aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/mesh.c
blob: 707ac61d63e51a8a1528c8c65204c92c94400768 (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
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
/*
 * Copyright (c) 2008, 2009 open80211s Ltd.
 * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
 * 	       Javier Cardona <javier@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/slab.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "mesh.h"

static int mesh_allocated;
static struct kmem_cache *rm_cache;

bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
{
	return (mgmt->u.action.u.mesh_action.action_code ==
			WLAN_MESH_ACTION_HWMP_PATH_SELECTION);
}

void ieee80211s_init(void)
{
	mesh_pathtbl_init();
	mesh_allocated = 1;
	rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
				     0, 0, NULL);
}

void ieee80211s_stop(void)
{
	if (!mesh_allocated)
		return;
	mesh_pathtbl_unregister();
	kmem_cache_destroy(rm_cache);
}

static void ieee80211_mesh_housekeeping_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata = (void *) data;
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);

	ieee80211_queue_work(&local->hw, &sdata->work);
}

/**
 * mesh_matches_local - check if the config of a mesh point matches ours
 *
 * @sdata: local mesh subif
 * @ie: information elements of a management frame from the mesh peer
 *
 * This function checks if the mesh configuration of a mesh point matches the
 * local mesh configuration, i.e. if both nodes belong to the same mesh network.
 */
bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
			struct ieee802_11_elems *ie)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u32 basic_rates = 0;
	struct cfg80211_chan_def sta_chan_def;

	/*
	 * As support for each feature is added, check for matching
	 * - On mesh config capabilities
	 *   - Power Save Support En
	 *   - Sync support enabled
	 *   - Sync support active
	 *   - Sync support required from peer
	 *   - MDA enabled
	 * - Power management control on fc
	 */
	if (!(ifmsh->mesh_id_len == ie->mesh_id_len &&
	     memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
	     (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
	     (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
	     (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
	     (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
		return false;

	ieee80211_sta_get_rates(sdata, ie, ieee80211_get_sdata_band(sdata),
				&basic_rates);

	if (sdata->vif.bss_conf.basic_rates != basic_rates)
		return false;

	ieee80211_ht_oper_to_chandef(sdata->vif.bss_conf.chandef.chan,
				     ie->ht_operation, &sta_chan_def);

	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
					 &sta_chan_def))
		return false;

	return true;
}

/**
 * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
 *
 * @ie: information elements of a management frame from the mesh peer
 */
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
{
	return (ie->mesh_config->meshconf_cap &
			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
}

/**
 * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
 *
 * @sdata: mesh interface in which mesh beacons are going to be updated
 *
 * Returns: beacon changed flag if the beacon content changed.
 */
u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
{
	bool free_plinks;
	u32 changed = 0;

	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
	 * the mesh interface might be able to establish plinks with peers that
	 * are already on the table but are not on PLINK_ESTAB state. However,
	 * in general the mesh interface is not accepting peer link requests
	 * from new peers, and that must be reflected in the beacon
	 */
	free_plinks = mesh_plink_availables(sdata);

	if (free_plinks != sdata->u.mesh.accepting_plinks) {
		sdata->u.mesh.accepting_plinks = free_plinks;
		changed = BSS_CHANGED_BEACON;
	}

	return changed;
}

/*
 * mesh_sta_cleanup - clean up any mesh sta state
 *
 * @sta: mesh sta to clean up.
 */
void mesh_sta_cleanup(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	u32 changed;

	/*
	 * maybe userspace handles peer allocation and peering, but in either
	 * case the beacon is still generated by the kernel and we might need
	 * an update.
	 */
	changed = mesh_accept_plinks_update(sdata);
	if (!sdata->u.mesh.user_mpm) {
		changed |= mesh_plink_deactivate(sta);
		del_timer_sync(&sta->plink_timer);
	}

	if (changed)
		ieee80211_mbss_info_change_notify(sdata, changed);
}

int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
{
	int i;

	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
	if (!sdata->u.mesh.rmc)
		return -ENOMEM;
	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
	for (i = 0; i < RMC_BUCKETS; i++)
		INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
	return 0;
}

void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
{
	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
	struct rmc_entry *p, *n;
	int i;

	if (!sdata->u.mesh.rmc)
		return;

	for (i = 0; i < RMC_BUCKETS; i++) {
		list_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
			list_del(&p->list);
			kmem_cache_free(rm_cache, p);
		}
	}

	kfree(rmc);
	sdata->u.mesh.rmc = NULL;
}

/**
 * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
 *
 * @sdata:	interface
 * @sa:		source address
 * @mesh_hdr:	mesh_header
 *
 * Returns: 0 if the frame is not in the cache, nonzero otherwise.
 *
 * Checks using the source address and the mesh sequence number if we have
 * received this frame lately. If the frame is not in the cache, it is added to
 * it.
 */
int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
{
	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
	u32 seqnum = 0;
	int entries = 0;
	u8 idx;
	struct rmc_entry *p, *n;

	/* Don't care about endianness since only match matters */
	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
	list_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
		++entries;
		if (time_after(jiffies, p->exp_time) ||
		    entries == RMC_QUEUE_MAX_LEN) {
			list_del(&p->list);
			kmem_cache_free(rm_cache, p);
			--entries;
		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
			return -1;
	}

	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
	if (!p)
		return 0;

	p->seqnum = seqnum;
	p->exp_time = jiffies + RMC_TIMEOUT;
	memcpy(p->sa, sa, ETH_ALEN);
	list_add(&p->list, &rmc->bucket[idx]);
	return 0;
}

int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
			 struct sk_buff *skb)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u8 *pos, neighbors;
	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);

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

	pos = skb_put(skb, 2 + meshconf_len);
	*pos++ = WLAN_EID_MESH_CONFIG;
	*pos++ = meshconf_len;

	/* Active path selection protocol ID */
	*pos++ = ifmsh->mesh_pp_id;
	/* Active path selection metric ID   */
	*pos++ = ifmsh->mesh_pm_id;
	/* Congestion control mode identifier */
	*pos++ = ifmsh->mesh_cc_id;
	/* Synchronization protocol identifier */
	*pos++ = ifmsh->mesh_sp_id;
	/* Authentication Protocol identifier */
	*pos++ = ifmsh->mesh_auth_id;
	/* Mesh Formation Info - number of neighbors */
	neighbors = atomic_read(&ifmsh->estab_plinks);
	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
	*pos++ = neighbors << 1;
	/* Mesh capability */
	*pos = 0x00;
	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
	*pos |= ifmsh->accepting_plinks ?
			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
	*pos |= ifmsh->ps_peers_deep_sleep ?
			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
	*pos++ |= ifmsh->adjusting_tbtt ?
			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING : 0x00;
	*pos++ = 0x00;

	return 0;
}

int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u8 *pos;

	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
		return -ENOMEM;

	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
	*pos++ = WLAN_EID_MESH_ID;
	*pos++ = ifmsh->mesh_id_len;
	if (ifmsh->mesh_id_len)
		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);

	return 0;
}

static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
				    struct sk_buff *skb)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u8 *pos;

	/* see IEEE802.11-2012 13.14.6 */
	if (ifmsh->ps_peers_light_sleep == 0 &&
	    ifmsh->ps_peers_deep_sleep == 0 &&
	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
		return 0;

	if (skb_tailroom(skb) < 4)
		return -ENOMEM;

	pos = skb_put(skb, 2 + 2);
	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
	*pos++ = 2;
	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);

	return 0;
}

int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
			struct sk_buff *skb)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u8 offset, len;
	const u8 *data;

	if (!ifmsh->ie || !ifmsh->ie_len)
		return 0;

	/* fast-forward to vendor IEs */
	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);

	if (offset) {
		len = ifmsh->ie_len - offset;
		data = ifmsh->ie + offset;
		if (skb_tailroom(skb) < len)
			return -ENOMEM;
		memcpy(skb_put(skb, len), data, len);
	}

	return 0;
}

int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u8 len = 0;
	const u8 *data;

	if (!ifmsh->ie || !ifmsh->ie_len)
		return 0;

	/* find RSN IE */
	data = ifmsh->ie;
	while (data < ifmsh->ie + ifmsh->ie_len) {
		if (*data == WLAN_EID_RSN) {
			len = data[1] + 2;
			break;
		}
		data++;
	}

	if (len) {
		if (skb_tailroom(skb) < len)
			return -ENOMEM;
		memcpy(skb_put(skb, len), data, len);
	}

	return 0;
}

static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
				 struct sk_buff *skb)
{
	struct ieee80211_chanctx_conf *chanctx_conf;
	struct ieee80211_channel *chan;
	u8 *pos;

	if (skb_tailroom(skb) < 3)
		return -ENOMEM;

	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON(!chanctx_conf)) {
		rcu_read_unlock();
		return -EINVAL;
	}
	chan = chanctx_conf->def.chan;
	rcu_read_unlock();

	pos = skb_put(skb, 2 + 1);
	*pos++ = WLAN_EID_DS_PARAMS;
	*pos++ = 1;
	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);

	return 0;
}

int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
		       struct sk_buff *skb)
{
	struct ieee80211_local *local = sdata->local;
	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
	struct ieee80211_supported_band *sband;
	u8 *pos;

	sband = local->hw.wiphy->bands[band];
	if (!sband->ht_cap.ht_supported ||
	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
		return 0;

	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
		return -ENOMEM;

	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);

	return 0;
}

int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
			struct sk_buff *skb)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx_conf *chanctx_conf;
	struct ieee80211_channel *channel;
	enum nl80211_channel_type channel_type =
		cfg80211_get_chandef_type(&sdata->vif.bss_conf.chandef);
	struct ieee80211_supported_band *sband;
	struct ieee80211_sta_ht_cap *ht_cap;
	u8 *pos;

	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON(!chanctx_conf)) {
		rcu_read_unlock();
		return -EINVAL;
	}
	channel = chanctx_conf->def.chan;
	rcu_read_unlock();

	sband = local->hw.wiphy->bands[channel->band];
	ht_cap = &sband->ht_cap;

	if (!ht_cap->ht_supported || channel_type == NL80211_CHAN_NO_HT)
		return 0;

	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
		return -ENOMEM;

	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
				   sdata->vif.bss_conf.ht_operation_mode);

	return 0;
}

static void ieee80211_mesh_path_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata =
		(struct ieee80211_sub_if_data *) data;

	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
}

static void ieee80211_mesh_path_root_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata =
		(struct ieee80211_sub_if_data *) data;
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);

	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
}

void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
{
	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
	else {
		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
		/* stop running timer */
		del_timer_sync(&ifmsh->mesh_path_root_timer);
	}
}

/**
 * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
 * @hdr:	802.11 frame header
 * @fc:		frame control field
 * @meshda:	destination address in the mesh
 * @meshsa:	source address address in the mesh.  Same as TA, as frame is
 *              locally originated.
 *
 * Return the length of the 802.11 (does not include a mesh control header)
 */
int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
				  const u8 *meshda, const u8 *meshsa)
{
	if (is_multicast_ether_addr(meshda)) {
		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
		/* DA TA SA */
		memcpy(hdr->addr1, meshda, ETH_ALEN);
		memcpy(hdr->addr2, meshsa, ETH_ALEN);
		memcpy(hdr->addr3, meshsa, ETH_ALEN);
		return 24;
	} else {
		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
		/* RA TA DA SA */
		memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
		memcpy(hdr->addr2, meshsa, ETH_ALEN);
		memcpy(hdr->addr3, meshda, ETH_ALEN);
		memcpy(hdr->addr4, meshsa, ETH_ALEN);
		return 30;
	}
}

/**
 * ieee80211_new_mesh_header - create a new mesh header
 * @sdata:	mesh interface to be used
 * @meshhdr:    uninitialized mesh header
 * @addr4or5:   1st address in the ae header, which may correspond to address 4
 *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
 *              be NULL.
 * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
 *              mesh frame
 *
 * Return the header length.
 */
int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
			      struct ieee80211s_hdr *meshhdr,
			      const char *addr4or5, const char *addr6)
{
	if (WARN_ON(!addr4or5 && addr6))
		return 0;

	memset(meshhdr, 0, sizeof(*meshhdr));

	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;

	/* FIXME: racy -- TX on multiple queues can be concurrent */
	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
	sdata->u.mesh.mesh_seqnum++;

	if (addr4or5 && !addr6) {
		meshhdr->flags |= MESH_FLAGS_AE_A4;
		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
		return 2 * ETH_ALEN;
	} else if (addr4or5 && addr6) {
		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
		return 3 * ETH_ALEN;
	}

	return ETH_ALEN;
}

static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u32 changed;

	ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
	mesh_path_expire(sdata);

	changed = mesh_accept_plinks_update(sdata);
	ieee80211_mbss_info_change_notify(sdata, changed);

	mod_timer(&ifmsh->housekeeping_timer,
		  round_jiffies(jiffies +
				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
}

static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u32 interval;

	mesh_path_tx_root_frame(sdata);

	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
	else
		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;

	mod_timer(&ifmsh->mesh_path_root_timer,
		  round_jiffies(TU_TO_EXP_TIME(interval)));
}

static int
ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
{
	struct beacon_data *bcn;
	int head_len, tail_len;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	struct ieee80211_chanctx_conf *chanctx_conf;
	enum ieee80211_band band;
	u8 *pos;
	struct ieee80211_sub_if_data *sdata;
	int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
		      sizeof(mgmt->u.beacon);

	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	band = chanctx_conf->def.chan->band;
	rcu_read_unlock();

	head_len = hdr_len +
		   2 + /* NULL SSID */
		   2 + 8 + /* supported rates */
		   2 + 3; /* DS params */
	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
		   2 + sizeof(struct ieee80211_ht_cap) +
		   2 + sizeof(struct ieee80211_ht_operation) +
		   2 + ifmsh->mesh_id_len +
		   2 + sizeof(struct ieee80211_meshconf_ie) +
		   2 + sizeof(__le16) + /* awake window */
		   ifmsh->ie_len;

	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
	/* need an skb for IE builders to operate on */
	skb = dev_alloc_skb(max(head_len, tail_len));

	if (!bcn || !skb)
		goto out_free;

	/*
	 * pointers go into the block we allocated,
	 * memory is | beacon_data | head | tail |
	 */
	bcn->head = ((u8 *) bcn) + sizeof(*bcn);

	/* fill in the head */
	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_BEACON);
	eth_broadcast_addr(mgmt->da);
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
	mgmt->u.beacon.beacon_int =
		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
	mgmt->u.beacon.capab_info |= cpu_to_le16(
		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);

	pos = skb_put(skb, 2);
	*pos++ = WLAN_EID_SSID;
	*pos++ = 0x0;

	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
	    mesh_add_ds_params_ie(sdata, skb))
		goto out_free;

	bcn->head_len = skb->len;
	memcpy(bcn->head, skb->data, bcn->head_len);

	/* now the tail */
	skb_trim(skb, 0);
	bcn->tail = bcn->head + bcn->head_len;

	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
	    mesh_add_rsn_ie(sdata, skb) ||
	    mesh_add_ht_cap_ie(sdata, skb) ||
	    mesh_add_ht_oper_ie(sdata, skb) ||
	    mesh_add_meshid_ie(sdata, skb) ||
	    mesh_add_meshconf_ie(sdata, skb) ||
	    mesh_add_awake_window_ie(sdata, skb) ||
	    mesh_add_vendor_ies(sdata, skb))
		goto out_free;

	bcn->tail_len = skb->len;
	memcpy(bcn->tail, skb->data, bcn->tail_len);

	dev_kfree_skb(skb);
	rcu_assign_pointer(ifmsh->beacon, bcn);
	return 0;
out_free:
	kfree(bcn);
	dev_kfree_skb(skb);
	return -ENOMEM;
}

static int
ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
{
	struct beacon_data *old_bcn;
	int ret;

	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
					    lockdep_is_held(&sdata->wdev.mtx));
	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
	if (ret)
		/* just reuse old beacon */
		return ret;

	if (old_bcn)
		kfree_rcu(old_bcn, rcu_head);
	return 0;
}

void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
				       u32 changed)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	unsigned long bits = changed;
	u32 bit;

	if (!bits)
		return;

	/* if we race with running work, worst case this work becomes a noop */
	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
		set_bit(bit, &ifmsh->mbss_changed);
	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
}

int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	struct ieee80211_local *local = sdata->local;
	u32 changed = BSS_CHANGED_BEACON |
		      BSS_CHANGED_BEACON_ENABLED |
		      BSS_CHANGED_HT |
		      BSS_CHANGED_BASIC_RATES |
		      BSS_CHANGED_BEACON_INT;

	local->fif_other_bss++;
	/* mesh ifaces must set allmulti to forward mcast traffic */
	atomic_inc(&local->iff_allmultis);
	ieee80211_configure_filter(local);

	ifmsh->mesh_cc_id = 0;	/* Disabled */
	/* register sync ops from extensible synchronization framework */
	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
	ifmsh->adjusting_tbtt = false;
	ifmsh->sync_offset_clockdrift_max = 0;
	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
	ieee80211_mesh_root_setup(ifmsh);
	ieee80211_queue_work(&local->hw, &sdata->work);
	sdata->vif.bss_conf.ht_operation_mode =
				ifmsh->mshcfg.ht_opmode;
	sdata->vif.bss_conf.enable_beacon = true;

	changed |= ieee80211_mps_local_status_update(sdata);

	if (ieee80211_mesh_build_beacon(ifmsh)) {
		ieee80211_stop_mesh(sdata);
		return -ENOMEM;
	}

	ieee80211_bss_info_change_notify(sdata, changed);

	netif_carrier_on(sdata->dev);
	return 0;
}

void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	struct beacon_data *bcn;

	netif_carrier_off(sdata->dev);

	/* stop the beacon */
	ifmsh->mesh_id_len = 0;
	sdata->vif.bss_conf.enable_beacon = false;
	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
	bcn = rcu_dereference_protected(ifmsh->beacon,
					lockdep_is_held(&sdata->wdev.mtx));
	rcu_assign_pointer(ifmsh->beacon, NULL);
	kfree_rcu(bcn, rcu_head);

	/* flush STAs and mpaths on this iface */
	sta_info_flush(sdata);
	mesh_path_flush_by_iface(sdata);

	/* free all potentially still buffered group-addressed frames */
	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
	skb_queue_purge(&ifmsh->ps.bc_buf);

	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
	del_timer_sync(&sdata->u.mesh.mesh_path_timer);

	/* clear any mesh work (for next join) we may have accrued */
	ifmsh->wrkq_flags = 0;
	ifmsh->mbss_changed = 0;

	local->fif_other_bss--;
	atomic_dec(&local->iff_allmultis);
	ieee80211_configure_filter(local);
}

static void
ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
			    struct ieee80211_mgmt *mgmt, size_t len)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	struct sk_buff *presp;
	struct beacon_data *bcn;
	struct ieee80211_mgmt *hdr;
	struct ieee802_11_elems elems;
	size_t baselen;
	u8 *pos;

	pos = mgmt->u.probe_req.variable;
	baselen = (u8 *) pos - (u8 *) mgmt;
	if (baselen > len)
		return;

	ieee802_11_parse_elems(pos, len - baselen, false, &elems);

	if (!elems.mesh_id)
		return;

	/* 802.11-2012 10.1.4.3.2 */
	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
	     !is_broadcast_ether_addr(mgmt->da)) ||
	    elems.ssid_len != 0)
		return;

	if (elems.mesh_id_len != 0 &&
	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
		return;

	rcu_read_lock();
	bcn = rcu_dereference(ifmsh->beacon);

	if (!bcn)
		goto out;

	presp = dev_alloc_skb(local->tx_headroom +
			      bcn->head_len + bcn->tail_len);
	if (!presp)
		goto out;

	skb_reserve(presp, local->tx_headroom);
	memcpy(skb_put(presp, bcn->head_len), bcn->head, bcn->head_len);
	memcpy(skb_put(presp, bcn->tail_len), bcn->tail, bcn->tail_len);
	hdr = (struct ieee80211_mgmt *) presp->data;
	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					 IEEE80211_STYPE_PROBE_RESP);
	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	ieee80211_tx_skb(sdata, presp);
out:
	rcu_read_unlock();
}

static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
					u16 stype,
					struct ieee80211_mgmt *mgmt,
					size_t len,
					struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	struct ieee802_11_elems elems;
	struct ieee80211_channel *channel;
	size_t baselen;
	int freq;
	enum ieee80211_band band = rx_status->band;

	/* ignore ProbeResp to foreign address */
	if (stype == IEEE80211_STYPE_PROBE_RESP &&
	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
		return;

	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
	if (baselen > len)
		return;

	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
			       false, &elems);

	/* ignore non-mesh or secure / unsecure mismatch */
	if ((!elems.mesh_id || !elems.mesh_config) ||
	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
		return;

	if (elems.ds_params)
		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
	else
		freq = rx_status->freq;

	channel = ieee80211_get_channel(local->hw.wiphy, freq);

	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
		return;

	if (mesh_matches_local(sdata, &elems))
		mesh_neighbour_update(sdata, mgmt->sa, &elems);

	if (ifmsh->sync_ops)
		ifmsh->sync_ops->rx_bcn_presp(sdata,
			stype, mgmt, &elems, rx_status);
}

static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
					  struct ieee80211_mgmt *mgmt,
					  size_t len,
					  struct ieee80211_rx_status *rx_status)
{
	switch (mgmt->u.action.category) {
	case WLAN_CATEGORY_SELF_PROTECTED:
		switch (mgmt->u.action.u.self_prot.action_code) {
		case WLAN_SP_MESH_PEERING_OPEN:
		case WLAN_SP_MESH_PEERING_CLOSE:
		case WLAN_SP_MESH_PEERING_CONFIRM:
			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
			break;
		}
		break;
	case WLAN_CATEGORY_MESH_ACTION:
		if (mesh_action_is_path_sel(mgmt))
			mesh_rx_path_sel_frame(sdata, mgmt, len);
		break;
	}
}

void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
				   struct sk_buff *skb)
{
	struct ieee80211_rx_status *rx_status;
	struct ieee80211_mgmt *mgmt;
	u16 stype;

	sdata_lock(sdata);

	/* mesh already went down */
	if (!sdata->wdev.mesh_id_len)
		goto out;

	rx_status = IEEE80211_SKB_RXCB(skb);
	mgmt = (struct ieee80211_mgmt *) skb->data;
	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;

	switch (stype) {
	case IEEE80211_STYPE_PROBE_RESP:
	case IEEE80211_STYPE_BEACON:
		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
					    rx_status);
		break;
	case IEEE80211_STYPE_PROBE_REQ:
		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
		break;
	case IEEE80211_STYPE_ACTION:
		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
		break;
	}
out:
	sdata_unlock(sdata);
}

static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	u32 bit, changed = 0;

	for_each_set_bit(bit, &ifmsh->mbss_changed,
			 sizeof(changed) * BITS_PER_BYTE) {
		clear_bit(bit, &ifmsh->mbss_changed);
		changed |= BIT(bit);
	}

	if (sdata->vif.bss_conf.enable_beacon &&
	    (changed & (BSS_CHANGED_BEACON |
			BSS_CHANGED_HT |
			BSS_CHANGED_BASIC_RATES |
			BSS_CHANGED_BEACON_INT)))
		if (ieee80211_mesh_rebuild_beacon(sdata))
			return;

	ieee80211_bss_info_change_notify(sdata, changed);
}

void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	sdata_lock(sdata);

	/* mesh already went down */
	if (!sdata->wdev.mesh_id_len)
		goto out;

	if (ifmsh->preq_queue_len &&
	    time_after(jiffies,
		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
		mesh_path_start_discovery(sdata);

	if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
		mesh_mpath_table_grow();

	if (test_and_clear_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags))
		mesh_mpp_table_grow();

	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
		ieee80211_mesh_housekeeping(sdata);

	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
		ieee80211_mesh_rootpath(sdata);

	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
		mesh_sync_adjust_tbtt(sdata);

	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
		mesh_bss_info_changed(sdata);
out:
	sdata_unlock(sdata);
}

void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list)
		if (ieee80211_vif_is_mesh(&sdata->vif) &&
		    ieee80211_sdata_running(sdata))
			ieee80211_queue_work(&local->hw, &sdata->work);
	rcu_read_unlock();
}

void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
	static u8 zero_addr[ETH_ALEN] = {};

	setup_timer(&ifmsh->housekeeping_timer,
		    ieee80211_mesh_housekeeping_timer,
		    (unsigned long) sdata);

	ifmsh->accepting_plinks = true;
	ifmsh->preq_id = 0;
	ifmsh->sn = 0;
	ifmsh->num_gates = 0;
	atomic_set(&ifmsh->mpaths, 0);
	mesh_rmc_init(sdata);
	ifmsh->last_preq = jiffies;
	ifmsh->next_perr = jiffies;
	/* Allocate all mesh structures when creating the first mesh interface. */
	if (!mesh_allocated)
		ieee80211s_init();
	setup_timer(&ifmsh->mesh_path_timer,
		    ieee80211_mesh_path_timer,
		    (unsigned long) sdata);
	setup_timer(&ifmsh->mesh_path_root_timer,
		    ieee80211_mesh_path_root_timer,
		    (unsigned long) sdata);
	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
	skb_queue_head_init(&ifmsh->ps.bc_buf);
	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
	spin_lock_init(&ifmsh->sync_offset_lock);
	RCU_INIT_POINTER(ifmsh->beacon, NULL);

	sdata->vif.bss_conf.bssid = zero_addr;
}