YARP - HttpRequestException：收到无效的状态行

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I have a YARP gateway inside a docker compose.network. On a development branch I see the following:

info: Yarp.ReverseProxy.Forwarder.HttpForwarder[9]
      Proxying to http://<my-route> HTTP/2 RequestVersionOrLower no-streaming
info: Yarp.ReverseProxy.Forwarder.HttpForwarder[48]
      Request: An error was encountered before receiving a response.
      System.Net.Http.HttpRequestException: Received an invalid status line: '3b'.
         at System.Net.Http.HttpConnection.ParseStatusLine(ReadOnlySpan`1 line, HttpResponseMessage response)
         at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
         at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
         at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
         at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
         at Yarp.ReverseProxy.Forwarder.HttpForwarder.SendAsync(HttpContext context, String destinationPrefix, HttpMessageInvoker httpClient, ForwarderRequestConfig requestConfig, HttpTransformer transformer)

This happens for POST, PUT and DELETE methods but GET method works fine.

The '3b' part changes. How can I find where this problem comes from?

Answer 1

A way to debug this issue would be to use a tool such as Fiddler or Charles to capture the HTTP requests and responses. This will allow you to see the exact request that is failing and the response that is being returned, which will help you to identify where the issue is coming from.

Alternatively , if you don't have access to such tools, you can also use a tool like Postman to make the request and inspect the response to help you narrow down the issue.

Answer 2

Looks like YARP is trying to parse a corrupted response as the status line is the first part of an HTTP response. To be honest, this type of issue is tough to debug without seeing application level traffic as we could be dealing with a corrupted response from the POST request itself or a corruption that took place in the previous request.

Example: sending an actual body of 100 bytes, but setting the Content-Length to 98. A web client could be tricked into parsing the first 98 bytes of a response, leaving the last 2 bytes in the.network buffer and then corrupting the next request's response.