Re: Mapping of RIDs to uid_t and gid_t

Jeremy Allison (jallison@whistle.com)
Fri, 03 Apr 1998 11:15:42 -0800

Date:	Fri, 03 Apr 1998 11:15:42 -0800
From:	Jeremy Allison <jallison@whistle.com>
To:	allan@umich.edu
Subject: Re: Mapping of RIDs to uid_t and gid_t

Allan Bjorklund wrote:
>
> This will not work at our site. We currently have
> 85060 active entries in our global password file
> (and growing).
>
> We have to use 32 bit UIDs and GIDs.

Well I wasn't excluding sites that are using
32 bit uids and gids, just ones that are using
them greater than 2^28 - 1.

Last time I looked 85060 is less than 2^28-1 :-)
so you should still be able to use the scheme, so
long as the uids and gids you have allocated
don't use the top 4 bits.

I don't have much of a choice here - I have
to give a 32 bit token back to NT and that's
all I will get back from it in order to unambiguously
differentiate a user or group.

Now what we may be able to do is add a lookup
table for uids and gids that are greater
then 2^28-1 and shift them down on a uid-by
-uid case basis, but this will be very slow
if a data structure walk has to be made when
many users map into this range.

Jeremy.

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