xref: /linux/net/mac80211/iface.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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 
24 /**
25  * DOC: Interface list locking
26  *
27  * The interface list in each struct ieee80211_local is protected
28  * three-fold:
29  *
30  * (1) modifications may only be done under the RTNL
31  * (2) modifications and readers are protected against each other by
32  *     the iflist_mtx.
33  * (3) modifications are done in an RCU manner so atomic readers
34  *     can traverse the list in RCU-safe blocks.
35  *
36  * As a consequence, reads (traversals) of the list can be protected
37  * by either the RTNL, the iflist_mtx or RCU.
38  */
39 
40 
41 static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
42 {
43 	int meshhdrlen;
44 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
45 
46 	meshhdrlen = (sdata->vif.type == NL80211_IFTYPE_MESH_POINT) ? 5 : 0;
47 
48 	/* FIX: what would be proper limits for MTU?
49 	 * This interface uses 802.3 frames. */
50 	if (new_mtu < 256 ||
51 	    new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
52 		return -EINVAL;
53 	}
54 
55 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
56 	printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
57 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
58 	dev->mtu = new_mtu;
59 	return 0;
60 }
61 
62 static inline int identical_mac_addr_allowed(int type1, int type2)
63 {
64 	return type1 == NL80211_IFTYPE_MONITOR ||
65 		type2 == NL80211_IFTYPE_MONITOR ||
66 		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
67 		(type1 == NL80211_IFTYPE_WDS &&
68 			(type2 == NL80211_IFTYPE_WDS ||
69 			 type2 == NL80211_IFTYPE_AP)) ||
70 		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
71 		(type1 == NL80211_IFTYPE_AP_VLAN &&
72 			(type2 == NL80211_IFTYPE_AP ||
73 			 type2 == NL80211_IFTYPE_AP_VLAN));
74 }
75 
76 static int ieee80211_open(struct net_device *dev)
77 {
78 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
79 	struct ieee80211_sub_if_data *nsdata;
80 	struct ieee80211_local *local = sdata->local;
81 	struct sta_info *sta;
82 	struct ieee80211_if_init_conf conf;
83 	u32 changed = 0;
84 	int res;
85 	u32 hw_reconf_flags = 0;
86 	u8 null_addr[ETH_ALEN] = {0};
87 
88 	/* fail early if user set an invalid address */
89 	if (compare_ether_addr(dev->dev_addr, null_addr) &&
90 	    !is_valid_ether_addr(dev->dev_addr))
91 		return -EADDRNOTAVAIL;
92 
93 	/* we hold the RTNL here so can safely walk the list */
94 	list_for_each_entry(nsdata, &local->interfaces, list) {
95 		struct net_device *ndev = nsdata->dev;
96 
97 		if (ndev != dev && netif_running(ndev)) {
98 			/*
99 			 * Allow only a single IBSS interface to be up at any
100 			 * time. This is restricted because beacon distribution
101 			 * cannot work properly if both are in the same IBSS.
102 			 *
103 			 * To remove this restriction we'd have to disallow them
104 			 * from setting the same SSID on different IBSS interfaces
105 			 * belonging to the same hardware. Then, however, we're
106 			 * faced with having to adopt two different TSF timers...
107 			 */
108 			if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
109 			    nsdata->vif.type == NL80211_IFTYPE_ADHOC)
110 				return -EBUSY;
111 
112 			/*
113 			 * The remaining checks are only performed for interfaces
114 			 * with the same MAC address.
115 			 */
116 			if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
117 				continue;
118 
119 			/*
120 			 * check whether it may have the same address
121 			 */
122 			if (!identical_mac_addr_allowed(sdata->vif.type,
123 							nsdata->vif.type))
124 				return -ENOTUNIQ;
125 
126 			/*
127 			 * can only add VLANs to enabled APs
128 			 */
129 			if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
130 			    nsdata->vif.type == NL80211_IFTYPE_AP)
131 				sdata->bss = &nsdata->u.ap;
132 		}
133 	}
134 
135 	switch (sdata->vif.type) {
136 	case NL80211_IFTYPE_WDS:
137 		if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
138 			return -ENOLINK;
139 		break;
140 	case NL80211_IFTYPE_AP_VLAN:
141 		if (!sdata->bss)
142 			return -ENOLINK;
143 		list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
144 		break;
145 	case NL80211_IFTYPE_AP:
146 		sdata->bss = &sdata->u.ap;
147 		break;
148 	case NL80211_IFTYPE_MESH_POINT:
149 		if (!ieee80211_vif_is_mesh(&sdata->vif))
150 			break;
151 		/* mesh ifaces must set allmulti to forward mcast traffic */
152 		atomic_inc(&local->iff_allmultis);
153 		break;
154 	case NL80211_IFTYPE_STATION:
155 	case NL80211_IFTYPE_MONITOR:
156 	case NL80211_IFTYPE_ADHOC:
157 		/* no special treatment */
158 		break;
159 	case NL80211_IFTYPE_UNSPECIFIED:
160 	case __NL80211_IFTYPE_AFTER_LAST:
161 		/* cannot happen */
162 		WARN_ON(1);
163 		break;
164 	}
165 
166 	if (local->open_count == 0) {
167 		res = 0;
168 		if (local->ops->start)
169 			res = local->ops->start(local_to_hw(local));
170 		if (res)
171 			goto err_del_bss;
172 		/* we're brought up, everything changes */
173 		hw_reconf_flags = ~0;
174 		ieee80211_led_radio(local, local->hw.conf.radio_enabled);
175 	}
176 
177 	/*
178 	 * Check all interfaces and copy the hopefully now-present
179 	 * MAC address to those that have the special null one.
180 	 */
181 	list_for_each_entry(nsdata, &local->interfaces, list) {
182 		struct net_device *ndev = nsdata->dev;
183 
184 		/*
185 		 * No need to check netif_running since we do not allow
186 		 * it to start up with this invalid address.
187 		 */
188 		if (compare_ether_addr(null_addr, ndev->dev_addr) == 0)
189 			memcpy(ndev->dev_addr,
190 			       local->hw.wiphy->perm_addr,
191 			       ETH_ALEN);
192 	}
193 
194 	if (compare_ether_addr(null_addr, local->mdev->dev_addr) == 0)
195 		memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr,
196 		       ETH_ALEN);
197 
198 	/*
199 	 * Validate the MAC address for this device.
200 	 */
201 	if (!is_valid_ether_addr(dev->dev_addr)) {
202 		if (!local->open_count && local->ops->stop)
203 			local->ops->stop(local_to_hw(local));
204 		return -EADDRNOTAVAIL;
205 	}
206 
207 	switch (sdata->vif.type) {
208 	case NL80211_IFTYPE_AP_VLAN:
209 		/* no need to tell driver */
210 		break;
211 	case NL80211_IFTYPE_MONITOR:
212 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
213 			local->cooked_mntrs++;
214 			break;
215 		}
216 
217 		/* must be before the call to ieee80211_configure_filter */
218 		local->monitors++;
219 		if (local->monitors == 1) {
220 			local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
221 			hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
222 		}
223 
224 		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
225 			local->fif_fcsfail++;
226 		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
227 			local->fif_plcpfail++;
228 		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
229 			local->fif_control++;
230 		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
231 			local->fif_other_bss++;
232 
233 		netif_addr_lock_bh(local->mdev);
234 		ieee80211_configure_filter(local);
235 		netif_addr_unlock_bh(local->mdev);
236 		break;
237 	case NL80211_IFTYPE_STATION:
238 	case NL80211_IFTYPE_ADHOC:
239 		if (sdata->vif.type == NL80211_IFTYPE_STATION)
240 			sdata->u.mgd.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
241 		else
242 			sdata->u.ibss.flags &= ~IEEE80211_IBSS_PREV_BSSID_SET;
243 		/* fall through */
244 	default:
245 		conf.vif = &sdata->vif;
246 		conf.type = sdata->vif.type;
247 		conf.mac_addr = dev->dev_addr;
248 		res = local->ops->add_interface(local_to_hw(local), &conf);
249 		if (res)
250 			goto err_stop;
251 
252 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
253 			local->fif_other_bss++;
254 			netif_addr_lock_bh(local->mdev);
255 			ieee80211_configure_filter(local);
256 			netif_addr_unlock_bh(local->mdev);
257 
258 			ieee80211_start_mesh(sdata);
259 		}
260 		changed |= ieee80211_reset_erp_info(sdata);
261 		ieee80211_bss_info_change_notify(sdata, changed);
262 		ieee80211_enable_keys(sdata);
263 
264 		if (sdata->vif.type == NL80211_IFTYPE_STATION)
265 			netif_carrier_off(dev);
266 		else
267 			netif_carrier_on(dev);
268 	}
269 
270 	if (sdata->vif.type == NL80211_IFTYPE_WDS) {
271 		/* Create STA entry for the WDS peer */
272 		sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
273 				     GFP_KERNEL);
274 		if (!sta) {
275 			res = -ENOMEM;
276 			goto err_del_interface;
277 		}
278 
279 		/* no locking required since STA is not live yet */
280 		sta->flags |= WLAN_STA_AUTHORIZED;
281 
282 		res = sta_info_insert(sta);
283 		if (res) {
284 			/* STA has been freed */
285 			goto err_del_interface;
286 		}
287 	}
288 
289 	if (local->open_count == 0) {
290 		res = dev_open(local->mdev);
291 		WARN_ON(res);
292 		if (res)
293 			goto err_del_interface;
294 		tasklet_enable(&local->tx_pending_tasklet);
295 		tasklet_enable(&local->tasklet);
296 	}
297 
298 	/*
299 	 * set_multicast_list will be invoked by the networking core
300 	 * which will check whether any increments here were done in
301 	 * error and sync them down to the hardware as filter flags.
302 	 */
303 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
304 		atomic_inc(&local->iff_allmultis);
305 
306 	if (sdata->flags & IEEE80211_SDATA_PROMISC)
307 		atomic_inc(&local->iff_promiscs);
308 
309 	local->open_count++;
310 	if (hw_reconf_flags) {
311 		ieee80211_hw_config(local, hw_reconf_flags);
312 		/*
313 		 * set default queue parameters so drivers don't
314 		 * need to initialise the hardware if the hardware
315 		 * doesn't start up with sane defaults
316 		 */
317 		ieee80211_set_wmm_default(sdata);
318 	}
319 
320 	/*
321 	 * ieee80211_sta_work is disabled while network interface
322 	 * is down. Therefore, some configuration changes may not
323 	 * yet be effective. Trigger execution of ieee80211_sta_work
324 	 * to fix this.
325 	 */
326 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
327 		queue_work(local->hw.workqueue, &sdata->u.mgd.work);
328 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
329 		queue_work(local->hw.workqueue, &sdata->u.ibss.work);
330 
331 	netif_tx_start_all_queues(dev);
332 
333 	return 0;
334  err_del_interface:
335 	local->ops->remove_interface(local_to_hw(local), &conf);
336  err_stop:
337 	if (!local->open_count && local->ops->stop)
338 		local->ops->stop(local_to_hw(local));
339  err_del_bss:
340 	sdata->bss = NULL;
341 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
342 		list_del(&sdata->u.vlan.list);
343 	return res;
344 }
345 
346 static int ieee80211_stop(struct net_device *dev)
347 {
348 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
349 	struct ieee80211_local *local = sdata->local;
350 	struct ieee80211_if_init_conf conf;
351 	struct sta_info *sta;
352 	u32 hw_reconf_flags = 0;
353 
354 	/*
355 	 * Stop TX on this interface first.
356 	 */
357 	netif_tx_stop_all_queues(dev);
358 
359 	/*
360 	 * Now delete all active aggregation sessions.
361 	 */
362 	rcu_read_lock();
363 
364 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
365 		if (sta->sdata == sdata)
366 			ieee80211_sta_tear_down_BA_sessions(sta);
367 	}
368 
369 	rcu_read_unlock();
370 
371 	/*
372 	 * Announce that we are leaving the network, in case we are a
373 	 * station interface type. This must be done before removing
374 	 * all stations associated with sta_info_flush, otherwise STA
375 	 * information will be gone and no announce being done.
376 	 */
377 	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
378 		if (sdata->u.mgd.state != IEEE80211_STA_MLME_DISABLED)
379 			ieee80211_sta_deauthenticate(sdata,
380 				WLAN_REASON_DEAUTH_LEAVING);
381 	}
382 
383 	/*
384 	 * Remove all stations associated with this interface.
385 	 *
386 	 * This must be done before calling ops->remove_interface()
387 	 * because otherwise we can later invoke ops->sta_notify()
388 	 * whenever the STAs are removed, and that invalidates driver
389 	 * assumptions about always getting a vif pointer that is valid
390 	 * (because if we remove a STA after ops->remove_interface()
391 	 * the driver will have removed the vif info already!)
392 	 *
393 	 * We could relax this and only unlink the stations from the
394 	 * hash table and list but keep them on a per-sdata list that
395 	 * will be inserted back again when the interface is brought
396 	 * up again, but I don't currently see a use case for that,
397 	 * except with WDS which gets a STA entry created when it is
398 	 * brought up.
399 	 */
400 	sta_info_flush(local, sdata);
401 
402 	/*
403 	 * Don't count this interface for promisc/allmulti while it
404 	 * is down. dev_mc_unsync() will invoke set_multicast_list
405 	 * on the master interface which will sync these down to the
406 	 * hardware as filter flags.
407 	 */
408 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
409 		atomic_dec(&local->iff_allmultis);
410 
411 	if (sdata->flags & IEEE80211_SDATA_PROMISC)
412 		atomic_dec(&local->iff_promiscs);
413 
414 	dev_mc_unsync(local->mdev, dev);
415 	del_timer_sync(&local->dynamic_ps_timer);
416 	cancel_work_sync(&local->dynamic_ps_enable_work);
417 
418 	/* APs need special treatment */
419 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
420 		struct ieee80211_sub_if_data *vlan, *tmp;
421 		struct beacon_data *old_beacon = sdata->u.ap.beacon;
422 
423 		/* remove beacon */
424 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
425 		synchronize_rcu();
426 		kfree(old_beacon);
427 
428 		/* down all dependent devices, that is VLANs */
429 		list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
430 					 u.vlan.list)
431 			dev_close(vlan->dev);
432 		WARN_ON(!list_empty(&sdata->u.ap.vlans));
433 	}
434 
435 	local->open_count--;
436 
437 	switch (sdata->vif.type) {
438 	case NL80211_IFTYPE_AP_VLAN:
439 		list_del(&sdata->u.vlan.list);
440 		/* no need to tell driver */
441 		break;
442 	case NL80211_IFTYPE_MONITOR:
443 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
444 			local->cooked_mntrs--;
445 			break;
446 		}
447 
448 		local->monitors--;
449 		if (local->monitors == 0) {
450 			local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
451 			hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
452 		}
453 
454 		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
455 			local->fif_fcsfail--;
456 		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
457 			local->fif_plcpfail--;
458 		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
459 			local->fif_control--;
460 		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
461 			local->fif_other_bss--;
462 
463 		netif_addr_lock_bh(local->mdev);
464 		ieee80211_configure_filter(local);
465 		netif_addr_unlock_bh(local->mdev);
466 		break;
467 	case NL80211_IFTYPE_STATION:
468 		memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
469 		del_timer_sync(&sdata->u.mgd.chswitch_timer);
470 		del_timer_sync(&sdata->u.mgd.timer);
471 		/*
472 		 * If the timer fired while we waited for it, it will have
473 		 * requeued the work. Now the work will be running again
474 		 * but will not rearm the timer again because it checks
475 		 * whether the interface is running, which, at this point,
476 		 * it no longer is.
477 		 */
478 		cancel_work_sync(&sdata->u.mgd.work);
479 		cancel_work_sync(&sdata->u.mgd.chswitch_work);
480 
481 		cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
482 
483 		/*
484 		 * When we get here, the interface is marked down.
485 		 * Call synchronize_rcu() to wait for the RX path
486 		 * should it be using the interface and enqueuing
487 		 * frames at this very time on another CPU.
488 		 */
489 		synchronize_rcu();
490 		skb_queue_purge(&sdata->u.mgd.skb_queue);
491 
492 		sdata->u.mgd.flags &= ~(IEEE80211_STA_PRIVACY_INVOKED |
493 					IEEE80211_STA_TKIP_WEP_USED);
494 		kfree(sdata->u.mgd.extra_ie);
495 		sdata->u.mgd.extra_ie = NULL;
496 		sdata->u.mgd.extra_ie_len = 0;
497 		/* fall through */
498 	case NL80211_IFTYPE_ADHOC:
499 		if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
500 			memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
501 			del_timer_sync(&sdata->u.ibss.timer);
502 			cancel_work_sync(&sdata->u.ibss.work);
503 			synchronize_rcu();
504 			skb_queue_purge(&sdata->u.ibss.skb_queue);
505 		}
506 		/* fall through */
507 	case NL80211_IFTYPE_MESH_POINT:
508 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
509 			/* other_bss and allmulti are always set on mesh
510 			 * ifaces */
511 			local->fif_other_bss--;
512 			atomic_dec(&local->iff_allmultis);
513 
514 			netif_addr_lock_bh(local->mdev);
515 			ieee80211_configure_filter(local);
516 			netif_addr_unlock_bh(local->mdev);
517 
518 			ieee80211_stop_mesh(sdata);
519 		}
520 		/* fall through */
521 	default:
522 		if (local->scan_sdata == sdata) {
523 			if (!local->ops->hw_scan)
524 				cancel_delayed_work_sync(&local->scan_work);
525 			/*
526 			 * The software scan can no longer run now, so we can
527 			 * clear out the scan_sdata reference. However, the
528 			 * hardware scan may still be running. The complete
529 			 * function must be prepared to handle a NULL value.
530 			 */
531 			local->scan_sdata = NULL;
532 			/*
533 			 * The memory barrier guarantees that another CPU
534 			 * that is hardware-scanning will now see the fact
535 			 * that this interface is gone.
536 			 */
537 			smp_mb();
538 			/*
539 			 * If software scanning, complete the scan but since
540 			 * the scan_sdata is NULL already don't send out a
541 			 * scan event to userspace -- the scan is incomplete.
542 			 */
543 			if (local->sw_scanning)
544 				ieee80211_scan_completed(&local->hw, true);
545 		}
546 
547 		conf.vif = &sdata->vif;
548 		conf.type = sdata->vif.type;
549 		conf.mac_addr = dev->dev_addr;
550 		/* disable all keys for as long as this netdev is down */
551 		ieee80211_disable_keys(sdata);
552 		local->ops->remove_interface(local_to_hw(local), &conf);
553 	}
554 
555 	sdata->bss = NULL;
556 
557 	if (local->open_count == 0) {
558 		if (netif_running(local->mdev))
559 			dev_close(local->mdev);
560 
561 		if (local->ops->stop)
562 			local->ops->stop(local_to_hw(local));
563 
564 		ieee80211_led_radio(local, 0);
565 
566 		flush_workqueue(local->hw.workqueue);
567 
568 		tasklet_disable(&local->tx_pending_tasklet);
569 		tasklet_disable(&local->tasklet);
570 
571 		/* no reconfiguring after stop! */
572 		hw_reconf_flags = 0;
573 	}
574 
575 	/* do after stop to avoid reconfiguring when we stop anyway */
576 	if (hw_reconf_flags)
577 		ieee80211_hw_config(local, hw_reconf_flags);
578 
579 	return 0;
580 }
581 
582 static void ieee80211_set_multicast_list(struct net_device *dev)
583 {
584 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
585 	struct ieee80211_local *local = sdata->local;
586 	int allmulti, promisc, sdata_allmulti, sdata_promisc;
587 
588 	allmulti = !!(dev->flags & IFF_ALLMULTI);
589 	promisc = !!(dev->flags & IFF_PROMISC);
590 	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
591 	sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
592 
593 	if (allmulti != sdata_allmulti) {
594 		if (dev->flags & IFF_ALLMULTI)
595 			atomic_inc(&local->iff_allmultis);
596 		else
597 			atomic_dec(&local->iff_allmultis);
598 		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
599 	}
600 
601 	if (promisc != sdata_promisc) {
602 		if (dev->flags & IFF_PROMISC)
603 			atomic_inc(&local->iff_promiscs);
604 		else
605 			atomic_dec(&local->iff_promiscs);
606 		sdata->flags ^= IEEE80211_SDATA_PROMISC;
607 	}
608 
609 	dev_mc_sync(local->mdev, dev);
610 }
611 
612 /*
613  * Called when the netdev is removed or, by the code below, before
614  * the interface type changes.
615  */
616 static void ieee80211_teardown_sdata(struct net_device *dev)
617 {
618 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
619 	struct ieee80211_local *local = sdata->local;
620 	struct beacon_data *beacon;
621 	struct sk_buff *skb;
622 	int flushed;
623 	int i;
624 
625 	/* free extra data */
626 	ieee80211_free_keys(sdata);
627 
628 	ieee80211_debugfs_remove_netdev(sdata);
629 
630 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
631 		__skb_queue_purge(&sdata->fragments[i].skb_list);
632 	sdata->fragment_next = 0;
633 
634 	switch (sdata->vif.type) {
635 	case NL80211_IFTYPE_AP:
636 		beacon = sdata->u.ap.beacon;
637 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
638 		synchronize_rcu();
639 		kfree(beacon);
640 
641 		while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
642 			local->total_ps_buffered--;
643 			dev_kfree_skb(skb);
644 		}
645 
646 		break;
647 	case NL80211_IFTYPE_MESH_POINT:
648 		if (ieee80211_vif_is_mesh(&sdata->vif))
649 			mesh_rmc_free(sdata);
650 		break;
651 	case NL80211_IFTYPE_ADHOC:
652 		kfree_skb(sdata->u.ibss.probe_resp);
653 		break;
654 	case NL80211_IFTYPE_STATION:
655 		kfree(sdata->u.mgd.extra_ie);
656 		kfree(sdata->u.mgd.assocreq_ies);
657 		kfree(sdata->u.mgd.assocresp_ies);
658 		kfree(sdata->u.mgd.sme_auth_ie);
659 		break;
660 	case NL80211_IFTYPE_WDS:
661 	case NL80211_IFTYPE_AP_VLAN:
662 	case NL80211_IFTYPE_MONITOR:
663 		break;
664 	case NL80211_IFTYPE_UNSPECIFIED:
665 	case __NL80211_IFTYPE_AFTER_LAST:
666 		BUG();
667 		break;
668 	}
669 
670 	flushed = sta_info_flush(local, sdata);
671 	WARN_ON(flushed);
672 }
673 
674 static const struct net_device_ops ieee80211_dataif_ops = {
675 	.ndo_open		= ieee80211_open,
676 	.ndo_stop		= ieee80211_stop,
677 	.ndo_uninit		= ieee80211_teardown_sdata,
678 	.ndo_start_xmit		= ieee80211_subif_start_xmit,
679 	.ndo_set_multicast_list = ieee80211_set_multicast_list,
680 	.ndo_change_mtu 	= ieee80211_change_mtu,
681 	.ndo_set_mac_address 	= eth_mac_addr,
682 };
683 
684 static const struct net_device_ops ieee80211_monitorif_ops = {
685 	.ndo_open		= ieee80211_open,
686 	.ndo_stop		= ieee80211_stop,
687 	.ndo_uninit		= ieee80211_teardown_sdata,
688 	.ndo_start_xmit		= ieee80211_monitor_start_xmit,
689 	.ndo_set_multicast_list = ieee80211_set_multicast_list,
690 	.ndo_change_mtu 	= ieee80211_change_mtu,
691 	.ndo_set_mac_address 	= eth_mac_addr,
692 };
693 
694 static void ieee80211_if_setup(struct net_device *dev)
695 {
696 	ether_setup(dev);
697 	dev->netdev_ops = &ieee80211_dataif_ops;
698 	dev->wireless_handlers = &ieee80211_iw_handler_def;
699 	dev->destructor = free_netdev;
700 }
701 
702 /*
703  * Helper function to initialise an interface to a specific type.
704  */
705 static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
706 				  enum nl80211_iftype type)
707 {
708 	/* clear type-dependent union */
709 	memset(&sdata->u, 0, sizeof(sdata->u));
710 
711 	/* and set some type-dependent values */
712 	sdata->vif.type = type;
713 	sdata->dev->netdev_ops = &ieee80211_dataif_ops;
714 	sdata->wdev.iftype = type;
715 
716 	/* only monitor differs */
717 	sdata->dev->type = ARPHRD_ETHER;
718 
719 	switch (type) {
720 	case NL80211_IFTYPE_AP:
721 		skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
722 		INIT_LIST_HEAD(&sdata->u.ap.vlans);
723 		break;
724 	case NL80211_IFTYPE_STATION:
725 		ieee80211_sta_setup_sdata(sdata);
726 		break;
727 	case NL80211_IFTYPE_ADHOC:
728 		ieee80211_ibss_setup_sdata(sdata);
729 		break;
730 	case NL80211_IFTYPE_MESH_POINT:
731 		if (ieee80211_vif_is_mesh(&sdata->vif))
732 			ieee80211_mesh_init_sdata(sdata);
733 		break;
734 	case NL80211_IFTYPE_MONITOR:
735 		sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
736 		sdata->dev->netdev_ops = &ieee80211_monitorif_ops;
737 		sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
738 				      MONITOR_FLAG_OTHER_BSS;
739 		break;
740 	case NL80211_IFTYPE_WDS:
741 	case NL80211_IFTYPE_AP_VLAN:
742 		break;
743 	case NL80211_IFTYPE_UNSPECIFIED:
744 	case __NL80211_IFTYPE_AFTER_LAST:
745 		BUG();
746 		break;
747 	}
748 
749 	ieee80211_debugfs_add_netdev(sdata);
750 }
751 
752 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
753 			     enum nl80211_iftype type)
754 {
755 	ASSERT_RTNL();
756 
757 	if (type == sdata->vif.type)
758 		return 0;
759 
760 	/* Setting ad-hoc mode on non-IBSS channel is not supported. */
761 	if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
762 	    type == NL80211_IFTYPE_ADHOC)
763 		return -EOPNOTSUPP;
764 
765 	/*
766 	 * We could, here, on changes between IBSS/STA/MESH modes,
767 	 * invoke an MLME function instead that disassociates etc.
768 	 * and goes into the requested mode.
769 	 */
770 
771 	if (netif_running(sdata->dev))
772 		return -EBUSY;
773 
774 	/* Purge and reset type-dependent state. */
775 	ieee80211_teardown_sdata(sdata->dev);
776 	ieee80211_setup_sdata(sdata, type);
777 
778 	/* reset some values that shouldn't be kept across type changes */
779 	sdata->vif.bss_conf.basic_rates =
780 		ieee80211_mandatory_rates(sdata->local,
781 			sdata->local->hw.conf.channel->band);
782 	sdata->drop_unencrypted = 0;
783 
784 	return 0;
785 }
786 
787 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
788 		     struct net_device **new_dev, enum nl80211_iftype type,
789 		     struct vif_params *params)
790 {
791 	struct net_device *ndev;
792 	struct ieee80211_sub_if_data *sdata = NULL;
793 	int ret, i;
794 
795 	ASSERT_RTNL();
796 
797 	ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
798 			    name, ieee80211_if_setup);
799 	if (!ndev)
800 		return -ENOMEM;
801 
802 	ndev->needed_headroom = local->tx_headroom +
803 				4*6 /* four MAC addresses */
804 				+ 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
805 				+ 6 /* mesh */
806 				+ 8 /* rfc1042/bridge tunnel */
807 				- ETH_HLEN /* ethernet hard_header_len */
808 				+ IEEE80211_ENCRYPT_HEADROOM;
809 	ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
810 
811 	ret = dev_alloc_name(ndev, ndev->name);
812 	if (ret < 0)
813 		goto fail;
814 
815 	memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
816 	SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
817 	ndev->features |= NETIF_F_NETNS_LOCAL;
818 
819 	/* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
820 	sdata = netdev_priv(ndev);
821 	ndev->ieee80211_ptr = &sdata->wdev;
822 
823 	/* initialise type-independent data */
824 	sdata->wdev.wiphy = local->hw.wiphy;
825 	sdata->local = local;
826 	sdata->dev = ndev;
827 
828 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
829 		skb_queue_head_init(&sdata->fragments[i].skb_list);
830 
831 	INIT_LIST_HEAD(&sdata->key_list);
832 
833 	sdata->force_unicast_rateidx = -1;
834 	sdata->max_ratectrl_rateidx = -1;
835 
836 	/* setup type-dependent data */
837 	ieee80211_setup_sdata(sdata, type);
838 
839 	ret = register_netdevice(ndev);
840 	if (ret)
841 		goto fail;
842 
843 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
844 	    params && params->mesh_id_len)
845 		ieee80211_sdata_set_mesh_id(sdata,
846 					    params->mesh_id_len,
847 					    params->mesh_id);
848 
849 	mutex_lock(&local->iflist_mtx);
850 	list_add_tail_rcu(&sdata->list, &local->interfaces);
851 	mutex_unlock(&local->iflist_mtx);
852 
853 	if (new_dev)
854 		*new_dev = ndev;
855 
856 	return 0;
857 
858  fail:
859 	free_netdev(ndev);
860 	return ret;
861 }
862 
863 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
864 {
865 	ASSERT_RTNL();
866 
867 	mutex_lock(&sdata->local->iflist_mtx);
868 	list_del_rcu(&sdata->list);
869 	mutex_unlock(&sdata->local->iflist_mtx);
870 
871 	synchronize_rcu();
872 	unregister_netdevice(sdata->dev);
873 }
874 
875 /*
876  * Remove all interfaces, may only be called at hardware unregistration
877  * time because it doesn't do RCU-safe list removals.
878  */
879 void ieee80211_remove_interfaces(struct ieee80211_local *local)
880 {
881 	struct ieee80211_sub_if_data *sdata, *tmp;
882 
883 	ASSERT_RTNL();
884 
885 	list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
886 		/*
887 		 * we cannot hold the iflist_mtx across unregister_netdevice,
888 		 * but we only need to hold it for list modifications to lock
889 		 * out readers since we're under the RTNL here as all other
890 		 * writers.
891 		 */
892 		mutex_lock(&local->iflist_mtx);
893 		list_del(&sdata->list);
894 		mutex_unlock(&local->iflist_mtx);
895 
896 		unregister_netdevice(sdata->dev);
897 	}
898 }
899