1.\" $NetBSD: dm.8,v 1.9 2003/08/07 09:37:11 agc Exp $ 2.\" 3.\" Copyright (c) 1987, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)dm.8 8.1 (Berkeley) 5/31/93 31.\" 32.Dd May 31, 1993 33.Dt DM 8 34.Os 35.Sh NAME 36.Nm dm 37.Nd dungeon master 38.Sh SYNOPSIS 39.Nm ln 40.Fl s Cm dm Ar game 41.Sh DESCRIPTION 42.Nm 43is a program used to regulate game playing. 44.Nm 45expects to be invoked with the name of a game that a user wishes to play. 46This is done by creating symbolic links to 47.Nm , 48in the directory 49.Pa /usr/games 50for all of the regulated games. 51The actual binaries for these games should be placed in a 52.Dq hidden 53directory, 54.Pa /usr/games/hide , 55that may only be accessed by the 56.Nm 57program. 58.Nm 59determines if the requested game is available and, if so, runs it. 60The file 61.Pa /etc/dm.conf 62controls the conditions under which games may be run. 63.Pp 64The file 65.Pa /etc/nogames 66may be used to 67.Dq turn off 68game playing. 69If the file exists, no game playing is allowed; the contents of the file 70will be displayed to any user requesting a game. 71.Sh FILES 72.Bl -tag -width /var/log/games.log -compact 73.It Pa /etc/dm.conf 74configuration file 75.It Pa /etc/nogames 76turns off game playing 77.It Pa /usr/games/hide 78directory of ``real'' binaries 79.It Pa /var/log/games.log 80game logging file 81.El 82.Sh SEE ALSO 83.Xr dm.conf 5 84.Sh HISTORY 85The 86.Nm 87command appeared in 88.Bx 4.3 tahoe . 89.Sh SECURITY CONSIDERATIONS 90Two issues result from 91.Nm 92running the games setgid 93.Dq games . 94First, all games that allow users to run 95.Ux 96commands should carefully 97set both the real and effective group ids immediately before executing 98those commands. 99Probably more important is that 100.Nm 101never be setgid anything but 102.Dq games 103so that compromising a game will result only in 104the user's ability to play games at will. 105Secondly, games which previously had no reason to run setgid and which 106accessed user files may have to be modified. 107