#!/bin/sh
#
# /etc/rc.d/rc.lxc-bridge, Christoph Willing (2015)
#
# Set up a bridge and a NAT network hanging off it.
#
# Below, set LXCBR_NAME to desired bridge interface name
#        set LXCBR0_NAT_NET for desired NAT network address
#        set OTHER_ROUTE_DEVICE to make bridged network available
#                               on other local network interfaces

DEFAULT_ROUTE_DEVICE=${DEFAULT_ROUTE_DEVICE:-$(/sbin/route | grep default | awk '{print $8}'|uniq)}
OTHER_ROUTE_DEVICE=${OTHER_ROUTE_DEVICE:-"eth0"}
LXCBR_NAME=${LXCBR_NAME:-lxcbr0}
LXCBR0_NAT_NET=${LXCBR0_NAT_NET:-192.168.100}
PATH=/sbin:/usr/sbin:$PATH

start()
{
  if brctl show |grep $LXCBR_NAME 1>/dev/null 2>/dev/null ; then
    echo "lxbr0 already exists"
  else
    echo "Setting up $LXCBR_NAME on $DEFAULT_ROUTE_DEVICE ..."
    echo 1 > /proc/sys/net/ipv4/ip_forward
    brctl addbr $LXCBR_NAME
    brctl setfd $LXCBR_NAME 0
    ifconfig $LXCBR_NAME ${LXCBR0_NAT_NET}.1 netmask 255.255.255.0 promisc up
    iptables -t nat -A POSTROUTING -o $DEFAULT_ROUTE_DEVICE -j MASQUERADE
    if [ -z $OTHER_ROUTE_DEVICE ] ; then
      echo "No other route device to NAT"
    else
      iptables -t nat -A POSTROUTING -o $OTHER_ROUTE_DEVICE -j MASQUERADE
    fi
  fi
}

stop()
{
  if brctl show |grep $LXCBR_NAME 1>/dev/null 2>/dev/null ; then
    ifconfig $LXCBR_NAME down
    brctl delbr $LXCBR_NAME
  else
    echo "$LXCBR_NAME is not there to shutdown"
  fi
}

status()
{
  if brctl show |grep $LXCBR_NAME 1>/dev/null 2>/dev/null ; then
    echo "$LXCBR_NAME exists."
  else
    echo "$LXCBR_NAME not found."
  fi
}

case "$1" in
'start')start;;
'stop')stop;;
'restart')stop;start;;
'status')status;;
*)echo "$0 start|stop|restart|status"
esac