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 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                         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 = 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                 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                 neigh_node_free_ref(curr_router);
 109 }
 110
 111 void 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 = 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                 neigh_node_free_ref(router);
 127 }
 128
 129 /* caller must hold the neigh_list_lock */
 130 void 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         neigh_node_free_ref(neigh_node);
 140         atomic_dec(&orig_node->bond_candidates);
 141
 142 out:
 143         return;
 144 }
 145
 146 void 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 = 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         bonding_candidate_del(orig_node, neigh_node);
 208
 209 out:
 210         spin_unlock_bh(&orig_node->neigh_list_lock);
 211
 212         if (router)
 213                 neigh_node_free_ref(router);
 214 }
 215
 216 /* copy primary address for bonding */
 217 void bonding_save_primary(const struct orig_node *orig_node,
 218                           struct orig_node *orig_neigh_node,
 219                           const struct batman_ogm_packet *batman_ogm_packet)
 220 {
 221         if (!(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
 222                 return;
 223
 224         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 225 }
 226
 227 /* checks whether the host restarted and is in the protection time.
 228  * returns:
 229  *  0 if the packet is to be accepted
 230  *  1 if the packet is to be ignored.
 231  */
 232 int window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
 233                      unsigned long *last_reset)
 234 {
 235         if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) ||
 236             (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
 237                 if (has_timed_out(*last_reset, RESET_PROTECTION_MS)) {
 238
 239                         *last_reset = jiffies;
 240                         bat_dbg(DBG_BATMAN, bat_priv,
 241                                 "old packet received, start protection\n");
 242
 243                         return 0;
 244                 } else {
 245                         return 1;
 246                 }
 247         }
 248         return 0;
 249 }
 250
 251 int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
 252 {
 253         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 254         struct ethhdr *ethhdr;
 255
 256         /* drop packet if it has not necessary minimum size */
 257         if (unlikely(!pskb_may_pull(skb, BATMAN_OGM_LEN)))
 258                 return NET_RX_DROP;
 259
 260         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 261
 262         /* packet with broadcast indication but unicast recipient */
 263         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 264                 return NET_RX_DROP;
 265
 266         /* packet with broadcast sender address */
 267         if (is_broadcast_ether_addr(ethhdr->h_source))
 268                 return NET_RX_DROP;
 269
 270         /* create a copy of the skb, if needed, to modify it. */
 271         if (skb_cow(skb, 0) < 0)
 272                 return NET_RX_DROP;
 273
 274         /* keep skb linear */
 275         if (skb_linearize(skb) < 0)
 276                 return NET_RX_DROP;
 277
 278         bat_priv->bat_algo_ops->bat_ogm_receive(hard_iface, skb);
 279
 280         kfree_skb(skb);
 281         return NET_RX_SUCCESS;
 282 }
 283
 284 static int recv_my_icmp_packet(struct bat_priv *bat_priv,
 285                                struct sk_buff *skb, size_t icmp_len)
 286 {
 287         struct hard_iface *primary_if = NULL;
 288         struct orig_node *orig_node = NULL;
 289         struct neigh_node *router = NULL;
 290         struct icmp_packet_rr *icmp_packet;
 291         int ret = NET_RX_DROP;
 292
 293         icmp_packet = (struct icmp_packet_rr *)skb->data;
 294
 295         /* add data to device queue */
 296         if (icmp_packet->msg_type != ECHO_REQUEST) {
 297                 bat_socket_receive_packet(icmp_packet, icmp_len);
 298                 goto out;
 299         }
 300
 301         primary_if = primary_if_get_selected(bat_priv);
 302         if (!primary_if)
 303                 goto out;
 304
 305         /* answer echo request (ping) */
 306         /* get routing information */
 307         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 308         if (!orig_node)
 309                 goto out;
 310
 311         router = orig_node_get_router(orig_node);
 312         if (!router)
 313                 goto out;
 314
 315         /* create a copy of the skb, if needed, to modify it. */
 316         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 317                 goto out;
 318
 319         icmp_packet = (struct icmp_packet_rr *)skb->data;
 320
 321         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 322         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 323         icmp_packet->msg_type = ECHO_REPLY;
 324         icmp_packet->header.ttl = TTL;
 325
 326         send_skb_packet(skb, router->if_incoming, router->addr);
 327         ret = NET_RX_SUCCESS;
 328
 329 out:
 330         if (primary_if)
 331                 hardif_free_ref(primary_if);
 332         if (router)
 333                 neigh_node_free_ref(router);
 334         if (orig_node)
 335                 orig_node_free_ref(orig_node);
 336         return ret;
 337 }
 338
 339 static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
 340                                   struct sk_buff *skb)
 341 {
 342         struct hard_iface *primary_if = NULL;
 343         struct orig_node *orig_node = NULL;
 344         struct neigh_node *router = NULL;
 345         struct icmp_packet *icmp_packet;
 346         int ret = NET_RX_DROP;
 347
 348         icmp_packet = (struct icmp_packet *)skb->data;
 349
 350         /* send TTL exceeded if packet is an echo request (traceroute) */
 351         if (icmp_packet->msg_type != ECHO_REQUEST) {
 352                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 353                          icmp_packet->orig, 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->header.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->header.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->header.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         uint16_t tt_len;
 582         struct ethhdr *ethhdr;
 583
 584         /* drop packet if it has not necessary minimum size */
 585         if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
 586                 goto out;
 587
 588         /* I could need to modify it */
 589         if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
 590                 goto out;
 591
 592         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 593
 594         /* packet with unicast indication but broadcast recipient */
 595         if (is_broadcast_ether_addr(ethhdr->h_dest))
 596                 goto out;
 597
 598         /* packet with broadcast sender address */
 599         if (is_broadcast_ether_addr(ethhdr->h_source))
 600                 goto out;
 601
 602         tt_query = (struct tt_query_packet *)skb->data;
 603
 604         tt_query->tt_data = ntohs(tt_query->tt_data);
 605
 606         switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
 607         case TT_REQUEST:
 608                 /* If we cannot provide an answer the tt_request is
 609                  * forwarded */
 610                 if (!send_tt_response(bat_priv, tt_query)) {
 611                         bat_dbg(DBG_TT, bat_priv,
 612                                 "Routing TT_REQUEST to %pM [%c]\n",
 613                                 tt_query->dst,
 614                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 615                         tt_query->tt_data = htons(tt_query->tt_data);
 616                         return route_unicast_packet(skb, recv_if);
 617                 }
 618                 break;
 619         case TT_RESPONSE:
 620                 if (is_my_mac(tt_query->dst)) {
 621                         /* packet needs to be linearized to access the TT
 622                          * changes */
 623                         if (skb_linearize(skb) < 0)
 624                                 goto out;
 625
 626                         tt_len = tt_query->tt_data * sizeof(struct tt_change);
 627
 628                         /* Ensure we have all the claimed data */
 629                         if (unlikely(skb_headlen(skb) <
 630                                      sizeof(struct tt_query_packet) + tt_len))
 631                                 goto out;
 632
 633                         handle_tt_response(bat_priv, tt_query);
 634                 } else {
 635                         bat_dbg(DBG_TT, bat_priv,
 636                                 "Routing TT_RESPONSE to %pM [%c]\n",
 637                                 tt_query->dst,
 638                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 639                         tt_query->tt_data = htons(tt_query->tt_data);
 640                         return route_unicast_packet(skb, recv_if);
 641                 }
 642                 break;
 643         }
 644
 645 out:
 646         /* returning NET_RX_DROP will make the caller function kfree the skb */
 647         return NET_RX_DROP;
 648 }
 649
 650 int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
 651 {
 652         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 653         struct roam_adv_packet *roam_adv_packet;
 654         struct orig_node *orig_node;
 655         struct ethhdr *ethhdr;
 656
 657         /* drop packet if it has not necessary minimum size */
 658         if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
 659                 goto out;
 660
 661         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 662
 663         /* packet with unicast indication but broadcast recipient */
 664         if (is_broadcast_ether_addr(ethhdr->h_dest))
 665                 goto out;
 666
 667         /* packet with broadcast sender address */
 668         if (is_broadcast_ether_addr(ethhdr->h_source))
 669                 goto out;
 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 (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         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 *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 = 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                 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         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                 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 = 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, sizeof(struct ethhdr)) < 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         /* route it */
 879         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 880         ret = NET_RX_SUCCESS;
 881
 882 out:
 883         if (neigh_node)
 884                 neigh_node_free_ref(neigh_node);
 885         if (orig_node)
 886                 orig_node_free_ref(orig_node);
 887         return ret;
 888 }
 889
 890 static int check_unicast_ttvn(struct bat_priv *bat_priv,
 891                                struct sk_buff *skb) {
 892         uint8_t curr_ttvn;
 893         struct orig_node *orig_node;
 894         struct ethhdr *ethhdr;
 895         struct hard_iface *primary_if;
 896         struct unicast_packet *unicast_packet;
 897         bool tt_poss_change;
 898
 899         /* I could need to modify it */
 900         if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
 901                 return 0;
 902
 903         unicast_packet = (struct unicast_packet *)skb->data;
 904
 905         if (is_my_mac(unicast_packet->dest)) {
 906                 tt_poss_change = bat_priv->tt_poss_change;
 907                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 908         } else {
 909                 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 910
 911                 if (!orig_node)
 912                         return 0;
 913
 914                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 915                 tt_poss_change = orig_node->tt_poss_change;
 916                 orig_node_free_ref(orig_node);
 917         }
 918
 919         /* Check whether I have to reroute the packet */
 920         if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
 921                 /* Linearize the skb before accessing it */
 922                 if (skb_linearize(skb) < 0)
 923                         return 0;
 924
 925                 ethhdr = (struct ethhdr *)(skb->data +
 926                         sizeof(struct unicast_packet));
 927                 orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
 928
 929                 if (!orig_node) {
 930                         if (!is_my_client(bat_priv, ethhdr->h_dest))
 931                                 return 0;
 932                         primary_if = primary_if_get_selected(bat_priv);
 933                         if (!primary_if)
 934                                 return 0;
 935                         memcpy(unicast_packet->dest,
 936                                primary_if->net_dev->dev_addr, ETH_ALEN);
 937                         hardif_free_ref(primary_if);
 938                 } else {
 939                         memcpy(unicast_packet->dest, orig_node->orig,
 940                                ETH_ALEN);
 941                         curr_ttvn = (uint8_t)
 942                                 atomic_read(&orig_node->last_ttvn);
 943                         orig_node_free_ref(orig_node);
 944                 }
 945
 946                 bat_dbg(DBG_ROUTES, bat_priv,
 947                         "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
 948                         unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
 949                         unicast_packet->dest);
 950
 951                 unicast_packet->ttvn = curr_ttvn;
 952         }
 953         return 1;
 954 }
 955
 956 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 957 {
 958         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 959         struct unicast_packet *unicast_packet;
 960         int hdr_size = sizeof(*unicast_packet);
 961
 962         if (check_unicast_packet(skb, hdr_size) < 0)
 963                 return NET_RX_DROP;
 964
 965         if (!check_unicast_ttvn(bat_priv, skb))
 966                 return NET_RX_DROP;
 967
 968         unicast_packet = (struct unicast_packet *)skb->data;
 969
 970         /* packet for me */
 971         if (is_my_mac(unicast_packet->dest)) {
 972                 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
 973                 return NET_RX_SUCCESS;
 974         }
 975
 976         return route_unicast_packet(skb, recv_if);
 977 }
 978
 979 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 980 {
 981         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 982         struct unicast_frag_packet *unicast_packet;
 983         int hdr_size = sizeof(*unicast_packet);
 984         struct sk_buff *new_skb = NULL;
 985         int ret;
 986
 987         if (check_unicast_packet(skb, hdr_size) < 0)
 988                 return NET_RX_DROP;
 989
 990         if (!check_unicast_ttvn(bat_priv, skb))
 991                 return NET_RX_DROP;
 992
 993         unicast_packet = (struct unicast_frag_packet *)skb->data;
 994
 995         /* packet for me */
 996         if (is_my_mac(unicast_packet->dest)) {
 997
 998                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 999
1000                 if (ret == NET_RX_DROP)
1001                         return NET_RX_DROP;
1002
1003                 /* packet was buffered for late merge */
1004                 if (!new_skb)
1005                         return NET_RX_SUCCESS;
1006
1007                 interface_rx(recv_if->soft_iface, new_skb, recv_if,
1008                              sizeof(struct unicast_packet));
1009                 return NET_RX_SUCCESS;
1010         }
1011
1012         return route_unicast_packet(skb, recv_if);
1013 }
1014
1015
1016 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1017 {
1018         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1019         struct orig_node *orig_node = NULL;
1020         struct bcast_packet *bcast_packet;
1021         struct ethhdr *ethhdr;
1022         int hdr_size = sizeof(*bcast_packet);
1023         int ret = NET_RX_DROP;
1024         int32_t seq_diff;
1025
1026         /* drop packet if it has not necessary minimum size */
1027         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1028                 goto out;
1029
1030         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1031
1032         /* packet with broadcast indication but unicast recipient */
1033         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1034                 goto out;
1035
1036         /* packet with broadcast sender address */
1037         if (is_broadcast_ether_addr(ethhdr->h_source))
1038                 goto out;
1039
1040         /* ignore broadcasts sent by myself */
1041         if (is_my_mac(ethhdr->h_source))
1042                 goto out;
1043
1044         bcast_packet = (struct bcast_packet *)skb->data;
1045
1046         /* ignore broadcasts originated by myself */
1047         if (is_my_mac(bcast_packet->orig))
1048                 goto out;
1049
1050         if (bcast_packet->header.ttl < 2)
1051                 goto out;
1052
1053         orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1054
1055         if (!orig_node)
1056                 goto out;
1057
1058         spin_lock_bh(&orig_node->bcast_seqno_lock);
1059
1060         /* check whether the packet is a duplicate */
1061         if (bat_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1062                          ntohl(bcast_packet->seqno)))
1063                 goto spin_unlock;
1064
1065         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1066
1067         /* check whether the packet is old and the host just restarted. */
1068         if (window_protected(bat_priv, seq_diff,
1069                              &orig_node->bcast_seqno_reset))
1070                 goto spin_unlock;
1071
1072         /* mark broadcast in flood history, update window position
1073          * if required. */
1074         if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1075                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1076
1077         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1078
1079         /* check whether this has been sent by another originator before */
1080         if (bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
1081                 goto out;
1082
1083         /* rebroadcast packet */
1084         add_bcast_packet_to_list(bat_priv, skb, 1);
1085
1086         /* don't hand the broadcast up if it is from an originator
1087          * from the same backbone.
1088          */
1089         if (bla_is_backbone_gw(skb, orig_node, hdr_size))
1090                 goto out;
1091
1092         /* broadcast for me */
1093         interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1094         ret = NET_RX_SUCCESS;
1095         goto out;
1096
1097 spin_unlock:
1098         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1099 out:
1100         if (orig_node)
1101                 orig_node_free_ref(orig_node);
1102         return ret;
1103 }
1104
1105 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1106 {
1107         struct vis_packet *vis_packet;
1108         struct ethhdr *ethhdr;
1109         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1110         int hdr_size = sizeof(*vis_packet);
1111
1112         /* keep skb linear */
1113         if (skb_linearize(skb) < 0)
1114                 return NET_RX_DROP;
1115
1116         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1117                 return NET_RX_DROP;
1118
1119         vis_packet = (struct vis_packet *)skb->data;
1120         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1121
1122         /* not for me */
1123         if (!is_my_mac(ethhdr->h_dest))
1124                 return NET_RX_DROP;
1125
1126         /* ignore own packets */
1127         if (is_my_mac(vis_packet->vis_orig))
1128                 return NET_RX_DROP;
1129
1130         if (is_my_mac(vis_packet->sender_orig))
1131                 return NET_RX_DROP;
1132
1133         switch (vis_packet->vis_type) {
1134         case VIS_TYPE_SERVER_SYNC:
1135                 receive_server_sync_packet(bat_priv, vis_packet,
1136                                            skb_headlen(skb));
1137                 break;
1138
1139         case VIS_TYPE_CLIENT_UPDATE:
1140                 receive_client_update_packet(bat_priv, vis_packet,
1141                                              skb_headlen(skb));
1142                 break;
1143
1144         default:        /* ignore unknown packet */
1145                 break;
1146         }
1147
1148         /* We take a copy of the data in the packet, so we should
1149            always free the skbuf. */
1150         return NET_RX_DROP;
1151 }