Subversion Repositories ALCASAR

#!/bin/bash
# $Id: alcasar-watchdog.sh 787 2012-01-02 23:05:28Z 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"
macallowed_file="/usr/local/etc/alcasar-macallowed"
conf_file="/usr/local/etc/alcasar.conf"
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 $private_ip_mask | cut -d"/" -f1`                      # ALCASAR LAN IP address
tmp_file="/tmp/watchdog.txt"
DIR_WEB="/var/www/html"
Index_Page="$DIR_WEB/index.php"
OLDIFS=$IFS
IFS=$'\n'

function lan_down_alert ()
# users are redirected on ALCASAR IP address if LAN Pb detected
{
        case $LAN_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
                ;;
        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
}

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

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
# 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 "Unicast reply"|wc -l`
                                if [[ $(expr $arp_reply) -eq 0 ]]
                                        then
                                        mac_allowed=`cat $macallowed_file |grep $noresponse_mac | wc -l`
                                        if [ $mac_allowed -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
                                        else
                                                logger "alcasar-watchdog $noresponse_ip ($noresponse_mac - macallowed) can't be contact. Alcasar release the IP address"
                                                /usr/sbin/chilli_query dhcp-release $noresponse_mac
                                        fi
                                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 $active_mac
                                fi
                        fi
                done
                ;;
esac    
IFS=$OLDIFS