limit-time-on-games

Used to place a daily time limit on games played by a five-year old
son or daughter in a network of computers at home.  A database runs on
one machine, while the other machines run an application that
periodically reads the database, and checks for the presence of any of
the games.  If a game is detected to be running, the the running time
for that group of games is incremented in the database.  When the
limit of running time for that group of games is reached, then any of
those games are killed by sending them an interrupt signal if they are
found to be running.

Setup:

1.  Put games.rc into /etc/games.rc and edit it to include whatever
    categories of games you wish to limit access to.  There are groups
    of games, so you can place different limits on different categories
    of games.
2.  Create a postgresql database called games, owned by the user you
    specify in step 3, making it available via TCP/IP.
3.  Put sample.gamesrc into the home directory of the user who has
    write access to the database, as the file ~/.gamesrc
4.  Edit ~/.gamesrc with the hostname of the database server, and the
    username, password you apply to access the database.
    games.
5.  Run init-games.pl to create the database from /etc/games.rc.
6.  Edit the top of time-left.pl and give the account of the person
    whos access you are controlling.  Give them read only access to the
    database games.  Provide the password in that file that you have
    assigned for that user to read the database.
7.  Copy ~/.gamesrc to the home directory of the account that can
    access the database on all the machines where you want to limit
    access to games.
8.  Copy limit-time-on-games-dp.pl into a directory that is on the
    $PATH, perhaps /etc/local/bin on all the machines on which you wish
    to control access to games
9.  Edit /etc/rc.d/rc.local, or create the equivalent in Debina/Ubuntu
    systems that starts limit-time-on-games-dp.pl as the user who owns
    the database.
10. If you want to change the time for playing games on different days
    (such as allowing more time on the weekend), then make a crontab
    entry for the user that owns the database like this:
# On weekends, half an hour each for silly and for educational games.
# On weekdays, 0 seconds only for each.
1 0 * * mon /home/nicku/bin/change-game-limits.sh silly 0
2 0 * * mon /home/nicku/bin/change-game-limits.sh educational 0
1 0 * * sat /home/nicku/bin/change-game-limits.sh silly 1800
2 0 * * sat /home/nicku/bin/change-game-limits.sh educational 1800
    Obviously you should specify the location to suit where you put
    those scripts, not specify in my home directory!

11. Ask me any questions at Nick Urbanik <nicku@nicku.org>.

Copyright (C) 2005  Nick Urbanik <nicku@nicku.org>

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  2satvhpfd
02111-1307, USA.

FILES
=====
change-game-limits.sh: change maximum time allowed for a group
change-game-time-left.sh: change time left for playing today in a group
change-game-time-played.sh: better to use  change-game-time-left.sh
games.rc: /etc/games.rc, configuration used to build the database
init-games.pl: program to create the database from /etc/games.rc
limit-time-on-games-db.pl: the application that monitors games
read-games-config-from-db.pl: show the configuration in DB.
README: this file
sample.gamesrc: edit and put as ~/.gamesrc in home dir of db owner
show-games.sh: Show games belonging to a particular group
time-left.pl: Let the person know how much time is left for playing

TODO
====

Increase security by getting more information about the games.  This
involves getting a fingerprint of each games process and using this
fingerprint to indentify the game process even if it is masquerading
under a different name.  This will be necessary when child reaches age
where they figure this out.

Make configuration simpler for the first time setup (could write a
script to create the initial database and users and their passwords)