je viens de faire
root@smtp:~# update-rc.d firewall.sh disable
update-rc.d: using dependency based boot sequencing
insserv: warning: current start runlevel(s) (empty) of script `firewall.sh' overrides LSB defaults (2 3 4 5).
insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `firewall.sh' overrides LSB defaults (0 1 6).
root@smtp:~# update-rc.d mesReglesIptables defaults
update-rc.d: using dependency based boot sequencing
contenu de firewall.sh
#!/bin/sh
#
# Simple Firewall configuration.
#
# Author: Nicolargo
#
# chkconfig: 2345 9 91
# description: Activates/Deactivates the firewall at boot time
#
### BEGIN INIT INFO
# Provides: firewall.sh
# Required-Start: $syslog $network
# Required-Stop: $syslog $network
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start firewall daemon at boot time
# Description: Custom Firewall scrip.
### END INIT INFO
PATH=/bin:/sbin:/usr/bin:/usr/sbin
# Services that the system will offer to the network
TCP_SERVICES="22 666 8080" # SSH
UDP_SERVICES=""
# Services the system will use from the network
REMOTE_TCP_SERVICES="80 443 993 465 443 25 8080" # web browsing
REMOTE_UDP_SERVICES="53" # DNS
# FTP backups
# Allow backups to an external FTP
FTP_BACKUPS=""
if ! [ -x /sbin/iptables ]; then
for PORT in $TCP_SERVICES; do
/sbin/iptables -A INPUT -p tcp --dport ${PORT} -j ACCEPT
done
fi
if [ -n "$UDP_SERVICES" ] ; then
for PORT in $UDP_SERVICES; do
/sbin/iptables -A INPUT -p udp --dport ${PORT} -j ACCEPT
done
fi
# Ftp backups
if [ -n "$FTP_BACKUPS" ] ; then
# The following two rules allow the inbound FTP connection
/sbin/iptables -A INPUT -p tcp --sport ${FTP_BACKUPS} -m state --state ESTABLISHED -j ACCEPT
/sbin/iptables -A OUTPUT -p tcp --dport ${FTP_BACKUPS} -m state --state NEW,ESTABLISHED -j ACCEPT
# The next 2 lines allow active ftp connections
#/sbin/iptables -A INPUT -p tcp --sport 20 -m state --state ESTABLISHED,RELATED -j ACCEPT
#/sbin/iptables -A OUTPUT -p tcp --dport 20 -m state --state ESTABLISHED -j ACCEPT
# These last two rules allow for passive transfers
/sbin/iptables -A INPUT -p tcp --sport 1024: --dport 1024: -m state --state ESTABLISHED -j ACCEPT
/sbin/iptables -A OUTPUT -p tcp --sport 1024: --dport 1024: -m state --state NEW,ESTABLISHED,RELATED -j$
fi
# Remote testing
/sbin/iptables -A INPUT -p icmp -j ACCEPT
/sbin/iptables -A INPUT -i lo -j ACCEPT
/sbin/iptables -P INPUT DROP
/sbin/iptables -A INPUT -j LOG
# Output:
/sbin/iptables -A OUTPUT -j ACCEPT -o lo
/sbin/iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# ICMP is permitted:
/sbin/iptables -A OUTPUT -p icmp -j ACCEPT
# So are security package updates:
# Note: You can hardcode the IP address here to prevent DNS spoofing
# and to setup the rules even if DNS does not work but then you
# will not "see" IP changes for this service:
/sbin/iptables -A OUTPUT -p tcp -d security.debian.org --dport 80 -j ACCEPT
# As well as the services we have defined:
if [ -n "$REMOTE_TCP_SERVICES" ] ; then
for PORT in $REMOTE_TCP_SERVICES; do
/sbin/iptables -A OUTPUT -p tcp --dport ${PORT} -j ACCEPT
done
fi
if [ -n "$REMOTE_UDP_SERVICES" ] ; then
for PORT in $REMOTE_UDP_SERVICES; do
/sbin/iptables -A OUTPUT -p udp --dport ${PORT} -j ACCEPT
done
fi
# All other connections are registered in syslog
/sbin/iptables -A OUTPUT -j LOG
/sbin/iptables -A OUTPUT -j REJECT
/sbin/iptables -P OUTPUT DROP
# Other network protections
# (some will only work with some kernel versions)
echo 1 > /proc/sys/net/ipv4/tcp_syncookies
echo 0 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
echo 1 > /proc/sys/net/ipv4/conf/all/log_martians
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
echo 0 > /proc/sys/net/ipv4/conf/all/send_redirects
echo 0 > /proc/sys/net/ipv4/conf/all/accept_source_route
}
##########################
# Stop the Firewall rules
##########################
fw_stop () {
/sbin/iptables -F
/sbin/iptables -t nat -F
/sbin/iptables -t mangle -F
/sbin/iptables -P INPUT DROP
/sbin/iptables -P FORWARD DROP
/sbin/iptables -P OUTPUT ACCEPT
}
##########################
# Clear the Firewall rules
##########################
fw_clear () {
/sbin/iptables -F
/sbin/iptables -t nat -F
/sbin/iptables -t mangle -F
/sbin/iptables -P INPUT ACCEPT
/sbin/iptables -P FORWARD ACCEPT
/sbin/iptables -P OUTPUT ACCEPT
}
############################
# Restart the Firewall rules
############################
fw_restart () {
fw_stop
fw_start
}
##########################
# Test the Firewall rules
##########################
fw_save () {
/sbin/iptables-save > /etc/iptables.backup
}
fw_restore () {
if [ -e /etc/iptables.backup ]; then
/sbin/iptables-restore < /etc/iptables.backup
fi
}
fw_test () {
fw_save
fw_restart
sleep 30
fw_restore
}
case "$1" in
start|restart)
echo -n "Starting firewall..."
fw_restart
echo "done."
;;
stop)
echo "\033[31;01mBE VERY CAREFUL !!! The incoming and outgoing connection (including the current one) will be s$
read -r -p "Stop all connections ? [Y/n] " response
case $response in
[yY][eE][sS]|[yY])
echo -n "Stopping firewall..."
fw_stop
echo "done."
;;
*)
echo "canceled"
;;
esac
;;
clear)
echo -n "Clearing firewall rules..."
fw_clear
echo "done."
;;
test)
echo -n "Test Firewall rules..."
echo -n "Previous configuration will be restore in 30 seconds"
fw_test
echo -n "Configuration as been restored"
;;
*)
echo "Usage: $0 {start|stop|restart|clear|test}"
echo "Be aware that stop drop all incoming/outgoing traffic !!!"
exit 1
;;
esac
exit 0
