Set location metadata in uplink messages forwarded by the AS

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Meta information and status events in the event views in the Console.
 - Support for setting the frame counter width of an end device in the Console.
 - Include consumed airtime metadata in uplink messages and join requests (see `uplink_message.consumed_airtime` field).
+- Add end device location metadata on forwarded uplink messages (see `uplink_message.locations` field).
 
 ### Changed
 

api/api.md

@@ -355,6 +355,7 @@
   - [Message `ApplicationServiceData`](#ttn.lorawan.v3.ApplicationServiceData)
   - [Message `ApplicationUp`](#ttn.lorawan.v3.ApplicationUp)
   - [Message `ApplicationUplink`](#ttn.lorawan.v3.ApplicationUplink)
+  - [Message `ApplicationUplink.LocationsEntry`](#ttn.lorawan.v3.ApplicationUplink.LocationsEntry)
   - [Message `DownlinkMessage`](#ttn.lorawan.v3.DownlinkMessage)
   - [Message `DownlinkQueueRequest`](#ttn.lorawan.v3.DownlinkQueueRequest)
   - [Message `GatewayUplinkMessage`](#ttn.lorawan.v3.GatewayUplinkMessage)
@@ -5062,6 +5063,7 @@ Encodes and decodes uplink messages.
 | `last_a_f_cnt_down` | [`uint32`](#uint32) |  | The last AFCntDown of the current session. This field is only present if the skip_payload_crypto field of the EndDevice is true. Can be used with app_s_key to encrypt downlink payloads. |
 | `confirmed` | [`bool`](#bool) |  |  |
 | `consumed_airtime` | [`google.protobuf.Duration`](#google.protobuf.Duration) |  | Consumed airtime for the transmission of the uplink message. Calculated by Network Server using the RawPayload size and the transmission settings. |
+| `locations` | [`ApplicationUplink.LocationsEntry`](#ttn.lorawan.v3.ApplicationUplink.LocationsEntry) | repeated | End device location metadata, set by the Application Server while handling the message. |
 
 #### Field Rules
 
@@ -5072,6 +5074,13 @@ Encodes and decodes uplink messages.
 | `rx_metadata` | <p>`repeated.min_items`: `1`</p> |
 | `settings` | <p>`message.required`: `true`</p> |
 
+### <a name="ttn.lorawan.v3.ApplicationUplink.LocationsEntry">Message `ApplicationUplink.LocationsEntry`</a>
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| `key` | [`string`](#string) |  |  |
+| `value` | [`Location`](#ttn.lorawan.v3.Location) |  |  |
+
 ### <a name="ttn.lorawan.v3.DownlinkMessage">Message `DownlinkMessage`</a>
 
 Downlink message from the network to the end device

api/api.swagger.json

@@ -9174,6 +9174,13 @@
         "consumed_airtime": {
           "type": "string",
           "description": "Consumed airtime for the transmission of the uplink message. Calculated by Network Server using the RawPayload size and the transmission settings."
+        },
+        "locations": {
+          "type": "object",
+          "additionalProperties": {
+            "$ref": "#/definitions/lorawanv3Location"
+          },
+          "description": "End device location metadata, set by the Application Server while handling the message."
         }
       }
     },

api/messages.proto

@@ -209,7 +209,10 @@ message ApplicationUplink {
   // Consumed airtime for the transmission of the uplink message. Calculated by Network Server using the RawPayload size and the transmission settings.
   google.protobuf.Duration consumed_airtime = 13 [(gogoproto.stdduration) = true, (gogoproto.nullable) = true];
 
-  // next: 14
+  // End device location metadata, set by the Application Server while handling the message.
+  map<string,Location> locations = 14;
+
+  // next: 15
 }
 
 message ApplicationLocation {

pkg/applicationserver/applicationserver.go

@@ -131,6 +131,10 @@ func New(c *component.Component, conf *Config) (as *ApplicationServer, err error
 		interopID:        conf.Interop.ID,
 		endDeviceFetcher: conf.EndDeviceFetcher.Fetcher,
 	}
+
+	if as.endDeviceFetcher == nil {
+		as.endDeviceFetcher = &NoopEndDeviceFetcher{}
+	}
 	retryIO := io.NewRetryServer(as)
 
 	as.grpc.asDevices = asEndDeviceRegistryServer{
@@ -935,6 +939,13 @@ func (as *ApplicationServer) handleUplink(ctx context.Context, ids ttnpb.EndDevi
 		uplink.LastAFCntDown = dev.Session.LastAFCntDown
 	}
 
+	isDev, err := as.endDeviceFetcher.Get(ctx, ids, "locations")
+	if err != nil {
+		logger.WithError(err).Warn("Failed to retrieve end device locations")
+	} else {
+		uplink.Locations = isDev.GetLocations()
+	}
+
 	// TODO: Run uplink messages through location solvers async (https://github.com/TheThingsNetwork/lorawan-stack/issues/37)
 	return nil
 }
@@ -950,6 +961,14 @@ func (as *ApplicationServer) handleSimulatedUplink(ctx context.Context, ids ttnp
 	if err != nil {
 		return err
 	}
+
+	isDev, err := as.endDeviceFetcher.Get(ctx, ids, "locations")
+	if err != nil {
+		log.FromContext(ctx).WithError(err).Warn("Failed to retrieve end device locations")
+	} else {
+		uplink.Locations = isDev.GetLocations()
+	}
+
 	return as.decodeUplink(ctx, dev, uplink, link.DefaultFormatters)
 }
 

pkg/applicationserver/applicationserver_test.go

@@ -2249,6 +2249,9 @@ func TestSkipPayloadCrypto(t *testing.T) {
 		LinkMode: "all",
 		Devices:  deviceRegistry,
 		Links:    linkRegistry,
+		EndDeviceFetcher: applicationserver.EndDeviceFetcherConfig{
+			Fetcher: &noopEndDeviceFetcher{},
+		},
 	}
 	as, err := applicationserver.New(c, config)
 	if !a.So(err, should.BeNil) {

pkg/applicationserver/device_fetcher.go

@@ -31,6 +31,14 @@ type EndDeviceFetcher interface {
 	Get(ctx context.Context, ids ttnpb.EndDeviceIdentifiers, fieldMaskPaths ...string) (*ttnpb.EndDevice, error)
 }
 
+// NoopEndDeviceFetcher is a no-op.
+type NoopEndDeviceFetcher struct{}
+
+// Get implements the EndDeviceFetcher interface.
+func (f *NoopEndDeviceFetcher) Get(ctx context.Context, ids ttnpb.EndDeviceIdentifiers, fieldMaskPaths ...string) (*ttnpb.EndDevice, error) {
+	return nil, errDeviceNotFound.WithAttributes("device_uid", unique.ID(ctx, ids))
+}
+
 // endDeviceFetcher fetches end devices
 type endDeviceFetcher struct {
 	c *component.Component