client: ignore http status header for gRPC streams

internal/transport/http2_client.go

@@ -1465,17 +1465,14 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		contentTypeErr = "malformed header: missing HTTP content-type"
 		grpcMessage    string
 		recvCompress   string
-		httpStatusCode *int
 		httpStatusErr  string
-		rawStatusCode  = codes.Unknown
+		// the code from the grpc-status header, if present
+		grpcStatusCode = codes.Internal
 		// headerError is set if an error is encountered while parsing the headers
 		headerError string
+		httpStatus  string
 	)
 
-	if initialHeader {
-		httpStatusErr = "malformed header: missing HTTP status"
-	}
-
 	for _, hf := range frame.Fields {
 		switch hf.Name {
 		case "content-type":
@@ -1495,69 +1492,71 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 				t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
 				return
 			}
-			rawStatusCode = codes.Code(uint32(code))
+			grpcStatusCode = codes.Code(uint32(code))
 		case "grpc-message":
 			grpcMessage = decodeGrpcMessage(hf.Value)
 		case ":status":
-			c, err := strconv.ParseInt(hf.Value, 10, 32)
+			httpStatus = hf.Value
+		default:
+			if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
+				break
+			}
+			v, err := decodeMetadataHeader(hf.Name, hf.Value)
 			if err != nil {
-				se := status.New(codes.Internal, fmt.Sprintf("transport: malformed http-status: %v", err))
+				headerError = fmt.Sprintf("transport: malformed %s: %v", hf.Name, err)
+				logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
+				break
+			}
+			mdata[hf.Name] = append(mdata[hf.Name], v)
+		}
+	}
+
+	// If a non-gRPC response is received, then evaluate the HTTP status to
+	// process the response and close the stream.
+	// In case http status doesn't provide any error information (status : 200),
+	// then evalute response code to be Unknown.
+	if !isGRPC {
+		var grpcErrorCode = codes.Internal
+		if httpStatus == "" {
+			httpStatusErr = "malformed header: missing HTTP status"
+		} else {
+			// Parse the status codes (e.g. "200", 404").
+			statusCode, err := strconv.Atoi(httpStatus)
+			if err != nil {
+				se := status.New(grpcErrorCode, fmt.Sprintf("transport: malformed http-status: %v", err))
 				t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
 				return
 			}
-			statusCode := int(c)
 			if statusCode >= 100 && statusCode < 200 {
 				if endStream {
 					se := status.New(codes.Internal, fmt.Sprintf(
 						"protocol error: informational header with status code %d must not have END_STREAM set", statusCode))
 					t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
 				}
+				// In case of informational headers, return.
 				return
 			}
-			httpStatusCode = &statusCode
-			if statusCode == 200 {
-				httpStatusErr = ""
-				break
-			}
-
 			httpStatusErr = fmt.Sprintf(
 				"unexpected HTTP status code received from server: %d (%s)",
 				statusCode,
 				http.StatusText(statusCode),
 			)
-		default:
-			if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
-				break
-			}
-			v, err := decodeMetadataHeader(hf.Name, hf.Value)
-			if err != nil {
-				headerError = fmt.Sprintf("transport: malformed %s: %v", hf.Name, err)
-				logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
-				break
-			}
-			mdata[hf.Name] = append(mdata[hf.Name], v)
-		}
-	}
-
-	if !isGRPC || httpStatusErr != "" {
-		var code = codes.Internal // when header does not include HTTP status, return INTERNAL
-
-		if httpStatusCode != nil {
 			var ok bool
-			code, ok = HTTPStatusConvTab[*httpStatusCode]
+			grpcErrorCode, ok = HTTPStatusConvTab[statusCode]
 			if !ok {
-				code = codes.Unknown
+				grpcErrorCode = codes.Unknown
 			}
 		}
 		var errs []string
 		if httpStatusErr != "" {
 			errs = append(errs, httpStatusErr)
 		}
+
 		if contentTypeErr != "" {
 			errs = append(errs, contentTypeErr)
 		}
-		// Verify the HTTP response is a 200.
-		se := status.New(code, strings.Join(errs, "; "))
+
+		se := status.New(grpcErrorCode, strings.Join(errs, "; "))
 		t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
 		return
 	}
@@ -1611,7 +1610,7 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		return
 	}
 
-	status := istatus.NewWithProto(rawStatusCode, grpcMessage, mdata[grpcStatusDetailsBinHeader])
+	status := istatus.NewWithProto(grpcStatusCode, grpcMessage, mdata[grpcStatusDetailsBinHeader])
 
 	// If client received END_STREAM from server while stream was still active,
 	// send RST_STREAM.