samba - Feb 2000 - use sysconf instead of NGROUPS_MAX

Currently samba (2.0.6) relies on the NGROUPS_MAX define. This makes
the number of allowed simultaneous (per-user) secondary groups a
compile-time decision.

$ find . -name \*.c | xargs grep NGROUPS   
./source/lib/system.c:  if (setlen > NGROUPS_MAX) {
./source/lib/replace.c: gid_t  grouplst[NGROUPS_MAX];
./source/lib/replace.c: while (i < NGROUPS_MAX && 
./source/smbd/password.c:#ifdef NGROUPS_MAX
./source/smbd/password.c:       if((groups = (gid_t
*)malloc(sizeof(gid_t)*NGROUPS_MAX)) == NULL)


POSIX defined sysconf in order to avoid this.

By using sysconf(_SC_NGROUPS_MAX) this value is determined at
run-time.


OTOH NGROUPS_MAX seems to be used incorrectly anyway:

source/smbd/password.c
#ifdef NGROUPS_MAX
        if((groups = (gid_t *)malloc(sizeof(gid_t)*NGROUPS_MAX)) == NULL)
#else /* NGROUPS_MAX */
        if((groups = (gid_t *)malloc(sizeof(gid_t)*ngroups)) == NULL)
#endif /* NGROUPS_MAX */

As Donald Lewine's POSIX book says: "The values returned by these
functions should be thought of as minimum guarantees. ... The values
returned by sysconf() and pathconf() are not suitable for allocating
memory."


Running samba on Linux only above-showed source/smbd/password.c seems
to be a problem since the other NGROUPS_MAX occurences only matter
when things like a sane initgroups are missing.

Suggestions etc. ?

	Sven

Dear Samba-team,

Since last year we've got SAMBA running here at the University of
Vechta on an Origin 200 running Irix6.5.
We want SAMBA to act as a trusted domain server for an
NT-PDC with 20 NT Workstations. Unfortunately no trust-relationships are
currently implemented- nontheless it's on your to-do-list.
We have been experimenting with samba 2. and a windows NT 4.0 server (SP4)
but came to no satisfying results. We almost did it but every logon we
got the message that no server-profile could be found though the 
system had access to the server profile and did use it. Except from this 
... message everything worked fine.

So actually we're interested in any news or progress and would offer you 
to participate as test environment.
If you are interested please contact me per e-mail for further details.


Jan C. Selke

--
Jan Christian Selke
Grosse Str. 1
D-49377 Vechta
Phone: +49 4441 851237
mail : Jan.Selke@Uni-Vechta.DE

Sven Rudolph wrote:
> 
> Currently samba (2.0.6) relies on the NGROUPS_MAX define. This makes
> the number of allowed simultaneous (per-user) secondary groups a
> compile-time decision.
> 
> $ find . -name \*.c | xargs grep NGROUPS
> /source/lib/system.c:  if (setlen > NGROUPS_MAX) {
> /source/lib/replace.c: gid_t  grouplst[NGROUPS_MAX];
> /source/lib/replace.c: while (i < NGROUPS_MAX &&
> /source/smbd/password.c:#ifdef NGROUPS_MAX
> /source/smbd/password.c:       if((groups = (gid_t
*)malloc(sizeof(gid_t)*NGROUPS_MAX)) == NULL)
> 
> POSIX defined sysconf in order to avoid this.
> 
> By using sysconf(_SC_NGROUPS_MAX) this value is determined at
> run-time.
> 
> OTOH NGROUPS_MAX seems to be used incorrectly anyway:
> 
> source/smbd/password.c
> #ifdef NGROUPS_MAX
>         if((groups = (gid_t *)malloc(sizeof(gid_t)*NGROUPS_MAX)) == NULL)
> #else /* NGROUPS_MAX */
>         if((groups = (gid_t *)malloc(sizeof(gid_t)*ngroups)) == NULL)
> #endif /* NGROUPS_MAX */
> 
> As Donald Lewine's POSIX book says: "The values returned by these
> functions should be thought of as minimum guarantees. ... The values
> returned by sysconf() and pathconf() are not suitable for allocating
> memory."
> 
> Running samba on Linux only above-showed source/smbd/password.c seems
> to be a problem since the other NGROUPS_MAX occurences only matter
> when things like a sane initgroups are missing.
I have fixed this in the HEAD and 2.0.x source trees
so that Samba now uses sysconf(_SC_NGROUPS_MAX) as
appropriate.

Thanks for pointing this out.

Regards,

	Jeremy Allison,
	Samba Team.

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a self-assembly Space Shuttle with no instructions.
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