.\" Copyright (c) 1987 Regents of the University of California.
.\" Redistribution and use in source and binary forms are permitted provided
.\" that: (1) source distributions retain this entire copyright notice and
.\" comment, and (2) distributions including binaries display the following
.\" acknowledgement: ``This product includes software developed by the
.\" University of California, Berkeley and its contributors'' in the
.\" documentation or other materials provided with the distribution and in
.\" all advertising materials mentioning features or use of this software.
.\" Neither the name of the University nor the names of its contributors may
.\" be used to endorse or promote products derived from this software without
.\" specific prior written permission.
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
.\" @(#)dm.8 5.8 (Berkeley) 6/26/90
is a program used to regulate game playing.
expects to be invoked with the name of a game that a user wishes to play.
This is done by creating symbolic links to
in the directory ``/usr/games'' for all of the regulated games.
The actual binaries for these games should be placed in a ``hidden''
directory, ``/usr/games/hide'', that may only be accessed by the
determines if the requested game is available and, if so, runs it.
The file ``/etc/dm.conf'' controls the conditions under which games may
The file ``/etc/nogames'' may be used to ``turn off'' game playing.
If the file exists, no game playing is allowed; the contents of the file
will be displayed to any user requesting a game.
.ta \w'/var/log/games.log 'u
/etc/dm.conf \- configuration file
/etc/nogames \- turns off game playing
/usr/games/hide \- directory of ``real'' binaries
/var/log/games.log \- game logging file
Two problems result from \fIdm\fP running the games setuid ``games''.
First, all games that allow users to run UNIX commands should carefully
set both the real and effective user id's immediately before executing
those commands. Probably more important is that \fIdm\fP never be setuid
anything but ``games'' so that compromising a game will result only in
the user's ability to play games at will. Secondly, games which previously
had no reason to run setuid and which accessed user files may have to
projects / unix-history / blob