/etc/xen/scripts/vif-route is in xen-utils-common 4.4.0-0ubuntu5.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | #!/bin/bash
#============================================================================
# ${XEN_SCRIPT_DIR}/vif-route
#
# Script for configuring a vif in routed mode.
# The hotplugging system will call this script if it is specified either in
# the device configuration given to Xend, or the default Xend configuration
# in ${XEN_CONFIG_DIR}/xend-config.sxp.  If the script is specified in
# neither of those places, then vif-bridge is the default.
#
# Usage:
# vif-route (add|remove|online|offline)
#
# Environment vars:
# dev         vif interface name (required).
# XENBUS_PATH path to this device's details in the XenStore (required).
#
# Read from the store:
# ip      list of IP networks for the vif, space-separated (default given in
#         this script).
#============================================================================
dir=$(dirname "$0")
. "${dir}/vif-common.sh"
main_ip=$(dom0_ip)
case "${command}" in
    online)
        ifconfig ${dev} ${main_ip} netmask 255.255.255.255 up
        echo 1 >/proc/sys/net/ipv4/conf/${dev}/proxy_arp
        ipcmd='add'
        cmdprefix=''
        ;;
    offline)
        do_without_error ifdown ${dev}
        ipcmd='del'
        cmdprefix='do_without_error'
        ;;
esac
if [ "${ip}" ] ; then
    # If we've been given a list of IP addresses, then add routes from dom0 to
    # the guest using those addresses.
    for addr in ${ip} ; do
      ${cmdprefix} ip route ${ipcmd} ${addr} dev ${dev} src ${main_ip}
    done
fi
handle_iptable
call_hooks vif post
log debug "Successful vif-route ${command} for ${dev}."
if [ "${command}" = "online" ]
then
  success
fi
 |