WebSVN – ALCASAR – Diff – /scripts/alcasar-iptables.sh



#!/bin/bash
# $Id: alcasar-iptables.sh 2454 2017-12-09 18:59:31Z tom.houdayer $
# Script de mise en place des regles du parefeu d'Alcasar (mode normal)
# This script writes the netfilter rules for ALCASAR
# Rexy - 3abtux - CPN
#
# Reminders
# There are four channels for log :
#	1 tracability of the consultation equipment with The 'Netflow' kernel module (iptables target = NETFLOW);
#	2 protection of ALCASAR with the Ulog group 1 (default group)
#	3 SSH on ALCASAR with the Ulog group 2;
#	4 extern access attempts on ALCASAR with the Ulog group 3.
# The bootps/dhcp (67) port is always open on tun0/INTIF by coova
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
TUNIF="tun0"								# listen device for chilli daemon
private_ip_mask=`grep ^PRIVATE_IP= $CONF_FILE|cut -d"=" -f2`

dns1=${dns1:=208.67.220.220}
dns2=${dns2:=208.67.222.222}
DNSSERVERS="$dns1,$dns2"						# first and second public DNS servers
BL_IP_CAT="/usr/local/share/iptables-bl-enabled"			# categories files of the BlackListed IP
WL_IP_CAT="/usr/local/share/iptables-wl-enabled"			# categories files of the WhiteListed IP
TMP_users_set_save="/tmp/users_set_save"				# tmp file for backup users set
TMP_set_save="/tmp/ipset_save"						# tmp file for blacklist and whitelist creation
SSH=`grep ^SSH= $CONF_FILE|cut -d"=" -f2`				# sshd active (on/off)
SSH=${SSH:=off}
SSH_ADMIN_FROM=`grep ^SSH_ADMIN_FROM= $CONF_FILE|cut -d"=" -f2`
SSH_ADMIN_FROM=${SSH_ADMIN_FROM:="0.0.0.0/0.0.0.0"}			# WAN IP address to reduce ssh access (all ip allowed on LAN side)

	cat $WL_IP_CAT/$category >> $TMP_set_save
done
ipset -! restore < $TMP_set_save
rm -f $TMP_set_save
 
# Restoration des SET des utilisateurs connectés si ils existent sinon création des SET
# Restoring the connected users SETs if available, otherwise creating SETs
if [ -e $TMP_users_set_save ];
then
	ipset -! restore < $TMP_users_set_save
	rm -f $TMP_users_set_save

 
# redirection DNS des usagers 'havp_wl' vers le port 55
# redirect DNS of 'havp_wl' users to port 55
$IPTABLES -A PREROUTING -t nat -i $TUNIF -m set --match-set havp_wl src -d $PRIVATE_IP -p udp --dport domain -j REDIRECT --to-port 55
 
# Journalisation HTTP_Internet des usagers 'havp_bl' (paquets SYN uniquement). Les autres protocoles sont journalisés en FORWARD par netflow.
# Log Internet HTTP of 'havp_bl' users" (only syn packets). Other protocols are logged in FORWARD by netflow
$IPTABLES -A PREROUTING -t nat -i $TUNIF -m set --match-set havp_bl src ! -d $PRIVATE_IP -p tcp --dport http -m state --state NEW -j NFLOG --nflog-group 1 --nflog-prefix "RULE F_http -- ACCEPT "
 
# Redirection HTTP des usagers 'havp_bl' cherchant à joindre les IP de la blacklist vers ALCASAR (page 'accès interdit')
# Redirect HTTP of 'havp_bl' users who want blacklist IP to ALCASAR ('access denied' page)

$IPTABLES -A INPUT -p tcp --tcp-flags ALL ALL -j DROP
$IPTABLES -A INPUT -p tcp --tcp-flags ALL NONE -j DROP
$IPTABLES -A INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
$IPTABLES -A INPUT -p tcp -m tcp ! --syn -m state --state NEW -j DROP
 
# Si configéré, on autorise les réponses DHCP
# Allow DHCP answers if configured
public_ip_mask=`grep ^PUBLIC_IP= $CONF_FILE|cut -d"=" -f2`		# ALCASAR WAN IP address
if [[ "$public_ip_mask" == "dhcp" ]]
then
	$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport 68 -j ACCEPT
	$IPTABLES -A OUTPUT -o $EXTIF -p udp --dport 68 -j ACCEPT
fi
# On rejette les trame en broadcast et en multicast sur EXTIF (évite leur journalisation)
# Drop broadcast & multicast on EXTIF to avoid log
$IPTABLES -A INPUT -m addrtype --dst-type BROADCAST,MULTICAST -j DROP
 
# On autorise les retours de connexions légitimes par INPUT
# Conntrack on INPUT
$IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 
# On interdit les connexions directes au port utilisé par DansGuardian (8080). Les packets concernés ont été marqués et loggués dans la table mangle (PREROUTING)
# Deny direct connections on DansGuardian port (8080). The concerned paquets have been marked and logged in mangle table (PREROUTING)
$IPTABLES -A INPUT -i $TUNIF -p tcp --dport 8080 -m mark --mark 1 -j REJECT --reject-with tcp-reset
 
# Autorisation des connexions légitimes à DansGuardian
# Allow connections for DansGuardian
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -p tcp --dport 8080 -m state --state NEW --syn -j ACCEPT
 
# On interdit les connexions directes au port utilisé par tinyproxy (8090). Les packets concernés ont été marqués et loggués dans la table mangle (PREROUTING)
# Deny direct connections on tinyproxy port (8090). The concerned paquets have been marked in mangle table (PREROUTING)
$IPTABLES -A INPUT -i $TUNIF -p tcp --dport 8090 -m mark --mark 2 -j REJECT --reject-with tcp-reset
 
# Autorisation des connexions légitimes vers tinyproxy
# Allow connections to tinyproxy
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -p tcp --dport 8090 -m state --state NEW --syn -j ACCEPT
 
# On interdit les connexions directes au port 54 (DNS-blacklist). Les packets concernés ont été marqués dans la table mangle (PREROUTING)
# Deny direct connections on port 54 (DNS-blacklist). The concerned paquets are marked in mangle table (PREROUTING)

$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p udp --dport 56 -j ACCEPT
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport 56 -j ACCEPT
 
# Accès direct aux services internes
# Internal services access
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p udp --dport domain -j ACCEPT	# DNS
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport domain -j ACCEPT	# DNS
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p icmp --icmp-type 8 -j ACCEPT	# Réponse ping # ping responce
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p icmp --icmp-type 0 -j ACCEPT	# Requête  ping # ping request
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport https -j ACCEPT	# Pages d'authentification et MCC # authentication pages and MCC
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport http -j ACCEPT	# Page d'avertissement filtrage # Filtering warning pages
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport 3990:3991 -j ACCEPT	# Requêtes de deconnexion usagers # Users logout requests
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p udp --dport ntp -j ACCEPT	# Serveur local de temps # local time server
 
# SSHD rules if activate
if [ $SSH = on ]
	then
	$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport ssh -m state --state NEW -j NFLOG --nflog-group 2 --nflog-prefix "RULE ssh-from-LAN -- ACCEPT"
	$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -d $PRIVATE_IP -p tcp --dport ssh -j ACCEPT
	$IPTABLES -A INPUT -i $EXTIF -s $SSH_ADMIN_FROM -d $PUBLIC_IP -p tcp --dport ssh -m state --state NEW --syn -j NFLOG --nflog-group 2 --nflog-prefix "RULE ssh-from-WAN -- ACCEPT"

fi
 
# Insertion de règles locales
# Here, we add local rules (i.e. VPN from Internet)
if [ -f /usr/local/etc/alcasar-iptables-local.sh ]; then
	. /usr/local/etc/alcasar-iptables-local.sh
fi
 
# Journalisation et rejet des connexions (autres que celles autorisées) effectuées depuis le LAN
# Deny and log on INPUT from the LAN
$IPTABLES -A INPUT -i $TUNIF -m state --state NEW -j NFLOG --nflog-group 1 --nflog-prefix "RULE rej-int -- REJECT "

 
# Active le suivi de session
# Allow Conntrack
$IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
 
# Compute uamallowed IP (IP address of equipments connected between ALCASAR and Internet (DMZ, own servers, ...)
nb_uamallowed=`wc -l /usr/local/etc/alcasar-uamallowed | cut -d" "  -f1`
if [ $nb_uamallowed != "0" ]
then
	while read ip_allowed_line
	do
		ip_allowed=`echo $ip_allowed_line|cut -d"\"" -f2`
		$IPTABLES -A FORWARD -i $TUNIF -d $ip_allowed -m state --state NEW -j NETFLOW
		$IPTABLES -A FORWARD -i $TUNIF -d $ip_allowed -m state --state NEW -j ACCEPT
	done < /usr/local/etc/alcasar-uamallowed

		fi
		$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_3 src -s $PRIVATE_NETWORK_MASK -p tcp -m multiport ! --dports $custom_tcp_protocols_list -m state --state NEW -j REJECT --reject-with tcp-reset
		$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_3 src -s $PRIVATE_NETWORK_MASK -p udp -m multiport ! --dports $custom_udp_protocols_list -m state --state NEW -j REJECT --reject-with icmp-port-unreachable
	fi
 
# journalisation et autorisation des connections sortant du LAN
# Allow forward connections with log
$IPTABLES -A FORWARD -i $TUNIF -s $PRIVATE_NETWORK_MASK -m state --state NEW -j NETFLOW
$IPTABLES -A FORWARD -i $TUNIF -s $PRIVATE_NETWORK_MASK -m state --state NEW -j ACCEPT
 
#############################

#############################
# On laisse tout sortir sur toutes les cartes sauf celle qui est connectée sur l'extérieur
# Everything is allowed but traffic through outside network interface
$IPTABLES -A OUTPUT ! -o $EXTIF -j ACCEPT
 
# Si configéré, on autorise les requêtes DHCP
# Allow DHCP requests if configured
public_ip_mask=`grep ^PUBLIC_IP= $CONF_FILE|cut -d"=" -f2`		# ALCASAR WAN IP address
if [[ "$public_ip_mask" == "dhcp" ]]
then
	$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport 67 -j ACCEPT
	$IPTABLES -A OUTPUT -o $EXTIF -p udp --dport 67 -j ACCEPT
fi
 
# On autorise les requêtes DNS vers les serveurs DNS identifiés
# Allow DNS requests to identified DNS servers
$IPTABLES -A OUTPUT -o $EXTIF -d $DNSSERVERS -p udp --dport domain -m state --state NEW -j ACCEPT
 
# On autorise les requêtes HTTP sortantes
# HTTP requests are allowed

 
# On autorise les requêtes RSYNC sortantes (maj BL de Toulouse)
# RSYNC requests are allowed (to update BL of Toulouse)
$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport rsync -j ACCEPT
 
# On autorise les requêtes FTP
# FTP requests are allowed
modprobe nf_conntrack_ftp
$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport ftp -j ACCEPT
$IPTABLES -A OUTPUT -o $EXTIF -m state --state ESTABLISHED,RELATED -j ACCEPT
 
# On autorise les requêtes NTP
# NTP requests are allowed
$IPTABLES -A OUTPUT -o $EXTIF -p udp --dport ntp -j ACCEPT
 
# On autorise les requêtes ICMP (ping)
# ICMP (ping) requests are allowed
$IPTABLES -A OUTPUT -o $EXTIF -p icmp --icmp-type 8 -j ACCEPT
 
# On autorise les requêtes LDAP si un serveur externe est configué
# LDAP requests are allowed if an external server is declared

# Traduction dynamique d'adresse en sortie
# Dynamic NAT on EXTIF
$IPTABLES -A POSTROUTING -t nat -o $EXTIF -j MASQUERADE
 
# End of script
 
Subversion Repositories ALCASAR

(root)/scripts/alcasar-iptables.sh – Rev 2386 → 2454
