#!/bin/sh
#============================================================================
# /etc/xen/vif-nat
#
# Script for configuring a vif in routed-nat mode.
# Xend calls a vif script when bringing a vif up or down.
# This script is the default - but it can be configured for each vif.
#
# Example invocation:
#
# vif-nat up domain=VM1 vif=vif1.0 ip="192.168.0.10/31"
#
# Usage:
# vif-nat (up|down) {VAR=VAL}*
#
# Vars:
#
# domain  name of the domain the interface is on (required).
# vif     vif interface name (required).
# ip      list of IP networks for the vif, space-separated (required).
#============================================================================

# Exit if anything goes wrong
set -e 

echo "*vif-nat $*" >&2

# Operation name.
OP=$1
shift

# Pull variables in args into environment
for arg ; do export "${arg}" ; done

# Required parameters. Fail if not set.
domain=${domain:?}
vif=${vif:?}
ip=${ip:?} 

# strip /netmask
vif_ip=`echo ${ip} | awk -F/ '{print $1}'`

main_ip=`ifconfig eth0 | grep "inet addr:" | sed -e 's/.*inet addr:\(\w\w*\.\w\w*\.\w\w*\.\w\w*\).*/\1/'`

# Are we going up or down?
case $OP in
    up)
        ifconfig ${vif} ${vif_ip} netmask 255.255.255.0 up
        echo 1 >/proc/sys/net/ipv4/conf/${vif}/proxy_arp
        iptcmd='-A'
        ipcmd='a'
        ;;
    down)
        ifconfig ${vif} down
        iptcmd='-D'
        ipcmd='d'
        ;;
    *)
        echo 'Invalid command: ' $OP >&2
        echo 'Valid commands are: up, down' >&2
        exit 1
        ;;
esac

ip r ${ipcmd} ${ip} dev ${vif} src ${main_ip}
#    iptables ${iptcmd} FORWARD -m physdev --physdev-in ${vif} -p udp --sport 68 --dport 67 -j ACCEPT