if_link_state
if (ifp->if_link_state != link) {
ifp->if_link_state = link;
if (!LINK_STATE_IS_UP(ifp->if_link_state)) {
return (ifp->if_link_state);
if (ifp->if_link_state == linkState)
ifp->if_link_state = linkState;
if (ifp->if_link_state == LINK_STATE_UP)
if (LINK_STATE_IS_UP(ifp->if_link_state)) {
if (nstate != ifp->if_link_state) {
ifp->if_link_state = nstate;