Re: What does this message mean?

[Matti Aarnio <mea@nic.funet.fi>]

On Sat, Dec 02, 2000 at 01:25:08AM +0100, Ralf Baechle wrote:
> On Sat, Dec 02, 2000 at 12:02:19AM +0200, Matti Aarnio wrote:
> 
> > 	It depends ... I used to get those too, not anymore.
> > 	(And no, it isn't WKS related. See man-page of 'smtp' about WKS.)
> 
> Does anything these days rely on WKS?  I saw one single WKS on a real
> DNS record all my life ...

	dig any poincare.tfy.utu.fi @ns1.utu.fi
	dig any hamilton.tfy.utu.fi @ns1.utu.fi

  My old alma-mater uses them still -- as a way to quickly bounce away
  email from queues when there is no change at delivering it.

> > 	The DNS specification says that the MX value must be hostname, and it
> > 	must have an address, specifically CNAME is not valid target for MX.
> 
> And nevertheless not an uncommon configuration ...

	Which is why the strict interpretation can't be used anymore..


> This is on the particular RH 6.2 / glibc 2.1.3 system:
> 
> [ralf@lappi ralf]$ /usr/lib/zmailer/getmxrr-test timeout-mx.zmailer.org
> DNS lookup reply: len=163 rcode=0 qdcount=1 ancount=1 nscount=2 arcount=2 RD=1 TC=0 AA=1 QR=1 RA=1
>  -> (3600s) MX[0] pref=0 host=timeout-zone.zmailer.org
>  MX lookup lacked ADDITIONAL SECTION Address for entry: MX 0 timeout-zone.zmailer.org
>   mx[0] mxtype=--(0) host='timeout-zone.zmailer.org'
>   getaddrinfo('timeout-zone.zmailer.org','0') (PF_INET) -> r=-2 (Name or service not known), ai=(nil)
>   getmxrr('timeout-mx.zmailer.org') -> nmx=1, maxpref=66000, realname=''
> getmxrr() rc=69 EX_UNAVAILABLE; mxcount=1
> getaddrinfo('timeout-mx.zmailer.org','smtp') -> r=-2 (Name or service not known), ai=(nil)
> [ralf@lappi ralf]$ 
> 
> Which should be the erroneous behavour you're describing.
> 
> > 	For that reason the configuration system has option:
> > 		--with-ipv6-replacement-libc
> 
> Thanks, will try.  What has this option to do with ipv6 btw?  The particular
> problem which I've reported did happen in an ipv4 only environment.

	There is separate option:  --with-ipv6   if you really want
	all of it activated.  The "--help" is fairly informative:

  --with-ipv6              Have IPv6 in system, and want to use it
  --with-ipv6-replacement-libc If system has broken  getaddrinfo() and friends

	My code uses IPv6 library APIs to do address lookups.
	That was cleanest way to incorporate the IPv6 support.

	The trick in smtp (server and client) is that even if the compiled
	code supports IPv6, it checks at the runtime if IPv6 type socket
	can be created.  If not, it refrains from doing AAAA DNS lookups.

>   Ralf

-- 
/Matti Aarnio	<mea@nic.funet.fi>