tproxy: added tproxy sockopt interface in the IPV6 layer

Support for IPV6_RECVORIGDSTADDR sockopt for UDP sockets were contributed by
Harry Mason.

Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/linux/in6.h b/include/linux/in6.h
index c4bf46f..097a34b 100644
--- a/include/linux/in6.h
+++ b/include/linux/in6.h
@@ -268,6 +268,10 @@
 /* RFC5082: Generalized Ttl Security Mechanism */
 #define IPV6_MINHOPCOUNT		73
 
+#define IPV6_ORIGDSTADDR        74
+#define IPV6_RECVORIGDSTADDR    IPV6_ORIGDSTADDR
+#define IPV6_TRANSPARENT        75
+
 /*
  * Multicast Routing:
  * see include/linux/mroute6.h.