firewall

#!/bin/sh
# firewall      Start iptables firewall
# chkconfig: 2345 97 87
# description:  Starts, stops and saves iptables firewall
# This script sets up the firewall for the INPUT chain (which is for
# the HN itself) and then processes the config files under
# /etc/firewall.d to set up additional rules in the FORWARD chain
# to allow access to containers' services.
# http://wiki.openvz.org/Setting_up_an_iptables_firewall

. /etc/init.d/functions

# the IP block allocated to this server
SEGMENT="78.47.95.216/29"
# the IP used by the hosting server itself
THISHOST="144.76.102.181"
# services that should be allowed to the HN;
# services for containers are configured in /etc/firewall.d/*
OKPORTS="22"
# hosts allowed full access through the firewall,
# to all containers and to this server
DMZS="78.47.95.217 144.76.102.185 78.47.95.218"

success() {
 echo -n "...success"
}
failure() {
 echo -n "...failure"
}

purge() {
  echo -n "Firewall: Purging and allowing all traffic"
  iptables -P OUTPUT ACCEPT
  iptables -P FORWARD ACCEPT
  iptables -P INPUT ACCEPT
  iptables -F
  success ; echo
}

setup() {
  echo -n "Firewall: Setting default policies to DROP"
  iptables -P INPUT DROP
  iptables -P FORWARD DROP
  iptables -I INPUT   -j ACCEPT -m state --state ESTABLISHED,RELATED
  iptables -I FORWARD -j ACCEPT -m state --state ESTABLISHED,RELATED
  iptables -I INPUT -j ACCEPT -i lo
  success ; echo

  echo "Firewall: Allowing access to HN"
  for port in $OKPORTS ; do
    echo -n "          port $port"
    iptables -I INPUT -j ACCEPT -d $THISHOST --protocol tcp --destination-port $port
    iptables -I INPUT -j ACCEPT -d $THISHOST --protocol udp --destination-port $port
    success ; echo
  done
  for ip in $DMZS ; do
    echo -n "          DMZ $ip"
    iptables -I INPUT   -i eth0 -j ACCEPT -s $ip
    iptables -I FORWARD -i eth0 -j ACCEPT -s $ip
    success ; echo
  done

  CTSETUPS=`echo /etc/firewall.d/*`
  if [ "$CTSETUPS" != "/etc/firewall.d/*" ] ; then
  echo "Firewall: Setting up container firewalls"
  for i in $CTSETUPS ; do
    . $i
    echo -n "          $CTNAME CT$CTID"
    if [ -n "$BANNED" ]; then
      for source in $BANNED ;  do iptables -I FORWARD -j DROP --destination $CTIP --source $source ; done
    fi
    if [ -n "$OPENPORTS" ]; then
      for port in $OPENPORTS ; do iptables -I FORWARD -j ACCEPT --protocol tcp --destination $CTIP --destination-port $port ; done
      for port in $OPENPORTS ; do iptables -I FORWARD -j ACCEPT --protocol udp --destination $CTIP --destination-port $port ; done
    fi
    if [ -n "$DMZS" ]; then
      for source in $DMZS ; do iptables -I FORWARD -j ACCEPT --protocol tcp --destination $CTIP --source $source ; done
      for source in $DMZS ; do iptables -I FORWARD -j ACCEPT --protocol udp --destination $CTIP --source $source ; done
    fi
    [ $? -eq 0 ] && success || failure
    echo
  done
  fi
}

case "$1" in
  start)
    echo "Starting firewall..."
    purge
    setup
    ;;
  stop)
    echo "Stopping firewall..."
    purge
    ;;
  restart)
    $0 stop
    $0 start
    ;;
  status)
    iptables -n -L
    ;;
  *)
    echo "Usage: $0 <start|stop|restart|status>"
    ;;
esac