92 lines
2.5 KiB
Bash
Executable file
92 lines
2.5 KiB
Bash
Executable file
#!/bin/sh
|
|
|
|
## Please make changes in /etc/firewall.user
|
|
|
|
. /etc/functions.sh
|
|
WAN=$(nvram get wan_ifname)
|
|
LAN=$(nvram get lan_ifname)
|
|
|
|
## CLEAR TABLES
|
|
for T in filter nat mangle; do
|
|
iptables -t $T -F
|
|
iptables -t $T -X
|
|
done
|
|
|
|
iptables -N input_rule
|
|
iptables -N output_rule
|
|
iptables -N forwarding_rule
|
|
|
|
iptables -t nat -N prerouting_rule
|
|
iptables -t nat -N postrouting_rule
|
|
|
|
### INPUT
|
|
### (connections with the router as destination)
|
|
|
|
# base case
|
|
iptables -P INPUT DROP
|
|
iptables -A INPUT -m state --state INVALID -j DROP
|
|
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
|
|
iptables -A INPUT -p tcp --syn --tcp-option \! 2 -j DROP
|
|
|
|
#
|
|
# insert accept rule or to jump to new accept-check table here
|
|
#
|
|
iptables -A INPUT -j input_rule
|
|
|
|
# allow
|
|
iptables -A INPUT -i \! $WAN -j ACCEPT # allow from lan/wifi interfaces
|
|
iptables -A INPUT -p icmp -j ACCEPT # allow ICMP
|
|
iptables -A INPUT -p gre -j ACCEPT # allow GRE
|
|
|
|
# reject (what to do with anything not allowed earlier)
|
|
iptables -A INPUT -p tcp -j REJECT --reject-with tcp-reset
|
|
iptables -A INPUT -j REJECT --reject-with icmp-port-unreachable
|
|
|
|
### OUTPUT
|
|
### (connections with the router as source)
|
|
|
|
# base case
|
|
iptables -P OUTPUT DROP
|
|
iptables -A OUTPUT -m state --state INVALID -j DROP
|
|
iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
|
|
|
|
#
|
|
# insert accept rule or to jump to new accept-check table here
|
|
#
|
|
iptables -A OUTPUT -j output_rule
|
|
|
|
# allow
|
|
iptables -A OUTPUT -j ACCEPT #allow everything out
|
|
|
|
# reject (what to do with anything not allowed earlier)
|
|
iptables -A OUTPUT -p tcp -j REJECT --reject-with tcp-reset
|
|
iptables -A OUTPUT -j REJECT --reject-with icmp-port-unreachable
|
|
|
|
### FORWARDING
|
|
### (connections routed through the router)
|
|
|
|
# base case
|
|
iptables -P FORWARD DROP
|
|
iptables -A FORWARD -m state --state INVALID -j DROP
|
|
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
|
|
iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
|
|
|
|
#
|
|
# insert accept rule or to jump to new accept-check table here
|
|
#
|
|
iptables -A FORWARD -j forwarding_rule
|
|
|
|
# allow
|
|
iptables -A FORWARD -i br0 -o br0 -j ACCEPT
|
|
iptables -A FORWARD -i $LAN -o $WAN -j ACCEPT
|
|
|
|
# reject (what to do with anything not allowed earlier)
|
|
# uses the default -P DROP
|
|
|
|
### MASQ
|
|
iptables -t nat -A PREROUTING -j prerouting_rule
|
|
iptables -t nat -A POSTROUTING -j postrouting_rule
|
|
iptables -t nat -A POSTROUTING -o $WAN -j MASQUERADE
|
|
|
|
## USER RULES
|
|
[ -f /etc/firewall.user ] && . /etc/firewall.user
|