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3d4631fec6
Since commit aade4edc1 ("BUG/MEDIUM: mux-h2: Don't handle pending read0
too early on streams"), we've met a few cases where an early connection
close wouldn't be properly handled if some data were pending in a frame
header, because the test now considers the buffer's contents before
accepting to report the close, but given that frame headers or preface
are consumed at once, the buffer cannot make progress when it's stuck
at intermediary lengths.
In order to address this, this patch introduces two flags in the h2c
connection to store any reported shutdown and failed parsing. The idea
is that we cannot rely on conn_xprt_read0_pending() in the parser since
it wouldn't consider data pending in the buffer nor intermediary layers,
but we know for certain that after a read0 is reported by the transport
layer in presence of an RD_SH on the connection, no more progress will
be made there. This alone is not sufficient to decide to end processing,
we can only do this once these final data have been submitted to a parser.
Therefore, now when a parser fails on missing data, we check if a read0
has already been reported on this connection, and if so we set a new
END_REACHED flag on the connection to indicate a failure to process the
final data. The h2c_read0_pending() function now simply reports this
flag's status. This way we're certain that the input shutdown is only
considered after the demux attempted to parse the last frame.
Maybe over the long term the subscribe() API should be improved to
synchronously fail when trying to subscribe for an even that will not
happen. This may be an elegant solution that could possibly work across
multiple layers and even muxes, and be usable at a few specific places
where that's needed.
Given the patch above was backported as far as 2.0, this one should be
backported there as well. It is possible that the fcgi mux has the same
issue, but this was not analysed yet.
Thanks to Pierre Cheynier for providing detailed traces allowing to
quickly narrow the problem down, and to Olivier for his analysis.
The HAProxy documentation has been split into a number of different files for ease of use. Please refer to the following files depending on what you're looking for : - INSTALL for instructions on how to build and install HAProxy - BRANCHES to understand the project's life cycle and what version to use - LICENSE for the project's license - CONTRIBUTING for the process to follow to submit contributions The more detailed documentation is located into the doc/ directory : - doc/intro.txt for a quick introduction on HAProxy - doc/configuration.txt for the configuration's reference manual - doc/lua.txt for the Lua's reference manual - doc/SPOE.txt for how to use the SPOE engine - doc/network-namespaces.txt for how to use network namespaces under Linux - doc/management.txt for the management guide - doc/regression-testing.txt for how to use the regression testing suite - doc/peers.txt for the peers protocol reference - doc/coding-style.txt for how to adopt HAProxy's coding style - doc/internals for developer-specific documentation (not all up to date)