X-Git-Url: https://git.distorted.org.uk/~mdw/firewall/blobdiff_plain/7dde20fa84bad82640c029a7c41e213a576d777a..2cc301c282ec3617e909b4ccc0f266cc759c1ebd:/radius.m4

diff --git a/radius.m4 b/radius.m4
index 180b8ac..090249c 100644
--- a/radius.m4
+++ b/radius.m4
@@ -57,6 +57,12 @@ iptables -A fwd-spec-nofrag -j ACCEPT \
 	-m mark --mark $from_untrusted/$MASK_FROM \
 	-m state --state ESTABLISHED
 
+## BCP38 filtering.  Note that addresses here are seen before NAT is applied.
+bcp38 4 ppp0 62.49.204.144/28 172.29.198.0/23
+bcp38 6 t6-he \
+	2001:470:1f08:1b98::2 2001:470:1f09:1b98::/64 \
+	2001:470:9740::/48
+
 ## NAT for RFC1918 addresses.
 for i in PREROUTING OUTPUT POSTROUTING; do
   run iptables -t nat -P $i ACCEPT 2>/dev/null || :
@@ -66,13 +72,18 @@ 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 eth0
+run iptables -t nat -A outbound -j RETURN ! -o ppp0
 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
 
+## TCP MSS clamping to help given Demon's sluggish approach to fragmentation-
+## needed errors.
+run ip46tables -t mangle -A FORWARD -o ppp0 -p tcp --tcp-flags SYN,RST SYN \
+	-j TCPMSS --clamp-mss-to-pmtu
+
 ## Set up NAT protocol helpers.  In particular, SIP needs some special
 ## twiddling.
 run modprobe nf_conntrack_sip \
@@ -83,7 +94,10 @@ for p in ftp sip h323; do
   run modprobe nf_nat_$p
 done
 
-## Forbid anything complicated to the NAT address.
+## Forbid anything complicated to the NAT address.  Be sure to allow ident,
+## though.
+run iptables -A INPUT -d 62.49.204.158 -p tcp -j ACCEPT \
+	-m multiport --destination-ports=113
 run iptables -A INPUT -d 62.49.204.158 ! -p icmp -j REJECT
 
 m4_divert(-1)