RTV_MTU
caseof(K_MTU, RTV_MTU, rmx_mtu);
setmetric(RTV_MTU, rmx_mtu);
!(rt->rt_rmx.rmx_locks & RTV_MTU) &&
!(rt->rt_rmx.rmx_locks & RTV_MTU)) {
rt->rt_rmx.rmx_locks |= RTV_MTU;
!(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
!(rt->rt_rmx.rmx_locks & RTV_MTU))
!(rt->rt_rmx.rmx_locks & RTV_MTU)) {
rt->rt_rmx.rmx_locks |= RTV_MTU;
if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
rtmes.m_rtm.rtm_inits |= RTV_MTU;