SCF_SACK_PERMITTED
sc->sc_flags |= SCF_SACK_PERMITTED;
sc->sc_flags &= ~SCF_SACK_PERMITTED;
sc->sc_flags |= SCF_SACK_PERMITTED;
((sc->sc_flags & SCF_SACK_PERMITTED) ?
if (sc->sc_flags & SCF_SACK_PERMITTED) {
if (sc->sc_flags & SCF_SACK_PERMITTED)