
pam_limits module:
	Imposing user limits on login.

THEORY OF OPERATION:

First, make a root-only-readable file (/etc/security/limits.conf by
default or INSTALLED_CONFILE defined Makefile) that describes the
resource limits you wish to impose. No priority changes and login 
limit checks are done on UID 0 accounts.

Each line describes a limit for a user in the form:

<domain>	<type>	<item>	<value>

Where:
<domain> can be:
	- an user name
	- a group name, with @group syntax
	- the wildcard *, for default entry

<type> can have the three values:
	- "soft" for enforcing the soft limits
	- "hard" for enforcing hard limits
        - "-" for enforcing both soft and hard limits

<item> can be one of the following:
	- core - limits the core file size (KB)
	- data - max data size (KB)
	- fsize - maximum filesize (KB)
	- memlock - max locked-in-memory address space (KB)
	- nofile - max number of open files
	- rss - max resident set size (KB) (ignored in Linux 2.4.30 or higher)
	- stack - max stack size (KB)
	- cpu - max CPU time (MIN)
	- nproc - max number of processes
	- as - address space limit
	- maxlogins - max number of logins for this user
	- maxsyslogins - max number of logins on the system
	- priority - lower the priority by given value (value can be -ve)
	- locks - max locked files (Linux 2.4 and higher)
	- sigpending - max number of pending signals (Linux 2.6 and higher)
	- msgqueue - max memory used by POSIX message queues (bytes) 
	  (Linux 2.6 and higher)

Note, if you specify a type of '-' but neglect to supply the item and
value fields then the module will never enforce any limits on the
specified user/group etc. .

Please remember that individual limits have priority over group
limits, so if you impose no limits for admin group, but one of the
members in this group has a limits line, the user will have its limits
set according to this line.

Also, please note that all limit settings are set PER LOGIN.  They are
not global, nor are they permanent (they apply for the session only).

In the LIMITS_FILE, the # character introduces a comment - the rest of the
line is ignored.

The pam_limits module does its best to report configuration problems found
in LIMITS_FILE via syslog.

EXAMPLE configuration file:
===========================
*               soft    core            0
*               hard    rss             10000
@student        hard    nproc           20
@faculty        soft    nproc           20
@faculty        hard    nproc           50
ftp             hard    nproc           0
@student        -       maxlogins       4


ARGUMENTS RECOGNIZED:
    debug		verbose logging

    conf=/path/to/file	the limits configuration file if different from the
			one set at compile time.

    change_uid		change real uid to the user for who the limits
    			are set up.  Use this option if you have problems
			like login not forking a shell for user who has
			no processes.  Be warned that something else
			may break when you do this.

    utmp_early		some broken applications actually allocate a
			utmp entry for the user before the user is
			admitted to the system. If the service you are
			configuring PAM for does this, you can use
			this module argument to compensate for this
			brokenness.

MODULE SERVICES PROVIDED:
	session            _open_session and _close_session (blank)

USAGE:
	For the services you need resources limits (login for example) put a
	the following line in /etc/pam.conf as the last line for that
	service (usually after the pam_unix session line:

	login   session    required     /lib/security/pam_limits.so

	Replace "login" for each service you are using this module, replace
	"/lib/security" path with your real modules path.

AUTHOR:
        Cristian Gafton <gafton@redhat.com>
	Thanks to Elliot Lee <sopwith@redhat.com> for his comments on
	improving this module, and Jens Sorensen for Linux 2.4 updates.
