FreeBSD rc.d script to switch CARP MASTER vhids to BACKUP state before shutdown

carpstop

#!/bin/sh
#
# $FreeBSD$
#

# PROVIDE: carpstop
# REQUIRE: securelevel
# KEYWORDS: nostart shutdown

. /etc/rc.subr

name="carpstop"
desc="Switch CARP vhid in MASTER state to BACKUP state. Run as the first thing when shutdown is initiated."
start_cmd=":"
stop_cmd="switch_carp_vhids_to_BACKUP"
rcvar="carpstop_enable"

switch_carp_vhids_to_BACKUP()
{
    for INTERFACE in $(ifconfig -l); do 
        if /sbin/ifconfig "${INTERFACE}" | grep -q "carp: MASTER vhid" ; then
            /sbin/ifconfig $INTERFACE | while read -r LINE; do
                if echo "$LINE" | grep -q "^carp: "; then
                    VHID=$(echo $LINE | cut -c 19- | cut -d " " -f 1)
                    logger -t carpstop "found CARP MASTER vhid ${VHID} on interface ${INTERFACE} - switching vhid to state BACKUP..."
                    /sbin/ifconfig ${INTERFACE} vhid ${VHID} state BACKUP
                fi
            done
        fi
    done
}

load_rc_config $name
run_rc_command "$1"