refactor(backend): reimplement speed limit logic

1. Refactor speed limit CRUD to sync with agents immediately via WebSocket (AddLimiters/DeleteLimiters).
2. Update unit conversion to match GOST v3 requirements (Mbps -> MB/s).
3. Update service config generation to reference Limiter IDs instead of hardcoded values.

go-backend/internal/http/handler/control_plane.go

@@ -234,9 +234,9 @@ func (h *Handler) getNodeRecord(nodeID int64) (*nodeRecord, error) {
 	return &n, nil
 }
 
-func (h *Handler) resolveUserTunnelAndLimiter(userID, tunnelID int64) (int64, *int, error) {
+func (h *Handler) resolveUserTunnelAndLimiter(userID, tunnelID int64) (int64, *int64, error) {
 	row := h.repo.DB().QueryRow(`
-		SELECT ut.id, sl.speed
+		SELECT ut.id, sl.id
 		FROM user_tunnel ut
 		LEFT JOIN speed_limit sl ON sl.id = ut.speed_id
 		WHERE ut.user_id = ? AND ut.tunnel_id = ?
@@ -244,18 +244,18 @@ func (h *Handler) resolveUserTunnelAndLimiter(userID, tunnelID int64) (int64, *i
 		LIMIT 1
 	`, userID, tunnelID)
 	var userTunnelID int64
-	var speed sql.NullInt64
+	var limiterID sql.NullInt64
-	err := row.Scan(&userTunnelID, &speed)
+	err := row.Scan(&userTunnelID, &limiterID)
 	if err != nil {
 		if errors.Is(err, sql.ErrNoRows) {
 			return 0, nil, nil
 		}
 		return 0, nil, err
 	}
-	if !speed.Valid || speed.Int64 <= 0 {
+	if !limiterID.Valid || limiterID.Int64 <= 0 {
 		return userTunnelID, nil, nil
 	}
-	v := int(speed.Int64)
+	v := limiterID.Int64
 	return userTunnelID, &v, nil
 }
 
@@ -328,7 +328,7 @@ func (h *Handler) syncForwardServices(forward *forwardRecord, method string, all
 		return errors.New("转发入口端口不存在")
 	}
 
-	userTunnelID, limiter, err := h.resolveUserTunnelAndLimiter(forward.UserID, forward.TunnelID)
+	userTunnelID, limiterID, err := h.resolveUserTunnelAndLimiter(forward.UserID, forward.TunnelID)
 	if err != nil {
 		return err
 	}
@@ -339,7 +339,7 @@ func (h *Handler) syncForwardServices(forward *forwardRecord, method string, all
 		if err != nil {
 			return err
 		}
-		services := buildForwardServiceConfigs(serviceBase, forward, tunnel, node, fp.Port, limiter)
+		services := buildForwardServiceConfigs(serviceBase, forward, tunnel, node, fp.Port, limiterID)
 		_, err = h.sendNodeCommand(node.ID, method, services, true, false)
 		if err != nil && allowFallbackAdd && method == "UpdateService" {
 			_, err = h.sendNodeCommand(node.ID, "AddService", services, true, false)
@@ -1003,7 +1003,7 @@ func isNotFoundError(err error) bool {
 	return strings.Contains(msg, "not found") || strings.Contains(msg, "不存在")
 }
 
-func buildForwardServiceConfigs(baseName string, forward *forwardRecord, tunnel *tunnelRecord, node *nodeRecord, port int, limiter *int) []map[string]interface{} {
+func buildForwardServiceConfigs(baseName string, forward *forwardRecord, tunnel *tunnelRecord, node *nodeRecord, port int, limiterID *int64) []map[string]interface{} {
 	protocols := []string{"tcp", "udp"}
 	services := make([]map[string]interface{}, 0, 2)
 	targets := splitRemoteTargets(forward.RemoteAddr)
@@ -1044,11 +1044,8 @@ func buildForwardServiceConfigs(baseName string, forward *forwardRecord, tunnel
 		if tunnel != nil && tunnel.Type == 1 && strings.TrimSpace(node.InterfaceName) != "" {
 			service["metadata"] = map[string]interface{}{"interface": node.InterfaceName}
 		}
-		if limiter != nil && *limiter > 0 {
+		if limiterID != nil && *limiterID > 0 {
-			// Convert Mbps to Bytes/s
+			service["limiter"] = strconv.FormatInt(*limiterID, 10)
-			// 1 Mbps = 1,000,000 bits/s = 125,000 Bytes/s
-			// We use decimal Mbps standard as is common in networking
-			service["limiter"] = strconv.Itoa(*limiter * 125000)
 		}
 		services = append(services, service)
 	}
@@ -1111,3 +1108,39 @@ func asBool(v interface{}, def bool) bool {
 		return def
 	}
 }
+
+func (h *Handler) sendLimiterConfig(limiterID int64, speedMbps int, tunnelID int64) error {
+	rate := float64(speedMbps) / 8.0
+	limitStr := fmt.Sprintf("$ %.1fMB %.1fMB", rate, rate)
+
+	payload := map[string]interface{}{
+		"name":   strconv.FormatInt(limiterID, 10),
+		"limits": []string{limitStr},
+	}
+
+	nodes, err := h.tunnelEntryNodeIDs(tunnelID)
+	if err != nil {
+		return err
+	}
+
+	for _, nodeID := range nodes {
+		_, _ = h.sendNodeCommand(nodeID, "AddLimiters", payload, false, false)
+	}
+	return nil
+}
+
+func (h *Handler) sendDeleteLimiterConfig(limiterID int64, tunnelID int64) error {
+	payload := map[string]interface{}{
+		"limiter": strconv.FormatInt(limiterID, 10),
+	}
+
+	nodes, err := h.tunnelEntryNodeIDs(tunnelID)
+	if err != nil {
+		return err
+	}
+
+	for _, nodeID := range nodes {
+		_, _ = h.sendNodeCommand(nodeID, "DeleteLimiters", payload, false, true)
+	}
+	return nil
+}

go-backend/internal/http/handler/mutations.go

@@ -1469,12 +1469,15 @@ func (h *Handler) speedLimitCreate(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	now := time.Now().UnixMilli()
-	_, err := h.repo.DB().Exec(`INSERT INTO speed_limit(name, speed, tunnel_id, tunnel_name, created_time, updated_time, status) VALUES(?, ?, ?, ?, ?, ?, ?)`,
+	speed := asInt(req["speed"], 100)
-		name, asInt(req["speed"], 100), tunnelID, tunnelName, now, now, asInt(req["status"], 1))
+	res, err := h.repo.DB().Exec(`INSERT INTO speed_limit(name, speed, tunnel_id, tunnel_name, created_time, updated_time, status) VALUES(?, ?, ?, ?, ?, ?, ?)`,
+		name, speed, tunnelID, tunnelName, now, now, asInt(req["status"], 1))
 	if err != nil {
 		response.WriteJSON(w, response.Err(-2, err.Error()))
 		return
 	}
+	id, _ := res.LastInsertId()
+	_ = h.sendLimiterConfig(id, speed, tunnelID)
 	response.WriteJSON(w, response.OKEmpty())
 }
 
@@ -1496,12 +1499,14 @@ func (h *Handler) speedLimitUpdate(w http.ResponseWriter, r *http.Request) {
 		response.WriteJSON(w, response.ErrDefault("隧道不存在"))
 		return
 	}
+	speed := asInt(req["speed"], 100)
 	_, err := h.repo.DB().Exec(`UPDATE speed_limit SET name=?, speed=?, tunnel_id=?, tunnel_name=?, status=?, updated_time=? WHERE id=?`,
-		asString(req["name"]), asInt(req["speed"], 100), tunnelID, tunnelName, asInt(req["status"], 1), time.Now().UnixMilli(), id)
+		asString(req["name"]), speed, tunnelID, tunnelName, asInt(req["status"], 1), time.Now().UnixMilli(), id)
 	if err != nil {
 		response.WriteJSON(w, response.Err(-2, err.Error()))
 		return
 	}
+	_ = h.sendLimiterConfig(id, speed, tunnelID)
 	response.WriteJSON(w, response.OKEmpty())
 }
 
@@ -1510,11 +1515,17 @@ func (h *Handler) speedLimitDelete(w http.ResponseWriter, r *http.Request) {
 	if id <= 0 {
 		return
 	}
+	var tunnelID int64
+	_ = h.repo.DB().QueryRow(`SELECT tunnel_id FROM speed_limit WHERE id = ?`, id).Scan(&tunnelID)
+
 	_, err := h.repo.DB().Exec(`DELETE FROM speed_limit WHERE id = ?`, id)
 	if err != nil {
 		response.WriteJSON(w, response.Err(-2, err.Error()))
 		return
 	}
+	if tunnelID > 0 {
+		_ = h.sendDeleteLimiterConfig(id, tunnelID)
+	}
 	response.WriteJSON(w, response.OKEmpty())
 }