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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/byteorder/generic.h>
22 #include <linux/errno.h>
23 #include <linux/fs.h>
24 #include <linux/if_arp.h>
25 #include <linux/if_ether.h>
26 #include <linux/if.h>
27 #include <linux/kernel.h>
28 #include <linux/list.h>
29 #include <linux/mutex.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 /**
50  * batadv_hardif_release - release hard interface from lists and queue for
51  *  free after rcu grace period
52  * @hard_iface: the hard interface to free
53  */
batadv_hardif_release(struct batadv_hard_iface * hard_iface)54 void batadv_hardif_release(struct batadv_hard_iface *hard_iface)
55 {
56 	dev_put(hard_iface->net_dev);
57 
58 	kfree_rcu(hard_iface, rcu);
59 }
60 
61 struct batadv_hard_iface *
batadv_hardif_get_by_netdev(const struct net_device * net_dev)62 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
63 {
64 	struct batadv_hard_iface *hard_iface;
65 
66 	rcu_read_lock();
67 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
68 		if (hard_iface->net_dev == net_dev &&
69 		    atomic_inc_not_zero(&hard_iface->refcount))
70 			goto out;
71 	}
72 
73 	hard_iface = NULL;
74 
75 out:
76 	rcu_read_unlock();
77 	return hard_iface;
78 }
79 
80 /**
81  * batadv_mutual_parents - check if two devices are each others parent
82  * @dev1: 1st net_device
83  * @dev2: 2nd net_device
84  *
85  * veth devices come in pairs and each is the parent of the other!
86  *
87  * Return: true if the devices are each others parent, otherwise false
88  */
batadv_mutual_parents(const struct net_device * dev1,const struct net_device * dev2)89 static bool batadv_mutual_parents(const struct net_device *dev1,
90 				  const struct net_device *dev2)
91 {
92 	int dev1_parent_iflink = dev_get_iflink(dev1);
93 	int dev2_parent_iflink = dev_get_iflink(dev2);
94 
95 	if (!dev1_parent_iflink || !dev2_parent_iflink)
96 		return false;
97 
98 	return (dev1_parent_iflink == dev2->ifindex) &&
99 	       (dev2_parent_iflink == dev1->ifindex);
100 }
101 
102 /**
103  * batadv_is_on_batman_iface - check if a device is a batman iface descendant
104  * @net_dev: the device to check
105  *
106  * If the user creates any virtual device on top of a batman-adv interface, it
107  * is important to prevent this new interface to be used to create a new mesh
108  * network (this behaviour would lead to a batman-over-batman configuration).
109  * This function recursively checks all the fathers of the device passed as
110  * argument looking for a batman-adv soft interface.
111  *
112  * Returns true if the device is descendant of a batman-adv mesh interface (or
113  * if it is a batman-adv interface itself), false otherwise
114  */
batadv_is_on_batman_iface(const struct net_device * net_dev)115 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
116 {
117 	struct net_device *parent_dev;
118 	bool ret;
119 
120 	/* check if this is a batman-adv mesh interface */
121 	if (batadv_softif_is_valid(net_dev))
122 		return true;
123 
124 	/* no more parents..stop recursion */
125 	if (dev_get_iflink(net_dev) == 0 ||
126 	    dev_get_iflink(net_dev) == net_dev->ifindex)
127 		return false;
128 
129 	/* recurse over the parent device */
130 	parent_dev = __dev_get_by_index(&init_net, dev_get_iflink(net_dev));
131 	/* if we got a NULL parent_dev there is something broken.. */
132 	if (!parent_dev) {
133 		pr_err("Cannot find parent device\n");
134 		return false;
135 	}
136 
137 	if (batadv_mutual_parents(net_dev, parent_dev))
138 		return false;
139 
140 	ret = batadv_is_on_batman_iface(parent_dev);
141 
142 	return ret;
143 }
144 
batadv_is_valid_iface(const struct net_device * net_dev)145 static int batadv_is_valid_iface(const struct net_device *net_dev)
146 {
147 	if (net_dev->flags & IFF_LOOPBACK)
148 		return 0;
149 
150 	if (net_dev->type != ARPHRD_ETHER)
151 		return 0;
152 
153 	if (net_dev->addr_len != ETH_ALEN)
154 		return 0;
155 
156 	/* no batman over batman */
157 	if (batadv_is_on_batman_iface(net_dev))
158 		return 0;
159 
160 	return 1;
161 }
162 
163 /**
164  * batadv_is_wifi_netdev - check if the given net_device struct is a wifi
165  *  interface
166  * @net_device: the device to check
167  *
168  * Returns true if the net device is a 802.11 wireless device, false otherwise.
169  */
batadv_is_wifi_netdev(struct net_device * net_device)170 bool batadv_is_wifi_netdev(struct net_device *net_device)
171 {
172 	if (!net_device)
173 		return false;
174 
175 #ifdef CONFIG_WIRELESS_EXT
176 	/* pre-cfg80211 drivers have to implement WEXT, so it is possible to
177 	 * check for wireless_handlers != NULL
178 	 */
179 	if (net_device->wireless_handlers)
180 		return true;
181 #endif
182 
183 	/* cfg80211 drivers have to set ieee80211_ptr */
184 	if (net_device->ieee80211_ptr)
185 		return true;
186 
187 	return false;
188 }
189 
190 static struct batadv_hard_iface *
batadv_hardif_get_active(const struct net_device * soft_iface)191 batadv_hardif_get_active(const struct net_device *soft_iface)
192 {
193 	struct batadv_hard_iface *hard_iface;
194 
195 	rcu_read_lock();
196 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
197 		if (hard_iface->soft_iface != soft_iface)
198 			continue;
199 
200 		if (hard_iface->if_status == BATADV_IF_ACTIVE &&
201 		    atomic_inc_not_zero(&hard_iface->refcount))
202 			goto out;
203 	}
204 
205 	hard_iface = NULL;
206 
207 out:
208 	rcu_read_unlock();
209 	return hard_iface;
210 }
211 
batadv_primary_if_update_addr(struct batadv_priv * bat_priv,struct batadv_hard_iface * oldif)212 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
213 					  struct batadv_hard_iface *oldif)
214 {
215 	struct batadv_hard_iface *primary_if;
216 
217 	primary_if = batadv_primary_if_get_selected(bat_priv);
218 	if (!primary_if)
219 		goto out;
220 
221 	batadv_dat_init_own_addr(bat_priv, primary_if);
222 	batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
223 out:
224 	if (primary_if)
225 		batadv_hardif_free_ref(primary_if);
226 }
227 
batadv_primary_if_select(struct batadv_priv * bat_priv,struct batadv_hard_iface * new_hard_iface)228 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
229 				     struct batadv_hard_iface *new_hard_iface)
230 {
231 	struct batadv_hard_iface *curr_hard_iface;
232 
233 	ASSERT_RTNL();
234 
235 	if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
236 		new_hard_iface = NULL;
237 
238 	curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
239 	rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
240 
241 	if (!new_hard_iface)
242 		goto out;
243 
244 	bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
245 	batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
246 
247 out:
248 	if (curr_hard_iface)
249 		batadv_hardif_free_ref(curr_hard_iface);
250 }
251 
252 static bool
batadv_hardif_is_iface_up(const struct batadv_hard_iface * hard_iface)253 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
254 {
255 	if (hard_iface->net_dev->flags & IFF_UP)
256 		return true;
257 
258 	return false;
259 }
260 
batadv_check_known_mac_addr(const struct net_device * net_dev)261 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
262 {
263 	const struct batadv_hard_iface *hard_iface;
264 
265 	rcu_read_lock();
266 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
267 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
268 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
269 			continue;
270 
271 		if (hard_iface->net_dev == net_dev)
272 			continue;
273 
274 		if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
275 					net_dev->dev_addr))
276 			continue;
277 
278 		pr_warn("The newly added mac address (%pM) already exists on: %s\n",
279 			net_dev->dev_addr, hard_iface->net_dev->name);
280 		pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
281 	}
282 	rcu_read_unlock();
283 }
284 
285 /**
286  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
287  * @soft_iface: netdev struct of the mesh interface
288  */
batadv_hardif_recalc_extra_skbroom(struct net_device * soft_iface)289 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
290 {
291 	const struct batadv_hard_iface *hard_iface;
292 	unsigned short lower_header_len = ETH_HLEN;
293 	unsigned short lower_headroom = 0;
294 	unsigned short lower_tailroom = 0;
295 	unsigned short needed_headroom;
296 
297 	rcu_read_lock();
298 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
299 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
300 			continue;
301 
302 		if (hard_iface->soft_iface != soft_iface)
303 			continue;
304 
305 		lower_header_len = max_t(unsigned short, lower_header_len,
306 					 hard_iface->net_dev->hard_header_len);
307 
308 		lower_headroom = max_t(unsigned short, lower_headroom,
309 				       hard_iface->net_dev->needed_headroom);
310 
311 		lower_tailroom = max_t(unsigned short, lower_tailroom,
312 				       hard_iface->net_dev->needed_tailroom);
313 	}
314 	rcu_read_unlock();
315 
316 	needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
317 	needed_headroom += batadv_max_header_len();
318 
319 	/* fragmentation headers don't strip the unicast/... header */
320 	needed_headroom += sizeof(struct batadv_frag_packet);
321 
322 	soft_iface->needed_headroom = needed_headroom;
323 	soft_iface->needed_tailroom = lower_tailroom;
324 }
325 
batadv_hardif_min_mtu(struct net_device * soft_iface)326 int batadv_hardif_min_mtu(struct net_device *soft_iface)
327 {
328 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
329 	const struct batadv_hard_iface *hard_iface;
330 	int min_mtu = INT_MAX;
331 
332 	rcu_read_lock();
333 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
334 		if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
335 		    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
336 			continue;
337 
338 		if (hard_iface->soft_iface != soft_iface)
339 			continue;
340 
341 		min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
342 	}
343 	rcu_read_unlock();
344 
345 	if (atomic_read(&bat_priv->fragmentation) == 0)
346 		goto out;
347 
348 	/* with fragmentation enabled the maximum size of internally generated
349 	 * packets such as translation table exchanges or tvlv containers, etc
350 	 * has to be calculated
351 	 */
352 	min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
353 	min_mtu -= sizeof(struct batadv_frag_packet);
354 	min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
355 
356 out:
357 	/* report to the other components the maximum amount of bytes that
358 	 * batman-adv can send over the wire (without considering the payload
359 	 * overhead). For example, this value is used by TT to compute the
360 	 * maximum local table table size
361 	 */
362 	atomic_set(&bat_priv->packet_size_max, min_mtu);
363 
364 	/* the real soft-interface MTU is computed by removing the payload
365 	 * overhead from the maximum amount of bytes that was just computed.
366 	 *
367 	 * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
368 	 */
369 	return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
370 }
371 
372 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
batadv_update_min_mtu(struct net_device * soft_iface)373 void batadv_update_min_mtu(struct net_device *soft_iface)
374 {
375 	soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
376 
377 	/* Check if the local translate table should be cleaned up to match a
378 	 * new (and smaller) MTU.
379 	 */
380 	batadv_tt_local_resize_to_mtu(soft_iface);
381 }
382 
383 static void
batadv_hardif_activate_interface(struct batadv_hard_iface * hard_iface)384 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
385 {
386 	struct batadv_priv *bat_priv;
387 	struct batadv_hard_iface *primary_if = NULL;
388 
389 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
390 		goto out;
391 
392 	bat_priv = netdev_priv(hard_iface->soft_iface);
393 
394 	bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
395 	hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
396 
397 	/* the first active interface becomes our primary interface or
398 	 * the next active interface after the old primary interface was removed
399 	 */
400 	primary_if = batadv_primary_if_get_selected(bat_priv);
401 	if (!primary_if)
402 		batadv_primary_if_select(bat_priv, hard_iface);
403 
404 	batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
405 		    hard_iface->net_dev->name);
406 
407 	batadv_update_min_mtu(hard_iface->soft_iface);
408 
409 out:
410 	if (primary_if)
411 		batadv_hardif_free_ref(primary_if);
412 }
413 
414 static void
batadv_hardif_deactivate_interface(struct batadv_hard_iface * hard_iface)415 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
416 {
417 	if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
418 	    (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
419 		return;
420 
421 	hard_iface->if_status = BATADV_IF_INACTIVE;
422 
423 	batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
424 		    hard_iface->net_dev->name);
425 
426 	batadv_update_min_mtu(hard_iface->soft_iface);
427 }
428 
429 /**
430  * batadv_master_del_slave - remove hard_iface from the current master interface
431  * @slave: the interface enslaved in another master
432  * @master: the master from which slave has to be removed
433  *
434  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
435  * is free'd and master can correctly change its internal state.
436  * Return 0 on success, a negative value representing the error otherwise
437  */
batadv_master_del_slave(struct batadv_hard_iface * slave,struct net_device * master)438 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
439 				   struct net_device *master)
440 {
441 	int ret;
442 
443 	if (!master)
444 		return 0;
445 
446 	ret = -EBUSY;
447 	if (master->netdev_ops->ndo_del_slave)
448 		ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
449 
450 	return ret;
451 }
452 
batadv_hardif_enable_interface(struct batadv_hard_iface * hard_iface,const char * iface_name)453 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
454 				   const char *iface_name)
455 {
456 	struct batadv_priv *bat_priv;
457 	struct net_device *soft_iface, *master;
458 	__be16 ethertype = htons(ETH_P_BATMAN);
459 	int max_header_len = batadv_max_header_len();
460 	int ret;
461 
462 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
463 		goto out;
464 
465 	if (!atomic_inc_not_zero(&hard_iface->refcount))
466 		goto out;
467 
468 	soft_iface = dev_get_by_name(&init_net, iface_name);
469 
470 	if (!soft_iface) {
471 		soft_iface = batadv_softif_create(iface_name);
472 
473 		if (!soft_iface) {
474 			ret = -ENOMEM;
475 			goto err;
476 		}
477 
478 		/* dev_get_by_name() increases the reference counter for us */
479 		dev_hold(soft_iface);
480 	}
481 
482 	if (!batadv_softif_is_valid(soft_iface)) {
483 		pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
484 		       soft_iface->name);
485 		ret = -EINVAL;
486 		goto err_dev;
487 	}
488 
489 	/* check if the interface is enslaved in another virtual one and
490 	 * in that case unlink it first
491 	 */
492 	master = netdev_master_upper_dev_get(hard_iface->net_dev);
493 	ret = batadv_master_del_slave(hard_iface, master);
494 	if (ret)
495 		goto err_dev;
496 
497 	hard_iface->soft_iface = soft_iface;
498 	bat_priv = netdev_priv(hard_iface->soft_iface);
499 
500 	if (bat_priv->num_ifaces >= UINT_MAX) {
501 		ret = -ENOSPC;
502 		goto err_dev;
503 	}
504 
505 	ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface);
506 	if (ret)
507 		goto err_dev;
508 
509 	ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
510 	if (ret < 0)
511 		goto err_upper;
512 
513 	hard_iface->if_num = bat_priv->num_ifaces;
514 	bat_priv->num_ifaces++;
515 	hard_iface->if_status = BATADV_IF_INACTIVE;
516 	ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
517 	if (ret < 0) {
518 		bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
519 		bat_priv->num_ifaces--;
520 		hard_iface->if_status = BATADV_IF_NOT_IN_USE;
521 		goto err_upper;
522 	}
523 
524 	hard_iface->batman_adv_ptype.type = ethertype;
525 	hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
526 	hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
527 	dev_add_pack(&hard_iface->batman_adv_ptype);
528 
529 	batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
530 		    hard_iface->net_dev->name);
531 
532 	if (atomic_read(&bat_priv->fragmentation) &&
533 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
534 		batadv_info(hard_iface->soft_iface,
535 			    "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",
536 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
537 			    ETH_DATA_LEN + max_header_len);
538 
539 	if (!atomic_read(&bat_priv->fragmentation) &&
540 	    hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
541 		batadv_info(hard_iface->soft_iface,
542 			    "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",
543 			    hard_iface->net_dev->name, hard_iface->net_dev->mtu,
544 			    ETH_DATA_LEN + max_header_len);
545 
546 	if (batadv_hardif_is_iface_up(hard_iface))
547 		batadv_hardif_activate_interface(hard_iface);
548 	else
549 		batadv_err(hard_iface->soft_iface,
550 			   "Not using interface %s (retrying later): interface not active\n",
551 			   hard_iface->net_dev->name);
552 
553 	batadv_hardif_recalc_extra_skbroom(soft_iface);
554 
555 	/* begin scheduling originator messages on that interface */
556 	batadv_schedule_bat_ogm(hard_iface);
557 
558 out:
559 	return 0;
560 
561 err_upper:
562 	netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
563 err_dev:
564 	hard_iface->soft_iface = NULL;
565 	dev_put(soft_iface);
566 err:
567 	batadv_hardif_free_ref(hard_iface);
568 	return ret;
569 }
570 
batadv_hardif_disable_interface(struct batadv_hard_iface * hard_iface,enum batadv_hard_if_cleanup autodel)571 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
572 				     enum batadv_hard_if_cleanup autodel)
573 {
574 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
575 	struct batadv_hard_iface *primary_if = NULL;
576 
577 	batadv_hardif_deactivate_interface(hard_iface);
578 
579 	if (hard_iface->if_status != BATADV_IF_INACTIVE)
580 		goto out;
581 
582 	batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
583 		    hard_iface->net_dev->name);
584 	dev_remove_pack(&hard_iface->batman_adv_ptype);
585 
586 	bat_priv->num_ifaces--;
587 	batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
588 
589 	primary_if = batadv_primary_if_get_selected(bat_priv);
590 	if (hard_iface == primary_if) {
591 		struct batadv_hard_iface *new_if;
592 
593 		new_if = batadv_hardif_get_active(hard_iface->soft_iface);
594 		batadv_primary_if_select(bat_priv, new_if);
595 
596 		if (new_if)
597 			batadv_hardif_free_ref(new_if);
598 	}
599 
600 	bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
601 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
602 
603 	/* delete all references to this hard_iface */
604 	batadv_purge_orig_ref(bat_priv);
605 	batadv_purge_outstanding_packets(bat_priv, hard_iface);
606 	dev_put(hard_iface->soft_iface);
607 
608 	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
609 	batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
610 
611 	/* nobody uses this interface anymore */
612 	if (bat_priv->num_ifaces == 0) {
613 		batadv_gw_check_client_stop(bat_priv);
614 
615 		if (autodel == BATADV_IF_CLEANUP_AUTO)
616 			batadv_softif_destroy_sysfs(hard_iface->soft_iface);
617 	}
618 
619 	hard_iface->soft_iface = NULL;
620 	batadv_hardif_free_ref(hard_iface);
621 
622 out:
623 	if (primary_if)
624 		batadv_hardif_free_ref(primary_if);
625 }
626 
627 /**
628  * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif
629  * @work: work queue item
630  *
631  * Free the parts of the hard interface which can not be removed under
632  * rtnl lock (to prevent deadlock situations).
633  */
batadv_hardif_remove_interface_finish(struct work_struct * work)634 static void batadv_hardif_remove_interface_finish(struct work_struct *work)
635 {
636 	struct batadv_hard_iface *hard_iface;
637 
638 	hard_iface = container_of(work, struct batadv_hard_iface,
639 				  cleanup_work);
640 
641 	batadv_debugfs_del_hardif(hard_iface);
642 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
643 	batadv_hardif_free_ref(hard_iface);
644 }
645 
646 static struct batadv_hard_iface *
batadv_hardif_add_interface(struct net_device * net_dev)647 batadv_hardif_add_interface(struct net_device *net_dev)
648 {
649 	struct batadv_hard_iface *hard_iface;
650 	int ret;
651 
652 	ASSERT_RTNL();
653 
654 	ret = batadv_is_valid_iface(net_dev);
655 	if (ret != 1)
656 		goto out;
657 
658 	dev_hold(net_dev);
659 
660 	hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
661 	if (!hard_iface)
662 		goto release_dev;
663 
664 	ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
665 	if (ret)
666 		goto free_if;
667 
668 	hard_iface->if_num = 0;
669 	hard_iface->net_dev = net_dev;
670 	hard_iface->soft_iface = NULL;
671 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;
672 
673 	ret = batadv_debugfs_add_hardif(hard_iface);
674 	if (ret)
675 		goto free_sysfs;
676 
677 	INIT_LIST_HEAD(&hard_iface->list);
678 	mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
679 	INIT_WORK(&hard_iface->cleanup_work,
680 		  batadv_hardif_remove_interface_finish);
681 
682 	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
683 	if (batadv_is_wifi_netdev(net_dev))
684 		hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
685 
686 	/* extra reference for return */
687 	atomic_set(&hard_iface->refcount, 2);
688 
689 	batadv_check_known_mac_addr(hard_iface->net_dev);
690 	list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
691 
692 	return hard_iface;
693 
694 free_sysfs:
695 	batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
696 free_if:
697 	kfree(hard_iface);
698 release_dev:
699 	dev_put(net_dev);
700 out:
701 	return NULL;
702 }
703 
batadv_hardif_remove_interface(struct batadv_hard_iface * hard_iface)704 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
705 {
706 	ASSERT_RTNL();
707 
708 	/* first deactivate interface */
709 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
710 		batadv_hardif_disable_interface(hard_iface,
711 						BATADV_IF_CLEANUP_AUTO);
712 
713 	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
714 		return;
715 
716 	hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
717 	queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
718 }
719 
batadv_hardif_remove_interfaces(void)720 void batadv_hardif_remove_interfaces(void)
721 {
722 	struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
723 
724 	rtnl_lock();
725 	list_for_each_entry_safe(hard_iface, hard_iface_tmp,
726 				 &batadv_hardif_list, list) {
727 		list_del_rcu(&hard_iface->list);
728 		batadv_hardif_remove_interface(hard_iface);
729 	}
730 	rtnl_unlock();
731 }
732 
733 /**
734  * batadv_hard_if_event_softif() - Handle events for soft interfaces
735  * @event: NETDEV_* event to handle
736  * @net_dev: net_device which generated an event
737  *
738  * Return: NOTIFY_* result
739  */
batadv_hard_if_event_softif(unsigned long event,struct net_device * net_dev)740 static int batadv_hard_if_event_softif(unsigned long event,
741 				       struct net_device *net_dev)
742 {
743 	struct batadv_priv *bat_priv;
744 
745 	switch (event) {
746 	case NETDEV_REGISTER:
747 		batadv_sysfs_add_meshif(net_dev);
748 		bat_priv = netdev_priv(net_dev);
749 		batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
750 		break;
751 	case NETDEV_CHANGENAME:
752 		batadv_debugfs_rename_meshif(net_dev);
753 		break;
754 	}
755 
756 	return NOTIFY_DONE;
757 }
758 
batadv_hard_if_event(struct notifier_block * this,unsigned long event,void * ptr)759 static int batadv_hard_if_event(struct notifier_block *this,
760 				unsigned long event, void *ptr)
761 {
762 	struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
763 	struct batadv_hard_iface *hard_iface;
764 	struct batadv_hard_iface *primary_if = NULL;
765 	struct batadv_priv *bat_priv;
766 
767 	if (batadv_softif_is_valid(net_dev))
768 		return batadv_hard_if_event_softif(event, net_dev);
769 
770 	hard_iface = batadv_hardif_get_by_netdev(net_dev);
771 	if (!hard_iface && event == NETDEV_REGISTER)
772 		hard_iface = batadv_hardif_add_interface(net_dev);
773 
774 	if (!hard_iface)
775 		goto out;
776 
777 	switch (event) {
778 	case NETDEV_UP:
779 		batadv_hardif_activate_interface(hard_iface);
780 		break;
781 	case NETDEV_GOING_DOWN:
782 	case NETDEV_DOWN:
783 		batadv_hardif_deactivate_interface(hard_iface);
784 		break;
785 	case NETDEV_UNREGISTER:
786 		list_del_rcu(&hard_iface->list);
787 
788 		batadv_hardif_remove_interface(hard_iface);
789 		break;
790 	case NETDEV_CHANGEMTU:
791 		if (hard_iface->soft_iface)
792 			batadv_update_min_mtu(hard_iface->soft_iface);
793 		break;
794 	case NETDEV_CHANGEADDR:
795 		if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
796 			goto hardif_put;
797 
798 		batadv_check_known_mac_addr(hard_iface->net_dev);
799 
800 		bat_priv = netdev_priv(hard_iface->soft_iface);
801 		bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
802 
803 		primary_if = batadv_primary_if_get_selected(bat_priv);
804 		if (!primary_if)
805 			goto hardif_put;
806 
807 		if (hard_iface == primary_if)
808 			batadv_primary_if_update_addr(bat_priv, NULL);
809 		break;
810 	case NETDEV_CHANGENAME:
811 		batadv_debugfs_rename_hardif(hard_iface);
812 		break;
813 	default:
814 		break;
815 	}
816 
817 hardif_put:
818 	batadv_hardif_free_ref(hard_iface);
819 out:
820 	if (primary_if)
821 		batadv_hardif_free_ref(primary_if);
822 	return NOTIFY_DONE;
823 }
824 
825 struct notifier_block batadv_hard_if_notifier = {
826 	.notifier_call = batadv_hard_if_event,
827 };
828