net/batman-adv/routing.c

   1 /*
   2  * Copyright (C) 2007-2011 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 "bat_ogm.h"
  33
  34 void slide_own_bcast_window(struct hard_iface *hard_iface)
  35 {
  36         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  37         struct hashtable_t *hash = bat_priv->orig_hash;
  38         struct hlist_node *node;
  39         struct hlist_head *head;
  40         struct orig_node *orig_node;
  41         unsigned long *word;
  42         int i;
  43         size_t word_index;
  44
  45         for (i = 0; i < hash->size; i++) {
  46                 head = &hash->table[i];
  47
  48                 rcu_read_lock();
  49                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  50                         spin_lock_bh(&orig_node->ogm_cnt_lock);
  51                         word_index = hard_iface->if_num * NUM_WORDS;
  52                         word = &(orig_node->bcast_own[word_index]);
  53
  54                         bit_get_packet(bat_priv, word, 1, 0);
  55                         orig_node->bcast_own_sum[hard_iface->if_num] =
  56                                 bit_packet_count(word);
  57                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
  58                 }
  59                 rcu_read_unlock();
  60         }
  61 }
  62
  63 static void _update_route(struct bat_priv *bat_priv,
  64                           struct orig_node *orig_node,
  65                           struct neigh_node *neigh_node)
  66 {
  67         struct neigh_node *curr_router;
  68
  69         curr_router = orig_node_get_router(orig_node);
  70
  71         /* route deleted */
  72         if ((curr_router) && (!neigh_node)) {
  73                 bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
  74                         orig_node->orig);
  75                 tt_global_del_orig(bat_priv, orig_node,
  76                                     "Deleted route towards originator");
  77
  78         /* route added */
  79         } else if ((!curr_router) && (neigh_node)) {
  80
  81                 bat_dbg(DBG_ROUTES, bat_priv,
  82                         "Adding route towards: %pM (via %pM)\n",
  83                         orig_node->orig, neigh_node->addr);
  84         /* route changed */
  85         } else if (neigh_node && curr_router) {
  86                 bat_dbg(DBG_ROUTES, bat_priv,
  87                         "Changing route towards: %pM "
  88                         "(now via %pM - was via %pM)\n",
  89                         orig_node->orig, neigh_node->addr,
  90                         curr_router->addr);
  91         }
  92
  93         if (curr_router)
  94                 neigh_node_free_ref(curr_router);
  95
  96         /* increase refcount of new best neighbor */
  97         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
  98                 neigh_node = NULL;
  99
 100         spin_lock_bh(&orig_node->neigh_list_lock);
 101         rcu_assign_pointer(orig_node->router, neigh_node);
 102         spin_unlock_bh(&orig_node->neigh_list_lock);
 103
 104         /* decrease refcount of previous best neighbor */
 105         if (curr_router)
 106                 neigh_node_free_ref(curr_router);
 107 }
 108
 109 void update_route(struct bat_priv *bat_priv, struct orig_node *orig_node,
 110                   struct neigh_node *neigh_node)
 111 {
 112         struct neigh_node *router = NULL;
 113
 114         if (!orig_node)
 115                 goto out;
 116
 117         router = orig_node_get_router(orig_node);
 118
 119         if (router != neigh_node)
 120                 _update_route(bat_priv, orig_node, neigh_node);
 121
 122 out:
 123         if (router)
 124                 neigh_node_free_ref(router);
 125 }
 126
 127 /* caller must hold the neigh_list_lock */
 128 void bonding_candidate_del(struct orig_node *orig_node,
 129                            struct neigh_node *neigh_node)
 130 {
 131         /* this neighbor is not part of our candidate list */
 132         if (list_empty(&neigh_node->bonding_list))
 133                 goto out;
 134
 135         list_del_rcu(&neigh_node->bonding_list);
 136         INIT_LIST_HEAD(&neigh_node->bonding_list);
 137         neigh_node_free_ref(neigh_node);
 138         atomic_dec(&orig_node->bond_candidates);
 139
 140 out:
 141         return;
 142 }
 143
 144 void bonding_candidate_add(struct orig_node *orig_node,
 145                            struct neigh_node *neigh_node)
 146 {
 147         struct hlist_node *node;
 148         struct neigh_node *tmp_neigh_node, *router = NULL;
 149         uint8_t interference_candidate = 0;
 150
 151         spin_lock_bh(&orig_node->neigh_list_lock);
 152
 153         /* only consider if it has the same primary address ...  */
 154         if (!compare_eth(orig_node->orig,
 155                          neigh_node->orig_node->primary_addr))
 156                 goto candidate_del;
 157
 158         router = orig_node_get_router(orig_node);
 159         if (!router)
 160                 goto candidate_del;
 161
 162         /* ... and is good enough to be considered */
 163         if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
 164                 goto candidate_del;
 165
 166         /**
 167          * check if we have another candidate with the same mac address or
 168          * interface. If we do, we won't select this candidate because of
 169          * possible interference.
 170          */
 171         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 172                                  &orig_node->neigh_list, list) {
 173
 174                 if (tmp_neigh_node == neigh_node)
 175                         continue;
 176
 177                 /* we only care if the other candidate is even
 178                 * considered as candidate. */
 179                 if (list_empty(&tmp_neigh_node->bonding_list))
 180                         continue;
 181
 182                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 183                     (compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
 184                         interference_candidate = 1;
 185                         break;
 186                 }
 187         }
 188
 189         /* don't care further if it is an interference candidate */
 190         if (interference_candidate)
 191                 goto candidate_del;
 192
 193         /* this neighbor already is part of our candidate list */
 194         if (!list_empty(&neigh_node->bonding_list))
 195                 goto out;
 196
 197         if (!atomic_inc_not_zero(&neigh_node->refcount))
 198                 goto out;
 199
 200         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 201         atomic_inc(&orig_node->bond_candidates);
 202         goto out;
 203
 204 candidate_del:
 205         bonding_candidate_del(orig_node, neigh_node);
 206
 207 out:
 208         spin_unlock_bh(&orig_node->neigh_list_lock);
 209
 210         if (router)
 211                 neigh_node_free_ref(router);
 212 }
 213
 214 /* copy primary address for bonding */
 215 void bonding_save_primary(const struct orig_node *orig_node,
 216                           struct orig_node *orig_neigh_node,
 217                           const struct batman_ogm_packet *batman_ogm_packet)
 218 {
 219         if (!(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
 220                 return;
 221
 222         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 223 }
 224
 225 /* checks whether the host restarted and is in the protection time.
 226  * returns:
 227  *  0 if the packet is to be accepted
 228  *  1 if the packet is to be ignored.
 229  */
 230 int window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
 231                      unsigned long *last_reset)
 232 {
 233         if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE)
 234                 || (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
 235                 if (time_after(jiffies, *last_reset +
 236                         msecs_to_jiffies(RESET_PROTECTION_MS))) {
 237
 238                         *last_reset = jiffies;
 239                         bat_dbg(DBG_BATMAN, bat_priv,
 240                                 "old packet received, start protection\n");
 241
 242                         return 0;
 243                 } else
 244                         return 1;
 245         }
 246         return 0;
 247 }
 248
 249 int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
 250 {
 251         struct ethhdr *ethhdr;
 252
 253         /* drop packet if it has not necessary minimum size */
 254         if (unlikely(!pskb_may_pull(skb, BATMAN_OGM_LEN)))
 255                 return NET_RX_DROP;
 256
 257         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 258
 259         /* packet with broadcast indication but unicast recipient */
 260         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 261                 return NET_RX_DROP;
 262
 263         /* packet with broadcast sender address */
 264         if (is_broadcast_ether_addr(ethhdr->h_source))
 265                 return NET_RX_DROP;
 266
 267         /* create a copy of the skb, if needed, to modify it. */
 268         if (skb_cow(skb, 0) < 0)
 269                 return NET_RX_DROP;
 270
 271         /* keep skb linear */
 272         if (skb_linearize(skb) < 0)
 273                 return NET_RX_DROP;
 274
 275         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 276
 277         bat_ogm_receive(ethhdr, skb->data, skb_headlen(skb), hard_iface);
 278
 279         kfree_skb(skb);
 280         return NET_RX_SUCCESS;
 281 }
 282
 283 static int recv_my_icmp_packet(struct bat_priv *bat_priv,
 284                                struct sk_buff *skb, size_t icmp_len)
 285 {
 286         struct hard_iface *primary_if = NULL;
 287         struct orig_node *orig_node = NULL;
 288         struct neigh_node *router = NULL;
 289         struct icmp_packet_rr *icmp_packet;
 290         int ret = NET_RX_DROP;
 291
 292         icmp_packet = (struct icmp_packet_rr *)skb->data;
 293
 294         /* add data to device queue */
 295         if (icmp_packet->msg_type != ECHO_REQUEST) {
 296                 bat_socket_receive_packet(icmp_packet, icmp_len);
 297                 goto out;
 298         }
 299
 300         primary_if = primary_if_get_selected(bat_priv);
 301         if (!primary_if)
 302                 goto out;
 303
 304         /* answer echo request (ping) */
 305         /* get routing information */
 306         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 307         if (!orig_node)
 308                 goto out;
 309
 310         router = orig_node_get_router(orig_node);
 311         if (!router)
 312                 goto out;
 313
 314         /* create a copy of the skb, if needed, to modify it. */
 315         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 316                 goto out;
 317
 318         icmp_packet = (struct icmp_packet_rr *)skb->data;
 319
 320         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 321         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 322         icmp_packet->msg_type = ECHO_REPLY;
 323         icmp_packet->ttl = TTL;
 324
 325         send_skb_packet(skb, router->if_incoming, router->addr);
 326         ret = NET_RX_SUCCESS;
 327
 328 out:
 329         if (primary_if)
 330                 hardif_free_ref(primary_if);
 331         if (router)
 332                 neigh_node_free_ref(router);
 333         if (orig_node)
 334                 orig_node_free_ref(orig_node);
 335         return ret;
 336 }
 337
 338 static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
 339                                   struct sk_buff *skb)
 340 {
 341         struct hard_iface *primary_if = NULL;
 342         struct orig_node *orig_node = NULL;
 343         struct neigh_node *router = NULL;
 344         struct icmp_packet *icmp_packet;
 345         int ret = NET_RX_DROP;
 346
 347         icmp_packet = (struct icmp_packet *)skb->data;
 348
 349         /* send TTL exceeded if packet is an echo request (traceroute) */
 350         if (icmp_packet->msg_type != ECHO_REQUEST) {
 351                 pr_debug("Warning - can't forward icmp packet from %pM to "
 352                          "%pM: ttl exceeded\n", icmp_packet->orig,
 353                          icmp_packet->dst);
 354                 goto out;
 355         }
 356
 357         primary_if = primary_if_get_selected(bat_priv);
 358         if (!primary_if)
 359                 goto out;
 360
 361         /* get routing information */
 362         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 363         if (!orig_node)
 364                 goto out;
 365
 366         router = orig_node_get_router(orig_node);
 367         if (!router)
 368                 goto out;
 369
 370         /* create a copy of the skb, if needed, to modify it. */
 371         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 372                 goto out;
 373
 374         icmp_packet = (struct icmp_packet *)skb->data;
 375
 376         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 377         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 378         icmp_packet->msg_type = TTL_EXCEEDED;
 379         icmp_packet->ttl = TTL;
 380
 381         send_skb_packet(skb, router->if_incoming, router->addr);
 382         ret = NET_RX_SUCCESS;
 383
 384 out:
 385         if (primary_if)
 386                 hardif_free_ref(primary_if);
 387         if (router)
 388                 neigh_node_free_ref(router);
 389         if (orig_node)
 390                 orig_node_free_ref(orig_node);
 391         return ret;
 392 }
 393
 394
 395 int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 396 {
 397         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 398         struct icmp_packet_rr *icmp_packet;
 399         struct ethhdr *ethhdr;
 400         struct orig_node *orig_node = NULL;
 401         struct neigh_node *router = NULL;
 402         int hdr_size = sizeof(struct icmp_packet);
 403         int ret = NET_RX_DROP;
 404
 405         /**
 406          * we truncate all incoming icmp packets if they don't match our size
 407          */
 408         if (skb->len >= sizeof(struct icmp_packet_rr))
 409                 hdr_size = sizeof(struct icmp_packet_rr);
 410
 411         /* drop packet if it has not necessary minimum size */
 412         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 413                 goto out;
 414
 415         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 416
 417         /* packet with unicast indication but broadcast recipient */
 418         if (is_broadcast_ether_addr(ethhdr->h_dest))
 419                 goto out;
 420
 421         /* packet with broadcast sender address */
 422         if (is_broadcast_ether_addr(ethhdr->h_source))
 423                 goto out;
 424
 425         /* not for me */
 426         if (!is_my_mac(ethhdr->h_dest))
 427                 goto out;
 428
 429         icmp_packet = (struct icmp_packet_rr *)skb->data;
 430
 431         /* add record route information if not full */
 432         if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
 433             (icmp_packet->rr_cur < BAT_RR_LEN)) {
 434                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
 435                         ethhdr->h_dest, ETH_ALEN);
 436                 icmp_packet->rr_cur++;
 437         }
 438
 439         /* packet for me */
 440         if (is_my_mac(icmp_packet->dst))
 441                 return recv_my_icmp_packet(bat_priv, skb, hdr_size);
 442
 443         /* TTL exceeded */
 444         if (icmp_packet->ttl < 2)
 445                 return recv_icmp_ttl_exceeded(bat_priv, skb);
 446
 447         /* get routing information */
 448         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
 449         if (!orig_node)
 450                 goto out;
 451
 452         router = orig_node_get_router(orig_node);
 453         if (!router)
 454                 goto out;
 455
 456         /* create a copy of the skb, if needed, to modify it. */
 457         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 458                 goto out;
 459
 460         icmp_packet = (struct icmp_packet_rr *)skb->data;
 461
 462         /* decrement ttl */
 463         icmp_packet->ttl--;
 464
 465         /* route it */
 466         send_skb_packet(skb, router->if_incoming, router->addr);
 467         ret = NET_RX_SUCCESS;
 468
 469 out:
 470         if (router)
 471                 neigh_node_free_ref(router);
 472         if (orig_node)
 473                 orig_node_free_ref(orig_node);
 474         return ret;
 475 }
 476
 477 /* In the bonding case, send the packets in a round
 478  * robin fashion over the remaining interfaces.
 479  *
 480  * This method rotates the bonding list and increases the
 481  * returned router's refcount. */
 482 static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
 483                                            const struct hard_iface *recv_if)
 484 {
 485         struct neigh_node *tmp_neigh_node;
 486         struct neigh_node *router = NULL, *first_candidate = NULL;
 487
 488         rcu_read_lock();
 489         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 490                                 bonding_list) {
 491                 if (!first_candidate)
 492                         first_candidate = tmp_neigh_node;
 493
 494                 /* recv_if == NULL on the first node. */
 495                 if (tmp_neigh_node->if_incoming == recv_if)
 496                         continue;
 497
 498                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 499                         continue;
 500
 501                 router = tmp_neigh_node;
 502                 break;
 503         }
 504
 505         /* use the first candidate if nothing was found. */
 506         if (!router && first_candidate &&
 507             atomic_inc_not_zero(&first_candidate->refcount))
 508                 router = first_candidate;
 509
 510         if (!router)
 511                 goto out;
 512
 513         /* selected should point to the next element
 514          * after the current router */
 515         spin_lock_bh(&primary_orig->neigh_list_lock);
 516         /* this is a list_move(), which unfortunately
 517          * does not exist as rcu version */
 518         list_del_rcu(&primary_orig->bond_list);
 519         list_add_rcu(&primary_orig->bond_list,
 520                      &router->bonding_list);
 521         spin_unlock_bh(&primary_orig->neigh_list_lock);
 522
 523 out:
 524         rcu_read_unlock();
 525         return router;
 526 }
 527
 528 /* Interface Alternating: Use the best of the
 529  * remaining candidates which are not using
 530  * this interface.
 531  *
 532  * Increases the returned router's refcount */
 533 static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
 534                                               const struct hard_iface *recv_if)
 535 {
 536         struct neigh_node *tmp_neigh_node;
 537         struct neigh_node *router = NULL, *first_candidate = NULL;
 538
 539         rcu_read_lock();
 540         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 541                                 bonding_list) {
 542                 if (!first_candidate)
 543                         first_candidate = tmp_neigh_node;
 544
 545                 /* recv_if == NULL on the first node. */
 546                 if (tmp_neigh_node->if_incoming == recv_if)
 547                         continue;
 548
 549                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 550                         continue;
 551
 552                 /* if we don't have a router yet
 553                  * or this one is better, choose it. */
 554                 if ((!router) ||
 555                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
 556                         /* decrement refcount of
 557                          * previously selected router */
 558                         if (router)
 559                                 neigh_node_free_ref(router);
 560
 561                         router = tmp_neigh_node;
 562                         atomic_inc_not_zero(&router->refcount);
 563                 }
 564
 565                 neigh_node_free_ref(tmp_neigh_node);
 566         }
 567
 568         /* use the first candidate if nothing was found. */
 569         if (!router && first_candidate &&
 570             atomic_inc_not_zero(&first_candidate->refcount))
 571                 router = first_candidate;
 572
 573         rcu_read_unlock();
 574         return router;
 575 }
 576
 577 int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
 578 {
 579         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 580         struct tt_query_packet *tt_query;
 581         struct ethhdr *ethhdr;
 582
 583         /* drop packet if it has not necessary minimum size */
 584         if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
 585                 goto out;
 586
 587         /* I could need to modify it */
 588         if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
 589                 goto out;
 590
 591         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 592
 593         /* packet with unicast indication but broadcast recipient */
 594         if (is_broadcast_ether_addr(ethhdr->h_dest))
 595                 goto out;
 596
 597         /* packet with broadcast sender address */
 598         if (is_broadcast_ether_addr(ethhdr->h_source))
 599                 goto out;
 600
 601         tt_query = (struct tt_query_packet *)skb->data;
 602
 603         tt_query->tt_data = ntohs(tt_query->tt_data);
 604
 605         switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
 606         case TT_REQUEST:
 607                 /* If we cannot provide an answer the tt_request is
 608                  * forwarded */
 609                 if (!send_tt_response(bat_priv, tt_query)) {
 610                         bat_dbg(DBG_TT, bat_priv,
 611                                 "Routing TT_REQUEST to %pM [%c]\n",
 612                                 tt_query->dst,
 613                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 614                         tt_query->tt_data = htons(tt_query->tt_data);
 615                         return route_unicast_packet(skb, recv_if);
 616                 }
 617                 break;
 618         case TT_RESPONSE:
 619                 /* packet needs to be linearized to access the TT changes */
 620                 if (skb_linearize(skb) < 0)
 621                         goto out;
 622
 623                 if (is_my_mac(tt_query->dst))
 624                         handle_tt_response(bat_priv, tt_query);
 625                 else {
 626                         bat_dbg(DBG_TT, bat_priv,
 627                                 "Routing TT_RESPONSE to %pM [%c]\n",
 628                                 tt_query->dst,
 629                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 630                         tt_query->tt_data = htons(tt_query->tt_data);
 631                         return route_unicast_packet(skb, recv_if);
 632                 }
 633                 break;
 634         }
 635
 636 out:
 637         /* returning NET_RX_DROP will make the caller function kfree the skb */
 638         return NET_RX_DROP;
 639 }
 640
 641 int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
 642 {
 643         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 644         struct roam_adv_packet *roam_adv_packet;
 645         struct orig_node *orig_node;
 646         struct ethhdr *ethhdr;
 647
 648         /* drop packet if it has not necessary minimum size */
 649         if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
 650                 goto out;
 651
 652         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 653
 654         /* packet with unicast indication but broadcast recipient */
 655         if (is_broadcast_ether_addr(ethhdr->h_dest))
 656                 goto out;
 657
 658         /* packet with broadcast sender address */
 659         if (is_broadcast_ether_addr(ethhdr->h_source))
 660                 goto out;
 661
 662         roam_adv_packet = (struct roam_adv_packet *)skb->data;
 663
 664         if (!is_my_mac(roam_adv_packet->dst))
 665                 return route_unicast_packet(skb, recv_if);
 666
 667         orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
 668         if (!orig_node)
 669                 goto out;
 670
 671         bat_dbg(DBG_TT, bat_priv, "Received ROAMING_ADV from %pM "
 672                 "(client %pM)\n", roam_adv_packet->src,
 673                 roam_adv_packet->client);
 674
 675         tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 676                       atomic_read(&orig_node->last_ttvn) + 1, true, false);
 677
 678         /* Roaming phase starts: I have new information but the ttvn has not
 679          * been incremented yet. This flag will make me check all the incoming
 680          * packets for the correct destination. */
 681         bat_priv->tt_poss_change = true;
 682
 683         orig_node_free_ref(orig_node);
 684 out:
 685         /* returning NET_RX_DROP will make the caller function kfree the skb */
 686         return NET_RX_DROP;
 687 }
 688
 689 /* find a suitable router for this originator, and use
 690  * bonding if possible. increases the found neighbors
 691  * refcount.*/
 692 struct neigh_node *find_router(struct bat_priv *bat_priv,
 693                                struct orig_node *orig_node,
 694                                const struct hard_iface *recv_if)
 695 {
 696         struct orig_node *primary_orig_node;
 697         struct orig_node *router_orig;
 698         struct neigh_node *router;
 699         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 700         int bonding_enabled;
 701
 702         if (!orig_node)
 703                 return NULL;
 704
 705         router = orig_node_get_router(orig_node);
 706         if (!router)
 707                 goto err;
 708
 709         /* without bonding, the first node should
 710          * always choose the default router. */
 711         bonding_enabled = atomic_read(&bat_priv->bonding);
 712
 713         rcu_read_lock();
 714         /* select default router to output */
 715         router_orig = router->orig_node;
 716         if (!router_orig)
 717                 goto err_unlock;
 718
 719         if ((!recv_if) && (!bonding_enabled))
 720                 goto return_router;
 721
 722         /* if we have something in the primary_addr, we can search
 723          * for a potential bonding candidate. */
 724         if (compare_eth(router_orig->primary_addr, zero_mac))
 725                 goto return_router;
 726
 727         /* find the orig_node which has the primary interface. might
 728          * even be the same as our router_orig in many cases */
 729
 730         if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
 731                 primary_orig_node = router_orig;
 732         } else {
 733                 primary_orig_node = orig_hash_find(bat_priv,
 734                                                    router_orig->primary_addr);
 735                 if (!primary_orig_node)
 736                         goto return_router;
 737
 738                 orig_node_free_ref(primary_orig_node);
 739         }
 740
 741         /* with less than 2 candidates, we can't do any
 742          * bonding and prefer the original router. */
 743         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 744                 goto return_router;
 745
 746         /* all nodes between should choose a candidate which
 747          * is is not on the interface where the packet came
 748          * in. */
 749
 750         neigh_node_free_ref(router);
 751
 752         if (bonding_enabled)
 753                 router = find_bond_router(primary_orig_node, recv_if);
 754         else
 755                 router = find_ifalter_router(primary_orig_node, recv_if);
 756
 757 return_router:
 758         if (router && router->if_incoming->if_status != IF_ACTIVE)
 759                 goto err_unlock;
 760
 761         rcu_read_unlock();
 762         return router;
 763 err_unlock:
 764         rcu_read_unlock();
 765 err:
 766         if (router)
 767                 neigh_node_free_ref(router);
 768         return NULL;
 769 }
 770
 771 static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
 772 {
 773         struct ethhdr *ethhdr;
 774
 775         /* drop packet if it has not necessary minimum size */
 776         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 777                 return -1;
 778
 779         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 780
 781         /* packet with unicast indication but broadcast recipient */
 782         if (is_broadcast_ether_addr(ethhdr->h_dest))
 783                 return -1;
 784
 785         /* packet with broadcast sender address */
 786         if (is_broadcast_ether_addr(ethhdr->h_source))
 787                 return -1;
 788
 789         /* not for me */
 790         if (!is_my_mac(ethhdr->h_dest))
 791                 return -1;
 792
 793         return 0;
 794 }
 795
 796 int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 797 {
 798         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 799         struct orig_node *orig_node = NULL;
 800         struct neigh_node *neigh_node = NULL;
 801         struct unicast_packet *unicast_packet;
 802         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 803         int ret = NET_RX_DROP;
 804         struct sk_buff *new_skb;
 805
 806         unicast_packet = (struct unicast_packet *)skb->data;
 807
 808         /* TTL exceeded */
 809         if (unicast_packet->ttl < 2) {
 810                 pr_debug("Warning - can't forward unicast packet from %pM to "
 811                          "%pM: ttl exceeded\n", ethhdr->h_source,
 812                          unicast_packet->dest);
 813                 goto out;
 814         }
 815
 816         /* get routing information */
 817         orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 818
 819         if (!orig_node)
 820                 goto out;
 821
 822         /* find_router() increases neigh_nodes refcount if found. */
 823         neigh_node = find_router(bat_priv, orig_node, recv_if);
 824
 825         if (!neigh_node)
 826                 goto out;
 827
 828         /* create a copy of the skb, if needed, to modify it. */
 829         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 830                 goto out;
 831
 832         unicast_packet = (struct unicast_packet *)skb->data;
 833
 834         if (unicast_packet->packet_type == BAT_UNICAST &&
 835             atomic_read(&bat_priv->fragmentation) &&
 836             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 837                 ret = frag_send_skb(skb, bat_priv,
 838                                     neigh_node->if_incoming, neigh_node->addr);
 839                 goto out;
 840         }
 841
 842         if (unicast_packet->packet_type == BAT_UNICAST_FRAG &&
 843             frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
 844
 845                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 846
 847                 if (ret == NET_RX_DROP)
 848                         goto out;
 849
 850                 /* packet was buffered for late merge */
 851                 if (!new_skb) {
 852                         ret = NET_RX_SUCCESS;
 853                         goto out;
 854                 }
 855
 856                 skb = new_skb;
 857                 unicast_packet = (struct unicast_packet *)skb->data;
 858         }
 859
 860         /* decrement ttl */
 861         unicast_packet->ttl--;
 862
 863         /* route it */
 864         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 865         ret = NET_RX_SUCCESS;
 866
 867 out:
 868         if (neigh_node)
 869                 neigh_node_free_ref(neigh_node);
 870         if (orig_node)
 871                 orig_node_free_ref(orig_node);
 872         return ret;
 873 }
 874
 875 static int check_unicast_ttvn(struct bat_priv *bat_priv,
 876                                struct sk_buff *skb) {
 877         uint8_t curr_ttvn;
 878         struct orig_node *orig_node;
 879         struct ethhdr *ethhdr;
 880         struct hard_iface *primary_if;
 881         struct unicast_packet *unicast_packet;
 882         bool tt_poss_change;
 883
 884         /* I could need to modify it */
 885         if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
 886                 return 0;
 887
 888         unicast_packet = (struct unicast_packet *)skb->data;
 889
 890         if (is_my_mac(unicast_packet->dest)) {
 891                 tt_poss_change = bat_priv->tt_poss_change;
 892                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 893         } else {
 894                 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 895
 896                 if (!orig_node)
 897                         return 0;
 898
 899                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 900                 tt_poss_change = orig_node->tt_poss_change;
 901                 orig_node_free_ref(orig_node);
 902         }
 903
 904         /* Check whether I have to reroute the packet */
 905         if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
 906                 /* Linearize the skb before accessing it */
 907                 if (skb_linearize(skb) < 0)
 908                         return 0;
 909
 910                 ethhdr = (struct ethhdr *)(skb->data +
 911                         sizeof(struct unicast_packet));
 912                 orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
 913
 914                 if (!orig_node) {
 915                         if (!is_my_client(bat_priv, ethhdr->h_dest))
 916                                 return 0;
 917                         primary_if = primary_if_get_selected(bat_priv);
 918                         if (!primary_if)
 919                                 return 0;
 920                         memcpy(unicast_packet->dest,
 921                                primary_if->net_dev->dev_addr, ETH_ALEN);
 922                         hardif_free_ref(primary_if);
 923                 } else {
 924                         memcpy(unicast_packet->dest, orig_node->orig,
 925                                ETH_ALEN);
 926                         curr_ttvn = (uint8_t)
 927                                 atomic_read(&orig_node->last_ttvn);
 928                         orig_node_free_ref(orig_node);
 929                 }
 930
 931                 bat_dbg(DBG_ROUTES, bat_priv, "TTVN mismatch (old_ttvn %u "
 932                         "new_ttvn %u)! Rerouting unicast packet (for %pM) to "
 933                         "%pM\n", unicast_packet->ttvn, curr_ttvn,
 934                         ethhdr->h_dest, unicast_packet->dest);
 935
 936                 unicast_packet->ttvn = curr_ttvn;
 937         }
 938         return 1;
 939 }
 940
 941 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 942 {
 943         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 944         struct unicast_packet *unicast_packet;
 945         int hdr_size = sizeof(*unicast_packet);
 946
 947         if (check_unicast_packet(skb, hdr_size) < 0)
 948                 return NET_RX_DROP;
 949
 950         if (!check_unicast_ttvn(bat_priv, skb))
 951                 return NET_RX_DROP;
 952
 953         unicast_packet = (struct unicast_packet *)skb->data;
 954
 955         /* packet for me */
 956         if (is_my_mac(unicast_packet->dest)) {
 957                 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
 958                 return NET_RX_SUCCESS;
 959         }
 960
 961         return route_unicast_packet(skb, recv_if);
 962 }
 963
 964 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 965 {
 966         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 967         struct unicast_frag_packet *unicast_packet;
 968         int hdr_size = sizeof(*unicast_packet);
 969         struct sk_buff *new_skb = NULL;
 970         int ret;
 971
 972         if (check_unicast_packet(skb, hdr_size) < 0)
 973                 return NET_RX_DROP;
 974
 975         if (!check_unicast_ttvn(bat_priv, skb))
 976                 return NET_RX_DROP;
 977
 978         unicast_packet = (struct unicast_frag_packet *)skb->data;
 979
 980         /* packet for me */
 981         if (is_my_mac(unicast_packet->dest)) {
 982
 983                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 984
 985                 if (ret == NET_RX_DROP)
 986                         return NET_RX_DROP;
 987
 988                 /* packet was buffered for late merge */
 989                 if (!new_skb)
 990                         return NET_RX_SUCCESS;
 991
 992                 interface_rx(recv_if->soft_iface, new_skb, recv_if,
 993                              sizeof(struct unicast_packet));
 994                 return NET_RX_SUCCESS;
 995         }
 996
 997         return route_unicast_packet(skb, recv_if);
 998 }
 999
1000
1001 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1002 {
1003         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1004         struct orig_node *orig_node = NULL;
1005         struct bcast_packet *bcast_packet;
1006         struct ethhdr *ethhdr;
1007         int hdr_size = sizeof(*bcast_packet);
1008         int ret = NET_RX_DROP;
1009         int32_t seq_diff;
1010
1011         /* drop packet if it has not necessary minimum size */
1012         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1013                 goto out;
1014
1015         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1016
1017         /* packet with broadcast indication but unicast recipient */
1018         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1019                 goto out;
1020
1021         /* packet with broadcast sender address */
1022         if (is_broadcast_ether_addr(ethhdr->h_source))
1023                 goto out;
1024
1025         /* ignore broadcasts sent by myself */
1026         if (is_my_mac(ethhdr->h_source))
1027                 goto out;
1028
1029         bcast_packet = (struct bcast_packet *)skb->data;
1030
1031         /* ignore broadcasts originated by myself */
1032         if (is_my_mac(bcast_packet->orig))
1033                 goto out;
1034
1035         if (bcast_packet->ttl < 2)
1036                 goto out;
1037
1038         orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1039
1040         if (!orig_node)
1041                 goto out;
1042
1043         spin_lock_bh(&orig_node->bcast_seqno_lock);
1044
1045         /* check whether the packet is a duplicate */
1046         if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1047                            ntohl(bcast_packet->seqno)))
1048                 goto spin_unlock;
1049
1050         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1051
1052         /* check whether the packet is old and the host just restarted. */
1053         if (window_protected(bat_priv, seq_diff,
1054                              &orig_node->bcast_seqno_reset))
1055                 goto spin_unlock;
1056
1057         /* mark broadcast in flood history, update window position
1058          * if required. */
1059         if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1060                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1061
1062         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1063
1064         /* rebroadcast packet */
1065         add_bcast_packet_to_list(bat_priv, skb, 1);
1066
1067         /* broadcast for me */
1068         interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1069         ret = NET_RX_SUCCESS;
1070         goto out;
1071
1072 spin_unlock:
1073         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1074 out:
1075         if (orig_node)
1076                 orig_node_free_ref(orig_node);
1077         return ret;
1078 }
1079
1080 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1081 {
1082         struct vis_packet *vis_packet;
1083         struct ethhdr *ethhdr;
1084         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1085         int hdr_size = sizeof(*vis_packet);
1086
1087         /* keep skb linear */
1088         if (skb_linearize(skb) < 0)
1089                 return NET_RX_DROP;
1090
1091         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1092                 return NET_RX_DROP;
1093
1094         vis_packet = (struct vis_packet *)skb->data;
1095         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1096
1097         /* not for me */
1098         if (!is_my_mac(ethhdr->h_dest))
1099                 return NET_RX_DROP;
1100
1101         /* ignore own packets */
1102         if (is_my_mac(vis_packet->vis_orig))
1103                 return NET_RX_DROP;
1104
1105         if (is_my_mac(vis_packet->sender_orig))
1106                 return NET_RX_DROP;
1107
1108         switch (vis_packet->vis_type) {
1109         case VIS_TYPE_SERVER_SYNC:
1110                 receive_server_sync_packet(bat_priv, vis_packet,
1111                                            skb_headlen(skb));
1112                 break;
1113
1114         case VIS_TYPE_CLIENT_UPDATE:
1115                 receive_client_update_packet(bat_priv, vis_packet,
1116                                              skb_headlen(skb));
1117                 break;
1118
1119         default:        /* ignore unknown packet */
1120                 break;
1121         }
1122
1123         /* We take a copy of the data in the packet, so we should
1124            always free the skbuf. */
1125         return NET_RX_DROP;
1126 }