add sniffing.fallback option for red handler

handler/redirect/tcp/handler.go

@@ -241,6 +241,10 @@ func (h *redirectHandler) handleHTTPS(ctx context.Context, rw io.ReadWriter, rad
 		cc, err = h.options.Router.Dial(ctx, "tcp", host)
 		if err != nil {
 			log.Error(err)
+
+			if !h.md.sniffingFallback {
+				return err
+			}
 		}
 	}
 

handler/redirect/tcp/metadata.go

@@ -11,11 +11,13 @@ type metadata struct {
 	tproxy          bool
 	sniffing        bool
 	sniffingTimeout time.Duration
+	sniffingFallback bool
 }
 
 func (h *redirectHandler) parseMetadata(md mdata.Metadata) (err error) {
 	h.md.tproxy = mdutil.GetBool(md, "tproxy")
 	h.md.sniffing = mdutil.GetBool(md, "sniffing")
 	h.md.sniffingTimeout = mdutil.GetDuration(md, "sniffing.timeout")
+	h.md.sniffingFallback = mdutil.GetBool(md, "sniffing.fallback")
 	return
 }