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 };
702