net/batman-adv/routing.c

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