06675db4bf
Mjson comes with its own strtod() implementation for portability reasons and probably also because many generic strtod() versions as provided by operating systems do not focus on resource preservation and may call malloc(), which is not welcome in a parser. The strtod() implementation used here apparently originally comes from https://gist.github.com/mattn/1890186 and seems to have purposely omitted a few parts that were considered as not needed in this context (e.g. skipping white spaces, or setting errno). But when subject to the relevant test cases of the designated file above, the current function provides the same results. The aforementioned implementation uses pow() to calculate exponents, but mjson authors visibly preferred not to introduce a libm dependency and replaced it with an iterative loop in O(exp) time. The problem is that the exponent is not bounded and that this loop can take a huge amount of time. There's even an issue already opened on mjson about this: https://github.com/cesanta/mjson/issues/59. In the case of haproxy, fortunately, the watchdog will quickly stop a runaway process but this remains a possible denial of service. A first approach would consist in reintroducing pow() like in the original implementation, but if haproxy is built without Lua nor 51Degrees, -lm is not used so this will not work everywhere. Anyway here we're dealing with integer exponents, so an easy alternate approach consists in simply using shifts and squares, to compute the exponent in O(log(exp)) time. Not only it doesn't introduce any new dependency, but it turns out to be even faster than the generic pow() (85k req/s per core vs 83.5k on the same machine). This must be backported as far as 2.4, where mjson was introduced. Many thanks to Oula Kivalo for reporting this issue. CVE-2025-11230 was assigned to this issue.
HAProxy
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:
- 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)
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.