shorewall_code/docs/CompiledPrograms.xml

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  <!--$Id$-->

  <articleinfo>
    <title>Compiled Firewall Programs and Shorewall Lite</title>

    <authorgroup>
      <author>
        <firstname>Tom</firstname>

        <surname>Eastep</surname>
      </author>
    </authorgroup>

    <pubdate><?dbtimestamp format="Y/m/d"?></pubdate>

    <copyright>
      <year>2006-2007</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><emphasis role="bold">This article applies to Shorewall 4.0 and
    later. If you are running a version of Shorewall earlier than Shorewall
    4.0.0 then please see the documentation appropriate for your
    version.</emphasis></para>
  </caution>

  <section id="Overview">
    <title>Overview</title>

    <para>Beginning with Shorewall version 3.1, Shorewall has the capability
    to compile a Shorewall configuration and produce a runnable firewall
    program script. The script is a complete program which can be placed on a
    system with <emphasis>Shorewall Lite</emphasis> installed and can serve as
    the firewall creation script for that system.</para>

    <section id="Restrictions">
      <title>Restrictions</title>

      <para>While compiled Shorewall programs are useful in many cases, there
      are some important restrictions that you should be aware of before
      attempting to use them.</para>

      <orderedlist>
        <listitem>
          <para>The <emphasis role="bold">detectnets</emphasis> interface
          option is not supported.</para>
        </listitem>

        <listitem>
          <para>DYNAMIC_ZONES=Yes in <filename>shorewall.conf</filename> is
          not supported.</para>
        </listitem>

        <listitem>
          <para>All extension scripts used are copied into the program (with
          the exception of <ulink url="shorewall_extension_scripts.htm">those
          executed a compile-time by Shorewall-perl</ulink>). The
          ramifications of this are:</para>

          <itemizedlist>
            <listitem>
              <para>If you update an extension script, the compiled program
              will not use the updated script.</para>
            </listitem>

            <listitem>
              <para>Beginning with Shorewall 3.2.9 and 3.4.0 RC2, the
              <filename>params</filename> file is only processed at compile
              time if you set EXPORTPARAMS=No in
              <filename>shorewall.conf</filename>. For run-time setting of
              shell variables, use the <filename>init</filename> extension
              script. Although the default setting is EXPORTPARAMS=Yes for
              compatibility, the recommended setting is
              EXPORTPARAMS=No.</para>

              <para>If the <filename>params</filename> file needs to set shell
              variables based on the configuration of the firewall system, you
              can use this trick:</para>

              <programlisting>EXT_IP=$(ssh root@firewall "/sbin/shorewall-lite call find_first_interface_address eth0")</programlisting>

              <para>The <command>shorewall-lite call</command> command allows
              you to to call interactively any Shorewall function that you can
              call in an extension script.</para>
            </listitem>
          </itemizedlist>
        </listitem>

        <listitem>
          <para>You must install Shorewall Lite on the system where you want
          to run the script. You then install the compiled program in
          /usr/share/shorewall-lite/firewall and use the /sbin/shorewall-lite
          program included with Shorewall Lite to control the firewall just as
          if the full Shorewall distribution was installed.</para>
        </listitem>
      </orderedlist>
    </section>
  </section>

  <section id="Compile">
    <title>The "shorewall compile" command</title>

    <para>A compiled script is produced using the <command>compile</command>
    command:</para>

    <blockquote>
      <para><command>shorewall compile [ -e ] [ C {perl|shell} ] [
      &lt;directory name&gt; ] &lt;path name&gt;</command></para>
    </blockquote>

    <para>where</para>

    <blockquote>
      <variablelist>
        <varlistentry>
          <term>-e</term>

          <listitem>
            <para>Indicates that the program is to be "exported" to another
            system. When this flag is set, neither the "detectnets" interface
            option nor DYNAMIC_ZONES=Yes in shorewall.conf are allowed. The
            created program may be run on a system that has only Shorewall
            Lite installed</para>

            <para>When this flag is given, Shorewall does not probe the
            current system to determine the kernel/iptables features that it
            supports. It rather reads those capabilities from
            <filename>/etc/shorewall/capabilities</filename>. See below for
            details.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>-C {perl|shell}</term>

          <listitem>
            <para>Specifies the compiler to use. Overrides the
            SHOREWALL_COMPILER setting in <ulink
            url="manpages/shorewall.conf.html">shorewall.conf</ulink>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>&lt;directory name&gt;</term>

          <listitem>
            <para>specifies a directory to be searched for configuration files
            before those directories listed in the CONFIG_PATH variable in
            <filename>shorewall.conf</filename>.</para>

            <para>When -e &lt;directory-name&gt; is included, only the
            SHOREWALL_SHELL and VERBOSITY settings from
            <filename>/etc/shorewall/shorewall.conf</filename> are used and
            these apply only to the compiler itself. The settings used by the
            compiled firewall script are determined by the contents of
            <filename>&lt;directory name&gt;/shorewall.conf</filename>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>&lt;path name&gt;</term>

          <listitem>
            <para>specifies the name of the script to be created.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </blockquote>
  </section>

  <section id="Lite">
    <title>Shorewall Lite</title>

    <para>Shorewall Lite is a companion product to Shorewall and is designed
    to allow you to maintain all Shorewall configuration information on a
    single system within your network.</para>

    <orderedlist numeration="loweralpha">
      <listitem>
        <para>You install the full Shorewall release on one system within your
        network. You need not configure Shorewall there and you may totally
        disable startup of Shorewall in your init scripts. For ease of
        reference, we call this system the 'administrative system'.</para>

        <caution>
          <para>If you want to be able to allow non-root users to manage
          remote firewall systems, then the files
          <filename>/etc/shorewall/params</filename> and
          <filename>/etc/shorewall/shorewall.conf</filename> must be readable
          by all users on the administrative system. Not all packages secure
          the files that way and you may have to change the file permissions
          yourself. /sbin/shorewall uses the SHOREWALL_COMPILER setting to
          determine which compiler to launch. If the compiler is
          shorewall-shell, then the SHOREWALL_SHELL setting from
          <filename>/etc/shorewall/shorewall.conf</filename> determines the
          shell to use. /sbin/shorewall also uses the VERBOSITY setting for
          determining how much output the compiler generates. All other
          settings are taken from the <filename>shorewall.conf </filename>file
          in the remote systems <firstterm>export directory</firstterm> (see
          below).</para>
        </caution>
      </listitem>

      <listitem>
        <para>On each system where you wish to run a Shorewall-generated
        firewall, you install Shorewall Lite. For ease of reference, we will
        call these systems the 'firewall systems'.</para>

        <note>
          <para>The firewall systems do <emphasis role="bold">NOT</emphasis>
          need to have the full Shorewall product installed but rather only
          the Shorewall Lite product. Shorewall and Shorewall Lite may be
          installed on the same system but that isn't encouraged.</para>
        </note>
      </listitem>

      <listitem>
        <para>On the administrative system you create a separate 'export
        directory' for each firewall system. You copy the contents of
        /usr/share/shorewall/configfiles into each export directory.</para>
      </listitem>

      <listitem>
        <para>If you are running Debian or one of its derivatives like Ubuntu
        then edit /etc/default/shorewall-lite and set startup=1.</para>
      </listitem>

      <listitem>
        <para>On the administrative system, for each firewall system you do
        the following (this may be done by a non-root user who has root ssh
        access to the firewall system):</para>

        <orderedlist>
          <listitem>
            <para>modify the files in the corresponding export directory
            appropriately. It's a good idea to include the IP address of the
            administrative system in the <filename>routestopped</filename>
            file.</para>

            <para>It is important to understand that with Shorewall Lite, the
            firewall's export directory on the administrative system acts as
            <filename class="directory">/etc/shorewall</filename> for that
            firewall. So when the Shorewall documentation gives instructions
            for placing entries in files in the firewall's <filename
            class="directory">/etc/shorewall</filename>, when using Shorewall
            Lite you make those changes in the firewall's export directory on
            the administrative system.</para>

            <para>The CONFIG_PATH variable is treated as follows:</para>

            <itemizedlist>
              <listitem>
                <para>The value of CONFIG_PATH in
                <filename>/etc/shorewall/shorewall.conf </filename>is ignored
                when compiling for export (the -e option in given) and when
                the <command>load</command> or <command>reload</command>
                command is being executed (see below).</para>
              </listitem>

              <listitem>
                <para>The value of CONFIG_PATH in the
                <filename>shorewall.conf</filename> file in the export
                directory is used to search for configuration files during
                compilation of that configuration.</para>
              </listitem>

              <listitem>
                <para>The value of CONFIG_PATH used when the script is run on
                the firewall system is
                "/etc/shorewall-lite:/usr/share/shorewall-lite".</para>
              </listitem>
            </itemizedlist>
          </listitem>

          <listitem>
            <programlisting><command>cd &lt;export directory&gt;</command>
<command>/sbin/shorewall load -c firewall</command></programlisting>

            <para>The <ulink
            url="starting_and_stopping_shorewall.htm#Load"><command>load</command></ulink>
            command compiles a firewall script from the configuration files in
            the current working directory (using <command>shorewall compile
            -e</command>), copies that file to the remote system via scp and
            starts Shorewall Lite on the remote system via ssh. The -c option
            causes the capabilities of the remote system to be generated and
            copied to a file named capabilities in the export directory. See
            <link linkend="Shorecap">below</link>.</para>

            <para>Example (firewall's DNS name is 'gateway'):</para>

            <para><command>/sbin/shorewall load -c gateway</command></para>
          </listitem>
        </orderedlist>
      </listitem>

      <listitem>
        <para>If you later need to change the firewall's configuration, change
        the appropriate files in the firewall's export directory then:</para>

        <programlisting><command>cd &lt;export directory&gt;</command>
<command>/sbin/shorewall reload firewall</command></programlisting>

        <para>The <ulink
        url="manpages/shorewall.html"><command>reload</command></ulink>
        command compiles a firewall script from the configuration files in the
        current working directory (using <command>shorewall compile
        -e</command>), copies that file to the remote system via scp and
        restarts Shorewall Lite on the remote system via ssh. Note: In
        Shorewall 3.2.6 and later, the <emphasis role="bold">reload</emphasis>
        command also supports the '-c' option.</para>

        <para>I personally place a <filename>Makefile</filename> in each
        export directory as follows:</para>

        <blockquote>
          <programlisting>#     Shorewall Packet Filtering Firewall Export Directory Makefile - V3.3
#
#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 2006 - Tom Eastep (teastep@shorewall.net)
#
#       Shorewall documentation is available at http://www.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.
################################################################################
# Place this file in each export directory. Modify each copy to set HOST
# to the name of the remote firewall corresponding to the directory.
#
#       To make the 'firewall' script, type "make".
# 
#       Once the script is compiling correctly, you can install it by
#       typing "make install".
#  
################################################################################
#                             V A R I A B L E S
#
# Files in the export directory on which the firewall script does not depend
#
IGNOREFILES =  firewall% Makefile% trace% %~
#
# Remote Firewall system
#
HOST = gateway
#
# Save some typing
#
LITEDIR = /var/lib/shorewall-lite
#
# Set this if the remote system has a non-standard modules directory
#
MODULESDIR=
#
# Default target is the firewall script
#
################################################################################
#                                T A R G E T S
#
all: firewall
#
# Only generate the capabilities file if it doesn't already exist
#
capabilities: 
        ssh root@$(HOST) "MODULESDIR=$(MODULESDIR) /usr/share/shorewall-lite/shorecap &gt; $(LITEDIR)/capabilities"
        scp root@$(HOST):$(LITEDIR)/capabilities .
#
# Compile the firewall script. Using the 'wildcard' function causes "*" to be expanded so that
# 'filter-out' will be presented with the list of files in this directory rather than "*"
#
firewall: $(filter-out $(IGNOREFILES) capabilities , $(wildcard *) ) capabilities
        shorewall compile -e . firewall
#
# Only reload on demand.
#
install: firewall
        scp firewall firewall.conf root@$(HOST):$(LITEDIR)
        ssh root@$(HOST) "/sbin/shorewall-lite restart"
#
# Save running configuration
#
save:
        ssh root@$(HOST) "/sbin/shorewall-lite save"
#
# Remove generated files
#
clean: 
        rm -f capabilities firewall firewall.conf reload
</programlisting>
        </blockquote>

        <para>That way, after I've changed the configuration, I can simply
        type <command>make</command> or <emphasis role="bold">make
        install</emphasis>.</para>

        <note>
          <para>The above Makefile is available at <ulink
          url="http://www1.shorewall.net/pub/shorewall/contrib/Shorewall-lite/">http://www.shorewall.net/pub/shorewall/contrib/Shorewall-lite/</ulink></para>
        </note>

        <note>
          <para>I omit trace% because I often trace compiler execution while
          I'm debugging new versions of Shorewall.</para>
        </note>
      </listitem>
    </orderedlist>

    <para>There is a <filename>shorewall-lite.conf</filename> file installed
    as part of Shorewall Lite
    (<filename>/etc/shorewall-lite/shorewall-lite.conf</filename>). You can
    use that file on the firewall system to override some of the settings from
    the shorewall.conf file in the export directory.</para>

    <para>Settings that you can override are:</para>

    <blockquote>
      <simplelist>
        <member>VERBOSITY</member>

        <member>LOGFILE</member>

        <member>LOGFORMAT</member>

        <member>IPTABLES</member>

        <member>PATH</member>

        <member>SHOREWALL_SHELL</member>

        <member>SUBSYSLOCK</member>

        <member>RESTOREFILE</member>
      </simplelist>
    </blockquote>

    <para>You will normally not need to touch
    <filename>/etc/shorewall-lite/shorewall-lite.conf</filename>.</para>

    <para>The <filename>/sbin/shorewall-lite</filename> program included with
    Shorewall Lite supports the same set of commands as the
    <filename>/sbin/shorewall</filename> program in a full Shorewall
    installation with the following exceptions:</para>

    <blockquote>
      <simplelist>
        <member>add</member>

        <member>compile</member>

        <member>delete</member>

        <member>refresh</member>

        <member>reload</member>

        <member>try</member>

        <member>safe-start</member>

        <member>safe-restart</member>

        <member>show actions</member>

        <member>show macros</member>
      </simplelist>
    </blockquote>

    <para>On systems with only Shorewall Lite installed, I recommend that you
    create a symbolic link <filename>/sbin/shorewall</filename> and point it
    at <filename>/sbin/shorewall-lite</filename>. That way, you can use
    <command>shorewall</command> as the command regardless of which product is
    installed.</para>

    <blockquote>
      <programlisting><command>ln -sf shorewall-lite /sbin/shorewall</command></programlisting>
    </blockquote>

    <section id="Converting">
      <title>Converting a system from Shorewall to Shorewall Lite</title>

      <para>Converting a firewall system that is currently running Shorewall
      to run Shorewall Lite instead is straight-forward.</para>

      <orderedlist numeration="loweralpha">
        <listitem>
          <para>On the administrative system, create an export directory for
          the firewall system.</para>
        </listitem>

        <listitem>
          <para>Copy the contents of <filename
          class="directory">/etc/shorewall/</filename> from the firewall
          system to the export directory on the administrative system.</para>
        </listitem>

        <listitem>
          <para>On the firewall system:</para>

          <para>Be sure that the IP address of the administrative system is
          included in <filename>/etc/shorewall/routestopped</filename>.</para>

          <programlisting><command>shorewall stop</command></programlisting>

          <para><emphasis role="bold">We recommend that you uninstall
          Shorewall at this point.</emphasis></para>
        </listitem>

        <listitem>
          <para>Install Shorewall Lite on the firewall system.</para>

          <para>If you are running Debian or one of its derivatives like
          Ubuntu then edit /etc/default/shorewall-lite and set
          startup=1.</para>
        </listitem>

        <listitem>
          <para>On the administrative system:</para>

          <para>It's a good idea to include the IP address of the
          administrative system in the firewall system's
          <filename>routestopped</filename> file.</para>

          <para>Also, edit the shorewall.conf file in the firewall's export
          directory and change the CONFIG_PATH setting to remove <filename
          class="directory">/etc/shorewall</filename>. You can replace it with
          <filename
          class="directory">/usr/share/shorewall/configfiles</filename> if you
          like.</para>

          <para>Example:</para>

          <blockquote>
            <para>Before editing:</para>

            <programlisting>CONFIG_PATH=/etc/shorewall:/usr/share/shorewall</programlisting>

            <para>After editing:</para>

            <programlisting>CONFIG_PATH=/usr/share/shorewall/configfiles:/usr/share/shorewall</programlisting>
          </blockquote>

          <para>Changing CONFIG_PATH will ensure that subsequent compilations
          using the export directory will not include any files from <filename
          class="directory">/etc/shorewall</filename>.</para>

          <para>If you set variables in the params file, there are a couple of
          issues:</para>

          <para>Beginning with Shorewall 3.2.9 and 3.4.0 RC2, the
          <filename>params</filename> file is only processed at compile time
          if you set EXPORTPARAMS=No in <filename>shorewall.conf</filename>.
          For run-time setting of shell variables, use the
          <filename>init</filename> extension script.</para>

          <para>If the <filename>params</filename> file needs to set shell
          variables based on the configuration of the firewall system, you can
          use this trick:</para>

          <programlisting>EXT_IP=$(ssh root@firewall "/sbin/shorewall-lite call find_first_interface_address eth0")</programlisting>

          <para>The <command>shorewall-lite call</command> command allows you
          to to call interactively any Shorewall function that you can call in
          an extension script.</para>

          <para>After having made the above changes to the firewall's export
          directory, execute the following commands.</para>

          <blockquote>
            <programlisting><command>cd &lt;export directory&gt;</command>
<command>/sbin/shorewall load -c &lt;firewall system&gt;</command>
</programlisting>

            <para>Example (firewall's DNS name is 'gateway'):</para>

            <para><command>/sbin/shorewall load -c gateway</command></para>
          </blockquote>

          <para>The <ulink
          url="starting_and_stopping_shorewall.htm#Load"><command>load</command></ulink>
          command compiles a firewall script from the configuration files in
          the current working directory (using <command>shorewall compile
          -e</command>), copies that file to the remote system via scp and
          starts Shorewall Lite on the remote system via ssh.</para>
        </listitem>

        <listitem>
          <para>If you later need to change the firewall's configuration,
          change the appropriate files in the firewall's export directory
          then:</para>

          <programlisting><command>cd &lt;export directory&gt;</command>
<command>/sbin/shorewall reload firewall</command></programlisting>

          <para>The <ulink
          url="starting_and_stopping_shorewall.htm#Reload"><command>reload</command></ulink>
          command compiles a firewall script from the configuration files in
          the current working directory (using <command>shorewall compile
          -e</command>), copies that file to the remote system via scp and
          restarts Shorewall Lite on the remote system via ssh.</para>
        </listitem>

        <listitem>
          <para>If the kernel/iptables configuration on the firewall later
          changes and you need to create a new capabilities file, do the
          following:</para>

          <programlisting><command>/usr/share/shorewall-lite/shorecap &gt; capabilities</command>
<command>scp capabilities &lt;admin system&gt;:&lt;this system's config dir&gt;</command></programlisting>

          <para>Or, if you are running Shorewall 3.2.6 or later, simply use
          the -c option the next time that you use the
          <command>reload</command> command.</para>
        </listitem>
      </orderedlist>
    </section>
  </section>

  <section id="Shorecap">
    <title>The /etc/shorewall/capabilities file and the shorecap
    program</title>

    <para>As mentioned above, the /etc/shorewall/capabilities file specifies
    that kernel/iptables capabilities of the target system. Here is a sample
    file:</para>

    <blockquote>
      <programlisting>#
# Shorewall  detected the following iptables/netfilter capabilities - Fri Jul 27 14:22:31 PDT 2007
#
NAT_ENABLED=Yes
MANGLE_ENABLED=Yes
MULTIPORT=Yes
XMULTIPORT=Yes
CONNTRACK_MATCH=Yes
USEPKTTYPE=Yes
POLICY_MATCH=Yes
PHYSDEV_MATCH=Yes
LENGTH_MATCH=Yes
IPRANGE_MATCH=Yes
RECENT_MATCH=Yes
OWNER_MATCH=Yes
IPSET_MATCH=
CONNMARK=Yes
XCONNMARK=Yes
CONNMARK_MATCH=Yes
XCONNMARK_MATCH=Yes
RAW_TABLE=Yes
IPP2P_MATCH=
CLASSIFY_TARGET=Yes
ENHANCED_REJECT=Yes
KLUDGEFREE=Yes
MARK=Yes
XMARK=Yes
MANGLE_FORWARD=Yes
COMMENTS=Yes
ADDRTYPE=Yes
CAPVERSION=30405</programlisting>
    </blockquote>

    <para>As you can see, the file contains a simple list of shell variable
    assignments — the variables correspond to the capabilities listed by the
    <command>shorewall show capabilities</command> command and they appear in
    the same order as the output of that command.</para>

    <para>To aid in creating this file, Shorewall Lite includes a
    <command>shorecap</command> program. The program is installed in the
    <filename>/usr/share/shorewall-lite/</filename> directory and may be run
    as follows:</para>

    <blockquote>
      <para><command>[ IPTABLES=&lt;iptables binary&gt; ] [
      MODULESDIR=&lt;kernel modules directory&gt; ]
      /usr/share/shorewall-lite/shorecap &gt; capabilities</command></para>
    </blockquote>

    <para>The IPTABLES and MODULESDIR options have their <ulink
    url="manpages/shorewall.conf.html">usual Shorewall default
    values</ulink>.</para>

    <para>The <filename>capabilities</filename> file may then be copied to a
    system with Shorewall installed and used when compiling firewall programs
    to run on the remote system.</para>

    <para>Beginning with Shorewall Lite version 3.2.2, the capabilities file
    may also be creating using
    <filename>/sbin/shorewall-lite:</filename><blockquote>
        <para><command>shorewall-lite show -f capabilities &gt;
        capabilities</command></para>
      </blockquote></para>

    <para>Note that unlike the shorecap program, the <command>show
    capabilities</command> command shows the kernel's current capabilities; it
    does not attempt to load additional kernel modules.</para>
  </section>

  <section id="Running">
    <title>Running compiled programs directly</title>

    <para>Compiled firewall programs are complete programs that support the
    following run-line 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 ]
        refresh</command></member>

        <member><command>&lt;program&gt; [ -q ] [ -v ] [ -n ]
        reset</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. The default VERBOSITY level
    is the level specified in the shorewall.conf file used when then program
    was compiled.</para>
  </section>
</article>