Method operateHeaders

internal/transport/http2_server.go:377–634

operateHeaders takes action on the decoded headers. Returns an error if fatal error encountered and transport needs to close, otherwise returns nil.

(ctx context.Context, frame *http2.MetaHeadersFrame, handle func(*ServerStream))

// operateHeaders takes action on the decoded headers. Returns an error if fatal
// error encountered and transport needs to close, otherwise returns nil.
func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeadersFrame, handle func(*ServerStream)) error {
	// Acquire max stream ID lock for entire duration
	t.maxStreamMu.Lock()
	defer t.maxStreamMu.Unlock()

	streamID := frame.Header().StreamID

	// frame.Truncated is set to true when framer detects that the current header
	// list size hits MaxHeaderListSize limit.
	if frame.Truncated {
		t.controlBuf.put(&cleanupStream{
			streamID: streamID,
			rst:      true,
			rstCode:  http2.ErrCodeFrameSize,
			onWrite:  func() {},
		})
		return nil
	}

	if streamID%2 != 1 || streamID <= t.maxStreamID {
		// illegal gRPC stream id.
		return fmt.Errorf("received an illegal stream id: %v. headers frame: %+v", streamID, frame)
	}
	t.maxStreamID = streamID

	s := &ServerStream{
		Stream: Stream{
			id: streamID,
			fc: inFlow{limit: uint32(t.initialWindowSize)},
		},
		st:               t,
		headerWireLength: int(frame.Header().Length),
	}
	s.Stream.buf.init()
	var (
		// if false, content-type was missing or invalid
		isGRPC      = false
		contentType = ""
		mdata       = make(metadata.MD, len(frame.Fields))
		httpMethod  string
		// these are set if an error is encountered while parsing the headers
		protocolError bool
		headerError   *status.Status

		timeoutSet bool
		timeout    time.Duration
	)

	for _, hf := range frame.Fields {
		switch hf.Name {
		case "content-type":
			contentSubtype, validContentType := grpcutil.ContentSubtype(hf.Value)
			if !validContentType {
				contentType = hf.Value
				break
			}
			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
			s.contentSubtype = contentSubtype