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 "originator.h"
  22 #include "hash.h"
  23 #include "translation-table.h"
  24 #include "routing.h"
  25 #include "gateway_client.h"
  26 #include "hard-interface.h"
  27 #include "unicast.h"
  28 #include "soft-interface.h"
  29 #include "bridge_loop_avoidance.h"
  30
  31 static void purge_orig(struct work_struct *work);
  32
  33 static void start_purge_timer(struct bat_priv *bat_priv)
  34 {
  35         INIT_DELAYED_WORK(&bat_priv->orig_work, purge_orig);
  36         queue_delayed_work(batadv_event_workqueue,
  37                            &bat_priv->orig_work, msecs_to_jiffies(1000));
  38 }
  39
  40 /* returns 1 if they are the same originator */
  41 static int compare_orig(const struct hlist_node *node, const void *data2)
  42 {
  43         const void *data1 = container_of(node, struct orig_node, hash_entry);
  44
  45         return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
  46 }
  47
  48 int batadv_originator_init(struct bat_priv *bat_priv)
  49 {
  50         if (bat_priv->orig_hash)
  51                 return 0;
  52
  53         bat_priv->orig_hash = batadv_hash_new(1024);
  54
  55         if (!bat_priv->orig_hash)
  56                 goto err;
  57
  58         start_purge_timer(bat_priv);
  59         return 0;
  60
  61 err:
  62         return -ENOMEM;
  63 }
  64
  65 void batadv_neigh_node_free_ref(struct neigh_node *neigh_node)
  66 {
  67         if (atomic_dec_and_test(&neigh_node->refcount))
  68                 kfree_rcu(neigh_node, rcu);
  69 }
  70
  71 /* increases the refcounter of a found router */
  72 struct neigh_node *batadv_orig_node_get_router(struct orig_node *orig_node)
  73 {
  74         struct neigh_node *router;
  75
  76         rcu_read_lock();
  77         router = rcu_dereference(orig_node->router);
  78
  79         if (router && !atomic_inc_not_zero(&router->refcount))
  80                 router = NULL;
  81
  82         rcu_read_unlock();
  83         return router;
  84 }
  85
  86 struct neigh_node *batadv_neigh_node_new(struct hard_iface *hard_iface,
  87                                          const uint8_t *neigh_addr,
  88                                          uint32_t seqno)
  89 {
  90         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  91         struct neigh_node *neigh_node;
  92
  93         neigh_node = kzalloc(sizeof(*neigh_node), GFP_ATOMIC);
  94         if (!neigh_node)
  95                 goto out;
  96
  97         INIT_HLIST_NODE(&neigh_node->list);
  98
  99         memcpy(neigh_node->addr, neigh_addr, ETH_ALEN);
 100         spin_lock_init(&neigh_node->lq_update_lock);
 101
 102         /* extra reference for return */
 103         atomic_set(&neigh_node->refcount, 2);
 104
 105         batadv_dbg(DBG_BATMAN, bat_priv,
 106                    "Creating new neighbor %pM, initial seqno %d\n",
 107                    neigh_addr, seqno);
 108
 109 out:
 110         return neigh_node;
 111 }
 112
 113 static void orig_node_free_rcu(struct rcu_head *rcu)
 114 {
 115         struct hlist_node *node, *node_tmp;
 116         struct neigh_node *neigh_node, *tmp_neigh_node;
 117         struct orig_node *orig_node;
 118
 119         orig_node = container_of(rcu, struct orig_node, rcu);
 120
 121         spin_lock_bh(&orig_node->neigh_list_lock);
 122
 123         /* for all bonding members ... */
 124         list_for_each_entry_safe(neigh_node, tmp_neigh_node,
 125                                  &orig_node->bond_list, bonding_list) {
 126                 list_del_rcu(&neigh_node->bonding_list);
 127                 batadv_neigh_node_free_ref(neigh_node);
 128         }
 129
 130         /* for all neighbors towards this originator ... */
 131         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 132                                   &orig_node->neigh_list, list) {
 133                 hlist_del_rcu(&neigh_node->list);
 134                 batadv_neigh_node_free_ref(neigh_node);
 135         }
 136
 137         spin_unlock_bh(&orig_node->neigh_list_lock);
 138
 139         batadv_frag_list_free(&orig_node->frag_list);
 140         batadv_tt_global_del_orig(orig_node->bat_priv, orig_node,
 141                                   "originator timed out");
 142
 143         kfree(orig_node->tt_buff);
 144         kfree(orig_node->bcast_own);
 145         kfree(orig_node->bcast_own_sum);
 146         kfree(orig_node);
 147 }
 148
 149 void batadv_orig_node_free_ref(struct orig_node *orig_node)
 150 {
 151         if (atomic_dec_and_test(&orig_node->refcount))
 152                 call_rcu(&orig_node->rcu, orig_node_free_rcu);
 153 }
 154
 155 void batadv_originator_free(struct bat_priv *bat_priv)
 156 {
 157         struct hashtable_t *hash = bat_priv->orig_hash;
 158         struct hlist_node *node, *node_tmp;
 159         struct hlist_head *head;
 160         spinlock_t *list_lock; /* spinlock to protect write access */
 161         struct orig_node *orig_node;
 162         uint32_t i;
 163
 164         if (!hash)
 165                 return;
 166
 167         cancel_delayed_work_sync(&bat_priv->orig_work);
 168
 169         bat_priv->orig_hash = NULL;
 170
 171         for (i = 0; i < hash->size; i++) {
 172                 head = &hash->table[i];
 173                 list_lock = &hash->list_locks[i];
 174
 175                 spin_lock_bh(list_lock);
 176                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 177                                           head, hash_entry) {
 178
 179                         hlist_del_rcu(node);
 180                         batadv_orig_node_free_ref(orig_node);
 181                 }
 182                 spin_unlock_bh(list_lock);
 183         }
 184
 185         batadv_hash_destroy(hash);
 186 }
 187
 188 /* this function finds or creates an originator entry for the given
 189  * address if it does not exits
 190  */
 191 struct orig_node *batadv_get_orig_node(struct bat_priv *bat_priv,
 192                                        const uint8_t *addr)
 193 {
 194         struct orig_node *orig_node;
 195         int size;
 196         int hash_added;
 197
 198         orig_node = batadv_orig_hash_find(bat_priv, addr);
 199         if (orig_node)
 200                 return orig_node;
 201
 202         batadv_dbg(DBG_BATMAN, bat_priv, "Creating new originator: %pM\n",
 203                    addr);
 204
 205         orig_node = kzalloc(sizeof(*orig_node), GFP_ATOMIC);
 206         if (!orig_node)
 207                 return NULL;
 208
 209         INIT_HLIST_HEAD(&orig_node->neigh_list);
 210         INIT_LIST_HEAD(&orig_node->bond_list);
 211         spin_lock_init(&orig_node->ogm_cnt_lock);
 212         spin_lock_init(&orig_node->bcast_seqno_lock);
 213         spin_lock_init(&orig_node->neigh_list_lock);
 214         spin_lock_init(&orig_node->tt_buff_lock);
 215
 216         /* extra reference for return */
 217         atomic_set(&orig_node->refcount, 2);
 218
 219         orig_node->tt_initialised = false;
 220         orig_node->tt_poss_change = false;
 221         orig_node->bat_priv = bat_priv;
 222         memcpy(orig_node->orig, addr, ETH_ALEN);
 223         orig_node->router = NULL;
 224         orig_node->tt_crc = 0;
 225         atomic_set(&orig_node->last_ttvn, 0);
 226         orig_node->tt_buff = NULL;
 227         orig_node->tt_buff_len = 0;
 228         atomic_set(&orig_node->tt_size, 0);
 229         orig_node->bcast_seqno_reset = jiffies - 1
 230                                         - msecs_to_jiffies(RESET_PROTECTION_MS);
 231         orig_node->batman_seqno_reset = jiffies - 1
 232                                         - msecs_to_jiffies(RESET_PROTECTION_MS);
 233
 234         atomic_set(&orig_node->bond_candidates, 0);
 235
 236         size = bat_priv->num_ifaces * sizeof(unsigned long) * NUM_WORDS;
 237
 238         orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
 239         if (!orig_node->bcast_own)
 240                 goto free_orig_node;
 241
 242         size = bat_priv->num_ifaces * sizeof(uint8_t);
 243         orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
 244
 245         INIT_LIST_HEAD(&orig_node->frag_list);
 246         orig_node->last_frag_packet = 0;
 247
 248         if (!orig_node->bcast_own_sum)
 249                 goto free_bcast_own;
 250
 251         hash_added = batadv_hash_add(bat_priv->orig_hash, compare_orig,
 252                                      batadv_choose_orig, orig_node,
 253                                      &orig_node->hash_entry);
 254         if (hash_added != 0)
 255                 goto free_bcast_own_sum;
 256
 257         return orig_node;
 258 free_bcast_own_sum:
 259         kfree(orig_node->bcast_own_sum);
 260 free_bcast_own:
 261         kfree(orig_node->bcast_own);
 262 free_orig_node:
 263         kfree(orig_node);
 264         return NULL;
 265 }
 266
 267 static bool purge_orig_neighbors(struct bat_priv *bat_priv,
 268                                  struct orig_node *orig_node,
 269                                  struct neigh_node **best_neigh_node)
 270 {
 271         struct hlist_node *node, *node_tmp;
 272         struct neigh_node *neigh_node;
 273         bool neigh_purged = false;
 274         unsigned long last_seen;
 275         struct hard_iface *if_incoming;
 276
 277         *best_neigh_node = NULL;
 278
 279         spin_lock_bh(&orig_node->neigh_list_lock);
 280
 281         /* for all neighbors towards this originator ... */
 282         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 283                                   &orig_node->neigh_list, list) {
 284
 285                 last_seen = neigh_node->last_seen;
 286                 if_incoming = neigh_node->if_incoming;
 287
 288                 if ((batadv_has_timed_out(last_seen, PURGE_TIMEOUT)) ||
 289                     (if_incoming->if_status == IF_INACTIVE) ||
 290                     (if_incoming->if_status == IF_NOT_IN_USE) ||
 291                     (if_incoming->if_status == IF_TO_BE_REMOVED)) {
 292
 293                         if ((if_incoming->if_status == IF_INACTIVE) ||
 294                             (if_incoming->if_status == IF_NOT_IN_USE) ||
 295                             (if_incoming->if_status == IF_TO_BE_REMOVED))
 296                                 batadv_dbg(DBG_BATMAN, bat_priv,
 297                                            "neighbor purge: originator %pM, neighbor: %pM, iface: %s\n",
 298                                            orig_node->orig, neigh_node->addr,
 299                                            if_incoming->net_dev->name);
 300                         else
 301                                 batadv_dbg(DBG_BATMAN, bat_priv,
 302                                            "neighbor timeout: originator %pM, neighbor: %pM, last_seen: %u\n",
 303                                            orig_node->orig, neigh_node->addr,
 304                                            jiffies_to_msecs(last_seen));
 305
 306                         neigh_purged = true;
 307
 308                         hlist_del_rcu(&neigh_node->list);
 309                         batadv_bonding_candidate_del(orig_node, neigh_node);
 310                         batadv_neigh_node_free_ref(neigh_node);
 311                 } else {
 312                         if ((!*best_neigh_node) ||
 313                             (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
 314                                 *best_neigh_node = neigh_node;
 315                 }
 316         }
 317
 318         spin_unlock_bh(&orig_node->neigh_list_lock);
 319         return neigh_purged;
 320 }
 321
 322 static bool purge_orig_node(struct bat_priv *bat_priv,
 323                             struct orig_node *orig_node)
 324 {
 325         struct neigh_node *best_neigh_node;
 326
 327         if (batadv_has_timed_out(orig_node->last_seen, 2 * PURGE_TIMEOUT)) {
 328                 batadv_dbg(DBG_BATMAN, bat_priv,
 329                            "Originator timeout: originator %pM, last_seen %u\n",
 330                            orig_node->orig,
 331                            jiffies_to_msecs(orig_node->last_seen));
 332                 return true;
 333         } else {
 334                 if (purge_orig_neighbors(bat_priv, orig_node,
 335                                          &best_neigh_node))
 336                         batadv_update_route(bat_priv, orig_node,
 337                                             best_neigh_node);
 338         }
 339
 340         return false;
 341 }
 342
 343 static void _purge_orig(struct bat_priv *bat_priv)
 344 {
 345         struct hashtable_t *hash = bat_priv->orig_hash;
 346         struct hlist_node *node, *node_tmp;
 347         struct hlist_head *head;
 348         spinlock_t *list_lock; /* spinlock to protect write access */
 349         struct orig_node *orig_node;
 350         uint32_t i;
 351
 352         if (!hash)
 353                 return;
 354
 355         /* for all origins... */
 356         for (i = 0; i < hash->size; i++) {
 357                 head = &hash->table[i];
 358                 list_lock = &hash->list_locks[i];
 359
 360                 spin_lock_bh(list_lock);
 361                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 362                                           head, hash_entry) {
 363                         if (purge_orig_node(bat_priv, orig_node)) {
 364                                 if (orig_node->gw_flags)
 365                                         batadv_gw_node_delete(bat_priv,
 366                                                               orig_node);
 367                                 hlist_del_rcu(node);
 368                                 batadv_orig_node_free_ref(orig_node);
 369                                 continue;
 370                         }
 371
 372                         if (batadv_has_timed_out(orig_node->last_frag_packet,
 373                                                  FRAG_TIMEOUT))
 374                                 batadv_frag_list_free(&orig_node->frag_list);
 375                 }
 376                 spin_unlock_bh(list_lock);
 377         }
 378
 379         batadv_gw_node_purge(bat_priv);
 380         batadv_gw_election(bat_priv);
 381 }
 382
 383 static void purge_orig(struct work_struct *work)
 384 {
 385         struct delayed_work *delayed_work =
 386                 container_of(work, struct delayed_work, work);
 387         struct bat_priv *bat_priv =
 388                 container_of(delayed_work, struct bat_priv, orig_work);
 389
 390         _purge_orig(bat_priv);
 391         start_purge_timer(bat_priv);
 392 }
 393
 394 void batadv_purge_orig_ref(struct bat_priv *bat_priv)
 395 {
 396         _purge_orig(bat_priv);
 397 }
 398
 399 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset)
 400 {
 401         struct net_device *net_dev = (struct net_device *)seq->private;
 402         struct bat_priv *bat_priv = netdev_priv(net_dev);
 403         struct hashtable_t *hash = bat_priv->orig_hash;
 404         struct hlist_node *node, *node_tmp;
 405         struct hlist_head *head;
 406         struct hard_iface *primary_if;
 407         struct orig_node *orig_node;
 408         struct neigh_node *neigh_node, *neigh_node_tmp;
 409         int batman_count = 0;
 410         int last_seen_secs;
 411         int last_seen_msecs;
 412         uint32_t i;
 413         int ret = 0;
 414
 415         primary_if = batadv_primary_if_get_selected(bat_priv);
 416
 417         if (!primary_if) {
 418                 ret = seq_printf(seq,
 419                                  "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 420                                  net_dev->name);
 421                 goto out;
 422         }
 423
 424         if (primary_if->if_status != IF_ACTIVE) {
 425                 ret = seq_printf(seq,
 426                                  "BATMAN mesh %s disabled - primary interface not active\n",
 427                                  net_dev->name);
 428                 goto out;
 429         }
 430
 431         seq_printf(seq, "[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
 432                    SOURCE_VERSION, primary_if->net_dev->name,
 433                    primary_if->net_dev->dev_addr, net_dev->name);
 434         seq_printf(seq, "  %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
 435                    "Originator", "last-seen", "#", TQ_MAX_VALUE, "Nexthop",
 436                    "outgoingIF", "Potential nexthops");
 437
 438         for (i = 0; i < hash->size; i++) {
 439                 head = &hash->table[i];
 440
 441                 rcu_read_lock();
 442                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 443                         neigh_node = batadv_orig_node_get_router(orig_node);
 444                         if (!neigh_node)
 445                                 continue;
 446
 447                         if (neigh_node->tq_avg == 0)
 448                                 goto next;
 449
 450                         last_seen_secs = jiffies_to_msecs(jiffies -
 451                                                 orig_node->last_seen) / 1000;
 452                         last_seen_msecs = jiffies_to_msecs(jiffies -
 453                                                 orig_node->last_seen) % 1000;
 454
 455                         seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
 456                                    orig_node->orig, last_seen_secs,
 457                                    last_seen_msecs, neigh_node->tq_avg,
 458                                    neigh_node->addr,
 459                                    neigh_node->if_incoming->net_dev->name);
 460
 461                         hlist_for_each_entry_rcu(neigh_node_tmp, node_tmp,
 462                                                  &orig_node->neigh_list, list) {
 463                                 seq_printf(seq, " %pM (%3i)",
 464                                            neigh_node_tmp->addr,
 465                                            neigh_node_tmp->tq_avg);
 466                         }
 467
 468                         seq_printf(seq, "\n");
 469                         batman_count++;
 470
 471 next:
 472                         batadv_neigh_node_free_ref(neigh_node);
 473                 }
 474                 rcu_read_unlock();
 475         }
 476
 477         if (batman_count == 0)
 478                 seq_printf(seq, "No batman nodes in range ...\n");
 479
 480 out:
 481         if (primary_if)
 482                 batadv_hardif_free_ref(primary_if);
 483         return ret;
 484 }
 485
 486 static int orig_node_add_if(struct orig_node *orig_node, int max_if_num)
 487 {
 488         void *data_ptr;
 489
 490         data_ptr = kmalloc(max_if_num * sizeof(unsigned long) * NUM_WORDS,
 491                            GFP_ATOMIC);
 492         if (!data_ptr)
 493                 return -ENOMEM;
 494
 495         memcpy(data_ptr, orig_node->bcast_own,
 496                (max_if_num - 1) * sizeof(unsigned long) * NUM_WORDS);
 497         kfree(orig_node->bcast_own);
 498         orig_node->bcast_own = data_ptr;
 499
 500         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 501         if (!data_ptr)
 502                 return -ENOMEM;
 503
 504         memcpy(data_ptr, orig_node->bcast_own_sum,
 505                (max_if_num - 1) * sizeof(uint8_t));
 506         kfree(orig_node->bcast_own_sum);
 507         orig_node->bcast_own_sum = data_ptr;
 508
 509         return 0;
 510 }
 511
 512 int batadv_orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num)
 513 {
 514         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 515         struct hashtable_t *hash = bat_priv->orig_hash;
 516         struct hlist_node *node;
 517         struct hlist_head *head;
 518         struct orig_node *orig_node;
 519         uint32_t i;
 520         int ret;
 521
 522         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 523          * if_num
 524          */
 525         for (i = 0; i < hash->size; i++) {
 526                 head = &hash->table[i];
 527
 528                 rcu_read_lock();
 529                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 530                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 531                         ret = orig_node_add_if(orig_node, max_if_num);
 532                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 533
 534                         if (ret == -ENOMEM)
 535                                 goto err;
 536                 }
 537                 rcu_read_unlock();
 538         }
 539
 540         return 0;
 541
 542 err:
 543         rcu_read_unlock();
 544         return -ENOMEM;
 545 }
 546
 547 static int orig_node_del_if(struct orig_node *orig_node,
 548                      int max_if_num, int del_if_num)
 549 {
 550         void *data_ptr = NULL;
 551         int chunk_size;
 552
 553         /* last interface was removed */
 554         if (max_if_num == 0)
 555                 goto free_bcast_own;
 556
 557         chunk_size = sizeof(unsigned long) * NUM_WORDS;
 558         data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
 559         if (!data_ptr)
 560                 return -ENOMEM;
 561
 562         /* copy first part */
 563         memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
 564
 565         /* copy second part */
 566         memcpy((char *)data_ptr + del_if_num * chunk_size,
 567                orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
 568                (max_if_num - del_if_num) * chunk_size);
 569
 570 free_bcast_own:
 571         kfree(orig_node->bcast_own);
 572         orig_node->bcast_own = data_ptr;
 573
 574         if (max_if_num == 0)
 575                 goto free_own_sum;
 576
 577         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 578         if (!data_ptr)
 579                 return -ENOMEM;
 580
 581         memcpy(data_ptr, orig_node->bcast_own_sum,
 582                del_if_num * sizeof(uint8_t));
 583
 584         memcpy((char *)data_ptr + del_if_num * sizeof(uint8_t),
 585                orig_node->bcast_own_sum + ((del_if_num + 1) * sizeof(uint8_t)),
 586                (max_if_num - del_if_num) * sizeof(uint8_t));
 587
 588 free_own_sum:
 589         kfree(orig_node->bcast_own_sum);
 590         orig_node->bcast_own_sum = data_ptr;
 591
 592         return 0;
 593 }
 594
 595 int batadv_orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num)
 596 {
 597         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 598         struct hashtable_t *hash = bat_priv->orig_hash;
 599         struct hlist_node *node;
 600         struct hlist_head *head;
 601         struct hard_iface *hard_iface_tmp;
 602         struct orig_node *orig_node;
 603         uint32_t i;
 604         int ret;
 605
 606         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 607          * if_num
 608          */
 609         for (i = 0; i < hash->size; i++) {
 610                 head = &hash->table[i];
 611
 612                 rcu_read_lock();
 613                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 614                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 615                         ret = orig_node_del_if(orig_node, max_if_num,
 616                                         hard_iface->if_num);
 617                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 618
 619                         if (ret == -ENOMEM)
 620                                 goto err;
 621                 }
 622                 rcu_read_unlock();
 623         }
 624
 625         /* renumber remaining batman interfaces _inside_ of orig_hash_lock */
 626         rcu_read_lock();
 627         list_for_each_entry_rcu(hard_iface_tmp, &batadv_hardif_list, list) {
 628                 if (hard_iface_tmp->if_status == IF_NOT_IN_USE)
 629                         continue;
 630
 631                 if (hard_iface == hard_iface_tmp)
 632                         continue;
 633
 634                 if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
 635                         continue;
 636
 637                 if (hard_iface_tmp->if_num > hard_iface->if_num)
 638                         hard_iface_tmp->if_num--;
 639         }
 640         rcu_read_unlock();
 641
 642         hard_iface->if_num = -1;
 643         return 0;
 644
 645 err:
 646         rcu_read_unlock();
 647         return -ENOMEM;
 648 }