Add NAT action

Here's a patch to add support for the nat action which is now
in the kernel.

Thanks,
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Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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--
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

include/linux/tc_act/tc_nat.h

+#ifndef __LINUX_TC_NAT_H
+#define __LINUX_TC_NAT_H
+
+#include <linux/pkt_cls.h>
+#include <linux/types.h>
+
+#define TCA_ACT_NAT 9
+
+enum
+{
+	TCA_NAT_UNSPEC,
+	TCA_NAT_PARMS,
+	TCA_NAT_TM,
+	__TCA_NAT_MAX
+};
+#define TCA_NAT_MAX (__TCA_NAT_MAX - 1)
+
+#define TCA_NAT_FLAG_EGRESS 1
+
+struct tc_nat
+{
+	tc_gen;
+	__be32 old_addr;
+	__be32 new_addr;
+	__be32 mask;
+	__u32 flags;
+};
+
+#endif