1 /* Copyright (C) 2007-2015 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 "hard-interface.h"
19 #include "main.h"
20 
21 #include <linux/bug.h>
22 #include <linux/byteorder/generic.h>
23 #include <linux/errno.h>
24 #include <linux/fs.h>
25 #include <linux/if_arp.h>
26 #include <linux/if_ether.h>
27 #include <linux/if.h>
28 #include <linux/kernel.h>
29 #include <linux/list.h>
30 #include <linux/netdevice.h>
31 #include <linux/printk.h>
32 #include <linux/rculist.h>
33 #include <linux/rtnetlink.h>
34 #include <linux/slab.h>
35 #include <linux/spinlock.h>
36 #include <linux/workqueue.h>
37 #include <net/net_namespace.h>
38 
39 #include "bridge_loop_avoidance.h"
40 #include "debugfs.h"
41 #include "distributed-arp-table.h"
42 #include "gateway_client.h"
43 #include "originator.h"
44 #include "packet.h"
45 #include "send.h"
46 #include "soft-interface.h"
47 #include "sysfs.h"
48 #include "translation-table.h"
49 
50 void batadv_hardif_free_rcu(struct rcu_head *rcu)
51 {
52 	struct batadv_hard_iface *hard_iface;
53 
54 	hard_iface = container_of(rcu, struct batadv_hard_iface, rcu);
55 	dev_put(hard_iface->net_dev);
56 	kfree(hard_iface);
57 }
58 
59 struct batadv_hard_iface *
60 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
61 {
62 	struct batadv_hard_iface *hard_iface;
63 
64 	rcu_read_lock();
65 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
66 		if (hard_iface->net_dev == net_dev &&
67 		    atomic_inc_not_zero(&hard_iface->refcount))
68 			goto out;
69 	}
70 
71 	hard_iface = NULL;
72 
73 out:
74 	rcu_read_unlock();
75 	return hard_iface;
76 }
77 
78 /**
79  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
80  * @net_dev: the device to check
81  *
82  * If the user creates any virtual device on top of a batman-adv interface, it
83  * is important to prevent this new interface to be used to create a new mesh
84  * network (this behaviour would lead to a batman-over-batman configuration).
85  * This function recursively checks all the fathers of the device passed as
86  * argument looking for a batman-adv soft interface.
87  *
88  * Returns true if the device is descendant of a batman-adv mesh interface (or
89  * if it is a batman-adv interface itself), false otherwise
90  */
91 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
92 {
93 	struct net_device *parent_dev;
94 	bool ret;
95 
96 	/* check if this is a batman-adv mesh interface */
97 	if (batadv_softif_is_valid(net_dev))
98 		return true;
99 
100 	/* no more parents..stop recursion */
101 	if (dev_get_iflink(net_dev) == 0 ||
102 	    dev_get_iflink(net_dev) == net_dev->ifindex)
103 		return false;
104 
105 	/* recurse over the parent device */
106 	parent_dev = __dev_get_by_index(&init_net, dev_get_iflink(net_dev));
107 	/* if we got a NULL parent_dev there is something broken.. */
108 	if (WARN(!parent_dev, "Cannot find parent device"))
109 		return false;
110 
111 	ret = batadv_is_on_batman_iface(parent_dev);
112 
113 	return ret;
114 }
115 
116 static int batadv_is_valid_iface(const struct net_device *net_dev)
117 {
118 	if (net_dev->flags & IFF_LOOPBACK)
119 		return 0;
120 
121 	if (net_dev->type != ARPHRD_ETHER)
122 		return 0;
123 
124 	if (net_dev->addr_len != ETH_ALEN)
125 		return 0;
126 
127 	/* no batman over batman */
128 	if (batadv_is_on_batman_iface(net_dev))
129 		return 0;
130 
131 	return 1;
132 }
133 
134 /**
135  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
136  *  interface
137  * @net_device: the device to check
138  *
139  * Returns true if the net device is a 802.11 wireless device, false otherwise.
140  */
141 bool batadv_is_wifi_netdev(struct net_device *net_device)
142 {
143 	if (!net_device)
144 		return false;
145 
146 #ifdef CONFIG_WIRELESS_EXT
147 	/* pre-cfg80211 drivers have to implement WEXT, so it is possible to
148 	 * check for wireless_handlers != NULL
149 	 */
150 	if (net_device->wireless_handlers)
151 		return true;
152 #endif
153 
154 	/* cfg80211 drivers have to set ieee80211_ptr */
155 	if (net_device->ieee80211_ptr)
156 		return true;
157 
158 	return false;
159 }
160 
161 static struct batadv_hard_iface *
162 batadv_hardif_get_active(const struct net_device *soft_iface)
163 {
164 	struct batadv_hard_iface *hard_iface;
165 
166 	rcu_read_lock();
167 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
168 		if (hard_iface->soft_iface != soft_iface)
169 			continue;
170 
171 		if (hard_iface->if_status == BATADV_IF_ACTIVE &&
172 		    atomic_inc_not_zero(&hard_iface->refcount))
173 			goto out;
174 	}
175 
176 	hard_iface = NULL;
177 
178 out:
179 	rcu_read_unlock();
180 	return hard_iface;
181 }
182 
183 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
184 					  struct batadv_hard_iface *oldif)
185 {
186 	struct batadv_hard_iface *primary_if;
187 
188 	primary_if = batadv_primary_if_get_selected(bat_priv);
189 	if (!primary_if)
190 		goto out;
191 
192 	batadv_dat_init_own_addr(bat_priv, primary_if);
193 	batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
194 out:
195 	if (primary_if)
196 		batadv_hardif_free_ref(primary_if);
197 }
198 
199 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
200 				     struct batadv_hard_iface *new_hard_iface)
201 {
202 	struct batadv_hard_iface *curr_hard_iface;
203 
204 	ASSERT_RTNL();
205 
206 	if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
207 		new_hard_iface = NULL;
208 
209 	curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
210 	rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
211 
212 	if (!new_hard_iface)
213 		goto out;
214 
215 	bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
216 	batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
217 
218 out:
219 	if (curr_hard_iface)
220 		batadv_hardif_free_ref(curr_hard_iface);
221 }
222 
223 static bool
224 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
225 {
226 	if (hard_iface->net_dev->flags & IFF_UP)
227 		return true;
228 
229 	return false;
230 }
231 
232 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
233 {
234 	const struct batadv_hard_iface *hard_iface;
235 
236 	rcu_read_lock();
237 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
238 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
239 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
240 			continue;
241 
242 		if (hard_iface->net_dev == net_dev)
243 			continue;
244 
245 		if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
246 					net_dev->dev_addr))
247 			continue;
248 
249 		pr_warn("The newly added mac address (%pM) already exists on: %s\n",
250 			net_dev->dev_addr, hard_iface->net_dev->name);
251 		pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
252 	}
253 	rcu_read_unlock();
254 }
255 
256 /**
257  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
258  * @soft_iface: netdev struct of the mesh interface
259  */
260 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
261 {
262 	const struct batadv_hard_iface *hard_iface;
263 	unsigned short lower_header_len = ETH_HLEN;
264 	unsigned short lower_headroom = 0;
265 	unsigned short lower_tailroom = 0;
266 	unsigned short needed_headroom;
267 
268 	rcu_read_lock();
269 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
270 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
271 			continue;
272 
273 		if (hard_iface->soft_iface != soft_iface)
274 			continue;
275 
276 		lower_header_len = max_t(unsigned short, lower_header_len,
277 					 hard_iface->net_dev->hard_header_len);
278 
279 		lower_headroom = max_t(unsigned short, lower_headroom,
280 				       hard_iface->net_dev->needed_headroom);
281 
282 		lower_tailroom = max_t(unsigned short, lower_tailroom,
283 				       hard_iface->net_dev->needed_tailroom);
284 	}
285 	rcu_read_unlock();
286 
287 	needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
288 	needed_headroom += batadv_max_header_len();
289 
290 	soft_iface->needed_headroom = needed_headroom;
291 	soft_iface->needed_tailroom = lower_tailroom;
292 }
293 
294 int batadv_hardif_min_mtu(struct net_device *soft_iface)
295 {
296 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
297 	const struct batadv_hard_iface *hard_iface;
298 	int min_mtu = INT_MAX;
299 
300 	rcu_read_lock();
301 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
302 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
303 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
304 			continue;
305 
306 		if (hard_iface->soft_iface != soft_iface)
307 			continue;
308 
309 		min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
310 	}
311 	rcu_read_unlock();
312 
313 	if (atomic_read(&bat_priv->fragmentation) == 0)
314 		goto out;
315 
316 	/* with fragmentation enabled the maximum size of internally generated
317 	 * packets such as translation table exchanges or tvlv containers, etc
318 	 * has to be calculated
319 	 */
320 	min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
321 	min_mtu -= sizeof(struct batadv_frag_packet);
322 	min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
323 
324 out:
325 	/* report to the other components the maximum amount of bytes that
326 	 * batman-adv can send over the wire (without considering the payload
327 	 * overhead). For example, this value is used by TT to compute the
328 	 * maximum local table table size
329 	 */
330 	atomic_set(&bat_priv->packet_size_max, min_mtu);
331 
332 	/* the real soft-interface MTU is computed by removing the payload
333 	 * overhead from the maximum amount of bytes that was just computed.
334 	 *
335 	 * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
336 	 */
337 	return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
338 }
339 
340 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
341 void batadv_update_min_mtu(struct net_device *soft_iface)
342 {
343 	soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
344 
345 	/* Check if the local translate table should be cleaned up to match a
346 	 * new (and smaller) MTU.
347 	 */
348 	batadv_tt_local_resize_to_mtu(soft_iface);
349 }
350 
351 static void
352 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
353 {
354 	struct batadv_priv *bat_priv;
355 	struct batadv_hard_iface *primary_if = NULL;
356 
357 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
358 		goto out;
359 
360 	bat_priv = netdev_priv(hard_iface->soft_iface);
361 
362 	bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
363 	hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
364 
365 	/* the first active interface becomes our primary interface or
366 	 * the next active interface after the old primary interface was removed
367 	 */
368 	primary_if = batadv_primary_if_get_selected(bat_priv);
369 	if (!primary_if)
370 		batadv_primary_if_select(bat_priv, hard_iface);
371 
372 	batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
373 		    hard_iface->net_dev->name);
374 
375 	batadv_update_min_mtu(hard_iface->soft_iface);
376 
377 out:
378 	if (primary_if)
379 		batadv_hardif_free_ref(primary_if);
380 }
381 
382 static void
383 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
384 {
385 	if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
386 	    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
387 		return;
388 
389 	hard_iface->if_status = BATADV_IF_INACTIVE;
390 
391 	batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
392 		    hard_iface->net_dev->name);
393 
394 	batadv_update_min_mtu(hard_iface->soft_iface);
395 }
396 
397 /**
398  * batadv_master_del_slave - remove hard_iface from the current master interface
399  * @slave: the interface enslaved in another master
400  * @master: the master from which slave has to be removed
401  *
402  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
403  * is free'd and master can correctly change its internal state.
404  * Return 0 on success, a negative value representing the error otherwise
405  */
406 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
407 				   struct net_device *master)
408 {
409 	int ret;
410 
411 	if (!master)
412 		return 0;
413 
414 	ret = -EBUSY;
415 	if (master->netdev_ops->ndo_del_slave)
416 		ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
417 
418 	return ret;
419 }
420 
421 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
422 				   const char *iface_name)
423 {
424 	struct batadv_priv *bat_priv;
425 	struct net_device *soft_iface, *master;
426 	__be16 ethertype = htons(ETH_P_BATMAN);
427 	int max_header_len = batadv_max_header_len();
428 	int ret;
429 
430 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
431 		goto out;
432 
433 	if (!atomic_inc_not_zero(&hard_iface->refcount))
434 		goto out;
435 
436 	soft_iface = dev_get_by_name(&init_net, iface_name);
437 
438 	if (!soft_iface) {
439 		soft_iface = batadv_softif_create(iface_name);
440 
441 		if (!soft_iface) {
442 			ret = -ENOMEM;
443 			goto err;
444 		}
445 
446 		/* dev_get_by_name() increases the reference counter for us */
447 		dev_hold(soft_iface);
448 	}
449 
450 	if (!batadv_softif_is_valid(soft_iface)) {
451 		pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
452 		       soft_iface->name);
453 		ret = -EINVAL;
454 		goto err_dev;
455 	}
456 
457 	/* check if the interface is enslaved in another virtual one and
458 	 * in that case unlink it first
459 	 */
460 	master = netdev_master_upper_dev_get(hard_iface->net_dev);
461 	ret = batadv_master_del_slave(hard_iface, master);
462 	if (ret)
463 		goto err_dev;
464 
465 	hard_iface->soft_iface = soft_iface;
466 	bat_priv = netdev_priv(hard_iface->soft_iface);
467 
468 	ret = netdev_master_upper_dev_link(hard_iface->net_dev,
469 					   soft_iface, NULL, NULL);
470 	if (ret)
471 		goto err_dev;
472 
473 	ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
474 	if (ret < 0)
475 		goto err_upper;
476 
477 	hard_iface->if_num = bat_priv->num_ifaces;
478 	bat_priv->num_ifaces++;
479 	hard_iface->if_status = BATADV_IF_INACTIVE;
480 	ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
481 	if (ret < 0) {
482 		bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
483 		bat_priv->num_ifaces--;
484 		hard_iface->if_status = BATADV_IF_NOT_IN_USE;
485 		goto err_upper;
486 	}
487 
488 	hard_iface->batman_adv_ptype.type = ethertype;
489 	hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
490 	hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
491 	dev_add_pack(&hard_iface->batman_adv_ptype);
492 
493 	batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
494 		    hard_iface->net_dev->name);
495 
496 	if (atomic_read(&bat_priv->fragmentation) &&
497 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
498 		batadv_info(hard_iface->soft_iface,
499 			    "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",
500 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
501 			    ETH_DATA_LEN + max_header_len);
502 
503 	if (!atomic_read(&bat_priv->fragmentation) &&
504 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
505 		batadv_info(hard_iface->soft_iface,
506 			    "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",
507 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
508 			    ETH_DATA_LEN + max_header_len);
509 
510 	if (batadv_hardif_is_iface_up(hard_iface))
511 		batadv_hardif_activate_interface(hard_iface);
512 	else
513 		batadv_err(hard_iface->soft_iface,
514 			   "Not using interface %s (retrying later): interface not active\n",
515 			   hard_iface->net_dev->name);
516 
517 	batadv_hardif_recalc_extra_skbroom(soft_iface);
518 
519 	/* begin scheduling originator messages on that interface */
520 	batadv_schedule_bat_ogm(hard_iface);
521 
522 out:
523 	return 0;
524 
525 err_upper:
526 	netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
527 err_dev:
528 	hard_iface->soft_iface = NULL;
529 	dev_put(soft_iface);
530 err:
531 	batadv_hardif_free_ref(hard_iface);
532 	return ret;
533 }
534 
535 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
536 				     enum batadv_hard_if_cleanup autodel)
537 {
538 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
539 	struct batadv_hard_iface *primary_if = NULL;
540 
541 	if (hard_iface->if_status == BATADV_IF_ACTIVE)
542 		batadv_hardif_deactivate_interface(hard_iface);
543 
544 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
545 		goto out;
546 
547 	batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
548 		    hard_iface->net_dev->name);
549 	dev_remove_pack(&hard_iface->batman_adv_ptype);
550 
551 	bat_priv->num_ifaces--;
552 	batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
553 
554 	primary_if = batadv_primary_if_get_selected(bat_priv);
555 	if (hard_iface == primary_if) {
556 		struct batadv_hard_iface *new_if;
557 
558 		new_if = batadv_hardif_get_active(hard_iface->soft_iface);
559 		batadv_primary_if_select(bat_priv, new_if);
560 
561 		if (new_if)
562 			batadv_hardif_free_ref(new_if);
563 	}
564 
565 	bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
566 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
567 
568 	/* delete all references to this hard_iface */
569 	batadv_purge_orig_ref(bat_priv);
570 	batadv_purge_outstanding_packets(bat_priv, hard_iface);
571 	dev_put(hard_iface->soft_iface);
572 
573 	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
574 	batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
575 
576 	/* nobody uses this interface anymore */
577 	if (!bat_priv->num_ifaces) {
578 		batadv_gw_check_client_stop(bat_priv);
579 
580 		if (autodel == BATADV_IF_CLEANUP_AUTO)
581 			batadv_softif_destroy_sysfs(hard_iface->soft_iface);
582 	}
583 
584 	hard_iface->soft_iface = NULL;
585 	batadv_hardif_free_ref(hard_iface);
586 
587 out:
588 	if (primary_if)
589 		batadv_hardif_free_ref(primary_if);
590 }
591 
592 /**
593  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
594  * @work: work queue item
595  *
596  * Free the parts of the hard interface which can not be removed under
597  * rtnl lock (to prevent deadlock situations).
598  */
599 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
600 {
601 	struct batadv_hard_iface *hard_iface;
602 
603 	hard_iface = container_of(work, struct batadv_hard_iface,
604 				  cleanup_work);
605 
606 	batadv_debugfs_del_hardif(hard_iface);
607 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
608 	batadv_hardif_free_ref(hard_iface);
609 }
610 
611 static struct batadv_hard_iface *
612 batadv_hardif_add_interface(struct net_device *net_dev)
613 {
614 	struct batadv_hard_iface *hard_iface;
615 	int ret;
616 
617 	ASSERT_RTNL();
618 
619 	ret = batadv_is_valid_iface(net_dev);
620 	if (ret != 1)
621 		goto out;
622 
623 	dev_hold(net_dev);
624 
625 	hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
626 	if (!hard_iface)
627 		goto release_dev;
628 
629 	ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
630 	if (ret)
631 		goto free_if;
632 
633 	hard_iface->if_num = -1;
634 	hard_iface->net_dev = net_dev;
635 	hard_iface->soft_iface = NULL;
636 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
637 
638 	ret = batadv_debugfs_add_hardif(hard_iface);
639 	if (ret)
640 		goto free_sysfs;
641 
642 	INIT_LIST_HEAD(&hard_iface->list);
643 	INIT_HLIST_HEAD(&hard_iface->neigh_list);
644 	INIT_WORK(&hard_iface->cleanup_work,
645 		  batadv_hardif_remove_interface_finish);
646 
647 	spin_lock_init(&hard_iface->neigh_list_lock);
648 
649 	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
650 	if (batadv_is_wifi_netdev(net_dev))
651 		hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
652 
653 	/* extra reference for return */
654 	atomic_set(&hard_iface->refcount, 2);
655 
656 	batadv_check_known_mac_addr(hard_iface->net_dev);
657 	list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
658 
659 	return hard_iface;
660 
661 free_sysfs:
662 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
663 free_if:
664 	kfree(hard_iface);
665 release_dev:
666 	dev_put(net_dev);
667 out:
668 	return NULL;
669 }
670 
671 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
672 {
673 	ASSERT_RTNL();
674 
675 	/* first deactivate interface */
676 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
677 		batadv_hardif_disable_interface(hard_iface,
678 						BATADV_IF_CLEANUP_AUTO);
679 
680 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
681 		return;
682 
683 	hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
684 	queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
685 }
686 
687 void batadv_hardif_remove_interfaces(void)
688 {
689 	struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
690 
691 	rtnl_lock();
692 	list_for_each_entry_safe(hard_iface, hard_iface_tmp,
693 				 &batadv_hardif_list, list) {
694 		list_del_rcu(&hard_iface->list);
695 		batadv_hardif_remove_interface(hard_iface);
696 	}
697 	rtnl_unlock();
698 }
699 
700 static int batadv_hard_if_event(struct notifier_block *this,
701 				unsigned long event, void *ptr)
702 {
703 	struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
704 	struct batadv_hard_iface *hard_iface;
705 	struct batadv_hard_iface *primary_if = NULL;
706 	struct batadv_priv *bat_priv;
707 
708 	if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
709 		batadv_sysfs_add_meshif(net_dev);
710 		bat_priv = netdev_priv(net_dev);
711 		batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
712 		return NOTIFY_DONE;
713 	}
714 
715 	hard_iface = batadv_hardif_get_by_netdev(net_dev);
716 	if (!hard_iface && (event == NETDEV_REGISTER ||
717 			    event == NETDEV_POST_TYPE_CHANGE))
718 		hard_iface = batadv_hardif_add_interface(net_dev);
719 
720 	if (!hard_iface)
721 		goto out;
722 
723 	switch (event) {
724 	case NETDEV_UP:
725 		batadv_hardif_activate_interface(hard_iface);
726 		break;
727 	case NETDEV_GOING_DOWN:
728 	case NETDEV_DOWN:
729 		batadv_hardif_deactivate_interface(hard_iface);
730 		break;
731 	case NETDEV_UNREGISTER:
732 	case NETDEV_PRE_TYPE_CHANGE:
733 		list_del_rcu(&hard_iface->list);
734 
735 		batadv_hardif_remove_interface(hard_iface);
736 		break;
737 	case NETDEV_CHANGEMTU:
738 		if (hard_iface->soft_iface)
739 			batadv_update_min_mtu(hard_iface->soft_iface);
740 		break;
741 	case NETDEV_CHANGEADDR:
742 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
743 			goto hardif_put;
744 
745 		batadv_check_known_mac_addr(hard_iface->net_dev);
746 
747 		bat_priv = netdev_priv(hard_iface->soft_iface);
748 		bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
749 
750 		primary_if = batadv_primary_if_get_selected(bat_priv);
751 		if (!primary_if)
752 			goto hardif_put;
753 
754 		if (hard_iface == primary_if)
755 			batadv_primary_if_update_addr(bat_priv, NULL);
756 		break;
757 	default:
758 		break;
759 	}
760 
761 hardif_put:
762 	batadv_hardif_free_ref(hard_iface);
763 out:
764 	if (primary_if)
765 		batadv_hardif_free_ref(primary_if);
766 	return NOTIFY_DONE;
767 }
768 
769 struct notifier_block batadv_hard_if_notifier = {
770 	.notifier_call = batadv_hard_if_event,
771 };
772