test_socket.py failure

[x2164 at mailcity.com]

Marc Christiansen <tolot at jupiter.solar-empire.de> wrote:
> x2164 at mailcity.com wrote:
> > Nick Coghlan <ncoghlan at iinet.net.au> wrote:
> >> Hmm, when the second argument is omitted, the system call looks like:
> >> 
> >> getservbyname("daytime", NULL);
> >> 
> >> Based on "man getservbyname" on my Linux PC, that should give
> >> the behaviour we 
> >> want - any protocol will match.
> >> 
> >> However:
> >> 
> >> Linux 2.6.4-52-default (Suse 9.1)
> >> Glibc 2.3.3
> >> gcc   3.3.3
> >> 
> >> So it may be that your older platform doesn't have this
> >> behaviour - I'd be very 
> >> interested in what 'man getservbyname' has to say.
> > 
> >    Just took a look at the man page for getservbyname on this
> >    system and it doesn't mention passing NULL as the second
> >    argument.  The pertinents: ;-)
> > 
> >        Linux kernel 2.6.10
> >        Glibc 2.2.5
> >        gcc   2.95.3

> Just to confuse the matter more, on my system the man page mentions
> passing NULL as the second argument and it works. Alas:
> SuSE 7.3
> Kernel 2.4.29 (vanilla)
> Glibc  2.2.4 (older than yours)
> gcc    2.95.3

> >    I'd say your probably right about there being a difference
> >    in the behaviour of getservbyname between libc 2.2.5 and 
> >    and libc-2.3.3 given the differences in man pages and 
> >    observed return values. I'll try and compare the libcs'
> >    getservbyname codes and let you know a little later in 
> >    the day.
> > 
> >    I wonder if the developers wanted to tie the python source
> >    code so closely to a glibc version and possibly gnu-libc
> >    specific?

> Perhaps SuSE did patch the glibc...

> Saluton
>   Marc



     hey Marc


     Oh man, not another problem that's just happening to
     me, again. :-)

     We all are still talking about python 2.4 aren't we?  I'm
     really running out of options on this.

     My manual page for getservbyname is dated "22 April 1996"
     and i think that it wasn't installed by glibc-2.2.5.  The
     info page for getservbyname which was installed by 2.2.5
     doesn't mention being able to pass NULL as a 'PROTO'
     argument.

     As for my saying above that i would take a look at the
     libcs' code for getservbyname, well, let's just say
     i won't be bantering about that idea so readily anytime
     soon. :-)

     What i believe happens in glibc-2.3.3 is that getservbyname
     is generated by two files: inet/getsrvbynm.c which contains
     a number of '#define's that then '#include's the file 
     nss/getXXbyYY.c which is sort of a template function that
     the '#define's fill out.  If your use to reading it
     nss/getXXbyYY.c probably is easy reading, but, for ego's sake,
     let's just say that i'm not use to reading it.  There's
     also  getsrvbynm_r.c and getXXbyYY_r.c for the reentrant
     versions of getservbyname plus some references to nss and
     nis versions of getservbyname.  Of course its also possilble
     that where i said "What i believe happens" at the beginning
     of this paragraph could be read as "I'm confused about what
     happens" and i don't mean that as critic of glibc.

     Marc, it is possible that there was a change between 
     glibc-2.2.4 and 2.2.5 that would account for the 
     difference in behaviour.  I think i'll write a little
     test program in C to check out getservbyname's return
     values in a little more controled environment.  I'll
     post the results tomorrow.

     
     pete jordan
     x2164   mailcity com


     

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