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672 richard 1 
#!/bin/bash
64 franck 2 
# $Id: alcasar-iptables-bypass.sh 1523 2014-12-20 18:30:19Z franck $
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672 richard 4 
# alcasar-iptables-bypass.sh
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# by Rexy - 3abtux
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# This script is distributed under the Gnu General Public License (GPL)
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672 richard 8 
# applique les regles du parefeu en mode ByPass
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# put the firewall rules in 'ByPass' mode
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1469 richard 11 
CONF_FILE="/usr/local/etc/alcasar.conf"
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private_ip_mask=`grep PRIVATE_IP= $CONF_FILE|cut -d"=" -f2`
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private_ip_mask=${private_ip_mask:=192.168.182.1/24}
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private_network=`/bin/ipcalc -n $private_ip_mask|cut -d"=" -f2`		# LAN IP address (ie.: 192.168.182.0)
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private_prefix=`/bin/ipcalc -p $private_ip_mask|cut -d"=" -f2`		# LAN prefix (ie. 24)
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IPTABLES="/sbin/iptables"
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EXTIF=`grep ^EXTIF= $CONF_FILE|cut -d"=" -f2`				# EXTernal InterFace
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INTIF=`grep ^INTIF= $CONF_FILE|cut -d"=" -f2`				# INTernal InterFace
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PRIVATE_NETWORK_MASK=$private_network/$private_prefix			# Lan IP address + prefix (192.168.182.0/24)
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PRIVATE_IP=`echo $private_ip_mask | cut -d"/" -f1`			# ALCASAR LAN IP address
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public_ip_mask=`grep PUBLIC_IP= $CONF_FILE|cut -d"=" -f2`		# ALCASAR WAN IP address
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PUBLIC_IP=`echo $public_ip_mask | cut -d"/" -f1`
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SSH=`grep SSH= $CONF_FILE|cut -d"=" -f2`				# sshd active (on/off)
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SSH=${SSH:=off}
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SSH_ADMIN_FROM=`grep SSH_ADMIN_FROM= $CONF_FILE|cut -d"=" -f2`
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SSH_ADMIN_FROM=${SSH_ADMIN_FROM:="0.0.0.0/0.0.0.0"}				# WAN IP address to reduce ssh access (all ip allowed on LAN side)
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PROTOCOLS_FILTERING=`grep PROTOCOLS_FILTERING= $conf_file|cut -d"=" -f2`        # Network protocols filter (on/off)
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PROTOCOLS_FILTERING=${PROTOCOLS_FILTERING:=off}
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1 root 31 
# On vide (flush) toutes les règles existantes
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# Flush all existing rules
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$IPTABLES -F
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$IPTABLES -t nat -F
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$IPTABLES -F INPUT
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$IPTABLES -F FORWARD
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$IPTABLES -F OUTPUT
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# On indique les politiques par défaut
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# Default policies
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$IPTABLES -P INPUT DROP
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$IPTABLES -P FORWARD DROP
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$IPTABLES -P OUTPUT ACCEPT
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$IPTABLES -t nat -P PREROUTING ACCEPT
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$IPTABLES -t nat -P POSTROUTING ACCEPT
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$IPTABLES -t nat -P OUTPUT ACCEPT
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# On efface toutes les chaînes qui ne sont pas par défaut dans les tables filter et nat
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# Flush non default rules on filter and nat tables
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$IPTABLES -X
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$IPTABLES -t nat -X
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# On autorise tout sur loopback
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# accept all on loopback
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$IPTABLES -A OUTPUT -o lo -j ACCEPT
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$IPTABLES -A INPUT -i lo -j ACCEPT
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856 franck 58 
# Insertion de règles de blocage (Devel)
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# Here, we add block rules (Devel)
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if [ -s /usr/local/etc/alcasar-iptables-block ]; then
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	while read ip_line
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	do
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		ip_on=`echo $ip_line|cut -b1`
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		if [ $ip_on != "#" ]
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		then
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			ip_blocked=`echo $ip_line|cut -d" " -f1`
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			$IPTABLES -A FORWARD -d $ip_blocked -j ULOG --ulog-prefix "RULE IP-blocked -- REJECT "
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			$IPTABLES -A FORWARD -d $ip_blocked -j REJECT
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		fi
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	done < /usr/local/etc/alcasar-iptables-block
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fi
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# SSHD rules if activate
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if [ $SSH = on ]
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	then
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	$IPTABLES -A INPUT -i $INTIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport ssh -m state --state NEW -j ULOG --ulog-nlgroup 2 --ulog-prefix "RULE ssh-from-LAN -- ACCEPT"
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	$IPTABLES -A INPUT -i $INTIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport ssh -m state --state NEW -j ACCEPT
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	$IPTABLES -A INPUT -i $EXTIF -s $SSH_ADMIN_FROM -d $PUBLIC_IP -p tcp --dport ssh -m state --state NEW -j ULOG --ulog-nlgroup 2 --ulog-prefix "RULE ssh-from-WAN -- ACCEPT"
1157 stephane 79 
	$IPTABLES -A INPUT -i $EXTIF -s $SSH_ADMIN_FROM -d $PUBLIC_IP -p tcp --dport ssh -m state --state NEW -j ACCEPT
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fi
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1062 richard 82 
# Insertion de règles locales
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# Here, we add local rules (i.e. VPN from Internet)
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if [ -f /usr/local/etc/alcasar-iptables-local.sh ]; then
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        . /usr/local/etc/alcasar-iptables-local.sh
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fi
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#  If protocols filter is activate
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if [ $PROTOCOLS_FILTERING = on ]; then
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        echo "PROTOCOL FILTERING = On"
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        # Compute exception IP (IP addresses that shouldn't be filtered)
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       nb_exceptions=`wc -l /usr/local/etc/alcasar-filter-exceptions | cut -d" " -f1`
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       if [ $nb_exceptions != "0" ]
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       then
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               while read ip_exception
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               do
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                       $IPTABLES -A FORWARD -i $INTIF -s $ip_exception -m state --state NEW -j ULOG --ulog-prefix "RULE IP-exception -- ACCEPT "
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#                       $IPTABLES -A FORWARD -i $INTIF -s $ip_exception -m state --state NEW -j NETFLOW
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                       $IPTABLES -A FORWARD -i $INTIF -s $ip_exception -m state --state NEW -j ACCEPT
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               done < /usr/local/etc/alcasar-filter-exceptions
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       fi
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#       # Compute uamallowed IP (IP address of equipments connected between ALCASAR and Internet (DMZ, own servers, ...)
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#       nb_uamallowed=`wc -l /usr/local/etc/alcasar-uamallowed | cut -d" "  -f1`
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#       if [ $nb_uamallowed != "0" ]
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#       then
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#               while read ip_allowed_line
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#               do
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#                       ip_allowed=`echo $ip_allowed_line|cut -d"\"" -f2`
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#                       $IPTABLES -A FORWARD -i $INTIF -d $ip_allowed -m state --state NEW -j ULOG --ulog-prefix "RULE IP-allowed -- ACCEPT "
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##                       $IPTABLES -A FORWARD -i $INTIF -d $ip_allowed -m state --state NEW -j NETFLOW
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#                       $IPTABLES -A FORWARD -i $INTIF -d $ip_allowed -m state --state NEW -j ACCEPT
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#               done < /usr/local/etc/alcasar-uamallowed
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#       fi
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        # Autorisation des protocoles non commentés
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        # Allow non comment protocols
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        while read svc_line
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        do
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                svc_on=`echo $svc_line|cut -b1`
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                if [ $svc_on != "#" ]
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                then
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                        svc_name=`echo $svc_line|cut -d" " -f1`
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                        svc_port=`echo $svc_line|cut -d" " -f2`
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                        if [ $svc_name = "icmp" ]
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                        then
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#                               $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p icmp -j NETFLOW
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                                $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p icmp -j ACCEPT
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                        else
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                                echo "Service = $svc_port  pour $svc_name"
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                                $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p tcp --dport $svc_port -m state --state NEW -j ULOG --ulog-prefix "RULE F_TCP-$svc_name -- ACCEPT "
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#                               $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p tcp --dport $svc_port -m state --state NEW -j NETFLOW
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                                $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p tcp --dport $svc_port -m state --state NEW -j ACCEPT
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#                               $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p udp --dport $svc_port -m state --state NEW -j ULOG --ulog-prefix "RULE F_UDP-$svc_name -- ACCEPT "
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##                              $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p udp --dport $svc_port -m state --state NEW -j NETFLOW
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#                               $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p udp --dport $svc_port -m state --state NEW -j ACCEPT
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                        fi
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                fi
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        done < /usr/local/etc/alcasar-services
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        # Don't forget the HTTP port
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	$IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p tcp --dport 80 -m state --state NEW -j ULOG --ulog-prefix "RULE F_TCP-http -- ACCEPT "
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#       $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p tcp --dport 80 -m state --state NEW -j NETFLOW
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        $IPTABLES -A FORWARD -i $INTIF -s $PRIVATE_NETWORK_MASK -p tcp --dport 80 -m state --state NEW -j ACCEPT
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        # Rejet explicite des autres protocoles
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        # reject the others protocols
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        $IPTABLES -A FORWARD -i $INTIF -j ULOG --ulog-prefix "RULE F_filter -- REJECT "
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        $IPTABLES -A FORWARD -i $INTIF -p tcp -j REJECT --reject-with tcp-reset
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        $IPTABLES -A FORWARD -i $INTIF -p udp -j REJECT --reject-with icmp-port-unreachable
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        $IPTABLES -A FORWARD -i $INTIF -p icmp -j REJECT
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else
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        ## On autorise les demandes de connexions sortantes
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        echo "PROTOCOL FILTERING = Off"
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        $IPTABLES -A FORWARD -i $INTIF -m state --state NEW -j ULOG --ulog-prefix "RULE Transfert -- ACCEPT "
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        $IPTABLES -A FORWARD -i $INTIF -m state --state NEW -j ACCEPT
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fi
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1 root 157 
# on autorise les requêtes dhcp
604 richard 158 
# accept dhcp
1 root 159 
$IPTABLES -A INPUT -i $INTIF -p udp -m udp --sport bootpc --dport bootps -j ACCEPT
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604 richard 161 
# On drop le broadcast et le multicast sur les interfaces (sans Log)
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# Drop broadcast & multicast
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$IPTABLES -A INPUT -m addrtype --dst-type BROADCAST,MULTICAST -j DROP
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604 richard 165 
# On laisse passer les ICMP echo-request et echo-reply en provenance du LAN
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# Allow ping (icmp N°0 & 8) from LAN
1 root 167 
$IPTABLES -A INPUT -i $INTIF -s $PRIVATE_NETWORK_MASK -p icmp --icmp-type 0 -j ACCEPT
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$IPTABLES -A INPUT -i $INTIF -s $PRIVATE_NETWORK_MASK -p icmp --icmp-type 8 -j ACCEPT
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604 richard 170 
# On autorise les retours de connexions légitimes par FORWARD
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# Conntrack on forward
1523 franck 172 
$IPTABLES -A FORWARD -p tcp -m state --state RELATED,ESTABLISHED -j ACCEPT
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$IPTABLES -A FORWARD -p udp -j DROP
1 root 174 
 
1062 richard 175 
# On autorise les flux entrant ntp et dns via INTIF
401 richard 176 
$IPTABLES -A INPUT -i $INTIF -d $PRIVATE_IP -p udp --dport domain -j ACCEPT
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$IPTABLES -A INPUT -i $INTIF -d $PRIVATE_IP -p udp --dport ntp -j ACCEPT
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401 richard 179 
# On autorise le retour des connexions entrante déjà acceptées
1 root 180 
$IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
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# On interdit et on log le reste sur les 2 interfaces d'accès
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$IPTABLES -A INPUT -i $INTIF -j ULOG --ulog-prefix "RULE rej-int -- REJECT "
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$IPTABLES -A INPUT -i $EXTIF -j ULOG --ulog-prefix "RULE rej-ext -- REJECT "
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$IPTABLES -A INPUT -p tcp -j REJECT --reject-with tcp-reset
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$IPTABLES -A INPUT -p udp -j REJECT --reject-with icmp-port-unreachable
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# On active le masquage d'adresse par translation (NAT)
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$IPTABLES -A POSTROUTING -t nat -o $EXTIF -j MASQUERADE
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1069 richard 191 
# on ne sauvegarde pas les règles. En cas de reboot, on repasse ainsi automatiquement en mode normal (bypass -off)
1 root 192 
# Fin du script des regles du parefeu