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 - games known to
work with dgamelaunch are for example NetHack (http://www.nethack.org) and
Crawl (http://crawl.develz.org).


DGAMELAUNCH VERSIONS
====================

Development version can be fetched from the source repository with git:

  git clone git://github.com/paxed/dgamelaunch.git

Releases are downloadable at http://alt.org/nethack/dgamelaunch/


REQUIREMENTS
============

- normal development tools (make, etc)
- autotools (autogen, autoconf, automake)
- ncurses library and development files
- bison (or yacc or byacc)
- flex (or lex)
- optionally sqlite3 library and development files


COMPILING
=========

Basically all you have to do is:

  ./autogen.sh && make

Some options you might want give to autogen:

 --with-config-file=/absolute/path/to/dgamelaunch.config
 --enable-shmem
 --enable-sqlite


Dgamelaunch should compile without issue on Linux, Solaris, FreeBSD 4 and 5.
(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.


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

These instructions are not current. For a more up-to-date ones, see
http://nethackwiki.com/wiki/User:Paxed/HowTo_setup_dgamelaunch




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) Make a copy of dgamelaunch.conf and edit it. 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 -q -f /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 -q -f /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.

NOTE: 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). Some other telnetds do not support anything
like this at all.

The -f option, followed by a filename, specifies the path to the config file
to use for dgamelaunch.  If you specify the right path for DEFCONFIG in the
Makefile, you may be able to omit this.

For dgamelaunch, the -q option will silence errors pertaining to the server
configuration. This is recommended for use within inetd to prevent spamming
the clients, but when testing and setting up we strongly suggest you leave it
off until running dgamelaunch produces no error output on stderr.

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.


COMMANDLINE PARAMETERS
======================

 -a		Ignored.
 -c		Shows error message and exits. (login shell command)
 -e		Ignored.
 -h		Ignored.
 -i user	Autologin and run the register -command hook for "user"
    		(with password "user").
 -p		Ignored.
 -q		Be quiet, suppress errors.
 -s		Show players currently playing.
 -W user:msg	Send message "msg" to all players. The message seems
    		to come from "user".
 -S 		Free the shared memory block.
 -D		Show contents of the shared memory block.


ENVIRONMENT VARIABLES
=====================

 Linux telnetd allows importing the USER environment variables via telnet,
 while FreeBSD does not.  FreeBSD, on the other hand, does allow the LOGNAME
 environment variable.  Dgamelaunch will first check USER, then LOGNAME,
 for "username:password", and tries autologin if either exists.
 Dgamelaunch-specific DGLAUTH is checked before either of those.


ERROR CODES
===========

   1	Could not terminate stale processes
   2	Cannot chroot()
   3	Cannot chdir()
   4	Cannot setgroups()
   5	Cannot setgid()
   6	Cannot setuid()
   7	Caught HUP
   8	Cannot run as root: Config file has shed_user = "root"
   9	Cannot run as root: Config file has shed_user set to UID 0 user.
  10	Could not setup player
  11	Cannot run as root: Config file has shed_uid = 0
  12	Config file has an unrecognized token
  13	Config file: Negative value not accepted
  15	dgamelaunch called with -c (login shell command); exited
  20	No menu defined, or no banner found for menu
  60	Cannot create a new terminal, or no termcap files.
  61	Cannot openpty()
  62	Cannot open /dev/ptmx
  65	Cannot open master ptsname
  68	Cannot fcntl inprogress-lock
  70	Cannot write to inprogress-lock
  71	ftok() error for shm_key, no "dgamelaunch" file found?
  72	ftok() error for shm_sem_key, no "dgamelaunch" file found?
  73	shmget() error, cannot connect to shared memory
  74	smat() error, cannot attach to shared memory
  75	Nothing in shared memory?
  76	sem_init() error, could not initialize shared memory
  77	sem_wait() error
  78	sem_post() error
  95	Cannot fnctl lockfile
  96	sqlite3_open() failed when checking user existence: could not open login database
  97	sqlite3_open() failed in writefile()
  98	sqlite3_exec() failed in writefile()
  99	Could not open password file
 100	Username field too long in login file
 101	Email field too long in login file
 102	password field too long in login file
 103	env field too long in login file
 104	Cannot read config file
 105	Cannot read default config file
 106	Cannot open lockfile or password file
 107	fcntl failed on login database in writefile()
 108	sqlite3_exec() failed when checking user existence.
 109	Too many registered users. (see maxusers setting in config file)
 110	Login failed
 111	Two users trying to register at the same time
 112	Error changing password: cannot have ':' in password
 113	Error parsing configuration file
 114	exec-command fork failed
 115	could not read lock file in writefile()
 116	Too many registered users. (see maxusers setting in config file)
 117	wall error: no message to send
 118	wall error: no players
 119	User has a retarded terminal
 120	wall error: message too long
 121	wall error: "from" username is too short
 122	Error changing password: struct "me" does not exist
 123	chdir() failed in dgl commands.
 140	populate_games(): Cannot open inprogress-dir
 145	populate_games(): Inprogress-filename does not have ':' in it
 146	populate_games(): Inprogress-filename does not have ': in it (pt. 2)
 200	purge_stale_locks(): could not open inprogress-dir
 201	purge_stale_locks(): inprogress-file did not have ':' in it
 202	purge_stale_locks(): could not read inprogress-file
 203	purge_stale_locks(): could not get inprogress-file contents