TUN_INITED
KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN,
tp->tun_flags |= TUN_INITED;
tp->tun_flags &= ~TUN_INITED;
if ((tp->tun_flags & TUN_INITED) == 0) {
#define TUN_READY (TUN_OPEN | TUN_INITED | TUN_IASET)