Parse optional 'meta' in RXPK.

The 'meta' field is not specified in PROTOCOL.TXT, but can be used by
custom packet-forwarder implementations to expose additional metadata.

Author: brocaar

internal/backend/semtechudp/packets/push_data.go

@@ -140,6 +140,7 @@ func getUplinkFrame(gatewayID lorawan.EUI64, rxpk RXPK, FakeRxInfoTime bool) (*g
 			Channel:   uint32(rxpk.Chan),
 			Board:     uint32(rxpk.Brd),
 			Context:   make([]byte, 4),
+			Metadata:  rxpk.Meta,
 		},
 	}
 
@@ -344,25 +345,26 @@ type Stat struct {
 
 // RXPK contain a RF packet and associated metadata.
 type RXPK struct {
-	Time  *CompactTime `json:"time"`  // UTC time of pkt RX, us precision, ISO 8601 'compact' format (e.g. 2013-03-31T16:21:17.528002Z)
-	Tmms  *int64       `json:"tmms"`  // GPS time of pkt RX, number of milliseconds since 06.Jan.1980
-	Tmst  uint32       `json:"tmst"`  // Internal timestamp of "RX finished" event (32b unsigned)
-	FTime *uint32      `json:"ftime"` // Fine timestamp, number of nanoseconds since last PPS [0..999999999] (Optional)
-	AESK  uint8        `json:"aesk"`  // AES key index used for encrypting fine timestamps
-	Chan  uint8        `json:"chan"`  // Concentrator "IF" channel used for RX (unsigned integer)
-	RFCh  uint8        `json:"rfch"`  // Concentrator "RF chain" used for RX (unsigned integer)
-	Stat  int8         `json:"stat"`  // CRC status: 1 = OK, -1 = fail, 0 = no CRC
-	Freq  float64      `json:"freq"`  // RX central frequency in MHz (unsigned float, Hz precision)
-	Brd   uint32       `json:"brd"`   // Concentrator board used for RX (unsigned integer)
-	RSSI  int16        `json:"rssi"`  // RSSI in dBm (signed integer, 1 dB precision)
-	Size  uint16       `json:"size"`  // RF packet payload size in bytes (unsigned integer)
-	DatR  DatR         `json:"datr"`  // LoRa datarate identifier (eg. SF12BW500) || FSK datarate (unsigned, in bits per second)
-	Modu  string       `json:"modu"`  // Modulation identifier "LORA" or "FSK"
-	CodR  string       `json:"codr"`  // LoRa ECC coding rate identifier
-	LSNR  float64      `json:"lsnr"`  // Lora SNR ratio in dB (signed float, 0.1 dB precision)
-	HPW   uint8        `json:"hpw"`   // LR-FHSS hopping grid number of steps.
-	Data  []byte       `json:"data"`  // Base64 encoded RF packet payload, padded
-	RSig  []RSig       `json:"rsig"`  // Received signal information, per antenna (Optional)
+	Time  *CompactTime      `json:"time"`  // UTC time of pkt RX, us precision, ISO 8601 'compact' format (e.g. 2013-03-31T16:21:17.528002Z)
+	Tmms  *int64            `json:"tmms"`  // GPS time of pkt RX, number of milliseconds since 06.Jan.1980
+	Tmst  uint32            `json:"tmst"`  // Internal timestamp of "RX finished" event (32b unsigned)
+	FTime *uint32           `json:"ftime"` // Fine timestamp, number of nanoseconds since last PPS [0..999999999] (Optional)
+	AESK  uint8             `json:"aesk"`  // AES key index used for encrypting fine timestamps
+	Chan  uint8             `json:"chan"`  // Concentrator "IF" channel used for RX (unsigned integer)
+	RFCh  uint8             `json:"rfch"`  // Concentrator "RF chain" used for RX (unsigned integer)
+	Stat  int8              `json:"stat"`  // CRC status: 1 = OK, -1 = fail, 0 = no CRC
+	Freq  float64           `json:"freq"`  // RX central frequency in MHz (unsigned float, Hz precision)
+	Brd   uint32            `json:"brd"`   // Concentrator board used for RX (unsigned integer)
+	RSSI  int16             `json:"rssi"`  // RSSI in dBm (signed integer, 1 dB precision)
+	Size  uint16            `json:"size"`  // RF packet payload size in bytes (unsigned integer)
+	DatR  DatR              `json:"datr"`  // LoRa datarate identifier (eg. SF12BW500) || FSK datarate (unsigned, in bits per second)
+	Modu  string            `json:"modu"`  // Modulation identifier "LORA" or "FSK"
+	CodR  string            `json:"codr"`  // LoRa ECC coding rate identifier
+	LSNR  float64           `json:"lsnr"`  // Lora SNR ratio in dB (signed float, 0.1 dB precision)
+	HPW   uint8             `json:"hpw"`   // LR-FHSS hopping grid number of steps.
+	Data  []byte            `json:"data"`  // Base64 encoded RF packet payload, padded
+	RSig  []RSig            `json:"rsig"`  // Received signal information, per antenna (Optional)
+	Meta  map[string]string `json:"meta"`  // Custom meta-data (Optional, not part of PROTOCOL.TXT)
 }
 
 // RSig contains the received signal information per antenna.

internal/backend/semtechudp/packets/push_data_test.go

@@ -455,6 +455,68 @@ func TestGetUplinkFrame(t *testing.T) {
 				},
 			},
 		},
+		{
+			Name: "uplink with meta",
+			PushDataPacket: PushDataPacket{
+				GatewayMAC:      lorawan.EUI64{1, 2, 3, 4, 5, 6, 7, 8},
+				ProtocolVersion: ProtocolVersion2,
+				Payload: PushDataPayload{
+					RXPK: []RXPK{
+						{
+							Time: &ctNow,
+							Tmst: 1000000,
+							Freq: 868.3,
+							Brd:  2,
+							Chan: 1,
+							RFCh: 3,
+							Stat: 1,
+							Modu: "LORA",
+							DatR: DatR{LoRa: "SF12BW500"},
+							CodR: "4/5",
+							RSSI: -60,
+							LSNR: 5.5,
+							Size: 5,
+							Data: []byte{1, 2, 3, 4, 5},
+							Meta: map[string]string{
+								"gateway_name": "test-gateway",
+							},
+						},
+					},
+				},
+			},
+			UplinkFrames: []*gw.UplinkFrame{
+				{
+					PhyPayload: []byte{1, 2, 3, 4, 5},
+					TxInfo: &gw.UplinkTxInfo{
+						Frequency: 868300000,
+						Modulation: &gw.Modulation{
+							Parameters: &gw.Modulation_Lora{
+								Lora: &gw.LoraModulationInfo{
+									Bandwidth:             500000,
+									SpreadingFactor:       12,
+									CodeRate:              gw.CodeRate_CR_4_5,
+									PolarizationInversion: false,
+								},
+							},
+						},
+					},
+					RxInfo: &gw.UplinkRxInfo{
+						GatewayId: "0102030405060708",
+						Time:      pbTime,
+						Rssi:      -60,
+						Snr:       5.5,
+						Channel:   1,
+						RfChain:   3,
+						Board:     2,
+						Antenna:   0,
+						Context:   []byte{0x00, 0x0f, 0x42, 0x40},
+						Metadata: map[string]string{
+							"gateway_name": "test-gateway",
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for _, test := range testTable {