arno-iptables-firewall 2.0.1.f-1.1 / usr / share / arno-iptables-firewall / plugins / 50multiroute.plugin

# ------------------------------------------------------------------------------
#                  -= Arno's iptables firewall - Multirouting plugin =-
#
PLUGIN_NAME="Multirouting plugin"
PLUGIN_VERSION="0.31BETA (EXPERIMENTAL!)"
PLUGIN_CONF_FILE="multiroute.conf"
#
# Last changed          : March 17, 2009
# Requirements          : iproute2 (package) + kernel 2.6 with the following options set in:
#                         Networking, Networking support, TCP/IP networking:
#                               CONFIG_IP_ADVANCED_ROUTER=y (IP: advanced router)
#                               CONFIG_IP_MULTIPLE_TABLES=y (IP: policy routing)
#                               CONFIG_IP_ROUTE_MULTIPATH=y (IP: equal cost multipath)
#
# Comments              : This plugin enables IP multirouting (load balancing). Note
#                         that it does NOT support redundant connections (fallback when
#                         one of the links is down). This is NOT a limitation of this
#                         plugin, but of the current Linux kernel that does not support
#                         this(yet). To obtain the information needed to configure this plugin
#                         use the 'ifconfig' and 'route' commands.
#
# Author                : (C) Copyright 2005-2009 by Arno van Amersfoort
# Homepage              : http://rocky.eld.leidenuniv.nl/
# Email                 : a r n o v a AT r o c k y DOT e l d DOT l e i d e n u n i v DOT n l
#                         (note: you must remove all spaces and substitute the @ and the .
#                         at the proper locations!)
# ------------------------------------------------------------------------------
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# version 2 as published by the Free Software Foundation.
#
# This program 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 program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
# ------------------------------------------------------------------------------

# Plugin start function
plugin_start()
{
  if [ "$RP_FILTER_DISABLE" = "1" ]; then
    # In some cases the rp_filter gives some problems, so we disable it and
    # rely on the anti-spoof rules in the firewall
    echo "${INDENT}Disabling RP_FILTER..."
    echo "0" >/proc/sys/net/ipv4/conf/$MULTIROUTE_EXT_IF1/rp_filter
    echo "0" >/proc/sys/net/ipv4/conf/$MULTIROUTE_EXT_IF2/rp_filter
  fi

  # Purge, just in case
  ip rule del from $MULTIROUTE_EXT_IP1 lookup 1 2>/dev/null
  ip rule del from $MULTIROUTE_EXT_IP2 lookup 2 2>/dev/null

  # Setup source IP routing rules for external interface 1
  echo "${INDENT}Setup source IP routing for $MULTIROUTE_EXT_IP1"
  ip rule add from $MULTIROUTE_EXT_IP1 lookup 1
#    ip route replace 0/0 via $MULTIROUTE_EXT_ROUTER1 table 1

  echo "${INDENT}Setting default route for $MULTIROUTE_EXT_IF1 to $MULTIROUTE_EXT_ROUTER1 (table 1)"
  ip route replace default via $MULTIROUTE_EXT_ROUTER1 dev $MULTIROUTE_EXT_IF1 table 1

  echo "${INDENT}Setting route for $MULTIROUTE_INT_NET to $MULTIROUTE_INT_IP (table 1)"
  ip route replace $MULTIROUTE_INT_NET via $MULTIROUTE_INT_IP table 1

  # Setup source IP routing rules for external interface 2
  echo "${INDENT}Setup source IP routing for $MULTIROUTE_EXT_IP2"
  ip rule add from $MULTIROUTE_EXT_IP2 lookup 2
#    ip route replace 0/0 via $MULTIROUTE_EXT_ROUTER2 table 2

  echo "${INDENT}Setting default route for $MULTIROUTE_EXT_IF2 to $MULTIROUTE_EXT_ROUTER2 (table 2)"
  ip route replace default via $MULTIROUTE_EXT_ROUTER2 dev $MULTIROUTE_EXT_IF2 table 2

  echo "${INDENT}Setting route for $MULTIROUTE_INT_NET to $MULTIROUTE_INT_IP (table 2)"
  ip route replace $MULTIROUTE_INT_NET via $MULTIROUTE_INT_IP table 2

  # Destroy old routes
  ip route del default via $MULTIROUTE_EXT_ROUTER1 dev $MULTIROUTE_EXT_IF1 2>/dev/null
  ip route del default via $MULTIROUTE_EXT_ROUTER2 dev $MULTIROUTE_EXT_IF2 2>/dev/null
  
  # Setup the actual loadbalancing
  echo "${INDENT}Enabling loadbalancing"
  echo "${INDENT} Adding external interface $MULTIROUTE_EXT_IF1, gw=$MULTIROUTE_EXT_ROUTER1, weight=$MULTIROUTE_EXT_WEIGHT1"
  echo "${INDENT} Adding external interface $MULTIROUTE_EXT_IF2, gw=$MULTIROUTE_EXT_ROUTER2, weight=$MULTIROUTE_EXT_WEIGHT2"
  ip route add default equalize \
    nexthop via $MULTIROUTE_EXT_ROUTER1 dev $MULTIROUTE_EXT_IF1 weight $MULTIROUTE_EXT_WEIGHT1 \
    nexthop via $MULTIROUTE_EXT_ROUTER2 dev $MULTIROUTE_EXT_IF2 weight $MULTIROUTE_EXT_WEIGHT2

  # Flush route cache
#    echo "1" >/proc/sys/net/ipv4/route/flush
  ip route flush cache

  return 0
}


# Plugin stop function
plugin_stop()
{
  echo "${INDENT}Removing lookup rules"
  ip rule del from $MULTIROUTE_EXT_IP1 lookup 1
  ip rule del from $MULTIROUTE_EXT_IP2 lookup 2
  
  ip route del default via $MULTIROUTE_EXT_ROUTER1 dev $MULTIROUTE_EXT_IF1 2>/dev/null
  ip route del default via $MULTIROUTE_EXT_ROUTER2 dev $MULTIROUTE_EXT_IF2 2>/dev/null

  # Set default route to the first interface
  echo "${INDENT}Setting default (single) route to $MULTIROUTE_EXT_ROUTER1 on interface $MULTIROUTE_EXT_IF1"
  ip route add default via $MULTIROUTE_EXT_ROUTER1 dev $MULTIROUTE_EXT_IF1

  # Flush route cache
#    echo "1" >/proc/sys/net/ipv4/route/flush
  ip route flush cache
    
  return 0
}


# Plugin status function
plugin_status()
{
  ip rule show
  ip route show
  
  return 0
}


# Check sanity of eg. environment
plugin_sanity_check()
{
  # Set default weight, if not specified
  if [ -z "$MULTIROUTE_EXT_WEIGHT1" ]; then
    MULTIROUTE_EXT_WEIGHT1=1
  fi
  
  # Set default weight, if not specified
  if [ -z "$MULTIROUTE_EXT_WEIGHT2" ]; then
    MULTIROUTE_EXT_WEIGHT2=1
  fi

  if [ -z "$MULTIROUTE_EXT_IF1" -o -z "$MULTIROUTE_EXT_ROUTER1" -o -z "$MULTIROUTE_EXT_IP1" -o \
       -z "$MULTIROUTE_EXT_IF2" -o -z "$MULTIROUTE_EXT_ROUTER2" -o -z "$MULTIROUTE_EXT_IP2" -o \
       -z "$MULTIROUTE_INT_IP"  -o -z "$MULTIROUTE_INT_NET" -o \
       $MULTIROUTE_EXT_WEIGHT1 -le 0 -o $MULTIROUTE_EXT_WEIGHT2 -le 0 ]; then
    printf "\033[40m\033[1;31m  ERROR: The plugin config file is not properly set!\033[0m\n" >&2
    return 1
  fi

  return 0
}


############
# Mainline #
############

# Check where to find the config file
CONF_FILE=""
if [ -n "$PLUGIN_CONF_PATH" ]; then
  CONF_FILE="$PLUGIN_CONF_PATH/$PLUGIN_CONF_FILE"
fi

# Preinit to success:
PLUGIN_RET_VAL=0

# Check if the config file exists
if [ ! -e "$CONF_FILE" ]; then
  printf "NOTE: Config file \"$CONF_FILE\" not found!\n        Plugin \"$PLUGIN_NAME v$PLUGIN_VERSION\" ignored!\n" >&2
else
  # Source the plugin config file
  . "$CONF_FILE"

  if [ "$ENABLED" = "1" ] ||
     [ -n "$PLUGIN_LOAD_FILE" -a "$PLUGIN_CMD" = "stop" ] ||
     [ -n "$PLUGIN_LOAD_FILE" -a "$PLUGIN_CMD" = "status" ]; then
    # Show who we are:
    echo "${INDENT}$PLUGIN_NAME v$PLUGIN_VERSION"

    # Increment indention
    INDENT="$INDENT "

    # Only proceed if environment ok
    if ! plugin_sanity_check; then
      PLUGIN_RET_VAL=1
    else
      case $PLUGIN_CMD in
        start|'') plugin_start; PLUGIN_RET_VAL=$? ;;
        stop    ) plugin_stop; PLUGIN_RET_VAL=$? ;;
        status  ) plugin_status; PLUGIN_RET_VAL=$? ;;
        *       ) PLUGIN_RET_VAL=1; printf "\033[40m\033[1;31m${INDENT}ERROR: Invalid plugin option \"$PLUGIN_CMD\"!\033[0m\n" >&2 ;;
      esac
    fi
  fi
fi