kernel/net/batman-adv/send.c

   1 /* Copyright (C) 2007-2015 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 "send.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/etherdevice.h>
  24 #include <linux/fs.h>
  25 #include <linux/if_ether.h>
  26 #include <linux/if.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/kernel.h>
  29 #include <linux/list.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/slab.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/stddef.h>
  38 #include <linux/workqueue.h>
  39
  40 #include "distributed-arp-table.h"
  41 #include "fragmentation.h"
  42 #include "gateway_client.h"
  43 #include "hard-interface.h"
  44 #include "network-coding.h"
  45 #include "originator.h"
  46 #include "routing.h"
  47 #include "soft-interface.h"
  48 #include "translation-table.h"
  49
  50 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  51
  52 /* send out an already prepared packet to the given address via the
  53  * specified batman interface
  54  */
  55 int batadv_send_skb_packet(struct sk_buff *skb,
  56                            struct batadv_hard_iface *hard_iface,
  57                            const u8 *dst_addr)
  58 {
  59         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  60         struct ethhdr *ethhdr;
  61
  62         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  63                 goto send_skb_err;
  64
  65         if (unlikely(!hard_iface->net_dev))
  66                 goto send_skb_err;
  67
  68         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  69                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  70                         hard_iface->net_dev->name);
  71                 goto send_skb_err;
  72         }
  73
  74         /* push to the ethernet header. */
  75         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  76                 goto send_skb_err;
  77
  78         skb_reset_mac_header(skb);
  79
  80         ethhdr = eth_hdr(skb);
  81         ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
  82         ether_addr_copy(ethhdr->h_dest, dst_addr);
  83         ethhdr->h_proto = htons(ETH_P_BATMAN);
  84
  85         skb_set_network_header(skb, ETH_HLEN);
  86         skb->protocol = htons(ETH_P_BATMAN);
  87
  88         skb->dev = hard_iface->net_dev;
  89
  90         /* Save a clone of the skb to use when decoding coded packets */
  91         batadv_nc_skb_store_for_decoding(bat_priv, skb);
  92
  93         /* dev_queue_xmit() returns a negative result on error.  However on
  94          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  95          * (which is > 0). This will not be treated as an error.
  96          */
  97         return dev_queue_xmit(skb);
  98 send_skb_err:
  99         kfree_skb(skb);
 100         return NET_XMIT_DROP;
 101 }
 102
 103 /**
 104  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
 105  * @skb: Packet to be transmitted.
 106  * @orig_node: Final destination of the packet.
 107  * @recv_if: Interface used when receiving the packet (can be NULL).
 108  *
 109  * Looks up the best next-hop towards the passed originator and passes the
 110  * skb on for preparation of MAC header. If the packet originated from this
 111  * host, NULL can be passed as recv_if and no interface alternating is
 112  * attempted.
 113  *
 114  * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
 115  * NET_XMIT_POLICED if the skb is buffered for later transmit.
 116  */
 117 int batadv_send_skb_to_orig(struct sk_buff *skb,
 118                             struct batadv_orig_node *orig_node,
 119                             struct batadv_hard_iface *recv_if)
 120 {
 121         struct batadv_priv *bat_priv = orig_node->bat_priv;
 122         struct batadv_neigh_node *neigh_node;
 123         int ret = NET_XMIT_DROP;
 124
 125         /* batadv_find_router() increases neigh_nodes refcount if found. */
 126         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 127         if (!neigh_node)
 128                 goto out;
 129
 130         /* Check if the skb is too large to send in one piece and fragment
 131          * it if needed.
 132          */
 133         if (atomic_read(&bat_priv->fragmentation) &&
 134             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 135                 /* Fragment and send packet. */
 136                 if (batadv_frag_send_packet(skb, orig_node, neigh_node))
 137                         ret = NET_XMIT_SUCCESS;
 138
 139                 goto out;
 140         }
 141
 142         /* try to network code the packet, if it is received on an interface
 143          * (i.e. being forwarded). If the packet originates from this node or if
 144          * network coding fails, then send the packet as usual.
 145          */
 146         if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
 147                 ret = NET_XMIT_POLICED;
 148         } else {
 149                 batadv_send_skb_packet(skb, neigh_node->if_incoming,
 150                                        neigh_node->addr);
 151                 ret = NET_XMIT_SUCCESS;
 152         }
 153
 154 out:
 155         if (neigh_node)
 156                 batadv_neigh_node_free_ref(neigh_node);
 157
 158         return ret;
 159 }
 160
 161 /**
 162  * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
 163  *  common fields for unicast packets
 164  * @skb: the skb carrying the unicast header to initialize
 165  * @hdr_size: amount of bytes to push at the beginning of the skb
 166  * @orig_node: the destination node
 167  *
 168  * Returns false if the buffer extension was not possible or true otherwise.
 169  */
 170 static bool
 171 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 172                                   struct batadv_orig_node *orig_node)
 173 {
 174         struct batadv_unicast_packet *unicast_packet;
 175         u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 176
 177         if (batadv_skb_head_push(skb, hdr_size) < 0)
 178                 return false;
 179
 180         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 181         unicast_packet->version = BATADV_COMPAT_VERSION;
 182         /* batman packet type: unicast */
 183         unicast_packet->packet_type = BATADV_UNICAST;
 184         /* set unicast ttl */
 185         unicast_packet->ttl = BATADV_TTL;
 186         /* copy the destination for faster routing */
 187         ether_addr_copy(unicast_packet->dest, orig_node->orig);
 188         /* set the destination tt version number */
 189         unicast_packet->ttvn = ttvn;
 190
 191         return true;
 192 }
 193
 194 /**
 195  * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
 196  * @skb: the skb containing the payload to encapsulate
 197  * @orig_node: the destination node
 198  *
 199  * Returns false if the payload could not be encapsulated or true otherwise.
 200  */
 201 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 202                                             struct batadv_orig_node *orig_node)
 203 {
 204         size_t uni_size = sizeof(struct batadv_unicast_packet);
 205
 206         return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 207 }
 208
 209 /**
 210  * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
 211  *  unicast 4addr header
 212  * @bat_priv: the bat priv with all the soft interface information
 213  * @skb: the skb containing the payload to encapsulate
 214  * @orig_node: the destination node
 215  * @packet_subtype: the unicast 4addr packet subtype to use
 216  *
 217  * Returns false if the payload could not be encapsulated or true otherwise.
 218  */
 219 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 220                                            struct sk_buff *skb,
 221                                            struct batadv_orig_node *orig,
 222                                            int packet_subtype)
 223 {
 224         struct batadv_hard_iface *primary_if;
 225         struct batadv_unicast_4addr_packet *uc_4addr_packet;
 226         bool ret = false;
 227
 228         primary_if = batadv_primary_if_get_selected(bat_priv);
 229         if (!primary_if)
 230                 goto out;
 231
 232         /* Pull the header space and fill the unicast_packet substructure.
 233          * We can do that because the first member of the uc_4addr_packet
 234          * is of type struct unicast_packet
 235          */
 236         if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 237                                                orig))
 238                 goto out;
 239
 240         uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 241         uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 242         ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
 243         uc_4addr_packet->subtype = packet_subtype;
 244         uc_4addr_packet->reserved = 0;
 245
 246         ret = true;
 247 out:
 248         if (primary_if)
 249                 batadv_hardif_free_ref(primary_if);
 250         return ret;
 251 }
 252
 253 /**
 254  * batadv_send_skb_unicast - encapsulate and send an skb via unicast
 255  * @bat_priv: the bat priv with all the soft interface information
 256  * @skb: payload to send
 257  * @packet_type: the batman unicast packet type to use
 258  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 259  *  4addr packets)
 260  * @orig_node: the originator to send the packet to
 261  * @vid: the vid to be used to search the translation table
 262  *
 263  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
 264  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
 265  * as packet_type. Then send this frame to the given orig_node and release a
 266  * reference to this orig_node.
 267  *
 268  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 269  */
 270 int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 271                             struct sk_buff *skb, int packet_type,
 272                             int packet_subtype,
 273                             struct batadv_orig_node *orig_node,
 274                             unsigned short vid)
 275 {
 276         struct batadv_unicast_packet *unicast_packet;
 277         struct ethhdr *ethhdr;
 278         int ret = NET_XMIT_DROP;
 279
 280         if (!orig_node)
 281                 goto out;
 282
 283         switch (packet_type) {
 284         case BATADV_UNICAST:
 285                 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 286                         goto out;
 287                 break;
 288         case BATADV_UNICAST_4ADDR:
 289                 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 290                                                            orig_node,
 291                                                            packet_subtype))
 292                         goto out;
 293                 break;
 294         default:
 295                 /* this function supports UNICAST and UNICAST_4ADDR only. It
 296                  * should never be invoked with any other packet type
 297                  */
 298                 goto out;
 299         }
 300
 301         /* skb->data might have been reallocated by
 302          * batadv_send_skb_prepare_unicast{,_4addr}()
 303          */
 304         ethhdr = eth_hdr(skb);
 305         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 306
 307         /* inform the destination node that we are still missing a correct route
 308          * for this client. The destination will receive this packet and will
 309          * try to reroute it because the ttvn contained in the header is less
 310          * than the current one
 311          */
 312         if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 313                 unicast_packet->ttvn = unicast_packet->ttvn - 1;
 314
 315         if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 316                 ret = NET_XMIT_SUCCESS;
 317
 318 out:
 319         if (orig_node)
 320                 batadv_orig_node_free_ref(orig_node);
 321         if (ret == NET_XMIT_DROP)
 322                 kfree_skb(skb);
 323         return ret;
 324 }
 325
 326 /**
 327  * batadv_send_skb_via_tt_generic - send an skb via TT lookup
 328  * @bat_priv: the bat priv with all the soft interface information
 329  * @skb: payload to send
 330  * @packet_type: the batman unicast packet type to use
 331  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 332  *  4addr packets)
 333  * @dst_hint: can be used to override the destination contained in the skb
 334  * @vid: the vid to be used to search the translation table
 335  *
 336  * Look up the recipient node for the destination address in the ethernet
 337  * header via the translation table. Wrap the given skb into a batman-adv
 338  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
 339  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
 340  * to the according destination node.
 341  *
 342  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 343  */
 344 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 345                                    struct sk_buff *skb, int packet_type,
 346                                    int packet_subtype, u8 *dst_hint,
 347                                    unsigned short vid)
 348 {
 349         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 350         struct batadv_orig_node *orig_node;
 351         u8 *src, *dst;
 352
 353         src = ethhdr->h_source;
 354         dst = ethhdr->h_dest;
 355
 356         /* if we got an hint! let's send the packet to this client (if any) */
 357         if (dst_hint) {
 358                 src = NULL;
 359                 dst = dst_hint;
 360         }
 361         orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
 362
 363         return batadv_send_skb_unicast(bat_priv, skb, packet_type,
 364                                        packet_subtype, orig_node, vid);
 365 }
 366
 367 /**
 368  * batadv_send_skb_via_gw - send an skb via gateway lookup
 369  * @bat_priv: the bat priv with all the soft interface information
 370  * @skb: payload to send
 371  * @vid: the vid to be used to search the translation table
 372  *
 373  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
 374  * unicast header and send this frame to this gateway node.
 375  *
 376  * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 377  */
 378 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 379                            unsigned short vid)
 380 {
 381         struct batadv_orig_node *orig_node;
 382
 383         orig_node = batadv_gw_get_selected_orig(bat_priv);
 384         return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
 385                                        orig_node, vid);
 386 }
 387
 388 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 389 {
 390         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 391
 392         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 393             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 394                 return;
 395
 396         /* the interface gets activated here to avoid race conditions between
 397          * the moment of activating the interface in
 398          * hardif_activate_interface() where the originator mac is set and
 399          * outdated packets (especially uninitialized mac addresses) in the
 400          * packet queue
 401          */
 402         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 403                 hard_iface->if_status = BATADV_IF_ACTIVE;
 404
 405         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 406 }
 407
 408 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 409 {
 410         if (forw_packet->skb)
 411                 kfree_skb(forw_packet->skb);
 412         if (forw_packet->if_incoming)
 413                 batadv_hardif_free_ref(forw_packet->if_incoming);
 414         if (forw_packet->if_outgoing)
 415                 batadv_hardif_free_ref(forw_packet->if_outgoing);
 416         kfree(forw_packet);
 417 }
 418
 419 static void
 420 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 421                                  struct batadv_forw_packet *forw_packet,
 422                                  unsigned long send_time)
 423 {
 424         /* add new packet to packet list */
 425         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 426         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 427         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 428
 429         /* start timer for this packet */
 430         queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 431                            send_time);
 432 }
 433
 434 /* add a broadcast packet to the queue and setup timers. broadcast packets
 435  * are sent multiple times to increase probability for being received.
 436  *
 437  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 438  * errors.
 439  *
 440  * The skb is not consumed, so the caller should make sure that the
 441  * skb is freed.
 442  */
 443 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 444                                     const struct sk_buff *skb,
 445                                     unsigned long delay)
 446 {
 447         struct batadv_hard_iface *primary_if = NULL;
 448         struct batadv_forw_packet *forw_packet;
 449         struct batadv_bcast_packet *bcast_packet;
 450         struct sk_buff *newskb;
 451
 452         if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 453                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 454                            "bcast packet queue full\n");
 455                 goto out;
 456         }
 457
 458         primary_if = batadv_primary_if_get_selected(bat_priv);
 459         if (!primary_if)
 460                 goto out_and_inc;
 461
 462         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 463
 464         if (!forw_packet)
 465                 goto out_and_inc;
 466
 467         newskb = skb_copy(skb, GFP_ATOMIC);
 468         if (!newskb)
 469                 goto packet_free;
 470
 471         /* as we have a copy now, it is safe to decrease the TTL */
 472         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 473         bcast_packet->ttl--;
 474
 475         skb_reset_mac_header(newskb);
 476
 477         forw_packet->skb = newskb;
 478         forw_packet->if_incoming = primary_if;
 479         forw_packet->if_outgoing = NULL;
 480
 481         /* how often did we send the bcast packet ? */
 482         forw_packet->num_packets = 0;
 483
 484         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 485                           batadv_send_outstanding_bcast_packet);
 486
 487         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 488         return NETDEV_TX_OK;
 489
 490 packet_free:
 491         kfree(forw_packet);
 492 out_and_inc:
 493         atomic_inc(&bat_priv->bcast_queue_left);
 494 out:
 495         if (primary_if)
 496                 batadv_hardif_free_ref(primary_if);
 497         return NETDEV_TX_BUSY;
 498 }
 499
 500 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 501 {
 502         struct batadv_hard_iface *hard_iface;
 503         struct delayed_work *delayed_work;
 504         struct batadv_forw_packet *forw_packet;
 505         struct sk_buff *skb1;
 506         struct net_device *soft_iface;
 507         struct batadv_priv *bat_priv;
 508
 509         delayed_work = container_of(work, struct delayed_work, work);
 510         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 511                                    delayed_work);
 512         soft_iface = forw_packet->if_incoming->soft_iface;
 513         bat_priv = netdev_priv(soft_iface);
 514
 515         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 516         hlist_del(&forw_packet->list);
 517         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 518
 519         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 520                 goto out;
 521
 522         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 523                 goto out;
 524
 525         /* rebroadcast packet */
 526         rcu_read_lock();
 527         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 528                 if (hard_iface->soft_iface != soft_iface)
 529                         continue;
 530
 531                 if (forw_packet->num_packets >= hard_iface->num_bcasts)
 532                         continue;
 533
 534                 /* send a copy of the saved skb */
 535                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 536                 if (skb1)
 537                         batadv_send_skb_packet(skb1, hard_iface,
 538                                                batadv_broadcast_addr);
 539         }
 540         rcu_read_unlock();
 541
 542         forw_packet->num_packets++;
 543
 544         /* if we still have some more bcasts to send */
 545         if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
 546                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 547                                                  msecs_to_jiffies(5));
 548                 return;
 549         }
 550
 551 out:
 552         batadv_forw_packet_free(forw_packet);
 553         atomic_inc(&bat_priv->bcast_queue_left);
 554 }
 555
 556 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 557 {
 558         struct delayed_work *delayed_work;
 559         struct batadv_forw_packet *forw_packet;
 560         struct batadv_priv *bat_priv;
 561
 562         delayed_work = container_of(work, struct delayed_work, work);
 563         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 564                                    delayed_work);
 565         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 566         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 567         hlist_del(&forw_packet->list);
 568         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 569
 570         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 571                 goto out;
 572
 573         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 574
 575         /* we have to have at least one packet in the queue to determine the
 576          * queues wake up time unless we are shutting down.
 577          *
 578          * only re-schedule if this is the "original" copy, e.g. the OGM of the
 579          * primary interface should only be rescheduled once per period, but
 580          * this function will be called for the forw_packet instances of the
 581          * other secondary interfaces as well.
 582          */
 583         if (forw_packet->own &&
 584             forw_packet->if_incoming == forw_packet->if_outgoing)
 585                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 586
 587 out:
 588         /* don't count own packet */
 589         if (!forw_packet->own)
 590                 atomic_inc(&bat_priv->batman_queue_left);
 591
 592         batadv_forw_packet_free(forw_packet);
 593 }
 594
 595 void
 596 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 597                                  const struct batadv_hard_iface *hard_iface)
 598 {
 599         struct batadv_forw_packet *forw_packet;
 600         struct hlist_node *safe_tmp_node;
 601         bool pending;
 602
 603         if (hard_iface)
 604                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 605                            "purge_outstanding_packets(): %s\n",
 606                            hard_iface->net_dev->name);
 607         else
 608                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 609                            "purge_outstanding_packets()\n");
 610
 611         /* free bcast list */
 612         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 613         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 614                                   &bat_priv->forw_bcast_list, list) {
 615                 /* if purge_outstanding_packets() was called with an argument
 616                  * we delete only packets belonging to the given interface
 617                  */
 618                 if ((hard_iface) &&
 619                     (forw_packet->if_incoming != hard_iface) &&
 620                     (forw_packet->if_outgoing != hard_iface))
 621                         continue;
 622
 623                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 624
 625                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 626                  * delete the item from the list
 627                  */
 628                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 629                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 630
 631                 if (pending) {
 632                         hlist_del(&forw_packet->list);
 633                         batadv_forw_packet_free(forw_packet);
 634                 }
 635         }
 636         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 637
 638         /* free batman packet list */
 639         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 640         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 641                                   &bat_priv->forw_bat_list, list) {
 642                 /* if purge_outstanding_packets() was called with an argument
 643                  * we delete only packets belonging to the given interface
 644                  */
 645                 if ((hard_iface) &&
 646                     (forw_packet->if_incoming != hard_iface) &&
 647                     (forw_packet->if_outgoing != hard_iface))
 648                         continue;
 649
 650                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 651
 652                 /* send_outstanding_bat_packet() will lock the list to
 653                  * delete the item from the list
 654                  */
 655                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 656                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 657
 658                 if (pending) {
 659                         hlist_del(&forw_packet->list);
 660                         batadv_forw_packet_free(forw_packet);
 661                 }
 662         }
 663         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 664 }