net/batman-adv/routing.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "routing.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/byteorder/generic.h>
  12 #include <linux/compiler.h>
  13 #include <linux/errno.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/kref.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/printk.h>
  20 #include <linux/rculist.h>
  21 #include <linux/rcupdate.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/stddef.h>
  25 #include <uapi/linux/batadv_packet.h>
  26
  27 #include "bitarray.h"
  28 #include "bridge_loop_avoidance.h"
  29 #include "distributed-arp-table.h"
  30 #include "fragmentation.h"
  31 #include "hard-interface.h"
  32 #include "icmp_socket.h"
  33 #include "log.h"
  34 #include "network-coding.h"
  35 #include "originator.h"
  36 #include "send.h"
  37 #include "soft-interface.h"
  38 #include "tp_meter.h"
  39 #include "translation-table.h"
  40 #include "tvlv.h"
  41
  42 static int batadv_route_unicast_packet(struct sk_buff *skb,
  43                                        struct batadv_hard_iface *recv_if);
  44
  45 /**
  46  * _batadv_update_route() - set the router for this originator
  47  * @bat_priv: the bat priv with all the soft interface information
  48  * @orig_node: orig node which is to be configured
  49  * @recv_if: the receive interface for which this route is set
  50  * @neigh_node: neighbor which should be the next router
  51  *
  52  * This function does not perform any error checks
  53  */
  54 static void _batadv_update_route(struct batadv_priv *bat_priv,
  55                                  struct batadv_orig_node *orig_node,
  56                                  struct batadv_hard_iface *recv_if,
  57                                  struct batadv_neigh_node *neigh_node)
  58 {
  59         struct batadv_orig_ifinfo *orig_ifinfo;
  60         struct batadv_neigh_node *curr_router;
  61
  62         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
  63         if (!orig_ifinfo)
  64                 return;
  65
  66         spin_lock_bh(&orig_node->neigh_list_lock);
  67         /* curr_router used earlier may not be the current orig_ifinfo->router
  68          * anymore because it was dereferenced outside of the neigh_list_lock
  69          * protected region. After the new best neighbor has replace the current
  70          * best neighbor the reference counter needs to decrease. Consequently,
  71          * the code needs to ensure the curr_router variable contains a pointer
  72          * to the replaced best neighbor.
  73          */
  74
  75         /* increase refcount of new best neighbor */
  76         if (neigh_node)
  77                 kref_get(&neigh_node->refcount);
  78
  79         curr_router = rcu_replace_pointer(orig_ifinfo->router, neigh_node,
  80                                           true);
  81         spin_unlock_bh(&orig_node->neigh_list_lock);
  82         batadv_orig_ifinfo_put(orig_ifinfo);
  83
  84         /* route deleted */
  85         if (curr_router && !neigh_node) {
  86                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  87                            "Deleting route towards: %pM\n", orig_node->orig);
  88                 batadv_tt_global_del_orig(bat_priv, orig_node, -1,
  89                                           "Deleted route towards originator");
  90
  91         /* route added */
  92         } else if (!curr_router && neigh_node) {
  93                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  94                            "Adding route towards: %pM (via %pM)\n",
  95                            orig_node->orig, neigh_node->addr);
  96         /* route changed */
  97         } else if (neigh_node && curr_router) {
  98                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  99                            "Changing route towards: %pM (now via %pM - was via %pM)\n",
 100                            orig_node->orig, neigh_node->addr,
 101                            curr_router->addr);
 102         }
 103
 104         /* decrease refcount of previous best neighbor */
 105         if (curr_router)
 106                 batadv_neigh_node_put(curr_router);
 107 }
 108
 109 /**
 110  * batadv_update_route() - set the router for this originator
 111  * @bat_priv: the bat priv with all the soft interface information
 112  * @orig_node: orig node which is to be configured
 113  * @recv_if: the receive interface for which this route is set
 114  * @neigh_node: neighbor which should be the next router
 115  */
 116 void batadv_update_route(struct batadv_priv *bat_priv,
 117                          struct batadv_orig_node *orig_node,
 118                          struct batadv_hard_iface *recv_if,
 119                          struct batadv_neigh_node *neigh_node)
 120 {
 121         struct batadv_neigh_node *router = NULL;
 122
 123         if (!orig_node)
 124                 goto out;
 125
 126         router = batadv_orig_router_get(orig_node, recv_if);
 127
 128         if (router != neigh_node)
 129                 _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);
 130
 131 out:
 132         if (router)
 133                 batadv_neigh_node_put(router);
 134 }
 135
 136 /**
 137  * batadv_window_protected() - checks whether the host restarted and is in the
 138  *  protection time.
 139  * @bat_priv: the bat priv with all the soft interface information
 140  * @seq_num_diff: difference between the current/received sequence number and
 141  *  the last sequence number
 142  * @seq_old_max_diff: maximum age of sequence number not considered as restart
 143  * @last_reset: jiffies timestamp of the last reset, will be updated when reset
 144  *  is detected
 145  * @protection_started: is set to true if the protection window was started,
 146  *   doesn't change otherwise.
 147  *
 148  * Return:
 149  *  false if the packet is to be accepted.
 150  *  true if the packet is to be ignored.
 151  */
 152 bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff,
 153                              s32 seq_old_max_diff, unsigned long *last_reset,
 154                              bool *protection_started)
 155 {
 156         if (seq_num_diff <= -seq_old_max_diff ||
 157             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
 158                 if (!batadv_has_timed_out(*last_reset,
 159                                           BATADV_RESET_PROTECTION_MS))
 160                         return true;
 161
 162                 *last_reset = jiffies;
 163                 if (protection_started)
 164                         *protection_started = true;
 165                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 166                            "old packet received, start protection\n");
 167         }
 168
 169         return false;
 170 }
 171
 172 /**
 173  * batadv_check_management_packet() - Check preconditions for management packets
 174  * @skb: incoming packet buffer
 175  * @hard_iface: incoming hard interface
 176  * @header_len: minimal header length of packet type
 177  *
 178  * Return: true when management preconditions are met, false otherwise
 179  */
 180 bool batadv_check_management_packet(struct sk_buff *skb,
 181                                     struct batadv_hard_iface *hard_iface,
 182                                     int header_len)
 183 {
 184         struct ethhdr *ethhdr;
 185
 186         /* drop packet if it has not necessary minimum size */
 187         if (unlikely(!pskb_may_pull(skb, header_len)))
 188                 return false;
 189
 190         ethhdr = eth_hdr(skb);
 191
 192         /* packet with broadcast indication but unicast recipient */
 193         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 194                 return false;
 195
 196         /* packet with invalid sender address */
 197         if (!is_valid_ether_addr(ethhdr->h_source))
 198                 return false;
 199
 200         /* create a copy of the skb, if needed, to modify it. */
 201         if (skb_cow(skb, 0) < 0)
 202                 return false;
 203
 204         /* keep skb linear */
 205         if (skb_linearize(skb) < 0)
 206                 return false;
 207
 208         return true;
 209 }
 210
 211 /**
 212  * batadv_recv_my_icmp_packet() - receive an icmp packet locally
 213  * @bat_priv: the bat priv with all the soft interface information
 214  * @skb: icmp packet to process
 215  *
 216  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 217  * otherwise.
 218  */
 219 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 220                                       struct sk_buff *skb)
 221 {
 222         struct batadv_hard_iface *primary_if = NULL;
 223         struct batadv_orig_node *orig_node = NULL;
 224         struct batadv_icmp_header *icmph;
 225         int res, ret = NET_RX_DROP;
 226
 227         icmph = (struct batadv_icmp_header *)skb->data;
 228
 229         switch (icmph->msg_type) {
 230         case BATADV_ECHO_REPLY:
 231         case BATADV_DESTINATION_UNREACHABLE:
 232         case BATADV_TTL_EXCEEDED:
 233                 /* receive the packet */
 234                 if (skb_linearize(skb) < 0)
 235                         break;
 236
 237                 batadv_socket_receive_packet(icmph, skb->len);
 238                 break;
 239         case BATADV_ECHO_REQUEST:
 240                 /* answer echo request (ping) */
 241                 primary_if = batadv_primary_if_get_selected(bat_priv);
 242                 if (!primary_if)
 243                         goto out;
 244
 245                 /* get routing information */
 246                 orig_node = batadv_orig_hash_find(bat_priv, icmph->orig);
 247                 if (!orig_node)
 248                         goto out;
 249
 250                 /* create a copy of the skb, if needed, to modify it. */
 251                 if (skb_cow(skb, ETH_HLEN) < 0)
 252                         goto out;
 253
 254                 icmph = (struct batadv_icmp_header *)skb->data;
 255
 256                 ether_addr_copy(icmph->dst, icmph->orig);
 257                 ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr);
 258                 icmph->msg_type = BATADV_ECHO_REPLY;
 259                 icmph->ttl = BATADV_TTL;
 260
 261                 res = batadv_send_skb_to_orig(skb, orig_node, NULL);
 262                 if (res == NET_XMIT_SUCCESS)
 263                         ret = NET_RX_SUCCESS;
 264
 265                 /* skb was consumed */
 266                 skb = NULL;
 267                 break;
 268         case BATADV_TP:
 269                 if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet)))
 270                         goto out;
 271
 272                 batadv_tp_meter_recv(bat_priv, skb);
 273                 ret = NET_RX_SUCCESS;
 274                 /* skb was consumed */
 275                 skb = NULL;
 276                 goto out;
 277         default:
 278                 /* drop unknown type */
 279                 goto out;
 280         }
 281 out:
 282         if (primary_if)
 283                 batadv_hardif_put(primary_if);
 284         if (orig_node)
 285                 batadv_orig_node_put(orig_node);
 286
 287         kfree_skb(skb);
 288
 289         return ret;
 290 }
 291
 292 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 293                                          struct sk_buff *skb)
 294 {
 295         struct batadv_hard_iface *primary_if = NULL;
 296         struct batadv_orig_node *orig_node = NULL;
 297         struct batadv_icmp_packet *icmp_packet;
 298         int res, ret = NET_RX_DROP;
 299
 300         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 301
 302         /* send TTL exceeded if packet is an echo request (traceroute) */
 303         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 304                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 305                          icmp_packet->orig, icmp_packet->dst);
 306                 goto out;
 307         }
 308
 309         primary_if = batadv_primary_if_get_selected(bat_priv);
 310         if (!primary_if)
 311                 goto out;
 312
 313         /* get routing information */
 314         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 315         if (!orig_node)
 316                 goto out;
 317
 318         /* create a copy of the skb, if needed, to modify it. */
 319         if (skb_cow(skb, ETH_HLEN) < 0)
 320                 goto out;
 321
 322         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 323
 324         ether_addr_copy(icmp_packet->dst, icmp_packet->orig);
 325         ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr);
 326         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
 327         icmp_packet->ttl = BATADV_TTL;
 328
 329         res = batadv_send_skb_to_orig(skb, orig_node, NULL);
 330         if (res == NET_RX_SUCCESS)
 331                 ret = NET_XMIT_SUCCESS;
 332
 333         /* skb was consumed */
 334         skb = NULL;
 335
 336 out:
 337         if (primary_if)
 338                 batadv_hardif_put(primary_if);
 339         if (orig_node)
 340                 batadv_orig_node_put(orig_node);
 341
 342         kfree_skb(skb);
 343
 344         return ret;
 345 }
 346
 347 /**
 348  * batadv_recv_icmp_packet() - Process incoming icmp packet
 349  * @skb: incoming packet buffer
 350  * @recv_if: incoming hard interface
 351  *
 352  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
 353  */
 354 int batadv_recv_icmp_packet(struct sk_buff *skb,
 355                             struct batadv_hard_iface *recv_if)
 356 {
 357         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 358         struct batadv_icmp_header *icmph;
 359         struct batadv_icmp_packet_rr *icmp_packet_rr;
 360         struct ethhdr *ethhdr;
 361         struct batadv_orig_node *orig_node = NULL;
 362         int hdr_size = sizeof(struct batadv_icmp_header);
 363         int res, ret = NET_RX_DROP;
 364
 365         /* drop packet if it has not necessary minimum size */
 366         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 367                 goto free_skb;
 368
 369         ethhdr = eth_hdr(skb);
 370
 371         /* packet with unicast indication but non-unicast recipient */
 372         if (!is_valid_ether_addr(ethhdr->h_dest))
 373                 goto free_skb;
 374
 375         /* packet with broadcast/multicast sender address */
 376         if (is_multicast_ether_addr(ethhdr->h_source))
 377                 goto free_skb;
 378
 379         /* not for me */
 380         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 381                 goto free_skb;
 382
 383         icmph = (struct batadv_icmp_header *)skb->data;
 384
 385         /* add record route information if not full */
 386         if ((icmph->msg_type == BATADV_ECHO_REPLY ||
 387              icmph->msg_type == BATADV_ECHO_REQUEST) &&
 388             skb->len >= sizeof(struct batadv_icmp_packet_rr)) {
 389                 if (skb_linearize(skb) < 0)
 390                         goto free_skb;
 391
 392                 /* create a copy of the skb, if needed, to modify it. */
 393                 if (skb_cow(skb, ETH_HLEN) < 0)
 394                         goto free_skb;
 395
 396                 ethhdr = eth_hdr(skb);
 397                 icmph = (struct batadv_icmp_header *)skb->data;
 398                 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
 399                 if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
 400                         goto free_skb;
 401
 402                 ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur],
 403                                 ethhdr->h_dest);
 404                 icmp_packet_rr->rr_cur++;
 405         }
 406
 407         /* packet for me */
 408         if (batadv_is_my_mac(bat_priv, icmph->dst))
 409                 return batadv_recv_my_icmp_packet(bat_priv, skb);
 410
 411         /* TTL exceeded */
 412         if (icmph->ttl < 2)
 413                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 414
 415         /* get routing information */
 416         orig_node = batadv_orig_hash_find(bat_priv, icmph->dst);
 417         if (!orig_node)
 418                 goto free_skb;
 419
 420         /* create a copy of the skb, if needed, to modify it. */
 421         if (skb_cow(skb, ETH_HLEN) < 0)
 422                 goto put_orig_node;
 423
 424         icmph = (struct batadv_icmp_header *)skb->data;
 425
 426         /* decrement ttl */
 427         icmph->ttl--;
 428
 429         /* route it */
 430         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 431         if (res == NET_XMIT_SUCCESS)
 432                 ret = NET_RX_SUCCESS;
 433
 434         /* skb was consumed */
 435         skb = NULL;
 436
 437 put_orig_node:
 438         if (orig_node)
 439                 batadv_orig_node_put(orig_node);
 440 free_skb:
 441         kfree_skb(skb);
 442
 443         return ret;
 444 }
 445
 446 /**
 447  * batadv_check_unicast_packet() - Check for malformed unicast packets
 448  * @bat_priv: the bat priv with all the soft interface information
 449  * @skb: packet to check
 450  * @hdr_size: size of header to pull
 451  *
 452  * Checks for short header and bad addresses in the given packet.
 453  *
 454  * Return: negative value when check fails and 0 otherwise. The negative value
 455  * depends on the reason: -ENODATA for bad header, -EBADR for broadcast
 456  * destination or source, and -EREMOTE for non-local (other host) destination.
 457  */
 458 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
 459                                        struct sk_buff *skb, int hdr_size)
 460 {
 461         struct ethhdr *ethhdr;
 462
 463         /* drop packet if it has not necessary minimum size */
 464         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 465                 return -ENODATA;
 466
 467         ethhdr = eth_hdr(skb);
 468
 469         /* packet with unicast indication but non-unicast recipient */
 470         if (!is_valid_ether_addr(ethhdr->h_dest))
 471                 return -EBADR;
 472
 473         /* packet with broadcast/multicast sender address */
 474         if (is_multicast_ether_addr(ethhdr->h_source))
 475                 return -EBADR;
 476
 477         /* not for me */
 478         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 479                 return -EREMOTE;
 480
 481         return 0;
 482 }
 483
 484 /**
 485  * batadv_last_bonding_get() - Get last_bonding_candidate of orig_node
 486  * @orig_node: originator node whose last bonding candidate should be retrieved
 487  *
 488  * Return: last bonding candidate of router or NULL if not found
 489  *
 490  * The object is returned with refcounter increased by 1.
 491  */
 492 static struct batadv_orig_ifinfo *
 493 batadv_last_bonding_get(struct batadv_orig_node *orig_node)
 494 {
 495         struct batadv_orig_ifinfo *last_bonding_candidate;
 496
 497         spin_lock_bh(&orig_node->neigh_list_lock);
 498         last_bonding_candidate = orig_node->last_bonding_candidate;
 499
 500         if (last_bonding_candidate)
 501                 kref_get(&last_bonding_candidate->refcount);
 502         spin_unlock_bh(&orig_node->neigh_list_lock);
 503
 504         return last_bonding_candidate;
 505 }
 506
 507 /**
 508  * batadv_last_bonding_replace() - Replace last_bonding_candidate of orig_node
 509  * @orig_node: originator node whose bonding candidates should be replaced
 510  * @new_candidate: new bonding candidate or NULL
 511  */
 512 static void
 513 batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
 514                             struct batadv_orig_ifinfo *new_candidate)
 515 {
 516         struct batadv_orig_ifinfo *old_candidate;
 517
 518         spin_lock_bh(&orig_node->neigh_list_lock);
 519         old_candidate = orig_node->last_bonding_candidate;
 520
 521         if (new_candidate)
 522                 kref_get(&new_candidate->refcount);
 523         orig_node->last_bonding_candidate = new_candidate;
 524         spin_unlock_bh(&orig_node->neigh_list_lock);
 525
 526         if (old_candidate)
 527                 batadv_orig_ifinfo_put(old_candidate);
 528 }
 529
 530 /**
 531  * batadv_find_router() - find a suitable router for this originator
 532  * @bat_priv: the bat priv with all the soft interface information
 533  * @orig_node: the destination node
 534  * @recv_if: pointer to interface this packet was received on
 535  *
 536  * Return: the router which should be used for this orig_node on
 537  * this interface, or NULL if not available.
 538  */
 539 struct batadv_neigh_node *
 540 batadv_find_router(struct batadv_priv *bat_priv,
 541                    struct batadv_orig_node *orig_node,
 542                    struct batadv_hard_iface *recv_if)
 543 {
 544         struct batadv_algo_ops *bao = bat_priv->algo_ops;
 545         struct batadv_neigh_node *first_candidate_router = NULL;
 546         struct batadv_neigh_node *next_candidate_router = NULL;
 547         struct batadv_neigh_node *router, *cand_router = NULL;
 548         struct batadv_neigh_node *last_cand_router = NULL;
 549         struct batadv_orig_ifinfo *cand, *first_candidate = NULL;
 550         struct batadv_orig_ifinfo *next_candidate = NULL;
 551         struct batadv_orig_ifinfo *last_candidate;
 552         bool last_candidate_found = false;
 553
 554         if (!orig_node)
 555                 return NULL;
 556
 557         router = batadv_orig_router_get(orig_node, recv_if);
 558
 559         if (!router)
 560                 return router;
 561
 562         /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop)
 563          * and if activated.
 564          */
 565         if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding)))
 566                 return router;
 567
 568         /* bonding: loop through the list of possible routers found
 569          * for the various outgoing interfaces and find a candidate after
 570          * the last chosen bonding candidate (next_candidate). If no such
 571          * router is found, use the first candidate found (the previously
 572          * chosen bonding candidate might have been the last one in the list).
 573          * If this can't be found either, return the previously chosen
 574          * router - obviously there are no other candidates.
 575          */
 576         rcu_read_lock();
 577         last_candidate = batadv_last_bonding_get(orig_node);
 578         if (last_candidate)
 579                 last_cand_router = rcu_dereference(last_candidate->router);
 580
 581         hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) {
 582                 /* acquire some structures and references ... */
 583                 if (!kref_get_unless_zero(&cand->refcount))
 584                         continue;
 585
 586                 cand_router = rcu_dereference(cand->router);
 587                 if (!cand_router)
 588                         goto next;
 589
 590                 if (!kref_get_unless_zero(&cand_router->refcount)) {
 591                         cand_router = NULL;
 592                         goto next;
 593                 }
 594
 595                 /* alternative candidate should be good enough to be
 596                  * considered
 597                  */
 598                 if (!bao->neigh.is_similar_or_better(cand_router,
 599                                                      cand->if_outgoing, router,
 600                                                      recv_if))
 601                         goto next;
 602
 603                 /* don't use the same router twice */
 604                 if (last_cand_router == cand_router)
 605                         goto next;
 606
 607                 /* mark the first possible candidate */
 608                 if (!first_candidate) {
 609                         kref_get(&cand_router->refcount);
 610                         kref_get(&cand->refcount);
 611                         first_candidate = cand;
 612                         first_candidate_router = cand_router;
 613                 }
 614
 615                 /* check if the loop has already passed the previously selected
 616                  * candidate ... this function should select the next candidate
 617                  * AFTER the previously used bonding candidate.
 618                  */
 619                 if (!last_candidate || last_candidate_found) {
 620                         next_candidate = cand;
 621                         next_candidate_router = cand_router;
 622                         break;
 623                 }
 624
 625                 if (last_candidate == cand)
 626                         last_candidate_found = true;
 627 next:
 628                 /* free references */
 629                 if (cand_router) {
 630                         batadv_neigh_node_put(cand_router);
 631                         cand_router = NULL;
 632                 }
 633                 batadv_orig_ifinfo_put(cand);
 634         }
 635         rcu_read_unlock();
 636
 637         /* After finding candidates, handle the three cases:
 638          * 1) there is a next candidate, use that
 639          * 2) there is no next candidate, use the first of the list
 640          * 3) there is no candidate at all, return the default router
 641          */
 642         if (next_candidate) {
 643                 batadv_neigh_node_put(router);
 644
 645                 kref_get(&next_candidate_router->refcount);
 646                 router = next_candidate_router;
 647                 batadv_last_bonding_replace(orig_node, next_candidate);
 648         } else if (first_candidate) {
 649                 batadv_neigh_node_put(router);
 650
 651                 kref_get(&first_candidate_router->refcount);
 652                 router = first_candidate_router;
 653                 batadv_last_bonding_replace(orig_node, first_candidate);
 654         } else {
 655                 batadv_last_bonding_replace(orig_node, NULL);
 656         }
 657
 658         /* cleanup of candidates */
 659         if (first_candidate) {
 660                 batadv_neigh_node_put(first_candidate_router);
 661                 batadv_orig_ifinfo_put(first_candidate);
 662         }
 663
 664         if (next_candidate) {
 665                 batadv_neigh_node_put(next_candidate_router);
 666                 batadv_orig_ifinfo_put(next_candidate);
 667         }
 668
 669         if (last_candidate)
 670                 batadv_orig_ifinfo_put(last_candidate);
 671
 672         return router;
 673 }
 674
 675 static int batadv_route_unicast_packet(struct sk_buff *skb,
 676                                        struct batadv_hard_iface *recv_if)
 677 {
 678         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 679         struct batadv_orig_node *orig_node = NULL;
 680         struct batadv_unicast_packet *unicast_packet;
 681         struct ethhdr *ethhdr = eth_hdr(skb);
 682         int res, hdr_len, ret = NET_RX_DROP;
 683         unsigned int len;
 684
 685         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 686
 687         /* TTL exceeded */
 688         if (unicast_packet->ttl < 2) {
 689                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 690                          ethhdr->h_source, unicast_packet->dest);
 691                 goto free_skb;
 692         }
 693
 694         /* get routing information */
 695         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 696
 697         if (!orig_node)
 698                 goto free_skb;
 699
 700         /* create a copy of the skb, if needed, to modify it. */
 701         if (skb_cow(skb, ETH_HLEN) < 0)
 702                 goto put_orig_node;
 703
 704         /* decrement ttl */
 705         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 706         unicast_packet->ttl--;
 707
 708         switch (unicast_packet->packet_type) {
 709         case BATADV_UNICAST_4ADDR:
 710                 hdr_len = sizeof(struct batadv_unicast_4addr_packet);
 711                 break;
 712         case BATADV_UNICAST:
 713                 hdr_len = sizeof(struct batadv_unicast_packet);
 714                 break;
 715         default:
 716                 /* other packet types not supported - yet */
 717                 hdr_len = -1;
 718                 break;
 719         }
 720
 721         if (hdr_len > 0)
 722                 batadv_skb_set_priority(skb, hdr_len);
 723
 724         len = skb->len;
 725         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 726
 727         /* translate transmit result into receive result */
 728         if (res == NET_XMIT_SUCCESS) {
 729                 ret = NET_RX_SUCCESS;
 730                 /* skb was transmitted and consumed */
 731                 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 732                 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 733                                    len + ETH_HLEN);
 734         }
 735
 736         /* skb was consumed */
 737         skb = NULL;
 738
 739 put_orig_node:
 740         batadv_orig_node_put(orig_node);
 741 free_skb:
 742         kfree_skb(skb);
 743
 744         return ret;
 745 }
 746
 747 /**
 748  * batadv_reroute_unicast_packet() - update the unicast header for re-routing
 749  * @bat_priv: the bat priv with all the soft interface information
 750  * @skb: unicast packet to process
 751  * @unicast_packet: the unicast header to be updated
 752  * @dst_addr: the payload destination
 753  * @vid: VLAN identifier
 754  *
 755  * Search the translation table for dst_addr and update the unicast header with
 756  * the new corresponding information (originator address where the destination
 757  * client currently is and its known TTVN)
 758  *
 759  * Return: true if the packet header has been updated, false otherwise
 760  */
 761 static bool
 762 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
 763                               struct batadv_unicast_packet *unicast_packet,
 764                               u8 *dst_addr, unsigned short vid)
 765 {
 766         struct batadv_orig_node *orig_node = NULL;
 767         struct batadv_hard_iface *primary_if = NULL;
 768         bool ret = false;
 769         u8 *orig_addr, orig_ttvn;
 770
 771         if (batadv_is_my_client(bat_priv, dst_addr, vid)) {
 772                 primary_if = batadv_primary_if_get_selected(bat_priv);
 773                 if (!primary_if)
 774                         goto out;
 775                 orig_addr = primary_if->net_dev->dev_addr;
 776                 orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
 777         } else {
 778                 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr,
 779                                                      vid);
 780                 if (!orig_node)
 781                         goto out;
 782
 783                 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
 784                         goto out;
 785
 786                 orig_addr = orig_node->orig;
 787                 orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 788         }
 789
 790         /* update the packet header */
 791         skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 792         ether_addr_copy(unicast_packet->dest, orig_addr);
 793         unicast_packet->ttvn = orig_ttvn;
 794         skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 795
 796         ret = true;
 797 out:
 798         if (primary_if)
 799                 batadv_hardif_put(primary_if);
 800         if (orig_node)
 801                 batadv_orig_node_put(orig_node);
 802
 803         return ret;
 804 }
 805
 806 static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 807                                       struct sk_buff *skb, int hdr_len)
 808 {
 809         struct batadv_unicast_packet *unicast_packet;
 810         struct batadv_hard_iface *primary_if;
 811         struct batadv_orig_node *orig_node;
 812         u8 curr_ttvn, old_ttvn;
 813         struct ethhdr *ethhdr;
 814         unsigned short vid;
 815         int is_old_ttvn;
 816
 817         /* check if there is enough data before accessing it */
 818         if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
 819                 return false;
 820
 821         /* create a copy of the skb (in case of for re-routing) to modify it. */
 822         if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
 823                 return false;
 824
 825         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 826         vid = batadv_get_vid(skb, hdr_len);
 827         ethhdr = (struct ethhdr *)(skb->data + hdr_len);
 828
 829         /* do not reroute multicast frames in a unicast header */
 830         if (is_multicast_ether_addr(ethhdr->h_dest))
 831                 return true;
 832
 833         /* check if the destination client was served by this node and it is now
 834          * roaming. In this case, it means that the node has got a ROAM_ADV
 835          * message and that it knows the new destination in the mesh to re-route
 836          * the packet to
 837          */
 838         if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
 839                 if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
 840                                                   ethhdr->h_dest, vid))
 841                         batadv_dbg_ratelimited(BATADV_DBG_TT,
 842                                                bat_priv,
 843                                                "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
 844                                                unicast_packet->dest,
 845                                                ethhdr->h_dest);
 846                 /* at this point the mesh destination should have been
 847                  * substituted with the originator address found in the global
 848                  * table. If not, let the packet go untouched anyway because
 849                  * there is nothing the node can do
 850                  */
 851                 return true;
 852         }
 853
 854         /* retrieve the TTVN known by this node for the packet destination. This
 855          * value is used later to check if the node which sent (or re-routed
 856          * last time) the packet had an updated information or not
 857          */
 858         curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
 859         if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 860                 orig_node = batadv_orig_hash_find(bat_priv,
 861                                                   unicast_packet->dest);
 862                 /* if it is not possible to find the orig_node representing the
 863                  * destination, the packet can immediately be dropped as it will
 864                  * not be possible to deliver it
 865                  */
 866                 if (!orig_node)
 867                         return false;
 868
 869                 curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 870                 batadv_orig_node_put(orig_node);
 871         }
 872
 873         /* check if the TTVN contained in the packet is fresher than what the
 874          * node knows
 875          */
 876         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 877         if (!is_old_ttvn)
 878                 return true;
 879
 880         old_ttvn = unicast_packet->ttvn;
 881         /* the packet was forged based on outdated network information. Its
 882          * destination can possibly be updated and forwarded towards the new
 883          * target host
 884          */
 885         if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
 886                                           ethhdr->h_dest, vid)) {
 887                 batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv,
 888                                        "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
 889                                        unicast_packet->dest, ethhdr->h_dest,
 890                                        old_ttvn, curr_ttvn);
 891                 return true;
 892         }
 893
 894         /* the packet has not been re-routed: either the destination is
 895          * currently served by this node or there is no destination at all and
 896          * it is possible to drop the packet
 897          */
 898         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid))
 899                 return false;
 900
 901         /* update the header in order to let the packet be delivered to this
 902          * node's soft interface
 903          */
 904         primary_if = batadv_primary_if_get_selected(bat_priv);
 905         if (!primary_if)
 906                 return false;
 907
 908         /* update the packet header */
 909         skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 910         ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
 911         unicast_packet->ttvn = curr_ttvn;
 912         skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 913
 914         batadv_hardif_put(primary_if);
 915
 916         return true;
 917 }
 918
 919 /**
 920  * batadv_recv_unhandled_unicast_packet() - receive and process packets which
 921  *      are in the unicast number space but not yet known to the implementation
 922  * @skb: unicast tvlv packet to process
 923  * @recv_if: pointer to interface this packet was received on
 924  *
 925  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 926  * otherwise.
 927  */
 928 int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,
 929                                          struct batadv_hard_iface *recv_if)
 930 {
 931         struct batadv_unicast_packet *unicast_packet;
 932         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 933         int check, hdr_size = sizeof(*unicast_packet);
 934
 935         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
 936         if (check < 0)
 937                 goto free_skb;
 938
 939         /* we don't know about this type, drop it. */
 940         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 941         if (batadv_is_my_mac(bat_priv, unicast_packet->dest))
 942                 goto free_skb;
 943
 944         return batadv_route_unicast_packet(skb, recv_if);
 945
 946 free_skb:
 947         kfree_skb(skb);
 948         return NET_RX_DROP;
 949 }
 950
 951 /**
 952  * batadv_recv_unicast_packet() - Process incoming unicast packet
 953  * @skb: incoming packet buffer
 954  * @recv_if: incoming hard interface
 955  *
 956  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
 957  */
 958 int batadv_recv_unicast_packet(struct sk_buff *skb,
 959                                struct batadv_hard_iface *recv_if)
 960 {
 961         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 962         struct batadv_unicast_packet *unicast_packet;
 963         struct batadv_unicast_4addr_packet *unicast_4addr_packet;
 964         u8 *orig_addr, *orig_addr_gw;
 965         struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL;
 966         int check, hdr_size = sizeof(*unicast_packet);
 967         enum batadv_subtype subtype;
 968         int ret = NET_RX_DROP;
 969         bool is4addr, is_gw;
 970
 971         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 972         is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
 973         /* the caller function should have already pulled 2 bytes */
 974         if (is4addr)
 975                 hdr_size = sizeof(*unicast_4addr_packet);
 976
 977         /* function returns -EREMOTE for promiscuous packets */
 978         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
 979
 980         /* Even though the packet is not for us, we might save it to use for
 981          * decoding a later received coded packet
 982          */
 983         if (check == -EREMOTE)
 984                 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
 985
 986         if (check < 0)
 987                 goto free_skb;
 988         if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
 989                 goto free_skb;
 990
 991         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 992
 993         /* packet for me */
 994         if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 995                 /* If this is a unicast packet from another backgone gw,
 996                  * drop it.
 997                  */
 998                 orig_addr_gw = eth_hdr(skb)->h_source;
 999                 orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw);
1000                 if (orig_node_gw) {
1001                         is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw,
1002                                                           hdr_size);
1003                         batadv_orig_node_put(orig_node_gw);
1004                         if (is_gw) {
1005                                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1006                                            "%s(): Dropped unicast pkt received from another backbone gw %pM.\n",
1007                                            __func__, orig_addr_gw);
1008                                 goto free_skb;
1009                         }
1010                 }
1011
1012                 if (is4addr) {
1013                         unicast_4addr_packet =
1014                                 (struct batadv_unicast_4addr_packet *)skb->data;
1015                         subtype = unicast_4addr_packet->subtype;
1016                         batadv_dat_inc_counter(bat_priv, subtype);
1017
1018                         /* Only payload data should be considered for speedy
1019                          * join. For example, DAT also uses unicast 4addr
1020                          * types, but those packets should not be considered
1021                          * for speedy join, since the clients do not actually
1022                          * reside at the sending originator.
1023                          */
1024                         if (subtype == BATADV_P_DATA) {
1025                                 orig_addr = unicast_4addr_packet->src;
1026                                 orig_node = batadv_orig_hash_find(bat_priv,
1027                                                                   orig_addr);
1028                         }
1029                 }
1030
1031                 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
1032                                                           hdr_size))
1033                         goto rx_success;
1034                 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
1035                                                         hdr_size))
1036                         goto rx_success;
1037
1038                 batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size);
1039
1040                 batadv_interface_rx(recv_if->soft_iface, skb, hdr_size,
1041                                     orig_node);
1042
1043 rx_success:
1044                 if (orig_node)
1045                         batadv_orig_node_put(orig_node);
1046
1047                 return NET_RX_SUCCESS;
1048         }
1049
1050         ret = batadv_route_unicast_packet(skb, recv_if);
1051         /* skb was consumed */
1052         skb = NULL;
1053
1054 free_skb:
1055         kfree_skb(skb);
1056
1057         return ret;
1058 }
1059
1060 /**
1061  * batadv_recv_unicast_tvlv() - receive and process unicast tvlv packets
1062  * @skb: unicast tvlv packet to process
1063  * @recv_if: pointer to interface this packet was received on
1064  *
1065  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1066  * otherwise.
1067  */
1068 int batadv_recv_unicast_tvlv(struct sk_buff *skb,
1069                              struct batadv_hard_iface *recv_if)
1070 {
1071         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1072         struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
1073         unsigned char *tvlv_buff;
1074         u16 tvlv_buff_len;
1075         int hdr_size = sizeof(*unicast_tvlv_packet);
1076         int ret = NET_RX_DROP;
1077
1078         if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
1079                 goto free_skb;
1080
1081         /* the header is likely to be modified while forwarding */
1082         if (skb_cow(skb, hdr_size) < 0)
1083                 goto free_skb;
1084
1085         /* packet needs to be linearized to access the tvlv content */
1086         if (skb_linearize(skb) < 0)
1087                 goto free_skb;
1088
1089         unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;
1090
1091         tvlv_buff = (unsigned char *)(skb->data + hdr_size);
1092         tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);
1093
1094         if (tvlv_buff_len > skb->len - hdr_size)
1095                 goto free_skb;
1096
1097         ret = batadv_tvlv_containers_process(bat_priv, false, NULL,
1098                                              unicast_tvlv_packet->src,
1099                                              unicast_tvlv_packet->dst,
1100                                              tvlv_buff, tvlv_buff_len);
1101
1102         if (ret != NET_RX_SUCCESS) {
1103                 ret = batadv_route_unicast_packet(skb, recv_if);
1104                 /* skb was consumed */
1105                 skb = NULL;
1106         }
1107
1108 free_skb:
1109         kfree_skb(skb);
1110
1111         return ret;
1112 }
1113
1114 /**
1115  * batadv_recv_frag_packet() - process received fragment
1116  * @skb: the received fragment
1117  * @recv_if: interface that the skb is received on
1118  *
1119  * This function does one of the three following things: 1) Forward fragment, if
1120  * the assembled packet will exceed our MTU; 2) Buffer fragment, if we still
1121  * lack further fragments; 3) Merge fragments, if we have all needed parts.
1122  *
1123  * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise.
1124  */
1125 int batadv_recv_frag_packet(struct sk_buff *skb,
1126                             struct batadv_hard_iface *recv_if)
1127 {
1128         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1129         struct batadv_orig_node *orig_node_src = NULL;
1130         struct batadv_frag_packet *frag_packet;
1131         int ret = NET_RX_DROP;
1132
1133         if (batadv_check_unicast_packet(bat_priv, skb,
1134                                         sizeof(*frag_packet)) < 0)
1135                 goto free_skb;
1136
1137         frag_packet = (struct batadv_frag_packet *)skb->data;
1138         orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig);
1139         if (!orig_node_src)
1140                 goto free_skb;
1141
1142         skb->priority = frag_packet->priority + 256;
1143
1144         /* Route the fragment if it is not for us and too big to be merged. */
1145         if (!batadv_is_my_mac(bat_priv, frag_packet->dest) &&
1146             batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) {
1147                 /* skb was consumed */
1148                 skb = NULL;
1149                 ret = NET_RX_SUCCESS;
1150                 goto put_orig_node;
1151         }
1152
1153         batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
1154         batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
1155
1156         /* Add fragment to buffer and merge if possible. */
1157         if (!batadv_frag_skb_buffer(&skb, orig_node_src))
1158                 goto put_orig_node;
1159
1160         /* Deliver merged packet to the appropriate handler, if it was
1161          * merged
1162          */
1163         if (skb) {
1164                 batadv_batman_skb_recv(skb, recv_if->net_dev,
1165                                        &recv_if->batman_adv_ptype, NULL);
1166                 /* skb was consumed */
1167                 skb = NULL;
1168         }
1169
1170         ret = NET_RX_SUCCESS;
1171
1172 put_orig_node:
1173         batadv_orig_node_put(orig_node_src);
1174 free_skb:
1175         kfree_skb(skb);
1176
1177         return ret;
1178 }
1179
1180 /**
1181  * batadv_recv_bcast_packet() - Process incoming broadcast packet
1182  * @skb: incoming packet buffer
1183  * @recv_if: incoming hard interface
1184  *
1185  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
1186  */
1187 int batadv_recv_bcast_packet(struct sk_buff *skb,
1188                              struct batadv_hard_iface *recv_if)
1189 {
1190         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1191         struct batadv_orig_node *orig_node = NULL;
1192         struct batadv_bcast_packet *bcast_packet;
1193         struct ethhdr *ethhdr;
1194         int hdr_size = sizeof(*bcast_packet);
1195         int ret = NET_RX_DROP;
1196         s32 seq_diff;
1197         u32 seqno;
1198
1199         /* drop packet if it has not necessary minimum size */
1200         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1201                 goto free_skb;
1202
1203         ethhdr = eth_hdr(skb);
1204
1205         /* packet with broadcast indication but unicast recipient */
1206         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1207                 goto free_skb;
1208
1209         /* packet with broadcast/multicast sender address */
1210         if (is_multicast_ether_addr(ethhdr->h_source))
1211                 goto free_skb;
1212
1213         /* ignore broadcasts sent by myself */
1214         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1215                 goto free_skb;
1216
1217         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1218
1219         /* ignore broadcasts originated by myself */
1220         if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
1221                 goto free_skb;
1222
1223         if (bcast_packet->ttl < 2)
1224                 goto free_skb;
1225
1226         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1227
1228         if (!orig_node)
1229                 goto free_skb;
1230
1231         spin_lock_bh(&orig_node->bcast_seqno_lock);
1232
1233         seqno = ntohl(bcast_packet->seqno);
1234         /* check whether the packet is a duplicate */
1235         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1236                             seqno))
1237                 goto spin_unlock;
1238
1239         seq_diff = seqno - orig_node->last_bcast_seqno;
1240
1241         /* check whether the packet is old and the host just restarted. */
1242         if (batadv_window_protected(bat_priv, seq_diff,
1243                                     BATADV_BCAST_MAX_AGE,
1244                                     &orig_node->bcast_seqno_reset, NULL))
1245                 goto spin_unlock;
1246
1247         /* mark broadcast in flood history, update window position
1248          * if required.
1249          */
1250         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1251                 orig_node->last_bcast_seqno = seqno;
1252
1253         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1254
1255         /* check whether this has been sent by another originator before */
1256         if (batadv_bla_check_bcast_duplist(bat_priv, skb))
1257                 goto free_skb;
1258
1259         batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
1260
1261         /* rebroadcast packet */
1262         batadv_add_bcast_packet_to_list(bat_priv, skb, 1, false);
1263
1264         /* don't hand the broadcast up if it is from an originator
1265          * from the same backbone.
1266          */
1267         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1268                 goto free_skb;
1269
1270         if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
1271                 goto rx_success;
1272         if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
1273                 goto rx_success;
1274
1275         batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size);
1276
1277         /* broadcast for me */
1278         batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node);
1279
1280 rx_success:
1281         ret = NET_RX_SUCCESS;
1282         goto out;
1283
1284 spin_unlock:
1285         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1286 free_skb:
1287         kfree_skb(skb);
1288 out:
1289         if (orig_node)
1290                 batadv_orig_node_put(orig_node);
1291         return ret;
1292 }