install a preliminary firewall that blocks everything, except ssh for the cases when shorewall doesn't properly come up, ensuring that it fails safe (#3339)

Change-Id: Id4f0bf6cf25f420aa2ad67635b37ae95f54e3d38

3 files changed, 89 insertions, 0 deletions

diff --git a/puppet/modules/site_config/manifests/firewall.pp b/puppet/modules/site_config/manifests/firewall.pp
new file mode 100644
index 00000000..b9fc5ffe
--- /dev/null
+++ b/puppet/modules/site_config/manifests/firewall.pp
@@ -0,0 +1,62 @@
+class site_config::initial_firewall {
+
+  # This class is intended to setup an initial firewall, before shorewall is
+  # configured. The purpose of this is for the rare case where shorewall fails
+  # to start, we should not expose services to the public.
+
+  $ssh_config = hiera('ssh')
+  $ssh_port   = $ssh_config['port']
+
+  package { 'iptables':
+    ensure => present
+  }
+
+  file {
+    # This firewall enables ssh access, dns lookups and web lookups (for
+    # package installation) but otherwise restricts all outgoing and incoming
+    # ports
+    '/etc/network/ipv4firewall_up.rules':
+      content => template('site_config/ipv4firewall_up.rules.erb'),
+      owner   => root,
+      group   => 0,
+      mode    => '0644';
+
+    # This firewall denys all ipv6 traffic - we will need to change this
+    # when we begin to support ipv6
+    '/etc/network/ipv6firewall_up.rules':
+      content => template('site_config/ipv6firewall_up.rules.erb'),
+      owner   => root,
+      group   => 0,
+      mode    => '0644';
+
+    # Run the iptables-restore in if-pre-up so that the network is locked down
+    # until the correct interfaces and ips are connected
+    '/etc/network/if-pre-up.d/ipv4tables':
+      content => "#!/bin/sh\n/sbin/iptables-restore < /etc/network/ipv4firewall_up.rules\n",
+      owner   => root,
+      group   => 0,
+      mode    => '0744';
+
+    # Same as above for IPv6
+    '/etc/network/if-pre-up.d/ipv6tables':
+      content => "#!/bin/sh\n/sbin/ip6tables-restore < /etc/network/ipv6firewall_up.rules\n",
+      owner   => root,
+      group   => 0,
+      mode    => '0744';
+  }
+
+  # Immediately setup these firewall rules, but only if shorewall is not running
+  exec {
+    'default_ipv4_firewall':
+      command   => '/sbin/iptables-restore < /etc/network/ipv4firewall_up.rules',
+      logoutput => true,
+      unless    => '/sbin/shorewall status',
+      require   => File['/etc/network/ipv4firewall_up.rules'];
+
+    'default_ipv6_firewall':
+      command   => '/sbin/ip6tables-restore < /etc/network/ipv6firewall_up.rules',
+      logoutput => true,
+      unless    => '/sbin/shorewall status',
+      require   => File['/etc/network/ipv6firewall_up.rules'];
+  }
+}
diff --git a/puppet/modules/site_config/templates/ipv4firewall_up.rules.erb b/puppet/modules/site_config/templates/ipv4firewall_up.rules.erb
new file mode 100644
index 00000000..c03716f3
--- /dev/null
+++ b/puppet/modules/site_config/templates/ipv4firewall_up.rules.erb
@@ -0,0 +1,20 @@
+# Generated by iptables-save v1.4.14 on Tue Aug 20 14:40:40 2013
+*filter
+:INPUT DROP [0:0]
+:FORWARD DROP [0:0]
+:OUTPUT DROP [0:0]
+-A INPUT -i lo -j ACCEPT
+-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
+-A INPUT -p tcp -m state --state NEW,ESTABLISHED --dport <%= @ssh_port %> -j ACCEPT
+-A INPUT -p udp -m udp --sport 53 -j ACCEPT
+-A INPUT -p icmp -m icmp --icmp-type 8 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
+-A INPUT -p icmp -m icmp --icmp-type 0 -m state --state RELATED,ESTABLISHED -j ACCEPT
+-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7
+-A OUTPUT -p icmp -m icmp --icmp-type 0 -m state --state RELATED,ESTABLISHED -j ACCEPT
+-A OUTPUT -p icmp -m icmp --icmp-type 8 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
+-A OUTPUT -p tcp -m state --state NEW,ESTABLISHED --sport <%= @ssh_port %> -j ACCEPT
+-A OUTPUT -p tcp -m state --state NEW,ESTABLISHED --dport 80 -j ACCEPT
+-A OUTPUT -p udp -m udp --dport 53 -j ACCEPT
+-A OUTPUT -p udp -m udp --dport 123 -j ACCEPT
+-A OUTPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7
+COMMIT
diff --git a/puppet/modules/site_config/templates/ipv6firewall_up.rules.erb b/puppet/modules/site_config/templates/ipv6firewall_up.rules.erb
new file mode 100644
index 00000000..e7fae52e
--- /dev/null
+++ b/puppet/modules/site_config/templates/ipv6firewall_up.rules.erb
@@ -0,0 +1,7 @@
+# Generated by ip6tables-save v1.4.20 on Tue Aug 20 12:19:43 2013
+*filter
+:INPUT DROP [24:1980]
+:FORWARD DROP [0:0]
+:OUTPUT DROP [14:8030]
+COMMIT
+# Completed on Tue Aug 20 12:19:43 2013