示例#1
0
func (h *handler) ConvertFromLoRaWAN(ctx log.Interface, ttnUp *pb_broker.DeduplicatedUplinkMessage, appUp *types.UplinkMessage) error {
	// Find Device
	dev, err := h.devices.Get(ttnUp.AppId, ttnUp.DevId)
	if err != nil {
		return err
	}

	// Check for LoRaWAN
	if lorawan := ttnUp.ProtocolMetadata.GetLorawan(); lorawan == nil {
		return errors.NewErrInvalidArgument("Activation", "does not contain LoRaWAN metadata")
	}

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

	ctx = ctx.WithField("FCnt", appUp.FCnt)

	// LoRaWAN: Validate MIC
	ok, err = phyPayload.ValidateMIC(lorawan.AES128Key(dev.NwkSKey))
	if err != nil {
		return err
	}
	if !ok {
		return errors.NewErrNotFound("device that validates MIC")
	}

	// LoRaWAN: Decrypt
	if macPayload.FPort != nil && *macPayload.FPort != 0 && len(macPayload.FRMPayload) == 1 {
		appUp.FPort = *macPayload.FPort
		ctx = ctx.WithField("FCnt", appUp.FPort)
		if err := phyPayload.DecryptFRMPayload(lorawan.AES128Key(dev.AppSKey)); err != nil {
			return errors.NewErrInternal("Could not decrypt payload")
		}
		if len(macPayload.FRMPayload) == 1 {
			payload, ok := macPayload.FRMPayload[0].(*lorawan.DataPayload)
			if !ok {
				return errors.NewErrInvalidArgument("Uplink FRMPayload", "must be of type *lorawan.DataPayload")
			}
			appUp.PayloadRaw = payload.Bytes
		}
	}

	// LoRaWAN: Publish ACKs as events
	if macPayload.FHDR.FCtrl.ACK {
		h.mqttEvent <- &types.DeviceEvent{
			AppID: appUp.AppID,
			DevID: appUp.DevID,
			Event: types.DownlinkAckEvent,
		}
	}

	return nil
}