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 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 583 {
 584         struct ethhdr *ethhdr;
 585
 586         /* drop packet if it has not necessary minimum size */
 587         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 588                 return -1;
 589
 590         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 591
 592         /* packet with unicast indication but broadcast recipient */
 593         if (is_broadcast_ether_addr(ethhdr->h_dest))
 594                 return -1;
 595
 596         /* packet with broadcast sender address */
 597         if (is_broadcast_ether_addr(ethhdr->h_source))
 598                 return -1;
 599
 600         /* not for me */
 601         if (!batadv_is_my_mac(ethhdr->h_dest))
 602                 return -1;
 603
 604         return 0;
 605 }
 606
 607 int batadv_recv_tt_query(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
 608 {
 609         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 610         struct batadv_tt_query_packet *tt_query;
 611         uint16_t tt_size;
 612         int hdr_size = sizeof(*tt_query);
 613         char tt_flag;
 614         size_t packet_size;
 615
 616         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
 617                 return NET_RX_DROP;
 618
 619         /* I could need to modify it */
 620         if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0)
 621                 goto out;
 622
 623         tt_query = (struct batadv_tt_query_packet *)skb->data;
 624
 625         switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) {
 626         case BATADV_TT_REQUEST:
 627                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX);
 628
 629                 /* If we cannot provide an answer the tt_request is
 630                  * forwarded
 631                  */
 632                 if (!batadv_send_tt_response(bat_priv, tt_query)) {
 633                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 634                                 tt_flag = 'F';
 635                         else
 636                                 tt_flag = '.';
 637
 638                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 639                                    "Routing TT_REQUEST to %pM [%c]\n",
 640                                    tt_query->dst,
 641                                    tt_flag);
 642                         return batadv_route_unicast_packet(skb, recv_if);
 643                 }
 644                 break;
 645         case BATADV_TT_RESPONSE:
 646                 batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX);
 647
 648                 if (batadv_is_my_mac(tt_query->dst)) {
 649                         /* packet needs to be linearized to access the TT
 650                          * changes
 651                          */
 652                         if (skb_linearize(skb) < 0)
 653                                 goto out;
 654                         /* skb_linearize() possibly changed skb->data */
 655                         tt_query = (struct batadv_tt_query_packet *)skb->data;
 656
 657                         tt_size = batadv_tt_len(ntohs(tt_query->tt_data));
 658
 659                         /* Ensure we have all the claimed data */
 660                         packet_size = sizeof(struct batadv_tt_query_packet);
 661                         packet_size += tt_size;
 662                         if (unlikely(skb_headlen(skb) < packet_size))
 663                                 goto out;
 664
 665                         batadv_handle_tt_response(bat_priv, tt_query);
 666                 } else {
 667                         if (tt_query->flags & BATADV_TT_FULL_TABLE)
 668                                 tt_flag =  'F';
 669                         else
 670                                 tt_flag = '.';
 671                         batadv_dbg(BATADV_DBG_TT, bat_priv,
 672                                    "Routing TT_RESPONSE to %pM [%c]\n",
 673                                    tt_query->dst,
 674                                    tt_flag);
 675                         return batadv_route_unicast_packet(skb, recv_if);
 676                 }
 677                 break;
 678         }
 679
 680 out:
 681         /* returning NET_RX_DROP will make the caller function kfree the skb */
 682         return NET_RX_DROP;
 683 }
 684
 685 int batadv_recv_roam_adv(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
 686 {
 687         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 688         struct batadv_roam_adv_packet *roam_adv_packet;
 689         struct batadv_orig_node *orig_node;
 690         struct ethhdr *ethhdr;
 691
 692         /* drop packet if it has not necessary minimum size */
 693         if (unlikely(!pskb_may_pull(skb,
 694                                     sizeof(struct batadv_roam_adv_packet))))
 695                 goto out;
 696
 697         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 698
 699         /* packet with unicast indication but broadcast recipient */
 700         if (is_broadcast_ether_addr(ethhdr->h_dest))
 701                 goto out;
 702
 703         /* packet with broadcast sender address */
 704         if (is_broadcast_ether_addr(ethhdr->h_source))
 705                 goto out;
 706
 707         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX);
 708
 709         roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data;
 710
 711         if (!batadv_is_my_mac(roam_adv_packet->dst))
 712                 return batadv_route_unicast_packet(skb, recv_if);
 713
 714         /* check if it is a backbone gateway. we don't accept
 715          * roaming advertisement from it, as it has the same
 716          * entries as we have.
 717          */
 718         if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
 719                 goto out;
 720
 721         orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src);
 722         if (!orig_node)
 723                 goto out;
 724
 725         batadv_dbg(BATADV_DBG_TT, bat_priv,
 726                    "Received ROAMING_ADV from %pM (client %pM)\n",
 727                    roam_adv_packet->src, roam_adv_packet->client);
 728
 729         batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 730                              BATADV_TT_CLIENT_ROAM,
 731                              atomic_read(&orig_node->last_ttvn) + 1);
 732
 733         /* Roaming phase starts: I have new information but the ttvn has not
 734          * been incremented yet. This flag will make me check all the incoming
 735          * packets for the correct destination.
 736          */
 737         bat_priv->tt.poss_change = true;
 738
 739         batadv_orig_node_free_ref(orig_node);
 740 out:
 741         /* returning NET_RX_DROP will make the caller function kfree the skb */
 742         return NET_RX_DROP;
 743 }
 744
 745 /* find a suitable router for this originator, and use
 746  * bonding if possible. increases the found neighbors
 747  * refcount.
 748  */
 749 struct batadv_neigh_node *
 750 batadv_find_router(struct batadv_priv *bat_priv,
 751                    struct batadv_orig_node *orig_node,
 752                    const struct batadv_hard_iface *recv_if)
 753 {
 754         struct batadv_orig_node *primary_orig_node;
 755         struct batadv_orig_node *router_orig;
 756         struct batadv_neigh_node *router;
 757         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 758         int bonding_enabled;
 759         uint8_t *primary_addr;
 760
 761         if (!orig_node)
 762                 return NULL;
 763
 764         router = batadv_orig_node_get_router(orig_node);
 765         if (!router)
 766                 goto err;
 767
 768         /* without bonding, the first node should
 769          * always choose the default router.
 770          */
 771         bonding_enabled = atomic_read(&bat_priv->bonding);
 772
 773         rcu_read_lock();
 774         /* select default router to output */
 775         router_orig = router->orig_node;
 776         if (!router_orig)
 777                 goto err_unlock;
 778
 779         if ((!recv_if) && (!bonding_enabled))
 780                 goto return_router;
 781
 782         primary_addr = router_orig->primary_addr;
 783
 784         /* if we have something in the primary_addr, we can search
 785          * for a potential bonding candidate.
 786          */
 787         if (batadv_compare_eth(primary_addr, zero_mac))
 788                 goto return_router;
 789
 790         /* find the orig_node which has the primary interface. might
 791          * even be the same as our router_orig in many cases
 792          */
 793         if (batadv_compare_eth(primary_addr, router_orig->orig)) {
 794                 primary_orig_node = router_orig;
 795         } else {
 796                 primary_orig_node = batadv_orig_hash_find(bat_priv,
 797                                                           primary_addr);
 798                 if (!primary_orig_node)
 799                         goto return_router;
 800
 801                 batadv_orig_node_free_ref(primary_orig_node);
 802         }
 803
 804         /* with less than 2 candidates, we can't do any
 805          * bonding and prefer the original router.
 806          */
 807         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 808                 goto return_router;
 809
 810         /* all nodes between should choose a candidate which
 811          * is is not on the interface where the packet came
 812          * in.
 813          */
 814         batadv_neigh_node_free_ref(router);
 815
 816         if (bonding_enabled)
 817                 router = batadv_find_bond_router(primary_orig_node, recv_if);
 818         else
 819                 router = batadv_find_ifalter_router(primary_orig_node, recv_if);
 820
 821 return_router:
 822         if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE)
 823                 goto err_unlock;
 824
 825         rcu_read_unlock();
 826         return router;
 827 err_unlock:
 828         rcu_read_unlock();
 829 err:
 830         if (router)
 831                 batadv_neigh_node_free_ref(router);
 832         return NULL;
 833 }
 834
 835 static int batadv_route_unicast_packet(struct sk_buff *skb,
 836                                        struct batadv_hard_iface *recv_if)
 837 {
 838         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 839         struct batadv_orig_node *orig_node = NULL;
 840         struct batadv_neigh_node *neigh_node = NULL;
 841         struct batadv_unicast_packet *unicast_packet;
 842         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 843         int ret = NET_RX_DROP;
 844         struct sk_buff *new_skb;
 845
 846         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 847
 848         /* TTL exceeded */
 849         if (unicast_packet->header.ttl < 2) {
 850                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 851                          ethhdr->h_source, unicast_packet->dest);
 852                 goto out;
 853         }
 854
 855         /* get routing information */
 856         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 857
 858         if (!orig_node)
 859                 goto out;
 860
 861         /* find_router() increases neigh_nodes refcount if found. */
 862         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 863
 864         if (!neigh_node)
 865                 goto out;
 866
 867         /* create a copy of the skb, if needed, to modify it. */
 868         if (skb_cow(skb, ETH_HLEN) < 0)
 869                 goto out;
 870
 871         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 872
 873         if (unicast_packet->header.packet_type == BATADV_UNICAST &&
 874             atomic_read(&bat_priv->fragmentation) &&
 875             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 876                 ret = batadv_frag_send_skb(skb, bat_priv,
 877                                            neigh_node->if_incoming,
 878                                            neigh_node->addr);
 879                 goto out;
 880         }
 881
 882         if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG &&
 883             batadv_frag_can_reassemble(skb,
 884                                        neigh_node->if_incoming->net_dev->mtu)) {
 885
 886                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
 887
 888                 if (ret == NET_RX_DROP)
 889                         goto out;
 890
 891                 /* packet was buffered for late merge */
 892                 if (!new_skb) {
 893                         ret = NET_RX_SUCCESS;
 894                         goto out;
 895                 }
 896
 897                 skb = new_skb;
 898                 unicast_packet = (struct batadv_unicast_packet *)skb->data;
 899         }
 900
 901         /* decrement ttl */
 902         unicast_packet->header.ttl--;
 903
 904         /* Update stats counter */
 905         batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 906         batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 907                            skb->len + ETH_HLEN);
 908
 909         /* route it */
 910         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 911         ret = NET_RX_SUCCESS;
 912
 913 out:
 914         if (neigh_node)
 915                 batadv_neigh_node_free_ref(neigh_node);
 916         if (orig_node)
 917                 batadv_orig_node_free_ref(orig_node);
 918         return ret;
 919 }
 920
 921 static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 922                                      struct sk_buff *skb) {
 923         uint8_t curr_ttvn;
 924         struct batadv_orig_node *orig_node;
 925         struct ethhdr *ethhdr;
 926         struct batadv_hard_iface *primary_if;
 927         struct batadv_unicast_packet *unicast_packet;
 928         bool tt_poss_change;
 929         int is_old_ttvn;
 930
 931         /* I could need to modify it */
 932         if (skb_cow(skb, sizeof(struct batadv_unicast_packet)) < 0)
 933                 return 0;
 934
 935         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 936
 937         if (batadv_is_my_mac(unicast_packet->dest)) {
 938                 tt_poss_change = bat_priv->tt.poss_change;
 939                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
 940         } else {
 941                 orig_node = batadv_orig_hash_find(bat_priv,
 942                                                   unicast_packet->dest);
 943
 944                 if (!orig_node)
 945                         return 0;
 946
 947                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 948                 tt_poss_change = orig_node->tt_poss_change;
 949                 batadv_orig_node_free_ref(orig_node);
 950         }
 951
 952         /* Check whether I have to reroute the packet */
 953         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 954         if (is_old_ttvn || tt_poss_change) {
 955                 /* check if there is enough data before accessing it */
 956                 if (pskb_may_pull(skb, sizeof(struct batadv_unicast_packet) +
 957                                   ETH_HLEN) < 0)
 958                         return 0;
 959
 960                 ethhdr = (struct ethhdr *)(skb->data + sizeof(*unicast_packet));
 961
 962                 /* we don't have an updated route for this client, so we should
 963                  * not try to reroute the packet!!
 964                  */
 965                 if (batadv_tt_global_client_is_roaming(bat_priv,
 966                                                        ethhdr->h_dest))
 967                         return 1;
 968
 969                 orig_node = batadv_transtable_search(bat_priv, NULL,
 970                                                      ethhdr->h_dest);
 971
 972                 if (!orig_node) {
 973                         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest))
 974                                 return 0;
 975                         primary_if = batadv_primary_if_get_selected(bat_priv);
 976                         if (!primary_if)
 977                                 return 0;
 978                         memcpy(unicast_packet->dest,
 979                                primary_if->net_dev->dev_addr, ETH_ALEN);
 980                         batadv_hardif_free_ref(primary_if);
 981                 } else {
 982                         memcpy(unicast_packet->dest, orig_node->orig,
 983                                ETH_ALEN);
 984                         curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 985                         batadv_orig_node_free_ref(orig_node);
 986                 }
 987
 988                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
 989                            "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
 990                            unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
 991                            unicast_packet->dest);
 992
 993                 unicast_packet->ttvn = curr_ttvn;
 994         }
 995         return 1;
 996 }
 997
 998 int batadv_recv_unicast_packet(struct sk_buff *skb,
 999                                struct batadv_hard_iface *recv_if)
1000 {
1001         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1002         struct batadv_unicast_packet *unicast_packet;
1003         int hdr_size = sizeof(*unicast_packet);
1004
1005         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1006                 return NET_RX_DROP;
1007
1008         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1009                 return NET_RX_DROP;
1010
1011         unicast_packet = (struct batadv_unicast_packet *)skb->data;
1012
1013         /* packet for me */
1014         if (batadv_is_my_mac(unicast_packet->dest)) {
1015                 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
1016                                     NULL);
1017
1018                 return NET_RX_SUCCESS;
1019         }
1020
1021         return batadv_route_unicast_packet(skb, recv_if);
1022 }
1023
1024 int batadv_recv_ucast_frag_packet(struct sk_buff *skb,
1025                                   struct batadv_hard_iface *recv_if)
1026 {
1027         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1028         struct batadv_unicast_frag_packet *unicast_packet;
1029         int hdr_size = sizeof(*unicast_packet);
1030         struct sk_buff *new_skb = NULL;
1031         int ret;
1032
1033         if (batadv_check_unicast_packet(skb, hdr_size) < 0)
1034                 return NET_RX_DROP;
1035
1036         if (!batadv_check_unicast_ttvn(bat_priv, skb))
1037                 return NET_RX_DROP;
1038
1039         unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
1040
1041         /* packet for me */
1042         if (batadv_is_my_mac(unicast_packet->dest)) {
1043
1044                 ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb);
1045
1046                 if (ret == NET_RX_DROP)
1047                         return NET_RX_DROP;
1048
1049                 /* packet was buffered for late merge */
1050                 if (!new_skb)
1051                         return NET_RX_SUCCESS;
1052
1053                 batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
1054                                     sizeof(struct batadv_unicast_packet), NULL);
1055                 return NET_RX_SUCCESS;
1056         }
1057
1058         return batadv_route_unicast_packet(skb, recv_if);
1059 }
1060
1061
1062 int batadv_recv_bcast_packet(struct sk_buff *skb,
1063                              struct batadv_hard_iface *recv_if)
1064 {
1065         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1066         struct batadv_orig_node *orig_node = NULL;
1067         struct batadv_bcast_packet *bcast_packet;
1068         struct ethhdr *ethhdr;
1069         int hdr_size = sizeof(*bcast_packet);
1070         int ret = NET_RX_DROP;
1071         int32_t seq_diff;
1072
1073         /* drop packet if it has not necessary minimum size */
1074         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1075                 goto out;
1076
1077         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1078
1079         /* packet with broadcast indication but unicast recipient */
1080         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1081                 goto out;
1082
1083         /* packet with broadcast sender address */
1084         if (is_broadcast_ether_addr(ethhdr->h_source))
1085                 goto out;
1086
1087         /* ignore broadcasts sent by myself */
1088         if (batadv_is_my_mac(ethhdr->h_source))
1089                 goto out;
1090
1091         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1092
1093         /* ignore broadcasts originated by myself */
1094         if (batadv_is_my_mac(bcast_packet->orig))
1095                 goto out;
1096
1097         if (bcast_packet->header.ttl < 2)
1098                 goto out;
1099
1100         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1101
1102         if (!orig_node)
1103                 goto out;
1104
1105         spin_lock_bh(&orig_node->bcast_seqno_lock);
1106
1107         /* check whether the packet is a duplicate */
1108         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1109                             ntohl(bcast_packet->seqno)))
1110                 goto spin_unlock;
1111
1112         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1113
1114         /* check whether the packet is old and the host just restarted. */
1115         if (batadv_window_protected(bat_priv, seq_diff,
1116                                     &orig_node->bcast_seqno_reset))
1117                 goto spin_unlock;
1118
1119         /* mark broadcast in flood history, update window position
1120          * if required.
1121          */
1122         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1123                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1124
1125         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1126
1127         /* keep skb linear for crc calculation */
1128         if (skb_linearize(skb) < 0)
1129                 goto out;
1130
1131         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1132
1133         /* check whether this has been sent by another originator before */
1134         if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, skb->len))
1135                 goto out;
1136
1137         /* rebroadcast packet */
1138         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1139
1140         /* don't hand the broadcast up if it is from an originator
1141          * from the same backbone.
1142          */
1143         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1144                 goto out;
1145
1146         /* broadcast for me */
1147         batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
1148                             orig_node);
1149         ret = NET_RX_SUCCESS;
1150         goto out;
1151
1152 spin_unlock:
1153         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1154 out:
1155         if (orig_node)
1156                 batadv_orig_node_free_ref(orig_node);
1157         return ret;
1158 }
1159
1160 int batadv_recv_vis_packet(struct sk_buff *skb,
1161                            struct batadv_hard_iface *recv_if)
1162 {
1163         struct batadv_vis_packet *vis_packet;
1164         struct ethhdr *ethhdr;
1165         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1166         int hdr_size = sizeof(*vis_packet);
1167
1168         /* keep skb linear */
1169         if (skb_linearize(skb) < 0)
1170                 return NET_RX_DROP;
1171
1172         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1173                 return NET_RX_DROP;
1174
1175         vis_packet = (struct batadv_vis_packet *)skb->data;
1176         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1177
1178         /* not for me */
1179         if (!batadv_is_my_mac(ethhdr->h_dest))
1180                 return NET_RX_DROP;
1181
1182         /* ignore own packets */
1183         if (batadv_is_my_mac(vis_packet->vis_orig))
1184                 return NET_RX_DROP;
1185
1186         if (batadv_is_my_mac(vis_packet->sender_orig))
1187                 return NET_RX_DROP;
1188
1189         switch (vis_packet->vis_type) {
1190         case BATADV_VIS_TYPE_SERVER_SYNC:
1191                 batadv_receive_server_sync_packet(bat_priv, vis_packet,
1192                                                   skb_headlen(skb));
1193                 break;
1194
1195         case BATADV_VIS_TYPE_CLIENT_UPDATE:
1196                 batadv_receive_client_update_packet(bat_priv, vis_packet,
1197                                                     skb_headlen(skb));
1198                 break;
1199
1200         default:        /* ignore unknown packet */
1201                 break;
1202         }
1203
1204         /* We take a copy of the data in the packet, so we should
1205          * always free the skbuf.
1206          */
1207         return NET_RX_DROP;
1208 }