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1 /* Copyright (C) 2007-2014 B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner, Simon Wunderlich
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of version 2 of the GNU General Public
7  * License as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17
18 #include "main.h"
19 #include "distributed-arp-table.h"
20 #include "hard-interface.h"
21 #include "soft-interface.h"
22 #include "send.h"
23 #include "translation-table.h"
24 #include "routing.h"
25 #include "sysfs.h"
26 #include "debugfs.h"
27 #include "originator.h"
28 #include "hash.h"
29 #include "bridge_loop_avoidance.h"
30 #include "gateway_client.h"
31
32 #include <linux/if_arp.h>
33 #include <linux/if_ether.h>
34
35 void batadv_hardif_free_rcu(struct rcu_head *rcu)
36 {
37         struct batadv_hard_iface *hard_iface;
38
39         hard_iface = container_of(rcu, struct batadv_hard_iface, rcu);
40         dev_put(hard_iface->net_dev);
41         kfree(hard_iface);
42 }
43
44 struct batadv_hard_iface *
45 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
46 {
47         struct batadv_hard_iface *hard_iface;
48
49         rcu_read_lock();
50         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
51                 if (hard_iface->net_dev == net_dev &&
52                     atomic_inc_not_zero(&hard_iface->refcount))
53                         goto out;
54         }
55
56         hard_iface = NULL;
57
58 out:
59         rcu_read_unlock();
60         return hard_iface;
61 }
62
63 /**
64  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
65  * @net_dev: the device to check
66  *
67  * If the user creates any virtual device on top of a batman-adv interface, it
68  * is important to prevent this new interface to be used to create a new mesh
69  * network (this behaviour would lead to a batman-over-batman configuration).
70  * This function recursively checks all the fathers of the device passed as
71  * argument looking for a batman-adv soft interface.
72  *
73  * Returns true if the device is descendant of a batman-adv mesh interface (or
74  * if it is a batman-adv interface itself), false otherwise
75  */
76 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
77 {
78         struct net_device *parent_dev;
79         bool ret;
80
81         /* check if this is a batman-adv mesh interface */
82         if (batadv_softif_is_valid(net_dev))
83                 return true;
84
85         /* no more parents..stop recursion */
86         if (net_dev->iflink == net_dev->ifindex)
87                 return false;
88
89         /* recurse over the parent device */
90         parent_dev = __dev_get_by_index(&init_net, net_dev->iflink);
91         /* if we got a NULL parent_dev there is something broken.. */
92         if (WARN(!parent_dev, "Cannot find parent device"))
93                 return false;
94
95         ret = batadv_is_on_batman_iface(parent_dev);
96
97         return ret;
98 }
99
100 static int batadv_is_valid_iface(const struct net_device *net_dev)
101 {
102         if (net_dev->flags & IFF_LOOPBACK)
103                 return 0;
104
105         if (net_dev->type != ARPHRD_ETHER)
106                 return 0;
107
108         if (net_dev->addr_len != ETH_ALEN)
109                 return 0;
110
111         /* no batman over batman */
112         if (batadv_is_on_batman_iface(net_dev))
113                 return 0;
114
115         return 1;
116 }
117
118 /**
119  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
120  *  interface
121  * @net_device: the device to check
122  *
123  * Returns true if the net device is a 802.11 wireless device, false otherwise.
124  */
125 bool batadv_is_wifi_netdev(struct net_device *net_device)
126 {
127         if (!net_device)
128                 return false;
129
130 #ifdef CONFIG_WIRELESS_EXT
131         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
132          * check for wireless_handlers != NULL
133          */
134         if (net_device->wireless_handlers)
135                 return true;
136 #endif
137
138         /* cfg80211 drivers have to set ieee80211_ptr */
139         if (net_device->ieee80211_ptr)
140                 return true;
141
142         return false;
143 }
144
145 static struct batadv_hard_iface *
146 batadv_hardif_get_active(const struct net_device *soft_iface)
147 {
148         struct batadv_hard_iface *hard_iface;
149
150         rcu_read_lock();
151         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
152                 if (hard_iface->soft_iface != soft_iface)
153                         continue;
154
155                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
156                     atomic_inc_not_zero(&hard_iface->refcount))
157                         goto out;
158         }
159
160         hard_iface = NULL;
161
162 out:
163         rcu_read_unlock();
164         return hard_iface;
165 }
166
167 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
168                                           struct batadv_hard_iface *oldif)
169 {
170         struct batadv_hard_iface *primary_if;
171
172         primary_if = batadv_primary_if_get_selected(bat_priv);
173         if (!primary_if)
174                 goto out;
175
176         batadv_dat_init_own_addr(bat_priv, primary_if);
177         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
178 out:
179         if (primary_if)
180                 batadv_hardif_free_ref(primary_if);
181 }
182
183 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
184                                      struct batadv_hard_iface *new_hard_iface)
185 {
186         struct batadv_hard_iface *curr_hard_iface;
187
188         ASSERT_RTNL();
189
190         if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
191                 new_hard_iface = NULL;
192
193         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
194         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
195
196         if (!new_hard_iface)
197                 goto out;
198
199         bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
200         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
201
202 out:
203         if (curr_hard_iface)
204                 batadv_hardif_free_ref(curr_hard_iface);
205 }
206
207 static bool
208 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
209 {
210         if (hard_iface->net_dev->flags & IFF_UP)
211                 return true;
212
213         return false;
214 }
215
216 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
217 {
218         const struct batadv_hard_iface *hard_iface;
219
220         rcu_read_lock();
221         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
222                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
223                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
224                         continue;
225
226                 if (hard_iface->net_dev == net_dev)
227                         continue;
228
229                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
230                                         net_dev->dev_addr))
231                         continue;
232
233                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
234                         net_dev->dev_addr, hard_iface->net_dev->name);
235                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
236         }
237         rcu_read_unlock();
238 }
239
240 int batadv_hardif_min_mtu(struct net_device *soft_iface)
241 {
242         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
243         const struct batadv_hard_iface *hard_iface;
244         int min_mtu = ETH_DATA_LEN;
245
246         rcu_read_lock();
247         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
248                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
249                     (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
250                         continue;
251
252                 if (hard_iface->soft_iface != soft_iface)
253                         continue;
254
255                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
256         }
257         rcu_read_unlock();
258
259         atomic_set(&bat_priv->packet_size_max, min_mtu);
260
261         if (atomic_read(&bat_priv->fragmentation) == 0)
262                 goto out;
263
264         /* with fragmentation enabled the maximum size of internally generated
265          * packets such as translation table exchanges or tvlv containers, etc
266          * has to be calculated
267          */
268         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
269         min_mtu -= sizeof(struct batadv_frag_packet);
270         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
271         atomic_set(&bat_priv->packet_size_max, min_mtu);
272
273         /* with fragmentation enabled we can fragment external packets easily */
274         min_mtu = min_t(int, min_mtu, ETH_DATA_LEN);
275
276 out:
277         return min_mtu - batadv_max_header_len();
278 }
279
280 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
281 void batadv_update_min_mtu(struct net_device *soft_iface)
282 {
283         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
284
285         /* Check if the local translate table should be cleaned up to match a
286          * new (and smaller) MTU.
287          */
288         batadv_tt_local_resize_to_mtu(soft_iface);
289 }
290
291 static void
292 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
293 {
294         struct batadv_priv *bat_priv;
295         struct batadv_hard_iface *primary_if = NULL;
296
297         if (hard_iface->if_status != BATADV_IF_INACTIVE)
298                 goto out;
299
300         bat_priv = netdev_priv(hard_iface->soft_iface);
301
302         bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
303         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
304
305         /* the first active interface becomes our primary interface or
306          * the next active interface after the old primary interface was removed
307          */
308         primary_if = batadv_primary_if_get_selected(bat_priv);
309         if (!primary_if)
310                 batadv_primary_if_select(bat_priv, hard_iface);
311
312         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
313                     hard_iface->net_dev->name);
314
315         batadv_update_min_mtu(hard_iface->soft_iface);
316
317 out:
318         if (primary_if)
319                 batadv_hardif_free_ref(primary_if);
320 }
321
322 static void
323 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
324 {
325         if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
326             (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
327                 return;
328
329         hard_iface->if_status = BATADV_IF_INACTIVE;
330
331         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
332                     hard_iface->net_dev->name);
333
334         batadv_update_min_mtu(hard_iface->soft_iface);
335 }
336
337 /**
338  * batadv_master_del_slave - remove hard_iface from the current master interface
339  * @slave: the interface enslaved in another master
340  * @master: the master from which slave has to be removed
341  *
342  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
343  * is free'd and master can correctly change its internal state.
344  * Return 0 on success, a negative value representing the error otherwise
345  */
346 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
347                                    struct net_device *master)
348 {
349         int ret;
350
351         if (!master)
352                 return 0;
353
354         ret = -EBUSY;
355         if (master->netdev_ops->ndo_del_slave)
356                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
357
358         return ret;
359 }
360
361 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
362                                    const char *iface_name)
363 {
364         struct batadv_priv *bat_priv;
365         struct net_device *soft_iface, *master;
366         __be16 ethertype = htons(ETH_P_BATMAN);
367         int max_header_len = batadv_max_header_len();
368         int ret;
369
370         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
371                 goto out;
372
373         if (!atomic_inc_not_zero(&hard_iface->refcount))
374                 goto out;
375
376         soft_iface = dev_get_by_name(&init_net, iface_name);
377
378         if (!soft_iface) {
379                 soft_iface = batadv_softif_create(iface_name);
380
381                 if (!soft_iface) {
382                         ret = -ENOMEM;
383                         goto err;
384                 }
385
386                 /* dev_get_by_name() increases the reference counter for us */
387                 dev_hold(soft_iface);
388         }
389
390         if (!batadv_softif_is_valid(soft_iface)) {
391                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
392                        soft_iface->name);
393                 ret = -EINVAL;
394                 goto err_dev;
395         }
396
397         /* check if the interface is enslaved in another virtual one and
398          * in that case unlink it first
399          */
400         master = netdev_master_upper_dev_get(hard_iface->net_dev);
401         ret = batadv_master_del_slave(hard_iface, master);
402         if (ret)
403                 goto err_dev;
404
405         hard_iface->soft_iface = soft_iface;
406         bat_priv = netdev_priv(hard_iface->soft_iface);
407
408         ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface);
409         if (ret)
410                 goto err_dev;
411
412         ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
413         if (ret < 0)
414                 goto err_upper;
415
416         hard_iface->if_num = bat_priv->num_ifaces;
417         bat_priv->num_ifaces++;
418         hard_iface->if_status = BATADV_IF_INACTIVE;
419         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
420         if (ret < 0) {
421                 bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
422                 bat_priv->num_ifaces--;
423                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
424                 goto err_upper;
425         }
426
427         hard_iface->batman_adv_ptype.type = ethertype;
428         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
429         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
430         dev_add_pack(&hard_iface->batman_adv_ptype);
431
432         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
433                     hard_iface->net_dev->name);
434
435         if (atomic_read(&bat_priv->fragmentation) &&
436             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
437                 batadv_info(hard_iface->soft_iface,
438                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %i would solve the problem.\n",
439                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
440                             ETH_DATA_LEN + max_header_len);
441
442         if (!atomic_read(&bat_priv->fragmentation) &&
443             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
444                 batadv_info(hard_iface->soft_iface,
445                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %i.\n",
446                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
447                             ETH_DATA_LEN + max_header_len);
448
449         if (batadv_hardif_is_iface_up(hard_iface))
450                 batadv_hardif_activate_interface(hard_iface);
451         else
452                 batadv_err(hard_iface->soft_iface,
453                            "Not using interface %s (retrying later): interface not active\n",
454                            hard_iface->net_dev->name);
455
456         /* begin scheduling originator messages on that interface */
457         batadv_schedule_bat_ogm(hard_iface);
458
459 out:
460         return 0;
461
462 err_upper:
463         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
464 err_dev:
465         hard_iface->soft_iface = NULL;
466         dev_put(soft_iface);
467 err:
468         batadv_hardif_free_ref(hard_iface);
469         return ret;
470 }
471
472 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
473                                      enum batadv_hard_if_cleanup autodel)
474 {
475         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
476         struct batadv_hard_iface *primary_if = NULL;
477
478         if (hard_iface->if_status == BATADV_IF_ACTIVE)
479                 batadv_hardif_deactivate_interface(hard_iface);
480
481         if (hard_iface->if_status != BATADV_IF_INACTIVE)
482                 goto out;
483
484         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
485                     hard_iface->net_dev->name);
486         dev_remove_pack(&hard_iface->batman_adv_ptype);
487
488         bat_priv->num_ifaces--;
489         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
490
491         primary_if = batadv_primary_if_get_selected(bat_priv);
492         if (hard_iface == primary_if) {
493                 struct batadv_hard_iface *new_if;
494
495                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
496                 batadv_primary_if_select(bat_priv, new_if);
497
498                 if (new_if)
499                         batadv_hardif_free_ref(new_if);
500         }
501
502         bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
503         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
504
505         /* delete all references to this hard_iface */
506         batadv_purge_orig_ref(bat_priv);
507         batadv_purge_outstanding_packets(bat_priv, hard_iface);
508         dev_put(hard_iface->soft_iface);
509
510         /* nobody uses this interface anymore */
511         if (!bat_priv->num_ifaces) {
512                 batadv_gw_check_client_stop(bat_priv);
513
514                 if (autodel == BATADV_IF_CLEANUP_AUTO)
515                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
516         }
517
518         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
519         hard_iface->soft_iface = NULL;
520         batadv_hardif_free_ref(hard_iface);
521
522 out:
523         if (primary_if)
524                 batadv_hardif_free_ref(primary_if);
525 }
526
527 /**
528  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
529  * @work: work queue item
530  *
531  * Free the parts of the hard interface which can not be removed under
532  * rtnl lock (to prevent deadlock situations).
533  */
534 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
535 {
536         struct batadv_hard_iface *hard_iface;
537
538         hard_iface = container_of(work, struct batadv_hard_iface,
539                                   cleanup_work);
540
541         batadv_debugfs_del_hardif(hard_iface);
542         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
543         batadv_hardif_free_ref(hard_iface);
544 }
545
546 static struct batadv_hard_iface *
547 batadv_hardif_add_interface(struct net_device *net_dev)
548 {
549         struct batadv_hard_iface *hard_iface;
550         int ret;
551
552         ASSERT_RTNL();
553
554         ret = batadv_is_valid_iface(net_dev);
555         if (ret != 1)
556                 goto out;
557
558         dev_hold(net_dev);
559
560         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
561         if (!hard_iface)
562                 goto release_dev;
563
564         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
565         if (ret)
566                 goto free_if;
567
568         hard_iface->if_num = -1;
569         hard_iface->net_dev = net_dev;
570         hard_iface->soft_iface = NULL;
571         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
572
573         ret = batadv_debugfs_add_hardif(hard_iface);
574         if (ret)
575                 goto free_sysfs;
576
577         INIT_LIST_HEAD(&hard_iface->list);
578         INIT_WORK(&hard_iface->cleanup_work,
579                   batadv_hardif_remove_interface_finish);
580
581         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
582         if (batadv_is_wifi_netdev(net_dev))
583                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
584
585         /* extra reference for return */
586         atomic_set(&hard_iface->refcount, 2);
587
588         batadv_check_known_mac_addr(hard_iface->net_dev);
589         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
590
591         return hard_iface;
592
593 free_sysfs:
594         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
595 free_if:
596         kfree(hard_iface);
597 release_dev:
598         dev_put(net_dev);
599 out:
600         return NULL;
601 }
602
603 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
604 {
605         ASSERT_RTNL();
606
607         /* first deactivate interface */
608         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
609                 batadv_hardif_disable_interface(hard_iface,
610                                                 BATADV_IF_CLEANUP_AUTO);
611
612         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
613                 return;
614
615         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
616         queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
617 }
618
619 void batadv_hardif_remove_interfaces(void)
620 {
621         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
622
623         rtnl_lock();
624         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
625                                  &batadv_hardif_list, list) {
626                 list_del_rcu(&hard_iface->list);
627                 batadv_hardif_remove_interface(hard_iface);
628         }
629         rtnl_unlock();
630 }
631
632 static int batadv_hard_if_event(struct notifier_block *this,
633                                 unsigned long event, void *ptr)
634 {
635         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
636         struct batadv_hard_iface *hard_iface;
637         struct batadv_hard_iface *primary_if = NULL;
638         struct batadv_priv *bat_priv;
639
640         if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
641                 batadv_sysfs_add_meshif(net_dev);
642                 bat_priv = netdev_priv(net_dev);
643                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
644                 return NOTIFY_DONE;
645         }
646
647         hard_iface = batadv_hardif_get_by_netdev(net_dev);
648         if (!hard_iface && event == NETDEV_REGISTER)
649                 hard_iface = batadv_hardif_add_interface(net_dev);
650
651         if (!hard_iface)
652                 goto out;
653
654         switch (event) {
655         case NETDEV_UP:
656                 batadv_hardif_activate_interface(hard_iface);
657                 break;
658         case NETDEV_GOING_DOWN:
659         case NETDEV_DOWN:
660                 batadv_hardif_deactivate_interface(hard_iface);
661                 break;
662         case NETDEV_UNREGISTER:
663                 list_del_rcu(&hard_iface->list);
664
665                 batadv_hardif_remove_interface(hard_iface);
666                 break;
667         case NETDEV_CHANGEMTU:
668                 if (hard_iface->soft_iface)
669                         batadv_update_min_mtu(hard_iface->soft_iface);
670                 break;
671         case NETDEV_CHANGEADDR:
672                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
673                         goto hardif_put;
674
675                 batadv_check_known_mac_addr(hard_iface->net_dev);
676
677                 bat_priv = netdev_priv(hard_iface->soft_iface);
678                 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
679
680                 primary_if = batadv_primary_if_get_selected(bat_priv);
681                 if (!primary_if)
682                         goto hardif_put;
683
684                 if (hard_iface == primary_if)
685                         batadv_primary_if_update_addr(bat_priv, NULL);
686                 break;
687         default:
688                 break;
689         }
690
691 hardif_put:
692         batadv_hardif_free_ref(hard_iface);
693 out:
694         if (primary_if)
695                 batadv_hardif_free_ref(primary_if);
696         return NOTIFY_DONE;
697 }
698
699 struct notifier_block batadv_hard_if_notifier = {
700         .notifier_call = batadv_hard_if_event,
701 };