bookends, classify, local: Fixes for IP multicasting.

[firewall] / local.m4

diff --git a/local.m4 b/local.m4
index 0d38497..4123a77 100644 (file)
--- a/local.m4
+++ b/local.m4
@@ -1,4 +1,4 @@
-### -*-m4-*-
+### -*-sh-*-
 ###
 ### Local firewall configuration
 ###
@@ -51,6 +51,9 @@ defiface $if_trusted \
        safe:172.29.199.64/27 \
        untrusted:default
 
+## Default NTP servers.
+ntp_servers="158.152.1.76 158.152.1.204 194.159.253.2 195.173.57.232"
+
 m4_divert(60)m4_dnl
 ###--------------------------------------------------------------------------
 ### Special forwarding exemptions.
@@ -63,15 +66,48 @@ run iptables -A FORWARD -j ACCEPT \
        -p icmp ! -f --icmp-type echo-reply \
        -m mark --mark $from_untrusted/$MASK_FROM \
        -m state --state ESTABLISHED
+run ip6tables -A FORWARD -j ACCEPT \
+       -p ipv6-icmp --icmpv6-type echo-request \
+       -m ipv6header --soft ! --header frag \
+       -m mark --mark $to_untrusted/$MASK_TO
+run ip6tables -A FORWARD -j ACCEPT \
+       -p ipv6-icmp --icmpv6-type echo-reply \
+       -m ipv6header --soft ! --header frag \
+       -m mark --mark $from_untrusted/$MASK_FROM \
+       -m state --state ESTABLISHED
 
 ## Allow SSH from safe/noloop to untrusted networks.
 run iptables -A FORWARD -j ACCEPT \
-       -p tcp ! -f --destination-port $port_ssh \
+       -p tcp ! -f --destination-port $port_ssh \
        -m mark --mark $to_untrusted/$MASK_TO
 run iptables -A FORWARD -j ACCEPT \
        -p tcp ! -f --source-port $port_ssh \
        -m mark --mark $from_untrusted/$MASK_FROM \
        -m state --state ESTABLISHED
+run ip6tables -A FORWARD -j ACCEPT \
+       -p tcp --destination-port $port_ssh \
+       -m ipv6header --soft ! --header frag \
+       -m mark --mark $to_untrusted/$MASK_TO
+run ip6tables -A FORWARD -j ACCEPT \
+       -p tcp --source-port $port_ssh \
+       -m ipv6header --soft ! --header frag \
+       -m mark --mark $from_untrusted/$MASK_FROM \
+       -m state --state ESTABLISHED
+
+m4_divert(60)m4_dnl
+###--------------------------------------------------------------------------
+### Kill things we don't understand properly.
+###
+### I don't like having to do this, but since I don't know how to do proper
+### multicast filtering, I'm just going to ban it from being forwarded.
+
+errorchain poorly-understood REJECT
+
+## Ban multicast destination addresses in forwarding.
+run iptables -A FORWARD -g poorly-understood \
+       -d 224.0.0.0/4
+run ip6tables -A FORWARD -g poorly-understood \
+       -d ff::/8
 
 m4_divert(80)m4_dnl
 ###--------------------------------------------------------------------------
@@ -92,20 +128,27 @@ run iptables -A inbound -j ACCEPT \
        -s 172.29.198.0/23 \
        -p udp --source-port $port_bootpc --destination-port $port_bootps
 
+## Incoming broadcast multicast on a network interface associated with the
+## trusted network is OK, since it must have originated there (or been
+## forwarded, but we don't do that yet).
+run iptables -A inbound -j ACCEPT \
+       -s 0.0.0.0 -d 224.0.0.0/24 \
+       -i $if_trusted
+
 ## Allow incoming ping.  This is the only ICMP left.
-run iptables -A inbound -j ACCEPT -p icmp
+run ip46tables -A inbound -j ACCEPT -p icmp
 
 m4_divert(88)m4_dnl
 ## Allow unusual things.
 openports inbound
 
 ## Inspect inbound packets from untrusted sources.
-run iptables -A inbound -j forbidden
-run iptables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
+run ip46tables -A inbound -j forbidden
+run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 
 ## Otherwise process as indicated by the mark.
 for i in INPUT FORWARD; do
-  run iptables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
+  run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 done
 
 m4_divert(-1)