if_get_bylla
struct ifnet *ifp = if_get_bylla(enaddr, ETHER_ADDR_LEN, &psref);
ifnet_t *if_get_bylla(const void *, unsigned char, struct psref *);
ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref);
ifp_ll = if_get_bylla(lladdr, ifp->if_addrlen, &psref_ll);