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#!/bin/bash
# $Id: alcasar-watchdog.sh 2107 2017-01-05 22:23:35Z raphael.pion $
# 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 ( si la fenetre status.php a été fermé. Les autorisations par adresse mac sont laissé de côté)
# - les adresses MAC sont usurpées
# This script tells users that Internet access is down
# it logs out users whose
# - PCs are quiet (it means that status.php has been closed. We put aside @MAC Authorization )
# - 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"
current_users_file="/tmp/current_users.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
# We disconnect inactive users (its means that status.php has been closed)
# Each user inform about his connectivity by filling in /tmp/current_users.txt his own @IP
# process each equipment known by chilli to check if any equipment is usurped (@MAC)
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 $system |cut -d" " -f6`
#We disconnect inactive user here :
#We check if this is not an auth @MAC and if he is still connected
if [ "$active_user" != "$active_mac" ] && [ $(echo $system | awk '$5 == 1' | wc -c) -gt 1 ]; then
# If /tmp/current_user.txt exists ...
if [ -e $current_users_file ]; then
# We check if user @IP is in 'current_users.txt'
cmp_user_ok=$(cat $current_users_file | grep $active_ip | wc -w)
# If this @IP is not in this file, we disconnect this user.
if [ $cmp_user_ok -eq 0 ]; then
logger "alcasar-watchdog $active_ip ($active_mac) can't be contact. Alcasar disconnects the user ($active_user)."
echo "Disconnect : $active_ip $active_mac $active_user"
/usr/sbin/chilli_query logout $active_mac
fi
# We clean 'current_users.txt'. Every user need to inform their @IP everytime to prove thier connectivity.
sed -i 'd' $current_users_file
else # If /tmp/current_user.txt does not exists we disconnect every users.
logger "Le fichier /tmp/current_users.txt n'existe pas."
logger "alcasar-watchdog $active_ip ($active_mac) can't be contact. Alcasar disconnects the user ($active_user)."
echo "Disconnect : $active_ip $active_mac $active_user"
/usr/sbin/chilli_query logout $active_mac
fi
fi
# 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`
# disconnect users whose equipement is usurped (@MAC). For example, if there are 2 same @MAC it will make 3 lines in output.
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