1 /*
2  * Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner, Simon Wunderlich
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA
19  *
20  */
21 
22 /* increase the reference counter for this originator */
23 
24 #include "main.h"
25 #include "originator.h"
26 #include "hash.h"
27 #include "translation-table.h"
28 #include "routing.h"
29 #include "gateway_client.h"
30 #include "hard-interface.h"
31 #include "unicast.h"
32 #include "soft-interface.h"
33 
34 static void purge_orig(struct work_struct *work);
35 
start_purge_timer(struct bat_priv * bat_priv)36 static void start_purge_timer(struct bat_priv *bat_priv)
37 {
38 	INIT_DELAYED_WORK(&bat_priv->orig_work, purge_orig);
39 	queue_delayed_work(bat_event_workqueue, &bat_priv->orig_work, 1 * HZ);
40 }
41 
originator_init(struct bat_priv * bat_priv)42 int originator_init(struct bat_priv *bat_priv)
43 {
44 	if (bat_priv->orig_hash)
45 		return 1;
46 
47 	bat_priv->orig_hash = hash_new(1024);
48 
49 	if (!bat_priv->orig_hash)
50 		goto err;
51 
52 	start_purge_timer(bat_priv);
53 	return 1;
54 
55 err:
56 	return 0;
57 }
58 
neigh_node_free_rcu(struct rcu_head * rcu)59 static void neigh_node_free_rcu(struct rcu_head *rcu)
60 {
61 	struct neigh_node *neigh_node;
62 
63 	neigh_node = container_of(rcu, struct neigh_node, rcu);
64 	kfree(neigh_node);
65 }
66 
neigh_node_free_ref(struct neigh_node * neigh_node)67 void neigh_node_free_ref(struct neigh_node *neigh_node)
68 {
69 	if (atomic_dec_and_test(&neigh_node->refcount))
70 		call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
71 }
72 
create_neighbor(struct orig_node * orig_node,struct orig_node * orig_neigh_node,uint8_t * neigh,struct hard_iface * if_incoming)73 struct neigh_node *create_neighbor(struct orig_node *orig_node,
74 				   struct orig_node *orig_neigh_node,
75 				   uint8_t *neigh,
76 				   struct hard_iface *if_incoming)
77 {
78 	struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
79 	struct neigh_node *neigh_node;
80 
81 	bat_dbg(DBG_BATMAN, bat_priv,
82 		"Creating new last-hop neighbor of originator\n");
83 
84 	neigh_node = kzalloc(sizeof(struct neigh_node), GFP_ATOMIC);
85 	if (!neigh_node)
86 		return NULL;
87 
88 	INIT_HLIST_NODE(&neigh_node->list);
89 	INIT_LIST_HEAD(&neigh_node->bonding_list);
90 
91 	memcpy(neigh_node->addr, neigh, ETH_ALEN);
92 	neigh_node->orig_node = orig_neigh_node;
93 	neigh_node->if_incoming = if_incoming;
94 
95 	/* extra reference for return */
96 	atomic_set(&neigh_node->refcount, 2);
97 
98 	spin_lock_bh(&orig_node->neigh_list_lock);
99 	hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
100 	spin_unlock_bh(&orig_node->neigh_list_lock);
101 	return neigh_node;
102 }
103 
orig_node_free_rcu(struct rcu_head * rcu)104 static void orig_node_free_rcu(struct rcu_head *rcu)
105 {
106 	struct hlist_node *node, *node_tmp;
107 	struct neigh_node *neigh_node, *tmp_neigh_node;
108 	struct orig_node *orig_node;
109 
110 	orig_node = container_of(rcu, struct orig_node, rcu);
111 
112 	spin_lock_bh(&orig_node->neigh_list_lock);
113 
114 	/* for all bonding members ... */
115 	list_for_each_entry_safe(neigh_node, tmp_neigh_node,
116 				 &orig_node->bond_list, bonding_list) {
117 		list_del_rcu(&neigh_node->bonding_list);
118 		neigh_node_free_ref(neigh_node);
119 	}
120 
121 	/* for all neighbors towards this originator ... */
122 	hlist_for_each_entry_safe(neigh_node, node, node_tmp,
123 				  &orig_node->neigh_list, list) {
124 		hlist_del_rcu(&neigh_node->list);
125 		neigh_node_free_ref(neigh_node);
126 	}
127 
128 	spin_unlock_bh(&orig_node->neigh_list_lock);
129 
130 	frag_list_free(&orig_node->frag_list);
131 	hna_global_del_orig(orig_node->bat_priv, orig_node,
132 			    "originator timed out");
133 
134 	kfree(orig_node->bcast_own);
135 	kfree(orig_node->bcast_own_sum);
136 	kfree(orig_node);
137 }
138 
orig_node_free_ref(struct orig_node * orig_node)139 void orig_node_free_ref(struct orig_node *orig_node)
140 {
141 	if (atomic_dec_and_test(&orig_node->refcount))
142 		call_rcu(&orig_node->rcu, orig_node_free_rcu);
143 }
144 
originator_free(struct bat_priv * bat_priv)145 void originator_free(struct bat_priv *bat_priv)
146 {
147 	struct hashtable_t *hash = bat_priv->orig_hash;
148 	struct hlist_node *node, *node_tmp;
149 	struct hlist_head *head;
150 	spinlock_t *list_lock; /* spinlock to protect write access */
151 	struct orig_node *orig_node;
152 	int i;
153 
154 	if (!hash)
155 		return;
156 
157 	cancel_delayed_work_sync(&bat_priv->orig_work);
158 
159 	bat_priv->orig_hash = NULL;
160 
161 	for (i = 0; i < hash->size; i++) {
162 		head = &hash->table[i];
163 		list_lock = &hash->list_locks[i];
164 
165 		spin_lock_bh(list_lock);
166 		hlist_for_each_entry_safe(orig_node, node, node_tmp,
167 					  head, hash_entry) {
168 
169 			hlist_del_rcu(node);
170 			orig_node_free_ref(orig_node);
171 		}
172 		spin_unlock_bh(list_lock);
173 	}
174 
175 	hash_destroy(hash);
176 }
177 
178 /* this function finds or creates an originator entry for the given
179  * address if it does not exits */
get_orig_node(struct bat_priv * bat_priv,uint8_t * addr)180 struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
181 {
182 	struct orig_node *orig_node;
183 	int size;
184 	int hash_added;
185 
186 	orig_node = orig_hash_find(bat_priv, addr);
187 	if (orig_node)
188 		return orig_node;
189 
190 	bat_dbg(DBG_BATMAN, bat_priv,
191 		"Creating new originator: %pM\n", addr);
192 
193 	orig_node = kzalloc(sizeof(struct orig_node), GFP_ATOMIC);
194 	if (!orig_node)
195 		return NULL;
196 
197 	INIT_HLIST_HEAD(&orig_node->neigh_list);
198 	INIT_LIST_HEAD(&orig_node->bond_list);
199 	spin_lock_init(&orig_node->ogm_cnt_lock);
200 	spin_lock_init(&orig_node->bcast_seqno_lock);
201 	spin_lock_init(&orig_node->neigh_list_lock);
202 
203 	/* extra reference for return */
204 	atomic_set(&orig_node->refcount, 2);
205 
206 	orig_node->bat_priv = bat_priv;
207 	memcpy(orig_node->orig, addr, ETH_ALEN);
208 	orig_node->router = NULL;
209 	orig_node->hna_buff = NULL;
210 	orig_node->bcast_seqno_reset = jiffies - 1
211 					- msecs_to_jiffies(RESET_PROTECTION_MS);
212 	orig_node->batman_seqno_reset = jiffies - 1
213 					- msecs_to_jiffies(RESET_PROTECTION_MS);
214 
215 	atomic_set(&orig_node->bond_candidates, 0);
216 
217 	size = bat_priv->num_ifaces * sizeof(unsigned long) * NUM_WORDS;
218 
219 	orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
220 	if (!orig_node->bcast_own)
221 		goto free_orig_node;
222 
223 	size = bat_priv->num_ifaces * sizeof(uint8_t);
224 	orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
225 
226 	INIT_LIST_HEAD(&orig_node->frag_list);
227 	orig_node->last_frag_packet = 0;
228 
229 	if (!orig_node->bcast_own_sum)
230 		goto free_bcast_own;
231 
232 	hash_added = hash_add(bat_priv->orig_hash, compare_orig,
233 			      choose_orig, orig_node, &orig_node->hash_entry);
234 	if (hash_added < 0)
235 		goto free_bcast_own_sum;
236 
237 	return orig_node;
238 free_bcast_own_sum:
239 	kfree(orig_node->bcast_own_sum);
240 free_bcast_own:
241 	kfree(orig_node->bcast_own);
242 free_orig_node:
243 	kfree(orig_node);
244 	return NULL;
245 }
246 
purge_orig_neighbors(struct bat_priv * bat_priv,struct orig_node * orig_node,struct neigh_node ** best_neigh_node)247 static bool purge_orig_neighbors(struct bat_priv *bat_priv,
248 				 struct orig_node *orig_node,
249 				 struct neigh_node **best_neigh_node)
250 {
251 	struct hlist_node *node, *node_tmp;
252 	struct neigh_node *neigh_node;
253 	bool neigh_purged = false;
254 
255 	*best_neigh_node = NULL;
256 
257 	spin_lock_bh(&orig_node->neigh_list_lock);
258 
259 	/* for all neighbors towards this originator ... */
260 	hlist_for_each_entry_safe(neigh_node, node, node_tmp,
261 				  &orig_node->neigh_list, list) {
262 
263 		if ((time_after(jiffies,
264 			neigh_node->last_valid + PURGE_TIMEOUT * HZ)) ||
265 		    (neigh_node->if_incoming->if_status == IF_INACTIVE) ||
266 		    (neigh_node->if_incoming->if_status == IF_NOT_IN_USE) ||
267 		    (neigh_node->if_incoming->if_status == IF_TO_BE_REMOVED)) {
268 
269 			if ((neigh_node->if_incoming->if_status ==
270 								IF_INACTIVE) ||
271 			    (neigh_node->if_incoming->if_status ==
272 							IF_NOT_IN_USE) ||
273 			    (neigh_node->if_incoming->if_status ==
274 							IF_TO_BE_REMOVED))
275 				bat_dbg(DBG_BATMAN, bat_priv,
276 					"neighbor purge: originator %pM, "
277 					"neighbor: %pM, iface: %s\n",
278 					orig_node->orig, neigh_node->addr,
279 					neigh_node->if_incoming->net_dev->name);
280 			else
281 				bat_dbg(DBG_BATMAN, bat_priv,
282 					"neighbor timeout: originator %pM, "
283 					"neighbor: %pM, last_valid: %lu\n",
284 					orig_node->orig, neigh_node->addr,
285 					(neigh_node->last_valid / HZ));
286 
287 			neigh_purged = true;
288 
289 			hlist_del_rcu(&neigh_node->list);
290 			bonding_candidate_del(orig_node, neigh_node);
291 			neigh_node_free_ref(neigh_node);
292 		} else {
293 			if ((!*best_neigh_node) ||
294 			    (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
295 				*best_neigh_node = neigh_node;
296 		}
297 	}
298 
299 	spin_unlock_bh(&orig_node->neigh_list_lock);
300 	return neigh_purged;
301 }
302 
purge_orig_node(struct bat_priv * bat_priv,struct orig_node * orig_node)303 static bool purge_orig_node(struct bat_priv *bat_priv,
304 			    struct orig_node *orig_node)
305 {
306 	struct neigh_node *best_neigh_node;
307 
308 	if (time_after(jiffies,
309 		orig_node->last_valid + 2 * PURGE_TIMEOUT * HZ)) {
310 
311 		bat_dbg(DBG_BATMAN, bat_priv,
312 			"Originator timeout: originator %pM, last_valid %lu\n",
313 			orig_node->orig, (orig_node->last_valid / HZ));
314 		return true;
315 	} else {
316 		if (purge_orig_neighbors(bat_priv, orig_node,
317 							&best_neigh_node)) {
318 			update_routes(bat_priv, orig_node,
319 				      best_neigh_node,
320 				      orig_node->hna_buff,
321 				      orig_node->hna_buff_len);
322 		}
323 	}
324 
325 	return false;
326 }
327 
_purge_orig(struct bat_priv * bat_priv)328 static void _purge_orig(struct bat_priv *bat_priv)
329 {
330 	struct hashtable_t *hash = bat_priv->orig_hash;
331 	struct hlist_node *node, *node_tmp;
332 	struct hlist_head *head;
333 	spinlock_t *list_lock; /* spinlock to protect write access */
334 	struct orig_node *orig_node;
335 	int i;
336 
337 	if (!hash)
338 		return;
339 
340 	/* for all origins... */
341 	for (i = 0; i < hash->size; i++) {
342 		head = &hash->table[i];
343 		list_lock = &hash->list_locks[i];
344 
345 		spin_lock_bh(list_lock);
346 		hlist_for_each_entry_safe(orig_node, node, node_tmp,
347 					  head, hash_entry) {
348 			if (purge_orig_node(bat_priv, orig_node)) {
349 				if (orig_node->gw_flags)
350 					gw_node_delete(bat_priv, orig_node);
351 				hlist_del_rcu(node);
352 				orig_node_free_ref(orig_node);
353 				continue;
354 			}
355 
356 			if (time_after(jiffies, orig_node->last_frag_packet +
357 						msecs_to_jiffies(FRAG_TIMEOUT)))
358 				frag_list_free(&orig_node->frag_list);
359 		}
360 		spin_unlock_bh(list_lock);
361 	}
362 
363 	gw_node_purge(bat_priv);
364 	gw_election(bat_priv);
365 
366 	softif_neigh_purge(bat_priv);
367 }
368 
purge_orig(struct work_struct * work)369 static void purge_orig(struct work_struct *work)
370 {
371 	struct delayed_work *delayed_work =
372 		container_of(work, struct delayed_work, work);
373 	struct bat_priv *bat_priv =
374 		container_of(delayed_work, struct bat_priv, orig_work);
375 
376 	_purge_orig(bat_priv);
377 	start_purge_timer(bat_priv);
378 }
379 
purge_orig_ref(struct bat_priv * bat_priv)380 void purge_orig_ref(struct bat_priv *bat_priv)
381 {
382 	_purge_orig(bat_priv);
383 }
384 
orig_seq_print_text(struct seq_file * seq,void * offset)385 int orig_seq_print_text(struct seq_file *seq, void *offset)
386 {
387 	struct net_device *net_dev = (struct net_device *)seq->private;
388 	struct bat_priv *bat_priv = netdev_priv(net_dev);
389 	struct hashtable_t *hash = bat_priv->orig_hash;
390 	struct hlist_node *node, *node_tmp;
391 	struct hlist_head *head;
392 	struct orig_node *orig_node;
393 	struct neigh_node *neigh_node;
394 	int batman_count = 0;
395 	int last_seen_secs;
396 	int last_seen_msecs;
397 	int i;
398 
399 	if ((!bat_priv->primary_if) ||
400 	    (bat_priv->primary_if->if_status != IF_ACTIVE)) {
401 		if (!bat_priv->primary_if)
402 			return seq_printf(seq, "BATMAN mesh %s disabled - "
403 				     "please specify interfaces to enable it\n",
404 				     net_dev->name);
405 
406 		return seq_printf(seq, "BATMAN mesh %s "
407 				  "disabled - primary interface not active\n",
408 				  net_dev->name);
409 	}
410 
411 	seq_printf(seq, "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
412 		   SOURCE_VERSION, REVISION_VERSION_STR,
413 		   bat_priv->primary_if->net_dev->name,
414 		   bat_priv->primary_if->net_dev->dev_addr, net_dev->name);
415 	seq_printf(seq, "  %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
416 		   "Originator", "last-seen", "#", TQ_MAX_VALUE, "Nexthop",
417 		   "outgoingIF", "Potential nexthops");
418 
419 	for (i = 0; i < hash->size; i++) {
420 		head = &hash->table[i];
421 
422 		rcu_read_lock();
423 		hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
424 			if (!orig_node->router)
425 				continue;
426 
427 			if (orig_node->router->tq_avg == 0)
428 				continue;
429 
430 			last_seen_secs = jiffies_to_msecs(jiffies -
431 						orig_node->last_valid) / 1000;
432 			last_seen_msecs = jiffies_to_msecs(jiffies -
433 						orig_node->last_valid) % 1000;
434 
435 			neigh_node = orig_node->router;
436 			seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
437 				   orig_node->orig, last_seen_secs,
438 				   last_seen_msecs, neigh_node->tq_avg,
439 				   neigh_node->addr,
440 				   neigh_node->if_incoming->net_dev->name);
441 
442 			hlist_for_each_entry_rcu(neigh_node, node_tmp,
443 						 &orig_node->neigh_list, list) {
444 				seq_printf(seq, " %pM (%3i)", neigh_node->addr,
445 						neigh_node->tq_avg);
446 			}
447 
448 			seq_printf(seq, "\n");
449 			batman_count++;
450 		}
451 		rcu_read_unlock();
452 	}
453 
454 	if ((batman_count == 0))
455 		seq_printf(seq, "No batman nodes in range ...\n");
456 
457 	return 0;
458 }
459 
orig_node_add_if(struct orig_node * orig_node,int max_if_num)460 static int orig_node_add_if(struct orig_node *orig_node, int max_if_num)
461 {
462 	void *data_ptr;
463 
464 	data_ptr = kmalloc(max_if_num * sizeof(unsigned long) * NUM_WORDS,
465 			   GFP_ATOMIC);
466 	if (!data_ptr) {
467 		pr_err("Can't resize orig: out of memory\n");
468 		return -1;
469 	}
470 
471 	memcpy(data_ptr, orig_node->bcast_own,
472 	       (max_if_num - 1) * sizeof(unsigned long) * NUM_WORDS);
473 	kfree(orig_node->bcast_own);
474 	orig_node->bcast_own = data_ptr;
475 
476 	data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
477 	if (!data_ptr) {
478 		pr_err("Can't resize orig: out of memory\n");
479 		return -1;
480 	}
481 
482 	memcpy(data_ptr, orig_node->bcast_own_sum,
483 	       (max_if_num - 1) * sizeof(uint8_t));
484 	kfree(orig_node->bcast_own_sum);
485 	orig_node->bcast_own_sum = data_ptr;
486 
487 	return 0;
488 }
489 
orig_hash_add_if(struct hard_iface * hard_iface,int max_if_num)490 int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num)
491 {
492 	struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
493 	struct hashtable_t *hash = bat_priv->orig_hash;
494 	struct hlist_node *node;
495 	struct hlist_head *head;
496 	struct orig_node *orig_node;
497 	int i, ret;
498 
499 	/* resize all orig nodes because orig_node->bcast_own(_sum) depend on
500 	 * if_num */
501 	for (i = 0; i < hash->size; i++) {
502 		head = &hash->table[i];
503 
504 		rcu_read_lock();
505 		hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
506 			spin_lock_bh(&orig_node->ogm_cnt_lock);
507 			ret = orig_node_add_if(orig_node, max_if_num);
508 			spin_unlock_bh(&orig_node->ogm_cnt_lock);
509 
510 			if (ret == -1)
511 				goto err;
512 		}
513 		rcu_read_unlock();
514 	}
515 
516 	return 0;
517 
518 err:
519 	rcu_read_unlock();
520 	return -ENOMEM;
521 }
522 
orig_node_del_if(struct orig_node * orig_node,int max_if_num,int del_if_num)523 static int orig_node_del_if(struct orig_node *orig_node,
524 		     int max_if_num, int del_if_num)
525 {
526 	void *data_ptr = NULL;
527 	int chunk_size;
528 
529 	/* last interface was removed */
530 	if (max_if_num == 0)
531 		goto free_bcast_own;
532 
533 	chunk_size = sizeof(unsigned long) * NUM_WORDS;
534 	data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
535 	if (!data_ptr) {
536 		pr_err("Can't resize orig: out of memory\n");
537 		return -1;
538 	}
539 
540 	/* copy first part */
541 	memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
542 
543 	/* copy second part */
544 	memcpy(data_ptr + del_if_num * chunk_size,
545 	       orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
546 	       (max_if_num - del_if_num) * chunk_size);
547 
548 free_bcast_own:
549 	kfree(orig_node->bcast_own);
550 	orig_node->bcast_own = data_ptr;
551 
552 	if (max_if_num == 0)
553 		goto free_own_sum;
554 
555 	data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
556 	if (!data_ptr) {
557 		pr_err("Can't resize orig: out of memory\n");
558 		return -1;
559 	}
560 
561 	memcpy(data_ptr, orig_node->bcast_own_sum,
562 	       del_if_num * sizeof(uint8_t));
563 
564 	memcpy(data_ptr + del_if_num * sizeof(uint8_t),
565 	       orig_node->bcast_own_sum + ((del_if_num + 1) * sizeof(uint8_t)),
566 	       (max_if_num - del_if_num) * sizeof(uint8_t));
567 
568 free_own_sum:
569 	kfree(orig_node->bcast_own_sum);
570 	orig_node->bcast_own_sum = data_ptr;
571 
572 	return 0;
573 }
574 
orig_hash_del_if(struct hard_iface * hard_iface,int max_if_num)575 int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num)
576 {
577 	struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
578 	struct hashtable_t *hash = bat_priv->orig_hash;
579 	struct hlist_node *node;
580 	struct hlist_head *head;
581 	struct hard_iface *hard_iface_tmp;
582 	struct orig_node *orig_node;
583 	int i, ret;
584 
585 	/* resize all orig nodes because orig_node->bcast_own(_sum) depend on
586 	 * if_num */
587 	for (i = 0; i < hash->size; i++) {
588 		head = &hash->table[i];
589 
590 		rcu_read_lock();
591 		hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
592 			spin_lock_bh(&orig_node->ogm_cnt_lock);
593 			ret = orig_node_del_if(orig_node, max_if_num,
594 					hard_iface->if_num);
595 			spin_unlock_bh(&orig_node->ogm_cnt_lock);
596 
597 			if (ret == -1)
598 				goto err;
599 		}
600 		rcu_read_unlock();
601 	}
602 
603 	/* renumber remaining batman interfaces _inside_ of orig_hash_lock */
604 	rcu_read_lock();
605 	list_for_each_entry_rcu(hard_iface_tmp, &hardif_list, list) {
606 		if (hard_iface_tmp->if_status == IF_NOT_IN_USE)
607 			continue;
608 
609 		if (hard_iface == hard_iface_tmp)
610 			continue;
611 
612 		if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
613 			continue;
614 
615 		if (hard_iface_tmp->if_num > hard_iface->if_num)
616 			hard_iface_tmp->if_num--;
617 	}
618 	rcu_read_unlock();
619 
620 	hard_iface->if_num = -1;
621 	return 0;
622 
623 err:
624 	rcu_read_unlock();
625 	return -ENOMEM;
626 }
627