[iomgr][Windows] Return proper error code to client when connection is reset

[drfloob]

Fixes #24206 by ensuring that IOCP/socket errors in the iomgr on_read callback are properly annotated with the gRPC Unavailable status. The WindowsEventEngine was already doing this correctly (try running the client with $env:GRPC_EXPERIMENTS="event_engine_client").

This also adds two small cleanups:

• Cleanly prints statuses with their child statuses in a few spots within the chttp2 transport logging (previously, child messages were printed with garbled bits)
• Adds friendly names to a subset of WSA errors that we're likely to see from common operations. The top-level status message will no longer just say "WSA Error" in many cases.

CC @Hamza-Q

[markdroth]

Thanks for fixing this!

[markdroth]

Does Windows not provide a function that does this already? I would have expected that it would. Posix has had strerror() for a long time.

[ctiller]

https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-formatmessage

[drfloob]

We use FormatMessage in gpr_format_message, but it produces longer messages. For example, for the WSAECONNRESET error, FormatMessage produces "An existing connection was forcibly closed by the remote host", but for a top-level Status summary (which becomes the error strings that clients receive), something like "Connection reset" will do. The short version seems friendlier.

Here is an example error:

D0620 18:33:23.211000000 15608 src/core/ext/transport/chttp2/transport/chttp2_transport.cc:2198] MARK_STREAM_CLOSED: t=000001946F442850 s=000001946F441290(id=1) read+write [UNKNOWN:Endpoint read failed {occurred_during_write:0, created_time:"2023-06-21T01:33:23.210383893+00:00", file_line:2534, file:"src/core/ext/transport/chttp2/transport/chttp2_transport.cc", children:[UNAVAILABLE:Connection Reset {file:"src/core/lib/iomgr/tcp_windows.cc", file_line:189, created_time:"2023-06-21T01:33:23.2102455+00:00", wsa_error:10054, grpc_status:14, os_error:"An existing connection was forcibly closed by the remote host.\r\n", syscall:"IOCP/Socket"}]}]

This propagates to the surface as an error with status GRPC_STATUS_UNAVAILABLE and message "Connection Reset".

Edit: adding linebreaks in the example for readability
Edit: Replaced the Cancel pings log with a "mark stream closed" log, which is actually what propagates up.

[drfloob]

Does Windows not provide a function that does this already?

To add, if you go code searching for things like WSAECONNRESET, you'll find that an error-to-short-name mapping is not uncommon. It does seem like an oversight for Windows to not provide this already.

[ctiller]

For my education: why is ToString not the right thing?

[drfloob]

On Windows at least, the child errors are printed with embedded hex when you use status.ToString(). Try to pick out the file line number for the child error in this example:

D0620 15:33:35.497000000 19492 src/core/ext/transport/chttp2/transport/chttp2_transport.cc:2198] MARK_STREAM_CLOSED: t=000001C9618D5830 s=000001C9618DB710(id=1) read+write [UNKNOWN: Endpoint read failed [type.googleapis.com/grpc.status.str.file='src/core/ext/transport/chttp2/transport/chttp2_transport.cc'] [type.googleapis.com/grpc.status.int.file_line='2534'] [type.googleapis.com/grpc.status.time.created_time='2023-06-20T22:33:35.497401355+00:00'] [type.googleapis.com/grpc.status.children=''\x01\x00\x00\x08\x02\x12\x44\x41n existing connection was forcibly closed by the remote host.%0D%0A\x1aX\n1type.googleapis.com/grpc.status.time.created_time\x12#2023-06-20T22:33:35.497371459+00:00\x1a\x34\n-type.googleapis.com/grpc.status.int.file_line\x12\x03\x31\x39\x30\x1aM\n(type.googleapis.com/grpc.status.str.file\x12!src/core/lib/iomgr/tcp_windows.cc'] [type.googleapis.com/grpc.status.int.occurred_during_write='0']]