4 files changed, 236 insertions, 0 deletions
diff --git a/package/iptables/files/firewall.awk b/package/iptables/files/firewall.awk
new file mode 100644
index 000000000..1b63f8386
--- /dev/null
+++ b/package/iptables/files/firewall.awk
@@ -0,0 +1,64 @@
+BEGIN {
+	print "proto=\"$wan_proto\""
+	print "[ -z \"$proto\" -o \"$proto\" = \"none\" ] && exit"
+	print "ifname=\"$wan_ifname\""
+	print "[ -z \"$ifname\" ] && exit"
+	print ""
+	print "iptables -X input_$ifname 2>&- >&-"
+	print "iptables -N input_$ifname"
+	print "iptables -X forward_$ifname 2>&- >&-"
+	print "iptables -N forward_$ifname"
+	print "iptables -t nat -X prerouting_$ifname 2>&- >&-"
+	print "iptables -t nat -N prerouting_$ifname"
+	print ""
+	print "iptables -A input_rule -i \"$ifname\" -j input_$ifname"
+	print "iptables -A forwarding_rule -i \"$ifname\" -j forward_$ifname"
+	print "iptables -t nat -A prerouting_rule -i \"$ifname\" -j prerouting_$ifname"
+	print ""
+	FS=":"
+}
+
+($1 == "accept") || ($1 == "drop") || ($1 == "forward") {
+	delete _opt
+	str2data($2)
+	if ((_l["proto"] == "") && (_l["sport"] _l["dport"] != "")) {
+		_opt[0] = " -p tcp"
+		_opt[1] = " -p udp"
+	} else {
+		_opt[0] = ""
+	}
+}
+
+($1 == "accept") {
+	target = " -j ACCEPT"
+	for (o in _opt) {
+		print "iptables -t nat -A prerouting_$ifname" _opt[o] str2ipt($2) target
+		print "iptables        -A input_$ifname     " _opt[o] str2ipt($2) target
+		print ""
+	}
+}
+
+($1 == "drop") {
+	for (o in _opt) {
+		print "iptables -t nat -A prerouting_$ifname" _opt[o] str2ipt($2) " -j DROP"
+		print ""
+	}
+}
+
+($1 == "forward") {
+	target = " -j DNAT --to " $3
+	fwopts = ""
+	if ($4 != "") {
+		if ((_l["proto"] == "tcp") || (_l["proto"] == "udp") || (_l["proto"] == "")) {
+			if (_l["proto"] != "") fwopts = " -p " _l["proto"]
+			fwopts = fwopts " --dport " $4
+			target = target ":" $4
+		}
+		else fwopts = ""
+	}
+	for (o in _opt) {
+		print "iptables -t nat -A prerouting_$ifname" _opt[o] str2ipt($2) target
+		print "iptables        -A forward_$ifname   " _opt[o] " -d " $3 fwopts " -j ACCEPT"
+		print ""
+	}
+}
diff --git a/package/iptables/files/firewall.config b/package/iptables/files/firewall.config
new file mode 100644
index 000000000..7edd4ba4e
--- /dev/null
+++ b/package/iptables/files/firewall.config
@@ -0,0 +1,46 @@
+# RULE SYNTAX:
+#
+# forward:<match>:<target>[:<port>]
+# 	- forwards all packets matched by <match> to <target>,
+# 	  optionally changing the port to <port>
+#
+# accept:<match>
+# 	- accepts all traffic matched by <match>
+#
+# drop:<match>
+#	- drops all traffic matched by <match>
+#
+#
+# MATCHING OPTIONS:
+#
+# src=<ip>
+# 	- match the source ip <ip>
+#
+# dest=<ip>
+# 	- match the destination ip <ip>
+#
+# proto=<proto>
+# 	- match the protocol by name or number
+#
+# sport=<port(s)>
+# 	- match the source port(s), see below for syntax
+#
+# dport=<port(s)>
+# 	- match the destination port(s), see below for syntax
+#
+#
+#
+# PORT SYNTAX:
+#
+# You can enter an arbitrary list of ports and port ranges in the following format:
+#   - 22,53,993,1000-1024 
+#
+# If you don't set the protocol to tcp or udp, it will apply to both
+#
+#
+#
+# EXAMPLES:
+#
+# drop:dport=22 src=1.3.3.7
+# accept:proto=tcp dport=22
+# forward:dport=60168:192.168.1.2:60169
diff --git a/package/iptables/files/firewall.init b/package/iptables/files/firewall.init
new file mode 100755
index 000000000..3804d044f
--- /dev/null
+++ b/package/iptables/files/firewall.init
@@ -0,0 +1,95 @@
+#!/bin/sh
+
+## Please make changes in /etc/firewall.user
+
+. /etc/config/network
+WAN="$wan_ifname"
+LAN="$lan_ifname"
+
+## CLEAR TABLES
+for T in filter nat; do
+  iptables -t $T -F
+  iptables -t $T -X
+done
+
+iptables -N input_rule
+iptables -N output_rule
+iptables -N forwarding_rule
+
+iptables -t nat -N prerouting_rule
+iptables -t nat -N postrouting_rule
+
+### INPUT
+###  (connections with the router as destination)
+
+  # base case
+  iptables -P INPUT DROP
+  iptables -A INPUT -m state --state INVALID -j DROP
+  iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
+  iptables -A INPUT -p tcp --tcp-flags SYN SYN --tcp-option \! 2 -j  DROP
+
+  #
+  # insert accept rule or to jump to new accept-check table here
+  #
+  iptables -A INPUT -j input_rule
+
+  # allow
+  [ -z "$WAN" ] || iptables -A INPUT -i \! $WAN	-j ACCEPT	# allow from lan/wifi interfaces 
+  iptables -A INPUT -p icmp	-j ACCEPT	# allow ICMP
+  iptables -A INPUT -p gre	-j ACCEPT	# allow GRE
+
+  # reject (what to do with anything not allowed earlier)
+  iptables -A INPUT -p tcp -j REJECT --reject-with tcp-reset
+  iptables -A INPUT -j REJECT --reject-with icmp-port-unreachable
+
+### OUTPUT
+### (connections with the router as source)
+
+  # base case
+  iptables -P OUTPUT DROP
+  iptables -A OUTPUT -m state --state INVALID -j DROP
+  iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
+
+  #
+  # insert accept rule or to jump to new accept-check table here
+  #
+  iptables -A OUTPUT -j output_rule
+
+  # allow
+  iptables -A OUTPUT -j ACCEPT		#allow everything out
+
+  # reject (what to do with anything not allowed earlier)
+  iptables -A OUTPUT -p tcp -j REJECT --reject-with tcp-reset
+  iptables -A OUTPUT -j REJECT --reject-with icmp-port-unreachable
+
+### FORWARDING
+### (connections routed through the router)
+
+  # base case
+  iptables -P FORWARD DROP 
+  iptables -A FORWARD -m state --state INVALID -j DROP
+  iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
+  iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
+
+  #
+  # insert accept rule or to jump to new accept-check table here
+  #
+  iptables -A FORWARD -j forwarding_rule
+
+  # allow
+  iptables -A FORWARD -i br0 -o br0 -j ACCEPT
+  [ -z "$WAN" ] || iptables -A FORWARD -i $LAN -o $WAN -j ACCEPT
+
+  # reject (what to do with anything not allowed earlier)
+  # uses the default -P DROP
+
+### MASQ
+  iptables -t nat -A PREROUTING -j prerouting_rule
+  iptables -t nat -A POSTROUTING -j postrouting_rule
+  [ -z "$WAN" ] || iptables -t nat -A POSTROUTING -o $WAN -j MASQUERADE
+
+## USER RULES
+[ -f /etc/firewall.user ] && . /etc/firewall.user
+[ -n "$WAN" -a -e /etc/config/firewall ] && {
+	awk -f /usr/lib/common.awk -f /usr/lib/firewall.awk /etc/config/firewall | ash
+}
diff --git a/package/iptables/files/firewall.user b/package/iptables/files/firewall.user
new file mode 100755
index 000000000..f13f50bf6
--- /dev/null
+++ b/package/iptables/files/firewall.user
@@ -0,0 +1,31 @@
+#!/bin/sh
+. /etc/config/network
+
+WAN="$wan_ifname"
+LAN="$lan_ifname"
+
+iptables -F input_rule
+iptables -F output_rule
+iptables -F forwarding_rule
+iptables -t nat -F prerouting_rule
+iptables -t nat -F postrouting_rule
+
+### BIG FAT DISCLAIMER
+## The "-i $WAN" is used to match packets that come in via the $WAN interface.
+## it WILL NOT MATCH packets sent from the $WAN ip address -- you won't be able
+## to see the effects from within the LAN.
+
+### Open port to WAN
+## -- This allows port 22 to be answered by (dropbear on) the router
+# iptables -t nat -A prerouting_rule -i $WAN -p tcp --dport 22 -j ACCEPT 
+# iptables        -A input_rule      -i $WAN -p tcp --dport 22 -j ACCEPT
+
+### Port forwarding
+## -- This forwards port 8080 on the WAN to port 80 on 192.168.1.2
+# iptables -t nat -A prerouting_rule -i $WAN -p tcp --dport 8080 -j DNAT --to 192.168.1.2:80
+# iptables        -A forwarding_rule -i $WAN -p tcp --dport 80 -d 192.168.1.2 -j ACCEPT
+
+### DMZ
+## -- Connections to ports not handled above will be forwarded to 192.168.1.2
+# iptables -t nat -A prerouting_rule -i $WAN -j DNAT --to 192.168.1.2
+# iptables        -A forwarding_rule -i $WAN -d 192.168.1.2 -j ACCEPT