originator.c 17 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654
  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. /* increase the reference counter for this originator */
  22. #include "main.h"
  23. #include "originator.h"
  24. #include "hash.h"
  25. #include "translation-table.h"
  26. #include "routing.h"
  27. #include "gateway_client.h"
  28. #include "hard-interface.h"
  29. #include "unicast.h"
  30. #include "soft-interface.h"
  31. static void purge_orig(struct work_struct *work);
  32. static void start_purge_timer(struct bat_priv *bat_priv)
  33. {
  34. INIT_DELAYED_WORK(&bat_priv->orig_work, purge_orig);
  35. queue_delayed_work(bat_event_workqueue, &bat_priv->orig_work, 1 * HZ);
  36. }
  37. int originator_init(struct bat_priv *bat_priv)
  38. {
  39. if (bat_priv->orig_hash)
  40. return 1;
  41. bat_priv->orig_hash = hash_new(1024);
  42. if (!bat_priv->orig_hash)
  43. goto err;
  44. start_purge_timer(bat_priv);
  45. return 1;
  46. err:
  47. return 0;
  48. }
  49. static void neigh_node_free_rcu(struct rcu_head *rcu)
  50. {
  51. struct neigh_node *neigh_node;
  52. neigh_node = container_of(rcu, struct neigh_node, rcu);
  53. kfree(neigh_node);
  54. }
  55. void neigh_node_free_ref(struct neigh_node *neigh_node)
  56. {
  57. if (atomic_dec_and_test(&neigh_node->refcount))
  58. call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
  59. }
  60. /* increases the refcounter of a found router */
  61. struct neigh_node *orig_node_get_router(struct orig_node *orig_node)
  62. {
  63. struct neigh_node *router;
  64. rcu_read_lock();
  65. router = rcu_dereference(orig_node->router);
  66. if (router && !atomic_inc_not_zero(&router->refcount))
  67. router = NULL;
  68. rcu_read_unlock();
  69. return router;
  70. }
  71. struct neigh_node *create_neighbor(struct orig_node *orig_node,
  72. struct orig_node *orig_neigh_node,
  73. uint8_t *neigh,
  74. struct hard_iface *if_incoming)
  75. {
  76. struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
  77. struct neigh_node *neigh_node;
  78. bat_dbg(DBG_BATMAN, bat_priv,
  79. "Creating new last-hop neighbor of originator\n");
  80. neigh_node = kzalloc(sizeof(struct neigh_node), GFP_ATOMIC);
  81. if (!neigh_node)
  82. return NULL;
  83. INIT_HLIST_NODE(&neigh_node->list);
  84. INIT_LIST_HEAD(&neigh_node->bonding_list);
  85. spin_lock_init(&neigh_node->tq_lock);
  86. memcpy(neigh_node->addr, neigh, ETH_ALEN);
  87. neigh_node->orig_node = orig_neigh_node;
  88. neigh_node->if_incoming = if_incoming;
  89. /* extra reference for return */
  90. atomic_set(&neigh_node->refcount, 2);
  91. spin_lock_bh(&orig_node->neigh_list_lock);
  92. hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
  93. spin_unlock_bh(&orig_node->neigh_list_lock);
  94. return neigh_node;
  95. }
  96. static void orig_node_free_rcu(struct rcu_head *rcu)
  97. {
  98. struct hlist_node *node, *node_tmp;
  99. struct neigh_node *neigh_node, *tmp_neigh_node;
  100. struct orig_node *orig_node;
  101. orig_node = container_of(rcu, struct orig_node, rcu);
  102. spin_lock_bh(&orig_node->neigh_list_lock);
  103. /* for all bonding members ... */
  104. list_for_each_entry_safe(neigh_node, tmp_neigh_node,
  105. &orig_node->bond_list, bonding_list) {
  106. list_del_rcu(&neigh_node->bonding_list);
  107. neigh_node_free_ref(neigh_node);
  108. }
  109. /* for all neighbors towards this originator ... */
  110. hlist_for_each_entry_safe(neigh_node, node, node_tmp,
  111. &orig_node->neigh_list, list) {
  112. hlist_del_rcu(&neigh_node->list);
  113. neigh_node_free_ref(neigh_node);
  114. }
  115. spin_unlock_bh(&orig_node->neigh_list_lock);
  116. frag_list_free(&orig_node->frag_list);
  117. hna_global_del_orig(orig_node->bat_priv, orig_node,
  118. "originator timed out");
  119. kfree(orig_node->bcast_own);
  120. kfree(orig_node->bcast_own_sum);
  121. kfree(orig_node);
  122. }
  123. void orig_node_free_ref(struct orig_node *orig_node)
  124. {
  125. if (atomic_dec_and_test(&orig_node->refcount))
  126. call_rcu(&orig_node->rcu, orig_node_free_rcu);
  127. }
  128. void originator_free(struct bat_priv *bat_priv)
  129. {
  130. struct hashtable_t *hash = bat_priv->orig_hash;
  131. struct hlist_node *node, *node_tmp;
  132. struct hlist_head *head;
  133. spinlock_t *list_lock; /* spinlock to protect write access */
  134. struct orig_node *orig_node;
  135. int i;
  136. if (!hash)
  137. return;
  138. cancel_delayed_work_sync(&bat_priv->orig_work);
  139. bat_priv->orig_hash = NULL;
  140. for (i = 0; i < hash->size; i++) {
  141. head = &hash->table[i];
  142. list_lock = &hash->list_locks[i];
  143. spin_lock_bh(list_lock);
  144. hlist_for_each_entry_safe(orig_node, node, node_tmp,
  145. head, hash_entry) {
  146. hlist_del_rcu(node);
  147. orig_node_free_ref(orig_node);
  148. }
  149. spin_unlock_bh(list_lock);
  150. }
  151. hash_destroy(hash);
  152. }
  153. /* this function finds or creates an originator entry for the given
  154. * address if it does not exits */
  155. struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
  156. {
  157. struct orig_node *orig_node;
  158. int size;
  159. int hash_added;
  160. orig_node = orig_hash_find(bat_priv, addr);
  161. if (orig_node)
  162. return orig_node;
  163. bat_dbg(DBG_BATMAN, bat_priv,
  164. "Creating new originator: %pM\n", addr);
  165. orig_node = kzalloc(sizeof(struct orig_node), GFP_ATOMIC);
  166. if (!orig_node)
  167. return NULL;
  168. INIT_HLIST_HEAD(&orig_node->neigh_list);
  169. INIT_LIST_HEAD(&orig_node->bond_list);
  170. spin_lock_init(&orig_node->ogm_cnt_lock);
  171. spin_lock_init(&orig_node->bcast_seqno_lock);
  172. spin_lock_init(&orig_node->neigh_list_lock);
  173. /* extra reference for return */
  174. atomic_set(&orig_node->refcount, 2);
  175. orig_node->bat_priv = bat_priv;
  176. memcpy(orig_node->orig, addr, ETH_ALEN);
  177. orig_node->router = NULL;
  178. orig_node->hna_buff = NULL;
  179. orig_node->bcast_seqno_reset = jiffies - 1
  180. - msecs_to_jiffies(RESET_PROTECTION_MS);
  181. orig_node->batman_seqno_reset = jiffies - 1
  182. - msecs_to_jiffies(RESET_PROTECTION_MS);
  183. atomic_set(&orig_node->bond_candidates, 0);
  184. size = bat_priv->num_ifaces * sizeof(unsigned long) * NUM_WORDS;
  185. orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
  186. if (!orig_node->bcast_own)
  187. goto free_orig_node;
  188. size = bat_priv->num_ifaces * sizeof(uint8_t);
  189. orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
  190. INIT_LIST_HEAD(&orig_node->frag_list);
  191. orig_node->last_frag_packet = 0;
  192. if (!orig_node->bcast_own_sum)
  193. goto free_bcast_own;
  194. hash_added = hash_add(bat_priv->orig_hash, compare_orig,
  195. choose_orig, orig_node, &orig_node->hash_entry);
  196. if (hash_added < 0)
  197. goto free_bcast_own_sum;
  198. return orig_node;
  199. free_bcast_own_sum:
  200. kfree(orig_node->bcast_own_sum);
  201. free_bcast_own:
  202. kfree(orig_node->bcast_own);
  203. free_orig_node:
  204. kfree(orig_node);
  205. return NULL;
  206. }
  207. static bool purge_orig_neighbors(struct bat_priv *bat_priv,
  208. struct orig_node *orig_node,
  209. struct neigh_node **best_neigh_node)
  210. {
  211. struct hlist_node *node, *node_tmp;
  212. struct neigh_node *neigh_node;
  213. bool neigh_purged = false;
  214. *best_neigh_node = NULL;
  215. spin_lock_bh(&orig_node->neigh_list_lock);
  216. /* for all neighbors towards this originator ... */
  217. hlist_for_each_entry_safe(neigh_node, node, node_tmp,
  218. &orig_node->neigh_list, list) {
  219. if ((time_after(jiffies,
  220. neigh_node->last_valid + PURGE_TIMEOUT * HZ)) ||
  221. (neigh_node->if_incoming->if_status == IF_INACTIVE) ||
  222. (neigh_node->if_incoming->if_status == IF_NOT_IN_USE) ||
  223. (neigh_node->if_incoming->if_status == IF_TO_BE_REMOVED)) {
  224. if ((neigh_node->if_incoming->if_status ==
  225. IF_INACTIVE) ||
  226. (neigh_node->if_incoming->if_status ==
  227. IF_NOT_IN_USE) ||
  228. (neigh_node->if_incoming->if_status ==
  229. IF_TO_BE_REMOVED))
  230. bat_dbg(DBG_BATMAN, bat_priv,
  231. "neighbor purge: originator %pM, "
  232. "neighbor: %pM, iface: %s\n",
  233. orig_node->orig, neigh_node->addr,
  234. neigh_node->if_incoming->net_dev->name);
  235. else
  236. bat_dbg(DBG_BATMAN, bat_priv,
  237. "neighbor timeout: originator %pM, "
  238. "neighbor: %pM, last_valid: %lu\n",
  239. orig_node->orig, neigh_node->addr,
  240. (neigh_node->last_valid / HZ));
  241. neigh_purged = true;
  242. hlist_del_rcu(&neigh_node->list);
  243. bonding_candidate_del(orig_node, neigh_node);
  244. neigh_node_free_ref(neigh_node);
  245. } else {
  246. if ((!*best_neigh_node) ||
  247. (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
  248. *best_neigh_node = neigh_node;
  249. }
  250. }
  251. spin_unlock_bh(&orig_node->neigh_list_lock);
  252. return neigh_purged;
  253. }
  254. static bool purge_orig_node(struct bat_priv *bat_priv,
  255. struct orig_node *orig_node)
  256. {
  257. struct neigh_node *best_neigh_node;
  258. if (time_after(jiffies,
  259. orig_node->last_valid + 2 * PURGE_TIMEOUT * HZ)) {
  260. bat_dbg(DBG_BATMAN, bat_priv,
  261. "Originator timeout: originator %pM, last_valid %lu\n",
  262. orig_node->orig, (orig_node->last_valid / HZ));
  263. return true;
  264. } else {
  265. if (purge_orig_neighbors(bat_priv, orig_node,
  266. &best_neigh_node)) {
  267. update_routes(bat_priv, orig_node,
  268. best_neigh_node,
  269. orig_node->hna_buff,
  270. orig_node->hna_buff_len);
  271. }
  272. }
  273. return false;
  274. }
  275. static void _purge_orig(struct bat_priv *bat_priv)
  276. {
  277. struct hashtable_t *hash = bat_priv->orig_hash;
  278. struct hlist_node *node, *node_tmp;
  279. struct hlist_head *head;
  280. spinlock_t *list_lock; /* spinlock to protect write access */
  281. struct orig_node *orig_node;
  282. int i;
  283. if (!hash)
  284. return;
  285. /* for all origins... */
  286. for (i = 0; i < hash->size; i++) {
  287. head = &hash->table[i];
  288. list_lock = &hash->list_locks[i];
  289. spin_lock_bh(list_lock);
  290. hlist_for_each_entry_safe(orig_node, node, node_tmp,
  291. head, hash_entry) {
  292. if (purge_orig_node(bat_priv, orig_node)) {
  293. if (orig_node->gw_flags)
  294. gw_node_delete(bat_priv, orig_node);
  295. hlist_del_rcu(node);
  296. orig_node_free_ref(orig_node);
  297. continue;
  298. }
  299. if (time_after(jiffies, orig_node->last_frag_packet +
  300. msecs_to_jiffies(FRAG_TIMEOUT)))
  301. frag_list_free(&orig_node->frag_list);
  302. }
  303. spin_unlock_bh(list_lock);
  304. }
  305. gw_node_purge(bat_priv);
  306. gw_election(bat_priv);
  307. softif_neigh_purge(bat_priv);
  308. }
  309. static void purge_orig(struct work_struct *work)
  310. {
  311. struct delayed_work *delayed_work =
  312. container_of(work, struct delayed_work, work);
  313. struct bat_priv *bat_priv =
  314. container_of(delayed_work, struct bat_priv, orig_work);
  315. _purge_orig(bat_priv);
  316. start_purge_timer(bat_priv);
  317. }
  318. void purge_orig_ref(struct bat_priv *bat_priv)
  319. {
  320. _purge_orig(bat_priv);
  321. }
  322. int orig_seq_print_text(struct seq_file *seq, void *offset)
  323. {
  324. struct net_device *net_dev = (struct net_device *)seq->private;
  325. struct bat_priv *bat_priv = netdev_priv(net_dev);
  326. struct hashtable_t *hash = bat_priv->orig_hash;
  327. struct hlist_node *node, *node_tmp;
  328. struct hlist_head *head;
  329. struct hard_iface *primary_if;
  330. struct orig_node *orig_node;
  331. struct neigh_node *neigh_node, *neigh_node_tmp;
  332. int batman_count = 0;
  333. int last_seen_secs;
  334. int last_seen_msecs;
  335. int i, ret = 0;
  336. primary_if = primary_if_get_selected(bat_priv);
  337. if (!primary_if) {
  338. ret = seq_printf(seq, "BATMAN mesh %s disabled - "
  339. "please specify interfaces to enable it\n",
  340. net_dev->name);
  341. goto out;
  342. }
  343. if (primary_if->if_status != IF_ACTIVE) {
  344. ret = seq_printf(seq, "BATMAN mesh %s "
  345. "disabled - primary interface not active\n",
  346. net_dev->name);
  347. goto out;
  348. }
  349. seq_printf(seq, "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
  350. SOURCE_VERSION, REVISION_VERSION_STR,
  351. primary_if->net_dev->name,
  352. primary_if->net_dev->dev_addr, net_dev->name);
  353. seq_printf(seq, " %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
  354. "Originator", "last-seen", "#", TQ_MAX_VALUE, "Nexthop",
  355. "outgoingIF", "Potential nexthops");
  356. for (i = 0; i < hash->size; i++) {
  357. head = &hash->table[i];
  358. rcu_read_lock();
  359. hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  360. neigh_node = orig_node_get_router(orig_node);
  361. if (!neigh_node)
  362. continue;
  363. if (neigh_node->tq_avg == 0)
  364. goto next;
  365. last_seen_secs = jiffies_to_msecs(jiffies -
  366. orig_node->last_valid) / 1000;
  367. last_seen_msecs = jiffies_to_msecs(jiffies -
  368. orig_node->last_valid) % 1000;
  369. seq_printf(seq, "%pM %4i.%03is (%3i) %pM [%10s]:",
  370. orig_node->orig, last_seen_secs,
  371. last_seen_msecs, neigh_node->tq_avg,
  372. neigh_node->addr,
  373. neigh_node->if_incoming->net_dev->name);
  374. hlist_for_each_entry_rcu(neigh_node_tmp, node_tmp,
  375. &orig_node->neigh_list, list) {
  376. seq_printf(seq, " %pM (%3i)",
  377. neigh_node_tmp->addr,
  378. neigh_node_tmp->tq_avg);
  379. }
  380. seq_printf(seq, "\n");
  381. batman_count++;
  382. next:
  383. neigh_node_free_ref(neigh_node);
  384. }
  385. rcu_read_unlock();
  386. }
  387. if (batman_count == 0)
  388. seq_printf(seq, "No batman nodes in range ...\n");
  389. out:
  390. if (primary_if)
  391. hardif_free_ref(primary_if);
  392. return ret;
  393. }
  394. static int orig_node_add_if(struct orig_node *orig_node, int max_if_num)
  395. {
  396. void *data_ptr;
  397. data_ptr = kmalloc(max_if_num * sizeof(unsigned long) * NUM_WORDS,
  398. GFP_ATOMIC);
  399. if (!data_ptr) {
  400. pr_err("Can't resize orig: out of memory\n");
  401. return -1;
  402. }
  403. memcpy(data_ptr, orig_node->bcast_own,
  404. (max_if_num - 1) * sizeof(unsigned long) * NUM_WORDS);
  405. kfree(orig_node->bcast_own);
  406. orig_node->bcast_own = data_ptr;
  407. data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
  408. if (!data_ptr) {
  409. pr_err("Can't resize orig: out of memory\n");
  410. return -1;
  411. }
  412. memcpy(data_ptr, orig_node->bcast_own_sum,
  413. (max_if_num - 1) * sizeof(uint8_t));
  414. kfree(orig_node->bcast_own_sum);
  415. orig_node->bcast_own_sum = data_ptr;
  416. return 0;
  417. }
  418. int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num)
  419. {
  420. struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  421. struct hashtable_t *hash = bat_priv->orig_hash;
  422. struct hlist_node *node;
  423. struct hlist_head *head;
  424. struct orig_node *orig_node;
  425. int i, ret;
  426. /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
  427. * if_num */
  428. for (i = 0; i < hash->size; i++) {
  429. head = &hash->table[i];
  430. rcu_read_lock();
  431. hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  432. spin_lock_bh(&orig_node->ogm_cnt_lock);
  433. ret = orig_node_add_if(orig_node, max_if_num);
  434. spin_unlock_bh(&orig_node->ogm_cnt_lock);
  435. if (ret == -1)
  436. goto err;
  437. }
  438. rcu_read_unlock();
  439. }
  440. return 0;
  441. err:
  442. rcu_read_unlock();
  443. return -ENOMEM;
  444. }
  445. static int orig_node_del_if(struct orig_node *orig_node,
  446. int max_if_num, int del_if_num)
  447. {
  448. void *data_ptr = NULL;
  449. int chunk_size;
  450. /* last interface was removed */
  451. if (max_if_num == 0)
  452. goto free_bcast_own;
  453. chunk_size = sizeof(unsigned long) * NUM_WORDS;
  454. data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
  455. if (!data_ptr) {
  456. pr_err("Can't resize orig: out of memory\n");
  457. return -1;
  458. }
  459. /* copy first part */
  460. memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
  461. /* copy second part */
  462. memcpy(data_ptr + del_if_num * chunk_size,
  463. orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
  464. (max_if_num - del_if_num) * chunk_size);
  465. free_bcast_own:
  466. kfree(orig_node->bcast_own);
  467. orig_node->bcast_own = data_ptr;
  468. if (max_if_num == 0)
  469. goto free_own_sum;
  470. data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
  471. if (!data_ptr) {
  472. pr_err("Can't resize orig: out of memory\n");
  473. return -1;
  474. }
  475. memcpy(data_ptr, orig_node->bcast_own_sum,
  476. del_if_num * sizeof(uint8_t));
  477. memcpy(data_ptr + del_if_num * sizeof(uint8_t),
  478. orig_node->bcast_own_sum + ((del_if_num + 1) * sizeof(uint8_t)),
  479. (max_if_num - del_if_num) * sizeof(uint8_t));
  480. free_own_sum:
  481. kfree(orig_node->bcast_own_sum);
  482. orig_node->bcast_own_sum = data_ptr;
  483. return 0;
  484. }
  485. int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num)
  486. {
  487. struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  488. struct hashtable_t *hash = bat_priv->orig_hash;
  489. struct hlist_node *node;
  490. struct hlist_head *head;
  491. struct hard_iface *hard_iface_tmp;
  492. struct orig_node *orig_node;
  493. int i, ret;
  494. /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
  495. * if_num */
  496. for (i = 0; i < hash->size; i++) {
  497. head = &hash->table[i];
  498. rcu_read_lock();
  499. hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  500. spin_lock_bh(&orig_node->ogm_cnt_lock);
  501. ret = orig_node_del_if(orig_node, max_if_num,
  502. hard_iface->if_num);
  503. spin_unlock_bh(&orig_node->ogm_cnt_lock);
  504. if (ret == -1)
  505. goto err;
  506. }
  507. rcu_read_unlock();
  508. }
  509. /* renumber remaining batman interfaces _inside_ of orig_hash_lock */
  510. rcu_read_lock();
  511. list_for_each_entry_rcu(hard_iface_tmp, &hardif_list, list) {
  512. if (hard_iface_tmp->if_status == IF_NOT_IN_USE)
  513. continue;
  514. if (hard_iface == hard_iface_tmp)
  515. continue;
  516. if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
  517. continue;
  518. if (hard_iface_tmp->if_num > hard_iface->if_num)
  519. hard_iface_tmp->if_num--;
  520. }
  521. rcu_read_unlock();
  522. hard_iface->if_num = -1;
  523. return 0;
  524. err:
  525. rcu_read_unlock();
  526. return -ENOMEM;
  527. }