net/batman-adv/originator.c

   1 /*
   2  * Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 /* increase the reference counter for this originator */
  23
  24 #include "main.h"
  25 #include "originator.h"
  26 #include "hash.h"
  27 #include "translation-table.h"
  28 #include "routing.h"
  29 #include "gateway_client.h"
  30 #include "hard-interface.h"
  31 #include "unicast.h"
  32 #include "soft-interface.h"
  33
  34 static void purge_orig(struct work_struct *work);
  35
  36 static void start_purge_timer(struct bat_priv *bat_priv)
  37 {
  38         INIT_DELAYED_WORK(&bat_priv->orig_work, purge_orig);
  39         queue_delayed_work(bat_event_workqueue, &bat_priv->orig_work, 1 * HZ);
  40 }
  41
  42 int originator_init(struct bat_priv *bat_priv)
  43 {
  44         if (bat_priv->orig_hash)
  45                 return 1;
  46
  47         spin_lock_bh(&bat_priv->orig_hash_lock);
  48         bat_priv->orig_hash = hash_new(1024);
  49
  50         if (!bat_priv->orig_hash)
  51                 goto err;
  52
  53         spin_unlock_bh(&bat_priv->orig_hash_lock);
  54         start_purge_timer(bat_priv);
  55         return 1;
  56
  57 err:
  58         spin_unlock_bh(&bat_priv->orig_hash_lock);
  59         return 0;
  60 }
  61
  62 static void neigh_node_free_rcu(struct rcu_head *rcu)
  63 {
  64         struct neigh_node *neigh_node;
  65
  66         neigh_node = container_of(rcu, struct neigh_node, rcu);
  67         kfree(neigh_node);
  68 }
  69
  70 void neigh_node_free_ref(struct neigh_node *neigh_node)
  71 {
  72         if (atomic_dec_and_test(&neigh_node->refcount))
  73                 call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
  74 }
  75
  76 struct neigh_node *create_neighbor(struct orig_node *orig_node,
  77                                    struct orig_node *orig_neigh_node,
  78                                    uint8_t *neigh,
  79                                    struct batman_if *if_incoming)
  80 {
  81         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
  82         struct neigh_node *neigh_node;
  83
  84         bat_dbg(DBG_BATMAN, bat_priv,
  85                 "Creating new last-hop neighbor of originator\n");
  86
  87         neigh_node = kzalloc(sizeof(struct neigh_node), GFP_ATOMIC);
  88         if (!neigh_node)
  89                 return NULL;
  90
  91         INIT_HLIST_NODE(&neigh_node->list);
  92         INIT_LIST_HEAD(&neigh_node->bonding_list);
  93
  94         memcpy(neigh_node->addr, neigh, ETH_ALEN);
  95         neigh_node->orig_node = orig_neigh_node;
  96         neigh_node->if_incoming = if_incoming;
  97
  98         /* extra reference for return */
  99         atomic_set(&neigh_node->refcount, 2);
 100
 101         spin_lock_bh(&orig_node->neigh_list_lock);
 102         hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
 103         spin_unlock_bh(&orig_node->neigh_list_lock);
 104         return neigh_node;
 105 }
 106
 107 static void orig_node_free_rcu(struct rcu_head *rcu)
 108 {
 109         struct hlist_node *node, *node_tmp;
 110         struct neigh_node *neigh_node, *tmp_neigh_node;
 111         struct orig_node *orig_node;
 112
 113         orig_node = container_of(rcu, struct orig_node, rcu);
 114
 115         spin_lock_bh(&orig_node->neigh_list_lock);
 116
 117         /* for all bonding members ... */
 118         list_for_each_entry_safe(neigh_node, tmp_neigh_node,
 119                                  &orig_node->bond_list, bonding_list) {
 120                 list_del_rcu(&neigh_node->bonding_list);
 121                 neigh_node_free_ref(neigh_node);
 122         }
 123
 124         /* for all neighbors towards this originator ... */
 125         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 126                                   &orig_node->neigh_list, list) {
 127                 hlist_del_rcu(&neigh_node->list);
 128                 neigh_node_free_ref(neigh_node);
 129         }
 130
 131         spin_unlock_bh(&orig_node->neigh_list_lock);
 132
 133         frag_list_free(&orig_node->frag_list);
 134         hna_global_del_orig(orig_node->bat_priv, orig_node,
 135                             "originator timed out");
 136
 137         kfree(orig_node->bcast_own);
 138         kfree(orig_node->bcast_own_sum);
 139         kfree(orig_node);
 140 }
 141
 142 void orig_node_free_ref(struct orig_node *orig_node)
 143 {
 144         if (atomic_dec_and_test(&orig_node->refcount))
 145                 call_rcu(&orig_node->rcu, orig_node_free_rcu);
 146 }
 147
 148 void originator_free(struct bat_priv *bat_priv)
 149 {
 150         struct hashtable_t *hash = bat_priv->orig_hash;
 151         struct hlist_node *node, *node_tmp;
 152         struct hlist_head *head;
 153         spinlock_t *list_lock; /* spinlock to protect write access */
 154         struct orig_node *orig_node;
 155         int i;
 156
 157         if (!hash)
 158                 return;
 159
 160         cancel_delayed_work_sync(&bat_priv->orig_work);
 161
 162         spin_lock_bh(&bat_priv->orig_hash_lock);
 163         bat_priv->orig_hash = NULL;
 164
 165         for (i = 0; i < hash->size; i++) {
 166                 head = &hash->table[i];
 167                 list_lock = &hash->list_locks[i];
 168
 169                 spin_lock_bh(list_lock);
 170                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 171                                           head, hash_entry) {
 172
 173                         hlist_del_rcu(node);
 174                         orig_node_free_ref(orig_node);
 175                 }
 176                 spin_unlock_bh(list_lock);
 177         }
 178
 179         hash_destroy(hash);
 180         spin_unlock_bh(&bat_priv->orig_hash_lock);
 181 }
 182
 183 /* this function finds or creates an originator entry for the given
 184  * address if it does not exits */
 185 struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
 186 {
 187         struct orig_node *orig_node;
 188         int size;
 189         int hash_added;
 190
 191         orig_node = orig_hash_find(bat_priv, addr);
 192         if (orig_node)
 193                 return orig_node;
 194
 195         bat_dbg(DBG_BATMAN, bat_priv,
 196                 "Creating new originator: %pM\n", addr);
 197
 198         orig_node = kzalloc(sizeof(struct orig_node), GFP_ATOMIC);
 199         if (!orig_node)
 200                 return NULL;
 201
 202         INIT_HLIST_HEAD(&orig_node->neigh_list);
 203         INIT_LIST_HEAD(&orig_node->bond_list);
 204         spin_lock_init(&orig_node->ogm_cnt_lock);
 205         spin_lock_init(&orig_node->bcast_seqno_lock);
 206         spin_lock_init(&orig_node->neigh_list_lock);
 207
 208         /* extra reference for return */
 209         atomic_set(&orig_node->refcount, 2);
 210
 211         orig_node->bat_priv = bat_priv;
 212         memcpy(orig_node->orig, addr, ETH_ALEN);
 213         orig_node->router = NULL;
 214         orig_node->hna_buff = NULL;
 215         orig_node->bcast_seqno_reset = jiffies - 1
 216                                         - msecs_to_jiffies(RESET_PROTECTION_MS);
 217         orig_node->batman_seqno_reset = jiffies - 1
 218                                         - msecs_to_jiffies(RESET_PROTECTION_MS);
 219
 220         atomic_set(&orig_node->bond_candidates, 0);
 221
 222         size = bat_priv->num_ifaces * sizeof(unsigned long) * NUM_WORDS;
 223
 224         orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
 225         if (!orig_node->bcast_own)
 226                 goto free_orig_node;
 227
 228         size = bat_priv->num_ifaces * sizeof(uint8_t);
 229         orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
 230
 231         INIT_LIST_HEAD(&orig_node->frag_list);
 232         orig_node->last_frag_packet = 0;
 233
 234         if (!orig_node->bcast_own_sum)
 235                 goto free_bcast_own;
 236
 237         hash_added = hash_add(bat_priv->orig_hash, compare_orig,
 238                               choose_orig, orig_node, &orig_node->hash_entry);
 239         if (hash_added < 0)
 240                 goto free_bcast_own_sum;
 241
 242         return orig_node;
 243 free_bcast_own_sum:
 244         kfree(orig_node->bcast_own_sum);
 245 free_bcast_own:
 246         kfree(orig_node->bcast_own);
 247 free_orig_node:
 248         kfree(orig_node);
 249         return NULL;
 250 }
 251
 252 static bool purge_orig_neighbors(struct bat_priv *bat_priv,
 253                                  struct orig_node *orig_node,
 254                                  struct neigh_node **best_neigh_node)
 255 {
 256         struct hlist_node *node, *node_tmp;
 257         struct neigh_node *neigh_node;
 258         bool neigh_purged = false;
 259
 260         *best_neigh_node = NULL;
 261
 262         spin_lock_bh(&orig_node->neigh_list_lock);
 263
 264         /* for all neighbors towards this originator ... */
 265         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 266                                   &orig_node->neigh_list, list) {
 267
 268                 if ((time_after(jiffies,
 269                         neigh_node->last_valid + PURGE_TIMEOUT * HZ)) ||
 270                     (neigh_node->if_incoming->if_status == IF_INACTIVE) ||
 271                     (neigh_node->if_incoming->if_status == IF_NOT_IN_USE) ||
 272                     (neigh_node->if_incoming->if_status == IF_TO_BE_REMOVED)) {
 273
 274                         if ((neigh_node->if_incoming->if_status ==
 275                                                                 IF_INACTIVE) ||
 276                             (neigh_node->if_incoming->if_status ==
 277                                                         IF_NOT_IN_USE) ||
 278                             (neigh_node->if_incoming->if_status ==
 279                                                         IF_TO_BE_REMOVED))
 280                                 bat_dbg(DBG_BATMAN, bat_priv,
 281                                         "neighbor purge: originator %pM, "
 282                                         "neighbor: %pM, iface: %s\n",
 283                                         orig_node->orig, neigh_node->addr,
 284                                         neigh_node->if_incoming->net_dev->name);
 285                         else
 286                                 bat_dbg(DBG_BATMAN, bat_priv,
 287                                         "neighbor timeout: originator %pM, "
 288                                         "neighbor: %pM, last_valid: %lu\n",
 289                                         orig_node->orig, neigh_node->addr,
 290                                         (neigh_node->last_valid / HZ));
 291
 292                         neigh_purged = true;
 293
 294                         hlist_del_rcu(&neigh_node->list);
 295                         bonding_candidate_del(orig_node, neigh_node);
 296                         neigh_node_free_ref(neigh_node);
 297                 } else {
 298                         if ((!*best_neigh_node) ||
 299                             (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
 300                                 *best_neigh_node = neigh_node;
 301                 }
 302         }
 303
 304         spin_unlock_bh(&orig_node->neigh_list_lock);
 305         return neigh_purged;
 306 }
 307
 308 static bool purge_orig_node(struct bat_priv *bat_priv,
 309                             struct orig_node *orig_node)
 310 {
 311         struct neigh_node *best_neigh_node;
 312
 313         if (time_after(jiffies,
 314                 orig_node->last_valid + 2 * PURGE_TIMEOUT * HZ)) {
 315
 316                 bat_dbg(DBG_BATMAN, bat_priv,
 317                         "Originator timeout: originator %pM, last_valid %lu\n",
 318                         orig_node->orig, (orig_node->last_valid / HZ));
 319                 return true;
 320         } else {
 321                 if (purge_orig_neighbors(bat_priv, orig_node,
 322                                                         &best_neigh_node)) {
 323                         update_routes(bat_priv, orig_node,
 324                                       best_neigh_node,
 325                                       orig_node->hna_buff,
 326                                       orig_node->hna_buff_len);
 327                 }
 328         }
 329
 330         return false;
 331 }
 332
 333 static void _purge_orig(struct bat_priv *bat_priv)
 334 {
 335         struct hashtable_t *hash = bat_priv->orig_hash;
 336         struct hlist_node *node, *node_tmp;
 337         struct hlist_head *head;
 338         spinlock_t *list_lock; /* spinlock to protect write access */
 339         struct orig_node *orig_node;
 340         int i;
 341
 342         if (!hash)
 343                 return;
 344
 345         spin_lock_bh(&bat_priv->orig_hash_lock);
 346
 347         /* for all origins... */
 348         for (i = 0; i < hash->size; i++) {
 349                 head = &hash->table[i];
 350                 list_lock = &hash->list_locks[i];
 351
 352                 spin_lock_bh(list_lock);
 353                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 354                                           head, hash_entry) {
 355                         if (purge_orig_node(bat_priv, orig_node)) {
 356                                 if (orig_node->gw_flags)
 357                                         gw_node_delete(bat_priv, orig_node);
 358                                 hlist_del_rcu(node);
 359                                 orig_node_free_ref(orig_node);
 360                                 continue;
 361                         }
 362
 363                         if (time_after(jiffies, orig_node->last_frag_packet +
 364                                                 msecs_to_jiffies(FRAG_TIMEOUT)))
 365                                 frag_list_free(&orig_node->frag_list);
 366                 }
 367                 spin_unlock_bh(list_lock);
 368         }
 369
 370         spin_unlock_bh(&bat_priv->orig_hash_lock);
 371
 372         gw_node_purge(bat_priv);
 373         gw_election(bat_priv);
 374
 375         softif_neigh_purge(bat_priv);
 376 }
 377
 378 static void purge_orig(struct work_struct *work)
 379 {
 380         struct delayed_work *delayed_work =
 381                 container_of(work, struct delayed_work, work);
 382         struct bat_priv *bat_priv =
 383                 container_of(delayed_work, struct bat_priv, orig_work);
 384
 385         _purge_orig(bat_priv);
 386         start_purge_timer(bat_priv);
 387 }
 388
 389 void purge_orig_ref(struct bat_priv *bat_priv)
 390 {
 391         _purge_orig(bat_priv);
 392 }
 393
 394 int orig_seq_print_text(struct seq_file *seq, void *offset)
 395 {
 396         struct net_device *net_dev = (struct net_device *)seq->private;
 397         struct bat_priv *bat_priv = netdev_priv(net_dev);
 398         struct hashtable_t *hash = bat_priv->orig_hash;
 399         struct hlist_node *node, *node_tmp;
 400         struct hlist_head *head;
 401         struct orig_node *orig_node;
 402         struct neigh_node *neigh_node;
 403         int batman_count = 0;
 404         int last_seen_secs;
 405         int last_seen_msecs;
 406         int i;
 407
 408         if ((!bat_priv->primary_if) ||
 409             (bat_priv->primary_if->if_status != IF_ACTIVE)) {
 410                 if (!bat_priv->primary_if)
 411                         return seq_printf(seq, "BATMAN mesh %s disabled - "
 412                                      "please specify interfaces to enable it\n",
 413                                      net_dev->name);
 414
 415                 return seq_printf(seq, "BATMAN mesh %s "
 416                                   "disabled - primary interface not active\n",
 417                                   net_dev->name);
 418         }
 419
 420         seq_printf(seq, "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
 421                    SOURCE_VERSION, REVISION_VERSION_STR,
 422                    bat_priv->primary_if->net_dev->name,
 423                    bat_priv->primary_if->net_dev->dev_addr, net_dev->name);
 424         seq_printf(seq, "  %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
 425                    "Originator", "last-seen", "#", TQ_MAX_VALUE, "Nexthop",
 426                    "outgoingIF", "Potential nexthops");
 427
 428         spin_lock_bh(&bat_priv->orig_hash_lock);
 429
 430         for (i = 0; i < hash->size; i++) {
 431                 head = &hash->table[i];
 432
 433                 rcu_read_lock();
 434                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 435                         if (!orig_node->router)
 436                                 continue;
 437
 438                         if (orig_node->router->tq_avg == 0)
 439                                 continue;
 440
 441                         last_seen_secs = jiffies_to_msecs(jiffies -
 442                                                 orig_node->last_valid) / 1000;
 443                         last_seen_msecs = jiffies_to_msecs(jiffies -
 444                                                 orig_node->last_valid) % 1000;
 445
 446                         neigh_node = orig_node->router;
 447                         seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
 448                                    orig_node->orig, last_seen_secs,
 449                                    last_seen_msecs, neigh_node->tq_avg,
 450                                    neigh_node->addr,
 451                                    neigh_node->if_incoming->net_dev->name);
 452
 453                         hlist_for_each_entry_rcu(neigh_node, node_tmp,
 454                                                  &orig_node->neigh_list, list) {
 455                                 seq_printf(seq, " %pM (%3i)", neigh_node->addr,
 456                                                 neigh_node->tq_avg);
 457                         }
 458
 459                         seq_printf(seq, "\n");
 460                         batman_count++;
 461                 }
 462                 rcu_read_unlock();
 463         }
 464
 465         spin_unlock_bh(&bat_priv->orig_hash_lock);
 466
 467         if ((batman_count == 0))
 468                 seq_printf(seq, "No batman nodes in range ...\n");
 469
 470         return 0;
 471 }
 472
 473 static int orig_node_add_if(struct orig_node *orig_node, int max_if_num)
 474 {
 475         void *data_ptr;
 476
 477         data_ptr = kmalloc(max_if_num * sizeof(unsigned long) * NUM_WORDS,
 478                            GFP_ATOMIC);
 479         if (!data_ptr) {
 480                 pr_err("Can't resize orig: out of memory\n");
 481                 return -1;
 482         }
 483
 484         memcpy(data_ptr, orig_node->bcast_own,
 485                (max_if_num - 1) * sizeof(unsigned long) * NUM_WORDS);
 486         kfree(orig_node->bcast_own);
 487         orig_node->bcast_own = data_ptr;
 488
 489         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 490         if (!data_ptr) {
 491                 pr_err("Can't resize orig: out of memory\n");
 492                 return -1;
 493         }
 494
 495         memcpy(data_ptr, orig_node->bcast_own_sum,
 496                (max_if_num - 1) * sizeof(uint8_t));
 497         kfree(orig_node->bcast_own_sum);
 498         orig_node->bcast_own_sum = data_ptr;
 499
 500         return 0;
 501 }
 502
 503 int orig_hash_add_if(struct batman_if *batman_if, int max_if_num)
 504 {
 505         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 506         struct hashtable_t *hash = bat_priv->orig_hash;
 507         struct hlist_node *node;
 508         struct hlist_head *head;
 509         struct orig_node *orig_node;
 510         int i, ret;
 511
 512         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 513          * if_num */
 514         spin_lock_bh(&bat_priv->orig_hash_lock);
 515
 516         for (i = 0; i < hash->size; i++) {
 517                 head = &hash->table[i];
 518
 519                 rcu_read_lock();
 520                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 521                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 522                         ret = orig_node_add_if(orig_node, max_if_num);
 523                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 524
 525                         if (ret == -1)
 526                                 goto err;
 527                 }
 528                 rcu_read_unlock();
 529         }
 530
 531         spin_unlock_bh(&bat_priv->orig_hash_lock);
 532         return 0;
 533
 534 err:
 535         rcu_read_unlock();
 536         spin_unlock_bh(&bat_priv->orig_hash_lock);
 537         return -ENOMEM;
 538 }
 539
 540 static int orig_node_del_if(struct orig_node *orig_node,
 541                      int max_if_num, int del_if_num)
 542 {
 543         void *data_ptr = NULL;
 544         int chunk_size;
 545
 546         /* last interface was removed */
 547         if (max_if_num == 0)
 548                 goto free_bcast_own;
 549
 550         chunk_size = sizeof(unsigned long) * NUM_WORDS;
 551         data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
 552         if (!data_ptr) {
 553                 pr_err("Can't resize orig: out of memory\n");
 554                 return -1;
 555         }
 556
 557         /* copy first part */
 558         memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
 559
 560         /* copy second part */
 561         memcpy(data_ptr + del_if_num * chunk_size,
 562                orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
 563                (max_if_num - del_if_num) * chunk_size);
 564
 565 free_bcast_own:
 566         kfree(orig_node->bcast_own);
 567         orig_node->bcast_own = data_ptr;
 568
 569         if (max_if_num == 0)
 570                 goto free_own_sum;
 571
 572         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 573         if (!data_ptr) {
 574                 pr_err("Can't resize orig: out of memory\n");
 575                 return -1;
 576         }
 577
 578         memcpy(data_ptr, orig_node->bcast_own_sum,
 579                del_if_num * sizeof(uint8_t));
 580
 581         memcpy(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 orig_hash_del_if(struct batman_if *batman_if, int max_if_num)
 593 {
 594         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 595         struct hashtable_t *hash = bat_priv->orig_hash;
 596         struct hlist_node *node;
 597         struct hlist_head *head;
 598         struct batman_if *batman_if_tmp;
 599         struct orig_node *orig_node;
 600         int i, ret;
 601
 602         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 603          * if_num */
 604         spin_lock_bh(&bat_priv->orig_hash_lock);
 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 = orig_node_del_if(orig_node, max_if_num,
 613                                         batman_if->if_num);
 614                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 615
 616                         if (ret == -1)
 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(batman_if_tmp, &if_list, list) {
 625                 if (batman_if_tmp->if_status == IF_NOT_IN_USE)
 626                         continue;
 627
 628                 if (batman_if == batman_if_tmp)
 629                         continue;
 630
 631                 if (batman_if->soft_iface != batman_if_tmp->soft_iface)
 632                         continue;
 633
 634                 if (batman_if_tmp->if_num > batman_if->if_num)
 635                         batman_if_tmp->if_num--;
 636         }
 637         rcu_read_unlock();
 638
 639         batman_if->if_num = -1;
 640         spin_unlock_bh(&bat_priv->orig_hash_lock);
 641         return 0;
 642
 643 err:
 644         rcu_read_unlock();
 645         spin_unlock_bh(&bat_priv->orig_hash_lock);
 646         return -ENOMEM;
 647 }