func decodePacket()

in ntp/chrony/packet.go [695:780]
86 lines of code
17 McCabe index (conditional complexity)

func decodePacket(response []byte) (ResponsePacket, error) {
	var err error
	r := bytes.NewReader(response)
	head := new(ReplyHead)
	if err = binary.Read(r, binary.BigEndian, head); err != nil {
		return nil, err
	}
	log.Debugf("response head: %+v", head)
	if head.Status != sttSuccess {
		return nil, fmt.Errorf("got status %s (%d)", head.Status, head.Status)
	}
	switch head.Reply {
	case rpyNSources:
		data := new(replySourcesContent)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplySources{
			ReplyHead: *head,
			NSources:  int(data.NSources),
		}, nil
	case rpySourceData:
		data := new(replySourceDataContent)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplySourceData{
			ReplyHead:  *head,
			SourceData: *newSourceData(data),
		}, nil
	case rpyTracking:
		data := new(replyTrackingContent)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplyTracking{
			ReplyHead: *head,
			Tracking:  *newTracking(data),
		}, nil
	case rpySourceStats:
		data := new(replySourceStatsContent)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplySourceStats{
			ReplyHead:   *head,
			SourceStats: *newSourceStats(data),
		}, nil
	case rpyServerStats:
		data := new(ServerStats)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplyServerStats{
			ReplyHead:   *head,
			ServerStats: *data,
		}, nil
	case rpyNTPData:
		data := new(replyNTPDataContent)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplyNTPData{
			ReplyHead: *head,
			NTPData:   *newNTPData(data),
		}, nil
	case rpyServerStats2:
		data := new(ServerStats2)
		if err = binary.Read(r, binary.BigEndian, data); err != nil {
			return nil, err
		}
		log.Debugf("response data: %+v", data)
		return &ReplyServerStats2{
			ReplyHead:    *head,
			ServerStats2: *data,
		}, nil
	default:
		return nil, fmt.Errorf("not implemented reply type %d from %+v", head.Reply, head)
	}
}