RTM_GETTFILTER
{.msgtype = RTM_GETTFILTER, .doit = tc_get_tfilter,
{ RTM_GETTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_READ },
.nlh.nlmsg_type = RTM_GETTFILTER,
req.nh.nlmsg_type = RTM_GETTFILTER;