From: Mark Wooding <mdw@distorted.org.uk>
Date: Wed, 15 Jun 2016 00:18:52 +0000 (+0100)
Subject: fender.m4: Provide NTP service to untrusted clients.
X-Git-Url: https://git.distorted.org.uk/~mdw/firewall/commitdiff_plain/f052839bbe7c27d13051afcde167724edad6fdc9

fender.m4: Provide NTP service to untrusted clients.

e.g., national, which has been languishing...
---

diff --git a/fender.m4 b/fender.m4
index b9ce79f..5f9597d 100644
--- a/fender.m4
+++ b/fender.m4
@@ -33,6 +33,14 @@ 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 2001:470:9740::/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