private ForwarderError HandleRequestBodyFailure(HttpContext context, StreamCopyResult requestBodyCopyResult, Exception requestBodyException, Exception additionalException)
{
ForwarderError requestBodyError;
int statusCode;
switch (requestBodyCopyResult)
{
// Failed while trying to copy the request body from the client. It's ambiguous if the request or response failed first.
case StreamCopyResult.InputError:
requestBodyError = ForwarderError.RequestBodyClient;
statusCode = StatusCodes.Status400BadRequest;
break;
// Failed while trying to copy the request body to the destination. It's ambiguous if the request or response failed first.
case StreamCopyResult.OutputError:
requestBodyError = ForwarderError.RequestBodyDestination;
statusCode = StatusCodes.Status502BadGateway;
break;
// Canceled while trying to copy the request body, either due to a client disconnect or a timeout. This probably caused the response to fail as a secondary error.
case StreamCopyResult.Canceled:
requestBodyError = ForwarderError.RequestBodyCanceled;
// Timeouts (504s) are handled at the SendAsync call site.
// The request body should only be canceled by the RequestAborted token.
statusCode = StatusCodes.Status502BadGateway;
break;
default:
throw new NotImplementedException(requestBodyCopyResult.ToString());
}
ReportProxyError(context, requestBodyError, new AggregateException(requestBodyException, additionalException));
// We don't know if the client is still around to see this error, but set it for diagnostics to see.
if (!context.Response.HasStarted)
{
// Nothing has been sent to the client yet, we can still send a good error response.
context.Response.Clear();
context.Response.StatusCode = statusCode;
return(requestBodyError);
}
ResetOrAbort(context, isCancelled: requestBodyCopyResult == StreamCopyResult.Canceled);
return(requestBodyError);
}
private async ValueTask <ForwarderError> HandleResponseBodyErrorAsync(HttpContext context, StreamCopyHttpContent?requestContent, StreamCopyResult responseBodyCopyResult, Exception responseBodyException, CancellationTokenSource requestCancellationSource)
{
if (requestContent is not null && requestContent.Started)
{
var alreadyFinished = requestContent.ConsumptionTask.IsCompleted == true;
if (!alreadyFinished)
{
requestCancellationSource.Cancel();
}
var(requestBodyCopyResult, requestBodyError) = await requestContent.ConsumptionTask;
// Check for request body errors, these may have triggered the response error.
if (alreadyFinished && requestBodyCopyResult != StreamCopyResult.Success)
{
return(HandleRequestBodyFailure(context, requestBodyCopyResult, requestBodyError !, responseBodyException));
}
}
var error = responseBodyCopyResult switch
{
StreamCopyResult.InputError => ForwarderError.ResponseBodyDestination,
StreamCopyResult.OutputError => ForwarderError.ResponseBodyClient,
StreamCopyResult.Canceled => ForwarderError.ResponseBodyCanceled,
_ => throw new NotImplementedException(responseBodyCopyResult.ToString()),
};
ReportProxyError(context, error, responseBodyException);
if (!context.Response.HasStarted)
{
// Nothing has been sent to the client yet, we can still send a good error response.
context.Response.Clear();
context.Response.StatusCode = StatusCodes.Status502BadGateway;
return(error);
}
// The response has already started, we must forcefully terminate it so the client doesn't get the
// the mistaken impression that the truncated response is complete.
ResetOrAbort(context, isCancelled: responseBodyCopyResult == StreamCopyResult.Canceled);
return(error);
}
