LE_CARRIER
if (sc->sc_flags & LE_CARRIER) {
sc->sc_flags &= ~LE_CARRIER;
if (!(sc->sc_flags & LE_CARRIER)) {
sc->sc_flags |= LE_CARRIER;
if (sc->sc_flags & LE_CARRIER) {
sc->sc_flags &= ~LE_CARRIER;
if (!(sc->sc_flags & LE_CARRIER)) {
sc->sc_flags |= LE_CARRIER;
if (sc->sc_flags & LE_CARRIER)