upstream: imp code

upstream/upstream_plain.go

@@ -66,7 +66,7 @@ func newPlain(addr *url.URL, opts *Options) (u *plainDNS, err error) {
 	return &plainDNS{
 		addr:      addr,
 		getDialer: getDialer,
-		net:       network(addr.Scheme),
+		net:       addr.Scheme,
 		timeout:   opts.Timeout,
 	}, nil
 }
@@ -102,15 +102,15 @@ func (p *plainDNS) dialExchange(
 	defer func() { logFinish(addr, network, err) }()
 
 	ctx := context.Background()
-	conn.Conn, err = dial(ctx, string(network), "")
+	conn.Conn, err = dial(ctx, network, "")
 	if err != nil {
 		return nil, fmt.Errorf("dialing %s over %s: %w", p.addr.Host, network, err)
 	}
 	defer func(c net.Conn) { err = errors.WithDeferred(err, c.Close()) }(conn.Conn)
 
 	resp, _, err = client.ExchangeWithConn(req, conn)
 	if isExpectedConnErr(err) {
-		conn.Conn, err = dial(ctx, string(network), "")
+		conn.Conn, err = dial(ctx, network, "")
 		if err != nil {
 			return nil, fmt.Errorf("dialing %s over %s again: %w", p.addr.Host, network, err)
 		}