nf_dup_ipv4
void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum,
EXPORT_SYMBOL_GPL(nf_dup_ipv4);
nf_dup_ipv4(nft_net(pkt), pkt->skb, nft_hook(pkt), &gw, oif);
nf_dup_ipv4(xt_net(par), skb, xt_hooknum(par), &info->gw.in, oif);