diff --git a/handlers/dsync.in b/handlers/dsync.in
new file mode 100644
index 0000000000000000000000000000000000000000..bf7b51d6643d5a1a8f3447b9c307f567c818a9d1
--- /dev/null
+++ b/handlers/dsync.in
@@ -0,0 +1,357 @@
+# -*- mode: sh; sh-basic-offset: 3; indent-tabs-mode: nil; -*-
+# vim: set filetype=sh sw=3 sts=3 expandtab autoindent:
+
+###############################################################
+#
+# This handler uses dovecot (version 2 or later) dsync backup
+# to backup mail to a remote server.
+#
+# Source and destination directories are typically configured
+# via the dovecot configuration, but can be overridden using
+# the settings here.
+#
+# if the configuration is setup to have keepdaily at 3,
+# keepweekly is 2, and keepmonthly is 1, then each user's
+# maildir backup snapshot directory will contain these files:
+# daily.1
+# daily.2
+# daily.3
+# weekly.1
+# weekly.2
+# monthly.1
+#
+# The basic algorithm is to dsync each user individually,
+# and to use hard links for retaining historical data.
+#
+# For the backup rotation to work, destuser must be able to run
+# arbitrary bash commands on the desthost.
+#
+# If 'remove' is set to 'yes' (default), then any mail directory
+# which is deleted from the source will be moved to a "deleted"
+# directory in the destination. It is up to you to periodically
+# remove this directory or old maildirs in it.
+#
+# Limitations:
+# . because we are not dynamically looking up anything with
+# dovecot's userdb, we expect all data to be under the same
+# tree on both the source and destination
+#
+# . we are assuming a backup to a backup server, so the
+# destination host should have its dovecot mail_location
+# configured to put the mail into
+# $stripped_destdir/$letter/$user/$current_backup
+#
+##############################################################
+
+getconf rotate yes
+getconf remove yes
+getconf backup yes
+
+getconf keepdaily 5
+getconf keepweekly 3
+getconf keepmonthly 1
+
+getconf srcconffile
+getconf destconffile
+getconf srcdir
+getconf destdir
+getconf current_backup current_backup
+getconf desthost
+getconf destport 22
+getconf destuser
+getconf destid_file /root/.ssh/id_rsa
+getconf sshoptions
+
+failedcount=0
+
+# strip leading mailbox specifier (eg. mdbox:; maildir:, etc)
+stripped_destdir=${destdir/*:/}
+stripped_srcdir=${srcdir/*:/}
+
+# strip trailing /
+destdir=${destdir%/}
+srcdir=${srcdir%/}
+
+if [ ! -n $destdir ]; then
+ destdir='-o mail_location=$destdir'
+fi
+if [ ! -n $srcdir ]; then
+ srcdir='-o mail_location=$srcdir'
+fi
+
+if [ ! -n $srcconffile ]; then
+ srcconffile='-c $srcconffile'
+fi
+
+if [ ! -n $destconffile ]; then
+ destconffile='-c $destconffile'
+fi
+
+[ -d $stripped_srcdir ] || fatal "source directory $srcdir doesn't exist"
+
+
+##################################################################
+### FUNCTIONS
+
+function do_user() {
+ local user=$1
+ local btype=$2
+ local letter=${user:0:1}
+ local target="$stripped_destdir/$letter/$user/$current_backup"
+
+ debug "syncing"
+ while [ $failedcount -lt 4 ]; do
+ debug $DSYNC $testflags -u $user backup $srcconffile $srcdir \
+ ssh -i $destid_file $destuser@$desthost $DSYNC $destconffile \
+ -u $user $destdir 2>&1
+ ret=`$DSYNC $testflags -u $user backup $srcconffile $srcdir \
+ ssh -i $destid_file $destuser@$desthost $DSYNC $destconffile \
+ -u $user $destdir 2>&1`
+ ret=$?
+ if [ $ret == 2 ]; then
+ # dsync needs to be run again
+ let "failedcount = failedcount + 1"
+ elif [ $ret == 0 ]; then
+ # things worked, so we break out of the loop
+ let "failedcount = 4"
+ # move the directory to the $btype.1 and make a 'created' file
+ ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions "mv $target ../$btype.1"
+ ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions "date +%c%n%s > ../$btype.1/created"
+ elif [ $ret != 0 ]; then
+ # things did not work in a good way, report it and try again
+ warning "dsync $user failed"
+ warning " returned: $ret"
+ let "failedcount = failedcount + 1"
+ fi
+
+ if [ $failedcount -gt 4 ]; then
+ fatal "dsync failed 3 times for this user -- something is not working right. bailing out."
+ fi
+ done
+}
+
+# remove any maildirs from backup which might have been deleted
+# and add new ones which have just been created.
+# (actually, it just moved them to the directory "deleted")
+
+function do_remove() {
+ local tmp1=`maketemp dsync-tmp-file`
+ local tmp2=`maketemp dsync-tmp-file`
+
+ ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost mkdir -p "${stripped_destdir}/deleted"
+ cd "$stripped_srcdir"
+ for userdir in `ls -d1 */`; do
+ ls -1 "$stripped_srcdir/$userdir" | sort > $tmp1
+ ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost ls -1 "$stripped_destdir/$userdir" | sort > $tmp2
+ for deluser in `join -v 2 $tmp1 $tmp2`; do
+ [ "$deluser" != "" ] || continue
+ info "removing $destuser@$desthost:$stripped_destdir/$userdir$deluser/"
+ ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost mv "$stripped_destdir/$userdir$deluser/" "$stripped_destdir/deleted"
+ ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost "date +%c%n%s > '$stripped_destdir/deleted/$deluser/deleted_on'"
+ done
+ done
+ rm $tmp1
+ rm $tmp2
+}
+
+function do_rotate() {
+ [ "$rotate" == "yes" ] || return;
+ local user=$1
+ local letter=${user:0:1}
+ local backuproot="$stripped_destdir/$letter/$user"
+ local target="$stripped_destdir/$letter/$user/$current_backup"
+(
+ ssh -T -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions <<EOF
+##### BEGIN REMOTE SCRIPT #####
+ seconds_daily=86400
+ seconds_weekly=604800
+ seconds_monthly=2628000
+ keepdaily=$keepdaily
+ keepweekly=$keepweekly
+ keepmonthly=$keepmonthly
+ now=\`date +%s\`
+
+ if [ ! -d "$backuproot" ]; then
+ echo "Debug: skipping rotate of $user. $backuproot doesn't exist."
+ exit
+ fi
+ for rottype in daily weekly monthly; do
+ seconds=\$((seconds_\${rottype}))
+
+ dir="$backuproot/\$rottype"
+ if [ ! -d \$dir.1 ]; then
+ echo "Debug: \$dir.1 does not exist, skipping."
+ continue 1
+ fi
+
+ if [ -f \$target ]; then
+ echo "Warning: \$target exists. Previous backup did not complete properly. Skipping rotation."
+ continue 1
+ fi
+
+ # Rotate the current list of backups, if we can.
+ oldest=\`find $backuproot -maxdepth 1 -type d -name \$rottype'.*' | @SED@ 's/^.*\.//' | sort -n | tail -1\`
+ #echo "Debug: oldest \$oldest"
+ [ "\$oldest" == "" ] && oldest=0
+ for (( i=\$oldest; i > 0; i-- )); do
+ if [ -d \$dir.\$i ]; then
+ if [ -f \$dir.\$i/created ]; then
+ created=\`tail -1 \$dir.\$i/created\`
+ else
+ created=0
+ fi
+ cutoff_time=\$(( now - (seconds*(i-1)) ))
+ if [ ! \$created -gt \$cutoff_time ]; then
+ next=\$(( i + 1 ))
+ if [ ! -d \$dir.\$next ]; then
+ echo "Debug: \$rottype.\$i --> \$rottype.\$next"
+ mv \$dir.\$i \$dir.\$next
+ date +%c%n%s > \$dir.\$next/rotated
+ else
+ echo "Debug: skipping rotation of \$dir.\$i because \$dir.\$next already exists."
+ fi
+ else
+ echo "Debug: skipping rotation of \$dir.\$i because it was created" \$(( (now-created)/86400)) "days ago ("\$(( (now-cutoff_time)/86400))" needed)."
+ fi
+ fi
+ done
+ done
+
+ max=\$((keepdaily+1))
+ if [ \( \$keepweekly -gt 0 -a -d $backuproot/daily.\$max \) -a ! -d $backuproot/weekly.1 ]; then
+ echo "Debug: daily.\$max --> weekly.1"
+ mv $backuproot/daily.\$max $backuproot/weekly.1
+ date +%c%n%s > $backuproot/weekly.1/rotated
+ fi
+
+ max=\$((keepweekly+1))
+ if [ \( \$keepmonthly -gt 0 -a -d $backuproot/weekly.\$max \) -a ! -d $backuproot/monthly.1 ]; then
+ echo "Debug: weekly.\$max --> monthly.1"
+ mv $backuproot/weekly.\$max $backuproot/monthly.1
+ date +%c%n%s > $backuproot/monthly.1/rotated
+ fi
+
+ for rottype in daily weekly monthly; do
+ max=\$((keep\${rottype}+1))
+ dir="$backuproot/\$rottype"
+ oldest=\`find $backuproot -maxdepth 1 -type d -name \$rottype'.*' | @SED@ 's/^.*\.//' | sort -n | tail -1\`
+ [ "\$oldest" == "" ] && oldest=0
+ # if we've rotated the last backup off the stack, remove it.
+ for (( i=\$oldest; i >= \$max; i-- )); do
+ if [ -d \$dir.\$i ]; then
+ if [ -d $backuproot/rotate.tmp ]; then
+ echo "Debug: removing rotate.tmp"
+ rm -rf $backuproot/rotate.tmp
+ fi
+ echo "Debug: moving \$rottype.\$i to rotate.tmp"
+ mv \$dir.\$i $backuproot/rotate.tmp
+ fi
+ done
+ done
+####### END REMOTE SCRIPT #######
+EOF
+) | (while read a; do passthru $a; done)
+
+}
+
+
+function setup_remote_dirs() {
+ local user=$1
+ local backuptype=$2
+ local letter=${user:0:1}
+ local dir="$stripped_destdir/$letter/$user/$backuptype"
+ local tmpdir="$stripped_destdir/$letter/$user/rotate.tmp"
+(
+ ssh -T -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions <<EOF
+ if [ ! -d $stripped_destdir ]; then
+ echo "Fatal: Destination directory $stripped_destdir does not exist on host $desthost."
+ exit 1
+ elif [ -d $dir.1 ]; then
+ if [ -f $dir.1/created ]; then
+ echo "Warning: $dir.1 already exists. Overwriting contents."
+ else
+ echo "Warning: we seem to be resuming a partially written $dir.1"
+ fi
+ else
+ if [ -d $tmpdir ]; then
+ mv $tmpdir $dir.1
+ if [ \$? == 1 ]; then
+ echo "Fatal: could mv $stripped_destdir/rotate.tmp $dir.1 on host $desthost"
+ exit 1
+ fi
+ else
+ mkdir --parents $dir.1
+ if [ \$? == 1 ]; then
+ echo "Fatal: could not create directory $dir.1 on host $desthost"
+ exit 1
+ fi
+ fi
+ if [ -d $dir.2 ]; then
+ echo "Debug: update links $backuptype.2 --> $backuptype.1"
+ cp -alf $dir.2/. $dir.1
+ #if [ \$? == 1 ]; then
+ # echo "Fatal: could not create hard links to $dir.1 on host $desthost"
+ # exit 1
+ #fi
+ fi
+ fi
+ [ -f $dir.1/created ] && rm $dir.1/created
+ [ -f $dir.1/rotated ] && rm $dir.1/rotated
+ exit 0
+EOF
+) | (while read a; do passthru $a; done)
+
+ if [ $? == 1 ]; then exit; fi
+}
+
+###
+##################################################################
+
+# see if we can login
+debug "ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions 'echo -n 1'"
+if [ ! $test ]; then
+ result=`ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions 'echo -n 1' 2>&1`
+ if [ "$result" != "1" ]; then
+ fatal "Can't connect to $desthost as $destuser using $destid_file."
+ fi
+fi
+
+## SANITY CHECKS ##
+status=`ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost "[ -d \"$stripped_destdir\" ] && echo 'ok'"`
+if [ "$status" != "ok" ]; then
+ fatal "Destination directory $stripped_destdir doesn't exist!"
+ exit
+fi
+
+### REMOVE OLD MAILDIRS ###
+
+if [ "$remove" == "yes" ]; then
+ do_remove
+fi
+
+### MAKE BACKUPS ###
+
+if [ "$backup" == "yes" ]; then
+ if [ $keepdaily -gt 0 ]; then btype=daily
+ elif [ $keepweekly -gt 0 ]; then btype=weekly
+ elif [ $keepmonthly -gt 0 ]; then btype=monthly
+ else fatal "keeping no backups"; fi
+
+ if [ "$testuser" != "" ]; then
+ cd "$stripped_srcdir/${user:0:1}"
+ do_rotate $testuser
+ setup_remote_dirs $testuser $btype
+ do_user $testuser $btype
+ else
+ [ -d "$stripped_srcdir" ] || fatal "directory $stripped_srcdir not found."
+ for user in `$DOVEADM user \* | cut -d@ -f1`
+ do
+ debug $user
+ [ "$user" != "" ] || continue
+ do_rotate $user
+ setup_remote_dirs $user $btype
+ do_user $user $btype
+ done
+ fi
+fi
+