aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/iface.c
blob: 8336fee68d3e05b717047e4d8a1ac5f3623542a8 (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
/*
 * Interface handling (except master interface)
 *
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
 * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
 *
 * 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/kernel.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "sta_info.h"
#include "debugfs_netdev.h"
#include "mesh.h"
#include "led.h"

static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
{
	int meshhdrlen;
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	meshhdrlen = (sdata->vif.type == NL80211_IFTYPE_MESH_POINT) ? 5 : 0;

	/* FIX: what would be proper limits for MTU?
	 * This interface uses 802.3 frames. */
	if (new_mtu < 256 ||
	    new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
		return -EINVAL;
	}

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
	dev->mtu = new_mtu;
	return 0;
}

static inline int identical_mac_addr_allowed(int type1, int type2)
{
	return type1 == NL80211_IFTYPE_MONITOR ||
		type2 == NL80211_IFTYPE_MONITOR ||
		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
		(type1 == NL80211_IFTYPE_WDS &&
			(type2 == NL80211_IFTYPE_WDS ||
			 type2 == NL80211_IFTYPE_AP)) ||
		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
		(type1 == NL80211_IFTYPE_AP_VLAN &&
			(type2 == NL80211_IFTYPE_AP ||
			 type2 == NL80211_IFTYPE_AP_VLAN));
}

static int ieee80211_open(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_sub_if_data *nsdata;
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	struct ieee80211_if_init_conf conf;
	u32 changed = 0;
	int res;
	bool need_hw_reconfig = 0;
	u8 null_addr[ETH_ALEN] = {0};

	/* fail early if user set an invalid address */
	if (compare_ether_addr(dev->dev_addr, null_addr) &&
	    !is_valid_ether_addr(dev->dev_addr))
		return -EADDRNOTAVAIL;

	/* we hold the RTNL here so can safely walk the list */
	list_for_each_entry(nsdata, &local->interfaces, list) {
		struct net_device *ndev = nsdata->dev;

		if (ndev != dev && netif_running(ndev)) {
			/*
			 * Allow only a single IBSS interface to be up at any
			 * time. This is restricted because beacon distribution
			 * cannot work properly if both are in the same IBSS.
			 *
			 * To remove this restriction we'd have to disallow them
			 * from setting the same SSID on different IBSS interfaces
			 * belonging to the same hardware. Then, however, we're
			 * faced with having to adopt two different TSF timers...
			 */
			if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
			    nsdata->vif.type == NL80211_IFTYPE_ADHOC)
				return -EBUSY;

			/*
			 * The remaining checks are only performed for interfaces
			 * with the same MAC address.
			 */
			if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
				continue;

			/*
			 * check whether it may have the same address
			 */
			if (!identical_mac_addr_allowed(sdata->vif.type,
							nsdata->vif.type))
				return -ENOTUNIQ;

			/*
			 * can only add VLANs to enabled APs
			 */
			if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
			    nsdata->vif.type == NL80211_IFTYPE_AP)
				sdata->bss = &nsdata->u.ap;
		}
	}

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_WDS:
		if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
			return -ENOLINK;
		break;
	case NL80211_IFTYPE_AP_VLAN:
		if (!sdata->bss)
			return -ENOLINK;
		list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
		break;
	case NL80211_IFTYPE_AP:
		sdata->bss = &sdata->u.ap;
		break;
	case NL80211_IFTYPE_MESH_POINT:
		if (!ieee80211_vif_is_mesh(&sdata->vif))
			break;
		/* mesh ifaces must set allmulti to forward mcast traffic */
		atomic_inc(&local->iff_allmultis);
		break;
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_MONITOR:
	case NL80211_IFTYPE_ADHOC:
		/* no special treatment */
		break;
	case NL80211_IFTYPE_UNSPECIFIED:
	case __NL80211_IFTYPE_AFTER_LAST:
		/* cannot happen */
		WARN_ON(1);
		break;
	}

	if (local->open_count == 0) {
		res = 0;
		if (local->ops->start)
			res = local->ops->start(local_to_hw(local));
		if (res)
			goto err_del_bss;
		need_hw_reconfig = 1;
		ieee80211_led_radio(local, local->hw.conf.radio_enabled);
	}

	/*
	 * Check all interfaces and copy the hopefully now-present
	 * MAC address to those that have the special null one.
	 */
	list_for_each_entry(nsdata, &local->interfaces, list) {
		struct net_device *ndev = nsdata->dev;

		/*
		 * No need to check netif_running since we do not allow
		 * it to start up with this invalid address.
		 */
		if (compare_ether_addr(null_addr, ndev->dev_addr) == 0)
			memcpy(ndev->dev_addr,
			       local->hw.wiphy->perm_addr,
			       ETH_ALEN);
	}

	if (compare_ether_addr(null_addr, local->mdev->dev_addr) == 0)
		memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr,
		       ETH_ALEN);

	/*
	 * Validate the MAC address for this device.
	 */
	if (!is_valid_ether_addr(dev->dev_addr)) {
		if (!local->open_count && local->ops->stop)
			local->ops->stop(local_to_hw(local));
		return -EADDRNOTAVAIL;
	}

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP_VLAN:
		/* no need to tell driver */
		break;
	case NL80211_IFTYPE_MONITOR:
		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
			local->cooked_mntrs++;
			break;
		}

		/* must be before the call to ieee80211_configure_filter */
		local->monitors++;
		if (local->monitors == 1)
			local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;

		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
			local->fif_fcsfail++;
		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
			local->fif_plcpfail++;
		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
			local->fif_control++;
		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
			local->fif_other_bss++;

		netif_addr_lock_bh(local->mdev);
		ieee80211_configure_filter(local);
		netif_addr_unlock_bh(local->mdev);
		break;
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
		sdata->u.sta.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
		/* fall through */
	default:
		conf.vif = &sdata->vif;
		conf.type = sdata->vif.type;
		conf.mac_addr = dev->dev_addr;
		res = local->ops->add_interface(local_to_hw(local), &conf);
		if (res)
			goto err_stop;

		if (ieee80211_vif_is_mesh(&sdata->vif))
			ieee80211_start_mesh(sdata);
		changed |= ieee80211_reset_erp_info(sdata);
		ieee80211_bss_info_change_notify(sdata, changed);
		ieee80211_enable_keys(sdata);

		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
		    !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
			netif_carrier_off(dev);
		else
			netif_carrier_on(dev);
	}

	if (sdata->vif.type == NL80211_IFTYPE_WDS) {
		/* Create STA entry for the WDS peer */
		sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
				     GFP_KERNEL);
		if (!sta) {
			res = -ENOMEM;
			goto err_del_interface;
		}

		/* no locking required since STA is not live yet */
		sta->flags |= WLAN_STA_AUTHORIZED;

		res = sta_info_insert(sta);
		if (res) {
			/* STA has been freed */
			goto err_del_interface;
		}
	}

	if (local->open_count == 0) {
		res = dev_open(local->mdev);
		WARN_ON(res);
		if (res)
			goto err_del_interface;
		tasklet_enable(&local->tx_pending_tasklet);
		tasklet_enable(&local->tasklet);
	}

	/*
	 * set_multicast_list will be invoked by the networking core
	 * which will check whether any increments here were done in
	 * error and sync them down to the hardware as filter flags.
	 */
	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
		atomic_inc(&local->iff_allmultis);

	if (sdata->flags & IEEE80211_SDATA_PROMISC)
		atomic_inc(&local->iff_promiscs);

	local->open_count++;
	if (need_hw_reconfig) {
		ieee80211_hw_config(local);
		/*
		 * set default queue parameters so drivers don't
		 * need to initialise the hardware if the hardware
		 * doesn't start up with sane defaults
		 */
		ieee80211_set_wmm_default(sdata);
	}

	/*
	 * ieee80211_sta_work is disabled while network interface
	 * is down. Therefore, some configuration changes may not
	 * yet be effective. Trigger execution of ieee80211_sta_work
	 * to fix this.
	 */
	if (sdata->vif.type == NL80211_IFTYPE_STATION ||
	    sdata->vif.type == NL80211_IFTYPE_ADHOC) {
		struct ieee80211_if_sta *ifsta = &sdata->u.sta;
		queue_work(local->hw.workqueue, &ifsta->work);
	}

	netif_tx_start_all_queues(dev);

	return 0;
 err_del_interface:
	local->ops->remove_interface(local_to_hw(local), &conf);
 err_stop:
	if (!local->open_count && local->ops->stop)
		local->ops->stop(local_to_hw(local));
 err_del_bss:
	sdata->bss = NULL;
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		list_del(&sdata->u.vlan.list);
	return res;
}

static int ieee80211_stop(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_init_conf conf;
	struct sta_info *sta;

	/*
	 * Stop TX on this interface first.
	 */
	netif_tx_stop_all_queues(dev);

	/*
	 * Now delete all active aggregation sessions.
	 */
	rcu_read_lock();

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sta->sdata == sdata)
			ieee80211_sta_tear_down_BA_sessions(sdata,
							    sta->sta.addr);
	}

	rcu_read_unlock();

	/*
	 * Remove all stations associated with this interface.
	 *
	 * This must be done before calling ops->remove_interface()
	 * because otherwise we can later invoke ops->sta_notify()
	 * whenever the STAs are removed, and that invalidates driver
	 * assumptions about always getting a vif pointer that is valid
	 * (because if we remove a STA after ops->remove_interface()
	 * the driver will have removed the vif info already!)
	 *
	 * We could relax this and only unlink the stations from the
	 * hash table and list but keep them on a per-sdata list that
	 * will be inserted back again when the interface is brought
	 * up again, but I don't currently see a use case for that,
	 * except with WDS which gets a STA entry created when it is
	 * brought up.
	 */
	sta_info_flush(local, sdata);

	/*
	 * Don't count this interface for promisc/allmulti while it
	 * is down. dev_mc_unsync() will invoke set_multicast_list
	 * on the master interface which will sync these down to the
	 * hardware as filter flags.
	 */
	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
		atomic_dec(&local->iff_allmultis);

	if (sdata->flags & IEEE80211_SDATA_PROMISC)
		atomic_dec(&local->iff_promiscs);

	dev_mc_unsync(local->mdev, dev);

	/* APs need special treatment */
	if (sdata->vif.type == NL80211_IFTYPE_AP) {
		struct ieee80211_sub_if_data *vlan, *tmp;
		struct beacon_data *old_beacon = sdata->u.ap.beacon;

		/* remove beacon */
		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
		synchronize_rcu();
		kfree(old_beacon);

		/* down all dependent devices, that is VLANs */
		list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
					 u.vlan.list)
			dev_close(vlan->dev);
		WARN_ON(!list_empty(&sdata->u.ap.vlans));
	}

	local->open_count--;

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP_VLAN:
		list_del(&sdata->u.vlan.list);
		/* no need to tell driver */
		break;
	case NL80211_IFTYPE_MONITOR:
		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
			local->cooked_mntrs--;
			break;
		}

		local->monitors--;
		if (local->monitors == 0)
			local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;

		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
			local->fif_fcsfail--;
		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
			local->fif_plcpfail--;
		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
			local->fif_control--;
		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
			local->fif_other_bss--;

		netif_addr_lock_bh(local->mdev);
		ieee80211_configure_filter(local);
		netif_addr_unlock_bh(local->mdev);
		break;
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
		sdata->u.sta.state = IEEE80211_STA_MLME_DISABLED;
		memset(sdata->u.sta.bssid, 0, ETH_ALEN);
		del_timer_sync(&sdata->u.sta.timer);
		/*
		 * If the timer fired while we waited for it, it will have
		 * requeued the work. Now the work will be running again
		 * but will not rearm the timer again because it checks
		 * whether the interface is running, which, at this point,
		 * it no longer is.
		 */
		cancel_work_sync(&sdata->u.sta.work);
		/*
		 * When we get here, the interface is marked down.
		 * Call synchronize_rcu() to wait for the RX path
		 * should it be using the interface and enqueuing
		 * frames at this very time on another CPU.
		 */
		synchronize_rcu();
		skb_queue_purge(&sdata->u.sta.skb_queue);

		sdata->u.sta.flags &= ~IEEE80211_STA_PRIVACY_INVOKED;
		kfree(sdata->u.sta.extra_ie);
		sdata->u.sta.extra_ie = NULL;
		sdata->u.sta.extra_ie_len = 0;
		/* fall through */
	case NL80211_IFTYPE_MESH_POINT:
		if (ieee80211_vif_is_mesh(&sdata->vif)) {
			/* allmulti is always set on mesh ifaces */
			atomic_dec(&local->iff_allmultis);
			ieee80211_stop_mesh(sdata);
		}
		/* fall through */
	default:
		if (local->scan_sdata == sdata) {
			if (!local->ops->hw_scan)
				cancel_delayed_work_sync(&local->scan_work);
			/*
			 * The software scan can no longer run now, so we can
			 * clear out the scan_sdata reference. However, the
			 * hardware scan may still be running. The complete
			 * function must be prepared to handle a NULL value.
			 */
			local->scan_sdata = NULL;
			/*
			 * The memory barrier guarantees that another CPU
			 * that is hardware-scanning will now see the fact
			 * that this interface is gone.
			 */
			smp_mb();
			/*
			 * If software scanning, complete the scan but since
			 * the scan_sdata is NULL already don't send out a
			 * scan event to userspace -- the scan is incomplete.
			 */
			if (local->sw_scanning)
				ieee80211_scan_completed(&local->hw);
		}

		conf.vif = &sdata->vif;
		conf.type = sdata->vif.type;
		conf.mac_addr = dev->dev_addr;
		/* disable all keys for as long as this netdev is down */
		ieee80211_disable_keys(sdata);
		local->ops->remove_interface(local_to_hw(local), &conf);
	}

	sdata->bss = NULL;

	if (local->open_count == 0) {
		if (netif_running(local->mdev))
			dev_close(local->mdev);

		if (local->ops->stop)
			local->ops->stop(local_to_hw(local));

		ieee80211_led_radio(local, 0);

		flush_workqueue(local->hw.workqueue);

		tasklet_disable(&local->tx_pending_tasklet);
		tasklet_disable(&local->tasklet);
	}

	return 0;
}

static void ieee80211_set_multicast_list(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
	int allmulti, promisc, sdata_allmulti, sdata_promisc;

	allmulti = !!(dev->flags & IFF_ALLMULTI);
	promisc = !!(dev->flags & IFF_PROMISC);
	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
	sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);

	if (allmulti != sdata_allmulti) {
		if (dev->flags & IFF_ALLMULTI)
			atomic_inc(&local->iff_allmultis);
		else
			atomic_dec(&local->iff_allmultis);
		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
	}

	if (promisc != sdata_promisc) {
		if (dev->flags & IFF_PROMISC)
			atomic_inc(&local->iff_promiscs);
		else
			atomic_dec(&local->iff_promiscs);
		sdata->flags ^= IEEE80211_SDATA_PROMISC;
	}

	dev_mc_sync(local->mdev, dev);
}

static void ieee80211_if_setup(struct net_device *dev)
{
	ether_setup(dev);
	dev->hard_start_xmit = ieee80211_subif_start_xmit;
	dev->wireless_handlers = &ieee80211_iw_handler_def;
	dev->set_multicast_list = ieee80211_set_multicast_list;
	dev->change_mtu = ieee80211_change_mtu;
	dev->open = ieee80211_open;
	dev->stop = ieee80211_stop;
	dev->destructor = free_netdev;
	/* we will validate the address ourselves in ->open */
	dev->validate_addr = NULL;
}
/*
 * Called when the netdev is removed or, by the code below, before
 * the interface type changes.
 */
static void ieee80211_teardown_sdata(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
	struct beacon_data *beacon;
	struct sk_buff *skb;
	int flushed;
	int i;

	/* free extra data */
	ieee80211_free_keys(sdata);

	ieee80211_debugfs_remove_netdev(sdata);

	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
		__skb_queue_purge(&sdata->fragments[i].skb_list);
	sdata->fragment_next = 0;

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP:
		beacon = sdata->u.ap.beacon;
		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
		synchronize_rcu();
		kfree(beacon);

		while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
			local->total_ps_buffered--;
			dev_kfree_skb(skb);
		}

		break;
	case NL80211_IFTYPE_MESH_POINT:
		if (ieee80211_vif_is_mesh(&sdata->vif))
			mesh_rmc_free(sdata);
		break;
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
		kfree(sdata->u.sta.extra_ie);
		kfree(sdata->u.sta.assocreq_ies);
		kfree(sdata->u.sta.assocresp_ies);
		kfree_skb(sdata->u.sta.probe_resp);
		break;
	case NL80211_IFTYPE_WDS:
	case NL80211_IFTYPE_AP_VLAN:
	case NL80211_IFTYPE_MONITOR:
		break;
	case NL80211_IFTYPE_UNSPECIFIED:
	case __NL80211_IFTYPE_AFTER_LAST:
		BUG();
		break;
	}

	flushed = sta_info_flush(local, sdata);
	WARN_ON(flushed);
}

/*
 * Helper function to initialise an interface to a specific type.
 */
static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
				  enum nl80211_iftype type)
{
	/* clear type-dependent union */
	memset(&sdata->u, 0, sizeof(sdata->u));

	/* and set some type-dependent values */
	sdata->vif.type = type;
	sdata->dev->hard_start_xmit = ieee80211_subif_start_xmit;
	sdata->wdev.iftype = type;

	/* only monitor differs */
	sdata->dev->type = ARPHRD_ETHER;

	switch (type) {
	case NL80211_IFTYPE_AP:
		skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
		INIT_LIST_HEAD(&sdata->u.ap.vlans);
		break;
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
		ieee80211_sta_setup_sdata(sdata);
		break;
	case NL80211_IFTYPE_MESH_POINT:
		if (ieee80211_vif_is_mesh(&sdata->vif))
			ieee80211_mesh_init_sdata(sdata);
		break;
	case NL80211_IFTYPE_MONITOR:
		sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
		sdata->dev->hard_start_xmit = ieee80211_monitor_start_xmit;
		sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
				      MONITOR_FLAG_OTHER_BSS;
		break;
	case NL80211_IFTYPE_WDS:
	case NL80211_IFTYPE_AP_VLAN:
		break;
	case NL80211_IFTYPE_UNSPECIFIED:
	case __NL80211_IFTYPE_AFTER_LAST:
		BUG();
		break;
	}

	ieee80211_debugfs_add_netdev(sdata);
}

int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
			     enum nl80211_iftype type)
{
	ASSERT_RTNL();

	if (type == sdata->vif.type)
		return 0;

	/*
	 * We could, here, on changes between IBSS/STA/MESH modes,
	 * invoke an MLME function instead that disassociates etc.
	 * and goes into the requested mode.
	 */

	if (netif_running(sdata->dev))
		return -EBUSY;

	/* Purge and reset type-dependent state. */
	ieee80211_teardown_sdata(sdata->dev);
	ieee80211_setup_sdata(sdata, type);

	/* reset some values that shouldn't be kept across type changes */
	sdata->bss_conf.basic_rates =
		ieee80211_mandatory_rates(sdata->local,
			sdata->local->hw.conf.channel->band);
	sdata->drop_unencrypted = 0;

	return 0;
}

int ieee80211_if_add(struct ieee80211_local *local, const char *name,
		     struct net_device **new_dev, enum nl80211_iftype type,
		     struct vif_params *params)
{
	struct net_device *ndev;
	struct ieee80211_sub_if_data *sdata = NULL;
	int ret, i;

	ASSERT_RTNL();

	ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
			    name, ieee80211_if_setup);
	if (!ndev)
		return -ENOMEM;

	ndev->needed_headroom = local->tx_headroom +
				4*6 /* four MAC addresses */
				+ 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
				+ 6 /* mesh */
				+ 8 /* rfc1042/bridge tunnel */
				- ETH_HLEN /* ethernet hard_header_len */
				+ IEEE80211_ENCRYPT_HEADROOM;
	ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;

	ret = dev_alloc_name(ndev, ndev->name);
	if (ret < 0)
		goto fail;

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

	/* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
	sdata = netdev_priv(ndev);
	ndev->ieee80211_ptr = &sdata->wdev;

	/* initialise type-independent data */
	sdata->wdev.wiphy = local->hw.wiphy;
	sdata->local = local;
	sdata->dev = ndev;

	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
		skb_queue_head_init(&sdata->fragments[i].skb_list);

	INIT_LIST_HEAD(&sdata->key_list);

	sdata->force_unicast_rateidx = -1;
	sdata->max_ratectrl_rateidx = -1;

	/* setup type-dependent data */
	ieee80211_setup_sdata(sdata, type);

	ret = register_netdevice(ndev);
	if (ret)
		goto fail;

	ndev->uninit = ieee80211_teardown_sdata;

	if (ieee80211_vif_is_mesh(&sdata->vif) &&
	    params && params->mesh_id_len)
		ieee80211_sdata_set_mesh_id(sdata,
					    params->mesh_id_len,
					    params->mesh_id);

	list_add_tail_rcu(&sdata->list, &local->interfaces);

	if (new_dev)
		*new_dev = ndev;

	return 0;

 fail:
	free_netdev(ndev);
	return ret;
}

void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
{
	ASSERT_RTNL();

	list_del_rcu(&sdata->list);
	synchronize_rcu();
	unregister_netdevice(sdata->dev);
}

/*
 * Remove all interfaces, may only be called at hardware unregistration
 * time because it doesn't do RCU-safe list removals.
 */
void ieee80211_remove_interfaces(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata, *tmp;

	ASSERT_RTNL();

	list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
		list_del(&sdata->list);
		unregister_netdevice(sdata->dev);
	}
}