feat: track jt808 registration identity

go/vehicle-gateway/internal/protocol/jt808/parser.go

@@ -151,6 +151,24 @@ func ParseFrame(raw []byte, receivedAtMS int64, sourceEndpoint string) (envelope
 		if location.TotalMileageKM != nil {
 			fields[envelope.FieldTotalMileageKM] = *location.TotalMileageKM
 		}
+	} else if messageID == 0x0100 {
+		registration, err := parseRegistration(body)
+		if err != nil {
+			return envelope.FrameEnvelope{}, err
+		}
+		parsed["registration"] = registration
+		if deviceID, ok := registration["device_id"].(string); ok {
+			fields["device_id"] = deviceID
+		}
+		if plate, ok := registration["plate"].(string); ok {
+			fields["plate"] = plate
+		}
+	} else if messageID == 0x0102 {
+		authentication := parseAuthentication(body)
+		parsed["authentication"] = authentication
+		if token, ok := authentication["token"].(string); ok {
+			fields["auth_token"] = token
+		}
 	}
 
 	env := envelope.FrameEnvelope{
@@ -166,10 +184,36 @@ func ParseFrame(raw []byte, receivedAtMS int64, sourceEndpoint string) (envelope
 		Fields:         fields,
 		ParseStatus:    envelope.ParseOK,
 	}
+	if registration, ok := parsed["registration"].(map[string]any); ok {
+		env.DeviceID, _ = registration["device_id"].(string)
+		env.Plate, _ = registration["plate"].(string)
+	}
 	env.EventID = env.StableEventID()
 	return env, nil
 }
 
+func parseRegistration(body []byte) (map[string]any, error) {
+	if len(body) < 37 {
+		return nil, fmt.Errorf("%w: registration body len=%d", ErrFrameTooShort, len(body))
+	}
+	registration := map[string]any{
+		"province":     binary.BigEndian.Uint16(body[0:2]),
+		"city":         binary.BigEndian.Uint16(body[2:4]),
+		"manufacturer": fixedText(body[4:9]),
+		"device_type":  fixedText(body[9:29]),
+		"device_id":    fixedText(body[29:36]),
+		"plate_color":  body[36],
+		"plate":        freeText(body[37:]),
+	}
+	return registration, nil
+}
+
+func parseAuthentication(body []byte) map[string]any {
+	token := freeText(body)
+	out := map[string]any{"token": token}
+	return out
+}
+
 func parseLocation(body []byte) (Location, error) {
 	if len(body) < 28 {
 		return Location{}, fmt.Errorf("%w: location body len=%d", ErrFrameTooShort, len(body))
@@ -269,6 +313,14 @@ func bcdString(data []byte) string {
 	return string(out)
 }
 
+func fixedText(data []byte) string {
+	return strings.Trim(freeText(data), "\x00 ")
+}
+
+func freeText(data []byte) string {
+	return strings.TrimRight(strings.TrimSpace(string(data)), "\x00")
+}
+
 func parseBCDTime(data []byte) time.Time {
 	if len(data) != 6 {
 		return time.Time{}

go/vehicle-gateway/internal/protocol/jt808/parser_test.go

@@ -1,6 +1,7 @@
 package jt808
 
 import (
+	"encoding/binary"
 	"encoding/hex"
 	"testing"
 
@@ -114,6 +115,61 @@ func TestParseFrameSupportsJT8082019VersionedHeader(t *testing.T) {
 	}
 }
 
+func TestParseFrameParsesRegistrationIdentity(t *testing.T) {
+	body := make([]byte, 0, 46)
+	body = binary.BigEndian.AppendUint16(body, 16)
+	body = binary.BigEndian.AppendUint16(body, 32)
+	body = appendFixedASCII(body, "YUTNG", 5)
+	body = appendFixedASCII(body, "ZK6105CHEVNPG4", 20)
+	body = appendFixedASCII(body, "DEV0001", 7)
+	body = append(body, 2)
+	body = append(body, []byte("TEST123")...)
+
+	env, err := ParseFrame(buildFrame(0x0100, "013079963379", 7, body), 1782918600000, "115.231.168.135:43625")
+	if err != nil {
+		t.Fatalf("ParseFrame() error = %v", err)
+	}
+	if env.MessageID != "0x0100" {
+		t.Fatalf("message id = %q", env.MessageID)
+	}
+	if env.Phone != "013079963379" {
+		t.Fatalf("phone = %q", env.Phone)
+	}
+	if env.DeviceID != "DEV0001" {
+		t.Fatalf("device id = %q", env.DeviceID)
+	}
+	if env.Plate != "TEST123" {
+		t.Fatalf("plate = %q", env.Plate)
+	}
+	registration, ok := env.Parsed["registration"].(map[string]any)
+	if !ok {
+		t.Fatalf("registration missing: %#v", env.Parsed)
+	}
+	if registration["manufacturer"] != "YUTNG" || registration["device_type"] != "ZK6105CHEVNPG4" {
+		t.Fatalf("registration fields = %#v", registration)
+	}
+	if registration["plate_color"] != uint8(2) {
+		t.Fatalf("plate color = %#v", registration["plate_color"])
+	}
+}
+
+func TestParseFrameParsesAuthenticationToken(t *testing.T) {
+	env, err := ParseFrame(buildFrame(0x0102, "064646848757", 8, []byte("g7gps")), 1782918600000, "115.231.168.135:43625")
+	if err != nil {
+		t.Fatalf("ParseFrame() error = %v", err)
+	}
+	if env.MessageID != "0x0102" {
+		t.Fatalf("message id = %q", env.MessageID)
+	}
+	auth, ok := env.Parsed["authentication"].(map[string]any)
+	if !ok {
+		t.Fatalf("authentication missing: %#v", env.Parsed)
+	}
+	if auth["token"] != "g7gps" {
+		t.Fatalf("token = %#v", auth["token"])
+	}
+}
+
 func TestExtractFramesHandlesEscapedPayload(t *testing.T) {
 	payload := []byte{0x02, 0x00, 0x00, 0x02, 0x01, 0x33, 0x07, 0x79, 0x54, 0x25, 0x00, 0x01, 0x7e, 0x7d}
 	frame := append([]byte{0x7e}, escape(append(payload, checksum(payload)))...)
@@ -131,6 +187,41 @@ func TestExtractFramesHandlesEscapedPayload(t *testing.T) {
 	}
 }
 
+func buildFrame(messageID uint16, phone string, sequence uint16, body []byte) []byte {
+	payload := make([]byte, 0, 12+len(body)+1)
+	payload = binary.BigEndian.AppendUint16(payload, messageID)
+	payload = binary.BigEndian.AppendUint16(payload, uint16(len(body)))
+	payload = append(payload, encodeBCD(phone, 6)...)
+	payload = binary.BigEndian.AppendUint16(payload, sequence)
+	payload = append(payload, body...)
+	payload = append(payload, checksum(payload))
+	return payload
+}
+
+func appendFixedASCII(out []byte, value string, size int) []byte {
+	start := len(out)
+	out = append(out, make([]byte, size)...)
+	copy(out[start:], []byte(value))
+	return out
+}
+
+func encodeBCD(value string, size int) []byte {
+	out := make([]byte, size)
+	if len(value)%2 == 1 {
+		value = "0" + value
+	}
+	if len(value) > size*2 {
+		value = value[len(value)-size*2:]
+	}
+	for len(value) < size*2 {
+		value = "0" + value
+	}
+	for i := 0; i < size; i++ {
+		out[i] = (value[i*2]-'0')<<4 | (value[i*2+1] - '0')
+	}
+	return out
+}
+
 func assertFloatField(t *testing.T, env envelope.FrameEnvelope, key string, want float64) {
 	t.Helper()
 	got, ok := env.Fields[key].(float64)