Milter-greylist

On Fri, Oct 24, 2008 at 01:34:42PM +0900, Hajimu UMEMOTO wrote:
> Hi,
> 
> >>>>> On Fri, 24 Oct 2008 05:27:18 +0200
> >>>>> manu@... said:
> 
> manu> People using --enable-dnsrbl may also have a problem on some systems.
> manu> dnsrbl.c contains:
> 
> manu> #if (defined(res_ninit) || (__RES >= 19991006) )
> manu> #define HAVE_RESN       1
> manu> #ifndef res_ndestroy
> manu> #define res_ndestroy(res)       res_nclose(res)
> manu> #endif
> manu> #else 
> manu> #define res_ninit(res) \
> manu>         ((_res.options & RES_INIT) == 0 && res_init())
> manu> #define res_nquery(res, req, class, type, ans, anslen)  \ 
> manu>         res_query(req, class, type, ans, anslen)
> manu> #define res_ndestroy(res) 
> manu> #endif
> 
> I contributed the chunk to milter-greylist.
> Where there is res_ndestroy(), we do use it.

That is only true on systems (at least Linux and NetBSD AFAIK) where
res_* consists of a macro layer which can easily checked with
preprocessor #ifdef but *not* on such systems where res_ndestroy is a
real library function! (e.g. Solaris).

For the 4.0 branch I contributed the __RES hack above (which addresses
the previous mentioned problem in a simple way), but this seems not to
help much if we want to know if res_ndestroy exists (Solaris 9 has
res_ndestroy, Solaris 8 not but both have the same __RES value ...).

> Where there is no res_ndestroy(), we use res_nclose().
> Where there is no res_n* API, we use old res_init API, and we don't
> need to issue res_nclose() nor res_ndestroy().
> I believe it covers all variations of the BIND resolver.
> If I'm thinking in a wrong way, please let me know.

What we need is an additional autoconf rule which checks the
res_ndestroy existence on a platform ...
BTW, the existence of res_ninit could be also checked (so we can
drop the somekind unreliable __RES hack).

To Manu: Yes, I know, you are expecting something that looks like
a patch ... I will try ASAP.

Johann Klasek