#!/bin/sh

# sdbgrey version 2008-04-18 by Ulric Eriksson

LD_LIBRARY_PATH="/usr/local/lib/mysql:/usr/local/lib:$LD_LIBRARY_PATH"
PATH="/usr/local/bin:$PATH"
export LD_LIBRARY_PATH PATH

database_url="mysql:uid=postfix:pwd=postfix:db=greylist:host=localhost"
greylist_delay=60
auto_whitelist_threshold=10

# No syslogging, just log to a file.
log_file=/var/log/greylist.log

sdb()
{
	test "$verbose" && echo "sdb $1" 1>&2
	sdb_client -c "$1" "$database_url"
}

smtpd_access_policy()
{
	if test $auto_whitelist_threshold -gt 0; then
		count=`sdb "select coalesce(greyvalue,0)
				from greylist
				where greykey = '$client_address'"`
		if test "$count" -gt $auto_whitelist_threshold; then
			echo dunno
			return
		fi
	fi
	key="$client_address/$sender/$recipient"
	time_stamp=`sdb "select greyvalue
			from greylist
			where greykey='$key'"`
	now=`sdb "select unix_timestamp()"`
	if test -z "$time_stamp"; then
		time_stamp="$now"
		sdb "replace into greylist (greykey, greyvalue)
			values ('$key', $time_stamp)"
	fi
	age=`expr $now - $time_stamp`
	test "$verbose" && echo "request age $age" 1>&2
	if test $age -gt $greylist_delay; then
		if test $auto_whitelist_threshold -gt 0; then
			sdb "replace into greylist (greykey, greyvalue)
				values ('$client_address', $count+1)"
		fi
		echo dunno
	else
		echo "defer_if_permit Service is unavailable"
		#echo "dunno Service is unavailable"
	fi
}

if test "$1" = '-v'; then
	verbose=1
fi

exec 2> $log_file

while read REPLY; do
	test "$verbose" && echo "Attribute: $REPLY" 1>&2
	case "$REPLY" in
	*=* )
		eval $REPLY
		;;
	'' )
		action=`smtpd_access_policy`
		test "$verbose" && echo "Action: $action" 1>&2
		echo "action=$action"
		echo
		client_address=
		sender=
		recipient=
		;;
	* )
		echo "warning: ignoring garbage $REPLY" 1>&2
		client_address=
		sender=
		recipient=
		;;
	esac
done