summaryrefslogtreecommitdiff
path: root/net/wireless/scan.c
blob: 9f0901f3e42b60db2c6aee7927b2b0ddc0ab7759 (plain) (blame)
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
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
/*
 * cfg80211 scan result handling
 *
 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 * Copyright 2016	Intel Deutschland GmbH
 */
#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"
#include "rdev-ops.h"

/**
 * DOC: BSS tree/list structure
 *
 * At the top level, the BSS list is kept in both a list in each
 * registered device (@bss_list) as well as an RB-tree for faster
 * lookup. In the RB-tree, entries can be looked up using their
 * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
 * for other BSSes.
 *
 * Due to the possibility of hidden SSIDs, there's a second level
 * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
 * The hidden_list connects all BSSes belonging to a single AP
 * that has a hidden SSID, and connects beacon and probe response
 * entries. For a probe response entry for a hidden SSID, the
 * hidden_beacon_bss pointer points to the BSS struct holding the
 * beacon's information.
 *
 * Reference counting is done for all these references except for
 * the hidden_list, so that a beacon BSS struct that is otherwise
 * not referenced has one reference for being on the bss_list and
 * one for each probe response entry that points to it using the
 * hidden_beacon_bss pointer. When a BSS struct that has such a
 * pointer is get/put, the refcount update is also propagated to
 * the referenced struct, this ensure that it cannot get removed
 * while somebody is using the probe response version.
 *
 * Note that the hidden_beacon_bss pointer never changes, due to
 * the reference counting. Therefore, no locking is needed for
 * it.
 *
 * Also note that the hidden_beacon_bss pointer is only relevant
 * if the driver uses something other than the IEs, e.g. private
 * data stored stored in the BSS struct, since the beacon IEs are
 * also linked into the probe response struct.
 */

/*
 * Limit the number of BSS entries stored in mac80211. Each one is
 * a bit over 4k at most, so this limits to roughly 4-5M of memory.
 * If somebody wants to really attack this though, they'd likely
 * use small beacons, and only one type of frame, limiting each of
 * the entries to a much smaller size (in order to generate more
 * entries in total, so overhead is bigger.)
 */
static int bss_entries_limit = 1000;
module_param(bss_entries_limit, int, 0644);
MODULE_PARM_DESC(bss_entries_limit,
                 "limit to number of scan BSS entries (per wiphy, default 1000)");

#define IEEE80211_SCAN_RESULT_EXPIRE	(30 * HZ)

static void bss_free(struct cfg80211_internal_bss *bss)
{
	struct cfg80211_bss_ies *ies;

	if (WARN_ON(atomic_read(&bss->hold)))
		return;

	ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
	if (ies && !bss->pub.hidden_beacon_bss)
		kfree_rcu(ies, rcu_head);
	ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
	if (ies)
		kfree_rcu(ies, rcu_head);

	/*
	 * This happens when the module is removed, it doesn't
	 * really matter any more save for completeness
	 */
	if (!list_empty(&bss->hidden_list))
		list_del(&bss->hidden_list);

	kfree(bss);
}

static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
			       struct cfg80211_internal_bss *bss)
{
	lockdep_assert_held(&rdev->bss_lock);

	bss->refcount++;
	if (bss->pub.hidden_beacon_bss) {
		bss = container_of(bss->pub.hidden_beacon_bss,
				   struct cfg80211_internal_bss,
				   pub);
		bss->refcount++;
	}
}

static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
			       struct cfg80211_internal_bss *bss)
{
	lockdep_assert_held(&rdev->bss_lock);

	if (bss->pub.hidden_beacon_bss) {
		struct cfg80211_internal_bss *hbss;
		hbss = container_of(bss->pub.hidden_beacon_bss,
				    struct cfg80211_internal_bss,
				    pub);
		hbss->refcount--;
		if (hbss->refcount == 0)
			bss_free(hbss);
	}
	bss->refcount--;
	if (bss->refcount == 0)
		bss_free(bss);
}

static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
				  struct cfg80211_internal_bss *bss)
{
	lockdep_assert_held(&rdev->bss_lock);

	if (!list_empty(&bss->hidden_list)) {
		/*
		 * don't remove the beacon entry if it has
		 * probe responses associated with it
		 */
		if (!bss->pub.hidden_beacon_bss)
			return false;
		/*
		 * if it's a probe response entry break its
		 * link to the other entries in the group
		 */
		list_del_init(&bss->hidden_list);
	}

	list_del_init(&bss->list);
	rb_erase(&bss->rbn, &rdev->bss_tree);
	rdev->bss_entries--;
	WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
		  "rdev bss entries[%d]/list[empty:%d] corruption\n",
		  rdev->bss_entries, list_empty(&rdev->bss_list));
	bss_ref_put(rdev, bss);
	return true;
}

static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
				  unsigned long expire_time)
{
	struct cfg80211_internal_bss *bss, *tmp;
	bool expired = false;

	lockdep_assert_held(&rdev->bss_lock);

	list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
		if (atomic_read(&bss->hold))
			continue;
		if (!time_after(expire_time, bss->ts))
			continue;

		if (__cfg80211_unlink_bss(rdev, bss))
			expired = true;
	}

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

static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
{
	struct cfg80211_internal_bss *bss, *oldest = NULL;
	bool ret;

	lockdep_assert_held(&rdev->bss_lock);

	list_for_each_entry(bss, &rdev->bss_list, list) {
		if (atomic_read(&bss->hold))
			continue;

		if (!list_empty(&bss->hidden_list) &&
		    !bss->pub.hidden_beacon_bss)
			continue;

		if (oldest && time_before(oldest->ts, bss->ts))
			continue;
		oldest = bss;
	}

	if (WARN_ON(!oldest))
		return false;

	/*
	 * The callers make sure to increase rdev->bss_generation if anything
	 * gets removed (and a new entry added), so there's no need to also do
	 * it here.
	 */

	ret = __cfg80211_unlink_bss(rdev, oldest);
	WARN_ON(!ret);
	return ret;
}

void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
			   bool send_message)
{
	struct cfg80211_scan_request *request;
	struct wireless_dev *wdev;
	struct sk_buff *msg;
#ifdef CONFIG_CFG80211_WEXT
	union iwreq_data wrqu;
#endif

	ASSERT_RTNL();

	if (rdev->scan_msg) {
		nl80211_send_scan_msg(rdev, rdev->scan_msg);
		rdev->scan_msg = NULL;
		return;
	}

	request = rdev->scan_req;
	if (!request)
		return;

	wdev = request->wdev;

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

	if (!request->info.aborted &&
	    request->flags & NL80211_SCAN_FLAG_FLUSH) {
		/* flush entries from previous scans */
		spin_lock_bh(&rdev->bss_lock);
		__cfg80211_bss_expire(rdev, request->scan_start);
		spin_unlock_bh(&rdev->bss_lock);
	}

	msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);

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

		wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
	}
#endif

	if (wdev->netdev)
		dev_put(wdev->netdev);

	rdev->scan_req = NULL;
	kfree(request);

	if (!send_message)
		rdev->scan_msg = msg;
	else
		nl80211_send_scan_msg(rdev, msg);
}

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

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

	rtnl_lock();
	___cfg80211_scan_done(rdev, true);
	rtnl_unlock();
}

void cfg80211_scan_done(struct cfg80211_scan_request *request,
			struct cfg80211_scan_info *info)
{
	trace_cfg80211_scan_done(request, info);
	WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);

	request->info = *info;
	request->notified = true;
	queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
}
EXPORT_SYMBOL(cfg80211_scan_done);

void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev,
				 struct cfg80211_sched_scan_request *req)
{
	ASSERT_RTNL();

	list_add_rcu(&req->list, &rdev->sched_scan_req_list);
}

static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev,
					struct cfg80211_sched_scan_request *req)
{
	ASSERT_RTNL();

	list_del_rcu(&req->list);
	kfree_rcu(req, rcu_head);
}

static struct cfg80211_sched_scan_request *
cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid)
{
	struct cfg80211_sched_scan_request *pos;

	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());

	list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list) {
		if (pos->reqid == reqid)
			return pos;
	}
	return NULL;
}

/*
 * Determines if a scheduled scan request can be handled. When a legacy
 * scheduled scan is running no other scheduled scan is allowed regardless
 * whether the request is for legacy or multi-support scan. When a multi-support
 * scheduled scan is running a request for legacy scan is not allowed. In this
 * case a request for multi-support scan can be handled if resources are
 * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached.
 */
int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev,
				     bool want_multi)
{
	struct cfg80211_sched_scan_request *pos;
	int i = 0;

	list_for_each_entry(pos, &rdev->sched_scan_req_list, list) {
		/* request id zero means legacy in progress */
		if (!i && !pos->reqid)
			return -EINPROGRESS;
		i++;
	}

	if (i) {
		/* no legacy allowed when multi request(s) are active */
		if (!want_multi)
			return -EINPROGRESS;

		/* resource limit reached */
		if (i == rdev->wiphy.max_sched_scan_reqs)
			return -ENOSPC;
	}
	return 0;
}

void cfg80211_sched_scan_results_wk(struct work_struct *work)
{
	struct cfg80211_registered_device *rdev;
	struct cfg80211_sched_scan_request *req, *tmp;

	rdev = container_of(work, struct cfg80211_registered_device,
			   sched_scan_res_wk);

	rtnl_lock();
	list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) {
		if (req->report_results) {
			req->report_results = false;
			if (req->flags & NL80211_SCAN_FLAG_FLUSH) {
				/* flush entries from previous scans */
				spin_lock_bh(&rdev->bss_lock);
				__cfg80211_bss_expire(rdev, req->scan_start);
				spin_unlock_bh(&rdev->bss_lock);
				req->scan_start = jiffies;
			}
			nl80211_send_sched_scan(req,
						NL80211_CMD_SCHED_SCAN_RESULTS);
		}
	}
	rtnl_unlock();
}

void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid)
{
	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
	struct cfg80211_sched_scan_request *request;

	trace_cfg80211_sched_scan_results(wiphy, reqid);
	/* ignore if we're not scanning */

	rcu_read_lock();
	request = cfg80211_find_sched_scan_req(rdev, reqid);
	if (request) {
		request->report_results = true;
		queue_work(cfg80211_wq, &rdev->sched_scan_res_wk);
	}
	rcu_read_unlock();
}
EXPORT_SYMBOL(cfg80211_sched_scan_results);

void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy, u64 reqid)
{
	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

	ASSERT_RTNL();

	trace_cfg80211_sched_scan_stopped(wiphy, reqid);

	__cfg80211_stop_sched_scan(rdev, reqid, true);
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);

void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid)
{
	rtnl_lock();
	cfg80211_sched_scan_stopped_rtnl(wiphy, reqid);
	rtnl_unlock();
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped);

int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev,
				 struct cfg80211_sched_scan_request *req,
				 bool driver_initiated)
{
	ASSERT_RTNL();

	if (!driver_initiated) {
		int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid);
		if (err)
			return err;
	}

	nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED);

	cfg80211_del_sched_scan_req(rdev, req);

	return 0;
}

int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
			       u64 reqid, bool driver_initiated)
{
	struct cfg80211_sched_scan_request *sched_scan_req;

	ASSERT_RTNL();

	sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid);
	if (!sched_scan_req)
		return -ENOENT;

	return cfg80211_stop_sched_scan_req(rdev, sched_scan_req,
					    driver_initiated);
}

void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
                      unsigned long age_secs)
{
	struct cfg80211_internal_bss *bss;
	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);

	spin_lock_bh(&rdev->bss_lock);
	list_for_each_entry(bss, &rdev->bss_list, list)
		bss->ts -= age_jiffies;
	spin_unlock_bh(&rdev->bss_lock);
}

void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
{
	__cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
}

const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len,
				 const u8 *match, int match_len,
				 int match_offset)
{
	/* match_offset can't be smaller than 2, unless match_len is
	 * zero, in which case match_offset must be zero as well.
	 */
	if (WARN_ON((match_len && match_offset < 2) ||
		    (!match_len && match_offset)))
		return NULL;

	while (len >= 2 && len >= ies[1] + 2) {
		if ((ies[0] == eid) &&
		    (ies[1] + 2 >= match_offset + match_len) &&
		    !memcmp(ies + match_offset, match, match_len))
			return ies;

		len -= ies[1] + 2;
		ies += ies[1] + 2;
	}

	return NULL;
}
EXPORT_SYMBOL(cfg80211_find_ie_match);

const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type,
				  const u8 *ies, int len)
{
	const u8 *ie;
	u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
	int match_len = (oui_type < 0) ? 3 : sizeof(match);

	if (WARN_ON(oui_type > 0xff))
		return NULL;

	ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
				    match, match_len, 2);

	if (ie && (ie[1] < 4))
		return NULL;

	return ie;
}
EXPORT_SYMBOL(cfg80211_find_vendor_ie);

static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
		   const u8 *ssid, size_t ssid_len)
{
	const struct cfg80211_bss_ies *ies;
	const u8 *ssidie;

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

	if (!ssid)
		return true;

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

/**
 * enum bss_compare_mode - BSS compare mode
 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 */
enum bss_compare_mode {
	BSS_CMP_REGULAR,
	BSS_CMP_HIDE_ZLEN,
	BSS_CMP_HIDE_NUL,
};

static int cmp_bss(struct cfg80211_bss *a,
		   struct cfg80211_bss *b,
		   enum bss_compare_mode mode)
{
	const struct cfg80211_bss_ies *a_ies, *b_ies;
	const u8 *ie1 = NULL;
	const u8 *ie2 = NULL;
	int i, r;

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

	a_ies = rcu_access_pointer(a->ies);
	if (!a_ies)
		return -1;
	b_ies = rcu_access_pointer(b->ies);
	if (!b_ies)
		return 1;

	if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
		ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
				       a_ies->data, a_ies->len);
	if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
		ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
				       b_ies->data, b_ies->len);
	if (ie1 && ie2) {
		int mesh_id_cmp;

		if (ie1[1] == ie2[1])
			mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
		else
			mesh_id_cmp = ie2[1] - ie1[1];

		ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
				       a_ies->data, a_ies->len);
		ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
				       b_ies->data, b_ies->len);
		if (ie1 && ie2) {
			if (mesh_id_cmp)
				return mesh_id_cmp;
			if (ie1[1] != ie2[1])
				return ie2[1] - ie1[1];
			return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
		}
	}

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

	ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
	ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);

	if (!ie1 && !ie2)
		return 0;

	/*
	 * Note that with "hide_ssid", the function returns a match if
	 * the already-present BSS ("b") is a hidden SSID beacon for
	 * the new BSS ("a").
	 */

	/* sort missing IE before (left of) present IE */
	if (!ie1)
		return -1;
	if (!ie2)
		return 1;

	switch (mode) {
	case BSS_CMP_HIDE_ZLEN:
		/*
		 * In ZLEN mode we assume the BSS entry we're
		 * looking for has a zero-length SSID. So if
		 * the one we're looking at right now has that,
		 * return 0. Otherwise, return the difference
		 * in length, but since we're looking for the
		 * 0-length it's really equivalent to returning
		 * the length of the one we're looking at.
		 *
		 * No content comparison is needed as we assume
		 * the content length is zero.
		 */
		return ie2[1];
	case BSS_CMP_REGULAR:
	default:
		/* sort by length first, then by contents */
		if (ie1[1] != ie2[1])
			return ie2[1] - ie1[1];
		return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
	case BSS_CMP_HIDE_NUL:
		if (ie1[1] != ie2[1])
			return ie2[1] - ie1[1];
		/* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
		for (i = 0; i < ie2[1]; i++)
			if (ie2[i + 2])
				return -1;
		return 0;
	}
}

static bool cfg80211_bss_type_match(u16 capability,
				    enum nl80211_band band,
				    enum ieee80211_bss_type bss_type)
{
	bool ret = true;
	u16 mask, val;

	if (bss_type == IEEE80211_BSS_TYPE_ANY)
		return ret;

	if (band == NL80211_BAND_60GHZ) {
		mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
		switch (bss_type) {
		case IEEE80211_BSS_TYPE_ESS:
			val = WLAN_CAPABILITY_DMG_TYPE_AP;
			break;
		case IEEE80211_BSS_TYPE_PBSS:
			val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
			break;
		case IEEE80211_BSS_TYPE_IBSS:
			val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
			break;
		default:
			return false;
		}
	} else {
		mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
		switch (bss_type) {
		case IEEE80211_BSS_TYPE_ESS:
			val = WLAN_CAPABILITY_ESS;
			break;
		case IEEE80211_BSS_TYPE_IBSS:
			val = WLAN_CAPABILITY_IBSS;
			break;
		case IEEE80211_BSS_TYPE_MBSS:
			val = 0;
			break;
		default:
			return false;
		}
	}

	ret = ((capability & mask) == val);
	return ret;
}

/* Returned bss is reference counted and must be cleaned up appropriately. */
struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
				      struct ieee80211_channel *channel,
				      const u8 *bssid,
				      const u8 *ssid, size_t ssid_len,
				      enum ieee80211_bss_type bss_type,
				      enum ieee80211_privacy privacy)
{
	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
	struct cfg80211_internal_bss *bss, *res = NULL;
	unsigned long now = jiffies;
	int bss_privacy;

	trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
			       privacy);

	spin_lock_bh(&rdev->bss_lock);

	list_for_each_entry(bss, &rdev->bss_list, list) {
		if (!cfg80211_bss_type_match(bss->pub.capability,
					     bss->pub.channel->band, bss_type))
			continue;

		bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
		if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
		    (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
			continue;
		if (channel && bss->pub.channel != channel)
			continue;
		if (!is_valid_ether_addr(bss->pub.bssid))
			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;
			bss_ref_get(rdev, res);
			break;
		}
	}

	spin_unlock_bh(&rdev->bss_lock);
	if (!res)
		return NULL;
	trace_cfg80211_return_bss(&res->pub);
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_get_bss);

static void rb_insert_bss(struct cfg80211_registered_device *rdev,
			  struct cfg80211_internal_bss *bss)
{
	struct rb_node **p = &rdev->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, BSS_CMP_REGULAR);

		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, &rdev->bss_tree);
}

static struct cfg80211_internal_bss *
rb_find_bss(struct cfg80211_registered_device *rdev,
	    struct cfg80211_internal_bss *res,
	    enum bss_compare_mode mode)
{
	struct rb_node *n = rdev->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, mode);

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

	return NULL;
}

static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
				   struct cfg80211_internal_bss *new)
{
	const struct cfg80211_bss_ies *ies;
	struct cfg80211_internal_bss *bss;
	const u8 *ie;
	int i, ssidlen;
	u8 fold = 0;
	u32 n_entries = 0;

	ies = rcu_access_pointer(new->pub.beacon_ies);
	if (WARN_ON(!ies))
		return false;

	ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
	if (!ie) {
		/* nothing to do */
		return true;
	}

	ssidlen = ie[1];
	for (i = 0; i < ssidlen; i++)
		fold |= ie[2 + i];

	if (fold) {
		/* not a hidden SSID */
		return true;
	}

	/* This is the bad part ... */

	list_for_each_entry(bss, &rdev->bss_list, list) {
		/*
		 * we're iterating all the entries anyway, so take the
		 * opportunity to validate the list length accounting
		 */
		n_entries++;

		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
			continue;
		if (bss->pub.channel != new->pub.channel)
			continue;
		if (bss->pub.scan_width != new->pub.scan_width)
			continue;
		if (rcu_access_pointer(bss->pub.beacon_ies))
			continue;
		ies = rcu_access_pointer(bss->pub.ies);
		if (!ies)
			continue;
		ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
		if (!ie)
			continue;
		if (ssidlen && ie[1] != ssidlen)
			continue;
		if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
			continue;
		if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
			list_del(&bss->hidden_list);
		/* combine them */
		list_add(&bss->hidden_list, &new->hidden_list);
		bss->pub.hidden_beacon_bss = &new->pub;
		new->refcount += bss->refcount;
		rcu_assign_pointer(bss->pub.beacon_ies,
				   new->pub.beacon_ies);
	}

	WARN_ONCE(n_entries != rdev->bss_entries,
		  "rdev bss entries[%d]/list[len:%d] corruption\n",
		  rdev->bss_entries, n_entries);

	return true;
}

/* Returned bss is reference counted and must be cleaned up appropriately. */
static struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *rdev,
		    struct cfg80211_internal_bss *tmp,
		    bool signal_valid)
{
	struct cfg80211_internal_bss *found = NULL;

	if (WARN_ON(!tmp->pub.channel))
		return NULL;

	tmp->ts = jiffies;

	spin_lock_bh(&rdev->bss_lock);

	if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
		spin_unlock_bh(&rdev->bss_lock);
		return NULL;
	}

	found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);

	if (found) {
		/* Update IEs */
		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
			const struct cfg80211_bss_ies *old;

			old = rcu_access_pointer(found->pub.proberesp_ies);

			rcu_assign_pointer(found->pub.proberesp_ies,
					   tmp->pub.proberesp_ies);
			/* Override possible earlier Beacon frame IEs */
			rcu_assign_pointer(found->pub.ies,
					   tmp->pub.proberesp_ies);
			if (old)
				kfree_rcu((struct cfg80211_bss_ies *)old,
					  rcu_head);
		} else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
			const struct cfg80211_bss_ies *old;
			struct cfg80211_internal_bss *bss;

			if (found->pub.hidden_beacon_bss &&
			    !list_empty(&found->hidden_list)) {
				const struct cfg80211_bss_ies *f;

				/*
				 * The found BSS struct is one of the probe
				 * response members of a group, but we're
				 * receiving a beacon (beacon_ies in the tmp
				 * bss is used). This can only mean that the
				 * AP changed its beacon from not having an
				 * SSID to showing it, which is confusing so
				 * drop this information.
				 */

				f = rcu_access_pointer(tmp->pub.beacon_ies);
				kfree_rcu((struct cfg80211_bss_ies *)f,
					  rcu_head);
				goto drop;
			}

			old = rcu_access_pointer(found->pub.beacon_ies);

			rcu_assign_pointer(found->pub.beacon_ies,
					   tmp->pub.beacon_ies);

			/* Override IEs if they were from a beacon before */
			if (old == rcu_access_pointer(found->pub.ies))
				rcu_assign_pointer(found->pub.ies,
						   tmp->pub.beacon_ies);

			/* Assign beacon IEs to all sub entries */
			list_for_each_entry(bss, &found->hidden_list,
					    hidden_list) {
				const struct cfg80211_bss_ies *ies;

				ies = rcu_access_pointer(bss->pub.beacon_ies);
				WARN_ON(ies != old);

				rcu_assign_pointer(bss->pub.beacon_ies,
						   tmp->pub.beacon_ies);
			}

			if (old)
				kfree_rcu((struct cfg80211_bss_ies *)old,
					  rcu_head);
		}

		found->pub.beacon_interval = tmp->pub.beacon_interval;
		/*
		 * don't update the signal if beacon was heard on
		 * adjacent channel.
		 */
		if (signal_valid)
			found->pub.signal = tmp->pub.signal;
		found->pub.capability = tmp->pub.capability;
		found->ts = tmp->ts;
		found->ts_boottime = tmp->ts_boottime;
		found->parent_tsf = tmp->parent_tsf;
		ether_addr_copy(found->parent_bssid, tmp->parent_bssid);
	} else {
		struct cfg80211_internal_bss *new;
		struct cfg80211_internal_bss *hidden;
		struct cfg80211_bss_ies *ies;

		/*
		 * create a copy -- the "res" variable that is passed in
		 * is allocated on the stack since it's not needed in the
		 * more common case of an update
		 */
		new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
			      GFP_ATOMIC);
		if (!new) {
			ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
			if (ies)
				kfree_rcu(ies, rcu_head);
			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
			if (ies)
				kfree_rcu(ies, rcu_head);
			goto drop;
		}
		memcpy(new, tmp, sizeof(*new));
		new->refcount = 1;
		INIT_LIST_HEAD(&new->hidden_list);

		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
			hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
			if (!hidden)
				hidden = rb_find_bss(rdev, tmp,
						     BSS_CMP_HIDE_NUL);
			if (hidden) {
				new->pub.hidden_beacon_bss = &hidden->pub;
				list_add(&new->hidden_list,
					 &hidden->hidden_list);
				hidden->refcount++;
				rcu_assign_pointer(new->pub.beacon_ies,
						   hidden->pub.beacon_ies);
			}
		} else {
			/*
			 * Ok so we found a beacon, and don't have an entry. If
			 * it's a beacon with hidden SSID, we might be in for an
			 * expensive search for any probe responses that should
			 * be grouped with this beacon for updates ...
			 */
			if (!cfg80211_combine_bsses(rdev, new)) {
				kfree(new);
				goto drop;
			}
		}

		if (rdev->bss_entries >= bss_entries_limit &&
		    !cfg80211_bss_expire_oldest(rdev)) {
			kfree(new);
			goto drop;
		}

		list_add_tail(&new->list, &rdev->bss_list);
		rdev->bss_entries++;
		rb_insert_bss(rdev, new);
		found = new;
	}

	rdev->bss_generation++;
	bss_ref_get(rdev, found);
	spin_unlock_bh(&rdev->bss_lock);

	return found;
 drop:
	spin_unlock_bh(&rdev->bss_lock);
	return NULL;
}

static struct ieee80211_channel *
cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
			 struct ieee80211_channel *channel)
{
	const u8 *tmp;
	u32 freq;
	int channel_number = -1;

	tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
	if (tmp && tmp[1] == 1) {
		channel_number = tmp[2];
	} else {
		tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
		if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
			struct ieee80211_ht_operation *htop = (void *)(tmp + 2);

			channel_number = htop->primary_chan;
		}
	}

	if (channel_number < 0)
		return channel;

	freq = ieee80211_channel_to_frequency(channel_number, channel->band);
	channel = ieee80211_get_channel(wiphy, freq);
	if (!channel)
		return NULL;
	if (channel->flags & IEEE80211_CHAN_DISABLED)
		return NULL;
	return channel;
}

/* Returned bss is reference counted and must be cleaned up appropriately. */
struct cfg80211_bss *
cfg80211_inform_bss_data(struct wiphy *wiphy,
			 struct cfg80211_inform_bss *data,
			 enum cfg80211_bss_frame_type ftype,
			 const u8 *bssid, u64 tsf, u16 capability,
			 u16 beacon_interval, const u8 *ie, size_t ielen,
			 gfp_t gfp)
{
	struct cfg80211_bss_ies *ies;
	struct ieee80211_channel *channel;
	struct cfg80211_internal_bss tmp = {}, *res;
	int bss_type;
	bool signal_valid;

	if (WARN_ON(!wiphy))
		return NULL;

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

	channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
	if (!channel)
		return NULL;

	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
	tmp.pub.channel = channel;
	tmp.pub.scan_width = data->scan_width;
	tmp.pub.signal = data->signal;
	tmp.pub.beacon_interval = beacon_interval;
	tmp.pub.capability = capability;
	tmp.ts_boottime = data->boottime_ns;

	/*
	 * If 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 IEs pointer should we have received an earlier
	 * indication of Probe Response data.
	 */
	ies = kzalloc(sizeof(*ies) + ielen, gfp);
	if (!ies)
		return NULL;
	ies->len = ielen;
	ies->tsf = tsf;
	ies->from_beacon = false;
	memcpy(ies->data, ie, ielen);

	switch (ftype) {
	case CFG80211_BSS_FTYPE_BEACON:
		ies->from_beacon = true;
		/* fall through to assign */
	case CFG80211_BSS_FTYPE_UNKNOWN:
		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
		break;
	case CFG80211_BSS_FTYPE_PRESP:
		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
		break;
	}
	rcu_assign_pointer(tmp.pub.ies, ies);

	signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
		wiphy->max_adj_channel_rssi_comp;
	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
	if (!res)
		return NULL;

	if (channel->band == NL80211_BAND_60GHZ) {
		bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
		if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
		    bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
			regulatory_hint_found_beacon(wiphy, channel, gfp);
	} else {
		if (res->pub.capability & WLAN_CAPABILITY_ESS)
			regulatory_hint_found_beacon(wiphy, channel, gfp);
	}

	trace_cfg80211_return_bss(&res->pub);
	/* cfg80211_bss_update gives us a referenced result */
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss_data);

/* cfg80211_inform_bss_width_frame helper */
struct cfg80211_bss *
cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
			       struct cfg80211_inform_bss *data,
			       struct ieee80211_mgmt *mgmt, size_t len,
			       gfp_t gfp)

{
	struct cfg80211_internal_bss tmp = {}, *res;
	struct cfg80211_bss_ies *ies;
	struct ieee80211_channel *channel;
	bool signal_valid;
	size_t ielen = len - offsetof(struct ieee80211_mgmt,
				      u.probe_resp.variable);
	int bss_type;

	BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
			offsetof(struct ieee80211_mgmt, u.beacon.variable));

	trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);

	if (WARN_ON(!mgmt))
		return NULL;

	if (WARN_ON(!wiphy))
		return NULL;

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

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

	channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
					   ielen, data->chan);
	if (!channel)
		return NULL;

	ies = kzalloc(sizeof(*ies) + ielen, gfp);
	if (!ies)
		return NULL;
	ies->len = ielen;
	ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
	ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
	memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);

	if (ieee80211_is_probe_resp(mgmt->frame_control))
		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
	else
		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
	rcu_assign_pointer(tmp.pub.ies, ies);

	memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
	tmp.pub.channel = channel;
	tmp.pub.scan_width = data->scan_width;
	tmp.pub.signal = data->signal;
	tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
	tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
	tmp.ts_boottime = data->boottime_ns;
	tmp.parent_tsf = data->parent_tsf;
	ether_addr_copy(tmp.parent_bssid, data->parent_bssid);

	signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
		wiphy->max_adj_channel_rssi_comp;
	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
	if (!res)
		return NULL;

	if (channel->band == NL80211_BAND_60GHZ) {
		bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
		if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
		    bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
			regulatory_hint_found_beacon(wiphy, channel, gfp);
	} else {
		if (res->pub.capability & WLAN_CAPABILITY_ESS)
			regulatory_hint_found_beacon(wiphy, channel, gfp);
	}

	trace_cfg80211_return_bss(&res->pub);
	/* cfg80211_bss_update gives us a referenced result */
	return &res->pub;
}
EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);

void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
	struct cfg80211_internal_bss *bss;

	if (!pub)
		return;

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

	spin_lock_bh(&rdev->bss_lock);
	bss_ref_get(rdev, bss);
	spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_ref_bss);

void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
	struct cfg80211_internal_bss *bss;

	if (!pub)
		return;

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

	spin_lock_bh(&rdev->bss_lock);
	bss_ref_put(rdev, bss);
	spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_put_bss);

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

	if (WARN_ON(!pub))
		return;

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

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

#ifdef CONFIG_CFG80211_WEXT
static struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
{
	struct cfg80211_registered_device *rdev;
	struct net_device *dev;

	ASSERT_RTNL();

	dev = dev_get_by_index(net, ifindex);
	if (!dev)
		return ERR_PTR(-ENODEV);
	if (dev->ieee80211_ptr)
		rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
	else
		rdev = ERR_PTR(-ENODEV);
	dev_put(dev);
	return rdev;
}

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 nl80211_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 || rdev->scan_msg) {
		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
		n_channels = ieee80211_get_num_supported_channels(wiphy);

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

	creq->wiphy = wiphy;
	creq->wdev = dev->ieee80211_ptr;
	/* SSIDs come after channels */
	creq->ssids = (void *)&creq->channels[n_channels];
	creq->n_channels = n_channels;
	creq->n_ssids = 1;
	creq->scan_start = jiffies;

	/* translate "Scan on frequencies" request */
	i = 0;
	for (band = 0; band < NUM_NL80211_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++) {
					struct iw_freq *freq =
						&wreq->channel_list[k];
					int wext_freq =
						cfg80211_wext_freq(freq);

					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 < NUM_NL80211_BANDS; i++)
		if (wiphy->bands[i])
			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;

	eth_broadcast_addr(creq->bssid);

	rdev->scan_req = creq;
	err = rdev_scan(rdev, creq);
	if (err) {
		rdev->scan_req = NULL;
		/* creq will be freed below */
	} else {
		nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
		/* creq now owned by driver */
		creq = NULL;
		dev_hold(dev);
	}
 out:
	kfree(creq);
	return err;
}
EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);

static char *ieee80211_scan_add_ies(struct iw_request_info *info,
				    const struct cfg80211_bss_ies *ies,
				    char *current_ev, char *end_buf)
{
	const u8 *pos, *end, *next;
	struct iw_event iwe;

	if (!ies)
		return current_ev;

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

	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_check(info, current_ev,
							end_buf, &iwe,
							(void *)pos);
		if (IS_ERR(current_ev))
			return current_ev;
		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_check(info, current_ev,
							end_buf, &iwe,
							(void *)pos);
		if (IS_ERR(current_ev))
			return current_ev;
	}

	return current_ev;
}

static char *
ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
	      struct cfg80211_internal_bss *bss, char *current_ev,
	      char *end_buf)
{
	const struct cfg80211_bss_ies *ies;
	struct iw_event iwe;
	const u8 *ie;
	u8 buf[50];
	u8 *cfg, *p, *tmp;
	int rem, 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_check(info, current_ev, end_buf, &iwe,
						IW_EV_ADDR_LEN);
	if (IS_ERR(current_ev))
		return current_ev;

	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_check(info, current_ev, end_buf, &iwe,
						IW_EV_FREQ_LEN);
	if (IS_ERR(current_ev))
		return current_ev;

	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_check(info, current_ev, end_buf, &iwe,
						IW_EV_FREQ_LEN);
	if (IS_ERR(current_ev))
		return current_ev;

	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_check(info, current_ev,
							end_buf, &iwe,
							IW_EV_QUAL_LEN);
		if (IS_ERR(current_ev))
			return current_ev;
	}

	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_check(info, current_ev, end_buf,
						&iwe, "");
	if (IS_ERR(current_ev))
		return current_ev;

	rcu_read_lock();
	ies = rcu_dereference(bss->pub.ies);
	rem = ies->len;
	ie = ies->data;

	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_check(info,
								current_ev,
								end_buf, &iwe,
								(u8 *)ie + 2);
			if (IS_ERR(current_ev))
				goto unlock;
			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_check(info,
								current_ev,
								end_buf, &iwe,
								(u8 *)ie + 2);
			if (IS_ERR(current_ev))
				goto unlock;
			break;
		case WLAN_EID_MESH_CONFIG:
			ismesh = true;
			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
				break;
			cfg = (u8 *)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_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			sprintf(buf, "Path Selection Metric ID: 0x%02X",
				cfg[1]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
				cfg[2]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
			iwe.u.data.length = strlen(buf);
			current_ev = iwe_stream_add_point_check(info,
								current_ev,
								end_buf,
								&iwe, buf);
			if (IS_ERR(current_ev))
				goto unlock;
			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);
				tmp = p;
				p = iwe_stream_add_value(info, current_ev, p,
							 end_buf, &iwe,
							 IW_EV_PARAM_LEN);
				if (p == tmp) {
					current_ev = ERR_PTR(-E2BIG);
					goto unlock;
				}
			}
			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_check(info, current_ev,
							end_buf, &iwe,
							IW_EV_UINT_LEN);
		if (IS_ERR(current_ev))
			goto unlock;
	}

	memset(&iwe, 0, sizeof(iwe));
	iwe.cmd = IWEVCUSTOM;
	sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
	iwe.u.data.length = strlen(buf);
	current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
						&iwe, buf);
	if (IS_ERR(current_ev))
		goto unlock;
	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_check(info, current_ev,
						end_buf, &iwe, buf);
	if (IS_ERR(current_ev))
		goto unlock;

	current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);

 unlock:
	rcu_read_unlock();
	return current_ev;
}


static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
				  struct iw_request_info *info,
				  char *buf, size_t len)
{
	char *current_ev = buf;
	char *end_buf = buf + len;
	struct cfg80211_internal_bss *bss;
	int err = 0;

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

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

	if (err)
		return err;
	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 || rdev->scan_msg)
		return -EAGAIN;

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

	return res;
}
EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
#endif