netfilter: nf_tables: add nft_payload_rebuild_vlan_hdr()

#include <linux/ip.h>

#include <linux/ipv6.h>

static bool nft_payload_rebuild_vlan_hdr(const struct sk_buff *skb, int mac_off,

					 struct vlan_ethhdr *veth)

{

	if (skb_copy_bits(skb, mac_off, veth, ETH_HLEN))

		return false;

	veth->h_vlan_proto = skb->vlan_proto;

	veth->h_vlan_TCI = htons(skb_vlan_tag_get(skb));

	veth->h_vlan_encapsulated_proto = skb->protocol;

	return true;

}

/* add vlan header into the user buffer for if tag was removed by offloads */

static bool

nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)

	if (offset < VLAN_ETH_HLEN) {

		u8 ethlen = len;

		if (skb_copy_bits(skb, mac_off, &veth, ETH_HLEN))

		if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))

			return false;

		veth.h_vlan_proto = skb->vlan_proto;

		veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));

		veth.h_vlan_encapsulated_proto = skb->protocol;

		if (offset + len > VLAN_ETH_HLEN)

			ethlen -= offset + len - VLAN_ETH_HLEN;