Aurelien DARRAGON ca53ee17b6 BUG/MINOR: counters: fix unexpected 127 char GUID truncation for shm-stats-file objects
As reported by GH @phihos on GH #3320, using the shm-stats-file feature
with objects exceeding 127 chars would result in object name being
unexpectedly truncated, while GUID API supports up to 128 chars.

Indeed, with the config below, and shm-stats-file enabled:
   server s1  127.0.0.1:1 guid srv:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:SRV_1 disabled
    server s10 127.0.0.1:1 guid srv:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:SRV_10 disabled

haproxy would store the second server object with the same id as the first
one, but upon reload, only the first one would be restored, which would
eventually cause shm-stats-file slot exhaustion with repetitive reloads.

@phihos, found out the underlying issue, in counters.c we used snprintf()
with sizeof(shm_obj->guid) - 1 as <size> parameter, while we should have
use sizeof(shm_obj->guid) instead since shm_obj->guid already takes the
terminating NULL byte into account.

So we simply apply the fix suggested by @phihos, and hopefully this should
solve the shm-stats-file slot leak that was observed.

Unfortunately, for now, we cannot warn the user that a duplicate
shm-stats-file object was found, because we accept duplicate objects
by design for 2 reasons. The first one is for a new process to be able
to change the object type for a previously known GUID while allowing
previous processes to use the old object as long as they are alive.
The second reason is that upon startup we cannot afford to scan the
whole object list, as soon as we find a match (type + GUID), we bind
the object, and this way we avoid unnecessary lookup time.

Perhaps we have room for improvement in the future, but for now let's
keep it this way.

It should be backported to 3.3

Big thanks to @phihos for the bug description, analysis and
suggestions.
2026-04-04 02:14:50 +02:00
2021-09-16 09:14:14 +02:00
2026-04-03 11:46:05 +02:00
2026-04-03 11:46:05 +02:00
2026-04-03 11:46:05 +02:00

HAProxy

alpine/musl AWS-LC Illumos NetBSD FreeBSD VTest

HAProxy logo

HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications.

Installation

The INSTALL file describes how to build HAProxy. A list of packages is also available on the wiki.

Getting help

The discourse and the mailing-list are available for questions or configuration assistance. You can also use the slack or IRC channel. Please don't use the issue tracker for these.

The issue tracker is only for bug reports or feature requests.

Documentation

The HAProxy documentation has been split into a number of different files for ease of use. It is available in text format as well as HTML. The wiki is also meant to replace the old architecture guide.

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:

License

HAProxy is licensed under GPL 2 or any later version, the headers under LGPL 2.1. See the LICENSE file for a more detailed explanation.

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