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When handling UDP datagram reception, it is possible to receive a QUIC packet for one connection to the socket attached to another connection. To protect against this, an explicit comparison is done against the packet DCID and the quic-conn CID. On no match, the datagram is requeued and dispatched via rxbuf and will be treated as if it arrived on the listener socket. One reason for this wrong reception is explained by the small race condition that exists between bind() and connect() syscalls during connection socket initialization. However, one other reason which was not thought initially is when clients reuse the same IP:PORT for different connections. In this case the current FD attribution is not optimal and this can cause a substantial number of requeuing. This situation has revealed a bug during requeuing. If rxbuf contig space is not big enough for the datagram, the incoming datagram was dropped, even if there is space at buffer origin. This can cause several datagrams to be dropped in a series until eventually buffer head is moved when passing through the listener FD. To fix this, allocate a fake datagram to consume contig space. This is similar to the handling of datagrams on the listener FD. This allows then to store the datagram to requeue on buffer head and continue. This can be reproduced by starting a lot of connections. To increase the phenomena, POST are used to increase the number of datagram dropping : $ while true; do curl -F "a=@~/50k" -k --http3-only -o /dev/null https://127.0.0.1:20443/; done |
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.github | ||
addons | ||
admin | ||
dev | ||
doc | ||
examples | ||
include | ||
reg-tests | ||
scripts | ||
src | ||
tests | ||
.cirrus.yml | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
.travis.yml | ||
BRANCHES | ||
BSDmakefile | ||
CHANGELOG | ||
CONTRIBUTING | ||
INSTALL | ||
LICENSE | ||
MAINTAINERS | ||
Makefile | ||
README | ||
SUBVERS | ||
VERDATE | ||
VERSION |
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)