inet4isset
if (inet4isset(&n->addr, b->plen)) {
if (inet4isset(&p, n->plen))
if (inet4isset(&n->addr, new->plen))
if (n->node && inet4isset(&n->plenmask, plen - 1))
if (inet4isset(prefix, n->plen))
if (inet4isset(prefix, n->plen))