bundles/iptables: introduce, add to home.router

bundles/iptables/files/iptables-enforce

@@ -0,0 +1,85 @@
+#!/bin/bash
+
+% if not node.metadata.get('iptables', {}).get('enabled', True):
+exit 0
+% endif
+
+lock_try=0
+while ! mkdir /run/bw-iptables.lock >/dev/null 2>&1
+do
+    ((lock_try++))
+    if (( lock_try == 10 ))
+    then
+        echo 'FATAL: iptables-enforce: Could not get lock!' >&2
+        exit 1
+    fi
+    sleep 1
+done
+trap 'rmdir /run/bw-iptables.lock' EXIT
+
+iptables_both()
+{
+    iptables "$@"
+    ip6tables "$@"
+}
+
+iptables_both -P INPUT DROP
+iptables_both -P OUTPUT ACCEPT
+iptables_both -P FORWARD DROP
+iptables_both -F
+iptables_both -X
+iptables_both -t nat -F
+iptables_both -t nat -X
+iptables_both -t nat -Z
+iptables_both -t filter -F
+iptables_both -t filter -X
+iptables_both -t filter -Z
+iptables_both -t mangle -F
+iptables_both -t mangle -X
+iptables_both -t mangle -Z
+
+# Workaround for CVE-2019-11477, CVE-2019-11478 and CVE-2019-11479
+# https://www.openwall.com/lists/oss-security/2019/06/17/5
+# https://people.canonical.com/~ubuntu-security/cve/2019/CVE-2019-11477.html
+iptables_both -I INPUT -p tcp -m tcpmss --mss 1:500 -j DROP
+
+# Dummy rules to make sure the conntrack table(s) will be updated.
+iptables_both -I INPUT -m state --state NEW,ESTABLISHED,RELATED
+iptables_both -I OUTPUT -m state --state NEW,ESTABLISHED,RELATED
+iptables_both -I FORWARD -m state --state NEW,ESTABLISHED,RELATED
+
+# open up local loopback
+iptables_both -A INPUT -i lo -j ACCEPT
+
+# Set Up counting rules
+% for ip in sorted(ipv4):
+iptables -A INPUT -d ${ip}
+iptables -A OUTPUT -s ${ip}
+% endfor
+
+% for ip in sorted(ipv6):
+ip6tables -A INPUT -d ${ip}
+ip6tables -A OUTPUT -s ${ip}
+% endfor
+
+iptables -A INPUT -p ICMP --icmp-type timestamp-request -j DROP
+iptables -A INPUT -p ICMP --icmp-type timestamp-reply -j DROP
+# allow ICMP -- answers for IPv4 are covered by conntrack
+iptables -A INPUT -p icmp -j ACCEPT
+
+# ICMP6 is used for so many things, we should under no circumstances
+# ignore it and thus should not rely on any conntrack heuristics.
+ip6tables -A INPUT -p ipv6-icmp -j ACCEPT
+
+# Allow incoming answers. Install this first (before the larger ruleset
+# from /etc/network/iptables-rules.d/), so that iptables can match/exit
+# early.
+iptables_both -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
+
+shopt -s nullglob
+for i in /etc/iptables-rules.d/*
+do
+    . "$i"
+done
+
+cat /etc/sysctl.d/*.conf /etc/sysctl.conf | sysctl -e -p -