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 #include "main.h"
  23 #include "originator.h"
  24 #include "hash.h"
  25 #include "translation-table.h"
  26 #include "routing.h"
  27 #include "gateway_client.h"
  28 #include "hard-interface.h"
  29 #include "unicast.h"
  30 #include "soft-interface.h"
  31
  32 static void purge_orig(struct work_struct *work);
  33
  34 static void start_purge_timer(struct bat_priv *bat_priv)
  35 {
  36         INIT_DELAYED_WORK(&bat_priv->orig_work, purge_orig);
  37         queue_delayed_work(bat_event_workqueue, &bat_priv->orig_work, 1 * HZ);
  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 originator_init(struct bat_priv *bat_priv)
  49 {
  50         if (bat_priv->orig_hash)
  51                 return 1;
  52
  53         bat_priv->orig_hash = hash_new(1024);
  54
  55         if (!bat_priv->orig_hash)
  56                 goto err;
  57
  58         start_purge_timer(bat_priv);
  59         return 1;
  60
  61 err:
  62         return 0;
  63 }
  64
  65 void 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 *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 *create_neighbor(struct orig_node *orig_node,
  87                                    struct orig_node *orig_neigh_node,
  88                                    const uint8_t *neigh,
  89                                    struct hard_iface *if_incoming)
  90 {
  91         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
  92         struct neigh_node *neigh_node;
  93
  94         bat_dbg(DBG_BATMAN, bat_priv,
  95                 "Creating new last-hop neighbor of originator\n");
  96
  97         neigh_node = kzalloc(sizeof(*neigh_node), GFP_ATOMIC);
  98         if (!neigh_node)
  99                 return NULL;
 100
 101         INIT_HLIST_NODE(&neigh_node->list);
 102         INIT_LIST_HEAD(&neigh_node->bonding_list);
 103         spin_lock_init(&neigh_node->tq_lock);
 104
 105         memcpy(neigh_node->addr, neigh, ETH_ALEN);
 106         neigh_node->orig_node = orig_neigh_node;
 107         neigh_node->if_incoming = if_incoming;
 108
 109         /* extra reference for return */
 110         atomic_set(&neigh_node->refcount, 2);
 111
 112         spin_lock_bh(&orig_node->neigh_list_lock);
 113         hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
 114         spin_unlock_bh(&orig_node->neigh_list_lock);
 115         return neigh_node;
 116 }
 117
 118 static void orig_node_free_rcu(struct rcu_head *rcu)
 119 {
 120         struct hlist_node *node, *node_tmp;
 121         struct neigh_node *neigh_node, *tmp_neigh_node;
 122         struct orig_node *orig_node;
 123
 124         orig_node = container_of(rcu, struct orig_node, rcu);
 125
 126         spin_lock_bh(&orig_node->neigh_list_lock);
 127
 128         /* for all bonding members ... */
 129         list_for_each_entry_safe(neigh_node, tmp_neigh_node,
 130                                  &orig_node->bond_list, bonding_list) {
 131                 list_del_rcu(&neigh_node->bonding_list);
 132                 neigh_node_free_ref(neigh_node);
 133         }
 134
 135         /* for all neighbors towards this originator ... */
 136         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 137                                   &orig_node->neigh_list, list) {
 138                 hlist_del_rcu(&neigh_node->list);
 139                 neigh_node_free_ref(neigh_node);
 140         }
 141
 142         spin_unlock_bh(&orig_node->neigh_list_lock);
 143
 144         frag_list_free(&orig_node->frag_list);
 145         tt_global_del_orig(orig_node->bat_priv, orig_node,
 146                             "originator timed out");
 147
 148         kfree(orig_node->tt_buff);
 149         kfree(orig_node->bcast_own);
 150         kfree(orig_node->bcast_own_sum);
 151         kfree(orig_node);
 152 }
 153
 154 void orig_node_free_ref(struct orig_node *orig_node)
 155 {
 156         if (atomic_dec_and_test(&orig_node->refcount))
 157                 call_rcu(&orig_node->rcu, orig_node_free_rcu);
 158 }
 159
 160 void originator_free(struct bat_priv *bat_priv)
 161 {
 162         struct hashtable_t *hash = bat_priv->orig_hash;
 163         struct hlist_node *node, *node_tmp;
 164         struct hlist_head *head;
 165         spinlock_t *list_lock; /* spinlock to protect write access */
 166         struct orig_node *orig_node;
 167         int i;
 168
 169         if (!hash)
 170                 return;
 171
 172         cancel_delayed_work_sync(&bat_priv->orig_work);
 173
 174         bat_priv->orig_hash = NULL;
 175
 176         for (i = 0; i < hash->size; i++) {
 177                 head = &hash->table[i];
 178                 list_lock = &hash->list_locks[i];
 179
 180                 spin_lock_bh(list_lock);
 181                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 182                                           head, hash_entry) {
 183
 184                         hlist_del_rcu(node);
 185                         orig_node_free_ref(orig_node);
 186                 }
 187                 spin_unlock_bh(list_lock);
 188         }
 189
 190         hash_destroy(hash);
 191 }
 192
 193 /* this function finds or creates an originator entry for the given
 194  * address if it does not exits */
 195 struct orig_node *get_orig_node(struct bat_priv *bat_priv, const uint8_t *addr)
 196 {
 197         struct orig_node *orig_node;
 198         int size;
 199         int hash_added;
 200
 201         orig_node = orig_hash_find(bat_priv, addr);
 202         if (orig_node)
 203                 return orig_node;
 204
 205         bat_dbg(DBG_BATMAN, bat_priv,
 206                 "Creating new originator: %pM\n", addr);
 207
 208         orig_node = kzalloc(sizeof(*orig_node), GFP_ATOMIC);
 209         if (!orig_node)
 210                 return NULL;
 211
 212         INIT_HLIST_HEAD(&orig_node->neigh_list);
 213         INIT_LIST_HEAD(&orig_node->bond_list);
 214         spin_lock_init(&orig_node->ogm_cnt_lock);
 215         spin_lock_init(&orig_node->bcast_seqno_lock);
 216         spin_lock_init(&orig_node->neigh_list_lock);
 217         spin_lock_init(&orig_node->tt_buff_lock);
 218
 219         /* extra reference for return */
 220         atomic_set(&orig_node->refcount, 2);
 221
 222         orig_node->tt_poss_change = false;
 223         orig_node->bat_priv = bat_priv;
 224         memcpy(orig_node->orig, addr, ETH_ALEN);
 225         orig_node->router = NULL;
 226         orig_node->tt_crc = 0;
 227         atomic_set(&orig_node->last_ttvn, 0);
 228         orig_node->tt_buff = NULL;
 229         orig_node->tt_buff_len = 0;
 230         atomic_set(&orig_node->tt_size, 0);
 231         orig_node->bcast_seqno_reset = jiffies - 1
 232                                         - msecs_to_jiffies(RESET_PROTECTION_MS);
 233         orig_node->batman_seqno_reset = jiffies - 1
 234                                         - msecs_to_jiffies(RESET_PROTECTION_MS);
 235
 236         atomic_set(&orig_node->bond_candidates, 0);
 237
 238         size = bat_priv->num_ifaces * sizeof(unsigned long) * NUM_WORDS;
 239
 240         orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
 241         if (!orig_node->bcast_own)
 242                 goto free_orig_node;
 243
 244         size = bat_priv->num_ifaces * sizeof(uint8_t);
 245         orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
 246
 247         INIT_LIST_HEAD(&orig_node->frag_list);
 248         orig_node->last_frag_packet = 0;
 249
 250         if (!orig_node->bcast_own_sum)
 251                 goto free_bcast_own;
 252
 253         hash_added = hash_add(bat_priv->orig_hash, compare_orig,
 254                               choose_orig, orig_node, &orig_node->hash_entry);
 255         if (hash_added != 0)
 256                 goto free_bcast_own_sum;
 257
 258         return orig_node;
 259 free_bcast_own_sum:
 260         kfree(orig_node->bcast_own_sum);
 261 free_bcast_own:
 262         kfree(orig_node->bcast_own);
 263 free_orig_node:
 264         kfree(orig_node);
 265         return NULL;
 266 }
 267
 268 static bool purge_orig_neighbors(struct bat_priv *bat_priv,
 269                                  struct orig_node *orig_node,
 270                                  struct neigh_node **best_neigh_node)
 271 {
 272         struct hlist_node *node, *node_tmp;
 273         struct neigh_node *neigh_node;
 274         bool neigh_purged = false;
 275
 276         *best_neigh_node = NULL;
 277
 278         spin_lock_bh(&orig_node->neigh_list_lock);
 279
 280         /* for all neighbors towards this originator ... */
 281         hlist_for_each_entry_safe(neigh_node, node, node_tmp,
 282                                   &orig_node->neigh_list, list) {
 283
 284                 if ((time_after(jiffies,
 285                         neigh_node->last_valid + PURGE_TIMEOUT * HZ)) ||
 286                     (neigh_node->if_incoming->if_status == IF_INACTIVE) ||
 287                     (neigh_node->if_incoming->if_status == IF_NOT_IN_USE) ||
 288                     (neigh_node->if_incoming->if_status == IF_TO_BE_REMOVED)) {
 289
 290                         if ((neigh_node->if_incoming->if_status ==
 291                                                                 IF_INACTIVE) ||
 292                             (neigh_node->if_incoming->if_status ==
 293                                                         IF_NOT_IN_USE) ||
 294                             (neigh_node->if_incoming->if_status ==
 295                                                         IF_TO_BE_REMOVED))
 296                                 bat_dbg(DBG_BATMAN, bat_priv,
 297                                         "neighbor purge: originator %pM, "
 298                                         "neighbor: %pM, iface: %s\n",
 299                                         orig_node->orig, neigh_node->addr,
 300                                         neigh_node->if_incoming->net_dev->name);
 301                         else
 302                                 bat_dbg(DBG_BATMAN, bat_priv,
 303                                         "neighbor timeout: originator %pM, "
 304                                         "neighbor: %pM, last_valid: %lu\n",
 305                                         orig_node->orig, neigh_node->addr,
 306                                         (neigh_node->last_valid / HZ));
 307
 308                         neigh_purged = true;
 309
 310                         hlist_del_rcu(&neigh_node->list);
 311                         bonding_candidate_del(orig_node, neigh_node);
 312                         neigh_node_free_ref(neigh_node);
 313                 } else {
 314                         if ((!*best_neigh_node) ||
 315                             (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
 316                                 *best_neigh_node = neigh_node;
 317                 }
 318         }
 319
 320         spin_unlock_bh(&orig_node->neigh_list_lock);
 321         return neigh_purged;
 322 }
 323
 324 static bool purge_orig_node(struct bat_priv *bat_priv,
 325                             struct orig_node *orig_node)
 326 {
 327         struct neigh_node *best_neigh_node;
 328
 329         if (time_after(jiffies,
 330                 orig_node->last_valid + 2 * PURGE_TIMEOUT * HZ)) {
 331
 332                 bat_dbg(DBG_BATMAN, bat_priv,
 333                         "Originator timeout: originator %pM, last_valid %lu\n",
 334                         orig_node->orig, (orig_node->last_valid / HZ));
 335                 return true;
 336         } else {
 337                 if (purge_orig_neighbors(bat_priv, orig_node,
 338                                                         &best_neigh_node)) {
 339                         update_routes(bat_priv, orig_node,
 340                                       best_neigh_node);
 341                 }
 342         }
 343
 344         return false;
 345 }
 346
 347 static void _purge_orig(struct bat_priv *bat_priv)
 348 {
 349         struct hashtable_t *hash = bat_priv->orig_hash;
 350         struct hlist_node *node, *node_tmp;
 351         struct hlist_head *head;
 352         spinlock_t *list_lock; /* spinlock to protect write access */
 353         struct orig_node *orig_node;
 354         int i;
 355
 356         if (!hash)
 357                 return;
 358
 359         /* for all origins... */
 360         for (i = 0; i < hash->size; i++) {
 361                 head = &hash->table[i];
 362                 list_lock = &hash->list_locks[i];
 363
 364                 spin_lock_bh(list_lock);
 365                 hlist_for_each_entry_safe(orig_node, node, node_tmp,
 366                                           head, hash_entry) {
 367                         if (purge_orig_node(bat_priv, orig_node)) {
 368                                 if (orig_node->gw_flags)
 369                                         gw_node_delete(bat_priv, orig_node);
 370                                 hlist_del_rcu(node);
 371                                 orig_node_free_ref(orig_node);
 372                                 continue;
 373                         }
 374
 375                         if (time_after(jiffies, orig_node->last_frag_packet +
 376                                                 msecs_to_jiffies(FRAG_TIMEOUT)))
 377                                 frag_list_free(&orig_node->frag_list);
 378                 }
 379                 spin_unlock_bh(list_lock);
 380         }
 381
 382         gw_node_purge(bat_priv);
 383         gw_election(bat_priv);
 384
 385         softif_neigh_purge(bat_priv);
 386 }
 387
 388 static void purge_orig(struct work_struct *work)
 389 {
 390         struct delayed_work *delayed_work =
 391                 container_of(work, struct delayed_work, work);
 392         struct bat_priv *bat_priv =
 393                 container_of(delayed_work, struct bat_priv, orig_work);
 394
 395         _purge_orig(bat_priv);
 396         start_purge_timer(bat_priv);
 397 }
 398
 399 void purge_orig_ref(struct bat_priv *bat_priv)
 400 {
 401         _purge_orig(bat_priv);
 402 }
 403
 404 int orig_seq_print_text(struct seq_file *seq, void *offset)
 405 {
 406         struct net_device *net_dev = (struct net_device *)seq->private;
 407         struct bat_priv *bat_priv = netdev_priv(net_dev);
 408         struct hashtable_t *hash = bat_priv->orig_hash;
 409         struct hlist_node *node, *node_tmp;
 410         struct hlist_head *head;
 411         struct hard_iface *primary_if;
 412         struct orig_node *orig_node;
 413         struct neigh_node *neigh_node, *neigh_node_tmp;
 414         int batman_count = 0;
 415         int last_seen_secs;
 416         int last_seen_msecs;
 417         int i, ret = 0;
 418
 419         primary_if = primary_if_get_selected(bat_priv);
 420
 421         if (!primary_if) {
 422                 ret = seq_printf(seq, "BATMAN mesh %s disabled - "
 423                                  "please specify interfaces to enable it\n",
 424                                  net_dev->name);
 425                 goto out;
 426         }
 427
 428         if (primary_if->if_status != IF_ACTIVE) {
 429                 ret = seq_printf(seq, "BATMAN mesh %s "
 430                                  "disabled - primary interface not active\n",
 431                                  net_dev->name);
 432                 goto out;
 433         }
 434
 435         seq_printf(seq, "[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
 436                    SOURCE_VERSION, primary_if->net_dev->name,
 437                    primary_if->net_dev->dev_addr, net_dev->name);
 438         seq_printf(seq, "  %-15s %s (%s/%i) %17s [%10s]: %20s ...\n",
 439                    "Originator", "last-seen", "#", TQ_MAX_VALUE, "Nexthop",
 440                    "outgoingIF", "Potential nexthops");
 441
 442         for (i = 0; i < hash->size; i++) {
 443                 head = &hash->table[i];
 444
 445                 rcu_read_lock();
 446                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 447                         neigh_node = orig_node_get_router(orig_node);
 448                         if (!neigh_node)
 449                                 continue;
 450
 451                         if (neigh_node->tq_avg == 0)
 452                                 goto next;
 453
 454                         last_seen_secs = jiffies_to_msecs(jiffies -
 455                                                 orig_node->last_valid) / 1000;
 456                         last_seen_msecs = jiffies_to_msecs(jiffies -
 457                                                 orig_node->last_valid) % 1000;
 458
 459                         seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
 460                                    orig_node->orig, last_seen_secs,
 461                                    last_seen_msecs, neigh_node->tq_avg,
 462                                    neigh_node->addr,
 463                                    neigh_node->if_incoming->net_dev->name);
 464
 465                         hlist_for_each_entry_rcu(neigh_node_tmp, node_tmp,
 466                                                  &orig_node->neigh_list, list) {
 467                                 seq_printf(seq, " %pM (%3i)",
 468                                            neigh_node_tmp->addr,
 469                                            neigh_node_tmp->tq_avg);
 470                         }
 471
 472                         seq_printf(seq, "\n");
 473                         batman_count++;
 474
 475 next:
 476                         neigh_node_free_ref(neigh_node);
 477                 }
 478                 rcu_read_unlock();
 479         }
 480
 481         if (batman_count == 0)
 482                 seq_printf(seq, "No batman nodes in range ...\n");
 483
 484 out:
 485         if (primary_if)
 486                 hardif_free_ref(primary_if);
 487         return ret;
 488 }
 489
 490 static int orig_node_add_if(struct orig_node *orig_node, int max_if_num)
 491 {
 492         void *data_ptr;
 493
 494         data_ptr = kmalloc(max_if_num * sizeof(unsigned long) * NUM_WORDS,
 495                            GFP_ATOMIC);
 496         if (!data_ptr) {
 497                 pr_err("Can't resize orig: out of memory\n");
 498                 return -1;
 499         }
 500
 501         memcpy(data_ptr, orig_node->bcast_own,
 502                (max_if_num - 1) * sizeof(unsigned long) * NUM_WORDS);
 503         kfree(orig_node->bcast_own);
 504         orig_node->bcast_own = data_ptr;
 505
 506         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 507         if (!data_ptr) {
 508                 pr_err("Can't resize orig: out of memory\n");
 509                 return -1;
 510         }
 511
 512         memcpy(data_ptr, orig_node->bcast_own_sum,
 513                (max_if_num - 1) * sizeof(uint8_t));
 514         kfree(orig_node->bcast_own_sum);
 515         orig_node->bcast_own_sum = data_ptr;
 516
 517         return 0;
 518 }
 519
 520 int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num)
 521 {
 522         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 523         struct hashtable_t *hash = bat_priv->orig_hash;
 524         struct hlist_node *node;
 525         struct hlist_head *head;
 526         struct orig_node *orig_node;
 527         int i, ret;
 528
 529         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 530          * if_num */
 531         for (i = 0; i < hash->size; i++) {
 532                 head = &hash->table[i];
 533
 534                 rcu_read_lock();
 535                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 536                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 537                         ret = orig_node_add_if(orig_node, max_if_num);
 538                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 539
 540                         if (ret == -1)
 541                                 goto err;
 542                 }
 543                 rcu_read_unlock();
 544         }
 545
 546         return 0;
 547
 548 err:
 549         rcu_read_unlock();
 550         return -ENOMEM;
 551 }
 552
 553 static int orig_node_del_if(struct orig_node *orig_node,
 554                      int max_if_num, int del_if_num)
 555 {
 556         void *data_ptr = NULL;
 557         int chunk_size;
 558
 559         /* last interface was removed */
 560         if (max_if_num == 0)
 561                 goto free_bcast_own;
 562
 563         chunk_size = sizeof(unsigned long) * NUM_WORDS;
 564         data_ptr = kmalloc(max_if_num * chunk_size, GFP_ATOMIC);
 565         if (!data_ptr) {
 566                 pr_err("Can't resize orig: out of memory\n");
 567                 return -1;
 568         }
 569
 570         /* copy first part */
 571         memcpy(data_ptr, orig_node->bcast_own, del_if_num * chunk_size);
 572
 573         /* copy second part */
 574         memcpy((char *)data_ptr + del_if_num * chunk_size,
 575                orig_node->bcast_own + ((del_if_num + 1) * chunk_size),
 576                (max_if_num - del_if_num) * chunk_size);
 577
 578 free_bcast_own:
 579         kfree(orig_node->bcast_own);
 580         orig_node->bcast_own = data_ptr;
 581
 582         if (max_if_num == 0)
 583                 goto free_own_sum;
 584
 585         data_ptr = kmalloc(max_if_num * sizeof(uint8_t), GFP_ATOMIC);
 586         if (!data_ptr) {
 587                 pr_err("Can't resize orig: out of memory\n");
 588                 return -1;
 589         }
 590
 591         memcpy(data_ptr, orig_node->bcast_own_sum,
 592                del_if_num * sizeof(uint8_t));
 593
 594         memcpy((char *)data_ptr + del_if_num * sizeof(uint8_t),
 595                orig_node->bcast_own_sum + ((del_if_num + 1) * sizeof(uint8_t)),
 596                (max_if_num - del_if_num) * sizeof(uint8_t));
 597
 598 free_own_sum:
 599         kfree(orig_node->bcast_own_sum);
 600         orig_node->bcast_own_sum = data_ptr;
 601
 602         return 0;
 603 }
 604
 605 int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num)
 606 {
 607         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 608         struct hashtable_t *hash = bat_priv->orig_hash;
 609         struct hlist_node *node;
 610         struct hlist_head *head;
 611         struct hard_iface *hard_iface_tmp;
 612         struct orig_node *orig_node;
 613         int i, ret;
 614
 615         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 616          * if_num */
 617         for (i = 0; i < hash->size; i++) {
 618                 head = &hash->table[i];
 619
 620                 rcu_read_lock();
 621                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
 622                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 623                         ret = orig_node_del_if(orig_node, max_if_num,
 624                                         hard_iface->if_num);
 625                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 626
 627                         if (ret == -1)
 628                                 goto err;
 629                 }
 630                 rcu_read_unlock();
 631         }
 632
 633         /* renumber remaining batman interfaces _inside_ of orig_hash_lock */
 634         rcu_read_lock();
 635         list_for_each_entry_rcu(hard_iface_tmp, &hardif_list, list) {
 636                 if (hard_iface_tmp->if_status == IF_NOT_IN_USE)
 637                         continue;
 638
 639                 if (hard_iface == hard_iface_tmp)
 640                         continue;
 641
 642                 if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
 643                         continue;
 644
 645                 if (hard_iface_tmp->if_num > hard_iface->if_num)
 646                         hard_iface_tmp->if_num--;
 647         }
 648         rcu_read_unlock();
 649
 650         hard_iface->if_num = -1;
 651         return 0;
 652
 653 err:
 654         rcu_read_unlock();
 655         return -ENOMEM;
 656 }