uucp using TLI

[Bill Kennedy]

Before I start this, many many thanks to Doug Mc Callum and Dick Dunn
at ISC for getting me straightened out on the address that nlsadmin
wants to make this work, to Bill Bunton at Tools & Techniques, Austin
for persevering as I stumble blundered through it, and to Bob Tracy
at CDC San Antonio for getting me started.

If you have no interest in a TLI based uucp over TCP/IP, hit `n' now,
but if you ever might, save this article, it will save your hair.

Here's the configuration and the problem.  I have two machines that are
networked together using ISC TCP/IP.  One of them has both printers that
used to be on a third machine connected by a direct 19.2Kbps uucp link.
My old lp scripts sort of went by the board when I no longer had a uucp
link to the system that had the printers.  It became obvious to me that I
had to figure out how to get uucp to work using TLI across the network.
TFM has some information on getting RFS to work, but it's silent with
respect to uucp using TLI.  A generous and TLI savvy neighbor, Bob Tracy,
was able to get things to almost work, but we kept failing in t_bind, it
couldn't allocate the address.  ISC lept to the rescue by explaining how
the address had to look for the listener to fundtion but we still (by now,
Bill Bunton had agreed to help but was falling into similar potholes)
couldn't get the originator's uucico to connect with its destination.  What
follows is a step-by-step recipe for something that works.  If there is a
more elegant way to do it, please feel free to mark it up and re-post.  If
there is any generally available documentation (cookbook please, not theory),
please tell us too.

Begin by editing /etc/services and create a port for nls.  We used
nls	256/tcp		# TLI port
if that doesn't suit you, keep track of the port number because you
need it to develop the nls address.  Now choose a name for the nls
"net_spec" (see NLSADMIN(1M)), we chose tcp.

Initialize the nls net_spec with nlsadmin -i tcp, it will create a
directory, /usr/net/nls/tcp and will create some files in it that it
uses to actually start the listener.  Now set up the nls service_code
nlsadmin -a 101 -c"/usr/lib/uucp/uucico -r0 -iTLI -u loginid" -y "comment" tcp
Here loginid is the name of the system who's going to be logging in, on
ssbn it's udunsel and on dunsel it's ussbn, both are no password logins
since they are local uucp over the ethernet.  I used "dunsel/ssbn uucico"
for the comment, all of this ends up in /usr/net/nls/tcp/dbf, you can make
a similar entry for cu, choose another service_code, avoid 105 because
that's rfs.

Now you have to work up your network address.  We'd have _never_ figured this
out without ISC's help!  This is a hex string that is composed of address
family (AF_INET), port number, IP address, and padding zeroes.  Here is the
format and an example:
\x02000100c0fafa010000000000000000    mapped as
  aaaappppiiiiiiiizzzzzzzzzzzzzzzz
  |   |   |       +------------------ sixteen padding zeroes
  |   |   +-------------------------- IP address 192.250.250.1 co.fa.fa.01
  |   +------------------------------ port address fm /etc/services (256)
  +---------------------------------- address family, socket address
Obviously your mileage is going to vary, but it shouldn't be hard to figure
out from this example.  Hang on to it, you're going to use it more than one
place...  You have to tell the listener what address he's going to use
nlsadmin -l "\x02000100c0fafa010000000000000000" tcp
and that number will appear in /usr/net/nls/tcp/addr to be used when you
start nls with nlsadmin -s tcp.  Look at /usr/net/nls/tcp/log to be sure
that you've gotten started, "Couldn't allocate address" means he can't
get to the address you specified, "Invalid argument" means you don't have
the right length.

Now you need to make some entries in /usr/lib/uucp/Systems, Devices, and
Dialers.  Remember that ssbn and dunsel don't have passwords on each
other, we can drop directly into uucico which is what we specified when
we added the 101 service code.

Systems:
# ssbn's Systems line for contacting dunsel, 192.250.250.2
dunsel Any wlknet Any \x02000100c0fafa020000000000000000
# dunsel's Systems line for contacting ssbn, 192.250.250.1
ssbn   Any wlknet Any \x02000100c0fafa010000000000000000

Devices:
wlknet,eg tcp - - TLI \D nls

Dialers:
nls "" "" NLPS:000:001:101\N\c

If you used a service_code other than 101 in the nlsadmin -a, replace the
101 in the Dialers entry with the code you used.  Also note that the Systems
lines need the address of the system that they are "calling", choose any
convenient Devices name, I used wlknet because that's the network name in my
/etc/networks.  Now you're ready to test the connection with Uutry.  It
goes by too fast to watch, but it's all recorded in /tmp/systemname.  You
might have to go through the usual /usr/lib/uucp/Permissions exercise to
make them actually talk to each other, but that's unrelated to nls or TCP/IP
(I _think_ :-)

Back to the original problem I had set out to solve, my ssbn resident lp
scripts just uux the stuff over to dunsel who is physically connected to
the printers.  Here's what I use to get to the dot matrix printer:

user=$2
options=$5
copies=$4
shift; shift; shift; shift; shift
files="$*"
for file in $files
do
	uux -  -a$user "dunsel!lp -o$options -n$copies 2>/dev/null" < $file
done

The lp setup on dunsel contains all the stuff that worries about lines
per inch, pitch, etc.  That's all passed in options, I don't try to use
more than one, so beware of quotes/apostrophes.

You'll get some astonishing transfer rates!  My lamebrained lp approach is
what I cobbled together because I don't have lpr/lpd and (you can probably
tell :-) probably wouldn't understand them if I did.  Don't forget, I didn't
claim that this was elegant, just that it works...
-- 
Bill Kennedy  usenet      {att,cs.utexas.edu,pyramid!daver}!ssbn.wlk.com!bill
              internet    bill at ssbn.WLK.COM   or attmail!ssbn!bill