mac80211: add interface list lock
[linux-2.6] / 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                 sdata->u.sta.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
240                 /* fall through */
241         default:
242                 conf.vif = &sdata->vif;
243                 conf.type = sdata->vif.type;
244                 conf.mac_addr = dev->dev_addr;
245                 res = local->ops->add_interface(local_to_hw(local), &conf);
246                 if (res)
247                         goto err_stop;
248
249                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
250                         local->fif_other_bss++;
251                         netif_addr_lock_bh(local->mdev);
252                         ieee80211_configure_filter(local);
253                         netif_addr_unlock_bh(local->mdev);
254
255                         ieee80211_start_mesh(sdata);
256                 }
257                 changed |= ieee80211_reset_erp_info(sdata);
258                 ieee80211_bss_info_change_notify(sdata, changed);
259                 ieee80211_enable_keys(sdata);
260
261                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
262                     !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
263                         netif_carrier_off(dev);
264                 else
265                         netif_carrier_on(dev);
266         }
267
268         if (sdata->vif.type == NL80211_IFTYPE_WDS) {
269                 /* Create STA entry for the WDS peer */
270                 sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
271                                      GFP_KERNEL);
272                 if (!sta) {
273                         res = -ENOMEM;
274                         goto err_del_interface;
275                 }
276
277                 /* no locking required since STA is not live yet */
278                 sta->flags |= WLAN_STA_AUTHORIZED;
279
280                 res = sta_info_insert(sta);
281                 if (res) {
282                         /* STA has been freed */
283                         goto err_del_interface;
284                 }
285         }
286
287         if (local->open_count == 0) {
288                 res = dev_open(local->mdev);
289                 WARN_ON(res);
290                 if (res)
291                         goto err_del_interface;
292                 tasklet_enable(&local->tx_pending_tasklet);
293                 tasklet_enable(&local->tasklet);
294         }
295
296         /*
297          * set_multicast_list will be invoked by the networking core
298          * which will check whether any increments here were done in
299          * error and sync them down to the hardware as filter flags.
300          */
301         if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
302                 atomic_inc(&local->iff_allmultis);
303
304         if (sdata->flags & IEEE80211_SDATA_PROMISC)
305                 atomic_inc(&local->iff_promiscs);
306
307         local->open_count++;
308         if (hw_reconf_flags) {
309                 ieee80211_hw_config(local, hw_reconf_flags);
310                 /*
311                  * set default queue parameters so drivers don't
312                  * need to initialise the hardware if the hardware
313                  * doesn't start up with sane defaults
314                  */
315                 ieee80211_set_wmm_default(sdata);
316         }
317
318         /*
319          * ieee80211_sta_work is disabled while network interface
320          * is down. Therefore, some configuration changes may not
321          * yet be effective. Trigger execution of ieee80211_sta_work
322          * to fix this.
323          */
324         if (sdata->vif.type == NL80211_IFTYPE_STATION ||
325             sdata->vif.type == NL80211_IFTYPE_ADHOC) {
326                 struct ieee80211_if_sta *ifsta = &sdata->u.sta;
327                 queue_work(local->hw.workqueue, &ifsta->work);
328         }
329
330         netif_tx_start_all_queues(dev);
331
332         return 0;
333  err_del_interface:
334         local->ops->remove_interface(local_to_hw(local), &conf);
335  err_stop:
336         if (!local->open_count && local->ops->stop)
337                 local->ops->stop(local_to_hw(local));
338  err_del_bss:
339         sdata->bss = NULL;
340         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
341                 list_del(&sdata->u.vlan.list);
342         return res;
343 }
344
345 static int ieee80211_stop(struct net_device *dev)
346 {
347         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
348         struct ieee80211_local *local = sdata->local;
349         struct ieee80211_if_init_conf conf;
350         struct sta_info *sta;
351         u32 hw_reconf_flags = 0;
352
353         /*
354          * Stop TX on this interface first.
355          */
356         netif_tx_stop_all_queues(dev);
357
358         /*
359          * Now delete all active aggregation sessions.
360          */
361         rcu_read_lock();
362
363         list_for_each_entry_rcu(sta, &local->sta_list, list) {
364                 if (sta->sdata == sdata)
365                         ieee80211_sta_tear_down_BA_sessions(sdata,
366                                                             sta->sta.addr);
367         }
368
369         rcu_read_unlock();
370
371         /*
372          * Remove all stations associated with this interface.
373          *
374          * This must be done before calling ops->remove_interface()
375          * because otherwise we can later invoke ops->sta_notify()
376          * whenever the STAs are removed, and that invalidates driver
377          * assumptions about always getting a vif pointer that is valid
378          * (because if we remove a STA after ops->remove_interface()
379          * the driver will have removed the vif info already!)
380          *
381          * We could relax this and only unlink the stations from the
382          * hash table and list but keep them on a per-sdata list that
383          * will be inserted back again when the interface is brought
384          * up again, but I don't currently see a use case for that,
385          * except with WDS which gets a STA entry created when it is
386          * brought up.
387          */
388         sta_info_flush(local, sdata);
389
390         /*
391          * Don't count this interface for promisc/allmulti while it
392          * is down. dev_mc_unsync() will invoke set_multicast_list
393          * on the master interface which will sync these down to the
394          * hardware as filter flags.
395          */
396         if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
397                 atomic_dec(&local->iff_allmultis);
398
399         if (sdata->flags & IEEE80211_SDATA_PROMISC)
400                 atomic_dec(&local->iff_promiscs);
401
402         dev_mc_unsync(local->mdev, dev);
403         del_timer_sync(&local->dynamic_ps_timer);
404         cancel_work_sync(&local->dynamic_ps_enable_work);
405
406         /* APs need special treatment */
407         if (sdata->vif.type == NL80211_IFTYPE_AP) {
408                 struct ieee80211_sub_if_data *vlan, *tmp;
409                 struct beacon_data *old_beacon = sdata->u.ap.beacon;
410
411                 /* remove beacon */
412                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
413                 synchronize_rcu();
414                 kfree(old_beacon);
415
416                 /* down all dependent devices, that is VLANs */
417                 list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
418                                          u.vlan.list)
419                         dev_close(vlan->dev);
420                 WARN_ON(!list_empty(&sdata->u.ap.vlans));
421         }
422
423         local->open_count--;
424
425         switch (sdata->vif.type) {
426         case NL80211_IFTYPE_AP_VLAN:
427                 list_del(&sdata->u.vlan.list);
428                 /* no need to tell driver */
429                 break;
430         case NL80211_IFTYPE_MONITOR:
431                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
432                         local->cooked_mntrs--;
433                         break;
434                 }
435
436                 local->monitors--;
437                 if (local->monitors == 0) {
438                         local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
439                         hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
440                 }
441
442                 if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
443                         local->fif_fcsfail--;
444                 if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
445                         local->fif_plcpfail--;
446                 if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
447                         local->fif_control--;
448                 if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
449                         local->fif_other_bss--;
450
451                 netif_addr_lock_bh(local->mdev);
452                 ieee80211_configure_filter(local);
453                 netif_addr_unlock_bh(local->mdev);
454                 break;
455         case NL80211_IFTYPE_STATION:
456         case NL80211_IFTYPE_ADHOC:
457                 /* Announce that we are leaving the network. */
458                 if (sdata->u.sta.state != IEEE80211_STA_MLME_DISABLED)
459                         ieee80211_sta_deauthenticate(sdata,
460                                                 WLAN_REASON_DEAUTH_LEAVING);
461
462                 memset(sdata->u.sta.bssid, 0, ETH_ALEN);
463                 del_timer_sync(&sdata->u.sta.chswitch_timer);
464                 del_timer_sync(&sdata->u.sta.timer);
465                 /*
466                  * If the timer fired while we waited for it, it will have
467                  * requeued the work. Now the work will be running again
468                  * but will not rearm the timer again because it checks
469                  * whether the interface is running, which, at this point,
470                  * it no longer is.
471                  */
472                 cancel_work_sync(&sdata->u.sta.work);
473                 cancel_work_sync(&sdata->u.sta.chswitch_work);
474                 /*
475                  * When we get here, the interface is marked down.
476                  * Call synchronize_rcu() to wait for the RX path
477                  * should it be using the interface and enqueuing
478                  * frames at this very time on another CPU.
479                  */
480                 synchronize_rcu();
481                 skb_queue_purge(&sdata->u.sta.skb_queue);
482
483                 sdata->u.sta.flags &= ~(IEEE80211_STA_PRIVACY_INVOKED |
484                                         IEEE80211_STA_TKIP_WEP_USED);
485                 kfree(sdata->u.sta.extra_ie);
486                 sdata->u.sta.extra_ie = NULL;
487                 sdata->u.sta.extra_ie_len = 0;
488                 /* fall through */
489         case NL80211_IFTYPE_MESH_POINT:
490                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
491                         /* other_bss and allmulti are always set on mesh
492                          * ifaces */
493                         local->fif_other_bss--;
494                         atomic_dec(&local->iff_allmultis);
495
496                         netif_addr_lock_bh(local->mdev);
497                         ieee80211_configure_filter(local);
498                         netif_addr_unlock_bh(local->mdev);
499
500                         ieee80211_stop_mesh(sdata);
501                 }
502                 /* fall through */
503         default:
504                 if (local->scan_sdata == sdata) {
505                         if (!local->ops->hw_scan)
506                                 cancel_delayed_work_sync(&local->scan_work);
507                         /*
508                          * The software scan can no longer run now, so we can
509                          * clear out the scan_sdata reference. However, the
510                          * hardware scan may still be running. The complete
511                          * function must be prepared to handle a NULL value.
512                          */
513                         local->scan_sdata = NULL;
514                         /*
515                          * The memory barrier guarantees that another CPU
516                          * that is hardware-scanning will now see the fact
517                          * that this interface is gone.
518                          */
519                         smp_mb();
520                         /*
521                          * If software scanning, complete the scan but since
522                          * the scan_sdata is NULL already don't send out a
523                          * scan event to userspace -- the scan is incomplete.
524                          */
525                         if (local->sw_scanning)
526                                 ieee80211_scan_completed(&local->hw);
527                 }
528
529                 conf.vif = &sdata->vif;
530                 conf.type = sdata->vif.type;
531                 conf.mac_addr = dev->dev_addr;
532                 /* disable all keys for as long as this netdev is down */
533                 ieee80211_disable_keys(sdata);
534                 local->ops->remove_interface(local_to_hw(local), &conf);
535         }
536
537         sdata->bss = NULL;
538
539         if (local->open_count == 0) {
540                 if (netif_running(local->mdev))
541                         dev_close(local->mdev);
542
543                 if (local->ops->stop)
544                         local->ops->stop(local_to_hw(local));
545
546                 ieee80211_led_radio(local, 0);
547
548                 flush_workqueue(local->hw.workqueue);
549
550                 tasklet_disable(&local->tx_pending_tasklet);
551                 tasklet_disable(&local->tasklet);
552
553                 /* no reconfiguring after stop! */
554                 hw_reconf_flags = 0;
555         }
556
557         /* do after stop to avoid reconfiguring when we stop anyway */
558         if (hw_reconf_flags)
559                 ieee80211_hw_config(local, hw_reconf_flags);
560
561         return 0;
562 }
563
564 static void ieee80211_set_multicast_list(struct net_device *dev)
565 {
566         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
567         struct ieee80211_local *local = sdata->local;
568         int allmulti, promisc, sdata_allmulti, sdata_promisc;
569
570         allmulti = !!(dev->flags & IFF_ALLMULTI);
571         promisc = !!(dev->flags & IFF_PROMISC);
572         sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
573         sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
574
575         if (allmulti != sdata_allmulti) {
576                 if (dev->flags & IFF_ALLMULTI)
577                         atomic_inc(&local->iff_allmultis);
578                 else
579                         atomic_dec(&local->iff_allmultis);
580                 sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
581         }
582
583         if (promisc != sdata_promisc) {
584                 if (dev->flags & IFF_PROMISC)
585                         atomic_inc(&local->iff_promiscs);
586                 else
587                         atomic_dec(&local->iff_promiscs);
588                 sdata->flags ^= IEEE80211_SDATA_PROMISC;
589         }
590
591         dev_mc_sync(local->mdev, dev);
592 }
593
594 static void ieee80211_if_setup(struct net_device *dev)
595 {
596         ether_setup(dev);
597         dev->hard_start_xmit = ieee80211_subif_start_xmit;
598         dev->wireless_handlers = &ieee80211_iw_handler_def;
599         dev->set_multicast_list = ieee80211_set_multicast_list;
600         dev->change_mtu = ieee80211_change_mtu;
601         dev->open = ieee80211_open;
602         dev->stop = ieee80211_stop;
603         dev->destructor = free_netdev;
604         /* we will validate the address ourselves in ->open */
605         dev->validate_addr = NULL;
606 }
607 /*
608  * Called when the netdev is removed or, by the code below, before
609  * the interface type changes.
610  */
611 static void ieee80211_teardown_sdata(struct net_device *dev)
612 {
613         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
614         struct ieee80211_local *local = sdata->local;
615         struct beacon_data *beacon;
616         struct sk_buff *skb;
617         int flushed;
618         int i;
619
620         /* free extra data */
621         ieee80211_free_keys(sdata);
622
623         ieee80211_debugfs_remove_netdev(sdata);
624
625         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
626                 __skb_queue_purge(&sdata->fragments[i].skb_list);
627         sdata->fragment_next = 0;
628
629         switch (sdata->vif.type) {
630         case NL80211_IFTYPE_AP:
631                 beacon = sdata->u.ap.beacon;
632                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
633                 synchronize_rcu();
634                 kfree(beacon);
635
636                 while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
637                         local->total_ps_buffered--;
638                         dev_kfree_skb(skb);
639                 }
640
641                 break;
642         case NL80211_IFTYPE_MESH_POINT:
643                 if (ieee80211_vif_is_mesh(&sdata->vif))
644                         mesh_rmc_free(sdata);
645                 break;
646         case NL80211_IFTYPE_STATION:
647         case NL80211_IFTYPE_ADHOC:
648                 kfree(sdata->u.sta.extra_ie);
649                 kfree(sdata->u.sta.assocreq_ies);
650                 kfree(sdata->u.sta.assocresp_ies);
651                 kfree_skb(sdata->u.sta.probe_resp);
652                 kfree(sdata->u.sta.ie_probereq);
653                 kfree(sdata->u.sta.ie_proberesp);
654                 kfree(sdata->u.sta.ie_auth);
655                 kfree(sdata->u.sta.ie_assocreq);
656                 kfree(sdata->u.sta.ie_reassocreq);
657                 kfree(sdata->u.sta.ie_deauth);
658                 kfree(sdata->u.sta.ie_disassoc);
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 /*
675  * Helper function to initialise an interface to a specific type.
676  */
677 static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
678                                   enum nl80211_iftype type)
679 {
680         /* clear type-dependent union */
681         memset(&sdata->u, 0, sizeof(sdata->u));
682
683         /* and set some type-dependent values */
684         sdata->vif.type = type;
685         sdata->dev->hard_start_xmit = ieee80211_subif_start_xmit;
686         sdata->wdev.iftype = type;
687
688         /* only monitor differs */
689         sdata->dev->type = ARPHRD_ETHER;
690
691         switch (type) {
692         case NL80211_IFTYPE_AP:
693                 skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
694                 INIT_LIST_HEAD(&sdata->u.ap.vlans);
695                 break;
696         case NL80211_IFTYPE_STATION:
697         case NL80211_IFTYPE_ADHOC:
698                 ieee80211_sta_setup_sdata(sdata);
699                 break;
700         case NL80211_IFTYPE_MESH_POINT:
701                 if (ieee80211_vif_is_mesh(&sdata->vif))
702                         ieee80211_mesh_init_sdata(sdata);
703                 break;
704         case NL80211_IFTYPE_MONITOR:
705                 sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
706                 sdata->dev->hard_start_xmit = ieee80211_monitor_start_xmit;
707                 sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
708                                       MONITOR_FLAG_OTHER_BSS;
709                 break;
710         case NL80211_IFTYPE_WDS:
711         case NL80211_IFTYPE_AP_VLAN:
712                 break;
713         case NL80211_IFTYPE_UNSPECIFIED:
714         case __NL80211_IFTYPE_AFTER_LAST:
715                 BUG();
716                 break;
717         }
718
719         ieee80211_debugfs_add_netdev(sdata);
720 }
721
722 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
723                              enum nl80211_iftype type)
724 {
725         ASSERT_RTNL();
726
727         if (type == sdata->vif.type)
728                 return 0;
729
730         /* Setting ad-hoc mode on non-IBSS channel is not supported. */
731         if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
732             type == NL80211_IFTYPE_ADHOC)
733                 return -EOPNOTSUPP;
734
735         /*
736          * We could, here, on changes between IBSS/STA/MESH modes,
737          * invoke an MLME function instead that disassociates etc.
738          * and goes into the requested mode.
739          */
740
741         if (netif_running(sdata->dev))
742                 return -EBUSY;
743
744         /* Purge and reset type-dependent state. */
745         ieee80211_teardown_sdata(sdata->dev);
746         ieee80211_setup_sdata(sdata, type);
747
748         /* reset some values that shouldn't be kept across type changes */
749         sdata->vif.bss_conf.basic_rates =
750                 ieee80211_mandatory_rates(sdata->local,
751                         sdata->local->hw.conf.channel->band);
752         sdata->drop_unencrypted = 0;
753
754         return 0;
755 }
756
757 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
758                      struct net_device **new_dev, enum nl80211_iftype type,
759                      struct vif_params *params)
760 {
761         struct net_device *ndev;
762         struct ieee80211_sub_if_data *sdata = NULL;
763         int ret, i;
764
765         ASSERT_RTNL();
766
767         ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
768                             name, ieee80211_if_setup);
769         if (!ndev)
770                 return -ENOMEM;
771
772         ndev->needed_headroom = local->tx_headroom +
773                                 4*6 /* four MAC addresses */
774                                 + 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
775                                 + 6 /* mesh */
776                                 + 8 /* rfc1042/bridge tunnel */
777                                 - ETH_HLEN /* ethernet hard_header_len */
778                                 + IEEE80211_ENCRYPT_HEADROOM;
779         ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
780
781         ret = dev_alloc_name(ndev, ndev->name);
782         if (ret < 0)
783                 goto fail;
784
785         memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
786         SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
787
788         /* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
789         sdata = netdev_priv(ndev);
790         ndev->ieee80211_ptr = &sdata->wdev;
791
792         /* initialise type-independent data */
793         sdata->wdev.wiphy = local->hw.wiphy;
794         sdata->local = local;
795         sdata->dev = ndev;
796
797         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
798                 skb_queue_head_init(&sdata->fragments[i].skb_list);
799
800         INIT_LIST_HEAD(&sdata->key_list);
801
802         sdata->force_unicast_rateidx = -1;
803         sdata->max_ratectrl_rateidx = -1;
804
805         /* setup type-dependent data */
806         ieee80211_setup_sdata(sdata, type);
807
808         ret = register_netdevice(ndev);
809         if (ret)
810                 goto fail;
811
812         ndev->uninit = ieee80211_teardown_sdata;
813
814         if (ieee80211_vif_is_mesh(&sdata->vif) &&
815             params && params->mesh_id_len)
816                 ieee80211_sdata_set_mesh_id(sdata,
817                                             params->mesh_id_len,
818                                             params->mesh_id);
819
820         mutex_lock(&local->iflist_mtx);
821         list_add_tail_rcu(&sdata->list, &local->interfaces);
822         mutex_unlock(&local->iflist_mtx);
823
824         if (new_dev)
825                 *new_dev = ndev;
826
827         return 0;
828
829  fail:
830         free_netdev(ndev);
831         return ret;
832 }
833
834 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
835 {
836         ASSERT_RTNL();
837
838         mutex_lock(&sdata->local->iflist_mtx);
839         list_del_rcu(&sdata->list);
840         mutex_unlock(&sdata->local->iflist_mtx);
841
842         synchronize_rcu();
843         unregister_netdevice(sdata->dev);
844 }
845
846 /*
847  * Remove all interfaces, may only be called at hardware unregistration
848  * time because it doesn't do RCU-safe list removals.
849  */
850 void ieee80211_remove_interfaces(struct ieee80211_local *local)
851 {
852         struct ieee80211_sub_if_data *sdata, *tmp;
853
854         ASSERT_RTNL();
855
856         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
857                 /*
858                  * we cannot hold the iflist_mtx across unregister_netdevice,
859                  * but we only need to hold it for list modifications to lock
860                  * out readers since we're under the RTNL here as all other
861                  * writers.
862                  */
863                 mutex_lock(&local->iflist_mtx);
864                 list_del(&sdata->list);
865                 mutex_unlock(&local->iflist_mtx);
866
867                 unregister_netdevice(sdata->dev);
868         }
869 }