/* -*- 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));

		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;

	smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */

	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_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);
		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);
		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;
	}

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

	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:
	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 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 int vlan_calculate_locking_subclass(struct net_device *real_dev)
{
	int subclass = 0;

	while (is_vlan_dev(real_dev)) {
		subclass++;
		real_dev = vlan_dev_priv(real_dev)->real_dev;
	}

	return subclass;
}

static void vlan_dev_mc_sync(struct net_device *to, struct net_device *from)
{
	int err = 0, subclass;

	subclass = vlan_calculate_locking_subclass(to);

	spin_lock_nested(&to->addr_list_lock, subclass);
	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
	if (!err)
		__dev_set_rx_mode(to);
	spin_unlock(&to->addr_list_lock);
}

static void vlan_dev_uc_sync(struct net_device *to, struct net_device *from)
{
	int err = 0, subclass;

	subclass = vlan_calculate_locking_subclass(to);

	spin_lock_nested(&to->addr_list_lock, subclass);
	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
	if (!err)
		__dev_set_rx_mode(to);
	spin_unlock(&to->addr_list_lock);
}

static void vlan_dev_set_rx_mode(struct net_device *vlan_dev)
{
	vlan_dev_mc_sync(vlan_dev_priv(vlan_dev)->real_dev, vlan_dev);
	vlan_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 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;
	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))
		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);

	subclass = vlan_calculate_locking_subclass(dev);
	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;
	netdev_features_t 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)
{
	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)
{

	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_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,
};

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);
}