X-Git-Url: https://git.distorted.org.uk/~mdw/firewall/blobdiff_plain/78af294cd1005453cf8b7a0dda4593ba101b345e..994ac8d0782c89a636f47b02a2dc096c72ff58c5:/fender.m4

diff --git a/fender.m4 b/fender.m4
index 05354bd..00375a2 100644
--- a/fender.m4
+++ b/fender.m4
@@ -24,7 +24,7 @@
 ###--------------------------------------------------------------------------
 ### fender-specific rules.
 
-m4_divert(82)m4_dnl
+m4_divert(86)m4_dnl
 ## Externally visible services.
 allowservices inbound tcp \
 	ssh \
@@ -33,5 +33,66 @@ allowservices inbound tcp \
 ## We have to provide NTP service.  The guests sync to our clock.
 ntpclient inbound $ntp_servers
 
+## Provide NTP service to untrusted clients.
+iptables -A inbound -p udp -j ACCEPT \
+	--source-port 123 --destination-port 123 \
+	-s 172.29.198.0/23
+ip6tables -A inbound -p udp -j ACCEPT \
+	--source-port 123 --destination-port 123 \
+	-s 2001:ba8:1d9::/48
+ip6tables -A inbound -p udp -j ACCEPT \
+	--source-port 123 --destination-port 123 \
+	-s 2001:8b0:c92::/48
+
+## Guaranteed black hole.  Put this at the very front of the chain.
+run iptables -I INPUT -d 212.13.198.78 -j DROP
+run ip6tables -I INPUT -d 2001:ba8:0:1d9::ffff -j DROP
+
+## Ethernet bridge-level filtering for source addresses.
+run ebtables -F
+for i in log limit ip ip6; do run modprobe ebt-$i; done
+
+for c in bad-source-addr check-eth0 bcp38 check-bcp38; do
+  run ebtables -X $c >/dev/null 2>&1 || :
+done
+
+for ch in bad-source-addr bcp38; do
+  run ebtables -N $ch
+  run ebtables -A $ch \
+	  --limit 20/second --limit-burst 100 \
+	  --log-prefix "fw: $ch(br)" --log-ip --log-ip6
+  run ebtables -A $ch -j DROP
+done
+
+run ebtables -N check-eth0
+run ebtables -A check-eth0 -j RETURN -p ip --ip-source ! 212.13.198.64/28
+run ebtables -A check-eth0 -j RETURN -p ip6 --ip6-source 2001:ba8:0:1d9::1
+run ebtables -A check-eth0 -j bad-source-addr \
+	-p ip6 --ip6-source 2001:ba8:1d9::/48
+run ebtables -A check-eth0 -j bad-source-addr \
+	-p ip6 --ip6-source 2001:ba8:0:1d9::/64
+run ebtables -A check-eth0 -j RETURN -p ip6
+run ebtables -A check-eth0 -j RETURN -p ip --ip-source 212.13.198.64/30
+run ebtables -A check-eth0 -j RETURN -p ip --ip-source 212.13.198.68
+run ebtables -A check-eth0 -j bad-source-addr -p ip
+run ebtables -A INPUT -j check-eth0 -i bond0
+run ebtables -A FORWARD -j check-eth0 -i bond0
+
+run ebtables -N check-bcp38
+run ebtables -A check-bcp38 -j RETURN -p ip --ip-source 212.13.198.64/28
+run ebtables -A check-bcp38 -j bcp38 -p ip
+run ebtables -A check-bcp38 -j RETURN -p ip6 --ip6-source 2001:ba8:0:1d9::/64
+run ebtables -A check-bcp38 -j RETURN -p ip6 --ip6-source 2001:ba8:1d9::/48
+run ebtables -A check-bcp38 -j RETURN -p ip6 --ip6-source fe80::/10
+run ebtables -A check-bcp38 -j bcp38 -p ip6
+run ebtables -A FORWARD -j check-bcp38 -o bond0
+
+## There's a hideous bug in Linux 3.2.51-1's ebtables: for some reason it
+## misparses (at least) locally originated multicast packets, and tries to
+## extract IP header fields relative to the start of the Ethernet frame.  The
+## result is obviously a hideous mess.  Don't try to do BCP38 checking for
+## locally originated packets until this is fixed.
+##run ebtables -A OUTPUT -j check-bcp38 -o bond0
+
 m4_divert(-1)
 ###----- That's all, folks --------------------------------------------------