#|
#|  I kept typing in this trace command so frequently, that eventually
#|  I just had to make for it into a single command... /Matti Aarnio
#|

rtrace () {
	trace all except rfc822 regexp
}


# set up output to log file (stdout) independent of current output redirection
log () {
	case "$LOGLEVEL" in
#| The LOGLEVEL variable is typically set in the $(ZCONFIG) file, usually
#| /etc/zmailer.conf.  If set, it will restrict log output to messages that
#| begin with tags in the string value of the variable.
	''|*"$1"*)
		echo "$(get envelopeinfo message-id):" "$@"  ;;
	*)	# We want to log anything that doesn't have a tag!
		case "$1" in
		*[^:])	echo "$(get envelopeinfo message-id):" "$@" ;;
		esac ;;
	esac
}
##exec 3>&1

#| The log function defined here will be used whenever the configuration
#| code wants to put something in the log.


# what to do to roll the log

##dribble (file) {
##	exec 3>&- 2>&- 1>&- 1>>$file 2>&1 3>&1
##}

#| The dribble function ensures that all output filedescriptors append to
#| the (log) file.

# We roll the log by sending a SIGHUP to the router; to avoid problems caused
# by the I/O state while processing a message, the SIGHUP handler is always
# invoked synchronously when the router is NOT processing a message.  HUP is
# the only signal handled in this way.

##trap "dribble $LOGDIR/router" 1

case "$-" in
*i*)	case "x$SMTPSERVER" in
	xy*)	# invoked from SMTP server, redirect stderr
		exec 2>&1
		;;
	esac
	exec 3>&1	# always redirect log
	;;
*)	# daemon
	##dribble $LOGDIR/router
	;;
esac

#| Logging is set up differently depending on the context.  If running as
#| a daemon, all output should go to the log file.  Otherwise, stdout or
#| stderr.  If invoked from the SMTP server, all output goes to stdout.

# set up the alias expansions table
# NOTE: the key hashing mechanism used presently (with symbol()), won't scale
# well if you alias expand arbitrary off-site addresses; they will all be
# stored in memory for the life of the process.  This will be fixed, later.
#
relation -lt incore expansions

# set up the host expansions cache -- same cavet as above, but propably can
# live with it [mea] 94-Aug-04
relation -lt incore hostexpansions

# count recipients (and do (perhaps) expansions match too ?)
relation -lt incore recipients

if [ -f $MAILVAR/db/thishost.zmsh ]; then
  . $MAILVAR/db/thishost.zmsh
else
  # We do local delivery, more or less, of mail arriving for these hostnames
  if [ -f $MAILVAR/db/localnames ]; then
    if [ -f $MAILVAR/db/localnames.zmsh ]; then
        if [ $MAILVAR/db/localnames -nt $MAILVAR/db/localnames.zmsh ]; then
	    local cmd
	    cmd="$MAILBIN/make-incore.sh"
	    "$cmd" thishost $MAILVAR/db/localnames $MAILVAR/db/localnames.zmsh
        fi
        . "$MAILVAR/db/localnames.zmsh"
    elif [ -f $MAILVAR/db/localnames$DBEXTtest ]; then
	if [ $MAILVAR/db/localnames -nt $MAILVAR/db/localnames$DBEXTtest ]; then
	    $MAILBIN/newdb -l $MAILVAR/db/localnames
	fi
	relation -lmt $DBTYPE -f $MAILVAR/db/localnames$DBEXT -d pathalias thishost
    else
        relation -lmt unordered -f $MAILVAR/db/localnames -d pathalias thishost
    fi
  else
	# The default set of hostnames is:
	#	$rawhostname - system hostname, from /bin/hostname (or whatever)
	#	$hostname - the canonicalized version of $rawhostname
	#	$rawhostname.X, where X is a member of the set of organizational
	#	domains in $orgdomains.
	# We use a function and an incore relation, because this
	# file is loaded before the siteinfo stuff.
	relation -lt incore -b thishostdb
	thishost(name) {
		local oldifs
		# If the relation hasn't been initialized, do so.
		if [ $(thishostdb "$hostname") ]; then :; else
			db add thishostdb "$hostname" ""
			if [ "$rawhostname" ]; then
				db add thishostdb "$rawhostname" ""
				oldifs="$IFS"
				IFS="|"
				for org in $orgdomains; do
					db add thishostdb "$rawhostname.$org" "$rawhostname.$org"
				done
				IFS="$oldifs"
			fi
		fi
		return $(thishostdb "$name")	# XX: Will it work and produce
						#     the canonic name/err ?
	}
  fi
fi

#| If the localnames file does not exist, assume we must do local
#| delivery for our own hostname.  If the localnames file does exist,
#| it must contain a simple list of (domain)names we should deliver
#| locally.  One per line.  Case is ignored.
#|
#| In some situations (a cluster of mail servers) it is prudent to be able
#| to have exclusions in the localnames file.  If we do this through
#| another file containing the names of the other mail servers, we can keep
#| the localnames file the same on all intimate mail servers.  It
#| describes the service domains.

if [ -f $MAILVAR/db/otherservers.zmsh ]; then
    . $MAILVAR/db/otherservers.zmsh
else
    if [ -f $MAILVAR/db/otherservers ]; then
	relation -lmt unordered -f $MAILVAR/db/otherservers -d pathalias otherservers
    else
	otherservers (name) { return 1 }
    fi
fi

#|  deliver(name) -> name'
#|
#|  Canonize our local hostname via  localnames  database
#|

deliver (name) {	# Produce rc=0 and output our CANONIC hostname
	local tmp
	if tmp="$(thishost "$name")" ; then
		if [ -z "$tmp" ]; then
			tmp="$name"	# Its blank -> its the original $name.
		fi
		$(otherservers "$name") || { echo "$tmp" ; return 0 }
	fi
	return 1
}


#| The code to use this is disabled in the rrouter function.  This
#| illustrates a possible mechanism.

# optional: uucp neighbours from L.sys
#relation -t unordered -f /usr/lib/uucp/L.sys -b ldotsys

#| Same comment.  Typically we do not wish to use all our UUCP
#| connections for mail, so this relation is useless to determine how a
#| message should be sent.  UUCP neighbours are specified in the
#| routes database using lines of the form:

#| neighbour    uucp!neighbour

default_attributes=(privilege ${NOBODY:-29999} type recipient)

#| This is the default attributes parameter to the router function
#| below.  It is typically used when doing interactive queries.  The
#| value of the type property indicates whether or not alias expansion
#| should be done.  If it is 'sender', no alias expansion is done.

#| We may decide that some combination of addresses, and message ids
#| is sure sign of SPAMs, and when we return non zero respose, the
#| main routine can return 'bitbucket' channel.

if [ -f $MAILVAR/db/msgidfilter.zmsh ]; then
  # This included source defines routine:
  #   msgidfilter(address, attributes) {
  #     local messageid
  #     messageid = $(get envelopeinfo message-id)
  #     ssift "$messageid" in
  #      <some-pattern@some\.where>
  #         return 1 ;;
  #     tfiss
  #     return 0
  #   }
  #
  . $MAILVAR/db/msgidfilter.zmsh
else
  msgidfilter () { return 0 }
fi



router (address, attributes) {

#| This is the address routing entry point.  The function name "router"
#| is known by the router program.

	local res tmp
	# set up default attributes for casual interactive use.  Any
	# privilege set here is only important when router is run as root,
	# otherwise it won't matter.
	: ${attributes:=default_attributes}
	defer=""

#| The defer variable is set to a deferral reason by the router internals
#| in case of database lookup timeouts or other problems.  We null it
#| here, and test it later to check for problems.

	log address: "$address"

#| A gratuitous log entry so we can later on tell the exact addresses
#| that were routed.  This could be removed if you like terse logs.

	#grind ${$attributes} 1>&3

	# If you want to do address expansion loop-prevention per-message,
	# instead of per-address, null the expansions list in the process()
	# function instead of here.

	db flush expansions

	tmp=$(msgidfilter "$address" $attributes) || \
		return ((( bitbucket - "$address" $attributes)))

#| Now call the actual address routing functions

	res=$(rrouter "$address" "$address" $attributes "")

#| The rrouter function does the real work of routing.  It should return
#| a list of addresses in the normal AND-XOR tree form.

	if [ "$defer" ]; then
		log deferred: $defer: "$address"
		return (((hold "$defer" "$address" $attributes)))
	fi

#| If an internal problem was detected during the routing, we ignore the
#| results of routing and redirect this address to the hold transport
#| queue for later resubmission.

	return $res
}

header_defer (address) {
	log header_defer: "$address"
	return "\"$address\""@$hostname
}

#| In case of internal problems during header address rewriting, this
#| function will determine the result of rewriting.  It should just quote
#| the original address and make it relative to the current host.  The
#| alternative is to delay the message until rewriting can be done
#| properly, however this is a very unpopular action.  The router program
#| does not give a choice.  The name "header_defer" is known by the
#| program.



#| Lets see if our main  router.cf  defines the preferred list outlook.
#| That is, for a  MAILVAR/lists/listname  we can have sender either as
#| "listname-owner", or "owner-listname".  Which it is ?  If neither is
#| set (or both are set!) then we set our default:

if [ -z "$preowner" -a -z "$postowner" ]; then
	preowner=""
	postowner="-owner"
elif [ ! -z "$preowner" -a ! -z "$postowner" ]; then
	preowner=""
	postowner="-owner"
fi

#| Domains with these toplevels will not be canonicalized via DNS lookup
#| This list is from ISOC table of 16-April-95  + "su" + bitnet + uucp

toplevels="ad ae af ag ai al am an ao aq ar as at au aw az ba
	bb bd be bf bg bh bi bj bm bn bo br bs bt bv bw by bz
	ca cc cf cg ch ci ck cl cm cn co com cr cu cv cx cy cz
	de dj dk dm do dz ec edu ee eg eh es et fi fj fk fm fo
	fr ga gb gd ge gf gh gi gl gm gn gov gp gq gr gt gu gw
	gy hk hm hn hr ht hu id ie il in int io iq ir is it jm
	jo jp ke kg kh ki km kn kp kr kw ky kz la lb lc li lk
	lr ls lt lu lv ly ma mc md mg mh mil ml mm mn mo mp mq
	mr ms mt mu mv mw mx my mz na nc ne net nf ng ni nl no
	np nr nt nu nz om org pa pe pf pg ph pk pl pm pn pr pt
	pw py qa re ro ru rw sa sb sc sd se sg sh si sj sk sl
	sm sn so sr st su sv sy sz tc td tf tg th tj tk tm tn
	to tp tr tt tv tw tz ua ug uk um us uy uz va vc ve vg
	vi vn vu wf ws ye yu za zm zr zw uucp bitnet"

relation -lbt incore istoplevel
for x in $toplevels
do
	db add istoplevel $x 1
done

toplevels=""
unset toplevels # No need for that variable anymore..

#| Kill certain RFC-822 envelope headers traveling thru this system
#| Commented ones are built-in, there is special treatment for Bcc
#| as that one requires internal semantics, and still must be killed!

#db add headers return-path		-:kill:-
#db add headers resent-return-path	-:kill:-
#db add headers x-orcpt			-:kill:-
#db add headers resent-x-orcpt		-:kill:-
#db add headers x-envid			-:kill:-
#db add headers resent-x-envid		-:kill:-

if [ -r $MAILVAR/db/kill-headers ]
then
  . $MAILVAR/db/kill-headers
fi