mac80211: add beacon filtering support
[linux-2.6.git] / net / mac80211 / iface.c
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 }