net/batman-adv/routing.c

   1 /* Copyright (C) 2007-2012 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
  32 static int batadv_route_unicast_packet(struct sk_buff *skb,
  33                                        struct hard_iface *recv_if);
  34
  35 void batadv_slide_own_bcast_window(struct hard_iface *hard_iface)
  36 {
  37         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  38         struct batadv_hashtable *hash = bat_priv->orig_hash;
  39         struct hlist_node *node;
  40         struct hlist_head *head;
  41         struct orig_node *orig_node;
  42         unsigned long *word;
  43         uint32_t i;
  44         size_t word_index;
  45         uint8_t *w;
  46
  47         for (i = 0; i < hash->size; i++) {
  48                 head = &hash->table[i];
  49
  50                 rcu_read_lock();
  51                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  52                         spin_lock_bh(&orig_node->ogm_cnt_lock);
  53                         word_index = hard_iface->if_num * BATADV_NUM_WORDS;
  54                         word = &(orig_node->bcast_own[word_index]);
  55
  56                         batadv_bit_get_packet(bat_priv, word, 1, 0);
  57                         w = &orig_node->bcast_own_sum[hard_iface->if_num];
  58                         *w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
  59                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
  60                 }
  61                 rcu_read_unlock();
  62         }
  63 }
  64
  65 static void _batadv_update_route(struct bat_priv *bat_priv,
  66                                  struct orig_node *orig_node,
  67                                  struct neigh_node *neigh_node)
  68 {
  69         struct neigh_node *curr_router;
  70
  71         curr_router = batadv_orig_node_get_router(orig_node);
  72
  73         /* route deleted */
  74         if ((curr_router) && (!neigh_node)) {
  75                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  76                            "Deleting route towards: %pM\n", orig_node->orig);
  77                 batadv_tt_global_del_orig(bat_priv, orig_node,
  78                                           "Deleted route towards originator");
  79
  80         /* route added */
  81         } else if ((!curr_router) && (neigh_node)) {
  82
  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 bat_priv *bat_priv, struct orig_node *orig_node,
 111                          struct neigh_node *neigh_node)
 112 {
 113         struct neigh_node *router = NULL;
 114
 115         if (!orig_node)
 116                 goto out;
 117
 118         router = batadv_orig_node_get_router(orig_node);
 119
 120         if (router != neigh_node)
 121                 _batadv_update_route(bat_priv, orig_node, neigh_node);
 122
 123 out:
 124         if (router)
 125                 batadv_neigh_node_free_ref(router);
 126 }
 127
 128 /* caller must hold the neigh_list_lock */
 129 void batadv_bonding_candidate_del(struct orig_node *orig_node,
 130                                   struct neigh_node *neigh_node)
 131 {
 132         /* this neighbor is not part of our candidate list */
 133         if (list_empty(&neigh_node->bonding_list))
 134                 goto out;
 135
 136         list_del_rcu(&neigh_node->bonding_list);
 137         INIT_LIST_HEAD(&neigh_node->bonding_list);
 138         batadv_neigh_node_free_ref(neigh_node);
 139         atomic_dec(&orig_node->bond_candidates);
 140
 141 out:
 142         return;
 143 }
 144
 145 void batadv_bonding_candidate_add(struct orig_node *orig_node,
 146                                   struct neigh_node *neigh_node)
 147 {
 148         struct hlist_node *node;
 149         struct 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, node,
 172                                  &orig_node->neigh_list, list) {
 173
 174                 if (tmp_neigh_node == neigh_node)
 175                         continue;
 176
 177                 /* we only care if the other candidate is even
 178                  * considered as candidate.
 179                  */
 180                 if (list_empty(&tmp_neigh_node->bonding_list))
 181                         continue;
 182
 183                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 184                     (batadv_compare_eth(neigh_node->addr,
 185                                         tmp_neigh_node->addr))) {
 186                         interference_candidate = 1;
 187                         break;
 188                 }
 189         }
 190
 191         /* don't care further if it is an interference candidate */
 192         if (interference_candidate)
 193                 goto candidate_del;
 194
 195         /* this neighbor already is part of our candidate list */
 196         if (!list_empty(&neigh_node->bonding_list))
 197                 goto out;
 198
 199         if (!atomic_inc_not_zero(&neigh_node->refcount))
 200                 goto out;
 201
 202         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 203         atomic_inc(&orig_node->bond_candidates);
 204         goto out;
 205
 206 candidate_del:
 207         batadv_bonding_candidate_del(orig_node, neigh_node);
 208
 209 out:
 210         spin_unlock_bh(&orig_node->neigh_list_lock);
 211
 212         if (router)
 213                 batadv_neigh_node_free_ref(router);
 214 }
 215
 216 /* copy primary address for bonding */
 217 void
 218 batadv_bonding_save_primary(const struct orig_node *orig_node,
 219                             struct orig_node *orig_neigh_node,
 220                             const struct batadv_ogm_packet *batman_ogm_packet)
 221 {
 222         if (!(batman_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP))
 223                 return;
 224
 225         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 226 }
 227
 228 /* checks whether the host restarted and is in the protection time.
 229  * returns:
 230  *  0 if the packet is to be accepted
 231  *  1 if the packet is to be ignored.
 232  */
 233 int batadv_window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
 234                             unsigned long *last_reset)
 235 {
 236         if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE ||
 237             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
 238                 if (!batadv_has_timed_out(*last_reset,
 239                                           BATADV_RESET_PROTECTION_MS))
 240                         return 1;
 241
 242                 *last_reset = jiffies;
 243                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 244                            "old packet received, start protection\n");
 245         }
 246
 247         return 0;
 248 }
 249
 250 bool batadv_check_management_packet(struct sk_buff *skb,
 251                                     struct hard_iface *hard_iface,
 252                                     int header_len)
 253 {
 254         struct ethhdr *ethhdr;
 255
 256         /* drop packet if it has not necessary minimum size */
 257         if (unlikely(!pskb_may_pull(skb, header_len)))
 258                 return false;
 259
 260         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 261
 262         /* packet with broadcast indication but unicast recipient */
 263         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 264                 return false;
 265
 266         /* packet with broadcast sender address */
 267         if (is_broadcast_ether_addr(ethhdr->h_source))
 268                 return false;
 269
 270         /* create a copy of the skb, if needed, to modify it. */
 271         if (skb_cow(skb, 0) < 0)
 272                 return false;
 273
 274         /* keep skb linear */
 275         if (skb_linearize(skb) < 0)
 276                 return false;
 277
 278         return true;
 279 }
 280
 281 static int batadv_recv_my_icmp_packet(struct bat_priv *bat_priv,
 282                                       struct sk_buff *skb, size_t icmp_len)
 283 {
 284         struct hard_iface *primary_if = NULL;
 285         struct orig_node *orig_node = NULL;
 286         struct neigh_node *router = NULL;
 287         struct batadv_icmp_packet_rr *icmp_packet;
 288         int ret = NET_RX_DROP;
 289
 290         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 291
 292         /* add data to device queue */
 293         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 294                 batadv_socket_receive_packet(icmp_packet, icmp_len);
 295                 goto out;
 296         }
 297
 298         primary_if = batadv_primary_if_get_selected(bat_priv);
 299         if (!primary_if)
 300                 goto out;
 301
 302         /* answer echo request (ping) */
 303         /* get routing information */
 304         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 305         if (!orig_node)
 306                 goto out;
 307
 308         router = batadv_orig_node_get_router(orig_node);
 309         if (!router)
 310                 goto out;
 311
 312         /* create a copy of the skb, if needed, to modify it. */
 313         if (skb_cow(skb, ETH_HLEN) < 0)
 314                 goto out;
 315
 316         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 317
 318         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 319         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 320         icmp_packet->msg_type = BATADV_ECHO_REPLY;
 321         icmp_packet->header.ttl = BATADV_TTL;
 322
 323         batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 324         ret = NET_RX_SUCCESS;
 325
 326 out:
 327         if (primary_if)
 328                 batadv_hardif_free_ref(primary_if);
 329         if (router)
 330                 batadv_neigh_node_free_ref(router);
 331         if (orig_node)
 332                 batadv_orig_node_free_ref(orig_node);
 333         return ret;
 334 }
 335
 336 static int batadv_recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
 337                                          struct sk_buff *skb)
 338 {
 339         struct hard_iface *primary_if = NULL;
 340         struct orig_node *orig_node = NULL;
 341         struct neigh_node *router = NULL;
 342         struct batadv_icmp_packet *icmp_packet;
 343         int ret = NET_RX_DROP;
 344
 345         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 346
 347         /* send TTL exceeded if packet is an echo request (traceroute) */
 348         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 349                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 350                          icmp_packet->orig, icmp_packet->dst);
 351                 goto out;
 352         }
 353
 354         primary_if = batadv_primary_if_get_selected(bat_priv);
 355         if (!primary_if)
 356                 goto out;
 357
 358         /* get routing information */
 359         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 360         if (!orig_node)
 361                 goto out;
 362
 363         router = batadv_orig_node_get_router(orig_node);
 364         if (!router)
 365                 goto out;
 366
 367         /* create a copy of the skb, if needed, to modify it. */
 368         if (skb_cow(skb, ETH_HLEN) < 0)
 369                 goto out;
 370
 371         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 372
 373         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 374         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 375         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
 376         icmp_packet->header.ttl = BATADV_TTL;
 377
 378         batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 379         ret = NET_RX_SUCCESS;
 380
 381 out:
 382         if (primary_if)
 383                 batadv_hardif_free_ref(primary_if);
 384         if (router)
 385                 batadv_neigh_node_free_ref(router);
 386         if (orig_node)
 387                 batadv_orig_node_free_ref(orig_node);
 388         return ret;
 389 }
 390
 391
 392 int batadv_recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 393 {
 394         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 395         struct batadv_icmp_packet_rr *icmp_packet;
 396         struct ethhdr *ethhdr;
 397         struct orig_node *orig_node = NULL;
 398         struct neigh_node *router = NULL;
 399         int hdr_size = sizeof(struct batadv_icmp_packet);
 400         int ret = NET_RX_DROP;
 401
 402         /* we truncate all incoming icmp packets if they don't match our size */
 403         if (skb->len >= sizeof(struct batadv_icmp_packet_rr))
 404                 hdr_size = sizeof(struct batadv_icmp_packet_rr);
 405
 406         /* drop packet if it has not necessary minimum size */
 407         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 408                 goto out;
 409
 410         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 411
 412         /* packet with unicast indication but broadcast recipient */
 413         if (is_broadcast_ether_addr(ethhdr->h_dest))
 414                 goto out;
 415
 416         /* packet with broadcast sender address */
 417         if (is_broadcast_ether_addr(ethhdr->h_source))
 418                 goto out;
 419
 420         /* not for me */
 421         if (!batadv_is_my_mac(ethhdr->h_dest))
 422                 goto out;
 423
 424         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 425
 426         /* add record route information if not full */
 427         if ((hdr_size == sizeof(struct batadv_icmp_packet_rr)) &&
 428             (icmp_packet->rr_cur < BATADV_RR_LEN)) {
 429                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
 430                        ethhdr->h_dest, ETH_ALEN);
 431                 icmp_packet->rr_cur++;
 432         }
 433
 434         /* packet for me */
 435         if (batadv_is_my_mac(icmp_packet->dst))
 436                 return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size);
 437
 438         /* TTL exceeded */
 439         if (icmp_packet->header.ttl < 2)
 440                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 441
 442         /* get routing information */
 443         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
 444         if (!orig_node)
 445                 goto out;
 446
 447         router = batadv_orig_node_get_router(orig_node);
 448         if (!router)
 449                 goto out;
 450
 451         /* create a copy of the skb, if needed, to modify it. */
 452         if (skb_cow(skb, ETH_HLEN) < 0)
 453                 goto out;
 454
 455         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 456
 457         /* decrement ttl */
 458         icmp_packet->header.ttl--;
 459
 460         /* route it */
 461         batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 462         ret = NET_RX_SUCCESS;
 463
 464 out:
 465         if (router)
 466                 batadv_neigh_node_free_ref(router);
 467         if (orig_node)
 468                 batadv_orig_node_free_ref(orig_node);
 469         return ret;
 470 }
 471
 472 /* In the bonding case, send the packets in a round
 473  * robin fashion over the remaining interfaces.
 474  *
 475  * This method rotates the bonding list and increases the
 476  * returned router's refcount.
 477  */
 478 static struct neigh_node *
 479 batadv_find_bond_router(struct orig_node *primary_orig,
 480                         const struct hard_iface *recv_if)
 481 {
 482         struct neigh_node *tmp_neigh_node;
 483         struct neigh_node *router = NULL, *first_candidate = NULL;
 484
 485         rcu_read_lock();
 486         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 487                                 bonding_list) {
 488                 if (!first_candidate)
 489                         first_candidate = tmp_neigh_node;
 490
 491                 /* recv_if == NULL on the first node. */
 492                 if (tmp_neigh_node->if_incoming == recv_if)
 493                         continue;
 494
 495                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 496                         continue;
 497
 498                 router = tmp_neigh_node;
 499                 break;
 500         }
 501
 502         /* use the first candidate if nothing was found. */
 503         if (!router && first_candidate &&
 504             atomic_inc_not_zero(&first_candidate->refcount))
 505                 router = first_candidate;
 506
 507         if (!router)
 508                 goto out;
 509
 510         /* selected should point to the next element
 511          * after the current router
 512          */
 513         spin_lock_bh(&primary_orig->neigh_list_lock);
 514         /* this is a list_move(), which unfortunately
 515          * does not exist as rcu version
 516          */
 517         list_del_rcu(&primary_orig->bond_list);
 518         list_add_rcu(&primary_orig->bond_list,
 519                      &router->bonding_list);
 520         spin_unlock_bh(&primary_orig->neigh_list_lock);
 521
 522 out:
 523         rcu_read_unlock();
 524         return router;
 525 }
 526
 527 /* Interface Alternating: Use the best of the
 528  * remaining candidates which are not using
 529  * this interface.
 530  *
 531  * Increases the returned router's refcount
 532  */
 533 static struct neigh_node *
 534 batadv_find_ifalter_router(struct orig_node *primary_orig,
 535                            const struct hard_iface *recv_if)
 536 {
 537         struct neigh_node *tmp_neigh_node;
 538         struct neigh_node *router = NULL, *first_candidate = NULL;
 539
 540         rcu_read_lock();
 541         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 542                                 bonding_list) {
 543                 if (!first_candidate)
 544                         first_candidate = tmp_neigh_node;
 545
 546                 /* recv_if == NULL on the first node. */
 547                 if (tmp_neigh_node->if_incoming == recv_if)
 548                         continue;
 549
 550                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 551                         continue;
 552
 553                 /* if we don't have a router yet
 554                  * or this one is better, choose it.
 555                  */
 556                 if ((!router) ||
 557                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
 558                         /* decrement refcount of
 559                          * previously selected router
 560                          */
 561                         if (router)
 562                                 batadv_neigh_node_free_ref(router);
 563
 564                         router = tmp_neigh_node;
 565                         atomic_inc_not_zero(&router->refcount);
 566                 }
 567
 568                 batadv_neigh_node_free_ref(tmp_neigh_node);
 569         }
 570
 571         /* use the first candidate if nothing was found. */
 572         if (!router && first_candidate &&
 573             atomic_inc_not_zero(&first_candidate->refcount))
 574                 router = first_candidate;
 575
 576         rcu_read_unlock();
 577         return router;
 578 }
 579
 580 int batadv_recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
 581 {
 582         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 583         struct batadv_tt_query_packet *tt_query;
 584         uint16_t tt_size;
 585         struct ethhdr *ethhdr;
 586         char tt_flag;
 587         size_t packet_size;
 588
 589         /* drop packet if it has not necessary minimum size */
 590         if (unlikely(!pskb_may_pull(skb,
 591                                     sizeof(struct batadv_tt_query_packet))))
 592                 goto out;
 593
 594         /* I could need to modify it */
 595         if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0)
 596                 goto out;
 597
 598         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 599
 600         /* packet with unicast indication but broadcast recipient */
 601         if (is_broadcast_ether_addr(ethhdr->h_dest))
 602                 goto out;
 603
 604         /* packet with broadcast sender address */
 605         if (is_broadcast_ether_addr(ethhdr->h_source))
 606                 goto out;
 607
 608         tt_query = (struct batadv_tt_query_packet *)skb->data;
 609
 610         switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) {
 611         case BATADV_TT_REQUEST:
 612                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX);
 613
 614                 /* If we cannot provide an answer the tt_request is
 615                  * forwarded
 616                  */
 617                 if (!batadv_send_tt_response(bat_priv, tt_query)) {
 618                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 619                                 tt_flag = 'F';
 620                         else
 621                                 tt_flag = '.';
 622
 623                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 624                                    "Routing TT_REQUEST to %pM [%c]\n",
 625                                    tt_query->dst,
 626                                    tt_flag);
 627                         return batadv_route_unicast_packet(skb, recv_if);
 628                 }
 629                 break;
 630         case BATADV_TT_RESPONSE:
 631                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX);
 632
 633                 if (batadv_is_my_mac(tt_query->dst)) {
 634                         /* packet needs to be linearized to access the TT
 635                          * changes
 636                          */
 637                         if (skb_linearize(skb) < 0)
 638                                 goto out;
 639                         /* skb_linearize() possibly changed skb->data */
 640                         tt_query = (struct batadv_tt_query_packet *)skb->data;
 641
 642                         tt_size = batadv_tt_len(ntohs(tt_query->tt_data));
 643
 644                         /* Ensure we have all the claimed data */
 645                         packet_size = sizeof(struct batadv_tt_query_packet);
 646                         packet_size += tt_size;
 647                         if (unlikely(skb_headlen(skb) < packet_size))
 648                                 goto out;
 649
 650                         batadv_handle_tt_response(bat_priv, tt_query);
 651                 } else {
 652                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 653                                 tt_flag =  'F';
 654                         else
 655                                 tt_flag = '.';
 656                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 657                                    "Routing TT_RESPONSE to %pM [%c]\n",
 658                                    tt_query->dst,
 659                                    tt_flag);
 660                         return batadv_route_unicast_packet(skb, recv_if);
 661                 }
 662                 break;
 663         }
 664
 665 out:
 666         /* returning NET_RX_DROP will make the caller function kfree the skb */
 667         return NET_RX_DROP;
 668 }
 669
 670 int batadv_recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
 671 {
 672         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 673         struct batadv_roam_adv_packet *roam_adv_packet;
 674         struct orig_node *orig_node;
 675         struct ethhdr *ethhdr;
 676
 677         /* drop packet if it has not necessary minimum size */
 678         if (unlikely(!pskb_may_pull(skb,
 679                                     sizeof(struct batadv_roam_adv_packet))))
 680                 goto out;
 681
 682         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 683
 684         /* packet with unicast indication but broadcast recipient */
 685         if (is_broadcast_ether_addr(ethhdr->h_dest))
 686                 goto out;
 687
 688         /* packet with broadcast sender address */
 689         if (is_broadcast_ether_addr(ethhdr->h_source))
 690                 goto out;
 691
 692         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX);
 693
 694         roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data;
 695
 696         if (!batadv_is_my_mac(roam_adv_packet->dst))
 697                 return batadv_route_unicast_packet(skb, recv_if);
 698
 699         /* check if it is a backbone gateway. we don't accept
 700          * roaming advertisement from it, as it has the same
 701          * entries as we have.
 702          */
 703         if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
 704                 goto out;
 705
 706         orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src);
 707         if (!orig_node)
 708                 goto out;
 709
 710         batadv_dbg(BATADV_DBG_TT, bat_priv,
 711                    "Received ROAMING_ADV from %pM (client %pM)\n",
 712                    roam_adv_packet->src, roam_adv_packet->client);
 713
 714         batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 715                              BATADV_TT_CLIENT_ROAM,
 716                              atomic_read(&orig_node->last_ttvn) + 1);
 717
 718         /* Roaming phase starts: I have new information but the ttvn has not
 719          * been incremented yet. This flag will make me check all the incoming
 720          * packets for the correct destination.
 721          */
 722         bat_priv->tt_poss_change = true;
 723
 724         batadv_orig_node_free_ref(orig_node);
 725 out:
 726         /* returning NET_RX_DROP will make the caller function kfree the skb */
 727         return NET_RX_DROP;
 728 }
 729
 730 /* find a suitable router for this originator, and use
 731  * bonding if possible. increases the found neighbors
 732  * refcount.
 733  */
 734 struct neigh_node *batadv_find_router(struct bat_priv *bat_priv,
 735                                       struct orig_node *orig_node,
 736                                       const struct hard_iface *recv_if)
 737 {
 738         struct orig_node *primary_orig_node;
 739         struct orig_node *router_orig;
 740         struct neigh_node *router;
 741         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 742         int bonding_enabled;
 743         uint8_t *primary_addr;
 744
 745         if (!orig_node)
 746                 return NULL;
 747
 748         router = batadv_orig_node_get_router(orig_node);
 749         if (!router)
 750                 goto err;
 751
 752         /* without bonding, the first node should
 753          * always choose the default router.
 754          */
 755         bonding_enabled = atomic_read(&bat_priv->bonding);
 756
 757         rcu_read_lock();
 758         /* select default router to output */
 759         router_orig = router->orig_node;
 760         if (!router_orig)
 761                 goto err_unlock;
 762
 763         if ((!recv_if) && (!bonding_enabled))
 764                 goto return_router;
 765
 766         primary_addr = router_orig->primary_addr;
 767
 768         /* if we have something in the primary_addr, we can search
 769          * for a potential bonding candidate.
 770          */
 771         if (batadv_compare_eth(primary_addr, zero_mac))
 772                 goto return_router;
 773
 774         /* find the orig_node which has the primary interface. might
 775          * even be the same as our router_orig in many cases
 776          */
 777         if (batadv_compare_eth(primary_addr, router_orig->orig)) {
 778                 primary_orig_node = router_orig;
 779         } else {
 780                 primary_orig_node = batadv_orig_hash_find(bat_priv,
 781                                                           primary_addr);
 782                 if (!primary_orig_node)
 783                         goto return_router;
 784
 785                 batadv_orig_node_free_ref(primary_orig_node);
 786         }
 787
 788         /* with less than 2 candidates, we can't do any
 789          * bonding and prefer the original router.
 790          */
 791         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 792                 goto return_router;
 793
 794         /* all nodes between should choose a candidate which
 795          * is is not on the interface where the packet came
 796          * in.
 797          */
 798         batadv_neigh_node_free_ref(router);
 799
 800         if (bonding_enabled)
 801                 router = batadv_find_bond_router(primary_orig_node, recv_if);
 802         else
 803                 router = batadv_find_ifalter_router(primary_orig_node, recv_if);
 804
 805 return_router:
 806         if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE)
 807                 goto err_unlock;
 808
 809         rcu_read_unlock();
 810         return router;
 811 err_unlock:
 812         rcu_read_unlock();
 813 err:
 814         if (router)
 815                 batadv_neigh_node_free_ref(router);
 816         return NULL;
 817 }
 818
 819 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 820 {
 821         struct ethhdr *ethhdr;
 822
 823         /* drop packet if it has not necessary minimum size */
 824         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 825                 return -1;
 826
 827         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 828
 829         /* packet with unicast indication but broadcast recipient */
 830         if (is_broadcast_ether_addr(ethhdr->h_dest))
 831                 return -1;
 832
 833         /* packet with broadcast sender address */
 834         if (is_broadcast_ether_addr(ethhdr->h_source))
 835                 return -1;
 836
 837         /* not for me */
 838         if (!batadv_is_my_mac(ethhdr->h_dest))
 839                 return -1;
 840
 841         return 0;
 842 }
 843
 844 static int batadv_route_unicast_packet(struct sk_buff *skb,
 845                                        struct hard_iface *recv_if)
 846 {
 847         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 848         struct orig_node *orig_node = NULL;
 849         struct neigh_node *neigh_node = NULL;
 850         struct batadv_unicast_packet *unicast_packet;
 851         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 852         int ret = NET_RX_DROP;
 853         struct sk_buff *new_skb;
 854
 855         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 856
 857         /* TTL exceeded */
 858         if (unicast_packet->header.ttl < 2) {
 859                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 860                          ethhdr->h_source, unicast_packet->dest);
 861                 goto out;
 862         }
 863
 864         /* get routing information */
 865         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 866
 867         if (!orig_node)
 868                 goto out;
 869
 870         /* find_router() increases neigh_nodes refcount if found. */
 871         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 872
 873         if (!neigh_node)
 874                 goto out;
 875
 876         /* create a copy of the skb, if needed, to modify it. */
 877         if (skb_cow(skb, ETH_HLEN) < 0)
 878                 goto out;
 879
 880         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 881
 882         if (unicast_packet->header.packet_type == BATADV_UNICAST &&
 883             atomic_read(&bat_priv->fragmentation) &&
 884             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 885                 ret = batadv_frag_send_skb(skb, bat_priv,
 886                                            neigh_node->if_incoming,
 887                                            neigh_node->addr);
 888                 goto out;
 889         }
 890
 891         if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG &&
 892             batadv_frag_can_reassemble(skb,
 893                                        neigh_node->if_incoming->net_dev->mtu)) {
 894
 895                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
 896
 897                 if (ret == NET_RX_DROP)
 898                         goto out;
 899
 900                 /* packet was buffered for late merge */
 901                 if (!new_skb) {
 902                         ret = NET_RX_SUCCESS;
 903                         goto out;
 904                 }
 905
 906                 skb = new_skb;
 907                 unicast_packet = (struct batadv_unicast_packet *)skb->data;
 908         }
 909
 910         /* decrement ttl */
 911         unicast_packet->header.ttl--;
 912
 913         /* Update stats counter */
 914         batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 915         batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 916                            skb->len + ETH_HLEN);
 917
 918         /* route it */
 919         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 920         ret = NET_RX_SUCCESS;
 921
 922 out:
 923         if (neigh_node)
 924                 batadv_neigh_node_free_ref(neigh_node);
 925         if (orig_node)
 926                 batadv_orig_node_free_ref(orig_node);
 927         return ret;
 928 }
 929
 930 static int batadv_check_unicast_ttvn(struct bat_priv *bat_priv,
 931                                      struct sk_buff *skb) {
 932         uint8_t curr_ttvn;
 933         struct orig_node *orig_node;
 934         struct ethhdr *ethhdr;
 935         struct hard_iface *primary_if;
 936         struct batadv_unicast_packet *unicast_packet;
 937         bool tt_poss_change;
 938         int is_old_ttvn;
 939
 940         /* I could need to modify it */
 941         if (skb_cow(skb, sizeof(struct batadv_unicast_packet)) < 0)
 942                 return 0;
 943
 944         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 945
 946         if (batadv_is_my_mac(unicast_packet->dest)) {
 947                 tt_poss_change = bat_priv->tt_poss_change;
 948                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 949         } else {
 950                 orig_node = batadv_orig_hash_find(bat_priv,
 951                                                   unicast_packet->dest);
 952
 953                 if (!orig_node)
 954                         return 0;
 955
 956                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 957                 tt_poss_change = orig_node->tt_poss_change;
 958                 batadv_orig_node_free_ref(orig_node);
 959         }
 960
 961         /* Check whether I have to reroute the packet */
 962         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 963         if (is_old_ttvn || tt_poss_change) {
 964                 /* check if there is enough data before accessing it */
 965                 if (pskb_may_pull(skb, sizeof(struct batadv_unicast_packet) +
 966                                   ETH_HLEN) < 0)
 967                         return 0;
 968
 969                 ethhdr = (struct ethhdr *)(skb->data +
 970                         sizeof(struct batadv_unicast_packet));
 971
 972                 /* we don't have an updated route for this client, so we should
 973                  * not try to reroute the packet!!
 974                  */
 975                 if (batadv_tt_global_client_is_roaming(bat_priv,
 976                                                        ethhdr->h_dest))
 977                         return 1;
 978
 979                 orig_node = batadv_transtable_search(bat_priv, NULL,
 980                                                      ethhdr->h_dest);
 981
 982                 if (!orig_node) {
 983                         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest))
 984                                 return 0;
 985                         primary_if = batadv_primary_if_get_selected(bat_priv);
 986                         if (!primary_if)
 987                                 return 0;
 988                         memcpy(unicast_packet->dest,
 989                                primary_if->net_dev->dev_addr, ETH_ALEN);
 990                         batadv_hardif_free_ref(primary_if);
 991                 } else {
 992                         memcpy(unicast_packet->dest, orig_node->orig,
 993                                ETH_ALEN);
 994                         curr_ttvn = (uint8_t)
 995                                 atomic_read(&orig_node->last_ttvn);
 996                         batadv_orig_node_free_ref(orig_node);
 997                 }
 998
 999                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
1000                            "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
1001                            unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
1002                            unicast_packet->dest);
1003
1004                 unicast_packet->ttvn = curr_ttvn;
1005         }
1006         return 1;
1007 }
1008
1009 int batadv_recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1010 {
1011         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1012         struct batadv_unicast_packet *unicast_packet;
1013         int hdr_size = sizeof(*unicast_packet);
1014
1015         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1016                 return NET_RX_DROP;
1017
1018         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1019                 return NET_RX_DROP;
1020
1021         unicast_packet = (struct batadv_unicast_packet *)skb->data;
1022
1023         /* packet for me */
1024         if (batadv_is_my_mac(unicast_packet->dest)) {
1025                 batadv_interface_rx(recv_if->soft_iface, skb, recv_if,
1026                                     hdr_size);
1027                 return NET_RX_SUCCESS;
1028         }
1029
1030         return batadv_route_unicast_packet(skb, recv_if);
1031 }
1032
1033 int batadv_recv_ucast_frag_packet(struct sk_buff *skb,
1034                                   struct hard_iface *recv_if)
1035 {
1036         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1037         struct batadv_unicast_frag_packet *unicast_packet;
1038         int hdr_size = sizeof(*unicast_packet);
1039         struct sk_buff *new_skb = NULL;
1040         int ret;
1041
1042         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1043                 return NET_RX_DROP;
1044
1045         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1046                 return NET_RX_DROP;
1047
1048         unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
1049
1050         /* packet for me */
1051         if (batadv_is_my_mac(unicast_packet->dest)) {
1052
1053                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
1054
1055                 if (ret == NET_RX_DROP)
1056                         return NET_RX_DROP;
1057
1058                 /* packet was buffered for late merge */
1059                 if (!new_skb)
1060                         return NET_RX_SUCCESS;
1061
1062                 batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
1063                                     sizeof(struct batadv_unicast_packet));
1064                 return NET_RX_SUCCESS;
1065         }
1066
1067         return batadv_route_unicast_packet(skb, recv_if);
1068 }
1069
1070
1071 int batadv_recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1072 {
1073         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1074         struct orig_node *orig_node = NULL;
1075         struct batadv_bcast_packet *bcast_packet;
1076         struct ethhdr *ethhdr;
1077         int hdr_size = sizeof(*bcast_packet);
1078         int ret = NET_RX_DROP;
1079         int32_t seq_diff;
1080
1081         /* drop packet if it has not necessary minimum size */
1082         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1083                 goto out;
1084
1085         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1086
1087         /* packet with broadcast indication but unicast recipient */
1088         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1089                 goto out;
1090
1091         /* packet with broadcast sender address */
1092         if (is_broadcast_ether_addr(ethhdr->h_source))
1093                 goto out;
1094
1095         /* ignore broadcasts sent by myself */
1096         if (batadv_is_my_mac(ethhdr->h_source))
1097                 goto out;
1098
1099         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1100
1101         /* ignore broadcasts originated by myself */
1102         if (batadv_is_my_mac(bcast_packet->orig))
1103                 goto out;
1104
1105         if (bcast_packet->header.ttl < 2)
1106                 goto out;
1107
1108         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1109
1110         if (!orig_node)
1111                 goto out;
1112
1113         spin_lock_bh(&orig_node->bcast_seqno_lock);
1114
1115         /* check whether the packet is a duplicate */
1116         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1117                             ntohl(bcast_packet->seqno)))
1118                 goto spin_unlock;
1119
1120         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1121
1122         /* check whether the packet is old and the host just restarted. */
1123         if (batadv_window_protected(bat_priv, seq_diff,
1124                                     &orig_node->bcast_seqno_reset))
1125                 goto spin_unlock;
1126
1127         /* mark broadcast in flood history, update window position
1128          * if required.
1129          */
1130         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1131                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1132
1133         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1134
1135         /* check whether this has been sent by another originator before */
1136         if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
1137                 goto out;
1138
1139         /* rebroadcast packet */
1140         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1141
1142         /* don't hand the broadcast up if it is from an originator
1143          * from the same backbone.
1144          */
1145         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1146                 goto out;
1147
1148         /* broadcast for me */
1149         batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1150         ret = NET_RX_SUCCESS;
1151         goto out;
1152
1153 spin_unlock:
1154         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1155 out:
1156         if (orig_node)
1157                 batadv_orig_node_free_ref(orig_node);
1158         return ret;
1159 }
1160
1161 int batadv_recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1162 {
1163         struct batadv_vis_packet *vis_packet;
1164         struct ethhdr *ethhdr;
1165         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1166         int hdr_size = sizeof(*vis_packet);
1167
1168         /* keep skb linear */
1169         if (skb_linearize(skb) < 0)
1170                 return NET_RX_DROP;
1171
1172         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1173                 return NET_RX_DROP;
1174
1175         vis_packet = (struct batadv_vis_packet *)skb->data;
1176         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1177
1178         /* not for me */
1179         if (!batadv_is_my_mac(ethhdr->h_dest))
1180                 return NET_RX_DROP;
1181
1182         /* ignore own packets */
1183         if (batadv_is_my_mac(vis_packet->vis_orig))
1184                 return NET_RX_DROP;
1185
1186         if (batadv_is_my_mac(vis_packet->sender_orig))
1187                 return NET_RX_DROP;
1188
1189         switch (vis_packet->vis_type) {
1190         case BATADV_VIS_TYPE_SERVER_SYNC:
1191                 batadv_receive_server_sync_packet(bat_priv, vis_packet,
1192                                                   skb_headlen(skb));
1193                 break;
1194
1195         case BATADV_VIS_TYPE_CLIENT_UPDATE:
1196                 batadv_receive_client_update_packet(bat_priv, vis_packet,
1197                                                     skb_headlen(skb));
1198                 break;
1199
1200         default:        /* ignore unknown packet */
1201                 break;
1202         }
1203
1204         /* We take a copy of the data in the packet, so we should
1205          * always free the skbuf.
1206          */
1207         return NET_RX_DROP;
1208 }