Add DERP service

include/tailscale_stub.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing-box/adapter/endpoint"
+	"github.com/sagernet/sing-box/adapter/service"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/dns"
 	"github.com/sagernet/sing-box/log"
@@ -25,3 +26,9 @@ func registerTailscaleTransport(registry *dns.TransportRegistry) {
 		return nil, E.New(`Tailscale is not included in this build, rebuild with -tags with_tailscale`)
 	})
 }
+
+func registerDERPService(registry *service.Registry) {
+	service.Register[option.DERPServiceOptions](registry, C.TypeDERP, func(ctx context.Context, logger log.ContextLogger, tag string, options option.DERPServiceOptions) (adapter.Service, error) {
+		return nil, E.New(`DERP is not included in this build, rebuild with -tags with_tailscale`)
+	})
+}