qubes-linux-template-builder/scripts_debian/extra-qubes-files/etc/xen/scripts/vif-nat

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#!/bin/bash
#============================================================================
# ${XEN_SCRIPT_DIR}/vif-nat
#
# Script for configuring a vif in routed-nat 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 ${XEN_CONFIG_DIR}/xend-config.sxp. If the script is specified in
# neither of those places, then vif-bridge is the default.
#
# Usage:
# vif-nat (add|remove|online|offline)
#
# Environment vars:
# dev vif interface name (required).
# XENBUS_PATH path to this device's details in the XenStore (required).
#
# Parameters:
# dhcp Whether to alter the local DHCP configuration to include this
# new host (default no).
#
# Read from the store:
# ip list of IP networks for the vif, space-separated (default given in
# this script).
#============================================================================
dir=$(dirname "$0")
. "$dir/vif-common.sh"
# turn on dhcp feature by default if dhcpd is installed
if [ -f /etc/dhcpd.conf ]
then
dhcp=${dhcp:-yes}
else
dhcp=${dhcp:-no}
fi
if [ "$dhcp" != 'no' ]
then
dhcpd_conf_file=$(find_dhcpd_conf_file)
dhcpd_init_file=$(find_dhcpd_init_file)
dhcpd_arg_file=$(find_dhcpd_arg_file)
if [ -z "$dhcpd_conf_file" ] || [ -z "$dhcpd_init_file" ] || [ -z "$dhcpd_arg_file" ]
then
echo 'Failed to find dhcpd configuration or init or args file.' >&2
exit 1
fi
fi
domid=$(xenstore_read "$XENBUS_PATH/frontend-id")
vifid=$(xenstore_read "$XENBUS_PATH/handle")
vifid=$(( $vifid + 1 ))
ip_from_dom()
{
local domid1=$(( $domid / 256 ))
local domid2=$(( $domid % 256 ))
echo "10.$domid1.$domid2.$vifid/16"
}
routing_ip()
{
echo $(echo $1 | awk -F. '{print $1"."$2"."$3"."$4 + 127}')
}
dotted_quad()
{
echo\
$(( ($1 & 0xFF000000) >> 24))\
.$(( ($1 & 0x00FF0000) >> 16))\
.$(( ($1 & 0x0000FF00) >> 8 ))\
.$(( $1 & 0x000000FF ))
}
if [ "$ip" = "" ]
then
ip=$(ip_from_dom)
fi
router_ip=$(routing_ip "$ip")
# Split the given IP/bits pair.
vif_ip=`echo ${ip} | awk -F/ '{print $1}'`
hostname=$(xenstore_read "$XENBUS_PATH/domain" | tr -- '_.:/+' '-----')
if [ "$vifid" != "1" ]
then
hostname="$hostname-$vifid"
fi
dhcparg_remove_entry()
{
local tmpfile=$(mktemp)
sed -e "s/${dev} //" "$dhcpd_arg_file" >"$tmpfile"
if diff "$tmpfile" "$dhcpd_arg_file" >/dev/null
then
rm "$tmpfile"
else
mv "$tmpfile" "$dhcpd_arg_file"
fi
}
dhcparg_add_entry()
{
dhcparg_remove_entry
local tmpfile=$(mktemp)
# handle Red Hat, SUSE, and Debian styles, with or without quotes
sed -e 's/^DHCPDARGS="*\([^"]*\)"*/DHCPDARGS="\1'"${dev} "'"/' \
"$dhcpd_arg_file" >"$tmpfile" && mv "$tmpfile" "$dhcpd_arg_file"
sed -e 's/^DHCPD_INTERFACE="*\([^"]*\)"*/DHCPD_INTERFACE="\1'"${dev} "'"/' \
"$dhcpd_arg_file" >"$tmpfile" && mv "$tmpfile" "$dhcpd_arg_file"
sed -e 's/^INTERFACES="*\([^"]*\)"*/INTERFACES="\1'"${dev} "'"/' \
"$dhcpd_arg_file" >"$tmpfile" && mv "$tmpfile" "$dhcpd_arg_file"
rm -f "$tmpfile"
}
dhcp_remove_entry()
{
local tmpfile=$(mktemp)
grep -v "host $hostname" "$dhcpd_conf_file" >"$tmpfile"
if diff "$tmpfile" "$dhcpd_conf_file" >/dev/null
then
rm "$tmpfile"
else
mv "$tmpfile" "$dhcpd_conf_file"
fi
dhcparg_remove_entry
}
dhcp_up()
{
claim_lock "vif-nat-dhcp"
dhcp_remove_entry
mac=$(xenstore_read "$XENBUS_PATH/mac")
echo >>"$dhcpd_conf_file" \
"host $hostname { hardware ethernet $mac; fixed-address $vif_ip; option routers $router_ip; option host-name \"$hostname\"; }"
dhcparg_add_entry
release_lock "vif-nat-dhcp"
"$dhcpd_init_file" restart || true
}
dhcp_down()
{
claim_lock "vif-nat-dhcp"
dhcp_remove_entry
release_lock "vif-nat-dhcp"
"$dhcpd_init_file" restart || true # We need to ignore failure because
# ISC dhcpd 3 borks if there is nothing
# for it to do, which is the case if
# the outgoing interface is not
# configured to offer leases and there
# are no vifs.
}
case "$command" in
online)
if ip route | grep -q "dev ${dev}"
then
log debug "${dev} already up"
exit 0
fi
do_or_die ip link set "${dev}" up arp on
do_or_die ip addr add "$router_ip" dev "${dev}"
do_or_die ip route add "$vif_ip" dev "${dev}" src "$router_ip"
echo 1 >/proc/sys/net/ipv4/conf/${dev}/proxy_arp
[ "$dhcp" != 'no' ] && dhcp_up
;;
offline)
[ "$dhcp" != 'no' ] && dhcp_down
do_without_error ifconfig "${dev}" down
;;
esac
handle_iptable
log debug "Successful vif-nat $command for ${dev}."
if [ "$command" = "online" ]
then
success
fi