net/batman-adv/originator.c

   1 /* Copyright (C) 2009-2012 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, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "distributed-arp-table.h"
  22 #include "originator.h"
  23 #include "hash.h"
  24 #include "translation-table.h"
  25 #include "routing.h"
  26 #include "gateway_client.h"
  27 #include "hard-interface.h"
  28 #include "unicast.h"
  29 #include "soft-interface.h"
  30 #include "bridge_loop_avoidance.h"
  31
  32 static void batadv_purge_orig(struct work_struct *work);
  33
  34 static void batadv_start_purge_timer(struct batadv_priv *bat_priv)
  35 {
  36         INIT_DELAYED_WORK(&bat_priv->orig_work, batadv_purge_orig);
  37         queue_delayed_work(batadv_event_workqueue,
  38                            &bat_priv->orig_work, msecs_to_jiffies(1000));
  39 }
  40
  41 /* returns 1 if they are the same originator */
  42 static int batadv_compare_orig(const struct hlist_node *node, const void *data2)
  43 {
  44         const void *data1 = container_of(node, struct batadv_orig_node,
  45                                          hash_entry);
  46
  47         return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
  48 }
  49
  50 int batadv_originator_init(struct batadv_priv *bat_priv)
  51 {
  52         if (bat_priv->orig_hash)
  53                 return 0;
  54
  55         bat_priv->orig_hash = batadv_hash_new(1024);
  56
  57         if (!bat_priv->orig_hash)
  58                 goto err;
  59
  60         batadv_start_purge_timer(bat_priv);
  61         return 0;
  62
  63 err:
  64         return -ENOMEM;
  65 }
  66
  67 void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node)
  68 {
  69         if (atomic_dec_and_test(&neigh_node->refcount))
  70                 kfree_rcu(neigh_node, rcu);
  71 }
  72
  73 /* increases the refcounter of a found router */
  74 struct batadv_neigh_node *
  75 batadv_orig_node_get_router(struct batadv_orig_node *orig_node)
  76 {
  77         struct batadv_neigh_node *router;
  78
  79         rcu_read_lock();
  80         router = rcu_dereference(orig_node->router);
  81
  82         if (router && !atomic_inc_not_zero(&router->refcount))
  83                 router = NULL;
  84
  85         rcu_read_unlock();
  86         return router;
  87 }
  88
  89 struct batadv_neigh_node *
  90 batadv_neigh_node_new(struct batadv_hard_iface *hard_iface,
  91                       const uint8_t *neigh_addr, uint32_t seqno)
  92 {
  93         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  94         struct batadv_neigh_node *neigh_node;
  95
  96         neigh_node = kzalloc(sizeof(*neigh_node), GFP_ATOMIC);
  97         if (!neigh_node)
  98                 goto out;
  99
 100         INIT_HLIST_NODE(&neigh_node->list);
 101
 102         memcpy(neigh_node->addr, neigh_addr, ETH_ALEN);
 103         spin_lock_init(&neigh_node->lq_update_lock);
 104
 105         /* extra reference for return */
 106         atomic_set(&neigh_node->refcount, 2);
 107
 108         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 109                    "Creating new neighbor %pM, initial seqno %d\n",
 110                    neigh_addr, seqno);
 111
 112 out:
 113         return neigh_node;
 114 }
 115
 116 static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
 117 {
 118         struct hlist_node *node, *node_tmp;
 119         struct batadv_neigh_node *neigh_node, *tmp_neigh_node;
 120         struct batadv_orig_node *orig_node;
 121
 122         orig_node = container_of(rcu, struct batadv_orig_node, rcu);
 123
 124         spin_lock_bh(&orig_node->neigh_list_lock);
 125
 126         /* for all bonding members ... */
 127         list_for_each_entry_safe(neigh_node, tmp_neigh_node,
 128                                  &orig_node->bond_list, bonding_list) {
 129                 list_del_rcu(&neigh_node->bonding_list);
 130                 batadv_neigh_node_free_ref(neigh_node);
 131         }
 132
 133         /* for all neighbors towards this originator ... */
 134         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 135                                   &orig_node->neigh_list, list) {
 136                 hlist_del_rcu(&neigh_node->list);
 137                 batadv_neigh_node_free_ref(neigh_node);
 138         }
 139
 140         spin_unlock_bh(&orig_node->neigh_list_lock);
 141
 142         batadv_frag_list_free(&orig_node->frag_list);
 143         batadv_tt_global_del_orig(orig_node->bat_priv, orig_node,
 144                                   "originator timed out");
 145
 146         kfree(orig_node->tt_buff);
 147         kfree(orig_node->bcast_own);
 148         kfree(orig_node->bcast_own_sum);
 149         kfree(orig_node);
 150 }
 151
 152 void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node)
 153 {
 154         if (atomic_dec_and_test(&orig_node->refcount))
 155                 call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu);
 156 }
 157
 158 void batadv_originator_free(struct batadv_priv *bat_priv)
 159 {
 160         struct batadv_hashtable *hash = bat_priv->orig_hash;
 161         struct hlist_node *node, *node_tmp;
 162         struct hlist_head *head;
 163         spinlock_t *list_lock; /* spinlock to protect write access */
 164         struct batadv_orig_node *orig_node;
 165         uint32_t i;
 166
 167         if (!hash)
 168                 return;
 169
 170         cancel_delayed_work_sync(&bat_priv->orig_work);
 171
 172         bat_priv->orig_hash = NULL;
 173
 174         for (i = 0; i < hash->size; i++) {
 175                 head = &hash->table[i];
 176                 list_lock = &hash->list_locks[i];
 177
 178                 spin_lock_bh(list_lock);
 179                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 180                                           head, hash_entry) {
 181
 182                         hlist_del_rcu(node);
 183                         batadv_orig_node_free_ref(orig_node);
 184                 }
 185                 spin_unlock_bh(list_lock);
 186         }
 187
 188         batadv_hash_destroy(hash);
 189 }
 190
 191 /* this function finds or creates an originator entry for the given
 192  * address if it does not exits
 193  */
 194 struct batadv_orig_node *batadv_get_orig_node(struct batadv_priv *bat_priv,
 195                                               const uint8_t *addr)
 196 {
 197         struct batadv_orig_node *orig_node;
 198         int size;
 199         int hash_added;
 200         unsigned long reset_time;
 201
 202         orig_node = batadv_orig_hash_find(bat_priv, addr);
 203         if (orig_node)
 204                 return orig_node;
 205
 206         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 207                    "Creating new originator: %pM\n", addr);
 208
 209         orig_node = kzalloc(sizeof(*orig_node), GFP_ATOMIC);
 210         if (!orig_node)
 211                 return NULL;
 212
 213         INIT_HLIST_HEAD(&orig_node->neigh_list);
 214         INIT_LIST_HEAD(&orig_node->bond_list);
 215         spin_lock_init(&orig_node->ogm_cnt_lock);
 216         spin_lock_init(&orig_node->bcast_seqno_lock);
 217         spin_lock_init(&orig_node->neigh_list_lock);
 218         spin_lock_init(&orig_node->tt_buff_lock);
 219
 220         /* extra reference for return */
 221         atomic_set(&orig_node->refcount, 2);
 222
 223         orig_node->tt_initialised = false;
 224         orig_node->bat_priv = bat_priv;
 225         memcpy(orig_node->orig, addr, ETH_ALEN);
 226         batadv_dat_init_orig_node_addr(orig_node);
 227         orig_node->router = NULL;
 228         orig_node->tt_crc = 0;
 229         atomic_set(&orig_node->last_ttvn, 0);
 230         orig_node->tt_buff = NULL;
 231         orig_node->tt_buff_len = 0;
 232         atomic_set(&orig_node->tt_size, 0);
 233         reset_time = jiffies - 1 - msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
 234         orig_node->bcast_seqno_reset = reset_time;
 235         orig_node->batman_seqno_reset = reset_time;
 236
 237         atomic_set(&orig_node->bond_candidates, 0);
 238
 239         size = bat_priv->num_ifaces * sizeof(unsigned long) * BATADV_NUM_WORDS;
 240
 241         orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
 242         if (!orig_node->bcast_own)
 243                 goto free_orig_node;
 244
 245         size = bat_priv->num_ifaces * sizeof(uint8_t);
 246         orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
 247
 248         INIT_LIST_HEAD(&orig_node->frag_list);
 249         orig_node->last_frag_packet = 0;
 250
 251         if (!orig_node->bcast_own_sum)
 252                 goto free_bcast_own;
 253
 254         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
 255                                      batadv_choose_orig, orig_node,
 256                                      &orig_node->hash_entry);
 257         if (hash_added != 0)
 258                 goto free_bcast_own_sum;
 259
 260         return orig_node;
 261 free_bcast_own_sum:
 262         kfree(orig_node->bcast_own_sum);
 263 free_bcast_own:
 264         kfree(orig_node->bcast_own);
 265 free_orig_node:
 266         kfree(orig_node);
 267         return NULL;
 268 }
 269
 270 static bool
 271 batadv_purge_orig_neighbors(struct batadv_priv *bat_priv,
 272                             struct batadv_orig_node *orig_node,
 273                             struct batadv_neigh_node **best_neigh_node)
 274 {
 275         struct hlist_node *node, *node_tmp;
 276         struct batadv_neigh_node *neigh_node;
 277         bool neigh_purged = false;
 278         unsigned long last_seen;
 279         struct batadv_hard_iface *if_incoming;
 280
 281         *best_neigh_node = NULL;
 282
 283         spin_lock_bh(&orig_node->neigh_list_lock);
 284
 285         /* for all neighbors towards this originator ... */
 286         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 287                                   &orig_node->neigh_list, list) {
 288
 289                 last_seen = neigh_node->last_seen;
 290                 if_incoming = neigh_node->if_incoming;
 291
 292                 if ((batadv_has_timed_out(last_seen, BATADV_PURGE_TIMEOUT)) ||
 293                     (if_incoming->if_status == BATADV_IF_INACTIVE) ||
 294                     (if_incoming->if_status == BATADV_IF_NOT_IN_USE) ||
 295                     (if_incoming->if_status == BATADV_IF_TO_BE_REMOVED)) {
 296
 297                         if ((if_incoming->if_status == BATADV_IF_INACTIVE) ||
 298                             (if_incoming->if_status == BATADV_IF_NOT_IN_USE) ||
 299                             (if_incoming->if_status == BATADV_IF_TO_BE_REMOVED))
 300                                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 301                                            "neighbor purge: originator %pM, neighbor: %pM, iface: %s\n",
 302                                            orig_node->orig, neigh_node->addr,
 303                                            if_incoming->net_dev->name);
 304                         else
 305                                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 306                                            "neighbor timeout: originator %pM, neighbor: %pM, last_seen: %u\n",
 307                                            orig_node->orig, neigh_node->addr,
 308                                            jiffies_to_msecs(last_seen));
 309
 310                         neigh_purged = true;
 311
 312                         hlist_del_rcu(&neigh_node->list);
 313                         batadv_bonding_candidate_del(orig_node, neigh_node);
 314                         batadv_neigh_node_free_ref(neigh_node);
 315                 } else {
 316                         if ((!*best_neigh_node) ||
 317                             (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
 318                                 *best_neigh_node = neigh_node;
 319                 }
 320         }
 321
 322         spin_unlock_bh(&orig_node->neigh_list_lock);
 323         return neigh_purged;
 324 }
 325
 326 static bool batadv_purge_orig_node(struct batadv_priv *bat_priv,
 327                                    struct batadv_orig_node *orig_node)
 328 {
 329         struct batadv_neigh_node *best_neigh_node;
 330
 331         if (batadv_has_timed_out(orig_node->last_seen,
 332                                  2 * BATADV_PURGE_TIMEOUT)) {
 333                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 334                            "Originator timeout: originator %pM, last_seen %u\n",
 335                            orig_node->orig,
 336                            jiffies_to_msecs(orig_node->last_seen));
 337                 return true;
 338         } else {
 339                 if (batadv_purge_orig_neighbors(bat_priv, orig_node,
 340                                                 &best_neigh_node))
 341                         batadv_update_route(bat_priv, orig_node,
 342                                             best_neigh_node);
 343         }
 344
 345         return false;
 346 }
 347
 348 static void _batadv_purge_orig(struct batadv_priv *bat_priv)
 349 {
 350         struct batadv_hashtable *hash = bat_priv->orig_hash;
 351         struct hlist_node *node, *node_tmp;
 352         struct hlist_head *head;
 353         spinlock_t *list_lock; /* spinlock to protect write access */
 354         struct batadv_orig_node *orig_node;
 355         uint32_t i;
 356
 357         if (!hash)
 358                 return;
 359
 360         /* for all origins... */
 361         for (i = 0; i < hash->size; i++) {
 362                 head = &hash->table[i];
 363                 list_lock = &hash->list_locks[i];
 364
 365                 spin_lock_bh(list_lock);
 366                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 367                                           head, hash_entry) {
 368                         if (batadv_purge_orig_node(bat_priv, orig_node)) {
 369                                 if (orig_node->gw_flags)
 370                                         batadv_gw_node_delete(bat_priv,
 371                                                               orig_node);
 372                                 hlist_del_rcu(node);
 373                                 batadv_orig_node_free_ref(orig_node);
 374                                 continue;
 375                         }
 376
 377                         if (batadv_has_timed_out(orig_node->last_frag_packet,
 378                                                  BATADV_FRAG_TIMEOUT))
 379                                 batadv_frag_list_free(&orig_node->frag_list);
 380                 }
 381                 spin_unlock_bh(list_lock);
 382         }
 383
 384         batadv_gw_node_purge(bat_priv);
 385         batadv_gw_election(bat_priv);
 386 }
 387
 388 static void batadv_purge_orig(struct work_struct *work)
 389 {
 390         struct delayed_work *delayed_work;
 391         struct batadv_priv *bat_priv;
 392
 393         delayed_work = container_of(work, struct delayed_work, work);
 394         bat_priv = container_of(delayed_work, struct batadv_priv, orig_work);
 395         _batadv_purge_orig(bat_priv);
 396         batadv_start_purge_timer(bat_priv);
 397 }
 398
 399 void batadv_purge_orig_ref(struct batadv_priv *bat_priv)
 400 {
 401         _batadv_purge_orig(bat_priv);
 402 }
 403
 404 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset)
 405 {
 406         struct net_device *net_dev = (struct net_device *)seq->private;
 407         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 408         struct batadv_hashtable *hash = bat_priv->orig_hash;
 409         struct hlist_node *node, *node_tmp;
 410         struct hlist_head *head;
 411         struct batadv_hard_iface *primary_if;
 412         struct batadv_orig_node *orig_node;
 413         struct batadv_neigh_node *neigh_node, *neigh_node_tmp;
 414         int batman_count = 0;
 415         int last_seen_secs;
 416         int last_seen_msecs;
 417         unsigned long last_seen_jiffies;
 418         uint32_t i;
 419
 420         primary_if = batadv_seq_print_text_primary_if_get(seq);
 421         if (!primary_if)
 422                 goto out;
 423
 424         seq_printf(seq, "[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
 425                    BATADV_SOURCE_VERSION, primary_if->net_dev->name,
 426                    primary_if->net_dev->dev_addr, net_dev->name);
 427         seq_printf(seq, "  %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
 428                    "Originator", "last-seen", "#", BATADV_TQ_MAX_VALUE,
 429                    "Nexthop", "outgoingIF", "Potential nexthops");
 430
 431         for (i = 0; i < hash->size; i++) {
 432                 head = &hash->table[i];
 433
 434                 rcu_read_lock();
 435                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 436                         neigh_node = batadv_orig_node_get_router(orig_node);
 437                         if (!neigh_node)
 438                                 continue;
 439
 440                         if (neigh_node->tq_avg == 0)
 441                                 goto next;
 442
 443                         last_seen_jiffies = jiffies - orig_node->last_seen;
 444                         last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
 445                         last_seen_secs = last_seen_msecs / 1000;
 446                         last_seen_msecs = last_seen_msecs % 1000;
 447
 448                         seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
 449                                    orig_node->orig, last_seen_secs,
 450                                    last_seen_msecs, neigh_node->tq_avg,
 451                                    neigh_node->addr,
 452                                    neigh_node->if_incoming->net_dev->name);
 453
 454                         hlist_for_each_entry_rcu(neigh_node_tmp, node_tmp,
 455                                                  &orig_node->neigh_list, list) {
 456                                 seq_printf(seq, " %pM (%3i)",
 457                                            neigh_node_tmp->addr,
 458                                            neigh_node_tmp->tq_avg);
 459                         }
 460
 461                         seq_printf(seq, "\n");
 462                         batman_count++;
 463
 464 next:
 465                         batadv_neigh_node_free_ref(neigh_node);
 466                 }
 467                 rcu_read_unlock();
 468         }
 469
 470         if (batman_count == 0)
 471                 seq_printf(seq, "No batman nodes in range ...\n");
 472
 473 out:
 474         if (primary_if)
 475                 batadv_hardif_free_ref(primary_if);
 476         return 0;
 477 }
 478
 479 static int batadv_orig_node_add_if(struct batadv_orig_node *orig_node,
 480                                    int max_if_num)
 481 {
 482         void *data_ptr;
 483         size_t data_size, old_size;
 484
 485         data_size = max_if_num * sizeof(unsigned long) * BATADV_NUM_WORDS;
 486         old_size = (max_if_num - 1) * sizeof(unsigned long) * BATADV_NUM_WORDS;
 487         data_ptr = kmalloc(data_size, GFP_ATOMIC);
 488         if (!data_ptr)
 489                 return -ENOMEM;
 490
 491         memcpy(data_ptr, orig_node->bcast_own, old_size);
 492         kfree(orig_node->bcast_own);
 493         orig_node->bcast_own = data_ptr;
 494
 495         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 496         if (!data_ptr)
 497                 return -ENOMEM;
 498
 499         memcpy(data_ptr, orig_node->bcast_own_sum,
 500                (max_if_num - 1) * sizeof(uint8_t));
 501         kfree(orig_node->bcast_own_sum);
 502         orig_node->bcast_own_sum = data_ptr;
 503
 504         return 0;
 505 }
 506
 507 int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface,
 508                             int max_if_num)
 509 {
 510         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 511         struct batadv_hashtable *hash = bat_priv->orig_hash;
 512         struct hlist_node *node;
 513         struct hlist_head *head;
 514         struct batadv_orig_node *orig_node;
 515         uint32_t i;
 516         int ret;
 517
 518         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 519          * if_num
 520          */
 521         for (i = 0; i < hash->size; i++) {
 522                 head = &hash->table[i];
 523
 524                 rcu_read_lock();
 525                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 526                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 527                         ret = batadv_orig_node_add_if(orig_node, max_if_num);
 528                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 529
 530                         if (ret == -ENOMEM)
 531                                 goto err;
 532                 }
 533                 rcu_read_unlock();
 534         }
 535
 536         return 0;
 537
 538 err:
 539         rcu_read_unlock();
 540         return -ENOMEM;
 541 }
 542
 543 static int batadv_orig_node_del_if(struct batadv_orig_node *orig_node,
 544                                    int max_if_num, int del_if_num)
 545 {
 546         void *data_ptr = NULL;
 547         int chunk_size;
 548
 549         /* last interface was removed */
 550         if (max_if_num == 0)
 551                 goto free_bcast_own;
 552
 553         chunk_size = sizeof(unsigned long) * BATADV_NUM_WORDS;
 554         data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
 555         if (!data_ptr)
 556                 return -ENOMEM;
 557
 558         /* copy first part */
 559         memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
 560
 561         /* copy second part */
 562         memcpy((char *)data_ptr + del_if_num * chunk_size,
 563                orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
 564                (max_if_num - del_if_num) * chunk_size);
 565
 566 free_bcast_own:
 567         kfree(orig_node->bcast_own);
 568         orig_node->bcast_own = data_ptr;
 569
 570         if (max_if_num == 0)
 571                 goto free_own_sum;
 572
 573         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 574         if (!data_ptr)
 575                 return -ENOMEM;
 576
 577         memcpy(data_ptr, orig_node->bcast_own_sum,
 578                del_if_num * sizeof(uint8_t));
 579
 580         memcpy((char *)data_ptr + del_if_num * sizeof(uint8_t),
 581                orig_node->bcast_own_sum + ((del_if_num + 1) * sizeof(uint8_t)),
 582                (max_if_num - del_if_num) * sizeof(uint8_t));
 583
 584 free_own_sum:
 585         kfree(orig_node->bcast_own_sum);
 586         orig_node->bcast_own_sum = data_ptr;
 587
 588         return 0;
 589 }
 590
 591 int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface,
 592                             int max_if_num)
 593 {
 594         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 595         struct batadv_hashtable *hash = bat_priv->orig_hash;
 596         struct hlist_node *node;
 597         struct hlist_head *head;
 598         struct batadv_hard_iface *hard_iface_tmp;
 599         struct batadv_orig_node *orig_node;
 600         uint32_t i;
 601         int ret;
 602
 603         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 604          * if_num
 605          */
 606         for (i = 0; i < hash->size; i++) {
 607                 head = &hash->table[i];
 608
 609                 rcu_read_lock();
 610                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 611                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 612                         ret = batadv_orig_node_del_if(orig_node, max_if_num,
 613                                                       hard_iface->if_num);
 614                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 615
 616                         if (ret == -ENOMEM)
 617                                 goto err;
 618                 }
 619                 rcu_read_unlock();
 620         }
 621
 622         /* renumber remaining batman interfaces _inside_ of orig_hash_lock */
 623         rcu_read_lock();
 624         list_for_each_entry_rcu(hard_iface_tmp, &batadv_hardif_list, list) {
 625                 if (hard_iface_tmp->if_status == BATADV_IF_NOT_IN_USE)
 626                         continue;
 627
 628                 if (hard_iface == hard_iface_tmp)
 629                         continue;
 630
 631                 if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
 632                         continue;
 633
 634                 if (hard_iface_tmp->if_num > hard_iface->if_num)
 635                         hard_iface_tmp->if_num--;
 636         }
 637         rcu_read_unlock();
 638
 639         hard_iface->if_num = -1;
 640         return 0;
 641
 642 err:
 643         rcu_read_unlock();
 644         return -ENOMEM;
 645 }