ifa_ifwithroute_psref
ifa = ifa_ifwithroute_psref(flags, dst, gateway, psref);
ifa = ifa_ifwithroute_psref(flags, sa, sa, psref);
ifa = ifa_ifwithroute_psref(rt->rt_flags, rt_getkey(rt),
static struct ifaddr *ifa_ifwithroute_psref(int, const struct sockaddr *,