int dns_scope_good_key(DnsScope *s, DnsResourceKey *key);
int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union *address);
int dns_scope_good_key(DnsScope *s, DnsResourceKey *key);
int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union *address);