Method read

pkg/encoding/lorawan/mac.go:1476–1524

(phy band.Band, r io.Reader, isUplink bool, cmd *ttnpb.MACCommand)

)

func (spec MACCommandSpec) read(phy band.Band, r io.Reader, isUplink bool, cmd *ttnpb.MACCommand) error {
	b := make([]byte, 1)
	_, err := r.Read(b)
	if err != nil {
		return err
	}

	cid := ttnpb.MACCommandIdentifier(b[0])

	desc, ok := spec[cid]
	if !ok || desc == nil {
		b, err := io.ReadAll(r)
		if err != nil {
			return err
		}

		payload := &ttnpb.MACCommand_RawPayload{
			RawPayload: b,
		}
		return cmd.SetFields(&ttnpb.MACCommand{Payload: payload, Cid: cid}, ttnpb.MACCommandFieldPathsTopLevel...)
	}

	var n uint16
	var unmarshaler func(phy band.Band, b []byte, cmd *ttnpb.MACCommand) error
	if isUplink {
		n = desc.UplinkLength
		unmarshaler = desc.UnmarshalUplink
	} else {
		n = desc.DownlinkLength
		unmarshaler = desc.UnmarshalDownlink
	}
	if unmarshaler == nil {
		return errNoUnmarshaler.WithAttributes("cid", fmt.Sprintf("0x%X", int32(cid)))
	}

	if n == 0 {
		b = nil
	} else {
		b = make([]byte, n)
		_, err = r.Read(b)
		if err != nil {
			return err
		}
	}
	if err := unmarshaler(phy, b, cmd); err != nil {
		return errDecodingMACCommand.WithAttributes("cid", fmt.Sprintf("0x%X", int32(cid))).WithCause(err)
	}
	return nil
}

// ReadUplink reads an uplink MACCommand from r into cmd and returns any errors encountered.
func (spec MACCommandSpec) ReadUplink(phy band.Band, r io.Reader, cmd *ttnpb.MACCommand) error {