Subversion Repositories ALCASAR

#!/bin/bash

# $Id: alcasar-watchdog.sh 1535 2014-12-21 22:14:47Z richard $

# alcasar-watchdog.sh

# by Rexy

# This script is distributed under the Gnu General Public License (GPL)

# Ce script prévient les usagers de l'indisponibilité de l'accès Internet

# il déconnecte les usagers dont

# - les équipements réseau ne répondent plus

# - les adresses MAC sont usurpées

# This script tells users that Internet access is down

# it logs out users whose 

# - PCs are quiet

# - MAC address is used by other systems (usurped)

CONF_FILE="/usr/local/etc/alcasar.conf"

EXTIF=`grep ^EXTIF= $CONF_FILE|cut -d"=" -f2`			# EXTernal InterFace

INTIF=`grep ^INTIF= $CONF_FILE|cut -d"=" -f2`			# INTernal InterFace

private_ip_mask=`grep PRIVATE_IP= $CONF_FILE|cut -d"=" -f2`

private_ip_mask=${private_ip_mask:=192.168.182.1/24}

PRIVATE_IP=`echo "$private_ip_mask" |cut -d"/" -f1`      # @ip du portail (côté LAN)

PRIVATE_IP=${PRIVATE_IP:=192.168.182.1}

tmp_file="/tmp/watchdog.txt"

DIR_WEB="/var/www/html"

Index_Page="$DIR_WEB/index.php"

IPTABLES="/sbin/iptables"

TUNIF="tun0"						# listen device for chilli daemon

OLDIFS=$IFS

IFS=$'\n'

function lan_down_alert ()

# users are redirected on ALCASAR IP address if a LAN problem is detected

{

	case $LAN_DOWN in

	"1")

		logger "$EXTIF (WAN card) link down"

		echo "$EXTIF (WAN card) link down"

		/bin/sed -i "s?diagnostic =.*?diagnostic = \"$EXTIF (WAN card) link down\";?g" $Index_Page

		;;

	"2")

		logger "can't contact the default router"

		echo "can't contact the default router"

		/bin/sed -i "s?diagnostic =.*?diagnostic = \"can't contact the default router\";?g" $Index_Page

		;;

	esac

	net_pb=`grep "network_pb = True;" $Index_Page|wc -l`

	if [ $net_pb = "0" ] # user alert (only the first time)	

		then

		/bin/sed -i "s?^\$network_pb.*?\$network_pb = True;?g" $Index_Page

		$IPTABLES -I PREROUTING -t nat -i $TUNIF -p udp --dport domain -j REDIRECT --to-port 56

	fi

}

function lan_test ()

# LAN connectiivity testing

{

	watchdog_process=`ps -C alcasar-watchdog.sh|wc -l`

	if [[ $(expr $watchdog_process) -gt 3 ]]

		then

		echo "ALCASAR watchdog is already running"

		exit 0

	fi

	# EXTIF testing

	LAN_DOWN="0"

	if [ `/sbin/ip link | grep $EXTIF|grep "NO-CARRIER" | wc -l` -eq "1" ]

		then

		LAN_DOWN="1"

	fi

	# Default GW testing

	if [ $LAN_DOWN -eq "0" ]

		then

		IP_GW=`/sbin/ip route list|grep ^default|cut -d" " -f3`

		arp_reply=`/usr/sbin/arping -I$EXTIF -c1 $IP_GW|grep response|cut -d" " -f2`

		if [ $arp_reply -eq "0" ]

	       		then

			LAN_DOWN="2"

		fi

	fi

	# if LAN pb detected, users are warned

	if [ $LAN_DOWN != "0" ]

		then

			lan_down_alert

	# else switch in normal mode

	else

		echo "Internet access is OK for now"

		net_pb=`grep "network_pb = True;" $Index_Page|wc -l`

		if [ $net_pb != "0" ]

			then

			/bin/sed -i "s?^\$network_pb.*?\$network_pb = False;?g" $Index_Page

			$IPTABLES -D PREROUTING -t nat -i $TUNIF -p udp --dport domain -j REDIRECT --to-port 56

		fi

	fi

}

usage="Usage: alcasar-watchdog.sh {-lt --lan_test}"

case $1 in

	-\? | -h* | --h*)

		echo "$usage"

		exit 0

		;;

	-lt | --lan_test)

		lan_test

		exit 0

		;;

	*)

		lan_test

		# read file that contains IP address of quiet equipments

		if [ -e $tmp_file ]; then

			cat $tmp_file | while read noresponse

			do

				noresponse_ip=`echo $noresponse | cut -d" " -f1`

				noresponse_mac=`echo $noresponse | cut -d" " -f2`

				noresponse_user=`echo $noresponse | cut -d" " -f3`

				arp_reply=`/usr/sbin/arping -b -I$INTIF -s$PRIVATE_IP -c1 -w4 $noresponse_ip|grep "Unicast reply"|wc -l`

				if [[ $(expr $arp_reply) -eq 0 ]]

	       				then

					logger "alcasar-watchdog $noresponse_ip ($noresponse_mac) can't be contact. Alcasar disconnects the user ($noresponse_user)."

					/usr/sbin/chilli_query logout $noresponse_mac

					/usr/sbin/chilli_query dhcp-release $noresponse_mac  # release dhcp for mac_auth equipment 

				fi

			done

			rm $tmp_file

		fi

# process each equipment known by chilli

		for system in `/usr/sbin/chilli_query list |grep -v "\.0\.0\.0"`

		do

			active_ip=`echo $system |cut -d" " -f2`

			active_session=`echo $system |cut -d" " -f5`

			active_mac=`echo $system | cut -d" " -f1`

			active_user=`echo $system |cut -d" " -f6`

# process only equipment with an authenticated user

			if [[ $(expr $active_session) -eq 1 ]]

			then

				arp_reply=`/usr/sbin/arping -b -I$INTIF -s$PRIVATE_IP -c2 -w4 $active_ip|grep "Unicast reply"|wc -l`

# store @IP of quiet equipments

				if [[ $(expr $arp_reply) -eq 0 ]]

	       				then

					PTN='^[[:xdigit:]][[:xdigit:]]-[[:xdigit:]][[:xdigit:]]-[[:xdigit:]][[:xdigit:]]-[[:xdigit:]][[:xdigit:]]-[[:xdigit:]][[:xdigit:]]-[[:xdigit:]][[:xdigit:]]$'

					if [[ $(expr $active_user : $PTN) -eq 0 ]] # don't process @mac auth equipments

					then

						echo "$active_ip $active_mac $active_user" >> $tmp_file

					fi

				fi

# disconnect users whose equipement is usurped (@MAC)

				if [[ $(expr $arp_reply) -gt 2 ]]

	       				then 

					echo "$(date "+[%x-%X] : ")alcasar-watchdog : $active_ip is usurped ($active_mac). Alcasar disconnect the user ($active_user)." >> /var/Save/security/watchdog.log

					logger "alcasar-watchdog : $active_ip is usurped ($active_mac). Alcasar disconnect the user ($active_user)."

					/usr/sbin/chilli_query logout $active_mac

					chmod 644 /var/Save/security/watchdog.log

				fi

			fi

		done

		;;

esac	

IFS=$OLDIFS