#!/bin/bash

function usage {
	echo "Usage: $0 <mode> <parent interface> <prv min> <prv max> <offset>"
	exit 1
}

if [ $# -ne 5 ]; then
	usage
fi

function up {
	iface=$1
	prv_min=$2
	prv_max=$3
	offset=$4

	echo "Adding VLANs $2 - $3"
	vconfig set_name_type DEV_PLUS_VID_NO_PAD
	for prv in $(seq $prv_min $prv_max); do
		vlan=$(($prv+$offset))
		bridge=prv$prv

		vconfig add $iface $vlan
		ifconfig $iface.$vlan up
		brctl addbr $bridge
		brctl setfd $bridge 0
		brctl addif $bridge $iface.$vlan # dev_plus_vid
		ifconfig $bridge up
	done
}

function down {
	iface=$1
	prv_min=$2
	prv_max=$3
	offset=$4

	echo "Removing VLANs $2 - $3"
	for prv in $(seq $prv_min $prv_max); do
		vlan=$(($prv+$offset))
		bridge=prv$prv

		(
		ifconfig $bridge down
		brctl delif $bridge $iface.$vlan # dev_plus_vid
		vconfig rem $iface.$vlan
		brctl delbr $bridge
		) 2>/dev/null
	done
}

mode=$1; shift
if [ "$mode" = "up" ]; then
	up $@
elif [ "$mode" = "down" ]; then
	down $@
else
	usage
fi