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