net/batman-adv/routing.c

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