#!/bin/bash

# dnsmasq DNS server with cache installation on Raspbian
#
# Copyleft 2017 by Ignacio Nunez Hernanz <nacho _a_t_ ownyourbits _d_o_t_ com>
# GPL licensed (see end of file) * Use at your own risk!
#
# More at: https://ownyourbits.com/2017/03/09/dnsmasq-as-dns-cache-server-for-nextcloudpi-and-raspbian/
#


install()
{
  set -x
  apt-get update
  apt-get install --no-install-recommends -y dnsmasq
  sleep 10
  rc=0
  service dnsmasq status > /dev/null 2>&1 || rc=$?
  if [[ $rc -eq 3 ]] && ! [[ "$INIT_SYSTEM" =~ ^("chroot"|"unknown")$ ]]
  then
    echo "Applying workaround for dnsmasq bug (compare issue #1446)"
    mkdir -p /etc/systemd/resolved.conf.d
    if systemctl status systemd-resolved
    then
  cat <<EOF > /etc/systemd/resolved.conf.d/nostublistener.conf
[Resolve]
DNSStubListener=no
EOF
      [[ "$INIT_SYSTEM" != "systemd" ]] || systemctl restart systemd-resolved
    elif systemctl status resolvconf
    then
      systemctl stop resolvconf
      systemctl start dnsmasq
      systemctl status dnsmasq
    else
      echo "dnsmasq failed to start and no workaround could be found. This means, the installer failed."
      false
    fi
#    service systemd-resolved stop || true
    systemctl start dnsmasq
    systemctl status dnsmasq
  fi

  service dnsmasq stop
  if [[ "$INIT_SYSTEM" == "systemd" ]] && systemctl list-unit-files resolvconf.service
  then
    systemctl start resolvconf
  fi
  update-rc.d dnsmasq disable || rm /etc/systemd/system/multi-user.target.wants/dnsmasq.service

  return 0
}

configure()
{
  [[ $ACTIVE != "yes" ]] && {
    service dnsmasq stop
    update-rc.d dnsmasq disable
    echo "dnmasq disabled"
    return
  }

  local IFACE IP
  IFACE=$( ip r | grep "default via"   | awk '{ print $5 }' | head -1 )
  IP=$( ncc config:system:get trusted_domains 6 | grep -oP '\d{1,3}(.\d{1,3}){3}' )
  [[ "$IP" == "" ]] && IP="$(get_ip)"

  [[ "$IP" == "" ]] && { echo "could not detect IP"; return 1; }

  cat > /etc/dnsmasq.conf <<EOF
interface=$IFACE
domain-needed         # Never forward plain names (without a dot or domain part)
bogus-priv            # Never forward addresses in the non-routed address spaces.
no-poll               # Don't poll for changes in /etc/resolv.conf
no-resolv             # Don't use /etc/resolv.conf or any other file
cache-size=$CACHESIZE
server=$DNSSERVER
address=/$DOMAIN/$IP  # This is optional if we add it to /etc/hosts
EOF

  # required to run in container
  test -d /data && echo "user=root" >> /etc/dnsmasq.conf

  sed -i 's|#\?IGNORE_RESOLVCONF=.*|IGNORE_RESOLVCONF=yes|' /etc/default/dnsmasq

  update-rc.d dnsmasq defaults
  update-rc.d dnsmasq enable
  service dnsmasq restart
  ncc config:system:set trusted_domains 2 --value="$DOMAIN"
  set-nc-domain "$DOMAIN" --no-trusted-domain
  echo "dnsmasq enabled"
}

# License
#
# This script is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This script is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this script; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330,
# Boston, MA  02111-1307  USA