net/batman-adv/main.c

   1 /* Copyright (C) 2007-2017  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
  20 #include <linux/atomic.h>
  21 #include <linux/bug.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/crc32c.h>
  24 #include <linux/errno.h>
  25 #include <linux/fs.h>
  26 #include <linux/genetlink.h>
  27 #include <linux/if_ether.h>
  28 #include <linux/if_vlan.h>
  29 #include <linux/init.h>
  30 #include <linux/ip.h>
  31 #include <linux/ipv6.h>
  32 #include <linux/kernel.h>
  33 #include <linux/kref.h>
  34 #include <linux/list.h>
  35 #include <linux/module.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/printk.h>
  38 #include <linux/rculist.h>
  39 #include <linux/rcupdate.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/skbuff.h>
  42 #include <linux/spinlock.h>
  43 #include <linux/stddef.h>
  44 #include <linux/string.h>
  45 #include <linux/workqueue.h>
  46 #include <net/dsfield.h>
  47 #include <net/rtnetlink.h>
  48 #include <uapi/linux/batman_adv.h>
  49
  50 #include "bat_algo.h"
  51 #include "bat_iv_ogm.h"
  52 #include "bat_v.h"
  53 #include "bridge_loop_avoidance.h"
  54 #include "debugfs.h"
  55 #include "distributed-arp-table.h"
  56 #include "gateway_client.h"
  57 #include "gateway_common.h"
  58 #include "hard-interface.h"
  59 #include "icmp_socket.h"
  60 #include "log.h"
  61 #include "multicast.h"
  62 #include "netlink.h"
  63 #include "network-coding.h"
  64 #include "originator.h"
  65 #include "packet.h"
  66 #include "routing.h"
  67 #include "send.h"
  68 #include "soft-interface.h"
  69 #include "tp_meter.h"
  70 #include "translation-table.h"
  71
  72 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
  73  * list traversals just rcu-locked
  74  */
  75 struct list_head batadv_hardif_list;
  76 static int (*batadv_rx_handler[256])(struct sk_buff *,
  77                                      struct batadv_hard_iface *);
  78
  79 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  80
  81 struct workqueue_struct *batadv_event_workqueue;
  82
  83 static void batadv_recv_handler_init(void);
  84
  85 static int __init batadv_init(void)
  86 {
  87         int ret;
  88
  89         ret = batadv_tt_cache_init();
  90         if (ret < 0)
  91                 return ret;
  92
  93         INIT_LIST_HEAD(&batadv_hardif_list);
  94         batadv_algo_init();
  95
  96         batadv_recv_handler_init();
  97
  98         batadv_v_init();
  99         batadv_iv_init();
 100         batadv_nc_init();
 101         batadv_tp_meter_init();
 102
 103         batadv_event_workqueue = create_singlethread_workqueue("bat_events");
 104         if (!batadv_event_workqueue)
 105                 goto err_create_wq;
 106
 107         batadv_socket_init();
 108         batadv_debugfs_init();
 109
 110         register_netdevice_notifier(&batadv_hard_if_notifier);
 111         rtnl_link_register(&batadv_link_ops);
 112         batadv_netlink_register();
 113
 114         pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
 115                 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
 116
 117         return 0;
 118
 119 err_create_wq:
 120         batadv_tt_cache_destroy();
 121
 122         return -ENOMEM;
 123 }
 124
 125 static void __exit batadv_exit(void)
 126 {
 127         batadv_debugfs_destroy();
 128         batadv_netlink_unregister();
 129         rtnl_link_unregister(&batadv_link_ops);
 130         unregister_netdevice_notifier(&batadv_hard_if_notifier);
 131         batadv_hardif_remove_interfaces();
 132
 133         flush_workqueue(batadv_event_workqueue);
 134         destroy_workqueue(batadv_event_workqueue);
 135         batadv_event_workqueue = NULL;
 136
 137         rcu_barrier();
 138
 139         batadv_tt_cache_destroy();
 140 }
 141
 142 int batadv_mesh_init(struct net_device *soft_iface)
 143 {
 144         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 145         int ret;
 146
 147         spin_lock_init(&bat_priv->forw_bat_list_lock);
 148         spin_lock_init(&bat_priv->forw_bcast_list_lock);
 149         spin_lock_init(&bat_priv->tt.changes_list_lock);
 150         spin_lock_init(&bat_priv->tt.req_list_lock);
 151         spin_lock_init(&bat_priv->tt.roam_list_lock);
 152         spin_lock_init(&bat_priv->tt.last_changeset_lock);
 153         spin_lock_init(&bat_priv->tt.commit_lock);
 154         spin_lock_init(&bat_priv->gw.list_lock);
 155 #ifdef CONFIG_BATMAN_ADV_MCAST
 156         spin_lock_init(&bat_priv->mcast.want_lists_lock);
 157 #endif
 158         spin_lock_init(&bat_priv->tvlv.container_list_lock);
 159         spin_lock_init(&bat_priv->tvlv.handler_list_lock);
 160         spin_lock_init(&bat_priv->softif_vlan_list_lock);
 161         spin_lock_init(&bat_priv->tp_list_lock);
 162
 163         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 164         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 165         INIT_HLIST_HEAD(&bat_priv->gw.gateway_list);
 166 #ifdef CONFIG_BATMAN_ADV_MCAST
 167         INIT_HLIST_HEAD(&bat_priv->mcast.want_all_unsnoopables_list);
 168         INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv4_list);
 169         INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv6_list);
 170 #endif
 171         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 172         INIT_HLIST_HEAD(&bat_priv->tt.req_list);
 173         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
 174 #ifdef CONFIG_BATMAN_ADV_MCAST
 175         INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);
 176 #endif
 177         INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
 178         INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
 179         INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
 180         INIT_HLIST_HEAD(&bat_priv->tp_list);
 181
 182         ret = batadv_v_mesh_init(bat_priv);
 183         if (ret < 0)
 184                 goto err;
 185
 186         ret = batadv_originator_init(bat_priv);
 187         if (ret < 0)
 188                 goto err;
 189
 190         ret = batadv_tt_init(bat_priv);
 191         if (ret < 0)
 192                 goto err;
 193
 194         ret = batadv_bla_init(bat_priv);
 195         if (ret < 0)
 196                 goto err;
 197
 198         ret = batadv_dat_init(bat_priv);
 199         if (ret < 0)
 200                 goto err;
 201
 202         ret = batadv_nc_mesh_init(bat_priv);
 203         if (ret < 0)
 204                 goto err;
 205
 206         batadv_gw_init(bat_priv);
 207         batadv_mcast_init(bat_priv);
 208
 209         atomic_set(&bat_priv->gw.reselect, 0);
 210         atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 211
 212         return 0;
 213
 214 err:
 215         batadv_mesh_free(soft_iface);
 216         return ret;
 217 }
 218
 219 void batadv_mesh_free(struct net_device *soft_iface)
 220 {
 221         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 222
 223         atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 224
 225         batadv_purge_outstanding_packets(bat_priv, NULL);
 226
 227         batadv_gw_node_free(bat_priv);
 228
 229         batadv_v_mesh_free(bat_priv);
 230         batadv_nc_mesh_free(bat_priv);
 231         batadv_dat_free(bat_priv);
 232         batadv_bla_free(bat_priv);
 233
 234         batadv_mcast_free(bat_priv);
 235
 236         /* Free the TT and the originator tables only after having terminated
 237          * all the other depending components which may use these structures for
 238          * their purposes.
 239          */
 240         batadv_tt_free(bat_priv);
 241
 242         /* Since the originator table clean up routine is accessing the TT
 243          * tables as well, it has to be invoked after the TT tables have been
 244          * freed and marked as empty. This ensures that no cleanup RCU callbacks
 245          * accessing the TT data are scheduled for later execution.
 246          */
 247         batadv_originator_free(bat_priv);
 248
 249         batadv_gw_free(bat_priv);
 250
 251         free_percpu(bat_priv->bat_counters);
 252         bat_priv->bat_counters = NULL;
 253
 254         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 255 }
 256
 257 /**
 258  * batadv_is_my_mac - check if the given mac address belongs to any of the real
 259  * interfaces in the current mesh
 260  * @bat_priv: the bat priv with all the soft interface information
 261  * @addr: the address to check
 262  *
 263  * Return: 'true' if the mac address was found, false otherwise.
 264  */
 265 bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr)
 266 {
 267         const struct batadv_hard_iface *hard_iface;
 268         bool is_my_mac = false;
 269
 270         rcu_read_lock();
 271         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 272                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 273                         continue;
 274
 275                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 276                         continue;
 277
 278                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 279                         is_my_mac = true;
 280                         break;
 281                 }
 282         }
 283         rcu_read_unlock();
 284         return is_my_mac;
 285 }
 286
 287 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
 288 /**
 289  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 290  *  function that requires the primary interface
 291  * @seq: debugfs table seq_file struct
 292  *
 293  * Return: primary interface if found or NULL otherwise.
 294  */
 295 struct batadv_hard_iface *
 296 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 297 {
 298         struct net_device *net_dev = (struct net_device *)seq->private;
 299         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 300         struct batadv_hard_iface *primary_if;
 301
 302         primary_if = batadv_primary_if_get_selected(bat_priv);
 303
 304         if (!primary_if) {
 305                 seq_printf(seq,
 306                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 307                            net_dev->name);
 308                 goto out;
 309         }
 310
 311         if (primary_if->if_status == BATADV_IF_ACTIVE)
 312                 goto out;
 313
 314         seq_printf(seq,
 315                    "BATMAN mesh %s disabled - primary interface not active\n",
 316                    net_dev->name);
 317         batadv_hardif_put(primary_if);
 318         primary_if = NULL;
 319
 320 out:
 321         return primary_if;
 322 }
 323 #endif
 324
 325 /**
 326  * batadv_max_header_len - calculate maximum encapsulation overhead for a
 327  *  payload packet
 328  *
 329  * Return: the maximum encapsulation overhead in bytes.
 330  */
 331 int batadv_max_header_len(void)
 332 {
 333         int header_len = 0;
 334
 335         header_len = max_t(int, header_len,
 336                            sizeof(struct batadv_unicast_packet));
 337         header_len = max_t(int, header_len,
 338                            sizeof(struct batadv_unicast_4addr_packet));
 339         header_len = max_t(int, header_len,
 340                            sizeof(struct batadv_bcast_packet));
 341
 342 #ifdef CONFIG_BATMAN_ADV_NC
 343         header_len = max_t(int, header_len,
 344                            sizeof(struct batadv_coded_packet));
 345 #endif
 346
 347         return header_len + ETH_HLEN;
 348 }
 349
 350 /**
 351  * batadv_skb_set_priority - sets skb priority according to packet content
 352  * @skb: the packet to be sent
 353  * @offset: offset to the packet content
 354  *
 355  * This function sets a value between 256 and 263 (802.1d priority), which
 356  * can be interpreted by the cfg80211 or other drivers.
 357  */
 358 void batadv_skb_set_priority(struct sk_buff *skb, int offset)
 359 {
 360         struct iphdr ip_hdr_tmp, *ip_hdr;
 361         struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
 362         struct ethhdr ethhdr_tmp, *ethhdr;
 363         struct vlan_ethhdr *vhdr, vhdr_tmp;
 364         u32 prio;
 365
 366         /* already set, do nothing */
 367         if (skb->priority >= 256 && skb->priority <= 263)
 368                 return;
 369
 370         ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
 371         if (!ethhdr)
 372                 return;
 373
 374         switch (ethhdr->h_proto) {
 375         case htons(ETH_P_8021Q):
 376                 vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
 377                                           sizeof(*vhdr), &vhdr_tmp);
 378                 if (!vhdr)
 379                         return;
 380                 prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
 381                 prio = prio >> VLAN_PRIO_SHIFT;
 382                 break;
 383         case htons(ETH_P_IP):
 384                 ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
 385                                             sizeof(*ip_hdr), &ip_hdr_tmp);
 386                 if (!ip_hdr)
 387                         return;
 388                 prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
 389                 break;
 390         case htons(ETH_P_IPV6):
 391                 ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
 392                                              sizeof(*ip6_hdr), &ip6_hdr_tmp);
 393                 if (!ip6_hdr)
 394                         return;
 395                 prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
 396                 break;
 397         default:
 398                 return;
 399         }
 400
 401         skb->priority = prio + 256;
 402 }
 403
 404 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 405                                         struct batadv_hard_iface *recv_if)
 406 {
 407         kfree_skb(skb);
 408
 409         return NET_RX_DROP;
 410 }
 411
 412 /* incoming packets with the batman ethertype received on any active hard
 413  * interface
 414  */
 415 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 416                            struct packet_type *ptype,
 417                            struct net_device *orig_dev)
 418 {
 419         struct batadv_priv *bat_priv;
 420         struct batadv_ogm_packet *batadv_ogm_packet;
 421         struct batadv_hard_iface *hard_iface;
 422         u8 idx;
 423
 424         hard_iface = container_of(ptype, struct batadv_hard_iface,
 425                                   batman_adv_ptype);
 426
 427         /* Prevent processing a packet received on an interface which is getting
 428          * shut down otherwise the packet may trigger de-reference errors
 429          * further down in the receive path.
 430          */
 431         if (!kref_get_unless_zero(&hard_iface->refcount))
 432                 goto err_out;
 433
 434         skb = skb_share_check(skb, GFP_ATOMIC);
 435
 436         /* skb was released by skb_share_check() */
 437         if (!skb)
 438                 goto err_put;
 439
 440         /* packet should hold at least type and version */
 441         if (unlikely(!pskb_may_pull(skb, 2)))
 442                 goto err_free;
 443
 444         /* expect a valid ethernet header here. */
 445         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 446                 goto err_free;
 447
 448         if (!hard_iface->soft_iface)
 449                 goto err_free;
 450
 451         bat_priv = netdev_priv(hard_iface->soft_iface);
 452
 453         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 454                 goto err_free;
 455
 456         /* discard frames on not active interfaces */
 457         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 458                 goto err_free;
 459
 460         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 461
 462         if (batadv_ogm_packet->version != BATADV_COMPAT_VERSION) {
 463                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 464                            "Drop packet: incompatible batman version (%i)\n",
 465                            batadv_ogm_packet->version);
 466                 goto err_free;
 467         }
 468
 469         /* reset control block to avoid left overs from previous users */
 470         memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
 471
 472         idx = batadv_ogm_packet->packet_type;
 473         (*batadv_rx_handler[idx])(skb, hard_iface);
 474
 475         batadv_hardif_put(hard_iface);
 476
 477         /* return NET_RX_SUCCESS in any case as we
 478          * most probably dropped the packet for
 479          * routing-logical reasons.
 480          */
 481         return NET_RX_SUCCESS;
 482
 483 err_free:
 484         kfree_skb(skb);
 485 err_put:
 486         batadv_hardif_put(hard_iface);
 487 err_out:
 488         return NET_RX_DROP;
 489 }
 490
 491 static void batadv_recv_handler_init(void)
 492 {
 493         int i;
 494
 495         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 496                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 497
 498         for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
 499                 batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
 500
 501         /* compile time checks for sizes */
 502         BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
 503         BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
 504         BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
 505         BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
 506         BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
 507         BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
 508         BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
 509         BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
 510         BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
 511         BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
 512         BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
 513         BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
 514         BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
 515         BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
 516         BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
 517         BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
 518
 519         i = FIELD_SIZEOF(struct sk_buff, cb);
 520         BUILD_BUG_ON(sizeof(struct batadv_skb_cb) > i);
 521
 522         /* broadcast packet */
 523         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 524
 525         /* unicast packets ... */
 526         /* unicast with 4 addresses packet */
 527         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 528         /* unicast packet */
 529         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 530         /* unicast tvlv packet */
 531         batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
 532         /* batman icmp packet */
 533         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 534         /* Fragmented packets */
 535         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
 536 }
 537
 538 int
 539 batadv_recv_handler_register(u8 packet_type,
 540                              int (*recv_handler)(struct sk_buff *,
 541                                                  struct batadv_hard_iface *))
 542 {
 543         int (*curr)(struct sk_buff *,
 544                     struct batadv_hard_iface *);
 545         curr = batadv_rx_handler[packet_type];
 546
 547         if ((curr != batadv_recv_unhandled_packet) &&
 548             (curr != batadv_recv_unhandled_unicast_packet))
 549                 return -EBUSY;
 550
 551         batadv_rx_handler[packet_type] = recv_handler;
 552         return 0;
 553 }
 554
 555 void batadv_recv_handler_unregister(u8 packet_type)
 556 {
 557         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 558 }
 559
 560 /**
 561  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 562  *  the header
 563  * @skb: skb pointing to fragmented socket buffers
 564  * @payload_ptr: Pointer to position inside the head buffer of the skb
 565  *  marking the start of the data to be CRC'ed
 566  *
 567  * payload_ptr must always point to an address in the skb head buffer and not to
 568  * a fragment.
 569  *
 570  * Return: big endian crc32c of the checksummed data
 571  */
 572 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 573 {
 574         u32 crc = 0;
 575         unsigned int from;
 576         unsigned int to = skb->len;
 577         struct skb_seq_state st;
 578         const u8 *data;
 579         unsigned int len;
 580         unsigned int consumed = 0;
 581
 582         from = (unsigned int)(payload_ptr - skb->data);
 583
 584         skb_prepare_seq_read(skb, from, to, &st);
 585         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 586                 crc = crc32c(crc, data, len);
 587                 consumed += len;
 588         }
 589
 590         return htonl(crc);
 591 }
 592
 593 /**
 594  * batadv_get_vid - extract the VLAN identifier from skb if any
 595  * @skb: the buffer containing the packet
 596  * @header_len: length of the batman header preceding the ethernet header
 597  *
 598  * Return: VID with the BATADV_VLAN_HAS_TAG flag when the packet embedded in the
 599  * skb is vlan tagged. Otherwise BATADV_NO_FLAGS.
 600  */
 601 unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
 602 {
 603         struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
 604         struct vlan_ethhdr *vhdr;
 605         unsigned short vid;
 606
 607         if (ethhdr->h_proto != htons(ETH_P_8021Q))
 608                 return BATADV_NO_FLAGS;
 609
 610         if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
 611                 return BATADV_NO_FLAGS;
 612
 613         vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
 614         vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
 615         vid |= BATADV_VLAN_HAS_TAG;
 616
 617         return vid;
 618 }
 619
 620 /**
 621  * batadv_vlan_ap_isola_get - return the AP isolation status for the given vlan
 622  * @bat_priv: the bat priv with all the soft interface information
 623  * @vid: the VLAN identifier for which the AP isolation attributed as to be
 624  *  looked up
 625  *
 626  * Return: true if AP isolation is on for the VLAN idenfied by vid, false
 627  * otherwise
 628  */
 629 bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
 630 {
 631         bool ap_isolation_enabled = false;
 632         struct batadv_softif_vlan *vlan;
 633
 634         /* if the AP isolation is requested on a VLAN, then check for its
 635          * setting in the proper VLAN private data structure
 636          */
 637         vlan = batadv_softif_vlan_get(bat_priv, vid);
 638         if (vlan) {
 639                 ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
 640                 batadv_softif_vlan_put(vlan);
 641         }
 642
 643         return ap_isolation_enabled;
 644 }
 645
 646 module_init(batadv_init);
 647 module_exit(batadv_exit);
 648
 649 MODULE_LICENSE("GPL");
 650
 651 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 652 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 653 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 654 MODULE_VERSION(BATADV_SOURCE_VERSION);
 655 MODULE_ALIAS_RTNL_LINK("batadv");
 656 MODULE_ALIAS_GENL_FAMILY(BATADV_NL_NAME);