<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Hi Marcus,<div><br></div><div>I am afraid that we can’t provide any guarantees about the BIND 9 internal libraries. We made a decision to drop the layers and layers of compatibility for the sake of maintainability.</div><div><br></div><div>That said, once the release is pronounced ESV (roughly a year from initial release), we try to minimize changes to that branch, but it could still happen if needed by a security fix.</div><div><br></div><div>As for the binary compatibility, there’s no guarantee whatsoever, I think you need to match the full version to check whether the plug-in should be loaded.</div><div><br></div><div>Honestly, the best way how to keep the plug-in that’s useful for wider audience maintained would be to contribute it to the BIND 9 with a promise that the authors will keep helping maintaining the plug-in. (We would like to avoid the situations where the author just dumps the code on us and don’t care anymore - there’s associated maintenance cost with any new feature.)</div><div><br></div><div>Ondrej<br><div dir="ltr"><div>--</div>Ondřej Surý — ISC (He/Him)<div><br></div><div>My working hours and your working hours may be different. Please do not feel obligated to reply outside your normal working hours.</div></div><div dir="ltr"><br><blockquote type="cite">On 15. 12. 2022, at 20:10, Marcus Kool <marcus.kool@urlfilterdb.com> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<p>Hi,</p>
<p>I have written a plugin for named and was wondering what the
policy behind the usage of plugin_version() is and what kind of
compatibility check it intends to perform.</p>
<p>It is common for plugins to use query_ctx_t and its members
fname, view, client (client.message, client.query) etc.<br>
Since these data structures may change between (patch) versions, a
plugin compiled for version A can get a SEGV signal because a data
structure changed and the plugin is used inside named version B.<br>
I have little experience with data structure changes of named and
observed only the addition of <font face="monospace">refresh_rrset</font>
in query_ctx (somewhere between 9.16.1 and 9.16.35) which did not
cause an issue since its 1-byte size did not change offsets of
most members inside the query_ctx struct.</p>
<p>In our plugin, plugin_register() checks for the major and minor
version number in named_g_version so a plugin compiled with 9.16.x
refuses to initialize inside a 9.18.y named process and vice
versa. But I have the impression that this might not be a 100%
guarantee that all is well.<br>
</p>
<p>Because we like to release as few as possible versions of the
plugin I have a second question: how can we be sure that a plugin
compiled with 9.X.1 will have no issues accessing named data
structures for all patch versions of 9.X?</p>
<p>Thanks,</p>
<p>Marcus</p>
<p><br>
</p>
<p><span style="font-family:monospace"><br>
</span></p>
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