var hints _C_struct_addrinfo
	switch network {
	case "ip": // no hints
	case "tcp", "tcp4", "tcp6":
		*_C_ai_socktype(&hints) = _C_SOCK_STREAM
		*_C_ai_protocol(&hints) = _C_IPPROTO_TCP
	case "udp", "udp4", "udp6":
		*_C_ai_socktype(&hints) = _C_SOCK_DGRAM
		*_C_ai_protocol(&hints) = _C_IPPROTO_UDP
	default:
		return 0, &DNSError{Err: "unknown network", Name: network + "/" + service}
	}