in6_setscope
if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
if (in6_setscope(&in6, ifp, NULL) != 0)
if (in6_setscope(&in6, ifp, NULL) != 0)
int in6_setscope (struct in6_addr *, struct ifnet *, u_int32_t *);