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 hashtable_t *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(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
  76                            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(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(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 batman_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(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 icmp_packet_rr *icmp_packet;
 288         int ret = NET_RX_DROP;
 289
 290         icmp_packet = (struct 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 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 icmp_packet *icmp_packet;
 343         int ret = NET_RX_DROP;
 344
 345         icmp_packet = (struct 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 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 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 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 icmp_packet_rr))
 404                 hdr_size = sizeof(struct 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 icmp_packet_rr *)skb->data;
 425
 426         /* add record route information if not full */
 427         if ((hdr_size == sizeof(struct 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 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 tt_query_packet *tt_query;
 584         uint16_t tt_size;
 585         struct ethhdr *ethhdr;
 586         char tt_flag;
 587
 588         /* drop packet if it has not necessary minimum size */
 589         if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
 590                 goto out;
 591
 592         /* I could need to modify it */
 593         if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
 594                 goto out;
 595
 596         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 597
 598         /* packet with unicast indication but broadcast recipient */
 599         if (is_broadcast_ether_addr(ethhdr->h_dest))
 600                 goto out;
 601
 602         /* packet with broadcast sender address */
 603         if (is_broadcast_ether_addr(ethhdr->h_source))
 604                 goto out;
 605
 606         tt_query = (struct tt_query_packet *)skb->data;
 607
 608         switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) {
 609         case BATADV_TT_REQUEST:
 610                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX);
 611
 612                 /* If we cannot provide an answer the tt_request is
 613                  * forwarded
 614                  */
 615                 if (!batadv_send_tt_response(bat_priv, tt_query)) {
 616                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 617                                 tt_flag = 'F';
 618                         else
 619                                 tt_flag = '.';
 620
 621                         batadv_dbg(DBG_TT, bat_priv,
 622                                    "Routing TT_REQUEST to %pM [%c]\n",
 623                                    tt_query->dst,
 624                                    tt_flag);
 625                         return batadv_route_unicast_packet(skb, recv_if);
 626                 }
 627                 break;
 628         case BATADV_TT_RESPONSE:
 629                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX);
 630
 631                 if (batadv_is_my_mac(tt_query->dst)) {
 632                         /* packet needs to be linearized to access the TT
 633                          * changes
 634                          */
 635                         if (skb_linearize(skb) < 0)
 636                                 goto out;
 637                         /* skb_linearize() possibly changed skb->data */
 638                         tt_query = (struct tt_query_packet *)skb->data;
 639
 640                         tt_size = batadv_tt_len(ntohs(tt_query->tt_data));
 641
 642                         /* Ensure we have all the claimed data */
 643                         if (unlikely(skb_headlen(skb) <
 644                                      sizeof(struct tt_query_packet) + tt_size))
 645                                 goto out;
 646
 647                         batadv_handle_tt_response(bat_priv, tt_query);
 648                 } else {
 649                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 650                                 tt_flag =  'F';
 651                         else
 652                                 tt_flag = '.';
 653                         batadv_dbg(DBG_TT, bat_priv,
 654                                    "Routing TT_RESPONSE to %pM [%c]\n",
 655                                    tt_query->dst,
 656                                    tt_flag);
 657                         return batadv_route_unicast_packet(skb, recv_if);
 658                 }
 659                 break;
 660         }
 661
 662 out:
 663         /* returning NET_RX_DROP will make the caller function kfree the skb */
 664         return NET_RX_DROP;
 665 }
 666
 667 int batadv_recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
 668 {
 669         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 670         struct roam_adv_packet *roam_adv_packet;
 671         struct orig_node *orig_node;
 672         struct ethhdr *ethhdr;
 673
 674         /* drop packet if it has not necessary minimum size */
 675         if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
 676                 goto out;
 677
 678         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 679
 680         /* packet with unicast indication but broadcast recipient */
 681         if (is_broadcast_ether_addr(ethhdr->h_dest))
 682                 goto out;
 683
 684         /* packet with broadcast sender address */
 685         if (is_broadcast_ether_addr(ethhdr->h_source))
 686                 goto out;
 687
 688         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX);
 689
 690         roam_adv_packet = (struct roam_adv_packet *)skb->data;
 691
 692         if (!batadv_is_my_mac(roam_adv_packet->dst))
 693                 return batadv_route_unicast_packet(skb, recv_if);
 694
 695         /* check if it is a backbone gateway. we don't accept
 696          * roaming advertisement from it, as it has the same
 697          * entries as we have.
 698          */
 699         if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
 700                 goto out;
 701
 702         orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src);
 703         if (!orig_node)
 704                 goto out;
 705
 706         batadv_dbg(DBG_TT, bat_priv,
 707                    "Received ROAMING_ADV from %pM (client %pM)\n",
 708                    roam_adv_packet->src, roam_adv_packet->client);
 709
 710         batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 711                              BATADV_TT_CLIENT_ROAM,
 712                              atomic_read(&orig_node->last_ttvn) + 1);
 713
 714         /* Roaming phase starts: I have new information but the ttvn has not
 715          * been incremented yet. This flag will make me check all the incoming
 716          * packets for the correct destination.
 717          */
 718         bat_priv->tt_poss_change = true;
 719
 720         batadv_orig_node_free_ref(orig_node);
 721 out:
 722         /* returning NET_RX_DROP will make the caller function kfree the skb */
 723         return NET_RX_DROP;
 724 }
 725
 726 /* find a suitable router for this originator, and use
 727  * bonding if possible. increases the found neighbors
 728  * refcount.
 729  */
 730 struct neigh_node *batadv_find_router(struct bat_priv *bat_priv,
 731                                       struct orig_node *orig_node,
 732                                       const struct hard_iface *recv_if)
 733 {
 734         struct orig_node *primary_orig_node;
 735         struct orig_node *router_orig;
 736         struct neigh_node *router;
 737         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 738         int bonding_enabled;
 739         uint8_t *primary_addr;
 740
 741         if (!orig_node)
 742                 return NULL;
 743
 744         router = batadv_orig_node_get_router(orig_node);
 745         if (!router)
 746                 goto err;
 747
 748         /* without bonding, the first node should
 749          * always choose the default router.
 750          */
 751         bonding_enabled = atomic_read(&bat_priv->bonding);
 752
 753         rcu_read_lock();
 754         /* select default router to output */
 755         router_orig = router->orig_node;
 756         if (!router_orig)
 757                 goto err_unlock;
 758
 759         if ((!recv_if) && (!bonding_enabled))
 760                 goto return_router;
 761
 762         primary_addr = router_orig->primary_addr;
 763
 764         /* if we have something in the primary_addr, we can search
 765          * for a potential bonding candidate.
 766          */
 767         if (batadv_compare_eth(primary_addr, zero_mac))
 768                 goto return_router;
 769
 770         /* find the orig_node which has the primary interface. might
 771          * even be the same as our router_orig in many cases
 772          */
 773         if (batadv_compare_eth(primary_addr, router_orig->orig)) {
 774                 primary_orig_node = router_orig;
 775         } else {
 776                 primary_orig_node = batadv_orig_hash_find(bat_priv,
 777                                                           primary_addr);
 778                 if (!primary_orig_node)
 779                         goto return_router;
 780
 781                 batadv_orig_node_free_ref(primary_orig_node);
 782         }
 783
 784         /* with less than 2 candidates, we can't do any
 785          * bonding and prefer the original router.
 786          */
 787         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 788                 goto return_router;
 789
 790         /* all nodes between should choose a candidate which
 791          * is is not on the interface where the packet came
 792          * in.
 793          */
 794         batadv_neigh_node_free_ref(router);
 795
 796         if (bonding_enabled)
 797                 router = batadv_find_bond_router(primary_orig_node, recv_if);
 798         else
 799                 router = batadv_find_ifalter_router(primary_orig_node, recv_if);
 800
 801 return_router:
 802         if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE)
 803                 goto err_unlock;
 804
 805         rcu_read_unlock();
 806         return router;
 807 err_unlock:
 808         rcu_read_unlock();
 809 err:
 810         if (router)
 811                 batadv_neigh_node_free_ref(router);
 812         return NULL;
 813 }
 814
 815 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 816 {
 817         struct ethhdr *ethhdr;
 818
 819         /* drop packet if it has not necessary minimum size */
 820         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 821                 return -1;
 822
 823         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 824
 825         /* packet with unicast indication but broadcast recipient */
 826         if (is_broadcast_ether_addr(ethhdr->h_dest))
 827                 return -1;
 828
 829         /* packet with broadcast sender address */
 830         if (is_broadcast_ether_addr(ethhdr->h_source))
 831                 return -1;
 832
 833         /* not for me */
 834         if (!batadv_is_my_mac(ethhdr->h_dest))
 835                 return -1;
 836
 837         return 0;
 838 }
 839
 840 static int batadv_route_unicast_packet(struct sk_buff *skb,
 841                                        struct hard_iface *recv_if)
 842 {
 843         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 844         struct orig_node *orig_node = NULL;
 845         struct neigh_node *neigh_node = NULL;
 846         struct unicast_packet *unicast_packet;
 847         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 848         int ret = NET_RX_DROP;
 849         struct sk_buff *new_skb;
 850
 851         unicast_packet = (struct unicast_packet *)skb->data;
 852
 853         /* TTL exceeded */
 854         if (unicast_packet->header.ttl < 2) {
 855                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 856                          ethhdr->h_source, unicast_packet->dest);
 857                 goto out;
 858         }
 859
 860         /* get routing information */
 861         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 862
 863         if (!orig_node)
 864                 goto out;
 865
 866         /* find_router() increases neigh_nodes refcount if found. */
 867         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 868
 869         if (!neigh_node)
 870                 goto out;
 871
 872         /* create a copy of the skb, if needed, to modify it. */
 873         if (skb_cow(skb, ETH_HLEN) < 0)
 874                 goto out;
 875
 876         unicast_packet = (struct unicast_packet *)skb->data;
 877
 878         if (unicast_packet->header.packet_type == BATADV_UNICAST &&
 879             atomic_read(&bat_priv->fragmentation) &&
 880             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 881                 ret = batadv_frag_send_skb(skb, bat_priv,
 882                                            neigh_node->if_incoming,
 883                                            neigh_node->addr);
 884                 goto out;
 885         }
 886
 887         if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG &&
 888             batadv_frag_can_reassemble(skb,
 889                                        neigh_node->if_incoming->net_dev->mtu)) {
 890
 891                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
 892
 893                 if (ret == NET_RX_DROP)
 894                         goto out;
 895
 896                 /* packet was buffered for late merge */
 897                 if (!new_skb) {
 898                         ret = NET_RX_SUCCESS;
 899                         goto out;
 900                 }
 901
 902                 skb = new_skb;
 903                 unicast_packet = (struct unicast_packet *)skb->data;
 904         }
 905
 906         /* decrement ttl */
 907         unicast_packet->header.ttl--;
 908
 909         /* Update stats counter */
 910         batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 911         batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 912                            skb->len + ETH_HLEN);
 913
 914         /* route it */
 915         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 916         ret = NET_RX_SUCCESS;
 917
 918 out:
 919         if (neigh_node)
 920                 batadv_neigh_node_free_ref(neigh_node);
 921         if (orig_node)
 922                 batadv_orig_node_free_ref(orig_node);
 923         return ret;
 924 }
 925
 926 static int batadv_check_unicast_ttvn(struct bat_priv *bat_priv,
 927                                      struct sk_buff *skb) {
 928         uint8_t curr_ttvn;
 929         struct orig_node *orig_node;
 930         struct ethhdr *ethhdr;
 931         struct hard_iface *primary_if;
 932         struct unicast_packet *unicast_packet;
 933         bool tt_poss_change;
 934         int is_old_ttvn;
 935
 936         /* I could need to modify it */
 937         if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
 938                 return 0;
 939
 940         unicast_packet = (struct unicast_packet *)skb->data;
 941
 942         if (batadv_is_my_mac(unicast_packet->dest)) {
 943                 tt_poss_change = bat_priv->tt_poss_change;
 944                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 945         } else {
 946                 orig_node = batadv_orig_hash_find(bat_priv,
 947                                                   unicast_packet->dest);
 948
 949                 if (!orig_node)
 950                         return 0;
 951
 952                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 953                 tt_poss_change = orig_node->tt_poss_change;
 954                 batadv_orig_node_free_ref(orig_node);
 955         }
 956
 957         /* Check whether I have to reroute the packet */
 958         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 959         if (is_old_ttvn || tt_poss_change) {
 960                 /* check if there is enough data before accessing it */
 961                 if (pskb_may_pull(skb, sizeof(struct unicast_packet) +
 962                                   ETH_HLEN) < 0)
 963                         return 0;
 964
 965                 ethhdr = (struct ethhdr *)(skb->data +
 966                         sizeof(struct unicast_packet));
 967
 968                 /* we don't have an updated route for this client, so we should
 969                  * not try to reroute the packet!!
 970                  */
 971                 if (batadv_tt_global_client_is_roaming(bat_priv,
 972                                                        ethhdr->h_dest))
 973                         return 1;
 974
 975                 orig_node = batadv_transtable_search(bat_priv, NULL,
 976                                                      ethhdr->h_dest);
 977
 978                 if (!orig_node) {
 979                         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest))
 980                                 return 0;
 981                         primary_if = batadv_primary_if_get_selected(bat_priv);
 982                         if (!primary_if)
 983                                 return 0;
 984                         memcpy(unicast_packet->dest,
 985                                primary_if->net_dev->dev_addr, ETH_ALEN);
 986                         batadv_hardif_free_ref(primary_if);
 987                 } else {
 988                         memcpy(unicast_packet->dest, orig_node->orig,
 989                                ETH_ALEN);
 990                         curr_ttvn = (uint8_t)
 991                                 atomic_read(&orig_node->last_ttvn);
 992                         batadv_orig_node_free_ref(orig_node);
 993                 }
 994
 995                 batadv_dbg(DBG_ROUTES, bat_priv,
 996                            "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
 997                            unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
 998                            unicast_packet->dest);
 999
1000                 unicast_packet->ttvn = curr_ttvn;
1001         }
1002         return 1;
1003 }
1004
1005 int batadv_recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1006 {
1007         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1008         struct unicast_packet *unicast_packet;
1009         int hdr_size = sizeof(*unicast_packet);
1010
1011         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1012                 return NET_RX_DROP;
1013
1014         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1015                 return NET_RX_DROP;
1016
1017         unicast_packet = (struct unicast_packet *)skb->data;
1018
1019         /* packet for me */
1020         if (batadv_is_my_mac(unicast_packet->dest)) {
1021                 batadv_interface_rx(recv_if->soft_iface, skb, recv_if,
1022                                     hdr_size);
1023                 return NET_RX_SUCCESS;
1024         }
1025
1026         return batadv_route_unicast_packet(skb, recv_if);
1027 }
1028
1029 int batadv_recv_ucast_frag_packet(struct sk_buff *skb,
1030                                   struct hard_iface *recv_if)
1031 {
1032         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1033         struct unicast_frag_packet *unicast_packet;
1034         int hdr_size = sizeof(*unicast_packet);
1035         struct sk_buff *new_skb = NULL;
1036         int ret;
1037
1038         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1039                 return NET_RX_DROP;
1040
1041         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1042                 return NET_RX_DROP;
1043
1044         unicast_packet = (struct unicast_frag_packet *)skb->data;
1045
1046         /* packet for me */
1047         if (batadv_is_my_mac(unicast_packet->dest)) {
1048
1049                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
1050
1051                 if (ret == NET_RX_DROP)
1052                         return NET_RX_DROP;
1053
1054                 /* packet was buffered for late merge */
1055                 if (!new_skb)
1056                         return NET_RX_SUCCESS;
1057
1058                 batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
1059                                     sizeof(struct unicast_packet));
1060                 return NET_RX_SUCCESS;
1061         }
1062
1063         return batadv_route_unicast_packet(skb, recv_if);
1064 }
1065
1066
1067 int batadv_recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1068 {
1069         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1070         struct orig_node *orig_node = NULL;
1071         struct bcast_packet *bcast_packet;
1072         struct ethhdr *ethhdr;
1073         int hdr_size = sizeof(*bcast_packet);
1074         int ret = NET_RX_DROP;
1075         int32_t seq_diff;
1076
1077         /* drop packet if it has not necessary minimum size */
1078         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1079                 goto out;
1080
1081         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1082
1083         /* packet with broadcast indication but unicast recipient */
1084         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1085                 goto out;
1086
1087         /* packet with broadcast sender address */
1088         if (is_broadcast_ether_addr(ethhdr->h_source))
1089                 goto out;
1090
1091         /* ignore broadcasts sent by myself */
1092         if (batadv_is_my_mac(ethhdr->h_source))
1093                 goto out;
1094
1095         bcast_packet = (struct bcast_packet *)skb->data;
1096
1097         /* ignore broadcasts originated by myself */
1098         if (batadv_is_my_mac(bcast_packet->orig))
1099                 goto out;
1100
1101         if (bcast_packet->header.ttl < 2)
1102                 goto out;
1103
1104         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1105
1106         if (!orig_node)
1107                 goto out;
1108
1109         spin_lock_bh(&orig_node->bcast_seqno_lock);
1110
1111         /* check whether the packet is a duplicate */
1112         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1113                             ntohl(bcast_packet->seqno)))
1114                 goto spin_unlock;
1115
1116         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1117
1118         /* check whether the packet is old and the host just restarted. */
1119         if (batadv_window_protected(bat_priv, seq_diff,
1120                                     &orig_node->bcast_seqno_reset))
1121                 goto spin_unlock;
1122
1123         /* mark broadcast in flood history, update window position
1124          * if required.
1125          */
1126         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1127                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1128
1129         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1130
1131         /* check whether this has been sent by another originator before */
1132         if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
1133                 goto out;
1134
1135         /* rebroadcast packet */
1136         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1137
1138         /* don't hand the broadcast up if it is from an originator
1139          * from the same backbone.
1140          */
1141         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1142                 goto out;
1143
1144         /* broadcast for me */
1145         batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1146         ret = NET_RX_SUCCESS;
1147         goto out;
1148
1149 spin_unlock:
1150         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1151 out:
1152         if (orig_node)
1153                 batadv_orig_node_free_ref(orig_node);
1154         return ret;
1155 }
1156
1157 int batadv_recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1158 {
1159         struct vis_packet *vis_packet;
1160         struct ethhdr *ethhdr;
1161         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1162         int hdr_size = sizeof(*vis_packet);
1163
1164         /* keep skb linear */
1165         if (skb_linearize(skb) < 0)
1166                 return NET_RX_DROP;
1167
1168         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1169                 return NET_RX_DROP;
1170
1171         vis_packet = (struct vis_packet *)skb->data;
1172         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1173
1174         /* not for me */
1175         if (!batadv_is_my_mac(ethhdr->h_dest))
1176                 return NET_RX_DROP;
1177
1178         /* ignore own packets */
1179         if (batadv_is_my_mac(vis_packet->vis_orig))
1180                 return NET_RX_DROP;
1181
1182         if (batadv_is_my_mac(vis_packet->sender_orig))
1183                 return NET_RX_DROP;
1184
1185         switch (vis_packet->vis_type) {
1186         case BATADV_VIS_TYPE_SERVER_SYNC:
1187                 batadv_receive_server_sync_packet(bat_priv, vis_packet,
1188                                                   skb_headlen(skb));
1189                 break;
1190
1191         case BATADV_VIS_TYPE_CLIENT_UPDATE:
1192                 batadv_receive_client_update_packet(bat_priv, vis_packet,
1193                                                     skb_headlen(skb));
1194                 break;
1195
1196         default:        /* ignore unknown packet */
1197                 break;
1198         }
1199
1200         /* We take a copy of the data in the packet, so we should
1201          * always free the skbuf.
1202          */
1203         return NET_RX_DROP;
1204 }