#!/bin/sh

#   bridge - This script determines the current host network settings
#            and reconfigures the network using a bridge
#   Copyright (C) 2004 Frank Sorenson (frank AT tuxrocks DOT com)
#
#   This program is free software; you can redistribute it and/or
#   modify it under the terms of the GNU General Public License
#   as published by the Free Software Foundation; either version 2
#   of the License, or (at your option) any later version.
#
#   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.
#

export IFCONFIG="/sbin/ifconfig"
export ROUTE="/sbin/route -F"
export BRCTL="/usr/sbin/brctl"
export SLEEP="/bin/sleep 1"

export HOST_IF=`route -n |egrep "^0\.0\.0\.0"|cut -c 73-`
export HOST_GW=`route -n | egrep "^0\.0\.0\.0"|cut -c 17-31`
export HOST_IP=`ifconfig ${HOST_IF} | grep "inet addr:" | cut -f 2 -d ":"|cut -f 1 -d " "`
export HOST_BCAST=`ifconfig ${HOST_IF} | grep "Bcast:" | cut -f 3 -d ":"|cut -f 1 -d " "`
export HOST_MASK=`ifconfig ${HOST_IF} | grep "Mask:" | cut -f 4 -d ":"|cut -f 1 -d " "`

echo "Current config: ${HOST_IF} is ${HOST_IP}/${HOST_MASK} (bcast ${HOST_BCAST})"

echo "Creating bridge"
${BRCTL} addbr bridge
${BRCTL} setfd bridge 1
${BRCTL} sethello bridge 1
${BRCTL} stp bridge off
${BRCTL} addif bridge ${HOST_IF}
echo "Configuring IP on the bridge"
${IFCONFIG} bridge ${HOST_IP} netmask ${HOST_MASK} broadcast ${HOST_BCAST} promisc up
${SLEEP}
${IFCONFIG} bridge down
${SLEEP}
${IFCONFIG} bridge up

${SLEEP}
echo "Setting ${HOST_IF} promisc"
#${IFCONFIG} ${HOST_IF} down
${IFCONFIG} ${HOST_IF} 0.0.0.0 promisc up

${SLEEP}
echo "Setting default gateway through bridge"
${ROUTE} add -net default gw ${HOST_GW} bridge