Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:77515
Return-Path: <mike.php.net@gmail.com>
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Delivered-To: mailing list internals@lists.php.net
Received: (qmail 70548 invoked from network); 23 Sep 2014 09:02:28 -0000
Received: from unknown (HELO lists.php.net) (127.0.0.1)
  by localhost with SMTP; 23 Sep 2014 09:02:28 -0000
Authentication-Results: pb1.pair.com header.from=mike.php.net@gmail.com; sender-id=pass
Authentication-Results: pb1.pair.com smtp.mail=mike.php.net@gmail.com; spf=pass; sender-id=pass
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.212.178 as permitted sender)
X-PHP-List-Original-Sender: mike.php.net@gmail.com
X-Host-Fingerprint: 209.85.212.178 mail-wi0-f178.google.com  
Received: from [209.85.212.178] ([209.85.212.178:35795] helo=mail-wi0-f178.google.com)
	by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP
	id 82/5A-09206-22731245 for <internals@lists.php.net>; Tue, 23 Sep 2014 05:02:27 -0400
Received: by mail-wi0-f178.google.com with SMTP id z2so4559375wiv.17
        for <internals@lists.php.net>; Tue, 23 Sep 2014 02:02:24 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20120113;
        h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject
         :references:in-reply-to:content-type:content-transfer-encoding;
        bh=4i5FZU6ME2GbD4aRM4fAkeRrmImeYwqbHGd15s+hpx4=;
        b=oe6pRm5LB+oAAfFALnF5q8VBbvG+3KkAqlJ50aIteSM9E0yUslyzIkwJeLkUH0ZEgY
         mybZLeC5er9wFXdgXIbMSZUtsXnhodhSh9po5KOdnEcFDnE5fCyzGCwp2utJ5A3R+Te0
         86Ijb+Sp3bG0OvDe6RSVX6U97TETiEuRmaciq1X84vQBWbad25gTK492f9pYJ6cABWHL
         6NsqsCQSTgIyzmw7+kK0GdQpKUJJP6jknrBuduBqVJoYpEbFnx22Dku2JFYqk/zHaDAT
         Fnfw6s4UGuvc9C3ATiB+uNGpI0yK0BtAqk29nJPIIYSNY68ED0/hIYb7Vs5/H4Yvbzpz
         rXeg==
X-Received: by 10.181.23.196 with SMTP id ic4mr20730968wid.69.1411462944013;
        Tue, 23 Sep 2014 02:02:24 -0700 (PDT)
Received: from [192.168.4.120] (178-18-170-101.customer.bnet.at. [178.18.170.101])
        by mx.google.com with ESMTPSA id t8sm1516294wib.8.2014.09.23.02.02.22
        for <multiple recipients>
        (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
        Tue, 23 Sep 2014 02:02:23 -0700 (PDT)
Sender: Michael Wallner <mike.php.net@gmail.com>
Message-ID: <5421371E.6070601@php.net>
Date: Tue, 23 Sep 2014 11:02:22 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0
MIME-Version: 1.0
To: Sanford Whiteman <figureonecpr@gmail.com>, 
 Pierre Joye <pierre.php@gmail.com>
CC: Kris Craig <kris.craig@gmail.com>, 
 PHP Internals <internals@lists.php.net>
References: <CAKOpQSyiCDEUDGhn50RuLL7ox_TJCCjD=4=qZ68OqbA5krXWkA@mail.gmail.com>	<CAA8DMBsjORWTDKDncgbrWZKHmrn-=VQaRgxSpwhKoRC-RmE=4w@mail.gmail.com>	<CAKOpQSx4FbBOyP+Q4NFrrVkRBGWdrZAfToVC6bvS_=wcpi2nrQ@mail.gmail.com>	<CAA8DMBstOx6Nfr0DPy5VMiJNrFwZLYz5SKo9rSu_6WQCEByhuA@mail.gmail.com>	<54212042.7060600@php.net>	<CAA8DMBtPvkko_joXjMVFHsauQq3A91YZjhgWNOfs2LaQDtFCcw@mail.gmail.com>	<CAEZPtU4463YX49_0wvMySdU=djyd+VuRBCFREpSkS=xjN4Nzaw@mail.gmail.com> <CAA8DMBteQszEYQuwjG2XQRoGvbQbMcas45a+Cd11_TLqEAg=8w@mail.gmail.com> <54213396.4080403@php.net>
In-Reply-To: <54213396.4080403@php.net>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] [RFC] Change checkdnsrr() $type argument behavior
From: mike@php.net (Michael Wallner)

On 2014-09-23 10:47, Michael Wallner wrote:
> On 2014-09-23 10:11, Sanford Whiteman wrote:
>>> if somehost.example.com has the MX, it should return true with
>>> checkdnsrr('somehost.example.com'). If example has the MX set to
>>> somehost.example.com or similar, it should return true as well. Or am
>>> I missing your point?
>>
>> You are missing it, as there are no MX records involved.  I'm
>> demonstrating that the function gives incorrect results in the absence
>> of an MX record because there is a bug in CNAME handling (or a bug in
>> A handling, if you prefer).
>>
>> somehost.example.com has no MX RR.  It has a CNAME (per DNS rules, the
>> CNAME must thus be the only record for somehost.example.com). The
>> CNAME  points to example.com.
>>
>> example.com has no MX RR.  It has an A pointing to 1.2.3.4.
>>
>> checkdnsrr('somehost.example.com') should return false. It returns true.
>> checkdnsrr('example.com') should return false.  It returns false.
>>
>> You could try to revise the docs and say, "Oh, it doesn't really mean
>> an MX lookup, it means an explicit MX *or* implicit MX, like how a
>> basic smtp-sender works. So that's why the CNAME --> A one returns
>> true."  Except then 'example.com' should return true as well.  It does
>> not: it returns false.  Changing the docs does not fix the bug.
> 
> Ah okay, I think you're right. It shouldn't accept the CNAME.
> 

Looking at the source, though, neither the code nor the docs make any
assertions on the actual type of response they got. So it could still be
seen as "works as expected", because it just checks if any answer is
received. If that functionality is useful could be debatable.


-- 
Regards,
Mike