if_getcounter
sc->sc_stats.ast_tx_packets += if_getcounter(ifp,
sc->sc_stats.ast_rx_packets += if_getcounter(ifp,
uint64_t if_getcounter(if_t ifp, ift_counter counter);
errrate = (((if_getcounter(ifp, IFCOUNTER_OERRORS) +
if_getcounter(ifp, IFCOUNTER_IERRORS)) / 100) << M_BITS)