Path: seismo!harvard!talcott!panda!Jim Crammond <seismo!mcvax!cs.hw.ac.uk!jim>
From: sources-request@panda.UUCP
Newsgroups: mod.sources
Subject: Sendmail UK-1.4 part 3 of 5
Message-ID: <1639@panda.UUCP>
Date: 10 Apr 86 23:05:18 GMT
Sender: jpn@panda.UUCP
Lines: 785
Approved: jpn@panda.UUCP

Mod.sources:  Volume 4, Issue 58
Submitted by: Jim Crammond <seismo!mcvax!cs.hw.ac.uk!jim>


#	This is a shell archive.
#	Remove everything above and including the cut line.
#	Then run the rest of the file through sh.
-----cut here-----cut here-----cut here-----cut here-----
#!/bin/sh
# shar:	Shell Archiver
#	Run the following text with /bin/sh to create:
#	chn
# This archive created: Mon Mar 17 16:56:47 1986
echo shar: creating directory chn
mkdir chn
cd chn
echo shar: extracting MAKE '(8731 characters)'
cat << \SHAR_EOF > MAKE
#!/bin/sh
#
#  shell script to generate a sendmail <host>.chn file containing all
#  the routing information for this host from a set of per-mailer channel
#  files containing in this directory.
#

if [ $# -le 1 ]
then	echo	usage: make host files...
	exit
fi

strip="sed -e /^#/d -e /^\$/d"
host=$1
shift
rm -f $host.chn

cp /dev/null chn.classes
cp /dev/null S15
cp /dev/null S16
cp /dev/null S17

#
# sort out which files refer to which mailers
#
rm -f $$.local $$.ether $$.luucp $$.csnet $$.janet $$.bitnet $$.uucp $$.top

for i in $*
do
	case $i in
	*local.chn)	$strip $i >> $$.local
			;;
	*ether.chn)	$strip $i >> $$.ether
			;;
	*luucp.chn)	$strip $i >> $$.luucp
			;;
	*csnet.chn)	$strip $i >> $$.csnet
			;;
	*janet.chn)	$strip $i >> $$.janet
			;;
	*bitnet.chn)	$strip $i >> $$.bitnet
			;;
	*uucp.chn)	$strip $i >> $$.uucp
			;;
	*top.chn)	$strip $i >> $$.top
			;;
	esac
done

#
#
#
if [ -f $$.local ]
then
	awk '{ printf "R$+@%s\t\t$@$>15$1@$J\n", $1 }' $$.local > S15
fi

#
#  Standard format channel tables
#
for chnf in $$.ether $$.luucp $$.csnet
do
	if [ -f $chnf ]
	then
		awk '
BEGIN	{
	mailer=substr(FILENAME, index(FILENAME,".")+1)
	MINCLSIZE = 3
	if (mailer == "ether")
	{	print "# Ethernet"	>>"S17"
		classes = "KLM"
	}
	else if (mailer == "luucp")
	{	print "# Local UUCP"	>>"S17"
		classes = "NOP"
	}
	else if (mailer == "csnet")
	{	print "# CSNet"		>>"S17"
		classes = "QRS"
	}
	c = 1
	}

/^#/	{	break	}

	{
	i = index($1, ".")
	subdom = substr($1,1,i-1)
	restdom = substr($1,i+1)
	
	if (subdom == $2)
		direct[restdom] = direct[restdom] " " subdom
	else
		printf "R$+@%s\t\t$@<$1@%s>%s.%s\n", $1, $1, $2, mailer	>>"S17"
	}

END	{
	for (i in direct)
	{	n = split(direct[i], sub, " ")
		if (n >= MINCLSIZE && c <= length(classes))
		{	C = substr(classes, c, 1)
			c++
			printf "C%s%s\n", C , direct[i]	>>"chn.classes"
			printf "R$+@$=%s.%s\t\t$@<$1@$2.%s>$2.%s\n",C,i,i,mailer >>"S17"
		}
		else
		{	for (j=1; j<=n; j++)
				printf "R$+@%s.%s\t\t$@<$1@%s.%s>%s.%s\n", \
					sub[j], i, sub[j], i, sub[j], mailer	>>"S17"
		}
	}
	print ""	>>"chn.classes"
	print ""	>>"S17"
	}
' $chnf

	fi
done

#
#   The Janet channel
#
if [ -f $$.janet ]
then
	awk '
BEGIN	{
	print "# Janet sites"
	print "# convert domain order to NRS style"
	print "R$+@$+			$:$>9$1@$2"
	print ""
	}

	{
	if ( $1 == $2 )
	{	if ( $1 ~ /^uk\./ )	# general rule will catch this
			break
		printf "R$+@%s\t\t$@<$1@%s>%s.janet\n", $1, $1, $1
	}
	else				# application relays
	{	jntaddr = "$1%" $1
		for (i=NF; i>2; i--)
			jntaddr = jntaddr "%" $i
		jntaddr = jntaddr "@" $2

		if ( $2 ~ /^uk\.ac\./ )	# uk.ac nodes
			printf "R$+@%s\t\t$@<%s>%s.janet\n", $1, jntaddr, substr($2,7)
		else				# all others
			printf "R$+@%s\t\t$@<%s>%s.janet\n", $1, jntaddr, $2
	}
	}

END	{
	print ""
	print "# convert domain order back to 822 style"
	print "R$+@$+			$:$>9$1@$2"
	print ""
	}
' $$.janet >>S17

fi

#
#  The Bitnet channel
#
if [ -f $$.bitnet ]
then
	awk '
BEGIN	{
	print "# Bitnet sites"
	}

	{
	if ($1 == $2 ".bitnet")		# general rule will catch this
		break

	printf "R$+@%s\t\t$@<$1>%s.bitnet\n", $1, $2
	}

END	{
	print ""
	}
' $$.bitnet >>S17

fi

#
#   The UUCP channel
#
if [ -f $$.uucp ]
then
	(sort +1 $$.uucp ; echo 'x.y z!x!%s') |
	awk '
BEGIN	{
	MINCLSIZE = 3
	classes = "UVWXYZ"
	c = 1
	m = 0
	print "# UUCP sites"						>>"S17"
	print "# convert to uucp addresses and try to find a match"	>>"S17"
	print "R$+@$+			$:$>8$1@$2"			>>"S17"
	print ""							>>"S17"
	}

	{
	i = index($1, ".")
	subdom = substr($1,1,i-1)
	restdom = substr($1,i+1)
	
	p = index($2, subdom)
	ps = subdom "!%s"

	if (p == 1 && $2 == ps)
		direct[restdom] = direct[restdom] " " subdom
	else if (p > 1 && substr($2, p-1) == ("!" ps))
	{	path = substr($2, 1, p-1)
		if (path != lastpath || restdom != lastrest)
		{	if (m >= MINCLSIZE && c <= length(classes))
			{	j = index(lastpath, "!")
				host = substr(lastpath,1,j-1)
				addr = substr(lastpath,j+1)

				rclass = ""
				for (j=1; j<=m; j++)
					rclass = rclass " " sub[j]

				C = substr(classes, c, 1)
				c++
				printf "C%s%s\n", C, rclass	>>"chn.classes"
				printf "R$=%s.%s!$+\t\t$@<%s$1!$2>%s.uucp\n", \
					C, lastrest, addr, host		>>"S17.2"
			}
			else
			{	for (i=1; i<=m; i++)
				{	j = index(lastpath, "!")
					host = substr(lastpath,1,j-1)
					addr = substr(lastpath,j+1) sub[i]
					printf "R%s.%s!$+\t\t$@<%s!$1>%s.uucp\n",\
					  sub[i], lastrest, addr, host	>>"S17.2"
				}
			}
			lastpath = path
			lastrest = restdom
			m = 0
		}
		sub[++m] = subdom
	}
	else
	{	i = index($2, "!")
		host = substr($2,1,i-1)
		addr = substr($2,i+1)
		addr = sprintf(addr,"$1")
		printf "R%s!$+\t\t$@<%s>%s.uucp\n", $1, addr, host	>>"S17.2"
	}
	}

END	{
	for (i in direct)
	{	n = split(direct[i],sub," ")
		if (n >= MINCLSIZE && c <= length(classes))
		{	C = substr(classes, c, 1)
			c++
			printf "C%s%s\n", C , direct[i]	>>"chn.classes"
			printf "R$=%s.%s!$+\t\t$@<$2>$1.uucp\n", C, i	>>"S17"
		}
		else
		{	for (j=1; j<=n; j++)
				printf "R%s.%s!$+\t\t$@<$1>%s.uucp\n", \
					sub[j], i, sub[j]		>>"S17"
		}
	}
	print ""	>>"chn.classes"
	print ""	>>"S17.2"
	print "# no match in uucp - change back to domain style"	>>"S17.2"
	print "R$+!$+			$:$>7$1!$2"			>>"S17.2"
	print ""	>>"S17.2"
	}
'
	cat S17.2 >> S17
	rm -f S17.2
fi

#
#   catch errors
#
cat >>S17 <<'EOF'
# Catch unknown subdomains local domain names
R$+@$J		$@<$1@$J>error
EOF

if [ -f $$.local ]
then
	awk '{ printf "R$+@%s\t\t$@<$1@$J>error\n", $1 }' $$.local >> S17
fi

#
#  complete ruleset 17
#
cat >>S17 <<'EOF'

# no match, return "<address>"
R$+			$@<$1>
EOF

#
#   Top Level Domain relaying
#
awk '{ printf "R<$+@%s>\t\t$@$>16$1@%s\n", $1, $2 }' $$.top > S16

#
#  The header
#
cat > $host.chn <<EOF
###############################################################################
###############################################################################
#####
#####	@(#)$host.chn	UK-1.4 sendmail configuration		12/2/86
#####
#####	The mailer selection and routing
#####
###############################################################################
###############################################################################

# classes
EOF

#
#  the classes
#
while read class group
do
	echo "$group" | fmt | sed "s/^/$class/"
done < chn.classes >> $host.chn

#
#  the rules
#
cat - S15 >> $host.chn <<'EOF'

###########################################
#  Ruleset 15  --  local domain handling  #
###########################################

#
#  This rule strips the domain part from local addresses
#  and passes the local part back into ruleset 3
#

S15
R$+@$J			$>3$1		strip local domain
EOF

cat - S16 >> $host.chn <<'EOF'

#############################
#  Ruleset 16  --  routing  #
#############################

#
#  This rule trys to find an "<address>host.network" triple for a given
#  domain address.  Given a domain address "u@a.b.c.d", it calls the
#  channel matcher with u@a.b.c.d, and if nothing matched, it calls
#  the channel matcher again, with "u%a.b.c.d@b.c.d" and  "u%a.b.c.d@c.d".
#  If there's still no match, then the top level domain relaying is done
#  e.g. "u%a.b.c.d@d" -> "u%a.b.c.d@x.y.z" and the rule is retried.
#

S16
R$+@$+			$:$>17$1@$2		initial routing
R<$+>$+			$@<$1>$2		success, return triple

#  initial match failed, retry with successively higher level domains
R<$+@$+>		$:<$1%$2@$2>		u@a.b.c -> u%a.b.c@a.b.c
R<$+@$-.$+>		$>17$1@$3		retry routing
R<$+>$+			$@<$1>$2		success, return triple

ifdef(`JANETNAME',`
#  general rule for janet - pass all uk addresses to hhcp
R<$+@uk>		$:$>4$1.janet		restore @ in address
R$+@$+.janet		$:$>9$1@janet.$2	convert to NRS order
R$+@uk.ac.$+.janet	$@<$1@uk.ac.$2>$2.janet	uk.ac nodes
R$+@$+.janet		$@<$1@$2>$2.janet	all others
')
ifdef(`BITNETNAME',`
#  general rule for bitnet - pass all bitnet addresses to rscs
R<$+@bitnet>		$:$>4$1			restore address
R$+@$+.bitnet		$@<$1>$2.bitnet		returns <user>host.bitnet
#  arpa and uucp relays via Bitnet
R<$+@arpa>		$:$>4$1.arpa		restore address
R$+@$+.arpa		$@<$1@$2>smtpuser@wiscvm.bsmtp
R<$+@uucp>		$:$>4$1.uucp		restore address
R$+@$+.uucp		$@<$1@$2>uucp@psuvax1.bsmtp
')

#
# top level domain - relaying sites
#
# This is a list of default relaying sites for addresses
# that dont match anything in the channel matcher.
#
EOF

cat - S17 >> $host.chn <<'EOF'

######################################
#  Ruleset 17  --  channel matching  #
######################################

#
#  This rule takes a full domain address and trys to match it with a
#  domain given on the LHS of a rule.
#  If one matches, the "<address>host.network" triple given on the RHS
#  is returned.  Else  "<address>" is returned.
#

S17
EOF

rm -f chn.classes S15 S16 S17 $$.*

echo $host.chn made
exit
SHAR_EOF
if test 8731 -ne "`wc -c MAKE`"
then
echo shar: error transmitting MAKE '(should have been 8731 characters)'
else
chmod a+x MAKE
fi
echo shar: extracting README '(5870 characters)'
cat << \SHAR_EOF > README
General
-------
Having expanded addresses into fully qualified domain addresses, sendmail
then selects the appropriate mailer and routing. The channel tables
provide the information to associate a domain name with a mailer and
transport address (or route).

The channel tables contain rules (1 per line) containing
two strings seperated by white space. In general, the string on the LHS
is a fully qualified domain name and the string on the RHS is the route
or "host to send to", e.g.:

	usc.ac.uk		vax6

specifies that addresses of the form "user@usc.ac.uk" should
be send to the host "vax1".

The actual format of the channel tables depends on the mailer,
(see below) which is determined by the file name containing the rules.

For example, any file whose name ends with "janet.chn" is assumed to be
a janet mailer channel table.

The minimum information you need to specify depends on what mailers you
have, but is essentially:
	a) the domain name(s) the local host is known by,
	b) the names of directly connected hosts,
	c) the list of top level domain relaying sites (see below).

The maximum information you can specify is limited by practical
considerations such as the number of rules sendmail can cope with
before running very slowly.  As a guide, if more than 100 rules are
generated in the sendmail <host>.chn file, you may need to cut down
the number of entries in the channel tables.  Careful use of top level
domain relays will often help (particularly with uucp).

For example, for uk sites, if ukc.ac.uk is specified as the uucp relay,
then there is no need to specify any routes for uucp sites which has
"ukc!" in the path. Ukc has an extensive nameserver to do further routing.


Channel Table Formats
---------------------
local.chn:
	This contains a list of (fully qualified) domain names which are
	to be treated as local mail.

ether.chn, luucp.chn, csnet.chn:
	These have the format described above; a domain name on the LHS
	and a hostname to send/relay to on the RHS.

janet.chn:
	The LHS domain name is in big-endian form in this table.
	The RHS contains domain name(s), also big-endian, which specify
	the route to reach the domain on the LHS.  By default, all "uk"
	sites are assumed to be directly connected.  Thus this table need
	only contain  (a) directly connected  non-"uk" sites, and
	(b) application relays. E.g.

		cern.cernvm		cern.cernvm
		uk.ac.cam.phx		uk.ac.cam.eng-icf

	The RHS may contain more than one domain:
		
		domain1		domainA domainB

	will send the mail to domainA, then to domainB and onto domain1.

	"uk.ac.<name>" domains on the RHS should have a corresponding
	entry in the x25/directory with the "uk.ac." part stripped; other
	domains on the RHS should have a matching entry in the directory.

bitnet.chn:
	This has the same format as the ether, luucp and csnet channel tables.
	In addition, by default, all "<name>.bitnet" domains are routed to
	"<name>" (actual routing is done by RSCS). Further, all arpa addresses
	are sent to usersmtp@wiscvm and uucp addresses to uucp@psuvax1, using
	the bsmtp program.

uucp.chn:
	This has a slightly different RHS syntax which the same as that
	produced by pathalias(1), e.g.:

		usc.ac.uk		vax2!vax1!%s

	where %s is the user part of the address (converted to uucp form).

top.chn:
	This has a top level domain name on the LHS and a domain name
	on the RHS, for example.:

		uk			ukc.ac.uk

	which states that any address in the "uk" domain, which did not
	match a domain name in one of the mailer channel tables, is sent to
	ukc.ac.uk.

	When sendmail fails to find a match for a domain, e.g.
	"vax6.cs.hw.ac.uk" in the main channel tables, then it retries
	with successively higher level domains, e.g. "cs.hw.ac.uk",
	"hw.ac.uk" and "ac.uk".  If these fail then the top level domain
	relaying rule is applied and  matching begins again with the RHS
	of the relaying rule.


Examples
--------
The archive Examples.a contains sample mailer channel files.


How to compile the channel tables
---------------------------------
1. Create a mailer channel file for each mailer you have.
   This is best done by extracting sample channel files from Examples.a
   and editing them to contain the relevent data for this host.

2. Run "MAKE host file1 file2... "
   This generates the sendmail classes and rules for channel selection
   and routing in a file <host>.chn.  e.g.
	MAKE hwcs local.chn luucp.chn ukuucp.chn

   This shell script does a lot of work so be prepared to wait!


Supported Mailers
-----------------
MAKE looks for tables for the following mailers:

	local.chn	(local mail)
	ether.chn	(ethernet)
	luucp.chn	(local uucp)
	uucp.chn	(uucp)
	janet.chn	(janet)
	bitnet.chn	(bitnet)
	csnet.chn	(csnet)
	top.chn		(top level relaying)

If you have other mailers not listed here, then you will need to add
some code the the MAKE shell script. Good Luck!


Note
----
Make sure that the domains on the RHS of the relaying rules in top.chn
eventually match some domain on the LHS of a rule in one of the mailer
channel tables.


Running Shared Configuration Files
----------------------------------
Suppose we have ten workstations connected to an ethernet with a
central machine attached that has connections to some external network.
Those ten workstations can share the same configuration file.

To do this we need to "generalise" the host dependent parts of the
channel tables so that all the workstations can use the same <host>.chn.

The trick is to use "$w" when specifying the host specific names in the
local.chn table (e.g. $w.cs.hw.ac.uk);  and to have, in above example,
all ten workstations in the ether.chn.

The two key components to this are that: (a) sendmail will determine
whether a domain is local or not before it attempts to locate the
domain in the other channel tables, and (b) sendmail's "$w" macro expands
to the local hostname at runtime.
SHAR_EOF
if test 5870 -ne "`wc -c README`"
then
echo shar: error transmitting README '(should have been 5870 characters)'
fi
echo shar: extracting Examples.a '(4550 characters)'
cat << \SHAR_EOF > Examples.a
!<arch>
ether.chn       508609177   217   4     100644  168       `
#
# Ethernet channel table
#  The domain name on the LHS is routed to the host on the RHS.
#	
brahma.cs.hw.ac.uk	brahma
oberon.cs.hw.ac.uk	oberon
odin.cs.hw.ac.uk	odin
luucp.chn       508609295   217   4     100644  155       `
#
# Local UUCP channel table
#  The domain name on the LHS is routed to the host on the RHS.
#	
ra.cs.hw.ac.uk		ra
jove.cs.hw.ac.uk	ra
zeus.cs.hw.ac.uk	ra

uucp.chn        508610006   217   4     100644  987       `
# UUCP Channel Table
#  The domain name on the LHS is mapped to a path on the RHS.
#  If "%s" is included in the RHS then the user part goes here
#  e.g. jim@hwcs.ac.uk ->  hwcs!%s  -> hwcs!jim

#  standard NRS names
aimmi.heriot-watt.ac.uk	aimmi!%s
ee.heriot-watt.ac.uk	hwee!%s
cstvax.edinburgh.ac.uk	cstvax!%s
caad.edinburgh.ac.uk	edcaad!%s
cs.kcl.ac.uk		kcl-cs!%s
spider.co.uk		spider!%s
stl.stc.co.uk		stl!%s
stc.co.uk		stl!stc!%s
dcs.leeds.ac.uk		ulcs!%s
cs.ucl.ac.uk		cstvax!cs.ucl.ac.uk!%s
ukc.ac.uk		cstvax!ukc.ac.uk!%s

#  abbreviated NRS names (where different from above)
aimmi.hw.ac.uk		aimmi!%s
ee.hw.ac.uk		hwee!%s
cstvax.ed.ac.uk		cstvax!%s
caad.ed.ac.uk		edcaad!%s

#  old uucp names
aimmi.uucp		aimmi!%s
cstvax.uucp		cstvax!%s
edcaad.uucp		edcaad!%s
kcl-cs.uucp		kcl-cs!%s
spider.uucp		spider!%s
stl.uucp		stl!%s
stc.uucp		stl!stc!%s
ulcs.uucp		ulcs!%s
ucl-cs.uucp		cstvax!cs.ucl.ac.uk!%s
ukc.uucp		cstvax!ukc.ac.uk!%s

# everything else goes to ukc for further routing

janet.chn       511450060   217   4     100644  783       `
#
# Janet channel table
#   The domain name on the LHS is routed to the domain name on the RHS.
#   Note that the domain names on the LHS are in big-endian form.
#   The domains on the RHS correspond to entries in the x25/directory as
#   follows:
#		uk.ac.<name>	->	<name>
#		uk.<name>	->	uk.<name>
#
#   Defining the janet mailer automatically includes the default rule
#   that all "uk" sites are directly connected.
#   So, only non-"uk" sites and application relays are required here.
#
cern.cernvm		cern.cernvm
cern.gec-a		cern.gec-a
uk.ac.cam.eng-dsl	uk.ac.cam.cl-jenny
uk.ac.cam.eng-44	uk.ac.cam.cl-jenny  uk.ac.cam.eng-dsl
uk.ac.cam.phx		uk.ac.cam.eng-icf
uk.ac.ncl.kelpie	uk.ac.ncl.cheviot
uk.ac.nott.maths	uk.ac.nott.cs
uk.ac.york.com		uk.ac.york.kl
uk.alvey		uk.ac.rl.gm

bitnet.chn      508610388   217   4     100644  400       `
#
# Bitnet channel table
#  Actual routing is done by the bitnet mailer itself.
#  Defining the bitnet mailer automatically includes the following mappings:
#	<any>.bitnet   ->   <any>
#	<any>.arpa     ->   smtpuser@wiscvm   (using bsmtp)
#	<any>.uucp     ->   uucp@psuvax1      (using bsmtp)
#
#  So, only bitnet sites with other domain names should be included here
#  e.g.   ucbjade.cc		ucbjade
#
top.chn         508609427   217   4     100644  469       `
#  Top level domains
#	If an address hasn't matched a domain name in any other table then
#	it should match something here. The RHS is a domain which specifies
#	where the message should be relayed for further routing.
#
uk		cstvax.ed.ac.uk
uucp		ukc.ac.uk
arpa		cs.ucl.ac.uk
com		cs.ucl.ac.uk
edu		cs.ucl.ac.uk
gov		cs.ucl.ac.uk
mil		cs.ucl.ac.uk
org		cs.ucl.ac.uk
oz		ukc.ac.uk
csnet		relay.cs.net
bitnet		wiscvm.wisc.edu
mailnet		multics.mit.edu
dec		decwrl.dec.com

local.chn       508609283   217   4     100644  289       `
#
#  The Local channel
#    The domain names listed here are local to this host
#
#	NRS names
cs.hw.ac.uk
cs.heriot-watt.ac.uk
#	UUCP name
hwcs.uucp
#
#  As we are a multihost site, we must include the following host names
#
brahma.cs.hw.ac.uk
brahma.cs.heriot-watt.ac.uk
brahma.hwcs.uucp

gen.top.chn     508609252   217   4     100644  381       `
#  Top level domains
#	This table sends uk mail to ukc, and all other top level domains to ucl.
#
#	The name "$=T" can be used to match all top level domains given in the
#	top.dom table.  This can save on the number of rules generated by MAKE
#
#	NOTE: A list of top level domains would need to be explicitly
#	      specified in ../dom/top.dom.
#
uk		ukc.ac.uk
$=T		cs.ucl.ac.uk

csnet.chn       508609142   217   4     100644  363       `
#
# CSNet PhoneNet channel table
#  The domain name on the LHS is routed to the host on the RHS.
#
#  Since PhoneNet sites all call csnet-relay, you just need to specify
#  the different names of csnet-relay in this table.  All other routing
#  is done in the top.chn table.
#	
csnet-relay.csnet	csnet-relay
csnet-relay.arpa	csnet-relay
relay.cs.net		csnet-relay

SHAR_EOF
if test 4550 -ne "`wc -c Examples.a`"
then
echo shar: error transmitting Examples.a '(should have been 4550 characters)'
fi
echo shar: done with directory chn
cd ..
#	End of shell archive
exit 0