Http2 Protocol Error, errorCode = ProtocolError

[JamesNK]

When I make HTTP/2 requests this error is thrown internally every time:

System.Net.Http.Http2Connection.Http2ProtocolException: 'Http2 Protocol Error, errorCode = ProtocolError'
   at System.Net.Http.Http2Connection.Http2Stream.OnResponseHeader(ReadOnlySpan`1 name, ReadOnlySpan`1 value)

[davidsh]

@rmkerr

[rmkerr]

Thanks for the report @JamesNK. Can you share any more details about the repro?

It looks like the exception is probably being thrown here (EDIT: This isn't the right location. See later comments)
https://github.com/dotnet/corefx/blob/304c0194b16a1f26c14cda92e2532efcf126c99f/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs#L297-L302

After recieving a headers frame without END_HEADERS we're expecting to receive continuation frames on the same stream until we get a frame with END_HEADERS set. There could be an actual protocol violation here, or an issue with how we're checking and enforcing that requirement.

[JamesNK]

Wireshark log

httpclient-grpc.zip

I don't know how useful it will be with HTTPS enable.

[JamesNK]

From the stacktrace it looks like it is thrown here:

https://github.com/dotnet/corefx/blob/304c0194b16a1f26c14cda92e2532efcf126c99f/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Stream.cs#L118-L127

[rmkerr]

This is actually simpler than I initially thought. These gRPC responses include trailing headers, which aren't supported yet. Support is introduced in pr dotnet/corefx#36128.

[JamesNK]

Ok, so is it best to wait until that PR lands and then retest?

[rmkerr]

Yep. If you're interested in getting some tests in ASAP you can build the branch with trailing header support and test against those binaries. Otherwise it will be easiest for the change to just make it into master.

[wfurt]

BTW older version of SockertHttpClient ignore trailing headers. You can try preview3 build instead of latest @JamesNK

[wfurt]

Should be fixed by dotnet/corefx#36128. Let me know if you have any other troubles @JamesNK