#!/system/bin/sh

DNSCRYPT_PROXY="/system/xbin/dnscrypt-proxy"
CONFFILE="/data/local/dnscrypt-proxy/dnscrypt-proxy.toml"
PIDFILE="/data/local/tmp/dnscrypt-proxy.pid"
APPEND="-A"
WAITFORDAEMON=10
STOP=0
nohup="nohup"

_log() {
  log -p i -t dnscrypt-init -- $1
  echo "$1" 1>&2
}

_wait_for_pid() {
  cnt=0

  while true ; do
    sleep 1

    if test -s "$PIDFILE" ; then
      pid=$(cat "$PIDFILE")

      if kill -0 $pid 2>/dev/null ; then
        return 0
      fi
    fi

    [ "`expr $cnt % 3`" != 2 ] || _log "."

    cnt=`expr $cnt + 1`
    if [ $cnt -gt $WAITFORDAEMON ] ; then
      break
    fi
  done

  return 1
}

## Begin

if [ "$1" = "--debug" ] ; then
  nohup=""
  _log "Attempting to run dnscrypt-proxy in foreground"
fi

if [ "$1" = "--stop" ] ; then
  STOP=1
  APPEND="-D"
  _log "Stopping dnscrypt-proxy"
else
  _log "Starting dnscrypt-proxy"
fi

if [ -s "$PIDFILE" ] ; then
  # if dnscrypt-proxy is running, kill
  kill $(cat "$PIDFILE")
  rm -f "$PIDFILE"
fi

if [ $STOP -eq 0 ] ; then
  cmd="""$DNSCRYPT_PROXY"" -config ""$CONFFILE"" -pidfile=""$PIDFILE"""

  if [ "$nohup" != "" ] ; then
    $nohup $cmd >/dev/null 2>&1 &
    _wait_for_pid
    if [ $? -ne 0 ] ; then
      # delete iptable rule
      APPEND="-D"
      _log "failed to start dnscrypt-proxy"
      _log "Try running '$0 --debug' or enable logging and check the logs for errors"
      exit 1
    fi
  else
    $cmd
  fi
fi

iptables -t nat $APPEND OUTPUT -p tcp --dport 53 -j DNAT --to-destination 127.0.0.1:533
iptables -t nat $APPEND OUTPUT -p udp --dport 53 -j DNAT --to-destination 127.0.0.1:533