L2TPD_STATE_SHUTTING_DOWN
(((l2tpd)->state != L2TPD_STATE_SHUTTING_DOWN && \
(((l2tpd)->state == L2TPD_STATE_SHUTTING_DOWN)? 1 : 0)
if (_this->state != L2TPD_STATE_SHUTTING_DOWN)
_this->state = L2TPD_STATE_SHUTTING_DOWN;