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_dccp.c b/net/ipv4/netfilter/nf_nat_proto_dccp.c
index 570faf2..c43d5b3 100644
--- a/net/ipv4/netfilter/nf_nat_proto_dccp.c
+++ b/net/ipv4/netfilter/nf_nat_proto_dccp.c
@@ -24,7 +24,7 @@
 
 static void
 dccp_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)
 {
@@ -54,7 +54,7 @@
 	iph = (struct iphdr *)(skb->data + iphdroff);
 	hdr = (struct dccp_hdr *)(skb->data + hdroff);
 
-	if (maniptype == IP_NAT_MANIP_SRC) {
+	if (maniptype == NF_NAT_MANIP_SRC) {
 		oldip = iph->saddr;
 		newip = tuple->src.u3.ip;
 		newport = tuple->src.u.dccp.port;