static int dns_server_compare_func(const DnsServer *x, const DnsServer *y) {
        int r;

        r = CMP(x->family, y->family);
        if (r != 0)
                return r;

        r = memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
        if (r != 0)
                return r;

        r = CMP(x->ifindex, y->ifindex);
        if (r != 0)
                return r;

        return 0;
}
static int dns_server_compare_func(const DnsServer *x, const DnsServer *y) {
        int r;

        r = CMP(x->family, y->family);
        if (r != 0)
                return r;

        r = memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
        if (r != 0)
                return r;

        r = CMP(x->ifindex, y->ifindex);
        if (r != 0)
                return r;

        return 0;
}