#!/bin/bash
#============================================================================
# ${XEN_SCRIPT_DIR}/vif-openvswitch
#
# Script for configuring a vif using Open vSwitch.
#
# Usage:
# vif-openvswitch (add|remove|online|offline)
#
# Environment vars:
# vif         vif interface name (required).
# XENBUS_PATH path to this device's details in the XenStore (required).
#
# Read from the store:
# bridge  bridge to add the vif to (optional).  Defaults to searching for the
#         bridge itself.
#
# up:
# Enslaves the vif interface to the bridge.
#
# down:
# Removes the vif interface from the bridge.
#============================================================================

dir=$(dirname "$0")
. "$dir/vif-common.sh"

bridge=${bridge:-}
bridge=$(xenstore_read_default "$XENBUS_PATH/bridge" "$bridge")

if [ -z "${bridge}" ]; then
	bridge=$(ovs-vsctl list-br | head -n 1)
	if [ -z "$bridge" ]; then
		fatal "Could not find bridge, and none was specified"
	fi
fi

tag=${tag:-}

# Domain on VLAN tagged bridge?
if ! ovs-vsctl br-exists ${bridge}; then
	if [[ $bridge =~ \.[[:digit:]]{1,4}$ ]]; then
		tag=${bridge##*.}
		bridge=${bridge%.[0-9]*}
	else
		fatal "Could not find bridge device ${bridge}"
	fi
fi

if ! ovs-vsctl br-exists ${bridge}; then
	fatal "Could not find bridge device ${bridge}"
fi

case "$command" in
  online|add)
	ip link set dev "${vif}" up
	if [ -z $tag ]; then
		ovs-vsctl -- --may-exist add-port ${bridge} ${vif}
	else
		ovs-vsctl -- --may-exist add-port ${bridge} ${vif} tag=${tag}
	fi
	;;
  offline)
	do_without_error ovs-vsctl -- --if-exists del-port ${bridge} ${vif}
	do_without_error ip link set dev "${vif}" down
	;;
esac

call_hooks vif post

if [ -z "${tag}" ]; then
	log debug "Successful vif-openvswitch $command for ${vif}, bridge ${bridge}."
else
	log debug "Successful vif-openvswitch $command for ${vif}, bridge ${bridge}, tag ${tag}."
fi

if [ "$command" == "online" ]; then
	success
fi