net: bridge: add src field to br_ip

Add a new src field to struct br_ip which will be used to lookup S, G
entries. When SSM option is added we will enable full br_ip lookups.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/if_bridge.h

@@ -18,6 +18,12 @@ struct br_ip {
 		__be32	ip4;
 #if IS_ENABLED(CONFIG_IPV6)
 		struct in6_addr ip6;
+#endif
+	} src;
+	union {
+		__be32	ip4;
+#if IS_ENABLED(CONFIG_IPV6)
+		struct in6_addr ip6;
 #endif
 	} u;
 	__be16		proto;