XTLS/Xray-core · error

failed to read http 1xx response

Error message

failed to read http 1xx response

What it means

Error "failed to read http 1xx response" thrown in XTLS/Xray-core.

Source

Thrown at proxy/http/server.go:332

}

// Sometimes, server might send 1xx response to client
// it should not be processed by http proxy handler, just forward it to client
func readResponseAndHandle100Continue(r *bufio.Reader, req *http.Request, writer io.Writer) (*http.Response, error) {
	// have a little look of response
	peekBytes, err := r.Peek(56)
	if err == nil || err == bufio.ErrBufferFull {
		str := string(peekBytes)
		ResponseLine := strings.Split(str, "\r\n")[0]
		_, status, _ := strings.Cut(ResponseLine, " ")
		// only handle 1xx response
		if strings.HasPrefix(status, "1") {
			ResponseHeader1xx := []byte{}
			// read until \r\n\r\n (end of http response header)
			for {
				data, err := r.ReadSlice('\n')
				if err != nil {
					return nil, errors.New("failed to read http 1xx response").Base(err)
				}
				ResponseHeader1xx = append(ResponseHeader1xx, data...)
				if bytes.Equal(ResponseHeader1xx[len(ResponseHeader1xx)-4:], []byte{'\r', '\n', '\r', '\n'}) {
					break
				}
				if len(ResponseHeader1xx) > 1024 {
					return nil, errors.New("too big http 1xx response")
				}
			}
			writer.Write(ResponseHeader1xx)
		}
	}
	return http.ReadResponse(r, req)
}

func init() {
	common.Must(common.RegisterConfig((*ServerConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
		return NewServer(ctx, config.(*ServerConfig))

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/http/server.go:332 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/a3cb21efcff479d9. Report an issue: GitHub.