Subject: Re: resolv.conf domain v. search

Re: resolv.conf domain v. search

From: Erik Kline <ek_at_google.com>
Date: Wed, 26 Aug 2009 15:44:01 -0700

2009/8/15 Erik Kline <ek_at_google.com>:
> 2009/3/17 Daniel Stenberg <daniel_at_haxx.se>:
>> On Thu, 12 Mar 2009, Erik Kline wrote:
>>
>>> However, looking at ares_init.c in init_by_resolv_conf(), lines 819 and
>>> 823 show that whichever line is encountered first wins.
>>
>> I'd say that sounds wrong then comparing with the docs you quoted.
>>
>>> I believe the change to bring the behaviour closer to parity would be to
>>> simply delete the "&& channel->ndomains == -1" check.  I verified that
>>> set_search() frees any domains already set and config_domain() proxies
>>> through to set_search() and believe this change would be safe.
>>
>> We should also add something to our docs about the importance of order and
>> how it is used when both are found.
>>
>>> But I'm not sure what the ramifications of this change would be to other
>>> systems' behaviour, nor am I sure what the "standard" for this is/should be,
>>> nor who sets such a standard.
>>
>> In general I think we need to mimic how other resolvers work as far as
>> possible to get happy users of our softwares, so I think you're clearly on
>> the right path here.
>>
>> Can you write up a proper patch and submit it here?
>>
>> --
>>
>>  / daniel.haxx.se
>>
>
> So I've found online references to resolv.conf man pages for OpenBSD
> and Solaris and they both have the exact same sentence about the
> priority of repeated search and domain directives.  Given the number
> of times that text has been repeated verbatim in variously licensed
> operating system one might assume copyright is not problem.  :-)
> Nonetheless, I'm not sure where I should add such text.  Let me know
> where I should add it, if you want me to take a stab at something.
>
> Attached is trivial patch that implements the behaviour change though.
>

Thoughts?
Received on 2009-08-27