[ILUG] router possibly running linux/*nix

[Gavin McCullagh]

Hi,

a year or so ago I bought a cheapish aDSL modem/router/4-port switch in
Marx Computers.  Cannot recall the brand off the top of my head but it is
an obscure one.  I've never used it myself but have lent it to a friend who
used it for several months with no problem.  I gave it to another guy the
other day and was looking through the web interface.  A few things
intrigued me:

1. There is a "System Log" page, the content of which looks rather like
   /var/log/syslog on a linux machine with pppd running.

2. When the machine is replugged the time goes back to 01/01/1970 00:00.

Both of these suggest to me that it's running some description of unix or
linux.  This doesn't appear to be advertised in the manual (although that's
entirely in Dutch) and there is no source code distributed.  It's now
running in a friend's house but I wouldn't mind replacing it temporarily
while I more thoroughly investigate it.  I could also drop round with a
laptop and have a rummage with it in place.

I may be wrong.  It might be legit (maybe it's not *nix at all or just a
non-gpl *nix).  I'd like some advice on:

1. I've heard of linux being used on a lot of these devices but seldom
   heard of other unixes.  What's the likelihood that I'm wrong and it's
   not running linux or any other GPL tools?

2. How can I better determine what's on it?  It has 4 UDP ports and a USB.
   I can portscan it of course and look for telnet or other services but
   that would seem a bit too easy.  Also nmap can make a guess at the OS.
   I guess I can look at the headers from it's little webserver.

I've heard of people using strings on the firmware but does anyone know how
I would get the firmware off it or is this where a firmware upgrade was
distributed?  Anyone know of sites that document how to analyse these
devices?  I've looked at gpl-violations.org and will pass this on to them
if I can determine beyond reasonable doubt that this is GPL sofware
provided without source.

Gavin