uid range on Ultrix

[Jeffrey Mogul]

In article <26ADE591.9398 at orion.oac.uci.edu> iglesias at orion.oac.uci.edu (Mike Iglesias) writes:
>
>
>It appears from the /etc/adduser script that the maximum uid Ultrix
>can handle is 32000, and tests seem to prove that out.  Is there some
>reason that the maximum uid is limited to 32000, when it could go as
>high as 32767?  We have uids grouped by department, and we'd really
>like to be able to be able to use uids between 32000 and 32767.  Does
>Ultrix v4.0 have the same restriction?

If you have an Ultrix system you should have /usr/include/sys/limits.h,
which includes this comment:
 * 005  Mark A. Parenti, 3-Sep-1987
 *      Add defines for POSIX compliance.
 *      Change UID_MAX from 60000 to 32000. The uid field is a short
 *      throughout the kernel and as such can only handle up to 32767.
 *      The 60000 is a remnant from System V which uses an unsigned
 *      short.  This change eases POSIX compliance in regards to error
 *      checking in the setuid() system call.

Now, I don't know why he set it to 32000 instead of 32767, unless
some requirement in the POSIX specs gives this limit.  And, as far
as I can discover, the limit is still 32000 in Ultrix 4.0

If you are unhappy about this this, you could file an SPR and complain;
perhaps by the next release it will be fixed.

Of course, if you had sources, you could recompile your kernel after
changing the value ... but that's probably not a cost-effective option.

-Jeff