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



#!/bin/bash
# $Id: alcasar-iptables.sh 2496 2018-02-26 01:47:02Z 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

# 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 conntrack --ctstate 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 PREROUTING -t nat -i $TUNIF -m set --match-set havp_bl src -m set --match-set bl_ip_blocked dst -p tcp --dport http -j REDIRECT --to-port 80
 

# Drop non standard connexions (FIN-URG-PUSH, XMAS, NullScan, SYN-RST et NEW not SYN)
$IPTABLES -A INPUT -p tcp --tcp-flags FIN,URG,PSH FIN,URG,PSH -j DROP
$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 conntrack --ctstate 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" ]]

# 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 conntrack --ctstate 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 conntrack --ctstate 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 conntrack --ctstate 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 -p udp --dport 54 -m mark --mark 3 -j REJECT --reject-with icmp-port-unreachable
$IPTABLES -A INPUT -i $TUNIF -p tcp --dport 54 -m mark --mark 3 -j REJECT --reject-with tcp-reset

$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 conntrack --ctstate 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 conntrack --ctstate NEW --syn -j NFLOG --nflog-group 2 --nflog-prefix "RULE ssh-from-WAN -- ACCEPT"
	$IPTABLES -A INPUT -i $EXTIF -s $SSH_ADMIN_FROM -d $PUBLIC_IP -p tcp --dport ssh -m conntrack --ctstate NEW -j 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 conntrack --ctstate NEW -j NFLOG --nflog-group 1 --nflog-prefix "RULE rej-int -- REJECT "
$IPTABLES -A INPUT -i $TUNIF -p tcp -j REJECT --reject-with tcp-reset
$IPTABLES -A INPUT -i $TUNIF -p udp -j REJECT --reject-with icmp-port-unreachable
 
# Interdiction d'accès à INTIF (n'est utile que lorsque chilli est arrêté).
# Reject INTIF access (only when chilli is down)
$IPTABLES -A INPUT -i $INTIF -j NFLOG --nflog-group 1 --nflog-prefix "RULE Protect1 -- REJECT "
$IPTABLES -A INPUT -i $INTIF -j REJECT
 
# Journalisation et rejet des connexions initiées depuis le réseau extérieur (test des effets du paramètre --limit en cours)
# On EXTIF, the access attempts are log in channel 2 (we should test --limit option to avoid deny of service)
$IPTABLES -A INPUT -i $EXTIF -m conntrack --ctstate NEW -j NFLOG --nflog-group 3 --nflog-threshold 10 --nflog-prefix "RULE rej-ext -- DROP"
 
#############################
#        FORWARD            #
#############################
 

$IPTABLES -A FORWARD -i $TUNIF -p udp --dport domain -j REJECT --reject-with icmp-port-unreachable
$IPTABLES -A FORWARD -i $TUNIF -p tcp --dport domain -j REJECT --reject-with tcp-reset
 
# Active le suivi de session
# Allow Conntrack
$IPTABLES -A FORWARD -m conntrack --ctstate 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 conntrack --ctstate NEW -j NETFLOW
		$IPTABLES -A FORWARD -i $TUNIF -d $ip_allowed -m conntrack --ctstate NEW -j ACCEPT
	done < /usr/local/etc/alcasar-uamallowed
fi
 
# filtrage protocole par utilisateur (profile 1 : http, https)
# protocols filtering for users (profil 1 : http, https)
	$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_1 src -s $PRIVATE_NETWORK_MASK -p tcp -m multiport ! --dports http,https -m conntrack --ctstate NEW -j REJECT --reject-with tcp-reset
	$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_1 src -s $PRIVATE_NETWORK_MASK -p udp -m multiport ! --dports http,https -m conntrack --ctstate NEW -j REJECT --reject-with icmp-port-unreachable
 
# filtrage protocole par utilisateur (profile 2 : http https pop3 pop3s imap imaps ftp sftp ssh)
# protocols filtering for users (profil 2 : http https pop3 pop3s imap imaps ftp sftp ssh)
 
	$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_2 src -s $PRIVATE_NETWORK_MASK -p tcp -m multiport ! --dports http,https,pop3,pop3s,imap,imaps,ftp,ftp-data,sftp,ssh -m conntrack --ctstate NEW -j REJECT --reject-with tcp-reset
	$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_2 src -s $PRIVATE_NETWORK_MASK -p udp -m multiport ! --dports http,https,pop3,pop3s,imap,imaps,ssh -m conntrack --ctstate NEW -j REJECT --reject-with icmp-port-unreachable
 
# filtrage protocole par utilisateur (profile 3 : personnalisable via l'ACC)
# protocols filtering for users (profil 3 : customized with ACC)
#profile 3 personalisables via l'ACC
custom_tcp_protocols_list='';custom_udp_protocols_list=''

	else
		if [ "$svc_icmp" != "on" ]
		then
			$IPTABLES -A FORWARD -i $TUNIF -m set --match-set proto_3 src -s $PRIVATE_NETWORK_MASK -p icmp -j REJECT --reject-with icmp-proto-unreachable
		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 conntrack --ctstate 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 conntrack --ctstate 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 conntrack --ctstate NEW -j NETFLOW
$IPTABLES -A FORWARD -i $TUNIF -s $PRIVATE_NETWORK_MASK -m conntrack --ctstate NEW -j ACCEPT
 
#############################
#         OUTPUT            #
#############################
# On laisse tout sortir à l'exception de la carte externe (cf ci-dessous)

	$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 conntrack --ctstate NEW -j ACCEPT
 
# On autorise les requêtes HTTP avec log Netflow (en provenance de Dansguardian)
# HTTPS requests are allowed with netflow log (from Dansguardian)
$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport http -j NETFLOW
$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport http -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 conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
 
# On autorise les requêtes NTP
# NTP requests are allowed
$IPTABLES -A OUTPUT -o $EXTIF -p udp --dport ntp -j ACCEPT
 

# ICMP (ping) requests are allowed
$IPTABLES -A OUTPUT -o $EXTIF -p icmp --icmp-type 8 -j ACCEPT
 
# On autorise les requêtes LDAP
# LDAP requests are allowed
$IPTABLES -A OUTPUT -o $EXTIF -p tcp -m multiport --dports ldap,ldaps -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
$IPTABLES -A OUTPUT -o $EXTIF -p udp -m multiport --dports ldap,ldaps -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
 
#############################
#       POSTROUTING         #
#############################
# Traduction dynamique d'adresse en sortie
Subversion Repositories ALCASAR

(root)/scripts/alcasar-iptables.sh – Rev 2495 → 2496
