PowerDNS Blog

dnsdist 1.7.0 released | PowerDNS Blog

Written by Remi Gacogne | Jan 17, 2022 5:00:00 AM

Hello!

We are proud to announce the release of dnsdist 1.7.0. This release contains several new exciting features since 1.6.1, as well as improvements and bug fixes. It contains one single change from the first release candidate, a fix for DynBlockRatioRule::warningRatioExceeded provided by Doug Freed.

In our view, the most exciting new feature of 1.7.0 is the support of outgoing DNS over TLS and DNS over HTTPS, as well as the ability to do “cross-protocol” queries, meaning a query received over a given protocol (UDP, TCP, DoT, DoH, …) can be forwarded over a different one. Now that dnsdist is capable of contacting its backend over an encrypted channel, full end-to-end encryption is possible, offering improved confidentiality and integrity.

Among the new features is the ability to add a custom EDNS option to a query before forwarding it to a backend, via SetEDNSOptionAction. phonedph1 also contributed a new rule making it possible to route a query based on the number of outstanding queries in a pool, PoolOutstandingRule.

Pierre Grié from Nameshield contributed an XDP program to reply to blocked UDP queries with a truncated response directly from the kernel, in a similar way to what we were already doing using eBPF socket filters. This version adds support for eBPF pinned maps, allowing dnsdist to populate the maps using our dynamic blocking mechanism, and letting the external XDP program do the actual blocking or response.

The packet cache has been improved so that one can now configure which EDNS options should be ignored, raising the cache hit ratio behind customer-premises equipment. The incoming and outgoing protocols have been added to the output of the grepq command for a better understanding of the recently processed traffic.

Dimitrios Mavrommatis improved the handling of AXFR and IXFR queries, making it possible to reuse a TCP connection used for a zone transfer much more efficiently.

We added support for generating the still experimental SVCB and HTTPS records directly from dnsdist, offering potential benefits to both performance and privacy.

Our LMDB code has gained the ability to do range-based lookups, and is now more performant even for simple lookups.

Extending the per-thread custom load-balancing policies introduced in 1.6.0, it is now possible to write blazing-fast, lock-less per-thread custom actions using the Lua foreign function interface.

Holger Hoffstätte also improved the reporting of an unavailable backend, making sure the existing metrics are no longer reported to prevent any confusion.

This release also reduces the memory footprint of dnsdist in several places, which makes it easier to use in resource-constrained environments.

Please see the dnsdist website for the more complete changelog and the current documentation.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

The release tarball and its signature are available on the downloads website, and packages for several distributions are available from our repository.

With this release, the 1.4.x releases become be EOL and the 1.5.x and 1.6.x releases go into critical security fixes only mode.

Finally, we would like to thank the PowerDNS community and all external contributors for their great work in this release!