static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
				const struct nf_conntrack_tuple *tuple,
				const struct nf_conntrack_l4proto *l4proto)
{
	int ret = 0;
	struct nlattr *nest_parms;

	nest_parms = nla_nest_start(skb, CTA_TUPLE_PROTO);
	if (!nest_parms)
		goto nla_put_failure;
	if (nla_put_u8(skb, CTA_PROTO_NUM, tuple->dst.protonum))
		goto nla_put_failure;

	if (likely(l4proto->tuple_to_nlattr))
		ret = l4proto->tuple_to_nlattr(skb, tuple);

	nla_nest_end(skb, nest_parms);

	return ret;

nla_put_failure:
	return -1;
}