1 #!/bin/sh /etc/rc.common
2 # Copyright (C) 2006 OpenWrt.org
4 ## Please make changes in /etc/firewall.user
9 config_load /var/state/network
11 config_get WAN wan ifname
12 config_get WANDEV wan device
13 config_get LAN lan ifname
14 config_get_bool NAT_LAN lan nat 1
17 config_get LAN_MASK lan netmask
18 config_get LAN_IP lan ipaddr
19 LAN_NET=$(/bin/ipcalc.sh $LAN_IP $LAN_MASK | grep NETWORK | cut -d= -f2)
23 for T in filter nat; do
28 iptables -N input_rule
30 iptables -N output_rule
31 iptables -N forwarding_rule
32 iptables -N forwarding_wan
34 iptables -t nat -N NEW
35 iptables -t nat -N prerouting_rule
36 iptables -t nat -N prerouting_wan
37 iptables -t nat -N postrouting_rule
39 iptables -N LAN_ACCEPT
40 [ -z "$WAN" ] || iptables -A LAN_ACCEPT -i "$WAN" -j RETURN
41 [ -z "$WANDEV" -o "$WANDEV" = "$WAN" ] || iptables -A LAN_ACCEPT -i "$WANDEV" -j RETURN
42 iptables -A LAN_ACCEPT -j ACCEPT
45 ### (connections with the router as destination)
48 iptables -P INPUT DROP
49 iptables -A INPUT -m state --state INVALID -j DROP
50 iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
51 iptables -A INPUT -p tcp --tcp-flags SYN SYN --tcp-option \! 2 -j DROP
54 # insert accept rule or to jump to new accept-check table here
56 iptables -A INPUT -j input_rule
57 [ -z "$WAN" ] || iptables -A INPUT -i $WAN -j input_wan
60 iptables -A INPUT -j LAN_ACCEPT # allow from lan/wifi interfaces
61 iptables -A INPUT -p icmp -j ACCEPT # allow ICMP
62 iptables -A INPUT -p gre -j ACCEPT # allow GRE
64 # reject (what to do with anything not allowed earlier)
65 iptables -A INPUT -p tcp -j REJECT --reject-with tcp-reset
66 iptables -A INPUT -j REJECT --reject-with icmp-port-unreachable
69 ### (connections with the router as source)
72 iptables -P OUTPUT DROP
73 iptables -A OUTPUT -m state --state INVALID -j DROP
74 iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
77 # insert accept rule or to jump to new accept-check table here
79 iptables -A OUTPUT -j output_rule
82 iptables -A OUTPUT -j ACCEPT #allow everything out
84 # reject (what to do with anything not allowed earlier)
85 iptables -A OUTPUT -p tcp -j REJECT --reject-with tcp-reset
86 iptables -A OUTPUT -j REJECT --reject-with icmp-port-unreachable
89 ### (connections routed through the router)
92 iptables -P FORWARD DROP
93 iptables -A FORWARD -m state --state INVALID -j DROP
94 iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
95 iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
98 # insert accept rule or to jump to new accept-check table here
100 iptables -A FORWARD -j forwarding_rule
101 [ -z "$WAN" ] || iptables -A FORWARD -i $WAN -j forwarding_wan
104 iptables -A FORWARD -i $LAN -o $LAN -j ACCEPT
105 [ -z "$WAN" ] || iptables -A FORWARD -i $LAN -o $WAN -j ACCEPT
107 # reject (what to do with anything not allowed earlier)
108 # uses the default -P DROP
111 iptables -t nat -A PREROUTING -m state --state NEW -p tcp -j NEW
112 iptables -t nat -A PREROUTING -j prerouting_rule
113 [ -z "$WAN" ] || iptables -t nat -A PREROUTING -i "$WAN" -j prerouting_wan
114 iptables -t nat -A POSTROUTING -j postrouting_rule
115 ### Only LAN, unless told not to
116 if [ $NAT_LAN -ne 0 ]
118 [ -z "$WAN" ] || iptables -t nat -A POSTROUTING --src $LAN_NET/$LAN_MASK -o $WAN -j MASQUERADE
121 iptables -t nat -A NEW -m limit --limit 50 --limit-burst 100 -j RETURN && \
122 iptables -t nat -A NEW -j DROP
125 [ -f /etc/firewall.user ] && . /etc/firewall.user
126 [ -n "$WAN" -a -e /etc/config/firewall ] && {
128 awk -f /usr/lib/common.awk -f /usr/lib/firewall.awk /etc/config/firewall | ash
133 iptables -P INPUT ACCEPT
134 iptables -P OUTPUT ACCEPT
135 iptables -P FORWARD ACCEPT
138 iptables -t nat -P PREROUTING ACCEPT
139 iptables -t nat -P POSTROUTING ACCEPT
140 iptables -t nat -P OUTPUT ACCEPT