Close idle connections of unreferenced outbounds and DNS servers

common/httpclient/manager.go

@@ -9,11 +9,13 @@ import (
 	"github.com/sagernet/sing-box/option"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
+	"github.com/sagernet/sing/service"
 )
 
 var (
 	_ adapter.HTTPClientManager = (*Manager)(nil)
 	_ adapter.LifecycleService  = (*Manager)(nil)
+	_ adapter.Referrer          = (*Manager)(nil)
 )
 
 type Manager struct {
@@ -177,3 +179,27 @@ func (m *Manager) Close() error {
 	m.sharedTransports = nil
 	return err
 }
+
+func (m *Manager) References() []string {
+	m.access.Lock()
+	defer m.access.Unlock()
+	var references []string
+	var needDefault bool
+	for _, transport := range m.managedTransports {
+		if transport.detour != "" {
+			references = append(references, transport.detour)
+		} else if transport.defaultOutbound {
+			needDefault = true
+		}
+	}
+	if needDefault {
+		outboundManager := service.FromContext[adapter.OutboundManager](m.ctx)
+		if outboundManager != nil {
+			defaultOutbound := outboundManager.Default()
+			if defaultOutbound != nil {
+				references = append(references, defaultOutbound.Tag())
+			}
+		}
+	}
+	return references
+}