IP6TNL_TUNL_DEV1
if (tc_prog_attach(IP6TNL_TUNL_DEV1, get_fd, set_fd))
delete_tunnel(IP6TNL_TUNL_DEV0, IP6TNL_TUNL_DEV1);
err = add_ipv6_tunnel(IP6TNL_TUNL_DEV0, IP6TNL_TUNL_DEV1, "ip6tnl", "");