Subversion Repositories ALCASAR

#!/bin/bash

# $Id: alcasar-watchdog.sh 771 2011-11-16 21:20:42Z richard $

# alcasar-watchdog.sh

# by Richard REY

# 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 are in used by other systems (usurped)

EXTIF="eth0"

INTIF="eth1"

PRIVATE_IP="192.168.182.1"

tmp_file="/tmp/watchdog.txt"

DIR_WEB="/var/www/html"

Index_Page="$DIR_WEB/index.php"

OLDIFS=$IFS

IFS=$'\n'

# Fonction appelée si un Pb de connectivité Internet

# On fait pointer les usagers sur l'adresse locale

function ext_down_alert ()

{

	case $EXT_DOWN in

	"1")

		logger "eth0 link down"

		/bin/sed -i "s?diagnostic =.*?diagnostic = \"eth0 link down\";?g" $Index_Page

		;;

	"2")

		logger "can't contact the default router"

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

		;;

	"3")

		logger "can't contact the Internet DNS"

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

		;;

	esac

	net_pb=`cat /etc/dnsmasq.conf|grep "address=/#/"|wc -l`

	if [ $net_pb = "0" ] # on alerte les usagers (si ce n'est pas déjà le cas).

		then

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

		/bin/sed -i "s?^conf-dir=.*?address=\/#\/$PRIVATE_IP?g" /etc/dnsmasq-blackhole.conf

		/bin/sed -i "1i\address=\/#\/$PRIVATE_IP" /etc/dnsmasq.conf

		/etc/init.d/dnsmasq restart

	fi

}

# On teste la connectivité réseau

# On teste l'état d'EXTIF

EXT_DOWN="0"

if [ "`/usr/sbin/ethtool $EXTIF|grep Link|cut -d' ' -f3`" != "yes" ]

	then

	EXT_DOWN="1"

fi

# si EXTIF ok, on teste la connectivité vers le routeur par défaut (Box FAI)

if [ $EXT_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

		EXT_DOWN="2"

	fi

fi

# si routeur OK, on teste la connectivité vers les DNS externes

# + tard (EXT_DOWN=3)

# si Pb réseau, on avertit les usagers

if [ $EXT_DOWN != "0" ]

	then

		ext_down_alert

	else

# sinon, le cas échéant, on rebascule en mode normal

	net_pb=`cat /etc/dnsmasq.conf|grep "address=/#/"|wc -l`

	if [ $net_pb != "0" ]

		then

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

		/bin/sed -i "s?^address=\/#\/.*?conf-dir=/usr/local/etc/alcasar-dnsfilter-enabled?g" /etc/dnsmasq-blackhole.conf

		/bin/sed -i "/^address=/d" /etc/dnsmasq.conf

		/etc/init.d/dnsmasq restart

	fi

fi

# lecture du fichier contenant les adresses IP des stations muettes

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`

		arp_reply=`/usr/sbin/arping -b -I$INTIF -s$PRIVATE_IP -c1 -w4 $noresponse_ip|grep response|cut -d" " -f2`

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

	       	then

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

			/usr/sbin/chilli_query logout $noresponse_mac

		fi

	done

	rm $tmp_file

fi

# on traite chaque équipements connus de 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`

# on ne traite que les équipements exploitées par un usager authentifié (test de 2 réponses en 4 secondes)

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`

# on stocke les adresses IP des stations muettes

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

	       	then

			echo "$active_ip $active_mac" >> $tmp_file

	fi

# on deconnecte l'usager d'une stations usurpée (@MAC)

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

	       	then

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

			/usr/sbin/chilli_query logout $active_mac

	fi

fi

done

IFS=$OLDIFS