net/batman-adv/routing.c

   1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "routing.h"
  22 #include "send.h"
  23 #include "soft-interface.h"
  24 #include "hard-interface.h"
  25 #include "icmp_socket.h"
  26 #include "translation-table.h"
  27 #include "originator.h"
  28 #include "vis.h"
  29 #include "unicast.h"
  30 #include "bridge_loop_avoidance.h"
  31
  32 static int batadv_route_unicast_packet(struct sk_buff *skb,
  33                                        struct batadv_hard_iface *recv_if);
  34
  35 void batadv_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
  36 {
  37         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  38         struct batadv_hashtable *hash = bat_priv->orig_hash;
  39         struct hlist_node *node;
  40         struct hlist_head *head;
  41         struct batadv_orig_node *orig_node;
  42         unsigned long *word;
  43         uint32_t i;
  44         size_t word_index;
  45         uint8_t *w;
  46
  47         for (i = 0; i < hash->size; i++) {
  48                 head = &hash->table[i];
  49
  50                 rcu_read_lock();
  51                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  52                         spin_lock_bh(&orig_node->ogm_cnt_lock);
  53                         word_index = hard_iface->if_num * BATADV_NUM_WORDS;
  54                         word = &(orig_node->bcast_own[word_index]);
  55
  56                         batadv_bit_get_packet(bat_priv, word, 1, 0);
  57                         w = &orig_node->bcast_own_sum[hard_iface->if_num];
  58                         *w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
  59                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
  60                 }
  61                 rcu_read_unlock();
  62         }
  63 }
  64
  65 static void _batadv_update_route(struct batadv_priv *bat_priv,
  66                                  struct batadv_orig_node *orig_node,
  67                                  struct batadv_neigh_node *neigh_node)
  68 {
  69         struct batadv_neigh_node *curr_router;
  70
  71         curr_router = batadv_orig_node_get_router(orig_node);
  72
  73         /* route deleted */
  74         if ((curr_router) && (!neigh_node)) {
  75                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  76                            "Deleting route towards: %pM\n", orig_node->orig);
  77                 batadv_tt_global_del_orig(bat_priv, orig_node,
  78                                           "Deleted route towards originator");
  79
  80         /* route added */
  81         } else if ((!curr_router) && (neigh_node)) {
  82
  83                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  84                            "Adding route towards: %pM (via %pM)\n",
  85                            orig_node->orig, neigh_node->addr);
  86         /* route changed */
  87         } else if (neigh_node && curr_router) {
  88                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  89                            "Changing route towards: %pM (now via %pM - was via %pM)\n",
  90                            orig_node->orig, neigh_node->addr,
  91                            curr_router->addr);
  92         }
  93
  94         if (curr_router)
  95                 batadv_neigh_node_free_ref(curr_router);
  96
  97         /* increase refcount of new best neighbor */
  98         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
  99                 neigh_node = NULL;
 100
 101         spin_lock_bh(&orig_node->neigh_list_lock);
 102         rcu_assign_pointer(orig_node->router, neigh_node);
 103         spin_unlock_bh(&orig_node->neigh_list_lock);
 104
 105         /* decrease refcount of previous best neighbor */
 106         if (curr_router)
 107                 batadv_neigh_node_free_ref(curr_router);
 108 }
 109
 110 void batadv_update_route(struct batadv_priv *bat_priv,
 111                          struct batadv_orig_node *orig_node,
 112                          struct batadv_neigh_node *neigh_node)
 113 {
 114         struct batadv_neigh_node *router = NULL;
 115
 116         if (!orig_node)
 117                 goto out;
 118
 119         router = batadv_orig_node_get_router(orig_node);
 120
 121         if (router != neigh_node)
 122                 _batadv_update_route(bat_priv, orig_node, neigh_node);
 123
 124 out:
 125         if (router)
 126                 batadv_neigh_node_free_ref(router);
 127 }
 128
 129 /* caller must hold the neigh_list_lock */
 130 void batadv_bonding_candidate_del(struct batadv_orig_node *orig_node,
 131                                   struct batadv_neigh_node *neigh_node)
 132 {
 133         /* this neighbor is not part of our candidate list */
 134         if (list_empty(&neigh_node->bonding_list))
 135                 goto out;
 136
 137         list_del_rcu(&neigh_node->bonding_list);
 138         INIT_LIST_HEAD(&neigh_node->bonding_list);
 139         batadv_neigh_node_free_ref(neigh_node);
 140         atomic_dec(&orig_node->bond_candidates);
 141
 142 out:
 143         return;
 144 }
 145
 146 void batadv_bonding_candidate_add(struct batadv_orig_node *orig_node,
 147                                   struct batadv_neigh_node *neigh_node)
 148 {
 149         struct hlist_node *node;
 150         struct batadv_neigh_node *tmp_neigh_node, *router = NULL;
 151         uint8_t interference_candidate = 0;
 152
 153         spin_lock_bh(&orig_node->neigh_list_lock);
 154
 155         /* only consider if it has the same primary address ...  */
 156         if (!batadv_compare_eth(orig_node->orig,
 157                                 neigh_node->orig_node->primary_addr))
 158                 goto candidate_del;
 159
 160         router = batadv_orig_node_get_router(orig_node);
 161         if (!router)
 162                 goto candidate_del;
 163
 164         /* ... and is good enough to be considered */
 165         if (neigh_node->tq_avg < router->tq_avg - BATADV_BONDING_TQ_THRESHOLD)
 166                 goto candidate_del;
 167
 168         /* check if we have another candidate with the same mac address or
 169          * interface. If we do, we won't select this candidate because of
 170          * possible interference.
 171          */
 172         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 173                                  &orig_node->neigh_list, list) {
 174
 175                 if (tmp_neigh_node == neigh_node)
 176                         continue;
 177
 178                 /* we only care if the other candidate is even
 179                  * considered as candidate.
 180                  */
 181                 if (list_empty(&tmp_neigh_node->bonding_list))
 182                         continue;
 183
 184                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 185                     (batadv_compare_eth(neigh_node->addr,
 186                                         tmp_neigh_node->addr))) {
 187                         interference_candidate = 1;
 188                         break;
 189                 }
 190         }
 191
 192         /* don't care further if it is an interference candidate */
 193         if (interference_candidate)
 194                 goto candidate_del;
 195
 196         /* this neighbor already is part of our candidate list */
 197         if (!list_empty(&neigh_node->bonding_list))
 198                 goto out;
 199
 200         if (!atomic_inc_not_zero(&neigh_node->refcount))
 201                 goto out;
 202
 203         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 204         atomic_inc(&orig_node->bond_candidates);
 205         goto out;
 206
 207 candidate_del:
 208         batadv_bonding_candidate_del(orig_node, neigh_node);
 209
 210 out:
 211         spin_unlock_bh(&orig_node->neigh_list_lock);
 212
 213         if (router)
 214                 batadv_neigh_node_free_ref(router);
 215 }
 216
 217 /* copy primary address for bonding */
 218 void
 219 batadv_bonding_save_primary(const struct batadv_orig_node *orig_node,
 220                             struct batadv_orig_node *orig_neigh_node,
 221                             const struct batadv_ogm_packet *batman_ogm_packet)
 222 {
 223         if (!(batman_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP))
 224                 return;
 225
 226         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 227 }
 228
 229 /* checks whether the host restarted and is in the protection time.
 230  * returns:
 231  *  0 if the packet is to be accepted
 232  *  1 if the packet is to be ignored.
 233  */
 234 int batadv_window_protected(struct batadv_priv *bat_priv, int32_t seq_num_diff,
 235                             unsigned long *last_reset)
 236 {
 237         if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE ||
 238             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
 239                 if (!batadv_has_timed_out(*last_reset,
 240                                           BATADV_RESET_PROTECTION_MS))
 241                         return 1;
 242
 243                 *last_reset = jiffies;
 244                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 245                            "old packet received, start protection\n");
 246         }
 247
 248         return 0;
 249 }
 250
 251 bool batadv_check_management_packet(struct sk_buff *skb,
 252                                     struct batadv_hard_iface *hard_iface,
 253                                     int header_len)
 254 {
 255         struct ethhdr *ethhdr;
 256
 257         /* drop packet if it has not necessary minimum size */
 258         if (unlikely(!pskb_may_pull(skb, header_len)))
 259                 return false;
 260
 261         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 262
 263         /* packet with broadcast indication but unicast recipient */
 264         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 265                 return false;
 266
 267         /* packet with broadcast sender address */
 268         if (is_broadcast_ether_addr(ethhdr->h_source))
 269                 return false;
 270
 271         /* create a copy of the skb, if needed, to modify it. */
 272         if (skb_cow(skb, 0) < 0)
 273                 return false;
 274
 275         /* keep skb linear */
 276         if (skb_linearize(skb) < 0)
 277                 return false;
 278
 279         return true;
 280 }
 281
 282 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 283                                       struct sk_buff *skb, size_t icmp_len)
 284 {
 285         struct batadv_hard_iface *primary_if = NULL;
 286         struct batadv_orig_node *orig_node = NULL;
 287         struct batadv_neigh_node *router = NULL;
 288         struct batadv_icmp_packet_rr *icmp_packet;
 289         int ret = NET_RX_DROP;
 290
 291         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 292
 293         /* add data to device queue */
 294         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 295                 batadv_socket_receive_packet(icmp_packet, icmp_len);
 296                 goto out;
 297         }
 298
 299         primary_if = batadv_primary_if_get_selected(bat_priv);
 300         if (!primary_if)
 301                 goto out;
 302
 303         /* answer echo request (ping) */
 304         /* get routing information */
 305         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 306         if (!orig_node)
 307                 goto out;
 308
 309         router = batadv_orig_node_get_router(orig_node);
 310         if (!router)
 311                 goto out;
 312
 313         /* create a copy of the skb, if needed, to modify it. */
 314         if (skb_cow(skb, ETH_HLEN) < 0)
 315                 goto out;
 316
 317         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 318
 319         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 320         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 321         icmp_packet->msg_type = BATADV_ECHO_REPLY;
 322         icmp_packet->header.ttl = BATADV_TTL;
 323
 324         batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 325         ret = NET_RX_SUCCESS;
 326
 327 out:
 328         if (primary_if)
 329                 batadv_hardif_free_ref(primary_if);
 330         if (router)
 331                 batadv_neigh_node_free_ref(router);
 332         if (orig_node)
 333                 batadv_orig_node_free_ref(orig_node);
 334         return ret;
 335 }
 336
 337 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 338                                          struct sk_buff *skb)
 339 {
 340         struct batadv_hard_iface *primary_if = NULL;
 341         struct batadv_orig_node *orig_node = NULL;
 342         struct batadv_neigh_node *router = NULL;
 343         struct batadv_icmp_packet *icmp_packet;
 344         int ret = NET_RX_DROP;
 345
 346         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 347
 348         /* send TTL exceeded if packet is an echo request (traceroute) */
 349         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 350                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 351                          icmp_packet->orig, icmp_packet->dst);
 352                 goto out;
 353         }
 354
 355         primary_if = batadv_primary_if_get_selected(bat_priv);
 356         if (!primary_if)
 357                 goto out;
 358
 359         /* get routing information */
 360         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 361         if (!orig_node)
 362                 goto out;
 363
 364         router = batadv_orig_node_get_router(orig_node);
 365         if (!router)
 366                 goto out;
 367
 368         /* create a copy of the skb, if needed, to modify it. */
 369         if (skb_cow(skb, ETH_HLEN) < 0)
 370                 goto out;
 371
 372         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 373
 374         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 375         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 376         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
 377         icmp_packet->header.ttl = BATADV_TTL;
 378
 379         batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 380         ret = NET_RX_SUCCESS;
 381
 382 out:
 383         if (primary_if)
 384                 batadv_hardif_free_ref(primary_if);
 385         if (router)
 386                 batadv_neigh_node_free_ref(router);
 387         if (orig_node)
 388                 batadv_orig_node_free_ref(orig_node);
 389         return ret;
 390 }
 391
 392
 393 int batadv_recv_icmp_packet(struct sk_buff *skb,
 394                             struct batadv_hard_iface *recv_if)
 395 {
 396         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 397         struct batadv_icmp_packet_rr *icmp_packet;
 398         struct ethhdr *ethhdr;
 399         struct batadv_orig_node *orig_node = NULL;
 400         struct batadv_neigh_node *router = NULL;
 401         int hdr_size = sizeof(struct batadv_icmp_packet);
 402         int ret = NET_RX_DROP;
 403
 404         /* we truncate all incoming icmp packets if they don't match our size */
 405         if (skb->len >= sizeof(struct batadv_icmp_packet_rr))
 406                 hdr_size = sizeof(struct batadv_icmp_packet_rr);
 407
 408         /* drop packet if it has not necessary minimum size */
 409         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 410                 goto out;
 411
 412         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 413
 414         /* packet with unicast indication but broadcast recipient */
 415         if (is_broadcast_ether_addr(ethhdr->h_dest))
 416                 goto out;
 417
 418         /* packet with broadcast sender address */
 419         if (is_broadcast_ether_addr(ethhdr->h_source))
 420                 goto out;
 421
 422         /* not for me */
 423         if (!batadv_is_my_mac(ethhdr->h_dest))
 424                 goto out;
 425
 426         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 427
 428         /* add record route information if not full */
 429         if ((hdr_size == sizeof(struct batadv_icmp_packet_rr)) &&
 430             (icmp_packet->rr_cur < BATADV_RR_LEN)) {
 431                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
 432                        ethhdr->h_dest, ETH_ALEN);
 433                 icmp_packet->rr_cur++;
 434         }
 435
 436         /* packet for me */
 437         if (batadv_is_my_mac(icmp_packet->dst))
 438                 return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size);
 439
 440         /* TTL exceeded */
 441         if (icmp_packet->header.ttl < 2)
 442                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 443
 444         /* get routing information */
 445         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
 446         if (!orig_node)
 447                 goto out;
 448
 449         router = batadv_orig_node_get_router(orig_node);
 450         if (!router)
 451                 goto out;
 452
 453         /* create a copy of the skb, if needed, to modify it. */
 454         if (skb_cow(skb, ETH_HLEN) < 0)
 455                 goto out;
 456
 457         icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 458
 459         /* decrement ttl */
 460         icmp_packet->header.ttl--;
 461
 462         /* route it */
 463         batadv_send_skb_packet(skb, router->if_incoming, router->addr);
 464         ret = NET_RX_SUCCESS;
 465
 466 out:
 467         if (router)
 468                 batadv_neigh_node_free_ref(router);
 469         if (orig_node)
 470                 batadv_orig_node_free_ref(orig_node);
 471         return ret;
 472 }
 473
 474 /* In the bonding case, send the packets in a round
 475  * robin fashion over the remaining interfaces.
 476  *
 477  * This method rotates the bonding list and increases the
 478  * returned router's refcount.
 479  */
 480 static struct batadv_neigh_node *
 481 batadv_find_bond_router(struct batadv_orig_node *primary_orig,
 482                         const struct batadv_hard_iface *recv_if)
 483 {
 484         struct batadv_neigh_node *tmp_neigh_node;
 485         struct batadv_neigh_node *router = NULL, *first_candidate = NULL;
 486
 487         rcu_read_lock();
 488         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 489                                 bonding_list) {
 490                 if (!first_candidate)
 491                         first_candidate = tmp_neigh_node;
 492
 493                 /* recv_if == NULL on the first node. */
 494                 if (tmp_neigh_node->if_incoming == recv_if)
 495                         continue;
 496
 497                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 498                         continue;
 499
 500                 router = tmp_neigh_node;
 501                 break;
 502         }
 503
 504         /* use the first candidate if nothing was found. */
 505         if (!router && first_candidate &&
 506             atomic_inc_not_zero(&first_candidate->refcount))
 507                 router = first_candidate;
 508
 509         if (!router)
 510                 goto out;
 511
 512         /* selected should point to the next element
 513          * after the current router
 514          */
 515         spin_lock_bh(&primary_orig->neigh_list_lock);
 516         /* this is a list_move(), which unfortunately
 517          * does not exist as rcu version
 518          */
 519         list_del_rcu(&primary_orig->bond_list);
 520         list_add_rcu(&primary_orig->bond_list,
 521                      &router->bonding_list);
 522         spin_unlock_bh(&primary_orig->neigh_list_lock);
 523
 524 out:
 525         rcu_read_unlock();
 526         return router;
 527 }
 528
 529 /* Interface Alternating: Use the best of the
 530  * remaining candidates which are not using
 531  * this interface.
 532  *
 533  * Increases the returned router's refcount
 534  */
 535 static struct batadv_neigh_node *
 536 batadv_find_ifalter_router(struct batadv_orig_node *primary_orig,
 537                            const struct batadv_hard_iface *recv_if)
 538 {
 539         struct batadv_neigh_node *tmp_neigh_node;
 540         struct batadv_neigh_node *router = NULL, *first_candidate = NULL;
 541
 542         rcu_read_lock();
 543         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 544                                 bonding_list) {
 545                 if (!first_candidate)
 546                         first_candidate = tmp_neigh_node;
 547
 548                 /* recv_if == NULL on the first node. */
 549                 if (tmp_neigh_node->if_incoming == recv_if)
 550                         continue;
 551
 552                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 553                         continue;
 554
 555                 /* if we don't have a router yet
 556                  * or this one is better, choose it.
 557                  */
 558                 if ((!router) ||
 559                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
 560                         /* decrement refcount of
 561                          * previously selected router
 562                          */
 563                         if (router)
 564                                 batadv_neigh_node_free_ref(router);
 565
 566                         router = tmp_neigh_node;
 567                         atomic_inc_not_zero(&router->refcount);
 568                 }
 569
 570                 batadv_neigh_node_free_ref(tmp_neigh_node);
 571         }
 572
 573         /* use the first candidate if nothing was found. */
 574         if (!router && first_candidate &&
 575             atomic_inc_not_zero(&first_candidate->refcount))
 576                 router = first_candidate;
 577
 578         rcu_read_unlock();
 579         return router;
 580 }
 581
 582 int batadv_recv_tt_query(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
 583 {
 584         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 585         struct batadv_tt_query_packet *tt_query;
 586         uint16_t tt_size;
 587         struct ethhdr *ethhdr;
 588         char tt_flag;
 589         size_t packet_size;
 590
 591         /* drop packet if it has not necessary minimum size */
 592         if (unlikely(!pskb_may_pull(skb,
 593                                     sizeof(struct batadv_tt_query_packet))))
 594                 goto out;
 595
 596         /* I could need to modify it */
 597         if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0)
 598                 goto out;
 599
 600         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 601
 602         /* packet with unicast indication but broadcast recipient */
 603         if (is_broadcast_ether_addr(ethhdr->h_dest))
 604                 goto out;
 605
 606         /* packet with broadcast sender address */
 607         if (is_broadcast_ether_addr(ethhdr->h_source))
 608                 goto out;
 609
 610         tt_query = (struct batadv_tt_query_packet *)skb->data;
 611
 612         switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) {
 613         case BATADV_TT_REQUEST:
 614                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX);
 615
 616                 /* If we cannot provide an answer the tt_request is
 617                  * forwarded
 618                  */
 619                 if (!batadv_send_tt_response(bat_priv, tt_query)) {
 620                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 621                                 tt_flag = 'F';
 622                         else
 623                                 tt_flag = '.';
 624
 625                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 626                                    "Routing TT_REQUEST to %pM [%c]\n",
 627                                    tt_query->dst,
 628                                    tt_flag);
 629                         return batadv_route_unicast_packet(skb, recv_if);
 630                 }
 631                 break;
 632         case BATADV_TT_RESPONSE:
 633                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX);
 634
 635                 if (batadv_is_my_mac(tt_query->dst)) {
 636                         /* packet needs to be linearized to access the TT
 637                          * changes
 638                          */
 639                         if (skb_linearize(skb) < 0)
 640                                 goto out;
 641                         /* skb_linearize() possibly changed skb->data */
 642                         tt_query = (struct batadv_tt_query_packet *)skb->data;
 643
 644                         tt_size = batadv_tt_len(ntohs(tt_query->tt_data));
 645
 646                         /* Ensure we have all the claimed data */
 647                         packet_size = sizeof(struct batadv_tt_query_packet);
 648                         packet_size += tt_size;
 649                         if (unlikely(skb_headlen(skb) < packet_size))
 650                                 goto out;
 651
 652                         batadv_handle_tt_response(bat_priv, tt_query);
 653                 } else {
 654                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 655                                 tt_flag =  'F';
 656                         else
 657                                 tt_flag = '.';
 658                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 659                                    "Routing TT_RESPONSE to %pM [%c]\n",
 660                                    tt_query->dst,
 661                                    tt_flag);
 662                         return batadv_route_unicast_packet(skb, recv_if);
 663                 }
 664                 break;
 665         }
 666
 667 out:
 668         /* returning NET_RX_DROP will make the caller function kfree the skb */
 669         return NET_RX_DROP;
 670 }
 671
 672 int batadv_recv_roam_adv(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
 673 {
 674         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 675         struct batadv_roam_adv_packet *roam_adv_packet;
 676         struct batadv_orig_node *orig_node;
 677         struct ethhdr *ethhdr;
 678
 679         /* drop packet if it has not necessary minimum size */
 680         if (unlikely(!pskb_may_pull(skb,
 681                                     sizeof(struct batadv_roam_adv_packet))))
 682                 goto out;
 683
 684         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 685
 686         /* packet with unicast indication but broadcast recipient */
 687         if (is_broadcast_ether_addr(ethhdr->h_dest))
 688                 goto out;
 689
 690         /* packet with broadcast sender address */
 691         if (is_broadcast_ether_addr(ethhdr->h_source))
 692                 goto out;
 693
 694         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX);
 695
 696         roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data;
 697
 698         if (!batadv_is_my_mac(roam_adv_packet->dst))
 699                 return batadv_route_unicast_packet(skb, recv_if);
 700
 701         /* check if it is a backbone gateway. we don't accept
 702          * roaming advertisement from it, as it has the same
 703          * entries as we have.
 704          */
 705         if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
 706                 goto out;
 707
 708         orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src);
 709         if (!orig_node)
 710                 goto out;
 711
 712         batadv_dbg(BATADV_DBG_TT, bat_priv,
 713                    "Received ROAMING_ADV from %pM (client %pM)\n",
 714                    roam_adv_packet->src, roam_adv_packet->client);
 715
 716         batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 717                              BATADV_TT_CLIENT_ROAM,
 718                              atomic_read(&orig_node->last_ttvn) + 1);
 719
 720         /* Roaming phase starts: I have new information but the ttvn has not
 721          * been incremented yet. This flag will make me check all the incoming
 722          * packets for the correct destination.
 723          */
 724         bat_priv->tt_poss_change = true;
 725
 726         batadv_orig_node_free_ref(orig_node);
 727 out:
 728         /* returning NET_RX_DROP will make the caller function kfree the skb */
 729         return NET_RX_DROP;
 730 }
 731
 732 /* find a suitable router for this originator, and use
 733  * bonding if possible. increases the found neighbors
 734  * refcount.
 735  */
 736 struct batadv_neigh_node *
 737 batadv_find_router(struct batadv_priv *bat_priv,
 738                    struct batadv_orig_node *orig_node,
 739                    const struct batadv_hard_iface *recv_if)
 740 {
 741         struct batadv_orig_node *primary_orig_node;
 742         struct batadv_orig_node *router_orig;
 743         struct batadv_neigh_node *router;
 744         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 745         int bonding_enabled;
 746         uint8_t *primary_addr;
 747
 748         if (!orig_node)
 749                 return NULL;
 750
 751         router = batadv_orig_node_get_router(orig_node);
 752         if (!router)
 753                 goto err;
 754
 755         /* without bonding, the first node should
 756          * always choose the default router.
 757          */
 758         bonding_enabled = atomic_read(&bat_priv->bonding);
 759
 760         rcu_read_lock();
 761         /* select default router to output */
 762         router_orig = router->orig_node;
 763         if (!router_orig)
 764                 goto err_unlock;
 765
 766         if ((!recv_if) && (!bonding_enabled))
 767                 goto return_router;
 768
 769         primary_addr = router_orig->primary_addr;
 770
 771         /* if we have something in the primary_addr, we can search
 772          * for a potential bonding candidate.
 773          */
 774         if (batadv_compare_eth(primary_addr, zero_mac))
 775                 goto return_router;
 776
 777         /* find the orig_node which has the primary interface. might
 778          * even be the same as our router_orig in many cases
 779          */
 780         if (batadv_compare_eth(primary_addr, router_orig->orig)) {
 781                 primary_orig_node = router_orig;
 782         } else {
 783                 primary_orig_node = batadv_orig_hash_find(bat_priv,
 784                                                           primary_addr);
 785                 if (!primary_orig_node)
 786                         goto return_router;
 787
 788                 batadv_orig_node_free_ref(primary_orig_node);
 789         }
 790
 791         /* with less than 2 candidates, we can't do any
 792          * bonding and prefer the original router.
 793          */
 794         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 795                 goto return_router;
 796
 797         /* all nodes between should choose a candidate which
 798          * is is not on the interface where the packet came
 799          * in.
 800          */
 801         batadv_neigh_node_free_ref(router);
 802
 803         if (bonding_enabled)
 804                 router = batadv_find_bond_router(primary_orig_node, recv_if);
 805         else
 806                 router = batadv_find_ifalter_router(primary_orig_node, recv_if);
 807
 808 return_router:
 809         if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE)
 810                 goto err_unlock;
 811
 812         rcu_read_unlock();
 813         return router;
 814 err_unlock:
 815         rcu_read_unlock();
 816 err:
 817         if (router)
 818                 batadv_neigh_node_free_ref(router);
 819         return NULL;
 820 }
 821
 822 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 823 {
 824         struct ethhdr *ethhdr;
 825
 826         /* drop packet if it has not necessary minimum size */
 827         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 828                 return -1;
 829
 830         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 831
 832         /* packet with unicast indication but broadcast recipient */
 833         if (is_broadcast_ether_addr(ethhdr->h_dest))
 834                 return -1;
 835
 836         /* packet with broadcast sender address */
 837         if (is_broadcast_ether_addr(ethhdr->h_source))
 838                 return -1;
 839
 840         /* not for me */
 841         if (!batadv_is_my_mac(ethhdr->h_dest))
 842                 return -1;
 843
 844         return 0;
 845 }
 846
 847 static int batadv_route_unicast_packet(struct sk_buff *skb,
 848                                        struct batadv_hard_iface *recv_if)
 849 {
 850         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 851         struct batadv_orig_node *orig_node = NULL;
 852         struct batadv_neigh_node *neigh_node = NULL;
 853         struct batadv_unicast_packet *unicast_packet;
 854         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 855         int ret = NET_RX_DROP;
 856         struct sk_buff *new_skb;
 857
 858         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 859
 860         /* TTL exceeded */
 861         if (unicast_packet->header.ttl < 2) {
 862                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 863                          ethhdr->h_source, unicast_packet->dest);
 864                 goto out;
 865         }
 866
 867         /* get routing information */
 868         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 869
 870         if (!orig_node)
 871                 goto out;
 872
 873         /* find_router() increases neigh_nodes refcount if found. */
 874         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 875
 876         if (!neigh_node)
 877                 goto out;
 878
 879         /* create a copy of the skb, if needed, to modify it. */
 880         if (skb_cow(skb, ETH_HLEN) < 0)
 881                 goto out;
 882
 883         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 884
 885         if (unicast_packet->header.packet_type == BATADV_UNICAST &&
 886             atomic_read(&bat_priv->fragmentation) &&
 887             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 888                 ret = batadv_frag_send_skb(skb, bat_priv,
 889                                            neigh_node->if_incoming,
 890                                            neigh_node->addr);
 891                 goto out;
 892         }
 893
 894         if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG &&
 895             batadv_frag_can_reassemble(skb,
 896                                        neigh_node->if_incoming->net_dev->mtu)) {
 897
 898                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
 899
 900                 if (ret == NET_RX_DROP)
 901                         goto out;
 902
 903                 /* packet was buffered for late merge */
 904                 if (!new_skb) {
 905                         ret = NET_RX_SUCCESS;
 906                         goto out;
 907                 }
 908
 909                 skb = new_skb;
 910                 unicast_packet = (struct batadv_unicast_packet *)skb->data;
 911         }
 912
 913         /* decrement ttl */
 914         unicast_packet->header.ttl--;
 915
 916         /* Update stats counter */
 917         batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 918         batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 919                            skb->len + ETH_HLEN);
 920
 921         /* route it */
 922         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 923         ret = NET_RX_SUCCESS;
 924
 925 out:
 926         if (neigh_node)
 927                 batadv_neigh_node_free_ref(neigh_node);
 928         if (orig_node)
 929                 batadv_orig_node_free_ref(orig_node);
 930         return ret;
 931 }
 932
 933 static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 934                                      struct sk_buff *skb) {
 935         uint8_t curr_ttvn;
 936         struct batadv_orig_node *orig_node;
 937         struct ethhdr *ethhdr;
 938         struct batadv_hard_iface *primary_if;
 939         struct batadv_unicast_packet *unicast_packet;
 940         bool tt_poss_change;
 941         int is_old_ttvn;
 942
 943         /* I could need to modify it */
 944         if (skb_cow(skb, sizeof(struct batadv_unicast_packet)) < 0)
 945                 return 0;
 946
 947         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 948
 949         if (batadv_is_my_mac(unicast_packet->dest)) {
 950                 tt_poss_change = bat_priv->tt_poss_change;
 951                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 952         } else {
 953                 orig_node = batadv_orig_hash_find(bat_priv,
 954                                                   unicast_packet->dest);
 955
 956                 if (!orig_node)
 957                         return 0;
 958
 959                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 960                 tt_poss_change = orig_node->tt_poss_change;
 961                 batadv_orig_node_free_ref(orig_node);
 962         }
 963
 964         /* Check whether I have to reroute the packet */
 965         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 966         if (is_old_ttvn || tt_poss_change) {
 967                 /* check if there is enough data before accessing it */
 968                 if (pskb_may_pull(skb, sizeof(struct batadv_unicast_packet) +
 969                                   ETH_HLEN) < 0)
 970                         return 0;
 971
 972                 ethhdr = (struct ethhdr *)(skb->data + sizeof(*unicast_packet));
 973
 974                 /* we don't have an updated route for this client, so we should
 975                  * not try to reroute the packet!!
 976                  */
 977                 if (batadv_tt_global_client_is_roaming(bat_priv,
 978                                                        ethhdr->h_dest))
 979                         return 1;
 980
 981                 orig_node = batadv_transtable_search(bat_priv, NULL,
 982                                                      ethhdr->h_dest);
 983
 984                 if (!orig_node) {
 985                         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest))
 986                                 return 0;
 987                         primary_if = batadv_primary_if_get_selected(bat_priv);
 988                         if (!primary_if)
 989                                 return 0;
 990                         memcpy(unicast_packet->dest,
 991                                primary_if->net_dev->dev_addr, ETH_ALEN);
 992                         batadv_hardif_free_ref(primary_if);
 993                 } else {
 994                         memcpy(unicast_packet->dest, orig_node->orig,
 995                                ETH_ALEN);
 996                         curr_ttvn = (uint8_t)
 997                                 atomic_read(&orig_node->last_ttvn);
 998                         batadv_orig_node_free_ref(orig_node);
 999                 }
1000
1001                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
1002                            "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
1003                            unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
1004                            unicast_packet->dest);
1005
1006                 unicast_packet->ttvn = curr_ttvn;
1007         }
1008         return 1;
1009 }
1010
1011 int batadv_recv_unicast_packet(struct sk_buff *skb,
1012                                struct batadv_hard_iface *recv_if)
1013 {
1014         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1015         struct batadv_unicast_packet *unicast_packet;
1016         int hdr_size = sizeof(*unicast_packet);
1017
1018         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1019                 return NET_RX_DROP;
1020
1021         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1022                 return NET_RX_DROP;
1023
1024         unicast_packet = (struct batadv_unicast_packet *)skb->data;
1025
1026         /* packet for me */
1027         if (batadv_is_my_mac(unicast_packet->dest)) {
1028                 batadv_interface_rx(recv_if->soft_iface, skb, recv_if,
1029                                     hdr_size);
1030                 return NET_RX_SUCCESS;
1031         }
1032
1033         return batadv_route_unicast_packet(skb, recv_if);
1034 }
1035
1036 int batadv_recv_ucast_frag_packet(struct sk_buff *skb,
1037                                   struct batadv_hard_iface *recv_if)
1038 {
1039         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1040         struct batadv_unicast_frag_packet *unicast_packet;
1041         int hdr_size = sizeof(*unicast_packet);
1042         struct sk_buff *new_skb = NULL;
1043         int ret;
1044
1045         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1046                 return NET_RX_DROP;
1047
1048         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1049                 return NET_RX_DROP;
1050
1051         unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
1052
1053         /* packet for me */
1054         if (batadv_is_my_mac(unicast_packet->dest)) {
1055
1056                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
1057
1058                 if (ret == NET_RX_DROP)
1059                         return NET_RX_DROP;
1060
1061                 /* packet was buffered for late merge */
1062                 if (!new_skb)
1063                         return NET_RX_SUCCESS;
1064
1065                 batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
1066                                     sizeof(struct batadv_unicast_packet));
1067                 return NET_RX_SUCCESS;
1068         }
1069
1070         return batadv_route_unicast_packet(skb, recv_if);
1071 }
1072
1073
1074 int batadv_recv_bcast_packet(struct sk_buff *skb,
1075                              struct batadv_hard_iface *recv_if)
1076 {
1077         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1078         struct batadv_orig_node *orig_node = NULL;
1079         struct batadv_bcast_packet *bcast_packet;
1080         struct ethhdr *ethhdr;
1081         int hdr_size = sizeof(*bcast_packet);
1082         int ret = NET_RX_DROP;
1083         int32_t seq_diff;
1084
1085         /* drop packet if it has not necessary minimum size */
1086         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1087                 goto out;
1088
1089         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1090
1091         /* packet with broadcast indication but unicast recipient */
1092         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1093                 goto out;
1094
1095         /* packet with broadcast sender address */
1096         if (is_broadcast_ether_addr(ethhdr->h_source))
1097                 goto out;
1098
1099         /* ignore broadcasts sent by myself */
1100         if (batadv_is_my_mac(ethhdr->h_source))
1101                 goto out;
1102
1103         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1104
1105         /* ignore broadcasts originated by myself */
1106         if (batadv_is_my_mac(bcast_packet->orig))
1107                 goto out;
1108
1109         if (bcast_packet->header.ttl < 2)
1110                 goto out;
1111
1112         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1113
1114         if (!orig_node)
1115                 goto out;
1116
1117         spin_lock_bh(&orig_node->bcast_seqno_lock);
1118
1119         /* check whether the packet is a duplicate */
1120         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1121                             ntohl(bcast_packet->seqno)))
1122                 goto spin_unlock;
1123
1124         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1125
1126         /* check whether the packet is old and the host just restarted. */
1127         if (batadv_window_protected(bat_priv, seq_diff,
1128                                     &orig_node->bcast_seqno_reset))
1129                 goto spin_unlock;
1130
1131         /* mark broadcast in flood history, update window position
1132          * if required.
1133          */
1134         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1135                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1136
1137         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1138
1139         /* check whether this has been sent by another originator before */
1140         if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
1141                 goto out;
1142
1143         /* rebroadcast packet */
1144         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1145
1146         /* don't hand the broadcast up if it is from an originator
1147          * from the same backbone.
1148          */
1149         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1150                 goto out;
1151
1152         /* broadcast for me */
1153         batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1154         ret = NET_RX_SUCCESS;
1155         goto out;
1156
1157 spin_unlock:
1158         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1159 out:
1160         if (orig_node)
1161                 batadv_orig_node_free_ref(orig_node);
1162         return ret;
1163 }
1164
1165 int batadv_recv_vis_packet(struct sk_buff *skb,
1166                            struct batadv_hard_iface *recv_if)
1167 {
1168         struct batadv_vis_packet *vis_packet;
1169         struct ethhdr *ethhdr;
1170         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1171         int hdr_size = sizeof(*vis_packet);
1172
1173         /* keep skb linear */
1174         if (skb_linearize(skb) < 0)
1175                 return NET_RX_DROP;
1176
1177         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1178                 return NET_RX_DROP;
1179
1180         vis_packet = (struct batadv_vis_packet *)skb->data;
1181         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1182
1183         /* not for me */
1184         if (!batadv_is_my_mac(ethhdr->h_dest))
1185                 return NET_RX_DROP;
1186
1187         /* ignore own packets */
1188         if (batadv_is_my_mac(vis_packet->vis_orig))
1189                 return NET_RX_DROP;
1190
1191         if (batadv_is_my_mac(vis_packet->sender_orig))
1192                 return NET_RX_DROP;
1193
1194         switch (vis_packet->vis_type) {
1195         case BATADV_VIS_TYPE_SERVER_SYNC:
1196                 batadv_receive_server_sync_packet(bat_priv, vis_packet,
1197                                                   skb_headlen(skb));
1198                 break;
1199
1200         case BATADV_VIS_TYPE_CLIENT_UPDATE:
1201                 batadv_receive_client_update_packet(bat_priv, vis_packet,
1202                                                     skb_headlen(skb));
1203                 break;
1204
1205         default:        /* ignore unknown packet */
1206                 break;
1207         }
1208
1209         /* We take a copy of the data in the packet, so we should
1210          * always free the skbuf.
1211          */
1212         return NET_RX_DROP;
1213 }