canonicalize() beta

[Alexis Yushin <alexis@NL.net>]

Greetings,

	Well, I'm pretty determined to rewrite canonicalize() and
this is the version I run on our mailservers. It looks pretty complete.
Please notice that it passed all the non-uucp hostnames to canonical())
which in turns resolves it through canon relation and it is very likely
that all the addresses will be rewritten into lowercase. Older canonicalize
would only try to put non-toplevel domains through canon, but nowadays
this behaviour is pretty obsolete. Well, let me know what you think
about this one.

	BTW, could we perhaps establish something like a contribute
directory somewhere on ftp site, or is there such a place already just
that I dont know of?
								alexis

Two zmsh scripts are attached: canonicalize.cf and canonicalize. The
later one is to test canonicalize.


#
# Zmailer Copyright 1988 by Rayan S. Zachariassen, all rights reserved
# Zmailer Copyright 1992-1997 by Matti Aarnio
#
# $Id: canonicalize.cf,v 1.4 1997/12/18 14:01:17 alexis Exp alexis $
#
# Alexis Yushin, NLnet Development, 1997
#
# Name Canonicalization
#
provide canonicalize

#
# Canonicalizes an RFC822/RFC976 address.
#
# Returns RFC822 focused and canonicalized address.
#
canonicalize (address) {
	address="$(dequote \"$address\")"
#
# We need string shift to detect '|' because '|' is not RFC822 special
#
	ssift "$address" in
	((\|.+)|(>.+)|(:include:.+))		# unqouted pipes and files
		echo "$address"			# path through
		return
		;;
	tfiss

	sift "$address" in
	((<>)|(:;))
		address="@"				# special case
		break
		;;
	(.*)<@(.*)>(.*)				# defocus
		address="\1@\2\3"
		continue
		;;
#
# RFC822 source routing
#
# @host3,@host2,@host1:user@host
#
	(@.+),(.+)				# RFC822 source routing
		address="\1:\2"			# change all "," to ":"
		continue
		;;
	(@.+):(.+:.+)
		address="\1,\2"			# undo all but the last one
		continue
		;;
	@([^,:]+)([,:].+)			# route-addr
		address="<@$(canonical \"\1\")>\2\3"
		break
		;;
#
# RFC822 addr-spec (localpart@domain) and variations
#
	(.*)::(.*)
		address="\2@\1"			# turn into localpart@domain
		continue
		;;
	(.*)@([^@]*.uucp)			# addr-spec host.uucp
		address="\1<@\2>"		# comment out if you want
		break				# canonical uucp names
		;;
	(.*)@([^@]*)				# addr-spec, rightmost '@'
		address="\1<@$(canonical \"\2\")>"
		break
		;;
#
# By this time localpart only
#
# RFC976 processing: '!' and '%' kludges
#
# a!b!c -> b!c@a
# a!b%c -> b%c@a
# a%b!c -> a!c@b	leading "%" has more priority than "!"
# a%b%c -> a%b@c
#
# We do not want people to start relying on this really weird routing.
# Comment it out if you do.
#
##	([^!%]*)%([^!%]*)\.([^!%]*)!(.*)	# very unusual case
##		canonicalize "\1!\4@\2.\3"
##		return
##		;;
##	([^!%]*)%([^.!%]*)!(.*)			# very unusual case (uucp node)
##		canonicalize "\1!\3@\2"
##		return
##		;;
	\[(.*)\]!(.*)				# leftmost '!', domain-literal
		canonicalize "\2@\[\1\]"
		return
		;;
	([^!.]*)!(.*)				# leftmost '!', pure uucp
		canonicalize "\2@\1.uucp"
		return
		;;
	([^!]*)!(.*)				# leftmost '!', domain uucp
		canonicalize "\2@\1"
		return
		;;
	(.*)%([^%]*)				# rightmost '%', source routing
		canonicalize "\1@\2"
		return
		;;
	tfis

	echo "$address"
}

#
# Returns canonical name of the given host
#
canonical (host) {
	local tmp
	tmp="$(deliver \"$host\")" || tmp="$(canon \"$host\")" || tmp="$host"
	echo "$tmp"
}

#
# Safeguard if canon() is not there
#
case "$(type canon)" in
*"not found")
	canon () { echo "$@" } ;;
esac
#
# Safeguard if deliver() is not there
#
case "$(type deliver)" in
*"not found")
	deliver () { return 1 } ;;
esac

##########################################################################
#!/usr/local/bin/router -f
#
# $Id:$
#
# Testing canonicalize routine
#
# Alexis Yushin, NLnet Development, 1997
#
#

ZCONFIG=/etc/zmailer.conf
. $ZCONFIG

PATH=.:$MAILSHARE/cf:$MAILBIN/bin ; export PATH
PS1=z$PS1

if [ $# = 0 ]; then
    set	\''user@host.domain'\' \
	'operator@nic.nl.net' \
	'host2!host1!user' \
	'host2!user%host1' \
	'host1%host2!user' \
	'user%host1%host2' \
	'host2.domain!host1!user' \
	'host2.domain!user%host1' \
	'host1%host2.domain!user' \
	'user%host1%host2.domain' \
	'"<>"@nowhere.at.all' \
	'"<user>"@host.domain' \
	'\[smtp:user@host.domain\]' \
	'smtp:user@host.domain' \
	'<user@host.domain>' \
	'<user@host.domain' \
	'user@host.domain>' \
	'user@[10.10.10.10]' \
	'[10.10.10.10]!user' \
	'user%[10.10.10.10]'
fi

. consist.cf
. standard.cf
. i-smtp.cf
. canonicalize.cf


for i in $*
do
	echo "Address: $i	Canonical: " "$(canonicalize \"$i\")"
done

-- 
			Where the wild horses run