/* -*- 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.
 */

#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));

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

        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_dev_priv *vlan = vlan_dev_priv(dev);
        struct vlan_hdr *vhdr;
        unsigned int vhdrlen = 0;
        u16 vlan_tci = 0;
        int rc;

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

                vlan_tci = vlan->vlan_id;
                vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb->priority);
                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 = vlan->vlan_proto;
                type = ntohs(vlan->vlan_proto);
                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->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 != vlan->vlan_proto ||
            vlan->flags & VLAN_FLAG_REORDER_HDR) {
                u16 vlan_tci;
                vlan_tci = vlan->vlan_id;
                vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb->priority);
                skb = __vlan_hwaccel_put_tag(skb, vlan->vlan_proto, 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;
        /* Before inserting this element in hash table, make sure all its fields
         * are committed to memory.
         * coupled with smp_rmb() in vlan_dev_get_egress_qos_mask()
         */
        smp_wmb();
        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 | VLAN_FLAG_MVRP))
                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);
        }

        if (netif_running(dev) && (vlan->flags ^ old_flags) & VLAN_FLAG_MVRP) {
                if (vlan->flags & VLAN_FLAG_MVRP)
                        vlan_mvrp_request_join(dev);
                else
                        vlan_mvrp_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;
        }

        ether_addr_copy(vlan->real_dev_addr, real_dev->dev_addr);

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

        if (vlan->flags & VLAN_FLAG_MVRP)
                vlan_mvrp_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:
        ether_addr_copy(dev->dev_addr, addr->sa_data);
        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 IS_ENABLED(CONFIG_FCOE)
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 int vlan_dev_get_lock_subclass(struct net_device *dev)
{
        return vlan_dev_priv(dev)->nest_level;
}

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_passthru_hard_header(struct sk_buff *skb, struct net_device *dev,
                                     unsigned short type,
                                     const void *daddr, const void *saddr,
                                     unsigned int len)
{
        struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
        struct net_device *real_dev = vlan->real_dev;

        if (saddr == NULL)
                saddr = dev->dev_addr;

        return dev_hard_header(skb, real_dev, type, daddr, saddr, len);
}

static const struct header_ops vlan_passthru_header_ops = {
        .create  = vlan_passthru_hard_header,
        .rebuild = dev_rebuild_header,
        .parse   = eth_header_parse,
};

static struct device_type vlan_type = {
        .name   = "vlan",
};

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;

        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;
        if (dev->features & NETIF_F_VLAN_FEATURES)
                netdev_warn(real_dev, "VLAN features are set incorrectly.  Q-in-Q configurations may not work correctly.\n");


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

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

#if IS_ENABLED(CONFIG_FCOE)
        dev->fcoe_ddp_xid = real_dev->fcoe_ddp_xid;
#endif

        dev->needed_headroom = real_dev->needed_headroom;
        if (vlan_hw_offload_capable(real_dev->features,
                                    vlan_dev_priv(dev)->vlan_proto)) {
                dev->header_ops      = &vlan_passthru_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;

        SET_NETDEV_DEVTYPE(dev, &vlan_type);

        vlan_dev_set_lockdep_class(dev, vlan_dev_get_lock_subclass(dev));

        vlan_dev_priv(dev)->vlan_pcpu_stats = netdev_alloc_pcpu_stats(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;

        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;
        netdev_features_t old_features = features;

        features = netdev_intersect_features(features, real_dev->vlan_features);
        features |= NETIF_F_RXCSUM;
        features = netdev_intersect_features(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)
{
        strlcpy(info->driver, vlan_fullname, sizeof(info->driver));
        strlcpy(info->version, vlan_version, sizeof(info->version));
        strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
}

static struct rtnl_link_stats64 *vlan_dev_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *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_irq(&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_irq(&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)
{
        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_KERNEL);
        err = -ENOMEM;
        if (!netpoll)
                goto out;

        err = __netpoll_setup(netpoll, real_dev);
        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_async(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 IS_ENABLED(CONFIG_FCOE)
        .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,
        .ndo_get_lock_subclass  = vlan_dev_get_lock_subclass,
};

static void vlan_dev_free(struct net_device *dev)
{
        struct vlan_dev_priv *vlan = vlan_dev_priv(dev);

        free_percpu(vlan->vlan_pcpu_stats);
        vlan->vlan_pcpu_stats = NULL;
        free_netdev(dev);
}

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         = vlan_dev_free;
        dev->ethtool_ops        = &vlan_ethtool_ops;

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