#!/bin/bash
# Version: 0.2.9
# Copyright (c) 2005-2017:
#   Darren 'Tadgy' Austin <darren (at) afterdark.org.uk>
# Licensed under the terms of the GNU General Public License version 3.

EXEC="/usr/sbin/in.tftpd"
ARGS=(--listen --address=FIXME --user tftp --secure /data/tftpboot)
PIDFILE=""

checkconfigured() {
  # This function can be used to perform any pre-start tests; hopfully to insure the daemon
  # can start correctly, before actually trying to start it.  A return value of 0 means the
  # tests were passed and the daemon should be started.  Any other value prevents the
  # daemon from being started and an error message will be emitted.
  return 0
}

checkstatus() {
  local RUNPIDS="$(pgrep -f "$EXEC")"
  if [ ! -z "$RUNPIDS" ]; then
    echo -n "${BASH_SOURCE##*/}: ${EXEC##*/}: running"
    if [ ! -z "$PIDFILE" ]; then
      if [ ! -e "$PIDFILE" ]; then
        echo -n ", but .pid file does not exist"
      elif ! echo "$RUNPIDS" | grep "\<$(cat "$PIDFILE")\>" >/dev/null 2>&1; then
        echo -n ", but .pid file is stale"
      fi
    fi
    echo
  else
    echo "${BASH_SOURCE##*/}: ${EXEC##*/}: stopped"
    return 1
  fi
  return 0
}

startdaemon() {
  if ! checkconfigured; then
    echo "${BASH_SOURCE##*/}: ${EXEC##*/}: not started - pre-start checks failed" >&2
    return 1
  elif [ ! -e "$EXEC" ]; then
    echo "${BASH_SOURCE##*/}: ${EXEC##*/}: not found" >&2
    return 1
  elif [ ! -x "$EXEC" ]; then
    echo "${BASH_SOURCE##*/}: ${EXEC##*/}: not executable" >&2
    return 1
  fi
  "$EXEC" "${ARGS[@]}"
  return $?
}

stopdaemon() {
  if ! kill -TERM "$(cat "$PIDFILE" 2>/dev/null)" >/dev/null 2>&1; then
    kill -TERM "$(pgrep -f "$EXEC")" >/dev/null 2>&1
  fi
  sleep 2
  if checkstatus >/dev/null; then
    echo "${BASH_SOURCE##*/}: ${EXEC##*/}: failed to stop gracefully - slaying" >&2
    kill -KILL "$(pgrep -f "$EXEC")" >/dev/null 2>&1
  fi
  return 0
}

case "$1" in
  'start')
    if checkstatus >/dev/null; then
      echo "${BASH_SOURCE##*/}: ${EXEC##*/}: already running" >&2
      echo "  Try: $BASH_SOURCE status" >&2
      ERR=1
    else
      startdaemon
      ERR=$?
    fi
    ;;
  'stop')
    if ! checkstatus >/dev/null; then
      echo "${BASH_SOURCE##*/}: ${EXEC##*/}: not running" >&2
      echo "  Try: $BASH_SOURCE status" >&2
      ERR=1
    else
      stopdaemon
      ERR=$?
    fi
    ;;
  'restart')
    if checkstatus >/dev/null; then
      stopdaemon && sleep 2 && startdaemon
      ERR=$?
    else
      startdaemon
      ERR=$?
    fi
    ;;
  'status')
    checkstatus
    ERR=$?
    ;;
  *)
    echo "Usage: $BASH_SOURCE <start|stop|restart|status>" >&2
    ERR=1
    ;;
esac

return $ERR 2>/dev/null || exit $ERR