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 
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 	if (parent_dev)
98 		dev_put(parent_dev);
99 	return ret;
100 }
101 
102 static int batadv_is_valid_iface(const struct net_device *net_dev)
103 {
104 	if (net_dev->flags & IFF_LOOPBACK)
105 		return 0;
106 
107 	if (net_dev->type != ARPHRD_ETHER)
108 		return 0;
109 
110 	if (net_dev->addr_len != ETH_ALEN)
111 		return 0;
112 
113 	/* no batman over batman */
114 	if (batadv_is_on_batman_iface(net_dev))
115 		return 0;
116 
117 	return 1;
118 }
119 
120 /**
121  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
122  *  interface
123  * @net_device: the device to check
124  *
125  * Returns true if the net device is a 802.11 wireless device, false otherwise.
126  */
127 static bool batadv_is_wifi_netdev(struct net_device *net_device)
128 {
129 #ifdef CONFIG_WIRELESS_EXT
130 	/* pre-cfg80211 drivers have to implement WEXT, so it is possible to
131 	 * check for wireless_handlers != NULL
132 	 */
133 	if (net_device->wireless_handlers)
134 		return true;
135 #endif
136 
137 	/* cfg80211 drivers have to set ieee80211_ptr */
138 	if (net_device->ieee80211_ptr)
139 		return true;
140 
141 	return false;
142 }
143 
144 /**
145  * batadv_is_wifi_iface - check if the given interface represented by ifindex
146  *  is a wifi interface
147  * @ifindex: interface index to check
148  *
149  * Returns true if the interface represented by ifindex is a 802.11 wireless
150  * device, false otherwise.
151  */
152 bool batadv_is_wifi_iface(int ifindex)
153 {
154 	struct net_device *net_device = NULL;
155 	bool ret = false;
156 
157 	if (ifindex == BATADV_NULL_IFINDEX)
158 		goto out;
159 
160 	net_device = dev_get_by_index(&init_net, ifindex);
161 	if (!net_device)
162 		goto out;
163 
164 	ret = batadv_is_wifi_netdev(net_device);
165 
166 out:
167 	if (net_device)
168 		dev_put(net_device);
169 	return ret;
170 }
171 
172 static struct batadv_hard_iface *
173 batadv_hardif_get_active(const struct net_device *soft_iface)
174 {
175 	struct batadv_hard_iface *hard_iface;
176 
177 	rcu_read_lock();
178 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
179 		if (hard_iface->soft_iface != soft_iface)
180 			continue;
181 
182 		if (hard_iface->if_status == BATADV_IF_ACTIVE &&
183 		    atomic_inc_not_zero(&hard_iface->refcount))
184 			goto out;
185 	}
186 
187 	hard_iface = NULL;
188 
189 out:
190 	rcu_read_unlock();
191 	return hard_iface;
192 }
193 
194 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
195 					  struct batadv_hard_iface *oldif)
196 {
197 	struct batadv_vis_packet *vis_packet;
198 	struct batadv_hard_iface *primary_if;
199 	struct sk_buff *skb;
200 
201 	primary_if = batadv_primary_if_get_selected(bat_priv);
202 	if (!primary_if)
203 		goto out;
204 
205 	batadv_dat_init_own_addr(bat_priv, primary_if);
206 
207 	skb = bat_priv->vis.my_info->skb_packet;
208 	vis_packet = (struct batadv_vis_packet *)skb->data;
209 	memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
210 	memcpy(vis_packet->sender_orig,
211 	       primary_if->net_dev->dev_addr, ETH_ALEN);
212 
213 	batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
214 out:
215 	if (primary_if)
216 		batadv_hardif_free_ref(primary_if);
217 }
218 
219 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
220 				     struct batadv_hard_iface *new_hard_iface)
221 {
222 	struct batadv_hard_iface *curr_hard_iface;
223 
224 	ASSERT_RTNL();
225 
226 	if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
227 		new_hard_iface = NULL;
228 
229 	curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
230 	rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
231 
232 	if (!new_hard_iface)
233 		goto out;
234 
235 	bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
236 	batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
237 
238 out:
239 	if (curr_hard_iface)
240 		batadv_hardif_free_ref(curr_hard_iface);
241 }
242 
243 static bool
244 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
245 {
246 	if (hard_iface->net_dev->flags & IFF_UP)
247 		return true;
248 
249 	return false;
250 }
251 
252 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
253 {
254 	const struct batadv_hard_iface *hard_iface;
255 
256 	rcu_read_lock();
257 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
258 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
259 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
260 			continue;
261 
262 		if (hard_iface->net_dev == net_dev)
263 			continue;
264 
265 		if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
266 					net_dev->dev_addr))
267 			continue;
268 
269 		pr_warn("The newly added mac address (%pM) already exists on: %s\n",
270 			net_dev->dev_addr, hard_iface->net_dev->name);
271 		pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
272 	}
273 	rcu_read_unlock();
274 }
275 
276 int batadv_hardif_min_mtu(struct net_device *soft_iface)
277 {
278 	const struct batadv_priv *bat_priv = netdev_priv(soft_iface);
279 	const struct batadv_hard_iface *hard_iface;
280 	/* allow big frames if all devices are capable to do so
281 	 * (have MTU > 1500 + BAT_HEADER_LEN)
282 	 */
283 	int min_mtu = ETH_DATA_LEN;
284 
285 	if (atomic_read(&bat_priv->fragmentation))
286 		goto out;
287 
288 	rcu_read_lock();
289 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
290 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
291 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
292 			continue;
293 
294 		if (hard_iface->soft_iface != soft_iface)
295 			continue;
296 
297 		min_mtu = min_t(int,
298 				hard_iface->net_dev->mtu - BATADV_HEADER_LEN,
299 				min_mtu);
300 	}
301 	rcu_read_unlock();
302 out:
303 	return min_mtu;
304 }
305 
306 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
307 void batadv_update_min_mtu(struct net_device *soft_iface)
308 {
309 	int min_mtu;
310 
311 	min_mtu = batadv_hardif_min_mtu(soft_iface);
312 	if (soft_iface->mtu != min_mtu)
313 		soft_iface->mtu = min_mtu;
314 }
315 
316 static void
317 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
318 {
319 	struct batadv_priv *bat_priv;
320 	struct batadv_hard_iface *primary_if = NULL;
321 
322 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
323 		goto out;
324 
325 	bat_priv = netdev_priv(hard_iface->soft_iface);
326 
327 	bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
328 	hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
329 
330 	/* the first active interface becomes our primary interface or
331 	 * the next active interface after the old primary interface was removed
332 	 */
333 	primary_if = batadv_primary_if_get_selected(bat_priv);
334 	if (!primary_if)
335 		batadv_primary_if_select(bat_priv, hard_iface);
336 
337 	batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
338 		    hard_iface->net_dev->name);
339 
340 	batadv_update_min_mtu(hard_iface->soft_iface);
341 
342 out:
343 	if (primary_if)
344 		batadv_hardif_free_ref(primary_if);
345 }
346 
347 static void
348 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
349 {
350 	if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
351 	    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
352 		return;
353 
354 	hard_iface->if_status = BATADV_IF_INACTIVE;
355 
356 	batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
357 		    hard_iface->net_dev->name);
358 
359 	batadv_update_min_mtu(hard_iface->soft_iface);
360 }
361 
362 /**
363  * batadv_master_del_slave - remove hard_iface from the current master interface
364  * @slave: the interface enslaved in another master
365  * @master: the master from which slave has to be removed
366  *
367  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
368  * is free'd and master can correctly change its internal state.
369  * Return 0 on success, a negative value representing the error otherwise
370  */
371 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
372 				   struct net_device *master)
373 {
374 	int ret;
375 
376 	if (!master)
377 		return 0;
378 
379 	ret = -EBUSY;
380 	if (master->netdev_ops->ndo_del_slave)
381 		ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
382 
383 	return ret;
384 }
385 
386 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
387 				   const char *iface_name)
388 {
389 	struct batadv_priv *bat_priv;
390 	struct net_device *soft_iface, *master;
391 	__be16 ethertype = __constant_htons(ETH_P_BATMAN);
392 	int ret;
393 
394 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
395 		goto out;
396 
397 	if (!atomic_inc_not_zero(&hard_iface->refcount))
398 		goto out;
399 
400 	soft_iface = dev_get_by_name(&init_net, iface_name);
401 
402 	if (!soft_iface) {
403 		soft_iface = batadv_softif_create(iface_name);
404 
405 		if (!soft_iface) {
406 			ret = -ENOMEM;
407 			goto err;
408 		}
409 
410 		/* dev_get_by_name() increases the reference counter for us */
411 		dev_hold(soft_iface);
412 	}
413 
414 	if (!batadv_softif_is_valid(soft_iface)) {
415 		pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
416 		       soft_iface->name);
417 		ret = -EINVAL;
418 		goto err_dev;
419 	}
420 
421 	/* check if the interface is enslaved in another virtual one and
422 	 * in that case unlink it first
423 	 */
424 	master = netdev_master_upper_dev_get(hard_iface->net_dev);
425 	ret = batadv_master_del_slave(hard_iface, master);
426 	if (ret)
427 		goto err_dev;
428 
429 	hard_iface->soft_iface = soft_iface;
430 	bat_priv = netdev_priv(hard_iface->soft_iface);
431 
432 	ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface);
433 	if (ret)
434 		goto err_dev;
435 
436 	ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
437 	if (ret < 0)
438 		goto err_upper;
439 
440 	hard_iface->if_num = bat_priv->num_ifaces;
441 	bat_priv->num_ifaces++;
442 	hard_iface->if_status = BATADV_IF_INACTIVE;
443 	ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
444 	if (ret < 0) {
445 		bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
446 		bat_priv->num_ifaces--;
447 		hard_iface->if_status = BATADV_IF_NOT_IN_USE;
448 		goto err_upper;
449 	}
450 
451 	hard_iface->batman_adv_ptype.type = ethertype;
452 	hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
453 	hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
454 	dev_add_pack(&hard_iface->batman_adv_ptype);
455 
456 	atomic_set(&hard_iface->frag_seqno, 1);
457 	batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
458 		    hard_iface->net_dev->name);
459 
460 	if (atomic_read(&bat_priv->fragmentation) &&
461 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN)
462 		batadv_info(hard_iface->soft_iface,
463 			    "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 %zi would solve the problem.\n",
464 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
465 			    ETH_DATA_LEN + BATADV_HEADER_LEN);
466 
467 	if (!atomic_read(&bat_priv->fragmentation) &&
468 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN)
469 		batadv_info(hard_iface->soft_iface,
470 			    "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 %zi.\n",
471 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
472 			    ETH_DATA_LEN + BATADV_HEADER_LEN);
473 
474 	if (batadv_hardif_is_iface_up(hard_iface))
475 		batadv_hardif_activate_interface(hard_iface);
476 	else
477 		batadv_err(hard_iface->soft_iface,
478 			   "Not using interface %s (retrying later): interface not active\n",
479 			   hard_iface->net_dev->name);
480 
481 	/* begin scheduling originator messages on that interface */
482 	batadv_schedule_bat_ogm(hard_iface);
483 
484 out:
485 	return 0;
486 
487 err_upper:
488 	netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
489 err_dev:
490 	hard_iface->soft_iface = NULL;
491 	dev_put(soft_iface);
492 err:
493 	batadv_hardif_free_ref(hard_iface);
494 	return ret;
495 }
496 
497 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
498 				     enum batadv_hard_if_cleanup autodel)
499 {
500 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
501 	struct batadv_hard_iface *primary_if = NULL;
502 
503 	if (hard_iface->if_status == BATADV_IF_ACTIVE)
504 		batadv_hardif_deactivate_interface(hard_iface);
505 
506 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
507 		goto out;
508 
509 	batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
510 		    hard_iface->net_dev->name);
511 	dev_remove_pack(&hard_iface->batman_adv_ptype);
512 
513 	bat_priv->num_ifaces--;
514 	batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
515 
516 	primary_if = batadv_primary_if_get_selected(bat_priv);
517 	if (hard_iface == primary_if) {
518 		struct batadv_hard_iface *new_if;
519 
520 		new_if = batadv_hardif_get_active(hard_iface->soft_iface);
521 		batadv_primary_if_select(bat_priv, new_if);
522 
523 		if (new_if)
524 			batadv_hardif_free_ref(new_if);
525 	}
526 
527 	bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
528 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
529 
530 	/* delete all references to this hard_iface */
531 	batadv_purge_orig_ref(bat_priv);
532 	batadv_purge_outstanding_packets(bat_priv, hard_iface);
533 	dev_put(hard_iface->soft_iface);
534 
535 	/* nobody uses this interface anymore */
536 	if (!bat_priv->num_ifaces && autodel == BATADV_IF_CLEANUP_AUTO)
537 		batadv_softif_destroy_sysfs(hard_iface->soft_iface);
538 
539 	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
540 	hard_iface->soft_iface = NULL;
541 	batadv_hardif_free_ref(hard_iface);
542 
543 out:
544 	if (primary_if)
545 		batadv_hardif_free_ref(primary_if);
546 }
547 
548 /**
549  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
550  * @work: work queue item
551  *
552  * Free the parts of the hard interface which can not be removed under
553  * rtnl lock (to prevent deadlock situations).
554  */
555 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
556 {
557 	struct batadv_hard_iface *hard_iface;
558 
559 	hard_iface = container_of(work, struct batadv_hard_iface,
560 				  cleanup_work);
561 
562 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
563 	batadv_hardif_free_ref(hard_iface);
564 }
565 
566 static struct batadv_hard_iface *
567 batadv_hardif_add_interface(struct net_device *net_dev)
568 {
569 	struct batadv_hard_iface *hard_iface;
570 	int ret;
571 
572 	ASSERT_RTNL();
573 
574 	ret = batadv_is_valid_iface(net_dev);
575 	if (ret != 1)
576 		goto out;
577 
578 	dev_hold(net_dev);
579 
580 	hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
581 	if (!hard_iface)
582 		goto release_dev;
583 
584 	ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
585 	if (ret)
586 		goto free_if;
587 
588 	hard_iface->if_num = -1;
589 	hard_iface->net_dev = net_dev;
590 	hard_iface->soft_iface = NULL;
591 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
592 	INIT_LIST_HEAD(&hard_iface->list);
593 	INIT_WORK(&hard_iface->cleanup_work,
594 		  batadv_hardif_remove_interface_finish);
595 
596 	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
597 	if (batadv_is_wifi_netdev(net_dev))
598 		hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
599 
600 	/* extra reference for return */
601 	atomic_set(&hard_iface->refcount, 2);
602 
603 	batadv_check_known_mac_addr(hard_iface->net_dev);
604 	list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
605 
606 	return hard_iface;
607 
608 free_if:
609 	kfree(hard_iface);
610 release_dev:
611 	dev_put(net_dev);
612 out:
613 	return NULL;
614 }
615 
616 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
617 {
618 	ASSERT_RTNL();
619 
620 	/* first deactivate interface */
621 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
622 		batadv_hardif_disable_interface(hard_iface,
623 						BATADV_IF_CLEANUP_AUTO);
624 
625 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
626 		return;
627 
628 	hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
629 	queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
630 }
631 
632 void batadv_hardif_remove_interfaces(void)
633 {
634 	struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
635 
636 	rtnl_lock();
637 	list_for_each_entry_safe(hard_iface, hard_iface_tmp,
638 				 &batadv_hardif_list, list) {
639 		list_del_rcu(&hard_iface->list);
640 		batadv_hardif_remove_interface(hard_iface);
641 	}
642 	rtnl_unlock();
643 }
644 
645 static int batadv_hard_if_event(struct notifier_block *this,
646 				unsigned long event, void *ptr)
647 {
648 	struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
649 	struct batadv_hard_iface *hard_iface;
650 	struct batadv_hard_iface *primary_if = NULL;
651 	struct batadv_priv *bat_priv;
652 
653 	if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
654 		batadv_sysfs_add_meshif(net_dev);
655 		return NOTIFY_DONE;
656 	}
657 
658 	hard_iface = batadv_hardif_get_by_netdev(net_dev);
659 	if (!hard_iface && event == NETDEV_REGISTER)
660 		hard_iface = batadv_hardif_add_interface(net_dev);
661 
662 	if (!hard_iface)
663 		goto out;
664 
665 	switch (event) {
666 	case NETDEV_UP:
667 		batadv_hardif_activate_interface(hard_iface);
668 		break;
669 	case NETDEV_GOING_DOWN:
670 	case NETDEV_DOWN:
671 		batadv_hardif_deactivate_interface(hard_iface);
672 		break;
673 	case NETDEV_UNREGISTER:
674 		list_del_rcu(&hard_iface->list);
675 
676 		batadv_hardif_remove_interface(hard_iface);
677 		break;
678 	case NETDEV_CHANGEMTU:
679 		if (hard_iface->soft_iface)
680 			batadv_update_min_mtu(hard_iface->soft_iface);
681 		break;
682 	case NETDEV_CHANGEADDR:
683 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
684 			goto hardif_put;
685 
686 		batadv_check_known_mac_addr(hard_iface->net_dev);
687 
688 		bat_priv = netdev_priv(hard_iface->soft_iface);
689 		bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
690 
691 		primary_if = batadv_primary_if_get_selected(bat_priv);
692 		if (!primary_if)
693 			goto hardif_put;
694 
695 		if (hard_iface == primary_if)
696 			batadv_primary_if_update_addr(bat_priv, NULL);
697 		break;
698 	default:
699 		break;
700 	}
701 
702 hardif_put:
703 	batadv_hardif_free_ref(hard_iface);
704 out:
705 	if (primary_if)
706 		batadv_hardif_free_ref(primary_if);
707 	return NOTIFY_DONE;
708 }
709 
710 struct notifier_block batadv_hard_if_notifier = {
711 	.notifier_call = batadv_hard_if_event,
712 };
713