vlan_dev.c

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/* -*- linux-c -*-
 * INET     802.1Q VLAN
 *      Ethernet-type device handling.
 *
 * Authors: Ben Greear <[email protected]>
 *              Please send support related email to: [email protected]
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 *
 * Fixes:       Mar 22 2001: Martin Bokaemper <[email protected]>
 *                - 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/slab.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>
#include <linux/netpoll.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 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 u16
vlan_dev_get_egress_qos_mask(struct net_device *dev, struct sk_buff *skb)
{
    struct vlan_priority_tci_mapping *mp;

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

        vlan_tci = vlan_dev_priv(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_3/2 we
         *  put the length in here instead.
         */
        if (type != ETH_P_802_3 && type != ETH_P_802_2)
            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_priv(dev)->real_dev;
    rc = dev_hard_header(skb, dev, type, daddr, saddr, len + vhdrlen);
    if (rc > 0)
        rc += vhdrlen;
    return rc;
}

static inline netdev_tx_t vlan_netpoll_send_skb(struct vlan_dev_priv *vlan, struct sk_buff *skb)
{
#ifdef CONFIG_NET_POLL_CONTROLLER
    if (vlan->netpoll)
        netpoll_send_skb(vlan->netpoll, skb);
#else
    BUG();
#endif
    return NETDEV_TX_OK;
}

static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
                        struct net_device *dev)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
    struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
    unsigned int len;
    int ret;

    /* 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->flags & VLAN_FLAG_REORDER_HDR) {
        u16 vlan_tci;
        vlan_tci = vlan->vlan_id;
        vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
        skb = __vlan_hwaccel_put_tag(skb, vlan_tci);
    }

    skb->dev = vlan->real_dev;
    len = skb->len;
    if (unlikely(netpoll_tx_running(dev)))
        return vlan_netpoll_send_skb(vlan, skb);

    ret = dev_queue_xmit(skb);

    if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
        struct vlan_pcpu_stats *stats;

        stats = this_cpu_ptr(vlan->vlan_pcpu_stats);
        u64_stats_update_begin(&stats->syncp);
        stats->tx_packets++;
        stats->tx_bytes += len;
        u64_stats_update_end(&stats->syncp);
    } else {
        this_cpu_inc(vlan->vlan_pcpu_stats->tx_dropped);
    }

    return ret;
}

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_priv(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_priv *vlan = vlan_dev_priv(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_priv *vlan = vlan_dev_priv(dev);
    struct vlan_priority_tci_mapping *mp = NULL;
    struct vlan_priority_tci_mapping *np;
    u32 vlan_qos = (vlan_prio << VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK;

    /* 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_priv *vlan = vlan_dev_priv(dev);
    u32 old_flags = vlan->flags;

    if (mask & ~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP |
             VLAN_FLAG_LOOSE_BINDING))
        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_priv(dev)->real_dev->name, 23);
}

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

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

    if (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr)) {
        err = dev_uc_add(real_dev, dev->dev_addr);
        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);

    if (netif_carrier_ok(real_dev))
        netif_carrier_on(dev);
    return 0;

clear_allmulti:
    if (dev->flags & IFF_ALLMULTI)
        dev_set_allmulti(real_dev, -1);
del_unicast:
    if (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr))
        dev_uc_del(real_dev, dev->dev_addr);
out:
    netif_carrier_off(dev);
    return err;
}

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

    dev_mc_unsync(real_dev, dev);
    dev_uc_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 (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr))
        dev_uc_del(real_dev, dev->dev_addr);

    netif_carrier_off(dev);
    return 0;
}

static int vlan_dev_set_mac_address(struct net_device *dev, void *p)
{
    struct net_device *real_dev = vlan_dev_priv(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 (!ether_addr_equal(addr->sa_data, real_dev->dev_addr)) {
        err = dev_uc_add(real_dev, addr->sa_data);
        if (err < 0)
            return err;
    }

    if (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr))
        dev_uc_del(real_dev, dev->dev_addr);

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_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    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 (netif_device_present(real_dev) && ops->ndo_do_ioctl)
            err = ops->ndo_do_ioctl(real_dev, &ifrr, cmd);
        break;
    }

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

    return err;
}

static int vlan_dev_neigh_setup(struct net_device *dev, struct neigh_parms *pa)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int err = 0;

    if (netif_device_present(real_dev) && ops->ndo_neigh_setup)
        err = ops->ndo_neigh_setup(real_dev, pa);

    return err;
}

#if defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)
static int vlan_dev_fcoe_ddp_setup(struct net_device *dev, u16 xid,
                   struct scatterlist *sgl, unsigned int sgc)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int rc = 0;

    if (ops->ndo_fcoe_ddp_setup)
        rc = ops->ndo_fcoe_ddp_setup(real_dev, xid, sgl, sgc);

    return rc;
}

static int vlan_dev_fcoe_ddp_done(struct net_device *dev, u16 xid)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int len = 0;

    if (ops->ndo_fcoe_ddp_done)
        len = ops->ndo_fcoe_ddp_done(real_dev, xid);

    return len;
}

static int vlan_dev_fcoe_enable(struct net_device *dev)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int rc = -EINVAL;

    if (ops->ndo_fcoe_enable)
        rc = ops->ndo_fcoe_enable(real_dev);
    return rc;
}

static int vlan_dev_fcoe_disable(struct net_device *dev)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int rc = -EINVAL;

    if (ops->ndo_fcoe_disable)
        rc = ops->ndo_fcoe_disable(real_dev);
    return rc;
}

static int vlan_dev_fcoe_get_wwn(struct net_device *dev, u64 *wwn, int type)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int rc = -EINVAL;

    if (ops->ndo_fcoe_get_wwn)
        rc = ops->ndo_fcoe_get_wwn(real_dev, wwn, type);
    return rc;
}

static int vlan_dev_fcoe_ddp_target(struct net_device *dev, u16 xid,
                    struct scatterlist *sgl, unsigned int sgc)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    const struct net_device_ops *ops = real_dev->netdev_ops;
    int rc = 0;

    if (ops->ndo_fcoe_ddp_target)
        rc = ops->ndo_fcoe_ddp_target(real_dev, xid, sgl, sgc);

    return rc;
}
#endif

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

    if (dev->flags & IFF_UP) {
        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_priv(vlan_dev)->real_dev, vlan_dev);
    dev_uc_sync(vlan_dev_priv(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 const struct net_device_ops vlan_netdev_ops;

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

    netif_carrier_off(dev);

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

    dev->hw_features = NETIF_F_ALL_CSUM | NETIF_F_SG |
               NETIF_F_FRAGLIST | NETIF_F_ALL_TSO |
               NETIF_F_HIGHDMA | NETIF_F_SCTP_CSUM |
               NETIF_F_ALL_FCOE;

    dev->features |= real_dev->vlan_features | NETIF_F_LLTX;
    dev->gso_max_size = real_dev->gso_max_size;

    /* 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 defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)
    dev->fcoe_ddp_xid = real_dev->fcoe_ddp_xid;
#endif

    dev->needed_headroom = real_dev->needed_headroom;
    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;
    } else {
        dev->header_ops      = &vlan_header_ops;
        dev->hard_header_len = real_dev->hard_header_len + VLAN_HLEN;
    }

    dev->netdev_ops = &vlan_netdev_ops;

    if (is_vlan_dev(real_dev))
        subclass = 1;

    vlan_dev_set_lockdep_class(dev, subclass);

    vlan_dev_priv(dev)->vlan_pcpu_stats = alloc_percpu(struct vlan_pcpu_stats);
    if (!vlan_dev_priv(dev)->vlan_pcpu_stats)
        return -ENOMEM;

    return 0;
}

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

    free_percpu(vlan->vlan_pcpu_stats);
    vlan->vlan_pcpu_stats = NULL;
    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 netdev_features_t vlan_dev_fix_features(struct net_device *dev,
    netdev_features_t features)
{
    struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
    u32 old_features = features;

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

    features |= old_features & NETIF_F_SOFT_FEATURES;
    features |= NETIF_F_LLTX;

    return features;
}

static int vlan_ethtool_get_settings(struct net_device *dev,
                     struct ethtool_cmd *cmd)
{
    const struct vlan_dev_priv *vlan = vlan_dev_priv(dev);

    return __ethtool_get_settings(vlan->real_dev, cmd);
}

static void vlan_ethtool_get_drvinfo(struct net_device *dev,
                     struct ethtool_drvinfo *info)
{
    strcpy(info->driver, vlan_fullname);
    strcpy(info->version, vlan_version);
    strcpy(info->fw_version, "N/A");
}

static struct rtnl_link_stats64 *vlan_dev_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
{

    if (vlan_dev_priv(dev)->vlan_pcpu_stats) {
        struct vlan_pcpu_stats *p;
        u32 rx_errors = 0, tx_dropped = 0;
        int i;

        for_each_possible_cpu(i) {
            u64 rxpackets, rxbytes, rxmulticast, txpackets, txbytes;
            unsigned int start;

            p = per_cpu_ptr(vlan_dev_priv(dev)->vlan_pcpu_stats, i);
            do {
                start = u64_stats_fetch_begin_bh(&p->syncp);
                rxpackets   = p->rx_packets;
                rxbytes     = p->rx_bytes;
                rxmulticast = p->rx_multicast;
                txpackets   = p->tx_packets;
                txbytes     = p->tx_bytes;
            } while (u64_stats_fetch_retry_bh(&p->syncp, start));

            stats->rx_packets   += rxpackets;
            stats->rx_bytes     += rxbytes;
            stats->multicast    += rxmulticast;
            stats->tx_packets   += txpackets;
            stats->tx_bytes     += txbytes;
            /* rx_errors & tx_dropped are u32 */
            rx_errors   += p->rx_errors;
            tx_dropped  += p->tx_dropped;
        }
        stats->rx_errors  = rx_errors;
        stats->tx_dropped = tx_dropped;
    }
    return stats;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void vlan_dev_poll_controller(struct net_device *dev)
{
    return;
}

static int vlan_dev_netpoll_setup(struct net_device *dev, struct netpoll_info *npinfo,
                  gfp_t gfp)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
    struct net_device *real_dev = vlan->real_dev;
    struct netpoll *netpoll;
    int err = 0;

    netpoll = kzalloc(sizeof(*netpoll), gfp);
    err = -ENOMEM;
    if (!netpoll)
        goto out;

    err = __netpoll_setup(netpoll, real_dev, gfp);
    if (err) {
        kfree(netpoll);
        goto out;
    }

    vlan->netpoll = netpoll;

out:
    return err;
}

static void vlan_dev_netpoll_cleanup(struct net_device *dev)
{
    struct vlan_dev_priv *vlan= vlan_dev_priv(dev);
    struct netpoll *netpoll = vlan->netpoll;

    if (!netpoll)
        return;

    vlan->netpoll = NULL;

    __netpoll_free_rcu(netpoll);
}
#endif /* CONFIG_NET_POLL_CONTROLLER */

static const struct ethtool_ops vlan_ethtool_ops = {
    .get_settings           = vlan_ethtool_get_settings,
    .get_drvinfo            = vlan_ethtool_get_drvinfo,
    .get_link       = ethtool_op_get_link,
};

static const struct net_device_ops vlan_netdev_ops = {
    .ndo_change_mtu     = vlan_dev_change_mtu,
    .ndo_init       = vlan_dev_init,
    .ndo_uninit     = vlan_dev_uninit,
    .ndo_open       = vlan_dev_open,
    .ndo_stop       = vlan_dev_stop,
    .ndo_start_xmit =  vlan_dev_hard_start_xmit,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_set_mac_address    = vlan_dev_set_mac_address,
    .ndo_set_rx_mode    = vlan_dev_set_rx_mode,
    .ndo_change_rx_flags    = vlan_dev_change_rx_flags,
    .ndo_do_ioctl       = vlan_dev_ioctl,
    .ndo_neigh_setup    = vlan_dev_neigh_setup,
    .ndo_get_stats64    = vlan_dev_get_stats64,
#if defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)
    .ndo_fcoe_ddp_setup = vlan_dev_fcoe_ddp_setup,
    .ndo_fcoe_ddp_done  = vlan_dev_fcoe_ddp_done,
    .ndo_fcoe_enable    = vlan_dev_fcoe_enable,
    .ndo_fcoe_disable   = vlan_dev_fcoe_disable,
    .ndo_fcoe_get_wwn   = vlan_dev_fcoe_get_wwn,
    .ndo_fcoe_ddp_target    = vlan_dev_fcoe_ddp_target,
#endif
#ifdef CONFIG_NET_POLL_CONTROLLER
    .ndo_poll_controller    = vlan_dev_poll_controller,
    .ndo_netpoll_setup  = vlan_dev_netpoll_setup,
    .ndo_netpoll_cleanup    = vlan_dev_netpoll_cleanup,
#endif
    .ndo_fix_features   = vlan_dev_fix_features,
};

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

    dev->priv_flags     |= IFF_802_1Q_VLAN;
    dev->priv_flags     &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
    dev->tx_queue_len   = 0;

    dev->netdev_ops     = &vlan_netdev_ops;
    dev->destructor     = free_netdev;
    dev->ethtool_ops    = &vlan_ethtool_ops;

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