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