Qubes RPC service generating a hosts file for a firewall VM

qubes.GetHostsFile

#!/bin/bash

# qubes.GetHostsFile - RPC service for retrieving a hosts file
#
# This will emit a hosts file containing the addresses of all qubes
# directly connected to the qube calling the service.
#
# It can be used in firewall VMs to get name resolution for these VMs.
#
# Note that using this script might create an information leak.
#
# Be sure that you know what you are doing!
#
#
#
# Add this to /rw/config/rc.local in your firewall vm:
#
#     qubes-client-vm dom0 qubes.GetHostsFile > /tmp/hosts.new \
#         && mv /tmp/hosts.new /etc/hosts
#
# And allow the RPC by creating /etc/qubes-rpc/policy/qubes.GetHostsFile:
#
#     sys-firewall	dom0	allow
#     $anyvm		$anyvm	deny
#
#

SELF="$QREXEC_REMOTE_DOMAIN"
ADDR="$(qvm-prefs ${SELF} ip)"

echo "127.0.0.1  localhost ip4-localhost ip4-loopback"
echo "::1        localhost ip6-localhost ip6-loopback"
echo "ff02::1    ip6-allnodes"
echo "ff02::2    ip6-allrouters"

echo "127.0.1.1  ${SELF}"

domains="$(qvm-ls --raw-data -O NAME,IP,GATEWAY | grep -v '|\-$' | grep "|${ADDR}\$" | cut -d \| -f 1)"
for domain in $domains; do
	address="$(qvm-prefs ${domain} ip)"
	echo "${address}	${domain}"
done