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