Limiting logons to licensed number: how?

[Robert Elz]

>   According to some notes I took at the Portland BSD4.3 internals
> course, Ultrix uses BSD's quota mechanism to enforce AT&T binary
> license restrictions.

That's true, but "misuses" might be a better word.

This raises a question I have never known the answer to.

What is a "user" for the purposes of the user count on
a binary licenced system.

The quota stuff counts uid's with active processes, so that's
what DEC has defined a user to be.  (On a system licenced for
'8 users' the same person can log in 200 times if there are enough
tty lines or net ports available).  (I believe that DEC add 2
to the number, one for "root" and one spare for random daemons).

Another scheme would be to count reead/write opens of tty lines.
I believe that plexus does this (probably others, maybe its unisoft).
That means that lots of users can log in, start a background process
and log out, allowing another user to use the vacated tty line, so there
are far more users running processes than the cpu is licenced for.
(But not more logged in).  Disadvantage of this scheme is that you
can't enable "getty"'s on more lines than you're icenced for,
even if they won't all be used at once.  (The DEC quota scheme
doesn't have that restriction).  This also doesn't seem to handle
net logins at all.

So, does anyone know what a "user" is ??

Robert Elz			ucbvax!kre  kre at ucb-vax.berkeley.edu