aboutsummaryrefslogtreecommitdiffstats
path: root/net/mac80211/ht.c
blob: b854483cf23f811483794b33761f4ec17069e293 (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
/*
 * HT handling
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2007-2008, Intel Corporation
 *
 * 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/ieee80211.h>
#include <net/wireless.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "sta_info.h"
#include "wme.h"

int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
				   struct ieee80211_ht_info *ht_info)
{

	if (ht_info == NULL)
		return -EINVAL;

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

	if (ht_cap_ie) {
		u8 ampdu_info = ht_cap_ie->ampdu_params_info;

		ht_info->ht_supported = 1;
		ht_info->cap = le16_to_cpu(ht_cap_ie->cap_info);
		ht_info->ampdu_factor =
			ampdu_info & IEEE80211_HT_CAP_AMPDU_FACTOR;
		ht_info->ampdu_density =
			(ampdu_info & IEEE80211_HT_CAP_AMPDU_DENSITY) >> 2;
		memcpy(ht_info->supp_mcs_set, ht_cap_ie->supp_mcs_set, 16);
	} else
		ht_info->ht_supported = 0;

	return 0;
}

int ieee80211_ht_addt_info_ie_to_ht_bss_info(
			struct ieee80211_ht_addt_info *ht_add_info_ie,
			struct ieee80211_ht_bss_info *bss_info)
{
	if (bss_info == NULL)
		return -EINVAL;

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

	if (ht_add_info_ie) {
		u16 op_mode;
		op_mode = le16_to_cpu(ht_add_info_ie->operation_mode);

		bss_info->primary_channel = ht_add_info_ie->control_chan;
		bss_info->bss_cap = ht_add_info_ie->ht_param;
		bss_info->bss_op_mode = (u8)(op_mode & 0xff);
	}

	return 0;
}

static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
					 const u8 *da, u16 tid,
					 u8 dialog_token, u16 start_seq_num,
					 u16 agg_size, u16 timeout)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u16 capab;

	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

	if (!skb) {
		printk(KERN_ERR "%s: failed to allocate buffer "
				"for addba request frame\n", sdata->dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);
	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, da, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	if (sdata->vif.type == NL80211_IFTYPE_AP)
		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
	else
		memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);

	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_ACTION);

	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));

	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;

	mgmt->u.action.u.addba_req.dialog_token = dialog_token;
	capab = (u16)(1 << 1);		/* bit 1 aggregation policy */
	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
	capab |= (u16)(agg_size << 6);	/* bit 15:6 max size of aggergation */

	mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);

	mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
	mgmt->u.action.u.addba_req.start_seq_num =
					cpu_to_le16(start_seq_num << 4);

	ieee80211_tx_skb(sdata, skb, 0);
}

static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
				      u8 dialog_token, u16 status, u16 policy,
				      u16 buf_size, u16 timeout)
{
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u16 capab;

	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer "
		       "for addba resp frame\n", sdata->dev->name);
		return;
	}

	skb_reserve(skb, local->hw.extra_tx_headroom);
	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, da, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	if (sdata->vif.type == NL80211_IFTYPE_AP)
		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
	else
		memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_ACTION);

	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;

	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */

	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);

	ieee80211_tx_skb(sdata, skb, 0);
}

static void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
				 const u8 *da, u16 tid,
				 u16 initiator, u16 reason_code)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u16 params;

	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

	if (!skb) {
		printk(KERN_ERR "%s: failed to allocate buffer "
					"for delba frame\n", sdata->dev->name);
		return;
	}

	skb_reserve(skb, local->hw.extra_tx_headroom);
	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, da, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	if (sdata->vif.type == NL80211_IFTYPE_AP)
		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
	else
		memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_ACTION);

	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));

	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
	params = (u16)(initiator << 11); 	/* bit 11 initiator */
	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */

	mgmt->u.action.u.delba.params = cpu_to_le16(params);
	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);

	ieee80211_tx_skb(sdata, skb, 0);
}

void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_bar *bar;
	u16 bar_control = 0;

	skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
	if (!skb) {
		printk(KERN_ERR "%s: failed to allocate buffer for "
			"bar frame\n", sdata->dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);
	bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
	memset(bar, 0, sizeof(*bar));
	bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
					 IEEE80211_STYPE_BACK_REQ);
	memcpy(bar->ra, ra, ETH_ALEN);
	memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
	bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
	bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
	bar_control |= (u16)(tid << 12);
	bar->control = cpu_to_le16(bar_control);
	bar->start_seq_num = cpu_to_le16(ssn);

	ieee80211_tx_skb(sdata, skb, 0);
}

void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
					u16 initiator, u16 reason)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_hw *hw = &local->hw;
	struct sta_info *sta;
	int ret, i;

	rcu_read_lock();

	sta = sta_info_get(local, ra);
	if (!sta) {
		rcu_read_unlock();
		return;
	}

	/* check if TID is in operational state */
	spin_lock_bh(&sta->lock);
	if (sta->ampdu_mlme.tid_state_rx[tid]
				!= HT_AGG_STATE_OPERATIONAL) {
		spin_unlock_bh(&sta->lock);
		rcu_read_unlock();
		return;
	}
	sta->ampdu_mlme.tid_state_rx[tid] =
		HT_AGG_STATE_REQ_STOP_BA_MSK |
		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
	spin_unlock_bh(&sta->lock);

	/* stop HW Rx aggregation. ampdu_action existence
	 * already verified in session init so we add the BUG_ON */
	BUG_ON(!local->ops->ampdu_action);

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
				       &sta->sta, tid, NULL);
	if (ret)
		printk(KERN_DEBUG "HW problem - can not stop rx "
				"aggregation for tid %d\n", tid);

	/* shutdown timer has not expired */
	if (initiator != WLAN_BACK_TIMER)
		del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);

	/* check if this is a self generated aggregation halt */
	if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
		ieee80211_send_delba(sdata, ra, tid, 0, reason);

	/* free the reordering buffer */
	for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
		if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
			/* release the reordered frames */
			dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
			sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
			sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
		}
	}
	/* free resources */
	kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
	kfree(sta->ampdu_mlme.tid_rx[tid]);
	sta->ampdu_mlme.tid_rx[tid] = NULL;
	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;

	rcu_read_unlock();
}


/*
 * After sending add Block Ack request we activated a timer until
 * add Block Ack response will arrive from the recipient.
 * If this timer expires sta_addba_resp_timer_expired will be executed.
 */
static void sta_addba_resp_timer_expired(unsigned long data)
{
	/* not an elegant detour, but there is no choice as the timer passes
	 * only one argument, and both sta_info and TID are needed, so init
	 * flow in sta_info_create gives the TID as data, while the timer_to_id
	 * array gives the sta through container_of */
	u16 tid = *(u8 *)data;
	struct sta_info *temp_sta = container_of((void *)data,
		struct sta_info, timer_to_tid[tid]);

	struct ieee80211_local *local = temp_sta->local;
	struct ieee80211_hw *hw = &local->hw;
	struct sta_info *sta;
	u8 *state;

	rcu_read_lock();

	sta = sta_info_get(local, temp_sta->sta.addr);
	if (!sta) {
		rcu_read_unlock();
		return;
	}

	state = &sta->ampdu_mlme.tid_state_tx[tid];
	/* check if the TID waits for addBA response */
	spin_lock_bh(&sta->lock);
	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
		spin_unlock_bh(&sta->lock);
		*state = HT_AGG_STATE_IDLE;
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "timer expired on tid %d but we are not "
				"expecting addBA response there", tid);
#endif
		goto timer_expired_exit;
	}

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
#endif

	/* go through the state check in stop_BA_session */
	*state = HT_AGG_STATE_OPERATIONAL;
	spin_unlock_bh(&sta->lock);
	ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
				     WLAN_BACK_INITIATOR);

timer_expired_exit:
	rcu_read_unlock();
}

void ieee80211_sta_tear_down_BA_sessions(struct ieee80211_sub_if_data *sdata, u8 *addr)
{
	struct ieee80211_local *local = sdata->local;
	int i;

	for (i = 0; i <  STA_TID_NUM; i++) {
		ieee80211_stop_tx_ba_session(&local->hw, addr, i,
					     WLAN_BACK_INITIATOR);
		ieee80211_sta_stop_rx_ba_session(sdata, addr, i,
						 WLAN_BACK_RECIPIENT,
						 WLAN_REASON_QSTA_LEAVE_QBSS);
	}
}

int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	struct ieee80211_sub_if_data *sdata;
	u16 start_seq_num;
	u8 *state;
	int ret;

	if (tid >= STA_TID_NUM)
		return -EINVAL;

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	rcu_read_lock();

	sta = sta_info_get(local, ra);
	if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Could not find the station\n");
#endif
		ret = -ENOENT;
		goto exit;
	}

	spin_lock_bh(&sta->lock);

	/* we have tried too many times, receiver does not want A-MPDU */
	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
		ret = -EBUSY;
		goto err_unlock_sta;
	}

	state = &sta->ampdu_mlme.tid_state_tx[tid];
	/* check if the TID is not in aggregation flow already */
	if (*state != HT_AGG_STATE_IDLE) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - session is not "
				 "idle on tid %u\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		ret = -EAGAIN;
		goto err_unlock_sta;
	}

	/* prepare A-MPDU MLME for Tx aggregation */
	sta->ampdu_mlme.tid_tx[tid] =
			kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
	if (!sta->ampdu_mlme.tid_tx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
					tid);
#endif
		ret = -ENOMEM;
		goto err_unlock_sta;
	}
	/* Tx timer */
	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
			sta_addba_resp_timer_expired;
	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
			(unsigned long)&sta->timer_to_tid[tid];
	init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);

	/* create a new queue for this aggregation */
	ret = ieee80211_ht_agg_queue_add(local, sta, tid);

	/* case no queue is available to aggregation
	 * don't switch to aggregation */
	if (ret) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - queue unavailable for"
					" tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		goto err_unlock_queue;
	}
	sdata = sta->sdata;

	/* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
	 * call back right away, it must see that the flow has begun */
	*state |= HT_ADDBA_REQUESTED_MSK;

	/* This is slightly racy because the queue isn't stopped */
	start_seq_num = sta->tid_seq[tid];

	if (local->ops->ampdu_action)
		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
					       &sta->sta, tid, &start_seq_num);

	if (ret) {
		/* No need to requeue the packets in the agg queue, since we
		 * held the tx lock: no packet could be enqueued to the newly
		 * allocated queue */
		ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - HW unavailable for"
					" tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		*state = HT_AGG_STATE_IDLE;
		goto err_unlock_queue;
	}

	/* Will put all the packets in the new SW queue */
	ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
	spin_unlock_bh(&sta->lock);

	/* send an addBA request */
	sta->ampdu_mlme.dialog_token_allocator++;
	sta->ampdu_mlme.tid_tx[tid]->dialog_token =
			sta->ampdu_mlme.dialog_token_allocator;
	sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;


	ieee80211_send_addba_request(sta->sdata, ra, tid,
			 sta->ampdu_mlme.tid_tx[tid]->dialog_token,
			 sta->ampdu_mlme.tid_tx[tid]->ssn,
			 0x40, 5000);
	/* activate the timer for the recipient's addBA response */
	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
				jiffies + ADDBA_RESP_INTERVAL;
	add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
#endif
	goto exit;

err_unlock_queue:
	kfree(sta->ampdu_mlme.tid_tx[tid]);
	sta->ampdu_mlme.tid_tx[tid] = NULL;
	ret = -EBUSY;
err_unlock_sta:
	spin_unlock_bh(&sta->lock);
exit:
	rcu_read_unlock();
	return ret;
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_session);

int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
				 u8 *ra, u16 tid,
				 enum ieee80211_back_parties initiator)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	u8 *state;
	int ret = 0;

	if (tid >= STA_TID_NUM)
		return -EINVAL;

	rcu_read_lock();
	sta = sta_info_get(local, ra);
	if (!sta) {
		rcu_read_unlock();
		return -ENOENT;
	}

	/* check if the TID is in aggregation */
	state = &sta->ampdu_mlme.tid_state_tx[tid];
	spin_lock_bh(&sta->lock);

	if (*state != HT_AGG_STATE_OPERATIONAL) {
		ret = -ENOENT;
		goto stop_BA_exit;
	}

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);

	*state = HT_AGG_STATE_REQ_STOP_BA_MSK |
		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);

	if (local->ops->ampdu_action)
		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
					       &sta->sta, tid, NULL);

	/* case HW denied going back to legacy */
	if (ret) {
		WARN_ON(ret != -EBUSY);
		*state = HT_AGG_STATE_OPERATIONAL;
		ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
		goto stop_BA_exit;
	}

stop_BA_exit:
	spin_unlock_bh(&sta->lock);
	rcu_read_unlock();
	return ret;
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);

void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	u8 *state;

	if (tid >= STA_TID_NUM) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
				tid, STA_TID_NUM);
#endif
		return;
	}

	rcu_read_lock();
	sta = sta_info_get(local, ra);
	if (!sta) {
		rcu_read_unlock();
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Could not find station: %pM\n", ra);
#endif
		return;
	}

	state = &sta->ampdu_mlme.tid_state_tx[tid];
	spin_lock_bh(&sta->lock);

	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
				*state);
#endif
		spin_unlock_bh(&sta->lock);
		rcu_read_unlock();
		return;
	}

	WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);

	*state |= HT_ADDBA_DRV_READY_MSK;

	if (*state == HT_AGG_STATE_OPERATIONAL) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
#endif
		ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
	}
	spin_unlock_bh(&sta->lock);
	rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);

void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sta_info *sta;
	u8 *state;
	int agg_queue;

	if (tid >= STA_TID_NUM) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
				tid, STA_TID_NUM);
#endif
		return;
	}

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
	       ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	rcu_read_lock();
	sta = sta_info_get(local, ra);
	if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "Could not find station: %pM\n", ra);
#endif
		rcu_read_unlock();
		return;
	}
	state = &sta->ampdu_mlme.tid_state_tx[tid];

	/* NOTE: no need to use sta->lock in this state check, as
	 * ieee80211_stop_tx_ba_session will let only one stop call to
	 * pass through per sta/tid
	 */
	if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
#endif
		rcu_read_unlock();
		return;
	}

	if (*state & HT_AGG_STATE_INITIATOR_MSK)
		ieee80211_send_delba(sta->sdata, ra, tid,
			WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);

	agg_queue = sta->tid_to_tx_q[tid];

	ieee80211_ht_agg_queue_remove(local, sta, tid, 1);

	/* We just requeued the all the frames that were in the
	 * removed queue, and since we might miss a softirq we do
	 * netif_schedule_queue.  ieee80211_wake_queue is not used
	 * here as this queue is not necessarily stopped
	 */
	netif_schedule_queue(netdev_get_tx_queue(local->mdev, agg_queue));
	spin_lock_bh(&sta->lock);
	*state = HT_AGG_STATE_IDLE;
	sta->ampdu_mlme.addba_req_num[tid] = 0;
	kfree(sta->ampdu_mlme.tid_tx[tid]);
	sta->ampdu_mlme.tid_tx[tid] = NULL;
	spin_unlock_bh(&sta->lock);

	rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);

void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
				      const u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_ra_tid *ra_tid;
	struct sk_buff *skb = dev_alloc_skb(0);

	if (unlikely(!skb)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_WARNING "%s: Not enough memory, "
			       "dropping start BA session", skb->dev->name);
#endif
		return;
	}
	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
	memcpy(&ra_tid->ra, ra, ETH_ALEN);
	ra_tid->tid = tid;

	skb->pkt_type = IEEE80211_ADDBA_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);

void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
				     const u8 *ra, u16 tid)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_ra_tid *ra_tid;
	struct sk_buff *skb = dev_alloc_skb(0);

	if (unlikely(!skb)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_WARNING "%s: Not enough memory, "
			       "dropping stop BA session", skb->dev->name);
#endif
		return;
	}
	ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
	memcpy(&ra_tid->ra, ra, ETH_ALEN);
	ra_tid->tid = tid;

	skb->pkt_type = IEEE80211_DELBA_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);

/*
 * After accepting the AddBA Request we activated a timer,
 * resetting it after each frame that arrives from the originator.
 * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
 */
static void sta_rx_agg_session_timer_expired(unsigned long data)
{
	/* not an elegant detour, but there is no choice as the timer passes
	 * only one argument, and various sta_info are needed here, so init
	 * flow in sta_info_create gives the TID as data, while the timer_to_id
	 * array gives the sta through container_of */
	u8 *ptid = (u8 *)data;
	u8 *timer_to_id = ptid - *ptid;
	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
					 timer_to_tid[0]);

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
#endif
	ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
					 (u16)*ptid, WLAN_BACK_TIMER,
					 WLAN_REASON_QSTA_TIMEOUT);
}

void ieee80211_process_addba_request(struct ieee80211_local *local,
				     struct sta_info *sta,
				     struct ieee80211_mgmt *mgmt,
				     size_t len)
{
	struct ieee80211_hw *hw = &local->hw;
	struct ieee80211_conf *conf = &hw->conf;
	struct tid_ampdu_rx *tid_agg_rx;
	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
	u8 dialog_token;
	int ret = -EOPNOTSUPP;

	/* extract session parameters from addba request frame */
	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
	start_seq_num =
		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;

	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;

	status = WLAN_STATUS_REQUEST_DECLINED;

	/* sanity check for incoming parameters:
	 * check if configuration can support the BA policy
	 * and if buffer size does not exceeds max value */
	if (((ba_policy != 1)
		&& (!(conf->ht_conf.cap & IEEE80211_HT_CAP_DELAY_BA)))
		|| (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
		status = WLAN_STATUS_INVALID_QOS_PARAM;
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_DEBUG "AddBA Req with bad params from "
				"%pM on tid %u. policy %d, buffer size %d\n",
				mgmt->sa, tid, ba_policy,
				buf_size);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		goto end_no_lock;
	}
	/* determine default buffer size */
	if (buf_size == 0) {
		struct ieee80211_supported_band *sband;

		sband = local->hw.wiphy->bands[conf->channel->band];
		buf_size = IEEE80211_MIN_AMPDU_BUF;
		buf_size = buf_size << sband->ht_info.ampdu_factor;
	}


	/* examine state machine */
	spin_lock_bh(&sta->lock);

	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_DEBUG "unexpected AddBA Req from "
				"%pM on tid %u\n",
				mgmt->sa, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		goto end;
	}

	/* prepare A-MPDU MLME for Rx aggregation */
	sta->ampdu_mlme.tid_rx[tid] =
			kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
	if (!sta->ampdu_mlme.tid_rx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
					tid);
#endif
		goto end;
	}
	/* rx timer */
	sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
				sta_rx_agg_session_timer_expired;
	sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
				(unsigned long)&sta->timer_to_tid[tid];
	init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);

	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];

	/* prepare reordering buffer */
	tid_agg_rx->reorder_buf =
		kmalloc(buf_size * sizeof(struct sk_buff *), GFP_ATOMIC);
	if (!tid_agg_rx->reorder_buf) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		if (net_ratelimit())
			printk(KERN_ERR "can not allocate reordering buffer "
			       "to tid %d\n", tid);
#endif
		kfree(sta->ampdu_mlme.tid_rx[tid]);
		goto end;
	}
	memset(tid_agg_rx->reorder_buf, 0,
		buf_size * sizeof(struct sk_buff *));

	if (local->ops->ampdu_action)
		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
					       &sta->sta, tid, &start_seq_num);
#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	if (ret) {
		kfree(tid_agg_rx->reorder_buf);
		kfree(tid_agg_rx);
		sta->ampdu_mlme.tid_rx[tid] = NULL;
		goto end;
	}

	/* change state and send addba resp */
	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
	tid_agg_rx->dialog_token = dialog_token;
	tid_agg_rx->ssn = start_seq_num;
	tid_agg_rx->head_seq_num = start_seq_num;
	tid_agg_rx->buf_size = buf_size;
	tid_agg_rx->timeout = timeout;
	tid_agg_rx->stored_mpdu_num = 0;
	status = WLAN_STATUS_SUCCESS;
end:
	spin_unlock_bh(&sta->lock);

end_no_lock:
	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
				  dialog_token, status, 1, buf_size, timeout);
}

void ieee80211_process_addba_resp(struct ieee80211_local *local,
				  struct sta_info *sta,
				  struct ieee80211_mgmt *mgmt,
				  size_t len)
{
	struct ieee80211_hw *hw = &local->hw;
	u16 capab;
	u16 tid;
	u8 *state;

	capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;

	state = &sta->ampdu_mlme.tid_state_tx[tid];

	spin_lock_bh(&sta->lock);

	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
		spin_unlock_bh(&sta->lock);
		return;
	}

	if (mgmt->u.action.u.addba_resp.dialog_token !=
		sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
		spin_unlock_bh(&sta->lock);
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		return;
	}

	del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
			== WLAN_STATUS_SUCCESS) {
		*state |= HT_ADDBA_RECEIVED_MSK;
		sta->ampdu_mlme.addba_req_num[tid] = 0;

		if (*state == HT_AGG_STATE_OPERATIONAL)
			ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);

		spin_unlock_bh(&sta->lock);
	} else {
		sta->ampdu_mlme.addba_req_num[tid]++;
		/* this will allow the state check in stop_BA_session */
		*state = HT_AGG_STATE_OPERATIONAL;
		spin_unlock_bh(&sta->lock);
		ieee80211_stop_tx_ba_session(hw, sta->sta.addr, tid,
					     WLAN_BACK_INITIATOR);
	}
}

void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
			     struct sta_info *sta,
			     struct ieee80211_mgmt *mgmt, size_t len)
{
	struct ieee80211_local *local = sdata->local;
	u16 tid, params;
	u16 initiator;

	params = le16_to_cpu(mgmt->u.action.u.delba.params);
	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;

#ifdef CONFIG_MAC80211_HT_DEBUG
	if (net_ratelimit())
		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
			mgmt->sa, initiator ? "initiator" : "recipient", tid,
			mgmt->u.action.u.delba.reason_code);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	if (initiator == WLAN_BACK_INITIATOR)
		ieee80211_sta_stop_rx_ba_session(sdata, sta->sta.addr, tid,
						 WLAN_BACK_INITIATOR, 0);
	else { /* WLAN_BACK_RECIPIENT */
		spin_lock_bh(&sta->lock);
		sta->ampdu_mlme.tid_state_tx[tid] =
				HT_AGG_STATE_OPERATIONAL;
		spin_unlock_bh(&sta->lock);
		ieee80211_stop_tx_ba_session(&local->hw, sta->sta.addr, tid,
					     WLAN_BACK_RECIPIENT);
	}
}