shorewall_code/docs/starting_and_stopping_shorewall.xml

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<article>
<!--$Id$-->
<articleinfo>
<title>Operating Shorewall</title>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Eastep</surname>
</author>
</authorgroup>
<pubdate>2006-06-04</pubdate>
<copyright>
<year>2004</year>
<year>2005</year>
<year>2006</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><emphasis role="bold">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</emphasis>.</para>
</caution>
<section>
<title>Operational Components</title>
<para>There are a number of files that comprise the operational components
of Shorewall.</para>
<itemizedlist>
<listitem>
<para><filename>/sbin/shorewall</filename> — The program that you use
to interact with Shorewall. Normally the root user's PATH includes
<filename>/sbin</filename> and the program can be run from a shell
prompt by simply typing <command>shorewall</command> followed by a
command.</para>
<warning>
<para>In some releases of KDE, the default configuration of the
<emphasis role="bold">konsole</emphasis> program is brain dead with
respect to the "Root Console". It executes the command "su" where it
should execute "su -"; the latter will cause a login shell to be
created which will in turn set PATH properly. You can correct this
problem as follows:</para>
<orderedlist>
<listitem>
<para>Click on "Settings" on the toolbar and select "Configure
Konsole"</para>
</listitem>
<listitem>
<para>Select the "Session" tab.</para>
</listitem>
<listitem>
<para>Click on "Root Console"</para>
</listitem>
<listitem>
<para>Change the Execute command from "su" to "su -"</para>
</listitem>
<listitem>
<para>Click on "Save Session"</para>
</listitem>
<listitem>
<para>Click on "Ok"</para>
</listitem>
</orderedlist>
</warning>
<para>To see a list of supported commands, use the
<command>help</command> command:</para>
<programlisting><command>shorewall help</command></programlisting>
<para>To get further information about a particular command, follow
<command>help</command> by the command:</para>
<programlisting><command>shorewall help start</command></programlisting>
</listitem>
<listitem>
<para><filename>/etc/shorewall</filename> — The default directory
where Shorewall looks for configuration files. See the sections
entitled <link linkend="AddDirectories">Additional Configuration
Directories</link> and <link linkend="AltConfig">Alternate
Configuration Directories</link> for information about how you can
direct Shorewall to look in other directories.</para>
</listitem>
<listitem>
<para><filename>/etc/init.d/shorewall</filename>
(<filename>/etc/rc.d/firewall.rc</filename> on Slackware) — The script
run by <command>init</command> (the program responsible for startup
and shutdown of your system) to start Shorewall at boot time and to
stop Shorewall at shutdown.</para>
</listitem>
<listitem>
<para><filename>/usr/share/shorewall/compiler</filename> — In
Shorewall 3.1 and later, the program that processes your Shorewall
configuration files and creates a script to start, stop, restart,
restore and clear the firewall.</para>
</listitem>
<listitem>
<para><filename>/usr/share/shorewall/firewall</filename> — In
Shorewall 3.0 and earlier, the program responsible for configuring
Netfilter based on your configuration files. In 3.2 and later
versions, this program implements the add, delete, stop, clear and
refresh commands.</para>
</listitem>
<listitem>
<para><filename>/usr/share/shorewall/functions</filename> — A library
of Bourne Shell functions used by<filename>
/sbin/shorewall</filename>,
<filename>/usr/share/shorewall/compiler</filename> and
<filename>/usr/share/shorewall/firewall</filename>.</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Starting, Stopping and Clearing</title>
<para>As explained in the <ulink
url="Introduction.html">Introduction</ulink>, Shorewall is not something
that runs all of the time in your system. Nevertheless, for integrating
Shorewall into your initialization scripts it is useful to speak of
<firstterm>starting</firstterm> Shorewall and
<emphasis>stopping</emphasis> Shorewall.</para>
<itemizedlist>
<listitem>
<para>Shorewall is started using the <command>shorewall
start</command> command. Once the start command completes
successfully, Netfilter is configured as described in your Shorewall
configuration files. If there is an error during <command>shorewall
start</command>, then if you have a <firstterm>saved
configuration</firstterm> then that configuration is restored.
Otherwise, an implicit <command>shorewall stop</command> is
executed.</para>
<important>
<para>Beginning with Shorewall 3.1, <command>shorewall
start</command> is implemented as a <firstterm>compile and
go</firstterm>; that is, the configuration is compiled and if there
are no compilation errors then the resulting compiled script is
executed. If there are compilation errors, the command is aborted
and the state of the firewall is not altered.</para>
</important>
</listitem>
<listitem>
<para>Shorewall is stopped using the <command>shorewall stop</command>
command.</para>
<important>
<para>The <command>shorewall stop</command> command does not remove
all netfilter rules and open your firewall for all traffic to pass.
It rather places your firewall in a safe state defined by the
contents of your <ulink
url="Documentation.htm#Routestopped">/etc/shorewall/routestopped</ulink>
file and the setting of ADMINISABSENTMINDED in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>.</para>
</important>
</listitem>
<listitem>
<para>If you want to remove all Netfilter rules and open your firewall
for all traffic to pass, use the <command>shorewall clear</command>
command.</para>
</listitem>
<listitem>
<para>If you change your configuration and want to install the
changes, use the <command>shorewall restart </command>command.</para>
</listitem>
</itemizedlist>
<para>For additional information, see the<link linkend="State"> Shorewall
State Diagram</link> section.</para>
</section>
<section>
<title>Tracing Command Execution</title>
<para>If you include the word <emphasis role="bold">trace</emphasis> as
the first parameter to an <filename>/sbin/shorewall</filename> command
that transfers control to
<filename>/usr/share/shorewall/firewall</filename>, execution of the
latter program will be traced to STDERR.</para>
<example>
<title>Tracing <command>shorewall start</command></title>
<para>To trace the execution of <command>shorewall start</command> and
write the trace to the file <filename>/tmp/trace</filename>, you would
enter:<programlisting><command>shorewall trace start 2&gt; /tmp/trace</command></programlisting></para>
</example>
</section>
<section>
<title>Having Shorewall Start Automatically at Boot Time</title>
<para>The .rpm, .deb and .tgz all try to configure your startup scripts so
that Shorewall will start automatically at boot time. If you are using the
<command>install.sh </command>script from the .tgz and it cannot determine
how to configure automatic startup, a message to that effect will be
displayed. You will need to consult your distribution's documentation to
see how to integrate the <filename>/etc/init.d/shorewall</filename> script
into the distribution's startup mechanism.<caution>
<itemizedlist>
<listitem>
<para>Shorewall startup is disabled by default. Once you have
configured your firewall, you can enable startup by editing
<filename>/etc/shorewall/shorewall.conf</filename> and setting
STARTUP_ENABLED=Yes.. Note: Users of the .deb package must rather
edit <filename>/etc/default/shorewall</filename> and set
<quote>startup=1</quote>.</para>
</listitem>
<listitem>
<para>If you use dialup or some flavor of PPP where your IP
address can change arbitrarily, you may want to start the firewall
in your <command>/etc/ppp/ip-up.local</command> script. I
recommend just placing <quote><command>/sbin/shorewall
restart</command></quote> in that script.</para>
</listitem>
</itemizedlist>
</caution></para>
</section>
<section id="Saved">
<title>Saving a Working Configuration for Error Recovery and Fast
Startup</title>
<para>Once you have Shorewall working the way that you want it to, you can
use <command>shorewall save</command> to <firstterm>save</firstterm> the
commands necessary to recreate that configuration in a <firstterm>restore
script</firstterm>.</para>
<para>In its simplest form, the save command is just:</para>
<programlisting><command>shorewall save</command></programlisting>
<para>That command creates the default restore script,
<filename>/var/lib/shorewall/restore</filename>. The default may be
changed using the RESTOREFILE option in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>. A
different file name may also be specified in the <command>save</command>
command:</para>
<programlisting><command>shorewall save &lt;filename&gt;</command></programlisting>
<para>Where &lt;<emphasis>filename</emphasis>&gt; is a simple file name
(no slashes).</para>
<para>Once created, the default restore script serves several useful
purposes:</para>
<itemizedlist>
<listitem>
<para>If you change your configuration and there is an error when you
try to restart Shorewall, the restore script will be run to restore
your firewall to working order.</para>
</listitem>
<listitem>
<para>Bootup is faster. The -f option of the start command (e.g.,
<command>shorewall -f start</command>) causes Shorewall to look for
the default restore script and if it exists, the script is run. This
is much faster than starting Shorewall using the normal mechanism of
reading the configuration files and running
<command>iptables</command> dozens or even hundreds of times.
<filename>By default, /etc/init.d/shorewall</filename>
(<filename>/etc/rc.d/firewall.rc</filename>) uses the -f option when
it is processing a request to start Shorewall.</para>
</listitem>
<listitem>
<para>The <command>shorewall restore</command> command can be used at
any time to quickly configure the firewall.</para>
<programlisting><command>shorewall restore [ &lt;filename&gt; ]</command></programlisting>
<para>If no &lt;<emphasis>filename</emphasis>&gt; is given, the
default restore script is used. Otherwise, the script
<filename>/var/lib/shorewall/&lt;filename&gt;</filename> is
used.</para>
</listitem>
</itemizedlist>
<para>The ability to have multiple restore scripts means that you can save
different Shorewall firewall configurations and switch between them
quickly using the <command>restore</command> command.</para>
<para>Restore scripts may be removed using the <command>shorewall
forget</command> command:</para>
<programlisting><command>shorewall forget [ &lt;filename&gt; ]</command></programlisting>
<para>If no &lt;<emphasis>filename</emphasis>&gt; is given, the default
restore script is removed. Otherwise,
<filename>/var/lib/shorewall/&lt;filename&gt;</filename> is removed (of
course, you can also use the Linux <command>rm</command> command from the
shell prompt to remove these files).</para>
</section>
<section id="AddDirectories">
<title>Additional Configuration Directories</title>
<para>The CONFIG_PATH setting in
<filename>/etc/shorewall/shorewall.conf</filename> determines where
Shorewall looks for configuration files. The default setting is
CONFIG_PATH=<filename
class="directory">/etc/shorewall</filename>:<filename
class="directory">/usr/share/shorewall</filename> which means that
<filename class="directory">/etc/shorewall</filename> is searched first
and if the file is not found then <filename
class="directory">/usr/share/shorewall</filename> is searched. You can
change the value of CONFIG_PATH to cause additional directories to be
searched but CONFIG_PATH should <emphasis>always</emphasis> include both
<filename class="directory">/etc/shorewall</filename> and <filename
class="directory">/usr/share/shorewall</filename>.</para>
<para>When an alternate configuration directory is specified as described
in the <link linkend="AddDirectories">next section</link>, that directory
is searched <emphasis>before</emphasis> those directories listed in
CONFIG_PATH.</para>
<para>Example - Search <filename
class="directory">/etc/shorewall</filename>, <filename
class="directory">/etc/shorewall/actiondir</filename> and <filename
class="directory">/usr/share/shorewall</filename> in that order:</para>
<programlisting>CONFIG_PATH=/etc/shorewall:/etc/shorewall/actiondir:/usr/share/shorewall</programlisting>
<para>The above is the setting that I once used to allow me to place all
of my user-defined 'action.' files in <filename
class="directory">/etc/shorewall/actiondir</filename>.</para>
</section>
<section id="AltConfig">
<title>Alternate Configuration Directories</title>
<para>As explained <link linkend="AddDirectories">above</link>, Shorewall
normally looks for configuration files in the directories specified by the
CONFIG_PATH option in <filename
class="directory">/etc/shorewall/shorewall.conf</filename>. The
<command>shorewall start</command>, <command>shorewall restart</command>,
<command>shorewall check</command>, and <command>shorewall try
</command>commands allow you to specify an additional directory for
Shorewall to check before looking in the directories listed in
CONFIG_PATH.</para>
<programlisting> <command>shorewall {start|restart|check} &lt;configuration-directory&gt;</command>
<command>shorewall try &lt;configuration-directory&gt; [ &lt;timeout&gt; ]</command></programlisting>
<para>If a <emphasis>&lt;configuration-directory</emphasis>&gt; is
specified, each time that Shorewall is going to read a file, it will first
look in the<emphasis> &lt;configuration-directory&gt;</emphasis> . If the
file is present in the
<emphasis>&lt;configuration-directory&gt;,</emphasis> that file will be
used; otherwise, the directories in the CONFIG_PATH will be searched. When
changing the configuration of a production firewall, I recommend the
following:</para>
<itemizedlist>
<listitem>
<para>If you haven't saved the current working configuration, do so
using <command>shorewall save</command>.</para>
</listitem>
<listitem>
<para><command>mkdir /etc/test</command></para>
</listitem>
<listitem>
<para><command>cd /etc/test</command></para>
</listitem>
<listitem>
<para>&lt;copy any files that you need to change from /etc/shorewall
to . and change them here&gt;</para>
</listitem>
<listitem>
<para><command>shorewall check ./</command></para>
</listitem>
<listitem>
<para>&lt;correct any errors found by check and check again&gt;</para>
</listitem>
<listitem>
<para><command>shorewall restart ./</command></para>
</listitem>
</itemizedlist>
<para>If the <command>restart</command> fails, your configuration will be
restored to it's state at the last <command>shorewall
save</command>.</para>
<para>When the new configuration works then just:</para>
<itemizedlist>
<listitem>
<para><command>cp -f * /etc/shorewall</command></para>
</listitem>
<listitem>
<para><command>cd</command></para>
</listitem>
<listitem>
<para><command>rm -rf /etc/test</command></para>
</listitem>
<listitem>
<para><command>shorewall save</command></para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Command Reference</title>
<para>The general form of a command in Shorewall 3.0 is:</para>
<blockquote>
<para><command>shorewall [ &lt;options&gt; ] &lt;command&gt; [
&lt;argument&gt; ... ]</command></para>
<para>Available options are:</para>
<variablelist>
<varlistentry>
<term>-c &lt;directory&gt;</term>
<listitem>
<para>Specifies an <link linkend="AltConfig">alternate
configuration directory</link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-f</term>
<listitem>
<para>Specifies fast restart. See the <command>start</command>
command below.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-n</term>
<listitem>
<para>Prevents the command from changing the firewall system's
routing configuration.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-q</term>
<listitem>
<para>In Shorewall versions prior to 3.2.0, causes some of the
output to be suppressed.</para>
<para>In 3.2.0 and later, reduces the verbosity level (see
VERBOSITY setting in <ulink
url="Documentation.htm#Config">shorewall.conf</ulink>). May be
repeated (e.g., "-qq") with each instance reducing the verbosity
level by one.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-v</term>
<listitem>
<para>In Shorewall versions prior to 3.2.0, causes Ethernet MAC
addresses to be included in log message displays.</para>
<para>In 3.2.0 and later, increases the verbosity level (see
VERBOSITY setting in <ulink
url="Documentation.htm#Config">shorewall.conf</ulink>). May be
repeated (e.g., "-qq") with each instance increasing the verbosity
level by one.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-x</term>
<listitem>
<para>Causes all iptables -L commands to display actual packet and
byte counts.</para>
</listitem>
</varlistentry>
</variablelist>
</blockquote>
<para>The general form of a command in Shorewall 3.1 and later is:</para>
<blockquote>
<para><command>shorewall [ &lt;options&gt; ] &lt;command&gt; [
&lt;command options&gt; ] [ &lt;argument&gt; ... ]</command></para>
<para>For compatibility, Shorewall 3.1 and later accept all of the 3.0
command options. In addition, 3.1 defines some new options and also
defines command-specific options that are entered after the command on
the run-line.</para>
<para>New options are:</para>
<variablelist>
<varlistentry>
<term>-t</term>
<listitem>
<para>All progress messages are timestamped with the date and
time.</para>
</listitem>
</varlistentry>
</variablelist>
<para>In addition, the <command>-q</command> and <command>-v</command>
options may be repeated to make the output less or more verbose
respectively. The default level of verbosity is determined by the
setting of the VERBOSITY option in
<filename>/etc/shorewall/shorewall.conf</filename>.</para>
</blockquote>
<para>Following in alphabetical order are the supported commands.</para>
<variablelist>
<varlistentry>
<term>add (Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall add &lt;interface&gt;[:&lt;host-list&gt;] …
&lt;zone&gt;</command></para>
<para>A &lt;host-list&gt; is a comma-separated list whose entries
are:</para>
<itemizedlist>
<listitem>
<para>A host or network address</para>
</listitem>
<listitem>
<para>The name of a bridge port</para>
</listitem>
<listitem>
<para>The name of a bridge port followed by a colon (":") and a
host or network address.</para>
</listitem>
</itemizedlist>
<para>Adds an interface (and list of hosts if included) to a dynamic
zone usually used with VPN's.</para>
<para>Example: <command>shorewall add ipsec0:192.0.2.24
vpn1</command></para>
<para>adds the address 192.0.2.24 from interface ipsec0 to the zone
vpn1.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>allow</term>
<listitem>
<para><command>shorewall allow &lt;address&gt; ...</command></para>
<para>Re-enables receipt of packets from hosts previously
blacklisted by a drop or reject command.</para>
<para>Shorewall allow, drop, rejct and save implement dynamic
blacklisting.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>check (Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall check [ &lt;configuration-directory&gt;
]</command></para>
<para>Performs a cursory validation of the zones, interfaces, hosts,
rules, policy, masq, blacklist, proxyarp, nat and provider files.
Use this if you are unsure of any edits you have made to the
shorewall configuration. See <link linkend="AltConfig">above</link>
for a recommended way to make changes.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>clear</term>
<listitem>
<para><command>shorewall clear</command></para>
<para>Clear will remove all rules and chains installed by Shorewall.
The firewall is then wide open and unprotected. Existing connections
are untouched. Clear is often used to see if the firewall is causing
connection problems.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>compile (Shorewall 3.1 and later - Not supported by Shorewall
Lite)</term>
<listitem>
<para><command>shorewall compile [ -e ] [ &lt;directory name&gt; ]
&lt;path name&gt;</command></para>
<para>Compiles the current configuration into the executable file
&lt;path name&gt;. If &lt;path name&gt; names a file in
/var/lib/shorewall then the file may be executed using the "restore"
command.</para>
<para>When -e is specified, the compilation is being performed on a
system other than where the compiled script will run under Shorewall
Lite. This option disables certain configuration options that
require the script to be compiled where it is to be run and allows
the script to be run on a system where Shorewall Lite is installed.
The file /etc/shorewall/capabilities must be present when -e is
used; that file specifies the iptables/kernel capabilities on the
target system.</para>
<para>The compiled script is a complete program that supports the
following commands:</para>
<blockquote>
<simplelist>
<member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
start</command></member>
<member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
stop</command></member>
<member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
clear</command></member>
<member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
restart</command></member>
<member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
status</command></member>
<member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
version</command></member>
</simplelist>
</blockquote>
<para>The options have their same meaning is when they are passed to
<filename>/sbin/shorewall</filename> itself.</para>
<para>For additional information about the
<command>compile</command> command, see <ulink
url="CompiledPrograms.html">this article</ulink>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>delete (Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall delete
&lt;interface&gt;[:&lt;host-list&gt;] …
&lt;zone&gt;</command></para>
<para>A &lt;host-list&gt; is a comma-separated list whose entries
are:</para>
<itemizedlist>
<listitem>
<para>A host or network address</para>
</listitem>
<listitem>
<para>The name of a bridge port</para>
</listitem>
<listitem>
<para>The name of a bridge port followed by a colon (":") and a
host or network address.</para>
</listitem>
</itemizedlist>
<para>Deletes the specified interface (and host list if included)
from the specified zone.</para>
<para>Example:</para>
<para><command>shorewall delete ipsec0:192.0.2.24
vpn1</command></para>
<para>deletes the address 192.0.2.24 from interface ipsec0 from zone
vpn1</para>
</listitem>
</varlistentry>
<varlistentry>
<term>drop</term>
<listitem>
<para><command>shorewall drop &lt;address&gt; ...</command></para>
<para>Causes packets from the specified
&lt;<emphasis>address</emphasis>&gt; to be ignored</para>
</listitem>
</varlistentry>
<varlistentry>
<term>dump</term>
<listitem>
<para><command>shorewall [ -x ] dump</command></para>
<para>Produce a verbose report about the firewall.</para>
<para>When -x is given, that option is also passed to iptables to
display actual packet and byte counts.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>forget</term>
<listitem>
<para><command>shorewall forget [ &lt;filename&gt;
]</command></para>
<para>Deletes<filename>
/var/lib/shorewall/&lt;filename&gt;</filename>. If no
&lt;<emphasis>filename</emphasis>&gt; is given then the file
specified by RESTOREFILE in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>
is removed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>help</term>
<listitem>
<para><command>shorewall help [&lt;command&gt; | host | address
]</command></para>
<para>Display helpful information about the shorewall
commands.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>hits</term>
<listitem>
<para><command>hits</command></para>
<para>Produces several reports about the Shorewall packet log
messages in the current log file specified by the LOGFILE option in
<ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>ipcalc</term>
<listitem>
<para><command>shorewall ipcalc { &lt;address&gt; &lt;mask&gt; |
&lt;address&gt;/&lt;vlsm&gt; }</command></para>
<para>Ipcalc displays the network address, broadcast address,
network in CIDR notation and netmask corresponding to the
input[s].</para>
<para>Example:</para>
<para><command>ipcalc 192.168.1.0/24</command></para>
</listitem>
</varlistentry>
<varlistentry>
<term>iprange</term>
<listitem>
<para><command>shorewall iprange
&lt;address1&gt;-&lt;address2&gt;</command></para>
<para>Iprange decomposes the specified range of IP addresses into
the equivalent list of network/host addresses.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>logdrop</term>
<listitem>
<para><command>shorewall logdrop &lt;address&gt;
...</command></para>
<para>Causes packets from the specified
&lt;<emphasis>address</emphasis>&gt; to be ignored and logged</para>
</listitem>
</varlistentry>
<varlistentry>
<term>logwatch</term>
<listitem>
<para><command>shorewall logwatch [ -m ] [&lt;refresh
interval&gt;]</command></para>
<para>Monitors the log file specified by theLOGFILE option in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>
and produces an audible alarm when new Shorewall messages are
logged.</para>
<para>The '-m' option is available in Shorewall version 3.2.0 Beta5
and later and causes the MAC address of each packet source to be
displayed if that information is available.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>logreject</term>
<listitem>
<para><command>shorewall logreject &lt;address&gt;
...</command></para>
<para>Causes packets from the specified
&lt;<emphasis>address</emphasis>&gt; to be rejected and
logged</para>
</listitem>
</varlistentry>
<varlistentry>
<term>refresh (Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall [ -q ] refresh</command></para>
<para>The rules involving the broadcast addresses of firewall
interfaces, the black list and ECN control rules are recreated to
reflect any changes made to your configuration files. Shorewall
versions prior to 3.2.0 Beta 5 also recreate the traffic shaping
rules as part of processing the <command>refresh</command> command.
Existing connections are untouched. If -q is specified, less detail
is displayed making it easier to spot warnings.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>reject</term>
<listitem>
<para><command>shorewall reject &lt;address&gt; ...</command></para>
<para>Causes packets from the specified
&lt;<emphasis>address</emphasis>&gt;s to be rejected</para>
</listitem>
</varlistentry>
<varlistentry>
<term>reset</term>
<listitem>
<para><command>shorewall reset</command></para>
<para>All the packet and byte counters in the firewall are
reset.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>restart</term>
<listitem>
<para><command>shorewall [ -q ] restart
&lt;configuration-directory&gt;</command></para>
<para>Restart is similar to <command>shorewall stop</command>
followed by <command>shorewall start</command>. Existing connections
are maintained. If -q is specified, less detail is displayed making
it easier to spot warnings</para>
</listitem>
</varlistentry>
<varlistentry>
<term>restore</term>
<listitem>
<para><command>shorewall [ -q ] restore [ &lt;filename&gt;
]</command></para>
<para>Restore Shorewall to a state saved using the
<command>shorewall save</command> command Existing connections are
maintained. The &lt;<emphasis>filename</emphasis>&gt; names a
restore file in <filename
class="directory">/var/lib/shorewall</filename> created using
<command>shorewall save</command>; if no
&lt;<emphasis>filename</emphasis>&gt; is given then Shorewall will
be restored from the file specified by the RESTOREFILE option in
<ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>safe-restart (Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall [ -q ] safe-restart [ &lt;filename&gt;
]</command></para>
<para>Only allowed if Shorewall is running. The current
configuration is saved in
<filename>/var/lib/shorewall/safe-restart</filename> (see the
<command>save</command> command below) that a restart is done. You
will then be prompted asking if you want to accept the new
configuration or not. If you answer "n" or if you fail to answer
within 60 seconds (such as when your new configuration has disabled
communication with your terminal), the configuration is restored
from the saved configuration.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>safe-start (Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall [ -q ] safe-start [ &lt;filename&gt;
]</command></para>
<para>Shorewall is started normally. You will then be prompted
asking if everything went all right. If you answer "n" or if you
fail to answer within 60 seconds (such as when your new
configuration has disabled communication with your terminal), a
<command>shorewall clear</command> is performed for you.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>save</term>
<listitem>
<para><command>shorewall save [ &lt;filename&gt; ]</command></para>
<para>The dynamic data is stored in /var/lib/shorewall/save. The
state of the firewall is stored in
<filename>/var/lib/shorewall/&lt;filename&gt;</filename> for use by
the <command>shorewall restore</command> and <command>shorewall -f
start</command> commands. If &lt;<emphasis>filename</emphasis>&gt;
is not given then the state is saved in the file specified by the
RESTOREFILE option in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>show</term>
<listitem>
<para><command>shorewall [ -x ] show [ &lt;chain&gt; [ &lt;chain&gt;
...] |classifiers|connections|log|nat|tc|tos]</command></para>
<para><command>shorewall [ -x ] show &lt;chain&gt; [ &lt;chain&gt;
... ] </command> - produce a verbose report about the Netfilter
chain(s). (<command>iptables -L chain -n -v</command>)</para>
<para><command>shorewall [ -x ] show mangle</command> - produce a
verbose report about the mangle table. (<command>iptables -t mangle
-L -n -v</command>)</para>
<para><command>shorewall [ -x ] show nat</command> - produce a
verbose report about the nat table. (<command>iptables -t nat -L -n
-v</command>)</para>
<para><command>shorewall show [- m ] log</command> - display the
last 20 packet log entries. The '-m' option is available in
Shorewall version 3.2.0 Beta5 and later and causes the MAC address
of each packet source to be displayed if that information is
available.</para>
<para><command>shorewall show capabilities</command> - Displays your
kernel/iptables capabilities</para>
<para><command>shorewall show connections</command> - displays the
IP connections currently being tracked by the firewall.</para>
<para><command>shorewall show classifiers</command> - displays
information about the traffic control/shaping classifiers.</para>
<para><command>shorewall show tc</command> - displays information
about the traffic control/shaping configuration.</para>
<para><command>shorewall show zones</command> — Displays the
composition of each zone.</para>
<para>When -x is given, that option is also passed to iptables to
display actual packet and byte counts.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>start</term>
<listitem>
<para><command>shorewall [ -q ] [ -f ] start [
&lt;configuration-directory&gt; ]</command></para>
<para>Start shorewall. Existing connections through shorewall
managed interfaces are untouched. New connections will be allowed
only if they are allowed by the firewall rules or policies. If -q is
specified, less detail is displayed making it easier to spot
warnings If -f is specified, the saved configuration specified by
the RESTOREFILE option in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>
will be restored if that saved configuration exists</para>
</listitem>
</varlistentry>
<varlistentry>
<term>stop</term>
<listitem>
<para><command>shorewall stop</command></para>
<para>Stops the firewall. All existing connections, except those
listed in <filename><ulink
url="Documentation.htm#Routestopped">/etc/shorewall/routestopped</ulink></filename>
or permitted by the ADMINISABSENTMINDED option in <ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>,
are taken down. The only new traffic permitted through the firewall
is from systems listed in
<filename>/etc/shorewall/routestopped</filename> or by
ADMINISABSENTMINDED.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>status</term>
<listitem>
<para><command>shorewall status</command></para>
<para>Produce a short report about the firewall's status and state
relative to <link linkend="State">the diagram below</link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>try (Deprecated - Not supported by Shorewall Lite)</term>
<listitem>
<para><command>shorewall try &lt;configuration-directory&gt; [
&lt;timeout&gt; ]</command></para>
<para>Restart shorewall using the specified configuration. If an
error occurs during the restart, then another shorewall restart is
performed using the default configuration. If a timeout is specified
then the restart is always performed after the timeout occurs and
uses the default configuration.</para>
<para>When restarting using the default configuration, if the
default restore script (as specified by the RESTOREFILE setting in
<ulink
url="Documentation.htm#Conf">/etc/shorewall/shorewall.conf</ulink>)
exists. then that script is used.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>version</term>
<listitem>
<para><command>shorewall version</command></para>
<para>Show the current shorewall version</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section id="State">
<title>Shorewall State Diagram</title>
<para>The Shorewall State Diargram is depicted below.</para>
<para><graphic align="center" fileref="images/State_Diagram.png" /></para>
<para>You will note that mose of the commands that result in state
transitions use the word <quote>firewall</quote> rather than
<quote>shorewall</quote>. That is because the actual transitions are done
by <command>/usr/share/shorewall/firewall</command>;
<command>/sbin/shorewall</command> runs <quote>firewall</quote> according
to the following table:</para>
<informaltable>
<tgroup cols="3">
<thead>
<row>
<entry align="center">/sbin/shorewall Command</entry>
<entry align="center">Resulting /usr/share/shorewall/firewall
Command</entry>
<entry align="center">Effect if the Command Succeeds</entry>
</row>
</thead>
<tbody>
<row>
<entry>shorewall start</entry>
<entry>firewall start</entry>
<entry>The system filters packets based on your current Shorewall
Configuration</entry>
</row>
<row>
<entry>shorewall stop</entry>
<entry>firewall stop</entry>
<entry>Only traffic to/from hosts listed in /etc/shorewall/hosts
is passed to/from/through the firewall. If ADMINISABSENTMINDED=Yes
in /etc/shorewall/shorewall.conf then in addition, all existing
connections are retained and all connection requests from the
firewall are accepted.</entry>
</row>
<row>
<entry>shorewall restart</entry>
<entry>firewall restart</entry>
<entry>Logically equivalent to <quote>firewall stop;firewall
start</quote></entry>
</row>
<row>
<entry>shorewall add</entry>
<entry>firewall add</entry>
<entry>Adds a host or subnet to a dynamic zone</entry>
</row>
<row>
<entry>shorewall delete</entry>
<entry>firewall delete</entry>
<entry>Deletes a host or subnet from a dynamic zone</entry>
</row>
<row>
<entry>shorewall refresh</entry>
<entry>firewall refresh</entry>
<entry>Reloads rules dealing with static blacklisting, traffic
control and ECN.</entry>
</row>
<row>
<entry>shorewall reset</entry>
<entry>firewall reset</entry>
<entry>Resets traffic counters</entry>
</row>
<row>
<entry>shorewall clear</entry>
<entry>firewall clear</entry>
<entry>Removes all Shorewall rules, chains, addresses, routes and
ARP entries.</entry>
</row>
<row>
<entry>shorewall try</entry>
<entry>firewall -c &lt;new configuration&gt; restart If
unsuccessful then firewall start (standard configuration) If
timeout then firewall restart (standard configuration)</entry>
<entry></entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>The only time that a program other than
<command>/usr/share/shorewall/firewall</command> performs a state
transition itself is when it executes the <command>shorewall
restore</command> command is executed. In that case, the
<command>/var/lib/shorewall/restore</command> program sets the state to
"Started".</para>
<section>
<title>Notes for Shorewall 3.2.0 and Later</title>
<para>With any command that involves compilation, there is no state
transition while the compiler is running. If compilation fails, the
state remains unchanged.</para>
<para>Also, <command>shorewall start</command> and <command>shorewall
restart</command> involve compilation followed by execution of the
compiled script. So it is the compiled script that performs the state
transition in these commands rather than
<command>/usr/share/shorewall/firewall</command>.</para>
<para>The compiled script is placed in <filename
class="directory">/var/lib/shorewall</filename> and is named either
<filename>.start</filename> or <filename>.restart</filename> depending
on the command.</para>
</section>
</section>
</article>