#!/bin/sh
# Start/stop qemu's private network
# Revised: 12/16/2009 JJO
### BEGIN INIT INFO
# Provides: qemunet
# Required-Start: $network
# Required-Stop: $network
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Description: Start the qemu private network
### END INIT INFO

# start qemu with: -net nic -net tap,ifname=tap0,script=no
# You can then assign any VM any static IP on the $ETHIP network

ETHIP=10.10.10.1
GATEWAY=
ETHBC=10.10.10.255
BRIDGE=br0
ETH=dummy0
TAP=tap0

# A little SuSE sanity check
[ -f /etc/SuSE-release ] && /sbin/rmmod dummy0 >/dev/null 2>&1

# Start the qemu private network
qemunet_start() {
  # Make sure the qemu private network isnt already running
  PROBLEM=FALSE
  for IF in $ETH $TAP $BRIDGE; do
    /sbin/ifconfig | grep $IF >/dev/null 2>&1
    [ $? = 0 ] && PROBLEM=TRUE
  done
  if [ $PROBLEM = TRUE ]; then
    echo "All or part of the qemu private network is already running!"
    echo "Cowardly refusing to start it again!  BYE!"
    exit 1
  fi

  echo "Starting the qemu private network..."
  # Make sure the kernel module is loaded
  /sbin/lsmod | grep dummy >/dev/null 2>&1
  [ $? = 1 ] && /sbin/modprobe dummy

  # First take interface down, then bring it up with IP 0.0.0.0
  /sbin/ifconfig $ETH down
  /sbin/ifconfig $ETH 0.0.0.0 promisc up

  # Bring up the tap device (name specified as first argument, by QEMU)
  /usr/sbin/openvpn --mktun --dev $TAP
  /sbin/ifconfig $TAP 0.0.0.0 promisc up

  # create the bridge between eth0 and the tap device
  /sbin/brctl addbr $BRIDGE
  /sbin/brctl addif $BRIDGE $ETH
  /sbin/brctl addif $BRIDGE $TAP
  # only a single bridge so loops are not possible, turn off spanning tree protocol
  /sbin/brctl stp $BRIDGE off

  # Bring up the bridge with ETHIP and add the default route
  /sbin/ifconfig br0 $ETHIP netmask 255.255.255.0 broadcast $ETHBC
  [ -n "$GATEWAY" ] && /sbin/route add default gw $GATEWAY
}

# Stop the qemu private network
qemunet_stop() {
  echo "Stopping the qemu private network..."
  # Bring down interface and br0
  /sbin/ifconfig $ETH down
  /sbin/ifconfig $BRIDGE down
  /sbin/rmmod dummy

  # Delete the bridge
  /sbin/brctl delbr $BRIDGE

  # delete the tap device
  /usr/sbin/openvpn --rmtun --dev $TAP
}

# Restart the qemu private network
qemunet_restart() {
  qemunet_stop
  sleep 1
  qemunet_start
}

# Check if the qemu private network is up and running
qemunet_status() {
  echo -n "Checking the qemu private network: "

  # Check the qemu private inetwork
  for IF in $ETH $TAP $BRIDGE; do
    /sbin/ifconfig | grep $IF >/dev/null 2>&1
    if [ $? = 1 ]; then
      echo -n "$IF is down"
    else
      echo -n "$IF is up"
    fi
    if [ $IF = $BRIDGE ]; then
      echo "."
    else
      echo -n ", "
    fi
  done
}

case "$1" in
'start') qemunet_start ;;
'stop')  qemunet_stop ;;
'restart') qemunet_restart ;;
'status')  qemunet_status ;;
*) echo "usage $0 start|stop|restart|status"
esac