Implement the fallthrough rule to support split tunnel VPNs.

Change-Id: Ibc48caedb5954c6b12bfa553d978bab56c4b09aa
diff --git a/server/RouteController.h b/server/RouteController.h
index aa2d8c9..3d00a66 100644
--- a/server/RouteController.h
+++ b/server/RouteController.h
@@ -75,6 +75,11 @@
                                const char* outputInterface) WARN_UNUSED_RESULT;
     static int disableTethering(const char* inputInterface,
                                 const char* outputInterface) WARN_UNUSED_RESULT;
+
+    static int addVirtualNetworkFallthrough(unsigned vpnNetId, const char* physicalInterface,
+                                            Permission permission) WARN_UNUSED_RESULT;
+    static int removeVirtualNetworkFallthrough(unsigned vpnNetId, const char* physicalInterface,
+                                               Permission permission) WARN_UNUSED_RESULT;
 };
 
 #endif  // NETD_SERVER_ROUTE_CONTROLLER_H