net/batman-adv/routing.c

   1 /* Copyright (C) 2007-2013 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 "routing.h"
  22 #include "send.h"
  23 #include "soft-interface.h"
  24 #include "hard-interface.h"
  25 #include "icmp_socket.h"
  26 #include "translation-table.h"
  27 #include "originator.h"
  28 #include "vis.h"
  29 #include "unicast.h"
  30 #include "bridge_loop_avoidance.h"
  31 #include "distributed-arp-table.h"
  32 #include "network-coding.h"
  33
  34 static int batadv_route_unicast_packet(struct sk_buff *skb,
  35                                        struct batadv_hard_iface *recv_if);
  36
  37 void batadv_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
  38 {
  39         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  40         struct batadv_hashtable *hash = bat_priv->orig_hash;
  41         struct hlist_head *head;
  42         struct batadv_orig_node *orig_node;
  43         unsigned long *word;
  44         uint32_t i;
  45         size_t word_index;
  46         uint8_t *w;
  47
  48         for (i = 0; i < hash->size; i++) {
  49                 head = &hash->table[i];
  50
  51                 rcu_read_lock();
  52                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
  53                         spin_lock_bh(&orig_node->ogm_cnt_lock);
  54                         word_index = hard_iface->if_num * BATADV_NUM_WORDS;
  55                         word = &(orig_node->bcast_own[word_index]);
  56
  57                         batadv_bit_get_packet(bat_priv, word, 1, 0);
  58                         w = &orig_node->bcast_own_sum[hard_iface->if_num];
  59                         *w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
  60                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
  61                 }
  62                 rcu_read_unlock();
  63         }
  64 }
  65
  66 static void _batadv_update_route(struct batadv_priv *bat_priv,
  67                                  struct batadv_orig_node *orig_node,
  68                                  struct batadv_neigh_node *neigh_node)
  69 {
  70         struct batadv_neigh_node *curr_router;
  71
  72         curr_router = batadv_orig_node_get_router(orig_node);
  73
  74         /* route deleted */
  75         if ((curr_router) && (!neigh_node)) {
  76                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  77                            "Deleting route towards: %pM\n", orig_node->orig);
  78                 batadv_tt_global_del_orig(bat_priv, orig_node,
  79                                           "Deleted route towards originator");
  80
  81         /* route added */
  82         } else if ((!curr_router) && (neigh_node)) {
  83                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  84                            "Adding route towards: %pM (via %pM)\n",
  85                            orig_node->orig, neigh_node->addr);
  86         /* route changed */
  87         } else if (neigh_node && curr_router) {
  88                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  89                            "Changing route towards: %pM (now via %pM - was via %pM)\n",
  90                            orig_node->orig, neigh_node->addr,
  91                            curr_router->addr);
  92         }
  93
  94         if (curr_router)
  95                 batadv_neigh_node_free_ref(curr_router);
  96
  97         /* increase refcount of new best neighbor */
  98         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
  99                 neigh_node = NULL;
 100
 101         spin_lock_bh(&orig_node->neigh_list_lock);
 102         rcu_assign_pointer(orig_node->router, neigh_node);
 103         spin_unlock_bh(&orig_node->neigh_list_lock);
 104
 105         /* decrease refcount of previous best neighbor */
 106         if (curr_router)
 107                 batadv_neigh_node_free_ref(curr_router);
 108 }
 109
 110 void batadv_update_route(struct batadv_priv *bat_priv,
 111                          struct batadv_orig_node *orig_node,
 112                          struct batadv_neigh_node *neigh_node)
 113 {
 114         struct batadv_neigh_node *router = NULL;
 115
 116         if (!orig_node)
 117                 goto out;
 118
 119         router = batadv_orig_node_get_router(orig_node);
 120
 121         if (router != neigh_node)
 122                 _batadv_update_route(bat_priv, orig_node, neigh_node);
 123
 124 out:
 125         if (router)
 126                 batadv_neigh_node_free_ref(router);
 127 }
 128
 129 /* caller must hold the neigh_list_lock */
 130 void batadv_bonding_candidate_del(struct batadv_orig_node *orig_node,
 131                                   struct batadv_neigh_node *neigh_node)
 132 {
 133         /* this neighbor is not part of our candidate list */
 134         if (list_empty(&neigh_node->bonding_list))
 135                 goto out;
 136
 137         list_del_rcu(&neigh_node->bonding_list);
 138         INIT_LIST_HEAD(&neigh_node->bonding_list);
 139         batadv_neigh_node_free_ref(neigh_node);
 140         atomic_dec(&orig_node->bond_candidates);
 141
 142 out:
 143         return;
 144 }
 145
 146 void batadv_bonding_candidate_add(struct batadv_orig_node *orig_node,
 147                                   struct batadv_neigh_node *neigh_node)
 148 {
 149         struct batadv_neigh_node *tmp_neigh_node, *router = NULL;
 150         uint8_t interference_candidate = 0;
 151
 152         spin_lock_bh(&orig_node->neigh_list_lock);
 153
 154         /* only consider if it has the same primary address ...  */
 155         if (!batadv_compare_eth(orig_node->orig,
 156                                 neigh_node->orig_node->primary_addr))
 157                 goto candidate_del;
 158
 159         router = batadv_orig_node_get_router(orig_node);
 160         if (!router)
 161                 goto candidate_del;
 162
 163         /* ... and is good enough to be considered */
 164         if (neigh_node->tq_avg < router->tq_avg - BATADV_BONDING_TQ_THRESHOLD)
 165                 goto candidate_del;
 166
 167         /* check if we have another candidate with the same mac address or
 168          * interface. If we do, we won't select this candidate because of
 169          * possible interference.
 170          */
 171         hlist_for_each_entry_rcu(tmp_neigh_node,
 172                                  &orig_node->neigh_list, list) {
 173                 if (tmp_neigh_node == neigh_node)
 174                         continue;
 175
 176                 /* we only care if the other candidate is even
 177                  * considered as candidate.
 178                  */
 179                 if (list_empty(&tmp_neigh_node->bonding_list))
 180                         continue;
 181
 182                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 183                     (batadv_compare_eth(neigh_node->addr,
 184                                         tmp_neigh_node->addr))) {
 185                         interference_candidate = 1;
 186                         break;
 187                 }
 188         }
 189
 190         /* don't care further if it is an interference candidate */
 191         if (interference_candidate)
 192                 goto candidate_del;
 193
 194         /* this neighbor already is part of our candidate list */
 195         if (!list_empty(&neigh_node->bonding_list))
 196                 goto out;
 197
 198         if (!atomic_inc_not_zero(&neigh_node->refcount))
 199                 goto out;
 200
 201         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 202         atomic_inc(&orig_node->bond_candidates);
 203         goto out;
 204
 205 candidate_del:
 206         batadv_bonding_candidate_del(orig_node, neigh_node);
 207
 208 out:
 209         spin_unlock_bh(&orig_node->neigh_list_lock);
 210
 211         if (router)
 212                 batadv_neigh_node_free_ref(router);
 213 }
 214
 215 /* copy primary address for bonding */
 216 void
 217 batadv_bonding_save_primary(const struct batadv_orig_node *orig_node,
 218                             struct batadv_orig_node *orig_neigh_node,
 219                             const struct batadv_ogm_packet *batman_ogm_packet)
 220 {
 221         if (!(batman_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP))
 222                 return;
 223
 224         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 225 }
 226
 227 /* checks whether the host restarted and is in the protection time.
 228  * returns:
 229  *  0 if the packet is to be accepted
 230  *  1 if the packet is to be ignored.
 231  */
 232 int batadv_window_protected(struct batadv_priv *bat_priv, int32_t seq_num_diff,
 233                             unsigned long *last_reset)
 234 {
 235         if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE ||
 236             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
 237                 if (!batadv_has_timed_out(*last_reset,
 238                                           BATADV_RESET_PROTECTION_MS))
 239                         return 1;
 240
 241                 *last_reset = jiffies;
 242                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 243                            "old packet received, start protection\n");
 244         }
 245
 246         return 0;
 247 }
 248
 249 bool batadv_check_management_packet(struct sk_buff *skb,
 250                                     struct batadv_hard_iface *hard_iface,
 251                                     int header_len)
 252 {
 253         struct ethhdr *ethhdr;
 254
 255         /* drop packet if it has not necessary minimum size */
 256         if (unlikely(!pskb_may_pull(skb, header_len)))
 257                 return false;
 258
 259         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 260
 261         /* packet with broadcast indication but unicast recipient */
 262         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 263                 return false;
 264
 265         /* packet with broadcast sender address */
 266         if (is_broadcast_ether_addr(ethhdr->h_source))
 267                 return false;
 268
 269         /* create a copy of the skb, if needed, to modify it. */
 270         if (skb_cow(skb, 0) < 0)
 271                 return false;
 272
 273         /* keep skb linear */
 274         if (skb_linearize(skb) < 0)
 275                 return false;
 276
 277         return true;
 278 }
 279
 280 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 281                                       struct sk_buff *skb, size_t icmp_len)
 282 {
 283         struct batadv_hard_iface *primary_if = NULL;
 284         struct batadv_orig_node *orig_node = NULL;
 285         struct batadv_icmp_packet_rr *icmp_packet;
 286         int ret = NET_RX_DROP;
 287
 288         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 289
 290         /* add data to device queue */
 291         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 292                 batadv_socket_receive_packet(icmp_packet, icmp_len);
 293                 goto out;
 294         }
 295
 296         primary_if = batadv_primary_if_get_selected(bat_priv);
 297         if (!primary_if)
 298                 goto out;
 299
 300         /* answer echo request (ping) */
 301         /* get routing information */
 302         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 303         if (!orig_node)
 304                 goto out;
 305
 306         /* create a copy of the skb, if needed, to modify it. */
 307         if (skb_cow(skb, ETH_HLEN) < 0)
 308                 goto out;
 309
 310         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 311
 312         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 313         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 314         icmp_packet->msg_type = BATADV_ECHO_REPLY;
 315         icmp_packet->header.ttl = BATADV_TTL;
 316
 317         if (batadv_send_skb_to_orig(skb, orig_node, NULL))
 318                 ret = NET_RX_SUCCESS;
 319
 320 out:
 321         if (primary_if)
 322                 batadv_hardif_free_ref(primary_if);
 323         if (orig_node)
 324                 batadv_orig_node_free_ref(orig_node);
 325         return ret;
 326 }
 327
 328 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 329                                          struct sk_buff *skb)
 330 {
 331         struct batadv_hard_iface *primary_if = NULL;
 332         struct batadv_orig_node *orig_node = NULL;
 333         struct batadv_icmp_packet *icmp_packet;
 334         int ret = NET_RX_DROP;
 335
 336         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 337
 338         /* send TTL exceeded if packet is an echo request (traceroute) */
 339         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 340                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 341                          icmp_packet->orig, icmp_packet->dst);
 342                 goto out;
 343         }
 344
 345         primary_if = batadv_primary_if_get_selected(bat_priv);
 346         if (!primary_if)
 347                 goto out;
 348
 349         /* get routing information */
 350         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 351         if (!orig_node)
 352                 goto out;
 353
 354         /* create a copy of the skb, if needed, to modify it. */
 355         if (skb_cow(skb, ETH_HLEN) < 0)
 356                 goto out;
 357
 358         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 359
 360         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 361         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 362         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
 363         icmp_packet->header.ttl = BATADV_TTL;
 364
 365         if (batadv_send_skb_to_orig(skb, orig_node, NULL))
 366                 ret = NET_RX_SUCCESS;
 367
 368 out:
 369         if (primary_if)
 370                 batadv_hardif_free_ref(primary_if);
 371         if (orig_node)
 372                 batadv_orig_node_free_ref(orig_node);
 373         return ret;
 374 }
 375
 376
 377 int batadv_recv_icmp_packet(struct sk_buff *skb,
 378                             struct batadv_hard_iface *recv_if)
 379 {
 380         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 381         struct batadv_icmp_packet_rr *icmp_packet;
 382         struct ethhdr *ethhdr;
 383         struct batadv_orig_node *orig_node = NULL;
 384         int hdr_size = sizeof(struct batadv_icmp_packet);
 385         int ret = NET_RX_DROP;
 386
 387         /* we truncate all incoming icmp packets if they don't match our size */
 388         if (skb->len >= sizeof(struct batadv_icmp_packet_rr))
 389                 hdr_size = sizeof(struct batadv_icmp_packet_rr);
 390
 391         /* drop packet if it has not necessary minimum size */
 392         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 393                 goto out;
 394
 395         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 396
 397         /* packet with unicast indication but broadcast recipient */
 398         if (is_broadcast_ether_addr(ethhdr->h_dest))
 399                 goto out;
 400
 401         /* packet with broadcast sender address */
 402         if (is_broadcast_ether_addr(ethhdr->h_source))
 403                 goto out;
 404
 405         /* not for me */
 406         if (!batadv_is_my_mac(ethhdr->h_dest))
 407                 goto out;
 408
 409         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 410
 411         /* add record route information if not full */
 412         if ((hdr_size == sizeof(struct batadv_icmp_packet_rr)) &&
 413             (icmp_packet->rr_cur < BATADV_RR_LEN)) {
 414                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
 415                        ethhdr->h_dest, ETH_ALEN);
 416                 icmp_packet->rr_cur++;
 417         }
 418
 419         /* packet for me */
 420         if (batadv_is_my_mac(icmp_packet->dst))
 421                 return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size);
 422
 423         /* TTL exceeded */
 424         if (icmp_packet->header.ttl < 2)
 425                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 426
 427         /* get routing information */
 428         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
 429         if (!orig_node)
 430                 goto out;
 431
 432         /* create a copy of the skb, if needed, to modify it. */
 433         if (skb_cow(skb, ETH_HLEN) < 0)
 434                 goto out;
 435
 436         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 437
 438         /* decrement ttl */
 439         icmp_packet->header.ttl--;
 440
 441         /* route it */
 442         if (batadv_send_skb_to_orig(skb, orig_node, recv_if))
 443                 ret = NET_RX_SUCCESS;
 444
 445 out:
 446         if (orig_node)
 447                 batadv_orig_node_free_ref(orig_node);
 448         return ret;
 449 }
 450
 451 /* In the bonding case, send the packets in a round
 452  * robin fashion over the remaining interfaces.
 453  *
 454  * This method rotates the bonding list and increases the
 455  * returned router's refcount.
 456  */
 457 static struct batadv_neigh_node *
 458 batadv_find_bond_router(struct batadv_orig_node *primary_orig,
 459                         const struct batadv_hard_iface *recv_if)
 460 {
 461         struct batadv_neigh_node *tmp_neigh_node;
 462         struct batadv_neigh_node *router = NULL, *first_candidate = NULL;
 463
 464         rcu_read_lock();
 465         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 466                                 bonding_list) {
 467                 if (!first_candidate)
 468                         first_candidate = tmp_neigh_node;
 469
 470                 /* recv_if == NULL on the first node. */
 471                 if (tmp_neigh_node->if_incoming == recv_if)
 472                         continue;
 473
 474                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 475                         continue;
 476
 477                 router = tmp_neigh_node;
 478                 break;
 479         }
 480
 481         /* use the first candidate if nothing was found. */
 482         if (!router && first_candidate &&
 483             atomic_inc_not_zero(&first_candidate->refcount))
 484                 router = first_candidate;
 485
 486         if (!router)
 487                 goto out;
 488
 489         /* selected should point to the next element
 490          * after the current router
 491          */
 492         spin_lock_bh(&primary_orig->neigh_list_lock);
 493         /* this is a list_move(), which unfortunately
 494          * does not exist as rcu version
 495          */
 496         list_del_rcu(&primary_orig->bond_list);
 497         list_add_rcu(&primary_orig->bond_list,
 498                      &router->bonding_list);
 499         spin_unlock_bh(&primary_orig->neigh_list_lock);
 500
 501 out:
 502         rcu_read_unlock();
 503         return router;
 504 }
 505
 506 /* Interface Alternating: Use the best of the
 507  * remaining candidates which are not using
 508  * this interface.
 509  *
 510  * Increases the returned router's refcount
 511  */
 512 static struct batadv_neigh_node *
 513 batadv_find_ifalter_router(struct batadv_orig_node *primary_orig,
 514                            const struct batadv_hard_iface *recv_if)
 515 {
 516         struct batadv_neigh_node *tmp_neigh_node;
 517         struct batadv_neigh_node *router = NULL, *first_candidate = NULL;
 518
 519         rcu_read_lock();
 520         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 521                                 bonding_list) {
 522                 if (!first_candidate)
 523                         first_candidate = tmp_neigh_node;
 524
 525                 /* recv_if == NULL on the first node. */
 526                 if (tmp_neigh_node->if_incoming == recv_if)
 527                         continue;
 528
 529                 if (router && tmp_neigh_node->tq_avg <= router->tq_avg)
 530                         continue;
 531
 532                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 533                         continue;
 534
 535                 /* decrement refcount of previously selected router */
 536                 if (router)
 537                         batadv_neigh_node_free_ref(router);
 538
 539                 /* we found a better router (or at least one valid router) */
 540                 router = tmp_neigh_node;
 541         }
 542
 543         /* use the first candidate if nothing was found. */
 544         if (!router && first_candidate &&
 545             atomic_inc_not_zero(&first_candidate->refcount))
 546                 router = first_candidate;
 547
 548         rcu_read_unlock();
 549         return router;
 550 }
 551
 552 /**
 553  * batadv_check_unicast_packet - Check for malformed unicast packets
 554  * @skb: packet to check
 555  * @hdr_size: size of header to pull
 556  *
 557  * Check for short header and bad addresses in given packet. Returns negative
 558  * value when check fails and 0 otherwise. The negative value depends on the
 559  * reason: -ENODATA for bad header, -EBADR for broadcast destination or source,
 560  * and -EREMOTE for non-local (other host) destination.
 561  */
 562 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 563 {
 564         struct ethhdr *ethhdr;
 565
 566         /* drop packet if it has not necessary minimum size */
 567         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 568                 return -ENODATA;
 569
 570         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 571
 572         /* packet with unicast indication but broadcast recipient */
 573         if (is_broadcast_ether_addr(ethhdr->h_dest))
 574                 return -EBADR;
 575
 576         /* packet with broadcast sender address */
 577         if (is_broadcast_ether_addr(ethhdr->h_source))
 578                 return -EBADR;
 579
 580         /* not for me */
 581         if (!batadv_is_my_mac(ethhdr->h_dest))
 582                 return -EREMOTE;
 583
 584         return 0;
 585 }
 586
 587 int batadv_recv_tt_query(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
 588 {
 589         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 590         struct batadv_tt_query_packet *tt_query;
 591         uint16_t tt_size;
 592         int hdr_size = sizeof(*tt_query);
 593         char tt_flag;
 594         size_t packet_size;
 595
 596         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
 597                 return NET_RX_DROP;
 598
 599         /* I could need to modify it */
 600         if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0)
 601                 goto out;
 602
 603         tt_query = (struct batadv_tt_query_packet *)skb->data;
 604
 605         switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) {
 606         case BATADV_TT_REQUEST:
 607                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX);
 608
 609                 /* If we cannot provide an answer the tt_request is
 610                  * forwarded
 611                  */
 612                 if (!batadv_send_tt_response(bat_priv, tt_query)) {
 613                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 614                                 tt_flag = 'F';
 615                         else
 616                                 tt_flag = '.';
 617
 618                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 619                                    "Routing TT_REQUEST to %pM [%c]\n",
 620                                    tt_query->dst,
 621                                    tt_flag);
 622                         return batadv_route_unicast_packet(skb, recv_if);
 623                 }
 624                 break;
 625         case BATADV_TT_RESPONSE:
 626                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX);
 627
 628                 if (batadv_is_my_mac(tt_query->dst)) {
 629                         /* packet needs to be linearized to access the TT
 630                          * changes
 631                          */
 632                         if (skb_linearize(skb) < 0)
 633                                 goto out;
 634                         /* skb_linearize() possibly changed skb->data */
 635                         tt_query = (struct batadv_tt_query_packet *)skb->data;
 636
 637                         tt_size = batadv_tt_len(ntohs(tt_query->tt_data));
 638
 639                         /* Ensure we have all the claimed data */
 640                         packet_size = sizeof(struct batadv_tt_query_packet);
 641                         packet_size += tt_size;
 642                         if (unlikely(skb_headlen(skb) < packet_size))
 643                                 goto out;
 644
 645                         batadv_handle_tt_response(bat_priv, tt_query);
 646                 } else {
 647                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 648                                 tt_flag =  'F';
 649                         else
 650                                 tt_flag = '.';
 651                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 652                                    "Routing TT_RESPONSE to %pM [%c]\n",
 653                                    tt_query->dst,
 654                                    tt_flag);
 655                         return batadv_route_unicast_packet(skb, recv_if);
 656                 }
 657                 break;
 658         }
 659
 660 out:
 661         /* returning NET_RX_DROP will make the caller function kfree the skb */
 662         return NET_RX_DROP;
 663 }
 664
 665 int batadv_recv_roam_adv(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
 666 {
 667         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 668         struct batadv_roam_adv_packet *roam_adv_packet;
 669         struct batadv_orig_node *orig_node;
 670
 671         if (batadv_check_unicast_packet(skb, sizeof(*roam_adv_packet)) < 0)
 672                 goto out;
 673
 674         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX);
 675
 676         roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data;
 677
 678         if (!batadv_is_my_mac(roam_adv_packet->dst))
 679                 return batadv_route_unicast_packet(skb, recv_if);
 680
 681         /* check if it is a backbone gateway. we don't accept
 682          * roaming advertisement from it, as it has the same
 683          * entries as we have.
 684          */
 685         if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
 686                 goto out;
 687
 688         orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src);
 689         if (!orig_node)
 690                 goto out;
 691
 692         batadv_dbg(BATADV_DBG_TT, bat_priv,
 693                    "Received ROAMING_ADV from %pM (client %pM)\n",
 694                    roam_adv_packet->src, roam_adv_packet->client);
 695
 696         batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 697                              BATADV_TT_CLIENT_ROAM,
 698                              atomic_read(&orig_node->last_ttvn) + 1);
 699
 700         batadv_orig_node_free_ref(orig_node);
 701 out:
 702         /* returning NET_RX_DROP will make the caller function kfree the skb */
 703         return NET_RX_DROP;
 704 }
 705
 706 /* find a suitable router for this originator, and use
 707  * bonding if possible. increases the found neighbors
 708  * refcount.
 709  */
 710 struct batadv_neigh_node *
 711 batadv_find_router(struct batadv_priv *bat_priv,
 712                    struct batadv_orig_node *orig_node,
 713                    const struct batadv_hard_iface *recv_if)
 714 {
 715         struct batadv_orig_node *primary_orig_node;
 716         struct batadv_orig_node *router_orig;
 717         struct batadv_neigh_node *router;
 718         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 719         int bonding_enabled;
 720         uint8_t *primary_addr;
 721
 722         if (!orig_node)
 723                 return NULL;
 724
 725         router = batadv_orig_node_get_router(orig_node);
 726         if (!router)
 727                 goto err;
 728
 729         /* without bonding, the first node should
 730          * always choose the default router.
 731          */
 732         bonding_enabled = atomic_read(&bat_priv->bonding);
 733
 734         rcu_read_lock();
 735         /* select default router to output */
 736         router_orig = router->orig_node;
 737         if (!router_orig)
 738                 goto err_unlock;
 739
 740         if ((!recv_if) && (!bonding_enabled))
 741                 goto return_router;
 742
 743         primary_addr = router_orig->primary_addr;
 744
 745         /* if we have something in the primary_addr, we can search
 746          * for a potential bonding candidate.
 747          */
 748         if (batadv_compare_eth(primary_addr, zero_mac))
 749                 goto return_router;
 750
 751         /* find the orig_node which has the primary interface. might
 752          * even be the same as our router_orig in many cases
 753          */
 754         if (batadv_compare_eth(primary_addr, router_orig->orig)) {
 755                 primary_orig_node = router_orig;
 756         } else {
 757                 primary_orig_node = batadv_orig_hash_find(bat_priv,
 758                                                           primary_addr);
 759                 if (!primary_orig_node)
 760                         goto return_router;
 761
 762                 batadv_orig_node_free_ref(primary_orig_node);
 763         }
 764
 765         /* with less than 2 candidates, we can't do any
 766          * bonding and prefer the original router.
 767          */
 768         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 769                 goto return_router;
 770
 771         /* all nodes between should choose a candidate which
 772          * is is not on the interface where the packet came
 773          * in.
 774          */
 775         batadv_neigh_node_free_ref(router);
 776
 777         if (bonding_enabled)
 778                 router = batadv_find_bond_router(primary_orig_node, recv_if);
 779         else
 780                 router = batadv_find_ifalter_router(primary_orig_node, recv_if);
 781
 782 return_router:
 783         if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE)
 784                 goto err_unlock;
 785
 786         rcu_read_unlock();
 787         return router;
 788 err_unlock:
 789         rcu_read_unlock();
 790 err:
 791         if (router)
 792                 batadv_neigh_node_free_ref(router);
 793         return NULL;
 794 }
 795
 796 static int batadv_route_unicast_packet(struct sk_buff *skb,
 797                                        struct batadv_hard_iface *recv_if)
 798 {
 799         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 800         struct batadv_orig_node *orig_node = NULL;
 801         struct batadv_neigh_node *neigh_node = NULL;
 802         struct batadv_unicast_packet *unicast_packet;
 803         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 804         int ret = NET_RX_DROP;
 805         struct sk_buff *new_skb;
 806
 807         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 808
 809         /* TTL exceeded */
 810         if (unicast_packet->header.ttl < 2) {
 811                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 812                          ethhdr->h_source, unicast_packet->dest);
 813                 goto out;
 814         }
 815
 816         /* get routing information */
 817         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 818
 819         if (!orig_node)
 820                 goto out;
 821
 822         /* find_router() increases neigh_nodes refcount if found. */
 823         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 824
 825         if (!neigh_node)
 826                 goto out;
 827
 828         /* create a copy of the skb, if needed, to modify it. */
 829         if (skb_cow(skb, ETH_HLEN) < 0)
 830                 goto out;
 831
 832         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 833
 834         if (unicast_packet->header.packet_type == BATADV_UNICAST &&
 835             atomic_read(&bat_priv->fragmentation) &&
 836             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 837                 ret = batadv_frag_send_skb(skb, bat_priv,
 838                                            neigh_node->if_incoming,
 839                                            neigh_node->addr);
 840                 goto out;
 841         }
 842
 843         if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG &&
 844             batadv_frag_can_reassemble(skb,
 845                                        neigh_node->if_incoming->net_dev->mtu)) {
 846                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
 847
 848                 if (ret == NET_RX_DROP)
 849                         goto out;
 850
 851                 /* packet was buffered for late merge */
 852                 if (!new_skb) {
 853                         ret = NET_RX_SUCCESS;
 854                         goto out;
 855                 }
 856
 857                 skb = new_skb;
 858                 unicast_packet = (struct batadv_unicast_packet *)skb->data;
 859         }
 860
 861         /* decrement ttl */
 862         unicast_packet->header.ttl--;
 863
 864         /* network code packet if possible */
 865         if (batadv_nc_skb_forward(skb, neigh_node, ethhdr)) {
 866                 ret = NET_RX_SUCCESS;
 867         } else if (batadv_send_skb_to_orig(skb, orig_node, recv_if)) {
 868                 ret = NET_RX_SUCCESS;
 869
 870                 /* Update stats counter */
 871                 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 872                 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 873                                    skb->len + ETH_HLEN);
 874         }
 875
 876 out:
 877         if (neigh_node)
 878                 batadv_neigh_node_free_ref(neigh_node);
 879         if (orig_node)
 880                 batadv_orig_node_free_ref(orig_node);
 881         return ret;
 882 }
 883
 884 /**
 885  * batadv_reroute_unicast_packet - update the unicast header for re-routing
 886  * @bat_priv: the bat priv with all the soft interface information
 887  * @unicast_packet: the unicast header to be updated
 888  * @dst_addr: the payload destination
 889  *
 890  * Search the translation table for dst_addr and update the unicast header with
 891  * the new corresponding information (originator address where the destination
 892  * client currently is and its known TTVN)
 893  *
 894  * Returns true if the packet header has been updated, false otherwise
 895  */
 896 static bool
 897 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv,
 898                               struct batadv_unicast_packet *unicast_packet,
 899                               uint8_t *dst_addr)
 900 {
 901         struct batadv_orig_node *orig_node = NULL;
 902         struct batadv_hard_iface *primary_if = NULL;
 903         bool ret = false;
 904         uint8_t *orig_addr, orig_ttvn;
 905
 906         if (batadv_is_my_client(bat_priv, dst_addr)) {
 907                 primary_if = batadv_primary_if_get_selected(bat_priv);
 908                 if (!primary_if)
 909                         goto out;
 910                 orig_addr = primary_if->net_dev->dev_addr;
 911                 orig_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
 912         } else {
 913                 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr);
 914                 if (!orig_node)
 915                         goto out;
 916
 917                 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
 918                         goto out;
 919
 920                 orig_addr = orig_node->orig;
 921                 orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 922         }
 923
 924         /* update the packet header */
 925         memcpy(unicast_packet->dest, orig_addr, ETH_ALEN);
 926         unicast_packet->ttvn = orig_ttvn;
 927
 928         ret = true;
 929 out:
 930         if (primary_if)
 931                 batadv_hardif_free_ref(primary_if);
 932         if (orig_node)
 933                 batadv_orig_node_free_ref(orig_node);
 934
 935         return ret;
 936 }
 937
 938 static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 939                                      struct sk_buff *skb) {
 940         uint8_t curr_ttvn, old_ttvn;
 941         struct batadv_orig_node *orig_node;
 942         struct ethhdr *ethhdr;
 943         struct batadv_hard_iface *primary_if;
 944         struct batadv_unicast_packet *unicast_packet;
 945         int is_old_ttvn;
 946
 947         /* check if there is enough data before accessing it */
 948         if (pskb_may_pull(skb, sizeof(*unicast_packet) + ETH_HLEN) < 0)
 949                 return 0;
 950
 951         /* create a copy of the skb (in case of for re-routing) to modify it. */
 952         if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
 953                 return 0;
 954
 955         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 956         ethhdr = (struct ethhdr *)(skb->data + sizeof(*unicast_packet));
 957
 958         /* check if the destination client was served by this node and it is now
 959          * roaming. In this case, it means that the node has got a ROAM_ADV
 960          * message and that it knows the new destination in the mesh to re-route
 961          * the packet to
 962          */
 963         if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest)) {
 964                 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
 965                                                   ethhdr->h_dest))
 966                         net_ratelimited_function(batadv_dbg, BATADV_DBG_TT,
 967                                                  bat_priv,
 968                                                  "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
 969                                                  unicast_packet->dest,
 970                                                  ethhdr->h_dest);
 971                 /* at this point the mesh destination should have been
 972                  * substituted with the originator address found in the global
 973                  * table. If not, let the packet go untouched anyway because
 974                  * there is nothing the node can do
 975                  */
 976                 return 1;
 977         }
 978
 979         /* retrieve the TTVN known by this node for the packet destination. This
 980          * value is used later to check if the node which sent (or re-routed
 981          * last time) the packet had an updated information or not
 982          */
 983         curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
 984         if (!batadv_is_my_mac(unicast_packet->dest)) {
 985                 orig_node = batadv_orig_hash_find(bat_priv,
 986                                                   unicast_packet->dest);
 987                 /* if it is not possible to find the orig_node representing the
 988                  * destination, the packet can immediately be dropped as it will
 989                  * not be possible to deliver it
 990                  */
 991                 if (!orig_node)
 992                         return 0;
 993
 994                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 995                 batadv_orig_node_free_ref(orig_node);
 996         }
 997
 998         /* check if the TTVN contained in the packet is fresher than what the
 999          * node knows
1000          */
1001         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
1002         if (!is_old_ttvn)
1003                 return 1;
1004
1005         old_ttvn = unicast_packet->ttvn;
1006         /* the packet was forged based on outdated network information. Its
1007          * destination can possibly be updated and forwarded towards the new
1008          * target host
1009          */
1010         if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
1011                                           ethhdr->h_dest)) {
1012                 net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, bat_priv,
1013                                          "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
1014                                          unicast_packet->dest, ethhdr->h_dest,
1015                                          old_ttvn, curr_ttvn);
1016                 return 1;
1017         }
1018
1019         /* the packet has not been re-routed: either the destination is
1020          * currently served by this node or there is no destination at all and
1021          * it is possible to drop the packet
1022          */
1023         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest))
1024                 return 0;
1025
1026         /* update the header in order to let the packet be delivered to this
1027          * node's soft interface
1028          */
1029         primary_if = batadv_primary_if_get_selected(bat_priv);
1030         if (!primary_if)
1031                 return 0;
1032
1033         memcpy(unicast_packet->dest, primary_if->net_dev->dev_addr, ETH_ALEN);
1034
1035         batadv_hardif_free_ref(primary_if);
1036
1037         unicast_packet->ttvn = curr_ttvn;
1038
1039         return 1;
1040 }
1041
1042 int batadv_recv_unicast_packet(struct sk_buff *skb,
1043                                struct batadv_hard_iface *recv_if)
1044 {
1045         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1046         struct batadv_unicast_packet *unicast_packet;
1047         struct batadv_unicast_4addr_packet *unicast_4addr_packet;
1048         uint8_t *orig_addr;
1049         struct batadv_orig_node *orig_node = NULL;
1050         int check, hdr_size = sizeof(*unicast_packet);
1051         bool is4addr;
1052
1053         unicast_packet = (struct batadv_unicast_packet *)skb->data;
1054         unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
1055
1056         is4addr = unicast_packet->header.packet_type == BATADV_UNICAST_4ADDR;
1057         /* the caller function should have already pulled 2 bytes */
1058         if (is4addr)
1059                 hdr_size = sizeof(*unicast_4addr_packet);
1060
1061         /* function returns -EREMOTE for promiscuous packets */
1062         check = batadv_check_unicast_packet(skb, hdr_size);
1063
1064         /* Even though the packet is not for us, we might save it to use for
1065          * decoding a later received coded packet
1066          */
1067         if (check == -EREMOTE)
1068                 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
1069
1070         if (check < 0)
1071                 return NET_RX_DROP;
1072
1073         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1074                 return NET_RX_DROP;
1075
1076         /* packet for me */
1077         if (batadv_is_my_mac(unicast_packet->dest)) {
1078                 if (is4addr) {
1079                         batadv_dat_inc_counter(bat_priv,
1080                                                unicast_4addr_packet->subtype);
1081                         orig_addr = unicast_4addr_packet->src;
1082                         orig_node = batadv_orig_hash_find(bat_priv, orig_addr);
1083                 }
1084
1085                 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
1086                                                           hdr_size))
1087                         goto rx_success;
1088                 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
1089                                                         hdr_size))
1090                         goto rx_success;
1091
1092                 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
1093                                     orig_node);
1094
1095 rx_success:
1096                 if (orig_node)
1097                         batadv_orig_node_free_ref(orig_node);
1098
1099                 return NET_RX_SUCCESS;
1100         }
1101
1102         return batadv_route_unicast_packet(skb, recv_if);
1103 }
1104
1105 int batadv_recv_ucast_frag_packet(struct sk_buff *skb,
1106                                   struct batadv_hard_iface *recv_if)
1107 {
1108         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1109         struct batadv_unicast_frag_packet *unicast_packet;
1110         int hdr_size = sizeof(*unicast_packet);
1111         struct sk_buff *new_skb = NULL;
1112         int ret;
1113
1114         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1115                 return NET_RX_DROP;
1116
1117         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1118                 return NET_RX_DROP;
1119
1120         unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
1121
1122         /* packet for me */
1123         if (batadv_is_my_mac(unicast_packet->dest)) {
1124                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
1125
1126                 if (ret == NET_RX_DROP)
1127                         return NET_RX_DROP;
1128
1129                 /* packet was buffered for late merge */
1130                 if (!new_skb)
1131                         return NET_RX_SUCCESS;
1132
1133                 if (batadv_dat_snoop_incoming_arp_request(bat_priv, new_skb,
1134                                                           hdr_size))
1135                         goto rx_success;
1136                 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, new_skb,
1137                                                         hdr_size))
1138                         goto rx_success;
1139
1140                 batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
1141                                     sizeof(struct batadv_unicast_packet), NULL);
1142
1143 rx_success:
1144                 return NET_RX_SUCCESS;
1145         }
1146
1147         return batadv_route_unicast_packet(skb, recv_if);
1148 }
1149
1150
1151 int batadv_recv_bcast_packet(struct sk_buff *skb,
1152                              struct batadv_hard_iface *recv_if)
1153 {
1154         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1155         struct batadv_orig_node *orig_node = NULL;
1156         struct batadv_bcast_packet *bcast_packet;
1157         struct ethhdr *ethhdr;
1158         int hdr_size = sizeof(*bcast_packet);
1159         int ret = NET_RX_DROP;
1160         int32_t seq_diff;
1161
1162         /* drop packet if it has not necessary minimum size */
1163         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1164                 goto out;
1165
1166         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1167
1168         /* packet with broadcast indication but unicast recipient */
1169         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1170                 goto out;
1171
1172         /* packet with broadcast sender address */
1173         if (is_broadcast_ether_addr(ethhdr->h_source))
1174                 goto out;
1175
1176         /* ignore broadcasts sent by myself */
1177         if (batadv_is_my_mac(ethhdr->h_source))
1178                 goto out;
1179
1180         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1181
1182         /* ignore broadcasts originated by myself */
1183         if (batadv_is_my_mac(bcast_packet->orig))
1184                 goto out;
1185
1186         if (bcast_packet->header.ttl < 2)
1187                 goto out;
1188
1189         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1190
1191         if (!orig_node)
1192                 goto out;
1193
1194         spin_lock_bh(&orig_node->bcast_seqno_lock);
1195
1196         /* check whether the packet is a duplicate */
1197         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1198                             ntohl(bcast_packet->seqno)))
1199                 goto spin_unlock;
1200
1201         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1202
1203         /* check whether the packet is old and the host just restarted. */
1204         if (batadv_window_protected(bat_priv, seq_diff,
1205                                     &orig_node->bcast_seqno_reset))
1206                 goto spin_unlock;
1207
1208         /* mark broadcast in flood history, update window position
1209          * if required.
1210          */
1211         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1212                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1213
1214         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1215
1216         /* check whether this has been sent by another originator before */
1217         if (batadv_bla_check_bcast_duplist(bat_priv, skb))
1218                 goto out;
1219
1220         /* rebroadcast packet */
1221         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1222
1223         /* don't hand the broadcast up if it is from an originator
1224          * from the same backbone.
1225          */
1226         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1227                 goto out;
1228
1229         if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
1230                 goto rx_success;
1231         if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
1232                 goto rx_success;
1233
1234         /* broadcast for me */
1235         batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
1236                             orig_node);
1237
1238 rx_success:
1239         ret = NET_RX_SUCCESS;
1240         goto out;
1241
1242 spin_unlock:
1243         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1244 out:
1245         if (orig_node)
1246                 batadv_orig_node_free_ref(orig_node);
1247         return ret;
1248 }
1249
1250 int batadv_recv_vis_packet(struct sk_buff *skb,
1251                            struct batadv_hard_iface *recv_if)
1252 {
1253         struct batadv_vis_packet *vis_packet;
1254         struct ethhdr *ethhdr;
1255         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1256         int hdr_size = sizeof(*vis_packet);
1257
1258         /* keep skb linear */
1259         if (skb_linearize(skb) < 0)
1260                 return NET_RX_DROP;
1261
1262         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1263                 return NET_RX_DROP;
1264
1265         vis_packet = (struct batadv_vis_packet *)skb->data;
1266         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1267
1268         /* not for me */
1269         if (!batadv_is_my_mac(ethhdr->h_dest))
1270                 return NET_RX_DROP;
1271
1272         /* ignore own packets */
1273         if (batadv_is_my_mac(vis_packet->vis_orig))
1274                 return NET_RX_DROP;
1275
1276         if (batadv_is_my_mac(vis_packet->sender_orig))
1277                 return NET_RX_DROP;
1278
1279         switch (vis_packet->vis_type) {
1280         case BATADV_VIS_TYPE_SERVER_SYNC:
1281                 batadv_receive_server_sync_packet(bat_priv, vis_packet,
1282                                                   skb_headlen(skb));
1283                 break;
1284
1285         case BATADV_VIS_TYPE_CLIENT_UPDATE:
1286                 batadv_receive_client_update_packet(bat_priv, vis_packet,
1287                                                     skb_headlen(skb));
1288                 break;
1289
1290         default:        /* ignore unknown packet */
1291                 break;
1292         }
1293
1294         /* We take a copy of the data in the packet, so we should
1295          * always free the skbuf.
1296          */
1297         return NET_RX_DROP;
1298 }