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