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