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 "hash.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "icmp_socket.h"
  29 #include "translation-table.h"
  30 #include "originator.h"
  31 #include "ring_buffer.h"
  32 #include "vis.h"
  33 #include "aggregation.h"
  34 #include "gateway_common.h"
  35 #include "gateway_client.h"
  36 #include "unicast.h"
  37
  38 void slide_own_bcast_window(struct hard_iface *hard_iface)
  39 {
  40         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  41         struct hashtable_t *hash = bat_priv->orig_hash;
  42         struct hlist_node *node;
  43         struct hlist_head *head;
  44         struct orig_node *orig_node;
  45         unsigned long *word;
  46         int i;
  47         size_t word_index;
  48
  49         for (i = 0; i < hash->size; i++) {
  50                 head = &hash->table[i];
  51
  52                 rcu_read_lock();
  53                 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  54                         spin_lock_bh(&orig_node->ogm_cnt_lock);
  55                         word_index = hard_iface->if_num * NUM_WORDS;
  56                         word = &(orig_node->bcast_own[word_index]);
  57
  58                         bit_get_packet(bat_priv, word, 1, 0);
  59                         orig_node->bcast_own_sum[hard_iface->if_num] =
  60                                 bit_packet_count(word);
  61                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
  62                 }
  63                 rcu_read_unlock();
  64         }
  65 }
  66
  67 static void update_transtable(struct bat_priv *bat_priv,
  68                               struct orig_node *orig_node,
  69                               const unsigned char *tt_buff,
  70                               uint8_t tt_num_changes, uint8_t ttvn,
  71                               uint16_t tt_crc)
  72 {
  73         uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
  74         bool full_table = true;
  75
  76         /* the ttvn increased by one -> we can apply the attached changes */
  77         if (ttvn - orig_ttvn == 1) {
  78                 /* the OGM could not contain the changes because they were too
  79                  * many to fit in one frame or because they have already been
  80                  * sent TT_OGM_APPEND_MAX times. In this case send a tt
  81                  * request */
  82                 if (!tt_num_changes) {
  83                         full_table = false;
  84                         goto request_table;
  85                 }
  86
  87                 tt_update_changes(bat_priv, orig_node, tt_num_changes, ttvn,
  88                                   (struct tt_change *)tt_buff);
  89
  90                 /* Even if we received the crc into the OGM, we prefer
  91                  * to recompute it to spot any possible inconsistency
  92                  * in the global table */
  93                 orig_node->tt_crc = tt_global_crc(bat_priv, orig_node);
  94
  95                 /* The ttvn alone is not enough to guarantee consistency
  96                  * because a single value could repesent different states
  97                  * (due to the wrap around). Thus a node has to check whether
  98                  * the resulting table (after applying the changes) is still
  99                  * consistent or not. E.g. a node could disconnect while its
 100                  * ttvn is X and reconnect on ttvn = X + TTVN_MAX: in this case
 101                  * checking the CRC value is mandatory to detect the
 102                  * inconsistency */
 103                 if (orig_node->tt_crc != tt_crc)
 104                         goto request_table;
 105
 106                 /* Roaming phase is over: tables are in sync again. I can
 107                  * unset the flag */
 108                 orig_node->tt_poss_change = false;
 109         } else {
 110                 /* if we missed more than one change or our tables are not
 111                  * in sync anymore -> request fresh tt data */
 112                 if (ttvn != orig_ttvn || orig_node->tt_crc != tt_crc) {
 113 request_table:
 114                         bat_dbg(DBG_TT, bat_priv, "TT inconsistency for %pM. "
 115                                 "Need to retrieve the correct information "
 116                                 "(ttvn: %u last_ttvn: %u crc: %u last_crc: "
 117                                 "%u num_changes: %u)\n", orig_node->orig, ttvn,
 118                                 orig_ttvn, tt_crc, orig_node->tt_crc,
 119                                 tt_num_changes);
 120                         send_tt_request(bat_priv, orig_node, ttvn, tt_crc,
 121                                         full_table);
 122                         return;
 123                 }
 124         }
 125 }
 126
 127 static void update_route(struct bat_priv *bat_priv,
 128                          struct orig_node *orig_node,
 129                          struct neigh_node *neigh_node)
 130 {
 131         struct neigh_node *curr_router;
 132
 133         curr_router = orig_node_get_router(orig_node);
 134
 135         /* route deleted */
 136         if ((curr_router) && (!neigh_node)) {
 137                 bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
 138                         orig_node->orig);
 139                 tt_global_del_orig(bat_priv, orig_node,
 140                                     "Deleted route towards originator");
 141
 142         /* route added */
 143         } else if ((!curr_router) && (neigh_node)) {
 144
 145                 bat_dbg(DBG_ROUTES, bat_priv,
 146                         "Adding route towards: %pM (via %pM)\n",
 147                         orig_node->orig, neigh_node->addr);
 148         /* route changed */
 149         } else if (neigh_node && curr_router) {
 150                 bat_dbg(DBG_ROUTES, bat_priv,
 151                         "Changing route towards: %pM "
 152                         "(now via %pM - was via %pM)\n",
 153                         orig_node->orig, neigh_node->addr,
 154                         curr_router->addr);
 155         }
 156
 157         if (curr_router)
 158                 neigh_node_free_ref(curr_router);
 159
 160         /* increase refcount of new best neighbor */
 161         if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
 162                 neigh_node = NULL;
 163
 164         spin_lock_bh(&orig_node->neigh_list_lock);
 165         rcu_assign_pointer(orig_node->router, neigh_node);
 166         spin_unlock_bh(&orig_node->neigh_list_lock);
 167
 168         /* decrease refcount of previous best neighbor */
 169         if (curr_router)
 170                 neigh_node_free_ref(curr_router);
 171 }
 172
 173 void update_routes(struct bat_priv *bat_priv, struct orig_node *orig_node,
 174                    struct neigh_node *neigh_node)
 175 {
 176         struct neigh_node *router = NULL;
 177
 178         if (!orig_node)
 179                 goto out;
 180
 181         router = orig_node_get_router(orig_node);
 182
 183         if (router != neigh_node)
 184                 update_route(bat_priv, orig_node, neigh_node);
 185
 186 out:
 187         if (router)
 188                 neigh_node_free_ref(router);
 189 }
 190
 191 static int is_bidirectional_neigh(struct orig_node *orig_node,
 192                                 struct orig_node *orig_neigh_node,
 193                                 struct batman_packet *batman_packet,
 194                                 struct hard_iface *if_incoming)
 195 {
 196         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 197         struct neigh_node *neigh_node = NULL, *tmp_neigh_node;
 198         struct hlist_node *node;
 199         uint8_t total_count;
 200         uint8_t orig_eq_count, neigh_rq_count, tq_own;
 201         int tq_asym_penalty, ret = 0;
 202
 203         /* find corresponding one hop neighbor */
 204         rcu_read_lock();
 205         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 206                                  &orig_neigh_node->neigh_list, list) {
 207
 208                 if (!compare_eth(tmp_neigh_node->addr, orig_neigh_node->orig))
 209                         continue;
 210
 211                 if (tmp_neigh_node->if_incoming != if_incoming)
 212                         continue;
 213
 214                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 215                         continue;
 216
 217                 neigh_node = tmp_neigh_node;
 218                 break;
 219         }
 220         rcu_read_unlock();
 221
 222         if (!neigh_node)
 223                 neigh_node = create_neighbor(orig_neigh_node,
 224                                              orig_neigh_node,
 225                                              orig_neigh_node->orig,
 226                                              if_incoming);
 227
 228         if (!neigh_node)
 229                 goto out;
 230
 231         /* if orig_node is direct neighbour update neigh_node last_valid */
 232         if (orig_node == orig_neigh_node)
 233                 neigh_node->last_valid = jiffies;
 234
 235         orig_node->last_valid = jiffies;
 236
 237         /* find packet count of corresponding one hop neighbor */
 238         spin_lock_bh(&orig_node->ogm_cnt_lock);
 239         orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
 240         neigh_rq_count = neigh_node->real_packet_count;
 241         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 242
 243         /* pay attention to not get a value bigger than 100 % */
 244         total_count = (orig_eq_count > neigh_rq_count ?
 245                        neigh_rq_count : orig_eq_count);
 246
 247         /* if we have too few packets (too less data) we set tq_own to zero */
 248         /* if we receive too few packets it is not considered bidirectional */
 249         if ((total_count < TQ_LOCAL_BIDRECT_SEND_MINIMUM) ||
 250             (neigh_rq_count < TQ_LOCAL_BIDRECT_RECV_MINIMUM))
 251                 tq_own = 0;
 252         else
 253                 /* neigh_node->real_packet_count is never zero as we
 254                  * only purge old information when getting new
 255                  * information */
 256                 tq_own = (TQ_MAX_VALUE * total_count) / neigh_rq_count;
 257
 258         /*
 259          * 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
 260          * affect the nearly-symmetric links only a little, but
 261          * punishes asymmetric links more.  This will give a value
 262          * between 0 and TQ_MAX_VALUE
 263          */
 264         tq_asym_penalty = TQ_MAX_VALUE - (TQ_MAX_VALUE *
 265                                 (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
 266                                 (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
 267                                 (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count)) /
 268                                         (TQ_LOCAL_WINDOW_SIZE *
 269                                          TQ_LOCAL_WINDOW_SIZE *
 270                                          TQ_LOCAL_WINDOW_SIZE);
 271
 272         batman_packet->tq = ((batman_packet->tq * tq_own * tq_asym_penalty) /
 273                                                 (TQ_MAX_VALUE * TQ_MAX_VALUE));
 274
 275         bat_dbg(DBG_BATMAN, bat_priv,
 276                 "bidirectional: "
 277                 "orig = %-15pM neigh = %-15pM => own_bcast = %2i, "
 278                 "real recv = %2i, local tq: %3i, asym_penalty: %3i, "
 279                 "total tq: %3i\n",
 280                 orig_node->orig, orig_neigh_node->orig, total_count,
 281                 neigh_rq_count, tq_own, tq_asym_penalty, batman_packet->tq);
 282
 283         /* if link has the minimum required transmission quality
 284          * consider it bidirectional */
 285         if (batman_packet->tq >= TQ_TOTAL_BIDRECT_LIMIT)
 286                 ret = 1;
 287
 288 out:
 289         if (neigh_node)
 290                 neigh_node_free_ref(neigh_node);
 291         return ret;
 292 }
 293
 294 /* caller must hold the neigh_list_lock */
 295 void bonding_candidate_del(struct orig_node *orig_node,
 296                            struct neigh_node *neigh_node)
 297 {
 298         /* this neighbor is not part of our candidate list */
 299         if (list_empty(&neigh_node->bonding_list))
 300                 goto out;
 301
 302         list_del_rcu(&neigh_node->bonding_list);
 303         INIT_LIST_HEAD(&neigh_node->bonding_list);
 304         neigh_node_free_ref(neigh_node);
 305         atomic_dec(&orig_node->bond_candidates);
 306
 307 out:
 308         return;
 309 }
 310
 311 static void bonding_candidate_add(struct orig_node *orig_node,
 312                                   struct neigh_node *neigh_node)
 313 {
 314         struct hlist_node *node;
 315         struct neigh_node *tmp_neigh_node, *router = NULL;
 316         uint8_t interference_candidate = 0;
 317
 318         spin_lock_bh(&orig_node->neigh_list_lock);
 319
 320         /* only consider if it has the same primary address ...  */
 321         if (!compare_eth(orig_node->orig,
 322                          neigh_node->orig_node->primary_addr))
 323                 goto candidate_del;
 324
 325         router = orig_node_get_router(orig_node);
 326         if (!router)
 327                 goto candidate_del;
 328
 329         /* ... and is good enough to be considered */
 330         if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
 331                 goto candidate_del;
 332
 333         /**
 334          * check if we have another candidate with the same mac address or
 335          * interface. If we do, we won't select this candidate because of
 336          * possible interference.
 337          */
 338         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 339                                  &orig_node->neigh_list, list) {
 340
 341                 if (tmp_neigh_node == neigh_node)
 342                         continue;
 343
 344                 /* we only care if the other candidate is even
 345                 * considered as candidate. */
 346                 if (list_empty(&tmp_neigh_node->bonding_list))
 347                         continue;
 348
 349                 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
 350                     (compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
 351                         interference_candidate = 1;
 352                         break;
 353                 }
 354         }
 355
 356         /* don't care further if it is an interference candidate */
 357         if (interference_candidate)
 358                 goto candidate_del;
 359
 360         /* this neighbor already is part of our candidate list */
 361         if (!list_empty(&neigh_node->bonding_list))
 362                 goto out;
 363
 364         if (!atomic_inc_not_zero(&neigh_node->refcount))
 365                 goto out;
 366
 367         list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
 368         atomic_inc(&orig_node->bond_candidates);
 369         goto out;
 370
 371 candidate_del:
 372         bonding_candidate_del(orig_node, neigh_node);
 373
 374 out:
 375         spin_unlock_bh(&orig_node->neigh_list_lock);
 376
 377         if (router)
 378                 neigh_node_free_ref(router);
 379 }
 380
 381 /* copy primary address for bonding */
 382 static void bonding_save_primary(const struct orig_node *orig_node,
 383                                  struct orig_node *orig_neigh_node,
 384                                  const struct batman_packet *batman_packet)
 385 {
 386         if (!(batman_packet->flags & PRIMARIES_FIRST_HOP))
 387                 return;
 388
 389         memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
 390 }
 391
 392 static void update_orig(struct bat_priv *bat_priv, struct orig_node *orig_node,
 393                         const struct ethhdr *ethhdr,
 394                         const struct batman_packet *batman_packet,
 395                         struct hard_iface *if_incoming,
 396                         const unsigned char *tt_buff, int is_duplicate)
 397 {
 398         struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
 399         struct neigh_node *router = NULL;
 400         struct orig_node *orig_node_tmp;
 401         struct hlist_node *node;
 402         uint8_t bcast_own_sum_orig, bcast_own_sum_neigh;
 403
 404         bat_dbg(DBG_BATMAN, bat_priv, "update_originator(): "
 405                 "Searching and updating originator entry of received packet\n");
 406
 407         rcu_read_lock();
 408         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 409                                  &orig_node->neigh_list, list) {
 410                 if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) &&
 411                     (tmp_neigh_node->if_incoming == if_incoming) &&
 412                      atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
 413                         if (neigh_node)
 414                                 neigh_node_free_ref(neigh_node);
 415                         neigh_node = tmp_neigh_node;
 416                         continue;
 417                 }
 418
 419                 if (is_duplicate)
 420                         continue;
 421
 422                 spin_lock_bh(&tmp_neigh_node->tq_lock);
 423                 ring_buffer_set(tmp_neigh_node->tq_recv,
 424                                 &tmp_neigh_node->tq_index, 0);
 425                 tmp_neigh_node->tq_avg =
 426                         ring_buffer_avg(tmp_neigh_node->tq_recv);
 427                 spin_unlock_bh(&tmp_neigh_node->tq_lock);
 428         }
 429
 430         if (!neigh_node) {
 431                 struct orig_node *orig_tmp;
 432
 433                 orig_tmp = get_orig_node(bat_priv, ethhdr->h_source);
 434                 if (!orig_tmp)
 435                         goto unlock;
 436
 437                 neigh_node = create_neighbor(orig_node, orig_tmp,
 438                                              ethhdr->h_source, if_incoming);
 439
 440                 orig_node_free_ref(orig_tmp);
 441                 if (!neigh_node)
 442                         goto unlock;
 443         } else
 444                 bat_dbg(DBG_BATMAN, bat_priv,
 445                         "Updating existing last-hop neighbor of originator\n");
 446
 447         rcu_read_unlock();
 448
 449         orig_node->flags = batman_packet->flags;
 450         neigh_node->last_valid = jiffies;
 451
 452         spin_lock_bh(&neigh_node->tq_lock);
 453         ring_buffer_set(neigh_node->tq_recv,
 454                         &neigh_node->tq_index,
 455                         batman_packet->tq);
 456         neigh_node->tq_avg = ring_buffer_avg(neigh_node->tq_recv);
 457         spin_unlock_bh(&neigh_node->tq_lock);
 458
 459         if (!is_duplicate) {
 460                 orig_node->last_ttl = batman_packet->ttl;
 461                 neigh_node->last_ttl = batman_packet->ttl;
 462         }
 463
 464         bonding_candidate_add(orig_node, neigh_node);
 465
 466         /* if this neighbor already is our next hop there is nothing
 467          * to change */
 468         router = orig_node_get_router(orig_node);
 469         if (router == neigh_node)
 470                 goto update_tt;
 471
 472         /* if this neighbor does not offer a better TQ we won't consider it */
 473         if (router && (router->tq_avg > neigh_node->tq_avg))
 474                 goto update_tt;
 475
 476         /* if the TQ is the same and the link not more symetric we
 477          * won't consider it either */
 478         if (router && (neigh_node->tq_avg == router->tq_avg)) {
 479                 orig_node_tmp = router->orig_node;
 480                 spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
 481                 bcast_own_sum_orig =
 482                         orig_node_tmp->bcast_own_sum[if_incoming->if_num];
 483                 spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
 484
 485                 orig_node_tmp = neigh_node->orig_node;
 486                 spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
 487                 bcast_own_sum_neigh =
 488                         orig_node_tmp->bcast_own_sum[if_incoming->if_num];
 489                 spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
 490
 491                 if (bcast_own_sum_orig >= bcast_own_sum_neigh)
 492                         goto update_tt;
 493         }
 494
 495         update_routes(bat_priv, orig_node, neigh_node);
 496
 497 update_tt:
 498         /* I have to check for transtable changes only if the OGM has been
 499          * sent through a primary interface */
 500         if (((batman_packet->orig != ethhdr->h_source) &&
 501                                 (batman_packet->ttl > 2)) ||
 502                                 (batman_packet->flags & PRIMARIES_FIRST_HOP))
 503                 update_transtable(bat_priv, orig_node, tt_buff,
 504                                   batman_packet->tt_num_changes,
 505                                   batman_packet->ttvn,
 506                                   batman_packet->tt_crc);
 507
 508         if (orig_node->gw_flags != batman_packet->gw_flags)
 509                 gw_node_update(bat_priv, orig_node, batman_packet->gw_flags);
 510
 511         orig_node->gw_flags = batman_packet->gw_flags;
 512
 513         /* restart gateway selection if fast or late switching was enabled */
 514         if ((orig_node->gw_flags) &&
 515             (atomic_read(&bat_priv->gw_mode) == GW_MODE_CLIENT) &&
 516             (atomic_read(&bat_priv->gw_sel_class) > 2))
 517                 gw_check_election(bat_priv, orig_node);
 518
 519         goto out;
 520
 521 unlock:
 522         rcu_read_unlock();
 523 out:
 524         if (neigh_node)
 525                 neigh_node_free_ref(neigh_node);
 526         if (router)
 527                 neigh_node_free_ref(router);
 528 }
 529
 530 /* checks whether the host restarted and is in the protection time.
 531  * returns:
 532  *  0 if the packet is to be accepted
 533  *  1 if the packet is to be ignored.
 534  */
 535 static int window_protected(struct bat_priv *bat_priv,
 536                             int32_t seq_num_diff,
 537                             unsigned long *last_reset)
 538 {
 539         if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE)
 540                 || (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
 541                 if (time_after(jiffies, *last_reset +
 542                         msecs_to_jiffies(RESET_PROTECTION_MS))) {
 543
 544                         *last_reset = jiffies;
 545                         bat_dbg(DBG_BATMAN, bat_priv,
 546                                 "old packet received, start protection\n");
 547
 548                         return 0;
 549                 } else
 550                         return 1;
 551         }
 552         return 0;
 553 }
 554
 555 /* processes a batman packet for all interfaces, adjusts the sequence number and
 556  * finds out whether it is a duplicate.
 557  * returns:
 558  *   1 the packet is a duplicate
 559  *   0 the packet has not yet been received
 560  *  -1 the packet is old and has been received while the seqno window
 561  *     was protected. Caller should drop it.
 562  */
 563 static int count_real_packets(const struct ethhdr *ethhdr,
 564                                const struct batman_packet *batman_packet,
 565                                const struct hard_iface *if_incoming)
 566 {
 567         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 568         struct orig_node *orig_node;
 569         struct neigh_node *tmp_neigh_node;
 570         struct hlist_node *node;
 571         int is_duplicate = 0;
 572         int32_t seq_diff;
 573         int need_update = 0;
 574         int set_mark, ret = -1;
 575
 576         orig_node = get_orig_node(bat_priv, batman_packet->orig);
 577         if (!orig_node)
 578                 return 0;
 579
 580         spin_lock_bh(&orig_node->ogm_cnt_lock);
 581         seq_diff = batman_packet->seqno - orig_node->last_real_seqno;
 582
 583         /* signalize caller that the packet is to be dropped. */
 584         if (window_protected(bat_priv, seq_diff,
 585                              &orig_node->batman_seqno_reset))
 586                 goto out;
 587
 588         rcu_read_lock();
 589         hlist_for_each_entry_rcu(tmp_neigh_node, node,
 590                                  &orig_node->neigh_list, list) {
 591
 592                 is_duplicate |= get_bit_status(tmp_neigh_node->real_bits,
 593                                                orig_node->last_real_seqno,
 594                                                batman_packet->seqno);
 595
 596                 if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) &&
 597                     (tmp_neigh_node->if_incoming == if_incoming))
 598                         set_mark = 1;
 599                 else
 600                         set_mark = 0;
 601
 602                 /* if the window moved, set the update flag. */
 603                 need_update |= bit_get_packet(bat_priv,
 604                                               tmp_neigh_node->real_bits,
 605                                               seq_diff, set_mark);
 606
 607                 tmp_neigh_node->real_packet_count =
 608                         bit_packet_count(tmp_neigh_node->real_bits);
 609         }
 610         rcu_read_unlock();
 611
 612         if (need_update) {
 613                 bat_dbg(DBG_BATMAN, bat_priv,
 614                         "updating last_seqno: old %d, new %d\n",
 615                         orig_node->last_real_seqno, batman_packet->seqno);
 616                 orig_node->last_real_seqno = batman_packet->seqno;
 617         }
 618
 619         ret = is_duplicate;
 620
 621 out:
 622         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 623         orig_node_free_ref(orig_node);
 624         return ret;
 625 }
 626
 627 void receive_bat_packet(const struct ethhdr *ethhdr,
 628                         struct batman_packet *batman_packet,
 629                         const unsigned char *tt_buff,
 630                         struct hard_iface *if_incoming)
 631 {
 632         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 633         struct hard_iface *hard_iface;
 634         struct orig_node *orig_neigh_node, *orig_node;
 635         struct neigh_node *router = NULL, *router_router = NULL;
 636         struct neigh_node *orig_neigh_router = NULL;
 637         int has_directlink_flag;
 638         int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
 639         int is_broadcast = 0, is_bidirectional, is_single_hop_neigh;
 640         int is_duplicate;
 641         uint32_t if_incoming_seqno;
 642
 643         /* Silently drop when the batman packet is actually not a
 644          * correct packet.
 645          *
 646          * This might happen if a packet is padded (e.g. Ethernet has a
 647          * minimum frame length of 64 byte) and the aggregation interprets
 648          * it as an additional length.
 649          *
 650          * TODO: A more sane solution would be to have a bit in the
 651          * batman_packet to detect whether the packet is the last
 652          * packet in an aggregation.  Here we expect that the padding
 653          * is always zero (or not 0x01)
 654          */
 655         if (batman_packet->packet_type != BAT_PACKET)
 656                 return;
 657
 658         /* could be changed by schedule_own_packet() */
 659         if_incoming_seqno = atomic_read(&if_incoming->seqno);
 660
 661         has_directlink_flag = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 662
 663         is_single_hop_neigh = (compare_eth(ethhdr->h_source,
 664                                            batman_packet->orig) ? 1 : 0);
 665
 666         bat_dbg(DBG_BATMAN, bat_priv,
 667                 "Received BATMAN packet via NB: %pM, IF: %s [%pM] "
 668                 "(from OG: %pM, via prev OG: %pM, seqno %d, ttvn %u, "
 669                 "crc %u, changes %u, td %d, TTL %d, V %d, IDF %d)\n",
 670                 ethhdr->h_source, if_incoming->net_dev->name,
 671                 if_incoming->net_dev->dev_addr, batman_packet->orig,
 672                 batman_packet->prev_sender, batman_packet->seqno,
 673                 batman_packet->ttvn, batman_packet->tt_crc,
 674                 batman_packet->tt_num_changes, batman_packet->tq,
 675                 batman_packet->ttl, batman_packet->version,
 676                 has_directlink_flag);
 677
 678         rcu_read_lock();
 679         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 680                 if (hard_iface->if_status != IF_ACTIVE)
 681                         continue;
 682
 683                 if (hard_iface->soft_iface != if_incoming->soft_iface)
 684                         continue;
 685
 686                 if (compare_eth(ethhdr->h_source,
 687                                 hard_iface->net_dev->dev_addr))
 688                         is_my_addr = 1;
 689
 690                 if (compare_eth(batman_packet->orig,
 691                                 hard_iface->net_dev->dev_addr))
 692                         is_my_orig = 1;
 693
 694                 if (compare_eth(batman_packet->prev_sender,
 695                                 hard_iface->net_dev->dev_addr))
 696                         is_my_oldorig = 1;
 697
 698                 if (is_broadcast_ether_addr(ethhdr->h_source))
 699                         is_broadcast = 1;
 700         }
 701         rcu_read_unlock();
 702
 703         if (batman_packet->version != COMPAT_VERSION) {
 704                 bat_dbg(DBG_BATMAN, bat_priv,
 705                         "Drop packet: incompatible batman version (%i)\n",
 706                         batman_packet->version);
 707                 return;
 708         }
 709
 710         if (is_my_addr) {
 711                 bat_dbg(DBG_BATMAN, bat_priv,
 712                         "Drop packet: received my own broadcast (sender: %pM"
 713                         ")\n",
 714                         ethhdr->h_source);
 715                 return;
 716         }
 717
 718         if (is_broadcast) {
 719                 bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
 720                 "ignoring all packets with broadcast source addr (sender: %pM"
 721                 ")\n", ethhdr->h_source);
 722                 return;
 723         }
 724
 725         if (is_my_orig) {
 726                 unsigned long *word;
 727                 int offset;
 728
 729                 orig_neigh_node = get_orig_node(bat_priv, ethhdr->h_source);
 730                 if (!orig_neigh_node)
 731                         return;
 732
 733                 /* neighbor has to indicate direct link and it has to
 734                  * come via the corresponding interface */
 735                 /* save packet seqno for bidirectional check */
 736                 if (has_directlink_flag &&
 737                     compare_eth(if_incoming->net_dev->dev_addr,
 738                                 batman_packet->orig)) {
 739                         offset = if_incoming->if_num * NUM_WORDS;
 740
 741                         spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
 742                         word = &(orig_neigh_node->bcast_own[offset]);
 743                         bit_mark(word,
 744                                  if_incoming_seqno - batman_packet->seqno - 2);
 745                         orig_neigh_node->bcast_own_sum[if_incoming->if_num] =
 746                                 bit_packet_count(word);
 747                         spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
 748                 }
 749
 750                 bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
 751                         "originator packet from myself (via neighbor)\n");
 752                 orig_node_free_ref(orig_neigh_node);
 753                 return;
 754         }
 755
 756         if (is_my_oldorig) {
 757                 bat_dbg(DBG_BATMAN, bat_priv,
 758                         "Drop packet: ignoring all rebroadcast echos (sender: "
 759                         "%pM)\n", ethhdr->h_source);
 760                 return;
 761         }
 762
 763         orig_node = get_orig_node(bat_priv, batman_packet->orig);
 764         if (!orig_node)
 765                 return;
 766
 767         is_duplicate = count_real_packets(ethhdr, batman_packet, if_incoming);
 768
 769         if (is_duplicate == -1) {
 770                 bat_dbg(DBG_BATMAN, bat_priv,
 771                         "Drop packet: packet within seqno protection time "
 772                         "(sender: %pM)\n", ethhdr->h_source);
 773                 goto out;
 774         }
 775
 776         if (batman_packet->tq == 0) {
 777                 bat_dbg(DBG_BATMAN, bat_priv,
 778                         "Drop packet: originator packet with tq equal 0\n");
 779                 goto out;
 780         }
 781
 782         router = orig_node_get_router(orig_node);
 783         if (router)
 784                 router_router = orig_node_get_router(router->orig_node);
 785
 786         /* avoid temporary routing loops */
 787         if (router && router_router &&
 788             (compare_eth(router->addr, batman_packet->prev_sender)) &&
 789             !(compare_eth(batman_packet->orig, batman_packet->prev_sender)) &&
 790             (compare_eth(router->addr, router_router->addr))) {
 791                 bat_dbg(DBG_BATMAN, bat_priv,
 792                         "Drop packet: ignoring all rebroadcast packets that "
 793                         "may make me loop (sender: %pM)\n", ethhdr->h_source);
 794                 goto out;
 795         }
 796
 797         /* if sender is a direct neighbor the sender mac equals
 798          * originator mac */
 799         orig_neigh_node = (is_single_hop_neigh ?
 800                            orig_node :
 801                            get_orig_node(bat_priv, ethhdr->h_source));
 802         if (!orig_neigh_node)
 803                 goto out;
 804
 805         orig_neigh_router = orig_node_get_router(orig_neigh_node);
 806
 807         /* drop packet if sender is not a direct neighbor and if we
 808          * don't route towards it */
 809         if (!is_single_hop_neigh && (!orig_neigh_router)) {
 810                 bat_dbg(DBG_BATMAN, bat_priv,
 811                         "Drop packet: OGM via unknown neighbor!\n");
 812                 goto out_neigh;
 813         }
 814
 815         is_bidirectional = is_bidirectional_neigh(orig_node, orig_neigh_node,
 816                                                 batman_packet, if_incoming);
 817
 818         bonding_save_primary(orig_node, orig_neigh_node, batman_packet);
 819
 820         /* update ranking if it is not a duplicate or has the same
 821          * seqno and similar ttl as the non-duplicate */
 822         if (is_bidirectional &&
 823             (!is_duplicate ||
 824              ((orig_node->last_real_seqno == batman_packet->seqno) &&
 825               (orig_node->last_ttl - 3 <= batman_packet->ttl))))
 826                 update_orig(bat_priv, orig_node, ethhdr, batman_packet,
 827                             if_incoming, tt_buff, is_duplicate);
 828
 829         /* is single hop (direct) neighbor */
 830         if (is_single_hop_neigh) {
 831
 832                 /* mark direct link on incoming interface */
 833                 schedule_forward_packet(orig_node, ethhdr, batman_packet,
 834                                         1, if_incoming);
 835
 836                 bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: "
 837                         "rebroadcast neighbor packet with direct link flag\n");
 838                 goto out_neigh;
 839         }
 840
 841         /* multihop originator */
 842         if (!is_bidirectional) {
 843                 bat_dbg(DBG_BATMAN, bat_priv,
 844                         "Drop packet: not received via bidirectional link\n");
 845                 goto out_neigh;
 846         }
 847
 848         if (is_duplicate) {
 849                 bat_dbg(DBG_BATMAN, bat_priv,
 850                         "Drop packet: duplicate packet received\n");
 851                 goto out_neigh;
 852         }
 853
 854         bat_dbg(DBG_BATMAN, bat_priv,
 855                 "Forwarding packet: rebroadcast originator packet\n");
 856         schedule_forward_packet(orig_node, ethhdr, batman_packet,
 857                                 0, if_incoming);
 858
 859 out_neigh:
 860         if ((orig_neigh_node) && (!is_single_hop_neigh))
 861                 orig_node_free_ref(orig_neigh_node);
 862 out:
 863         if (router)
 864                 neigh_node_free_ref(router);
 865         if (router_router)
 866                 neigh_node_free_ref(router_router);
 867         if (orig_neigh_router)
 868                 neigh_node_free_ref(orig_neigh_router);
 869
 870         orig_node_free_ref(orig_node);
 871 }
 872
 873 int recv_bat_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
 874 {
 875         struct ethhdr *ethhdr;
 876
 877         /* drop packet if it has not necessary minimum size */
 878         if (unlikely(!pskb_may_pull(skb, sizeof(struct batman_packet))))
 879                 return NET_RX_DROP;
 880
 881         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 882
 883         /* packet with broadcast indication but unicast recipient */
 884         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 885                 return NET_RX_DROP;
 886
 887         /* packet with broadcast sender address */
 888         if (is_broadcast_ether_addr(ethhdr->h_source))
 889                 return NET_RX_DROP;
 890
 891         /* create a copy of the skb, if needed, to modify it. */
 892         if (skb_cow(skb, 0) < 0)
 893                 return NET_RX_DROP;
 894
 895         /* keep skb linear */
 896         if (skb_linearize(skb) < 0)
 897                 return NET_RX_DROP;
 898
 899         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 900
 901         receive_aggr_bat_packet(ethhdr,
 902                                 skb->data,
 903                                 skb_headlen(skb),
 904                                 hard_iface);
 905
 906         kfree_skb(skb);
 907         return NET_RX_SUCCESS;
 908 }
 909
 910 static int recv_my_icmp_packet(struct bat_priv *bat_priv,
 911                                struct sk_buff *skb, size_t icmp_len)
 912 {
 913         struct hard_iface *primary_if = NULL;
 914         struct orig_node *orig_node = NULL;
 915         struct neigh_node *router = NULL;
 916         struct icmp_packet_rr *icmp_packet;
 917         int ret = NET_RX_DROP;
 918
 919         icmp_packet = (struct icmp_packet_rr *)skb->data;
 920
 921         /* add data to device queue */
 922         if (icmp_packet->msg_type != ECHO_REQUEST) {
 923                 bat_socket_receive_packet(icmp_packet, icmp_len);
 924                 goto out;
 925         }
 926
 927         primary_if = primary_if_get_selected(bat_priv);
 928         if (!primary_if)
 929                 goto out;
 930
 931         /* answer echo request (ping) */
 932         /* get routing information */
 933         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 934         if (!orig_node)
 935                 goto out;
 936
 937         router = orig_node_get_router(orig_node);
 938         if (!router)
 939                 goto out;
 940
 941         /* create a copy of the skb, if needed, to modify it. */
 942         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 943                 goto out;
 944
 945         icmp_packet = (struct icmp_packet_rr *)skb->data;
 946
 947         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 948         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 949         icmp_packet->msg_type = ECHO_REPLY;
 950         icmp_packet->ttl = TTL;
 951
 952         send_skb_packet(skb, router->if_incoming, router->addr);
 953         ret = NET_RX_SUCCESS;
 954
 955 out:
 956         if (primary_if)
 957                 hardif_free_ref(primary_if);
 958         if (router)
 959                 neigh_node_free_ref(router);
 960         if (orig_node)
 961                 orig_node_free_ref(orig_node);
 962         return ret;
 963 }
 964
 965 static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
 966                                   struct sk_buff *skb)
 967 {
 968         struct hard_iface *primary_if = NULL;
 969         struct orig_node *orig_node = NULL;
 970         struct neigh_node *router = NULL;
 971         struct icmp_packet *icmp_packet;
 972         int ret = NET_RX_DROP;
 973
 974         icmp_packet = (struct icmp_packet *)skb->data;
 975
 976         /* send TTL exceeded if packet is an echo request (traceroute) */
 977         if (icmp_packet->msg_type != ECHO_REQUEST) {
 978                 pr_debug("Warning - can't forward icmp packet from %pM to "
 979                          "%pM: ttl exceeded\n", icmp_packet->orig,
 980                          icmp_packet->dst);
 981                 goto out;
 982         }
 983
 984         primary_if = primary_if_get_selected(bat_priv);
 985         if (!primary_if)
 986                 goto out;
 987
 988         /* get routing information */
 989         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 990         if (!orig_node)
 991                 goto out;
 992
 993         router = orig_node_get_router(orig_node);
 994         if (!router)
 995                 goto out;
 996
 997         /* create a copy of the skb, if needed, to modify it. */
 998         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 999                 goto out;
1000
1001         icmp_packet = (struct icmp_packet *)skb->data;
1002
1003         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
1004         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
1005         icmp_packet->msg_type = TTL_EXCEEDED;
1006         icmp_packet->ttl = TTL;
1007
1008         send_skb_packet(skb, router->if_incoming, router->addr);
1009         ret = NET_RX_SUCCESS;
1010
1011 out:
1012         if (primary_if)
1013                 hardif_free_ref(primary_if);
1014         if (router)
1015                 neigh_node_free_ref(router);
1016         if (orig_node)
1017                 orig_node_free_ref(orig_node);
1018         return ret;
1019 }
1020
1021
1022 int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1023 {
1024         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1025         struct icmp_packet_rr *icmp_packet;
1026         struct ethhdr *ethhdr;
1027         struct orig_node *orig_node = NULL;
1028         struct neigh_node *router = NULL;
1029         int hdr_size = sizeof(struct icmp_packet);
1030         int ret = NET_RX_DROP;
1031
1032         /**
1033          * we truncate all incoming icmp packets if they don't match our size
1034          */
1035         if (skb->len >= sizeof(struct icmp_packet_rr))
1036                 hdr_size = sizeof(struct icmp_packet_rr);
1037
1038         /* drop packet if it has not necessary minimum size */
1039         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1040                 goto out;
1041
1042         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1043
1044         /* packet with unicast indication but broadcast recipient */
1045         if (is_broadcast_ether_addr(ethhdr->h_dest))
1046                 goto out;
1047
1048         /* packet with broadcast sender address */
1049         if (is_broadcast_ether_addr(ethhdr->h_source))
1050                 goto out;
1051
1052         /* not for me */
1053         if (!is_my_mac(ethhdr->h_dest))
1054                 goto out;
1055
1056         icmp_packet = (struct icmp_packet_rr *)skb->data;
1057
1058         /* add record route information if not full */
1059         if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
1060             (icmp_packet->rr_cur < BAT_RR_LEN)) {
1061                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
1062                         ethhdr->h_dest, ETH_ALEN);
1063                 icmp_packet->rr_cur++;
1064         }
1065
1066         /* packet for me */
1067         if (is_my_mac(icmp_packet->dst))
1068                 return recv_my_icmp_packet(bat_priv, skb, hdr_size);
1069
1070         /* TTL exceeded */
1071         if (icmp_packet->ttl < 2)
1072                 return recv_icmp_ttl_exceeded(bat_priv, skb);
1073
1074         /* get routing information */
1075         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
1076         if (!orig_node)
1077                 goto out;
1078
1079         router = orig_node_get_router(orig_node);
1080         if (!router)
1081                 goto out;
1082
1083         /* create a copy of the skb, if needed, to modify it. */
1084         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
1085                 goto out;
1086
1087         icmp_packet = (struct icmp_packet_rr *)skb->data;
1088
1089         /* decrement ttl */
1090         icmp_packet->ttl--;
1091
1092         /* route it */
1093         send_skb_packet(skb, router->if_incoming, router->addr);
1094         ret = NET_RX_SUCCESS;
1095
1096 out:
1097         if (router)
1098                 neigh_node_free_ref(router);
1099         if (orig_node)
1100                 orig_node_free_ref(orig_node);
1101         return ret;
1102 }
1103
1104 /* In the bonding case, send the packets in a round
1105  * robin fashion over the remaining interfaces.
1106  *
1107  * This method rotates the bonding list and increases the
1108  * returned router's refcount. */
1109 static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
1110                                            const struct hard_iface *recv_if)
1111 {
1112         struct neigh_node *tmp_neigh_node;
1113         struct neigh_node *router = NULL, *first_candidate = NULL;
1114
1115         rcu_read_lock();
1116         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
1117                                 bonding_list) {
1118                 if (!first_candidate)
1119                         first_candidate = tmp_neigh_node;
1120
1121                 /* recv_if == NULL on the first node. */
1122                 if (tmp_neigh_node->if_incoming == recv_if)
1123                         continue;
1124
1125                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
1126                         continue;
1127
1128                 router = tmp_neigh_node;
1129                 break;
1130         }
1131
1132         /* use the first candidate if nothing was found. */
1133         if (!router && first_candidate &&
1134             atomic_inc_not_zero(&first_candidate->refcount))
1135                 router = first_candidate;
1136
1137         if (!router)
1138                 goto out;
1139
1140         /* selected should point to the next element
1141          * after the current router */
1142         spin_lock_bh(&primary_orig->neigh_list_lock);
1143         /* this is a list_move(), which unfortunately
1144          * does not exist as rcu version */
1145         list_del_rcu(&primary_orig->bond_list);
1146         list_add_rcu(&primary_orig->bond_list,
1147                      &router->bonding_list);
1148         spin_unlock_bh(&primary_orig->neigh_list_lock);
1149
1150 out:
1151         rcu_read_unlock();
1152         return router;
1153 }
1154
1155 /* Interface Alternating: Use the best of the
1156  * remaining candidates which are not using
1157  * this interface.
1158  *
1159  * Increases the returned router's refcount */
1160 static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
1161                                               const struct hard_iface *recv_if)
1162 {
1163         struct neigh_node *tmp_neigh_node;
1164         struct neigh_node *router = NULL, *first_candidate = NULL;
1165
1166         rcu_read_lock();
1167         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
1168                                 bonding_list) {
1169                 if (!first_candidate)
1170                         first_candidate = tmp_neigh_node;
1171
1172                 /* recv_if == NULL on the first node. */
1173                 if (tmp_neigh_node->if_incoming == recv_if)
1174                         continue;
1175
1176                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
1177                         continue;
1178
1179                 /* if we don't have a router yet
1180                  * or this one is better, choose it. */
1181                 if ((!router) ||
1182                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
1183                         /* decrement refcount of
1184                          * previously selected router */
1185                         if (router)
1186                                 neigh_node_free_ref(router);
1187
1188                         router = tmp_neigh_node;
1189                         atomic_inc_not_zero(&router->refcount);
1190                 }
1191
1192                 neigh_node_free_ref(tmp_neigh_node);
1193         }
1194
1195         /* use the first candidate if nothing was found. */
1196         if (!router && first_candidate &&
1197             atomic_inc_not_zero(&first_candidate->refcount))
1198                 router = first_candidate;
1199
1200         rcu_read_unlock();
1201         return router;
1202 }
1203
1204 int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
1205 {
1206         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1207         struct tt_query_packet *tt_query;
1208         struct ethhdr *ethhdr;
1209
1210         /* drop packet if it has not necessary minimum size */
1211         if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
1212                 goto out;
1213
1214         /* I could need to modify it */
1215         if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
1216                 goto out;
1217
1218         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1219
1220         /* packet with unicast indication but broadcast recipient */
1221         if (is_broadcast_ether_addr(ethhdr->h_dest))
1222                 goto out;
1223
1224         /* packet with broadcast sender address */
1225         if (is_broadcast_ether_addr(ethhdr->h_source))
1226                 goto out;
1227
1228         tt_query = (struct tt_query_packet *)skb->data;
1229
1230         tt_query->tt_data = ntohs(tt_query->tt_data);
1231
1232         switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
1233         case TT_REQUEST:
1234                 /* If we cannot provide an answer the tt_request is
1235                  * forwarded */
1236                 if (!send_tt_response(bat_priv, tt_query)) {
1237                         bat_dbg(DBG_TT, bat_priv,
1238                                 "Routing TT_REQUEST to %pM [%c]\n",
1239                                 tt_query->dst,
1240                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
1241                         tt_query->tt_data = htons(tt_query->tt_data);
1242                         return route_unicast_packet(skb, recv_if);
1243                 }
1244                 break;
1245         case TT_RESPONSE:
1246                 /* packet needs to be linearised to access the TT changes */
1247                 if (skb_linearize(skb) < 0)
1248                         goto out;
1249
1250                 if (is_my_mac(tt_query->dst))
1251                         handle_tt_response(bat_priv, tt_query);
1252                 else {
1253                         bat_dbg(DBG_TT, bat_priv,
1254                                 "Routing TT_RESPONSE to %pM [%c]\n",
1255                                 tt_query->dst,
1256                                 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
1257                         tt_query->tt_data = htons(tt_query->tt_data);
1258                         return route_unicast_packet(skb, recv_if);
1259                 }
1260                 break;
1261         }
1262
1263 out:
1264         /* returning NET_RX_DROP will make the caller function kfree the skb */
1265         return NET_RX_DROP;
1266 }
1267
1268 int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
1269 {
1270         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1271         struct roam_adv_packet *roam_adv_packet;
1272         struct orig_node *orig_node;
1273         struct ethhdr *ethhdr;
1274
1275         /* drop packet if it has not necessary minimum size */
1276         if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
1277                 goto out;
1278
1279         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1280
1281         /* packet with unicast indication but broadcast recipient */
1282         if (is_broadcast_ether_addr(ethhdr->h_dest))
1283                 goto out;
1284
1285         /* packet with broadcast sender address */
1286         if (is_broadcast_ether_addr(ethhdr->h_source))
1287                 goto out;
1288
1289         roam_adv_packet = (struct roam_adv_packet *)skb->data;
1290
1291         if (!is_my_mac(roam_adv_packet->dst))
1292                 return route_unicast_packet(skb, recv_if);
1293
1294         orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
1295         if (!orig_node)
1296                 goto out;
1297
1298         bat_dbg(DBG_TT, bat_priv, "Received ROAMING_ADV from %pM "
1299                 "(client %pM)\n", roam_adv_packet->src,
1300                 roam_adv_packet->client);
1301
1302         tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
1303                       atomic_read(&orig_node->last_ttvn) + 1, true);
1304
1305         /* Roaming phase starts: I have new information but the ttvn has not
1306          * been incremented yet. This flag will make me check all the incoming
1307          * packets for the correct destination. */
1308         bat_priv->tt_poss_change = true;
1309
1310         orig_node_free_ref(orig_node);
1311 out:
1312         /* returning NET_RX_DROP will make the caller function kfree the skb */
1313         return NET_RX_DROP;
1314 }
1315
1316 /* find a suitable router for this originator, and use
1317  * bonding if possible. increases the found neighbors
1318  * refcount.*/
1319 struct neigh_node *find_router(struct bat_priv *bat_priv,
1320                                struct orig_node *orig_node,
1321                                const struct hard_iface *recv_if)
1322 {
1323         struct orig_node *primary_orig_node;
1324         struct orig_node *router_orig;
1325         struct neigh_node *router;
1326         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
1327         int bonding_enabled;
1328
1329         if (!orig_node)
1330                 return NULL;
1331
1332         router = orig_node_get_router(orig_node);
1333         if (!router)
1334                 goto err;
1335
1336         /* without bonding, the first node should
1337          * always choose the default router. */
1338         bonding_enabled = atomic_read(&bat_priv->bonding);
1339
1340         rcu_read_lock();
1341         /* select default router to output */
1342         router_orig = router->orig_node;
1343         if (!router_orig)
1344                 goto err_unlock;
1345
1346         if ((!recv_if) && (!bonding_enabled))
1347                 goto return_router;
1348
1349         /* if we have something in the primary_addr, we can search
1350          * for a potential bonding candidate. */
1351         if (compare_eth(router_orig->primary_addr, zero_mac))
1352                 goto return_router;
1353
1354         /* find the orig_node which has the primary interface. might
1355          * even be the same as our router_orig in many cases */
1356
1357         if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
1358                 primary_orig_node = router_orig;
1359         } else {
1360                 primary_orig_node = orig_hash_find(bat_priv,
1361                                                    router_orig->primary_addr);
1362                 if (!primary_orig_node)
1363                         goto return_router;
1364
1365                 orig_node_free_ref(primary_orig_node);
1366         }
1367
1368         /* with less than 2 candidates, we can't do any
1369          * bonding and prefer the original router. */
1370         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
1371                 goto return_router;
1372
1373         /* all nodes between should choose a candidate which
1374          * is is not on the interface where the packet came
1375          * in. */
1376
1377         neigh_node_free_ref(router);
1378
1379         if (bonding_enabled)
1380                 router = find_bond_router(primary_orig_node, recv_if);
1381         else
1382                 router = find_ifalter_router(primary_orig_node, recv_if);
1383
1384 return_router:
1385         if (router && router->if_incoming->if_status != IF_ACTIVE)
1386                 goto err_unlock;
1387
1388         rcu_read_unlock();
1389         return router;
1390 err_unlock:
1391         rcu_read_unlock();
1392 err:
1393         if (router)
1394                 neigh_node_free_ref(router);
1395         return NULL;
1396 }
1397
1398 static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
1399 {
1400         struct ethhdr *ethhdr;
1401
1402         /* drop packet if it has not necessary minimum size */
1403         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1404                 return -1;
1405
1406         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1407
1408         /* packet with unicast indication but broadcast recipient */
1409         if (is_broadcast_ether_addr(ethhdr->h_dest))
1410                 return -1;
1411
1412         /* packet with broadcast sender address */
1413         if (is_broadcast_ether_addr(ethhdr->h_source))
1414                 return -1;
1415
1416         /* not for me */
1417         if (!is_my_mac(ethhdr->h_dest))
1418                 return -1;
1419
1420         return 0;
1421 }
1422
1423 int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1424 {
1425         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1426         struct orig_node *orig_node = NULL;
1427         struct neigh_node *neigh_node = NULL;
1428         struct unicast_packet *unicast_packet;
1429         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
1430         int ret = NET_RX_DROP;
1431         struct sk_buff *new_skb;
1432
1433         unicast_packet = (struct unicast_packet *)skb->data;
1434
1435         /* TTL exceeded */
1436         if (unicast_packet->ttl < 2) {
1437                 pr_debug("Warning - can't forward unicast packet from %pM to "
1438                          "%pM: ttl exceeded\n", ethhdr->h_source,
1439                          unicast_packet->dest);
1440                 goto out;
1441         }
1442
1443         /* get routing information */
1444         orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
1445
1446         if (!orig_node)
1447                 goto out;
1448
1449         /* find_router() increases neigh_nodes refcount if found. */
1450         neigh_node = find_router(bat_priv, orig_node, recv_if);
1451
1452         if (!neigh_node)
1453                 goto out;
1454
1455         /* create a copy of the skb, if needed, to modify it. */
1456         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
1457                 goto out;
1458
1459         unicast_packet = (struct unicast_packet *)skb->data;
1460
1461         if (unicast_packet->packet_type == BAT_UNICAST &&
1462             atomic_read(&bat_priv->fragmentation) &&
1463             skb->len > neigh_node->if_incoming->net_dev->mtu) {
1464                 ret = frag_send_skb(skb, bat_priv,
1465                                     neigh_node->if_incoming, neigh_node->addr);
1466                 goto out;
1467         }
1468
1469         if (unicast_packet->packet_type == BAT_UNICAST_FRAG &&
1470             frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
1471
1472                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
1473
1474                 if (ret == NET_RX_DROP)
1475                         goto out;
1476
1477                 /* packet was buffered for late merge */
1478                 if (!new_skb) {
1479                         ret = NET_RX_SUCCESS;
1480                         goto out;
1481                 }
1482
1483                 skb = new_skb;
1484                 unicast_packet = (struct unicast_packet *)skb->data;
1485         }
1486
1487         /* decrement ttl */
1488         unicast_packet->ttl--;
1489
1490         /* route it */
1491         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
1492         ret = NET_RX_SUCCESS;
1493
1494 out:
1495         if (neigh_node)
1496                 neigh_node_free_ref(neigh_node);
1497         if (orig_node)
1498                 orig_node_free_ref(orig_node);
1499         return ret;
1500 }
1501
1502 static int check_unicast_ttvn(struct bat_priv *bat_priv,
1503                                struct sk_buff *skb) {
1504         uint8_t curr_ttvn;
1505         struct orig_node *orig_node;
1506         struct ethhdr *ethhdr;
1507         struct hard_iface *primary_if;
1508         struct unicast_packet *unicast_packet;
1509         bool tt_poss_change;
1510
1511         /* I could need to modify it */
1512         if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
1513                 return 0;
1514
1515         unicast_packet = (struct unicast_packet *)skb->data;
1516
1517         if (is_my_mac(unicast_packet->dest)) {
1518                 tt_poss_change = bat_priv->tt_poss_change;
1519                 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
1520         } else {
1521                 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
1522
1523                 if (!orig_node)
1524                         return 0;
1525
1526                 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
1527                 tt_poss_change = orig_node->tt_poss_change;
1528                 orig_node_free_ref(orig_node);
1529         }
1530
1531         /* Check whether I have to reroute the packet */
1532         if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
1533                 /* Linearize the skb before accessing it */
1534                 if (skb_linearize(skb) < 0)
1535                         return 0;
1536
1537                 ethhdr = (struct ethhdr *)(skb->data +
1538                         sizeof(struct unicast_packet));
1539                 orig_node = transtable_search(bat_priv, ethhdr->h_dest);
1540
1541                 if (!orig_node) {
1542                         if (!is_my_client(bat_priv, ethhdr->h_dest))
1543                                 return 0;
1544                         primary_if = primary_if_get_selected(bat_priv);
1545                         if (!primary_if)
1546                                 return 0;
1547                         memcpy(unicast_packet->dest,
1548                                primary_if->net_dev->dev_addr, ETH_ALEN);
1549                         hardif_free_ref(primary_if);
1550                 } else {
1551                         memcpy(unicast_packet->dest, orig_node->orig,
1552                                ETH_ALEN);
1553                         curr_ttvn = (uint8_t)
1554                                 atomic_read(&orig_node->last_ttvn);
1555                         orig_node_free_ref(orig_node);
1556                 }
1557
1558                 bat_dbg(DBG_ROUTES, bat_priv, "TTVN mismatch (old_ttvn %u "
1559                         "new_ttvn %u)! Rerouting unicast packet (for %pM) to "
1560                         "%pM\n", unicast_packet->ttvn, curr_ttvn,
1561                         ethhdr->h_dest, unicast_packet->dest);
1562
1563                 unicast_packet->ttvn = curr_ttvn;
1564         }
1565         return 1;
1566 }
1567
1568 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1569 {
1570         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1571         struct unicast_packet *unicast_packet;
1572         int hdr_size = sizeof(*unicast_packet);
1573
1574         if (check_unicast_packet(skb, hdr_size) < 0)
1575                 return NET_RX_DROP;
1576
1577         if (!check_unicast_ttvn(bat_priv, skb))
1578                 return NET_RX_DROP;
1579
1580         unicast_packet = (struct unicast_packet *)skb->data;
1581
1582         /* packet for me */
1583         if (is_my_mac(unicast_packet->dest)) {
1584                 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1585                 return NET_RX_SUCCESS;
1586         }
1587
1588         return route_unicast_packet(skb, recv_if);
1589 }
1590
1591 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1592 {
1593         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1594         struct unicast_frag_packet *unicast_packet;
1595         int hdr_size = sizeof(*unicast_packet);
1596         struct sk_buff *new_skb = NULL;
1597         int ret;
1598
1599         if (check_unicast_packet(skb, hdr_size) < 0)
1600                 return NET_RX_DROP;
1601
1602         if (!check_unicast_ttvn(bat_priv, skb))
1603                 return NET_RX_DROP;
1604
1605         unicast_packet = (struct unicast_frag_packet *)skb->data;
1606
1607         /* packet for me */
1608         if (is_my_mac(unicast_packet->dest)) {
1609
1610                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
1611
1612                 if (ret == NET_RX_DROP)
1613                         return NET_RX_DROP;
1614
1615                 /* packet was buffered for late merge */
1616                 if (!new_skb)
1617                         return NET_RX_SUCCESS;
1618
1619                 interface_rx(recv_if->soft_iface, new_skb, recv_if,
1620                              sizeof(struct unicast_packet));
1621                 return NET_RX_SUCCESS;
1622         }
1623
1624         return route_unicast_packet(skb, recv_if);
1625 }
1626
1627
1628 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1629 {
1630         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1631         struct orig_node *orig_node = NULL;
1632         struct bcast_packet *bcast_packet;
1633         struct ethhdr *ethhdr;
1634         int hdr_size = sizeof(*bcast_packet);
1635         int ret = NET_RX_DROP;
1636         int32_t seq_diff;
1637
1638         /* drop packet if it has not necessary minimum size */
1639         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1640                 goto out;
1641
1642         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1643
1644         /* packet with broadcast indication but unicast recipient */
1645         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1646                 goto out;
1647
1648         /* packet with broadcast sender address */
1649         if (is_broadcast_ether_addr(ethhdr->h_source))
1650                 goto out;
1651
1652         /* ignore broadcasts sent by myself */
1653         if (is_my_mac(ethhdr->h_source))
1654                 goto out;
1655
1656         bcast_packet = (struct bcast_packet *)skb->data;
1657
1658         /* ignore broadcasts originated by myself */
1659         if (is_my_mac(bcast_packet->orig))
1660                 goto out;
1661
1662         if (bcast_packet->ttl < 2)
1663                 goto out;
1664
1665         orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1666
1667         if (!orig_node)
1668                 goto out;
1669
1670         spin_lock_bh(&orig_node->bcast_seqno_lock);
1671
1672         /* check whether the packet is a duplicate */
1673         if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1674                            ntohl(bcast_packet->seqno)))
1675                 goto spin_unlock;
1676
1677         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1678
1679         /* check whether the packet is old and the host just restarted. */
1680         if (window_protected(bat_priv, seq_diff,
1681                              &orig_node->bcast_seqno_reset))
1682                 goto spin_unlock;
1683
1684         /* mark broadcast in flood history, update window position
1685          * if required. */
1686         if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1687                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1688
1689         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1690
1691         /* rebroadcast packet */
1692         add_bcast_packet_to_list(bat_priv, skb, 1);
1693
1694         /* broadcast for me */
1695         interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1696         ret = NET_RX_SUCCESS;
1697         goto out;
1698
1699 spin_unlock:
1700         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1701 out:
1702         if (orig_node)
1703                 orig_node_free_ref(orig_node);
1704         return ret;
1705 }
1706
1707 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1708 {
1709         struct vis_packet *vis_packet;
1710         struct ethhdr *ethhdr;
1711         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1712         int hdr_size = sizeof(*vis_packet);
1713
1714         /* keep skb linear */
1715         if (skb_linearize(skb) < 0)
1716                 return NET_RX_DROP;
1717
1718         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1719                 return NET_RX_DROP;
1720
1721         vis_packet = (struct vis_packet *)skb->data;
1722         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1723
1724         /* not for me */
1725         if (!is_my_mac(ethhdr->h_dest))
1726                 return NET_RX_DROP;
1727
1728         /* ignore own packets */
1729         if (is_my_mac(vis_packet->vis_orig))
1730                 return NET_RX_DROP;
1731
1732         if (is_my_mac(vis_packet->sender_orig))
1733                 return NET_RX_DROP;
1734
1735         switch (vis_packet->vis_type) {
1736         case VIS_TYPE_SERVER_SYNC:
1737                 receive_server_sync_packet(bat_priv, vis_packet,
1738                                            skb_headlen(skb));
1739                 break;
1740
1741         case VIS_TYPE_CLIENT_UPDATE:
1742                 receive_client_update_packet(bat_priv, vis_packet,
1743                                              skb_headlen(skb));
1744                 break;
1745
1746         default:        /* ignore unknown packet */
1747                 break;
1748         }
1749
1750         /* We take a copy of the data in the packet, so we should
1751            always free the skbuf. */
1752         return NET_RX_DROP;
1753 }