1 /* Copyright (C) 2007-2013 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, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA
18  */
19 
20 #include "main.h"
21 #include "distributed-arp-table.h"
22 #include "hard-interface.h"
23 #include "soft-interface.h"
24 #include "send.h"
25 #include "translation-table.h"
26 #include "routing.h"
27 #include "sysfs.h"
28 #include "originator.h"
29 #include "hash.h"
30 #include "bridge_loop_avoidance.h"
31 #include "gateway_client.h"
32 
33 #include <linux/if_arp.h>
34 #include <linux/if_ether.h>
35 
36 void batadv_hardif_free_rcu(struct rcu_head *rcu)
37 {
38 	struct batadv_hard_iface *hard_iface;
39 
40 	hard_iface = container_of(rcu, struct batadv_hard_iface, rcu);
41 	dev_put(hard_iface->net_dev);
42 	kfree(hard_iface);
43 }
44 
45 struct batadv_hard_iface *
46 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
47 {
48 	struct batadv_hard_iface *hard_iface;
49 
50 	rcu_read_lock();
51 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
52 		if (hard_iface->net_dev == net_dev &&
53 		    atomic_inc_not_zero(&hard_iface->refcount))
54 			goto out;
55 	}
56 
57 	hard_iface = NULL;
58 
59 out:
60 	rcu_read_unlock();
61 	return hard_iface;
62 }
63 
64 /**
65  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
66  * @net_dev: the device to check
67  *
68  * If the user creates any virtual device on top of a batman-adv interface, it
69  * is important to prevent this new interface to be used to create a new mesh
70  * network (this behaviour would lead to a batman-over-batman configuration).
71  * This function recursively checks all the fathers of the device passed as
72  * argument looking for a batman-adv soft interface.
73  *
74  * Returns true if the device is descendant of a batman-adv mesh interface (or
75  * if it is a batman-adv interface itself), false otherwise
76  */
77 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
78 {
79 	struct net_device *parent_dev;
80 	bool ret;
81 
82 	/* check if this is a batman-adv mesh interface */
83 	if (batadv_softif_is_valid(net_dev))
84 		return true;
85 
86 	/* no more parents..stop recursion */
87 	if (net_dev->iflink == net_dev->ifindex)
88 		return false;
89 
90 	/* recurse over the parent device */
91 	parent_dev = dev_get_by_index(&init_net, net_dev->iflink);
92 	/* if we got a NULL parent_dev there is something broken.. */
93 	if (WARN(!parent_dev, "Cannot find parent device"))
94 		return false;
95 
96 	ret = batadv_is_on_batman_iface(parent_dev);
97 
98 	if (parent_dev)
99 		dev_put(parent_dev);
100 	return ret;
101 }
102 
103 static int batadv_is_valid_iface(const struct net_device *net_dev)
104 {
105 	if (net_dev->flags & IFF_LOOPBACK)
106 		return 0;
107 
108 	if (net_dev->type != ARPHRD_ETHER)
109 		return 0;
110 
111 	if (net_dev->addr_len != ETH_ALEN)
112 		return 0;
113 
114 	/* no batman over batman */
115 	if (batadv_is_on_batman_iface(net_dev))
116 		return 0;
117 
118 	return 1;
119 }
120 
121 /**
122  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
123  *  interface
124  * @net_device: the device to check
125  *
126  * Returns true if the net device is a 802.11 wireless device, false otherwise.
127  */
128 bool batadv_is_wifi_netdev(struct net_device *net_device)
129 {
130 	if (!net_device)
131 		return false;
132 
133 #ifdef CONFIG_WIRELESS_EXT
134 	/* pre-cfg80211 drivers have to implement WEXT, so it is possible to
135 	 * check for wireless_handlers != NULL
136 	 */
137 	if (net_device->wireless_handlers)
138 		return true;
139 #endif
140 
141 	/* cfg80211 drivers have to set ieee80211_ptr */
142 	if (net_device->ieee80211_ptr)
143 		return true;
144 
145 	return false;
146 }
147 
148 static struct batadv_hard_iface *
149 batadv_hardif_get_active(const struct net_device *soft_iface)
150 {
151 	struct batadv_hard_iface *hard_iface;
152 
153 	rcu_read_lock();
154 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
155 		if (hard_iface->soft_iface != soft_iface)
156 			continue;
157 
158 		if (hard_iface->if_status == BATADV_IF_ACTIVE &&
159 		    atomic_inc_not_zero(&hard_iface->refcount))
160 			goto out;
161 	}
162 
163 	hard_iface = NULL;
164 
165 out:
166 	rcu_read_unlock();
167 	return hard_iface;
168 }
169 
170 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
171 					  struct batadv_hard_iface *oldif)
172 {
173 	struct batadv_hard_iface *primary_if;
174 
175 	primary_if = batadv_primary_if_get_selected(bat_priv);
176 	if (!primary_if)
177 		goto out;
178 
179 	batadv_dat_init_own_addr(bat_priv, primary_if);
180 	batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
181 out:
182 	if (primary_if)
183 		batadv_hardif_free_ref(primary_if);
184 }
185 
186 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
187 				     struct batadv_hard_iface *new_hard_iface)
188 {
189 	struct batadv_hard_iface *curr_hard_iface;
190 
191 	ASSERT_RTNL();
192 
193 	if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
194 		new_hard_iface = NULL;
195 
196 	curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
197 	rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
198 
199 	if (!new_hard_iface)
200 		goto out;
201 
202 	bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
203 	batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
204 
205 out:
206 	if (curr_hard_iface)
207 		batadv_hardif_free_ref(curr_hard_iface);
208 }
209 
210 static bool
211 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
212 {
213 	if (hard_iface->net_dev->flags & IFF_UP)
214 		return true;
215 
216 	return false;
217 }
218 
219 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
220 {
221 	const struct batadv_hard_iface *hard_iface;
222 
223 	rcu_read_lock();
224 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
225 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
226 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
227 			continue;
228 
229 		if (hard_iface->net_dev == net_dev)
230 			continue;
231 
232 		if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
233 					net_dev->dev_addr))
234 			continue;
235 
236 		pr_warn("The newly added mac address (%pM) already exists on: %s\n",
237 			net_dev->dev_addr, hard_iface->net_dev->name);
238 		pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
239 	}
240 	rcu_read_unlock();
241 }
242 
243 int batadv_hardif_min_mtu(struct net_device *soft_iface)
244 {
245 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
246 	const struct batadv_hard_iface *hard_iface;
247 	int min_mtu = ETH_DATA_LEN;
248 
249 	rcu_read_lock();
250 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
251 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
252 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
253 			continue;
254 
255 		if (hard_iface->soft_iface != soft_iface)
256 			continue;
257 
258 		min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
259 	}
260 	rcu_read_unlock();
261 
262 	atomic_set(&bat_priv->packet_size_max, min_mtu);
263 
264 	if (atomic_read(&bat_priv->fragmentation) == 0)
265 		goto out;
266 
267 	/* with fragmentation enabled the maximum size of internally generated
268 	 * packets such as translation table exchanges or tvlv containers, etc
269 	 * has to be calculated
270 	 */
271 	min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
272 	min_mtu -= sizeof(struct batadv_frag_packet);
273 	min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
274 	atomic_set(&bat_priv->packet_size_max, min_mtu);
275 
276 	/* with fragmentation enabled we can fragment external packets easily */
277 	min_mtu = min_t(int, min_mtu, ETH_DATA_LEN);
278 
279 out:
280 	return min_mtu - batadv_max_header_len();
281 }
282 
283 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
284 void batadv_update_min_mtu(struct net_device *soft_iface)
285 {
286 	soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
287 
288 	/* Check if the local translate table should be cleaned up to match a
289 	 * new (and smaller) MTU.
290 	 */
291 	batadv_tt_local_resize_to_mtu(soft_iface);
292 }
293 
294 static void
295 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
296 {
297 	struct batadv_priv *bat_priv;
298 	struct batadv_hard_iface *primary_if = NULL;
299 
300 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
301 		goto out;
302 
303 	bat_priv = netdev_priv(hard_iface->soft_iface);
304 
305 	bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
306 	hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
307 
308 	/* the first active interface becomes our primary interface or
309 	 * the next active interface after the old primary interface was removed
310 	 */
311 	primary_if = batadv_primary_if_get_selected(bat_priv);
312 	if (!primary_if)
313 		batadv_primary_if_select(bat_priv, hard_iface);
314 
315 	batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
316 		    hard_iface->net_dev->name);
317 
318 	batadv_update_min_mtu(hard_iface->soft_iface);
319 
320 out:
321 	if (primary_if)
322 		batadv_hardif_free_ref(primary_if);
323 }
324 
325 static void
326 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
327 {
328 	if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
329 	    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
330 		return;
331 
332 	hard_iface->if_status = BATADV_IF_INACTIVE;
333 
334 	batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
335 		    hard_iface->net_dev->name);
336 
337 	batadv_update_min_mtu(hard_iface->soft_iface);
338 }
339 
340 /**
341  * batadv_master_del_slave - remove hard_iface from the current master interface
342  * @slave: the interface enslaved in another master
343  * @master: the master from which slave has to be removed
344  *
345  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
346  * is free'd and master can correctly change its internal state.
347  * Return 0 on success, a negative value representing the error otherwise
348  */
349 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
350 				   struct net_device *master)
351 {
352 	int ret;
353 
354 	if (!master)
355 		return 0;
356 
357 	ret = -EBUSY;
358 	if (master->netdev_ops->ndo_del_slave)
359 		ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
360 
361 	return ret;
362 }
363 
364 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
365 				   const char *iface_name)
366 {
367 	struct batadv_priv *bat_priv;
368 	struct net_device *soft_iface, *master;
369 	__be16 ethertype = htons(ETH_P_BATMAN);
370 	int max_header_len = batadv_max_header_len();
371 	int ret;
372 
373 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
374 		goto out;
375 
376 	if (!atomic_inc_not_zero(&hard_iface->refcount))
377 		goto out;
378 
379 	soft_iface = dev_get_by_name(&init_net, iface_name);
380 
381 	if (!soft_iface) {
382 		soft_iface = batadv_softif_create(iface_name);
383 
384 		if (!soft_iface) {
385 			ret = -ENOMEM;
386 			goto err;
387 		}
388 
389 		/* dev_get_by_name() increases the reference counter for us */
390 		dev_hold(soft_iface);
391 	}
392 
393 	if (!batadv_softif_is_valid(soft_iface)) {
394 		pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
395 		       soft_iface->name);
396 		ret = -EINVAL;
397 		goto err_dev;
398 	}
399 
400 	/* check if the interface is enslaved in another virtual one and
401 	 * in that case unlink it first
402 	 */
403 	master = netdev_master_upper_dev_get(hard_iface->net_dev);
404 	ret = batadv_master_del_slave(hard_iface, master);
405 	if (ret)
406 		goto err_dev;
407 
408 	hard_iface->soft_iface = soft_iface;
409 	bat_priv = netdev_priv(hard_iface->soft_iface);
410 
411 	ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface);
412 	if (ret)
413 		goto err_dev;
414 
415 	ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
416 	if (ret < 0)
417 		goto err_upper;
418 
419 	hard_iface->if_num = bat_priv->num_ifaces;
420 	bat_priv->num_ifaces++;
421 	hard_iface->if_status = BATADV_IF_INACTIVE;
422 	ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
423 	if (ret < 0) {
424 		bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
425 		bat_priv->num_ifaces--;
426 		hard_iface->if_status = BATADV_IF_NOT_IN_USE;
427 		goto err_upper;
428 	}
429 
430 	hard_iface->batman_adv_ptype.type = ethertype;
431 	hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
432 	hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
433 	dev_add_pack(&hard_iface->batman_adv_ptype);
434 
435 	batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
436 		    hard_iface->net_dev->name);
437 
438 	if (atomic_read(&bat_priv->fragmentation) &&
439 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
440 		batadv_info(hard_iface->soft_iface,
441 			    "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",
442 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
443 			    ETH_DATA_LEN + max_header_len);
444 
445 	if (!atomic_read(&bat_priv->fragmentation) &&
446 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
447 		batadv_info(hard_iface->soft_iface,
448 			    "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",
449 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
450 			    ETH_DATA_LEN + max_header_len);
451 
452 	if (batadv_hardif_is_iface_up(hard_iface))
453 		batadv_hardif_activate_interface(hard_iface);
454 	else
455 		batadv_err(hard_iface->soft_iface,
456 			   "Not using interface %s (retrying later): interface not active\n",
457 			   hard_iface->net_dev->name);
458 
459 	/* begin scheduling originator messages on that interface */
460 	batadv_schedule_bat_ogm(hard_iface);
461 
462 out:
463 	return 0;
464 
465 err_upper:
466 	netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
467 err_dev:
468 	hard_iface->soft_iface = NULL;
469 	dev_put(soft_iface);
470 err:
471 	batadv_hardif_free_ref(hard_iface);
472 	return ret;
473 }
474 
475 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
476 				     enum batadv_hard_if_cleanup autodel)
477 {
478 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
479 	struct batadv_hard_iface *primary_if = NULL;
480 
481 	if (hard_iface->if_status == BATADV_IF_ACTIVE)
482 		batadv_hardif_deactivate_interface(hard_iface);
483 
484 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
485 		goto out;
486 
487 	batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
488 		    hard_iface->net_dev->name);
489 	dev_remove_pack(&hard_iface->batman_adv_ptype);
490 
491 	bat_priv->num_ifaces--;
492 	batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
493 
494 	primary_if = batadv_primary_if_get_selected(bat_priv);
495 	if (hard_iface == primary_if) {
496 		struct batadv_hard_iface *new_if;
497 
498 		new_if = batadv_hardif_get_active(hard_iface->soft_iface);
499 		batadv_primary_if_select(bat_priv, new_if);
500 
501 		if (new_if)
502 			batadv_hardif_free_ref(new_if);
503 	}
504 
505 	bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
506 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
507 
508 	/* delete all references to this hard_iface */
509 	batadv_purge_orig_ref(bat_priv);
510 	batadv_purge_outstanding_packets(bat_priv, hard_iface);
511 	dev_put(hard_iface->soft_iface);
512 
513 	/* nobody uses this interface anymore */
514 	if (!bat_priv->num_ifaces) {
515 		batadv_gw_check_client_stop(bat_priv);
516 
517 		if (autodel == BATADV_IF_CLEANUP_AUTO)
518 			batadv_softif_destroy_sysfs(hard_iface->soft_iface);
519 	}
520 
521 	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
522 	hard_iface->soft_iface = NULL;
523 	batadv_hardif_free_ref(hard_iface);
524 
525 out:
526 	if (primary_if)
527 		batadv_hardif_free_ref(primary_if);
528 }
529 
530 /**
531  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
532  * @work: work queue item
533  *
534  * Free the parts of the hard interface which can not be removed under
535  * rtnl lock (to prevent deadlock situations).
536  */
537 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
538 {
539 	struct batadv_hard_iface *hard_iface;
540 
541 	hard_iface = container_of(work, struct batadv_hard_iface,
542 				  cleanup_work);
543 
544 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
545 	batadv_hardif_free_ref(hard_iface);
546 }
547 
548 static struct batadv_hard_iface *
549 batadv_hardif_add_interface(struct net_device *net_dev)
550 {
551 	struct batadv_hard_iface *hard_iface;
552 	int ret;
553 
554 	ASSERT_RTNL();
555 
556 	ret = batadv_is_valid_iface(net_dev);
557 	if (ret != 1)
558 		goto out;
559 
560 	dev_hold(net_dev);
561 
562 	hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
563 	if (!hard_iface)
564 		goto release_dev;
565 
566 	ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
567 	if (ret)
568 		goto free_if;
569 
570 	hard_iface->if_num = -1;
571 	hard_iface->net_dev = net_dev;
572 	hard_iface->soft_iface = NULL;
573 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
574 	INIT_LIST_HEAD(&hard_iface->list);
575 	INIT_WORK(&hard_iface->cleanup_work,
576 		  batadv_hardif_remove_interface_finish);
577 
578 	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
579 	if (batadv_is_wifi_netdev(net_dev))
580 		hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
581 
582 	/* extra reference for return */
583 	atomic_set(&hard_iface->refcount, 2);
584 
585 	batadv_check_known_mac_addr(hard_iface->net_dev);
586 	list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
587 
588 	return hard_iface;
589 
590 free_if:
591 	kfree(hard_iface);
592 release_dev:
593 	dev_put(net_dev);
594 out:
595 	return NULL;
596 }
597 
598 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
599 {
600 	ASSERT_RTNL();
601 
602 	/* first deactivate interface */
603 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
604 		batadv_hardif_disable_interface(hard_iface,
605 						BATADV_IF_CLEANUP_AUTO);
606 
607 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
608 		return;
609 
610 	hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
611 	queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
612 }
613 
614 void batadv_hardif_remove_interfaces(void)
615 {
616 	struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
617 
618 	rtnl_lock();
619 	list_for_each_entry_safe(hard_iface, hard_iface_tmp,
620 				 &batadv_hardif_list, list) {
621 		list_del_rcu(&hard_iface->list);
622 		batadv_hardif_remove_interface(hard_iface);
623 	}
624 	rtnl_unlock();
625 }
626 
627 static int batadv_hard_if_event(struct notifier_block *this,
628 				unsigned long event, void *ptr)
629 {
630 	struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
631 	struct batadv_hard_iface *hard_iface;
632 	struct batadv_hard_iface *primary_if = NULL;
633 	struct batadv_priv *bat_priv;
634 
635 	if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
636 		batadv_sysfs_add_meshif(net_dev);
637 		bat_priv = netdev_priv(net_dev);
638 		batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
639 		return NOTIFY_DONE;
640 	}
641 
642 	hard_iface = batadv_hardif_get_by_netdev(net_dev);
643 	if (!hard_iface && event == NETDEV_REGISTER)
644 		hard_iface = batadv_hardif_add_interface(net_dev);
645 
646 	if (!hard_iface)
647 		goto out;
648 
649 	switch (event) {
650 	case NETDEV_UP:
651 		batadv_hardif_activate_interface(hard_iface);
652 		break;
653 	case NETDEV_GOING_DOWN:
654 	case NETDEV_DOWN:
655 		batadv_hardif_deactivate_interface(hard_iface);
656 		break;
657 	case NETDEV_UNREGISTER:
658 		list_del_rcu(&hard_iface->list);
659 
660 		batadv_hardif_remove_interface(hard_iface);
661 		break;
662 	case NETDEV_CHANGEMTU:
663 		if (hard_iface->soft_iface)
664 			batadv_update_min_mtu(hard_iface->soft_iface);
665 		break;
666 	case NETDEV_CHANGEADDR:
667 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
668 			goto hardif_put;
669 
670 		batadv_check_known_mac_addr(hard_iface->net_dev);
671 
672 		bat_priv = netdev_priv(hard_iface->soft_iface);
673 		bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
674 
675 		primary_if = batadv_primary_if_get_selected(bat_priv);
676 		if (!primary_if)
677 			goto hardif_put;
678 
679 		if (hard_iface == primary_if)
680 			batadv_primary_if_update_addr(bat_priv, NULL);
681 		break;
682 	default:
683 		break;
684 	}
685 
686 hardif_put:
687 	batadv_hardif_free_ref(hard_iface);
688 out:
689 	if (primary_if)
690 		batadv_hardif_free_ref(primary_if);
691 	return NOTIFY_DONE;
692 }
693 
694 struct notifier_block batadv_hard_if_notifier = {
695 	.notifier_call = batadv_hard_if_event,
696 };
697