CCP_HDRLEN
if (dp + CCP_HDRLEN > ep)
slen >= CCP_HDRLEN + CCP_OPT_MINLEN &&
slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
dp + CCP_HDRLEN, slen - CCP_HDRLEN,
sc->sc_rc_state, dp + CCP_HDRLEN,
slen - CCP_HDRLEN, sc->sc_unit, 0,