musl - Re: getaddrinfo() fails for domains with no AAAA records (regression?)

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Message-ID: <5463e48e-c6b7-f6e3-e405-6cf654b35c57@gmail.com>
Date: Mon, 19 Jul 2021 23:07:21 +0200
From: "Olivier A." <olivier.antoine@...il.com>
To: musl@...ts.openwall.com
Subject: Re: getaddrinfo() fails for domains with no AAAA records
 (regression?)

On 19/07/2021 14:58, Yuri Kanivetsky wrote:
>   [..]

Hi,

I notice that too. If both A and AAAA are sent and there is a response 
for A and NXDomain for AAAA

musl-libc discard both results. It's the expected behaviour according to 
this commit:

https://git.musl-libc.org/cgit/musl/commit/src/network/lookup_name.c?id=5cf1ac2443ad0dba263559a3fe043d929e0e5c4c

And it conform to https://datatracker.ietf.org/doc/html/rfc8020

It's was not the case before Alpine-Linux 3.13

But I also notice that if the DNS reply ServFailed instead of NXDomain 
for AAAA request, musl-libc retry 10 times, return 'bad address' and do 
not fallback to return a A record.

According to https://datatracker.ietf.org/doc/html/rfc4074#section-4.3 
it's not expected.

Yours,

-- 

Olivier Antoine

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