*** Notice: This is a modified version of xforward.

It has no security whatsoever. It no longer requires any X 
libraries or Motif. RUN IT AT YOUR OWN RISK.
The original xforward source is now named xforward.c.org.


It now simply acts as a proxy. I use it for a simple firewall application.

Suppose you have a firewall and machines behind the firewall that require
X access. Run xforward (on the router) for every machine that requires X
access.

Example: your firewall is called brick and the local machines
are called fred and wilma. The non local machines are barney and betty.


Invoke it like so (on the router):

brick# xforward -display fred:0 &
brick# xforward -display wilma:0 &

Now, xforward assigns display numbers on brick to correspond to the local
machines. If there is no X server on brick, then brick:0 will be forwarded
to fred:0 and brick:1 will be forwarded to wilma:0
You can now run remote X applications by setting the DISPLAY env variable
properly on the remote machine (call it barney), like so:

barney > setenv DISPLAY=brick:1
barney > xterm &

will pop up an xterm on wilma as long as wilma allows clients from barney;
i.e. must have 
wilma > xhost +barney

Since xforward no longer checks authentication on the client machines,
you can run it as part of a startup script, even if both fred and wilma
are off.


Original README follows:



This is version 1.0 of xforward, a program for relaying X11
connections across network boundaries.  While it may be used to cross
security boundaries, Digital Equipment Corporation does not warrant
this software for security or any other purpose.

See the file NOTICE included in this distribution for information about
copying and using this software.

xforward currently uses the Motif user interface toolkit, so you will
need Motif to compile it.

xforward has only been used and tested on DECstations running ULTRIX 4.2
or ULTRIX 4.3 with Digital's Motif product.  If you use it on another
platform, please let us know.

Installation
------------

1. Check the Makefile to make sure you like the paths and compiler
options.  Non-DEC platforms will probably require some changes for the
header file and library file paths.  (Yes, an Imakefile would be nice.
But I have yet to see a way to make a portable Imakefile for using
Motif.)

2. Execute "make all"

3. Execute "make install"

Bug fixes, reports, and other changes should be sent to
treese@crl.dec.com.

Where to Get Xforward
---------------------

The current version of xforward can be copied by anonymous FTP from
crl.dec.com:/pub/DEC/xforward.tar.Z.

Reading About Xforward
----------------------

The design and implementation of xforward are described in

	Treese, G. Winfield and Alec Wolman
	X Through the Firewall, and Other Application Relays
	Proceedings of the USENIX Summer Conference, June, 1993

A preprint of this paper is available as technical report 93/10 from
the Cambridge Research Lab of Digital Equipment Corporation, which can
be obtained by anonymous FTP from
crl.dec.com:/pub/DEC/CRL/tech-reports/93.10.ps.Z, or by sending an
electronic mail message with the word "help" in the body to
techreports@crl.dec.com.

Acknowledgements
----------------

xforward is derived from a program originally written by John Kohl.
Win Treese designed and Alec Wolman implemented the host access and
dialog box mechanisms.

Win Treese
Cambridge Research Lab
Digital Equipment Corp.
treese@crl.dec.com
4 June 1993