4bsd-uucp

This is a script and a set of template files which customises a generic 4.3BSD SimH disk image so that it acts as a uucp node and connects to other uucp nodes via TCP links.

Installation

You will need the bsdtar program installed so that tarballs compatible with 4.3BSD can be installed. On Ubuntu, sudo apt-get install bsdtar. Can someone add instructions for other systems? The source for bsdtar is at http://www.libarchive.org/

Download the SimH Github repository at https://github.com/simh/simh. In your local copy, build a vax780 SimH binary and copy the resulting binary somewhere useful:

make vax780
sudo cp BIN/vax780 /usr/local/bin

Download this Github repository. In this repository, compile the mktape program:

cc -o mktape mktape.c

You will see the generic 4.3BSD SimH image, rq.dsk.gz. The buildimg script builds a tar for each uucp system with the specific changes for that system.

As an example, look at the site_generate script:

# An example of three uucp sites connected in series
#
#    site5 ----- site6 ----- site7
#
./buildimg site5:5000 site6:localhost:6000
./buildimg site6:6000 site5:localhost:5000 site7:localhost:7000
./buildimg site7:7000 site6:localhost:6000

site5 allows you to telnet in on TCP port 5000. Ditto site6 and TCP port 6000, and site7 and TCP port 7000.

site5 has a (simulated) hard-wired serial connection to site6 through TCP port 6000. The syntax allows site6 to be on a remote computer, e.g. available through www.somewhere.com:6000.

site6 has a (simulated) hard-wired serial connection to site5 and site7. Finally site7 has a (simulated) hard-wired serial connection to site6. This means that each site can initiate a connection to another site; they don't have to wait for the other site to dial in.

For each site, there are two files generated:

• siteX.ini is the SimH config file to run this system
• siteX.tap is a tarball in tap format with the customisations

We also need to copy the generic disk image rq.dsk.gz to be the disk for each site:

zcat rq.dsk.gz | dd conv=sparse > site5.dsk
zcat rq.dsk.gz | dd conv=sparse > site6.dsk
zcat rq.dsk.gz | dd conv=sparse > site7.dsk

I prefer to use dd conv=sparse because a lot of the disk image is empty and this saves disk space for these files.

Customising each System

Once you have a disk, a config file and the customisation tape, here is how you customise the system. Boot up the system:

vax780 site5.ini

At the login: prompt, login as root with no password. At the shell prompt, read in and unpack the tarball, and run a script which sets appropriate file permissions:

myname# tar xf /dev/rmt12
tar: blocksize = 1
myname# ./mkdirs
29 password entries, maximum length 93
Now logout and login again

Logout (ctrl-D) and login as root. Your system now has a hostname:

login: root
Last login: Wed Mar  7 10:52:10 on console
You have mail.
Don't login as root, use su
site5#

Repeat the process for the other sites, e.g. site6 and site7. SET ROOT PASSWORDS NOW!!

Sending E-mail

On site5 you can send e-mail to site6!root and site6!site7!root. Watch out for escaping the bang characters as the shell is csh, e.g.

echo Hello there | mail site6\!site7\!root

You should be able to work out the bangpaths to send e-mails on the other systems.

Performing UUCP Connections

Right now, I haven't set up any cron jobs to periodically make uucp connections, so here is how to perform a manual uucp connection. On site5, to call site6:

# /usr/lib/uucp/uucico -r1 -ssite6 -x7
root site6 (3/9-06:27-166) DEBUG (Local Enabled)
finds (site6) called
getto: call no. tty00 for sys site6
Using DIR to call
Opening /dev/tty00
login called
wanted """"
got: that
. . .
Password:got: that
send "uucp"
root site6 (3/9-06:27-166) SUCCEEDED (call to site6 )
imsg looking for SYNC<
\20>
imsg input<Shere=site6\0>got 11 characters
omsg <Ssite5 -Q0 -x7>
imsg looking for SYNC<
. . .
Proto started g
protocol g
root site6 (3/9-06:27-166) OK (startup tty00 9600 baud)
*** TOP ***  -  role=MASTER
daemon site6 (3/9-06:27-166) REQUEST (S D.site5B00D2 D.site5S00D2 daemon)
. . .
PROCESS: msg - SY
SNDFILE:
send 0221
send 0231
send 0241
rec h->cntl 042
state - 010
. . .
daemon site6 (3/9-06:27-166) OK (conversation complete)
send OO 0,omsg <OOOOOO>
imsg looking for SYNC<\0\0\20>
imsg input<     \5*%\3\20>
imsg input<     "*\10   \20>
imsg input<     "*\10   \20>
imsg input<OOOOOO\0>got 6 characters
site5#

Now go to site6 and run a similar command to forward the e-mail to site7:

# /usr/lib/uucp/uucico -r1 -ssite7 -x7

On site7, you can now read your e-mail:

site7# mail
Mail version 2.18 5/19/83.  Type ? for help.
"/usr/spool/mail/root": 3 messages 3 new
>N  1 MAILER-DAEMON Sat Jul  9 23:21  35/1191 "Returned mail: Host unknown"
 N  2 MAILER-DAEMON Sat Jul  9 23:22  33/986 "Returned mail: Host unknown"
 N  3 site5!root Wed Mar  7 11:02  14/422
& 3
Message  3:
From site6!site5!root Wed Mar  7 11:02:14 1984
Received: by site7.ARPA (4.12/4.7)
        id AA00173; Wed, 7 Mar 84 11:02:14 pst
Received: by site6.ARPA (4.12/4.7)
        id AA00168; Wed, 7 Mar 84 10:58:33 pst
Received: by site5.ARPA (4.12/4.7)
        id AA00170; Wed, 7 Mar 84 10:55:27 pst
Date: Wed, 7 Mar 84 10:55:27 pst
From: site6!site5!root (Charlie Root)
Message-Id: <8403071855.AA00170@site5.ARPA>
To: site6!site7!root
Status: R

Hello there

&

Automating uucp Connections

You can edit /usr/lib/crontab to have entries that run uucico for each site that you connection to. Here is an example line that connects to site6 every minute:

* * * * * /usr/lib/uucp/uucico -r1 -ssite6

Testing against an External System

I've set up a simulated decvax at simh.tuhs.org port 5000. If you want to try sending e-mail to this system, here is what you can do. In your SimH .ini file, put (or change) this line to say:

attach dz line=0,Connect=simh.tuhs.org:5000

which will connect /dev/tty00 to simh.tuhs.org port 5000. Then in your simulated 4.3BSD system, edit the dialer line in /etc/remote to say:

dialer:dv=/dev/tty00:br#9600:

Now try:

# tip dialer

which should connect out over /dev/tty00 to decvax via the TCP connection. Hit Return a few times to see if there is any response. On your host system, do netstat -a | grep ESTAB and see if there is a TCP connection to simh.tuhs.org:5000. To get out of tip, type in the two characters ~.

To send mail to decvax!root, you need to do a few extra things. Set up your /usr/lib/uucp/L.sys file with a line that says:

decvax Any;9 DIR 9600 tty00 "" "" ogin:--ogin:--ogin: uucp ssword: uucp

so that the uucp site decvax can be contacted via /dev/tty00. Edit your /usr/lib/sendmail.cf with an extra line that identifies decvax as a remote site:

CWdecvax                 (near the other CW lines)

Then you can try doing:

# echo hello there | mail decvax\!root
  <wait a few seconds>
# /usr/lib/uucp/uucico -r1 -decvax -x7

and you should see the debug information with parts of the uucp conversation.

Security

The tty lines are exposed to the Internet through the bound TCP port, so you may want to implement some firewall rules to only allow connections from specific IP addresses.

The tty lines are set as insecure in the 4.3BSD /etc/ttys, so they won't allow root logins. You can only login as root on the console, i.e. the place where you ran vax780 system.ini. It is a good idea to add a non-root user so that you can telnet in on the TCP port: only do this on localhost, as the telnet session is not encrypted. If you add this non-root user to the group wheel (in /etc/group), then you can su and become root.

Disabling the Telnet Protocol

If you are running a SimH site which accepts connections from non-SimH uucp sites (or vice versa), then there can be a problem because SimH uses the Telnet protocol on the TCP port to, for example, know when to echo/not echo text (think: passwords). This can cause uucp protocol problems, as the Telnet can interpret the incoming uucp data, which screws up the uucp protocol.

If you have this situation, you can set up an incoming TCP port with Telnet disabled. You will still want some of your simulated tty lines doing Telnet, so that you can log into your simulated 4.3BSD system and have your password hidden. Here is an example SimH configuration file with Telnet disabled.

# Set up eight DZ serial ports in 8-bit mode.
# Connect to a remote uucp site on 127.0.0.1:6000
# Listen on TCP port 5001 with Telnet disabled
# All other DZ lines will listen on port 5000 with Telnet enabled
set dz lines=8
set dz 8b
attach dz -a -m line=0,Connect=127.0.0.1:6000
attach dz -a -m line=1,5001;notelnet
attach dz -a -m 5000

Notes and Gotchas

If you telnet into one of your sites, you will see garbage instead of a nice login: prompt. This is because I had to set the DZ simulated lines in 8-bit mode, as this is needed by uucp. However, type in root and Return and you will log in.

We need to find a way in SimH to set the uucp lines in 8-bit mode but the getty lines in 7-bit mode. Alternatively, in 4.3BSD, to set no parity on the getty lines. Anybody have any ideas on this?

What Next?

This all got thrown together in a couple of days, so feel free to make suggestions or improvements. The next thing is to get C-News and a newsreader working on these systems. Then, to get a bunch of people to host simulated uucp sites so that we can recreate a semblance of the uucp network that existed in the 1980s.