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|
#! /bin/sh
#set -x
action=$1
shift
#
#* Single end device with untrusted inet connection
#
ETH_EXTERN=eth0
IP_EXTERN_SELF=$( /sbin/ip -o -f inet addr show dev $ETH_EXTERN scope global | awk ' { print $4; } ' )
IP_EXTERN_GW=$( /sbin/ip -o -f inet route show dev $ETH_EXTERN | grep default | awk ' { print $3; } ' )
##
##
IPTABLES=/sbin/iptables
if [ "$action" != "start" -a "$action" != "stop" ] ; then
echo usage $0 \( start \| stop \)
echo
echo $0 start
echo $0 stop
exit 1
fi
if [ "$action" = "stop" ] ; then
echo "IPTABLES rules down"
$IPTABLES -F acl_external_input
$IPTABLES -F acl_srv_connect
$IPTABLES -F acl_srv_web
$IPTABLES -F acl_srv_shared
$IPTABLES -F acl_srv_email
$IPTABLES -F acl_srv_login_sec
$IPTABLES -F INPUT
$IPTABLES -F FORWARD
$IPTABLES -X acl_external_input
$IPTABLES -X acl_srv_connect
$IPTABLES -X acl_srv_web
$IPTABLES -X acl_srv_shared
$IPTABLES -X acl_srv_email
$IPTABLES -X acl_srv_login_sec
$IPTABLES -P INPUT ACCEPT
$IPTABLES -P FORWARD ACCEPT
exit 0
fi
if [ "$action" = "start" ] ; then
echo "IPTABLES rules up"
# Anti-spoofing
#
# Since we don't have any asymmetric routing,
# we can simply turn on anti-spoofing for all interfaces.
#
#for f in /proc/sys/net/ipv4/conf/*ppp*/rp_filter; do echo 1 > $f; done
echo 1 > /proc/sys/net/ipv4/conf/$ETH_EXTERN/rp_filter
/sbin/modprobe iptable_filter
/sbin/modprobe iptable_mangle
/sbin/modprobe iptable_nat
/sbin/modprobe ip_tables
/sbin/modprobe ipt_LOG
/sbin/modprobe ipt_MASQUERADE
/sbin/modprobe ipt_NETMAP
/sbin/modprobe ipt_REDIRECT
/sbin/modprobe ipt_REJECT
/sbin/modprobe ipt_ULOG
/sbin/modprobe nf_conntrack_ipv4
/sbin/modprobe nf_conntrack_sane
/sbin/modprobe nf_conntrack_sip
/sbin/modprobe nf_conntrack_snmp
/sbin/modprobe nf_conntrack_tftp
/sbin/modprobe nf_nat_ftp
/sbin/modprobe nf_nat_h323
/sbin/modprobe nf_nat_irc
/sbin/modprobe nf_nat
/sbin/modprobe nf_nat_pptp
/sbin/modprobe nf_nat_sip
/sbin/modprobe nf_nat_snmp_basic
/sbin/modprobe nf_nat_tftp
$IPTABLES -P INPUT DROP
$IPTABLES -P FORWARD DROP
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -N acl_external_input
$IPTABLES -N acl_srv_connect
$IPTABLES -N acl_srv_web
$IPTABLES -N acl_srv_shared
$IPTABLES -N acl_srv_email
$IPTABLES -N acl_srv_login_sec
###################################################################
###################################################################
#
# INPUT -> user chains
#
# Unfortunately, we only know (in the FORWARD chain) the outgoing interface.
# Thus, to figure out what interface the packet came in on,
# we use the source address (the anti-spoofing prevents address faking).
#
# Note that we log anything which doesn't match any of these (obviously, this should never happen).
#
#
# INPUT Allow FIREWALL itself !
#
$IPTABLES -p all -A INPUT -i $ETH_EXTERN -s $IP_EXTERN_SELF -j ACCEPT
$IPTABLES -p all -A INPUT -i lo -j ACCEPT
$IPTABLES -p all -A INPUT -i $ETH_EXTERN -j acl_external_input
$IPTABLES -p all -A INPUT -i $ETH_EXTERN -j LOG --log-level debug --log-prefix "FW4-IN: rej acl_ext input "
$IPTABLES -p all -A INPUT -i $ETH_EXTERN -j REJECT
#
# INPUT Log & Reject any
#
$IPTABLES -p all -A INPUT -j LOG --log-level debug --log-prefix "FW4-IN: rej ANY input "
$IPTABLES -p all -A INPUT -j REJECT
#
###################################################################
###################################################################
###################################################################
#
# FORWARD -> user chains
#
#
# FORWARD Allow FIREWALL itself !
#
$IPTABLES -p all -A FORWARD -i $ETH_EXTERN -s $IP_EXTERN_SELF -j ACCEPT
$IPTABLES -p all -A FORWARD -i lo -j ACCEPT
$IPTABLES -p all -A FORWARD -i $ETH_EXTERN -j acl_external_input
$IPTABLES -p all -A FORWARD -i $ETH_EXTERN -j LOG --log-level debug --log-prefix "FW4-FWD: rej acl_ext input "
$IPTABLES -p all -A FORWARD -i $ETH_EXTERN -j REJECT
#
# FORWARD Log & Reject any
#
$IPTABLES -p all -A FORWARD -j LOG --log-level debug --log-prefix "FW4-FWD: rej ANY input "
$IPTABLES -p all -A FORWARD -j REJECT
#
#
#########################################################################################################################
#########################################################################################################################
#########################################################################################################################
#
# acl_extern_
#
#
# Allow fragments (second etc. parts of a huge packet ..)
# Allow icmp notification: 3/4 destination-unreachable/fragmentation-needed
#
# ATTENTION .. can be anything (ICMP), but the very 1st will be filtered ok !
#
$IPTABLES -A acl_external_input -p icmp --icmp-type echo-request -m limit --limit 5/s -j ACCEPT
$IPTABLES -A acl_external_input -p icmp --icmp-type destination-unreachable -j ACCEPT
$IPTABLES -A acl_external_input -p icmp --icmp-type time-exceeded -j ACCEPT
$IPTABLES -A acl_external_input -p icmp --icmp-type parameter-problem -j ACCEPT
$IPTABLES -A acl_external_input -p icmp --icmp-type timestamp-request -j ACCEPT
$IPTABLES -p all -A acl_external_input -j acl_srv_connect # includes: allow to answer ..
$IPTABLES -p all -A acl_external_input -j acl_srv_login_sec
$IPTABLES -p all -A acl_external_input -j acl_srv_web
$IPTABLES -p all -A acl_external_input -j acl_srv_shared
$IPTABLES -p all -A acl_external_input -j acl_srv_email
# --syn == "--tcp-flags SYN,RST,ACK SYN"
#$IPTABLES -p tcp -A acl_external_input ! --syn -j LOG --log-level debug --log-prefix "FW4-Ext: rej INET !syn "
#$IPTABLES -p tcp -A acl_external_input ! --syn -j REJECT
#$IPTABLES -p all -A acl_external_input -m state ! --state ESTABLISHED,RELATED -j LOG --log-level debug --log-prefix "FW4-Ext: rej INET !resp "
#$IPTABLES -p all -A acl_external_input -m state ! --state ESTABLISHED,RELATED -j REJECT
#
#########################################################################################################################
#########################################################################################################################
#########################################################################################################################
#
# INPUT Allow acl_srv_shared
#
# FTP, SAMBA, GNUnet clients
#
# ANONYMOUS FTP
#
#$IPTABLES -p tcp -A acl_srv_shared --dport ftp-data:ftp -j ACCEPT
#$IPTABLES -p udp -A acl_srv_shared --dport ftp-data:ftp -j ACCEPT
$IPTABLES -p tcp -A acl_srv_shared --dport git -j ACCEPT
$IPTABLES -p udp -A acl_srv_shared --dport git -j ACCEPT
#
#
#########################################################################################################################
#
# INPUT Allow acl_srv_login_sec
#
# SSH
#
# SSH
#
#$IPTABLES -p tcp -A acl_srv_login_sec --dport ssh -j LOG --log-level debug --log-prefix "FW4-ACL_SSH: "
$IPTABLES -p tcp -A acl_srv_login_sec --dport ssh -j ACCEPT
$IPTABLES -p udp -A acl_srv_login_sec --dport ssh -j ACCEPT
#
#
#########################################################################################################################
#
# INPUT Allow acl_srv_email
#
# POP3s, SMTP
#
# IMAPs
#
$IPTABLES -p tcp -A acl_srv_email --dport imaps -j ACCEPT
# POP3s
#
$IPTABLES -p tcp -A acl_srv_email --dport pop3s -j ACCEPT
# ident
#
$IPTABLES -p tcp -A acl_srv_email --dport ident -j ACCEPT
# SMTPs
#
$IPTABLES -p tcp -A acl_srv_email --dport smtp -j ACCEPT
$IPTABLES -p tcp -A acl_srv_email --dport smtps -j ACCEPT
$IPTABLES -p tcp -A acl_srv_email --dport sieve -j ACCEPT
#
#########################################################################################################################
#
# INPUT Allow acl_srv_web
#
# HTTP, NTP
#
# HTTP
#
$IPTABLES -p tcp -A acl_srv_web --dport http -j ACCEPT
$IPTABLES -p tcp -A acl_srv_web --dport https -j ACCEPT
#$IPTABLES -p tcp -A acl_srv_web --dport http-alt -j ACCEPT
#$IPTABLES -p tcp -A acl_srv_web --dport webcache -j ACCEPT
#$IPTABLES -p tcp -A acl_srv_web --dport squid -j ACCEPT
#
#
#########################################################################################################################
#
# INPUT Allow acl_srv_connect
#
# ICMP, NTP, DHCP, DNS, ANSWER
#
# IPSEC
#
$IPTABLES -p ah -A acl_srv_connect -j ACCEPT
$IPTABLES -p esp -A acl_srv_connect -j ACCEPT
# DHCP .. TFTP
#
$IPTABLES -p udp -A acl_srv_connect -i $ETH_EXTERN --dport mdns -s $IP_EXTERN_SELF -j ACCEPT #
$IPTABLES -p udp -A acl_srv_connect -i $ETH_EXTERN --dport bootps:tftp -s $IP_EXTERN_GW -j ACCEPT #
$IPTABLES -p tcp -A acl_srv_connect -i $ETH_EXTERN --dport bootps:69 -s $IP_EXTERN_GW -j ACCEPT #
# DNS
#
# $IPTABLES -p tcp -A acl_srv_connect --dport mdns -j ACCEPT
# $IPTABLES -p udp -A acl_srv_connect --dport mdns -j ACCEPT
# $IPTABLES -p tcp -A acl_srv_connect --dport domain -j ACCEPT
# $IPTABLES -p udp -A acl_srv_connect --dport domain -j ACCEPT
# $IPTABLES -p tcp -A acl_srv_connect --dport netbios-ns:netbios-ssn -j ACCEPT
# $IPTABLES -p udp -A acl_srv_connect --dport netbios-ns:netbios-ssn -j ACCEPT
#
# acl_srv_connect Allow * to answer,
# only for known connections - no new unknown ones !
#
$IPTABLES -p all -A acl_srv_connect -m state --state ESTABLISHED,RELATED -j ACCEPT
#
#
#########################################################################################################################
fi
|
