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