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