Fixes#35632 by allowing both outcomes of a race condition.
The server behavior is unchanged: in response to a malformed request
we send an error code and disconnect. The issue is that sometimes
on Windows the RST is caught by the platform and the receive buffer
is discarded before the Python client can process it with recv().
We can also be much more polite to misbehaving clients by
implementing SO_LINGER as suggested in #35780 but that will require
more review.
On some systems, such as NetBSD, the non-default
`-rpcmaxconnections=128` is too high, so bitcoind refuses to start:
```
Error: Not enough file descriptors available. 256 available, 290 required.
```
The test only needs a value above the default of 16. Use 64 and lower
`-maxconnections` in that case so the total fits in 256.
Instead of sending 403 Forbidden, disconnect as soon as possible.
To facilitate unit testing, this commit includes a refactor
that moves the subnet allow list and relevant methods
into the HTTPServer class instead of file-scope static scope.
- Only one node needed for test
- Use ascii encoding instead of utf-8
- Make tests independent of each other
- Expect HTTP error code 413 for too-large request
- Clarify python client race condition in comment
Covers:
- http pipelining
- rpcservertimeout
Testing this requires adding an option to TestNode to force
the test framework to establish a new HTTP connection for
every RPC. Otherwise, attempting to reuse a persistent connection
would cause framework RPCs during startup and shutdown to fail.
- "chunked" Transfer-Encoding
The previous diff touched most files in ./test/, so bump the headers to
avoid having to touch them again for a bump later.
-BEGIN VERIFY SCRIPT-
./contrib/devtools/copyright_header.py update ./test/
-END VERIFY SCRIPT-
