Upstream connection events, EOF and I/O errors are never propagated to network filters

[PiotrSikora]

The read/write network filters never receive information about:

• upstream connection events (connected, local/remote close),
• mid-stream I/O errors (see: Mid-stream I/O errors are silently ignored in TCP proxy and other network filters #13939),
• EOF (in case of connections without half-close semantics),

which significantly limits robustness and capabilities of WebAssembly and ext_proc extensions.

cc @mattklein123 @gbrail @kyessenov

[kyessenov]

Thanks for digging into it. I wonder if it is possible to solve this fully for raw byte streams without application-level semantics on framing. I think there's some just some inherent non-determinism in closure with TIME_WAIT and proxy in the middle.

[antoniovicente]

What actions would wasm filters want to take of midstream errors or EOF?

I assume that there's also a logging issue; are HTTP requests that fail after partial response tagged appropriately?

[PiotrSikora]

Because upstream connection events are not propagated to network filters, Wasm is currently using end_stream=true (which is missing in case of mid-stream error) as a signal for upstream connection close events.

More generally, I'd like to be able to log that the connection was prematurely closed from within Wasm plugins.

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This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted" or "no stalebot". Thank you for your contributions.