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Deadwood 3.1.01 released

 

November 27 2011

While everyone else in the USA has been celebrating Thanksgiving, I have been taking advantage of the days off from my day job to implement something in Deadwood that I didn't have a chance to implement before. I would like to thank Nicholas Bamber, again, for his sponsorship that makes this work possible.

One issue Deadwood 3.0 has had is that it doesn't use cached incomplete CNAME referrals. Let me explain...

When trying to resolve, say, news.yahoo.com, we end up getting a reply like this: "news.yahoo.com's name is actually some-horrible-really-long-name.yahoodns.net, and I am not going to tell you where to find some-horrible-really-long-name.yahoodns.net". So, Deadwood has to go to all of the effort to locate this really long horrible name.

Now, 15 minutes later, once news.yahoo.com has expired from the cache, let us suppose someone else asks for news.yahoo.com. While Deadwood, in fact, notes that news.yahoo.com really uses some other name, Deadwood 3 does not actually use this information and has to start over to find news.yahoo.com.

Deadwood 3.1.01 fixes all this. Deadwood will now use an incomplete CNAME record that is in its cache to speed up solving these kinds of difficult-to-resolve CNAME chains. Since Deadwood has always cached these records, this change to the code doesn't even change the binary format for Deadwood's cache file.

Since this required re-factoring quite a bit of Deadwood's recursive resolver, it was rather difficult to implement. Also, due to the amount of code rewritten, this is a testing release. Please only use this release if you are willing to subscribe to the MaraDNS mailing list to report bugs. It can be downloaded here:

http://www.maradns.org/deadwood/testing/

Update: Last minute testing discovered a crash in Deadwood 3.1.01 (there were cases when a pointer would be uninitialized, causing Deadwood to segfault when dereferencing the pointer); I have released Deadwood 3.1.02 with this fixed.

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