Pileus Git - ~andy/linux/blob - 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
  33 void slide_own_bcast_window(struct hard_iface *hard_iface)
  34 {
  35         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  36         struct hashtable_t *hash = bat_priv->orig_hash;
  37         struct hlist_node *node;
  38         struct hlist_head *head;
  39         struct orig_node *orig_node;
  40         unsigned long *word;
  41         uint32_t i;
  42         size_t word_index;
  43
  44         for (i = 0; i < hash->size; i++) {
  45                 head = &hash->table[i];
  46
  47                 rcu_read_lock();
  48                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  49                         spin_lock_bh(&orig_node->ogm_cnt_lock);
  50                         word_index = hard_iface->if_num * NUM_WORDS;
  51                         word = &(orig_node->bcast_own[word_index]);
  52
  53                         bit_get_packet(bat_priv, word, 1, 0);
  54                         orig_node->bcast_own_sum[hard_iface->if_num] =
  55                                 bit_packet_count(word);
  56                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
  57                 }
  58                 rcu_read_unlock();
  59         }
  60 }
  61
  62 static void _update_route(struct bat_priv *bat_priv,
  63                           struct orig_node *orig_node,
  64                           struct neigh_node *neigh_node)
  65 {
  66         struct neigh_node *curr_router;
  67
  68         curr_router = orig_node_get_router(orig_node);
  69
  70         /* route deleted */
  71         if ((curr_router) && (!neigh_node)) {
  72                 bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
  73                         orig_node->orig);
  74                 tt_global_del_orig(bat_priv, orig_node,
  75                                    "Deleted route towards originator");
  76
  77         /* route added */
  78         } else if ((!curr_router) && (neigh_node)) {
  79
  80                 bat_dbg(DBG_ROUTES, bat_priv,
  81                         "Adding route towards: %pM (via %pM)\n",
  82                         orig_node->orig, neigh_node->addr);
  83         /* route changed */
  84         } else if (neigh_node && curr_router) {
  85                 bat_dbg(DBG_ROUTES, bat_priv,
  86                         "Changing route towards: %pM "
  87                         "(now via %pM - was via %pM)\n",
  88                         orig_node->orig, neigh_node->addr,
  89                         curr_router->addr);
  90         }
  91
  92         if (curr_router)
  93                 neigh_node_free_ref(curr_router);
  94
  95         /* increase refcount of new best neighbor */
  96         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
  97                 neigh_node = NULL;
  98
  99         spin_lock_bh(&orig_node->neigh_list_lock);
 100         rcu_assign_pointer(orig_node->router, neigh_node);
 101         spin_unlock_bh(&orig_node->neigh_list_lock);
 102
 103         /* decrease refcount of previous best neighbor */
 104         if (curr_router)
 105                 neigh_node_free_ref(curr_router);
 106 }
 107
 108 void update_route(struct bat_priv *bat_priv, struct orig_node *orig_node,
 109                   struct neigh_node *neigh_node)
 110 {
 111         struct neigh_node *router = NULL;
 112
 113         if (!orig_node)
 114                 goto out;
 115
 116         router = orig_node_get_router(orig_node);
 117
 118         if (router != neigh_node)
 119                 _update_route(bat_priv, orig_node, neigh_node);
 120
 121 out:
 122         if (router)
 123                 neigh_node_free_ref(router);
 124 }
 125
 126 /* caller must hold the neigh_list_lock */
 127 void bonding_candidate_del(struct orig_node *orig_node,
 128                            struct neigh_node *neigh_node)
 129 {
 130         /* this neighbor is not part of our candidate list */
 131         if (list_empty(&neigh_node->bonding_list))
 132                 goto out;
 133
 134         list_del_rcu(&neigh_node->bonding_list);
 135         INIT_LIST_HEAD(&neigh_node->bonding_list);
 136         neigh_node_free_ref(neigh_node);
 137         atomic_dec(&orig_node->bond_candidates);
 138
 139 out:
 140         return;
 141 }
 142
 143 void bonding_candidate_add(struct orig_node *orig_node,
 144                            struct neigh_node *neigh_node)
 145 {
 146         struct hlist_node *node;
 147         struct neigh_node *tmp_neigh_node, *router = NULL;
 148         uint8_t interference_candidate = 0;
 149
 150         spin_lock_bh(&orig_node->neigh_list_lock);
 151
 152         /* only consider if it has the same primary address ...  */
 153         if (!compare_eth(orig_node->orig,
 154                          neigh_node->orig_node->primary_addr))
 155                 goto candidate_del;
 156
 157         router = orig_node_get_router(orig_node);
 158         if (!router)
 159                 goto candidate_del;
 160
 161         /* ... and is good enough to be considered */
 162         if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
 163                 goto candidate_del;
 164
 165         /**
 166          * check if we have another candidate with the same mac address or
 167          * interface. If we do, we won't select this candidate because of
 168          * possible interference.
 169          */
 170         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 171                                  &orig_node->neigh_list, list) {
 172
 173                 if (tmp_neigh_node == neigh_node)
 174                         continue;
 175
 176                 /* we only care if the other candidate is even
 177                 * considered as candidate. */
 178                 if (list_empty(&tmp_neigh_node->bonding_list))
 179                         continue;
 180
 181                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 182                     (compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
 183                         interference_candidate = 1;
 184                         break;
 185                 }
 186         }
 187
 188         /* don't care further if it is an interference candidate */
 189         if (interference_candidate)
 190                 goto candidate_del;
 191
 192         /* this neighbor already is part of our candidate list */
 193         if (!list_empty(&neigh_node->bonding_list))
 194                 goto out;
 195
 196         if (!atomic_inc_not_zero(&neigh_node->refcount))
 197                 goto out;
 198
 199         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 200         atomic_inc(&orig_node->bond_candidates);
 201         goto out;
 202
 203 candidate_del:
 204         bonding_candidate_del(orig_node, neigh_node);
 205
 206 out:
 207         spin_unlock_bh(&orig_node->neigh_list_lock);
 208
 209         if (router)
 210                 neigh_node_free_ref(router);
 211 }
 212
 213 /* copy primary address for bonding */
 214 void bonding_save_primary(const struct orig_node *orig_node,
 215                           struct orig_node *orig_neigh_node,
 216                           const struct batman_ogm_packet *batman_ogm_packet)
 217 {
 218         if (!(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
 219                 return;
 220
 221         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 222 }
 223
 224 /* checks whether the host restarted and is in the protection time.
 225  * returns:
 226  *  0 if the packet is to be accepted
 227  *  1 if the packet is to be ignored.
 228  */
 229 int window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
 230                      unsigned long *last_reset)
 231 {
 232         if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) ||
 233             (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
 234                 if (has_timed_out(*last_reset, RESET_PROTECTION_MS)) {
 235
 236                         *last_reset = jiffies;
 237                         bat_dbg(DBG_BATMAN, bat_priv,
 238                                 "old packet received, start protection\n");
 239
 240                         return 0;
 241                 } else
 242                         return 1;
 243         }
 244         return 0;
 245 }
 246
 247 int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
 248 {
 249         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 250         struct ethhdr *ethhdr;
 251
 252         /* drop packet if it has not necessary minimum size */
 253         if (unlikely(!pskb_may_pull(skb, BATMAN_OGM_LEN)))
 254                 return NET_RX_DROP;
 255
 256         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 257
 258         /* packet with broadcast indication but unicast recipient */
 259         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 260                 return NET_RX_DROP;
 261
 262         /* packet with broadcast sender address */
 263         if (is_broadcast_ether_addr(ethhdr->h_source))
 264                 return NET_RX_DROP;
 265
 266         /* create a copy of the skb, if needed, to modify it. */
 267         if (skb_cow(skb, 0) < 0)
 268                 return NET_RX_DROP;
 269
 270         /* keep skb linear */
 271         if (skb_linearize(skb) < 0)
 272                 return NET_RX_DROP;
 273
 274         bat_priv->bat_algo_ops->bat_ogm_receive(hard_iface, skb);
 275
 276         kfree_skb(skb);
 277         return NET_RX_SUCCESS;
 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                 bat_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 = 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, sizeof(struct ethhdr)) < 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         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                 neigh_node_free_ref(router);
 330         if (orig_node)
 331                 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 "
 349                          "%pM: ttl exceeded\n", icmp_packet->orig,
 350                          icmp_packet->dst);
 351                 goto out;
 352         }
 353
 354         primary_if = primary_if_get_selected(bat_priv);
 355         if (!primary_if)
 356                 goto out;
 357
 358         /* get routing information */
 359         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 360         if (!orig_node)
 361                 goto out;
 362
 363         router = orig_node_get_router(orig_node);
 364         if (!router)
 365                 goto out;
 366
 367         /* create a copy of the skb, if needed, to modify it. */
 368         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 369                 goto out;
 370
 371         icmp_packet = (struct icmp_packet *)skb->data;
 372
 373         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 374         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 375         icmp_packet->msg_type = TTL_EXCEEDED;
 376         icmp_packet->header.ttl = TTL;
 377
 378         send_skb_packet(skb, router->if_incoming, router->addr);
 379         ret = NET_RX_SUCCESS;
 380
 381 out:
 382         if (primary_if)
 383                 hardif_free_ref(primary_if);
 384         if (router)
 385                 neigh_node_free_ref(router);
 386         if (orig_node)
 387                 orig_node_free_ref(orig_node);
 388         return ret;
 389 }
 390
 391
 392 int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 393 {
 394         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 395         struct icmp_packet_rr *icmp_packet;
 396         struct ethhdr *ethhdr;
 397         struct orig_node *orig_node = NULL;
 398         struct neigh_node *router = NULL;
 399         int hdr_size = sizeof(struct icmp_packet);
 400         int ret = NET_RX_DROP;
 401
 402         /**
 403          * we truncate all incoming icmp packets if they don't match our size
 404          */
 405         if (skb->len >= sizeof(struct icmp_packet_rr))
 406                 hdr_size = sizeof(struct 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 (!is_my_mac(ethhdr->h_dest))
 424                 goto out;
 425
 426         icmp_packet = (struct icmp_packet_rr *)skb->data;
 427
 428         /* add record route information if not full */
 429         if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
 430             (icmp_packet->rr_cur < BAT_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 (is_my_mac(icmp_packet->dst))
 438                 return recv_my_icmp_packet(bat_priv, skb, hdr_size);
 439
 440         /* TTL exceeded */
 441         if (icmp_packet->header.ttl < 2)
 442                 return recv_icmp_ttl_exceeded(bat_priv, skb);
 443
 444         /* get routing information */
 445         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
 446         if (!orig_node)
 447                 goto out;
 448
 449         router = 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, sizeof(struct ethhdr)) < 0)
 455                 goto out;
 456
 457         icmp_packet = (struct icmp_packet_rr *)skb->data;
 458
 459         /* decrement ttl */
 460         icmp_packet->header.ttl--;
 461
 462         /* route it */
 463         send_skb_packet(skb, router->if_incoming, router->addr);
 464         ret = NET_RX_SUCCESS;
 465
 466 out:
 467         if (router)
 468                 neigh_node_free_ref(router);
 469         if (orig_node)
 470                 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 static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
 480                                            const struct hard_iface *recv_if)
 481 {
 482         struct neigh_node *tmp_neigh_node;
 483         struct neigh_node *router = NULL, *first_candidate = NULL;
 484
 485         rcu_read_lock();
 486         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 487                                 bonding_list) {
 488                 if (!first_candidate)
 489                         first_candidate = tmp_neigh_node;
 490
 491                 /* recv_if == NULL on the first node. */
 492                 if (tmp_neigh_node->if_incoming == recv_if)
 493                         continue;
 494
 495                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 496                         continue;
 497
 498                 router = tmp_neigh_node;
 499                 break;
 500         }
 501
 502         /* use the first candidate if nothing was found. */
 503         if (!router && first_candidate &&
 504             atomic_inc_not_zero(&first_candidate->refcount))
 505                 router = first_candidate;
 506
 507         if (!router)
 508                 goto out;
 509
 510         /* selected should point to the next element
 511          * after the current router */
 512         spin_lock_bh(&primary_orig->neigh_list_lock);
 513         /* this is a list_move(), which unfortunately
 514          * does not exist as rcu version */
 515         list_del_rcu(&primary_orig->bond_list);
 516         list_add_rcu(&primary_orig->bond_list,
 517                      &router->bonding_list);
 518         spin_unlock_bh(&primary_orig->neigh_list_lock);
 519
 520 out:
 521         rcu_read_unlock();
 522         return router;
 523 }
 524
 525 /* Interface Alternating: Use the best of the
 526  * remaining candidates which are not using
 527  * this interface.
 528  *
 529  * Increases the returned router's refcount */
 530 static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
 531                                               const struct hard_iface *recv_if)
 532 {
 533         struct neigh_node *tmp_neigh_node;
 534         struct neigh_node *router = NULL, *first_candidate = NULL;
 535
 536         rcu_read_lock();
 537         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 538                                 bonding_list) {
 539                 if (!first_candidate)
 540                         first_candidate = tmp_neigh_node;
 541
 542                 /* recv_if == NULL on the first node. */
 543                 if (tmp_neigh_node->if_incoming == recv_if)
 544                         continue;
 545
 546                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 547                         continue;
 548
 549                 /* if we don't have a router yet
 550                  * or this one is better, choose it. */
 551                 if ((!router) ||
 552                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
 553                         /* decrement refcount of
 554                          * previously selected router */
 555                         if (router)
 556                                 neigh_node_free_ref(router);
 557
 558                         router = tmp_neigh_node;
 559                         atomic_inc_not_zero(&router->refcount);
 560                 }
 561
 562                 neigh_node_free_ref(tmp_neigh_node);
 563         }
 564
 565         /* use the first candidate if nothing was found. */
 566         if (!router && first_candidate &&
 567             atomic_inc_not_zero(&first_candidate->refcount))
 568                 router = first_candidate;
 569
 570         rcu_read_unlock();
 571         return router;
 572 }
 573
 574 int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
 575 {
 576         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 577         struct tt_query_packet *tt_query;
 578         uint16_t tt_len;
 579         struct ethhdr *ethhdr;
 580
 581         /* drop packet if it has not necessary minimum size */
 582         if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
 583                 goto out;
 584
 585         /* I could need to modify it */
 586         if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
 587                 goto out;
 588
 589         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 590
 591         /* packet with unicast indication but broadcast recipient */
 592         if (is_broadcast_ether_addr(ethhdr->h_dest))
 593                 goto out;
 594
 595         /* packet with broadcast sender address */
 596         if (is_broadcast_ether_addr(ethhdr->h_source))
 597                 goto out;
 598
 599         tt_query = (struct tt_query_packet *)skb->data;
 600
 601         tt_query->tt_data = ntohs(tt_query->tt_data);
 602
 603         switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
 604         case TT_REQUEST:
 605                 /* If we cannot provide an answer the tt_request is
 606                  * forwarded */
 607                 if (!send_tt_response(bat_priv, tt_query)) {
 608                         bat_dbg(DBG_TT, bat_priv,
 609                                 "Routing TT_REQUEST to %pM [%c]\n",
 610                                 tt_query->dst,
 611                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 612                         tt_query->tt_data = htons(tt_query->tt_data);
 613                         return route_unicast_packet(skb, recv_if);
 614                 }
 615                 break;
 616         case TT_RESPONSE:
 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
 623                         tt_len = tt_query->tt_data * sizeof(struct tt_change);
 624
 625                         /* Ensure we have all the claimed data */
 626                         if (unlikely(skb_headlen(skb) <
 627                                      sizeof(struct tt_query_packet) + tt_len))
 628                                 goto out;
 629
 630                         handle_tt_response(bat_priv, tt_query);
 631                 } else {
 632                         bat_dbg(DBG_TT, bat_priv,
 633                                 "Routing TT_RESPONSE to %pM [%c]\n",
 634                                 tt_query->dst,
 635                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 636                         tt_query->tt_data = htons(tt_query->tt_data);
 637                         return route_unicast_packet(skb, recv_if);
 638                 }
 639                 break;
 640         }
 641
 642 out:
 643         /* returning NET_RX_DROP will make the caller function kfree the skb */
 644         return NET_RX_DROP;
 645 }
 646
 647 int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
 648 {
 649         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 650         struct roam_adv_packet *roam_adv_packet;
 651         struct orig_node *orig_node;
 652         struct ethhdr *ethhdr;
 653
 654         /* drop packet if it has not necessary minimum size */
 655         if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
 656                 goto out;
 657
 658         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 659
 660         /* packet with unicast indication but broadcast recipient */
 661         if (is_broadcast_ether_addr(ethhdr->h_dest))
 662                 goto out;
 663
 664         /* packet with broadcast sender address */
 665         if (is_broadcast_ether_addr(ethhdr->h_source))
 666                 goto out;
 667
 668         roam_adv_packet = (struct roam_adv_packet *)skb->data;
 669
 670         if (!is_my_mac(roam_adv_packet->dst))
 671                 return route_unicast_packet(skb, recv_if);
 672
 673         orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
 674         if (!orig_node)
 675                 goto out;
 676
 677         bat_dbg(DBG_TT, bat_priv, "Received ROAMING_ADV from %pM "
 678                 "(client %pM)\n", roam_adv_packet->src,
 679                 roam_adv_packet->client);
 680
 681         tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 682                       atomic_read(&orig_node->last_ttvn) + 1, true, false);
 683
 684         /* Roaming phase starts: I have new information but the ttvn has not
 685          * been incremented yet. This flag will make me check all the incoming
 686          * packets for the correct destination. */
 687         bat_priv->tt_poss_change = true;
 688
 689         orig_node_free_ref(orig_node);
 690 out:
 691         /* returning NET_RX_DROP will make the caller function kfree the skb */
 692         return NET_RX_DROP;
 693 }
 694
 695 /* find a suitable router for this originator, and use
 696  * bonding if possible. increases the found neighbors
 697  * refcount.*/
 698 struct neigh_node *find_router(struct bat_priv *bat_priv,
 699                                struct orig_node *orig_node,
 700                                const struct hard_iface *recv_if)
 701 {
 702         struct orig_node *primary_orig_node;
 703         struct orig_node *router_orig;
 704         struct neigh_node *router;
 705         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 706         int bonding_enabled;
 707
 708         if (!orig_node)
 709                 return NULL;
 710
 711         router = orig_node_get_router(orig_node);
 712         if (!router)
 713                 goto err;
 714
 715         /* without bonding, the first node should
 716          * always choose the default router. */
 717         bonding_enabled = atomic_read(&bat_priv->bonding);
 718
 719         rcu_read_lock();
 720         /* select default router to output */
 721         router_orig = router->orig_node;
 722         if (!router_orig)
 723                 goto err_unlock;
 724
 725         if ((!recv_if) && (!bonding_enabled))
 726                 goto return_router;
 727
 728         /* if we have something in the primary_addr, we can search
 729          * for a potential bonding candidate. */
 730         if (compare_eth(router_orig->primary_addr, zero_mac))
 731                 goto return_router;
 732
 733         /* find the orig_node which has the primary interface. might
 734          * even be the same as our router_orig in many cases */
 735
 736         if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
 737                 primary_orig_node = router_orig;
 738         } else {
 739                 primary_orig_node = orig_hash_find(bat_priv,
 740                                                    router_orig->primary_addr);
 741                 if (!primary_orig_node)
 742                         goto return_router;
 743
 744                 orig_node_free_ref(primary_orig_node);
 745         }
 746
 747         /* with less than 2 candidates, we can't do any
 748          * bonding and prefer the original router. */
 749         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 750                 goto return_router;
 751
 752         /* all nodes between should choose a candidate which
 753          * is is not on the interface where the packet came
 754          * in. */
 755
 756         neigh_node_free_ref(router);
 757
 758         if (bonding_enabled)
 759                 router = find_bond_router(primary_orig_node, recv_if);
 760         else
 761                 router = find_ifalter_router(primary_orig_node, recv_if);
 762
 763 return_router:
 764         if (router && router->if_incoming->if_status != IF_ACTIVE)
 765                 goto err_unlock;
 766
 767         rcu_read_unlock();
 768         return router;
 769 err_unlock:
 770         rcu_read_unlock();
 771 err:
 772         if (router)
 773                 neigh_node_free_ref(router);
 774         return NULL;
 775 }
 776
 777 static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
 778 {
 779         struct ethhdr *ethhdr;
 780
 781         /* drop packet if it has not necessary minimum size */
 782         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 783                 return -1;
 784
 785         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 786
 787         /* packet with unicast indication but broadcast recipient */
 788         if (is_broadcast_ether_addr(ethhdr->h_dest))
 789                 return -1;
 790
 791         /* packet with broadcast sender address */
 792         if (is_broadcast_ether_addr(ethhdr->h_source))
 793                 return -1;
 794
 795         /* not for me */
 796         if (!is_my_mac(ethhdr->h_dest))
 797                 return -1;
 798
 799         return 0;
 800 }
 801
 802 int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 803 {
 804         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 805         struct orig_node *orig_node = NULL;
 806         struct neigh_node *neigh_node = NULL;
 807         struct unicast_packet *unicast_packet;
 808         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 809         int ret = NET_RX_DROP;
 810         struct sk_buff *new_skb;
 811
 812         unicast_packet = (struct unicast_packet *)skb->data;
 813
 814         /* TTL exceeded */
 815         if (unicast_packet->header.ttl < 2) {
 816                 pr_debug("Warning - can't forward unicast packet from %pM to "
 817                          "%pM: ttl exceeded\n", ethhdr->h_source,
 818                          unicast_packet->dest);
 819                 goto out;
 820         }
 821
 822         /* get routing information */
 823         orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 824
 825         if (!orig_node)
 826                 goto out;
 827
 828         /* find_router() increases neigh_nodes refcount if found. */
 829         neigh_node = find_router(bat_priv, orig_node, recv_if);
 830
 831         if (!neigh_node)
 832                 goto out;
 833
 834         /* create a copy of the skb, if needed, to modify it. */
 835         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 836                 goto out;
 837
 838         unicast_packet = (struct unicast_packet *)skb->data;
 839
 840         if (unicast_packet->header.packet_type == BAT_UNICAST &&
 841             atomic_read(&bat_priv->fragmentation) &&
 842             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 843                 ret = frag_send_skb(skb, bat_priv,
 844                                     neigh_node->if_incoming, neigh_node->addr);
 845                 goto out;
 846         }
 847
 848         if (unicast_packet->header.packet_type == BAT_UNICAST_FRAG &&
 849             frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
 850
 851                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 852
 853                 if (ret == NET_RX_DROP)
 854                         goto out;
 855
 856                 /* packet was buffered for late merge */
 857                 if (!new_skb) {
 858                         ret = NET_RX_SUCCESS;
 859                         goto out;
 860                 }
 861
 862                 skb = new_skb;
 863                 unicast_packet = (struct unicast_packet *)skb->data;
 864         }
 865
 866         /* decrement ttl */
 867         unicast_packet->header.ttl--;
 868
 869         /* route it */
 870         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 871         ret = NET_RX_SUCCESS;
 872
 873 out:
 874         if (neigh_node)
 875                 neigh_node_free_ref(neigh_node);
 876         if (orig_node)
 877                 orig_node_free_ref(orig_node);
 878         return ret;
 879 }
 880
 881 static int check_unicast_ttvn(struct bat_priv *bat_priv,
 882                                struct sk_buff *skb) {
 883         uint8_t curr_ttvn;
 884         struct orig_node *orig_node;
 885         struct ethhdr *ethhdr;
 886         struct hard_iface *primary_if;
 887         struct unicast_packet *unicast_packet;
 888         bool tt_poss_change;
 889
 890         /* I could need to modify it */
 891         if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
 892                 return 0;
 893
 894         unicast_packet = (struct unicast_packet *)skb->data;
 895
 896         if (is_my_mac(unicast_packet->dest)) {
 897                 tt_poss_change = bat_priv->tt_poss_change;
 898                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 899         } else {
 900                 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 901
 902                 if (!orig_node)
 903                         return 0;
 904
 905                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 906                 tt_poss_change = orig_node->tt_poss_change;
 907                 orig_node_free_ref(orig_node);
 908         }
 909
 910         /* Check whether I have to reroute the packet */
 911         if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
 912                 /* Linearize the skb before accessing it */
 913                 if (skb_linearize(skb) < 0)
 914                         return 0;
 915
 916                 ethhdr = (struct ethhdr *)(skb->data +
 917                         sizeof(struct unicast_packet));
 918                 orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
 919
 920                 if (!orig_node) {
 921                         if (!is_my_client(bat_priv, ethhdr->h_dest))
 922                                 return 0;
 923                         primary_if = primary_if_get_selected(bat_priv);
 924                         if (!primary_if)
 925                                 return 0;
 926                         memcpy(unicast_packet->dest,
 927                                primary_if->net_dev->dev_addr, ETH_ALEN);
 928                         hardif_free_ref(primary_if);
 929                 } else {
 930                         memcpy(unicast_packet->dest, orig_node->orig,
 931                                ETH_ALEN);
 932                         curr_ttvn = (uint8_t)
 933                                 atomic_read(&orig_node->last_ttvn);
 934                         orig_node_free_ref(orig_node);
 935                 }
 936
 937                 bat_dbg(DBG_ROUTES, bat_priv, "TTVN mismatch (old_ttvn %u "
 938                         "new_ttvn %u)! Rerouting unicast packet (for %pM) to "
 939                         "%pM\n", unicast_packet->ttvn, curr_ttvn,
 940                         ethhdr->h_dest, unicast_packet->dest);
 941
 942                 unicast_packet->ttvn = curr_ttvn;
 943         }
 944         return 1;
 945 }
 946
 947 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 948 {
 949         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 950         struct unicast_packet *unicast_packet;
 951         int hdr_size = sizeof(*unicast_packet);
 952
 953         if (check_unicast_packet(skb, hdr_size) < 0)
 954                 return NET_RX_DROP;
 955
 956         if (!check_unicast_ttvn(bat_priv, skb))
 957                 return NET_RX_DROP;
 958
 959         unicast_packet = (struct unicast_packet *)skb->data;
 960
 961         /* packet for me */
 962         if (is_my_mac(unicast_packet->dest)) {
 963                 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
 964                 return NET_RX_SUCCESS;
 965         }
 966
 967         return route_unicast_packet(skb, recv_if);
 968 }
 969
 970 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 971 {
 972         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 973         struct unicast_frag_packet *unicast_packet;
 974         int hdr_size = sizeof(*unicast_packet);
 975         struct sk_buff *new_skb = NULL;
 976         int ret;
 977
 978         if (check_unicast_packet(skb, hdr_size) < 0)
 979                 return NET_RX_DROP;
 980
 981         if (!check_unicast_ttvn(bat_priv, skb))
 982                 return NET_RX_DROP;
 983
 984         unicast_packet = (struct unicast_frag_packet *)skb->data;
 985
 986         /* packet for me */
 987         if (is_my_mac(unicast_packet->dest)) {
 988
 989                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 990
 991                 if (ret == NET_RX_DROP)
 992                         return NET_RX_DROP;
 993
 994                 /* packet was buffered for late merge */
 995                 if (!new_skb)
 996                         return NET_RX_SUCCESS;
 997
 998                 interface_rx(recv_if->soft_iface, new_skb, recv_if,
 999                              sizeof(struct unicast_packet));
1000                 return NET_RX_SUCCESS;
1001         }
1002
1003         return route_unicast_packet(skb, recv_if);
1004 }
1005
1006
1007 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1008 {
1009         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1010         struct orig_node *orig_node = NULL;
1011         struct bcast_packet *bcast_packet;
1012         struct ethhdr *ethhdr;
1013         int hdr_size = sizeof(*bcast_packet);
1014         int ret = NET_RX_DROP;
1015         int32_t seq_diff;
1016
1017         /* drop packet if it has not necessary minimum size */
1018         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1019                 goto out;
1020
1021         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1022
1023         /* packet with broadcast indication but unicast recipient */
1024         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1025                 goto out;
1026
1027         /* packet with broadcast sender address */
1028         if (is_broadcast_ether_addr(ethhdr->h_source))
1029                 goto out;
1030
1031         /* ignore broadcasts sent by myself */
1032         if (is_my_mac(ethhdr->h_source))
1033                 goto out;
1034
1035         bcast_packet = (struct bcast_packet *)skb->data;
1036
1037         /* ignore broadcasts originated by myself */
1038         if (is_my_mac(bcast_packet->orig))
1039                 goto out;
1040
1041         if (bcast_packet->header.ttl < 2)
1042                 goto out;
1043
1044         orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1045
1046         if (!orig_node)
1047                 goto out;
1048
1049         spin_lock_bh(&orig_node->bcast_seqno_lock);
1050
1051         /* check whether the packet is a duplicate */
1052         if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1053                            ntohl(bcast_packet->seqno)))
1054                 goto spin_unlock;
1055
1056         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1057
1058         /* check whether the packet is old and the host just restarted. */
1059         if (window_protected(bat_priv, seq_diff,
1060                              &orig_node->bcast_seqno_reset))
1061                 goto spin_unlock;
1062
1063         /* mark broadcast in flood history, update window position
1064          * if required. */
1065         if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1066                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1067
1068         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1069
1070         /* rebroadcast packet */
1071         add_bcast_packet_to_list(bat_priv, skb, 1);
1072
1073         /* broadcast for me */
1074         interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1075         ret = NET_RX_SUCCESS;
1076         goto out;
1077
1078 spin_unlock:
1079         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1080 out:
1081         if (orig_node)
1082                 orig_node_free_ref(orig_node);
1083         return ret;
1084 }
1085
1086 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1087 {
1088         struct vis_packet *vis_packet;
1089         struct ethhdr *ethhdr;
1090         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1091         int hdr_size = sizeof(*vis_packet);
1092
1093         /* keep skb linear */
1094         if (skb_linearize(skb) < 0)
1095                 return NET_RX_DROP;
1096
1097         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1098                 return NET_RX_DROP;
1099
1100         vis_packet = (struct vis_packet *)skb->data;
1101         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1102
1103         /* not for me */
1104         if (!is_my_mac(ethhdr->h_dest))
1105                 return NET_RX_DROP;
1106
1107         /* ignore own packets */
1108         if (is_my_mac(vis_packet->vis_orig))
1109                 return NET_RX_DROP;
1110
1111         if (is_my_mac(vis_packet->sender_orig))
1112                 return NET_RX_DROP;
1113
1114         switch (vis_packet->vis_type) {
1115         case VIS_TYPE_SERVER_SYNC:
1116                 receive_server_sync_packet(bat_priv, vis_packet,
1117                                            skb_headlen(skb));
1118                 break;
1119
1120         case VIS_TYPE_CLIENT_UPDATE:
1121                 receive_client_update_packet(bat_priv, vis_packet,
1122                                              skb_headlen(skb));
1123                 break;
1124
1125         default:        /* ignore unknown packet */
1126                 break;
1127         }
1128
1129         /* We take a copy of the data in the packet, so we should
1130            always free the skbuf. */
1131         return NET_RX_DROP;
1132 }