DAD_FAILURES
dad_failures = atomic_load_int(&DAD_FAILURES(ifp));
atomic_store_int(&DAD_FAILURES(ifp), 0);
u_int dad_failures = atomic_load_int(&DAD_FAILURES(ifp));
atomic_add_int(&DAD_FAILURES(ifp), 1);
atomic_load_int(&DAD_FAILURES(ifp)) <= V_ip6_stableaddr_maxretries &&