Bom dia Pessoal,
Estou tentando instalar firewall e gostaria da opinião dos senhores a
respeito do script abaixo.
--------------------------------------
#! /bin/bash
case "$1" in
start)
###############
# TITULO ABRE #
###############
echo "Iniciando a Configuração do Firewall"
########################
# Zera todas as Regras #
########################
echo "Regras Zeradas"
iptables -F
########################################
# Bloqueia tudo, nada entra e nada sai #
########################################
echo "Fechando tudo"
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP
############################################################################
# Impede ataques DoS a maquina limitando a quantidade de respostas
do ping #
############################################################################
#echo "Previne ataques DoS"
# iptables -A INPUT -p icmp --icmp-type echo-request -m limit
--limit 1/s -j ACCEPT
#################################
# Bloqieia completamente o ping #
#################################
echo "Bloqueia o pings"
iptables -A INPUT -p icmp --icmp-type echo-request -j DROP
##########################
# Politicas de segurança #
##########################
echo "Implementação de politicas de segurança"
echo 0 > /proc/sys/net/ipv4/conf/all/accept_source_route # Impede
falsear pacote
echo 0 > /proc/sys/net/ipv4/conf/all/accept_redirects # Perigo de
descobrimento de rotas de roteamento (desativar em roteador)
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts # Risco
de DoS
echo 1 > /proc/sys/net/ipv4/tcp_syncookies # Só inicia a conexão
quando recebe a confirmação, diminuindo a banda gasta
echo 1 > /proc/sys/net/ipv4/conf/default/rp_filter # Faz o
firewall responder apenas a placa de rede que recebeu o pacote
iptables -A INPUT -m state --state INVALID -j DROP # Elimina os
pacotes invalidos
#################################
# Libera conexoes estabelecidas #
#################################
echo "Liberando conexões estabelecidas"
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -m state --state RELATED,ESTABLISHED,NEW -j
ACCEPT
iptables -A OUTPUT -m state --state RELATED,ESTABLISHED,NEW -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT
#######################################################################################
# Libera o acesso via SSH e Limita o número de tentativas de acesso
a 4 a cada minuto #
#######################################################################################
echo "Liberando o SSH"
iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW
-m recent --update --seconds 60 --hitcount 4 -j DROP
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p udp --dport 22 -j ACCEPT
##################
# Libera o Samba #
##################
echo "Liberando o Samba"
iptables -A INPUT -p tcp --dport 137:139 -j ACCEPT
iptables -A INPUT -p udp --dport 137:139 -j ACCEPT
###################
# Libera o Apache #
###################
echo "Liberando o Apache"
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
################
# TITULO FECHA #
################
echo "Configuração do Firewall Concluida."
;;
stop)
echo "Finalizando o Firewall"
rm -rf /var/lock/subsys/firewall
# -----------------------------------------------------------------
# Remove todas as regras existentes
# -----------------------------------------------------------------
iptables -F
iptables -X
iptables -t mangle -F
# -----------------------------------------------------------------
# Reseta as politicas padrões, aceitar tudo
# -----------------------------------------------------------------
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
;;
restart|reload)
$0 stop
$0 start
;;
*)
echo "Selecione uma opção valida {start|stop|status|restart|reload}"
exit 1
esac
exit 0
--
Wilson Bom
Serprodata Informática Ltda.
Av. Marcelino Pires, 1405 - Sala 216
79800-004 - Dourados - MS
(067) 3421-3343 - 8407-4808 - 8407-8808
Messenger: [email protected]
E-mail...: [email protected]
[email protected]
[email protected]
[email protected]
Ubuntu Lucid Lynx 10.04 - 2.6.32-25 #44
Linux Counter: 292553
Dataflex 3.2 Linux - Dataflex 3.2 MS-Dos
--
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