radius.m4: Handy ipset hook for ad-hoc safe/unstrusted exceptions.

[firewall] / radius.m4

diff --git a/radius.m4 b/radius.m4
index 75a7700..ecf64b7 100644 (file)
--- a/radius.m4
+++ b/radius.m4
@@ -22,31 +22,9 @@
 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 ###--------------------------------------------------------------------------
-### Config settings.
-
-## This router is involved in a routing asymmetry.
-setconf(rp_filter, 0)
-setconf(log_martians, 0)
-
-###--------------------------------------------------------------------------
-### Network interfaces.
-
-m4_divert(28)m4_dnl
-## Interface definitions.
-if_dmz=eth0
-if_trusted=eth1
-if_safe=eth2
-if_untrusted=eth3
-if_vpn=$if_dmz,$if_trusted
-if_iodine=$if_dmz,$if_trusted
-if_its_mz=$if_dmz,$if_trusted
-if_its_pi=$if_dmz,$if_trusted
-
-m4_divert(-1)
-###--------------------------------------------------------------------------
 ### radius-specific rules.
 
-m4_divert(84)m4_dnl
+m4_divert(86)m4_dnl
 ## Externally visible services.
 allowservices inbound tcp \
        ident \
@@ -75,6 +53,18 @@ dnsresolver inbound
 run iptables -A inbound -j ACCEPT \
        -p $proto_ipv6 -s 216.66.80.26
 
+## Permitted special forwarding.
+makeset fwd-allow-http nethash || :
+iptables -A fwd-spec-nofrag -j ACCEPT \
+       -m set --match-set fwd-allow-http dst \
+       -p tcp --destination-port $port_http \
+       -m mark --mark $to_untrusted/$MASK_TO
+iptables -A fwd-spec-nofrag -j ACCEPT \
+       -m set --match-set fwd-allow-http src \
+       -p tcp --destination-port $port_http \
+       -m mark --mark $from_untrusted/$MASK_FROM \
+       -m state --state ESTABLISHED
+
 ## NAT for RFC1918 addresses.
 for i in PREROUTING OUTPUT POSTROUTING; do
   run iptables -t nat -P $i ACCEPT 2>/dev/null || :
@@ -84,12 +74,25 @@ run iptables -t nat -F
 run iptables -t nat -X
 
 run iptables -t nat -N outbound
-run iptables -t nat -A outbound -j RETURN ! -o $if_dmz
+run iptables -t nat -A outbound -j RETURN ! -o eth0
 run iptables -t nat -A outbound -j RETURN ! -s 172.29.198.0/23
 run iptables -t nat -A outbound -j RETURN -d 62.49.204.144/28
 run iptables -t nat -A outbound -j RETURN -d 172.29.198.0/23
 run iptables -t nat -A outbound -j SNAT --to-source 62.49.204.158
 run iptables -t nat -A POSTROUTING -j outbound
 
+## Set up NAT protocol helpers.  In particular, SIP needs some special
+## twiddling.
+run modprobe nf_conntrack_sip \
+  ports=5060 \
+  sip_direct_signalling=0 \
+  sip_direct_media=0
+for p in ftp sip h323; do
+  run modprobe nf_nat_$p
+done
+
+## Forbid anything complicated to the NAT address.
+run iptables -A INPUT -d 62.49.204.158 ! -p icmp -j REJECT
+
 m4_divert(-1)
 ###----- That's all, folks --------------------------------------------------