Limit no. of login

juno · 12-09-2002, 02:16 AM

How to limit the max. no. user of login to the linux system? Thx.

Mik · 12-09-2002, 04:30 AM

What are you actually trying to accomplish by limiting the number of users allowed to login? Wouldn't you be better off limiting what users are allowed to do instead of limiting the amount of users. It only takes one user to bring a system to a crawl by stealing all the resources.
Have you looked at the possibilities of PAM? If never really got into using it but it has lots of different possibilities of limiting access.
If you can't find anything with PAM you could always write a simple script which disables users from logging in.

Code:

if [ `w -h | wc -l` -gt 10 ]
then
  echo "Too many users" > /etc/nologin
else
  rm -f /etc/nologin
fi

You could run that from cron or have it triggered when a new user logs in.

juno · 12-09-2002, 04:48 AM

I didn't find the /etc/nologin file , should i create one? how to use the file ? thx.

Mik · 12-09-2002, 04:55 AM

You shouldn't have that file. The program login checks for that file. If it is present then it displays the contents of the file to the terminal and then closes the connection. Read 'man login' for more information. If the file is present then nobody will be allowed to login into the system. Even root will not be allowed to login so you should be careful how you use it.

stickman · 12-09-2002, 10:30 AM

You could always use xinetd to control the total number of connections and the connections per source.

juno · 12-10-2002, 03:27 AM

Hi stickman,

Can suggest how to use xinetd to control the login ? thx.

acid_kewpie · 12-10-2002, 03:51 AM

like mik said, WHY are you trying to do this? It's a slightly bizarre apparoach you seem to have thougth of, as it's easy to be logged in to your own system 3 or 4 times from just from opening terminals. I would think it very likely that there is a much ore elegant solution to what you are trying to do.

stickman · 12-12-2002, 02:38 PM

Quote:

Originally posted by juno
Can suggest how to use xinetd to control the login ? thx.

You can do this by setting the instances and per_source values in xinetd.conf. This will at least allow you to throttle any service that get started via xinetd.