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->tt_poss_change = false;
 225         orig_node->bat_priv = bat_priv;
 226         memcpy(orig_node->orig, addr, ETH_ALEN);
 227         batadv_dat_init_orig_node_addr(orig_node);
 228         orig_node->router = NULL;
 229         orig_node->tt_crc = 0;
 230         atomic_set(&orig_node->last_ttvn, 0);
 231         orig_node->tt_buff = NULL;
 232         orig_node->tt_buff_len = 0;
 233         atomic_set(&orig_node->tt_size, 0);
 234         reset_time = jiffies - 1 - msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
 235         orig_node->bcast_seqno_reset = reset_time;
 236         orig_node->batman_seqno_reset = reset_time;
 237
 238         atomic_set(&orig_node->bond_candidates, 0);
 239
 240         size = bat_priv->num_ifaces * sizeof(unsigned long) * BATADV_NUM_WORDS;
 241
 242         orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
 243         if (!orig_node->bcast_own)
 244                 goto free_orig_node;
 245
 246         size = bat_priv->num_ifaces * sizeof(uint8_t);
 247         orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
 248
 249         INIT_LIST_HEAD(&orig_node->frag_list);
 250         orig_node->last_frag_packet = 0;
 251
 252         if (!orig_node->bcast_own_sum)
 253                 goto free_bcast_own;
 254
 255         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
 256                                      batadv_choose_orig, orig_node,
 257                                      &orig_node->hash_entry);
 258         if (hash_added != 0)
 259                 goto free_bcast_own_sum;
 260
 261         return orig_node;
 262 free_bcast_own_sum:
 263         kfree(orig_node->bcast_own_sum);
 264 free_bcast_own:
 265         kfree(orig_node->bcast_own);
 266 free_orig_node:
 267         kfree(orig_node);
 268         return NULL;
 269 }
 270
 271 static bool
 272 batadv_purge_orig_neighbors(struct batadv_priv *bat_priv,
 273                             struct batadv_orig_node *orig_node,
 274                             struct batadv_neigh_node **best_neigh_node)
 275 {
 276         struct hlist_node *node, *node_tmp;
 277         struct batadv_neigh_node *neigh_node;
 278         bool neigh_purged = false;
 279         unsigned long last_seen;
 280         struct batadv_hard_iface *if_incoming;
 281
 282         *best_neigh_node = NULL;
 283
 284         spin_lock_bh(&orig_node->neigh_list_lock);
 285
 286         /* for all neighbors towards this originator ... */
 287         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 288                                   &orig_node->neigh_list, list) {
 289
 290                 last_seen = neigh_node->last_seen;
 291                 if_incoming = neigh_node->if_incoming;
 292
 293                 if ((batadv_has_timed_out(last_seen, BATADV_PURGE_TIMEOUT)) ||
 294                     (if_incoming->if_status == BATADV_IF_INACTIVE) ||
 295                     (if_incoming->if_status == BATADV_IF_NOT_IN_USE) ||
 296                     (if_incoming->if_status == BATADV_IF_TO_BE_REMOVED)) {
 297
 298                         if ((if_incoming->if_status == BATADV_IF_INACTIVE) ||
 299                             (if_incoming->if_status == BATADV_IF_NOT_IN_USE) ||
 300                             (if_incoming->if_status == BATADV_IF_TO_BE_REMOVED))
 301                                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 302                                            "neighbor purge: originator %pM, neighbor: %pM, iface: %s\n",
 303                                            orig_node->orig, neigh_node->addr,
 304                                            if_incoming->net_dev->name);
 305                         else
 306                                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 307                                            "neighbor timeout: originator %pM, neighbor: %pM, last_seen: %u\n",
 308                                            orig_node->orig, neigh_node->addr,
 309                                            jiffies_to_msecs(last_seen));
 310
 311                         neigh_purged = true;
 312
 313                         hlist_del_rcu(&neigh_node->list);
 314                         batadv_bonding_candidate_del(orig_node, neigh_node);
 315                         batadv_neigh_node_free_ref(neigh_node);
 316                 } else {
 317                         if ((!*best_neigh_node) ||
 318                             (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
 319                                 *best_neigh_node = neigh_node;
 320                 }
 321         }
 322
 323         spin_unlock_bh(&orig_node->neigh_list_lock);
 324         return neigh_purged;
 325 }
 326
 327 static bool batadv_purge_orig_node(struct batadv_priv *bat_priv,
 328                                    struct batadv_orig_node *orig_node)
 329 {
 330         struct batadv_neigh_node *best_neigh_node;
 331
 332         if (batadv_has_timed_out(orig_node->last_seen,
 333                                  2 * BATADV_PURGE_TIMEOUT)) {
 334                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 335                            "Originator timeout: originator %pM, last_seen %u\n",
 336                            orig_node->orig,
 337                            jiffies_to_msecs(orig_node->last_seen));
 338                 return true;
 339         } else {
 340                 if (batadv_purge_orig_neighbors(bat_priv, orig_node,
 341                                                 &best_neigh_node))
 342                         batadv_update_route(bat_priv, orig_node,
 343                                             best_neigh_node);
 344         }
 345
 346         return false;
 347 }
 348
 349 static void _batadv_purge_orig(struct batadv_priv *bat_priv)
 350 {
 351         struct batadv_hashtable *hash = bat_priv->orig_hash;
 352         struct hlist_node *node, *node_tmp;
 353         struct hlist_head *head;
 354         spinlock_t *list_lock; /* spinlock to protect write access */
 355         struct batadv_orig_node *orig_node;
 356         uint32_t i;
 357
 358         if (!hash)
 359                 return;
 360
 361         /* for all origins... */
 362         for (i = 0; i < hash->size; i++) {
 363                 head = &hash->table[i];
 364                 list_lock = &hash->list_locks[i];
 365
 366                 spin_lock_bh(list_lock);
 367                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 368                                           head, hash_entry) {
 369                         if (batadv_purge_orig_node(bat_priv, orig_node)) {
 370                                 if (orig_node->gw_flags)
 371                                         batadv_gw_node_delete(bat_priv,
 372                                                               orig_node);
 373                                 hlist_del_rcu(node);
 374                                 batadv_orig_node_free_ref(orig_node);
 375                                 continue;
 376                         }
 377
 378                         if (batadv_has_timed_out(orig_node->last_frag_packet,
 379                                                  BATADV_FRAG_TIMEOUT))
 380                                 batadv_frag_list_free(&orig_node->frag_list);
 381                 }
 382                 spin_unlock_bh(list_lock);
 383         }
 384
 385         batadv_gw_node_purge(bat_priv);
 386         batadv_gw_election(bat_priv);
 387 }
 388
 389 static void batadv_purge_orig(struct work_struct *work)
 390 {
 391         struct delayed_work *delayed_work;
 392         struct batadv_priv *bat_priv;
 393
 394         delayed_work = container_of(work, struct delayed_work, work);
 395         bat_priv = container_of(delayed_work, struct batadv_priv, orig_work);
 396         _batadv_purge_orig(bat_priv);
 397         batadv_start_purge_timer(bat_priv);
 398 }
 399
 400 void batadv_purge_orig_ref(struct batadv_priv *bat_priv)
 401 {
 402         _batadv_purge_orig(bat_priv);
 403 }
 404
 405 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset)
 406 {
 407         struct net_device *net_dev = (struct net_device *)seq->private;
 408         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 409         struct batadv_hashtable *hash = bat_priv->orig_hash;
 410         struct hlist_node *node, *node_tmp;
 411         struct hlist_head *head;
 412         struct batadv_hard_iface *primary_if;
 413         struct batadv_orig_node *orig_node;
 414         struct batadv_neigh_node *neigh_node, *neigh_node_tmp;
 415         int batman_count = 0;
 416         int last_seen_secs;
 417         int last_seen_msecs;
 418         unsigned long last_seen_jiffies;
 419         uint32_t i;
 420
 421         primary_if = batadv_seq_print_text_primary_if_get(seq);
 422         if (!primary_if)
 423                 goto out;
 424
 425         seq_printf(seq, "[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
 426                    BATADV_SOURCE_VERSION, primary_if->net_dev->name,
 427                    primary_if->net_dev->dev_addr, net_dev->name);
 428         seq_printf(seq, "  %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
 429                    "Originator", "last-seen", "#", BATADV_TQ_MAX_VALUE,
 430                    "Nexthop", "outgoingIF", "Potential nexthops");
 431
 432         for (i = 0; i < hash->size; i++) {
 433                 head = &hash->table[i];
 434
 435                 rcu_read_lock();
 436                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 437                         neigh_node = batadv_orig_node_get_router(orig_node);
 438                         if (!neigh_node)
 439                                 continue;
 440
 441                         if (neigh_node->tq_avg == 0)
 442                                 goto next;
 443
 444                         last_seen_jiffies = jiffies - orig_node->last_seen;
 445                         last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
 446                         last_seen_secs = last_seen_msecs / 1000;
 447                         last_seen_msecs = last_seen_msecs % 1000;
 448
 449                         seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
 450                                    orig_node->orig, last_seen_secs,
 451                                    last_seen_msecs, neigh_node->tq_avg,
 452                                    neigh_node->addr,
 453                                    neigh_node->if_incoming->net_dev->name);
 454
 455                         hlist_for_each_entry_rcu(neigh_node_tmp, node_tmp,
 456                                                  &orig_node->neigh_list, list) {
 457                                 seq_printf(seq, " %pM (%3i)",
 458                                            neigh_node_tmp->addr,
 459                                            neigh_node_tmp->tq_avg);
 460                         }
 461
 462                         seq_printf(seq, "\n");
 463                         batman_count++;
 464
 465 next:
 466                         batadv_neigh_node_free_ref(neigh_node);
 467                 }
 468                 rcu_read_unlock();
 469         }
 470
 471         if (batman_count == 0)
 472                 seq_printf(seq, "No batman nodes in range ...\n");
 473
 474 out:
 475         if (primary_if)
 476                 batadv_hardif_free_ref(primary_if);
 477         return 0;
 478 }
 479
 480 static int batadv_orig_node_add_if(struct batadv_orig_node *orig_node,
 481                                    int max_if_num)
 482 {
 483         void *data_ptr;
 484         size_t data_size, old_size;
 485
 486         data_size = max_if_num * sizeof(unsigned long) * BATADV_NUM_WORDS;
 487         old_size = (max_if_num - 1) * sizeof(unsigned long) * BATADV_NUM_WORDS;
 488         data_ptr = kmalloc(data_size, GFP_ATOMIC);
 489         if (!data_ptr)
 490                 return -ENOMEM;
 491
 492         memcpy(data_ptr, orig_node->bcast_own, old_size);
 493         kfree(orig_node->bcast_own);
 494         orig_node->bcast_own = data_ptr;
 495
 496         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 497         if (!data_ptr)
 498                 return -ENOMEM;
 499
 500         memcpy(data_ptr, orig_node->bcast_own_sum,
 501                (max_if_num - 1) * sizeof(uint8_t));
 502         kfree(orig_node->bcast_own_sum);
 503         orig_node->bcast_own_sum = data_ptr;
 504
 505         return 0;
 506 }
 507
 508 int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface,
 509                             int max_if_num)
 510 {
 511         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 512         struct batadv_hashtable *hash = bat_priv->orig_hash;
 513         struct hlist_node *node;
 514         struct hlist_head *head;
 515         struct batadv_orig_node *orig_node;
 516         uint32_t i;
 517         int ret;
 518
 519         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 520          * if_num
 521          */
 522         for (i = 0; i < hash->size; i++) {
 523                 head = &hash->table[i];
 524
 525                 rcu_read_lock();
 526                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 527                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 528                         ret = batadv_orig_node_add_if(orig_node, max_if_num);
 529                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 530
 531                         if (ret == -ENOMEM)
 532                                 goto err;
 533                 }
 534                 rcu_read_unlock();
 535         }
 536
 537         return 0;
 538
 539 err:
 540         rcu_read_unlock();
 541         return -ENOMEM;
 542 }
 543
 544 static int batadv_orig_node_del_if(struct batadv_orig_node *orig_node,
 545                                    int max_if_num, int del_if_num)
 546 {
 547         void *data_ptr = NULL;
 548         int chunk_size;
 549
 550         /* last interface was removed */
 551         if (max_if_num == 0)
 552                 goto free_bcast_own;
 553
 554         chunk_size = sizeof(unsigned long) * BATADV_NUM_WORDS;
 555         data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
 556         if (!data_ptr)
 557                 return -ENOMEM;
 558
 559         /* copy first part */
 560         memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
 561
 562         /* copy second part */
 563         memcpy((char *)data_ptr + del_if_num * chunk_size,
 564                orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
 565                (max_if_num - del_if_num) * chunk_size);
 566
 567 free_bcast_own:
 568         kfree(orig_node->bcast_own);
 569         orig_node->bcast_own = data_ptr;
 570
 571         if (max_if_num == 0)
 572                 goto free_own_sum;
 573
 574         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 575         if (!data_ptr)
 576                 return -ENOMEM;
 577
 578         memcpy(data_ptr, orig_node->bcast_own_sum,
 579                del_if_num * sizeof(uint8_t));
 580
 581         memcpy((char *)data_ptr + del_if_num * sizeof(uint8_t),
 582                orig_node->bcast_own_sum + ((del_if_num + 1) * sizeof(uint8_t)),
 583                (max_if_num - del_if_num) * sizeof(uint8_t));
 584
 585 free_own_sum:
 586         kfree(orig_node->bcast_own_sum);
 587         orig_node->bcast_own_sum = data_ptr;
 588
 589         return 0;
 590 }
 591
 592 int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface,
 593                             int max_if_num)
 594 {
 595         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 596         struct batadv_hashtable *hash = bat_priv->orig_hash;
 597         struct hlist_node *node;
 598         struct hlist_head *head;
 599         struct batadv_hard_iface *hard_iface_tmp;
 600         struct batadv_orig_node *orig_node;
 601         uint32_t i;
 602         int ret;
 603
 604         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 605          * if_num
 606          */
 607         for (i = 0; i < hash->size; i++) {
 608                 head = &hash->table[i];
 609
 610                 rcu_read_lock();
 611                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 612                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 613                         ret = batadv_orig_node_del_if(orig_node, max_if_num,
 614                                                       hard_iface->if_num);
 615                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 616
 617                         if (ret == -ENOMEM)
 618                                 goto err;
 619                 }
 620                 rcu_read_unlock();
 621         }
 622
 623         /* renumber remaining batman interfaces _inside_ of orig_hash_lock */
 624         rcu_read_lock();
 625         list_for_each_entry_rcu(hard_iface_tmp, &batadv_hardif_list, list) {
 626                 if (hard_iface_tmp->if_status == BATADV_IF_NOT_IN_USE)
 627                         continue;
 628
 629                 if (hard_iface == hard_iface_tmp)
 630                         continue;
 631
 632                 if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
 633                         continue;
 634
 635                 if (hard_iface_tmp->if_num > hard_iface->if_num)
 636                         hard_iface_tmp->if_num--;
 637         }
 638         rcu_read_unlock();
 639
 640         hard_iface->if_num = -1;
 641         return 0;
 642
 643 err:
 644         rcu_read_unlock();
 645         return -ENOMEM;
 646 }