#!/bin/sh
# $Id$
# Qemu environment preparation script
# ---------------------------------------------------------------------------
#
# After running this startup script, run a QEMU virtual machine in this way:
#
#     vdeqemu [qemu_option [qemu_option], ...]
#
# The vdeqemu program will automatically connect
# the QEMU virtual machine to the VDE switch.
#
# ---------------------------------------------------------------------------

# The IP configuration for the tap device that will be used for
# the virtual machine network:

TAP_DEV=tap0
TAP_IP=10.111.111.254
TAP_MASK=255.255.255.0

TAP_BCAST=`/bin/ipmask ${TAP_MASK} ${TAP_IP} | cut -f 1 -d ' '`

# Host interfaces that need to be NAT-ed (in case we're not bridging):
NAT_IFS="eth+"

# Definitions for the LAN segment the Qemu virtual machines will be in.
# These definitions will be fed to dnsmasq - this program will provide DNS
# and DHCP to the Qemu LAN.

# The VM_IPLOW and VM_IPHIGH addresses must agree with the definitions for
# the tap0 device above. These 'low' and 'high' values are the IP address
# range for the DHCP server to use.

VM_DOMAIN=qemu.lan
VM_IPLOW=10.111.111.128
VM_IPHIGH=10.111.111.199
VM_BCAST=${TAP_BCAST}
VM_MASK=${TAP_MASK}

# For additional options to dnsmasq:
#DNSMASQ_OPTIONS="--server /my.net/192.168.1.1"
DNSMASQ_OPTIONS=""

# See how we were called.

case "$1" in
  start)
        echo -n "Starting VDE network for QEMU: "

        # Load tun module
        /sbin/modprobe tun 2>/dev/null
        # Wait for the module to be loaded
        while ! /bin/lsmod |grep -q "^tun"; do echo Waiting for tun device;sleep 1; done

        # Start tap switch
        vde_switch -tap ${TAP_DEV} -daemon
        sleep 1

        # Bring tap interface up
        ifconfig ${TAP_DEV} ${TAP_IP} broadcast ${TAP_BCAST} netmask ${TAP_MASK}

        # Start IP Forwarding
        echo "1" > /proc/sys/net/ipv4/ip_forward
        for NIC in ${NAT_IFS}; do
          iptables -t nat -A POSTROUTING -o ${NIC} -j MASQUERADE
        done

        # Change pipe permission (vde2 uses a different pipe directory)
        #chmod 666 /tmp/vde.ctl
        chmod -R a+rwx /var/run/vde.ctl

        # If we are not running 2.6, apply workaround
        if uname -r | grep '^2.4'; then
          echo 1024 > /proc/sys/dev/rtc/max-user-freq
        fi

        # Start dnsmasq, the DNS/DHCP server
        # for our Virtual Machines behind the tap0 interface
        /usr/sbin/dnsmasq \
          --log-queries \
          --user=named \
          --dhcp-leasefile=/var/state/dhcp/qemu-dhcpd.leases \
          --dhcp-range=${VM_IPLOW},${VM_IPHIGH},${VM_MASK},${VM_BCAST},8h \
          --interface=${TAP_DEV} \
          --domain=${VM_DOMAIN} \
          $DNSMASQ_OPTIONS
        echo
        ;;
  stop)
        echo -n "Stopping VDE network for QEMU: "
        {
        # Delete the NAT rules
        for NIC in ${NAT_IFS}; do
          iptables -t nat -D POSTROUTING -o ${NIC} -j MASQUERADE
        done
        # Bring tap interface down
        ifconfig ${TAP_DEV} down
        # Kill VDE switch
        pgrep -f vde_switch | xargs kill -TERM
        # Remove the control socket (vde2 uses a different location)
        #rm -f /tmp/vde.ctl
        rmdir /var/run/vde.ctl
        # Stop dnsmasq
        pgrep -f dnsmasq | xargs kill -TERM
        } >/dev/null 2>&1
        echo
        ;;
  restart|reload)
        $0 stop
        $0 start
        ;;
  *)
        echo "Usage: $0 {start|stop|restart|reload}"
        exit 1
esac