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 if (neigh_node && curr_router) {
 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         uint8_t 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                         int 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 int 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         int 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         int has_directlink_flag;
 606         int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
 607         int is_broadcast = 0, is_bidirectional, is_single_hop_neigh;
 608         int 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 (is_broadcast_ether_addr(ethhdr->h_source))
 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                 /* save packet seqno for bidirectional check */
 702                 if (has_directlink_flag &&
 703                     compare_eth(if_incoming->net_dev->dev_addr,
 704                                 batman_packet->orig)) {
 705                         offset = if_incoming->if_num * NUM_WORDS;
 706
 707                         spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
 708                         word = &(orig_neigh_node->bcast_own[offset]);
 709                         bit_mark(word,
 710                                  if_incoming_seqno - batman_packet->seqno - 2);
 711                         orig_neigh_node->bcast_own_sum[if_incoming->if_num] =
 712                                 bit_packet_count(word);
 713                         spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
 714                 }
 715
 716                 bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
 717                         "originator packet from myself (via neighbor)\n");
 718                 orig_node_free_ref(orig_neigh_node);
 719                 return;
 720         }
 721
 722         if (is_my_oldorig) {
 723                 bat_dbg(DBG_BATMAN, bat_priv,
 724                         "Drop packet: ignoring all rebroadcast echos (sender: "
 725                         "%pM)\n", ethhdr->h_source);
 726                 return;
 727         }
 728
 729         orig_node = get_orig_node(bat_priv, batman_packet->orig);
 730         if (!orig_node)
 731                 return;
 732
 733         is_duplicate = count_real_packets(ethhdr, batman_packet, if_incoming);
 734
 735         if (is_duplicate == -1) {
 736                 bat_dbg(DBG_BATMAN, bat_priv,
 737                         "Drop packet: packet within seqno protection time "
 738                         "(sender: %pM)\n", ethhdr->h_source);
 739                 goto out;
 740         }
 741
 742         if (batman_packet->tq == 0) {
 743                 bat_dbg(DBG_BATMAN, bat_priv,
 744                         "Drop packet: originator packet with tq equal 0\n");
 745                 goto out;
 746         }
 747
 748         router = orig_node_get_router(orig_node);
 749         if (router)
 750                 router_router = orig_node_get_router(router->orig_node);
 751
 752         /* avoid temporary routing loops */
 753         if (router && router_router &&
 754             (compare_eth(router->addr, batman_packet->prev_sender)) &&
 755             !(compare_eth(batman_packet->orig, batman_packet->prev_sender)) &&
 756             (compare_eth(router->addr, router_router->addr))) {
 757                 bat_dbg(DBG_BATMAN, bat_priv,
 758                         "Drop packet: ignoring all rebroadcast packets that "
 759                         "may make me loop (sender: %pM)\n", ethhdr->h_source);
 760                 goto out;
 761         }
 762
 763         /* if sender is a direct neighbor the sender mac equals
 764          * originator mac */
 765         orig_neigh_node = (is_single_hop_neigh ?
 766                            orig_node :
 767                            get_orig_node(bat_priv, ethhdr->h_source));
 768         if (!orig_neigh_node)
 769                 goto out;
 770
 771         orig_neigh_router = orig_node_get_router(orig_neigh_node);
 772
 773         /* drop packet if sender is not a direct neighbor and if we
 774          * don't route towards it */
 775         if (!is_single_hop_neigh && (!orig_neigh_router)) {
 776                 bat_dbg(DBG_BATMAN, bat_priv,
 777                         "Drop packet: OGM via unknown neighbor!\n");
 778                 goto out_neigh;
 779         }
 780
 781         is_bidirectional = is_bidirectional_neigh(orig_node, orig_neigh_node,
 782                                                 batman_packet, if_incoming);
 783
 784         bonding_save_primary(orig_node, orig_neigh_node, batman_packet);
 785
 786         /* update ranking if it is not a duplicate or has the same
 787          * seqno and similar ttl as the non-duplicate */
 788         if (is_bidirectional &&
 789             (!is_duplicate ||
 790              ((orig_node->last_real_seqno == batman_packet->seqno) &&
 791               (orig_node->last_ttl - 3 <= batman_packet->ttl))))
 792                 update_orig(bat_priv, orig_node, ethhdr, batman_packet,
 793                             if_incoming, tt_buff, tt_buff_len, is_duplicate);
 794
 795         /* is single hop (direct) neighbor */
 796         if (is_single_hop_neigh) {
 797
 798                 /* mark direct link on incoming interface */
 799                 schedule_forward_packet(orig_node, ethhdr, batman_packet,
 800                                         1, tt_buff_len, if_incoming);
 801
 802                 bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: "
 803                         "rebroadcast neighbor packet with direct link flag\n");
 804                 goto out_neigh;
 805         }
 806
 807         /* multihop originator */
 808         if (!is_bidirectional) {
 809                 bat_dbg(DBG_BATMAN, bat_priv,
 810                         "Drop packet: not received via bidirectional link\n");
 811                 goto out_neigh;
 812         }
 813
 814         if (is_duplicate) {
 815                 bat_dbg(DBG_BATMAN, bat_priv,
 816                         "Drop packet: duplicate packet received\n");
 817                 goto out_neigh;
 818         }
 819
 820         bat_dbg(DBG_BATMAN, bat_priv,
 821                 "Forwarding packet: rebroadcast originator packet\n");
 822         schedule_forward_packet(orig_node, ethhdr, batman_packet,
 823                                 0, tt_buff_len, if_incoming);
 824
 825 out_neigh:
 826         if ((orig_neigh_node) && (!is_single_hop_neigh))
 827                 orig_node_free_ref(orig_neigh_node);
 828 out:
 829         if (router)
 830                 neigh_node_free_ref(router);
 831         if (router_router)
 832                 neigh_node_free_ref(router_router);
 833         if (orig_neigh_router)
 834                 neigh_node_free_ref(orig_neigh_router);
 835
 836         orig_node_free_ref(orig_node);
 837 }
 838
 839 int recv_bat_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
 840 {
 841         struct ethhdr *ethhdr;
 842
 843         /* drop packet if it has not necessary minimum size */
 844         if (unlikely(!pskb_may_pull(skb, sizeof(struct batman_packet))))
 845                 return NET_RX_DROP;
 846
 847         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 848
 849         /* packet with broadcast indication but unicast recipient */
 850         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 851                 return NET_RX_DROP;
 852
 853         /* packet with broadcast sender address */
 854         if (is_broadcast_ether_addr(ethhdr->h_source))
 855                 return NET_RX_DROP;
 856
 857         /* create a copy of the skb, if needed, to modify it. */
 858         if (skb_cow(skb, 0) < 0)
 859                 return NET_RX_DROP;
 860
 861         /* keep skb linear */
 862         if (skb_linearize(skb) < 0)
 863                 return NET_RX_DROP;
 864
 865         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 866
 867         receive_aggr_bat_packet(ethhdr,
 868                                 skb->data,
 869                                 skb_headlen(skb),
 870                                 hard_iface);
 871
 872         kfree_skb(skb);
 873         return NET_RX_SUCCESS;
 874 }
 875
 876 static int recv_my_icmp_packet(struct bat_priv *bat_priv,
 877                                struct sk_buff *skb, size_t icmp_len)
 878 {
 879         struct hard_iface *primary_if = NULL;
 880         struct orig_node *orig_node = NULL;
 881         struct neigh_node *router = NULL;
 882         struct icmp_packet_rr *icmp_packet;
 883         int ret = NET_RX_DROP;
 884
 885         icmp_packet = (struct icmp_packet_rr *)skb->data;
 886
 887         /* add data to device queue */
 888         if (icmp_packet->msg_type != ECHO_REQUEST) {
 889                 bat_socket_receive_packet(icmp_packet, icmp_len);
 890                 goto out;
 891         }
 892
 893         primary_if = primary_if_get_selected(bat_priv);
 894         if (!primary_if)
 895                 goto out;
 896
 897         /* answer echo request (ping) */
 898         /* get routing information */
 899         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 900         if (!orig_node)
 901                 goto out;
 902
 903         router = orig_node_get_router(orig_node);
 904         if (!router)
 905                 goto out;
 906
 907         /* create a copy of the skb, if needed, to modify it. */
 908         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 909                 goto out;
 910
 911         icmp_packet = (struct icmp_packet_rr *)skb->data;
 912
 913         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 914         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 915         icmp_packet->msg_type = ECHO_REPLY;
 916         icmp_packet->ttl = TTL;
 917
 918         send_skb_packet(skb, router->if_incoming, router->addr);
 919         ret = NET_RX_SUCCESS;
 920
 921 out:
 922         if (primary_if)
 923                 hardif_free_ref(primary_if);
 924         if (router)
 925                 neigh_node_free_ref(router);
 926         if (orig_node)
 927                 orig_node_free_ref(orig_node);
 928         return ret;
 929 }
 930
 931 static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
 932                                   struct sk_buff *skb)
 933 {
 934         struct hard_iface *primary_if = NULL;
 935         struct orig_node *orig_node = NULL;
 936         struct neigh_node *router = NULL;
 937         struct icmp_packet *icmp_packet;
 938         int ret = NET_RX_DROP;
 939
 940         icmp_packet = (struct icmp_packet *)skb->data;
 941
 942         /* send TTL exceeded if packet is an echo request (traceroute) */
 943         if (icmp_packet->msg_type != ECHO_REQUEST) {
 944                 pr_debug("Warning - can't forward icmp packet from %pM to "
 945                          "%pM: ttl exceeded\n", icmp_packet->orig,
 946                          icmp_packet->dst);
 947                 goto out;
 948         }
 949
 950         primary_if = primary_if_get_selected(bat_priv);
 951         if (!primary_if)
 952                 goto out;
 953
 954         /* get routing information */
 955         orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
 956         if (!orig_node)
 957                 goto out;
 958
 959         router = orig_node_get_router(orig_node);
 960         if (!router)
 961                 goto out;
 962
 963         /* create a copy of the skb, if needed, to modify it. */
 964         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
 965                 goto out;
 966
 967         icmp_packet = (struct icmp_packet *)skb->data;
 968
 969         memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
 970         memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 971         icmp_packet->msg_type = TTL_EXCEEDED;
 972         icmp_packet->ttl = TTL;
 973
 974         send_skb_packet(skb, router->if_incoming, router->addr);
 975         ret = NET_RX_SUCCESS;
 976
 977 out:
 978         if (primary_if)
 979                 hardif_free_ref(primary_if);
 980         if (router)
 981                 neigh_node_free_ref(router);
 982         if (orig_node)
 983                 orig_node_free_ref(orig_node);
 984         return ret;
 985 }
 986
 987
 988 int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
 989 {
 990         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 991         struct icmp_packet_rr *icmp_packet;
 992         struct ethhdr *ethhdr;
 993         struct orig_node *orig_node = NULL;
 994         struct neigh_node *router = NULL;
 995         int hdr_size = sizeof(struct icmp_packet);
 996         int ret = NET_RX_DROP;
 997
 998         /**
 999          * we truncate all incoming icmp packets if they don't match our size
1000          */
1001         if (skb->len >= sizeof(struct icmp_packet_rr))
1002                 hdr_size = sizeof(struct icmp_packet_rr);
1003
1004         /* drop packet if it has not necessary minimum size */
1005         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1006                 goto out;
1007
1008         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1009
1010         /* packet with unicast indication but broadcast recipient */
1011         if (is_broadcast_ether_addr(ethhdr->h_dest))
1012                 goto out;
1013
1014         /* packet with broadcast sender address */
1015         if (is_broadcast_ether_addr(ethhdr->h_source))
1016                 goto out;
1017
1018         /* not for me */
1019         if (!is_my_mac(ethhdr->h_dest))
1020                 goto out;
1021
1022         icmp_packet = (struct icmp_packet_rr *)skb->data;
1023
1024         /* add record route information if not full */
1025         if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
1026             (icmp_packet->rr_cur < BAT_RR_LEN)) {
1027                 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
1028                         ethhdr->h_dest, ETH_ALEN);
1029                 icmp_packet->rr_cur++;
1030         }
1031
1032         /* packet for me */
1033         if (is_my_mac(icmp_packet->dst))
1034                 return recv_my_icmp_packet(bat_priv, skb, hdr_size);
1035
1036         /* TTL exceeded */
1037         if (icmp_packet->ttl < 2)
1038                 return recv_icmp_ttl_exceeded(bat_priv, skb);
1039
1040         /* get routing information */
1041         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
1042         if (!orig_node)
1043                 goto out;
1044
1045         router = orig_node_get_router(orig_node);
1046         if (!router)
1047                 goto out;
1048
1049         /* create a copy of the skb, if needed, to modify it. */
1050         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
1051                 goto out;
1052
1053         icmp_packet = (struct icmp_packet_rr *)skb->data;
1054
1055         /* decrement ttl */
1056         icmp_packet->ttl--;
1057
1058         /* route it */
1059         send_skb_packet(skb, router->if_incoming, router->addr);
1060         ret = NET_RX_SUCCESS;
1061
1062 out:
1063         if (router)
1064                 neigh_node_free_ref(router);
1065         if (orig_node)
1066                 orig_node_free_ref(orig_node);
1067         return ret;
1068 }
1069
1070 /* In the bonding case, send the packets in a round
1071  * robin fashion over the remaining interfaces.
1072  *
1073  * This method rotates the bonding list and increases the
1074  * returned router's refcount. */
1075 static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
1076                                            const struct hard_iface *recv_if)
1077 {
1078         struct neigh_node *tmp_neigh_node;
1079         struct neigh_node *router = NULL, *first_candidate = NULL;
1080
1081         rcu_read_lock();
1082         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
1083                                 bonding_list) {
1084                 if (!first_candidate)
1085                         first_candidate = tmp_neigh_node;
1086
1087                 /* recv_if == NULL on the first node. */
1088                 if (tmp_neigh_node->if_incoming == recv_if)
1089                         continue;
1090
1091                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
1092                         continue;
1093
1094                 router = tmp_neigh_node;
1095                 break;
1096         }
1097
1098         /* use the first candidate if nothing was found. */
1099         if (!router && first_candidate &&
1100             atomic_inc_not_zero(&first_candidate->refcount))
1101                 router = first_candidate;
1102
1103         if (!router)
1104                 goto out;
1105
1106         /* selected should point to the next element
1107          * after the current router */
1108         spin_lock_bh(&primary_orig->neigh_list_lock);
1109         /* this is a list_move(), which unfortunately
1110          * does not exist as rcu version */
1111         list_del_rcu(&primary_orig->bond_list);
1112         list_add_rcu(&primary_orig->bond_list,
1113                      &router->bonding_list);
1114         spin_unlock_bh(&primary_orig->neigh_list_lock);
1115
1116 out:
1117         rcu_read_unlock();
1118         return router;
1119 }
1120
1121 /* Interface Alternating: Use the best of the
1122  * remaining candidates which are not using
1123  * this interface.
1124  *
1125  * Increases the returned router's refcount */
1126 static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
1127                                               const struct hard_iface *recv_if)
1128 {
1129         struct neigh_node *tmp_neigh_node;
1130         struct neigh_node *router = NULL, *first_candidate = NULL;
1131
1132         rcu_read_lock();
1133         list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
1134                                 bonding_list) {
1135                 if (!first_candidate)
1136                         first_candidate = tmp_neigh_node;
1137
1138                 /* recv_if == NULL on the first node. */
1139                 if (tmp_neigh_node->if_incoming == recv_if)
1140                         continue;
1141
1142                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
1143                         continue;
1144
1145                 /* if we don't have a router yet
1146                  * or this one is better, choose it. */
1147                 if ((!router) ||
1148                     (tmp_neigh_node->tq_avg > router->tq_avg)) {
1149                         /* decrement refcount of
1150                          * previously selected router */
1151                         if (router)
1152                                 neigh_node_free_ref(router);
1153
1154                         router = tmp_neigh_node;
1155                         atomic_inc_not_zero(&router->refcount);
1156                 }
1157
1158                 neigh_node_free_ref(tmp_neigh_node);
1159         }
1160
1161         /* use the first candidate if nothing was found. */
1162         if (!router && first_candidate &&
1163             atomic_inc_not_zero(&first_candidate->refcount))
1164                 router = first_candidate;
1165
1166         rcu_read_unlock();
1167         return router;
1168 }
1169
1170 /* find a suitable router for this originator, and use
1171  * bonding if possible. increases the found neighbors
1172  * refcount.*/
1173 struct neigh_node *find_router(struct bat_priv *bat_priv,
1174                                struct orig_node *orig_node,
1175                                const struct hard_iface *recv_if)
1176 {
1177         struct orig_node *primary_orig_node;
1178         struct orig_node *router_orig;
1179         struct neigh_node *router;
1180         static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
1181         int bonding_enabled;
1182
1183         if (!orig_node)
1184                 return NULL;
1185
1186         router = orig_node_get_router(orig_node);
1187         if (!router)
1188                 goto err;
1189
1190         /* without bonding, the first node should
1191          * always choose the default router. */
1192         bonding_enabled = atomic_read(&bat_priv->bonding);
1193
1194         rcu_read_lock();
1195         /* select default router to output */
1196         router_orig = router->orig_node;
1197         if (!router_orig)
1198                 goto err_unlock;
1199
1200         if ((!recv_if) && (!bonding_enabled))
1201                 goto return_router;
1202
1203         /* if we have something in the primary_addr, we can search
1204          * for a potential bonding candidate. */
1205         if (compare_eth(router_orig->primary_addr, zero_mac))
1206                 goto return_router;
1207
1208         /* find the orig_node which has the primary interface. might
1209          * even be the same as our router_orig in many cases */
1210
1211         if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
1212                 primary_orig_node = router_orig;
1213         } else {
1214                 primary_orig_node = orig_hash_find(bat_priv,
1215                                                    router_orig->primary_addr);
1216                 if (!primary_orig_node)
1217                         goto return_router;
1218
1219                 orig_node_free_ref(primary_orig_node);
1220         }
1221
1222         /* with less than 2 candidates, we can't do any
1223          * bonding and prefer the original router. */
1224         if (atomic_read(&primary_orig_node->bond_candidates) < 2)
1225                 goto return_router;
1226
1227         /* all nodes between should choose a candidate which
1228          * is is not on the interface where the packet came
1229          * in. */
1230
1231         neigh_node_free_ref(router);
1232
1233         if (bonding_enabled)
1234                 router = find_bond_router(primary_orig_node, recv_if);
1235         else
1236                 router = find_ifalter_router(primary_orig_node, recv_if);
1237
1238 return_router:
1239         if (router && router->if_incoming->if_status != IF_ACTIVE)
1240                 goto err_unlock;
1241
1242         rcu_read_unlock();
1243         return router;
1244 err_unlock:
1245         rcu_read_unlock();
1246 err:
1247         if (router)
1248                 neigh_node_free_ref(router);
1249         return NULL;
1250 }
1251
1252 static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
1253 {
1254         struct ethhdr *ethhdr;
1255
1256         /* drop packet if it has not necessary minimum size */
1257         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1258                 return -1;
1259
1260         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1261
1262         /* packet with unicast indication but broadcast recipient */
1263         if (is_broadcast_ether_addr(ethhdr->h_dest))
1264                 return -1;
1265
1266         /* packet with broadcast sender address */
1267         if (is_broadcast_ether_addr(ethhdr->h_source))
1268                 return -1;
1269
1270         /* not for me */
1271         if (!is_my_mac(ethhdr->h_dest))
1272                 return -1;
1273
1274         return 0;
1275 }
1276
1277 int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1278 {
1279         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1280         struct orig_node *orig_node = NULL;
1281         struct neigh_node *neigh_node = NULL;
1282         struct unicast_packet *unicast_packet;
1283         struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
1284         int ret = NET_RX_DROP;
1285         struct sk_buff *new_skb;
1286
1287         unicast_packet = (struct unicast_packet *)skb->data;
1288
1289         /* TTL exceeded */
1290         if (unicast_packet->ttl < 2) {
1291                 pr_debug("Warning - can't forward unicast packet from %pM to "
1292                          "%pM: ttl exceeded\n", ethhdr->h_source,
1293                          unicast_packet->dest);
1294                 goto out;
1295         }
1296
1297         /* get routing information */
1298         orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
1299
1300         if (!orig_node)
1301                 goto out;
1302
1303         /* find_router() increases neigh_nodes refcount if found. */
1304         neigh_node = find_router(bat_priv, orig_node, recv_if);
1305
1306         if (!neigh_node)
1307                 goto out;
1308
1309         /* create a copy of the skb, if needed, to modify it. */
1310         if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
1311                 goto out;
1312
1313         unicast_packet = (struct unicast_packet *)skb->data;
1314
1315         if (unicast_packet->packet_type == BAT_UNICAST &&
1316             atomic_read(&bat_priv->fragmentation) &&
1317             skb->len > neigh_node->if_incoming->net_dev->mtu) {
1318                 ret = frag_send_skb(skb, bat_priv,
1319                                     neigh_node->if_incoming, neigh_node->addr);
1320                 goto out;
1321         }
1322
1323         if (unicast_packet->packet_type == BAT_UNICAST_FRAG &&
1324             frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
1325
1326                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
1327
1328                 if (ret == NET_RX_DROP)
1329                         goto out;
1330
1331                 /* packet was buffered for late merge */
1332                 if (!new_skb) {
1333                         ret = NET_RX_SUCCESS;
1334                         goto out;
1335                 }
1336
1337                 skb = new_skb;
1338                 unicast_packet = (struct unicast_packet *)skb->data;
1339         }
1340
1341         /* decrement ttl */
1342         unicast_packet->ttl--;
1343
1344         /* route it */
1345         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
1346         ret = NET_RX_SUCCESS;
1347
1348 out:
1349         if (neigh_node)
1350                 neigh_node_free_ref(neigh_node);
1351         if (orig_node)
1352                 orig_node_free_ref(orig_node);
1353         return ret;
1354 }
1355
1356 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1357 {
1358         struct unicast_packet *unicast_packet;
1359         int hdr_size = sizeof(*unicast_packet);
1360
1361         if (check_unicast_packet(skb, hdr_size) < 0)
1362                 return NET_RX_DROP;
1363
1364         unicast_packet = (struct unicast_packet *)skb->data;
1365
1366         /* packet for me */
1367         if (is_my_mac(unicast_packet->dest)) {
1368                 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1369                 return NET_RX_SUCCESS;
1370         }
1371
1372         return route_unicast_packet(skb, recv_if);
1373 }
1374
1375 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1376 {
1377         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1378         struct unicast_frag_packet *unicast_packet;
1379         int hdr_size = sizeof(*unicast_packet);
1380         struct sk_buff *new_skb = NULL;
1381         int ret;
1382
1383         if (check_unicast_packet(skb, hdr_size) < 0)
1384                 return NET_RX_DROP;
1385
1386         unicast_packet = (struct unicast_frag_packet *)skb->data;
1387
1388         /* packet for me */
1389         if (is_my_mac(unicast_packet->dest)) {
1390
1391                 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
1392
1393                 if (ret == NET_RX_DROP)
1394                         return NET_RX_DROP;
1395
1396                 /* packet was buffered for late merge */
1397                 if (!new_skb)
1398                         return NET_RX_SUCCESS;
1399
1400                 interface_rx(recv_if->soft_iface, new_skb, recv_if,
1401                              sizeof(struct unicast_packet));
1402                 return NET_RX_SUCCESS;
1403         }
1404
1405         return route_unicast_packet(skb, recv_if);
1406 }
1407
1408
1409 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1410 {
1411         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1412         struct orig_node *orig_node = NULL;
1413         struct bcast_packet *bcast_packet;
1414         struct ethhdr *ethhdr;
1415         int hdr_size = sizeof(*bcast_packet);
1416         int ret = NET_RX_DROP;
1417         int32_t seq_diff;
1418
1419         /* drop packet if it has not necessary minimum size */
1420         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1421                 goto out;
1422
1423         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1424
1425         /* packet with broadcast indication but unicast recipient */
1426         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1427                 goto out;
1428
1429         /* packet with broadcast sender address */
1430         if (is_broadcast_ether_addr(ethhdr->h_source))
1431                 goto out;
1432
1433         /* ignore broadcasts sent by myself */
1434         if (is_my_mac(ethhdr->h_source))
1435                 goto out;
1436
1437         bcast_packet = (struct bcast_packet *)skb->data;
1438
1439         /* ignore broadcasts originated by myself */
1440         if (is_my_mac(bcast_packet->orig))
1441                 goto out;
1442
1443         if (bcast_packet->ttl < 2)
1444                 goto out;
1445
1446         orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1447
1448         if (!orig_node)
1449                 goto out;
1450
1451         spin_lock_bh(&orig_node->bcast_seqno_lock);
1452
1453         /* check whether the packet is a duplicate */
1454         if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1455                            ntohl(bcast_packet->seqno)))
1456                 goto spin_unlock;
1457
1458         seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1459
1460         /* check whether the packet is old and the host just restarted. */
1461         if (window_protected(bat_priv, seq_diff,
1462                              &orig_node->bcast_seqno_reset))
1463                 goto spin_unlock;
1464
1465         /* mark broadcast in flood history, update window position
1466          * if required. */
1467         if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1468                 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1469
1470         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1471
1472         /* rebroadcast packet */
1473         add_bcast_packet_to_list(bat_priv, skb);
1474
1475         /* broadcast for me */
1476         interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1477         ret = NET_RX_SUCCESS;
1478         goto out;
1479
1480 spin_unlock:
1481         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1482 out:
1483         if (orig_node)
1484                 orig_node_free_ref(orig_node);
1485         return ret;
1486 }
1487
1488 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1489 {
1490         struct vis_packet *vis_packet;
1491         struct ethhdr *ethhdr;
1492         struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1493         int hdr_size = sizeof(*vis_packet);
1494
1495         /* keep skb linear */
1496         if (skb_linearize(skb) < 0)
1497                 return NET_RX_DROP;
1498
1499         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1500                 return NET_RX_DROP;
1501
1502         vis_packet = (struct vis_packet *)skb->data;
1503         ethhdr = (struct ethhdr *)skb_mac_header(skb);
1504
1505         /* not for me */
1506         if (!is_my_mac(ethhdr->h_dest))
1507                 return NET_RX_DROP;
1508
1509         /* ignore own packets */
1510         if (is_my_mac(vis_packet->vis_orig))
1511                 return NET_RX_DROP;
1512
1513         if (is_my_mac(vis_packet->sender_orig))
1514                 return NET_RX_DROP;
1515
1516         switch (vis_packet->vis_type) {
1517         case VIS_TYPE_SERVER_SYNC:
1518                 receive_server_sync_packet(bat_priv, vis_packet,
1519                                            skb_headlen(skb));
1520                 break;
1521
1522         case VIS_TYPE_CLIENT_UPDATE:
1523                 receive_client_update_packet(bat_priv, vis_packet,
1524                                              skb_headlen(skb));
1525                 break;
1526
1527         default:        /* ignore unknown packet */
1528                 break;
1529         }
1530
1531         /* We take a copy of the data in the packet, so we should
1532            always free the skbuf. */
1533         return NET_RX_DROP;
1534 }