[NETFILTER]: New iptables DCCP protocol header match

Using this new iptables DCCP protocol header match, it is possible to
create simplistic stateless packet filtering rules for DCCP.  It
permits matching of port numbers, packet type and options.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index fd1412d..431d589 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -242,10 +242,15 @@
 	return (struct dccp_hdr_ext *)(skb->h.raw + sizeof(struct dccp_hdr));
 }
 
+static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
+{
+	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
+}
+
 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
 {
 	const struct dccp_hdr *dh = dccp_hdr(skb);
-	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
+	return __dccp_basic_hdr_len(dh);
 }
 
 static inline __u64 dccp_hdr_seq(const struct sk_buff *skb)
@@ -297,10 +302,15 @@
 	return (struct dccp_hdr_reset *)(skb->h.raw + dccp_basic_hdr_len(skb));
 }
 
+static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
+{
+	return __dccp_basic_hdr_len(dh) +
+	       dccp_packet_hdr_len(dh->dccph_type);
+}
+
 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
 {
-	return dccp_basic_hdr_len(skb) +
-	       dccp_packet_hdr_len(dccp_hdr(skb)->dccph_type);
+	return __dccp_hdr_len(dccp_hdr(skb));
 }