Re: dn_expand() confuses postfix

[orc <orc@sibserver.ru>]

On Tue, 13 Aug 2013 14:38:17 -0400
Rich Felker <dalias@aerifal.cx> wrote:

> On Wed, Aug 14, 2013 at 02:19:20AM +0800, orc wrote:
> > musl's dn_expand() confuses postfix - always returns 0, then
> > postfix's libdns.a gets wrong shifts and gives up with something
> > like:
> > 
> > ../test_dns_lookup: lookup yandex.ru type MX flags 2
> > ../test_dns_lookup: dns_query: yandex.ru (MX): OK
> > ../test_dns_lookup: warning: dns_get_fixed: bad class: 30722
> > ../test_dns_lookup: fatal: Name service error for name=yandex.ru
> > type=MX: Malformed or unexpected name server reply
> > 
> > If someone will face same error with postfix & musl, then get
> > portable dn_expand.c from
> > http://tclsysdns.googlecode.com/svn/trunk/unix/dn_expand.c and put
> > it in src/dns (edit Makefile.in to include src & obj).
> 
> Cleaning up this code is part of the roadmap for 0.9.13, but I wasn't
> aware that it was returning the wrong value. Thanks for bringing that
> to my attention.
> 
> > (btw running whole LAMP/FTP stack with musl - some issues appear
> > like iconv need to be replaced with libiconv to make some CMS
> > happy, so I have some compatibility experience here.
> 
> Do you know what problems they hit with iconv? It's my intention that
> iconv not need to be replaced. My guess is that the issue is failure
> to automatically detect UTF-16 endianness via BOM, or missing charset
> aliases for some charset strings.

I don't know why some hacked-up CMS did not liked current iconv. But in
phpinfo, iconv version shown as "unknown" which is probably traced to
absense of /include/gnu/libc-version.h and I suspect that they check it
or use some nonstandard extensions or PHP is mad. Building PHP 5.4
statically with gnu libiconv.a reset version to known one and
everything works.
I need to ask our php hackers about this (they maintain stuff) or
grep for all iconv which appears in sources.

> 
> > Musl much more perfect than I
> > expected)
> 
> Great to hear. :-)

I replaced gnu libc stack with musl one on our middly loaded sites in
large LAN/MAN and it works great and easier to maintain, fix and modify
in a way you want :)

> 
> Rich