shorewall_code/Shorewall/configfiles/isusable

#
# Shorewall -- /etc/shorewall/isusable
#
# This script is called when Shorewall is attempting to determine
# if an interface named in /etc/shorewall/providers is usable.
#
# The script is invoked inside a function that accepts an interface
# name as a single argument. The file below is designed to work with
# both swping and lsm as described at
# https://shorewall.org/MultiISP.html
#
# See https://shorewall.org/shorewall_extension_scripts.htm for additional
# information.
#
###############################################################################

local status
status=0

[ -f ${VARDIR}/${1}.status ] && status=$(cat ${VARDIR}/${1}.status)

return $status