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