347 lines
11 KiB
Bash
Executable File
347 lines
11 KiB
Bash
Executable File
#!/bin/bash
|
|
|
|
### BEGIN INIT INFO
|
|
# Provides: firewall
|
|
# Required-Start: $remote_fs $syslog $network
|
|
# Required-Stop: $remote_fs $syslog $network
|
|
# Default-Start: 2 3 4 5
|
|
# Default-Stop: 0 1 6
|
|
# Short-Description: Iptables firewall
|
|
# Description: An iptables firewall
|
|
### END INIT INFO
|
|
|
|
. /lib/lsb/init-functions
|
|
|
|
NAME="firewall"
|
|
|
|
abort()
|
|
{
|
|
message=$@
|
|
log_failure_msg "$message"
|
|
exit 1
|
|
}
|
|
|
|
if [ -f "/etc/firewall/firewall.conf" ]; then
|
|
source /etc/firewall/firewall.conf
|
|
else
|
|
abort "No configuration file /etc/firewall/firewall.conf"
|
|
fi
|
|
|
|
clean()
|
|
{
|
|
$IPTABLES -t filter -F
|
|
$IPTABLES -t filter -X
|
|
|
|
$IPTABLES -t filter -P INPUT ACCEPT
|
|
$IPTABLES -t filter -P FORWARD ACCEPT
|
|
$IPTABLES -t filter -P OUTPUT ACCEPT
|
|
|
|
$IPTABLES -t nat -F
|
|
$IPTABLES -t nat -X
|
|
|
|
$IPTABLES -t nat -P PREROUTING ACCEPT
|
|
$IPTABLES -t nat -P OUTPUT ACCEPT
|
|
$IPTABLES -t nat -P POSTROUTING ACCEPT
|
|
|
|
$IPTABLES -t mangle -F
|
|
$IPTABLES -t mangle -X
|
|
|
|
$IPTABLES -t mangle -P PREROUTING ACCEPT
|
|
$IPTABLES -t mangle -P INPUT ACCEPT
|
|
$IPTABLES -t mangle -P FORWARD ACCEPT
|
|
}
|
|
|
|
test_config()
|
|
{
|
|
# FIXME: test if the interface and the ip exist
|
|
if [ ! "$WAN_INT" -o ! "$IP" ]; then
|
|
abort "Bad configuration please check /etc/firewall/firewall.conf"
|
|
fi
|
|
}
|
|
|
|
critical_return()
|
|
{
|
|
if [ `echo $?` != 0 ]; then
|
|
log_failure_msg "Error on the last command firewall will be stop"
|
|
stop
|
|
exit 1
|
|
fi
|
|
}
|
|
|
|
forward_port()
|
|
{
|
|
if [ $# != 4 ]; then
|
|
log_warning_msg "Bad syntax for port forward : $*"
|
|
return
|
|
fi
|
|
|
|
local source=$1
|
|
local port=$2
|
|
local destination=$3
|
|
local proto=$4
|
|
|
|
if echo "$destination" | grep -q ":"; then
|
|
dest_ip=$(echo $destination | cut -d ":" -f1)
|
|
dest_port=$(echo $destination | cut -d ":" -f2)
|
|
if [ ! "$LAN_INT" ]; then
|
|
log_warning_msg "You must add a LAN interface (LAN_INT) for a port forward"
|
|
else
|
|
log_action_msg "Forward $port to $destination for protocol $proto"
|
|
$IPTABLES -A FORWARD -i $WAN_INT -o $LAN_INT -p $proto -s $source -d $dest_ip --dport $dest_port -m state --state ESTABLISHED,RELATED,NEW -j ACCEPT
|
|
$IPTABLES -t nat -A PREROUTING -i $WAN_INT -p $proto -s $source -d $IP --dport $port -j DNAT --to $destination
|
|
fi
|
|
fi
|
|
|
|
}
|
|
|
|
open_port()
|
|
{
|
|
if [ $# == 4 ]; then
|
|
local destination=$2
|
|
local proto=$3
|
|
local ports=$4
|
|
elif [ $# == 3 ]; then
|
|
local destination=$IP
|
|
local proto=$2
|
|
local ports=$3
|
|
else
|
|
log_warning_msg "Open port bad syntax : $*"
|
|
fi
|
|
source=$1
|
|
log_action_msg "Open port(s) $ports from $source to $destination for protocol $proto"
|
|
$IPTABLES -A INPUT -i $WAN_INT -p $proto -s $source -d $destination -m multiport --dports $ports -m state --state NEW -j ACCEPT
|
|
critical_return
|
|
}
|
|
|
|
port_redirection()
|
|
{
|
|
if [ $# != 4 ]; then
|
|
log_warning_msg "Bad syntax for port redirection : $*"
|
|
return
|
|
fi
|
|
|
|
local if=$1
|
|
local proto=$2
|
|
local srcport=$3
|
|
local destport=$4
|
|
|
|
log_action_msg "Redirect $if port $srcport to $destport for portocol $proto"
|
|
iptables -t nat -A PREROUTING -i $if -p $proto --dport $srcport -j REDIRECT --to-port $destport
|
|
}
|
|
|
|
port_knocking()
|
|
{
|
|
if [ $# != 3 ]; then
|
|
log_warning_msg "Bad syntax for port knocking : $*"
|
|
return
|
|
fi
|
|
|
|
local ports=$1
|
|
local knock_ports=$2
|
|
local knock_number=$3
|
|
local i=0
|
|
|
|
for kport in $(echo $knock_ports | sed 's/,/ /g'); do
|
|
((i++))
|
|
tock_number=$knock_number$i
|
|
if [ $i -gt 1 ]; then
|
|
iptables -N toc${tock_number}
|
|
iptables -A toc${tock_number} -m recent --name toc$((${tock_number}-1)) --remove
|
|
iptables -A toc${tock_number} -m recent --name toc${tock_number} --set
|
|
iptables -A INPUT -i $WAN_INT -p tcp --dport $kport -m recent --rcheck --name toc$((${tock_number}-1)) -j toc${tock_number}
|
|
else
|
|
iptables -A INPUT -i $WAN_INT -p tcp --dport $kport -m recent --set --name toc${tock_number}
|
|
fi
|
|
done
|
|
log_action_msg "Port knocking for $ports with combinaison $knock_ports on $WAN_INT"
|
|
for port in $(echo $ports | sed 's/,/ /g'); do
|
|
iptables -A INPUT -i $WAN_INT -p tcp --dport $port -m recent --rcheck --seconds 15 --name toc${tock_number} -m state --state NEW -j ACCEPT
|
|
done
|
|
}
|
|
|
|
start()
|
|
{
|
|
test_config
|
|
modprobe ip_conntrack
|
|
clean
|
|
|
|
# default policies
|
|
$IPTABLES -P INPUT DROP
|
|
$IPTABLES -P FORWARD DROP
|
|
$IPTABLES -P OUTPUT DROP
|
|
|
|
## allow packets coming from the machine
|
|
$IPTABLES -A INPUT -i lo -j ACCEPT
|
|
$IPTABLES -A OUTPUT -o lo -j ACCEPT
|
|
|
|
log_action_msg "Allow WAN outgoing traffic"
|
|
$IPTABLES -A OUTPUT -o $WAN_INT -p all -m state --state ESTABLISHED,RELATED,NEW -j ACCEPT
|
|
$IPTABLES -A INPUT -i $WAN_INT -p all -m state --state ESTABLISHED,RELATED -j ACCEPT
|
|
|
|
critical_return
|
|
|
|
if [ $LAN == 1 ]; then
|
|
log_action_msg "Allow WAN outgoing traffic from lan"
|
|
$IPTABLES -A FORWARD -i $WAN_INT -o $LAN_INT -p all -d $LAN_NETWORK -m state --state RELATED,ESTABLISHED -j ACCEPT
|
|
$IPTABLES -A FORWARD -i $LAN_INT -o $WAN_INT -p all -s $LAN_NETWORK -m state --state ESTABLISHED,RELATED,NEW -j ACCEPT
|
|
log_action_msg "Allow local network"
|
|
$IPTABLES -A OUTPUT -o $LAN_INT -s $LAN_NETWORK -p all -j ACCEPT
|
|
$IPTABLES -A INPUT -i $LAN_INT -d $LAN_NETWORK -p all -j ACCEPT
|
|
fi
|
|
|
|
## block spoofing
|
|
log_action_msg "Block spoofing, scan port, Xmas Tree, null scanning, SYN/RST and SYN/FIN"
|
|
echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
|
|
## NMAP FIN/URG/PSH
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL FIN,URG,PSH -j LOG --log-prefix 'iptables: Port scan: ' --log-level 4
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL FIN,URG,PSH -j DROP
|
|
## stop Xmas Tree type scanning
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL ALL -j LOG --log-prefix "iptables: Xmas tree: " --log-level 4
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL ALL -j DROP
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j LOG --log-prefix "iptables: Xmas tree: " --log-level 4
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
|
|
## stop null scanning
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL NONE -j LOG --log-prefix "iptables: Null scanning: " --log-level 4
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags ALL NONE -j DROP
|
|
## SYN/RST
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags SYN,RST SYN,RST -j LOG --log-prefix "iptables: SYN/RST: " --log-level 4
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
|
|
## SYN/FIN
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags SYN,FIN SYN,FIN -j LOG --log-prefix "iptables: SYN/FIN: " --log-level 4
|
|
$IPTABLES -A INPUT -i $WAN_INT -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP
|
|
|
|
## stop sync flood
|
|
log_action_msg "Block Syn flood"
|
|
echo "1" >/proc/sys/net/ipv4/tcp_syncookies
|
|
echo "1024" > /proc/sys/net/ipv4/tcp_max_syn_backlog
|
|
|
|
if [ $PING == 1 ]; then
|
|
log_action_msg "PING allowed"
|
|
iptables -A INPUT -p icmp --icmp-type ping -j ACCEPT
|
|
iptables -A OUTPUT -p icmp --icmp-type ping -j ACCEPT
|
|
iptables -A FORWARD -p icmp --icmp-type ping -j ACCEPT
|
|
fi
|
|
|
|
if [ $FTP == 1 ]; then
|
|
log_action_msg "FTP allowed"
|
|
modprobe ip_conntrack_ftp
|
|
$IPTABLES -A INPUT -i $WAN_INT -d $IP -p tcp --dport ftp -m state --state NEW,ESTABLISHED -j ACCEPT
|
|
$IPTABLES -A OUTPUT -o $WAN_INT -s $IP -p tcp --sport ftp -m state --state ESTABLISHED -j ACCEPT
|
|
# Data
|
|
$IPTABLES -A INPUT -i $WAN_INT -d $IP -p tcp --dport ftp-data -m state --state ESTABLISHED -j ACCEPT
|
|
$IPTABLES -A OUTPUT -o $WAN_INT -s $IP -p tcp --sport ftp-data -m state --state ESTABLISHED,RELATED -j ACCEPT
|
|
# Passive mod
|
|
$IPTABLES -A INPUT -i $WAN_INT -d $IP -p tcp --sport 1024: --dport 1024: -m state --state ESTABLISHED -j ACCEPT
|
|
$IPTABLES -A OUTPUT -o $WAN_INT -s $IP -p tcp --sport 1024: --dport 1024: -m state --state ESTABLISHED,RELATED -j ACCEPT
|
|
fi
|
|
|
|
## Open Ports
|
|
for args in "${OPEN_PORTS[@]}"; do
|
|
open_port $args
|
|
done
|
|
|
|
## Port knocking
|
|
local i=1
|
|
for args in "${PORT_KNOCK[@]}"; do
|
|
port_knocking $args $i
|
|
((i++))
|
|
done
|
|
|
|
## Port forwading
|
|
for args in "${TRAFFICS[@]}"; do
|
|
forward_port $args
|
|
done
|
|
|
|
## Port redirection
|
|
for args in "${REDIRECTIONS[@]}"; do
|
|
port_redirection $args
|
|
done
|
|
|
|
## Old: Whitelist
|
|
for arg in "${WHITELIST_SSH[@]}"; do
|
|
log_warning_msg "WHITELIST_SSH is obsolete: this option will be removed in next version"
|
|
open_port $arg tcp ssh
|
|
done
|
|
|
|
for ip in "${WHITELIST[@]}"; do
|
|
for args in "${WHITELIST_OPEN_PORTS[@]}"; do
|
|
open_port $ip $args
|
|
done
|
|
done
|
|
|
|
## NAT
|
|
if [ $NAT == 1 ]; then
|
|
log_action_msg "Activate nat"
|
|
for proto in ftp irc sip h323; do modprobe nf_nat_$proto; done
|
|
$IPTABLES -t nat -A POSTROUTING -o $WAN_INT -s $LAN_NETWORK -j SNAT --to-source $IP
|
|
fi
|
|
|
|
ipt_hook
|
|
|
|
## LOG
|
|
## Create a LOGDROP chain to log and drop packets
|
|
$IPTABLES -N LOGDROP
|
|
$IPTABLES -A LOGDROP -p tcp -m limit --limit 1/min -j LOG --log-prefix "iptables: denied tcp: " --log-level 4
|
|
$IPTABLES -A LOGDROP -p udp -m limit --limit 1/min -j LOG --log-prefix "iptables: denied udp: " --log-level 4
|
|
$IPTABLES -A LOGDROP -p icmp -m limit --limit 1/min -j LOG --log-prefix "iptables: denied icmp: " --log-level 4
|
|
$IPTABLES -A LOGDROP -j DROP
|
|
|
|
$IPTABLES -A INPUT -j LOGDROP
|
|
$IPTABLES -A OUTPUT -j LOGDROP
|
|
$IPTABLES -A FORWARD -j LOGDROP
|
|
|
|
}
|
|
|
|
|
|
stop()
|
|
{
|
|
clean
|
|
}
|
|
|
|
case "$1" in
|
|
start|restore)
|
|
log_daemon_msg "Starting firewall"
|
|
if [ -f /etc/network/iptables-save ]; then
|
|
iptables-restore < /etc/network/iptables-save
|
|
else
|
|
log_warning_msg "No iptables rules saved please use test and save script options"
|
|
fi
|
|
log_end_msg 0
|
|
;;
|
|
stop)
|
|
log_daemon_msg "Stopping firewall"
|
|
stop || exit 1
|
|
log_end_msg 0
|
|
;;
|
|
test)
|
|
log_action_msg "Testing new rules"
|
|
log_action_msg "You have 30 seconds to test your new rules"
|
|
start || exit 1
|
|
log_end_msg 0
|
|
log_action_msg "... Please test your rules"
|
|
sleep 30
|
|
log_action_msg "---- The test is finished ----"
|
|
if [ -f /etc/network/iptables-save ]; then
|
|
iptables-restore < /etc/network/iptables-save
|
|
log_action_msg "Old rules restored"
|
|
else
|
|
stop
|
|
log_action_msg "Rules flushed"
|
|
fi
|
|
log_action_msg "If you are happy with this new rules please use save option"
|
|
;;
|
|
save)
|
|
log_action_msg "Starting and saving new rules"
|
|
start || exit 1
|
|
iptables-save > /etc/network/iptables-save
|
|
log_end_msg 0
|
|
;;
|
|
*)
|
|
N=/etc/init.d/$NAME
|
|
echo "Usage: $N {start|restore|save|test|stop}"
|
|
exit 2
|
|
;;
|
|
esac
|
|
|
|
exit 0
|