tag:
priority: 310 # before real devices that redirect
type: txt
help: Input functional block (IFB) interface name
val_help: <ifbN>; Input functional block interface name

syntax:expression: pattern $VAR(@) "^ifb[0-9]+$" ; "name must be (ifb0-ifb999)"

begin: [ -d /sys/module/ifb ] || sudo modprobe ifb numifbs=0

create:	sudo ip link add $VAR(@) type ifb && sudo ip link set $VAR(@) up

delete: [ -d /sys/class/net/$VAR(@) ] || exit 0
   /opt/vyatta/sbin/vyatta-qos.pl --check-target $VAR(@) || exit 1
   sudo ip link delete dev $VAR(@)