rfkill: document the rfkill struct locking (v2)

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / 8021q / vlan_dev.c

/* -*- linux-c -*-
 * INET         802.1Q VLAN
 *              Ethernet-type device handling.
 *
 * Authors:     Ben Greear <greearb@candelatech.com>
 *              Please send support related email to: netdev@vger.kernel.org
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 *
 * Fixes:       Mar 22 2001: Martin Bokaemper <mbokaemper@unispherenetworks.com>
 *                - reset skb->pkt_type on incoming packets when MAC was changed
 *                - see that changed MAC is saddr for outgoing packets
 *              Oct 20, 2001:  Ard van Breeman:
 *                - Fix MC-list, finally.
 *                - Flush MC-list on VLAN destroy.
 *
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <net/arp.h>

#include "vlan.h"
#include "vlanproc.h"
#include <linux/if_vlan.h>

/*
 *      Rebuild the Ethernet MAC header. This is called after an ARP
 *      (or in future other address resolution) has completed on this
 *      sk_buff. We now let ARP fill in the other fields.
 *
 *      This routine CANNOT use cached dst->neigh!
 *      Really, it is used only when dst->neigh is wrong.
 *
 * TODO:  This needs a checkup, I'm ignorant here. --BLG
 */
static int vlan_dev_rebuild_header(struct sk_buff *skb)
{
        struct net_device *dev = skb->dev;
        struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);

        switch (veth->h_vlan_encapsulated_proto) {
#ifdef CONFIG_INET
        case __constant_htons(ETH_P_IP):

                /* TODO:  Confirm this will work with VLAN headers... */
                return arp_find(veth->h_dest, skb);
#endif
        default:
                pr_debug("%s: unable to resolve type %X addresses.\n",
                         dev->name, ntohs(veth->h_vlan_encapsulated_proto));

                memcpy(veth->h_source, dev->dev_addr, ETH_ALEN);
                break;
        }

        return 0;
}

static inline struct sk_buff *vlan_check_reorder_header(struct sk_buff *skb)
{
        if (vlan_dev_info(skb->dev)->flags & VLAN_FLAG_REORDER_HDR) {
                if (skb_cow(skb, skb_headroom(skb)) < 0)
                        skb = NULL;
                if (skb) {
                        /* Lifted from Gleb's VLAN code... */
                        memmove(skb->data - ETH_HLEN,
                                skb->data - VLAN_ETH_HLEN, 12);
                        skb->mac_header += VLAN_HLEN;
                }
        }

        return skb;
}

static inline void vlan_set_encap_proto(struct sk_buff *skb,
                struct vlan_hdr *vhdr)
{
        __be16 proto;
        unsigned char *rawp;

        /*
         * Was a VLAN packet, grab the encapsulated protocol, which the layer
         * three protocols care about.
         */

        proto = vhdr->h_vlan_encapsulated_proto;
        if (ntohs(proto) >= 1536) {
                skb->protocol = proto;
                return;
        }

        rawp = skb->data;
        if (*(unsigned short *)rawp == 0xFFFF)
                /*
                 * This is a magic hack to spot IPX packets. Older Novell
                 * breaks the protocol design and runs IPX over 802.3 without
                 * an 802.2 LLC layer. We look for FFFF which isn't a used
                 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
                 * but does for the rest.
                 */
                skb->protocol = htons(ETH_P_802_3);
        else
                /*
                 * Real 802.2 LLC
                 */
                skb->protocol = htons(ETH_P_802_2);
}

/*
 *      Determine the packet's protocol ID. The rule here is that we
 *      assume 802.3 if the type field is short enough to be a length.
 *      This is normal practice and works for any 'now in use' protocol.
 *
 *  Also, at this point we assume that we ARE dealing exclusively with
 *  VLAN packets, or packets that should be made into VLAN packets based
 *  on a default VLAN ID.
 *
 *  NOTE:  Should be similar to ethernet/eth.c.
 *
 *  SANITY NOTE:  This method is called when a packet is moving up the stack
 *                towards userland.  To get here, it would have already passed
 *                through the ethernet/eth.c eth_type_trans() method.
 *  SANITY NOTE 2: We are referencing to the VLAN_HDR frields, which MAY be
 *                 stored UNALIGNED in the memory.  RISC systems don't like
 *                 such cases very much...
 *  SANITY NOTE 2a: According to Dave Miller & Alexey, it will always be
 *                  aligned, so there doesn't need to be any of the unaligned
 *                  stuff.  It has been commented out now...  --Ben
 *
 */
int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
                  struct packet_type *ptype, struct net_device *orig_dev)
{
        struct vlan_hdr *vhdr;
        struct net_device_stats *stats;
        u16 vlan_id;
        u16 vlan_tci;

        skb = skb_share_check(skb, GFP_ATOMIC);
        if (skb == NULL)
                goto err_free;

        if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
                goto err_free;

        vhdr = (struct vlan_hdr *)skb->data;
        vlan_tci = ntohs(vhdr->h_vlan_TCI);
        vlan_id = vlan_tci & VLAN_VID_MASK;

        rcu_read_lock();
        skb->dev = __find_vlan_dev(dev, vlan_id);
        if (!skb->dev) {
                pr_debug("%s: ERROR: No net_device for VID: %u on dev: %s\n",
                         __func__, vlan_id, dev->name);
                goto err_unlock;
        }

        skb->dev->last_rx = jiffies;

        stats = &skb->dev->stats;
        stats->rx_packets++;
        stats->rx_bytes += skb->len;

        skb_pull_rcsum(skb, VLAN_HLEN);

        skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tci);

        pr_debug("%s: priority: %u for TCI: %hu\n",
                 __func__, skb->priority, vlan_tci);

        switch (skb->pkt_type) {
        case PACKET_BROADCAST: /* Yeah, stats collect these together.. */
                /* stats->broadcast ++; // no such counter :-( */
                break;

        case PACKET_MULTICAST:
                stats->multicast++;
                break;

        case PACKET_OTHERHOST:
                /* Our lower layer thinks this is not local, let's make sure.
                 * This allows the VLAN to have a different MAC than the
                 * underlying device, and still route correctly.
                 */
                if (!compare_ether_addr(eth_hdr(skb)->h_dest,
                                        skb->dev->dev_addr))
                        skb->pkt_type = PACKET_HOST;
                break;
        default:
                break;
        }

        vlan_set_encap_proto(skb, vhdr);

        skb = vlan_check_reorder_header(skb);
        if (!skb) {
                stats->rx_errors++;
                goto err_unlock;
        }

        netif_rx(skb);
        rcu_read_unlock();
        return NET_RX_SUCCESS;

err_unlock:
        rcu_read_unlock();
err_free:
        kfree_skb(skb);
        return NET_RX_DROP;
}

static inline u16
vlan_dev_get_egress_qos_mask(struct net_device *dev, struct sk_buff *skb)
{
        struct vlan_priority_tci_mapping *mp;

        mp = vlan_dev_info(dev)->egress_priority_map[(skb->priority & 0xF)];
        while (mp) {
                if (mp->priority == skb->priority) {
                        return mp->vlan_qos; /* This should already be shifted
                                              * to mask correctly with the
                                              * VLAN's TCI */
                }
                mp = mp->next;
        }
        return 0;
}

/*
 *      Create the VLAN header for an arbitrary protocol layer
 *
 *      saddr=NULL      means use device source address
 *      daddr=NULL      means leave destination address (eg unresolved arp)
 *
 *  This is called when the SKB is moving down the stack towards the
 *  physical devices.
 */
static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
                                unsigned short type,
                                const void *daddr, const void *saddr,
                                unsigned int len)
{
        struct vlan_hdr *vhdr;
        unsigned int vhdrlen = 0;
        u16 vlan_tci = 0;
        int rc;

        if (WARN_ON(skb_headroom(skb) < dev->hard_header_len))
                return -ENOSPC;

        if (!(vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR)) {
                vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);

                vlan_tci = vlan_dev_info(dev)->vlan_id;
                vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
                vhdr->h_vlan_TCI = htons(vlan_tci);

                /*
                 *  Set the protocol type. For a packet of type ETH_P_802_3 we
                 *  put the length in here instead. It is up to the 802.2
                 *  layer to carry protocol information.
                 */
                if (type != ETH_P_802_3)
                        vhdr->h_vlan_encapsulated_proto = htons(type);
                else
                        vhdr->h_vlan_encapsulated_proto = htons(len);

                skb->protocol = htons(ETH_P_8021Q);
                type = ETH_P_8021Q;
                vhdrlen = VLAN_HLEN;
        }

        /* Before delegating work to the lower layer, enter our MAC-address */
        if (saddr == NULL)
                saddr = dev->dev_addr;

        /* Now make the underlying real hard header */
        dev = vlan_dev_info(dev)->real_dev;
        rc = dev_hard_header(skb, dev, type, daddr, saddr, len + vhdrlen);
        if (rc > 0)
                rc += vhdrlen;
        return rc;
}

static int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct net_device_stats *stats = &dev->stats;
        struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);

        /* Handle non-VLAN frames if they are sent to us, for example by DHCP.
         *
         * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
         * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
         */
        if (veth->h_vlan_proto != htons(ETH_P_8021Q) ||
            vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR) {
                unsigned int orig_headroom = skb_headroom(skb);
                u16 vlan_tci;

                vlan_dev_info(dev)->cnt_encap_on_xmit++;

                vlan_tci = vlan_dev_info(dev)->vlan_id;
                vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
                skb = __vlan_put_tag(skb, vlan_tci);
                if (!skb) {
                        stats->tx_dropped++;
                        return NETDEV_TX_OK;
                }

                if (orig_headroom < VLAN_HLEN)
                        vlan_dev_info(dev)->cnt_inc_headroom_on_tx++;
        }

        stats->tx_packets++;
        stats->tx_bytes += skb->len;

        skb->dev = vlan_dev_info(dev)->real_dev;
        dev_queue_xmit(skb);
        return NETDEV_TX_OK;
}

static int vlan_dev_hwaccel_hard_start_xmit(struct sk_buff *skb,
                                            struct net_device *dev)
{
        struct net_device_stats *stats = &dev->stats;
        u16 vlan_tci;

        vlan_tci = vlan_dev_info(dev)->vlan_id;
        vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
        skb = __vlan_hwaccel_put_tag(skb, vlan_tci);

        stats->tx_packets++;
        stats->tx_bytes += skb->len;

        skb->dev = vlan_dev_info(dev)->real_dev;
        dev_queue_xmit(skb);
        return NETDEV_TX_OK;
}

static int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
{
        /* TODO: gotta make sure the underlying layer can handle it,
         * maybe an IFF_VLAN_CAPABLE flag for devices?
         */
        if (vlan_dev_info(dev)->real_dev->mtu < new_mtu)
                return -ERANGE;

        dev->mtu = new_mtu;

        return 0;
}

void vlan_dev_set_ingress_priority(const struct net_device *dev,
                                   u32 skb_prio, u16 vlan_prio)
{
        struct vlan_dev_info *vlan = vlan_dev_info(dev);

        if (vlan->ingress_priority_map[vlan_prio & 0x7] && !skb_prio)
                vlan->nr_ingress_mappings--;
        else if (!vlan->ingress_priority_map[vlan_prio & 0x7] && skb_prio)
                vlan->nr_ingress_mappings++;

        vlan->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
}

int vlan_dev_set_egress_priority(const struct net_device *dev,
                                 u32 skb_prio, u16 vlan_prio)
{
        struct vlan_dev_info *vlan = vlan_dev_info(dev);
        struct vlan_priority_tci_mapping *mp = NULL;
        struct vlan_priority_tci_mapping *np;
        u32 vlan_qos = (vlan_prio << 13) & 0xE000;

        /* See if a priority mapping exists.. */
        mp = vlan->egress_priority_map[skb_prio & 0xF];
        while (mp) {
                if (mp->priority == skb_prio) {
                        if (mp->vlan_qos && !vlan_qos)
                                vlan->nr_egress_mappings--;
                        else if (!mp->vlan_qos && vlan_qos)
                                vlan->nr_egress_mappings++;
                        mp->vlan_qos = vlan_qos;
                        return 0;
                }
                mp = mp->next;
        }

        /* Create a new mapping then. */
        mp = vlan->egress_priority_map[skb_prio & 0xF];
        np = kmalloc(sizeof(struct vlan_priority_tci_mapping), GFP_KERNEL);
        if (!np)
                return -ENOBUFS;

        np->next = mp;
        np->priority = skb_prio;
        np->vlan_qos = vlan_qos;
        vlan->egress_priority_map[skb_prio & 0xF] = np;
        if (vlan_qos)
                vlan->nr_egress_mappings++;
        return 0;
}

/* Flags are defined in the vlan_flags enum in include/linux/if_vlan.h file. */
int vlan_dev_change_flags(const struct net_device *dev, u32 flags, u32 mask)
{
        struct vlan_dev_info *vlan = vlan_dev_info(dev);
        u32 old_flags = vlan->flags;

        if (mask & ~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP))
                return -EINVAL;

        vlan->flags = (old_flags & ~mask) | (flags & mask);

        if (netif_running(dev) && (vlan->flags ^ old_flags) & VLAN_FLAG_GVRP) {
                if (vlan->flags & VLAN_FLAG_GVRP)
                        vlan_gvrp_request_join(dev);
                else
                        vlan_gvrp_request_leave(dev);
        }
        return 0;
}

void vlan_dev_get_realdev_name(const struct net_device *dev, char *result)
{
        strncpy(result, vlan_dev_info(dev)->real_dev->name, 23);
}

static int vlan_dev_open(struct net_device *dev)
{
        struct vlan_dev_info *vlan = vlan_dev_info(dev);
        struct net_device *real_dev = vlan->real_dev;
        int err;

        if (!(real_dev->flags & IFF_UP))
                return -ENETDOWN;

        if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr)) {
                err = dev_unicast_add(real_dev, dev->dev_addr, ETH_ALEN);
                if (err < 0)
                        goto out;
        }

        if (dev->flags & IFF_ALLMULTI) {
                err = dev_set_allmulti(real_dev, 1);
                if (err < 0)
                        goto del_unicast;
        }
        if (dev->flags & IFF_PROMISC) {
                err = dev_set_promiscuity(real_dev, 1);
                if (err < 0)
                        goto clear_allmulti;
        }

        memcpy(vlan->real_dev_addr, real_dev->dev_addr, ETH_ALEN);

        if (vlan->flags & VLAN_FLAG_GVRP)
                vlan_gvrp_request_join(dev);

        return 0;

clear_allmulti:
        if (dev->flags & IFF_ALLMULTI)
                dev_set_allmulti(real_dev, -1);
del_unicast:
        if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
                dev_unicast_delete(real_dev, dev->dev_addr, ETH_ALEN);
out:
        return err;
}

static int vlan_dev_stop(struct net_device *dev)
{
        struct vlan_dev_info *vlan = vlan_dev_info(dev);
        struct net_device *real_dev = vlan->real_dev;

        if (vlan->flags & VLAN_FLAG_GVRP)
                vlan_gvrp_request_leave(dev);

        dev_mc_unsync(real_dev, dev);
        dev_unicast_unsync(real_dev, dev);
        if (dev->flags & IFF_ALLMULTI)
                dev_set_allmulti(real_dev, -1);
        if (dev->flags & IFF_PROMISC)
                dev_set_promiscuity(real_dev, -1);

        if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
                dev_unicast_delete(real_dev, dev->dev_addr, dev->addr_len);

        return 0;
}

static int vlan_dev_set_mac_address(struct net_device *dev, void *p)
{
        struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
        struct sockaddr *addr = p;
        int err;

        if (!is_valid_ether_addr(addr->sa_data))
                return -EADDRNOTAVAIL;

        if (!(dev->flags & IFF_UP))
                goto out;

        if (compare_ether_addr(addr->sa_data, real_dev->dev_addr)) {
                err = dev_unicast_add(real_dev, addr->sa_data, ETH_ALEN);
                if (err < 0)
                        return err;
        }

        if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
                dev_unicast_delete(real_dev, dev->dev_addr, ETH_ALEN);

out:
        memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
        return 0;
}

static int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
        struct ifreq ifrr;
        int err = -EOPNOTSUPP;

        strncpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
        ifrr.ifr_ifru = ifr->ifr_ifru;

        switch (cmd) {
        case SIOCGMIIPHY:
        case SIOCGMIIREG:
        case SIOCSMIIREG:
                if (real_dev->do_ioctl && netif_device_present(real_dev))
                        err = real_dev->do_ioctl(real_dev, &ifrr, cmd);
                break;
        }

        if (!err)
                ifr->ifr_ifru = ifrr.ifr_ifru;

        return err;
}

static void vlan_dev_change_rx_flags(struct net_device *dev, int change)
{
        struct net_device *real_dev = vlan_dev_info(dev)->real_dev;

        if (change & IFF_ALLMULTI)
                dev_set_allmulti(real_dev, dev->flags & IFF_ALLMULTI ? 1 : -1);
        if (change & IFF_PROMISC)
                dev_set_promiscuity(real_dev, dev->flags & IFF_PROMISC ? 1 : -1);
}

static void vlan_dev_set_rx_mode(struct net_device *vlan_dev)
{
        dev_mc_sync(vlan_dev_info(vlan_dev)->real_dev, vlan_dev);
        dev_unicast_sync(vlan_dev_info(vlan_dev)->real_dev, vlan_dev);
}

/*
 * vlan network devices have devices nesting below it, and are a special
 * "super class" of normal network devices; split their locks off into a
 * separate class since they always nest.
 */
static struct lock_class_key vlan_netdev_xmit_lock_key;
static struct lock_class_key vlan_netdev_addr_lock_key;

static void vlan_dev_set_lockdep_one(struct net_device *dev,
                                     struct netdev_queue *txq,
                                     void *_subclass)
{
        lockdep_set_class_and_subclass(&txq->_xmit_lock,
                                       &vlan_netdev_xmit_lock_key,
                                       *(int *)_subclass);
}

static void vlan_dev_set_lockdep_class(struct net_device *dev, int subclass)
{
        lockdep_set_class_and_subclass(&dev->addr_list_lock,
                                       &vlan_netdev_addr_lock_key,
                                       subclass);
        netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, &subclass);
}

static const struct header_ops vlan_header_ops = {
        .create  = vlan_dev_hard_header,
        .rebuild = vlan_dev_rebuild_header,
        .parse   = eth_header_parse,
};

static int vlan_dev_init(struct net_device *dev)
{
        struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
        int subclass = 0;

        /* IFF_BROADCAST|IFF_MULTICAST; ??? */
        dev->flags  = real_dev->flags & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI);
        dev->iflink = real_dev->ifindex;
        dev->state  = (real_dev->state & ((1<<__LINK_STATE_NOCARRIER) |
                                          (1<<__LINK_STATE_DORMANT))) |
                      (1<<__LINK_STATE_PRESENT);

        dev->features |= real_dev->features & real_dev->vlan_features;

        /* ipv6 shared card related stuff */
        dev->dev_id = real_dev->dev_id;

        if (is_zero_ether_addr(dev->dev_addr))
                memcpy(dev->dev_addr, real_dev->dev_addr, dev->addr_len);
        if (is_zero_ether_addr(dev->broadcast))
                memcpy(dev->broadcast, real_dev->broadcast, dev->addr_len);

        if (real_dev->features & NETIF_F_HW_VLAN_TX) {
                dev->header_ops      = real_dev->header_ops;
                dev->hard_header_len = real_dev->hard_header_len;
                dev->hard_start_xmit = vlan_dev_hwaccel_hard_start_xmit;
        } else {
                dev->header_ops      = &vlan_header_ops;
                dev->hard_header_len = real_dev->hard_header_len + VLAN_HLEN;
                dev->hard_start_xmit = vlan_dev_hard_start_xmit;
        }

        if (is_vlan_dev(real_dev))
                subclass = 1;

        vlan_dev_set_lockdep_class(dev, subclass);
        return 0;
}

static void vlan_dev_uninit(struct net_device *dev)
{
        struct vlan_priority_tci_mapping *pm;
        struct vlan_dev_info *vlan = vlan_dev_info(dev);
        int i;

        for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) {
                while ((pm = vlan->egress_priority_map[i]) != NULL) {
                        vlan->egress_priority_map[i] = pm->next;
                        kfree(pm);
                }
        }
}

static u32 vlan_ethtool_get_rx_csum(struct net_device *dev)
{
        const struct vlan_dev_info *vlan = vlan_dev_info(dev);
        struct net_device *real_dev = vlan->real_dev;

        if (real_dev->ethtool_ops == NULL ||
            real_dev->ethtool_ops->get_rx_csum == NULL)
                return 0;
        return real_dev->ethtool_ops->get_rx_csum(real_dev);
}

static u32 vlan_ethtool_get_flags(struct net_device *dev)
{
        const struct vlan_dev_info *vlan = vlan_dev_info(dev);
        struct net_device *real_dev = vlan->real_dev;

        if (!(real_dev->features & NETIF_F_HW_VLAN_RX) ||
            real_dev->ethtool_ops == NULL ||
            real_dev->ethtool_ops->get_flags == NULL)
                return 0;
        return real_dev->ethtool_ops->get_flags(real_dev);
}

static const struct ethtool_ops vlan_ethtool_ops = {
        .get_link               = ethtool_op_get_link,
        .get_rx_csum            = vlan_ethtool_get_rx_csum,
        .get_flags              = vlan_ethtool_get_flags,
};

void vlan_setup(struct net_device *dev)
{
        ether_setup(dev);

        dev->priv_flags         |= IFF_802_1Q_VLAN;
        dev->tx_queue_len       = 0;

        dev->change_mtu         = vlan_dev_change_mtu;
        dev->init               = vlan_dev_init;
        dev->uninit             = vlan_dev_uninit;
        dev->open               = vlan_dev_open;
        dev->stop               = vlan_dev_stop;
        dev->set_mac_address    = vlan_dev_set_mac_address;
        dev->set_rx_mode        = vlan_dev_set_rx_mode;
        dev->set_multicast_list = vlan_dev_set_rx_mode;
        dev->change_rx_flags    = vlan_dev_change_rx_flags;
        dev->do_ioctl           = vlan_dev_ioctl;
        dev->destructor         = free_netdev;
        dev->ethtool_ops        = &vlan_ethtool_ops;

        memset(dev->broadcast, 0, ETH_ALEN);
}