#!/bin/sh
# Script to start/stop a hostapd-based access point
#
# Symbols for needed programs

IPTABLES=/sbin/iptables
IFCONFIG=/sbin/ifconfig
DHCPD=/usr/sbin/dhcpd3

# Symbols for internal and external interfaces

NET_INT=$2
NET_EXT=eth0

# IP address for the AP

INT_ADDR=192.168.0.1
date '+%s%N'
case "$1" in
start)
        echo " This script sets up iptables to configure IP packet forwarding\n" 
        echo " between $NET_INT and $NET_EXT"
        sleep 2;
        # Disable packet forwarding
	echo " Disable IP packet forwarding"
        echo 0 > /proc/sys/net/ipv4/ip_forward
	killall dhcpd3
        #Set up forwarding
	echo " Set up IP packet forwarding"
        $IPTABLES -t nat -A POSTROUTING -o $NET_EXT -j MASQUERADE
        $IPTABLES -A FORWARD -i $NET_EXT -o $NET_INT -m state \
		--state RELATED,ESTABLISHED -j ACCEPT
        $IPTABLES -A FORWARD -i $NET_INT -o $NET_EXT -j ACCEPT
        # Enable packet forwarding
	echo " Enable IP packet forwarding"
        echo 1 > /proc/sys/net/ipv4/ip_forward
        # Get the internal interface in the right state
	echo "  Get the internal interface in the right state"
        $IFCONFIG $NET_INT down
        $IFCONFIG $NET_INT up
        $IFCONFIG $NET_INT $INT_ADDR
        # dhcpd needs to have a leases file available - create it if needed
        if [ ! -f /var/lib/dhcp3/dhcpd.leases ]; then
		echo "  dhcpd needs to have a leases file available - create it if needed"
                touch /var/lib/dhcp3/dhcpd.leases
        fi
        # Bring up the DHCP server
	echo " Bring up the DHCP server for $NET_INT"
        #/etc/init.d/dhcp3-server start
        $DHCPD -cf /etc/dhcp3/dhcpd.conf $NET_INT
        # Bring up AP
	echo " Now Bring up AP"
        
        ;;
stop)
        echo " Make sure that AP is stopped "
        sleep 2;
        echo " Stopping DHCP server on $NET_INT"
	killall dhcpd3

        # Get the internal interface in the right state
	echo " Get the internal interface in the right state"
        $IFCONFIG $NET_INT down
        $IFCONFIG $NET_INT up
	$IFCONFIG $NET_INT $INT_ADDR
        ;;

*)
        echo "  Usage: $0 {start|stop} {AP interface name eg.eth1,wlan2..}"
        exit 1
        ;;
esac