[dns-wg] AAAA lookup misbehaviour

On Fri, Jul 02, 2004 at 01:42:55PM +0200, Alvaro Vives wrote:
> Hi David,
> 
> Only problems with DNS servers will be covered? I mean, won't you
> include something related with resolvers.
> 
> I can send some info regarding a bug in the resolver library of
> Windows XP+SP1 and Windows 2003, which causes a failure when a domain
> name has A and AAAA records.

There's also the really-annoying "getnaneinfo() can't handle
IPv4-mapped-IPv6 addresses" problem that creeped into some BSD code
(most notably OS X resolver library) and lately glibc through some
ancient ISC code people blindly-copied I think.  

This seems to be the most common problem on *nix platforms anyway,
luckily enough it's easily work-aroundable, for an example work-around
see:

 http://cvs.apache.org/viewcvs.cgi/apr/network_io/unix/sockaddr.c?view=markup

 Workaround description:

 Test the address against IN6_IS_ADDR_V4MAPPED, and setup a (IPv4)
 sockaddr_in structure based on the last 32-bits of the mapped
 address, and resolve it instead.

That's about the only big problem I've seen in any wide deployment with
APR which has been used with Apache 2 for over 2 years now.

-- 
Colm MacCárthaigh                        Public Key: colm+pgp at stdlib.net