aboutsummaryrefslogtreecommitdiff
path: root/net/wireless/scan.c
blob: 0fb1424104047ced0d99949be89388509e05fc5c (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
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
/*
 * cfg80211 scan result handling
 *
 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/wireless.h>
#include <linux/nl80211.h>
#include <linux/etherdevice.h>
#include <net/arp.h>
#include <net/cfg80211.h>
#include <net/cfg80211-wext.h>
#include <net/iw_handler.h>
#include "core.h"
#include "nl80211.h"
#include "wext-compat.h"

#define IEEE80211_SCAN_RESULT_EXPIRE	(15 * HZ)

void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
{
	struct cfg80211_scan_request *request;
	struct net_device *dev;
#ifdef CONFIG_CFG80211_WEXT
	union iwreq_data wrqu;
#endif

	ASSERT_RDEV_LOCK(rdev);

	request = rdev->scan_req;

	if (!request)
		return;

	dev = request->dev;

	/*
	 * This must be before sending the other events!
	 * Otherwise, wpa_supplicant gets completely confused with
	 * wext events.
	 */
	cfg80211_sme_scan_done(dev);

	if (request->aborted)
		nl80211_send_scan_aborted(rdev, dev);
	else
		nl80211_send_scan_done(rdev, dev);

#ifdef CONFIG_CFG80211_WEXT
	if (!request->aborted) {
		memset(&wrqu, 0, sizeof(wrqu));

		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
	}
#endif

	dev_put(dev);

	rdev->scan_req = NULL;

	/*
	 * OK. If this is invoked with "leak" then we can't
	 * free this ... but we've cleaned it up anyway. The
	 * driver failed to call the scan_done callback, so
	 * all bets are off, it might still be trying to use
	 * the scan request or not ... if it accesses the dev
	 * in there (it shouldn't anyway) then it may crash.
	 */
	if (!leak)
		kfree(request);
}

void __cfg80211_scan_done(struct work_struct *wk)
{
	struct cfg80211_registered_device *rdev;

	rdev = container_of(wk, struct cfg80211_registered_device,
			    scan_done_wk);

	cfg80211_lock_rdev(rdev);
	___cfg80211_scan_done(rdev, false);
	cfg80211_unlock_rdev(rdev);
}

void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
{
	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);

	request->aborted = aborted;
	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
}
EXPORT_SYMBOL(cfg80211_scan_done);

void __cfg80211_sched_scan_results(struct work_struct *wk)
{
	struct cfg80211_registered_device *rdev;

	rdev = container_of(wk, struct cfg80211_registered_device,
			    sched_scan_results_wk);

	mutex_lock(&rdev->sched_scan_mtx);

	/* we don't have sched_scan_req anymore if the scan is stopping */
	if (rdev->sched_scan_req)
		nl80211_send_sched_scan_results(rdev,
						rdev->sched_scan_req->dev);

	mutex_unlock(&rdev->sched_scan_mtx);
}

void cfg80211_sched_scan_results(struct wiphy *wiphy)
{
	/* ignore if we're not scanning */
	if (wiphy_to_dev(wiphy)->sched_scan_req)
		queue_work(cfg80211_wq,
			   &wiphy_to_dev(wiphy)->sched_scan_results_wk);
}
EXPORT_SYMBOL(cfg80211_sched_scan_results);

void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
{
	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);

	mutex_lock(&rdev->sched_scan_mtx);
	__cfg80211_stop_sched_scan(rdev, true);
	mutex_unlock(&rdev->sched_scan_mtx);
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped);

int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
			       bool driver_initiated)
{
	struct net_device *dev;

	lockdep_assert_held(&rdev->sched_scan_mtx);

	if (!rdev->sched_scan_req)
		return -ENOENT;

	dev = rdev->sched_scan_req->dev;

	if (!driver_initiated) {
		int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
		if (err)
			return err;
	}

	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);

	kfree(rdev->sched_scan_req);
	rdev->sched_scan_req = NULL;

	return 0;
}

static void bss_release(struct kref *ref)
{
	struct cfg80211_internal_bss *bss;

	bss = container_of(ref, struct cfg80211_internal_bss, ref);
	if (bss->pub.free_priv)
		bss->pub.free_priv(&bss->pub);

	if (bss->beacon_ies_allocated)
		kfree(bss->pub.beacon_ies);
	if (bss->proberesp_ies_allocated)
		kfree(bss->pub.proberesp_ies);

	BUG_ON(atomic_read(&bss->hold));

	kfree(bss);
}

/* must hold dev->bss_lock! */
void cfg80211_bss_age(struct cfg80211_registered_device *dev,
                      unsigned long age_secs)
{
	struct cfg80211_internal_bss *bss;
	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);

	list_for_each_entry(bss, &dev->bss_list, list) {
		bss->ts -= age_jiffies;
	}
}

/* must hold dev->bss_lock! */
static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
				  struct cfg80211_internal_bss *bss)
{
	list_del_init(&bss->list);
	rb_erase(&bss->rbn, &dev->bss_tree);
	kref_put(&bss->ref, bss_release);
}

/* must hold dev->bss_lock! */
void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
{
	struct cfg80211_internal_bss *bss, *tmp;
	bool expired = false;

	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
		if (atomic_read(&bss->hold))
			continue;
		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
			continue;
		__cfg80211_unlink_bss(dev, bss);
		expired = true;
	}

	if (expired)
		dev->bss_generation++;
}

const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
{
	while (len > 2 && ies[0] != eid) {
		len -= ies[1] + 2;
		ies += ies[1] + 2;
	}
	if (len < 2)
		return NULL;
	if (len < 2 + ies[1])
		return NULL;
	return ies;
}
EXPORT_SYMBOL(cfg80211_find_ie);

const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
				  const u8 *ies, int len)
{
	struct ieee80211_vendor_ie *ie;
	const u8 *pos = ies, *end = ies + len;
	int ie_oui;

	while (pos < end) {
		pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
				       end - pos);
		if (!pos)
			return NULL;

		if (end - pos < sizeof(*ie))
			return NULL;

		ie = (struct ieee80211_vendor_ie *)pos;
		ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
		if (ie_oui == oui && ie->oui_type == oui_type)
			return pos;

		pos += 2 + ie->len;
	}
	return NULL;
}
EXPORT_SYMBOL(cfg80211_find_vendor_ie);

static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
{
	const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
	const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
	int r;

	if (!ie1 && !ie2)
		return 0;
	if (!ie1 || !ie2)
		return -1;

	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
	if (r == 0 && ie1[1] != ie2[1])
		return ie2[1] - ie1[1];
	return r;
}

static bool is_bss(struct cfg80211_bss *a,
		   const u8 *bssid,
		   const u8 *ssid, size_t ssid_len)
{
	const u8 *ssidie;

	if (bssid && compare_ether_addr(a->bssid, bssid))
		return false;

	if (!ssid)
		return true;

	ssidie = cfg80211_find_ie(WLAN_EID_SSID,
				  a->information_elements,
				  a->len_information_elements);
	if (!ssidie)
		return false;
	if (ssidie[1] != ssid_len)
		return false;
	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
}

static bool is_mesh_bss(struct cfg80211_bss *a)
{
	const u8 *ie;

	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
		return false;

	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
			      a->information_elements,
			      a->len_information_elements);
	if (!ie)
		return false;

	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
			      a->information_elements,
			      a->len_information_elements);
	if (!ie)
		return false;

	return true;
}

static bool is_mesh(struct cfg80211_bss *a,
		    const u8 *meshid, size_t meshidlen,
		    const u8 *meshcfg)
{
	const u8 *ie;

	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
		return false;

	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
			      a->information_elements,
			      a->len_information_elements);
	if (!ie)
		return false;
	if (ie[1] != meshidlen)
		return false;
	if (memcmp(ie + 2, meshid, meshidlen))
		return false;

	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
			      a->information_elements,
			      a->len_information_elements);
	if (!ie)
		return false;
	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
		return false;

	/*
	 * Ignore mesh capability (last two bytes of the IE) when
	 * comparing since that may differ between stations taking
	 * part in the same mesh.
	 */
	return memcmp(ie + 2, meshcfg,
	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
}

static int cmp_bss(struct cfg80211_bss *a,
		   struct cfg80211_bss *b)
{
	int r;

	if (a->channel != b->channel)
		return b->channel->center_freq - a->channel->center_freq;

	if (is_mesh_bss(a) && is_mesh_bss(b)) {
		r = cmp_ies(WLAN_EID_MESH_ID,
			    a->information_elements,
			    a->len_information_elements,
			    b->information_elements,
			    b->len_information_elements);
		if (r)
			return r;
		return cmp_ies(WLAN_EID_MESH_CONFIG,
			       a->information_elements,
			       a->len_information_elements,
			       b->information_elements,
			       b->len_information_elements);
	}

	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
	if (r)
		return r;

	return cmp_ies(WLAN_EID_SSID,
		       a->information_elements,
		       a->len_information_elements,
		       b->information_elements,
		       b->len_information_elements);
}

struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
				      struct ieee80211_channel *channel,
				      const u8 *bssid,
				      const u8 *ssid, size_t ssid_len,
				      u16 capa_mask, u16 capa_val)
{
	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
	struct cfg80211_internal_bss *bss, *res = NULL;
	unsigned long now = jiffies;

	spin_lock_bh(&dev->bss_lock);

	list_for_each_entry(bss, &dev->bss_list, list) {
		if ((bss->pub.capability & capa_mask) != capa_val)
			continue;
		if (channel && bss->pub.channel != channel)
			continue;
		/* Don't get expired BSS structs */
		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
		    !atomic_read(&bss->hold))
			continue;
		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
			res = bss;
			kref_get(&res->ref);
			break;
		}
	}

	spin_unlock_bh(&dev->bss_lock);
	if (!res)
		return NULL;
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_get_bss);

struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
				       struct ieee80211_channel *channel,
				       const u8 *meshid, size_t meshidlen,
				       const u8 *meshcfg)
{
	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
	struct cfg80211_internal_bss *bss, *res = NULL;

	spin_lock_bh(&dev->bss_lock);

	list_for_each_entry(bss, &dev->bss_list, list) {
		if (channel && bss->pub.channel != channel)
			continue;
		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
			res = bss;
			kref_get(&res->ref);
			break;
		}
	}

	spin_unlock_bh(&dev->bss_lock);
	if (!res)
		return NULL;
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_get_mesh);


static void rb_insert_bss(struct cfg80211_registered_device *dev,
			  struct cfg80211_internal_bss *bss)
{
	struct rb_node **p = &dev->bss_tree.rb_node;
	struct rb_node *parent = NULL;
	struct cfg80211_internal_bss *tbss;
	int cmp;

	while (*p) {
		parent = *p;
		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);

		cmp = cmp_bss(&bss->pub, &tbss->pub);

		if (WARN_ON(!cmp)) {
			/* will sort of leak this BSS */
			return;
		}

		if (cmp < 0)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	rb_link_node(&bss->rbn, parent, p);
	rb_insert_color(&bss->rbn, &dev->bss_tree);
}

static struct cfg80211_internal_bss *
rb_find_bss(struct cfg80211_registered_device *dev,
	    struct cfg80211_internal_bss *res)
{
	struct rb_node *n = dev->bss_tree.rb_node;
	struct cfg80211_internal_bss *bss;
	int r;

	while (n) {
		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
		r = cmp_bss(&res->pub, &bss->pub);

		if (r == 0)
			return bss;
		else if (r < 0)
			n = n->rb_left;
		else
			n = n->rb_right;
	}

	return NULL;
}

static struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *dev,
		    struct cfg80211_internal_bss *res)
{
	struct cfg80211_internal_bss *found = NULL;

	/*
	 * The reference to "res" is donated to this function.
	 */

	if (WARN_ON(!res->pub.channel)) {
		kref_put(&res->ref, bss_release);
		return NULL;
	}

	res->ts = jiffies;

	spin_lock_bh(&dev->bss_lock);

	found = rb_find_bss(dev, res);

	if (found) {
		found->pub.beacon_interval = res->pub.beacon_interval;
		found->pub.tsf = res->pub.tsf;
		found->pub.signal = res->pub.signal;
		found->pub.capability = res->pub.capability;
		found->ts = res->ts;

		/* Update IEs */
		if (res->pub.proberesp_ies) {
			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
			size_t ielen = res->pub.len_proberesp_ies;

			if (found->pub.proberesp_ies &&
			    !found->proberesp_ies_allocated &&
			    ksize(found) >= used + ielen) {
				memcpy(found->pub.proberesp_ies,
				       res->pub.proberesp_ies, ielen);
				found->pub.len_proberesp_ies = ielen;
			} else {
				u8 *ies = found->pub.proberesp_ies;

				if (found->proberesp_ies_allocated)
					ies = krealloc(ies, ielen, GFP_ATOMIC);
				else
					ies = kmalloc(ielen, GFP_ATOMIC);

				if (ies) {
					memcpy(ies, res->pub.proberesp_ies,
					       ielen);
					found->proberesp_ies_allocated = true;
					found->pub.proberesp_ies = ies;
					found->pub.len_proberesp_ies = ielen;
				}
			}

			/* Override possible earlier Beacon frame IEs */
			found->pub.information_elements =
				found->pub.proberesp_ies;
			found->pub.len_information_elements =
				found->pub.len_proberesp_ies;
		}
		if (res->pub.beacon_ies) {
			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
			size_t ielen = res->pub.len_beacon_ies;
			bool information_elements_is_beacon_ies =
				(found->pub.information_elements ==
				 found->pub.beacon_ies);

			if (found->pub.beacon_ies &&
			    !found->beacon_ies_allocated &&
			    ksize(found) >= used + ielen) {
				memcpy(found->pub.beacon_ies,
				       res->pub.beacon_ies, ielen);
				found->pub.len_beacon_ies = ielen;
			} else {
				u8 *ies = found->pub.beacon_ies;

				if (found->beacon_ies_allocated)
					ies = krealloc(ies, ielen, GFP_ATOMIC);
				else
					ies = kmalloc(ielen, GFP_ATOMIC);

				if (ies) {
					memcpy(ies, res->pub.beacon_ies,
					       ielen);
					found->beacon_ies_allocated = true;
					found->pub.beacon_ies = ies;
					found->pub.len_beacon_ies = ielen;
				}
			}

			/* Override IEs if they were from a beacon before */
			if (information_elements_is_beacon_ies) {
				found->pub.information_elements =
					found->pub.beacon_ies;
				found->pub.len_information_elements =
					found->pub.len_beacon_ies;
			}
		}

		kref_put(&res->ref, bss_release);
	} else {
		/* this "consumes" the reference */
		list_add_tail(&res->list, &dev->bss_list);
		rb_insert_bss(dev, res);
		found = res;
	}

	dev->bss_generation++;
	spin_unlock_bh(&dev->bss_lock);

	kref_get(&found->ref);
	return found;
}

struct cfg80211_bss*
cfg80211_inform_bss(struct wiphy *wiphy,
		    struct ieee80211_channel *channel,
		    const u8 *bssid,
		    u64 timestamp, u16 capability, u16 beacon_interval,
		    const u8 *ie, size_t ielen,
		    s32 signal, gfp_t gfp)
{
	struct cfg80211_internal_bss *res;
	size_t privsz;

	if (WARN_ON(!wiphy))
		return NULL;

	privsz = wiphy->bss_priv_size;

	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
			(signal < 0 || signal > 100)))
		return NULL;

	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
	if (!res)
		return NULL;

	memcpy(res->pub.bssid, bssid, ETH_ALEN);
	res->pub.channel = channel;
	res->pub.signal = signal;
	res->pub.tsf = timestamp;
	res->pub.beacon_interval = beacon_interval;
	res->pub.capability = capability;
	/*
	 * Since we do not know here whether the IEs are from a Beacon or Probe
	 * Response frame, we need to pick one of the options and only use it
	 * with the driver that does not provide the full Beacon/Probe Response
	 * frame. Use Beacon frame pointer to avoid indicating that this should
	 * override the information_elements pointer should we have received an
	 * earlier indication of Probe Response data.
	 *
	 * The initial buffer for the IEs is allocated with the BSS entry and
	 * is located after the private area.
	 */
	res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
	memcpy(res->pub.beacon_ies, ie, ielen);
	res->pub.len_beacon_ies = ielen;
	res->pub.information_elements = res->pub.beacon_ies;
	res->pub.len_information_elements = res->pub.len_beacon_ies;

	kref_init(&res->ref);

	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
	if (!res)
		return NULL;

	if (res->pub.capability & WLAN_CAPABILITY_ESS)
		regulatory_hint_found_beacon(wiphy, channel, gfp);

	/* cfg80211_bss_update gives us a referenced result */
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss);

struct cfg80211_bss *
cfg80211_inform_bss_frame(struct wiphy *wiphy,
			  struct ieee80211_channel *channel,
			  struct ieee80211_mgmt *mgmt, size_t len,
			  s32 signal, gfp_t gfp)
{
	struct cfg80211_internal_bss *res;
	size_t ielen = len - offsetof(struct ieee80211_mgmt,
				      u.probe_resp.variable);
	size_t privsz;

	if (WARN_ON(!mgmt))
		return NULL;

	if (WARN_ON(!wiphy))
		return NULL;

	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
	            (signal < 0 || signal > 100)))
		return NULL;

	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
		return NULL;

	privsz = wiphy->bss_priv_size;

	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
	if (!res)
		return NULL;

	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
	res->pub.channel = channel;
	res->pub.signal = signal;
	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
	/*
	 * The initial buffer for the IEs is allocated with the BSS entry and
	 * is located after the private area.
	 */
	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
		res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
		memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
		       ielen);
		res->pub.len_proberesp_ies = ielen;
		res->pub.information_elements = res->pub.proberesp_ies;
		res->pub.len_information_elements = res->pub.len_proberesp_ies;
	} else {
		res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
		memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
		res->pub.len_beacon_ies = ielen;
		res->pub.information_elements = res->pub.beacon_ies;
		res->pub.len_information_elements = res->pub.len_beacon_ies;
	}

	kref_init(&res->ref);

	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
	if (!res)
		return NULL;

	if (res->pub.capability & WLAN_CAPABILITY_ESS)
		regulatory_hint_found_beacon(wiphy, channel, gfp);

	/* cfg80211_bss_update gives us a referenced result */
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss_frame);

void cfg80211_put_bss(struct cfg80211_bss *pub)
{
	struct cfg80211_internal_bss *bss;

	if (!pub)
		return;

	bss = container_of(pub, struct cfg80211_internal_bss, pub);
	kref_put(&bss->ref, bss_release);
}
EXPORT_SYMBOL(cfg80211_put_bss);

void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
	struct cfg80211_internal_bss *bss;

	if (WARN_ON(!pub))
		return;

	bss = container_of(pub, struct cfg80211_internal_bss, pub);

	spin_lock_bh(&dev->bss_lock);
	if (!list_empty(&bss->list)) {
		__cfg80211_unlink_bss(dev, bss);
		dev->bss_generation++;
	}
	spin_unlock_bh(&dev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_unlink_bss);

#ifdef CONFIG_CFG80211_WEXT
int cfg80211_wext_siwscan(struct net_device *dev,
			  struct iw_request_info *info,
			  union iwreq_data *wrqu, char *extra)
{
	struct cfg80211_registered_device *rdev;
	struct wiphy *wiphy;
	struct iw_scan_req *wreq = NULL;
	struct cfg80211_scan_request *creq = NULL;
	int i, err, n_channels = 0;
	enum ieee80211_band band;

	if (!netif_running(dev))
		return -ENETDOWN;

	if (wrqu->data.length == sizeof(struct iw_scan_req))
		wreq = (struct iw_scan_req *)extra;

	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);

	if (IS_ERR(rdev))
		return PTR_ERR(rdev);

	if (rdev->scan_req) {
		err = -EBUSY;
		goto out;
	}

	wiphy = &rdev->wiphy;

	/* Determine number of channels, needed to allocate creq */
	if (wreq && wreq->num_channels)
		n_channels = wreq->num_channels;
	else {
		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
			if (wiphy->bands[band])
				n_channels += wiphy->bands[band]->n_channels;
	}

	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
		       n_channels * sizeof(void *),
		       GFP_ATOMIC);
	if (!creq) {
		err = -ENOMEM;
		goto out;
	}

	creq->wiphy = wiphy;
	creq->dev = dev;
	/* SSIDs come after channels */
	creq->ssids = (void *)&creq->channels[n_channels];
	creq->n_channels = n_channels;
	creq->n_ssids = 1;

	/* translate "Scan on frequencies" request */
	i = 0;
	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		int j;

		if (!wiphy->bands[band])
			continue;

		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
			/* ignore disabled channels */
			if (wiphy->bands[band]->channels[j].flags &
						IEEE80211_CHAN_DISABLED)
				continue;

			/* If we have a wireless request structure and the
			 * wireless request specifies frequencies, then search
			 * for the matching hardware channel.
			 */
			if (wreq && wreq->num_channels) {
				int k;
				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
				for (k = 0; k < wreq->num_channels; k++) {
					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
					if (wext_freq == wiphy_freq)
						goto wext_freq_found;
				}
				goto wext_freq_not_found;
			}

		wext_freq_found:
			creq->channels[i] = &wiphy->bands[band]->channels[j];
			i++;
		wext_freq_not_found: ;
		}
	}
	/* No channels found? */
	if (!i) {
		err = -EINVAL;
		goto out;
	}

	/* Set real number of channels specified in creq->channels[] */
	creq->n_channels = i;

	/* translate "Scan for SSID" request */
	if (wreq) {
		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
				err = -EINVAL;
				goto out;
			}
			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
			creq->ssids[0].ssid_len = wreq->essid_len;
		}
		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
			creq->n_ssids = 0;
	}

	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
		if (wiphy->bands[i])
			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;

	rdev->scan_req = creq;
	err = rdev->ops->scan(wiphy, dev, creq);
	if (err) {
		rdev->scan_req = NULL;
		/* creq will be freed below */
	} else {
		nl80211_send_scan_start(rdev, dev);
		/* creq now owned by driver */
		creq = NULL;
		dev_hold(dev);
	}
 out:
	kfree(creq);
	cfg80211_unlock_rdev(rdev);
	return err;
}
EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);

static void ieee80211_scan_add_ies(struct iw_request_info *info,
				   struct cfg80211_bss *bss,
				   char **current_ev, char *end_buf)
{
	u8 *pos, *end, *next;
	struct iw_event iwe;

	if (!bss->information_elements ||
	    !bss->len_information_elements)
		return;

	/*
	 * If needed, fragment the IEs buffer (at IE boundaries) into short
	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
	 */
	pos = bss->information_elements;
	end = pos + bss->len_information_elements;

	while (end - pos > IW_GENERIC_IE_MAX) {
		next = pos + 2 + pos[1];
		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
			next = next + 2 + next[1];

		memset(&iwe, 0, sizeof(iwe));
		iwe.cmd = IWEVGENIE;
		iwe.u.data.length = next - pos;
		*current_ev = iwe_stream_add_point(info, *current_ev,
						   end_buf, &iwe, pos);

		pos = next;
	}

	if (end > pos) {
		memset(&iwe, 0, sizeof(iwe));
		iwe.cmd = IWEVGENIE;
		iwe.u.data.length = end - pos;
		*current_ev = iwe_stream_add_point(info, *current_ev,
						   end_buf, &iwe, pos);
	}
}

static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
{
	unsigned long end = jiffies;

	if (end >= start)
		return jiffies_to_msecs(end - start);

	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
}

static char *
ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
	      struct cfg80211_internal_bss *bss, char *current_ev,
	      char *end_buf)
{
	struct iw_event iwe;
	u8 *buf, *cfg, *p;
	u8 *ie = bss->pub.information_elements;
	int rem = bss->pub.len_information_elements, i, sig;
	bool ismesh = false;

	memset(&iwe, 0, sizeof(iwe));
	iwe.cmd = SIOCGIWAP;
	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
					  IW_EV_ADDR_LEN);

	memset(&iwe, 0, sizeof(iwe));
	iwe.cmd = SIOCGIWFREQ;
	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
	iwe.u.freq.e = 0;
	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
					  IW_EV_FREQ_LEN);

	memset(&iwe, 0, sizeof(iwe));
	iwe.cmd = SIOCGIWFREQ;
	iwe.u.freq.m = bss->pub.channel->center_freq;
	iwe.u.freq.e = 6;
	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
					  IW_EV_FREQ_LEN);

	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
		memset(&iwe, 0, sizeof(iwe));
		iwe.cmd = IWEVQUAL;
		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
				     IW_QUAL_NOISE_INVALID |
				     IW_QUAL_QUAL_UPDATED;
		switch (wiphy->signal_type) {
		case CFG80211_SIGNAL_TYPE_MBM:
			sig = bss->pub.signal / 100;
			iwe.u.qual.level = sig;
			iwe.u.qual.updated |= IW_QUAL_DBM;
			if (sig < -110)		/* rather bad */
				sig = -110;
			else if (sig > -40)	/* perfect */
				sig = -40;
			/* will give a range of 0 .. 70 */
			iwe.u.qual.qual = sig + 110;
			break;
		case CFG80211_SIGNAL_TYPE_UNSPEC:
			iwe.u.qual.level = bss->pub.signal;
			/* will give range 0 .. 100 */
			iwe.u.qual.qual = bss->pub.signal;
			break;
		default:
			/* not reached */
			break;
		}
		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
						  &iwe, IW_EV_QUAL_LEN);
	}

	memset(&iwe, 0, sizeof(iwe));
	iwe.cmd = SIOCGIWENCODE;
	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
	else
		iwe.u.data.flags = IW_ENCODE_DISABLED;
	iwe.u.data.length = 0;
	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
					  &iwe, "");

	while (rem >= 2) {
		/* invalid data */
		if (ie[1] > rem - 2)
			break;

		switch (ie[0]) {
		case WLAN_EID_SSID:
			memset(&iwe, 0, sizeof(iwe));
			iwe.cmd = SIOCGIWESSID;
			iwe.u.data.length = ie[1];
			iwe.u.data.flags = 1;
			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
							  &iwe, ie + 2);
			break;
		case WLAN_EID_MESH_ID:
			memset(&iwe, 0, sizeof(iwe));
			iwe.cmd = SIOCGIWESSID;
			iwe.u.data.length = ie[1];
			iwe.u.data.flags = 1;
			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
							  &iwe, ie + 2);
			break;
		case WLAN_EID_MESH_CONFIG:
			ismesh = true;
			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
				break;
			buf = kmalloc(50, GFP_ATOMIC);
			if (!buf)
				break;
			cfg = ie + 2;
			memset(&iwe, 0, sizeof(iwe));
			iwe.cmd = IWEVCUSTOM;
			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
				"0x%02X", cfg[0]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			sprintf(buf, "Path Selection Metric ID: 0x%02X",
				cfg[1]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
				cfg[2]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point(info, current_ev,
							  end_buf,
							  &iwe, buf);
			kfree(buf);
			break;
		case WLAN_EID_SUPP_RATES:
		case WLAN_EID_EXT_SUPP_RATES:
			/* display all supported rates in readable format */
			p = current_ev + iwe_stream_lcp_len(info);

			memset(&iwe, 0, sizeof(iwe));
			iwe.cmd = SIOCGIWRATE;
			/* Those two flags are ignored... */
			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;

			for (i = 0; i < ie[1]; i++) {
				iwe.u.bitrate.value =
					((ie[i + 2] & 0x7f) * 500000);
				p = iwe_stream_add_value(info, current_ev, p,
						end_buf, &iwe, IW_EV_PARAM_LEN);
			}
			current_ev = p;
			break;
		}
		rem -= ie[1] + 2;
		ie += ie[1] + 2;
	}

	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
	    ismesh) {
		memset(&iwe, 0, sizeof(iwe));
		iwe.cmd = SIOCGIWMODE;
		if (ismesh)
			iwe.u.mode = IW_MODE_MESH;
		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
			iwe.u.mode = IW_MODE_MASTER;
		else
			iwe.u.mode = IW_MODE_ADHOC;
		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
						  &iwe, IW_EV_UINT_LEN);
	}

	buf = kmalloc(30, GFP_ATOMIC);
	if (buf) {
		memset(&iwe, 0, sizeof(iwe));
		iwe.cmd = IWEVCUSTOM;
		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
		iwe.u.data.length = strlen(buf);
		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
						  &iwe, buf);
		memset(&iwe, 0, sizeof(iwe));
		iwe.cmd = IWEVCUSTOM;
		sprintf(buf, " Last beacon: %ums ago",
			elapsed_jiffies_msecs(bss->ts));
		iwe.u.data.length = strlen(buf);
		current_ev = iwe_stream_add_point(info, current_ev,
						  end_buf, &iwe, buf);
		kfree(buf);
	}

	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);

	return current_ev;
}


static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
				  struct iw_request_info *info,
				  char *buf, size_t len)
{
	char *current_ev = buf;
	char *end_buf = buf + len;
	struct cfg80211_internal_bss *bss;

	spin_lock_bh(&dev->bss_lock);
	cfg80211_bss_expire(dev);

	list_for_each_entry(bss, &dev->bss_list, list) {
		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
			spin_unlock_bh(&dev->bss_lock);
			return -E2BIG;
		}
		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
					   current_ev, end_buf);
	}
	spin_unlock_bh(&dev->bss_lock);
	return current_ev - buf;
}


int cfg80211_wext_giwscan(struct net_device *dev,
			  struct iw_request_info *info,
			  struct iw_point *data, char *extra)
{
	struct cfg80211_registered_device *rdev;
	int res;

	if (!netif_running(dev))
		return -ENETDOWN;

	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);

	if (IS_ERR(rdev))
		return PTR_ERR(rdev);

	if (rdev->scan_req) {
		res = -EAGAIN;
		goto out;
	}

	res = ieee80211_scan_results(rdev, info, extra, data->length);
	data->length = 0;
	if (res >= 0) {
		data->length = res;
		res = 0;
	}

 out:
	cfg80211_unlock_rdev(rdev);
	return res;
}
EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
#endif