From: Florian Weimer <fw@deneb.enyo.de>
To: Rich Felker <dalias@libc.org>
Cc: Christian <list-christian@web.de>, musl@lists.openwall.com
Subject: Re: [musl] Resolver routines, Postfix DNSSEC troubles - how to check for incompatibilities?
Date: Tue, 14 Apr 2020 11:57:17 +0200 [thread overview]
Message-ID: <87blnuo0ea.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <20200413163800.GV11469@brightrain.aerifal.cx> (Rich Felker's message of "Mon, 13 Apr 2020 12:38:00 -0400")
* Rich Felker:
> On Mon, Apr 13, 2020 at 05:52:34PM +0200, Florian Weimer wrote:
>> * Christian:
>>
>> > So Viktor did some digging:
>> >
>> > "The comment on line 25:
>> >
>> > https://github.com/runtimejs/musl-libc/blob/master/include/resolv.h#L25
>> >
>> > is not encouraging. It suggests that _res is unused. If so, Postfix
>> > DNS does not work correctly with this C library. And not just for DANE, since Postfix is also unable to to control RES_DEFNAMES and RES_DNSRCH.
>>
>> Are these changes to the RES_DEFNAMES and RES_DNSRCH flags really
>> necessary? Why doesn't Postfix use res_query (or perhaps res_send) as
>> appropriate?
>
> But to actually answer these questions, modifying the flags is
> presumably because traditional req_query builds an rfc1035 query or
> edns query based on these flags derived from from resolv.conf, and
> Postfix either assumes or wants to support the case where resolv.conf
> is not already configured for edns, perhaps because it was generated
> by a dhcp client.
In my comment above, I specifically meant RES_DEFNAMES and RES_DNSRCH.
RES_USE_EDNS0 seems different; I would expect applications to use
their own DNS libraries if they need to access DNSSEC data and
non-address record types (where there is no benefit gained form
integrating with /etc/hosts or other data sources).
next prev parent reply other threads:[~2020-04-14 9:57 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-13 9:25 Christian
2020-04-13 11:20 ` Christian
2020-04-13 15:29 ` Rich Felker
2020-04-13 15:52 ` Florian Weimer
2020-04-13 16:07 ` Rich Felker
2020-04-13 16:38 ` Rich Felker
2020-04-13 17:51 ` Christian
2020-04-13 18:04 ` Rich Felker
2020-04-14 9:57 ` Florian Weimer [this message]
2020-04-14 15:53 ` Rich Felker
2020-04-14 16:54 ` Florian Weimer
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