

YPX - A utility to transfer NIS maps beyond a local network.

Introduction
------------
ypx is a utility which I wrote about a year ago, when I was studying
the Network Programming manual, as an experiment. Since older copies I
sent to a couple of friends seem to be spreading fast, I've decided to
post it to alt.sources.

Disclaimer
----------
Warning ! I am not responsible for the use, or the failure to use this
program. Use at your own risk. Overenthousiastic use of this program
might break existing local laws. Like any tool, illegal actions are not
the responsibility of the writer of the program, but of the user who
runs it. If you take the time to read the source, you'll find that the
internals are very simple. Anyone could write such a program, many have
already done this.

Installing and running ypx
--------------------------
Unpack the source (either a shar file or .zip file) in a directory, and
type 'make'. If make gives any warnings or errors, please send mail to
the adress below, so I can make the next release more portable. The
make step will produce the "ypx" binary, ready to run.

Documentation
-------------
A short document describes the command line options, it's called
"ypx.1".  This document is in the standard manual page format. The make
step will convert this file to an ASCII file called "ypx.doc". Install
"ypx.1" in a directory where man(1) can find it, optionally.

The future
----------
Since this is a first release, bugfixes and improvements will undoubtably
follow. Some ideas for improvements are:
- Find out how to transfer a map if the domainname is unknown.
- Avoid the portmapper by scanning a range of port numbers.
- Anything else I can think of.

Progress is also made in effort to protect your system from NIS map
transfers by unauthorized individuals with unknown motives.
- SUN will soon publish a bugfix, which contains new binaries for
ypserv and other programs, to add access control.
- Wietse Venema, the world's #1 security expert, has released a
version of portmap.c with access control similar to his exellent
tcpwrapper package. It is probably ftp'able from cert.sei.cmu.edu
and ftp.win.tue.nl. His email adress is wietse@wzv.win.tue.nl.

Comments
--------
Any comments and suggestions are welcome. Send mail to:
rob@wzv.win.tue.nl. I'll be happy to hear from you.

References
----------
Network Programming manual from SunOS 4.1
/usr/include/rpcsvc/yp*

Rob J. Nauta

