Estou configurando um PI de framboesa como roteador doméstico e abaixo está meu script atual do iptables. O roteador também tem
- um proxy,
- samba,
- CUPS,
- bind9,
- um ponto de acesso WLAN e
- um servidor DHCP.
Não tenho certeza se a configuração abaixo funciona, se a ligação não puder responder a um pedido de DNS: Preciso tornar possível abrir uma conexão "NEW" na porta 53 na cadeia de saída? Ou eu tenho que colocá-lo na cadeia FORWARD, porque o cliente da LAN faz o pedido de upstream em vez de ligar.
O roteador deve obter um IP (para a interface WAN) via DHCP do meu provedor. O roteador também distribuirá IPs para os clientes (W) da LAN. Eu tenho que permitir a porta udp 67/68 em todas as interfaces para a cadeia de entrada e saída para isso?
Existe uma maneira de tornar meu script mais curto, ou seja, obter o mesmo resultado, melhorando a legibilidade? Meu objetivo básico é fornecer os serviços instalados (veja acima) para clientes de rede local (W) e fornecer aos clientes de rede local (W) acesso a HTTP (s), IMAP (s), SMTP, NTP e WhatsApp.
#!/bin/sh
log() {
echo "$(date '+%b %d %H:%M:%S') $(hostname) iptablesInit: $1"
echo "$(date '+%b %d %H:%M:%S') $(hostname) iptablesInit: $1" >> /var/log/iptablesInit.log
}
IPT="/sbin/iptables"
WAN="WAN"
LAN="LAN"
WLAN="WLAN"
# Flush all chaines
log 'Flush everything...'
$IPT -F
$IPT -X
$IPT -t mangle -F
$IPT -t mangle -X
$IPT -t nat -F
$IPT -t nat -X
$IPT -F INPUT
$IPT -F FORWARD
$IPT -F OUTPUT
log 'Flush done'
# unlimited
$IPT -A INPUT -i lo -j ACCEPT
$IPT -A OUTPUT -o lo -j ACCEPT
# set policies
$IPT -P INPUT DROP
$IPT -P OUTPUT DROP
$IPT -P FORWARD DROP
# NAT
$IPT -t nat -A POSTROUTING -o ${WAN} -j MASQUERADE
#===== BLOCK =====
# Block sync
$IPT -A INPUT -i ${WAN} -p tcp ! --syn -m state --state NEW -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Drop Sync"
$IPT -A INPUT -i ${WAN} -p tcp ! --syn -m state --state NEW -j DROP
# Block Fragments
$IPT -A INPUT -i ${WAN} -f -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Fragments Packets"
$IPT -A INPUT -i ${WAN} -f -j DROP
# Block bad stuff
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags ALL FIN,URG,PSH -j DROP
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags ALL ALL -j DROP
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags ALL NONE -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "NULL Packets"
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags ALL NONE -j DROP # NULL packets
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags SYN,FIN SYN,FIN -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "XMAS Packets"
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP #XMAS
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags FIN,ACK FIN -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Fin Packets Scan"
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags FIN,ACK FIN -j DROP # FIN packet scans
$IPT -A INPUT -i ${WAN} -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
# Block CUPS WAN access
$IPT -A OUTPUT -o ${WAN} -p tcp --dport 631 -j REJECT
$IPT -A OUTPUT -o ${WAN} -p udp --dport 631 -j REJECT
#===== ALLOW =====
# Allow full connection but no incomming stuff between LAN and router
#$IPT -A INPUT -i ${LAN} -m state --state ESTABLISHED,RELATED -j ACCEPT
#$IPT -A OUTPUT -o ${LAN} -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
# Allow ssh
$IPT -A INPUT -i ${LAN} -p tcp --dport 22 -j ACCEPT
$IPT -A OUTPUT -o ${LAN} -p tcp --dport 22 -m state --state ESTABLISHED,RELATED -j ACCEPT
# allow ICMP ping pong stuff
$IPT -A INPUT -i ${LAN} -p icmp -j ACCEPT
$IPT -A OUTPUT -o ${LAN} -p icmp -j ACCEPT
$IPT -A INPUT -i ${WLAN} -p icmp -j ACCEPT
$IPT -A OUTPUT -o ${WLAN} -p icmp -j ACCEPT
# Allow port 53 tcp/udp (DNS Server)
$IPT -A INPUT -p tcp --dport 53 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A OUTPUT -p tcp --sport 53 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A INPUT -p udp --dport 53 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A OUTPUT -p udp --sport 53 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A INPUT -p tcp --dport 953 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A OUTPUT -p tcp --sport 953 -m state --state ESTABLISHED,RELATED -j ACCEPT
# Proxy
$IPT -A INPUT -i ${LAN} -p tcp --dport 3128 -j ACCEPT
$IPT -A INPUT -i ${WLAN} -p tcp --dport 3128 -j ACCEPT
#DHCP
$IPT -A INPUT -p udp --dport 67 -j ACCEPT
$IPT -A INPUT -p udp --dport 68 -j ACCEPT
# Open port 631 for CUPS/Printing
$IPT -A INPUT -i ${LAN} -p tcp --dport 631 -j ACCEPT
$IPT -A INPUT -i ${LAN} -p udp --dport 631 -j ACCEPT
$IPT -A INPUT -i ${WLAN} -p tcp --dport 631 -j ACCEPT
$IPT -A INPUT -i ${WLAN} -p udp --dport 631 -j ACCEPT
# Samba
$IPT -A INPUT -p tcp -m multiport --dport 139,445 -j ACCEPT
$IPT -A INPUT -p udp -m multiport --dport 137,138 -j ACCEPT
#===== FORWARD =====
# HTTP(s)
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p tcp -m multiport --dport 80,443 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p udp -m multiport --dport 80,443 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p tcp -m multiport --dport 80,443 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p udp -m multiport --dport 80,443 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p tcp -m multiport --dport 80,443 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p udp -m multiport --dport 80,443 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p tcp -m multiport --dport 80,443 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p udp -m multiport --dport 80,443 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
# IMAP(s)
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p tcp -m multiport --dport 143,993 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p udp -m multiport --dport 143,993 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p tcp -m multiport --dport 143,993 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p udp -m multiport --dport 143,993 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p tcp -m multiport --dport 143,993 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p udp -m multiport --dport 143,993 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p tcp -m multiport --dport 143,993 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p udp -m multiport --dport 143,993 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
# SMTP
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p tcp --dport 25 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p udp --dport 25 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p tcp --dport 25 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p udp --dport 25 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p tcp --dport 25 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p udp --dport 25 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p tcp --dport 25 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p udp --dport 25 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
# NTP
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p udp --dport 123 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p udp --dport 123 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p udp --dport 123 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p udp --dport 123 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
# WhatsApp
$IPT -A FORWARD -i ${WAN} -o ${LAN} -p tcp --dport 5222 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${LAN} -o ${WAN} -p tcp --dport 5222 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WAN} -o ${WLAN} -p tcp --dport 5222 -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -A FORWARD -i ${WLAN} -o ${WAN} -p tcp --dport 5222 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
# Reject (W)LAN Traffic rather than drop
$IPT -A INPUT -i ${LAN} -j REJECT --reject-with icmp-host-prohibited
$IPT -A INPUT -i ${WLAN} -j REJECT --reject-with icmp-host-prohibited
$IPT -A FORWARD -i ${LAN} -j REJECT --reject-with icmp-host-prohibited
$IPT -A FORWARD -i ${WLAN} -j REJECT --reject-with icmp-host-prohibited
$IPT -A OUTPUT -j REJECT --reject-with icmp-host-prohibited
exit 0