dgamelaunch
===========

dgamelaunch is a network-based game shell where anyone can sign up for an
account and start playing any game which suits your fancy - currently, though,
it only supports NetHack (see http://www.nethack.org).

It requires the ncurses library and development headers to build and should
compile without issue on Linux, Solaris, FreeBSD 4 and 5. On Solaris you need
to remove the USE_OPENPTY and NOSTREAMS definitions in dgamelaunch.h, remove
-lutil from LIBS in the Makefile, and probably add something to make sure
ncurses can be found (e.g. LD_RUN_PATH, -R, LD_LIBRARY_PATH).
(Whether it _runs_ on all of these platforms is a different issue. We'd
like to hear about it.)

dgamelaunch was originally developed by M. Drew Streib <dtype@dtype.org> but
is now a collaborative project. Copyright and contact information is in the 
COPYING file, included with this package.
Mailing list: http://alt.org/mailman/listinfo/nethack/

BASIC SETUP INSTRUCTIONS
========================

1) Setup a chroot jail. There is a helpful script included to accomplish this,
called dgl-create-chroot, in the source directory. The default settings are
viewable by editing the script; to customize the installation, look at
dgl-create-chroot.conf.example (also in the source directory) and edit it to
suit your needs, and save it into the same directory as dgl-create-chroot as
dgl-create-chroot.conf. It's very likely you need to run the script as root.
The script will not work with the very limited System V /bin/sh, such found on
Solaris; start it with ksh instead.

If you decide to not use dgl-create-chroot, you're on your own and we assume
you have enough clue to figure out exactly what's needed for the chroot to
operate correctly.

2) Compile nethack. Make sure the directories in the chroot match up with
where nethack thinks everything is. You may need to edit the VAR_PLAYGROUND
variable in include/unixconf.h and/or the HACKDIR variable in include/config.h.

(Note: Try not to, for security, to put anything else in the chroot. You may
need to put gzip in there though if you compile nethack to use it for 
compression.)

3) Edit dgamelaunch.conf. This will contain information for dgamelaunch
about what uid/username, gid/group to shed privileges to at runtime. It
must also contain the path to nethack, and needs to know certain aspects
of your chroot.

Note that using a username in dgamelaunch.conf will cause (part of) your
passwd database to be loaded into dgamelaunch's memory space. If you use BSD,
this will also include encrypted passwords. Therefore, it's recommended to
put the uid in the dgamelaunch.conf. The same applies to groups, but openpty(3)
often looks up the tty group anyway.

4) Setup dgamelaunch as one of the following:
        a) The shell for a single login.
        b) An (x)inetd service.

If you choose a login shell make sure dgamelaunch is setuid root. (that is,
chmod 4755 dgamelaunch.) It will shed privs right after entering the chroot
jail though.

Example xinetd lines:

service telnet
{
  socket_type     = stream
  protocol  = tcp
  wait      = no
  user      = root
  server    = /usr/sbin/in.telnetd
  server_args     = -h -L /opt/nethack/nethack.dtype.org/dgamelaunch /etc/dgamelaunch.conf
  rlimit_cpu      = 3600
  bind      = 64.71.163.206
}

A classic inetd line would look like this:

telnet stream tcp nowait root.root /usr/sbin/tcpd /usr/sbin/in.telnetd -h -L /usr/sbin/dgamelaunch /etc/dgamelaunch.conf

In both cases, the -L specifies an alternate login program (telnetlogin is
invoked by default) and -h prevents revealing of a login banner (for 
example, "Debian GNU/Linux testing/unstable influx") before starting the
login shell.

It goes without saying that the argument after -L must point to dgamelaunch's
exact location. Also, the location of dgamelaunch.conf is variable and of
course should be customized by you.

It appears that the -L option is not very widely supported. FreeBSD's
telnetd uses -p instead, and you can't give arguments (arguments appropriate
to standard login are used), so it's necessary to start a shell script from
it.  Some other telnetds do not support anything like this at all.

5) Test your compilation of dgamelaunch by running it as root. If this
works, a shell login or (x)inetd will work with the correct configuration.
If you have problems with dgamelaunch's display make sure that your chroot's
/etc/terminfo directory (or whatever directory your ncurses uses) is
populated.