net/batman-adv/send.c

   1 /* Copyright (C) 2007-2014 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "main.h"
  19 #include "distributed-arp-table.h"
  20 #include "send.h"
  21 #include "routing.h"
  22 #include "translation-table.h"
  23 #include "soft-interface.h"
  24 #include "hard-interface.h"
  25 #include "gateway_common.h"
  26 #include "gateway_client.h"
  27 #include "originator.h"
  28 #include "network-coding.h"
  29 #include "fragmentation.h"
  30
  31 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  32
  33 /* send out an already prepared packet to the given address via the
  34  * specified batman interface
  35  */
  36 int batadv_send_skb_packet(struct sk_buff *skb,
  37                            struct batadv_hard_iface *hard_iface,
  38                            const uint8_t *dst_addr)
  39 {
  40         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  41         struct ethhdr *ethhdr;
  42
  43         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  44                 goto send_skb_err;
  45
  46         if (unlikely(!hard_iface->net_dev))
  47                 goto send_skb_err;
  48
  49         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  50                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  51                         hard_iface->net_dev->name);
  52                 goto send_skb_err;
  53         }
  54
  55         /* push to the ethernet header. */
  56         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  57                 goto send_skb_err;
  58
  59         skb_reset_mac_header(skb);
  60
  61         ethhdr = eth_hdr(skb);
  62         ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
  63         ether_addr_copy(ethhdr->h_dest, dst_addr);
  64         ethhdr->h_proto = htons(ETH_P_BATMAN);
  65
  66         skb_set_network_header(skb, ETH_HLEN);
  67         skb->protocol = htons(ETH_P_BATMAN);
  68
  69         skb->dev = hard_iface->net_dev;
  70
  71         /* Save a clone of the skb to use when decoding coded packets */
  72         batadv_nc_skb_store_for_decoding(bat_priv, skb);
  73
  74         /* dev_queue_xmit() returns a negative result on error.  However on
  75          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  76          * (which is > 0). This will not be treated as an error.
  77          */
  78         return dev_queue_xmit(skb);
  79 send_skb_err:
  80         kfree_skb(skb);
  81         return NET_XMIT_DROP;
  82 }
  83
  84 /**
  85  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  86  * @skb: Packet to be transmitted.
  87  * @orig_node: Final destination of the packet.
  88  * @recv_if: Interface used when receiving the packet (can be NULL).
  89  *
  90  * Looks up the best next-hop towards the passed originator and passes the
  91  * skb on for preparation of MAC header. If the packet originated from this
  92  * host, NULL can be passed as recv_if and no interface alternating is
  93  * attempted.
  94  *
  95  * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
  96  * NET_XMIT_POLICED if the skb is buffered for later transmit.
  97  */
  98 int batadv_send_skb_to_orig(struct sk_buff *skb,
  99                             struct batadv_orig_node *orig_node,
 100                             struct batadv_hard_iface *recv_if)
 101 {
 102         struct batadv_priv *bat_priv = orig_node->bat_priv;
 103         struct batadv_neigh_node *neigh_node;
 104         int ret = NET_XMIT_DROP;
 105
 106         /* batadv_find_router() increases neigh_nodes refcount if found. */
 107         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 108         if (!neigh_node)
 109                 goto out;
 110
 111         /* Check if the skb is too large to send in one piece and fragment
 112          * it if needed.
 113          */
 114         if (atomic_read(&bat_priv->fragmentation) &&
 115             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 116                 /* Fragment and send packet. */
 117                 if (batadv_frag_send_packet(skb, orig_node, neigh_node))
 118                         ret = NET_XMIT_SUCCESS;
 119
 120                 goto out;
 121         }
 122
 123         /* try to network code the packet, if it is received on an interface
 124          * (i.e. being forwarded). If the packet originates from this node or if
 125          * network coding fails, then send the packet as usual.
 126          */
 127         if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
 128                 ret = NET_XMIT_POLICED;
 129         } else {
 130                 batadv_send_skb_packet(skb, neigh_node->if_incoming,
 131                                        neigh_node->addr);
 132                 ret = NET_XMIT_SUCCESS;
 133         }
 134
 135 out:
 136         if (neigh_node)
 137                 batadv_neigh_node_free_ref(neigh_node);
 138
 139         return ret;
 140 }
 141
 142 /**
 143  * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
 144  *  common fields for unicast packets
 145  * @skb: the skb carrying the unicast header to initialize
 146  * @hdr_size: amount of bytes to push at the beginning of the skb
 147  * @orig_node: the destination node
 148  *
 149  * Returns false if the buffer extension was not possible or true otherwise.
 150  */
 151 static bool
 152 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 153                                   struct batadv_orig_node *orig_node)
 154 {
 155         struct batadv_unicast_packet *unicast_packet;
 156         uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
 157
 158         if (batadv_skb_head_push(skb, hdr_size) < 0)
 159                 return false;
 160
 161         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 162         unicast_packet->version = BATADV_COMPAT_VERSION;
 163         /* batman packet type: unicast */
 164         unicast_packet->packet_type = BATADV_UNICAST;
 165         /* set unicast ttl */
 166         unicast_packet->ttl = BATADV_TTL;
 167         /* copy the destination for faster routing */
 168         ether_addr_copy(unicast_packet->dest, orig_node->orig);
 169         /* set the destination tt version number */
 170         unicast_packet->ttvn = ttvn;
 171
 172         return true;
 173 }
 174
 175 /**
 176  * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
 177  * @skb: the skb containing the payload to encapsulate
 178  * @orig_node: the destination node
 179  *
 180  * Returns false if the payload could not be encapsulated or true otherwise.
 181  */
 182 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 183                                             struct batadv_orig_node *orig_node)
 184 {
 185         size_t uni_size = sizeof(struct batadv_unicast_packet);
 186
 187         return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 188 }
 189
 190 /**
 191  * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
 192  *  unicast 4addr header
 193  * @bat_priv: the bat priv with all the soft interface information
 194  * @skb: the skb containing the payload to encapsulate
 195  * @orig_node: the destination node
 196  * @packet_subtype: the unicast 4addr packet subtype to use
 197  *
 198  * Returns false if the payload could not be encapsulated or true otherwise.
 199  */
 200 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 201                                            struct sk_buff *skb,
 202                                            struct batadv_orig_node *orig,
 203                                            int packet_subtype)
 204 {
 205         struct batadv_hard_iface *primary_if;
 206         struct batadv_unicast_4addr_packet *uc_4addr_packet;
 207         bool ret = false;
 208
 209         primary_if = batadv_primary_if_get_selected(bat_priv);
 210         if (!primary_if)
 211                 goto out;
 212
 213         /* Pull the header space and fill the unicast_packet substructure.
 214          * We can do that because the first member of the uc_4addr_packet
 215          * is of type struct unicast_packet
 216          */
 217         if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 218                                                orig))
 219                 goto out;
 220
 221         uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 222         uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 223         ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
 224         uc_4addr_packet->subtype = packet_subtype;
 225         uc_4addr_packet->reserved = 0;
 226
 227         ret = true;
 228 out:
 229         if (primary_if)
 230                 batadv_hardif_free_ref(primary_if);
 231         return ret;
 232 }
 233
 234 /**
 235  * batadv_send_skb_unicast - encapsulate and send an skb via unicast
 236  * @bat_priv: the bat priv with all the soft interface information
 237  * @skb: payload to send
 238  * @packet_type: the batman unicast packet type to use
 239  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 240  *  4addr packets)
 241  * @orig_node: the originator to send the packet to
 242  * @vid: the vid to be used to search the translation table
 243  *
 244  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
 245  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
 246  * as packet_type. Then send this frame to the given orig_node and release a
 247  * reference to this orig_node.
 248  *
 249  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 250  */
 251 static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 252                                    struct sk_buff *skb, int packet_type,
 253                                    int packet_subtype,
 254                                    struct batadv_orig_node *orig_node,
 255                                    unsigned short vid)
 256 {
 257         struct ethhdr *ethhdr;
 258         struct batadv_unicast_packet *unicast_packet;
 259         int ret = NET_XMIT_DROP;
 260
 261         if (!orig_node)
 262                 goto out;
 263
 264         switch (packet_type) {
 265         case BATADV_UNICAST:
 266                 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 267                         goto out;
 268                 break;
 269         case BATADV_UNICAST_4ADDR:
 270                 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 271                                                            orig_node,
 272                                                            packet_subtype))
 273                         goto out;
 274                 break;
 275         default:
 276                 /* this function supports UNICAST and UNICAST_4ADDR only. It
 277                  * should never be invoked with any other packet type
 278                  */
 279                 goto out;
 280         }
 281
 282         /* skb->data might have been reallocated by
 283          * batadv_send_skb_prepare_unicast{,_4addr}()
 284          */
 285         ethhdr = eth_hdr(skb);
 286         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 287
 288         /* inform the destination node that we are still missing a correct route
 289          * for this client. The destination will receive this packet and will
 290          * try to reroute it because the ttvn contained in the header is less
 291          * than the current one
 292          */
 293         if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 294                 unicast_packet->ttvn = unicast_packet->ttvn - 1;
 295
 296         if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 297                 ret = NET_XMIT_SUCCESS;
 298
 299 out:
 300         if (orig_node)
 301                 batadv_orig_node_free_ref(orig_node);
 302         if (ret == NET_XMIT_DROP)
 303                 kfree_skb(skb);
 304         return ret;
 305 }
 306
 307 /**
 308  * batadv_send_skb_via_tt_generic - send an skb via TT lookup
 309  * @bat_priv: the bat priv with all the soft interface information
 310  * @skb: payload to send
 311  * @packet_type: the batman unicast packet type to use
 312  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 313  *  4addr packets)
 314  * @vid: the vid to be used to search the translation table
 315  *
 316  * Look up the recipient node for the destination address in the ethernet
 317  * header via the translation table. Wrap the given skb into a batman-adv
 318  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
 319  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
 320  * to the according destination node.
 321  *
 322  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 323  */
 324 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 325                                    struct sk_buff *skb, int packet_type,
 326                                    int packet_subtype, uint8_t *dst_hint,
 327                                    unsigned short vid)
 328 {
 329         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 330         struct batadv_orig_node *orig_node;
 331         uint8_t *src, *dst;
 332
 333         src = ethhdr->h_source;
 334         dst = ethhdr->h_dest;
 335
 336         /* if we got an hint! let's send the packet to this client (if any) */
 337         if (dst_hint) {
 338                 src = NULL;
 339                 dst = dst_hint;
 340         }
 341         orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
 342
 343         return batadv_send_skb_unicast(bat_priv, skb, packet_type,
 344                                        packet_subtype, orig_node, vid);
 345 }
 346
 347 /**
 348  * batadv_send_skb_via_gw - send an skb via gateway lookup
 349  * @bat_priv: the bat priv with all the soft interface information
 350  * @skb: payload to send
 351  * @vid: the vid to be used to search the translation table
 352  *
 353  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
 354  * unicast header and send this frame to this gateway node.
 355  *
 356  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 357  */
 358 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 359                            unsigned short vid)
 360 {
 361         struct batadv_orig_node *orig_node;
 362
 363         orig_node = batadv_gw_get_selected_orig(bat_priv);
 364         return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
 365                                        orig_node, vid);
 366 }
 367
 368 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 369 {
 370         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 371
 372         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 373             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 374                 return;
 375
 376         /* the interface gets activated here to avoid race conditions between
 377          * the moment of activating the interface in
 378          * hardif_activate_interface() where the originator mac is set and
 379          * outdated packets (especially uninitialized mac addresses) in the
 380          * packet queue
 381          */
 382         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 383                 hard_iface->if_status = BATADV_IF_ACTIVE;
 384
 385         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 386 }
 387
 388 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 389 {
 390         if (forw_packet->skb)
 391                 kfree_skb(forw_packet->skb);
 392         if (forw_packet->if_incoming)
 393                 batadv_hardif_free_ref(forw_packet->if_incoming);
 394         if (forw_packet->if_outgoing)
 395                 batadv_hardif_free_ref(forw_packet->if_outgoing);
 396         kfree(forw_packet);
 397 }
 398
 399 static void
 400 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 401                                  struct batadv_forw_packet *forw_packet,
 402                                  unsigned long send_time)
 403 {
 404         /* add new packet to packet list */
 405         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 406         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 407         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 408
 409         /* start timer for this packet */
 410         queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 411                            send_time);
 412 }
 413
 414 /* add a broadcast packet to the queue and setup timers. broadcast packets
 415  * are sent multiple times to increase probability for being received.
 416  *
 417  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 418  * errors.
 419  *
 420  * The skb is not consumed, so the caller should make sure that the
 421  * skb is freed.
 422  */
 423 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 424                                     const struct sk_buff *skb,
 425                                     unsigned long delay)
 426 {
 427         struct batadv_hard_iface *primary_if = NULL;
 428         struct batadv_forw_packet *forw_packet;
 429         struct batadv_bcast_packet *bcast_packet;
 430         struct sk_buff *newskb;
 431
 432         if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 433                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 434                            "bcast packet queue full\n");
 435                 goto out;
 436         }
 437
 438         primary_if = batadv_primary_if_get_selected(bat_priv);
 439         if (!primary_if)
 440                 goto out_and_inc;
 441
 442         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 443
 444         if (!forw_packet)
 445                 goto out_and_inc;
 446
 447         newskb = skb_copy(skb, GFP_ATOMIC);
 448         if (!newskb)
 449                 goto packet_free;
 450
 451         /* as we have a copy now, it is safe to decrease the TTL */
 452         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 453         bcast_packet->ttl--;
 454
 455         skb_reset_mac_header(newskb);
 456
 457         forw_packet->skb = newskb;
 458         forw_packet->if_incoming = primary_if;
 459         forw_packet->if_outgoing = NULL;
 460
 461         /* how often did we send the bcast packet ? */
 462         forw_packet->num_packets = 0;
 463
 464         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 465                           batadv_send_outstanding_bcast_packet);
 466
 467         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 468         return NETDEV_TX_OK;
 469
 470 packet_free:
 471         kfree(forw_packet);
 472 out_and_inc:
 473         atomic_inc(&bat_priv->bcast_queue_left);
 474 out:
 475         if (primary_if)
 476                 batadv_hardif_free_ref(primary_if);
 477         return NETDEV_TX_BUSY;
 478 }
 479
 480 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 481 {
 482         struct batadv_hard_iface *hard_iface;
 483         struct delayed_work *delayed_work;
 484         struct batadv_forw_packet *forw_packet;
 485         struct sk_buff *skb1;
 486         struct net_device *soft_iface;
 487         struct batadv_priv *bat_priv;
 488
 489         delayed_work = container_of(work, struct delayed_work, work);
 490         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 491                                    delayed_work);
 492         soft_iface = forw_packet->if_incoming->soft_iface;
 493         bat_priv = netdev_priv(soft_iface);
 494
 495         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 496         hlist_del(&forw_packet->list);
 497         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 498
 499         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 500                 goto out;
 501
 502         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 503                 goto out;
 504
 505         /* rebroadcast packet */
 506         rcu_read_lock();
 507         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 508                 if (hard_iface->soft_iface != soft_iface)
 509                         continue;
 510
 511                 if (forw_packet->num_packets >= hard_iface->num_bcasts)
 512                         continue;
 513
 514                 /* send a copy of the saved skb */
 515                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 516                 if (skb1)
 517                         batadv_send_skb_packet(skb1, hard_iface,
 518                                                batadv_broadcast_addr);
 519         }
 520         rcu_read_unlock();
 521
 522         forw_packet->num_packets++;
 523
 524         /* if we still have some more bcasts to send */
 525         if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
 526                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 527                                                  msecs_to_jiffies(5));
 528                 return;
 529         }
 530
 531 out:
 532         batadv_forw_packet_free(forw_packet);
 533         atomic_inc(&bat_priv->bcast_queue_left);
 534 }
 535
 536 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 537 {
 538         struct delayed_work *delayed_work;
 539         struct batadv_forw_packet *forw_packet;
 540         struct batadv_priv *bat_priv;
 541
 542         delayed_work = container_of(work, struct delayed_work, work);
 543         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 544                                    delayed_work);
 545         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 546         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 547         hlist_del(&forw_packet->list);
 548         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 549
 550         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 551                 goto out;
 552
 553         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 554
 555         /* we have to have at least one packet in the queue to determine the
 556          * queues wake up time unless we are shutting down.
 557          *
 558          * only re-schedule if this is the "original" copy, e.g. the OGM of the
 559          * primary interface should only be rescheduled once per period, but
 560          * this function will be called for the forw_packet instances of the
 561          * other secondary interfaces as well.
 562          */
 563         if (forw_packet->own &&
 564             forw_packet->if_incoming == forw_packet->if_outgoing)
 565                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 566
 567 out:
 568         /* don't count own packet */
 569         if (!forw_packet->own)
 570                 atomic_inc(&bat_priv->batman_queue_left);
 571
 572         batadv_forw_packet_free(forw_packet);
 573 }
 574
 575 void
 576 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 577                                  const struct batadv_hard_iface *hard_iface)
 578 {
 579         struct batadv_forw_packet *forw_packet;
 580         struct hlist_node *safe_tmp_node;
 581         bool pending;
 582
 583         if (hard_iface)
 584                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 585                            "purge_outstanding_packets(): %s\n",
 586                            hard_iface->net_dev->name);
 587         else
 588                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 589                            "purge_outstanding_packets()\n");
 590
 591         /* free bcast list */
 592         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 593         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 594                                   &bat_priv->forw_bcast_list, list) {
 595                 /* if purge_outstanding_packets() was called with an argument
 596                  * we delete only packets belonging to the given interface
 597                  */
 598                 if ((hard_iface) &&
 599                     (forw_packet->if_incoming != hard_iface))
 600                         continue;
 601
 602                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 603
 604                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 605                  * delete the item from the list
 606                  */
 607                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 608                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 609
 610                 if (pending) {
 611                         hlist_del(&forw_packet->list);
 612                         batadv_forw_packet_free(forw_packet);
 613                 }
 614         }
 615         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 616
 617         /* free batman packet list */
 618         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 619         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 620                                   &bat_priv->forw_bat_list, list) {
 621                 /* if purge_outstanding_packets() was called with an argument
 622                  * we delete only packets belonging to the given interface
 623                  */
 624                 if ((hard_iface) &&
 625                     (forw_packet->if_incoming != hard_iface) &&
 626                     (forw_packet->if_outgoing != hard_iface))
 627                         continue;
 628
 629                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 630
 631                 /* send_outstanding_bat_packet() will lock the list to
 632                  * delete the item from the list
 633                  */
 634                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 635                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 636
 637                 if (pending) {
 638                         hlist_del(&forw_packet->list);
 639                         batadv_forw_packet_free(forw_packet);
 640                 }
 641         }
 642         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 643 }