[Dnsmasq-discuss] Conceptual patch to reject CNAME as NODATA

Josh Soref jsoref at gmail.com
Tue Nov 7 04:08:10 GMT 2017


This isn't tested [1], but I wanted to toss it out as an idea...

The existing codepath says:
> if we forwarded a query for a locally known name (because it was for
> an unknown type) and the answer is NXDOMAIN, convert that to NODATA,
> since we know that the domain exists, even if upstream doesn't

Just as NXDOMAIN should be mapped to NODATA, the same logic should be
applied for CNAME, because CNAME is by definition incompatible with
any other entries. So, the idea is to check if the answer is a CNAME
and then map it as NODATA.

I suspect I've made a number of errors in this patch, but the idea
seems reasonable.

[1] https://github.com/jsoref/dnsmasq/commit/7c55d91ce41255d83501d95ec03a97f82563e180.patch



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