xref: /linux/net/batman-adv/hard-interface.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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/workqueue.h>
36 #include <net/net_namespace.h>
37 
38 #include "bridge_loop_avoidance.h"
39 #include "debugfs.h"
40 #include "distributed-arp-table.h"
41 #include "gateway_client.h"
42 #include "originator.h"
43 #include "packet.h"
44 #include "send.h"
45 #include "soft-interface.h"
46 #include "sysfs.h"
47 #include "translation-table.h"
48 
49 void batadv_hardif_free_rcu(struct rcu_head *rcu)
50 {
51 	struct batadv_hard_iface *hard_iface;
52 
53 	hard_iface = container_of(rcu, struct batadv_hard_iface, rcu);
54 	dev_put(hard_iface->net_dev);
55 	kfree(hard_iface);
56 }
57 
58 struct batadv_hard_iface *
59 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
60 {
61 	struct batadv_hard_iface *hard_iface;
62 
63 	rcu_read_lock();
64 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
65 		if (hard_iface->net_dev == net_dev &&
66 		    atomic_inc_not_zero(&hard_iface->refcount))
67 			goto out;
68 	}
69 
70 	hard_iface = NULL;
71 
72 out:
73 	rcu_read_unlock();
74 	return hard_iface;
75 }
76 
77 /**
78  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
79  * @net_dev: the device to check
80  *
81  * If the user creates any virtual device on top of a batman-adv interface, it
82  * is important to prevent this new interface to be used to create a new mesh
83  * network (this behaviour would lead to a batman-over-batman configuration).
84  * This function recursively checks all the fathers of the device passed as
85  * argument looking for a batman-adv soft interface.
86  *
87  * Returns true if the device is descendant of a batman-adv mesh interface (or
88  * if it is a batman-adv interface itself), false otherwise
89  */
90 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
91 {
92 	struct net_device *parent_dev;
93 	bool ret;
94 
95 	/* check if this is a batman-adv mesh interface */
96 	if (batadv_softif_is_valid(net_dev))
97 		return true;
98 
99 	/* no more parents..stop recursion */
100 	if (dev_get_iflink(net_dev) == 0 ||
101 	    dev_get_iflink(net_dev) == net_dev->ifindex)
102 		return false;
103 
104 	/* recurse over the parent device */
105 	parent_dev = __dev_get_by_index(&init_net, dev_get_iflink(net_dev));
106 	/* if we got a NULL parent_dev there is something broken.. */
107 	if (WARN(!parent_dev, "Cannot find parent device"))
108 		return false;
109 
110 	ret = batadv_is_on_batman_iface(parent_dev);
111 
112 	return ret;
113 }
114 
115 static int batadv_is_valid_iface(const struct net_device *net_dev)
116 {
117 	if (net_dev->flags & IFF_LOOPBACK)
118 		return 0;
119 
120 	if (net_dev->type != ARPHRD_ETHER)
121 		return 0;
122 
123 	if (net_dev->addr_len != ETH_ALEN)
124 		return 0;
125 
126 	/* no batman over batman */
127 	if (batadv_is_on_batman_iface(net_dev))
128 		return 0;
129 
130 	return 1;
131 }
132 
133 /**
134  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
135  *  interface
136  * @net_device: the device to check
137  *
138  * Returns true if the net device is a 802.11 wireless device, false otherwise.
139  */
140 bool batadv_is_wifi_netdev(struct net_device *net_device)
141 {
142 	if (!net_device)
143 		return false;
144 
145 #ifdef CONFIG_WIRELESS_EXT
146 	/* pre-cfg80211 drivers have to implement WEXT, so it is possible to
147 	 * check for wireless_handlers != NULL
148 	 */
149 	if (net_device->wireless_handlers)
150 		return true;
151 #endif
152 
153 	/* cfg80211 drivers have to set ieee80211_ptr */
154 	if (net_device->ieee80211_ptr)
155 		return true;
156 
157 	return false;
158 }
159 
160 static struct batadv_hard_iface *
161 batadv_hardif_get_active(const struct net_device *soft_iface)
162 {
163 	struct batadv_hard_iface *hard_iface;
164 
165 	rcu_read_lock();
166 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
167 		if (hard_iface->soft_iface != soft_iface)
168 			continue;
169 
170 		if (hard_iface->if_status == BATADV_IF_ACTIVE &&
171 		    atomic_inc_not_zero(&hard_iface->refcount))
172 			goto out;
173 	}
174 
175 	hard_iface = NULL;
176 
177 out:
178 	rcu_read_unlock();
179 	return hard_iface;
180 }
181 
182 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
183 					  struct batadv_hard_iface *oldif)
184 {
185 	struct batadv_hard_iface *primary_if;
186 
187 	primary_if = batadv_primary_if_get_selected(bat_priv);
188 	if (!primary_if)
189 		goto out;
190 
191 	batadv_dat_init_own_addr(bat_priv, primary_if);
192 	batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
193 out:
194 	if (primary_if)
195 		batadv_hardif_free_ref(primary_if);
196 }
197 
198 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
199 				     struct batadv_hard_iface *new_hard_iface)
200 {
201 	struct batadv_hard_iface *curr_hard_iface;
202 
203 	ASSERT_RTNL();
204 
205 	if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
206 		new_hard_iface = NULL;
207 
208 	curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
209 	rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
210 
211 	if (!new_hard_iface)
212 		goto out;
213 
214 	bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
215 	batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
216 
217 out:
218 	if (curr_hard_iface)
219 		batadv_hardif_free_ref(curr_hard_iface);
220 }
221 
222 static bool
223 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
224 {
225 	if (hard_iface->net_dev->flags & IFF_UP)
226 		return true;
227 
228 	return false;
229 }
230 
231 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
232 {
233 	const struct batadv_hard_iface *hard_iface;
234 
235 	rcu_read_lock();
236 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
237 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
238 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
239 			continue;
240 
241 		if (hard_iface->net_dev == net_dev)
242 			continue;
243 
244 		if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
245 					net_dev->dev_addr))
246 			continue;
247 
248 		pr_warn("The newly added mac address (%pM) already exists on: %s\n",
249 			net_dev->dev_addr, hard_iface->net_dev->name);
250 		pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
251 	}
252 	rcu_read_unlock();
253 }
254 
255 /**
256  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
257  * @soft_iface: netdev struct of the mesh interface
258  */
259 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
260 {
261 	const struct batadv_hard_iface *hard_iface;
262 	unsigned short lower_header_len = ETH_HLEN;
263 	unsigned short lower_headroom = 0;
264 	unsigned short lower_tailroom = 0;
265 	unsigned short needed_headroom;
266 
267 	rcu_read_lock();
268 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
269 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
270 			continue;
271 
272 		if (hard_iface->soft_iface != soft_iface)
273 			continue;
274 
275 		lower_header_len = max_t(unsigned short, lower_header_len,
276 					 hard_iface->net_dev->hard_header_len);
277 
278 		lower_headroom = max_t(unsigned short, lower_headroom,
279 				       hard_iface->net_dev->needed_headroom);
280 
281 		lower_tailroom = max_t(unsigned short, lower_tailroom,
282 				       hard_iface->net_dev->needed_tailroom);
283 	}
284 	rcu_read_unlock();
285 
286 	needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
287 	needed_headroom += batadv_max_header_len();
288 
289 	soft_iface->needed_headroom = needed_headroom;
290 	soft_iface->needed_tailroom = lower_tailroom;
291 }
292 
293 int batadv_hardif_min_mtu(struct net_device *soft_iface)
294 {
295 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
296 	const struct batadv_hard_iface *hard_iface;
297 	int min_mtu = INT_MAX;
298 
299 	rcu_read_lock();
300 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
301 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
302 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
303 			continue;
304 
305 		if (hard_iface->soft_iface != soft_iface)
306 			continue;
307 
308 		min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
309 	}
310 	rcu_read_unlock();
311 
312 	if (atomic_read(&bat_priv->fragmentation) == 0)
313 		goto out;
314 
315 	/* with fragmentation enabled the maximum size of internally generated
316 	 * packets such as translation table exchanges or tvlv containers, etc
317 	 * has to be calculated
318 	 */
319 	min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
320 	min_mtu -= sizeof(struct batadv_frag_packet);
321 	min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
322 
323 out:
324 	/* report to the other components the maximum amount of bytes that
325 	 * batman-adv can send over the wire (without considering the payload
326 	 * overhead). For example, this value is used by TT to compute the
327 	 * maximum local table table size
328 	 */
329 	atomic_set(&bat_priv->packet_size_max, min_mtu);
330 
331 	/* the real soft-interface MTU is computed by removing the payload
332 	 * overhead from the maximum amount of bytes that was just computed.
333 	 *
334 	 * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
335 	 */
336 	return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
337 }
338 
339 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
340 void batadv_update_min_mtu(struct net_device *soft_iface)
341 {
342 	soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
343 
344 	/* Check if the local translate table should be cleaned up to match a
345 	 * new (and smaller) MTU.
346 	 */
347 	batadv_tt_local_resize_to_mtu(soft_iface);
348 }
349 
350 static void
351 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
352 {
353 	struct batadv_priv *bat_priv;
354 	struct batadv_hard_iface *primary_if = NULL;
355 
356 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
357 		goto out;
358 
359 	bat_priv = netdev_priv(hard_iface->soft_iface);
360 
361 	bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
362 	hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
363 
364 	/* the first active interface becomes our primary interface or
365 	 * the next active interface after the old primary interface was removed
366 	 */
367 	primary_if = batadv_primary_if_get_selected(bat_priv);
368 	if (!primary_if)
369 		batadv_primary_if_select(bat_priv, hard_iface);
370 
371 	batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
372 		    hard_iface->net_dev->name);
373 
374 	batadv_update_min_mtu(hard_iface->soft_iface);
375 
376 out:
377 	if (primary_if)
378 		batadv_hardif_free_ref(primary_if);
379 }
380 
381 static void
382 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
383 {
384 	if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
385 	    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
386 		return;
387 
388 	hard_iface->if_status = BATADV_IF_INACTIVE;
389 
390 	batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
391 		    hard_iface->net_dev->name);
392 
393 	batadv_update_min_mtu(hard_iface->soft_iface);
394 }
395 
396 /**
397  * batadv_master_del_slave - remove hard_iface from the current master interface
398  * @slave: the interface enslaved in another master
399  * @master: the master from which slave has to be removed
400  *
401  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
402  * is free'd and master can correctly change its internal state.
403  * Return 0 on success, a negative value representing the error otherwise
404  */
405 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
406 				   struct net_device *master)
407 {
408 	int ret;
409 
410 	if (!master)
411 		return 0;
412 
413 	ret = -EBUSY;
414 	if (master->netdev_ops->ndo_del_slave)
415 		ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
416 
417 	return ret;
418 }
419 
420 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
421 				   const char *iface_name)
422 {
423 	struct batadv_priv *bat_priv;
424 	struct net_device *soft_iface, *master;
425 	__be16 ethertype = htons(ETH_P_BATMAN);
426 	int max_header_len = batadv_max_header_len();
427 	int ret;
428 
429 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
430 		goto out;
431 
432 	if (!atomic_inc_not_zero(&hard_iface->refcount))
433 		goto out;
434 
435 	soft_iface = dev_get_by_name(&init_net, iface_name);
436 
437 	if (!soft_iface) {
438 		soft_iface = batadv_softif_create(iface_name);
439 
440 		if (!soft_iface) {
441 			ret = -ENOMEM;
442 			goto err;
443 		}
444 
445 		/* dev_get_by_name() increases the reference counter for us */
446 		dev_hold(soft_iface);
447 	}
448 
449 	if (!batadv_softif_is_valid(soft_iface)) {
450 		pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
451 		       soft_iface->name);
452 		ret = -EINVAL;
453 		goto err_dev;
454 	}
455 
456 	/* check if the interface is enslaved in another virtual one and
457 	 * in that case unlink it first
458 	 */
459 	master = netdev_master_upper_dev_get(hard_iface->net_dev);
460 	ret = batadv_master_del_slave(hard_iface, master);
461 	if (ret)
462 		goto err_dev;
463 
464 	hard_iface->soft_iface = soft_iface;
465 	bat_priv = netdev_priv(hard_iface->soft_iface);
466 
467 	ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface);
468 	if (ret)
469 		goto err_dev;
470 
471 	ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
472 	if (ret < 0)
473 		goto err_upper;
474 
475 	hard_iface->if_num = bat_priv->num_ifaces;
476 	bat_priv->num_ifaces++;
477 	hard_iface->if_status = BATADV_IF_INACTIVE;
478 	ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
479 	if (ret < 0) {
480 		bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
481 		bat_priv->num_ifaces--;
482 		hard_iface->if_status = BATADV_IF_NOT_IN_USE;
483 		goto err_upper;
484 	}
485 
486 	hard_iface->batman_adv_ptype.type = ethertype;
487 	hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
488 	hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
489 	dev_add_pack(&hard_iface->batman_adv_ptype);
490 
491 	batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
492 		    hard_iface->net_dev->name);
493 
494 	if (atomic_read(&bat_priv->fragmentation) &&
495 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
496 		batadv_info(hard_iface->soft_iface,
497 			    "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",
498 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
499 			    ETH_DATA_LEN + max_header_len);
500 
501 	if (!atomic_read(&bat_priv->fragmentation) &&
502 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
503 		batadv_info(hard_iface->soft_iface,
504 			    "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",
505 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
506 			    ETH_DATA_LEN + max_header_len);
507 
508 	if (batadv_hardif_is_iface_up(hard_iface))
509 		batadv_hardif_activate_interface(hard_iface);
510 	else
511 		batadv_err(hard_iface->soft_iface,
512 			   "Not using interface %s (retrying later): interface not active\n",
513 			   hard_iface->net_dev->name);
514 
515 	batadv_hardif_recalc_extra_skbroom(soft_iface);
516 
517 	/* begin scheduling originator messages on that interface */
518 	batadv_schedule_bat_ogm(hard_iface);
519 
520 out:
521 	return 0;
522 
523 err_upper:
524 	netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
525 err_dev:
526 	hard_iface->soft_iface = NULL;
527 	dev_put(soft_iface);
528 err:
529 	batadv_hardif_free_ref(hard_iface);
530 	return ret;
531 }
532 
533 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
534 				     enum batadv_hard_if_cleanup autodel)
535 {
536 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
537 	struct batadv_hard_iface *primary_if = NULL;
538 
539 	if (hard_iface->if_status == BATADV_IF_ACTIVE)
540 		batadv_hardif_deactivate_interface(hard_iface);
541 
542 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
543 		goto out;
544 
545 	batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
546 		    hard_iface->net_dev->name);
547 	dev_remove_pack(&hard_iface->batman_adv_ptype);
548 
549 	bat_priv->num_ifaces--;
550 	batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
551 
552 	primary_if = batadv_primary_if_get_selected(bat_priv);
553 	if (hard_iface == primary_if) {
554 		struct batadv_hard_iface *new_if;
555 
556 		new_if = batadv_hardif_get_active(hard_iface->soft_iface);
557 		batadv_primary_if_select(bat_priv, new_if);
558 
559 		if (new_if)
560 			batadv_hardif_free_ref(new_if);
561 	}
562 
563 	bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
564 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
565 
566 	/* delete all references to this hard_iface */
567 	batadv_purge_orig_ref(bat_priv);
568 	batadv_purge_outstanding_packets(bat_priv, hard_iface);
569 	dev_put(hard_iface->soft_iface);
570 
571 	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
572 	batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
573 
574 	/* nobody uses this interface anymore */
575 	if (!bat_priv->num_ifaces) {
576 		batadv_gw_check_client_stop(bat_priv);
577 
578 		if (autodel == BATADV_IF_CLEANUP_AUTO)
579 			batadv_softif_destroy_sysfs(hard_iface->soft_iface);
580 	}
581 
582 	hard_iface->soft_iface = NULL;
583 	batadv_hardif_free_ref(hard_iface);
584 
585 out:
586 	if (primary_if)
587 		batadv_hardif_free_ref(primary_if);
588 }
589 
590 /**
591  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
592  * @work: work queue item
593  *
594  * Free the parts of the hard interface which can not be removed under
595  * rtnl lock (to prevent deadlock situations).
596  */
597 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
598 {
599 	struct batadv_hard_iface *hard_iface;
600 
601 	hard_iface = container_of(work, struct batadv_hard_iface,
602 				  cleanup_work);
603 
604 	batadv_debugfs_del_hardif(hard_iface);
605 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
606 	batadv_hardif_free_ref(hard_iface);
607 }
608 
609 static struct batadv_hard_iface *
610 batadv_hardif_add_interface(struct net_device *net_dev)
611 {
612 	struct batadv_hard_iface *hard_iface;
613 	int ret;
614 
615 	ASSERT_RTNL();
616 
617 	ret = batadv_is_valid_iface(net_dev);
618 	if (ret != 1)
619 		goto out;
620 
621 	dev_hold(net_dev);
622 
623 	hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
624 	if (!hard_iface)
625 		goto release_dev;
626 
627 	ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
628 	if (ret)
629 		goto free_if;
630 
631 	hard_iface->if_num = -1;
632 	hard_iface->net_dev = net_dev;
633 	hard_iface->soft_iface = NULL;
634 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
635 
636 	ret = batadv_debugfs_add_hardif(hard_iface);
637 	if (ret)
638 		goto free_sysfs;
639 
640 	INIT_LIST_HEAD(&hard_iface->list);
641 	INIT_WORK(&hard_iface->cleanup_work,
642 		  batadv_hardif_remove_interface_finish);
643 
644 	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
645 	if (batadv_is_wifi_netdev(net_dev))
646 		hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
647 
648 	/* extra reference for return */
649 	atomic_set(&hard_iface->refcount, 2);
650 
651 	batadv_check_known_mac_addr(hard_iface->net_dev);
652 	list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
653 
654 	return hard_iface;
655 
656 free_sysfs:
657 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
658 free_if:
659 	kfree(hard_iface);
660 release_dev:
661 	dev_put(net_dev);
662 out:
663 	return NULL;
664 }
665 
666 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
667 {
668 	ASSERT_RTNL();
669 
670 	/* first deactivate interface */
671 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
672 		batadv_hardif_disable_interface(hard_iface,
673 						BATADV_IF_CLEANUP_AUTO);
674 
675 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
676 		return;
677 
678 	hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
679 	queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
680 }
681 
682 void batadv_hardif_remove_interfaces(void)
683 {
684 	struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
685 
686 	rtnl_lock();
687 	list_for_each_entry_safe(hard_iface, hard_iface_tmp,
688 				 &batadv_hardif_list, list) {
689 		list_del_rcu(&hard_iface->list);
690 		batadv_hardif_remove_interface(hard_iface);
691 	}
692 	rtnl_unlock();
693 }
694 
695 static int batadv_hard_if_event(struct notifier_block *this,
696 				unsigned long event, void *ptr)
697 {
698 	struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
699 	struct batadv_hard_iface *hard_iface;
700 	struct batadv_hard_iface *primary_if = NULL;
701 	struct batadv_priv *bat_priv;
702 
703 	if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
704 		batadv_sysfs_add_meshif(net_dev);
705 		bat_priv = netdev_priv(net_dev);
706 		batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
707 		return NOTIFY_DONE;
708 	}
709 
710 	hard_iface = batadv_hardif_get_by_netdev(net_dev);
711 	if (!hard_iface && event == NETDEV_REGISTER)
712 		hard_iface = batadv_hardif_add_interface(net_dev);
713 
714 	if (!hard_iface)
715 		goto out;
716 
717 	switch (event) {
718 	case NETDEV_UP:
719 		batadv_hardif_activate_interface(hard_iface);
720 		break;
721 	case NETDEV_GOING_DOWN:
722 	case NETDEV_DOWN:
723 		batadv_hardif_deactivate_interface(hard_iface);
724 		break;
725 	case NETDEV_UNREGISTER:
726 		list_del_rcu(&hard_iface->list);
727 
728 		batadv_hardif_remove_interface(hard_iface);
729 		break;
730 	case NETDEV_CHANGEMTU:
731 		if (hard_iface->soft_iface)
732 			batadv_update_min_mtu(hard_iface->soft_iface);
733 		break;
734 	case NETDEV_CHANGEADDR:
735 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
736 			goto hardif_put;
737 
738 		batadv_check_known_mac_addr(hard_iface->net_dev);
739 
740 		bat_priv = netdev_priv(hard_iface->soft_iface);
741 		bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
742 
743 		primary_if = batadv_primary_if_get_selected(bat_priv);
744 		if (!primary_if)
745 			goto hardif_put;
746 
747 		if (hard_iface == primary_if)
748 			batadv_primary_if_update_addr(bat_priv, NULL);
749 		break;
750 	default:
751 		break;
752 	}
753 
754 hardif_put:
755 	batadv_hardif_free_ref(hard_iface);
756 out:
757 	if (primary_if)
758 		batadv_hardif_free_ref(primary_if);
759 	return NOTIFY_DONE;
760 }
761 
762 struct notifier_block batadv_hard_if_notifier = {
763 	.notifier_call = batadv_hard_if_event,
764 };
765