Minimalist iptables init script

iptables.sh

#!/bin/bash
#Simple iptables init script.

#Config

iptables_path="/sbin"
iptables="$iptables_path/iptables"
iptables_save="$iptables_path/iptables-save"
iptables_restore="$iptables_path/iptables-restore"
iptables_rules="/etc/iptables_rules"

#Check for needed files and permissions

req_binaries=($iptables $iptables_save $iptables_restore)
for e in ${req_binaries[@]}; do
  if [ ! -x $e ]; then
    echo "Could not find required binary located at '$e'" >&2
    exit 1
  fi
done

if [ ! -f $iptables_rules ]; then
  echo "Firewall rules file not found, creating empty rules file at '$iptables_rules'" >&2
  touch $iptables_rules
fi

#Some Helpers

function clear_rules() {
  echo "Clearing existing rules"
  $iptables -F
}

#Do what I'm told

case $1 in
  stop)
    clear_rules
    ;;
  save)
    echo "Saving current iptables configuration to '$iptables_rules'"
    $iptables_save > $iptables_rules
    ;;
  status)
    $iptables -L
    ;;
  start | restart | force-reload)
    clear_rules
    echo "Loading iptables rules from '$iptables_rules'"
    $iptables_restore < $iptables_rules
    ;;
  *)
    echo "Invalid/No argument specified. Try (start|stop|restart|status|save)."
    ;;
esac

great script, thank you very much!