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MaraDNS updates


November 29 2022

I have been making a lot of MaraDNS updates this last week. Let’s go over them.


A couple of years ago, I removed maradns.exe from MaraDNS’s download files because it had some Y2038 issues. maradns.exe is back because I finally got a chance to go over the source code and clean up a few lingering Y2038 issues.

Some features which require underlying libraries to work past Y2038, such as localized timestamps for SOA serial numbers and timestamps, are simply disabled on systems with a 32-bit time_t. It’s better for stuff like that to be disabled than to have it do something broken at Y2038. Users with a 64-bit time_t are not affected by these changes.

I have made other code Y2038 compliant on systems which still use a 32-bit time_t by moving the 136-year long window from 1901 to 2038 to another range of dates. Current timestamps should be good until sometime in 2156; timestamps for when zone files have been changed (to generate synthetic SOA serial numbers) should be good until sometime in 2136. While localtime functions (log timestamps, localized time SOA serial numbers) are disabled in the 32-bit Windows maradns.exe build, it uses Y2038 compliant native Win32 calls to find a file timestamp to generate a synthetic SOA serial number.

There is only a 136-year long window on systems with a 32-bit time_t; the majority of current real-world systems which use a 64-bit time_t will not have timestamp issues comes 2136, 2156, or whatever. There is an issue with synthetic SOA serial numbers wrapping back to 0 come 2841, so anyone using MaraDNS in the 2800s should be sure that replica (“slave”) DNS servers do not expect a SOA serial to increment, only change.

I should note that synthetic SOA serial numbers are not used in zone files with a SOA record in them—that’s another solution come 2800 or so (mid-2136 if one insists on still having a 32-bit time_t).

These fixes are important enough that I have backported them to the 3.4 branch of MaraDNS.


While MaraDNS generally does not follow RFCs which came out after 2010, there is one very useful RFC from 2019 with security implications: RFC8482. DNS has supported for a long time ANY records, but they are a moderate pain to implement. I implemented ANY records back in 2001 since an RFC-compliant DNS server needed to support them.

The only real world use case for ANY records is from Qmail supporting them because of a bug in Bind 4.9.3, released back in 1996. RFC8482 has been carefully designed to handle the Qmail corner case, and there is no other real-world use case for ANY. On the other hand, ANY has been abused by bad actors in denial of service attacks.

While the security implications for ANY are limited with MaraDNS (which does not have large packet support), there are security issues so I now consider having RFC8482 support essential. Indeed, it’s important enough I have backported RFC8482 support to the 3.4 branch of MaraDNS.

==Updating “make install”==

The Debian port of MaraDNS has not been maintained for a while. That in mind, since I use MaraDNS in Ubuntu 22.04 (note: Ubuntu is derived from Debian), and since the RFC8482 issue is serious enough to merit updating MaraDNS, it’s time for me to maintain MaraDNS for modern Linux distributions again.

That in mind, I spent all weekend researching systemd and have updated MaraDNS to have a proper unit file for systemd. Systemd is a lot better than many other init systems because, not only does it have full daemonization support (it does what duende did back in the sysvinit days), it also allows old sysvinit scripts to run.

Now, when running make install in MaraDNS, it will do the right thing in Ubuntu 22.04: It will install systemd unit files and enable the services with systemd.

In addition, “make install” will now install coLunacyDNS (a new Lua-based DNS server which uses Lua scripts to make custom DNS replies) as well as Lunacy (my personal fork of Lua 5.1 which I use for MaraDNS testing and for converting MaraDNS’s documents in to HTML pages, man pages, and plain text files).

Since I am a Ubuntu 22.04 user, I can only guarantee that “make install” will work with Ubuntu 22.04. People using other distributions are on their own, but I will keep duende and the old sysvinit init files around. I have even hacked them to work with OpenRC—note I am not actively supporting OpenRC because I only use Alpine Linux for MaraDNS unit/regression testing.

While discussing distributions, a shout out to Tomasz Torcz who maintains a current port of MaraDNS for Fedora core; this is the only distro-specific port of MaraDNS I know of which is still actively maintained.

==Getting MaraDNS==

MaraDNS, as always, is available here:

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