aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/ibss.c
blob: b7bf6d76f1d91bb8fd41be910ac0919cdf44f7b4 (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
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
/*
 * IBSS mode implementation
 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2009, 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/delay.h>
#include <linux/slab.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>

#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"

#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)

#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				      const u8 *bssid, const int beacon_int,
				      struct ieee80211_channel *chan,
				      const u32 basic_rates,
				      const u16 capability, u64 tsf,
				      bool creator)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	int rates, i;
	struct ieee80211_mgmt *mgmt;
	u8 *pos;
	struct ieee80211_supported_band *sband;
	struct cfg80211_bss *bss;
	u32 bss_change;
	u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
	struct cfg80211_chan_def chandef;
	struct beacon_data *presp;
	int frame_len;

	lockdep_assert_held(&ifibss->mtx);

	/* Reset own TSF to allow time synchronization work. */
	drv_reset_tsf(local, sdata);

	if (!ether_addr_equal(ifibss->bssid, bssid))
		sta_info_flush(sdata);

	/* if merging, indicate to driver that we leave the old IBSS */
	if (sdata->vif.bss_conf.ibss_joined) {
		sdata->vif.bss_conf.ibss_joined = false;
		sdata->vif.bss_conf.ibss_creator = false;
		sdata->vif.bss_conf.enable_beacon = false;
		netif_carrier_off(sdata->dev);
		ieee80211_bss_info_change_notify(sdata,
						 BSS_CHANGED_IBSS |
						 BSS_CHANGED_BEACON_ENABLED);
	}

	presp = rcu_dereference_protected(ifibss->presp,
					  lockdep_is_held(&ifibss->mtx));
	rcu_assign_pointer(ifibss->presp, NULL);
	if (presp)
		kfree_rcu(presp, rcu_head);

	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;

	cfg80211_chandef_create(&chandef, chan, ifibss->channel_type);
	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
		chandef.width = NL80211_CHAN_WIDTH_20;
		chandef.center_freq1 = chan->center_freq;
	}

	ieee80211_vif_release_channel(sdata);
	if (ieee80211_vif_use_channel(sdata, &chandef,
				      ifibss->fixed_channel ?
					IEEE80211_CHANCTX_SHARED :
					IEEE80211_CHANCTX_EXCLUSIVE)) {
		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
		return;
	}

	memcpy(ifibss->bssid, bssid, ETH_ALEN);

	sband = local->hw.wiphy->bands[chan->band];

	/* Build IBSS probe response */
	frame_len = sizeof(struct ieee80211_hdr_3addr) +
		    12 /* struct ieee80211_mgmt.u.beacon */ +
		    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
		    2 + 8 /* max Supported Rates */ +
		    3 /* max DS params */ +
		    4 /* IBSS params */ +
		    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
		    2 + sizeof(struct ieee80211_ht_cap) +
		    2 + sizeof(struct ieee80211_ht_operation) +
		    ifibss->ie_len;
	presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
	if (!presp)
		return;

	presp->head = (void *)(presp + 1);

	mgmt = (void *) presp->head;
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_PROBE_RESP);
	eth_broadcast_addr(mgmt->da);
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
	mgmt->u.beacon.capab_info = cpu_to_le16(capability);

	pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);

	*pos++ = WLAN_EID_SSID;
	*pos++ = ifibss->ssid_len;
	memcpy(pos, ifibss->ssid, ifibss->ssid_len);
	pos += ifibss->ssid_len;

	rates = min_t(int, 8, sband->n_bitrates);
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = rates;
	for (i = 0; i < rates; i++) {
		int rate = sband->bitrates[i].bitrate;
		u8 basic = 0;
		if (basic_rates & BIT(i))
			basic = 0x80;
		*pos++ = basic | (u8) (rate / 5);
	}

	if (sband->band == IEEE80211_BAND_2GHZ) {
		*pos++ = WLAN_EID_DS_PARAMS;
		*pos++ = 1;
		*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
	}

	*pos++ = WLAN_EID_IBSS_PARAMS;
	*pos++ = 2;
	/* FIX: set ATIM window based on scan results */
	*pos++ = 0;
	*pos++ = 0;

	if (sband->n_bitrates > 8) {
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
		*pos++ = sband->n_bitrates - 8;
		for (i = 8; i < sband->n_bitrates; i++) {
			int rate = sband->bitrates[i].bitrate;
			u8 basic = 0;
			if (basic_rates & BIT(i))
				basic = 0x80;
			*pos++ = basic | (u8) (rate / 5);
		}
	}

	if (ifibss->ie_len) {
		memcpy(pos, ifibss->ie, ifibss->ie_len);
		pos += ifibss->ie_len;
	}

	/* add HT capability and information IEs */
	if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
	    sband->ht_cap.ht_supported) {
		pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
						sband->ht_cap.cap);
		/*
		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
		 * field and RIFS Mode are reserved in IBSS mode, therefore
		 * keep them at 0
		 */
		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
						 &chandef, 0);
	}

	if (local->hw.queues >= IEEE80211_NUM_ACS) {
		*pos++ = WLAN_EID_VENDOR_SPECIFIC;
		*pos++ = 7; /* len */
		*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
		*pos++ = 0x50;
		*pos++ = 0xf2;
		*pos++ = 2; /* WME */
		*pos++ = 0; /* WME info */
		*pos++ = 1; /* WME ver */
		*pos++ = 0; /* U-APSD no in use */
	}

	presp->head_len = pos - presp->head;
	if (WARN_ON(presp->head_len > frame_len))
		return;

	rcu_assign_pointer(ifibss->presp, presp);

	sdata->vif.bss_conf.enable_beacon = true;
	sdata->vif.bss_conf.beacon_int = beacon_int;
	sdata->vif.bss_conf.basic_rates = basic_rates;
	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
	bss_change = BSS_CHANGED_BEACON_INT;
	bss_change |= ieee80211_reset_erp_info(sdata);
	bss_change |= BSS_CHANGED_BSSID;
	bss_change |= BSS_CHANGED_BEACON;
	bss_change |= BSS_CHANGED_BEACON_ENABLED;
	bss_change |= BSS_CHANGED_BASIC_RATES;
	bss_change |= BSS_CHANGED_HT;
	bss_change |= BSS_CHANGED_IBSS;
	bss_change |= BSS_CHANGED_SSID;

	/*
	 * In 5 GHz/802.11a, we can always use short slot time.
	 * (IEEE 802.11-2012 18.3.8.7)
	 *
	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
	 * reasons.
	 * (IEEE 802.11-2012 19.4.5)
	 *
	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
	 */
	sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
	bss_change |= BSS_CHANGED_ERP_SLOT;

	sdata->vif.bss_conf.ibss_joined = true;
	sdata->vif.bss_conf.ibss_creator = creator;
	ieee80211_bss_info_change_notify(sdata, bss_change);

	ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);

	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));

	bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
					mgmt, presp->head_len, 0, GFP_KERNEL);
	cfg80211_put_bss(local->hw.wiphy, bss);
	netif_carrier_on(sdata->dev);
	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
}

static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_bss *bss)
{
	struct cfg80211_bss *cbss =
		container_of((void *)bss, struct cfg80211_bss, priv);
	struct ieee80211_supported_band *sband;
	u32 basic_rates;
	int i, j;
	u16 beacon_int = cbss->beacon_interval;
	const struct cfg80211_bss_ies *ies;
	u64 tsf;

	lockdep_assert_held(&sdata->u.ibss.mtx);

	if (beacon_int < 10)
		beacon_int = 10;

	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];

	basic_rates = 0;

	for (i = 0; i < bss->supp_rates_len; i++) {
		int rate = (bss->supp_rates[i] & 0x7f) * 5;
		bool is_basic = !!(bss->supp_rates[i] & 0x80);

		for (j = 0; j < sband->n_bitrates; j++) {
			if (sband->bitrates[j].bitrate == rate) {
				if (is_basic)
					basic_rates |= BIT(j);
				break;
			}
		}
	}

	rcu_read_lock();
	ies = rcu_dereference(cbss->ies);
	tsf = ies->tsf;
	rcu_read_unlock();

	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
				  beacon_int,
				  cbss->channel,
				  basic_rates,
				  cbss->capability,
				  tsf, false);
}

static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
						  bool auth)
	__acquires(RCU)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	u8 addr[ETH_ALEN];

	memcpy(addr, sta->sta.addr, ETH_ALEN);

	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);

	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
	/* authorize the station only if the network is not RSN protected. If
	 * not wait for the userspace to authorize it */
	if (!sta->sdata->u.ibss.control_port)
		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);

	rate_control_rate_init(sta);

	/* If it fails, maybe we raced another insertion? */
	if (sta_info_insert_rcu(sta))
		return sta_info_get(sdata, addr);
	if (auth && !sdata->u.ibss.auth_frame_registrations) {
		ibss_dbg(sdata,
			 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
			 sdata->vif.addr, addr, sdata->u.ibss.bssid);
		ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
				    addr, sdata->u.ibss.bssid, NULL, 0, 0, 0);
	}
	return sta;
}

static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
		       const u8 *bssid, const u8 *addr,
		       u32 supp_rates, bool auth)
	__acquires(RCU)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	struct ieee80211_chanctx_conf *chanctx_conf;
	int band;

	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
				    sdata->name, addr);
		rcu_read_lock();
		return NULL;
	}

	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
		rcu_read_lock();
		return NULL;
	}

	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
		rcu_read_lock();
		return NULL;
	}

	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON_ONCE(!chanctx_conf))
		return NULL;
	band = chanctx_conf->def.chan->band;
	rcu_read_unlock();

	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
	if (!sta) {
		rcu_read_lock();
		return NULL;
	}

	sta->last_rx = jiffies;

	/* make sure mandatory rates are always added */
	sta->sta.supp_rates[band] = supp_rates |
			ieee80211_mandatory_rates(local, band);

	return ieee80211_ibss_finish_sta(sta, auth);
}

static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
					  struct ieee80211_mgmt *mgmt,
					  size_t len)
{
	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);

	if (len < IEEE80211_DEAUTH_FRAME_LEN)
		return;

	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, reason);
	sta_info_destroy_addr(sdata, mgmt->sa);
}

static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_mgmt *mgmt,
					size_t len)
{
	u16 auth_alg, auth_transaction;
	struct sta_info *sta;
	u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];

	lockdep_assert_held(&sdata->u.ibss.mtx);

	if (len < 24 + 6)
		return;

	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);

	ibss_dbg(sdata,
		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);

	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
		return;

	sta_info_destroy_addr(sdata, mgmt->sa);
	sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
	rcu_read_unlock();

	/*
	 * if we have any problem in allocating the new station, we reply with a
	 * DEAUTH frame to tell the other end that we had a problem
	 */
	if (!sta) {
		ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
					       IEEE80211_STYPE_DEAUTH,
					       WLAN_REASON_UNSPECIFIED, true,
					       deauth_frame_buf);
		return;
	}

	/*
	 * IEEE 802.11 standard does not require authentication in IBSS
	 * networks and most implementations do not seem to use it.
	 * However, try to reply to authentication attempts if someone
	 * has actually implemented this.
	 */
	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
}

static void ieee80211_rx_bss_info(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 ieee80211_local *local = sdata->local;
	int freq;
	struct cfg80211_bss *cbss;
	struct ieee80211_bss *bss;
	struct sta_info *sta;
	struct ieee80211_channel *channel;
	u64 beacon_timestamp, rx_timestamp;
	u32 supp_rates = 0;
	enum ieee80211_band band = rx_status->band;
	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
	bool rates_updated = false;

	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 (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
	    ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {

		rcu_read_lock();
		sta = sta_info_get(sdata, mgmt->sa);

		if (elems->supp_rates) {
			supp_rates = ieee80211_sta_get_rates(local, elems,
							     band, NULL);
			if (sta) {
				u32 prev_rates;

				prev_rates = sta->sta.supp_rates[band];
				/* make sure mandatory rates are always added */
				sta->sta.supp_rates[band] = supp_rates |
					ieee80211_mandatory_rates(local, band);

				if (sta->sta.supp_rates[band] != prev_rates) {
					ibss_dbg(sdata,
						 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
						 sta->sta.addr, prev_rates,
						 sta->sta.supp_rates[band]);
					rates_updated = true;
				}
			} else {
				rcu_read_unlock();
				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
						mgmt->sa, supp_rates, true);
			}
		}

		if (sta && elems->wmm_info)
			set_sta_flag(sta, WLAN_STA_WME);

		if (sta && elems->ht_operation && elems->ht_cap_elem &&
		    sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
			/* we both use HT */
			struct ieee80211_ht_cap htcap_ie;
			struct cfg80211_chan_def chandef;

			ieee80211_ht_oper_to_chandef(channel,
						     elems->ht_operation,
						     &chandef);

			memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));

			/*
			 * fall back to HT20 if we don't use or use
			 * the other extension channel
			 */
			if (cfg80211_get_chandef_type(&chandef) !=
						sdata->u.ibss.channel_type)
				htcap_ie.cap_info &=
					cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);

			rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
						sdata, sband, &htcap_ie, sta);
		}

		if (sta && rates_updated) {
			drv_sta_rc_update(local, sdata, &sta->sta,
					  IEEE80211_RC_SUPP_RATES_CHANGED);
			rate_control_rate_init(sta);
		}

		rcu_read_unlock();
	}

	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
					channel);
	if (!bss)
		return;

	cbss = container_of((void *)bss, struct cfg80211_bss, priv);

	/* same for beacon and probe response */
	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);

	/* check if we need to merge IBSS */

	/* we use a fixed BSSID */
	if (sdata->u.ibss.fixed_bssid)
		goto put_bss;

	/* not an IBSS */
	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
		goto put_bss;

	/* different channel */
	if (sdata->u.ibss.fixed_channel &&
	    sdata->u.ibss.channel != cbss->channel)
		goto put_bss;

	/* different SSID */
	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
	    memcmp(elems->ssid, sdata->u.ibss.ssid,
				sdata->u.ibss.ssid_len))
		goto put_bss;

	/* same BSSID */
	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
		goto put_bss;

	if (ieee80211_have_rx_timestamp(rx_status)) {
		/* time when timestamp field was received */
		rx_timestamp =
			ieee80211_calculate_rx_timestamp(local, rx_status,
							 len + FCS_LEN, 24);
	} else {
		/*
		 * second best option: get current TSF
		 * (will return -1 if not supported)
		 */
		rx_timestamp = drv_get_tsf(local, sdata);
	}

	ibss_dbg(sdata,
		 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
		 mgmt->sa, mgmt->bssid,
		 (unsigned long long)rx_timestamp,
		 (unsigned long long)beacon_timestamp,
		 (unsigned long long)(rx_timestamp - beacon_timestamp),
		 jiffies);

	if (beacon_timestamp > rx_timestamp) {
		ibss_dbg(sdata,
			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
			 mgmt->bssid);
		ieee80211_sta_join_ibss(sdata, bss);
		supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
				       supp_rates, true);
		rcu_read_unlock();
	}

 put_bss:
	ieee80211_rx_bss_put(local, bss);
}

void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
			      const u8 *bssid, const u8 *addr,
			      u32 supp_rates)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	struct ieee80211_chanctx_conf *chanctx_conf;
	int band;

	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
				    sdata->name, addr);
		return;
	}

	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
		return;

	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
		return;

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

	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
	if (!sta)
		return;

	sta->last_rx = jiffies;

	/* make sure mandatory rates are always added */
	sta->sta.supp_rates[band] = supp_rates |
			ieee80211_mandatory_rates(local, band);

	spin_lock(&ifibss->incomplete_lock);
	list_add(&sta->list, &ifibss->incomplete_stations);
	spin_unlock(&ifibss->incomplete_lock);
	ieee80211_queue_work(&local->hw, &sdata->work);
}

static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	int active = 0;
	struct sta_info *sta;

	lockdep_assert_held(&sdata->u.ibss.mtx);

	rcu_read_lock();

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sta->sdata == sdata &&
		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
			       jiffies)) {
			active++;
			break;
		}
	}

	rcu_read_unlock();

	return active;
}

/*
 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 */

static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

	lockdep_assert_held(&ifibss->mtx);

	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));

	ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);

	if (time_before(jiffies, ifibss->last_scan_completed +
		       IEEE80211_IBSS_MERGE_INTERVAL))
		return;

	if (ieee80211_sta_active_ibss(sdata))
		return;

	if (ifibss->fixed_channel)
		return;

	sdata_info(sdata,
		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");

	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
				    NULL);
}

static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	u8 bssid[ETH_ALEN];
	u16 capability;
	int i;

	lockdep_assert_held(&ifibss->mtx);

	if (ifibss->fixed_bssid) {
		memcpy(bssid, ifibss->bssid, ETH_ALEN);
	} else {
		/* Generate random, not broadcast, locally administered BSSID. Mix in
		 * own MAC address to make sure that devices that do not have proper
		 * random number generator get different BSSID. */
		get_random_bytes(bssid, ETH_ALEN);
		for (i = 0; i < ETH_ALEN; i++)
			bssid[i] ^= sdata->vif.addr[i];
		bssid[0] &= ~0x01;
		bssid[0] |= 0x02;
	}

	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);

	capability = WLAN_CAPABILITY_IBSS;

	if (ifibss->privacy)
		capability |= WLAN_CAPABILITY_PRIVACY;
	else
		sdata->drop_unencrypted = 0;

	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
				  ifibss->channel, ifibss->basic_rates,
				  capability, 0, true);
}

/*
 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 */

static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct cfg80211_bss *cbss;
	struct ieee80211_channel *chan = NULL;
	const u8 *bssid = NULL;
	int active_ibss;
	u16 capability;

	lockdep_assert_held(&ifibss->mtx);

	active_ibss = ieee80211_sta_active_ibss(sdata);
	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);

	if (active_ibss)
		return;

	capability = WLAN_CAPABILITY_IBSS;
	if (ifibss->privacy)
		capability |= WLAN_CAPABILITY_PRIVACY;
	if (ifibss->fixed_bssid)
		bssid = ifibss->bssid;
	if (ifibss->fixed_channel)
		chan = ifibss->channel;
	if (!is_zero_ether_addr(ifibss->bssid))
		bssid = ifibss->bssid;
	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
				ifibss->ssid, ifibss->ssid_len,
				WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
				capability);

	if (cbss) {
		struct ieee80211_bss *bss;

		bss = (void *)cbss->priv;
		ibss_dbg(sdata,
			 "sta_find_ibss: selected %pM current %pM\n",
			 cbss->bssid, ifibss->bssid);
		sdata_info(sdata,
			   "Selected IBSS BSSID %pM based on configured SSID\n",
			   cbss->bssid);

		ieee80211_sta_join_ibss(sdata, bss);
		ieee80211_rx_bss_put(local, bss);
		return;
	}

	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");

	/* Selected IBSS not found in current scan results - try to scan */
	if (time_after(jiffies, ifibss->last_scan_completed +
					IEEE80211_SCAN_INTERVAL)) {
		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");

		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
					    ifibss->ssid_len, chan);
	} else {
		int interval = IEEE80211_SCAN_INTERVAL;

		if (time_after(jiffies, ifibss->ibss_join_req +
			       IEEE80211_IBSS_JOIN_TIMEOUT))
			ieee80211_sta_create_ibss(sdata);

		mod_timer(&ifibss->timer,
			  round_jiffies(jiffies + interval));
	}
}

static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
					struct sk_buff *req)
{
	struct ieee80211_mgmt *mgmt = (void *)req->data;
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	int tx_last_beacon, len = req->len;
	struct sk_buff *skb;
	struct beacon_data *presp;
	u8 *pos, *end;

	lockdep_assert_held(&ifibss->mtx);

	presp = rcu_dereference_protected(ifibss->presp,
					  lockdep_is_held(&ifibss->mtx));

	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
	    len < 24 + 2 || !presp)
		return;

	tx_last_beacon = drv_tx_last_beacon(local);

	ibss_dbg(sdata,
		 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);

	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
		return;

	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
	    !is_broadcast_ether_addr(mgmt->bssid))
		return;

	end = ((u8 *) mgmt) + len;
	pos = mgmt->u.probe_req.variable;
	if (pos[0] != WLAN_EID_SSID ||
	    pos + 2 + pos[1] > end) {
		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
			 mgmt->sa);
		return;
	}
	if (pos[1] != 0 &&
	    (pos[1] != ifibss->ssid_len ||
	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
		/* Ignore ProbeReq for foreign SSID */
		return;
	}

	/* Reply with ProbeResp */
	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
	if (!skb)
		return;

	skb_reserve(skb, local->tx_headroom);
	memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);

	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	ieee80211_tx_skb(sdata, skb);
}

static
void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_mgmt *mgmt, size_t len,
				    struct ieee80211_rx_status *rx_status)
{
	size_t baselen;
	struct ieee802_11_elems elems;

	BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
		     offsetof(typeof(mgmt->u.beacon), variable));

	/*
	 * either beacon or probe_resp but the variable field is at the
	 * same offset
	 */
	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
	if (baselen > len)
		return;

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

	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
}

void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
				   struct sk_buff *skb)
{
	struct ieee80211_rx_status *rx_status;
	struct ieee80211_mgmt *mgmt;
	u16 fc;

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

	mutex_lock(&sdata->u.ibss.mtx);

	if (!sdata->u.ibss.ssid_len)
		goto mgmt_out; /* not ready to merge yet */

	switch (fc & IEEE80211_FCTL_STYPE) {
	case IEEE80211_STYPE_PROBE_REQ:
		ieee80211_rx_mgmt_probe_req(sdata, skb);
		break;
	case IEEE80211_STYPE_PROBE_RESP:
	case IEEE80211_STYPE_BEACON:
		ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
					       rx_status);
		break;
	case IEEE80211_STYPE_AUTH:
		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
		break;
	case IEEE80211_STYPE_DEAUTH:
		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
		break;
	}

 mgmt_out:
	mutex_unlock(&sdata->u.ibss.mtx);
}

void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct sta_info *sta;

	mutex_lock(&ifibss->mtx);

	/*
	 * Work could be scheduled after scan or similar
	 * when we aren't even joined (or trying) with a
	 * network.
	 */
	if (!ifibss->ssid_len)
		goto out;

	spin_lock_bh(&ifibss->incomplete_lock);
	while (!list_empty(&ifibss->incomplete_stations)) {
		sta = list_first_entry(&ifibss->incomplete_stations,
				       struct sta_info, list);
		list_del(&sta->list);
		spin_unlock_bh(&ifibss->incomplete_lock);

		ieee80211_ibss_finish_sta(sta, true);
		rcu_read_unlock();
		spin_lock_bh(&ifibss->incomplete_lock);
	}
	spin_unlock_bh(&ifibss->incomplete_lock);

	switch (ifibss->state) {
	case IEEE80211_IBSS_MLME_SEARCH:
		ieee80211_sta_find_ibss(sdata);
		break;
	case IEEE80211_IBSS_MLME_JOINED:
		ieee80211_sta_merge_ibss(sdata);
		break;
	default:
		WARN_ON(1);
		break;
	}

 out:
	mutex_unlock(&ifibss->mtx);
}

static void ieee80211_ibss_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata =
		(struct ieee80211_sub_if_data *) data;

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

void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
		    (unsigned long) sdata);
	mutex_init(&ifibss->mtx);
	INIT_LIST_HEAD(&ifibss->incomplete_stations);
	spin_lock_init(&ifibss->incomplete_lock);
}

/* scan finished notification */
void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (!ieee80211_sdata_running(sdata))
			continue;
		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
			continue;
		sdata->u.ibss.last_scan_completed = jiffies;
		ieee80211_queue_work(&local->hw, &sdata->work);
	}
	mutex_unlock(&local->iflist_mtx);
}

int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
			struct cfg80211_ibss_params *params)
{
	u32 changed = 0;

	mutex_lock(&sdata->u.ibss.mtx);

	if (params->bssid) {
		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
		sdata->u.ibss.fixed_bssid = true;
	} else
		sdata->u.ibss.fixed_bssid = false;

	sdata->u.ibss.privacy = params->privacy;
	sdata->u.ibss.control_port = params->control_port;
	sdata->u.ibss.basic_rates = params->basic_rates;
	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
	       sizeof(params->mcast_rate));

	sdata->vif.bss_conf.beacon_int = params->beacon_interval;

	sdata->u.ibss.channel = params->chandef.chan;
	sdata->u.ibss.channel_type =
		cfg80211_get_chandef_type(&params->chandef);
	sdata->u.ibss.fixed_channel = params->channel_fixed;

	if (params->ie) {
		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
					   GFP_KERNEL);
		if (sdata->u.ibss.ie)
			sdata->u.ibss.ie_len = params->ie_len;
	}

	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
	sdata->u.ibss.ibss_join_req = jiffies;

	memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
	sdata->u.ibss.ssid_len = params->ssid_len;

	mutex_unlock(&sdata->u.ibss.mtx);

	/*
	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
	 * reserved, but an HT STA shall protect HT transmissions as though
	 * the HT Protection field were set to non-HT mixed mode.
	 *
	 * In an IBSS, the RIFS Mode field of the HT Operation element is
	 * also reserved, but an HT STA shall operate as though this field
	 * were set to 1.
	 */

	sdata->vif.bss_conf.ht_operation_mode |=
		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
		| IEEE80211_HT_PARAM_RIFS_MODE;

	changed |= BSS_CHANGED_HT;
	ieee80211_bss_info_change_notify(sdata, changed);

	sdata->smps_mode = IEEE80211_SMPS_OFF;
	sdata->needed_rx_chains = sdata->local->rx_chains;

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

	return 0;
}

int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct cfg80211_bss *cbss;
	u16 capability;
	int active_ibss;
	struct sta_info *sta;
	struct beacon_data *presp;

	mutex_lock(&sdata->u.ibss.mtx);

	active_ibss = ieee80211_sta_active_ibss(sdata);

	if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
		capability = WLAN_CAPABILITY_IBSS;

		if (ifibss->privacy)
			capability |= WLAN_CAPABILITY_PRIVACY;

		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
					ifibss->bssid, ifibss->ssid,
					ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
					WLAN_CAPABILITY_PRIVACY,
					capability);

		if (cbss) {
			cfg80211_unlink_bss(local->hw.wiphy, cbss);
			cfg80211_put_bss(local->hw.wiphy, cbss);
		}
	}

	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
	memset(ifibss->bssid, 0, ETH_ALEN);
	ifibss->ssid_len = 0;

	sta_info_flush(sdata);

	spin_lock_bh(&ifibss->incomplete_lock);
	while (!list_empty(&ifibss->incomplete_stations)) {
		sta = list_first_entry(&ifibss->incomplete_stations,
				       struct sta_info, list);
		list_del(&sta->list);
		spin_unlock_bh(&ifibss->incomplete_lock);

		sta_info_free(local, sta);
		spin_lock_bh(&ifibss->incomplete_lock);
	}
	spin_unlock_bh(&ifibss->incomplete_lock);

	netif_carrier_off(sdata->dev);

	/* remove beacon */
	kfree(sdata->u.ibss.ie);
	presp = rcu_dereference_protected(ifibss->presp,
					  lockdep_is_held(&sdata->u.ibss.mtx));
	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
	sdata->vif.bss_conf.ibss_joined = false;
	sdata->vif.bss_conf.ibss_creator = false;
	sdata->vif.bss_conf.enable_beacon = false;
	sdata->vif.bss_conf.ssid_len = 0;
	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
						BSS_CHANGED_IBSS);
	synchronize_rcu();
	kfree(presp);

	skb_queue_purge(&sdata->skb_queue);

	del_timer_sync(&sdata->u.ibss.timer);

	mutex_unlock(&sdata->u.ibss.mtx);

	return 0;
}