DM(8)                                                       BSD System Manager's Manual                                                      DM(8)

NAME

     dm -- dungeon master

SYNOPSIS

     ln -s dm game

DESCRIPTION

     dm is a program used to regulate game playing.  dm expects to be invoked with the name of a game that a user wishes to play.  This is done by
     creating symbolic links to dm, 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/lib/games/dm, that may only be accessed by the dm program.  dm determines if the requested game is
     available and, if so, runs it.  The file /etc/dm.conf controls the conditions under which games may be run.

     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.

FILES

     /etc/dm.conf          configuration file
     /etc/nogames          turns off game playing
     /usr/lib/games/dm     directory of ``real'' binaries
     /var/games/games.log  game logging file

SEE ALSO

     dm.conf(5)

HISTORY

     The dm command appeared in 4.3BSD-Tahoe.

SECURITY CONSIDERATIONS

     Two issues result from dm running the games setgid ``games''.  First, all games that allow users to run UNIX commands should carefully set
     both the real and effective group ids immediately before executing those commands.  Probably more important is that dm never be setgid any-
     thing but ``games'' so that compromising a game will result only in the user's ability to play games at will.  Secondly, games which previ-
     ously had no reason to run setgid and which accessed user files may have to be modified.

BSD                                                                May 31, 1993                                                                BSD