summaryrefslogtreecommitdiffstats
path: root/net/mac80211/sta_info.c
blob: d2eb64e1235383e9b0e6aade66710f74ec1b4f3f (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
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
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/timer.h>
#include <linux/rtnetlink.h>

#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#include "sta_info.h"
#include "debugfs_sta.h"
#include "mesh.h"
#include "wme.h"

/**
 * DOC: STA information lifetime rules
 *
 * STA info structures (&struct sta_info) are managed in a hash table
 * for faster lookup and a list for iteration. They are managed using
 * RCU, i.e. access to the list and hash table is protected by RCU.
 *
 * Upon allocating a STA info structure with sta_info_alloc(), the caller
 * owns that structure. It must then insert it into the hash table using
 * either sta_info_insert() or sta_info_insert_rcu(); only in the latter
 * case (which acquires an rcu read section but must not be called from
 * within one) will the pointer still be valid after the call. Note that
 * the caller may not do much with the STA info before inserting it, in
 * particular, it may not start any mesh peer link management or add
 * encryption keys.
 *
 * When the insertion fails (sta_info_insert()) returns non-zero), the
 * structure will have been freed by sta_info_insert()!
 *
 * Station entries are added by mac80211 when you establish a link with a
 * peer. This means different things for the different type of interfaces
 * we support. For a regular station this mean we add the AP sta when we
 * receive an association response from the AP. For IBSS this occurs when
 * get to know about a peer on the same IBSS. For WDS we add the sta for
 * the peer immediately upon device open. When using AP mode we add stations
 * for each respective station upon request from userspace through nl80211.
 *
 * In order to remove a STA info structure, various sta_info_destroy_*()
 * calls are available.
 *
 * There is no concept of ownership on a STA entry, each structure is
 * owned by the global hash table/list until it is removed. All users of
 * the structure need to be RCU protected so that the structure won't be
 * freed before they are done using it.
 */

/* Caller must hold local->sta_mtx */
static int sta_info_hash_del(struct ieee80211_local *local,
			     struct sta_info *sta)
{
	struct sta_info *s;

	s = rcu_dereference_protected(local->sta_hash[STA_HASH(sta->sta.addr)],
				      lockdep_is_held(&local->sta_mtx));
	if (!s)
		return -ENOENT;
	if (s == sta) {
		rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)],
				   s->hnext);
		return 0;
	}

	while (rcu_access_pointer(s->hnext) &&
	       rcu_access_pointer(s->hnext) != sta)
		s = rcu_dereference_protected(s->hnext,
					lockdep_is_held(&local->sta_mtx));
	if (rcu_access_pointer(s->hnext)) {
		rcu_assign_pointer(s->hnext, sta->hnext);
		return 0;
	}

	return -ENOENT;
}

static void free_sta_work(struct work_struct *wk)
{
	struct sta_info *sta = container_of(wk, struct sta_info, free_sta_wk);
	int ac, i;
	struct tid_ampdu_tx *tid_tx;
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;

	/*
	 * At this point, when being called as call_rcu callback,
	 * neither mac80211 nor the driver can reference this
	 * sta struct any more except by still existing timers
	 * associated with this station that we clean up below.
	 */

	if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
		BUG_ON(!sdata->bss);

		clear_sta_flag(sta, WLAN_STA_PS_STA);

		atomic_dec(&sdata->bss->num_sta_ps);
		sta_info_recalc_tim(sta);
	}

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		local->total_ps_buffered -= skb_queue_len(&sta->ps_tx_buf[ac]);
		ieee80211_purge_tx_queue(&local->hw, &sta->ps_tx_buf[ac]);
		ieee80211_purge_tx_queue(&local->hw, &sta->tx_filtered[ac]);
	}

#ifdef CONFIG_MAC80211_MESH
	if (ieee80211_vif_is_mesh(&sdata->vif)) {
		mesh_accept_plinks_update(sdata);
		mesh_plink_deactivate(sta);
		del_timer_sync(&sta->plink_timer);
	}
#endif

	cancel_work_sync(&sta->drv_unblock_wk);

	/*
	 * Destroy aggregation state here. It would be nice to wait for the
	 * driver to finish aggregation stop and then clean up, but for now
	 * drivers have to handle aggregation stop being requested, followed
	 * directly by station destruction.
	 */
	for (i = 0; i < STA_TID_NUM; i++) {
		tid_tx = rcu_dereference_raw(sta->ampdu_mlme.tid_tx[i]);
		if (!tid_tx)
			continue;
		ieee80211_purge_tx_queue(&local->hw, &tid_tx->pending);
		kfree(tid_tx);
	}

	sta_info_free(local, sta);
}

static void free_sta_rcu(struct rcu_head *h)
{
	struct sta_info *sta = container_of(h, struct sta_info, rcu_head);

	ieee80211_queue_work(&sta->local->hw, &sta->free_sta_wk);
}

/* protected by RCU */
struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
			      const u8 *addr)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;

	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
				    lockdep_is_held(&local->sta_mtx));
	while (sta) {
		if (sta->sdata == sdata &&
		    ether_addr_equal(sta->sta.addr, addr))
			break;
		sta = rcu_dereference_check(sta->hnext,
					    lockdep_is_held(&local->sta_mtx));
	}
	return sta;
}

/*
 * Get sta info either from the specified interface
 * or from one of its vlans
 */
struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
				  const u8 *addr)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;

	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
				    lockdep_is_held(&local->sta_mtx));
	while (sta) {
		if ((sta->sdata == sdata ||
		     (sta->sdata->bss && sta->sdata->bss == sdata->bss)) &&
		    ether_addr_equal(sta->sta.addr, addr))
			break;
		sta = rcu_dereference_check(sta->hnext,
					    lockdep_is_held(&local->sta_mtx));
	}
	return sta;
}

struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
				     int idx)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	int i = 0;

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sdata != sta->sdata)
			continue;
		if (i < idx) {
			++i;
			continue;
		}
		return sta;
	}

	return NULL;
}

/**
 * sta_info_free - free STA
 *
 * @local: pointer to the global information
 * @sta: STA info to free
 *
 * This function must undo everything done by sta_info_alloc()
 * that may happen before sta_info_insert(). It may only be
 * called when sta_info_insert() has not been attempted (and
 * if that fails, the station is freed anyway.)
 */
void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
{
	if (sta->rate_ctrl)
		rate_control_free_sta(sta);

	sta_dbg(sta->sdata, "Destroyed STA %pM\n", sta->sta.addr);

	kfree(sta);
}

/* Caller must hold local->sta_mtx */
static void sta_info_hash_add(struct ieee80211_local *local,
			      struct sta_info *sta)
{
	lockdep_assert_held(&local->sta_mtx);
	sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)];
	rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
}

static void sta_unblock(struct work_struct *wk)
{
	struct sta_info *sta;

	sta = container_of(wk, struct sta_info, drv_unblock_wk);

	if (sta->dead)
		return;

	if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
		local_bh_disable();
		ieee80211_sta_ps_deliver_wakeup(sta);
		local_bh_enable();
	} else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL)) {
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);

		local_bh_disable();
		ieee80211_sta_ps_deliver_poll_response(sta);
		local_bh_enable();
	} else if (test_and_clear_sta_flag(sta, WLAN_STA_UAPSD)) {
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);

		local_bh_disable();
		ieee80211_sta_ps_deliver_uapsd(sta);
		local_bh_enable();
	} else
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
}

static int sta_prepare_rate_control(struct ieee80211_local *local,
				    struct sta_info *sta, gfp_t gfp)
{
	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
		return 0;

	sta->rate_ctrl = local->rate_ctrl;
	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
						     &sta->sta, gfp);
	if (!sta->rate_ctrl_priv)
		return -ENOMEM;

	return 0;
}

struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
				const u8 *addr, gfp_t gfp)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	struct timespec uptime;
	int i;

	sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
	if (!sta)
		return NULL;

	spin_lock_init(&sta->lock);
	INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
	INIT_WORK(&sta->free_sta_wk, free_sta_work);
	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
	mutex_init(&sta->ampdu_mlme.mtx);

	memcpy(sta->sta.addr, addr, ETH_ALEN);
	sta->local = local;
	sta->sdata = sdata;
	sta->last_rx = jiffies;

	sta->sta_state = IEEE80211_STA_NONE;

	do_posix_clock_monotonic_gettime(&uptime);
	sta->last_connected = uptime.tv_sec;
	ewma_init(&sta->avg_signal, 1024, 8);

	if (sta_prepare_rate_control(local, sta, gfp)) {
		kfree(sta);
		return NULL;
	}

	for (i = 0; i < STA_TID_NUM; i++) {
		/*
		 * timer_to_tid must be initialized with identity mapping
		 * to enable session_timer's data differentiation. See
		 * sta_rx_agg_session_timer_expired for usage.
		 */
		sta->timer_to_tid[i] = i;
	}
	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
		skb_queue_head_init(&sta->ps_tx_buf[i]);
		skb_queue_head_init(&sta->tx_filtered[i]);
	}

	for (i = 0; i < NUM_RX_DATA_QUEUES; i++)
		sta->last_seq_ctrl[i] = cpu_to_le16(USHRT_MAX);

	sta_dbg(sdata, "Allocated STA %pM\n", sta->sta.addr);

#ifdef CONFIG_MAC80211_MESH
	sta->plink_state = NL80211_PLINK_LISTEN;
	init_timer(&sta->plink_timer);
#endif

	return sta;
}

static int sta_info_insert_check(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;

	/*
	 * Can't be a WARN_ON because it can be triggered through a race:
	 * something inserts a STA (on one CPU) without holding the RTNL
	 * and another CPU turns off the net device.
	 */
	if (unlikely(!ieee80211_sdata_running(sdata)))
		return -ENETDOWN;

	if (WARN_ON(ether_addr_equal(sta->sta.addr, sdata->vif.addr) ||
		    is_multicast_ether_addr(sta->sta.addr)))
		return -EINVAL;

	return 0;
}

static int sta_info_insert_drv_state(struct ieee80211_local *local,
				     struct ieee80211_sub_if_data *sdata,
				     struct sta_info *sta)
{
	enum ieee80211_sta_state state;
	int err = 0;

	for (state = IEEE80211_STA_NOTEXIST; state < sta->sta_state; state++) {
		err = drv_sta_state(local, sdata, sta, state, state + 1);
		if (err)
			break;
	}

	if (!err) {
		/*
		 * Drivers using legacy sta_add/sta_remove callbacks only
		 * get uploaded set to true after sta_add is called.
		 */
		if (!local->ops->sta_add)
			sta->uploaded = true;
		return 0;
	}

	if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
		sdata_info(sdata,
			   "failed to move IBSS STA %pM to state %d (%d) - keeping it anyway\n",
			   sta->sta.addr, state + 1, err);
		err = 0;
	}

	/* unwind on error */
	for (; state > IEEE80211_STA_NOTEXIST; state--)
		WARN_ON(drv_sta_state(local, sdata, sta, state, state - 1));

	return err;
}

/*
 * should be called with sta_mtx locked
 * this function replaces the mutex lock
 * with a RCU lock
 */
static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
{
	struct ieee80211_local *local = sta->local;
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct station_info sinfo;
	int err = 0;

	lockdep_assert_held(&local->sta_mtx);

	/* check if STA exists already */
	if (sta_info_get_bss(sdata, sta->sta.addr)) {
		err = -EEXIST;
		goto out_err;
	}

	/* notify driver */
	err = sta_info_insert_drv_state(local, sdata, sta);
	if (err)
		goto out_err;

	local->num_sta++;
	local->sta_generation++;
	smp_mb();

	/* make the station visible */
	sta_info_hash_add(local, sta);

	list_add_rcu(&sta->list, &local->sta_list);

	set_sta_flag(sta, WLAN_STA_INSERTED);

	ieee80211_sta_debugfs_add(sta);
	rate_control_add_sta_debugfs(sta);

	memset(&sinfo, 0, sizeof(sinfo));
	sinfo.filled = 0;
	sinfo.generation = local->sta_generation;
	cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL);

	sta_dbg(sdata, "Inserted STA %pM\n", sta->sta.addr);

	/* move reference to rcu-protected */
	rcu_read_lock();
	mutex_unlock(&local->sta_mtx);

	if (ieee80211_vif_is_mesh(&sdata->vif))
		mesh_accept_plinks_update(sdata);

	return 0;
 out_err:
	mutex_unlock(&local->sta_mtx);
	rcu_read_lock();
	return err;
}

int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)
{
	struct ieee80211_local *local = sta->local;
	int err = 0;

	might_sleep();

	err = sta_info_insert_check(sta);
	if (err) {
		rcu_read_lock();
		goto out_free;
	}

	mutex_lock(&local->sta_mtx);

	err = sta_info_insert_finish(sta);
	if (err)
		goto out_free;

	return 0;
 out_free:
	BUG_ON(!err);
	sta_info_free(local, sta);
	return err;
}

int sta_info_insert(struct sta_info *sta)
{
	int err = sta_info_insert_rcu(sta);

	rcu_read_unlock();

	return err;
}

static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
{
	/*
	 * This format has been mandated by the IEEE specifications,
	 * so this line may not be changed to use the __set_bit() format.
	 */
	bss->tim[aid / 8] |= (1 << (aid % 8));
}

static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
{
	/*
	 * This format has been mandated by the IEEE specifications,
	 * so this line may not be changed to use the __clear_bit() format.
	 */
	bss->tim[aid / 8] &= ~(1 << (aid % 8));
}

static unsigned long ieee80211_tids_for_ac(int ac)
{
	/* If we ever support TIDs > 7, this obviously needs to be adjusted */
	switch (ac) {
	case IEEE80211_AC_VO:
		return BIT(6) | BIT(7);
	case IEEE80211_AC_VI:
		return BIT(4) | BIT(5);
	case IEEE80211_AC_BE:
		return BIT(0) | BIT(3);
	case IEEE80211_AC_BK:
		return BIT(1) | BIT(2);
	default:
		WARN_ON(1);
		return 0;
	}
}

void sta_info_recalc_tim(struct sta_info *sta)
{
	struct ieee80211_local *local = sta->local;
	struct ieee80211_if_ap *bss = sta->sdata->bss;
	unsigned long flags;
	bool indicate_tim = false;
	u8 ignore_for_tim = sta->sta.uapsd_queues;
	int ac;

	if (WARN_ON_ONCE(!sta->sdata->bss))
		return;

	/* No need to do anything if the driver does all */
	if (local->hw.flags & IEEE80211_HW_AP_LINK_PS)
		return;

	if (sta->dead)
		goto done;

	/*
	 * If all ACs are delivery-enabled then we should build
	 * the TIM bit for all ACs anyway; if only some are then
	 * we ignore those and build the TIM bit using only the
	 * non-enabled ones.
	 */
	if (ignore_for_tim == BIT(IEEE80211_NUM_ACS) - 1)
		ignore_for_tim = 0;

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		unsigned long tids;

		if (ignore_for_tim & BIT(ac))
			continue;

		indicate_tim |= !skb_queue_empty(&sta->tx_filtered[ac]) ||
				!skb_queue_empty(&sta->ps_tx_buf[ac]);
		if (indicate_tim)
			break;

		tids = ieee80211_tids_for_ac(ac);

		indicate_tim |=
			sta->driver_buffered_tids & tids;
	}

 done:
	spin_lock_irqsave(&local->tim_lock, flags);

	if (indicate_tim)
		__bss_tim_set(bss, sta->sta.aid);
	else
		__bss_tim_clear(bss, sta->sta.aid);

	if (local->ops->set_tim) {
		local->tim_in_locked_section = true;
		drv_set_tim(local, &sta->sta, indicate_tim);
		local->tim_in_locked_section = false;
	}

	spin_unlock_irqrestore(&local->tim_lock, flags);
}

static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)
{
	struct ieee80211_tx_info *info;
	int timeout;

	if (!skb)
		return false;

	info = IEEE80211_SKB_CB(skb);

	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
	timeout = (sta->listen_interval *
		   sta->sdata->vif.bss_conf.beacon_int *
		   32 / 15625) * HZ;
	if (timeout < STA_TX_BUFFER_EXPIRE)
		timeout = STA_TX_BUFFER_EXPIRE;
	return time_after(jiffies, info->control.jiffies + timeout);
}


static bool sta_info_cleanup_expire_buffered_ac(struct ieee80211_local *local,
						struct sta_info *sta, int ac)
{
	unsigned long flags;
	struct sk_buff *skb;

	/*
	 * First check for frames that should expire on the filtered
	 * queue. Frames here were rejected by the driver and are on
	 * a separate queue to avoid reordering with normal PS-buffered
	 * frames. They also aren't accounted for right now in the
	 * total_ps_buffered counter.
	 */
	for (;;) {
		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
		skb = skb_peek(&sta->tx_filtered[ac]);
		if (sta_info_buffer_expired(sta, skb))
			skb = __skb_dequeue(&sta->tx_filtered[ac]);
		else
			skb = NULL;
		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);

		/*
		 * Frames are queued in order, so if this one
		 * hasn't expired yet we can stop testing. If
		 * we actually reached the end of the queue we
		 * also need to stop, of course.
		 */
		if (!skb)
			break;
		ieee80211_free_txskb(&local->hw, skb);
	}

	/*
	 * Now also check the normal PS-buffered queue, this will
	 * only find something if the filtered queue was emptied
	 * since the filtered frames are all before the normal PS
	 * buffered frames.
	 */
	for (;;) {
		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
		skb = skb_peek(&sta->ps_tx_buf[ac]);
		if (sta_info_buffer_expired(sta, skb))
			skb = __skb_dequeue(&sta->ps_tx_buf[ac]);
		else
			skb = NULL;
		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);

		/*
		 * frames are queued in order, so if this one
		 * hasn't expired yet (or we reached the end of
		 * the queue) we can stop testing
		 */
		if (!skb)
			break;

		local->total_ps_buffered--;
		ps_dbg(sta->sdata, "Buffered frame expired (STA %pM)\n",
		       sta->sta.addr);
		ieee80211_free_txskb(&local->hw, skb);
	}

	/*
	 * Finally, recalculate the TIM bit for this station -- it might
	 * now be clear because the station was too slow to retrieve its
	 * frames.
	 */
	sta_info_recalc_tim(sta);

	/*
	 * Return whether there are any frames still buffered, this is
	 * used to check whether the cleanup timer still needs to run,
	 * if there are no frames we don't need to rearm the timer.
	 */
	return !(skb_queue_empty(&sta->ps_tx_buf[ac]) &&
		 skb_queue_empty(&sta->tx_filtered[ac]));
}

static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
					     struct sta_info *sta)
{
	bool have_buffered = false;
	int ac;

	/* This is only necessary for stations on BSS interfaces */
	if (!sta->sdata->bss)
		return false;

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
		have_buffered |=
			sta_info_cleanup_expire_buffered_ac(local, sta, ac);

	return have_buffered;
}

int __must_check __sta_info_destroy(struct sta_info *sta)
{
	struct ieee80211_local *local;
	struct ieee80211_sub_if_data *sdata;
	int ret, i;

	might_sleep();

	if (!sta)
		return -ENOENT;

	local = sta->local;
	sdata = sta->sdata;

	lockdep_assert_held(&local->sta_mtx);

	/*
	 * Before removing the station from the driver and
	 * rate control, it might still start new aggregation
	 * sessions -- block that to make sure the tear-down
	 * will be sufficient.
	 */
	set_sta_flag(sta, WLAN_STA_BLOCK_BA);
	ieee80211_sta_tear_down_BA_sessions(sta, false);

	ret = sta_info_hash_del(local, sta);
	if (ret)
		return ret;

	list_del_rcu(&sta->list);

	mutex_lock(&local->key_mtx);
	for (i = 0; i < NUM_DEFAULT_KEYS; i++)
		__ieee80211_key_free(key_mtx_dereference(local, sta->gtk[i]));
	if (sta->ptk)
		__ieee80211_key_free(key_mtx_dereference(local, sta->ptk));
	mutex_unlock(&local->key_mtx);

	sta->dead = true;

	local->num_sta--;
	local->sta_generation++;

	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);

	while (sta->sta_state > IEEE80211_STA_NONE) {
		ret = sta_info_move_state(sta, sta->sta_state - 1);
		if (ret) {
			WARN_ON_ONCE(1);
			break;
		}
	}

	if (sta->uploaded) {
		ret = drv_sta_state(local, sdata, sta, IEEE80211_STA_NONE,
				    IEEE80211_STA_NOTEXIST);
		WARN_ON_ONCE(ret != 0);
	}

	sta_dbg(sdata, "Removed STA %pM\n", sta->sta.addr);

	cfg80211_del_sta(sdata->dev, sta->sta.addr, GFP_KERNEL);

	rate_control_remove_sta_debugfs(sta);
	ieee80211_sta_debugfs_remove(sta);

	call_rcu(&sta->rcu_head, free_sta_rcu);

	return 0;
}

int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata, const u8 *addr)
{
	struct sta_info *sta;
	int ret;

	mutex_lock(&sdata->local->sta_mtx);
	sta = sta_info_get(sdata, addr);
	ret = __sta_info_destroy(sta);
	mutex_unlock(&sdata->local->sta_mtx);

	return ret;
}

int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
			      const u8 *addr)
{
	struct sta_info *sta;
	int ret;

	mutex_lock(&sdata->local->sta_mtx);
	sta = sta_info_get_bss(sdata, addr);
	ret = __sta_info_destroy(sta);
	mutex_unlock(&sdata->local->sta_mtx);

	return ret;
}

static void sta_info_cleanup(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *) data;
	struct sta_info *sta;
	bool timer_needed = false;

	rcu_read_lock();
	list_for_each_entry_rcu(sta, &local->sta_list, list)
		if (sta_info_cleanup_expire_buffered(local, sta))
			timer_needed = true;
	rcu_read_unlock();

	if (local->quiescing)
		return;

	if (!timer_needed)
		return;

	mod_timer(&local->sta_cleanup,
		  round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL));
}

void sta_info_init(struct ieee80211_local *local)
{
	spin_lock_init(&local->tim_lock);
	mutex_init(&local->sta_mtx);
	INIT_LIST_HEAD(&local->sta_list);

	setup_timer(&local->sta_cleanup, sta_info_cleanup,
		    (unsigned long)local);
}

void sta_info_stop(struct ieee80211_local *local)
{
	del_timer(&local->sta_cleanup);
	sta_info_flush(local, NULL);
}

/**
 * sta_info_flush - flush matching STA entries from the STA table
 *
 * Returns the number of removed STA entries.
 *
 * @local: local interface data
 * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs
 */
int sta_info_flush(struct ieee80211_local *local,
		   struct ieee80211_sub_if_data *sdata)
{
	struct sta_info *sta, *tmp;
	int ret = 0;

	might_sleep();

	mutex_lock(&local->sta_mtx);
	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
		if (!sdata || sdata == sta->sdata) {
			WARN_ON(__sta_info_destroy(sta));
			ret++;
		}
	}
	mutex_unlock(&local->sta_mtx);

	return ret;
}

void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
			  unsigned long exp_time)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta, *tmp;

	mutex_lock(&local->sta_mtx);

	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
		if (sdata != sta->sdata)
			continue;

		if (time_after(jiffies, sta->last_rx + exp_time)) {
			ibss_dbg(sdata, "expiring inactive STA %pM\n",
				 sta->sta.addr);
			WARN_ON(__sta_info_destroy(sta));
		}
	}

	mutex_unlock(&local->sta_mtx);
}

struct ieee80211_sta *ieee80211_find_sta_by_ifaddr(struct ieee80211_hw *hw,
					       const u8 *addr,
					       const u8 *localaddr)
{
	struct sta_info *sta, *nxt;

	/*
	 * Just return a random station if localaddr is NULL
	 * ... first in list.
	 */
	for_each_sta_info(hw_to_local(hw), addr, sta, nxt) {
		if (localaddr &&
		    !ether_addr_equal(sta->sdata->vif.addr, localaddr))
			continue;
		if (!sta->uploaded)
			return NULL;
		return &sta->sta;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(ieee80211_find_sta_by_ifaddr);

struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_vif *vif,
					 const u8 *addr)
{
	struct sta_info *sta;

	if (!vif)
		return NULL;

	sta = sta_info_get_bss(vif_to_sdata(vif), addr);
	if (!sta)
		return NULL;

	if (!sta->uploaded)
		return NULL;

	return &sta->sta;
}
EXPORT_SYMBOL(ieee80211_find_sta);

static void clear_sta_ps_flags(void *_sta)
{
	struct sta_info *sta = _sta;
	struct ieee80211_sub_if_data *sdata = sta->sdata;

	clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
	if (test_and_clear_sta_flag(sta, WLAN_STA_PS_STA))
		atomic_dec(&sdata->bss->num_sta_ps);
}

/* powersave support code */
void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct sk_buff_head pending;
	int filtered = 0, buffered = 0, ac;
	unsigned long flags;

	clear_sta_flag(sta, WLAN_STA_SP);

	BUILD_BUG_ON(BITS_TO_LONGS(STA_TID_NUM) > 1);
	sta->driver_buffered_tids = 0;

	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
		drv_sta_notify(local, sdata, STA_NOTIFY_AWAKE, &sta->sta);

	skb_queue_head_init(&pending);

	/* Send all buffered frames to the station */
	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		int count = skb_queue_len(&pending), tmp;

		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
		skb_queue_splice_tail_init(&sta->tx_filtered[ac], &pending);
		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);
		tmp = skb_queue_len(&pending);
		filtered += tmp - count;
		count = tmp;

		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
		skb_queue_splice_tail_init(&sta->ps_tx_buf[ac], &pending);
		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);
		tmp = skb_queue_len(&pending);
		buffered += tmp - count;
	}

	ieee80211_add_pending_skbs_fn(local, &pending, clear_sta_ps_flags, sta);

	local->total_ps_buffered -= buffered;

	sta_info_recalc_tim(sta);

	ps_dbg(sdata,
	       "STA %pM aid %d sending %d filtered/%d PS frames since STA not sleeping anymore\n",
	       sta->sta.addr, sta->sta.aid, filtered, buffered);
}

static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,
					 struct sta_info *sta, int tid,
					 enum ieee80211_frame_release_type reason)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_qos_hdr *nullfunc;
	struct sk_buff *skb;
	int size = sizeof(*nullfunc);
	__le16 fc;
	bool qos = test_sta_flag(sta, WLAN_STA_WME);
	struct ieee80211_tx_info *info;

	if (qos) {
		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
				 IEEE80211_STYPE_QOS_NULLFUNC |
				 IEEE80211_FCTL_FROMDS);
	} else {
		size -= 2;
		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
				 IEEE80211_STYPE_NULLFUNC |
				 IEEE80211_FCTL_FROMDS);
	}

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size);
	if (!skb)
		return;

	skb_reserve(skb, local->hw.extra_tx_headroom);

	nullfunc = (void *) skb_put(skb, size);
	nullfunc->frame_control = fc;
	nullfunc->duration_id = 0;
	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
	memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
	memcpy(nullfunc->addr3, sdata->vif.addr, ETH_ALEN);

	skb->priority = tid;
	skb_set_queue_mapping(skb, ieee802_1d_to_ac[tid]);
	if (qos) {
		nullfunc->qos_ctrl = cpu_to_le16(tid);

		if (reason == IEEE80211_FRAME_RELEASE_UAPSD)
			nullfunc->qos_ctrl |=
				cpu_to_le16(IEEE80211_QOS_CTL_EOSP);
	}

	info = IEEE80211_SKB_CB(skb);

	/*
	 * Tell TX path to send this frame even though the
	 * STA may still remain is PS mode after this frame
	 * exchange. Also set EOSP to indicate this packet
	 * ends the poll/service period.
	 */
	info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
		       IEEE80211_TX_STATUS_EOSP |
		       IEEE80211_TX_CTL_REQ_TX_STATUS;

	drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);

	ieee80211_xmit(sdata, skb);
}

static void
ieee80211_sta_ps_deliver_response(struct sta_info *sta,
				  int n_frames, u8 ignored_acs,
				  enum ieee80211_frame_release_type reason)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	bool found = false;
	bool more_data = false;
	int ac;
	unsigned long driver_release_tids = 0;
	struct sk_buff_head frames;

	/* Service or PS-Poll period starts */
	set_sta_flag(sta, WLAN_STA_SP);

	__skb_queue_head_init(&frames);

	/*
	 * Get response frame(s) and more data bit for it.
	 */
	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		unsigned long tids;

		if (ignored_acs & BIT(ac))
			continue;

		tids = ieee80211_tids_for_ac(ac);

		if (!found) {
			driver_release_tids = sta->driver_buffered_tids & tids;
			if (driver_release_tids) {
				found = true;
			} else {
				struct sk_buff *skb;

				while (n_frames > 0) {
					skb = skb_dequeue(&sta->tx_filtered[ac]);
					if (!skb) {
						skb = skb_dequeue(
							&sta->ps_tx_buf[ac]);
						if (skb)
							local->total_ps_buffered--;
					}
					if (!skb)
						break;
					n_frames--;
					found = true;
					__skb_queue_tail(&frames, skb);
				}
			}

			/*
			 * If the driver has data on more than one TID then
			 * certainly there's more data if we release just a
			 * single frame now (from a single TID).
			 */
			if (reason == IEEE80211_FRAME_RELEASE_PSPOLL &&
			    hweight16(driver_release_tids) > 1) {
				more_data = true;
				driver_release_tids =
					BIT(ffs(driver_release_tids) - 1);
				break;
			}
		}

		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
		    !skb_queue_empty(&sta->ps_tx_buf[ac])) {
			more_data = true;
			break;
		}
	}

	if (!found) {
		int tid;

		/*
		 * For PS-Poll, this can only happen due to a race condition
		 * when we set the TIM bit and the station notices it, but
		 * before it can poll for the frame we expire it.
		 *
		 * For uAPSD, this is said in the standard (11.2.1.5 h):
		 *	At each unscheduled SP for a non-AP STA, the AP shall
		 *	attempt to transmit at least one MSDU or MMPDU, but no
		 *	more than the value specified in the Max SP Length field
		 *	in the QoS Capability element from delivery-enabled ACs,
		 *	that are destined for the non-AP STA.
		 *
		 * Since we have no other MSDU/MMPDU, transmit a QoS null frame.
		 */

		/* This will evaluate to 1, 3, 5 or 7. */
		tid = 7 - ((ffs(~ignored_acs) - 1) << 1);

		ieee80211_send_null_response(sdata, sta, tid, reason);
		return;
	}

	if (!driver_release_tids) {
		struct sk_buff_head pending;
		struct sk_buff *skb;
		int num = 0;
		u16 tids = 0;

		skb_queue_head_init(&pending);

		while ((skb = __skb_dequeue(&frames))) {
			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
			struct ieee80211_hdr *hdr = (void *) skb->data;
			u8 *qoshdr = NULL;

			num++;

			/*
			 * Tell TX path to send this frame even though the
			 * STA may still remain is PS mode after this frame
			 * exchange.
			 */
			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;

			/*
			 * Use MoreData flag to indicate whether there are
			 * more buffered frames for this STA
			 */
			if (more_data || !skb_queue_empty(&frames))
				hdr->frame_control |=
					cpu_to_le16(IEEE80211_FCTL_MOREDATA);
			else
				hdr->frame_control &=
					cpu_to_le16(~IEEE80211_FCTL_MOREDATA);

			if (ieee80211_is_data_qos(hdr->frame_control) ||
			    ieee80211_is_qos_nullfunc(hdr->frame_control))
				qoshdr = ieee80211_get_qos_ctl(hdr);

			/* end service period after last frame */
			if (skb_queue_empty(&frames)) {
				if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
				    qoshdr)
					*qoshdr |= IEEE80211_QOS_CTL_EOSP;

				info->flags |= IEEE80211_TX_STATUS_EOSP |
					       IEEE80211_TX_CTL_REQ_TX_STATUS;
			}

			if (qoshdr)
				tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);
			else
				tids |= BIT(0);

			__skb_queue_tail(&pending, skb);
		}

		drv_allow_buffered_frames(local, sta, tids, num,
					  reason, more_data);

		ieee80211_add_pending_skbs(local, &pending);

		sta_info_recalc_tim(sta);
	} else {
		/*
		 * We need to release a frame that is buffered somewhere in the
		 * driver ... it'll have to handle that.
		 * Note that, as per the comment above, it'll also have to see
		 * if there is more than just one frame on the specific TID that
		 * we're releasing from, and it needs to set the more-data bit
		 * accordingly if we tell it that there's no more data. If we do
		 * tell it there's more data, then of course the more-data bit
		 * needs to be set anyway.
		 */
		drv_release_buffered_frames(local, sta, driver_release_tids,
					    n_frames, reason, more_data);

		/*
		 * Note that we don't recalculate the TIM bit here as it would
		 * most likely have no effect at all unless the driver told us
		 * that the TID became empty before returning here from the
		 * release function.
		 * Either way, however, when the driver tells us that the TID
		 * became empty we'll do the TIM recalculation.
		 */
	}
}

void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta)
{
	u8 ignore_for_response = sta->sta.uapsd_queues;

	/*
	 * If all ACs are delivery-enabled then we should reply
	 * from any of them, if only some are enabled we reply
	 * only from the non-enabled ones.
	 */
	if (ignore_for_response == BIT(IEEE80211_NUM_ACS) - 1)
		ignore_for_response = 0;

	ieee80211_sta_ps_deliver_response(sta, 1, ignore_for_response,
					  IEEE80211_FRAME_RELEASE_PSPOLL);
}

void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta)
{
	int n_frames = sta->sta.max_sp;
	u8 delivery_enabled = sta->sta.uapsd_queues;

	/*
	 * If we ever grow support for TSPEC this might happen if
	 * the TSPEC update from hostapd comes in between a trigger
	 * frame setting WLAN_STA_UAPSD in the RX path and this
	 * actually getting called.
	 */
	if (!delivery_enabled)
		return;

	switch (sta->sta.max_sp) {
	case 1:
		n_frames = 2;
		break;
	case 2:
		n_frames = 4;
		break;
	case 3:
		n_frames = 6;
		break;
	case 0:
		/* XXX: what is a good value? */
		n_frames = 8;
		break;
	}

	ieee80211_sta_ps_deliver_response(sta, n_frames, ~delivery_enabled,
					  IEEE80211_FRAME_RELEASE_UAPSD);
}

void ieee80211_sta_block_awake(struct ieee80211_hw *hw,
			       struct ieee80211_sta *pubsta, bool block)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);

	trace_api_sta_block_awake(sta->local, pubsta, block);

	if (block)
		set_sta_flag(sta, WLAN_STA_PS_DRIVER);
	else if (test_sta_flag(sta, WLAN_STA_PS_DRIVER))
		ieee80211_queue_work(hw, &sta->drv_unblock_wk);
}
EXPORT_SYMBOL(ieee80211_sta_block_awake);

void ieee80211_sta_eosp_irqsafe(struct ieee80211_sta *pubsta)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
	struct ieee80211_local *local = sta->local;
	struct sk_buff *skb;
	struct skb_eosp_msg_data *data;

	trace_api_eosp(local, pubsta);

	skb = alloc_skb(0, GFP_ATOMIC);
	if (!skb) {
		/* too bad ... but race is better than loss */
		clear_sta_flag(sta, WLAN_STA_SP);
		return;
	}

	data = (void *)skb->cb;
	memcpy(data->sta, pubsta->addr, ETH_ALEN);
	memcpy(data->iface, sta->sdata->vif.addr, ETH_ALEN);
	skb->pkt_type = IEEE80211_EOSP_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_sta_eosp_irqsafe);

void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta,
				u8 tid, bool buffered)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);

	if (WARN_ON(tid >= STA_TID_NUM))
		return;

	if (buffered)
		set_bit(tid, &sta->driver_buffered_tids);
	else
		clear_bit(tid, &sta->driver_buffered_tids);

	sta_info_recalc_tim(sta);
}
EXPORT_SYMBOL(ieee80211_sta_set_buffered);

int sta_info_move_state(struct sta_info *sta,
			enum ieee80211_sta_state new_state)
{
	might_sleep();

	if (sta->sta_state == new_state)
		return 0;

	/* check allowed transitions first */

	switch (new_state) {
	case IEEE80211_STA_NONE:
		if (sta->sta_state != IEEE80211_STA_AUTH)
			return -EINVAL;
		break;
	case IEEE80211_STA_AUTH:
		if (sta->sta_state != IEEE80211_STA_NONE &&
		    sta->sta_state != IEEE80211_STA_ASSOC)
			return -EINVAL;
		break;
	case IEEE80211_STA_ASSOC:
		if (sta->sta_state != IEEE80211_STA_AUTH &&
		    sta->sta_state != IEEE80211_STA_AUTHORIZED)
			return -EINVAL;
		break;
	case IEEE80211_STA_AUTHORIZED:
		if (sta->sta_state != IEEE80211_STA_ASSOC)
			return -EINVAL;
		break;
	default:
		WARN(1, "invalid state %d", new_state);
		return -EINVAL;
	}

	sta_dbg(sta->sdata, "moving STA %pM to state %d\n",
		sta->sta.addr, new_state);

	/*
	 * notify the driver before the actual changes so it can
	 * fail the transition
	 */
	if (test_sta_flag(sta, WLAN_STA_INSERTED)) {
		int err = drv_sta_state(sta->local, sta->sdata, sta,
					sta->sta_state, new_state);
		if (err)
			return err;
	}

	/* reflect the change in all state variables */

	switch (new_state) {
	case IEEE80211_STA_NONE:
		if (sta->sta_state == IEEE80211_STA_AUTH)
			clear_bit(WLAN_STA_AUTH, &sta->_flags);
		break;
	case IEEE80211_STA_AUTH:
		if (sta->sta_state == IEEE80211_STA_NONE)
			set_bit(WLAN_STA_AUTH, &sta->_flags);
		else if (sta->sta_state == IEEE80211_STA_ASSOC)
			clear_bit(WLAN_STA_ASSOC, &sta->_flags);
		break;
	case IEEE80211_STA_ASSOC:
		if (sta->sta_state == IEEE80211_STA_AUTH) {
			set_bit(WLAN_STA_ASSOC, &sta->_flags);
		} else if (sta->sta_state == IEEE80211_STA_AUTHORIZED) {
			if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
			    (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
			     !sta->sdata->u.vlan.sta))
				atomic_dec(&sta->sdata->bss->num_mcast_sta);
			clear_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
		}
		break;
	case IEEE80211_STA_AUTHORIZED:
		if (sta->sta_state == IEEE80211_STA_ASSOC) {
			if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
			    (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
			     !sta->sdata->u.vlan.sta))
				atomic_inc(&sta->sdata->bss->num_mcast_sta);
			set_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
		}
		break;
	default:
		break;
	}

	sta->sta_state = new_state;

	return 0;
}
OpenPOWER on IntegriCloud