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 (now via %pM - was via %pM)\n",
  87                         orig_node->orig, neigh_node->addr,
  88                         curr_router->addr);
  89         }
  90
  91         if (curr_router)
  92                 neigh_node_free_ref(curr_router);
  93
  94         /* increase refcount of new best neighbor */
  95         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
  96                 neigh_node = NULL;
  97
  98         spin_lock_bh(&orig_node->neigh_list_lock);
  99         rcu_assign_pointer(orig_node->router, neigh_node);
 100         spin_unlock_bh(&orig_node->neigh_list_lock);
 101
 102         /* decrease refcount of previous best neighbor */
 103         if (curr_router)
 104                 neigh_node_free_ref(curr_router);
 105 }
 106
 107 void update_route(struct bat_priv *bat_priv, struct orig_node *orig_node,
 108                   struct neigh_node *neigh_node)
 109 {
 110         struct neigh_node *router = NULL;
 111
 112         if (!orig_node)
 113                 goto out;
 114
 115         router = orig_node_get_router(orig_node);
 116
 117         if (router != neigh_node)
 118                 _update_route(bat_priv, orig_node, neigh_node);
 119
 120 out:
 121         if (router)
 122                 neigh_node_free_ref(router);
 123 }
 124
 125 /* caller must hold the neigh_list_lock */
 126 void bonding_candidate_del(struct orig_node *orig_node,
 127                            struct neigh_node *neigh_node)
 128 {
 129         /* this neighbor is not part of our candidate list */
 130         if (list_empty(&neigh_node->bonding_list))
 131                 goto out;
 132
 133         list_del_rcu(&neigh_node->bonding_list);
 134         INIT_LIST_HEAD(&neigh_node->bonding_list);
 135         neigh_node_free_ref(neigh_node);
 136         atomic_dec(&orig_node->bond_candidates);
 137
 138 out:
 139         return;
 140 }
 141
 142 void bonding_candidate_add(struct orig_node *orig_node,
 143                            struct neigh_node *neigh_node)
 144 {
 145         struct hlist_node *node;
 146         struct neigh_node *tmp_neigh_node, *router = NULL;
 147         uint8_t interference_candidate = 0;
 148
 149         spin_lock_bh(&orig_node->neigh_list_lock);
 150
 151         /* only consider if it has the same primary address ...  */
 152         if (!compare_eth(orig_node->orig,
 153                          neigh_node->orig_node->primary_addr))
 154                 goto candidate_del;
 155
 156         router = orig_node_get_router(orig_node);
 157         if (!router)
 158                 goto candidate_del;
 159
 160         /* ... and is good enough to be considered */
 161         if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
 162                 goto candidate_del;
 163
 164         /**
 165          * check if we have another candidate with the same mac address or
 166          * interface. If we do, we won't select this candidate because of
 167          * possible interference.
 168          */
 169         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 170                                  &orig_node->neigh_list, list) {
 171
 172                 if (tmp_neigh_node == neigh_node)
 173                         continue;
 174
 175                 /* we only care if the other candidate is even
 176                 * considered as candidate. */
 177                 if (list_empty(&tmp_neigh_node->bonding_list))
 178                         continue;
 179
 180                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 181                     (compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
 182                         interference_candidate = 1;
 183                         break;
 184                 }
 185         }
 186
 187         /* don't care further if it is an interference candidate */
 188         if (interference_candidate)
 189                 goto candidate_del;
 190
 191         /* this neighbor already is part of our candidate list */
 192         if (!list_empty(&neigh_node->bonding_list))
 193                 goto out;
 194
 195         if (!atomic_inc_not_zero(&neigh_node->refcount))
 196                 goto out;
 197
 198         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 199         atomic_inc(&orig_node->bond_candidates);
 200         goto out;
 201
 202 candidate_del:
 203         bonding_candidate_del(orig_node, neigh_node);
 204
 205 out:
 206         spin_unlock_bh(&orig_node->neigh_list_lock);
 207
 208         if (router)
 209                 neigh_node_free_ref(router);
 210 }
 211
 212 /* copy primary address for bonding */
 213 void bonding_save_primary(const struct orig_node *orig_node,
 214                           struct orig_node *orig_neigh_node,
 215                           const struct batman_ogm_packet *batman_ogm_packet)
 216 {
 217         if (!(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
 218                 return;
 219
 220         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 221 }
 222
 223 /* checks whether the host restarted and is in the protection time.
 224  * returns:
 225  *  0 if the packet is to be accepted
 226  *  1 if the packet is to be ignored.
 227  */
 228 int window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
 229                      unsigned long *last_reset)
 230 {
 231         if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) ||
 232             (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
 233                 if (has_timed_out(*last_reset, RESET_PROTECTION_MS)) {
 234
 235                         *last_reset = jiffies;
 236                         bat_dbg(DBG_BATMAN, bat_priv,
 237                                 "old packet received, start protection\n");
 238
 239                         return 0;
 240                 } else {
 241                         return 1;
 242                 }
 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 %pM: ttl exceeded\n",
 349                          icmp_packet->orig, icmp_packet->dst);
 350                 goto out;
 351         }
 352
 353         primary_if = primary_if_get_selected(bat_priv);
 354         if (!primary_if)
 355                 goto out;
 356
 357         /* get routing information */
 358         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 359         if (!orig_node)
 360                 goto out;
 361
 362         router = orig_node_get_router(orig_node);
 363         if (!router)
 364                 goto out;
 365
 366         /* create a copy of the skb, if needed, to modify it. */
 367         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 368                 goto out;
 369
 370         icmp_packet = (struct icmp_packet *)skb->data;
 371
 372         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 373         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 374         icmp_packet->msg_type = TTL_EXCEEDED;
 375         icmp_packet->header.ttl = TTL;
 376
 377         send_skb_packet(skb, router->if_incoming, router->addr);
 378         ret = NET_RX_SUCCESS;
 379
 380 out:
 381         if (primary_if)
 382                 hardif_free_ref(primary_if);
 383         if (router)
 384                 neigh_node_free_ref(router);
 385         if (orig_node)
 386                 orig_node_free_ref(orig_node);
 387         return ret;
 388 }
 389
 390
 391 int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 392 {
 393         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 394         struct icmp_packet_rr *icmp_packet;
 395         struct ethhdr *ethhdr;
 396         struct orig_node *orig_node = NULL;
 397         struct neigh_node *router = NULL;
 398         int hdr_size = sizeof(struct icmp_packet);
 399         int ret = NET_RX_DROP;
 400
 401         /**
 402          * we truncate all incoming icmp packets if they don't match our size
 403          */
 404         if (skb->len >= sizeof(struct icmp_packet_rr))
 405                 hdr_size = sizeof(struct icmp_packet_rr);
 406
 407         /* drop packet if it has not necessary minimum size */
 408         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 409                 goto out;
 410
 411         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 412
 413         /* packet with unicast indication but broadcast recipient */
 414         if (is_broadcast_ether_addr(ethhdr->h_dest))
 415                 goto out;
 416
 417         /* packet with broadcast sender address */
 418         if (is_broadcast_ether_addr(ethhdr->h_source))
 419                 goto out;
 420
 421         /* not for me */
 422         if (!is_my_mac(ethhdr->h_dest))
 423                 goto out;
 424
 425         icmp_packet = (struct icmp_packet_rr *)skb->data;
 426
 427         /* add record route information if not full */
 428         if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
 429             (icmp_packet->rr_cur < BAT_RR_LEN)) {
 430                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
 431                        ethhdr->h_dest, ETH_ALEN);
 432                 icmp_packet->rr_cur++;
 433         }
 434
 435         /* packet for me */
 436         if (is_my_mac(icmp_packet->dst))
 437                 return recv_my_icmp_packet(bat_priv, skb, hdr_size);
 438
 439         /* TTL exceeded */
 440         if (icmp_packet->header.ttl < 2)
 441                 return recv_icmp_ttl_exceeded(bat_priv, skb);
 442
 443         /* get routing information */
 444         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
 445         if (!orig_node)
 446                 goto out;
 447
 448         router = orig_node_get_router(orig_node);
 449         if (!router)
 450                 goto out;
 451
 452         /* create a copy of the skb, if needed, to modify it. */
 453         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 454                 goto out;
 455
 456         icmp_packet = (struct icmp_packet_rr *)skb->data;
 457
 458         /* decrement ttl */
 459         icmp_packet->header.ttl--;
 460
 461         /* route it */
 462         send_skb_packet(skb, router->if_incoming, router->addr);
 463         ret = NET_RX_SUCCESS;
 464
 465 out:
 466         if (router)
 467                 neigh_node_free_ref(router);
 468         if (orig_node)
 469                 orig_node_free_ref(orig_node);
 470         return ret;
 471 }
 472
 473 /* In the bonding case, send the packets in a round
 474  * robin fashion over the remaining interfaces.
 475  *
 476  * This method rotates the bonding list and increases the
 477  * returned router's refcount. */
 478 static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
 479                                            const struct hard_iface *recv_if)
 480 {
 481         struct neigh_node *tmp_neigh_node;
 482         struct neigh_node *router = NULL, *first_candidate = NULL;
 483
 484         rcu_read_lock();
 485         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 486                                 bonding_list) {
 487                 if (!first_candidate)
 488                         first_candidate = tmp_neigh_node;
 489
 490                 /* recv_if == NULL on the first node. */
 491                 if (tmp_neigh_node->if_incoming == recv_if)
 492                         continue;
 493
 494                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 495                         continue;
 496
 497                 router = tmp_neigh_node;
 498                 break;
 499         }
 500
 501         /* use the first candidate if nothing was found. */
 502         if (!router && first_candidate &&
 503             atomic_inc_not_zero(&first_candidate->refcount))
 504                 router = first_candidate;
 505
 506         if (!router)
 507                 goto out;
 508
 509         /* selected should point to the next element
 510          * after the current router */
 511         spin_lock_bh(&primary_orig->neigh_list_lock);
 512         /* this is a list_move(), which unfortunately
 513          * does not exist as rcu version */
 514         list_del_rcu(&primary_orig->bond_list);
 515         list_add_rcu(&primary_orig->bond_list,
 516                      &router->bonding_list);
 517         spin_unlock_bh(&primary_orig->neigh_list_lock);
 518
 519 out:
 520         rcu_read_unlock();
 521         return router;
 522 }
 523
 524 /* Interface Alternating: Use the best of the
 525  * remaining candidates which are not using
 526  * this interface.
 527  *
 528  * Increases the returned router's refcount */
 529 static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
 530                                               const struct hard_iface *recv_if)
 531 {
 532         struct neigh_node *tmp_neigh_node;
 533         struct neigh_node *router = NULL, *first_candidate = NULL;
 534
 535         rcu_read_lock();
 536         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
 537                                 bonding_list) {
 538                 if (!first_candidate)
 539                         first_candidate = tmp_neigh_node;
 540
 541                 /* recv_if == NULL on the first node. */
 542                 if (tmp_neigh_node->if_incoming == recv_if)
 543                         continue;
 544
 545                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 546                         continue;
 547
 548                 /* if we don't have a router yet
 549                  * or this one is better, choose it. */
 550                 if ((!router) ||
 551                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
 552                         /* decrement refcount of
 553                          * previously selected router */
 554                         if (router)
 555                                 neigh_node_free_ref(router);
 556
 557                         router = tmp_neigh_node;
 558                         atomic_inc_not_zero(&router->refcount);
 559                 }
 560
 561                 neigh_node_free_ref(tmp_neigh_node);
 562         }
 563
 564         /* use the first candidate if nothing was found. */
 565         if (!router && first_candidate &&
 566             atomic_inc_not_zero(&first_candidate->refcount))
 567                 router = first_candidate;
 568
 569         rcu_read_unlock();
 570         return router;
 571 }
 572
 573 int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
 574 {
 575         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 576         struct tt_query_packet *tt_query;
 577         uint16_t tt_len;
 578         struct ethhdr *ethhdr;
 579
 580         /* drop packet if it has not necessary minimum size */
 581         if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
 582                 goto out;
 583
 584         /* I could need to modify it */
 585         if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
 586                 goto out;
 587
 588         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 589
 590         /* packet with unicast indication but broadcast recipient */
 591         if (is_broadcast_ether_addr(ethhdr->h_dest))
 592                 goto out;
 593
 594         /* packet with broadcast sender address */
 595         if (is_broadcast_ether_addr(ethhdr->h_source))
 596                 goto out;
 597
 598         tt_query = (struct tt_query_packet *)skb->data;
 599
 600         tt_query->tt_data = ntohs(tt_query->tt_data);
 601
 602         switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
 603         case TT_REQUEST:
 604                 /* If we cannot provide an answer the tt_request is
 605                  * forwarded */
 606                 if (!send_tt_response(bat_priv, tt_query)) {
 607                         bat_dbg(DBG_TT, bat_priv,
 608                                 "Routing TT_REQUEST to %pM [%c]\n",
 609                                 tt_query->dst,
 610                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 611                         tt_query->tt_data = htons(tt_query->tt_data);
 612                         return route_unicast_packet(skb, recv_if);
 613                 }
 614                 break;
 615         case TT_RESPONSE:
 616                 if (is_my_mac(tt_query->dst)) {
 617                         /* packet needs to be linearized to access the TT
 618                          * changes */
 619                         if (skb_linearize(skb) < 0)
 620                                 goto out;
 621
 622                         tt_len = tt_query->tt_data * sizeof(struct tt_change);
 623
 624                         /* Ensure we have all the claimed data */
 625                         if (unlikely(skb_headlen(skb) <
 626                                      sizeof(struct tt_query_packet) + tt_len))
 627                                 goto out;
 628
 629                         handle_tt_response(bat_priv, tt_query);
 630                 } else {
 631                         bat_dbg(DBG_TT, bat_priv,
 632                                 "Routing TT_RESPONSE to %pM [%c]\n",
 633                                 tt_query->dst,
 634                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
 635                         tt_query->tt_data = htons(tt_query->tt_data);
 636                         return route_unicast_packet(skb, recv_if);
 637                 }
 638                 break;
 639         }
 640
 641 out:
 642         /* returning NET_RX_DROP will make the caller function kfree the skb */
 643         return NET_RX_DROP;
 644 }
 645
 646 int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
 647 {
 648         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 649         struct roam_adv_packet *roam_adv_packet;
 650         struct orig_node *orig_node;
 651         struct ethhdr *ethhdr;
 652
 653         /* drop packet if it has not necessary minimum size */
 654         if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
 655                 goto out;
 656
 657         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 658
 659         /* packet with unicast indication but broadcast recipient */
 660         if (is_broadcast_ether_addr(ethhdr->h_dest))
 661                 goto out;
 662
 663         /* packet with broadcast sender address */
 664         if (is_broadcast_ether_addr(ethhdr->h_source))
 665                 goto out;
 666
 667         roam_adv_packet = (struct roam_adv_packet *)skb->data;
 668
 669         if (!is_my_mac(roam_adv_packet->dst))
 670                 return route_unicast_packet(skb, recv_if);
 671
 672         orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
 673         if (!orig_node)
 674                 goto out;
 675
 676         bat_dbg(DBG_TT, bat_priv,
 677                 "Received ROAMING_ADV from %pM (client %pM)\n",
 678                 roam_adv_packet->src, roam_adv_packet->client);
 679
 680         tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
 681                       atomic_read(&orig_node->last_ttvn) + 1, true, false);
 682
 683         /* Roaming phase starts: I have new information but the ttvn has not
 684          * been incremented yet. This flag will make me check all the incoming
 685          * packets for the correct destination. */
 686         bat_priv->tt_poss_change = true;
 687
 688         orig_node_free_ref(orig_node);
 689 out:
 690         /* returning NET_RX_DROP will make the caller function kfree the skb */
 691         return NET_RX_DROP;
 692 }
 693
 694 /* find a suitable router for this originator, and use
 695  * bonding if possible. increases the found neighbors
 696  * refcount.*/
 697 struct neigh_node *find_router(struct bat_priv *bat_priv,
 698                                struct orig_node *orig_node,
 699                                const struct hard_iface *recv_if)
 700 {
 701         struct orig_node *primary_orig_node;
 702         struct orig_node *router_orig;
 703         struct neigh_node *router;
 704         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
 705         int bonding_enabled;
 706
 707         if (!orig_node)
 708                 return NULL;
 709
 710         router = orig_node_get_router(orig_node);
 711         if (!router)
 712                 goto err;
 713
 714         /* without bonding, the first node should
 715          * always choose the default router. */
 716         bonding_enabled = atomic_read(&bat_priv->bonding);
 717
 718         rcu_read_lock();
 719         /* select default router to output */
 720         router_orig = router->orig_node;
 721         if (!router_orig)
 722                 goto err_unlock;
 723
 724         if ((!recv_if) && (!bonding_enabled))
 725                 goto return_router;
 726
 727         /* if we have something in the primary_addr, we can search
 728          * for a potential bonding candidate. */
 729         if (compare_eth(router_orig->primary_addr, zero_mac))
 730                 goto return_router;
 731
 732         /* find the orig_node which has the primary interface. might
 733          * even be the same as our router_orig in many cases */
 734
 735         if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
 736                 primary_orig_node = router_orig;
 737         } else {
 738                 primary_orig_node = orig_hash_find(bat_priv,
 739                                                    router_orig->primary_addr);
 740                 if (!primary_orig_node)
 741                         goto return_router;
 742
 743                 orig_node_free_ref(primary_orig_node);
 744         }
 745
 746         /* with less than 2 candidates, we can't do any
 747          * bonding and prefer the original router. */
 748         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
 749                 goto return_router;
 750
 751         /* all nodes between should choose a candidate which
 752          * is is not on the interface where the packet came
 753          * in. */
 754
 755         neigh_node_free_ref(router);
 756
 757         if (bonding_enabled)
 758                 router = find_bond_router(primary_orig_node, recv_if);
 759         else
 760                 router = find_ifalter_router(primary_orig_node, recv_if);
 761
 762 return_router:
 763         if (router && router->if_incoming->if_status != IF_ACTIVE)
 764                 goto err_unlock;
 765
 766         rcu_read_unlock();
 767         return router;
 768 err_unlock:
 769         rcu_read_unlock();
 770 err:
 771         if (router)
 772                 neigh_node_free_ref(router);
 773         return NULL;
 774 }
 775
 776 static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
 777 {
 778         struct ethhdr *ethhdr;
 779
 780         /* drop packet if it has not necessary minimum size */
 781         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 782                 return -1;
 783
 784         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 785
 786         /* packet with unicast indication but broadcast recipient */
 787         if (is_broadcast_ether_addr(ethhdr->h_dest))
 788                 return -1;
 789
 790         /* packet with broadcast sender address */
 791         if (is_broadcast_ether_addr(ethhdr->h_source))
 792                 return -1;
 793
 794         /* not for me */
 795         if (!is_my_mac(ethhdr->h_dest))
 796                 return -1;
 797
 798         return 0;
 799 }
 800
 801 int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 802 {
 803         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 804         struct orig_node *orig_node = NULL;
 805         struct neigh_node *neigh_node = NULL;
 806         struct unicast_packet *unicast_packet;
 807         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
 808         int ret = NET_RX_DROP;
 809         struct sk_buff *new_skb;
 810
 811         unicast_packet = (struct unicast_packet *)skb->data;
 812
 813         /* TTL exceeded */
 814         if (unicast_packet->header.ttl < 2) {
 815                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 816                          ethhdr->h_source, unicast_packet->dest);
 817                 goto out;
 818         }
 819
 820         /* get routing information */
 821         orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 822
 823         if (!orig_node)
 824                 goto out;
 825
 826         /* find_router() increases neigh_nodes refcount if found. */
 827         neigh_node = find_router(bat_priv, orig_node, recv_if);
 828
 829         if (!neigh_node)
 830                 goto out;
 831
 832         /* create a copy of the skb, if needed, to modify it. */
 833         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 834                 goto out;
 835
 836         unicast_packet = (struct unicast_packet *)skb->data;
 837
 838         if (unicast_packet->header.packet_type == BAT_UNICAST &&
 839             atomic_read(&bat_priv->fragmentation) &&
 840             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 841                 ret = frag_send_skb(skb, bat_priv,
 842                                     neigh_node->if_incoming, neigh_node->addr);
 843                 goto out;
 844         }
 845
 846         if (unicast_packet->header.packet_type == BAT_UNICAST_FRAG &&
 847             frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
 848
 849                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 850
 851                 if (ret == NET_RX_DROP)
 852                         goto out;
 853
 854                 /* packet was buffered for late merge */
 855                 if (!new_skb) {
 856                         ret = NET_RX_SUCCESS;
 857                         goto out;
 858                 }
 859
 860                 skb = new_skb;
 861                 unicast_packet = (struct unicast_packet *)skb->data;
 862         }
 863
 864         /* decrement ttl */
 865         unicast_packet->header.ttl--;
 866
 867         /* route it */
 868         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 869         ret = NET_RX_SUCCESS;
 870
 871 out:
 872         if (neigh_node)
 873                 neigh_node_free_ref(neigh_node);
 874         if (orig_node)
 875                 orig_node_free_ref(orig_node);
 876         return ret;
 877 }
 878
 879 static int check_unicast_ttvn(struct bat_priv *bat_priv,
 880                                struct sk_buff *skb) {
 881         uint8_t curr_ttvn;
 882         struct orig_node *orig_node;
 883         struct ethhdr *ethhdr;
 884         struct hard_iface *primary_if;
 885         struct unicast_packet *unicast_packet;
 886         bool tt_poss_change;
 887
 888         /* I could need to modify it */
 889         if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
 890                 return 0;
 891
 892         unicast_packet = (struct unicast_packet *)skb->data;
 893
 894         if (is_my_mac(unicast_packet->dest)) {
 895                 tt_poss_change = bat_priv->tt_poss_change;
 896                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
 897         } else {
 898                 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
 899
 900                 if (!orig_node)
 901                         return 0;
 902
 903                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 904                 tt_poss_change = orig_node->tt_poss_change;
 905                 orig_node_free_ref(orig_node);
 906         }
 907
 908         /* Check whether I have to reroute the packet */
 909         if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
 910                 /* Linearize the skb before accessing it */
 911                 if (skb_linearize(skb) < 0)
 912                         return 0;
 913
 914                 ethhdr = (struct ethhdr *)(skb->data +
 915                         sizeof(struct unicast_packet));
 916                 orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
 917
 918                 if (!orig_node) {
 919                         if (!is_my_client(bat_priv, ethhdr->h_dest))
 920                                 return 0;
 921                         primary_if = primary_if_get_selected(bat_priv);
 922                         if (!primary_if)
 923                                 return 0;
 924                         memcpy(unicast_packet->dest,
 925                                primary_if->net_dev->dev_addr, ETH_ALEN);
 926                         hardif_free_ref(primary_if);
 927                 } else {
 928                         memcpy(unicast_packet->dest, orig_node->orig,
 929                                ETH_ALEN);
 930                         curr_ttvn = (uint8_t)
 931                                 atomic_read(&orig_node->last_ttvn);
 932                         orig_node_free_ref(orig_node);
 933                 }
 934
 935                 bat_dbg(DBG_ROUTES, bat_priv,
 936                         "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
 937                         unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
 938                         unicast_packet->dest);
 939
 940                 unicast_packet->ttvn = curr_ttvn;
 941         }
 942         return 1;
 943 }
 944
 945 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 946 {
 947         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 948         struct unicast_packet *unicast_packet;
 949         int hdr_size = sizeof(*unicast_packet);
 950
 951         if (check_unicast_packet(skb, hdr_size) < 0)
 952                 return NET_RX_DROP;
 953
 954         if (!check_unicast_ttvn(bat_priv, skb))
 955                 return NET_RX_DROP;
 956
 957         unicast_packet = (struct unicast_packet *)skb->data;
 958
 959         /* packet for me */
 960         if (is_my_mac(unicast_packet->dest)) {
 961                 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
 962                 return NET_RX_SUCCESS;
 963         }
 964
 965         return route_unicast_packet(skb, recv_if);
 966 }
 967
 968 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 969 {
 970         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 971         struct unicast_frag_packet *unicast_packet;
 972         int hdr_size = sizeof(*unicast_packet);
 973         struct sk_buff *new_skb = NULL;
 974         int ret;
 975
 976         if (check_unicast_packet(skb, hdr_size) < 0)
 977                 return NET_RX_DROP;
 978
 979         if (!check_unicast_ttvn(bat_priv, skb))
 980                 return NET_RX_DROP;
 981
 982         unicast_packet = (struct unicast_frag_packet *)skb->data;
 983
 984         /* packet for me */
 985         if (is_my_mac(unicast_packet->dest)) {
 986
 987                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
 988
 989                 if (ret == NET_RX_DROP)
 990                         return NET_RX_DROP;
 991
 992                 /* packet was buffered for late merge */
 993                 if (!new_skb)
 994                         return NET_RX_SUCCESS;
 995
 996                 interface_rx(recv_if->soft_iface, new_skb, recv_if,
 997                              sizeof(struct unicast_packet));
 998                 return NET_RX_SUCCESS;
 999         }
1000
1001         return route_unicast_packet(skb, recv_if);
1002 }
1003
1004
1005 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1006 {
1007         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1008         struct orig_node *orig_node = NULL;
1009         struct bcast_packet *bcast_packet;
1010         struct ethhdr *ethhdr;
1011         int hdr_size = sizeof(*bcast_packet);
1012         int ret = NET_RX_DROP;
1013         int32_t seq_diff;
1014
1015         /* drop packet if it has not necessary minimum size */
1016         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1017                 goto out;
1018
1019         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1020
1021         /* packet with broadcast indication but unicast recipient */
1022         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1023                 goto out;
1024
1025         /* packet with broadcast sender address */
1026         if (is_broadcast_ether_addr(ethhdr->h_source))
1027                 goto out;
1028
1029         /* ignore broadcasts sent by myself */
1030         if (is_my_mac(ethhdr->h_source))
1031                 goto out;
1032
1033         bcast_packet = (struct bcast_packet *)skb->data;
1034
1035         /* ignore broadcasts originated by myself */
1036         if (is_my_mac(bcast_packet->orig))
1037                 goto out;
1038
1039         if (bcast_packet->header.ttl < 2)
1040                 goto out;
1041
1042         orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1043
1044         if (!orig_node)
1045                 goto out;
1046
1047         spin_lock_bh(&orig_node->bcast_seqno_lock);
1048
1049         /* check whether the packet is a duplicate */
1050         if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1051                            ntohl(bcast_packet->seqno)))
1052                 goto spin_unlock;
1053
1054         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1055
1056         /* check whether the packet is old and the host just restarted. */
1057         if (window_protected(bat_priv, seq_diff,
1058                              &orig_node->bcast_seqno_reset))
1059                 goto spin_unlock;
1060
1061         /* mark broadcast in flood history, update window position
1062          * if required. */
1063         if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1064                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1065
1066         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1067
1068         /* rebroadcast packet */
1069         add_bcast_packet_to_list(bat_priv, skb, 1);
1070
1071         /* broadcast for me */
1072         interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1073         ret = NET_RX_SUCCESS;
1074         goto out;
1075
1076 spin_unlock:
1077         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1078 out:
1079         if (orig_node)
1080                 orig_node_free_ref(orig_node);
1081         return ret;
1082 }
1083
1084 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1085 {
1086         struct vis_packet *vis_packet;
1087         struct ethhdr *ethhdr;
1088         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1089         int hdr_size = sizeof(*vis_packet);
1090
1091         /* keep skb linear */
1092         if (skb_linearize(skb) < 0)
1093                 return NET_RX_DROP;
1094
1095         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1096                 return NET_RX_DROP;
1097
1098         vis_packet = (struct vis_packet *)skb->data;
1099         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1100
1101         /* not for me */
1102         if (!is_my_mac(ethhdr->h_dest))
1103                 return NET_RX_DROP;
1104
1105         /* ignore own packets */
1106         if (is_my_mac(vis_packet->vis_orig))
1107                 return NET_RX_DROP;
1108
1109         if (is_my_mac(vis_packet->sender_orig))
1110                 return NET_RX_DROP;
1111
1112         switch (vis_packet->vis_type) {
1113         case VIS_TYPE_SERVER_SYNC:
1114                 receive_server_sync_packet(bat_priv, vis_packet,
1115                                            skb_headlen(skb));
1116                 break;
1117
1118         case VIS_TYPE_CLIENT_UPDATE:
1119                 receive_client_update_packet(bat_priv, vis_packet,
1120                                              skb_headlen(skb));
1121                 break;
1122
1123         default:        /* ignore unknown packet */
1124                 break;
1125         }
1126
1127         /* We take a copy of the data in the packet, so we should
1128            always free the skbuf. */
1129         return NET_RX_DROP;
1130 }