feat(platform): harden telemetry pipeline and unify Semi UI workspaces

go/vehicle-gateway/internal/feichibridge/target.go

@@ -0,0 +1,193 @@
+package feichibridge
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+)
+
+type TargetConfig struct {
+	Address    string
+	PlatformID string
+	Username   string
+	Password   string
+	Timeout    time.Duration
+}
+
+type Target struct {
+	mu      sync.Mutex
+	config  TargetConfig
+	state   *StateStore
+	dialer  net.Dialer
+	conn    net.Conn
+	lastACK time.Time
+}
+
+func NewTarget(config TargetConfig, state *StateStore) (*Target, error) {
+	if strings.TrimSpace(config.Address) == "" {
+		return nil, errors.New("GB/T 32960 target address is required")
+	}
+	if len(config.PlatformID) != 17 {
+		return nil, fmt.Errorf("target platform ID must be exactly 17 bytes")
+	}
+	if state == nil {
+		return nil, errors.New("state store is required")
+	}
+	if config.Timeout <= 0 {
+		config.Timeout = 10 * time.Second
+	}
+	return &Target{
+		config: config,
+		state:  state,
+		dialer: net.Dialer{Timeout: config.Timeout, KeepAlive: 30 * time.Second},
+	}, nil
+}
+
+func (t *Target) Send(ctx context.Context, frame []byte) error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	var lastErr error
+	for attempt := 0; attempt < 2; attempt++ {
+		if err := t.ensureConnected(ctx); err != nil {
+			lastErr = err
+			t.closeLocked()
+			continue
+		}
+		if err := t.sendAndACK(ctx, frame); err != nil {
+			lastErr = err
+			t.closeLocked()
+			continue
+		}
+		t.lastACK = time.Now()
+		return nil
+	}
+	return fmt.Errorf("send GB/T 32960 frame after reconnect: %w", lastErr)
+}
+
+func (t *Target) Connect(ctx context.Context) error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if err := t.ensureConnected(ctx); err != nil {
+		t.closeLocked()
+		return err
+	}
+	return nil
+}
+
+func (t *Target) Close() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.conn == nil {
+		return nil
+	}
+	err := t.conn.Close()
+	t.conn = nil
+	return err
+}
+
+func (t *Target) LastACK() time.Time {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.lastACK
+}
+
+func (t *Target) ensureConnected(ctx context.Context) error {
+	if t.conn != nil {
+		return nil
+	}
+	conn, err := t.dialer.DialContext(ctx, "tcp", t.config.Address)
+	if err != nil {
+		return fmt.Errorf("dial target %s: %w", t.config.Address, err)
+	}
+	t.conn = conn
+	serial, err := t.state.NextPlatformSerial()
+	if err != nil {
+		return fmt.Errorf("allocate platform login serial: %w", err)
+	}
+	login, err := LoginFrame(t.config.PlatformID, t.config.Username, t.config.Password, serial, time.Now())
+	if err != nil {
+		return err
+	}
+	if err := t.sendAndACK(ctx, login); err != nil {
+		return fmt.Errorf("GB/T 32960 platform login: %w", err)
+	}
+	t.lastACK = time.Now()
+	return nil
+}
+
+func (t *Target) sendAndACK(ctx context.Context, frame []byte) error {
+	if t.conn == nil {
+		return errors.New("target connection is closed")
+	}
+	deadline := time.Now().Add(t.config.Timeout)
+	if contextDeadline, ok := ctx.Deadline(); ok && contextDeadline.Before(deadline) {
+		deadline = contextDeadline
+	}
+	if err := t.conn.SetDeadline(deadline); err != nil {
+		return err
+	}
+	if err := writeFull(t.conn, frame); err != nil {
+		return fmt.Errorf("write target frame: %w", err)
+	}
+	response, err := readFrame(t.conn)
+	if err != nil {
+		return fmt.Errorf("read target ACK: %w", err)
+	}
+	if response[2] != frame[2] {
+		return fmt.Errorf("target ACK command mismatch: got 0x%02X want 0x%02X", response[2], frame[2])
+	}
+	if response[3] != 0x01 {
+		return fmt.Errorf("target rejected command 0x%02X with response 0x%02X", response[2], response[3])
+	}
+	if string(response[4:21]) != string(frame[4:21]) {
+		return errors.New("target ACK identifier mismatch")
+	}
+	return nil
+}
+
+func (t *Target) closeLocked() {
+	if t.conn != nil {
+		_ = t.conn.Close()
+		t.conn = nil
+	}
+}
+
+func readFrame(reader io.Reader) ([]byte, error) {
+	header := make([]byte, 24)
+	if _, err := io.ReadFull(reader, header); err != nil {
+		return nil, err
+	}
+	if (header[0] != '#' || header[1] != '#') && (header[0] != '$' || header[1] != '$') {
+		return nil, fmt.Errorf("bad GB/T 32960 ACK start %q", header[:2])
+	}
+	bodyLength := int(binary.BigEndian.Uint16(header[22:24]))
+	tail := make([]byte, bodyLength+1)
+	if _, err := io.ReadFull(reader, tail); err != nil {
+		return nil, err
+	}
+	frame := append(header, tail...)
+	if got, want := bcc(frame[2:len(frame)-1]), frame[len(frame)-1]; got != want {
+		return nil, fmt.Errorf("bad GB/T 32960 ACK BCC: got 0x%02X want 0x%02X", got, want)
+	}
+	return frame, nil
+}
+
+func writeFull(writer io.Writer, value []byte) error {
+	for len(value) > 0 {
+		written, err := writer.Write(value)
+		if err != nil {
+			return err
+		}
+		if written == 0 {
+			return io.ErrShortWrite
+		}
+		value = value[written:]
+	}
+	return nil
+}