ifpromisc
if ((error = ifpromisc(ifp, on ? 1 : 0)) != 0)
(void) ifpromisc(ifs, 0);
error = ifpromisc(ifs, 1);
{IFF_PROMISC, ifpromisc},
int ifpromisc(if_t, int);
{IFF_PROMISC, ifpromisc},
if ((error = ifpromisc(priv->ifp, want)) != 0)
(void)ifpromisc(priv->ifp, 0);
if ((error = ifpromisc(ifp, 1)) != 0)
ifpromisc(ifp, 0);