This gets us to the point of seemingly being able to wrap and unwrap IPv4

Remarkably hard to test this on a single computer

pass-1/unwrapper.c

@@ -20,8 +20,8 @@ int main(int argc, char** argv)
     ssize_t count;
     int result;
     
-    if ( argc < 4 ) {
-        warn( "Usage: %s <rloc database> <listen_ifname> <output_ifname>", argv[0] );
+    if ( argc < 6 ) {
+        warn( "Usage: %s <rloc database> <listen_ifname> <output_ifname> <rloc> <keyfile> [<rloc> <keyfile>]n", argv[0] );
         return 1;
     }
 
@@ -30,6 +30,12 @@ int main(int argc, char** argv)
         warn( "Failed to set up session, exiting" );
         return 1;
     }
+    
+    if ( !session_upgrade_rlocs( &unwrap, argc - 4, argv + 4 ) ) {
+        warn( "Failed to upgrade rlocs for session, exiting" );
+        session_teardown( &unwrap );
+       return 1;
+    }
 
     memset( &recv_pkt, 0, sizeof( struct recv_pkt ) );
     memset( &to_send, 0, sizeof( struct rsp_data ) );