net/batman-adv/routing.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2018  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "routing.h"
  20 #include "main.h"
  21
  22 #include <linux/atomic.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/compiler.h>
  25 #include <linux/errno.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/if_ether.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/kref.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/printk.h>
  32 #include <linux/rculist.h>
  33 #include <linux/rcupdate.h>
  34 #include <linux/skbuff.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/stddef.h>
  37 #include <uapi/linux/batadv_packet.h>
  38
  39 #include "bitarray.h"
  40 #include "bridge_loop_avoidance.h"
  41 #include "distributed-arp-table.h"
  42 #include "fragmentation.h"
  43 #include "hard-interface.h"
  44 #include "icmp_socket.h"
  45 #include "log.h"
  46 #include "network-coding.h"
  47 #include "originator.h"
  48 #include "send.h"
  49 #include "soft-interface.h"
  50 #include "tp_meter.h"
  51 #include "translation-table.h"
  52 #include "tvlv.h"
  53
  54 static int batadv_route_unicast_packet(struct sk_buff *skb,
  55                                        struct batadv_hard_iface *recv_if);
  56
  57 /**
  58  * _batadv_update_route() - set the router for this originator
  59  * @bat_priv: the bat priv with all the soft interface information
  60  * @orig_node: orig node which is to be configured
  61  * @recv_if: the receive interface for which this route is set
  62  * @neigh_node: neighbor which should be the next router
  63  *
  64  * This function does not perform any error checks
  65  */
  66 static void _batadv_update_route(struct batadv_priv *bat_priv,
  67                                  struct batadv_orig_node *orig_node,
  68                                  struct batadv_hard_iface *recv_if,
  69                                  struct batadv_neigh_node *neigh_node)
  70 {
  71         struct batadv_orig_ifinfo *orig_ifinfo;
  72         struct batadv_neigh_node *curr_router;
  73
  74         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
  75         if (!orig_ifinfo)
  76                 return;
  77
  78         spin_lock_bh(&orig_node->neigh_list_lock);
  79         /* curr_router used earlier may not be the current orig_ifinfo->router
  80          * anymore because it was dereferenced outside of the neigh_list_lock
  81          * protected region. After the new best neighbor has replace the current
  82          * best neighbor the reference counter needs to decrease. Consequently,
  83          * the code needs to ensure the curr_router variable contains a pointer
  84          * to the replaced best neighbor.
  85          */
  86         curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
  87
  88         /* increase refcount of new best neighbor */
  89         if (neigh_node)
  90                 kref_get(&neigh_node->refcount);
  91
  92         rcu_assign_pointer(orig_ifinfo->router, neigh_node);
  93         spin_unlock_bh(&orig_node->neigh_list_lock);
  94         batadv_orig_ifinfo_put(orig_ifinfo);
  95
  96         /* route deleted */
  97         if (curr_router && !neigh_node) {
  98                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
  99                            "Deleting route towards: %pM\n", orig_node->orig);
 100                 batadv_tt_global_del_orig(bat_priv, orig_node, -1,
 101                                           "Deleted route towards originator");
 102
 103         /* route added */
 104         } else if (!curr_router && neigh_node) {
 105                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
 106                            "Adding route towards: %pM (via %pM)\n",
 107                            orig_node->orig, neigh_node->addr);
 108         /* route changed */
 109         } else if (neigh_node && curr_router) {
 110                 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
 111                            "Changing route towards: %pM (now via %pM - was via %pM)\n",
 112                            orig_node->orig, neigh_node->addr,
 113                            curr_router->addr);
 114         }
 115
 116         /* decrease refcount of previous best neighbor */
 117         if (curr_router)
 118                 batadv_neigh_node_put(curr_router);
 119 }
 120
 121 /**
 122  * batadv_update_route() - set the router for this originator
 123  * @bat_priv: the bat priv with all the soft interface information
 124  * @orig_node: orig node which is to be configured
 125  * @recv_if: the receive interface for which this route is set
 126  * @neigh_node: neighbor which should be the next router
 127  */
 128 void batadv_update_route(struct batadv_priv *bat_priv,
 129                          struct batadv_orig_node *orig_node,
 130                          struct batadv_hard_iface *recv_if,
 131                          struct batadv_neigh_node *neigh_node)
 132 {
 133         struct batadv_neigh_node *router = NULL;
 134
 135         if (!orig_node)
 136                 goto out;
 137
 138         router = batadv_orig_router_get(orig_node, recv_if);
 139
 140         if (router != neigh_node)
 141                 _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);
 142
 143 out:
 144         if (router)
 145                 batadv_neigh_node_put(router);
 146 }
 147
 148 /**
 149  * batadv_window_protected() - checks whether the host restarted and is in the
 150  *  protection time.
 151  * @bat_priv: the bat priv with all the soft interface information
 152  * @seq_num_diff: difference between the current/received sequence number and
 153  *  the last sequence number
 154  * @seq_old_max_diff: maximum age of sequence number not considered as restart
 155  * @last_reset: jiffies timestamp of the last reset, will be updated when reset
 156  *  is detected
 157  * @protection_started: is set to true if the protection window was started,
 158  *   doesn't change otherwise.
 159  *
 160  * Return:
 161  *  false if the packet is to be accepted.
 162  *  true if the packet is to be ignored.
 163  */
 164 bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff,
 165                              s32 seq_old_max_diff, unsigned long *last_reset,
 166                              bool *protection_started)
 167 {
 168         if (seq_num_diff <= -seq_old_max_diff ||
 169             seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
 170                 if (!batadv_has_timed_out(*last_reset,
 171                                           BATADV_RESET_PROTECTION_MS))
 172                         return true;
 173
 174                 *last_reset = jiffies;
 175                 if (protection_started)
 176                         *protection_started = true;
 177                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 178                            "old packet received, start protection\n");
 179         }
 180
 181         return false;
 182 }
 183
 184 /**
 185  * batadv_check_management_packet() - Check preconditions for management packets
 186  * @skb: incoming packet buffer
 187  * @hard_iface: incoming hard interface
 188  * @header_len: minimal header length of packet type
 189  *
 190  * Return: true when management preconditions are met, false otherwise
 191  */
 192 bool batadv_check_management_packet(struct sk_buff *skb,
 193                                     struct batadv_hard_iface *hard_iface,
 194                                     int header_len)
 195 {
 196         struct ethhdr *ethhdr;
 197
 198         /* drop packet if it has not necessary minimum size */
 199         if (unlikely(!pskb_may_pull(skb, header_len)))
 200                 return false;
 201
 202         ethhdr = eth_hdr(skb);
 203
 204         /* packet with broadcast indication but unicast recipient */
 205         if (!is_broadcast_ether_addr(ethhdr->h_dest))
 206                 return false;
 207
 208         /* packet with invalid sender address */
 209         if (!is_valid_ether_addr(ethhdr->h_source))
 210                 return false;
 211
 212         /* create a copy of the skb, if needed, to modify it. */
 213         if (skb_cow(skb, 0) < 0)
 214                 return false;
 215
 216         /* keep skb linear */
 217         if (skb_linearize(skb) < 0)
 218                 return false;
 219
 220         return true;
 221 }
 222
 223 /**
 224  * batadv_recv_my_icmp_packet() - receive an icmp packet locally
 225  * @bat_priv: the bat priv with all the soft interface information
 226  * @skb: icmp packet to process
 227  *
 228  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 229  * otherwise.
 230  */
 231 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 232                                       struct sk_buff *skb)
 233 {
 234         struct batadv_hard_iface *primary_if = NULL;
 235         struct batadv_orig_node *orig_node = NULL;
 236         struct batadv_icmp_header *icmph;
 237         int res, ret = NET_RX_DROP;
 238
 239         icmph = (struct batadv_icmp_header *)skb->data;
 240
 241         switch (icmph->msg_type) {
 242         case BATADV_ECHO_REPLY:
 243         case BATADV_DESTINATION_UNREACHABLE:
 244         case BATADV_TTL_EXCEEDED:
 245                 /* receive the packet */
 246                 if (skb_linearize(skb) < 0)
 247                         break;
 248
 249                 batadv_socket_receive_packet(icmph, skb->len);
 250                 break;
 251         case BATADV_ECHO_REQUEST:
 252                 /* answer echo request (ping) */
 253                 primary_if = batadv_primary_if_get_selected(bat_priv);
 254                 if (!primary_if)
 255                         goto out;
 256
 257                 /* get routing information */
 258                 orig_node = batadv_orig_hash_find(bat_priv, icmph->orig);
 259                 if (!orig_node)
 260                         goto out;
 261
 262                 /* create a copy of the skb, if needed, to modify it. */
 263                 if (skb_cow(skb, ETH_HLEN) < 0)
 264                         goto out;
 265
 266                 icmph = (struct batadv_icmp_header *)skb->data;
 267
 268                 ether_addr_copy(icmph->dst, icmph->orig);
 269                 ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr);
 270                 icmph->msg_type = BATADV_ECHO_REPLY;
 271                 icmph->ttl = BATADV_TTL;
 272
 273                 res = batadv_send_skb_to_orig(skb, orig_node, NULL);
 274                 if (res == NET_XMIT_SUCCESS)
 275                         ret = NET_RX_SUCCESS;
 276
 277                 /* skb was consumed */
 278                 skb = NULL;
 279                 break;
 280         case BATADV_TP:
 281                 if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet)))
 282                         goto out;
 283
 284                 batadv_tp_meter_recv(bat_priv, skb);
 285                 ret = NET_RX_SUCCESS;
 286                 /* skb was consumed */
 287                 skb = NULL;
 288                 goto out;
 289         default:
 290                 /* drop unknown type */
 291                 goto out;
 292         }
 293 out:
 294         if (primary_if)
 295                 batadv_hardif_put(primary_if);
 296         if (orig_node)
 297                 batadv_orig_node_put(orig_node);
 298
 299         kfree_skb(skb);
 300
 301         return ret;
 302 }
 303
 304 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 305                                          struct sk_buff *skb)
 306 {
 307         struct batadv_hard_iface *primary_if = NULL;
 308         struct batadv_orig_node *orig_node = NULL;
 309         struct batadv_icmp_packet *icmp_packet;
 310         int res, ret = NET_RX_DROP;
 311
 312         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 313
 314         /* send TTL exceeded if packet is an echo request (traceroute) */
 315         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 316                 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
 317                          icmp_packet->orig, icmp_packet->dst);
 318                 goto out;
 319         }
 320
 321         primary_if = batadv_primary_if_get_selected(bat_priv);
 322         if (!primary_if)
 323                 goto out;
 324
 325         /* get routing information */
 326         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
 327         if (!orig_node)
 328                 goto out;
 329
 330         /* create a copy of the skb, if needed, to modify it. */
 331         if (skb_cow(skb, ETH_HLEN) < 0)
 332                 goto out;
 333
 334         icmp_packet = (struct batadv_icmp_packet *)skb->data;
 335
 336         ether_addr_copy(icmp_packet->dst, icmp_packet->orig);
 337         ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr);
 338         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
 339         icmp_packet->ttl = BATADV_TTL;
 340
 341         res = batadv_send_skb_to_orig(skb, orig_node, NULL);
 342         if (res == NET_RX_SUCCESS)
 343                 ret = NET_XMIT_SUCCESS;
 344
 345         /* skb was consumed */
 346         skb = NULL;
 347
 348 out:
 349         if (primary_if)
 350                 batadv_hardif_put(primary_if);
 351         if (orig_node)
 352                 batadv_orig_node_put(orig_node);
 353
 354         kfree_skb(skb);
 355
 356         return ret;
 357 }
 358
 359 /**
 360  * batadv_recv_icmp_packet() - Process incoming icmp packet
 361  * @skb: incoming packet buffer
 362  * @recv_if: incoming hard interface
 363  *
 364  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
 365  */
 366 int batadv_recv_icmp_packet(struct sk_buff *skb,
 367                             struct batadv_hard_iface *recv_if)
 368 {
 369         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 370         struct batadv_icmp_header *icmph;
 371         struct batadv_icmp_packet_rr *icmp_packet_rr;
 372         struct ethhdr *ethhdr;
 373         struct batadv_orig_node *orig_node = NULL;
 374         int hdr_size = sizeof(struct batadv_icmp_header);
 375         int res, ret = NET_RX_DROP;
 376
 377         /* drop packet if it has not necessary minimum size */
 378         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 379                 goto free_skb;
 380
 381         ethhdr = eth_hdr(skb);
 382
 383         /* packet with unicast indication but non-unicast recipient */
 384         if (!is_valid_ether_addr(ethhdr->h_dest))
 385                 goto free_skb;
 386
 387         /* packet with broadcast/multicast sender address */
 388         if (is_multicast_ether_addr(ethhdr->h_source))
 389                 goto free_skb;
 390
 391         /* not for me */
 392         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 393                 goto free_skb;
 394
 395         icmph = (struct batadv_icmp_header *)skb->data;
 396
 397         /* add record route information if not full */
 398         if ((icmph->msg_type == BATADV_ECHO_REPLY ||
 399              icmph->msg_type == BATADV_ECHO_REQUEST) &&
 400             skb->len >= sizeof(struct batadv_icmp_packet_rr)) {
 401                 if (skb_linearize(skb) < 0)
 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 free_skb;
 407
 408                 ethhdr = eth_hdr(skb);
 409                 icmph = (struct batadv_icmp_header *)skb->data;
 410                 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
 411                 if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
 412                         goto free_skb;
 413
 414                 ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur],
 415                                 ethhdr->h_dest);
 416                 icmp_packet_rr->rr_cur++;
 417         }
 418
 419         /* packet for me */
 420         if (batadv_is_my_mac(bat_priv, icmph->dst))
 421                 return batadv_recv_my_icmp_packet(bat_priv, skb);
 422
 423         /* TTL exceeded */
 424         if (icmph->ttl < 2)
 425                 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 426
 427         /* get routing information */
 428         orig_node = batadv_orig_hash_find(bat_priv, icmph->dst);
 429         if (!orig_node)
 430                 goto free_skb;
 431
 432         /* create a copy of the skb, if needed, to modify it. */
 433         if (skb_cow(skb, ETH_HLEN) < 0)
 434                 goto put_orig_node;
 435
 436         icmph = (struct batadv_icmp_header *)skb->data;
 437
 438         /* decrement ttl */
 439         icmph->ttl--;
 440
 441         /* route it */
 442         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 443         if (res == NET_XMIT_SUCCESS)
 444                 ret = NET_RX_SUCCESS;
 445
 446         /* skb was consumed */
 447         skb = NULL;
 448
 449 put_orig_node:
 450         if (orig_node)
 451                 batadv_orig_node_put(orig_node);
 452 free_skb:
 453         kfree_skb(skb);
 454
 455         return ret;
 456 }
 457
 458 /**
 459  * batadv_check_unicast_packet() - Check for malformed unicast packets
 460  * @bat_priv: the bat priv with all the soft interface information
 461  * @skb: packet to check
 462  * @hdr_size: size of header to pull
 463  *
 464  * Check for short header and bad addresses in given packet.
 465  *
 466  * Return: negative value when check fails and 0 otherwise. The negative value
 467  * depends on the reason: -ENODATA for bad header, -EBADR for broadcast
 468  * destination or source, and -EREMOTE for non-local (other host) destination.
 469  */
 470 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
 471                                        struct sk_buff *skb, int hdr_size)
 472 {
 473         struct ethhdr *ethhdr;
 474
 475         /* drop packet if it has not necessary minimum size */
 476         if (unlikely(!pskb_may_pull(skb, hdr_size)))
 477                 return -ENODATA;
 478
 479         ethhdr = eth_hdr(skb);
 480
 481         /* packet with unicast indication but non-unicast recipient */
 482         if (!is_valid_ether_addr(ethhdr->h_dest))
 483                 return -EBADR;
 484
 485         /* packet with broadcast/multicast sender address */
 486         if (is_multicast_ether_addr(ethhdr->h_source))
 487                 return -EBADR;
 488
 489         /* not for me */
 490         if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
 491                 return -EREMOTE;
 492
 493         return 0;
 494 }
 495
 496 /**
 497  * batadv_last_bonding_get() - Get last_bonding_candidate of orig_node
 498  * @orig_node: originator node whose last bonding candidate should be retrieved
 499  *
 500  * Return: last bonding candidate of router or NULL if not found
 501  *
 502  * The object is returned with refcounter increased by 1.
 503  */
 504 static struct batadv_orig_ifinfo *
 505 batadv_last_bonding_get(struct batadv_orig_node *orig_node)
 506 {
 507         struct batadv_orig_ifinfo *last_bonding_candidate;
 508
 509         spin_lock_bh(&orig_node->neigh_list_lock);
 510         last_bonding_candidate = orig_node->last_bonding_candidate;
 511
 512         if (last_bonding_candidate)
 513                 kref_get(&last_bonding_candidate->refcount);
 514         spin_unlock_bh(&orig_node->neigh_list_lock);
 515
 516         return last_bonding_candidate;
 517 }
 518
 519 /**
 520  * batadv_last_bonding_replace() - Replace last_bonding_candidate of orig_node
 521  * @orig_node: originator node whose bonding candidates should be replaced
 522  * @new_candidate: new bonding candidate or NULL
 523  */
 524 static void
 525 batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
 526                             struct batadv_orig_ifinfo *new_candidate)
 527 {
 528         struct batadv_orig_ifinfo *old_candidate;
 529
 530         spin_lock_bh(&orig_node->neigh_list_lock);
 531         old_candidate = orig_node->last_bonding_candidate;
 532
 533         if (new_candidate)
 534                 kref_get(&new_candidate->refcount);
 535         orig_node->last_bonding_candidate = new_candidate;
 536         spin_unlock_bh(&orig_node->neigh_list_lock);
 537
 538         if (old_candidate)
 539                 batadv_orig_ifinfo_put(old_candidate);
 540 }
 541
 542 /**
 543  * batadv_find_router() - find a suitable router for this originator
 544  * @bat_priv: the bat priv with all the soft interface information
 545  * @orig_node: the destination node
 546  * @recv_if: pointer to interface this packet was received on
 547  *
 548  * Return: the router which should be used for this orig_node on
 549  * this interface, or NULL if not available.
 550  */
 551 struct batadv_neigh_node *
 552 batadv_find_router(struct batadv_priv *bat_priv,
 553                    struct batadv_orig_node *orig_node,
 554                    struct batadv_hard_iface *recv_if)
 555 {
 556         struct batadv_algo_ops *bao = bat_priv->algo_ops;
 557         struct batadv_neigh_node *first_candidate_router = NULL;
 558         struct batadv_neigh_node *next_candidate_router = NULL;
 559         struct batadv_neigh_node *router, *cand_router = NULL;
 560         struct batadv_neigh_node *last_cand_router = NULL;
 561         struct batadv_orig_ifinfo *cand, *first_candidate = NULL;
 562         struct batadv_orig_ifinfo *next_candidate = NULL;
 563         struct batadv_orig_ifinfo *last_candidate;
 564         bool last_candidate_found = false;
 565
 566         if (!orig_node)
 567                 return NULL;
 568
 569         router = batadv_orig_router_get(orig_node, recv_if);
 570
 571         if (!router)
 572                 return router;
 573
 574         /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop)
 575          * and if activated.
 576          */
 577         if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding)))
 578                 return router;
 579
 580         /* bonding: loop through the list of possible routers found
 581          * for the various outgoing interfaces and find a candidate after
 582          * the last chosen bonding candidate (next_candidate). If no such
 583          * router is found, use the first candidate found (the previously
 584          * chosen bonding candidate might have been the last one in the list).
 585          * If this can't be found either, return the previously chosen
 586          * router - obviously there are no other candidates.
 587          */
 588         rcu_read_lock();
 589         last_candidate = batadv_last_bonding_get(orig_node);
 590         if (last_candidate)
 591                 last_cand_router = rcu_dereference(last_candidate->router);
 592
 593         hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) {
 594                 /* acquire some structures and references ... */
 595                 if (!kref_get_unless_zero(&cand->refcount))
 596                         continue;
 597
 598                 cand_router = rcu_dereference(cand->router);
 599                 if (!cand_router)
 600                         goto next;
 601
 602                 if (!kref_get_unless_zero(&cand_router->refcount)) {
 603                         cand_router = NULL;
 604                         goto next;
 605                 }
 606
 607                 /* alternative candidate should be good enough to be
 608                  * considered
 609                  */
 610                 if (!bao->neigh.is_similar_or_better(cand_router,
 611                                                      cand->if_outgoing, router,
 612                                                      recv_if))
 613                         goto next;
 614
 615                 /* don't use the same router twice */
 616                 if (last_cand_router == cand_router)
 617                         goto next;
 618
 619                 /* mark the first possible candidate */
 620                 if (!first_candidate) {
 621                         kref_get(&cand_router->refcount);
 622                         kref_get(&cand->refcount);
 623                         first_candidate = cand;
 624                         first_candidate_router = cand_router;
 625                 }
 626
 627                 /* check if the loop has already passed the previously selected
 628                  * candidate ... this function should select the next candidate
 629                  * AFTER the previously used bonding candidate.
 630                  */
 631                 if (!last_candidate || last_candidate_found) {
 632                         next_candidate = cand;
 633                         next_candidate_router = cand_router;
 634                         break;
 635                 }
 636
 637                 if (last_candidate == cand)
 638                         last_candidate_found = true;
 639 next:
 640                 /* free references */
 641                 if (cand_router) {
 642                         batadv_neigh_node_put(cand_router);
 643                         cand_router = NULL;
 644                 }
 645                 batadv_orig_ifinfo_put(cand);
 646         }
 647         rcu_read_unlock();
 648
 649         /* After finding candidates, handle the three cases:
 650          * 1) there is a next candidate, use that
 651          * 2) there is no next candidate, use the first of the list
 652          * 3) there is no candidate at all, return the default router
 653          */
 654         if (next_candidate) {
 655                 batadv_neigh_node_put(router);
 656
 657                 kref_get(&next_candidate_router->refcount);
 658                 router = next_candidate_router;
 659                 batadv_last_bonding_replace(orig_node, next_candidate);
 660         } else if (first_candidate) {
 661                 batadv_neigh_node_put(router);
 662
 663                 kref_get(&first_candidate_router->refcount);
 664                 router = first_candidate_router;
 665                 batadv_last_bonding_replace(orig_node, first_candidate);
 666         } else {
 667                 batadv_last_bonding_replace(orig_node, NULL);
 668         }
 669
 670         /* cleanup of candidates */
 671         if (first_candidate) {
 672                 batadv_neigh_node_put(first_candidate_router);
 673                 batadv_orig_ifinfo_put(first_candidate);
 674         }
 675
 676         if (next_candidate) {
 677                 batadv_neigh_node_put(next_candidate_router);
 678                 batadv_orig_ifinfo_put(next_candidate);
 679         }
 680
 681         if (last_candidate)
 682                 batadv_orig_ifinfo_put(last_candidate);
 683
 684         return router;
 685 }
 686
 687 static int batadv_route_unicast_packet(struct sk_buff *skb,
 688                                        struct batadv_hard_iface *recv_if)
 689 {
 690         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 691         struct batadv_orig_node *orig_node = NULL;
 692         struct batadv_unicast_packet *unicast_packet;
 693         struct ethhdr *ethhdr = eth_hdr(skb);
 694         int res, hdr_len, ret = NET_RX_DROP;
 695         unsigned int len;
 696
 697         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 698
 699         /* TTL exceeded */
 700         if (unicast_packet->ttl < 2) {
 701                 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
 702                          ethhdr->h_source, unicast_packet->dest);
 703                 goto free_skb;
 704         }
 705
 706         /* get routing information */
 707         orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
 708
 709         if (!orig_node)
 710                 goto free_skb;
 711
 712         /* create a copy of the skb, if needed, to modify it. */
 713         if (skb_cow(skb, ETH_HLEN) < 0)
 714                 goto put_orig_node;
 715
 716         /* decrement ttl */
 717         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 718         unicast_packet->ttl--;
 719
 720         switch (unicast_packet->packet_type) {
 721         case BATADV_UNICAST_4ADDR:
 722                 hdr_len = sizeof(struct batadv_unicast_4addr_packet);
 723                 break;
 724         case BATADV_UNICAST:
 725                 hdr_len = sizeof(struct batadv_unicast_packet);
 726                 break;
 727         default:
 728                 /* other packet types not supported - yet */
 729                 hdr_len = -1;
 730                 break;
 731         }
 732
 733         if (hdr_len > 0)
 734                 batadv_skb_set_priority(skb, hdr_len);
 735
 736         len = skb->len;
 737         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 738
 739         /* translate transmit result into receive result */
 740         if (res == NET_XMIT_SUCCESS) {
 741                 ret = NET_RX_SUCCESS;
 742                 /* skb was transmitted and consumed */
 743                 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 744                 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 745                                    len + ETH_HLEN);
 746         }
 747
 748         /* skb was consumed */
 749         skb = NULL;
 750
 751 put_orig_node:
 752         batadv_orig_node_put(orig_node);
 753 free_skb:
 754         kfree_skb(skb);
 755
 756         return ret;
 757 }
 758
 759 /**
 760  * batadv_reroute_unicast_packet() - update the unicast header for re-routing
 761  * @bat_priv: the bat priv with all the soft interface information
 762  * @skb: unicast packet to process
 763  * @unicast_packet: the unicast header to be updated
 764  * @dst_addr: the payload destination
 765  * @vid: VLAN identifier
 766  *
 767  * Search the translation table for dst_addr and update the unicast header with
 768  * the new corresponding information (originator address where the destination
 769  * client currently is and its known TTVN)
 770  *
 771  * Return: true if the packet header has been updated, false otherwise
 772  */
 773 static bool
 774 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
 775                               struct batadv_unicast_packet *unicast_packet,
 776                               u8 *dst_addr, unsigned short vid)
 777 {
 778         struct batadv_orig_node *orig_node = NULL;
 779         struct batadv_hard_iface *primary_if = NULL;
 780         bool ret = false;
 781         u8 *orig_addr, orig_ttvn;
 782
 783         if (batadv_is_my_client(bat_priv, dst_addr, vid)) {
 784                 primary_if = batadv_primary_if_get_selected(bat_priv);
 785                 if (!primary_if)
 786                         goto out;
 787                 orig_addr = primary_if->net_dev->dev_addr;
 788                 orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
 789         } else {
 790                 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr,
 791                                                      vid);
 792                 if (!orig_node)
 793                         goto out;
 794
 795                 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
 796                         goto out;
 797
 798                 orig_addr = orig_node->orig;
 799                 orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 800         }
 801
 802         /* update the packet header */
 803         skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 804         ether_addr_copy(unicast_packet->dest, orig_addr);
 805         unicast_packet->ttvn = orig_ttvn;
 806         skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 807
 808         ret = true;
 809 out:
 810         if (primary_if)
 811                 batadv_hardif_put(primary_if);
 812         if (orig_node)
 813                 batadv_orig_node_put(orig_node);
 814
 815         return ret;
 816 }
 817
 818 static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 819                                       struct sk_buff *skb, int hdr_len)
 820 {
 821         struct batadv_unicast_packet *unicast_packet;
 822         struct batadv_hard_iface *primary_if;
 823         struct batadv_orig_node *orig_node;
 824         u8 curr_ttvn, old_ttvn;
 825         struct ethhdr *ethhdr;
 826         unsigned short vid;
 827         int is_old_ttvn;
 828
 829         /* check if there is enough data before accessing it */
 830         if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
 831                 return false;
 832
 833         /* create a copy of the skb (in case of for re-routing) to modify it. */
 834         if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
 835                 return false;
 836
 837         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 838         vid = batadv_get_vid(skb, hdr_len);
 839         ethhdr = (struct ethhdr *)(skb->data + hdr_len);
 840
 841         /* do not reroute multicast frames in a unicast header */
 842         if (is_multicast_ether_addr(ethhdr->h_dest))
 843                 return true;
 844
 845         /* check if the destination client was served by this node and it is now
 846          * roaming. In this case, it means that the node has got a ROAM_ADV
 847          * message and that it knows the new destination in the mesh to re-route
 848          * the packet to
 849          */
 850         if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
 851                 if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
 852                                                   ethhdr->h_dest, vid))
 853                         batadv_dbg_ratelimited(BATADV_DBG_TT,
 854                                                bat_priv,
 855                                                "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
 856                                                unicast_packet->dest,
 857                                                ethhdr->h_dest);
 858                 /* at this point the mesh destination should have been
 859                  * substituted with the originator address found in the global
 860                  * table. If not, let the packet go untouched anyway because
 861                  * there is nothing the node can do
 862                  */
 863                 return true;
 864         }
 865
 866         /* retrieve the TTVN known by this node for the packet destination. This
 867          * value is used later to check if the node which sent (or re-routed
 868          * last time) the packet had an updated information or not
 869          */
 870         curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
 871         if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 872                 orig_node = batadv_orig_hash_find(bat_priv,
 873                                                   unicast_packet->dest);
 874                 /* if it is not possible to find the orig_node representing the
 875                  * destination, the packet can immediately be dropped as it will
 876                  * not be possible to deliver it
 877                  */
 878                 if (!orig_node)
 879                         return false;
 880
 881                 curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 882                 batadv_orig_node_put(orig_node);
 883         }
 884
 885         /* check if the TTVN contained in the packet is fresher than what the
 886          * node knows
 887          */
 888         is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
 889         if (!is_old_ttvn)
 890                 return true;
 891
 892         old_ttvn = unicast_packet->ttvn;
 893         /* the packet was forged based on outdated network information. Its
 894          * destination can possibly be updated and forwarded towards the new
 895          * target host
 896          */
 897         if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
 898                                           ethhdr->h_dest, vid)) {
 899                 batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv,
 900                                        "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
 901                                        unicast_packet->dest, ethhdr->h_dest,
 902                                        old_ttvn, curr_ttvn);
 903                 return true;
 904         }
 905
 906         /* the packet has not been re-routed: either the destination is
 907          * currently served by this node or there is no destination at all and
 908          * it is possible to drop the packet
 909          */
 910         if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid))
 911                 return false;
 912
 913         /* update the header in order to let the packet be delivered to this
 914          * node's soft interface
 915          */
 916         primary_if = batadv_primary_if_get_selected(bat_priv);
 917         if (!primary_if)
 918                 return false;
 919
 920         /* update the packet header */
 921         skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 922         ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
 923         unicast_packet->ttvn = curr_ttvn;
 924         skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 925
 926         batadv_hardif_put(primary_if);
 927
 928         return true;
 929 }
 930
 931 /**
 932  * batadv_recv_unhandled_unicast_packet() - receive and process packets which
 933  *      are in the unicast number space but not yet known to the implementation
 934  * @skb: unicast tvlv packet to process
 935  * @recv_if: pointer to interface this packet was received on
 936  *
 937  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
 938  * otherwise.
 939  */
 940 int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,
 941                                          struct batadv_hard_iface *recv_if)
 942 {
 943         struct batadv_unicast_packet *unicast_packet;
 944         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 945         int check, hdr_size = sizeof(*unicast_packet);
 946
 947         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
 948         if (check < 0)
 949                 goto free_skb;
 950
 951         /* we don't know about this type, drop it. */
 952         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 953         if (batadv_is_my_mac(bat_priv, unicast_packet->dest))
 954                 goto free_skb;
 955
 956         return batadv_route_unicast_packet(skb, recv_if);
 957
 958 free_skb:
 959         kfree_skb(skb);
 960         return NET_RX_DROP;
 961 }
 962
 963 /**
 964  * batadv_recv_unicast_packet() - Process incoming unicast packet
 965  * @skb: incoming packet buffer
 966  * @recv_if: incoming hard interface
 967  *
 968  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
 969  */
 970 int batadv_recv_unicast_packet(struct sk_buff *skb,
 971                                struct batadv_hard_iface *recv_if)
 972 {
 973         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
 974         struct batadv_unicast_packet *unicast_packet;
 975         struct batadv_unicast_4addr_packet *unicast_4addr_packet;
 976         u8 *orig_addr, *orig_addr_gw;
 977         struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL;
 978         int check, hdr_size = sizeof(*unicast_packet);
 979         enum batadv_subtype subtype;
 980         int ret = NET_RX_DROP;
 981         bool is4addr, is_gw;
 982
 983         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 984         is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
 985         /* the caller function should have already pulled 2 bytes */
 986         if (is4addr)
 987                 hdr_size = sizeof(*unicast_4addr_packet);
 988
 989         /* function returns -EREMOTE for promiscuous packets */
 990         check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
 991
 992         /* Even though the packet is not for us, we might save it to use for
 993          * decoding a later received coded packet
 994          */
 995         if (check == -EREMOTE)
 996                 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
 997
 998         if (check < 0)
 999                 goto free_skb;
1000         if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
1001                 goto free_skb;
1002
1003         unicast_packet = (struct batadv_unicast_packet *)skb->data;
1004
1005         /* packet for me */
1006         if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
1007                 /* If this is a unicast packet from another backgone gw,
1008                  * drop it.
1009                  */
1010                 orig_addr_gw = eth_hdr(skb)->h_source;
1011                 orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw);
1012                 if (orig_node_gw) {
1013                         is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw,
1014                                                           hdr_size);
1015                         batadv_orig_node_put(orig_node_gw);
1016                         if (is_gw) {
1017                                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1018                                            "%s(): Dropped unicast pkt received from another backbone gw %pM.\n",
1019                                            __func__, orig_addr_gw);
1020                                 goto free_skb;
1021                         }
1022                 }
1023
1024                 if (is4addr) {
1025                         unicast_4addr_packet =
1026                                 (struct batadv_unicast_4addr_packet *)skb->data;
1027                         subtype = unicast_4addr_packet->subtype;
1028                         batadv_dat_inc_counter(bat_priv, subtype);
1029
1030                         /* Only payload data should be considered for speedy
1031                          * join. For example, DAT also uses unicast 4addr
1032                          * types, but those packets should not be considered
1033                          * for speedy join, since the clients do not actually
1034                          * reside at the sending originator.
1035                          */
1036                         if (subtype == BATADV_P_DATA) {
1037                                 orig_addr = unicast_4addr_packet->src;
1038                                 orig_node = batadv_orig_hash_find(bat_priv,
1039                                                                   orig_addr);
1040                         }
1041                 }
1042
1043                 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
1044                                                           hdr_size))
1045                         goto rx_success;
1046                 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
1047                                                         hdr_size))
1048                         goto rx_success;
1049
1050                 batadv_interface_rx(recv_if->soft_iface, skb, hdr_size,
1051                                     orig_node);
1052
1053 rx_success:
1054                 if (orig_node)
1055                         batadv_orig_node_put(orig_node);
1056
1057                 return NET_RX_SUCCESS;
1058         }
1059
1060         ret = batadv_route_unicast_packet(skb, recv_if);
1061         /* skb was consumed */
1062         skb = NULL;
1063
1064 free_skb:
1065         kfree_skb(skb);
1066
1067         return ret;
1068 }
1069
1070 /**
1071  * batadv_recv_unicast_tvlv() - receive and process unicast tvlv packets
1072  * @skb: unicast tvlv packet to process
1073  * @recv_if: pointer to interface this packet was received on
1074  *
1075  * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1076  * otherwise.
1077  */
1078 int batadv_recv_unicast_tvlv(struct sk_buff *skb,
1079                              struct batadv_hard_iface *recv_if)
1080 {
1081         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1082         struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
1083         unsigned char *tvlv_buff;
1084         u16 tvlv_buff_len;
1085         int hdr_size = sizeof(*unicast_tvlv_packet);
1086         int ret = NET_RX_DROP;
1087
1088         if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
1089                 goto free_skb;
1090
1091         /* the header is likely to be modified while forwarding */
1092         if (skb_cow(skb, hdr_size) < 0)
1093                 goto free_skb;
1094
1095         /* packet needs to be linearized to access the tvlv content */
1096         if (skb_linearize(skb) < 0)
1097                 goto free_skb;
1098
1099         unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;
1100
1101         tvlv_buff = (unsigned char *)(skb->data + hdr_size);
1102         tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);
1103
1104         if (tvlv_buff_len > skb->len - hdr_size)
1105                 goto free_skb;
1106
1107         ret = batadv_tvlv_containers_process(bat_priv, false, NULL,
1108                                              unicast_tvlv_packet->src,
1109                                              unicast_tvlv_packet->dst,
1110                                              tvlv_buff, tvlv_buff_len);
1111
1112         if (ret != NET_RX_SUCCESS) {
1113                 ret = batadv_route_unicast_packet(skb, recv_if);
1114                 /* skb was consumed */
1115                 skb = NULL;
1116         }
1117
1118 free_skb:
1119         kfree_skb(skb);
1120
1121         return ret;
1122 }
1123
1124 /**
1125  * batadv_recv_frag_packet() - process received fragment
1126  * @skb: the received fragment
1127  * @recv_if: interface that the skb is received on
1128  *
1129  * This function does one of the three following things: 1) Forward fragment, if
1130  * the assembled packet will exceed our MTU; 2) Buffer fragment, if we till
1131  * lack further fragments; 3) Merge fragments, if we have all needed parts.
1132  *
1133  * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise.
1134  */
1135 int batadv_recv_frag_packet(struct sk_buff *skb,
1136                             struct batadv_hard_iface *recv_if)
1137 {
1138         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1139         struct batadv_orig_node *orig_node_src = NULL;
1140         struct batadv_frag_packet *frag_packet;
1141         int ret = NET_RX_DROP;
1142
1143         if (batadv_check_unicast_packet(bat_priv, skb,
1144                                         sizeof(*frag_packet)) < 0)
1145                 goto free_skb;
1146
1147         frag_packet = (struct batadv_frag_packet *)skb->data;
1148         orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig);
1149         if (!orig_node_src)
1150                 goto free_skb;
1151
1152         skb->priority = frag_packet->priority + 256;
1153
1154         /* Route the fragment if it is not for us and too big to be merged. */
1155         if (!batadv_is_my_mac(bat_priv, frag_packet->dest) &&
1156             batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) {
1157                 /* skb was consumed */
1158                 skb = NULL;
1159                 ret = NET_RX_SUCCESS;
1160                 goto put_orig_node;
1161         }
1162
1163         batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
1164         batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
1165
1166         /* Add fragment to buffer and merge if possible. */
1167         if (!batadv_frag_skb_buffer(&skb, orig_node_src))
1168                 goto put_orig_node;
1169
1170         /* Deliver merged packet to the appropriate handler, if it was
1171          * merged
1172          */
1173         if (skb) {
1174                 batadv_batman_skb_recv(skb, recv_if->net_dev,
1175                                        &recv_if->batman_adv_ptype, NULL);
1176                 /* skb was consumed */
1177                 skb = NULL;
1178         }
1179
1180         ret = NET_RX_SUCCESS;
1181
1182 put_orig_node:
1183         batadv_orig_node_put(orig_node_src);
1184 free_skb:
1185         kfree_skb(skb);
1186
1187         return ret;
1188 }
1189
1190 /**
1191  * batadv_recv_bcast_packet() - Process incoming broadcast packet
1192  * @skb: incoming packet buffer
1193  * @recv_if: incoming hard interface
1194  *
1195  * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
1196  */
1197 int batadv_recv_bcast_packet(struct sk_buff *skb,
1198                              struct batadv_hard_iface *recv_if)
1199 {
1200         struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1201         struct batadv_orig_node *orig_node = NULL;
1202         struct batadv_bcast_packet *bcast_packet;
1203         struct ethhdr *ethhdr;
1204         int hdr_size = sizeof(*bcast_packet);
1205         int ret = NET_RX_DROP;
1206         s32 seq_diff;
1207         u32 seqno;
1208
1209         /* drop packet if it has not necessary minimum size */
1210         if (unlikely(!pskb_may_pull(skb, hdr_size)))
1211                 goto free_skb;
1212
1213         ethhdr = eth_hdr(skb);
1214
1215         /* packet with broadcast indication but unicast recipient */
1216         if (!is_broadcast_ether_addr(ethhdr->h_dest))
1217                 goto free_skb;
1218
1219         /* packet with broadcast/multicast sender address */
1220         if (is_multicast_ether_addr(ethhdr->h_source))
1221                 goto free_skb;
1222
1223         /* ignore broadcasts sent by myself */
1224         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1225                 goto free_skb;
1226
1227         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1228
1229         /* ignore broadcasts originated by myself */
1230         if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
1231                 goto free_skb;
1232
1233         if (bcast_packet->ttl < 2)
1234                 goto free_skb;
1235
1236         orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1237
1238         if (!orig_node)
1239                 goto free_skb;
1240
1241         spin_lock_bh(&orig_node->bcast_seqno_lock);
1242
1243         seqno = ntohl(bcast_packet->seqno);
1244         /* check whether the packet is a duplicate */
1245         if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1246                             seqno))
1247                 goto spin_unlock;
1248
1249         seq_diff = seqno - orig_node->last_bcast_seqno;
1250
1251         /* check whether the packet is old and the host just restarted. */
1252         if (batadv_window_protected(bat_priv, seq_diff,
1253                                     BATADV_BCAST_MAX_AGE,
1254                                     &orig_node->bcast_seqno_reset, NULL))
1255                 goto spin_unlock;
1256
1257         /* mark broadcast in flood history, update window position
1258          * if required.
1259          */
1260         if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1261                 orig_node->last_bcast_seqno = seqno;
1262
1263         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1264
1265         /* check whether this has been sent by another originator before */
1266         if (batadv_bla_check_bcast_duplist(bat_priv, skb))
1267                 goto free_skb;
1268
1269         batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
1270
1271         /* rebroadcast packet */
1272         batadv_add_bcast_packet_to_list(bat_priv, skb, 1, false);
1273
1274         /* don't hand the broadcast up if it is from an originator
1275          * from the same backbone.
1276          */
1277         if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1278                 goto free_skb;
1279
1280         if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
1281                 goto rx_success;
1282         if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
1283                 goto rx_success;
1284
1285         /* broadcast for me */
1286         batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node);
1287
1288 rx_success:
1289         ret = NET_RX_SUCCESS;
1290         goto out;
1291
1292 spin_unlock:
1293         spin_unlock_bh(&orig_node->bcast_seqno_lock);
1294 free_skb:
1295         kfree_skb(skb);
1296 out:
1297         if (orig_node)
1298                 batadv_orig_node_put(orig_node);
1299         return ret;
1300 }