netfilter: nf_nat: export NAT definitions to userspace

Export the NAT definitions to userspace. So far userspace (specifically,
iptables) has been copying the headers files from include/net. Also
rename some structures and definitions in preparation for IPv6 NAT.
Since these have never been officially exported, this doesn't affect
existing userspace code.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/ipv4/netfilter/nf_nat_proto_udp.c b/net/ipv4/netfilter/nf_nat_proto_udp.c
index 0b1b860..18ea44e 100644
--- a/net/ipv4/netfilter/nf_nat_proto_udp.c
+++ b/net/ipv4/netfilter/nf_nat_proto_udp.c
@@ -22,7 +22,7 @@
 
 static void
 udp_unique_tuple(struct nf_conntrack_tuple *tuple,
-		 const struct nf_nat_range *range,
+		 const struct nf_nat_ipv4_range *range,
 		 enum nf_nat_manip_type maniptype,
 		 const struct nf_conn *ct)
 {
@@ -47,7 +47,7 @@
 	iph = (struct iphdr *)(skb->data + iphdroff);
 	hdr = (struct udphdr *)(skb->data + hdroff);
 
-	if (maniptype == IP_NAT_MANIP_SRC) {
+	if (maniptype == NF_NAT_MANIP_SRC) {
 		/* Get rid of src ip and src pt */
 		oldip = iph->saddr;
 		newip = tuple->src.u3.ip;