aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/main.c
blob: fa0cc7a1e6b4b7146356cc49fab39733dac463f8 (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
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, 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 <net/mac80211.h>
#include <net/ieee80211_radiotap.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/rtnetlink.h>
#include <linux/bitmap.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>

#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"
#include "wep.h"
#include "wme.h"
#include "aes_ccm.h"
#include "led.h"
#include "cfg.h"
#include "debugfs.h"
#include "debugfs_netdev.h"

/*
 * For seeing transmitted packets on monitor interfaces
 * we have a radiotap header too.
 */
struct ieee80211_tx_status_rtap_hdr {
	struct ieee80211_radiotap_header hdr;
	u8 rate;
	u8 padding_for_rate;
	__le16 tx_flags;
	u8 data_retries;
} __attribute__ ((packed));


/* must be called under mdev tx lock */
void ieee80211_configure_filter(struct ieee80211_local *local)
{
	unsigned int changed_flags;
	unsigned int new_flags = 0;

	if (atomic_read(&local->iff_promiscs))
		new_flags |= FIF_PROMISC_IN_BSS;

	if (atomic_read(&local->iff_allmultis))
		new_flags |= FIF_ALLMULTI;

	if (local->monitors)
		new_flags |= FIF_BCN_PRBRESP_PROMISC;

	if (local->fif_fcsfail)
		new_flags |= FIF_FCSFAIL;

	if (local->fif_plcpfail)
		new_flags |= FIF_PLCPFAIL;

	if (local->fif_control)
		new_flags |= FIF_CONTROL;

	if (local->fif_other_bss)
		new_flags |= FIF_OTHER_BSS;

	changed_flags = local->filter_flags ^ new_flags;

	/* be a bit nasty */
	new_flags |= (1<<31);

	local->ops->configure_filter(local_to_hw(local),
				     changed_flags, &new_flags,
				     local->mdev->mc_count,
				     local->mdev->mc_list);

	WARN_ON(new_flags & (1<<31));

	local->filter_flags = new_flags & ~(1<<31);
}

/* master interface */

static int header_parse_80211(const struct sk_buff *skb, unsigned char *haddr)
{
	memcpy(haddr, skb_mac_header(skb) + 10, ETH_ALEN); /* addr2 */
	return ETH_ALEN;
}

static const struct header_ops ieee80211_header_ops = {
	.create		= eth_header,
	.parse		= header_parse_80211,
	.rebuild	= eth_rebuild_header,
	.cache		= eth_header_cache,
	.cache_update	= eth_header_cache_update,
};

static int ieee80211_master_open(struct net_device *dev)
{
	struct ieee80211_master_priv *mpriv = netdev_priv(dev);
	struct ieee80211_local *local = mpriv->local;
	struct ieee80211_sub_if_data *sdata;
	int res = -EOPNOTSUPP;

	/* we hold the RTNL here so can safely walk the list */
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (netif_running(sdata->dev)) {
			res = 0;
			break;
		}
	}

	if (res)
		return res;

	netif_tx_start_all_queues(local->mdev);

	return 0;
}

static int ieee80211_master_stop(struct net_device *dev)
{
	struct ieee80211_master_priv *mpriv = netdev_priv(dev);
	struct ieee80211_local *local = mpriv->local;
	struct ieee80211_sub_if_data *sdata;

	/* we hold the RTNL here so can safely walk the list */
	list_for_each_entry(sdata, &local->interfaces, list)
		if (netif_running(sdata->dev))
			dev_close(sdata->dev);

	return 0;
}

static void ieee80211_master_set_multicast_list(struct net_device *dev)
{
	struct ieee80211_master_priv *mpriv = netdev_priv(dev);
	struct ieee80211_local *local = mpriv->local;

	ieee80211_configure_filter(local);
}

/* everything else */

int ieee80211_if_config(struct ieee80211_sub_if_data *sdata, u32 changed)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_conf conf;

	if (WARN_ON(!netif_running(sdata->dev)))
		return 0;

	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
		return -EINVAL;

	if (!local->ops->config_interface)
		return 0;

	memset(&conf, 0, sizeof(conf));
	conf.changed = changed;

	if (sdata->vif.type == NL80211_IFTYPE_STATION ||
	    sdata->vif.type == NL80211_IFTYPE_ADHOC) {
		conf.bssid = sdata->u.sta.bssid;
		conf.ssid = sdata->u.sta.ssid;
		conf.ssid_len = sdata->u.sta.ssid_len;
	} else if (sdata->vif.type == NL80211_IFTYPE_AP) {
		conf.bssid = sdata->dev->dev_addr;
		conf.ssid = sdata->u.ap.ssid;
		conf.ssid_len = sdata->u.ap.ssid_len;
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
		u8 zero[ETH_ALEN] = { 0 };
		conf.bssid = zero;
		conf.ssid = zero;
		conf.ssid_len = 0;
	} else {
		WARN_ON(1);
		return -EINVAL;
	}

	if (WARN_ON(!conf.bssid && (changed & IEEE80211_IFCC_BSSID)))
		return -EINVAL;

	if (WARN_ON(!conf.ssid && (changed & IEEE80211_IFCC_SSID)))
		return -EINVAL;

	return local->ops->config_interface(local_to_hw(local),
					    &sdata->vif, &conf);
}

int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
{
	struct ieee80211_channel *chan;
	int ret = 0;
	int power;

	might_sleep();

	if (local->sw_scanning)
		chan = local->scan_channel;
	else
		chan = local->oper_channel;

	if (chan != local->hw.conf.channel) {
		local->hw.conf.channel = chan;
		changed |= IEEE80211_CONF_CHANGE_CHANNEL;
	}


	if (!local->hw.conf.power_level)
		power = chan->max_power;
	else
		power = min(chan->max_power, local->hw.conf.power_level);
	if (local->hw.conf.power_level != power) {
		changed |= IEEE80211_CONF_CHANGE_POWER;
		local->hw.conf.power_level = power;
	}

	if (changed && local->open_count) {
		ret = local->ops->config(local_to_hw(local), changed);
		/*
		 * HW reconfiguration should never fail, the driver has told
		 * us what it can support so it should live up to that promise.
		 */
		WARN_ON(ret);
	}

	return ret;
}

void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
				      u32 changed)
{
	struct ieee80211_local *local = sdata->local;

	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
		return;

	if (!changed)
		return;

	if (local->ops->bss_info_changed)
		local->ops->bss_info_changed(local_to_hw(local),
					     &sdata->vif,
					     &sdata->vif.bss_conf,
					     changed);
}

u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata)
{
	sdata->vif.bss_conf.use_cts_prot = false;
	sdata->vif.bss_conf.use_short_preamble = false;
	sdata->vif.bss_conf.use_short_slot = false;
	return BSS_CHANGED_ERP_CTS_PROT |
	       BSS_CHANGED_ERP_PREAMBLE |
	       BSS_CHANGED_ERP_SLOT;
}

void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
				 struct sk_buff *skb)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	int tmp;

	skb->dev = local->mdev;
	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
		       &local->skb_queue : &local->skb_queue_unreliable, skb);
	tmp = skb_queue_len(&local->skb_queue) +
		skb_queue_len(&local->skb_queue_unreliable);
	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
		dev_kfree_skb_irq(skb);
		tmp--;
		I802_DEBUG_INC(local->tx_status_drop);
	}
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);

static void ieee80211_tasklet_handler(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *) data;
	struct sk_buff *skb;
	struct ieee80211_rx_status rx_status;
	struct ieee80211_ra_tid *ra_tid;

	while ((skb = skb_dequeue(&local->skb_queue)) ||
	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
		switch (skb->pkt_type) {
		case IEEE80211_RX_MSG:
			/* status is in skb->cb */
			memcpy(&rx_status, skb->cb, sizeof(rx_status));
			/* Clear skb->pkt_type in order to not confuse kernel
			 * netstack. */
			skb->pkt_type = 0;
			__ieee80211_rx(local_to_hw(local), skb, &rx_status);
			break;
		case IEEE80211_TX_STATUS_MSG:
			skb->pkt_type = 0;
			ieee80211_tx_status(local_to_hw(local), skb);
			break;
		case IEEE80211_DELBA_MSG:
			ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
			ieee80211_stop_tx_ba_cb(local_to_hw(local),
						ra_tid->ra, ra_tid->tid);
			dev_kfree_skb(skb);
			break;
		case IEEE80211_ADDBA_MSG:
			ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
			ieee80211_start_tx_ba_cb(local_to_hw(local),
						 ra_tid->ra, ra_tid->tid);
			dev_kfree_skb(skb);
			break ;
		default:
			WARN_ON(1);
			dev_kfree_skb(skb);
			break;
		}
	}
}

/* Remove added headers (e.g., QoS control), encryption header/MIC, etc. to
 * make a prepared TX frame (one that has been given to hw) to look like brand
 * new IEEE 802.11 frame that is ready to go through TX processing again.
 */
static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
				      struct ieee80211_key *key,
				      struct sk_buff *skb)
{
	unsigned int hdrlen, iv_len, mic_len;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);

	if (!key)
		goto no_key;

	switch (key->conf.alg) {
	case ALG_WEP:
		iv_len = WEP_IV_LEN;
		mic_len = WEP_ICV_LEN;
		break;
	case ALG_TKIP:
		iv_len = TKIP_IV_LEN;
		mic_len = TKIP_ICV_LEN;
		break;
	case ALG_CCMP:
		iv_len = CCMP_HDR_LEN;
		mic_len = CCMP_MIC_LEN;
		break;
	default:
		goto no_key;
	}

	if (skb->len >= hdrlen + mic_len &&
	    !(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
		skb_trim(skb, skb->len - mic_len);
	if (skb->len >= hdrlen + iv_len) {
		memmove(skb->data + iv_len, skb->data, hdrlen);
		hdr = (struct ieee80211_hdr *)skb_pull(skb, iv_len);
	}

no_key:
	if (ieee80211_is_data_qos(hdr->frame_control)) {
		hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
		memmove(skb->data + IEEE80211_QOS_CTL_LEN, skb->data,
			hdrlen - IEEE80211_QOS_CTL_LEN);
		skb_pull(skb, IEEE80211_QOS_CTL_LEN);
	}
}

static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
					    struct sta_info *sta,
					    struct sk_buff *skb)
{
	sta->tx_filtered_count++;

	/*
	 * Clear the TX filter mask for this STA when sending the next
	 * packet. If the STA went to power save mode, this will happen
	 * when it wakes up for the next time.
	 */
	set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);

	/*
	 * This code races in the following way:
	 *
	 *  (1) STA sends frame indicating it will go to sleep and does so
	 *  (2) hardware/firmware adds STA to filter list, passes frame up
	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
	 *  (4) we get TX status before having processed the frame and
	 *	knowing that the STA has gone to sleep.
	 *
	 * This is actually quite unlikely even when both those events are
	 * processed from interrupts coming in quickly after one another or
	 * even at the same time because we queue both TX status events and
	 * RX frames to be processed by a tasklet and process them in the
	 * same order that they were received or TX status last. Hence, there
	 * is no race as long as the frame RX is processed before the next TX
	 * status, which drivers can ensure, see below.
	 *
	 * Note that this can only happen if the hardware or firmware can
	 * actually add STAs to the filter list, if this is done by the
	 * driver in response to set_tim() (which will only reduce the race
	 * this whole filtering tries to solve, not completely solve it)
	 * this situation cannot happen.
	 *
	 * To completely solve this race drivers need to make sure that they
	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
	 *	functions and
	 *  (b) always process RX events before TX status events if ordering
	 *      can be unknown, for example with different interrupt status
	 *	bits.
	 */
	if (test_sta_flags(sta, WLAN_STA_PS) &&
	    skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
		ieee80211_remove_tx_extra(local, sta->key, skb);
		skb_queue_tail(&sta->tx_filtered, skb);
		return;
	}

	if (!test_sta_flags(sta, WLAN_STA_PS) && !skb->requeue) {
		/* Software retry the packet once */
		skb->requeue = 1;
		ieee80211_remove_tx_extra(local, sta->key, skb);
		dev_queue_xmit(skb);
		return;
	}

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	if (net_ratelimit())
		printk(KERN_DEBUG "%s: dropped TX filtered frame, "
		       "queue_len=%d PS=%d @%lu\n",
		       wiphy_name(local->hw.wiphy),
		       skb_queue_len(&sta->tx_filtered),
		       !!test_sta_flags(sta, WLAN_STA_PS), jiffies);
#endif
	dev_kfree_skb(skb);
}

void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
{
	struct sk_buff *skb2;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	u16 frag, type;
	__le16 fc;
	struct ieee80211_supported_band *sband;
	struct ieee80211_tx_status_rtap_hdr *rthdr;
	struct ieee80211_sub_if_data *sdata;
	struct net_device *prev_dev = NULL;
	struct sta_info *sta;
	int retry_count = -1, i;

	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
		/* the HW cannot have attempted that rate */
		if (i >= hw->max_rates) {
			info->status.rates[i].idx = -1;
			info->status.rates[i].count = 0;
		}

		retry_count += info->status.rates[i].count;
	}
	if (retry_count < 0)
		retry_count = 0;

	rcu_read_lock();

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

	sta = sta_info_get(local, hdr->addr1);

	if (sta) {
		if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
		    test_sta_flags(sta, WLAN_STA_PS)) {
			/*
			 * The STA is in power save mode, so assume
			 * that this TX packet failed because of that.
			 */
			ieee80211_handle_filtered_frame(local, sta, skb);
			rcu_read_unlock();
			return;
		}

		fc = hdr->frame_control;

		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
		    (ieee80211_is_data_qos(fc))) {
			u16 tid, ssn;
			u8 *qc;

			qc = ieee80211_get_qos_ctl(hdr);
			tid = qc[0] & 0xf;
			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
						& IEEE80211_SCTL_SEQ);
			ieee80211_send_bar(sta->sdata, hdr->addr1,
					   tid, ssn);
		}

		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
			ieee80211_handle_filtered_frame(local, sta, skb);
			rcu_read_unlock();
			return;
		} else {
			if (!(info->flags & IEEE80211_TX_STAT_ACK))
				sta->tx_retry_failed++;
			sta->tx_retry_count += retry_count;
		}

		rate_control_tx_status(local, sband, sta, skb);
	}

	rcu_read_unlock();

	ieee80211_led_tx(local, 0);

	/* SNMP counters
	 * Fragments are passed to low-level drivers as separate skbs, so these
	 * are actually fragments, not frames. Update frame counters only for
	 * the first fragment of the frame. */

	frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
	type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;

	if (info->flags & IEEE80211_TX_STAT_ACK) {
		if (frag == 0) {
			local->dot11TransmittedFrameCount++;
			if (is_multicast_ether_addr(hdr->addr1))
				local->dot11MulticastTransmittedFrameCount++;
			if (retry_count > 0)
				local->dot11RetryCount++;
			if (retry_count > 1)
				local->dot11MultipleRetryCount++;
		}

		/* This counter shall be incremented for an acknowledged MPDU
		 * with an individual address in the address 1 field or an MPDU
		 * with a multicast address in the address 1 field of type Data
		 * or Management. */
		if (!is_multicast_ether_addr(hdr->addr1) ||
		    type == IEEE80211_FTYPE_DATA ||
		    type == IEEE80211_FTYPE_MGMT)
			local->dot11TransmittedFragmentCount++;
	} else {
		if (frag == 0)
			local->dot11FailedCount++;
	}

	/* this was a transmitted frame, but now we want to reuse it */
	skb_orphan(skb);

	/*
	 * This is a bit racy but we can avoid a lot of work
	 * with this test...
	 */
	if (!local->monitors && !local->cooked_mntrs) {
		dev_kfree_skb(skb);
		return;
	}

	/* send frame to monitor interfaces now */

	if (skb_headroom(skb) < sizeof(*rthdr)) {
		printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
		dev_kfree_skb(skb);
		return;
	}

	rthdr = (struct ieee80211_tx_status_rtap_hdr *)
				skb_push(skb, sizeof(*rthdr));

	memset(rthdr, 0, sizeof(*rthdr));
	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
	rthdr->hdr.it_present =
		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES) |
			    (1 << IEEE80211_RADIOTAP_RATE));

	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
	    !is_multicast_ether_addr(hdr->addr1))
		rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);

	/*
	 * XXX: Once radiotap gets the bitmap reset thing the vendor
	 *	extensions proposal contains, we can actually report
	 *	the whole set of tries we did.
	 */
	if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
	    (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
		rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
	else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
		rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);
	if (info->status.rates[0].idx >= 0 &&
	    !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
		rthdr->rate = sband->bitrates[
				info->status.rates[0].idx].bitrate / 5;

	/* for now report the total retry_count */
	rthdr->data_retries = retry_count;

	/* XXX: is this sufficient for BPF? */
	skb_set_mac_header(skb, 0);
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	skb->pkt_type = PACKET_OTHERHOST;
	skb->protocol = htons(ETH_P_802_2);
	memset(skb->cb, 0, sizeof(skb->cb));

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
			if (!netif_running(sdata->dev))
				continue;

			if (prev_dev) {
				skb2 = skb_clone(skb, GFP_ATOMIC);
				if (skb2) {
					skb2->dev = prev_dev;
					netif_rx(skb2);
				}
			}

			prev_dev = sdata->dev;
		}
	}
	if (prev_dev) {
		skb->dev = prev_dev;
		netif_rx(skb);
		skb = NULL;
	}
	rcu_read_unlock();
	dev_kfree_skb(skb);
}
EXPORT_SYMBOL(ieee80211_tx_status);

struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
					const struct ieee80211_ops *ops)
{
	struct ieee80211_local *local;
	int priv_size;
	struct wiphy *wiphy;

	/* Ensure 32-byte alignment of our private data and hw private data.
	 * We use the wiphy priv data for both our ieee80211_local and for
	 * the driver's private data
	 *
	 * In memory it'll be like this:
	 *
	 * +-------------------------+
	 * | struct wiphy	    |
	 * +-------------------------+
	 * | struct ieee80211_local  |
	 * +-------------------------+
	 * | driver's private data   |
	 * +-------------------------+
	 *
	 */
	priv_size = ((sizeof(struct ieee80211_local) +
		      NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST) +
		    priv_data_len;

	wiphy = wiphy_new(&mac80211_config_ops, priv_size);

	if (!wiphy)
		return NULL;

	wiphy->privid = mac80211_wiphy_privid;

	local = wiphy_priv(wiphy);
	local->hw.wiphy = wiphy;

	local->hw.priv = (char *)local +
			 ((sizeof(struct ieee80211_local) +
			   NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);

	BUG_ON(!ops->tx);
	BUG_ON(!ops->start);
	BUG_ON(!ops->stop);
	BUG_ON(!ops->config);
	BUG_ON(!ops->add_interface);
	BUG_ON(!ops->remove_interface);
	BUG_ON(!ops->configure_filter);
	local->ops = ops;

	/* set up some defaults */
	local->hw.queues = 1;
	local->hw.max_rates = 1;
	local->rts_threshold = IEEE80211_MAX_RTS_THRESHOLD;
	local->fragmentation_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
	local->hw.conf.long_frame_max_tx_count = 4;
	local->hw.conf.short_frame_max_tx_count = 7;
	local->hw.conf.radio_enabled = true;

	INIT_LIST_HEAD(&local->interfaces);

	spin_lock_init(&local->key_lock);

	INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work);

	sta_info_init(local);

	tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending,
		     (unsigned long)local);
	tasklet_disable(&local->tx_pending_tasklet);

	tasklet_init(&local->tasklet,
		     ieee80211_tasklet_handler,
		     (unsigned long) local);
	tasklet_disable(&local->tasklet);

	skb_queue_head_init(&local->skb_queue);
	skb_queue_head_init(&local->skb_queue_unreliable);

	return local_to_hw(local);
}
EXPORT_SYMBOL(ieee80211_alloc_hw);

int ieee80211_register_hw(struct ieee80211_hw *hw)
{
	struct ieee80211_local *local = hw_to_local(hw);
	const char *name;
	int result;
	enum ieee80211_band band;
	struct net_device *mdev;
	struct ieee80211_master_priv *mpriv;

	/*
	 * generic code guarantees at least one band,
	 * set this very early because much code assumes
	 * that hw.conf.channel is assigned
	 */
	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		struct ieee80211_supported_band *sband;

		sband = local->hw.wiphy->bands[band];
		if (sband) {
			/* init channel we're on */
			local->hw.conf.channel =
			local->oper_channel =
			local->scan_channel = &sband->channels[0];
			break;
		}
	}

	/* if low-level driver supports AP, we also support VLAN */
	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP))
		local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);

	/* mac80211 always supports monitor */
	local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR);

	result = wiphy_register(local->hw.wiphy);
	if (result < 0)
		return result;

	/*
	 * We use the number of queues for feature tests (QoS, HT) internally
	 * so restrict them appropriately.
	 */
	if (hw->queues > IEEE80211_MAX_QUEUES)
		hw->queues = IEEE80211_MAX_QUEUES;
	if (hw->ampdu_queues > IEEE80211_MAX_AMPDU_QUEUES)
		hw->ampdu_queues = IEEE80211_MAX_AMPDU_QUEUES;
	if (hw->queues < 4)
		hw->ampdu_queues = 0;

	mdev = alloc_netdev_mq(sizeof(struct ieee80211_master_priv),
			       "wmaster%d", ether_setup,
			       ieee80211_num_queues(hw));
	if (!mdev)
		goto fail_mdev_alloc;

	mpriv = netdev_priv(mdev);
	mpriv->local = local;
	local->mdev = mdev;

	ieee80211_rx_bss_list_init(local);

	mdev->hard_start_xmit = ieee80211_master_start_xmit;
	mdev->open = ieee80211_master_open;
	mdev->stop = ieee80211_master_stop;
	mdev->type = ARPHRD_IEEE80211;
	mdev->header_ops = &ieee80211_header_ops;
	mdev->set_multicast_list = ieee80211_master_set_multicast_list;

	name = wiphy_dev(local->hw.wiphy)->driver->name;
	local->hw.workqueue = create_freezeable_workqueue(name);
	if (!local->hw.workqueue) {
		result = -ENOMEM;
		goto fail_workqueue;
	}

	/*
	 * The hardware needs headroom for sending the frame,
	 * and we need some headroom for passing the frame to monitor
	 * interfaces, but never both at the same time.
	 */
	local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom,
				   sizeof(struct ieee80211_tx_status_rtap_hdr));

	debugfs_hw_add(local);

	if (local->hw.conf.beacon_int < 10)
		local->hw.conf.beacon_int = 100;

	if (local->hw.max_listen_interval == 0)
		local->hw.max_listen_interval = 1;

	local->hw.conf.listen_interval = local->hw.max_listen_interval;

	local->wstats_flags |= local->hw.flags & (IEEE80211_HW_SIGNAL_UNSPEC |
						  IEEE80211_HW_SIGNAL_DB |
						  IEEE80211_HW_SIGNAL_DBM) ?
			       IW_QUAL_QUAL_UPDATED : IW_QUAL_QUAL_INVALID;
	local->wstats_flags |= local->hw.flags & IEEE80211_HW_NOISE_DBM ?
			       IW_QUAL_NOISE_UPDATED : IW_QUAL_NOISE_INVALID;
	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
		local->wstats_flags |= IW_QUAL_DBM;

	result = sta_info_start(local);
	if (result < 0)
		goto fail_sta_info;

	rtnl_lock();
	result = dev_alloc_name(local->mdev, local->mdev->name);
	if (result < 0)
		goto fail_dev;

	memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
	SET_NETDEV_DEV(local->mdev, wiphy_dev(local->hw.wiphy));

	result = register_netdevice(local->mdev);
	if (result < 0)
		goto fail_dev;

	result = ieee80211_init_rate_ctrl_alg(local,
					      hw->rate_control_algorithm);
	if (result < 0) {
		printk(KERN_DEBUG "%s: Failed to initialize rate control "
		       "algorithm\n", wiphy_name(local->hw.wiphy));
		goto fail_rate;
	}

	result = ieee80211_wep_init(local);

	if (result < 0) {
		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
		       wiphy_name(local->hw.wiphy), result);
		goto fail_wep;
	}

	local->mdev->select_queue = ieee80211_select_queue;

	/* add one default STA interface */
	result = ieee80211_if_add(local, "wlan%d", NULL,
				  NL80211_IFTYPE_STATION, NULL);
	if (result)
		printk(KERN_WARNING "%s: Failed to add default virtual iface\n",
		       wiphy_name(local->hw.wiphy));

	rtnl_unlock();

	ieee80211_led_init(local);

	return 0;

fail_wep:
	rate_control_deinitialize(local);
fail_rate:
	unregister_netdevice(local->mdev);
	local->mdev = NULL;
fail_dev:
	rtnl_unlock();
	sta_info_stop(local);
fail_sta_info:
	debugfs_hw_del(local);
	destroy_workqueue(local->hw.workqueue);
fail_workqueue:
	if (local->mdev)
		free_netdev(local->mdev);
fail_mdev_alloc:
	wiphy_unregister(local->hw.wiphy);
	return result;
}
EXPORT_SYMBOL(ieee80211_register_hw);

void ieee80211_unregister_hw(struct ieee80211_hw *hw)
{
	struct ieee80211_local *local = hw_to_local(hw);

	tasklet_kill(&local->tx_pending_tasklet);
	tasklet_kill(&local->tasklet);

	rtnl_lock();

	/*
	 * At this point, interface list manipulations are fine
	 * because the driver cannot be handing us frames any
	 * more and the tasklet is killed.
	 */

	/* First, we remove all virtual interfaces. */
	ieee80211_remove_interfaces(local);

	/* then, finally, remove the master interface */
	unregister_netdevice(local->mdev);

	rtnl_unlock();

	ieee80211_rx_bss_list_deinit(local);
	ieee80211_clear_tx_pending(local);
	sta_info_stop(local);
	rate_control_deinitialize(local);
	debugfs_hw_del(local);

	if (skb_queue_len(&local->skb_queue)
			|| skb_queue_len(&local->skb_queue_unreliable))
		printk(KERN_WARNING "%s: skb_queue not empty\n",
		       wiphy_name(local->hw.wiphy));
	skb_queue_purge(&local->skb_queue);
	skb_queue_purge(&local->skb_queue_unreliable);

	destroy_workqueue(local->hw.workqueue);
	wiphy_unregister(local->hw.wiphy);
	ieee80211_wep_free(local);
	ieee80211_led_exit(local);
	free_netdev(local->mdev);
}
EXPORT_SYMBOL(ieee80211_unregister_hw);

void ieee80211_free_hw(struct ieee80211_hw *hw)
{
	struct ieee80211_local *local = hw_to_local(hw);

	wiphy_free(local->hw.wiphy);
}
EXPORT_SYMBOL(ieee80211_free_hw);

static int __init ieee80211_init(void)
{
	struct sk_buff *skb;
	int ret;

	BUILD_BUG_ON(sizeof(struct ieee80211_tx_info) > sizeof(skb->cb));
	BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, driver_data) +
		     IEEE80211_TX_INFO_DRIVER_DATA_SIZE > sizeof(skb->cb));

	ret = rc80211_minstrel_init();
	if (ret)
		return ret;

	ret = rc80211_pid_init();
	if (ret)
		return ret;

	ieee80211_debugfs_netdev_init();

	return 0;
}

static void __exit ieee80211_exit(void)
{
	rc80211_pid_exit();
	rc80211_minstrel_exit();

	/*
	 * For key todo, it'll be empty by now but the work
	 * might still be scheduled.
	 */
	flush_scheduled_work();

	if (mesh_allocated)
		ieee80211s_stop();

	ieee80211_debugfs_netdev_exit();
}


subsys_initcall(ieee80211_init);
module_exit(ieee80211_exit);

MODULE_DESCRIPTION("IEEE 802.11 subsystem");
MODULE_LICENSE("GPL");