Chore: split enhanced mode instance (#936)

Co-authored-by: Dreamacro <305009791@qq.com>

dns/server.go

@@ -27,16 +27,22 @@ func (s *Server) ServeDNS(w D.ResponseWriter, r *D.Msg) {
 		return
 	}
 
-	s.handler(w, r)
+	msg, err := s.handler(r)
+	if err != nil {
+		D.HandleFailed(w, r)
+		return
+	}
+
+	w.WriteMsg(msg)
 }
 
 func (s *Server) setHandler(handler handler) {
 	s.handler = handler
 }
 
-func ReCreateServer(addr string, resolver *Resolver) error {
+func ReCreateServer(addr string, resolver *Resolver, mapper *ResolverEnhancer) error {
 	if addr == address && resolver != nil {
-		handler := newHandler(resolver)
+		handler := newHandler(resolver, mapper)
 		server.setHandler(handler)
 		return nil
 	}
@@ -68,7 +74,7 @@ func ReCreateServer(addr string, resolver *Resolver) error {
 	}
 
 	address = addr
-	handler := newHandler(resolver)
+	handler := newHandler(resolver, mapper)
 	server = &Server{handler: handler}
 	server.Server = &D.Server{Addr: addr, PacketConn: p, Handler: server}