mirror of
https://gitlab.com/shorewall/code.git
synced 2024-12-04 21:41:15 +01:00
016acfb9de
Signed-off-by: Tom Eastep <teastep@shorewall.net>
993 lines
39 KiB
XML
993 lines
39 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
|
|
<article>
|
|
<!--$Id$-->
|
|
|
|
<articleinfo>
|
|
<title>Xen and the Art of Consolidation</title>
|
|
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Tom</firstname>
|
|
|
|
<surname>Eastep</surname>
|
|
</author>
|
|
</authorgroup>
|
|
|
|
<pubdate><?dbtimestamp format="Y/m/d"?></pubdate>
|
|
|
|
<copyright>
|
|
<year>2006</year>
|
|
|
|
<year>2007</year>
|
|
|
|
<holder>Thomas M. Eastep</holder>
|
|
</copyright>
|
|
|
|
<legalnotice>
|
|
<para>Permission is granted to copy, distribute and/or modify this
|
|
document under the terms of the GNU Free Documentation License, Version
|
|
1.2 or any later version published by the Free Software Foundation; with
|
|
no Invariant Sections, with no Front-Cover, and with no Back-Cover
|
|
Texts. A copy of the license is included in the section entitled
|
|
<quote><ulink url="GnuCopyright.htm">GNU Free Documentation
|
|
License</ulink></quote>.</para>
|
|
</legalnotice>
|
|
</articleinfo>
|
|
|
|
<caution>
|
|
<para>This article applies to Shorewall 3.0 and later. If you are running
|
|
a version of Shorewall earlier than Shorewall 3.0.0 then please see the
|
|
documentation for that release.</para>
|
|
</caution>
|
|
|
|
<section>
|
|
<title>Xen Network Environment</title>
|
|
|
|
<para><ulink
|
|
url="http://www.cl.cam.ac.uk/Research/SRG/netos/xen/">Xen</ulink> is a
|
|
<firstterm>paravirtualization</firstterm> tool that allows you to run
|
|
multiple virtual machines on one physical machine. It is available on a
|
|
wide number of platforms and is included in recent
|
|
<trademark>SUSE</trademark> distributions.</para>
|
|
|
|
<para>Xen refers to the virtual machines as
|
|
<firstterm>Domains</firstterm>. Domains are numbered with the first domain
|
|
being domain 0, the second domain 1, and so on. Domain 0
|
|
(<firstterm>Dom0</firstterm>) is special because that is the domain
|
|
created when the machine is booted. Additional domains (called
|
|
<firstterm>DomU</firstterm>'s) are created using the <command>xm
|
|
create</command> command from within Domain 0. Additional domains can also
|
|
be created automatically at boot time by using the
|
|
<command>xendomains</command> service.</para>
|
|
|
|
<para>Xen virtualizes a network interface named <filename
|
|
class="devicefile">eth0</filename><footnote>
|
|
<para>This assumes the default Xen configuration created by
|
|
<command>xend </command>and assumes that the host system has a single
|
|
Ethernet interface named <filename
|
|
class="devicefile">eth0</filename>.</para>
|
|
</footnote>in each domain. In Dom0, Xen also creates a bridge (<filename
|
|
class="devicefile">xenbr0</filename>) and a number of virtual interfaces
|
|
as shown in the following diagram.</para>
|
|
|
|
<graphic align="center" fileref="images/Xen1.png"/>
|
|
|
|
<para>I use the term <firstterm>Extended Dom0</firstterm> to distinguish
|
|
the bridge and virtual interfaces from Dom0 itself. That distinction is
|
|
important when we try to apply Shorewall in this environment.</para>
|
|
|
|
<para>The bridge has a number of ports:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>peth0 — This is the port that connects to the physical network
|
|
interface in your system.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>vif0.0 — This is the bridge port that is used by traffic to/from
|
|
Domain 0.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>vifX.0 — This is the bridge port that is used by traffic to/from
|
|
Domain X.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</section>
|
|
|
|
<section id="Before">
|
|
<title>Before Xen</title>
|
|
|
|
<para>Prior to adopting Xen, I had a home office crowded with 5 systems,
|
|
three monitors a scanner and a printer. The systems were:</para>
|
|
|
|
<orderedlist>
|
|
<listitem>
|
|
<para>Firewall</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Public Server in a DMZ (mail)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Private Server (wookie)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>My personal Linux Desktop (ursa)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>My work system (docked laptop running Windows XP).</para>
|
|
</listitem>
|
|
</orderedlist>
|
|
|
|
<para>The result was a very crowded and noisy room.</para>
|
|
</section>
|
|
|
|
<section id="After">
|
|
<title>After Xen</title>
|
|
|
|
<para>Xen has allowed me to reduce the noise and clutter considerably. I
|
|
now have three systems with two monitors. I've also replaced the
|
|
individual printer and scanner with a Multifunction
|
|
FAX/Scanner/Printer.</para>
|
|
|
|
<para>The systems now include:</para>
|
|
|
|
<orderedlist>
|
|
<listitem>
|
|
<para>Combination Firewall/Public Server/Private Server/Wireless
|
|
Gateway using Xen (created by building out my Linux desktop
|
|
system).</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>My work system.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>My Linux desktop (wookie, which is actually the old public
|
|
server box)</para>
|
|
</listitem>
|
|
</orderedlist>
|
|
|
|
<para>Most of the Linux systems run <trademark>SUSE </trademark>10.1; my
|
|
personal Linux desktop system and our Linux Laptop run
|
|
<trademark>Ubuntu</trademark> "Dapper Drake".</para>
|
|
|
|
<para><emphasis role="bold">The configuration described below uses a
|
|
bridged Xen Networking configuration; if you want to see how to accomplish
|
|
a similar configuration using a Routed Xen configuration then please see
|
|
<ulink url="XenMyWay-Routed.html">this article</ulink>. I am now using the
|
|
routed configuration because it results in one fewer domains to
|
|
administer.</emphasis></para>
|
|
|
|
<para>Here is a high-level diagram of our network.</para>
|
|
|
|
<graphic align="center" fileref="images/Xen5.png"/>
|
|
|
|
<para>As shown in this diagram, the Xen system has three physical network
|
|
interfaces. These are:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para><filename class="devicefile">eth0</filename> -- connected to the
|
|
switch in my office. That switch is cabled to a second switch in my
|
|
wife's office where my wife has her desktop and networked printer (I
|
|
sure wish that there had been wireless back when I strung that CAT-5
|
|
cable halfway across the house).</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para><filename class="devicefile">eth1</filename> -- connected to our
|
|
DSL "Modem".</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para><filename class="devicefile">eth2</filename> -- connected to a
|
|
Wireless Access Point (WAP) that interfaces to our wireless
|
|
network.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>There are three Xen domains.</para>
|
|
|
|
<orderedlist>
|
|
<listitem>
|
|
<para>Dom0 (DNS name ursa.shorewall.net) is used as a local file
|
|
server (NFS and Samba).</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>The first DomU (Dom name <emphasis
|
|
role="bold">firewall</emphasis>, DNS name gateway.shorewall.net) is
|
|
used as our main firewall and wireless gateway.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>The second DomU (Dom name <emphasis
|
|
role="bold">lists</emphasis>, DNS name lists.shorewall.net) is used as
|
|
a public Web/FTP/Mail/DNS server.</para>
|
|
</listitem>
|
|
</orderedlist>
|
|
|
|
<para>Shorewall runs in Dom0 and in the firewall domain.</para>
|
|
|
|
<caution>
|
|
<para>As the developer of Shorewall, I have enough experience to be very
|
|
comfortable with Linux networking and Shorewall/iptables. I arrived at
|
|
this configuration after a fair amount of trial and error
|
|
experimentation. If you are a Linux networking novice, I recommend that
|
|
you do not attempt a configuration like this one for your first
|
|
Shorewall installation. You are very likely to frustrate both yourself
|
|
and the Shorewall support team. Rather I suggest that you start with
|
|
something simple like a <ulink url="standalone.htm">standalone
|
|
installation</ulink> in a domU; once you are comfortable with that then
|
|
you will be ready to try something more substantial.</para>
|
|
|
|
<para>As Paul Gear says: <emphasis>Shorewall might make iptables easy,
|
|
but it doesn't make understanding fundamental networking principles,
|
|
traffic shaping, or multi-ISP routing any easier</emphasis>.</para>
|
|
|
|
<para>The same goes for Xen networking.</para>
|
|
</caution>
|
|
|
|
<section id="Domains">
|
|
<title>Domain Configuration</title>
|
|
|
|
<para>Below are the relevant configuration files for the three domains.
|
|
I use partitions on my hard drives for DomU storage devices.</para>
|
|
|
|
<blockquote>
|
|
<para><filename>/boot/grub/menu.lst</filename> — here is the entry
|
|
that boots Xen in Dom0.</para>
|
|
|
|
<programlisting>title XEN
|
|
root (hd0,1)
|
|
kernel /boot/xen.gz dom0_mem=458752 sched=bvt
|
|
module /boot/vmlinuz-xen root=/dev/hda2 vga=0x31a selinux=0 resume=/dev/hda1 splash=silent showopts
|
|
module /boot/initrd-xen</programlisting>
|
|
|
|
<para><filename>/etc/modprobe.conf.local</filename></para>
|
|
|
|
<para><filename class="devicefile">eth1</filename> (PCI 00:09.0) and
|
|
<filename class="devicefile">eth2</filename> (PCI 00:0a.0) are
|
|
delegated to the firewall DomU where they become <filename
|
|
class="devicefile">eth3</filename> and <filename
|
|
class="devicefile">eth4</filename> respectively. The SUSE 10.1 Xen
|
|
kernel compiles pciback as a module so the instructions for PCI
|
|
delegation in the Xen Users Manual can't be followed directly (see
|
|
<ulink
|
|
url="http://wiki.xensource.com/xenwiki/Assign_hardware_to_DomU_with_PCIBack_as_module">http://wiki.xensource.com/xenwiki/Assign_hardware_to_DomU_with_PCIBack_as_module</ulink>).</para>
|
|
|
|
<programlisting>options pciback hide=(00:09.0)(00:0a.0)
|
|
install tulip /sbin/modprobe pciback ; /sbin/modprobe --first-time --ignore-install tulip
|
|
options netloop nloopbacks=1</programlisting>
|
|
|
|
<para><filename>/etc/xen/auto/01-firewall</filename> — configuration
|
|
file for the firewall domain</para>
|
|
|
|
<programlisting># -*- mode: python; -*-
|
|
|
|
# configuration name:
|
|
name = "firewall"
|
|
|
|
# usable ram:
|
|
memory = 384
|
|
|
|
# kernel and initrd:
|
|
kernel = "/xen2/vmlinuz-xen"
|
|
ramdisk = "/xen2/initrd-xen"
|
|
|
|
# boot device:
|
|
root = "/dev/hdb2"
|
|
|
|
# boot to run level:
|
|
extra = "3"
|
|
|
|
# network interface:
|
|
vif = [ 'mac=aa:cc:00:00:00:02, bridge=xenbr0', 'mac=aa:cc:00:00:00:03, bridge=xenbr1' ]
|
|
# Interfaces delegated from Dom0
|
|
pci=[ '00:09.0' , '00:0a.0' ]
|
|
|
|
# storage devices:
|
|
disk = [ 'phy:hdb2,hdb2,w' ]</programlisting>
|
|
|
|
<para><filename>/etc/xen/auto/02-lists</filename> — configuration file
|
|
for the lists domain</para>
|
|
|
|
<programlisting># -*- mode: python; -*-
|
|
|
|
# configuration name:
|
|
name = "lists"
|
|
|
|
# usable ram:
|
|
memory = 512
|
|
|
|
# kernel and initrd:
|
|
kernel = "/xen2/vmlinuz-xen"
|
|
ramdisk = "/xen2/initrd-xen"
|
|
|
|
# boot device:
|
|
root = "/dev/hda3"
|
|
|
|
# boot to run level:
|
|
extra = "3"
|
|
|
|
# network interface:
|
|
vif = [ 'mac=aa:cc:00:00:00:01, bridge=xenbr1' ]
|
|
hostname = name
|
|
|
|
# storage devices:
|
|
disk = [ 'phy:hda3,hda3,w' ]</programlisting>
|
|
</blockquote>
|
|
|
|
<para>With all three Xen domains up and running, the system looks as
|
|
shown in the following diagram.</para>
|
|
|
|
<graphic align="center" fileref="images/Xen4.png"/>
|
|
|
|
<para>The zones correspond to the Shorewall zones in the firewall DomU
|
|
configuration.</para>
|
|
|
|
<note>
|
|
<para>If you want to run a simple NAT gateway in a Xen DomU, just omit
|
|
the second bridge (xenbr1), the second delegated interface, and the
|
|
second DomU from the above configuration. You can then install the
|
|
<ulink url="two-interface.htm">normal Shorewall two-interface sample
|
|
configuration</ulink> in the DomU.</para>
|
|
</note>
|
|
|
|
<caution>
|
|
<para>Under some circumstances, UDP and/or TCP communication from a
|
|
domU won't work for no obvious reason. That happened with the
|
|
<emphasis role="bold">lists</emphasis> domain in my setup. Looking at
|
|
the IP traffic with <command>tcpdump -nvvi eth1</command> in the
|
|
<emphasis role="bold">firewall</emphasis> domU showed that UDP packets
|
|
from the <emphasis role="bold">lists</emphasis> domU had incorrect
|
|
checksums. That problem was corrected by arranging for the following
|
|
command to be executed in the <emphasis role="bold">lists</emphasis>
|
|
domain when its <filename class="devicefile">eth0</filename> device
|
|
was brought up:</para>
|
|
|
|
<para><command>ethtool -K eth0 tx off</command></para>
|
|
|
|
<para>Under SUSE 10.1, I placed the following in
|
|
<filename>/etc/sysconfig/network/if-up.d/resettx</filename> (that file
|
|
is executable):</para>
|
|
|
|
<programlisting>#!/bin/sh
|
|
|
|
if [ $2 = eth0 ]; then
|
|
ethtool -K eth0 tx off
|
|
echo "TX Checksum reset on eth0"
|
|
fi</programlisting>
|
|
|
|
<para>Under other distributions, the technique will vary. For example,
|
|
under <trademark>Debian</trademark> or <trademark>Ubuntu</trademark>,
|
|
you can just add a 'post-up' entry to
|
|
<filename>/etc/network/interfaces</filename> as shown here:</para>
|
|
|
|
<programlisting> iface eth0 inet static
|
|
address 206.124.146.177
|
|
netmask 255.255.255.0
|
|
post-up ethtool -K eth0 tx off</programlisting>
|
|
</caution>
|
|
|
|
<caution>
|
|
<para>Update. Under SUSE 10.2, communication from a domU works okay
|
|
without running ethtool <emphasis role="bold">but traffic shaping in
|
|
dom0 doesn't work!</emphasis> So it's a good idea to run it just to be
|
|
safe.</para>
|
|
</caution>
|
|
|
|
<para>SUSE 10.1 includes Xen 3.0.2 which supports PCI delegation. The
|
|
network interfaces that connect to the net and wifi zones are delegated
|
|
to the firewall DomU.</para>
|
|
|
|
<para>When Shorewall starts during bootup of Dom0, it creates the two
|
|
bridges using this <filename>/etc/shorewall/init</filename> extension
|
|
script:</para>
|
|
|
|
<blockquote>
|
|
<programlisting>for bridge in xenbr0 xenbr1; do
|
|
if [ -z "$(/sbin/brctl show 2> /dev/null | fgrep $bridge)" ]; then
|
|
/sbin/brctl addbr $bridge
|
|
/sbin/ip link set dev $bridge up
|
|
fi
|
|
done</programlisting>
|
|
</blockquote>
|
|
</section>
|
|
|
|
<section id="Dom0">
|
|
<title>Dom0 Configuration</title>
|
|
|
|
<para>The goals for the Shorewall configuration in Dom0 are as
|
|
follows:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>Allow traffic to flow unrestricted through the two bridges.
|
|
This is done by configuring the hosts connected to each bridge as a
|
|
separate zone and relying on Shorewall's implicit intra-zone ACCEPT
|
|
policy to permit traffic through the bridge.</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Ensure that there is no stray traffic between the zones. This
|
|
is a "belt+suspenders" measure since there should be no routing
|
|
between the bridges (because they don't have IP addresses).</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>The configuration is a simple one:</para>
|
|
|
|
<blockquote>
|
|
<para><filename>/etc/shorewall/zones</filename>:</para>
|
|
|
|
<programlisting>#ZONE TYPE OPTIONS IN_OPTIONS OUT_OPTIONS
|
|
fw firewall
|
|
loc ipv4
|
|
dmz ipv4</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/policy</filename> (Note the unusual use
|
|
of an ACCEPT all->all policy):</para>
|
|
|
|
<programlisting>#SOURCE DEST POLICY LOGLEVEL LIMIT
|
|
dmz all REJECT info
|
|
all dmz REJECT info
|
|
all all ACCEPT</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/interfaces</filename>:</para>
|
|
|
|
<programlisting>#ZONE INTERFACE BROADCAST OPTIONS
|
|
loc xenbr0 192.168.1.255 dhcp,routeback
|
|
dmz xenbr1 - routeback</programlisting>
|
|
</blockquote>
|
|
</section>
|
|
|
|
<section id="Firewall">
|
|
<title>Firewall DomU Configuration</title>
|
|
|
|
<para>In the firewall DomU, I run a conventional three-interface
|
|
firewall with Proxy ARP DMZ -- it is very similar to the firewall
|
|
described in the <ulink url="shorewall_setup_guide.htm">Shorewall Setup
|
|
Guide</ulink> with the exception that I've added a fourth interface for
|
|
our wireless network. The firewall runs a routed <ulink
|
|
url="OPENVPN.html">OpenVPN server</ulink> to provide road warrior access
|
|
for our two laptops and a bridged OpenVPN server for the wireless
|
|
network in our home. Here is the firewall's view of the network:</para>
|
|
|
|
<graphic align="center" fileref="images/network4.png"/>
|
|
|
|
<para>The two laptops can be directly attached to the LAN as shown above
|
|
or they can be attached wirelessly -- their IP addresses are the same in
|
|
either case; when they are directly attached, the IP address is assigned
|
|
by the DHCP server running in Dom0 and when they are attached
|
|
wirelessly, the IP address is assigned by OpenVPN.</para>
|
|
|
|
<para>The Shorewall configuration files are shown below. All routing and
|
|
secondary IP addresses are handled in the SUSE network
|
|
configuration.</para>
|
|
|
|
<blockquote>
|
|
<para>/etc/shorewall/shorewall.conf:</para>
|
|
|
|
<programlisting>STARTUP_ENABLED=Yes
|
|
VERBOSITY=0
|
|
LOGFILE=/var/log/firewall
|
|
LOGFORMAT="Shorewall:%s:%s:"
|
|
LOGTAGONLY=No
|
|
LOGRATE=
|
|
LOGBURST=
|
|
LOGALLNEW=
|
|
BLACKLIST_LOGLEVEL=
|
|
MACLIST_LOG_LEVEL=$LOG
|
|
TCP_FLAGS_LOG_LEVEL=$LOG
|
|
SMURF_LOG_LEVEL=$LOG
|
|
LOG_MARTIANS=No
|
|
IPTABLES=/usr/sbin/iptables
|
|
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin:/usr/local/sbin
|
|
SHOREWALL_SHELL=/bin/bash
|
|
SUBSYSLOCK=
|
|
MODULESDIR=
|
|
CONFIG_PATH=/etc/shorewall:/usr/share/shorewall
|
|
RESTOREFILE=standard
|
|
IPSECFILE=zones
|
|
IP_FORWARDING=On
|
|
ADD_IP_ALIASES=No
|
|
ADD_SNAT_ALIASES=No
|
|
RETAIN_ALIASES=No
|
|
TC_ENABLED=Internal
|
|
CLEAR_TC=Yes
|
|
MARK_IN_FORWARD_CHAIN=Yes
|
|
CLAMPMSS=Yes
|
|
ROUTE_FILTER=No
|
|
DETECT_DNAT_IPADDRS=Yes
|
|
MUTEX_TIMEOUT=60
|
|
ADMINISABSENTMINDED=Yes
|
|
BLACKLISTNEWONLY=Yes
|
|
DELAYBLACKLISTLOAD=No
|
|
MODULE_SUFFIX=
|
|
DISABLE_IPV6=Yes
|
|
BRIDGING=No
|
|
DYNAMIC_ZONES=No
|
|
PKTTYPE=No
|
|
MACLIST_TTL=60
|
|
SAVE_IPSETS=No
|
|
MAPOLDACTIONS=No
|
|
FASTACCEPT=Yes
|
|
BLACKLIST_DISPOSITION=DROP
|
|
MACLIST_TABLE=mangle
|
|
MACLIST_DISPOSITION=DROP
|
|
TCP_FLAGS_DISPOSITION=DROP</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/zones</filename>:</para>
|
|
|
|
<programlisting>#ZONE TYPE OPTIONS IN_OPTIONS OUT_OPTIONS
|
|
fw firewall
|
|
net ipv4 #Internet
|
|
loc ipv4 #Local wired Zone
|
|
dmz ipv4 #DMZ
|
|
vpn ipv4 #Open VPN clients
|
|
wifi ipv4 #Local Wireless Zone</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/policy</filename>:</para>
|
|
|
|
<programlisting>#SOURCE DEST POLICY LOGLEVEL LIMIT
|
|
$FW $FW ACCEPT
|
|
$FW net ACCEPT
|
|
loc net ACCEPT
|
|
$FW vpn ACCEPT
|
|
vpn net ACCEPT
|
|
vpn loc ACCEPT
|
|
loc vpn ACCEPT
|
|
$FW loc ACCEPT
|
|
wifi all REJECT $LOG
|
|
loc $FW REJECT $LOG
|
|
net $FW DROP $LOG 1/sec:2
|
|
net loc DROP $LOG 2/sec:4
|
|
net dmz DROP $LOG 8/sec:30
|
|
net vpn DROP $LOG
|
|
all all REJECT $LOG</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/params (edited)</filename>:</para>
|
|
|
|
<programlisting>MIRRORS=<comma-separated list of Shorewall mirrors>
|
|
|
|
NTPSERVERS=<comma-separated list of NTP servers I sync with>
|
|
|
|
POPSERVERS=<comma-separated list of server IP addresses>
|
|
|
|
LOG=info
|
|
|
|
INT_IF=eth0
|
|
DMZ_IF=eth1
|
|
EXT_IF=eth3
|
|
WIFI_IF=eth4
|
|
|
|
OMAK=<IP address at our second home></programlisting>
|
|
|
|
<para><filename>/etc/shorewall/init</filename>:</para>
|
|
|
|
<programlisting>echo 1 > /proc/sys/net/ipv4/netfilter/ip_conntrack_tcp_be_liberal</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/interfaces</filename>:</para>
|
|
|
|
<programlisting>#ZONE INTERFACE BROADCAST OPTIONS
|
|
net $EXT_IF 206.124.146.255 dhcp,logmartians,blacklist,tcpflags,nosmurfs
|
|
dmz $DMZ_IF 192.168.0.255 logmartians
|
|
loc $INT_IF 192.168.1.255 dhcp,routeback,logmartians
|
|
wifi $WIFI_IF 192.168.3.255 dhcp,maclist
|
|
vpn tun+ -
|
|
</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/nat</filename>:</para>
|
|
|
|
<programlisting>#EXTERNAL INTERFACE INTERNAL ALLINTS LOCAL
|
|
206.124.146.178 $EXT_IF 192.168.1.3 No No #Wookie
|
|
206.124.146.180 $EXT_IF 192.168.1.6 No No #Work LapTop
|
|
</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/masq (Note the cute trick here and in
|
|
the <filename>following proxyarp</filename> file that allows me to
|
|
access the DSL "Modem" using its default IP address
|
|
(192.168.1.1))</filename>. The leading "+" is required to place the
|
|
rule before the SNAT rules generated by entries in
|
|
<filename>/etc/shorewall/nat</filename> above.</para>
|
|
|
|
<programlisting>#INTERFACE SUBNET ADDRESS PROTO DPORT IPSEC
|
|
+$EXT_IF:192.168.1.1 0.0.0.0/0 192.168.1.254
|
|
$EXT_IF 192.168.0.0/22 206.124.146.179</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/proxyarp</filename>:</para>
|
|
|
|
<programlisting>#ADDRESS INTERFACE EXTERNAL HAVEROUTE PERSISTENT
|
|
192.168.1.1 $EXT_IF $INT_IF yes
|
|
206.124.146.177 $DMZ_IF $EXT_IF yes</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/tunnels</filename>:</para>
|
|
|
|
<programlisting>#TYPE ZONE GATEWAY GATEWAY_ZONE
|
|
openvpnserver:udp net 0.0.0.0/0 #Routed server for RoadWarrior access
|
|
openvpnserver:udp wifi 192.168.3.0/24 #Home wireless network server
|
|
</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/actions</filename>:</para>
|
|
|
|
<programlisting>#ACTION
|
|
Mirrors # Accept traffic from Shorewall Mirrors
|
|
</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/action.Mirrors</filename>:</para>
|
|
|
|
<programlisting>#TARGET SOURCE DEST PROTO PORT SPORT ORIGDEST RATE
|
|
ACCEPT $MIRRORS</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/rules</filename>:</para>
|
|
|
|
<programlisting>?SECTION NEW
|
|
###############################################################################################################################################################################
|
|
#ACTION SOURCE DEST PROTO DPORT SPORT ORIGDEST RATE USER
|
|
###############################################################################################################################################################################
|
|
REJECT:$LOG loc net tcp 25
|
|
REJECT:$LOG loc net udp 1025:1031
|
|
#
|
|
# Stop NETBIOS crap
|
|
#
|
|
REJECT loc net tcp 137,445
|
|
REJECT loc net udp 137:139
|
|
#
|
|
# Stop my idiotic work laptop from sending to the net with an HP source/dest IP address
|
|
#
|
|
DROP loc:!192.168.0.0/22 net
|
|
###############################################################################################################################################################################
|
|
# Local Network to Firewall
|
|
#
|
|
DROP loc:!192.168.0.0/22 fw # Silently drop traffic with an HP source IP from my XP box
|
|
ACCEPT loc fw tcp 22
|
|
ACCEPT loc fw tcp time,631,8080
|
|
ACCEPT loc fw udp 161,ntp,631
|
|
ACCEPT loc:192.168.1.5 fw udp 111
|
|
DROP loc fw tcp 3185 #SUSE Meta pppd
|
|
Ping(ACCEPT) loc fw
|
|
REDIRECT loc 3128 tcp 80 - !206.124.146.177
|
|
###############################################################################################################################################################################
|
|
# Road Warriors to Firewall
|
|
#
|
|
ACCEPT vpn fw tcp ssh,time,631,8080
|
|
ACCEPT vpn fw udp 161,ntp,631
|
|
Ping(ACCEPT) vpn fw
|
|
###############################################################################################################################################################################
|
|
# Road Warriors to DMZ
|
|
#
|
|
ACCEPT vpn dmz udp domain
|
|
ACCEPT vpn dmz tcp www,smtp,smtps,domain,ssh,imap,https,imaps,ftp,10023,pop3 -
|
|
Ping(ACCEPT) vpn dmz
|
|
###############################################################################################################################################################################
|
|
# Local network to DMZ
|
|
#
|
|
ACCEPT loc dmz udp domain
|
|
ACCEPT loc dmz tcp ssh,smtps,www,ftp,imaps,domain,https -
|
|
ACCEPT loc dmz tcp smtp
|
|
Trcrt(ACCEPT) loc dmz
|
|
###############################################################################################################################################################################
|
|
# Internet to ALL -- drop NewNotSyn packets
|
|
#
|
|
dropNotSyn net fw tcp
|
|
dropNotSyn net loc tcp
|
|
dropNotSyn net dmz tcp
|
|
###############################################################################################################################################################################
|
|
# Internet to DMZ
|
|
#
|
|
ACCEPT net dmz udp domain
|
|
ACCEPT net dmz tcp smtps,www,ftp,imaps,domain,https -
|
|
ACCEPT net dmz tcp smtp - 206.124.146.177,206.124.146.178
|
|
ACCEPT net dmz udp 33434:33454
|
|
Mirrors net dmz tcp rsync
|
|
Limit:$LOG:SSHA,3,60\
|
|
net dmz tcp 22
|
|
Trcrt(ACCEPT) net dmz
|
|
##############################################################################################################################################################################
|
|
#
|
|
# Net to Local
|
|
#
|
|
# When I'm "on the road", the following two rules allow me VPN access back home using PPTP.
|
|
#
|
|
DNAT net loc:192.168.1.4 tcp 1729
|
|
DNAT net loc:192.168.1.4 gre
|
|
#
|
|
# Roadwarrior access to Wookie
|
|
#
|
|
ACCEPT net:$OMAK loc tcp 22
|
|
Limit:$LOG:SSHA,3,60\
|
|
net loc tcp 22
|
|
|
|
#
|
|
# ICQ
|
|
#
|
|
ACCEPT net loc:192.168.1.3 tcp 113,4000:4100
|
|
#
|
|
# Bittorrent
|
|
#
|
|
ACCEPT net loc:192.168.1.3 tcp 6881:6889,6969
|
|
ACCEPT net loc:192.168.1.3 udp 6881:6889,6969
|
|
#
|
|
# Skype
|
|
#
|
|
ACCEPT net loc:192.168.1.6 tcp 1194
|
|
#
|
|
# Traceroute
|
|
#
|
|
Trcrt(ACCEPT) net loc:192.168.1.3
|
|
#
|
|
# Silently Handle common probes
|
|
#
|
|
REJECT net loc tcp www,ftp,https
|
|
DROP net loc icmp 8
|
|
###############################################################################################################################################################################
|
|
# DMZ to Internet
|
|
#
|
|
ACCEPT dmz net udp domain,ntp
|
|
ACCEPT dmz net tcp echo,ftp,ssh,smtp,whois,domain,www,81,https,cvspserver,2702,2703,8080
|
|
ACCEPT dmz net:$POPSERVERS tcp pop3
|
|
Ping(ACCEPT) dmz net
|
|
#
|
|
# Some FTP clients seem prone to sending the PORT command split over two packets. This prevents the FTP connection tracking
|
|
# code from processing the command and setting up the proper expectation. The following rule allows active FTP to work in these cases
|
|
# but logs the connection so I can keep an eye on this potential security hole.
|
|
#
|
|
ACCEPT:$LOG dmz net tcp 1024: 20
|
|
###############################################################################################################################################################################
|
|
# Local to DMZ
|
|
#
|
|
ACCEPT loc dmz udp domain,xdmcp
|
|
ACCEPT loc dmz tcp www,smtp,smtps,domain,ssh,imap,rsync,https,imaps,ftp,10023,pop3,3128
|
|
Trcrt(ACCEPT) loc dmz
|
|
###############################################################################################################################################################################
|
|
# DMZ to Local
|
|
#
|
|
ACCEPT dmz loc:192.168.1.5 udp 123
|
|
ACCEPT dmz loc:192.168.1.5 tcp 21
|
|
Ping(ACCEPT) dmz loc
|
|
|
|
###############################################################################################################################################################################
|
|
# DMZ to Firewall -- ntp & snmp, Silently reject Auth
|
|
#
|
|
ACCEPT dmz fw tcp 161,ssh
|
|
ACCEPT dmz fw udp 161
|
|
REJECT dmz fw tcp auth
|
|
Ping(ACCEPT) dmz fw
|
|
###############################################################################################################################################################################
|
|
# Internet to Firewall
|
|
#
|
|
REJECT net fw tcp www,ftp,https
|
|
DROP net fw icmp 8
|
|
ACCEPT net fw udp 33434:33454
|
|
ACCEPT net:$OMAK fw udp ntp
|
|
ACCEPT net fw tcp auth
|
|
ACCEPT net:$OMAK fw tcp 22
|
|
Limit:$LOG:SSHA,3,60\
|
|
net fw tcp 22
|
|
Trcrt(ACCEPT) net fw
|
|
###############################################################################################################################################################################
|
|
# Firewall to DMZ
|
|
#
|
|
ACCEPT fw dmz tcp domain,www,ftp,ssh,smtp,https,993,465
|
|
ACCEPT fw dmz udp domain
|
|
REJECT fw dmz udp 137:139
|
|
Ping(ACCEPT) fw dmz
|
|
##############################################################################################################################################################################
|
|
# Avoid logging Freenode.net probes
|
|
#
|
|
DROP net:82.96.96.3 all
|
|
</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/tcdevices</filename></para>
|
|
|
|
<programlisting>#INTERFACE IN_BANDWITH OUT_BANDWIDTH
|
|
$EXT_IF 1300kbit 384kbit</programlisting>
|
|
|
|
<para><filename>/etc/shorewall/tcclasses</filename><programlisting>#INTERFACE MARK RATE CEIL PRIORITY OPTIONS
|
|
$EXT_IF 10 5*full/10 full 1 tcp-ack,tos-minimize-delay
|
|
$EXT_IF 20 3*full/10 9*full/10 2 default
|
|
$EXT_IF 30 2*full/10 6*full/10 3</programlisting></para>
|
|
|
|
<para><filename>/etc/shorewall/mangle</filename><programlisting>#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST
|
|
CLASSIFY(1:110) 192.168.0.0/22 $EXT_IF #Our internal nets get priority
|
|
#over the server
|
|
CLASSIFY(1:130) 206.124.146.177 $EXT_IF tcp - 873 #Throttle rsync traffic to the
|
|
#Shorewall Mirrors.
|
|
</programlisting></para>
|
|
</blockquote>
|
|
|
|
<para>The tap0 device used by the bridged OpenVPN server is bridged to
|
|
eth0 using a SUSE-specific SysV init script:</para>
|
|
|
|
<blockquote>
|
|
<programlisting>#!/bin/sh
|
|
#
|
|
# The Shoreline Firewall (Shorewall) Packet Filtering Firewall - V3.0
|
|
#
|
|
# This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
|
|
#
|
|
# (c) 1999,2000,2001,2002,2003,2004,2005 - Tom Eastep (teastep@shorewall.net)
|
|
#
|
|
# On most distributions, this file should be called /etc/init.d/shorewall.
|
|
#
|
|
# Complete documentation is available at http://shorewall.net
|
|
#
|
|
# This program is free software; you can redistribute it and/or modify
|
|
# it under the terms of Version 2 of the GNU General Public License
|
|
# as published by the Free Software Foundation.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program; if not, write to the Free Software
|
|
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
#
|
|
# If an error occurs while starting or restarting the firewall, the
|
|
# firewall is automatically stopped.
|
|
#
|
|
# Commands are:
|
|
#
|
|
# bridge start Starts the bridge
|
|
# bridge restart Restarts the bridge
|
|
# bridge reload Restarts the bridge
|
|
# bridge stop Stops the bridge
|
|
# bridge status Displays bridge status
|
|
#
|
|
|
|
# chkconfig: 2345 4 99
|
|
# description: Packet filtering firewall
|
|
|
|
### BEGIN INIT INFO
|
|
# Provides: bridge
|
|
# Required-Start: boot.udev
|
|
# Required-Stop:
|
|
# Default-Start: 2 3 5
|
|
# Default-Stop: 0 1 6
|
|
# Description: starts and stops the bridge
|
|
### END INIT INFO
|
|
|
|
################################################################################
|
|
# Interfaces to be bridged -- may be listed by device name or by MAC
|
|
#
|
|
INTERFACES="eth0"
|
|
|
|
#
|
|
# Tap Devices
|
|
#
|
|
TAPS="tap0"
|
|
|
|
################################################################################
|
|
# Give Usage Information #
|
|
################################################################################
|
|
usage() {
|
|
echo "Usage: $0 start|stop|reload|restart|status"
|
|
exit 1
|
|
}
|
|
#################################################################################
|
|
# Find the interface with the passed MAC address
|
|
#################################################################################
|
|
find_interface_by_mac() {
|
|
local mac
|
|
mac=$1
|
|
local first
|
|
local second
|
|
local rest
|
|
local dev
|
|
|
|
/sbin/ip link ls | while read first second rest; do
|
|
case $first in
|
|
*:)
|
|
dev=$second
|
|
;;
|
|
*)
|
|
if [ "$second" = $mac ]; then
|
|
echo ${dev%:}
|
|
return
|
|
fi
|
|
esac
|
|
done
|
|
}
|
|
################################################################################
|
|
# Convert MAC addresses to interface names
|
|
################################################################################
|
|
get_interfaces() {
|
|
local interfaces
|
|
interfaces=
|
|
local interface
|
|
|
|
for interface in $INTERFACES; do
|
|
case $interface in
|
|
*:*:*)
|
|
interface=$(find_interface_by_mac $interface)
|
|
[ -n "$interface" ] || echo "WARNING: Can't find an interface with MAC address $mac"
|
|
;;
|
|
esac
|
|
interfaces="$interfaces $interface"
|
|
done
|
|
|
|
INTERFACES="$interfaces"
|
|
}
|
|
################################################################################
|
|
# Start the Bridge
|
|
################################################################################
|
|
do_start()
|
|
{
|
|
local interface
|
|
|
|
get_interfaces
|
|
|
|
for interface in $TAPS; do
|
|
/usr/sbin/openvpn --mktun --dev $interface
|
|
done
|
|
|
|
/sbin/brctl addbr br0
|
|
|
|
for interface in $INTERFACES $TAPS; do
|
|
/sbin/ip link set $interface up
|
|
/sbin/brctl addif br0 $interface
|
|
done
|
|
}
|
|
################################################################################
|
|
# Stop the Bridge
|
|
################################################################################
|
|
do_stop()
|
|
{
|
|
local interface
|
|
|
|
get_interfaces
|
|
|
|
for interface in $INTERFACES $TAPS; do
|
|
/sbin/brctl delif br0 $interface
|
|
/sbin/ip link set $interface down
|
|
done
|
|
|
|
/sbin/ip link set br0 down
|
|
|
|
/sbin/brctl delbr br0
|
|
|
|
for interface in $TAPS; do
|
|
/usr/sbin/openvpn --rmtun --dev $interface
|
|
done
|
|
}
|
|
################################################################################
|
|
# E X E C U T I O N B E G I N S H E R E #
|
|
################################################################################
|
|
command="$1"
|
|
|
|
case "$command" in
|
|
start)
|
|
do_start
|
|
;;
|
|
stop)
|
|
do_stop
|
|
;;
|
|
restart|reload)
|
|
do_stop
|
|
do_start
|
|
;;
|
|
status)
|
|
/sbin/brctl show
|
|
;;
|
|
*)
|
|
usage
|
|
;;
|
|
esac
|
|
</programlisting>
|
|
</blockquote>
|
|
</section>
|
|
</section>
|
|
</article>
|