xref: /linux/net/mac80211/iface.c (revision 6000fc4d6f3e55ad52cce8d76317187fe01af2aa)
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 	}
192 
193 	if (compare_ether_addr(null_addr, local->mdev->dev_addr) == 0)
194 		memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr,
195 		       ETH_ALEN);
196 
197 	/*
198 	 * Validate the MAC address for this device.
199 	 */
200 	if (!is_valid_ether_addr(dev->dev_addr)) {
201 		if (!local->open_count)
202 			drv_stop(local);
203 		return -EADDRNOTAVAIL;
204 	}
205 
206 	switch (sdata->vif.type) {
207 	case NL80211_IFTYPE_AP_VLAN:
208 		/* no need to tell driver */
209 		break;
210 	case NL80211_IFTYPE_MONITOR:
211 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
212 			local->cooked_mntrs++;
213 			break;
214 		}
215 
216 		/* must be before the call to ieee80211_configure_filter */
217 		local->monitors++;
218 		if (local->monitors == 1) {
219 			local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
220 			hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
221 		}
222 
223 		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
224 			local->fif_fcsfail++;
225 		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
226 			local->fif_plcpfail++;
227 		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
228 			local->fif_control++;
229 		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
230 			local->fif_other_bss++;
231 
232 		netif_addr_lock_bh(local->mdev);
233 		ieee80211_configure_filter(local);
234 		netif_addr_unlock_bh(local->mdev);
235 		break;
236 	case NL80211_IFTYPE_STATION:
237 		sdata->u.mgd.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
238 		/* fall through */
239 	default:
240 		conf.vif = &sdata->vif;
241 		conf.type = sdata->vif.type;
242 		conf.mac_addr = dev->dev_addr;
243 		res = drv_add_interface(local, &conf);
244 		if (res)
245 			goto err_stop;
246 
247 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
248 			local->fif_other_bss++;
249 			netif_addr_lock_bh(local->mdev);
250 			ieee80211_configure_filter(local);
251 			netif_addr_unlock_bh(local->mdev);
252 
253 			ieee80211_start_mesh(sdata);
254 		}
255 		changed |= ieee80211_reset_erp_info(sdata);
256 		ieee80211_bss_info_change_notify(sdata, changed);
257 		ieee80211_enable_keys(sdata);
258 
259 		if (sdata->vif.type == NL80211_IFTYPE_STATION)
260 			netif_carrier_off(dev);
261 		else
262 			netif_carrier_on(dev);
263 	}
264 
265 	if (sdata->vif.type == NL80211_IFTYPE_WDS) {
266 		/* Create STA entry for the WDS peer */
267 		sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
268 				     GFP_KERNEL);
269 		if (!sta) {
270 			res = -ENOMEM;
271 			goto err_del_interface;
272 		}
273 
274 		/* no locking required since STA is not live yet */
275 		sta->flags |= WLAN_STA_AUTHORIZED;
276 
277 		res = sta_info_insert(sta);
278 		if (res) {
279 			/* STA has been freed */
280 			goto err_del_interface;
281 		}
282 	}
283 
284 	if (local->open_count == 0) {
285 		res = dev_open(local->mdev);
286 		WARN_ON(res);
287 		if (res)
288 			goto err_del_interface;
289 		tasklet_enable(&local->tx_pending_tasklet);
290 		tasklet_enable(&local->tasklet);
291 	}
292 
293 	/*
294 	 * set_multicast_list will be invoked by the networking core
295 	 * which will check whether any increments here were done in
296 	 * error and sync them down to the hardware as filter flags.
297 	 */
298 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
299 		atomic_inc(&local->iff_allmultis);
300 
301 	if (sdata->flags & IEEE80211_SDATA_PROMISC)
302 		atomic_inc(&local->iff_promiscs);
303 
304 	hw_reconf_flags |= __ieee80211_recalc_idle(local);
305 
306 	local->open_count++;
307 	if (hw_reconf_flags) {
308 		ieee80211_hw_config(local, hw_reconf_flags);
309 		/*
310 		 * set default queue parameters so drivers don't
311 		 * need to initialise the hardware if the hardware
312 		 * doesn't start up with sane defaults
313 		 */
314 		ieee80211_set_wmm_default(sdata);
315 	}
316 
317 	ieee80211_recalc_ps(local, -1);
318 
319 	/*
320 	 * ieee80211_sta_work is disabled while network interface
321 	 * is down. Therefore, some configuration changes may not
322 	 * yet be effective. Trigger execution of ieee80211_sta_work
323 	 * to fix this.
324 	 */
325 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
326 		queue_work(local->hw.workqueue, &sdata->u.mgd.work);
327 
328 	netif_tx_start_all_queues(dev);
329 
330 	return 0;
331  err_del_interface:
332 	drv_remove_interface(local, &conf);
333  err_stop:
334 	if (!local->open_count)
335 		drv_stop(local);
336  err_del_bss:
337 	sdata->bss = NULL;
338 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
339 		list_del(&sdata->u.vlan.list);
340 	return res;
341 }
342 
343 static int ieee80211_stop(struct net_device *dev)
344 {
345 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
346 	struct ieee80211_local *local = sdata->local;
347 	struct ieee80211_if_init_conf conf;
348 	struct sta_info *sta;
349 	u32 hw_reconf_flags = 0;
350 
351 	/*
352 	 * Stop TX on this interface first.
353 	 */
354 	netif_tx_stop_all_queues(dev);
355 
356 	/*
357 	 * Now delete all active aggregation sessions.
358 	 */
359 	rcu_read_lock();
360 
361 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
362 		if (sta->sdata == sdata)
363 			ieee80211_sta_tear_down_BA_sessions(sta);
364 	}
365 
366 	rcu_read_unlock();
367 
368 	/*
369 	 * Announce that we are leaving the network, in case we are a
370 	 * station interface type. This must be done before removing
371 	 * all stations associated with sta_info_flush, otherwise STA
372 	 * information will be gone and no announce being done.
373 	 */
374 	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
375 		if (sdata->u.mgd.state != IEEE80211_STA_MLME_DISABLED)
376 			ieee80211_sta_deauthenticate(sdata,
377 				WLAN_REASON_DEAUTH_LEAVING);
378 	}
379 
380 	/*
381 	 * Remove all stations associated with this interface.
382 	 *
383 	 * This must be done before calling ops->remove_interface()
384 	 * because otherwise we can later invoke ops->sta_notify()
385 	 * whenever the STAs are removed, and that invalidates driver
386 	 * assumptions about always getting a vif pointer that is valid
387 	 * (because if we remove a STA after ops->remove_interface()
388 	 * the driver will have removed the vif info already!)
389 	 *
390 	 * We could relax this and only unlink the stations from the
391 	 * hash table and list but keep them on a per-sdata list that
392 	 * will be inserted back again when the interface is brought
393 	 * up again, but I don't currently see a use case for that,
394 	 * except with WDS which gets a STA entry created when it is
395 	 * brought up.
396 	 */
397 	sta_info_flush(local, sdata);
398 
399 	/*
400 	 * Don't count this interface for promisc/allmulti while it
401 	 * is down. dev_mc_unsync() will invoke set_multicast_list
402 	 * on the master interface which will sync these down to the
403 	 * hardware as filter flags.
404 	 */
405 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
406 		atomic_dec(&local->iff_allmultis);
407 
408 	if (sdata->flags & IEEE80211_SDATA_PROMISC)
409 		atomic_dec(&local->iff_promiscs);
410 
411 	dev_mc_unsync(local->mdev, dev);
412 	del_timer_sync(&local->dynamic_ps_timer);
413 	cancel_work_sync(&local->dynamic_ps_enable_work);
414 
415 	/* APs need special treatment */
416 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
417 		struct ieee80211_sub_if_data *vlan, *tmp;
418 		struct beacon_data *old_beacon = sdata->u.ap.beacon;
419 
420 		/* remove beacon */
421 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
422 		synchronize_rcu();
423 		kfree(old_beacon);
424 
425 		/* down all dependent devices, that is VLANs */
426 		list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
427 					 u.vlan.list)
428 			dev_close(vlan->dev);
429 		WARN_ON(!list_empty(&sdata->u.ap.vlans));
430 	}
431 
432 	local->open_count--;
433 
434 	switch (sdata->vif.type) {
435 	case NL80211_IFTYPE_AP_VLAN:
436 		list_del(&sdata->u.vlan.list);
437 		/* no need to tell driver */
438 		break;
439 	case NL80211_IFTYPE_MONITOR:
440 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
441 			local->cooked_mntrs--;
442 			break;
443 		}
444 
445 		local->monitors--;
446 		if (local->monitors == 0) {
447 			local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
448 			hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
449 		}
450 
451 		if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
452 			local->fif_fcsfail--;
453 		if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
454 			local->fif_plcpfail--;
455 		if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
456 			local->fif_control--;
457 		if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
458 			local->fif_other_bss--;
459 
460 		netif_addr_lock_bh(local->mdev);
461 		ieee80211_configure_filter(local);
462 		netif_addr_unlock_bh(local->mdev);
463 		break;
464 	case NL80211_IFTYPE_STATION:
465 		memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
466 		del_timer_sync(&sdata->u.mgd.chswitch_timer);
467 		del_timer_sync(&sdata->u.mgd.timer);
468 		/*
469 		 * If the timer fired while we waited for it, it will have
470 		 * requeued the work. Now the work will be running again
471 		 * but will not rearm the timer again because it checks
472 		 * whether the interface is running, which, at this point,
473 		 * it no longer is.
474 		 */
475 		cancel_work_sync(&sdata->u.mgd.work);
476 		cancel_work_sync(&sdata->u.mgd.chswitch_work);
477 
478 		cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
479 
480 		/*
481 		 * When we get here, the interface is marked down.
482 		 * Call synchronize_rcu() to wait for the RX path
483 		 * should it be using the interface and enqueuing
484 		 * frames at this very time on another CPU.
485 		 */
486 		synchronize_rcu();
487 		skb_queue_purge(&sdata->u.mgd.skb_queue);
488 
489 		sdata->u.mgd.flags &= ~(IEEE80211_STA_PRIVACY_INVOKED |
490 					IEEE80211_STA_TKIP_WEP_USED);
491 		kfree(sdata->u.mgd.extra_ie);
492 		sdata->u.mgd.extra_ie = NULL;
493 		sdata->u.mgd.extra_ie_len = 0;
494 		/* fall through */
495 	case NL80211_IFTYPE_ADHOC:
496 		if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
497 			del_timer_sync(&sdata->u.ibss.timer);
498 			cancel_work_sync(&sdata->u.ibss.work);
499 			synchronize_rcu();
500 			skb_queue_purge(&sdata->u.ibss.skb_queue);
501 		}
502 		/* fall through */
503 	case NL80211_IFTYPE_MESH_POINT:
504 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
505 			/* other_bss and allmulti are always set on mesh
506 			 * ifaces */
507 			local->fif_other_bss--;
508 			atomic_dec(&local->iff_allmultis);
509 
510 			netif_addr_lock_bh(local->mdev);
511 			ieee80211_configure_filter(local);
512 			netif_addr_unlock_bh(local->mdev);
513 
514 			ieee80211_stop_mesh(sdata);
515 		}
516 		/* fall through */
517 	default:
518 		if (local->scan_sdata == sdata) {
519 			if (!local->ops->hw_scan)
520 				cancel_delayed_work_sync(&local->scan_work);
521 			/*
522 			 * The software scan can no longer run now, so we can
523 			 * clear out the scan_sdata reference. However, the
524 			 * hardware scan may still be running. The complete
525 			 * function must be prepared to handle a NULL value.
526 			 */
527 			local->scan_sdata = NULL;
528 			/*
529 			 * The memory barrier guarantees that another CPU
530 			 * that is hardware-scanning will now see the fact
531 			 * that this interface is gone.
532 			 */
533 			smp_mb();
534 			/*
535 			 * If software scanning, complete the scan but since
536 			 * the scan_sdata is NULL already don't send out a
537 			 * scan event to userspace -- the scan is incomplete.
538 			 */
539 			if (local->sw_scanning)
540 				ieee80211_scan_completed(&local->hw, true);
541 		}
542 
543 		conf.vif = &sdata->vif;
544 		conf.type = sdata->vif.type;
545 		conf.mac_addr = dev->dev_addr;
546 		/* disable all keys for as long as this netdev is down */
547 		ieee80211_disable_keys(sdata);
548 		drv_remove_interface(local, &conf);
549 	}
550 
551 	sdata->bss = NULL;
552 
553 	hw_reconf_flags |= __ieee80211_recalc_idle(local);
554 
555 	ieee80211_recalc_ps(local, -1);
556 
557 	if (local->open_count == 0) {
558 		if (netif_running(local->mdev))
559 			dev_close(local->mdev);
560 
561 		drv_stop(local);
562 
563 		ieee80211_led_radio(local, false);
564 
565 		flush_workqueue(local->hw.workqueue);
566 
567 		tasklet_disable(&local->tx_pending_tasklet);
568 		tasklet_disable(&local->tasklet);
569 
570 		/* no reconfiguring after stop! */
571 		hw_reconf_flags = 0;
572 	}
573 
574 	/* do after stop to avoid reconfiguring when we stop anyway */
575 	if (hw_reconf_flags)
576 		ieee80211_hw_config(local, hw_reconf_flags);
577 
578 	return 0;
579 }
580 
581 static void ieee80211_set_multicast_list(struct net_device *dev)
582 {
583 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
584 	struct ieee80211_local *local = sdata->local;
585 	int allmulti, promisc, sdata_allmulti, sdata_promisc;
586 
587 	allmulti = !!(dev->flags & IFF_ALLMULTI);
588 	promisc = !!(dev->flags & IFF_PROMISC);
589 	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
590 	sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
591 
592 	if (allmulti != sdata_allmulti) {
593 		if (dev->flags & IFF_ALLMULTI)
594 			atomic_inc(&local->iff_allmultis);
595 		else
596 			atomic_dec(&local->iff_allmultis);
597 		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
598 	}
599 
600 	if (promisc != sdata_promisc) {
601 		if (dev->flags & IFF_PROMISC)
602 			atomic_inc(&local->iff_promiscs);
603 		else
604 			atomic_dec(&local->iff_promiscs);
605 		sdata->flags ^= IEEE80211_SDATA_PROMISC;
606 	}
607 
608 	dev_mc_sync(local->mdev, dev);
609 }
610 
611 /*
612  * Called when the netdev is removed or, by the code below, before
613  * the interface type changes.
614  */
615 static void ieee80211_teardown_sdata(struct net_device *dev)
616 {
617 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
618 	struct ieee80211_local *local = sdata->local;
619 	struct beacon_data *beacon;
620 	struct sk_buff *skb;
621 	int flushed;
622 	int i;
623 
624 	/* free extra data */
625 	ieee80211_free_keys(sdata);
626 
627 	ieee80211_debugfs_remove_netdev(sdata);
628 
629 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
630 		__skb_queue_purge(&sdata->fragments[i].skb_list);
631 	sdata->fragment_next = 0;
632 
633 	switch (sdata->vif.type) {
634 	case NL80211_IFTYPE_AP:
635 		beacon = sdata->u.ap.beacon;
636 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
637 		synchronize_rcu();
638 		kfree(beacon);
639 
640 		while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
641 			local->total_ps_buffered--;
642 			dev_kfree_skb(skb);
643 		}
644 
645 		break;
646 	case NL80211_IFTYPE_MESH_POINT:
647 		if (ieee80211_vif_is_mesh(&sdata->vif))
648 			mesh_rmc_free(sdata);
649 		break;
650 	case NL80211_IFTYPE_ADHOC:
651 		if (WARN_ON(sdata->u.ibss.presp))
652 			kfree_skb(sdata->u.ibss.presp);
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 
900 static u32 ieee80211_idle_off(struct ieee80211_local *local,
901 			      const char *reason)
902 {
903 	if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE))
904 		return 0;
905 
906 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
907 	printk(KERN_DEBUG "%s: device no longer idle - %s\n",
908 	       wiphy_name(local->hw.wiphy), reason);
909 #endif
910 
911 	local->hw.conf.flags &= ~IEEE80211_CONF_IDLE;
912 	return IEEE80211_CONF_CHANGE_IDLE;
913 }
914 
915 static u32 ieee80211_idle_on(struct ieee80211_local *local)
916 {
917 	if (local->hw.conf.flags & IEEE80211_CONF_IDLE)
918 		return 0;
919 
920 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
921 	printk(KERN_DEBUG "%s: device now idle\n",
922 	       wiphy_name(local->hw.wiphy));
923 #endif
924 
925 	local->hw.conf.flags |= IEEE80211_CONF_IDLE;
926 	return IEEE80211_CONF_CHANGE_IDLE;
927 }
928 
929 u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
930 {
931 	struct ieee80211_sub_if_data *sdata;
932 	int count = 0;
933 
934 	if (local->hw_scanning || local->sw_scanning)
935 		return ieee80211_idle_off(local, "scanning");
936 
937 	list_for_each_entry(sdata, &local->interfaces, list) {
938 		if (!netif_running(sdata->dev))
939 			continue;
940 		/* do not count disabled managed interfaces */
941 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
942 		    sdata->u.mgd.state == IEEE80211_STA_MLME_DISABLED)
943 			continue;
944 		/* do not count unused IBSS interfaces */
945 		if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
946 		    !sdata->u.ibss.ssid_len)
947 			continue;
948 		/* count everything else */
949 		count++;
950 	}
951 
952 	if (!count)
953 		return ieee80211_idle_on(local);
954 	else
955 		return ieee80211_idle_off(local, "in use");
956 
957 	return 0;
958 }
959 
960 void ieee80211_recalc_idle(struct ieee80211_local *local)
961 {
962 	u32 chg;
963 
964 	mutex_lock(&local->iflist_mtx);
965 	chg = __ieee80211_recalc_idle(local);
966 	mutex_unlock(&local->iflist_mtx);
967 	if (chg)
968 		ieee80211_hw_config(local, chg);
969 }
970