static inline void mesh_plink_fsm_restart(struct sta_info *sta)
{
	sta->plink_state = NL80211_PLINK_LISTEN;
	sta->llid = sta->plid = sta->reason = 0;
	sta->plink_retries = 0;
}

/*
 * Allocate mesh sta entry and insert into station table
 */
static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
					 u8 *hw_addr)
{
	struct sta_info *sta;

	if (sdata->local->num_sta >= MESH_MAX_PLINKS)
		return NULL;

	sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
	if (!sta)
		return NULL;

	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
	sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);

	set_sta_flag(sta, WLAN_STA_WME);

	return sta;
}

/** mesh_set_ht_prot_mode - set correct HT protection mode
 *
 * Section 9.23.3.5 of IEEE 80211s standard describes the protection rules for
 * HT mesh STA in a MBSS. Three HT protection modes are supported for now,
 * non-HT mixed mode, 20MHz-protection and no-protection mode. non-HT mixed
 * mode is selected if any non-HT peers are present in our MBSS.
 * 20MHz-protection mode is selected if all peers in our 20/40MHz MBSS support
 * HT and atleast one HT20 peer is present. Otherwise no-protection mode is
 * selected.
 */
static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	u32 changed = 0;
	u16 ht_opmode;
	bool non_ht_sta = false, ht20_sta = false;

	if (local->_oper_channel_type == NL80211_CHAN_NO_HT)
		return 0;

	rcu_read_lock();
	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sdata == sta->sdata &&
		    sta->plink_state == NL80211_PLINK_ESTAB) {
			switch (sta->ch_type) {
			case NL80211_CHAN_NO_HT:
				mpl_dbg("mesh_plink %pM: nonHT sta (%pM) is present",
					sdata->vif.addr, sta->sta.addr);
				non_ht_sta = true;
				goto out;
			case NL80211_CHAN_HT20:
				mpl_dbg("mesh_plink %pM: HT20 sta (%pM) is present",
					sdata->vif.addr, sta->sta.addr);
				ht20_sta = true;
			default:
				break;
			}
		}
	}
out:
	rcu_read_unlock();

	if (non_ht_sta)
		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
	else if (ht20_sta && local->_oper_channel_type > NL80211_CHAN_HT20)
		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
	else
		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;

	if (sdata->vif.bss_conf.ht_operation_mode != ht_opmode) {
		sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
		sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
		changed = BSS_CHANGED_HT;
		mpl_dbg("mesh_plink %pM: protection mode changed to %d",
			sdata->vif.addr, ht_opmode);
	}

	return changed;
}

/**
 * __mesh_plink_deactivate - deactivate mesh peer link
 *
 * @sta: mesh peer link to deactivate
 *
 * All mesh paths with this peer as next hop will be flushed
 *
 * Locking: the caller must hold sta->lock
 */
static bool __mesh_plink_deactivate(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	bool deactivated = false;

	if (sta->plink_state == NL80211_PLINK_ESTAB) {
		mesh_plink_dec_estab_count(sdata);
		deactivated = true;
	}
	sta->plink_state = NL80211_PLINK_BLOCKED;
	mesh_path_flush_by_nexthop(sta);

	return deactivated;
}

/**
 * mesh_plink_deactivate - deactivate mesh peer link
 *
 * @sta: mesh peer link to deactivate
 *
 * All mesh paths with this peer as next hop will be flushed
 */
void mesh_plink_deactivate(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	bool deactivated;

	spin_lock_bh(&sta->lock);
	deactivated = __mesh_plink_deactivate(sta);
	sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
	mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
			    sta->sta.addr, sta->llid, sta->plid,
			    sta->reason);
	spin_unlock_bh(&sta->lock);

	if (deactivated)
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
}

static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
		enum ieee80211_self_protected_actioncode action,
		u8 *da, __le16 llid, __le16 plid, __le16 reason) {
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	bool include_plid = false;
	u16 peering_proto = 0;
	u8 *pos, ie_len = 4;
	int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
		      sizeof(mgmt->u.action.u.self_prot);

	skb = dev_alloc_skb(local->tx_headroom +
			    hdr_len +
			    2 + /* capability info */
			    2 + /* AID */
			    2 + 8 + /* supported rates */
			    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
			    2 + sdata->u.mesh.mesh_id_len +
			    2 + sizeof(struct ieee80211_meshconf_ie) +
			    2 + sizeof(struct ieee80211_ht_cap) +
			    2 + sizeof(struct ieee80211_ht_operation) +
			    2 + 8 + /* peering IE */
			    sdata->u.mesh.ie_len);
	if (!skb)
		return -1;
	skb_reserve(skb, local->tx_headroom);
	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
	memset(mgmt, 0, hdr_len);
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_ACTION);
	memcpy(mgmt->da, da, ETH_ALEN);
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
	mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
	mgmt->u.action.u.self_prot.action_code = action;

	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
		/* capability info */
		pos = skb_put(skb, 2);
		memset(pos, 0, 2);
		if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
			/* AID */
			pos = skb_put(skb, 2);
			memcpy(pos + 2, &plid, 2);
		}
		if (ieee80211_add_srates_ie(&sdata->vif, skb, true) ||
		    ieee80211_add_ext_srates_ie(&sdata->vif, skb, true) ||
		    mesh_add_rsn_ie(skb, sdata) ||
		    mesh_add_meshid_ie(skb, sdata) ||
		    mesh_add_meshconf_ie(skb, sdata))
			return -1;
	} else {	/* WLAN_SP_MESH_PEERING_CLOSE */
		if (mesh_add_meshid_ie(skb, sdata))
			return -1;
	}

	/* Add Mesh Peering Management element */
	switch (action) {
	case WLAN_SP_MESH_PEERING_OPEN:
		break;
	case WLAN_SP_MESH_PEERING_CONFIRM:
		ie_len += 2;
		include_plid = true;
		break;
	case WLAN_SP_MESH_PEERING_CLOSE:
		if (plid) {
			ie_len += 2;
			include_plid = true;
		}
		ie_len += 2;	/* reason code */
		break;
	default:
		return -EINVAL;
	}

	if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
		return -ENOMEM;

	pos = skb_put(skb, 2 + ie_len);
	*pos++ = WLAN_EID_PEER_MGMT;
	*pos++ = ie_len;
	memcpy(pos, &peering_proto, 2);
	pos += 2;
	memcpy(pos, &llid, 2);
	pos += 2;
	if (include_plid) {
		memcpy(pos, &plid, 2);
		pos += 2;
	}
	if (action == WLAN_SP_MESH_PEERING_CLOSE) {
		memcpy(pos, &reason, 2);
		pos += 2;
	}

	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
		if (mesh_add_ht_cap_ie(skb, sdata) ||
		    mesh_add_ht_oper_ie(skb, sdata))
			return -1;
	}

	if (mesh_add_vendor_ies(skb, sdata))
		return -1;

	ieee80211_tx_skb(sdata, skb);
	return 0;
}

/* mesh_peer_init - initialize new mesh peer and return resulting sta_info
 *
 * @sdata: local meshif
 * @addr: peer's address
 * @elems: IEs from beacon or mesh peering frame
 *
 * call under RCU
 */
static struct sta_info *mesh_peer_init(struct ieee80211_sub_if_data *sdata,
				       u8 *addr,
				       struct ieee802_11_elems *elems)
{
	struct ieee80211_local *local = sdata->local;
	enum ieee80211_band band = local->oper_channel->band;
	struct ieee80211_supported_band *sband;
	u32 rates, basic_rates = 0;
	struct sta_info *sta;
	bool insert = false;

	sband = local->hw.wiphy->bands[band];
	rates = ieee80211_sta_get_rates(local, elems, band, &basic_rates);

	sta = sta_info_get(sdata, addr);
	if (!sta) {
		sta = mesh_plink_alloc(sdata, addr);
		if (!sta)
			return NULL;
		insert = true;
	}

	spin_lock_bh(&sta->lock);
	sta->last_rx = jiffies;
	sta->sta.supp_rates[band] = rates;
	if (elems->ht_cap_elem &&
	    sdata->local->_oper_channel_type != NL80211_CHAN_NO_HT)
		ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
						  elems->ht_cap_elem,
						  &sta->sta.ht_cap);
	else
		memset(&sta->sta.ht_cap, 0, sizeof(sta->sta.ht_cap));

	if (elems->ht_operation) {
		if (!(elems->ht_operation->ht_param &
		      IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
			sta->sta.ht_cap.cap &=
					    ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
		sta->ch_type =
			ieee80211_ht_oper_to_channel_type(elems->ht_operation);
	}

	rate_control_rate_init(sta);
	spin_unlock_bh(&sta->lock);

	if (insert && sta_info_insert(sta))
		return NULL;

	return sta;
}

void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
			   u8 *hw_addr,
			   struct ieee802_11_elems *elems)
{
	struct sta_info *sta;

	/* Userspace handles peer allocation when security is enabled */
	if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
		cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
						   elems->ie_start,
						   elems->total_len,
						   GFP_KERNEL);
		return;
	}

	rcu_read_lock();
	sta = mesh_peer_init(sdata, hw_addr, elems);
	if (!sta)
		goto out;

	if (mesh_peer_accepts_plinks(elems) &&
	    sta->plink_state == NL80211_PLINK_LISTEN &&
	    sdata->u.mesh.accepting_plinks &&
	    sdata->u.mesh.mshcfg.auto_open_plinks &&
	    rssi_threshold_check(sta, sdata))
		mesh_plink_open(sta);

out:
	rcu_read_unlock();
}

static void mesh_plink_timer(unsigned long data)
{
	struct sta_info *sta;
	__le16 llid, plid, reason;
	struct ieee80211_sub_if_data *sdata;

	/*
	 * This STA is valid because sta_info_destroy() will
	 * del_timer_sync() this timer after having made sure
	 * it cannot be readded (by deleting the plink.)
	 */
	sta = (struct sta_info *) data;

	if (sta->sdata->local->quiescing) {
		sta->plink_timer_was_running = true;
		return;
	}

	spin_lock_bh(&sta->lock);
	if (sta->ignore_plink_timer) {
		sta->ignore_plink_timer = false;
		spin_unlock_bh(&sta->lock);
		return;
	}
	mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
		sta->sta.addr, sta->plink_state);
	reason = 0;
	llid = sta->llid;
	plid = sta->plid;
	sdata = sta->sdata;

	switch (sta->plink_state) {
	case NL80211_PLINK_OPN_RCVD:
	case NL80211_PLINK_OPN_SNT:
		/* retry timer */
		if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
			u32 rand;
			mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
				sta->sta.addr, sta->plink_retries,
				sta->plink_timeout);
			get_random_bytes(&rand, sizeof(u32));
			sta->plink_timeout = sta->plink_timeout +
					     rand % sta->plink_timeout;
			++sta->plink_retries;
			mod_plink_timer(sta, sta->plink_timeout);
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
					    sta->sta.addr, llid, 0, 0);
			break;
		}
		reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
		/* fall through on else */
	case NL80211_PLINK_CNF_RCVD:
		/* confirm timer */
		if (!reason)
			reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
		sta->plink_state = NL80211_PLINK_HOLDING;
		mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
		spin_unlock_bh(&sta->lock);
		mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
				    sta->sta.addr, llid, plid, reason);
		break;
	case NL80211_PLINK_HOLDING:
		/* holding timer */
		del_timer(&sta->plink_timer);
		mesh_plink_fsm_restart(sta);
		spin_unlock_bh(&sta->lock);
		break;
	default:
		spin_unlock_bh(&sta->lock);
		break;
	}
}

#ifdef CONFIG_PM
void mesh_plink_quiesce(struct sta_info *sta)
{
	if (del_timer_sync(&sta->plink_timer))
		sta->plink_timer_was_running = true;
}

void mesh_plink_restart(struct sta_info *sta)
{
	if (sta->plink_timer_was_running) {
		add_timer(&sta->plink_timer);
		sta->plink_timer_was_running = false;
	}
}
#endif

static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
{
	sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
	sta->plink_timer.data = (unsigned long) sta;
	sta->plink_timer.function = mesh_plink_timer;
	sta->plink_timeout = timeout;
	add_timer(&sta->plink_timer);
}

int mesh_plink_open(struct sta_info *sta)
{
	__le16 llid;
	struct ieee80211_sub_if_data *sdata = sta->sdata;

	if (!test_sta_flag(sta, WLAN_STA_AUTH))
		return -EPERM;

	spin_lock_bh(&sta->lock);
	get_random_bytes(&llid, 2);
	sta->llid = llid;
	if (sta->plink_state != NL80211_PLINK_LISTEN) {
		spin_unlock_bh(&sta->lock);
		return -EBUSY;
	}
	sta->plink_state = NL80211_PLINK_OPN_SNT;
	mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
	spin_unlock_bh(&sta->lock);
	mpl_dbg("Mesh plink: starting establishment with %pM\n",
		sta->sta.addr);

	return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
				   sta->sta.addr, llid, 0, 0);
}

void mesh_plink_block(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	bool deactivated;

	spin_lock_bh(&sta->lock);
	deactivated = __mesh_plink_deactivate(sta);
	sta->plink_state = NL80211_PLINK_BLOCKED;
	spin_unlock_bh(&sta->lock);

	if (deactivated)
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
}


void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
			 size_t len, struct ieee80211_rx_status *rx_status)
{
	struct ieee802_11_elems elems;
	struct sta_info *sta;
	enum plink_event event;
	enum ieee80211_self_protected_actioncode ftype;
	size_t baselen;
	bool matches_local = true;
	u8 ie_len;
	u8 *baseaddr;
	u32 changed = 0;
	__le16 plid, llid, reason;
#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
	static const char *mplstates[] = {
		[NL80211_PLINK_LISTEN] = "LISTEN",
		[NL80211_PLINK_OPN_SNT] = "OPN-SNT",
		[NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
		[NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
		[NL80211_PLINK_ESTAB] = "ESTAB",
		[NL80211_PLINK_HOLDING] = "HOLDING",
		[NL80211_PLINK_BLOCKED] = "BLOCKED"
	};
#endif

	/* need action_code, aux */
	if (len < IEEE80211_MIN_ACTION_SIZE + 3)
		return;

	if (is_multicast_ether_addr(mgmt->da)) {
		mpl_dbg("Mesh plink: ignore frame from multicast address");
		return;
	}

	baseaddr = mgmt->u.action.u.self_prot.variable;
	baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
	if (mgmt->u.action.u.self_prot.action_code ==
						WLAN_SP_MESH_PEERING_CONFIRM) {
		baseaddr += 4;
		baselen += 4;
	}
	ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
	if (!elems.peering) {
		mpl_dbg("Mesh plink: missing necessary peer link ie\n");
		return;
	}
	if (elems.rsn_len &&
			sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
		mpl_dbg("Mesh plink: can't establish link with secure peer\n");
		return;
	}

	ftype = mgmt->u.action.u.self_prot.action_code;
	ie_len = elems.peering_len;
	if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
	    (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
							&& ie_len != 8)) {
		mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
		    ftype, ie_len);
		return;
	}

	if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
				(!elems.mesh_id || !elems.mesh_config)) {
		mpl_dbg("Mesh plink: missing necessary ie\n");
		return;
	}
	/* Note the lines below are correct, the llid in the frame is the plid
	 * from the point of view of this host.
	 */
	memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
	if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
		memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);

	rcu_read_lock();

	sta = sta_info_get(sdata, mgmt->sa);
	if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
		mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
		rcu_read_unlock();
		return;
	}

	if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
	    !rssi_threshold_check(sta, sdata)) {
		mpl_dbg("Mesh plink: %pM does not meet rssi threshold\n",
			mgmt->sa);
		rcu_read_unlock();
		return;
	}

	if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
		mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
		rcu_read_unlock();
		return;
	}

	if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
		rcu_read_unlock();
		return;
	}

	/* Now we will figure out the appropriate event... */
	event = PLINK_UNDEFINED;
	if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
	    !mesh_matches_local(sdata, &elems)) {
		matches_local = false;
		switch (ftype) {
		case WLAN_SP_MESH_PEERING_OPEN:
			event = OPN_RJCT;
			break;
		case WLAN_SP_MESH_PEERING_CONFIRM:
			event = CNF_RJCT;
			break;
		default:
			break;
		}
	}

	if (!sta && !matches_local) {
		rcu_read_unlock();
		reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
		llid = 0;
		mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
				    mgmt->sa, llid, plid, reason);
		return;
	} else if (!sta) {
		/* ftype == WLAN_SP_MESH_PEERING_OPEN */
		if (!mesh_plink_free_count(sdata)) {
			mpl_dbg("Mesh plink error: no more free plinks\n");
			rcu_read_unlock();
			return;
		}
		event = OPN_ACPT;
	} else if (matches_local) {
		switch (ftype) {
		case WLAN_SP_MESH_PEERING_OPEN:
			if (!mesh_plink_free_count(sdata) ||
			    (sta->plid && sta->plid != plid))
				event = OPN_IGNR;
			else
				event = OPN_ACPT;
			break;
		case WLAN_SP_MESH_PEERING_CONFIRM:
			if (!mesh_plink_free_count(sdata) ||
			    (sta->llid != llid || sta->plid != plid))
				event = CNF_IGNR;
			else
				event = CNF_ACPT;
			break;
		case WLAN_SP_MESH_PEERING_CLOSE:
			if (sta->plink_state == NL80211_PLINK_ESTAB)
				/* Do not check for llid or plid. This does not
				 * follow the standard but since multiple plinks
				 * per sta are not supported, it is necessary in
				 * order to avoid a livelock when MP A sees an
				 * establish peer link to MP B but MP B does not
				 * see it. This can be caused by a timeout in
				 * B's peer link establishment or B beign
				 * restarted.
				 */
				event = CLS_ACPT;
			else if (sta->plid != plid)
				event = CLS_IGNR;
			else if (ie_len == 7 && sta->llid != llid)
				event = CLS_IGNR;
			else
				event = CLS_ACPT;
			break;
		default:
			mpl_dbg("Mesh plink: unknown frame subtype\n");
			rcu_read_unlock();
			return;
		}
	}

	if (event == OPN_ACPT) {
		/* allocate sta entry if necessary and update info */
		sta = mesh_peer_init(sdata, mgmt->sa, &elems);
		if (!sta) {
			mpl_dbg("Mesh plink: failed to init peer!\n");
			rcu_read_unlock();
			return;
		}
	}

	mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
		mgmt->sa, mplstates[sta->plink_state],
		le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
		event);
	reason = 0;
	spin_lock_bh(&sta->lock);
	switch (sta->plink_state) {
		/* spin_unlock as soon as state is updated at each case */
	case NL80211_PLINK_LISTEN:
		switch (event) {
		case CLS_ACPT:
			mesh_plink_fsm_restart(sta);
			spin_unlock_bh(&sta->lock);
			break;
		case OPN_ACPT:
			sta->plink_state = NL80211_PLINK_OPN_RCVD;
			sta->plid = plid;
			get_random_bytes(&llid, 2);
			sta->llid = llid;
			mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_OPEN,
					    sta->sta.addr, llid, 0, 0);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CONFIRM,
					    sta->sta.addr, llid, plid, 0);
			break;
		default:
			spin_unlock_bh(&sta->lock);
			break;
		}
		break;

	case NL80211_PLINK_OPN_SNT:
		switch (event) {
		case OPN_RJCT:
		case CNF_RJCT:
			reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
		case CLS_ACPT:
			if (!reason)
				reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
			sta->reason = reason;
			sta->plink_state = NL80211_PLINK_HOLDING;
			if (!mod_plink_timer(sta,
					     dot11MeshHoldingTimeout(sdata)))
				sta->ignore_plink_timer = true;

			llid = sta->llid;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CLOSE,
					    sta->sta.addr, llid, plid, reason);
			break;
		case OPN_ACPT:
			/* retry timer is left untouched */
			sta->plink_state = NL80211_PLINK_OPN_RCVD;
			sta->plid = plid;
			llid = sta->llid;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CONFIRM,
					    sta->sta.addr, llid, plid, 0);
			break;
		case CNF_ACPT:
			sta->plink_state = NL80211_PLINK_CNF_RCVD;
			if (!mod_plink_timer(sta,
					     dot11MeshConfirmTimeout(sdata)))
				sta->ignore_plink_timer = true;

			spin_unlock_bh(&sta->lock);
			break;
		default:
			spin_unlock_bh(&sta->lock);
			break;
		}
		break;

	case NL80211_PLINK_OPN_RCVD:
		switch (event) {
		case OPN_RJCT:
		case CNF_RJCT:
			reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
		case CLS_ACPT:
			if (!reason)
				reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
			sta->reason = reason;
			sta->plink_state = NL80211_PLINK_HOLDING;
			if (!mod_plink_timer(sta,
					     dot11MeshHoldingTimeout(sdata)))
				sta->ignore_plink_timer = true;

			llid = sta->llid;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
					    sta->sta.addr, llid, plid, reason);
			break;
		case OPN_ACPT:
			llid = sta->llid;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CONFIRM,
					    sta->sta.addr, llid, plid, 0);
			break;
		case CNF_ACPT:
			del_timer(&sta->plink_timer);
			sta->plink_state = NL80211_PLINK_ESTAB;
			spin_unlock_bh(&sta->lock);
			mesh_plink_inc_estab_count(sdata);
			changed |= mesh_set_ht_prot_mode(sdata);
			changed |= BSS_CHANGED_BEACON;
			mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
				sta->sta.addr);
			break;
		default:
			spin_unlock_bh(&sta->lock);
			break;
		}
		break;

	case NL80211_PLINK_CNF_RCVD:
		switch (event) {
		case OPN_RJCT:
		case CNF_RJCT:
			reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
		case CLS_ACPT:
			if (!reason)
				reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
			sta->reason = reason;
			sta->plink_state = NL80211_PLINK_HOLDING;
			if (!mod_plink_timer(sta,
					     dot11MeshHoldingTimeout(sdata)))
				sta->ignore_plink_timer = true;

			llid = sta->llid;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CLOSE,
					    sta->sta.addr, llid, plid, reason);
			break;
		case OPN_ACPT:
			del_timer(&sta->plink_timer);
			sta->plink_state = NL80211_PLINK_ESTAB;
			spin_unlock_bh(&sta->lock);
			mesh_plink_inc_estab_count(sdata);
			changed |= mesh_set_ht_prot_mode(sdata);
			changed |= BSS_CHANGED_BEACON;
			mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
				sta->sta.addr);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CONFIRM,
					    sta->sta.addr, llid, plid, 0);
			break;
		default:
			spin_unlock_bh(&sta->lock);
			break;
		}
		break;

	case NL80211_PLINK_ESTAB:
		switch (event) {
		case CLS_ACPT:
			reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
			sta->reason = reason;
			__mesh_plink_deactivate(sta);
			sta->plink_state = NL80211_PLINK_HOLDING;
			llid = sta->llid;
			mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
			spin_unlock_bh(&sta->lock);
			changed |= mesh_set_ht_prot_mode(sdata);
			changed |= BSS_CHANGED_BEACON;
			mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
					    sta->sta.addr, llid, plid, reason);
			break;
		case OPN_ACPT:
			llid = sta->llid;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata,
					    WLAN_SP_MESH_PEERING_CONFIRM,
					    sta->sta.addr, llid, plid, 0);
			break;
		default:
			spin_unlock_bh(&sta->lock);
			break;
		}
		break;
	case NL80211_PLINK_HOLDING:
		switch (event) {
		case CLS_ACPT:
			if (del_timer(&sta->plink_timer))
				sta->ignore_plink_timer = 1;
			mesh_plink_fsm_restart(sta);
			spin_unlock_bh(&sta->lock);
			break;
		case OPN_ACPT:
		case CNF_ACPT:
		case OPN_RJCT:
		case CNF_RJCT:
			llid = sta->llid;
			reason = sta->reason;
			spin_unlock_bh(&sta->lock);
			mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
					    sta->sta.addr, llid, plid, reason);
			break;
		default:
			spin_unlock_bh(&sta->lock);
		}
		break;
	default:
		/* should not get here, PLINK_BLOCKED is dealt with at the
		 * beginning of the function
		 */
		spin_unlock_bh(&sta->lock);
		break;
	}

	rcu_read_unlock();

	if (changed)
		ieee80211_bss_info_change_notify(sdata, changed);
}