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