xref: /openbmc/linux/net/mac80211/iface.c (revision 7dd65feb)
1 /*
2  * Interface handling (except master interface)
3  *
4  * Copyright 2002-2005, Instant802 Networks, Inc.
5  * Copyright 2005-2006, Devicescape Software, Inc.
6  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
7  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 #include <linux/kernel.h>
14 #include <linux/if_arp.h>
15 #include <linux/netdevice.h>
16 #include <linux/rtnetlink.h>
17 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "sta_info.h"
20 #include "debugfs_netdev.h"
21 #include "mesh.h"
22 #include "led.h"
23 #include "driver-ops.h"
24 
25 /**
26  * DOC: Interface list locking
27  *
28  * The interface list in each struct ieee80211_local is protected
29  * three-fold:
30  *
31  * (1) modifications may only be done under the RTNL
32  * (2) modifications and readers are protected against each other by
33  *     the iflist_mtx.
34  * (3) modifications are done in an RCU manner so atomic readers
35  *     can traverse the list in RCU-safe blocks.
36  *
37  * As a consequence, reads (traversals) of the list can be protected
38  * by either the RTNL, the iflist_mtx or RCU.
39  */
40 
41 
42 static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
43 {
44 	int meshhdrlen;
45 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
46 
47 	meshhdrlen = (sdata->vif.type == NL80211_IFTYPE_MESH_POINT) ? 5 : 0;
48 
49 	/* FIX: what would be proper limits for MTU?
50 	 * This interface uses 802.3 frames. */
51 	if (new_mtu < 256 ||
52 	    new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
53 		return -EINVAL;
54 	}
55 
56 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
57 	printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
58 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
59 	dev->mtu = new_mtu;
60 	return 0;
61 }
62 
63 static inline int identical_mac_addr_allowed(int type1, int type2)
64 {
65 	return type1 == NL80211_IFTYPE_MONITOR ||
66 		type2 == NL80211_IFTYPE_MONITOR ||
67 		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
68 		(type1 == NL80211_IFTYPE_WDS &&
69 			(type2 == NL80211_IFTYPE_WDS ||
70 			 type2 == NL80211_IFTYPE_AP)) ||
71 		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
72 		(type1 == NL80211_IFTYPE_AP_VLAN &&
73 			(type2 == NL80211_IFTYPE_AP ||
74 			 type2 == NL80211_IFTYPE_AP_VLAN));
75 }
76 
77 static int ieee80211_open(struct net_device *dev)
78 {
79 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
80 	struct ieee80211_sub_if_data *nsdata;
81 	struct ieee80211_local *local = sdata->local;
82 	struct sta_info *sta;
83 	struct ieee80211_if_init_conf conf;
84 	u32 changed = 0;
85 	int res;
86 	u32 hw_reconf_flags = 0;
87 	u8 null_addr[ETH_ALEN] = {0};
88 
89 	/* fail early if user set an invalid address */
90 	if (compare_ether_addr(dev->dev_addr, null_addr) &&
91 	    !is_valid_ether_addr(dev->dev_addr))
92 		return -EADDRNOTAVAIL;
93 
94 	/* we hold the RTNL here so can safely walk the list */
95 	list_for_each_entry(nsdata, &local->interfaces, list) {
96 		struct net_device *ndev = nsdata->dev;
97 
98 		if (ndev != dev && netif_running(ndev)) {
99 			/*
100 			 * Allow only a single IBSS interface to be up at any
101 			 * time. This is restricted because beacon distribution
102 			 * cannot work properly if both are in the same IBSS.
103 			 *
104 			 * To remove this restriction we'd have to disallow them
105 			 * from setting the same SSID on different IBSS interfaces
106 			 * belonging to the same hardware. Then, however, we're
107 			 * faced with having to adopt two different TSF timers...
108 			 */
109 			if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
110 			    nsdata->vif.type == NL80211_IFTYPE_ADHOC)
111 				return -EBUSY;
112 
113 			/*
114 			 * The remaining checks are only performed for interfaces
115 			 * with the same MAC address.
116 			 */
117 			if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
118 				continue;
119 
120 			/*
121 			 * check whether it may have the same address
122 			 */
123 			if (!identical_mac_addr_allowed(sdata->vif.type,
124 							nsdata->vif.type))
125 				return -ENOTUNIQ;
126 
127 			/*
128 			 * can only add VLANs to enabled APs
129 			 */
130 			if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
131 			    nsdata->vif.type == NL80211_IFTYPE_AP)
132 				sdata->bss = &nsdata->u.ap;
133 		}
134 	}
135 
136 	switch (sdata->vif.type) {
137 	case NL80211_IFTYPE_WDS:
138 		if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
139 			return -ENOLINK;
140 		break;
141 	case NL80211_IFTYPE_AP_VLAN:
142 		if (!sdata->bss)
143 			return -ENOLINK;
144 		list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
145 		break;
146 	case NL80211_IFTYPE_AP:
147 		sdata->bss = &sdata->u.ap;
148 		break;
149 	case NL80211_IFTYPE_MESH_POINT:
150 		if (!ieee80211_vif_is_mesh(&sdata->vif))
151 			break;
152 		/* mesh ifaces must set allmulti to forward mcast traffic */
153 		atomic_inc(&local->iff_allmultis);
154 		break;
155 	case NL80211_IFTYPE_STATION:
156 	case NL80211_IFTYPE_MONITOR:
157 	case NL80211_IFTYPE_ADHOC:
158 		/* no special treatment */
159 		break;
160 	case NL80211_IFTYPE_UNSPECIFIED:
161 	case __NL80211_IFTYPE_AFTER_LAST:
162 		/* cannot happen */
163 		WARN_ON(1);
164 		break;
165 	}
166 
167 	if (local->open_count == 0) {
168 		res = drv_start(local);
169 		if (res)
170 			goto err_del_bss;
171 		/* we're brought up, everything changes */
172 		hw_reconf_flags = ~0;
173 		ieee80211_led_radio(local, true);
174 	}
175 
176 	/*
177 	 * Check all interfaces and copy the hopefully now-present
178 	 * MAC address to those that have the special null one.
179 	 */
180 	list_for_each_entry(nsdata, &local->interfaces, list) {
181 		struct net_device *ndev = nsdata->dev;
182 
183 		/*
184 		 * No need to check netif_running since we do not allow
185 		 * it to start up with this invalid address.
186 		 */
187 		if (compare_ether_addr(null_addr, ndev->dev_addr) == 0) {
188 			memcpy(ndev->dev_addr,
189 			       local->hw.wiphy->perm_addr,
190 			       ETH_ALEN);
191 			memcpy(ndev->perm_addr, ndev->dev_addr, ETH_ALEN);
192 		}
193 	}
194 
195 	/*
196 	 * Validate the MAC address for this device.
197 	 */
198 	if (!is_valid_ether_addr(dev->dev_addr)) {
199 		if (!local->open_count)
200 			drv_stop(local);
201 		return -EADDRNOTAVAIL;
202 	}
203 
204 	switch (sdata->vif.type) {
205 	case NL80211_IFTYPE_AP_VLAN:
206 		/* no need to tell driver */
207 		break;
208 	case NL80211_IFTYPE_MONITOR:
209 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
210 			local->cooked_mntrs++;
211 			break;
212 		}
213 
214 		/* must be before the call to ieee80211_configure_filter */
215 		local->monitors++;
216 		if (local->monitors == 1) {
217 			local->hw.conf.flags |= IEEE80211_CONF_MONITOR;
218 			hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
219 		}
220 
221 		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
222 			local->fif_fcsfail++;
223 		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
224 			local->fif_plcpfail++;
225 		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL) {
226 			local->fif_control++;
227 			local->fif_pspoll++;
228 		}
229 		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
230 			local->fif_other_bss++;
231 
232 		ieee80211_configure_filter(local);
233 		break;
234 	default:
235 		conf.vif = &sdata->vif;
236 		conf.type = sdata->vif.type;
237 		conf.mac_addr = dev->dev_addr;
238 		res = drv_add_interface(local, &conf);
239 		if (res)
240 			goto err_stop;
241 
242 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
243 			local->fif_other_bss++;
244 			ieee80211_configure_filter(local);
245 
246 			ieee80211_start_mesh(sdata);
247 		} else if (sdata->vif.type == NL80211_IFTYPE_AP) {
248 			local->fif_pspoll++;
249 
250 			ieee80211_configure_filter(local);
251 		}
252 
253 		changed |= ieee80211_reset_erp_info(sdata);
254 		ieee80211_bss_info_change_notify(sdata, changed);
255 		ieee80211_enable_keys(sdata);
256 
257 		if (sdata->vif.type == NL80211_IFTYPE_STATION)
258 			netif_carrier_off(dev);
259 		else
260 			netif_carrier_on(dev);
261 	}
262 
263 	if (sdata->vif.type == NL80211_IFTYPE_WDS) {
264 		/* Create STA entry for the WDS peer */
265 		sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
266 				     GFP_KERNEL);
267 		if (!sta) {
268 			res = -ENOMEM;
269 			goto err_del_interface;
270 		}
271 
272 		/* no locking required since STA is not live yet */
273 		sta->flags |= WLAN_STA_AUTHORIZED;
274 
275 		res = sta_info_insert(sta);
276 		if (res) {
277 			/* STA has been freed */
278 			goto err_del_interface;
279 		}
280 	}
281 
282 	/*
283 	 * set_multicast_list will be invoked by the networking core
284 	 * which will check whether any increments here were done in
285 	 * error and sync them down to the hardware as filter flags.
286 	 */
287 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
288 		atomic_inc(&local->iff_allmultis);
289 
290 	if (sdata->flags & IEEE80211_SDATA_PROMISC)
291 		atomic_inc(&local->iff_promiscs);
292 
293 	hw_reconf_flags |= __ieee80211_recalc_idle(local);
294 
295 	local->open_count++;
296 	if (hw_reconf_flags) {
297 		ieee80211_hw_config(local, hw_reconf_flags);
298 		/*
299 		 * set default queue parameters so drivers don't
300 		 * need to initialise the hardware if the hardware
301 		 * doesn't start up with sane defaults
302 		 */
303 		ieee80211_set_wmm_default(sdata);
304 	}
305 
306 	ieee80211_recalc_ps(local, -1);
307 
308 	/*
309 	 * ieee80211_sta_work is disabled while network interface
310 	 * is down. Therefore, some configuration changes may not
311 	 * yet be effective. Trigger execution of ieee80211_sta_work
312 	 * to fix this.
313 	 */
314 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
315 		ieee80211_queue_work(&local->hw, &sdata->u.mgd.work);
316 
317 	netif_start_queue(dev);
318 
319 	return 0;
320  err_del_interface:
321 	drv_remove_interface(local, &conf);
322  err_stop:
323 	if (!local->open_count)
324 		drv_stop(local);
325  err_del_bss:
326 	sdata->bss = NULL;
327 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
328 		list_del(&sdata->u.vlan.list);
329 	return res;
330 }
331 
332 static int ieee80211_stop(struct net_device *dev)
333 {
334 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
335 	struct ieee80211_local *local = sdata->local;
336 	struct ieee80211_if_init_conf conf;
337 	struct sta_info *sta;
338 	unsigned long flags;
339 	struct sk_buff *skb, *tmp;
340 	u32 hw_reconf_flags = 0;
341 	int i;
342 
343 	/*
344 	 * Stop TX on this interface first.
345 	 */
346 	netif_stop_queue(dev);
347 
348 	/*
349 	 * Now delete all active aggregation sessions.
350 	 */
351 	rcu_read_lock();
352 
353 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
354 		if (sta->sdata == sdata)
355 			ieee80211_sta_tear_down_BA_sessions(sta);
356 	}
357 
358 	rcu_read_unlock();
359 
360 	/*
361 	 * Remove all stations associated with this interface.
362 	 *
363 	 * This must be done before calling ops->remove_interface()
364 	 * because otherwise we can later invoke ops->sta_notify()
365 	 * whenever the STAs are removed, and that invalidates driver
366 	 * assumptions about always getting a vif pointer that is valid
367 	 * (because if we remove a STA after ops->remove_interface()
368 	 * the driver will have removed the vif info already!)
369 	 *
370 	 * We could relax this and only unlink the stations from the
371 	 * hash table and list but keep them on a per-sdata list that
372 	 * will be inserted back again when the interface is brought
373 	 * up again, but I don't currently see a use case for that,
374 	 * except with WDS which gets a STA entry created when it is
375 	 * brought up.
376 	 */
377 	sta_info_flush(local, sdata);
378 
379 	/*
380 	 * Don't count this interface for promisc/allmulti while it
381 	 * is down. dev_mc_unsync() will invoke set_multicast_list
382 	 * on the master interface which will sync these down to the
383 	 * hardware as filter flags.
384 	 */
385 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
386 		atomic_dec(&local->iff_allmultis);
387 
388 	if (sdata->flags & IEEE80211_SDATA_PROMISC)
389 		atomic_dec(&local->iff_promiscs);
390 
391 	if (sdata->vif.type == NL80211_IFTYPE_AP)
392 		local->fif_pspoll--;
393 
394 	netif_addr_lock_bh(dev);
395 	spin_lock_bh(&local->filter_lock);
396 	__dev_addr_unsync(&local->mc_list, &local->mc_count,
397 			  &dev->mc_list, &dev->mc_count);
398 	spin_unlock_bh(&local->filter_lock);
399 	netif_addr_unlock_bh(dev);
400 
401 	ieee80211_configure_filter(local);
402 
403 	del_timer_sync(&local->dynamic_ps_timer);
404 	cancel_work_sync(&local->dynamic_ps_enable_work);
405 
406 	/* APs need special treatment */
407 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
408 		struct ieee80211_sub_if_data *vlan, *tmpsdata;
409 		struct beacon_data *old_beacon = sdata->u.ap.beacon;
410 
411 		/* remove beacon */
412 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
413 		synchronize_rcu();
414 		kfree(old_beacon);
415 
416 		/* down all dependent devices, that is VLANs */
417 		list_for_each_entry_safe(vlan, tmpsdata, &sdata->u.ap.vlans,
418 					 u.vlan.list)
419 			dev_close(vlan->dev);
420 		WARN_ON(!list_empty(&sdata->u.ap.vlans));
421 	}
422 
423 	local->open_count--;
424 
425 	switch (sdata->vif.type) {
426 	case NL80211_IFTYPE_AP_VLAN:
427 		list_del(&sdata->u.vlan.list);
428 		/* no need to tell driver */
429 		break;
430 	case NL80211_IFTYPE_MONITOR:
431 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
432 			local->cooked_mntrs--;
433 			break;
434 		}
435 
436 		local->monitors--;
437 		if (local->monitors == 0) {
438 			local->hw.conf.flags &= ~IEEE80211_CONF_MONITOR;
439 			hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
440 		}
441 
442 		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
443 			local->fif_fcsfail--;
444 		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
445 			local->fif_plcpfail--;
446 		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL) {
447 			local->fif_pspoll--;
448 			local->fif_control--;
449 		}
450 		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
451 			local->fif_other_bss--;
452 
453 		ieee80211_configure_filter(local);
454 		break;
455 	case NL80211_IFTYPE_STATION:
456 		del_timer_sync(&sdata->u.mgd.chswitch_timer);
457 		del_timer_sync(&sdata->u.mgd.timer);
458 		del_timer_sync(&sdata->u.mgd.conn_mon_timer);
459 		del_timer_sync(&sdata->u.mgd.bcn_mon_timer);
460 		/*
461 		 * If any of the timers fired while we waited for it, it will
462 		 * have queued its work. Now the work will be running again
463 		 * but will not rearm the timer again because it checks
464 		 * whether the interface is running, which, at this point,
465 		 * it no longer is.
466 		 */
467 		cancel_work_sync(&sdata->u.mgd.work);
468 		cancel_work_sync(&sdata->u.mgd.chswitch_work);
469 		cancel_work_sync(&sdata->u.mgd.monitor_work);
470 		cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
471 
472 		/*
473 		 * When we get here, the interface is marked down.
474 		 * Call synchronize_rcu() to wait for the RX path
475 		 * should it be using the interface and enqueuing
476 		 * frames at this very time on another CPU.
477 		 */
478 		synchronize_rcu();
479 		skb_queue_purge(&sdata->u.mgd.skb_queue);
480 		/* fall through */
481 	case NL80211_IFTYPE_ADHOC:
482 		if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
483 			del_timer_sync(&sdata->u.ibss.timer);
484 			cancel_work_sync(&sdata->u.ibss.work);
485 			synchronize_rcu();
486 			skb_queue_purge(&sdata->u.ibss.skb_queue);
487 		}
488 		/* fall through */
489 	case NL80211_IFTYPE_MESH_POINT:
490 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
491 			/* other_bss and allmulti are always set on mesh
492 			 * ifaces */
493 			local->fif_other_bss--;
494 			atomic_dec(&local->iff_allmultis);
495 
496 			ieee80211_configure_filter(local);
497 
498 			ieee80211_stop_mesh(sdata);
499 		}
500 		/* fall through */
501 	default:
502 		if (local->scan_sdata == sdata)
503 			ieee80211_scan_cancel(local);
504 
505 		/*
506 		 * Disable beaconing for AP and mesh, IBSS can't
507 		 * still be joined to a network at this point.
508 		 */
509 		if (sdata->vif.type == NL80211_IFTYPE_AP ||
510 		    sdata->vif.type == NL80211_IFTYPE_MESH_POINT) {
511 			ieee80211_bss_info_change_notify(sdata,
512 				BSS_CHANGED_BEACON_ENABLED);
513 		}
514 
515 		conf.vif = &sdata->vif;
516 		conf.type = sdata->vif.type;
517 		conf.mac_addr = dev->dev_addr;
518 		/* disable all keys for as long as this netdev is down */
519 		ieee80211_disable_keys(sdata);
520 		drv_remove_interface(local, &conf);
521 	}
522 
523 	sdata->bss = NULL;
524 
525 	hw_reconf_flags |= __ieee80211_recalc_idle(local);
526 
527 	ieee80211_recalc_ps(local, -1);
528 
529 	if (local->open_count == 0) {
530 		ieee80211_clear_tx_pending(local);
531 		ieee80211_stop_device(local);
532 
533 		/* no reconfiguring after stop! */
534 		hw_reconf_flags = 0;
535 	}
536 
537 	/* do after stop to avoid reconfiguring when we stop anyway */
538 	if (hw_reconf_flags)
539 		ieee80211_hw_config(local, hw_reconf_flags);
540 
541 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
542 	for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
543 		skb_queue_walk_safe(&local->pending[i], skb, tmp) {
544 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
545 			if (info->control.vif == &sdata->vif) {
546 				__skb_unlink(skb, &local->pending[i]);
547 				dev_kfree_skb_irq(skb);
548 			}
549 		}
550 	}
551 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
552 
553 	return 0;
554 }
555 
556 static void ieee80211_set_multicast_list(struct net_device *dev)
557 {
558 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
559 	struct ieee80211_local *local = sdata->local;
560 	int allmulti, promisc, sdata_allmulti, sdata_promisc;
561 
562 	allmulti = !!(dev->flags & IFF_ALLMULTI);
563 	promisc = !!(dev->flags & IFF_PROMISC);
564 	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
565 	sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
566 
567 	if (allmulti != sdata_allmulti) {
568 		if (dev->flags & IFF_ALLMULTI)
569 			atomic_inc(&local->iff_allmultis);
570 		else
571 			atomic_dec(&local->iff_allmultis);
572 		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
573 	}
574 
575 	if (promisc != sdata_promisc) {
576 		if (dev->flags & IFF_PROMISC)
577 			atomic_inc(&local->iff_promiscs);
578 		else
579 			atomic_dec(&local->iff_promiscs);
580 		sdata->flags ^= IEEE80211_SDATA_PROMISC;
581 	}
582 	spin_lock_bh(&local->filter_lock);
583 	__dev_addr_sync(&local->mc_list, &local->mc_count,
584 			&dev->mc_list, &dev->mc_count);
585 	spin_unlock_bh(&local->filter_lock);
586 	ieee80211_queue_work(&local->hw, &local->reconfig_filter);
587 }
588 
589 /*
590  * Called when the netdev is removed or, by the code below, before
591  * the interface type changes.
592  */
593 static void ieee80211_teardown_sdata(struct net_device *dev)
594 {
595 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
596 	struct ieee80211_local *local = sdata->local;
597 	struct beacon_data *beacon;
598 	struct sk_buff *skb;
599 	int flushed;
600 	int i;
601 
602 	/* free extra data */
603 	ieee80211_free_keys(sdata);
604 
605 	ieee80211_debugfs_remove_netdev(sdata);
606 
607 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
608 		__skb_queue_purge(&sdata->fragments[i].skb_list);
609 	sdata->fragment_next = 0;
610 
611 	switch (sdata->vif.type) {
612 	case NL80211_IFTYPE_AP:
613 		beacon = sdata->u.ap.beacon;
614 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
615 		synchronize_rcu();
616 		kfree(beacon);
617 
618 		while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
619 			local->total_ps_buffered--;
620 			dev_kfree_skb(skb);
621 		}
622 
623 		break;
624 	case NL80211_IFTYPE_MESH_POINT:
625 		if (ieee80211_vif_is_mesh(&sdata->vif))
626 			mesh_rmc_free(sdata);
627 		break;
628 	case NL80211_IFTYPE_ADHOC:
629 		if (WARN_ON(sdata->u.ibss.presp))
630 			kfree_skb(sdata->u.ibss.presp);
631 		break;
632 	case NL80211_IFTYPE_STATION:
633 	case NL80211_IFTYPE_WDS:
634 	case NL80211_IFTYPE_AP_VLAN:
635 	case NL80211_IFTYPE_MONITOR:
636 		break;
637 	case NL80211_IFTYPE_UNSPECIFIED:
638 	case __NL80211_IFTYPE_AFTER_LAST:
639 		BUG();
640 		break;
641 	}
642 
643 	flushed = sta_info_flush(local, sdata);
644 	WARN_ON(flushed);
645 }
646 
647 static const struct net_device_ops ieee80211_dataif_ops = {
648 	.ndo_open		= ieee80211_open,
649 	.ndo_stop		= ieee80211_stop,
650 	.ndo_uninit		= ieee80211_teardown_sdata,
651 	.ndo_start_xmit		= ieee80211_subif_start_xmit,
652 	.ndo_set_multicast_list = ieee80211_set_multicast_list,
653 	.ndo_change_mtu 	= ieee80211_change_mtu,
654 	.ndo_set_mac_address 	= eth_mac_addr,
655 };
656 
657 static const struct net_device_ops ieee80211_monitorif_ops = {
658 	.ndo_open		= ieee80211_open,
659 	.ndo_stop		= ieee80211_stop,
660 	.ndo_uninit		= ieee80211_teardown_sdata,
661 	.ndo_start_xmit		= ieee80211_monitor_start_xmit,
662 	.ndo_set_multicast_list = ieee80211_set_multicast_list,
663 	.ndo_change_mtu 	= ieee80211_change_mtu,
664 	.ndo_set_mac_address 	= eth_mac_addr,
665 };
666 
667 static void ieee80211_if_setup(struct net_device *dev)
668 {
669 	ether_setup(dev);
670 	dev->netdev_ops = &ieee80211_dataif_ops;
671 	dev->destructor = free_netdev;
672 }
673 
674 /*
675  * Helper function to initialise an interface to a specific type.
676  */
677 static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
678 				  enum nl80211_iftype type)
679 {
680 	/* clear type-dependent union */
681 	memset(&sdata->u, 0, sizeof(sdata->u));
682 
683 	/* and set some type-dependent values */
684 	sdata->vif.type = type;
685 	sdata->dev->netdev_ops = &ieee80211_dataif_ops;
686 	sdata->wdev.iftype = type;
687 
688 	/* only monitor differs */
689 	sdata->dev->type = ARPHRD_ETHER;
690 
691 	switch (type) {
692 	case NL80211_IFTYPE_AP:
693 		skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
694 		INIT_LIST_HEAD(&sdata->u.ap.vlans);
695 		break;
696 	case NL80211_IFTYPE_STATION:
697 		ieee80211_sta_setup_sdata(sdata);
698 		break;
699 	case NL80211_IFTYPE_ADHOC:
700 		ieee80211_ibss_setup_sdata(sdata);
701 		break;
702 	case NL80211_IFTYPE_MESH_POINT:
703 		if (ieee80211_vif_is_mesh(&sdata->vif))
704 			ieee80211_mesh_init_sdata(sdata);
705 		break;
706 	case NL80211_IFTYPE_MONITOR:
707 		sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
708 		sdata->dev->netdev_ops = &ieee80211_monitorif_ops;
709 		sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
710 				      MONITOR_FLAG_OTHER_BSS;
711 		break;
712 	case NL80211_IFTYPE_WDS:
713 	case NL80211_IFTYPE_AP_VLAN:
714 		break;
715 	case NL80211_IFTYPE_UNSPECIFIED:
716 	case __NL80211_IFTYPE_AFTER_LAST:
717 		BUG();
718 		break;
719 	}
720 
721 	ieee80211_debugfs_add_netdev(sdata);
722 }
723 
724 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
725 			     enum nl80211_iftype type)
726 {
727 	ASSERT_RTNL();
728 
729 	if (type == sdata->vif.type)
730 		return 0;
731 
732 	/* Setting ad-hoc mode on non-IBSS channel is not supported. */
733 	if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
734 	    type == NL80211_IFTYPE_ADHOC)
735 		return -EOPNOTSUPP;
736 
737 	/*
738 	 * We could, here, on changes between IBSS/STA/MESH modes,
739 	 * invoke an MLME function instead that disassociates etc.
740 	 * and goes into the requested mode.
741 	 */
742 
743 	if (netif_running(sdata->dev))
744 		return -EBUSY;
745 
746 	/* Purge and reset type-dependent state. */
747 	ieee80211_teardown_sdata(sdata->dev);
748 	ieee80211_setup_sdata(sdata, type);
749 
750 	/* reset some values that shouldn't be kept across type changes */
751 	sdata->vif.bss_conf.basic_rates =
752 		ieee80211_mandatory_rates(sdata->local,
753 			sdata->local->hw.conf.channel->band);
754 	sdata->drop_unencrypted = 0;
755 	if (type == NL80211_IFTYPE_STATION)
756 		sdata->u.mgd.use_4addr = false;
757 
758 	return 0;
759 }
760 
761 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
762 		     struct net_device **new_dev, enum nl80211_iftype type,
763 		     struct vif_params *params)
764 {
765 	struct net_device *ndev;
766 	struct ieee80211_sub_if_data *sdata = NULL;
767 	int ret, i;
768 
769 	ASSERT_RTNL();
770 
771 	ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
772 			    name, ieee80211_if_setup);
773 	if (!ndev)
774 		return -ENOMEM;
775 	dev_net_set(ndev, wiphy_net(local->hw.wiphy));
776 
777 	ndev->needed_headroom = local->tx_headroom +
778 				4*6 /* four MAC addresses */
779 				+ 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
780 				+ 6 /* mesh */
781 				+ 8 /* rfc1042/bridge tunnel */
782 				- ETH_HLEN /* ethernet hard_header_len */
783 				+ IEEE80211_ENCRYPT_HEADROOM;
784 	ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
785 
786 	ret = dev_alloc_name(ndev, ndev->name);
787 	if (ret < 0)
788 		goto fail;
789 
790 	memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
791 	memcpy(ndev->perm_addr, ndev->dev_addr, ETH_ALEN);
792 	SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
793 
794 	/* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
795 	sdata = netdev_priv(ndev);
796 	ndev->ieee80211_ptr = &sdata->wdev;
797 
798 	/* initialise type-independent data */
799 	sdata->wdev.wiphy = local->hw.wiphy;
800 	sdata->local = local;
801 	sdata->dev = ndev;
802 
803 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
804 		skb_queue_head_init(&sdata->fragments[i].skb_list);
805 
806 	INIT_LIST_HEAD(&sdata->key_list);
807 
808 	sdata->force_unicast_rateidx = -1;
809 	sdata->max_ratectrl_rateidx = -1;
810 
811 	/* setup type-dependent data */
812 	ieee80211_setup_sdata(sdata, type);
813 
814 	if (params) {
815 		ndev->ieee80211_ptr->use_4addr = params->use_4addr;
816 		if (type == NL80211_IFTYPE_STATION)
817 			sdata->u.mgd.use_4addr = params->use_4addr;
818 	}
819 
820 	ret = register_netdevice(ndev);
821 	if (ret)
822 		goto fail;
823 
824 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
825 	    params && params->mesh_id_len)
826 		ieee80211_sdata_set_mesh_id(sdata,
827 					    params->mesh_id_len,
828 					    params->mesh_id);
829 
830 	mutex_lock(&local->iflist_mtx);
831 	list_add_tail_rcu(&sdata->list, &local->interfaces);
832 	mutex_unlock(&local->iflist_mtx);
833 
834 	if (new_dev)
835 		*new_dev = ndev;
836 
837 	return 0;
838 
839  fail:
840 	free_netdev(ndev);
841 	return ret;
842 }
843 
844 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
845 {
846 	ASSERT_RTNL();
847 
848 	mutex_lock(&sdata->local->iflist_mtx);
849 	list_del_rcu(&sdata->list);
850 	mutex_unlock(&sdata->local->iflist_mtx);
851 
852 	synchronize_rcu();
853 	unregister_netdevice(sdata->dev);
854 }
855 
856 /*
857  * Remove all interfaces, may only be called at hardware unregistration
858  * time because it doesn't do RCU-safe list removals.
859  */
860 void ieee80211_remove_interfaces(struct ieee80211_local *local)
861 {
862 	struct ieee80211_sub_if_data *sdata, *tmp;
863 	LIST_HEAD(unreg_list);
864 
865 	ASSERT_RTNL();
866 
867 	mutex_lock(&local->iflist_mtx);
868 	list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
869 		list_del(&sdata->list);
870 
871 		unregister_netdevice_queue(sdata->dev, &unreg_list);
872 	}
873 	mutex_unlock(&local->iflist_mtx);
874 	unregister_netdevice_many(&unreg_list);
875 }
876 
877 static u32 ieee80211_idle_off(struct ieee80211_local *local,
878 			      const char *reason)
879 {
880 	if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE))
881 		return 0;
882 
883 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
884 	printk(KERN_DEBUG "%s: device no longer idle - %s\n",
885 	       wiphy_name(local->hw.wiphy), reason);
886 #endif
887 
888 	local->hw.conf.flags &= ~IEEE80211_CONF_IDLE;
889 	return IEEE80211_CONF_CHANGE_IDLE;
890 }
891 
892 static u32 ieee80211_idle_on(struct ieee80211_local *local)
893 {
894 	if (local->hw.conf.flags & IEEE80211_CONF_IDLE)
895 		return 0;
896 
897 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
898 	printk(KERN_DEBUG "%s: device now idle\n",
899 	       wiphy_name(local->hw.wiphy));
900 #endif
901 
902 	local->hw.conf.flags |= IEEE80211_CONF_IDLE;
903 	return IEEE80211_CONF_CHANGE_IDLE;
904 }
905 
906 u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
907 {
908 	struct ieee80211_sub_if_data *sdata;
909 	int count = 0;
910 
911 	if (local->scanning)
912 		return ieee80211_idle_off(local, "scanning");
913 
914 	list_for_each_entry(sdata, &local->interfaces, list) {
915 		if (!netif_running(sdata->dev))
916 			continue;
917 		/* do not count disabled managed interfaces */
918 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
919 		    !sdata->u.mgd.associated &&
920 		    list_empty(&sdata->u.mgd.work_list))
921 			continue;
922 		/* do not count unused IBSS interfaces */
923 		if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
924 		    !sdata->u.ibss.ssid_len)
925 			continue;
926 		/* count everything else */
927 		count++;
928 	}
929 
930 	if (!count)
931 		return ieee80211_idle_on(local);
932 	else
933 		return ieee80211_idle_off(local, "in use");
934 
935 	return 0;
936 }
937 
938 void ieee80211_recalc_idle(struct ieee80211_local *local)
939 {
940 	u32 chg;
941 
942 	mutex_lock(&local->iflist_mtx);
943 	chg = __ieee80211_recalc_idle(local);
944 	mutex_unlock(&local->iflist_mtx);
945 	if (chg)
946 		ieee80211_hw_config(local, chg);
947 }
948