drivers/net/macvlan.c

   1 /*
   2  * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * The code this is based on carried the following copyright notice:
  10  * ---
  11  * (C) Copyright 2001-2006
  12  * Alex Zeffertt, Cambridge Broadband Ltd, ajz@cambridgebroadband.com
  13  * Re-worked by Ben Greear <greearb@candelatech.com>
  14  * ---
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/module.h>
  19 #include <linux/init.h>
  20 #include <linux/errno.h>
  21 #include <linux/slab.h>
  22 #include <linux/string.h>
  23 #include <linux/rculist.h>
  24 #include <linux/notifier.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/ethtool.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_link.h>
  30 #include <linux/if_macvlan.h>
  31 #include <net/rtnetlink.h>
  32
  33 #define MACVLAN_HASH_SIZE       (1 << BITS_PER_BYTE)
  34
  35 struct macvlan_port {
  36         struct net_device       *dev;
  37         struct hlist_head       vlan_hash[MACVLAN_HASH_SIZE];
  38         struct list_head        vlans;
  39 };
  40
  41 struct macvlan_dev {
  42         struct net_device       *dev;
  43         struct list_head        list;
  44         struct hlist_node       hlist;
  45         struct macvlan_port     *port;
  46         struct net_device       *lowerdev;
  47 };
  48
  49
  50 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
  51                                                const unsigned char *addr)
  52 {
  53         struct macvlan_dev *vlan;
  54         struct hlist_node *n;
  55
  56         hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
  57                 if (!compare_ether_addr_64bits(vlan->dev->dev_addr, addr))
  58                         return vlan;
  59         }
  60         return NULL;
  61 }
  62
  63 static void macvlan_hash_add(struct macvlan_dev *vlan)
  64 {
  65         struct macvlan_port *port = vlan->port;
  66         const unsigned char *addr = vlan->dev->dev_addr;
  67
  68         hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
  69 }
  70
  71 static void macvlan_hash_del(struct macvlan_dev *vlan)
  72 {
  73         hlist_del_rcu(&vlan->hlist);
  74         synchronize_rcu();
  75 }
  76
  77 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
  78                                         const unsigned char *addr)
  79 {
  80         macvlan_hash_del(vlan);
  81         /* Now that we are unhashed it is safe to change the device
  82          * address without confusing packet delivery.
  83          */
  84         memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
  85         macvlan_hash_add(vlan);
  86 }
  87
  88 static int macvlan_addr_busy(const struct macvlan_port *port,
  89                                 const unsigned char *addr)
  90 {
  91         /* Test to see if the specified multicast address is
  92          * currently in use by the underlying device or
  93          * another macvlan.
  94          */
  95         if (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
  96                 return 1;
  97
  98         if (macvlan_hash_lookup(port, addr))
  99                 return 1;
 100
 101         return 0;
 102 }
 103
 104 static void macvlan_broadcast(struct sk_buff *skb,
 105                               const struct macvlan_port *port)
 106 {
 107         const struct ethhdr *eth = eth_hdr(skb);
 108         const struct macvlan_dev *vlan;
 109         struct hlist_node *n;
 110         struct net_device *dev;
 111         struct sk_buff *nskb;
 112         unsigned int i;
 113
 114         if (skb->protocol == htons(ETH_P_PAUSE))
 115                 return;
 116
 117         for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
 118                 hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
 119                         dev = vlan->dev;
 120
 121                         nskb = skb_clone(skb, GFP_ATOMIC);
 122                         if (nskb == NULL) {
 123                                 dev->stats.rx_errors++;
 124                                 dev->stats.rx_dropped++;
 125                                 continue;
 126                         }
 127
 128                         dev->stats.rx_bytes += skb->len + ETH_HLEN;
 129                         dev->stats.rx_packets++;
 130                         dev->stats.multicast++;
 131
 132                         nskb->dev = dev;
 133                         if (!compare_ether_addr_64bits(eth->h_dest, dev->broadcast))
 134                                 nskb->pkt_type = PACKET_BROADCAST;
 135                         else
 136                                 nskb->pkt_type = PACKET_MULTICAST;
 137
 138                         netif_rx(nskb);
 139                 }
 140         }
 141 }
 142
 143 /* called under rcu_read_lock() from netif_receive_skb */
 144 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
 145 {
 146         const struct ethhdr *eth = eth_hdr(skb);
 147         const struct macvlan_port *port;
 148         const struct macvlan_dev *vlan;
 149         struct net_device *dev;
 150
 151         port = rcu_dereference(skb->dev->macvlan_port);
 152         if (port == NULL)
 153                 return skb;
 154
 155         if (is_multicast_ether_addr(eth->h_dest)) {
 156                 macvlan_broadcast(skb, port);
 157                 return skb;
 158         }
 159
 160         vlan = macvlan_hash_lookup(port, eth->h_dest);
 161         if (vlan == NULL)
 162                 return skb;
 163
 164         dev = vlan->dev;
 165         if (unlikely(!(dev->flags & IFF_UP))) {
 166                 kfree_skb(skb);
 167                 return NULL;
 168         }
 169
 170         skb = skb_share_check(skb, GFP_ATOMIC);
 171         if (skb == NULL) {
 172                 dev->stats.rx_errors++;
 173                 dev->stats.rx_dropped++;
 174                 return NULL;
 175         }
 176
 177         dev->stats.rx_bytes += skb->len + ETH_HLEN;
 178         dev->stats.rx_packets++;
 179
 180         skb->dev = dev;
 181         skb->pkt_type = PACKET_HOST;
 182
 183         netif_rx(skb);
 184         return NULL;
 185 }
 186
 187 static netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
 188                                       struct net_device *dev)
 189 {
 190         int i = skb_get_queue_mapping(skb);
 191         struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 192         const struct macvlan_dev *vlan = netdev_priv(dev);
 193         unsigned int len = skb->len;
 194         int ret;
 195
 196         skb->dev = vlan->lowerdev;
 197         ret = dev_queue_xmit(skb);
 198
 199         if (likely(ret == NET_XMIT_SUCCESS)) {
 200                 txq->tx_packets++;
 201                 txq->tx_bytes += len;
 202         } else
 203                 txq->tx_dropped++;
 204
 205         return NETDEV_TX_OK;
 206 }
 207
 208 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
 209                                unsigned short type, const void *daddr,
 210                                const void *saddr, unsigned len)
 211 {
 212         const struct macvlan_dev *vlan = netdev_priv(dev);
 213         struct net_device *lowerdev = vlan->lowerdev;
 214
 215         return dev_hard_header(skb, lowerdev, type, daddr,
 216                                saddr ? : dev->dev_addr, len);
 217 }
 218
 219 static const struct header_ops macvlan_hard_header_ops = {
 220         .create         = macvlan_hard_header,
 221         .rebuild        = eth_rebuild_header,
 222         .parse          = eth_header_parse,
 223         .cache          = eth_header_cache,
 224         .cache_update   = eth_header_cache_update,
 225 };
 226
 227 static int macvlan_open(struct net_device *dev)
 228 {
 229         struct macvlan_dev *vlan = netdev_priv(dev);
 230         struct net_device *lowerdev = vlan->lowerdev;
 231         int err;
 232
 233         err = -EBUSY;
 234         if (macvlan_addr_busy(vlan->port, dev->dev_addr))
 235                 goto out;
 236
 237         err = dev_unicast_add(lowerdev, dev->dev_addr);
 238         if (err < 0)
 239                 goto out;
 240         if (dev->flags & IFF_ALLMULTI) {
 241                 err = dev_set_allmulti(lowerdev, 1);
 242                 if (err < 0)
 243                         goto del_unicast;
 244         }
 245         macvlan_hash_add(vlan);
 246         return 0;
 247
 248 del_unicast:
 249         dev_unicast_delete(lowerdev, dev->dev_addr);
 250 out:
 251         return err;
 252 }
 253
 254 static int macvlan_stop(struct net_device *dev)
 255 {
 256         struct macvlan_dev *vlan = netdev_priv(dev);
 257         struct net_device *lowerdev = vlan->lowerdev;
 258
 259         dev_mc_unsync(lowerdev, dev);
 260         if (dev->flags & IFF_ALLMULTI)
 261                 dev_set_allmulti(lowerdev, -1);
 262
 263         dev_unicast_delete(lowerdev, dev->dev_addr);
 264
 265         macvlan_hash_del(vlan);
 266         return 0;
 267 }
 268
 269 static int macvlan_set_mac_address(struct net_device *dev, void *p)
 270 {
 271         struct macvlan_dev *vlan = netdev_priv(dev);
 272         struct net_device *lowerdev = vlan->lowerdev;
 273         struct sockaddr *addr = p;
 274         int err;
 275
 276         if (!is_valid_ether_addr(addr->sa_data))
 277                 return -EADDRNOTAVAIL;
 278
 279         if (!(dev->flags & IFF_UP)) {
 280                 /* Just copy in the new address */
 281                 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 282         } else {
 283                 /* Rehash and update the device filters */
 284                 if (macvlan_addr_busy(vlan->port, addr->sa_data))
 285                         return -EBUSY;
 286
 287                 err = dev_unicast_add(lowerdev, addr->sa_data);
 288                 if (err)
 289                         return err;
 290
 291                 dev_unicast_delete(lowerdev, dev->dev_addr);
 292
 293                 macvlan_hash_change_addr(vlan, addr->sa_data);
 294         }
 295         return 0;
 296 }
 297
 298 static void macvlan_change_rx_flags(struct net_device *dev, int change)
 299 {
 300         struct macvlan_dev *vlan = netdev_priv(dev);
 301         struct net_device *lowerdev = vlan->lowerdev;
 302
 303         if (change & IFF_ALLMULTI)
 304                 dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
 305 }
 306
 307 static void macvlan_set_multicast_list(struct net_device *dev)
 308 {
 309         struct macvlan_dev *vlan = netdev_priv(dev);
 310
 311         dev_mc_sync(vlan->lowerdev, dev);
 312 }
 313
 314 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
 315 {
 316         struct macvlan_dev *vlan = netdev_priv(dev);
 317
 318         if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
 319                 return -EINVAL;
 320         dev->mtu = new_mtu;
 321         return 0;
 322 }
 323
 324 /*
 325  * macvlan network devices have devices nesting below it and are a special
 326  * "super class" of normal network devices; split their locks off into a
 327  * separate class since they always nest.
 328  */
 329 static struct lock_class_key macvlan_netdev_xmit_lock_key;
 330 static struct lock_class_key macvlan_netdev_addr_lock_key;
 331
 332 #define MACVLAN_FEATURES \
 333         (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
 334          NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
 335          NETIF_F_TSO_ECN | NETIF_F_TSO6)
 336
 337 #define MACVLAN_STATE_MASK \
 338         ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
 339
 340 static void macvlan_set_lockdep_class_one(struct net_device *dev,
 341                                           struct netdev_queue *txq,
 342                                           void *_unused)
 343 {
 344         lockdep_set_class(&txq->_xmit_lock,
 345                           &macvlan_netdev_xmit_lock_key);
 346 }
 347
 348 static void macvlan_set_lockdep_class(struct net_device *dev)
 349 {
 350         lockdep_set_class(&dev->addr_list_lock,
 351                           &macvlan_netdev_addr_lock_key);
 352         netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
 353 }
 354
 355 static int macvlan_init(struct net_device *dev)
 356 {
 357         struct macvlan_dev *vlan = netdev_priv(dev);
 358         const struct net_device *lowerdev = vlan->lowerdev;
 359
 360         dev->state              = (dev->state & ~MACVLAN_STATE_MASK) |
 361                                   (lowerdev->state & MACVLAN_STATE_MASK);
 362         dev->features           = lowerdev->features & MACVLAN_FEATURES;
 363         dev->gso_max_size       = lowerdev->gso_max_size;
 364         dev->iflink             = lowerdev->ifindex;
 365         dev->hard_header_len    = lowerdev->hard_header_len;
 366
 367         macvlan_set_lockdep_class(dev);
 368
 369         return 0;
 370 }
 371
 372 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
 373                                         struct ethtool_drvinfo *drvinfo)
 374 {
 375         snprintf(drvinfo->driver, 32, "macvlan");
 376         snprintf(drvinfo->version, 32, "0.1");
 377 }
 378
 379 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
 380 {
 381         const struct macvlan_dev *vlan = netdev_priv(dev);
 382         return dev_ethtool_get_rx_csum(vlan->lowerdev);
 383 }
 384
 385 static int macvlan_ethtool_get_settings(struct net_device *dev,
 386                                         struct ethtool_cmd *cmd)
 387 {
 388         const struct macvlan_dev *vlan = netdev_priv(dev);
 389         return dev_ethtool_get_settings(vlan->lowerdev, cmd);
 390 }
 391
 392 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
 393 {
 394         const struct macvlan_dev *vlan = netdev_priv(dev);
 395         return dev_ethtool_get_flags(vlan->lowerdev);
 396 }
 397
 398 static const struct ethtool_ops macvlan_ethtool_ops = {
 399         .get_link               = ethtool_op_get_link,
 400         .get_settings           = macvlan_ethtool_get_settings,
 401         .get_rx_csum            = macvlan_ethtool_get_rx_csum,
 402         .get_drvinfo            = macvlan_ethtool_get_drvinfo,
 403         .get_flags              = macvlan_ethtool_get_flags,
 404 };
 405
 406 static const struct net_device_ops macvlan_netdev_ops = {
 407         .ndo_init               = macvlan_init,
 408         .ndo_open               = macvlan_open,
 409         .ndo_stop               = macvlan_stop,
 410         .ndo_start_xmit         = macvlan_start_xmit,
 411         .ndo_change_mtu         = macvlan_change_mtu,
 412         .ndo_change_rx_flags    = macvlan_change_rx_flags,
 413         .ndo_set_mac_address    = macvlan_set_mac_address,
 414         .ndo_set_multicast_list = macvlan_set_multicast_list,
 415         .ndo_validate_addr      = eth_validate_addr,
 416 };
 417
 418 static void macvlan_setup(struct net_device *dev)
 419 {
 420         ether_setup(dev);
 421
 422         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
 423         dev->netdev_ops         = &macvlan_netdev_ops;
 424         dev->destructor         = free_netdev;
 425         dev->header_ops         = &macvlan_hard_header_ops,
 426         dev->ethtool_ops        = &macvlan_ethtool_ops;
 427         dev->tx_queue_len       = 0;
 428 }
 429
 430 static int macvlan_port_create(struct net_device *dev)
 431 {
 432         struct macvlan_port *port;
 433         unsigned int i;
 434
 435         if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
 436                 return -EINVAL;
 437
 438         port = kzalloc(sizeof(*port), GFP_KERNEL);
 439         if (port == NULL)
 440                 return -ENOMEM;
 441
 442         port->dev = dev;
 443         INIT_LIST_HEAD(&port->vlans);
 444         for (i = 0; i < MACVLAN_HASH_SIZE; i++)
 445                 INIT_HLIST_HEAD(&port->vlan_hash[i]);
 446         rcu_assign_pointer(dev->macvlan_port, port);
 447         return 0;
 448 }
 449
 450 static void macvlan_port_destroy(struct net_device *dev)
 451 {
 452         struct macvlan_port *port = dev->macvlan_port;
 453
 454         rcu_assign_pointer(dev->macvlan_port, NULL);
 455         synchronize_rcu();
 456         kfree(port);
 457 }
 458
 459 static void macvlan_transfer_operstate(struct net_device *dev)
 460 {
 461         struct macvlan_dev *vlan = netdev_priv(dev);
 462         const struct net_device *lowerdev = vlan->lowerdev;
 463
 464         if (lowerdev->operstate == IF_OPER_DORMANT)
 465                 netif_dormant_on(dev);
 466         else
 467                 netif_dormant_off(dev);
 468
 469         if (netif_carrier_ok(lowerdev)) {
 470                 if (!netif_carrier_ok(dev))
 471                         netif_carrier_on(dev);
 472         } else {
 473                 if (netif_carrier_ok(dev))
 474                         netif_carrier_off(dev);
 475         }
 476 }
 477
 478 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
 479 {
 480         if (tb[IFLA_ADDRESS]) {
 481                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 482                         return -EINVAL;
 483                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 484                         return -EADDRNOTAVAIL;
 485         }
 486         return 0;
 487 }
 488
 489 static int macvlan_get_tx_queues(struct net *net,
 490                                  struct nlattr *tb[],
 491                                  unsigned int *num_tx_queues,
 492                                  unsigned int *real_num_tx_queues)
 493 {
 494         struct net_device *real_dev;
 495
 496         if (!tb[IFLA_LINK])
 497                 return -EINVAL;
 498
 499         real_dev = __dev_get_by_index(net, nla_get_u32(tb[IFLA_LINK]));
 500         if (!real_dev)
 501                 return -ENODEV;
 502
 503         *num_tx_queues      = real_dev->num_tx_queues;
 504         *real_num_tx_queues = real_dev->real_num_tx_queues;
 505         return 0;
 506 }
 507
 508 static int macvlan_newlink(struct net_device *dev,
 509                            struct nlattr *tb[], struct nlattr *data[])
 510 {
 511         struct macvlan_dev *vlan = netdev_priv(dev);
 512         struct macvlan_port *port;
 513         struct net_device *lowerdev;
 514         int err;
 515
 516         if (!tb[IFLA_LINK])
 517                 return -EINVAL;
 518
 519         lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
 520         if (lowerdev == NULL)
 521                 return -ENODEV;
 522
 523         /* When creating macvlans on top of other macvlans - use
 524          * the real device as the lowerdev.
 525          */
 526         if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
 527                 struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
 528                 lowerdev = lowervlan->lowerdev;
 529         }
 530
 531         if (!tb[IFLA_MTU])
 532                 dev->mtu = lowerdev->mtu;
 533         else if (dev->mtu > lowerdev->mtu)
 534                 return -EINVAL;
 535
 536         if (!tb[IFLA_ADDRESS])
 537                 random_ether_addr(dev->dev_addr);
 538
 539         if (lowerdev->macvlan_port == NULL) {
 540                 err = macvlan_port_create(lowerdev);
 541                 if (err < 0)
 542                         return err;
 543         }
 544         port = lowerdev->macvlan_port;
 545
 546         vlan->lowerdev = lowerdev;
 547         vlan->dev      = dev;
 548         vlan->port     = port;
 549
 550         err = register_netdevice(dev);
 551         if (err < 0)
 552                 return err;
 553
 554         list_add_tail(&vlan->list, &port->vlans);
 555         macvlan_transfer_operstate(dev);
 556         return 0;
 557 }
 558
 559 static void macvlan_dellink(struct net_device *dev)
 560 {
 561         struct macvlan_dev *vlan = netdev_priv(dev);
 562         struct macvlan_port *port = vlan->port;
 563
 564         list_del(&vlan->list);
 565         unregister_netdevice(dev);
 566
 567         if (list_empty(&port->vlans))
 568                 macvlan_port_destroy(port->dev);
 569 }
 570
 571 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
 572         .kind           = "macvlan",
 573         .priv_size      = sizeof(struct macvlan_dev),
 574         .get_tx_queues  = macvlan_get_tx_queues,
 575         .setup          = macvlan_setup,
 576         .validate       = macvlan_validate,
 577         .newlink        = macvlan_newlink,
 578         .dellink        = macvlan_dellink,
 579 };
 580
 581 static int macvlan_device_event(struct notifier_block *unused,
 582                                 unsigned long event, void *ptr)
 583 {
 584         struct net_device *dev = ptr;
 585         struct macvlan_dev *vlan, *next;
 586         struct macvlan_port *port;
 587
 588         port = dev->macvlan_port;
 589         if (port == NULL)
 590                 return NOTIFY_DONE;
 591
 592         switch (event) {
 593         case NETDEV_CHANGE:
 594                 list_for_each_entry(vlan, &port->vlans, list)
 595                         macvlan_transfer_operstate(vlan->dev);
 596                 break;
 597         case NETDEV_FEAT_CHANGE:
 598                 list_for_each_entry(vlan, &port->vlans, list) {
 599                         vlan->dev->features = dev->features & MACVLAN_FEATURES;
 600                         vlan->dev->gso_max_size = dev->gso_max_size;
 601                         netdev_features_change(vlan->dev);
 602                 }
 603                 break;
 604         case NETDEV_UNREGISTER:
 605                 list_for_each_entry_safe(vlan, next, &port->vlans, list)
 606                         macvlan_dellink(vlan->dev);
 607                 break;
 608         }
 609         return NOTIFY_DONE;
 610 }
 611
 612 static struct notifier_block macvlan_notifier_block __read_mostly = {
 613         .notifier_call  = macvlan_device_event,
 614 };
 615
 616 static int __init macvlan_init_module(void)
 617 {
 618         int err;
 619
 620         register_netdevice_notifier(&macvlan_notifier_block);
 621         macvlan_handle_frame_hook = macvlan_handle_frame;
 622
 623         err = rtnl_link_register(&macvlan_link_ops);
 624         if (err < 0)
 625                 goto err1;
 626         return 0;
 627 err1:
 628         macvlan_handle_frame_hook = NULL;
 629         unregister_netdevice_notifier(&macvlan_notifier_block);
 630         return err;
 631 }
 632
 633 static void __exit macvlan_cleanup_module(void)
 634 {
 635         rtnl_link_unregister(&macvlan_link_ops);
 636         macvlan_handle_frame_hook = NULL;
 637         unregister_netdevice_notifier(&macvlan_notifier_block);
 638 }
 639
 640 module_init(macvlan_init_module);
 641 module_exit(macvlan_cleanup_module);
 642
 643 MODULE_LICENSE("GPL");
 644 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 645 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
 646 MODULE_ALIAS_RTNL_LINK("macvlan");