net/batman-adv/hard-interface.c

   1 /*
   2  * Copyright (C) 2007-2011 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, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "hard-interface.h"
  24 #include "soft-interface.h"
  25 #include "send.h"
  26 #include "translation-table.h"
  27 #include "routing.h"
  28 #include "bat_sysfs.h"
  29 #include "originator.h"
  30 #include "hash.h"
  31
  32 #include <linux/if_arp.h>
  33
  34 /* protect update critical side of hardif_list - but not the content */
  35 static DEFINE_SPINLOCK(hardif_list_lock);
  36
  37
  38 static int batman_skb_recv(struct sk_buff *skb,
  39                            struct net_device *dev,
  40                            struct packet_type *ptype,
  41                            struct net_device *orig_dev);
  42
  43 void hardif_free_rcu(struct rcu_head *rcu)
  44 {
  45         struct hard_iface *hard_iface;
  46
  47         hard_iface = container_of(rcu, struct hard_iface, rcu);
  48         dev_put(hard_iface->net_dev);
  49         kfree(hard_iface);
  50 }
  51
  52 struct hard_iface *hardif_get_by_netdev(struct net_device *net_dev)
  53 {
  54         struct hard_iface *hard_iface;
  55
  56         rcu_read_lock();
  57         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  58                 if (hard_iface->net_dev == net_dev &&
  59                     atomic_inc_not_zero(&hard_iface->refcount))
  60                         goto out;
  61         }
  62
  63         hard_iface = NULL;
  64
  65 out:
  66         rcu_read_unlock();
  67         return hard_iface;
  68 }
  69
  70 static int is_valid_iface(struct net_device *net_dev)
  71 {
  72         if (net_dev->flags & IFF_LOOPBACK)
  73                 return 0;
  74
  75         if (net_dev->type != ARPHRD_ETHER)
  76                 return 0;
  77
  78         if (net_dev->addr_len != ETH_ALEN)
  79                 return 0;
  80
  81         /* no batman over batman */
  82         if (softif_is_valid(net_dev))
  83                 return 0;
  84
  85         /* Device is being bridged */
  86         /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
  87                 return 0; */
  88
  89         return 1;
  90 }
  91
  92 static struct hard_iface *hardif_get_active(struct net_device *soft_iface)
  93 {
  94         struct hard_iface *hard_iface;
  95
  96         rcu_read_lock();
  97         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  98                 if (hard_iface->soft_iface != soft_iface)
  99                         continue;
 100
 101                 if (hard_iface->if_status == IF_ACTIVE &&
 102                     atomic_inc_not_zero(&hard_iface->refcount))
 103                         goto out;
 104         }
 105
 106         hard_iface = NULL;
 107
 108 out:
 109         rcu_read_unlock();
 110         return hard_iface;
 111 }
 112
 113 static void primary_if_update_addr(struct bat_priv *bat_priv)
 114 {
 115         struct vis_packet *vis_packet;
 116         struct hard_iface *primary_if;
 117
 118         primary_if = primary_if_get_selected(bat_priv);
 119         if (!primary_if)
 120                 goto out;
 121
 122         vis_packet = (struct vis_packet *)
 123                                 bat_priv->my_vis_info->skb_packet->data;
 124         memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
 125         memcpy(vis_packet->sender_orig,
 126                primary_if->net_dev->dev_addr, ETH_ALEN);
 127
 128 out:
 129         if (primary_if)
 130                 hardif_free_ref(primary_if);
 131 }
 132
 133 static void primary_if_select(struct bat_priv *bat_priv,
 134                               struct hard_iface *new_hard_iface)
 135 {
 136         struct hard_iface *curr_hard_iface;
 137         struct batman_packet *batman_packet;
 138
 139         spin_lock_bh(&hardif_list_lock);
 140
 141         if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
 142                 new_hard_iface = NULL;
 143
 144         curr_hard_iface = bat_priv->primary_if;
 145         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 146
 147         if (curr_hard_iface)
 148                 hardif_free_ref(curr_hard_iface);
 149
 150         if (!new_hard_iface)
 151                 goto out;
 152
 153         batman_packet = (struct batman_packet *)(new_hard_iface->packet_buff);
 154         batman_packet->flags = PRIMARIES_FIRST_HOP;
 155         batman_packet->ttl = TTL;
 156
 157         primary_if_update_addr(bat_priv);
 158
 159         /***
 160          * hacky trick to make sure that we send the HNA information via
 161          * our new primary interface
 162          */
 163         atomic_set(&bat_priv->hna_local_changed, 1);
 164
 165 out:
 166         spin_unlock_bh(&hardif_list_lock);
 167 }
 168
 169 static bool hardif_is_iface_up(struct hard_iface *hard_iface)
 170 {
 171         if (hard_iface->net_dev->flags & IFF_UP)
 172                 return true;
 173
 174         return false;
 175 }
 176
 177 static void update_mac_addresses(struct hard_iface *hard_iface)
 178 {
 179         memcpy(((struct batman_packet *)(hard_iface->packet_buff))->orig,
 180                hard_iface->net_dev->dev_addr, ETH_ALEN);
 181         memcpy(((struct batman_packet *)(hard_iface->packet_buff))->prev_sender,
 182                hard_iface->net_dev->dev_addr, ETH_ALEN);
 183 }
 184
 185 static void check_known_mac_addr(struct net_device *net_dev)
 186 {
 187         struct hard_iface *hard_iface;
 188
 189         rcu_read_lock();
 190         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 191                 if ((hard_iface->if_status != IF_ACTIVE) &&
 192                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 193                         continue;
 194
 195                 if (hard_iface->net_dev == net_dev)
 196                         continue;
 197
 198                 if (!compare_eth(hard_iface->net_dev->dev_addr,
 199                                  net_dev->dev_addr))
 200                         continue;
 201
 202                 pr_warning("The newly added mac address (%pM) already exists "
 203                            "on: %s\n", net_dev->dev_addr,
 204                            hard_iface->net_dev->name);
 205                 pr_warning("It is strongly recommended to keep mac addresses "
 206                            "unique to avoid problems!\n");
 207         }
 208         rcu_read_unlock();
 209 }
 210
 211 int hardif_min_mtu(struct net_device *soft_iface)
 212 {
 213         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 214         struct hard_iface *hard_iface;
 215         /* allow big frames if all devices are capable to do so
 216          * (have MTU > 1500 + BAT_HEADER_LEN) */
 217         int min_mtu = ETH_DATA_LEN;
 218
 219         if (atomic_read(&bat_priv->fragmentation))
 220                 goto out;
 221
 222         rcu_read_lock();
 223         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 224                 if ((hard_iface->if_status != IF_ACTIVE) &&
 225                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 226                         continue;
 227
 228                 if (hard_iface->soft_iface != soft_iface)
 229                         continue;
 230
 231                 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
 232                                 min_mtu);
 233         }
 234         rcu_read_unlock();
 235 out:
 236         return min_mtu;
 237 }
 238
 239 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 240 void update_min_mtu(struct net_device *soft_iface)
 241 {
 242         int min_mtu;
 243
 244         min_mtu = hardif_min_mtu(soft_iface);
 245         if (soft_iface->mtu != min_mtu)
 246                 soft_iface->mtu = min_mtu;
 247 }
 248
 249 static void hardif_activate_interface(struct hard_iface *hard_iface)
 250 {
 251         struct bat_priv *bat_priv;
 252         struct hard_iface *primary_if = NULL;
 253
 254         if (hard_iface->if_status != IF_INACTIVE)
 255                 goto out;
 256
 257         bat_priv = netdev_priv(hard_iface->soft_iface);
 258
 259         update_mac_addresses(hard_iface);
 260         hard_iface->if_status = IF_TO_BE_ACTIVATED;
 261
 262         /**
 263          * the first active interface becomes our primary interface or
 264          * the next active interface after the old primay interface was removed
 265          */
 266         primary_if = primary_if_get_selected(bat_priv);
 267         if (!primary_if)
 268                 primary_if_select(bat_priv, hard_iface);
 269
 270         bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
 271                  hard_iface->net_dev->name);
 272
 273         update_min_mtu(hard_iface->soft_iface);
 274
 275 out:
 276         if (primary_if)
 277                 hardif_free_ref(primary_if);
 278 }
 279
 280 static void hardif_deactivate_interface(struct hard_iface *hard_iface)
 281 {
 282         if ((hard_iface->if_status != IF_ACTIVE) &&
 283             (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 284                 return;
 285
 286         hard_iface->if_status = IF_INACTIVE;
 287
 288         bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 289                  hard_iface->net_dev->name);
 290
 291         update_min_mtu(hard_iface->soft_iface);
 292 }
 293
 294 int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
 295 {
 296         struct bat_priv *bat_priv;
 297         struct batman_packet *batman_packet;
 298         struct net_device *soft_iface;
 299         int ret;
 300
 301         if (hard_iface->if_status != IF_NOT_IN_USE)
 302                 goto out;
 303
 304         if (!atomic_inc_not_zero(&hard_iface->refcount))
 305                 goto out;
 306
 307         soft_iface = dev_get_by_name(&init_net, iface_name);
 308
 309         if (!soft_iface) {
 310                 soft_iface = softif_create(iface_name);
 311
 312                 if (!soft_iface) {
 313                         ret = -ENOMEM;
 314                         goto err;
 315                 }
 316
 317                 /* dev_get_by_name() increases the reference counter for us */
 318                 dev_hold(soft_iface);
 319         }
 320
 321         if (!softif_is_valid(soft_iface)) {
 322                 pr_err("Can't create batman mesh interface %s: "
 323                        "already exists as regular interface\n",
 324                        soft_iface->name);
 325                 dev_put(soft_iface);
 326                 ret = -EINVAL;
 327                 goto err;
 328         }
 329
 330         hard_iface->soft_iface = soft_iface;
 331         bat_priv = netdev_priv(hard_iface->soft_iface);
 332         hard_iface->packet_len = BAT_PACKET_LEN;
 333         hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC);
 334
 335         if (!hard_iface->packet_buff) {
 336                 bat_err(hard_iface->soft_iface, "Can't add interface packet "
 337                         "(%s): out of memory\n", hard_iface->net_dev->name);
 338                 ret = -ENOMEM;
 339                 goto err;
 340         }
 341
 342         batman_packet = (struct batman_packet *)(hard_iface->packet_buff);
 343         batman_packet->packet_type = BAT_PACKET;
 344         batman_packet->version = COMPAT_VERSION;
 345         batman_packet->flags = 0;
 346         batman_packet->ttl = 2;
 347         batman_packet->tq = TQ_MAX_VALUE;
 348         batman_packet->num_hna = 0;
 349
 350         hard_iface->if_num = bat_priv->num_ifaces;
 351         bat_priv->num_ifaces++;
 352         hard_iface->if_status = IF_INACTIVE;
 353         orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 354
 355         hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 356         hard_iface->batman_adv_ptype.func = batman_skb_recv;
 357         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 358         dev_add_pack(&hard_iface->batman_adv_ptype);
 359
 360         atomic_set(&hard_iface->seqno, 1);
 361         atomic_set(&hard_iface->frag_seqno, 1);
 362         bat_info(hard_iface->soft_iface, "Adding interface: %s\n",
 363                  hard_iface->net_dev->name);
 364
 365         if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 366                 ETH_DATA_LEN + BAT_HEADER_LEN)
 367                 bat_info(hard_iface->soft_iface,
 368                         "The MTU of interface %s is too small (%i) to handle "
 369                         "the transport of batman-adv packets. Packets going "
 370                         "over this interface will be fragmented on layer2 "
 371                         "which could impact the performance. Setting the MTU "
 372                         "to %zi would solve the problem.\n",
 373                         hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 374                         ETH_DATA_LEN + BAT_HEADER_LEN);
 375
 376         if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 377                 ETH_DATA_LEN + BAT_HEADER_LEN)
 378                 bat_info(hard_iface->soft_iface,
 379                         "The MTU of interface %s is too small (%i) to handle "
 380                         "the transport of batman-adv packets. If you experience"
 381                         " problems getting traffic through try increasing the "
 382                         "MTU to %zi.\n",
 383                         hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 384                         ETH_DATA_LEN + BAT_HEADER_LEN);
 385
 386         if (hardif_is_iface_up(hard_iface))
 387                 hardif_activate_interface(hard_iface);
 388         else
 389                 bat_err(hard_iface->soft_iface, "Not using interface %s "
 390                         "(retrying later): interface not active\n",
 391                         hard_iface->net_dev->name);
 392
 393         /* begin scheduling originator messages on that interface */
 394         schedule_own_packet(hard_iface);
 395
 396 out:
 397         return 0;
 398
 399 err:
 400         hardif_free_ref(hard_iface);
 401         return ret;
 402 }
 403
 404 void hardif_disable_interface(struct hard_iface *hard_iface)
 405 {
 406         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 407         struct hard_iface *primary_if = NULL;
 408
 409         if (hard_iface->if_status == IF_ACTIVE)
 410                 hardif_deactivate_interface(hard_iface);
 411
 412         if (hard_iface->if_status != IF_INACTIVE)
 413                 goto out;
 414
 415         bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
 416                  hard_iface->net_dev->name);
 417         dev_remove_pack(&hard_iface->batman_adv_ptype);
 418
 419         bat_priv->num_ifaces--;
 420         orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 421
 422         primary_if = primary_if_get_selected(bat_priv);
 423         if (hard_iface == primary_if) {
 424                 struct hard_iface *new_if;
 425
 426                 new_if = hardif_get_active(hard_iface->soft_iface);
 427                 primary_if_select(bat_priv, new_if);
 428
 429                 if (new_if)
 430                         hardif_free_ref(new_if);
 431         }
 432
 433         kfree(hard_iface->packet_buff);
 434         hard_iface->packet_buff = NULL;
 435         hard_iface->if_status = IF_NOT_IN_USE;
 436
 437         /* delete all references to this hard_iface */
 438         purge_orig_ref(bat_priv);
 439         purge_outstanding_packets(bat_priv, hard_iface);
 440         dev_put(hard_iface->soft_iface);
 441
 442         /* nobody uses this interface anymore */
 443         if (!bat_priv->num_ifaces)
 444                 softif_destroy(hard_iface->soft_iface);
 445
 446         hard_iface->soft_iface = NULL;
 447         hardif_free_ref(hard_iface);
 448
 449 out:
 450         if (primary_if)
 451                 hardif_free_ref(primary_if);
 452 }
 453
 454 static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
 455 {
 456         struct hard_iface *hard_iface;
 457         int ret;
 458
 459         ret = is_valid_iface(net_dev);
 460         if (ret != 1)
 461                 goto out;
 462
 463         dev_hold(net_dev);
 464
 465         hard_iface = kmalloc(sizeof(struct hard_iface), GFP_ATOMIC);
 466         if (!hard_iface) {
 467                 pr_err("Can't add interface (%s): out of memory\n",
 468                        net_dev->name);
 469                 goto release_dev;
 470         }
 471
 472         ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 473         if (ret)
 474                 goto free_if;
 475
 476         hard_iface->if_num = -1;
 477         hard_iface->net_dev = net_dev;
 478         hard_iface->soft_iface = NULL;
 479         hard_iface->if_status = IF_NOT_IN_USE;
 480         INIT_LIST_HEAD(&hard_iface->list);
 481         /* extra reference for return */
 482         atomic_set(&hard_iface->refcount, 2);
 483
 484         check_known_mac_addr(hard_iface->net_dev);
 485
 486         spin_lock(&hardif_list_lock);
 487         list_add_tail_rcu(&hard_iface->list, &hardif_list);
 488         spin_unlock(&hardif_list_lock);
 489
 490         return hard_iface;
 491
 492 free_if:
 493         kfree(hard_iface);
 494 release_dev:
 495         dev_put(net_dev);
 496 out:
 497         return NULL;
 498 }
 499
 500 static void hardif_remove_interface(struct hard_iface *hard_iface)
 501 {
 502         /* first deactivate interface */
 503         if (hard_iface->if_status != IF_NOT_IN_USE)
 504                 hardif_disable_interface(hard_iface);
 505
 506         if (hard_iface->if_status != IF_NOT_IN_USE)
 507                 return;
 508
 509         hard_iface->if_status = IF_TO_BE_REMOVED;
 510         sysfs_del_hardif(&hard_iface->hardif_obj);
 511         hardif_free_ref(hard_iface);
 512 }
 513
 514 void hardif_remove_interfaces(void)
 515 {
 516         struct hard_iface *hard_iface, *hard_iface_tmp;
 517         struct list_head if_queue;
 518
 519         INIT_LIST_HEAD(&if_queue);
 520
 521         spin_lock(&hardif_list_lock);
 522         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 523                                  &hardif_list, list) {
 524                 list_del_rcu(&hard_iface->list);
 525                 list_add_tail(&hard_iface->list, &if_queue);
 526         }
 527         spin_unlock(&hardif_list_lock);
 528
 529         rtnl_lock();
 530         list_for_each_entry_safe(hard_iface, hard_iface_tmp, &if_queue, list) {
 531                 hardif_remove_interface(hard_iface);
 532         }
 533         rtnl_unlock();
 534 }
 535
 536 static int hard_if_event(struct notifier_block *this,
 537                          unsigned long event, void *ptr)
 538 {
 539         struct net_device *net_dev = (struct net_device *)ptr;
 540         struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
 541         struct hard_iface *primary_if = NULL;
 542         struct bat_priv *bat_priv;
 543
 544         if (!hard_iface && event == NETDEV_REGISTER)
 545                 hard_iface = hardif_add_interface(net_dev);
 546
 547         if (!hard_iface)
 548                 goto out;
 549
 550         switch (event) {
 551         case NETDEV_UP:
 552                 hardif_activate_interface(hard_iface);
 553                 break;
 554         case NETDEV_GOING_DOWN:
 555         case NETDEV_DOWN:
 556                 hardif_deactivate_interface(hard_iface);
 557                 break;
 558         case NETDEV_UNREGISTER:
 559                 spin_lock(&hardif_list_lock);
 560                 list_del_rcu(&hard_iface->list);
 561                 spin_unlock(&hardif_list_lock);
 562
 563                 hardif_remove_interface(hard_iface);
 564                 break;
 565         case NETDEV_CHANGEMTU:
 566                 if (hard_iface->soft_iface)
 567                         update_min_mtu(hard_iface->soft_iface);
 568                 break;
 569         case NETDEV_CHANGEADDR:
 570                 if (hard_iface->if_status == IF_NOT_IN_USE)
 571                         goto hardif_put;
 572
 573                 check_known_mac_addr(hard_iface->net_dev);
 574                 update_mac_addresses(hard_iface);
 575
 576                 bat_priv = netdev_priv(hard_iface->soft_iface);
 577                 primary_if = primary_if_get_selected(bat_priv);
 578                 if (!primary_if)
 579                         goto hardif_put;
 580
 581                 if (hard_iface == primary_if)
 582                         primary_if_update_addr(bat_priv);
 583                 break;
 584         default:
 585                 break;
 586         };
 587
 588 hardif_put:
 589         hardif_free_ref(hard_iface);
 590 out:
 591         if (primary_if)
 592                 hardif_free_ref(primary_if);
 593         return NOTIFY_DONE;
 594 }
 595
 596 /* receive a packet with the batman ethertype coming on a hard
 597  * interface */
 598 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 599                            struct packet_type *ptype,
 600                            struct net_device *orig_dev)
 601 {
 602         struct bat_priv *bat_priv;
 603         struct batman_packet *batman_packet;
 604         struct hard_iface *hard_iface;
 605         int ret;
 606
 607         hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype);
 608         skb = skb_share_check(skb, GFP_ATOMIC);
 609
 610         /* skb was released by skb_share_check() */
 611         if (!skb)
 612                 goto err_out;
 613
 614         /* packet should hold at least type and version */
 615         if (unlikely(!pskb_may_pull(skb, 2)))
 616                 goto err_free;
 617
 618         /* expect a valid ethernet header here. */
 619         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 620                                 || !skb_mac_header(skb)))
 621                 goto err_free;
 622
 623         if (!hard_iface->soft_iface)
 624                 goto err_free;
 625
 626         bat_priv = netdev_priv(hard_iface->soft_iface);
 627
 628         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 629                 goto err_free;
 630
 631         /* discard frames on not active interfaces */
 632         if (hard_iface->if_status != IF_ACTIVE)
 633                 goto err_free;
 634
 635         batman_packet = (struct batman_packet *)skb->data;
 636
 637         if (batman_packet->version != COMPAT_VERSION) {
 638                 bat_dbg(DBG_BATMAN, bat_priv,
 639                         "Drop packet: incompatible batman version (%i)\n",
 640                         batman_packet->version);
 641                 goto err_free;
 642         }
 643
 644         /* all receive handlers return whether they received or reused
 645          * the supplied skb. if not, we have to free the skb. */
 646
 647         switch (batman_packet->packet_type) {
 648                 /* batman originator packet */
 649         case BAT_PACKET:
 650                 ret = recv_bat_packet(skb, hard_iface);
 651                 break;
 652
 653                 /* batman icmp packet */
 654         case BAT_ICMP:
 655                 ret = recv_icmp_packet(skb, hard_iface);
 656                 break;
 657
 658                 /* unicast packet */
 659         case BAT_UNICAST:
 660                 ret = recv_unicast_packet(skb, hard_iface);
 661                 break;
 662
 663                 /* fragmented unicast packet */
 664         case BAT_UNICAST_FRAG:
 665                 ret = recv_ucast_frag_packet(skb, hard_iface);
 666                 break;
 667
 668                 /* broadcast packet */
 669         case BAT_BCAST:
 670                 ret = recv_bcast_packet(skb, hard_iface);
 671                 break;
 672
 673                 /* vis packet */
 674         case BAT_VIS:
 675                 ret = recv_vis_packet(skb, hard_iface);
 676                 break;
 677         default:
 678                 ret = NET_RX_DROP;
 679         }
 680
 681         if (ret == NET_RX_DROP)
 682                 kfree_skb(skb);
 683
 684         /* return NET_RX_SUCCESS in any case as we
 685          * most probably dropped the packet for
 686          * routing-logical reasons. */
 687
 688         return NET_RX_SUCCESS;
 689
 690 err_free:
 691         kfree_skb(skb);
 692 err_out:
 693         return NET_RX_DROP;
 694 }
 695
 696 struct notifier_block hard_if_notifier = {
 697         .notifier_call = hard_if_event,
 698 };