Servidor Bind + Rede interna

#!/bin/sh

#Declaração de variaveis
PATH=/sbin:/bin:/usr/sbin:/usr/bin
IPTABLES="/sbin/iptables"

PROGRAMA="/usr/local/bin/firewall"

PORTSLIB="/etc/configuracao/portlib"
PORTSBLO="/etc/configuracao/portblo"

#Interfaces de Rede
LAN=eth1
WAN=eth0
REDE="192.168.1.1/24"

# Os diversos módulos do iptables são chamdos através do modprobe
modprobe ip_tables
modprobe iptable_nat
modprobe ip_conntrack
modprobe ip_conntrack_ftp
modprobe ip_nat_ftp
modprobe ipt_LOG
modprobe ipt_REJECT
modprobe ipt_MASQUERADE
modprobe ipt_state
modprobe ipt_multiport
modprobe iptable_mangle
modprobe ipt_tos
modprobe ipt_limit
modprobe ipt_mark
modprobe ipt_MARK

case "$1" in
start)

$IPTABLES -F
$IPTABLES -F INPUT
$IPTABLES -F OUTPUT
$IPTABLES -F FORWARD

$IPTABLES -t mangle -F
$IPTABLES -t nat -F
$IPTABLES -X

# Determina a política padrão
$IPTABLES -P INPUT ACCEPT
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -P FORWARD ACCEPT

# ativar o redirecionamento no arquivo ip_forward
echo "1" > /proc/sys/net/ipv4/ip_forward

#habilitando o fluxo interno entre os processos
$IPTABLES -A INPUT -i lo -j ACCEPT
$IPTABLES -A OUTPUT -o lo -j ACCEPT

#liberar as portas principais do servidor
for i in `cat $PORTSLIB`; do
$IPTABLES -A INPUT -p tcp --dport $i -j ACCEPT
$IPTABLES -A FORWARD -p tcp --dport $i -j ACCEPT
$IPTABLES -A OUTPUT -p tcp --sport $i -j ACCEPT
done
$IPTABLES -A INPUT -p tcp --dport 25000:30000 -j ACCEPT

#Estabeliza coneção
$IPTABLES -I INPUT -m state --state ESTABLISHED -j ACCEPT
$IPTABLES -I INPUT -m state --state RELATED -j ACCEPT
$IPTABLES -I OUTPUT -p icmp -o $WAN -j ACCEPT
$IPTABLES -I INPUT -p icmp -j ACCEPT

#Bloqueio ping da morte
echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_all
$IPTABLES -N PING-MORTE
$IPTABLES -A INPUT -p icmp --icmp-type echo-request -j PING-MORTE
$IPTABLES -A PING-MORTE -m limit --limit 1/s --limit-burst 4 -j RETURN
$IPTABLES -A PING-MORTE -j DROP

#bloquear ataque do tipo SYN-FLOOD
echo "1" > /proc/sys/net/ipv4/tcp_syncookies
$IPTABLES -N syn-flood
$IPTABLES -A INPUT -i $WAN -p tcp --syn -j syn-flood
$IPTABLES -A syn-flood -m limit --limit 1/s --limit-burst 4 -j RETURN
$IPTABLES -A syn-flood -j DROP

#Bloqueio de ataque ssh de força bruta
$IPTABLES -N SSH-BRUT-FORCE
$IPTABLES -A INPUT -i $WAN -p tcp --dport 22 -j SSH-BRUT-FORCE
$IPTABLES -A SSH-BRUT-FORCE -m limit --limit 1/s --limit-burst 4 -j RETURN
$IPTABLES -A SSH-BRUT-FORCE -j DROP

#Bloqueio de portas
for i in `cat $PORTSBLO`; do
$IPTABLES -A INPUT -p tcp -i $WAN --dport $i -j DROP
$IPTABLES -A INPUT -p udp -i $WAN --dport $i -j DROP
$IPTABLES -A FORWARD -p tcp --dport $i -j DROP
done

#bloqueio Anti-Spoofings
$IPTABLES -A INPUT -s 10.0.0.0/8 -i $WAN -j DROP
$IPTABLES -A INPUT -s 127.0.0.0/8 -i $WAN -j DROP
$IPTABLES -A INPUT -s 172.16.0.0/12 -i $WAN -j DROP
$IPTABLES -A INPUT -s 192.168.1.0/16 -i $WAN -j DROP

#Bloqueio de scanners ocultos (Shealt Scan)
$IPTABLES -A FORWARD -p tcp --tcp-flags SYN,ACK, FIN, -m limit --limit 1/s -j ACCEPT

### Segurança Diversa

### Regras de Liberacao #########

#Regra Liberando acesso ao sql
$IPTABLES -t nat -A PREROUTING -d XXX.xx.xx.xx-p tcp -m tcp --dport 1433 -j DNAT --to-destination 192.168.1.2:1433
este é minha maquina que eu digo que esta lenta
# Passando para o msn-proxy
#$IPTABLES -t nat -I PREROUTING -i $LAN -p tcp --dport 1863 -j REDIRECT --to-port 1863
#proxy transparente
#$IPTABLES -t nat -A PREROUTING -i $LAN -p tcp --dport 80 -j REDIRECT --to-port 3128
# ativar o mascaramento
$IPTABLES -t nat -A POSTROUTING -o $WAN -j MASQUERADE
# Fim Fecho tudo que nao tiver no firewall
$IPTABLES -A INPUT -j LOG --log-prefix "FIREWALL: INPUT "
$IPTABLES -A INPUT -j DROP

#cabecalho do firewall exibido na tela
echo
echo "==============================================================================="
echo "| REGRAS DO FIREWALL CARREGADAS COM SUCESSO |"
echo "==============================================================================="
echo
;;

stop)

$IPTABLES -F
$IPTABLES -F INPUT
$IPTABLES -F OUTPUT
$IPTABLES -F FORWARD
$IPTABLES -t mangle -F
$IPTABLES -t nat -F
$IPTABLES -t nat -F
$IPTABLES -X
$IPTABLES -Z
$IPTABLES -P INPUT ACCEPT
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -P FORWARD ACCEPT
echo
echo "==============================================================================="
echo "| FIREWALL DESLIGADO |"
echo "==============================================================================="
echo

;;

restart)
$PROGRAMA stop
$PROGRAMA start
;;
*)
echo -e "{TTEXTO}33[01;31mATENCAO \c";tput sgr0
echo -e "Argumento Invalido!!!"
echo "Uso Correto: firewall {start|stop|restart}" >&2
echo
echo "Restartando o Firewall..."
echo
sleep 5
$PROGRAMA restart
exit 1
esac
exit 0