// newReferenceUplink returns a default uplink message
func newReferenceUplink() *pb.UplinkMessage {
	gtwID := "eui-0102030405060708"

	phy := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.UnconfirmedDataUp,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.MACPayload{
			FHDR: lorawan.FHDR{
				DevAddr: lorawan.DevAddr([4]byte{1, 2, 3, 4}),
			},
		},
	}
	bytes, _ := phy.MarshalBinary()

	up := &pb.UplinkMessage{
		Payload: bytes,
		ProtocolMetadata: &pb_protocol.RxMetadata{Protocol: &pb_protocol.RxMetadata_Lorawan{Lorawan: &pb_lorawan.Metadata{
			CodingRate: "4/5",
			DataRate:   "SF7BW125",
			Modulation: pb_lorawan.Modulation_LORA,
		}}},
		GatewayMetadata: &pb_gateway.RxMetadata{
			GatewayId: gtwID,
			Timestamp: 100,
			Frequency: 868100000,
			Rssi:      -25.0,
			Snr:       5.0,
		},
	}
	return up
}

// newRXPacketFromRXPK transforms a Semtech packet into a models.RXPacket.
func newRXPacketFromRXPK(mac lorawan.EUI64, rxpk RXPK) (models.RXPacket, error) {
	var phy lorawan.PHYPayload
	if err := phy.UnmarshalText([]byte(rxpk.Data)); err != nil {
		return models.RXPacket{}, fmt.Errorf("gateway: could not unmarshal PHYPayload: %s", err)
	}

	dataRate, err := newDataRateFromDatR(rxpk.DatR)
	if err != nil {
		return models.RXPacket{}, fmt.Errorf("gateway: could not get DataRate from DatR: %s", err)
	}

	rxPacket := models.RXPacket{
		PHYPayload: phy,
		RXInfo: models.RXInfo{
			MAC:       mac,
			Time:      time.Time(rxpk.Time),
			Timestamp: rxpk.Tmst,
			Frequency: int(rxpk.Freq * 1000000),
			Channel:   int(rxpk.Chan),
			RFChain:   int(rxpk.RFCh),
			CRCStatus: int(rxpk.Stat),
			DataRate:  dataRate,
			CodeRate:  rxpk.CodR,
			RSSI:      int(rxpk.RSSI),
			LoRaSNR:   rxpk.LSNR,
			Size:      int(rxpk.Size),
		},
	}
	return rxPacket, nil
}

func msgFromPayload(payload []byte) (*pb_protocol.Message, error) {
	var phy lorawan.PHYPayload
	if err := phy.UnmarshalBinary(payload); err != nil {
		return nil, err
	}
	msg := pb_lorawan.MessageFromPHYPayload(phy)
	return &pb_protocol.Message{Protocol: &pb_protocol.Message_Lorawan{Lorawan: &msg}}, nil
}

// UnmarshalPayload unmarshals the Payload into Message if Message is nil
func (m *DeviceActivationResponse) UnmarshalPayload() error {
	if m.GetMessage() == nil && m.GetDownlinkOption() != nil && m.DownlinkOption.GetProtocolConfig() != nil && m.DownlinkOption.ProtocolConfig.GetLorawan() != nil {
		var phy lorawan.PHYPayload
		if err := phy.UnmarshalBinary(m.Payload); err != nil {
			return err
		}
		msg := pb_lorawan.MessageFromPHYPayload(phy)
		m.Message = &pb_protocol.Message{Protocol: &pb_protocol.Message_Lorawan{Lorawan: &msg}}
	}
	return nil
}

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
}

func doTestHandleActivation(h *handler, appEUI types.AppEUI, devEUI types.DevEUI, devNonce [2]byte, appKey types.AppKey) (*pb.DeviceActivationResponse, error) {
	devAddr := types.DevAddr{1, 2, 3, 4}

	requestPHY := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.JoinRequest,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.JoinRequestPayload{
			AppEUI:   lorawan.EUI64(appEUI),
			DevEUI:   lorawan.EUI64(devEUI),
			DevNonce: devNonce,
		},
	}
	requestPHY.SetMIC(lorawan.AES128Key(appKey))
	requestBytes, _ := requestPHY.MarshalBinary()

	responsePHY := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.JoinAccept,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.JoinAcceptPayload{},
	}
	templateBytes, _ := responsePHY.MarshalBinary()
	return h.HandleActivation(&pb_broker.DeduplicatedDeviceActivationRequest{
		Payload: requestBytes,
		AppEui:  &appEUI,
		AppId:   appEUI.String(),
		DevEui:  &devEUI,
		DevId:   devEUI.String(),
		ActivationMetadata: &pb_protocol.ActivationMetadata{Protocol: &pb_protocol.ActivationMetadata_Lorawan{
			Lorawan: &pb_lorawan.ActivationMetadata{
				DevAddr: &devAddr,
			},
		}},
		ResponseTemplate: &pb_broker.DeviceActivationResponse{
			Payload: templateBytes,
		},
	})
}

func TestHandleUplink(t *testing.T) {
	a := New(t)
	ns := &networkServer{
		devices: device.NewRedisDeviceStore(GetRedisClient(), "ns-test-handle-uplink"),
	}
	ns.InitStatus()

	appEUI := types.AppEUI(getEUI(1, 2, 3, 4, 5, 6, 7, 8))
	devEUI := types.DevEUI(getEUI(1, 2, 3, 4, 5, 6, 7, 8))
	devAddr := getDevAddr(1, 2, 3, 4)

	// Device Not Found
	message := &pb_broker.DeduplicatedUplinkMessage{
		AppEui:  &appEUI,
		DevEui:  &devEUI,
		Payload: []byte{},
	}
	_, err := ns.HandleUplink(message)
	a.So(err, ShouldNotBeNil)

	ns.devices.Set(&device.Device{
		DevAddr: devAddr,
		AppEUI:  appEUI,
		DevEUI:  devEUI,
	})
	defer func() {
		ns.devices.Delete(appEUI, devEUI)
	}()

	// Invalid Payload
	message = &pb_broker.DeduplicatedUplinkMessage{
		AppEui:  &appEUI,
		DevEui:  &devEUI,
		Payload: []byte{},
	}
	_, err = ns.HandleUplink(message)
	a.So(err, ShouldNotBeNil)

	phy := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.UnconfirmedDataUp,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.MACPayload{
			FHDR: lorawan.FHDR{
				DevAddr: lorawan.DevAddr([4]byte{1, 2, 3, 4}),
				FCnt:    1,
				FCtrl: lorawan.FCtrl{
					ADR:       true,
					ADRACKReq: true,
				},
				FOpts: []lorawan.MACCommand{
					lorawan.MACCommand{CID: lorawan.LinkCheckReq},
				},
			},
		},
	}
	bytes, _ := phy.MarshalBinary()

	// Valid Uplink
	message = &pb_broker.DeduplicatedUplinkMessage{
		AppEui:           &appEUI,
		DevEui:           &devEUI,
		Payload:          bytes,
		ResponseTemplate: &pb_broker.DownlinkMessage{},
		GatewayMetadata: []*pb_gateway.RxMetadata{
			&pb_gateway.RxMetadata{},
		},
		ProtocolMetadata: &pb_protocol.RxMetadata{Protocol: &pb_protocol.RxMetadata_Lorawan{
			Lorawan: &pb_lorawan.Metadata{
				DataRate: "SF7BW125",
			},
		}},
	}
	res, err := ns.HandleUplink(message)
	a.So(err, ShouldBeNil)
	a.So(res.ResponseTemplate, ShouldNotBeNil)

	// LoRaWAN: Unmarshal
	var phyPayload lorawan.PHYPayload
	phyPayload.UnmarshalBinary(res.ResponseTemplate.Payload)
	macPayload, _ := phyPayload.MACPayload.(*lorawan.MACPayload)

	// ResponseTemplate DevAddr should match
	a.So([4]byte(macPayload.FHDR.DevAddr), ShouldEqual, [4]byte(devAddr))

	// ResponseTemplate should ACK the ADRACKReq
	a.So(macPayload.FHDR.FCtrl.ACK, ShouldBeTrue)
	a.So(macPayload.FHDR.FOpts, ShouldHaveLength, 1)
	a.So(macPayload.FHDR.FOpts[0].Payload, ShouldResemble, &lorawan.LinkCheckAnsPayload{GwCnt: 1, Margin: 7})

	// Frame Counter should have been updated
	dev, _ := ns.devices.Get(appEUI, devEUI)
	a.So(dev.FCntUp, ShouldEqual, 1)
	a.So(time.Now().Sub(dev.LastSeen), ShouldBeLessThan, 1*time.Second)
}

func (b *broker) HandleActivation(activation *pb.DeviceActivationRequest) (res *pb.DeviceActivationResponse, err error) {
	ctx := b.Ctx.WithFields(log.Fields{
		"GatewayID": activation.GatewayMetadata.GatewayId,
		"AppEUI":    *activation.AppEui,
		"DevEUI":    *activation.DevEui,
	})
	start := time.Now()
	defer func() {
		if err != nil {
			ctx.WithError(err).Warn("Could not handle activation")
		} else {
			ctx.WithField("Duration", time.Now().Sub(start)).Info("Handled activation")
		}
	}()

	time := time.Now()

	b.status.activations.Mark(1)

	// De-duplicate uplink messages
	duplicates := b.deduplicateActivation(activation)
	if len(duplicates) == 0 {
		return nil, errDuplicateActivation
	}

	b.status.activationsUnique.Mark(1)

	base := duplicates[0]

	// Collect GatewayMetadata and DownlinkOptions
	var gatewayMetadata []*gateway.RxMetadata
	var downlinkOptions []*pb.DownlinkOption
	var deviceActivationResponse *pb.DeviceActivationResponse
	for _, duplicate := range duplicates {
		gatewayMetadata = append(gatewayMetadata, duplicate.GatewayMetadata)
		downlinkOptions = append(downlinkOptions, duplicate.DownlinkOptions...)
	}

	// Select best DownlinkOption
	if len(downlinkOptions) > 0 {
		deviceActivationResponse = &pb.DeviceActivationResponse{
			DownlinkOption: selectBestDownlink(downlinkOptions),
		}
	}

	// Build Uplink
	deduplicatedActivationRequest := &pb.DeduplicatedDeviceActivationRequest{
		Payload:            base.Payload,
		DevEui:             base.DevEui,
		AppEui:             base.AppEui,
		ProtocolMetadata:   base.ProtocolMetadata,
		GatewayMetadata:    gatewayMetadata,
		ActivationMetadata: base.ActivationMetadata,
		ServerTime:         time.UnixNano(),
		ResponseTemplate:   deviceActivationResponse,
	}

	// Send Activate to NS
	deduplicatedActivationRequest, err = b.ns.PrepareActivation(b.Component.GetContext(b.nsToken), deduplicatedActivationRequest)
	if err != nil {
		return nil, errors.Wrap(errors.FromGRPCError(err), "NetworkServer refused to prepare activation")
	}

	ctx = ctx.WithFields(log.Fields{
		"AppID": deduplicatedActivationRequest.AppId,
		"DevID": deduplicatedActivationRequest.DevId,
	})

	// Find Handler (based on AppEUI)
	var announcements []*pb_discovery.Announcement
	announcements, err = b.Discovery.GetAllHandlersForAppID(deduplicatedActivationRequest.AppId)
	if err != nil {
		return nil, err
	}
	if len(announcements) == 0 {
		return nil, errors.NewErrNotFound(fmt.Sprintf("Handler for AppID %s", deduplicatedActivationRequest.AppId))
	}

	ctx = ctx.WithField("NumHandlers", len(announcements))

	// LoRaWAN: Unmarshal and prepare version without MIC
	var phyPayload lorawan.PHYPayload
	err = phyPayload.UnmarshalBinary(deduplicatedActivationRequest.Payload)
	if err != nil {
		return nil, err
	}
	correctMIC := phyPayload.MIC
	phyPayload.MIC = [4]byte{0, 0, 0, 0}
	phyPayloadWithoutMIC, err := phyPayload.MarshalBinary()
	if err != nil {
		return nil, err
	}

	// Build Challenge
	challenge := &pb.ActivationChallengeRequest{
		Payload: phyPayloadWithoutMIC,
		AppId:   deduplicatedActivationRequest.AppId,
		DevId:   deduplicatedActivationRequest.DevId,
		AppEui:  deduplicatedActivationRequest.AppEui,
		DevEui:  deduplicatedActivationRequest.DevEui,
//.........这里部分代码省略.........

func (b *broker) HandleUplink(uplink *pb.UplinkMessage) (err error) {
	ctx := b.Ctx.WithField("GatewayID", uplink.GatewayMetadata.GatewayId)
	start := time.Now()
	defer func() {
		if err != nil {
			ctx.WithError(err).Warn("Could not handle uplink")
		} else {
			ctx.WithField("Duration", time.Now().Sub(start)).Info("Handled uplink")
		}
	}()

	time := time.Now()

	b.status.uplink.Mark(1)

	// De-duplicate uplink messages
	duplicates := b.deduplicateUplink(uplink)
	if len(duplicates) == 0 {
		return nil
	}

	b.status.uplinkUnique.Mark(1)

	ctx = ctx.WithField("Duplicates", len(duplicates))

	base := duplicates[0]

	if base.ProtocolMetadata.GetLorawan() == nil {
		return errors.NewErrInvalidArgument("Uplink", "does not contain LoRaWAN metadata")
	}

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

	// Request devices from NS
	devAddr := types.DevAddr(macPayload.FHDR.DevAddr)
	ctx = ctx.WithFields(log.Fields{
		"DevAddr": devAddr,
		"FCnt":    macPayload.FHDR.FCnt,
	})
	var getDevicesResp *networkserver.DevicesResponse
	getDevicesResp, err = b.ns.GetDevices(b.Component.GetContext(b.nsToken), &networkserver.DevicesRequest{
		DevAddr: &devAddr,
		FCnt:    macPayload.FHDR.FCnt,
	})
	if err != nil {
		return errors.Wrap(errors.FromGRPCError(err), "NetworkServer did not return devices")
	}
	b.status.deduplication.Update(int64(len(getDevicesResp.Results)))
	if len(getDevicesResp.Results) == 0 {
		return errors.NewErrNotFound(fmt.Sprintf("Device with DevAddr %s and FCnt <= %d", devAddr, macPayload.FHDR.FCnt))
	}
	ctx = ctx.WithField("DevAddrResults", len(getDevicesResp.Results))

	// Sort by FCntUp to optimize the number of MIC checks
	sort.Sort(ByFCntUp(getDevicesResp.Results))

	// Find AppEUI/DevEUI through MIC check
	var device *pb_lorawan.Device
	var micChecks int
	var originalFCnt uint32
	for _, candidate := range getDevicesResp.Results {
		nwkSKey := lorawan.AES128Key(*candidate.NwkSKey)

		// First check with the 16 bit counter
		micChecks++
		ok, err = phyPayload.ValidateMIC(nwkSKey)
		if err != nil {
			return err
		}
		if ok {
			device = candidate
			break
		}

		originalFCnt = macPayload.FHDR.FCnt
		if candidate.Uses32BitFCnt {
			macPayload.FHDR.FCnt = fcnt.GetFull(candidate.FCntUp, uint16(originalFCnt))

			// If 32 bit counter has different value, perform another MIC check
			if macPayload.FHDR.FCnt != originalFCnt {
				micChecks++
				ok, err = phyPayload.ValidateMIC(nwkSKey)
				if err != nil {
					return err
				}
				if ok {
					device = candidate
					break
				}
			}
		}
//.........这里部分代码省略.........

func handleDataDownReply(ctx Context, rxPacket models.RXPacket, ns models.NodeSession) error {
	macPL, ok := rxPacket.PHYPayload.MACPayload.(*lorawan.MACPayload)
	if !ok {
		return fmt.Errorf("expected *lorawan.MACPayload, got: %T", rxPacket.PHYPayload.MACPayload)
	}

	// the last payload was received by the node
	if macPL.FHDR.FCtrl.ACK {
		txPayload, err := clearInProcessTXPayload(ctx.RedisPool, ns.DevEUI)
		if err != nil {
			return err
		}
		ns.FCntDown++
		if err = saveNodeSession(ctx.RedisPool, ns); err != nil {
			return err
		}
		if txPayload != nil {
			err = ctx.Application.SendNotification(ns.DevEUI, ns.AppEUI, models.ACKNotificationType, models.ACKNotification{
				Reference: txPayload.Reference,
				DevEUI:    ns.DevEUI,
			})
			if err != nil {
				return err
			}
		}
	}

	// check if there are payloads pending in the queue
	txPayload, remaining, err := getTXPayloadAndRemainingFromQueue(ctx.RedisPool, ns.DevEUI)
	if err != nil {
		return err
	}

	// nothing pending in the queue and no need to ACK RXPacket
	if rxPacket.PHYPayload.MHDR.MType != lorawan.ConfirmedDataUp && txPayload == nil {
		return nil
	}

	// get TX DR
	uplinkDR, err := Band.GetDataRate(rxPacket.RXInfo.DataRate)
	if err != nil {
		return err
	}
	// get TX channel
	uplinkChannel, err := Band.GetChannel(rxPacket.RXInfo.Frequency, uplinkDR)
	if err != nil {
		return err
	}
	// get RX1 channel
	rx1Channel := Band.GetRX1Channel(uplinkChannel)
	// get RX1 DR
	rx1DR, err := Band.GetRX1DataRateForOffset(uplinkDR, int(ns.RX1DROffset))
	if err != nil {
		return err
	}
	// get rx delay
	rxDelay := Band.ReceiveDelay1
	if ns.RXDelay > 0 {
		rxDelay = time.Duration(ns.RXDelay) * time.Second
	}

	phy := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.UnconfirmedDataDown,
			Major: lorawan.LoRaWANR1,
		},
	}
	macPL = &lorawan.MACPayload{
		FHDR: lorawan.FHDR{
			DevAddr: ns.DevAddr,
			FCtrl: lorawan.FCtrl{
				ACK: rxPacket.PHYPayload.MHDR.MType == lorawan.ConfirmedDataUp, // set ACK to true when received packet needs an ACK
			},
			FCnt: ns.FCntDown,
		},
	}
	phy.MACPayload = macPL

	// add the payload from the queue
	if txPayload != nil {
		// validate the max payload size
		if len(txPayload.Data) > Band.MaxPayloadSize[rx1DR].N {
			// remove the payload from the queue regarding confirmed or not
			if _, err := clearInProcessTXPayload(ctx.RedisPool, ns.DevEUI); err != nil {
				return err
			}

			log.WithFields(log.Fields{
				"dev_eui":             ns.DevEUI,
				"data_rate":           rx1DR,
				"frmpayload_size":     len(txPayload.Data),
				"max_frmpayload_size": Band.MaxPayloadSize[rx1DR].N,
			}).Warning("downlink payload max size exceeded")
			err = ctx.Application.SendNotification(ns.DevEUI, ns.AppEUI, models.ErrorNotificationType, models.ErrorNotification{
				Reference: txPayload.Reference,
				DevEUI:    ns.DevEUI,
				Message:   fmt.Sprintf("downlink payload max size exceeded (dr: %d, allowed: %d, got: %d)", rx1DR, Band.MaxPayloadSize[rx1DR].N, len(txPayload.Data)),
			})
			if err != nil {
				return err
//.........这里部分代码省略.........

// handleCollectedJoinRequestPackets handles the received join-request.
func handleCollectedJoinRequestPackets(ctx Context, rxPackets RXPackets) error {
	if len(rxPackets) == 0 {
		return errors.New("packet collector returned 0 packets")
	}
	rxPacket := rxPackets[0]

	var macs []string
	for _, p := range rxPackets {
		macs = append(macs, p.RXInfo.MAC.String())
	}

	// MACPayload must be of type *lorawan.JoinRequestPayload
	jrPL, ok := rxPacket.PHYPayload.MACPayload.(*lorawan.JoinRequestPayload)
	if !ok {
		return fmt.Errorf("expected *lorawan.JoinRequestPayload, got: %T", rxPacket.PHYPayload.MACPayload)
	}

	log.WithFields(log.Fields{
		"dev_eui":  jrPL.DevEUI,
		"gw_count": len(rxPackets),
		"gw_macs":  strings.Join(macs, ", "),
		"mtype":    rxPackets[0].PHYPayload.MHDR.MType,
	}).Info("packet(s) collected")

	// get node information for this DevEUI
	node, err := getNode(ctx.DB, jrPL.DevEUI)
	if err != nil {
		return err
	}

	// validate the given nonce
	if !node.ValidateDevNonce(jrPL.DevNonce) {
		return fmt.Errorf("given dev-nonce %x has already been used before for node %s", jrPL.DevNonce, jrPL.DevEUI)
	}

	// get random (free) DevAddr
	devAddr, err := getRandomDevAddr(ctx.RedisPool, ctx.NetID)
	if err != nil {
		return fmt.Errorf("get random DevAddr error: %s", err)
	}

	// get app nonce
	appNonce, err := getAppNonce()
	if err != nil {
		return fmt.Errorf("get AppNonce error: %s", err)
	}

	// get the (optional) CFList
	cFList, err := getCFListForNode(ctx.DB, node)
	if err != nil {
		return fmt.Errorf("get CFList for node error: %s", err)
	}

	// get keys
	nwkSKey, err := getNwkSKey(node.AppKey, ctx.NetID, appNonce, jrPL.DevNonce)
	if err != nil {
		return fmt.Errorf("get NwkSKey error: %s", err)
	}
	appSKey, err := getAppSKey(node.AppKey, ctx.NetID, appNonce, jrPL.DevNonce)
	if err != nil {
		return fmt.Errorf("get AppSKey error: %s", err)
	}

	ns := models.NodeSession{
		DevAddr:  devAddr,
		DevEUI:   jrPL.DevEUI,
		AppSKey:  appSKey,
		NwkSKey:  nwkSKey,
		FCntUp:   0,
		FCntDown: 0,

		AppEUI:      node.AppEUI,
		RXDelay:     node.RXDelay,
		RX1DROffset: node.RX1DROffset,
	}
	if err = saveNodeSession(ctx.RedisPool, ns); err != nil {
		return fmt.Errorf("save node-session error: %s", err)
	}

	// update the node (with updated used dev-nonces)
	if err = updateNode(ctx.DB, node); err != nil {
		return fmt.Errorf("update node error: %s", err)
	}

	// construct the lorawan packet
	phy := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.JoinAccept,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.JoinAcceptPayload{
			AppNonce: appNonce,
			NetID:    ctx.NetID,
			DevAddr:  ns.DevAddr,
			RXDelay:  ns.RXDelay,
			DLSettings: lorawan.DLSettings{
				RX2DataRate: uint8(Band.RX2DataRate),
				RX1DROffset: ns.RX1DROffset,
			},
//.........这里部分代码省略.........

func (n *networkServer) HandlePrepareActivation(activation *pb_broker.DeduplicatedDeviceActivationRequest) (*pb_broker.DeduplicatedDeviceActivationRequest, error) {
	if activation.AppEui == nil || activation.DevEui == nil {
		return nil, errors.NewErrInvalidArgument("Activation", "missing AppEUI or DevEUI")
	}
	dev, err := n.devices.Get(*activation.AppEui, *activation.DevEui)
	if err != nil {
		return nil, err
	}
	activation.AppId = dev.AppID
	activation.DevId = dev.DevID

	// Get activation constraints (for DevAddr prefix selection)
	activationConstraints := strings.Split(dev.Options.ActivationConstraints, ",")
	if len(activationConstraints) == 1 && activationConstraints[0] == "" {
		activationConstraints = []string{}
	}
	activationConstraints = append(activationConstraints, "otaa")

	// Build activation metadata if not present
	if meta := activation.GetActivationMetadata(); meta == nil {
		activation.ActivationMetadata = &pb_protocol.ActivationMetadata{}
	}
	// Build lorawan metadata if not present
	if lorawan := activation.ActivationMetadata.GetLorawan(); lorawan == nil {
		return nil, errors.NewErrInvalidArgument("Activation", "missing LoRaWAN metadata")
	}

	// Build response template if not present
	if pld := activation.GetResponseTemplate(); pld == nil {
		return nil, errors.NewErrInvalidArgument("Activation", "missing response template")
	}
	lorawanMeta := activation.ActivationMetadata.GetLorawan()

	// Get a random device address
	devAddr, err := n.getDevAddr(activationConstraints...)
	if err != nil {
		return nil, err
	}

	// Set the DevAddr in the Activation Metadata
	lorawanMeta.DevAddr = &devAddr

	// Build JoinAccept Payload
	phy := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.JoinAccept,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.JoinAcceptPayload{
			NetID:      n.netID,
			DLSettings: lorawan.DLSettings{RX2DataRate: uint8(lorawanMeta.Rx2Dr), RX1DROffset: uint8(lorawanMeta.Rx1DrOffset)},
			RXDelay:    uint8(lorawanMeta.RxDelay),
			DevAddr:    lorawan.DevAddr(devAddr),
		},
	}
	if lorawanMeta.CfList != nil {
		var cfList lorawan.CFList
		for i, cfListItem := range lorawanMeta.CfList.Freq {
			cfList[i] = cfListItem
		}
		phy.MACPayload.(*lorawan.JoinAcceptPayload).CFList = &cfList
	}

	// Set the Payload
	phyBytes, err := phy.MarshalBinary()
	if err != nil {
		return nil, err
	}
	activation.ResponseTemplate.Payload = phyBytes

	return activation, nil
}

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
}

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
}

func handleDataDownReply(ctx Context, rxPacket models.RXPacket, ns models.NodeSession) error {
	macPL, ok := rxPacket.PHYPayload.MACPayload.(*lorawan.MACPayload)
	if !ok {
		return fmt.Errorf("expected *lorawan.MACPayload, got: %T", rxPacket.PHYPayload.MACPayload)
	}

	// get data down properies
	properties, err := getDataDownProperties(rxPacket.RXInfo, ns)
	if err != nil {
		return fmt.Errorf("get data down properties error: %s", err)
	}

	var frmMACCommands bool
	var macPayloads []models.MACPayload
	allMACPayloads, err := storage.ReadMACPayloadTXQueue(ctx.RedisPool, ns.DevAddr)
	if err != nil {
		return fmt.Errorf("read mac-payload tx queue error: %s", err)
	}

	if len(allMACPayloads) > 0 {
		if allMACPayloads[0].FRMPayload {
			// the first mac-commands must be sent as FRMPayload, filter the rest
			// of the MACPayload items with the same property, respecting the
			// max FRMPayload size for the data-rate.
			frmMACCommands = true
			macPayloads = storage.FilterMACPayloads(allMACPayloads, true, common.Band.MaxPayloadSize[properties.rx1DR].N)
		} else {
			// the first mac-command must be sent as FOpts, filter the rest of
			// the MACPayload items with the same property, respecting the
			// max FOpts size of 15.
			macPayloads = storage.FilterMACPayloads(allMACPayloads, false, 15)
		}
	}

	// if the MACCommands (if any) are not sent as FRMPayload, check if there
	// is a tx-payload in the queue and validate if the FOpts + FRMPayload
	// does not exceed the max payload size.
	var txPayload *models.TXPayload
	if !frmMACCommands {
		// check if there are payloads pending in the queue
		txPayload, err = getNextValidTXPayloadForDRFromQueue(ctx, ns, properties.rx1DR)
		if err != nil {
			return fmt.Errorf("get next valid tx-payload error: %s", err)
		}

		var macByteCount int
		for _, mac := range macPayloads {
			macByteCount += len(mac.MACCommand)
		}

		if txPayload != nil && len(txPayload.Data)+macByteCount > common.Band.MaxPayloadSize[properties.rx1DR].N {
			log.WithFields(log.Fields{
				"data_rate": properties.rx1DR,
				"dev_eui":   ns.DevEUI,
				"reference": txPayload.Reference,
			}).Info("scheduling tx-payload for next downlink, mac-commands + payload exceeds max size")
			txPayload = nil
		}
	}

	// convert the MACPayload items into MACCommand items
	var macCommmands []lorawan.MACCommand
	for _, pl := range macPayloads {
		var mac lorawan.MACCommand
		if err := mac.UnmarshalBinary(false, pl.MACCommand); err != nil {
			// in case the mac commands can't be unmarshaled, the payload
			// is ignored and an error sent to the network-controller
			errStr := fmt.Sprintf("unmarshal mac command error: %s", err)
			log.WithFields(log.Fields{
				"dev_eui":   ns.DevEUI,
				"reference": pl.Reference,
			}).Warning(errStr)
			err = ctx.Controller.SendErrorPayload(ns.AppEUI, ns.DevEUI, models.ErrorPayload{
				Reference: pl.Reference,
				DevEUI:    ns.DevEUI,
				Message:   errStr,
			})
			if err != nil {
				return fmt.Errorf("send error payload to network-controller error: %s", err)
			}
			continue
		}
		macCommmands = append(macCommmands, mac)
	}

	// uplink was unconfirmed and no downlink data in queue and no mac commands to send
	if txPayload == nil && rxPacket.PHYPayload.MHDR.MType == lorawan.UnconfirmedDataUp && len(macCommmands) == 0 {
		return nil
	}

	// get the queue size (the size includes the current payload)
	queueSize, err := storage.GetTXPayloadQueueSize(ctx.RedisPool, ns.DevEUI)
	if err != nil {
		return err
	}
	if txPayload != nil {
		queueSize-- // substract the current tx-payload from the queue-size
	}

	phy := lorawan.PHYPayload{
//.........这里部分代码省略.........

func TestHandlePrepareActivation(t *testing.T) {
	a := New(t)
	ns := &networkServer{
		netID: [3]byte{0x00, 0x00, 0x13},
		prefixes: map[types.DevAddrPrefix][]string{
			types.DevAddrPrefix{DevAddr: [4]byte{0x26, 0x00, 0x00, 0x00}, Length: 7}: []string{
				"otaa",
				"local",
			},
		},
		devices: device.NewRedisDeviceStore(GetRedisClient(), "test-handle-prepare-activation"),
	}

	appEUI := types.AppEUI(getEUI(2, 2, 3, 4, 5, 6, 7, 8))
	devEUI := types.DevEUI(getEUI(2, 2, 3, 4, 5, 6, 7, 8))

	// Device not registered
	resp, err := ns.HandlePrepareActivation(&pb_broker.DeduplicatedDeviceActivationRequest{
		ActivationMetadata: &pb_protocol.ActivationMetadata{Protocol: &pb_protocol.ActivationMetadata_Lorawan{
			Lorawan: &pb_lorawan.ActivationMetadata{
				CfList: &pb_lorawan.CFList{Freq: []uint32{867100000, 867300000, 867500000, 867700000, 867900000}},
			},
		}},
		ResponseTemplate: &pb_broker.DeviceActivationResponse{},
	})
	a.So(err, ShouldNotBeNil)

	dev := &device.Device{AppEUI: appEUI, DevEUI: devEUI, Options: device.Options{
		ActivationConstraints: "private",
	}}
	a.So(ns.devices.Set(dev), ShouldBeNil)

	defer func() {
		ns.devices.Delete(appEUI, devEUI)
	}()

	// Constrained Device
	resp, err = ns.HandlePrepareActivation(&pb_broker.DeduplicatedDeviceActivationRequest{
		DevEui: &devEUI,
		AppEui: &appEUI,
		ActivationMetadata: &pb_protocol.ActivationMetadata{Protocol: &pb_protocol.ActivationMetadata_Lorawan{
			Lorawan: &pb_lorawan.ActivationMetadata{
				CfList: &pb_lorawan.CFList{Freq: []uint32{867100000, 867300000, 867500000, 867700000, 867900000}},
			},
		}},
		ResponseTemplate: &pb_broker.DeviceActivationResponse{},
	})
	a.So(err, ShouldNotBeNil)

	dev.StartUpdate()
	dev.Options = device.Options{}
	a.So(ns.devices.Set(dev), ShouldBeNil)

	// Device registered
	resp, err = ns.HandlePrepareActivation(&pb_broker.DeduplicatedDeviceActivationRequest{
		DevEui: &devEUI,
		AppEui: &appEUI,
		ActivationMetadata: &pb_protocol.ActivationMetadata{Protocol: &pb_protocol.ActivationMetadata_Lorawan{
			Lorawan: &pb_lorawan.ActivationMetadata{
				CfList: &pb_lorawan.CFList{Freq: []uint32{867100000, 867300000, 867500000, 867700000, 867900000}},
			},
		}},
		ResponseTemplate: &pb_broker.DeviceActivationResponse{},
	})
	a.So(err, ShouldBeNil)
	devAddr := resp.ActivationMetadata.GetLorawan().DevAddr
	a.So(devAddr.IsEmpty(), ShouldBeFalse)
	a.So(devAddr[0]&254, ShouldEqual, 19<<1) // 7 MSB should be NetID

	var resPHY lorawan.PHYPayload
	resPHY.UnmarshalBinary(resp.ResponseTemplate.Payload)
	resMAC, _ := resPHY.MACPayload.(*lorawan.DataPayload)
	joinAccept := &lorawan.JoinAcceptPayload{}
	joinAccept.UnmarshalBinary(false, resMAC.Bytes)

	a.So(joinAccept.DevAddr[0]&254, ShouldEqual, 19<<1)
	a.So(*joinAccept.CFList, ShouldEqual, lorawan.CFList{867100000, 867300000, 867500000, 867700000, 867900000})
}

func TestHandleJoinRequestPackets(t *testing.T) {
	conf := common.GetTestConfig()

	Convey("Given a dummy gateway and application backend and a clean Postgres and Redis database", t, func() {
		a := &testApplicationBackend{
			rxPayloadChan:           make(chan models.RXPayload, 1),
			notificationPayloadChan: make(chan interface{}, 10),
		}
		g := &testGatewayBackend{
			rxPacketChan: make(chan models.RXPacket, 1),
			txPacketChan: make(chan models.TXPacket, 1),
		}
		p := storage.NewRedisPool(conf.RedisURL)
		common.MustFlushRedis(p)
		db, err := storage.OpenDatabase(conf.PostgresDSN)
		So(err, ShouldBeNil)
		common.MustResetDB(db)

		ctx := Context{
			RedisPool:   p,
			Gateway:     g,
			Application: a,
			DB:          db,
		}

		Convey("Given a node and application in the database", func() {
			app := models.Application{
				AppEUI: [8]byte{1, 2, 3, 4, 5, 6, 7, 8},
				Name:   "test app",
			}
			So(storage.CreateApplication(ctx.DB, app), ShouldBeNil)

			node := models.Node{
				DevEUI: [8]byte{8, 7, 6, 5, 4, 3, 2, 1},
				AppEUI: app.AppEUI,
				AppKey: [16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16},

				RXDelay:     3,
				RX1DROffset: 2,
			}
			So(storage.CreateNode(ctx.DB, node), ShouldBeNil)

			Convey("Given a JoinRequest with correct DevEUI but incorrect AppEUI", func() {
				phy := lorawan.PHYPayload{
					MHDR: lorawan.MHDR{
						MType: lorawan.JoinRequest,
						Major: lorawan.LoRaWANR1,
					},
					MACPayload: &lorawan.JoinRequestPayload{
						AppEUI:   [8]byte{1, 2, 3, 4, 5, 6, 7, 9},
						DevEUI:   node.DevEUI,
						DevNonce: [2]byte{1, 2},
					},
				}
				So(phy.SetMIC(node.AppKey), ShouldBeNil)

				rxPacket := models.RXPacket{
					PHYPayload: phy,
					RXInfo: models.RXInfo{
						Frequency: common.Band.UplinkChannels[0].Frequency,
						DataRate:  common.Band.DataRates[common.Band.UplinkChannels[0].DataRates[0]],
					},
				}

				Convey("then handleRXPacket returns an error", func() {
					So(handleRXPacket(ctx, rxPacket), ShouldResemble, errors.New("node 0807060504030201 belongs to application 0102030405060708, 0102030405060709 was given"))
				})
			})

			Convey("Given a JoinRequest packet", func() {
				phy := lorawan.PHYPayload{
					MHDR: lorawan.MHDR{
						MType: lorawan.JoinRequest,
						Major: lorawan.LoRaWANR1,
					},
					MACPayload: &lorawan.JoinRequestPayload{
						AppEUI:   app.AppEUI,
						DevEUI:   node.DevEUI,
						DevNonce: [2]byte{1, 2},
					},
				}
				So(phy.SetMIC(node.AppKey), ShouldBeNil)

				rxPacket := models.RXPacket{
					PHYPayload: phy,
					RXInfo: models.RXInfo{
						Frequency: common.Band.UplinkChannels[0].Frequency,
						DataRate:  common.Band.DataRates[common.Band.UplinkChannels[0].DataRates[0]],
					},
				}

				Convey("When calling handleRXPacket", func() {
					So(handleRXPacket(ctx, rxPacket), ShouldBeNil)

					Convey("Then a JoinAccept was sent to the node", func() {
						txPacket := <-g.txPacketChan
						phy := txPacket.PHYPayload
						So(phy.DecryptJoinAcceptPayload(node.AppKey), ShouldBeNil)
						So(phy.MHDR.MType, ShouldEqual, lorawan.JoinAccept)

//.........这里部分代码省略.........

func TestHandleDownlink(t *testing.T) {
	a := New(t)
	ns := &networkServer{
		devices: device.NewRedisDeviceStore(GetRedisClient(), "test-handle-downlink"),
	}
	ns.InitStatus()

	appEUI := types.AppEUI(getEUI(1, 2, 3, 4, 5, 6, 7, 8))
	devEUI := types.DevEUI(getEUI(1, 2, 3, 4, 5, 6, 7, 8))
	devAddr := getDevAddr(1, 2, 3, 4)

	// Device Not Found
	message := &pb_broker.DownlinkMessage{
		AppEui:  &appEUI,
		DevEui:  &devEUI,
		Payload: []byte{},
	}
	_, err := ns.HandleDownlink(message)
	a.So(err, ShouldNotBeNil)

	ns.devices.Set(&device.Device{
		DevAddr: devAddr,
		AppEUI:  appEUI,
		DevEUI:  devEUI,
	})
	defer func() {
		ns.devices.Delete(appEUI, devEUI)
	}()

	// Invalid Payload
	message = &pb_broker.DownlinkMessage{
		AppEui:  &appEUI,
		DevEui:  &devEUI,
		Payload: []byte{},
	}
	_, err = ns.HandleDownlink(message)
	a.So(err, ShouldNotBeNil)

	fPort := uint8(3)
	phy := lorawan.PHYPayload{
		MHDR: lorawan.MHDR{
			MType: lorawan.UnconfirmedDataDown,
			Major: lorawan.LoRaWANR1,
		},
		MACPayload: &lorawan.MACPayload{
			FPort: &fPort,
			FHDR: lorawan.FHDR{
				FCtrl: lorawan.FCtrl{
					ACK: true,
				},
			},
		},
	}
	bytes, _ := phy.MarshalBinary()

	message = &pb_broker.DownlinkMessage{
		AppEui:  &appEUI,
		DevEui:  &devEUI,
		Payload: bytes,
	}
	res, err := ns.HandleDownlink(message)
	a.So(err, ShouldBeNil)

	var phyPayload lorawan.PHYPayload
	phyPayload.UnmarshalBinary(res.Payload)
	macPayload, _ := phyPayload.MACPayload.(*lorawan.MACPayload)
	a.So(*macPayload.FPort, ShouldEqual, 3)
	a.So(macPayload.FHDR.DevAddr, ShouldEqual, lorawan.DevAddr{1, 2, 3, 4})
	a.So(macPayload.FHDR.FCnt, ShouldEqual, 0)                // The first Frame counter is zero
	a.So(phyPayload.MIC, ShouldNotEqual, [4]byte{0, 0, 0, 0}) // MIC should be set, we'll check it with actual examples in the integration test

	dev, _ := ns.devices.Get(appEUI, devEUI)
	a.So(dev.FCntDown, ShouldEqual, 1)

}