I'm having problems with «$dnstype=~CNAME»

[DandelionSprout]

As good as I usually am with adblocker tools' syntaxes, I've encountered a fairly big problem where $dnstype=~CNAME isn't being recognised properly:

There's a lot of double negatives that are probably confusing me, but I thought ||example.org^$dnstype=~CNAME means that a domain is not blocked by CNAME or IP, and is only blocked when the domain itself is being requested. What am I missing out on here?

[ameshkov]

Well, that's not how dnstype works. You see, the type of the request is actually A, not CNAME, and that's why this modifier simply does not work as you expect it to even though it evaluates the CNAME record.

On the other hand, your problem seems absolutely valid to me. When evaluating response records, we should pass the record type, not the question type, to the filtering engine.

@ainar-g this should probably be categorized as enhancement, not a bug report. We'll also need to update the documentation as well.

[ainar-g]

@ameshkov, I'm not entirely sure I follow. What should be the correct result here?

[ameshkov]

A new issue in the repo that will improve the dnstype semantics and cover the case when we apply rules to response records.

[ainar-g]

Ah, I see now, thanks. I've filed #4238.

[EugeneOne1]

@DandelionSprout, hello again. We've just pushed the edge build that should consider record types of responses instead of a question while filtering the response. Could you please check, if it works properly?

[DandelionSprout]

Sorry for the late reply. My current AdGuard Home setup doesn't seem entirely stable, so I wasn't able to switch to the nightlies out of fear of breaking something. I'll apply the 0.108.0-b.3 beta pretty soon now, and will get the results from that in a couple days or so.