From brian@UCB.EDU.BZ Fri Jan 26 07:28:26 1996
Date: Fri, 12 Jan 1996 10:38:18 -0600
From: Brian Candler <brian@UCB.EDU.BZ>
To: Multiple recipients of list BIG-LINUX <BIG-LINUX@NETSPACE.ORG>
Subject: Re: Mailbox Routing help

> What I want to do is have a machine
> that is on the net 24/7 connect to my machine at home via uucp over tcp/ip
> - - I'll have my home machine poll for mail every x hours.   What I need to
> know is, how do I configure sendmail on the live net machine, and how do I
> configure it on the intermittently connected home machine?

We have been using uucp over TCP/IP here. Here's what you need to do on the
machine which is initiating the uucp call:

(1) Make sure you have the following in /etc/services

uucp            540/tcp         uucpd           # uucp daemon

(2) Add the following line to /var/lib/uucp/hdb_config/Devices

TCP uucp - -

(3) The /var/lib/uucp/hdb_config/Systems file entry looks like this:

<uucpname> Any TCP - <hostname> in:--in: <username> word: <password>

Where <uucpname> is the uucpname of the other end of the link, <hostname> is
the domain name to call up (it goes where the telephone number is normally)

(4) If you include multiple adjacent lines for the same uucpname they will
be tried in turn; this lets you attempt uucp over TCP/IP, with an automatic
dial-up backup. Example:

uunet Any TCP - relay1.uu.net in:--in: myname word: wombat
uunet Any ACU 38400 18001234567 in:--in: myname word: wombat

(5) If this is a dial-up TCP/IP link you have to arrange that the line is
brought up automatically. If you have diald installed and running, problem
solved. If not, you need a script. Here's one I use; it is programmed
defensively since there have been problems with our service provider.

---------------------------- cut here ------------------------------
#!/bin/sh
# /usr/local/bin/poll-slip
# Do a mail poll. Call host; bring up and down the SLIP link if necessary
# (a kludge until I get diald running)

PROG=uucico
HOST=route      # uucpname
HOSTIP=rg.net   # domain name or IP number
CLOCKIP=rip.psg.com # machine to set clock to

UUCICO=/usr/lib/uucp/$PROG

didslip=""

# bring up SLIP if necessary

function downslip() {
  if [ "$didslip" != "" ]; then
    sleep 3   # let TCP connection hang up properly
    /sbin/dip -k &>/dev/tty8 </dev/tty8
    didslip=""
  fi
}

# Bring up the slip link if necessary (if there is already a link
# to the Internet - we check for a default route - then don't bother)

function checkslip() {
  { /sbin/route -n | grep default } &>/dev/null
  if [ "$?" != "0" ]; then
    date &>/dev/tty8
    /sbin/dip -v /etc/isp.dip &>/dev/tty8 </dev/tty8
    sleep 2
    { /sbin/route -n | grep default } &>/dev/null
    if [ "$?" != "0" ]; then
      /sbin/dip -v /etc/isp.dip &>/dev/tty8 </dev/tty8
      sleep 2
    fi
    didslip="Y"
  fi
  # Check if our host is available. If not, bring down the
  # slip link. (uucico can still run since it may have a telephone
  # backup in the Systems file)
  { ping -c3 $HOSTIP | grep "bytes from" } &>/dev/null
  if [ "$?" != "0" ]; then
     downslip
     sleep 5   # wait for line to drop so uucico can use it if req'd
  fi

}

# function checklastpoll:
# Check for possible errors: all matching ports in use; line disconnected
# (also tends to give write I/O errors when our uucp tries to send uucp
# shutdown sequence); timed out in chat script (=remote end not answering)
# If these don't apply, then we expect the call was completed OK so we exit.

function checklastpoll() {
    tail -2 /usr/spool/uucp/.Log/$PROG/$HOST | grep "ERROR" > /dev/null
    if [ "$?" != "0" ]; then
        tail -3 /usr/spool/uucp/.Log/$PROG/$HOST | grep "Timed out" > /dev/null
        if [ "$?" != "0" ]; then
            exit 0
        fi
    fi
}

# START HERE!

trap downslip EXIT      # so we drop SLIP when this script terminates

checkslip               # bring up SLIP
if [ "$didslip" = "Y" -a "$(date +%H)" -lt 5 ]; then
  # Set our clock from our host (only during our overnight poll)
  /usr/sbin/netdate ${CLOCKIP:-$HOSTIP} &>/dev/null
  /sbin/clock -w
fi

$UUCICO -S $HOST -x 2
checklastpoll

# wait, try again
downslip
sleep 9m
checkslip

checklastpoll
$UUCICO -S $HOST -x 2
checklastpoll

######### For the time being, give up after 2 attempts ########
exit 1
###############################################################

# wait, try again
downslip
sleep 14m
checkslip

checklastpoll
$UUCICO -S $HOST -x 2
checklastpoll

# Admit defeat!
exit 1
--------------------------- end cut ---------------------------

At the end which is answering the call you need to have the uucico daemon
start on an incoming connection on port 540:

(1) Make sure you have the following in /etc/services

uucp            540/tcp         uucpd           # uucp daemon

(2) Make sure you have the following in /etc/inetd.conf

uucp    stream  tcp     nowait  uucp    /usr/sbin/tcpd  /usr/lib/uucp/uucico -l

(do "killall -1 inetd" if you have changed it)

(3) Put username:password pairs in /var/lib/uucp/taylor_config/passwd

freddy:catNmouse

(This is correct for the Taylor uucp supplied with Slackware 3.0; it uses
cleartext passwords, so make sure you protect the file!)

To test it out, do "telnet localhost 540", enter the username and password,
and it should come back with "Shere=<uucpname>". Type ^[ close <enter>
to get out.

> I'm a bit intimidated by the prospect of messing with sendmail, having seen
> the big Sendmail book.

Me too, so I use Smail. The compiled version which comes in the 'contrib'
directory of Slackware 3.0 works very nicely.

> If this is in a FAQ, I haven't found it and would welcome pointers,
> preferably URLs.

Check out the UUCP-HOWTO and Mail-HOWTO for other aspects of uucp/mail
setup.

----
Brian Candler                   E-mail: brian@ucb.edu.bz
University College of Belize        or: brian%ucb.edu.bz@rg.net
PO Box 990                      Tel:    +501 2 32732
Belize City                     Fax:    +501 2 30255
BELIZE, Central America