#!/bin/bash
#
# Maxim Krasnyansky <max_mk@yahoo.com>
# reroute,v 1.2.6.1 2006/11/16 04:04:59 mtbishop Exp
#
IP=/sbin/ip

if [ $# -ne 3 ]; then
   echo "Usage: reroute option Source_IP Destination_IP"
   echo "Options:"
   echo "   -m - Move route Source_IP -> Destination_IP to table 100."
   echo "        Configure source based routing." 

   echo "   -r - Restore route Source_IP -> Destination_IP to default table."
   echo "        Delete source based routing."
   exit 1;
fi

MODE=$1
IP_S=$2
IP_D=$3

# Get original route
ROUTE=`$IP route get $IP_D from $IP_S | grep dev`

# Parse route 
set - $ROUTE
while [ "$1" != "" ]; do
    if [ "$1" = "src" ]; then
	shift
	O_SRC=$1
    fi
    if [ "$1" = "dev" ]; then
	shift
	O_DEV=$1
    fi
    if [ "$1" = "via" ]; then
	shift
	O_GW=$1
    fi
    shift
done

# Flush all routes, rules and cache for that IP 
$IP route flush $IP_D table all >/dev/null 2>&1
$IP rule del from $IP_S to $IP_D >/dev/null 2>&1

case $MODE in
   -m)
	# Add route via orig device to table 100
	$IP route add $ROUTE table 100 >/dev/null 2>&1

	# Add source based routing 
	$IP rule add from $IP_S to $IP_D table 100 >/dev/null 2>&1
	;;

   -r)
	# Add route via orig device to defaul table
	$IP route add $ROUTE >/dev/null 2>&1
	;;
esac

exit 0