コード例 #1
0
ファイル: downlink.go プロジェクト: TheThingsNetwork/ttn
func (n *networkServer) HandleDownlink(message *pb_broker.DownlinkMessage) (*pb_broker.DownlinkMessage, error) {
	// Get Device
	dev, err := n.devices.Get(*message.AppEui, *message.DevEui)
	if err != nil {
		return nil, err
	}

	n.status.downlink.Mark(1)

	dev.StartUpdate()

	if dev.AppID != message.AppId || dev.DevID != message.DevId {
		return nil, errors.NewErrInvalidArgument("Downlink", "AppID and DevID do not match AppEUI and DevEUI")
	}

	// Unmarshal LoRaWAN Payload
	var phyPayload lorawan.PHYPayload
	err = phyPayload.UnmarshalBinary(message.Payload)
	if err != nil {
		return nil, err
	}
	macPayload, ok := phyPayload.MACPayload.(*lorawan.MACPayload)
	if !ok {
		return nil, errors.NewErrInvalidArgument("Downlink", "does not contain a MAC payload")
	}

	// Set DevAddr
	macPayload.FHDR.DevAddr = lorawan.DevAddr(dev.DevAddr)

	// FIRST set and THEN increment FCntDown
	// TODO: For confirmed downlink, FCntDown should be incremented AFTER ACK
	macPayload.FHDR.FCnt = dev.FCntDown
	dev.FCntDown++
	err = n.devices.Set(dev)
	if err != nil {
		return nil, err
	}

	// Sign MIC
	phyPayload.SetMIC(lorawan.AES128Key(dev.NwkSKey))

	// Update message
	bytes, err := phyPayload.MarshalBinary()
	if err != nil {
		return nil, err
	}
	message.Payload = bytes

	return message, nil
}
コード例 #2
0
func (h *handler) ConvertToLoRaWAN(ctx log.Interface, appDown *types.DownlinkMessage, ttnDown *pb_broker.DownlinkMessage) error {
	// Find Device
	dev, err := h.devices.Get(appDown.AppID, appDown.DevID)
	if err != nil {
		return err
	}

	// LoRaWAN: Unmarshal Downlink
	var phyPayload lorawan.PHYPayload
	err = phyPayload.UnmarshalBinary(ttnDown.Payload)
	if err != nil {
		return err
	}
	macPayload, ok := phyPayload.MACPayload.(*lorawan.MACPayload)
	if !ok {
		return errors.NewErrInvalidArgument("Downlink", "does not contain a MAC payload")
	}
	if ttnDown.DownlinkOption != nil && ttnDown.DownlinkOption.ProtocolConfig.GetLorawan() != nil {
		macPayload.FHDR.FCnt = ttnDown.DownlinkOption.ProtocolConfig.GetLorawan().FCnt
	}

	// Abort when downlink not needed
	if len(appDown.PayloadRaw) == 0 && !macPayload.FHDR.FCtrl.ACK && len(macPayload.FHDR.FOpts) == 0 {
		return ErrNotNeeded
	}

	// Set FPort
	if appDown.FPort != 0 {
		macPayload.FPort = &appDown.FPort
	}

	// Set Payload
	if len(appDown.PayloadRaw) > 0 {
		macPayload.FRMPayload = []lorawan.Payload{&lorawan.DataPayload{Bytes: appDown.PayloadRaw}}
		if macPayload.FPort == nil || *macPayload.FPort == 0 {
			macPayload.FPort = pointer.Uint8(1)
		}
	} else {
		macPayload.FRMPayload = []lorawan.Payload{}
	}

	// Encrypt
	err = phyPayload.EncryptFRMPayload(lorawan.AES128Key(dev.AppSKey))
	if err != nil {
		return err
	}

	// Set MIC
	err = phyPayload.SetMIC(lorawan.AES128Key(dev.NwkSKey))
	if err != nil {
		return err
	}

	// Marshal
	phyPayloadBytes, err := phyPayload.MarshalBinary()
	if err != nil {
		return err
	}

	ttnDown.Payload = phyPayloadBytes

	return nil
}