shorewall_code/manpages/shorewall-policy.xml

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<refentry>
  <refmeta>
    <refentrytitle>shorewall-policy</refentrytitle>

    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>policy</refname>

    <refpurpose>Shorewall policy file</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>/etc/shorewall/policy</command>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>This file defines the high-level policy for connections between
    zones defined in /etc/shorewall/zones.</para>

    <important>
      <para>The order of entries in this file is important</para>

      <para>This file determines what to do with a new connection request if
      we don't get a match from the /etc/shorewall/rules file . For each
      source/destination pair, the file is processed in order until a match is
      found ("all" will match any client or server).</para>
    </important>

    <important>
      <para>Intra-zone policies are pre-defined</para>

      <para>For $FW and for all of the zones defined in /etc/shorewall/zones,
      the POLICY for connections from the zone to itself is ACCEPT (with no
      logging or TCP connection rate limiting but may be overridden by an
      entry in this file. The overriding entry must be explicit (cannot use
      "all" in the SOURCE or DEST).</para>

      <para>Similarly, if you have IMPLICIT_CONTINUE=Yes in shorewall.conf,
      then the implicit policy to/from any sub-zone is CONTINUE. These
      implicit CONTINUE policies may also be overridden by an explicit entry
      in this file.</para>
    </important>

    <para>The columns in the file are as follows.</para>

    <variablelist>
      <varlistentry>
        <term><emphasis role="bold">SOURCE</emphasis></term>

        <listitem>
          <para>Source zone. Must be the name of a zone defined in
          /etc/shorewall/zones, $FW or "all".</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">DEST</emphasis></term>

        <listitem>
          <para>Destination zone. Must be the name of a zone defined in
          /etc/shorewall/zones, $FW or "all"</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">POLICY</emphasis></term>

        <listitem>
          <para>Policy if no match from the rules file is found. Must be
          "ACCEPT", "DROP", "REJECT", "CONTINUE" or "NONE".</para>

          <variablelist>
            <varlistentry>
              <term><emphasis role="bold">ACCEPT</emphasis></term>

              <listitem>
                <para>Accept the connection.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">DROP</emphasis></term>

              <listitem>
                <para>Ignore the connection request.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">REJECT</emphasis></term>

              <listitem>
                <para>For TCP, send RST. For all other, send an "unreachable"
                ICMP.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">CONTINUE</emphasis></term>

              <listitem>
                <para>Pass the connection request past any other rules that it
                might also match (where the source or destination zone in
                those rules is a superset of the SOURCE or DEST in this
                policy).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">NONE</emphasis></term>

              <listitem>
                <para>Assume that there will never be any packets from this
                SOURCE to this DEST. Shorewall will not create any
                infrastructure to handle such packets and you may not have any
                rules with this SOURCE and DEST in the /etc/shorewall/rules
                file. If such a packet <emphasis role="bold">is</emphasis>
                received, the result is undefined. NONE may not be used if the
                SOURCE or DEST columns contain the firewall zone ($FW) or
                "all".</para>
              </listitem>
            </varlistentry>
          </variablelist>

          <para>If the policy is DROP or REJECT then the policy may be
          followed by ":" and one of the following:</para>

          <orderedlist numeration="loweralpha">
            <listitem>
              <para>The word "None" or "none". This causes any default action
              defined in /etc/shorewall/shorewall.conf to be omitted for this
              policy.</para>
            </listitem>

            <listitem>
              <para>The name of an action (requires that USE_ACTIONS=Yes in
              shorewall.conf). That action will be invoked before the policy
              is enforced.</para>
            </listitem>

            <listitem>
              <para>The name of a macro. The rules in that macro will be
              applied before the policy is enforced. This does not require
              USE_ACTIONS=Yes.</para>
            </listitem>
          </orderedlist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">LOG LEVEL</emphasis> (Optional)</term>

        <listitem>
          <para>If supplied, each connection handled under the default POLICY
          is logged at that level. If not supplied, no log message is
          generated. See syslog.conf(5) for a description of log
          levels.</para>

          <para>You may also specify ULOG (must be in upper case). This will
          log to the ULOG target and will send to a separate log through use
          of ulogd (http://www.gnumonks.org/projects/ulogd).</para>

          <para>If you don't want to log but need to specify the following
          column, place "-" here.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">BURST:LIMIT</emphasis></term>

        <listitem>
          <para>If passed, specifies the maximum TCP connection rate and the
          size of an acceptable burst. If not specified, TCP connections are
          not limited.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Example</title>

    <orderedlist numeration="loweralpha">
      <listitem>
        <para>All connections from the local network to the internet are
        allowed</para>
      </listitem>

      <listitem>
        <para>All connections from the internet are ignored but logged at
        syslog level KERNEL.INFO.</para>
      </listitem>

      <listitem>
        <para>All other connection requests are rejected and logged at level
        KERNEL.INFO.</para>
      </listitem>
    </orderedlist>

    <programlisting>#SOURCE         DEST            POLICY          LOG           BURST:LIMIT
#                                               LEVEL
loc             net             ACCEPT
net             all             DROP            info
#
# THE FOLLOWING POLICY MUST BE LAST
#
all             all             REJECT          info</programlisting>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <para>/etc/shorewall/policy</para>
  </refsect1>

  <refsect1>
    <title>See ALSO</title>

    <para><ulink
    url="http://shorewall.net/Documentation.htm#Policy">http://shorewall.net/Documentation.htm#Policy</ulink></para>

    <para>shorewall(8), shorewall-accounting(5), shorewall-actions(5),
    shorewall-blacklist(5), shorewall-hosts(5), shorewall-interfaces(5),
    shorewall-ipsec(5), shorewall-maclist(5), shorewall-masq(5),
    shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
    shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5),
    shorewall-route_routes(5), shorewall-routestopped(5), shorewall-rules(5),
    shorewall.conf(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
    shorewall-tcrules(5), shorewall-tos(5), shorewall-tunnels(5),
    shorewall-zones(5)</para>
  </refsect1>
</refentry>