shorewall_code/manpages6/shorewall6-rules.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
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<refentry>
  <refmeta>
    <refentrytitle>shorewall6-rules</refentrytitle>

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

  <refnamediv>
    <refname>rules</refname>

    <refpurpose>Shorewall6 rules file</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>/etc/shorewall6/rules</command>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>Entries in this file govern connection establishment by defining
    exceptions to the policies layed out in <ulink
    url="shorewall6-policy.html">shorewall6-policy</ulink>(5). By default,
    subsequent requests and responses are automatically allowed using
    connection tracking. For any particular (source,dest) pair of zones, the
    rules are evaluated in the order in which they appear in this file and the
    first terminating match is the one that determines the disposition of the
    request. All rules are terminating except LOG and QUEUE rules.</para>

    <para>The rules file is divided into sections. Each section is introduced
    by a "Section Header" which is a line beginning with SECTION and followed
    by the section name.</para>

    <para>Sections are as follows and must appear in the order listed:</para>

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

        <listitem>
          <para>This section was added in Shorewall 4.4.23. rules in this
          section are applied, regardless of the connection tracking state of
          the packet.</para>
        </listitem>
      </varlistentry>

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

        <listitem>
          <para>Packets in the ESTABLISHED state are processed by rules in
          this section.</para>

          <para>The only ACTIONs allowed in this section are ACCEPT, DROP,
          REJECT, LOG and QUEUE</para>

          <para>There is an implicit ACCEPT rule inserted at the end of this
          section.</para>
        </listitem>
      </varlistentry>

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

        <listitem>
          <para>Packets in the RELATED state are processed by rules in this
          section.</para>

          <para>The only ACTIONs allowed in this section are ACCEPT, DROP,
          REJECT, LOG and QUEUE</para>

          <para>There is an implicit ACCEPT rule inserted at the end of this
          section.</para>
        </listitem>
      </varlistentry>

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

        <listitem>
          <para>Packets in the NEW, INVALID and UNTRACKED states are processed
          by rules in this section.</para>
        </listitem>
      </varlistentry>
    </variablelist>

    <note>
      <para>If you are not familiar with Netfilter to the point where you are
      comfortable with the differences between the various connection tracking
      states, then it is suggested that you omit the <emphasis
      role="bold">ESTABLISHED</emphasis> and <emphasis
      role="bold">RELATED</emphasis> sections and place all of your rules in
      the NEW section (That's after the line that reads SECTION NEW').</para>
    </note>

    <warning>
      <para>If you specify FASTACCEPT=Yes in <ulink
      url="shorewall6.conf.html">shorewall6.conf</ulink>(5) then the <emphasis
      role="bold">ESTABLISHED</emphasis> and <emphasis
      role="bold">RELATED</emphasis> sections must be empty.</para>
    </warning>

    <para>You may omit any section that you don't need. If no Section Headers
    appear in the file then all rules are assumed to be in the NEW
    section.</para>

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

    <variablelist>
      <varlistentry>
        <term><emphasis role="bold">ACTION</emphasis> - {<emphasis
        role="bold">ACCEPT</emphasis>[<emphasis
        role="bold"><option>+</option>|<option>!</option></emphasis>]|<emphasis
        role="bold">DROP[<option>!</option>]</emphasis>|<emphasis
        role="bold">REJECT</emphasis>[<option>!</option>]|<emphasis
        role="bold">DNAT</emphasis>[<emphasis
        role="bold">-</emphasis>]|<emphasis
        role="bold">SAME</emphasis>[<emphasis
        role="bold">-</emphasis>]|<emphasis
        role="bold">CONTINUE</emphasis>[<option>!</option>]|<emphasis
        role="bold">LOG</emphasis>|<emphasis
        role="bold">QUEUE</emphasis>[<option>!</option>]|<emphasis
        role="bold">NFQUEUE</emphasis>[<emphasis
        role="bold">(</emphasis><emphasis>queuenumber</emphasis><emphasis
        role="bold">)</emphasis>]<emphasis
        role="bold">|COMMENT</emphasis>|<emphasis>action</emphasis>|<emphasis>macro</emphasis>[<emphasis
        role="bold">(</emphasis><emphasis>target</emphasis><emphasis
        role="bold">)</emphasis>]}<emphasis
        role="bold">[:</emphasis>{<emphasis>log-level</emphasis>|<emphasis
        role="bold">none</emphasis>}[<emphasis role="bold"><emphasis
        role="bold">!</emphasis></emphasis>][<emphasis
        role="bold">:</emphasis><emphasis>tag</emphasis>]]</term>

        <listitem>
          <para>Specifies the action to be taken if the connection request
          matches the rule. Must be one of the following.</para>

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

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

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

              <listitem>
                <para>like ACCEPT but exempts the rule from being suppressed
                by OPTIMIZE=1 in <ulink
                url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>A_ACCEPT and A_ACCEPT!</term>

              <listitem>
                <para>Added in Shorewall 4.4.20. Audited versions of ACCEPT
                and ACCEPT! respectively. Require AUDIT_TARGET support in the
                kernel and ip6tables.</para>
              </listitem>
            </varlistentry>

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

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

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

              <listitem>
                <para>like DROP but exempts the rule from being suppressed by
                OPTIMIZE=1 in <ulink
                url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>A_DROP and A_DROP!</term>

              <listitem>
                <para>Added in Shorewall 4.4.20. Audited versions of DROP and
                DROP! respectively. Require AUDIT_TARGET support in the kernel
                and ip6tables.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>disallow the request and return an icmp-unreachable or
                an RST packet.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>like REJECT but exempts the rule from being suppressed
                by OPTIMIZE=1 in <ulink
                url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>A_REJECT AND A_REJECT!</term>

              <listitem>
                <para>Added in Shorewall 4.4.20. Audited versions of REJECT
                and REJECT! respectively. Require AUDIT_TARGET support in the
                kernel and ip6tables.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>For experts only.</para>

                <para>Do not process any of the following rules for this
                (source zone,destination zone). If the source and/or
                destination IP address falls into a zone defined later in
                <ulink url="shorewall6-zones.html">shorewall6-zones</ulink>(5)
                or in a parent zone of the source or destination zones, then
                this connection request will be passed to the rules defined
                for that (those) zone(s). See <ulink
                url="shorewall6-nesting.html">shorewall6-nesting</ulink>(5)
                for additional information.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>like CONTINUE but exempts the rule from being suppressed
                by OPTIMIZE=1 in <ulink
                url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Simply log the packet and continue with the next
                rule.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Queue the packet to a user-space application such as
                ftwall (http://p2pwall.sf.net). The application may reinsert
                the packet for further processing.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">QUEUE!</emphasis></term>

              <listitem>
                <para>like QUEUE but exempts the rule from being suppressed by
                OPTIMIZE=1 in <ulink
                url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis
              role="bold">NFLOG</emphasis>[(<replaceable>nflog-parameters</replaceable>)]</term>

              <listitem>
                <para>queues matching packets to a backend logging daemon via
                a netlink socket then continues to the next rule. See <ulink
                url="http://www.shorewall.net/shorewall.logging.html">http://www.shorewall.net/shorewall_logging.html</ulink>.</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>Queues the packet to a user-space application using the
                nfnetlink_queue mechanism. If a
                <replaceable>queuenumber</replaceable> is not specified, queue
                zero (0) is assumed.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">NFQUEUE!</emphasis></term>

              <listitem>
                <para>like NFQUEUE but exempts the rule from being suppressed
                by OPTIMIZE=1 in <ulink
                url="shorewall6.conf.html">shorewall6.conf</ulink>(5).</para>
              </listitem>
            </varlistentry>

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

              <listitem>
                <para>the rest of the line will be attached as a comment to
                the Netfilter rule(s) generated by the following entries. The
                comment will appear delimited by "/* ... */" in the output of
                "shorewall6 show &lt;chain&gt;". To stop the comment from
                being attached to further rules, simply include COMMENT on a
                line by itself.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis>action</emphasis></term>

              <listitem>
                <para>The name of an <emphasis>action</emphasis> declared in
                <ulink
                url="shorewall6-actions.html">shorewall6-actions</ulink>(5) or
                in /usr/share/shorewall6/actions.std.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis>macro</emphasis></term>

              <listitem>
                <para>The name of a macro defined in a file named
                macro.<emphasis>macro</emphasis>. If the macro accepts an
                action parameter (Look at the macro source to see if it has
                PARAM in the TARGET column) then the
                <emphasis>macro</emphasis> name is followed by the
                parenthesized <emphasis>target</emphasis> (<emphasis
                role="bold">ACCEPT</emphasis>, <emphasis
                role="bold">DROP</emphasis>, <emphasis
                role="bold">REJECT</emphasis>, ...) to be substituted for the
                parameter.</para>

                <para>Example: FTP(ACCEPT).</para>

                <para>The older syntax where the macro name and the target are
                separated by a slash (e.g. FTP/ACCEPT) is still allowed but is
                deprecated.</para>
              </listitem>
            </varlistentry>
          </variablelist>

          <para>The <emphasis role="bold">ACTION</emphasis> may optionally be
          followed by ":" and a syslog log level (e.g, REJECT:info or
          Web(ACCEPT):debug). This causes the packet to be logged at the
          specified level.</para>

          <para>If the <emphasis role="bold">ACTION</emphasis> names an
          <emphasis>action</emphasis> declared in <ulink
          url="shorewall6-actions.html">shorewall6-actions</ulink>(5) or in
          /usr/share/shorewall6/actions.std then:</para>

          <itemizedlist>
            <listitem>
              <para>If the log level is followed by "!' then all rules in the
              action are logged at the log level.</para>
            </listitem>

            <listitem>
              <para>If the log level is not followed by "!" then only those
              rules in the action that do not specify logging are logged at
              the specified level.</para>
            </listitem>

            <listitem>
              <para>The special log level <emphasis
              role="bold">none!</emphasis> suppresses logging by the
              action.</para>
            </listitem>
          </itemizedlist>

          <para>You may also specify <emphasis role="bold">NFLOG</emphasis>
          (must be in upper case) as a log level.This will log to the NFLOG
          target for routing to a separate log through use of ulogd (<ulink
          url="http://www.netfilter.org/projects/ulogd/index.html">http://www.netfilter.org/projects/ulogd/index.html</ulink>).</para>

          <para>Actions specifying logging may be followed by a log tag (a
          string of alphanumeric characters) which is appended to the string
          generated by the LOGPREFIX (in <ulink
          url="shorewall6.conf.html">shorewall6.conf</ulink>(5)).</para>

          <para>Example: ACCEPT:info:ftp would include 'ftp ' at the end of
          the log prefix generated by the LOGPREFIX setting.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">SOURCE</emphasis> -
        {<emphasis>zone</emphasis>|<emphasis>zone-list</emphasis>[+]|<emphasis
        role="bold">{all|any}</emphasis>[<emphasis
        role="bold">+</emphasis>][<emphasis
        role="bold">-</emphasis>]}<emphasis
        role="bold">[:</emphasis><emphasis>interface</emphasis>][<emphasis
        role="bold">:<option>&lt;</option></emphasis>{<emphasis>address-or-range</emphasis>[,<emphasis>address-or-range</emphasis>]...[<emphasis>exclusion</emphasis>]<option>&gt;</option>|<emphasis>exclusion</emphasis>|<emphasis
        role="bold">+</emphasis><emphasis>ipset</emphasis>}</term>

        <listitem>
          <para>Source hosts to which the rule applies. May be a zone declared
          in /etc/shorewall6/zones, <emphasis role="bold">$FW</emphasis> to
          indicate the firewall itself, <emphasis role="bold">all</emphasis>,
          <emphasis role="bold">all+</emphasis>, <emphasis
          role="bold">all-</emphasis>, <emphasis role="bold">all+-</emphasis>
          or <emphasis role="bold">none</emphasis>.</para>

          <para>Beginning with Shorewall 4.4.13, you may use a
          <replaceable>zone-list </replaceable>which consists of a
          comma-separated list of zones declared in <ulink
          url="shorewall-zones.html">shorewall-zones</ulink> (5). Ths
          <replaceable>zone-list</replaceable> may be optionally followed by
          "+" to indicate that the rule is to apply to intra-zone traffic as
          well as inter-zone traffic.</para>

          <para>When <emphasis role="bold">none</emphasis> is used either in
          the <emphasis role="bold">SOURCE</emphasis> or <emphasis
          role="bold">DEST</emphasis> column, the rule is ignored.</para>

          <para><emphasis role="bold">all</emphasis> means "All Zones",
          including the firewall itself. <emphasis role="bold">all-</emphasis>
          means "All Zones, except the firewall itself". When <emphasis
          role="bold">all</emphasis>[<emphasis role="bold">-</emphasis>] is
          used either in the <emphasis role="bold">SOURCE</emphasis> or
          <emphasis role="bold">DEST</emphasis> column intra-zone traffic is
          not affected. When <emphasis role="bold">all+</emphasis>[<emphasis
          role="bold">-</emphasis>] is "used, intra-zone traffic is affected.
          Beginning with Shorewall 4.4.13, exclusion is supported -- see see
          <ulink
          url="shorewall6-exclusion.html">shorewall6-exclusion</ulink>(5).</para>

          <para>Except when <emphasis role="bold">all</emphasis>[<emphasis
          role="bold">+</emphasis>][<emphasis role="bold">-</emphasis>] or
          <emphasis role="bold">any</emphasis>[<emphasis
          role="bold">+</emphasis>][<emphasis role="bold">-</emphasis>] is
          specified, clients may be further restricted to a list of networks
          and/or hosts by appending ":" and a comma-separated list of network
          and/or host addresses. Hosts may be specified by IP or MAC address;
          mac addresses must begin with "~" and must use "-" as a
          separator.</para>

          <para><emphasis role="bold">any</emphasis> is equivalent to
          <emphasis role="bold">all</emphasis> when there are no nested zones.
          When there are nested zones, <emphasis role="bold">any</emphasis>
          only refers to top-level zones (those with no parent zones). Note
          that <emphasis role="bold">any</emphasis> excludes all vserver
          zones, since those zones are nested within the firewall zone.</para>

          <para>Hosts may also be specified as an IP address range using the
          syntax
          <emphasis>lowaddress</emphasis>-<emphasis>highaddress</emphasis>.
          This requires that your kernel and ip6tables contain iprange match
          support. If your kernel and ip6tables have ipset match support then
          you may give the name of an ipset prefaced by "+". The ipset name
          may be optionally followed by a number from 1 to 6 enclosed in
          square brackets ([]) to indicate the number of levels of source
          bindings to be matched.</para>

          <para>Beginning with Shorewall6 4.4.17, the primary IP address of a
          firewall interface can be specified by an apersand ('&amp;')
          followed by the logican name of the interface as found in the
          INTERFACE column of <ulink
          url="shorewall-interfaces.html">shorewall6-interfaces</ulink>
          (5).</para>

          <para>When an <replaceable>interface</replaceable> is not specified,
          you may omit the angled brackets ('&lt;' and '&gt;') around the
          address(es) or you may supply them to improve readability.</para>

          <para>You may exclude certain hosts from the set already defined
          through use of an <emphasis>exclusion</emphasis> (see <ulink
          url="shorewall6-exclusion.html">shorewall6-exclusion</ulink>(5)).</para>

          <para>Examples:</para>

          <variablelist>
            <varlistentry>
              <term>dmz:2002:ce7c::92b4:1::2</term>

              <listitem>
                <para>Host 2002:ce7c:92b4:1::2 in the DMZ</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>net:2001:4d48:ad51:24::/64</term>

              <listitem>
                <para>Subnet 2001:4d48:ad51:24::/64 on the Internet</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>loc:&lt;2002:cec792b4:1::2,2002:cec792b4:1::44&gt;</term>

              <listitem>
                <para>Hosts 2002:cec792b4:1::2 and 2002:cec792b4:1::44 in the
                local zone.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>loc:~00-A0-C9-15-39-78</term>

              <listitem>
                <para>Host in the local zone with MAC address
                00:A0:C9:15:39:78.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>net:2001:4d48:ad51:24::/64!2001:4d48:ad51:24:6:/80!2001:4d48:ad51:24:6:/80</term>

              <listitem>
                <para>Subnet 2001:4d48:ad51:24::/64 on the Internet except for
                2001:4d48:ad51:24:6:/80.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>$FW:&amp;eth0</term>

              <listitem>
                <para>The primary IP address of eth0 in the firewall zone
                (Shorewall6 4.4.17 and later).</para>
              </listitem>
            </varlistentry>
          </variablelist>

          <para>Alternatively, clients may be specified by interface by
          appending ":" to the zone name followed by the interface name. For
          example, <emphasis role="bold">loc:eth1</emphasis> specifies a
          client that communicates with the firewall system through eth1. This
          may be optionally followed by another colon (":") and an
          IP/MAC/subnet address as described above (e.g., <emphasis
          role="bold">loc:eth1:&lt;2002:ce7c::92b4:1::2&gt;</emphasis>).</para>

          <para>Examples:</para>

          <variablelist>
            <varlistentry>
              <term>loc:eth1:&lt;2002:cec792b4:1::2,2002:cec792b4:1::44&gt;</term>

              <listitem>
                <para>Hosts 2002:cec792b4:1::2 and 2002:cec792b4:1::44 in the
                Local zone, with <emphasis role="bold">both</emphasis>
                originating from eth1</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold"><emphasis role="bold">DEST</emphasis> -
        {<emphasis>zone|zone-list</emphasis>[+]|<emphasis
        role="bold">all</emphasis>[<emphasis
        role="bold">+</emphasis>][<emphasis
        role="bold">-</emphasis>]}<emphasis
        role="bold">[:</emphasis><emphasis>interface</emphasis>][<emphasis
        role="bold">:<option>&lt;</option></emphasis>{<emphasis>address-or-range</emphasis>[,<emphasis>address-or-range</emphasis>]...[<emphasis>exclusion</emphasis>]<option>&gt;</option>|<emphasis>exclusion</emphasis>|<emphasis
        role="bold">+</emphasis><emphasis>ipset</emphasis>}</emphasis></term>

        <listitem>
          <para>Location of Server. May be a zone declared in <ulink
          url="shorewall6-zones.html">shorewall6-zones</ulink>(5), $<emphasis
          role="bold">FW</emphasis> to indicate the firewall itself, <emphasis
          role="bold">all</emphasis>. <emphasis role="bold">all+</emphasis> or
          <emphasis role="bold">none</emphasis>.</para>

          <para>Beginning with Shorewall 4.4.13, you may use a
          <replaceable>zone-list </replaceable>which consists of a
          comma-separated list of zones declared in <ulink
          url="shorewall-zones.html">shorewall-zones</ulink> (5). Ths
          <replaceable>zone-list</replaceable> may be optionally followed by
          "+" to indicate that the rule is to apply to intra-zone traffic as
          well as inter-zone traffic. Beginning with Shorewall-4.4.13,
          exclusion is supported -- see see <ulink
          url="shorewall6-exclusion.html">shorewall6-exclusion</ulink>(5).</para>

          <para>Beginning with Shorewall6 4.4.17, the primary IP address of a
          firewall interface can be specified by an apersand ('&amp;')
          followed by the logican name of the interface as found in the
          INTERFACE column of <ulink
          url="shorewall-interfaces.html">shorewall6-interfaces</ulink>
          (5).</para>

          <para>When <emphasis role="bold">none</emphasis> is used either in
          the <emphasis role="bold">SOURCE</emphasis> or <emphasis
          role="bold">DEST</emphasis> column, the rule is ignored.</para>

          <para>When <emphasis role="bold">all</emphasis> is used either in
          the <emphasis role="bold">SOURCE</emphasis> or <emphasis
          role="bold">DEST</emphasis> column intra-zone traffic is not
          affected. When <emphasis role="bold">all+</emphasis> is used,
          intra-zone traffic is affected.</para>

          <para>If the DEST <replaceable>zone</replaceable> is a bport zone,
          then either:<orderedlist numeration="loweralpha">
              <listitem>
                <para>the SOURCE must be <option>all[+][-]</option>, or</para>
              </listitem>

              <listitem>
                <para>the SOURCE <replaceable>zone</replaceable> must be
                another bport zone associated with the same bridge, or</para>
              </listitem>

              <listitem>
                <para>the SOURCE <replaceable>zone</replaceable> must be an
                ipv4 zone that is associated with only the same bridge.</para>
              </listitem>
            </orderedlist></para>

          <blockquote>
            <para>Except when <emphasis role="bold">all</emphasis>[<emphasis
            role="bold">+]|[-</emphasis>] is specified, the server may be
            further restricted to a particular network, host or interface by
            appending ":" and the network, host or interface. See <emphasis
            role="bold">SOURCE</emphasis> above.</para>

            <para>You may exclude certain hosts from the set already defined
            through use of an <emphasis>exclusion</emphasis> (see <ulink
            url="shorewall6-exclusion.html">shorewall6-exclusion</ulink>(5)).</para>

            <para>Restrictions:</para>

            <para>1. MAC addresses are not allowed (this is a Netfilter
            restriction).</para>

            <para>If you kernel and ip6tables have ipset match support then
            you may give the name of an ipset prefaced by "+". The ipset name
            may be optionally followed by a number from 1 to 6 enclosed in
            square brackets ([]) to indicate the number of levels of
            destination bindings to be matched. Only one of the <emphasis
            role="bold">SOURCE</emphasis> and <emphasis
            role="bold">DEST</emphasis> columns may specify an ipset
            name.</para>
          </blockquote>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">PROTO</emphasis> (Optional) - {<emphasis
        role="bold">-</emphasis>|<emphasis
        role="bold">tcp:syn</emphasis>|<emphasis
        role="bold">ipp2p</emphasis>|<emphasis
        role="bold">ipp2p:udp</emphasis>|<emphasis
        role="bold">ipp2p:all</emphasis>|<emphasis>protocol-number</emphasis>|<emphasis>protocol-name</emphasis>|<emphasis
        role="bold">all}</emphasis></term>

        <listitem>
          <para>Protocol - <emphasis role="bold">ipp2p</emphasis>* requires
          ipp2p match support in your kernel and ip6tables. <emphasis
          role="bold">tcp:syn</emphasis> implies <emphasis
          role="bold">tcp</emphasis> plus the SYN flag must be set and the
          RST,ACK and FIN flags must be reset.</para>

          <para>Beginning with Shorewall6 4.4.19, this column can contain a
          comma-separated list of protocol-numbers and/or protocol names
          (e.g., <emphasis role="bold">tcp,udp</emphasis>).</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">DEST PORT(S) </emphasis>(Optional) -
        {<emphasis
        role="bold">-</emphasis>|<emphasis>port-name-number-or-range</emphasis>[<emphasis
        role="bold">,</emphasis><emphasis>port-name-number-or-range</emphasis>]...}</term>

        <listitem>
          <para>Destination Ports. A comma-separated list of Port names (from
          services(5)), port numbers or port ranges; if the protocol is
          <emphasis role="bold">icmp</emphasis>, this column is interpreted as
          the destination icmp-type(s). ICMP types may be specified as a
          numeric type, a numberic type and code separated by a slash (e.g.,
          3/4), or a typename. See <ulink
          url="http://www.shorewall.net/configuration_file_basics.htm#ICMP">http://www.shorewall.net/configuration_file_basics.htm#ICMP</ulink>.
          Note that prior to Shorewall6 4.4.19, only a single ICMP type may be
          listsed.</para>

          <para>If the protocol is <emphasis role="bold">ipp2p</emphasis>,
          this column is interpreted as an ipp2p option without the leading
          "--" (example <emphasis role="bold">bit</emphasis> for bit-torrent).
          If no port is given, <emphasis role="bold">ipp2p</emphasis> is
          assumed.</para>

          <para>A port range is expressed as
          <emphasis>lowport</emphasis>:<emphasis>highport</emphasis>.</para>

          <para>This column is ignored if <emphasis
          role="bold">PROTO</emphasis> = <emphasis role="bold">all</emphasis>
          but must be entered if any of the following columns are supplied. In
          that case, it is suggested that this field contain a dash (<emphasis
          role="bold">-</emphasis>).</para>

          <para>If your kernel contains multi-port match support, then only a
          single Netfilter rule will be generated if in this list and the
          <emphasis role="bold">CLIENT PORT(S)</emphasis> list below:</para>

          <para>1. There are 15 or less ports listed.</para>

          <para>2. No port ranges are included or your kernel and ip6tables
          contain extended multiport match support.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">SOURCE PORT(S)</emphasis> (Optional) -
        {<emphasis
        role="bold">-</emphasis>|<emphasis>port-name-number-or-range</emphasis>[<emphasis
        role="bold">,</emphasis><emphasis>port-name-number-or-range</emphasis>]...}</term>

        <listitem>
          <para>Port(s) used by the client. If omitted, any source port is
          acceptable. Specified as a comma- separated list of port names, port
          numbers or port ranges.</para>

          <warning>
            <para>Unless you really understand IP, you should leave this
            column empty or place a dash (<emphasis role="bold">-</emphasis>)
            in the column. Most people who try to use this column get it
            wrong.</para>
          </warning>

          <blockquote>
            <para>If you don't want to restrict client ports but need to
            specify a later column, then place "-" in this column.</para>

            <para>If your kernel contains multi-port match support, then only
            a single Netfilter rule will be generated if in this list and the
            <emphasis role="bold">DEST PORT(S)</emphasis> list above:</para>

            <para>1. There are 15 or less ports listed.</para>

            <para>2. No port ranges are included or your kernel and ip6tables
            contain extended multiport match support.</para>
          </blockquote>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">ORIGINAL DEST</emphasis> (Optional) -
        [<emphasis role="bold">-</emphasis>]</term>

        <listitem>
          <para>Included for compatibility with Shorewall. Enter '-' in this
          column if you need to specify one of the later columns.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">RATE LIMIT</emphasis> (Optional) -
        [<emphasis role="bold">-</emphasis>|[{<emphasis>s</emphasis>|<emphasis
        role="bold">d</emphasis>}:[[<replaceable>name</replaceable>]:]]]<emphasis>rate</emphasis><emphasis
        role="bold">/</emphasis>{<emphasis
        role="bold">sec</emphasis>|<emphasis
        role="bold">min</emphasis>|<emphasis
        role="bold">hour</emphasis>|<emphasis
        role="bold">day</emphasis>}[:<emphasis>burst</emphasis>]</term>

        <listitem>
          <para>You may rate-limit the rule by placing a value in this
          column:</para>

          <para><emphasis>rate</emphasis> is the number of connections per
          interval (<emphasis role="bold">sec</emphasis> or <emphasis
          role="bold">min</emphasis>) and <emphasis>burst</emphasis> is the
          largest burst permitted. If no <emphasis>burst</emphasis> is given,
          a value of 5 is assumed. There may be no no whitespace embedded in
          the specification.</para>

          <para>Example: <emphasis role="bold">10/sec:20</emphasis></para>

          <para>When <option>s:</option> or <option>d:</option> is specified,
          the rate applies per source IP address or per destination IP address
          respectively. The <replaceable>name</replaceable> may be chosen by
          the user and specifies a hash table to be used to count matching
          connections. If not given, the name <emphasis
          role="bold">shorewallN</emphasis> (where N is a unique integer) is
          assumed. Where more than one POLICY specifies the same name, the
          connections counts for the rules are aggregated and the individual
          rates apply to the aggregated count.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">USER/GROUP</emphasis> (Optional) -
        [<emphasis
        role="bold">!</emphasis>][<emphasis>user-name-or-number</emphasis>][<emphasis
        role="bold">:</emphasis><emphasis>group-name-or-number</emphasis>]</term>

        <listitem>
          <para>This column may only be non-empty if the SOURCE is the
          firewall itself.</para>

          <para>When this column is non-empty, the rule applies only if the
          program generating the output is running under the effective
          <emphasis>user</emphasis> and/or <emphasis>group</emphasis>
          specified (or is NOT running under that id if "!" is given).</para>

          <para>Examples:</para>

          <variablelist>
            <varlistentry>
              <term>joe</term>

              <listitem>
                <para>program must be run by joe</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>:kids</term>

              <listitem>
                <para>program must be run by a member of the 'kids'
                group</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>!:kids</term>

              <listitem>
                <para>program must not be run by a member of the 'kids'
                group</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">MARK</emphasis> - [<emphasis
        role="bold">!</emphasis>]<emphasis>value</emphasis>[/<emphasis>mask</emphasis>][<emphasis
        role="bold">:C</emphasis>]</term>

        <listitem>
          <para>Defines a test on the existing packet or connection mark. The
          rule will match only if the test returns true.</para>

          <para>If you don't want to define a test but need to specify
          anything in the following columns, place a "-" in this field.</para>

          <variablelist>
            <varlistentry>
              <term>!</term>

              <listitem>
                <para>Inverts the test (not equal)</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis>value</emphasis></term>

              <listitem>
                <para>Value of the packet or connection mark.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis>mask</emphasis></term>

              <listitem>
                <para>A mask to be applied to the mark before testing.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">:C</emphasis></term>

              <listitem>
                <para>Designates a connection mark. If omitted, the packet
                mark's value is tested.</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">CONNLIMIT</emphasis> - [<emphasis
        role="bold">!</emphasis>]<emphasis>limit</emphasis>[:<emphasis>mask</emphasis>]</term>

        <listitem>
          <para>May be used to limit the number of simultaneous connections
          from each individual host to <replaceable>limit</replaceable>
          connections. Requires connlimit match in your kernel and ip6tables.
          While the limit is only checked on rules specifying CONNLIMIT, the
          number of current connections is calculated over all current
          connections from the SOURCE host. By default, the limit is applied
          to each host but can be made to apply to networks of hosts by
          specifying a <replaceable>mask</replaceable>. The
          <replaceable>mask</replaceable> specifies the width of a VLSM mask
          to be applied to the source address; the number of current
          connections is then taken over all hosts in the subnet
          <replaceable>source-address</replaceable>/<replaceable>mask</replaceable>.
          When<option> !</option> is specified, the rule matches when the
          number of connection exceeds the
          <replaceable>limit</replaceable>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">TIME</emphasis> -
        <emphasis>timeelement</emphasis>[&amp;<emphasis>timelement</emphasis>...]</term>

        <listitem>
          <para>May be used to limit the rule to a particular time period each
          day, to particular days of the week or month, or to a range defined
          by dates and times. Requires time match support in your kernel and
          ip6tables.</para>

          <para><replaceable>timeelement</replaceable> may be:</para>

          <variablelist>
            <varlistentry>
              <term>timestart=<replaceable>hh</replaceable>:<replaceable>mm</replaceable>[:<replaceable>ss</replaceable>]</term>

              <listitem>
                <para>Defines the starting time of day.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>timestop=<replaceable>hh</replaceable>:<replaceable>mm</replaceable>[:<replaceable>ss</replaceable>]</term>

              <listitem>
                <para>Defines the ending time of day.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>utc</term>

              <listitem>
                <para>Times are expressed in Greenwich Mean Time.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>localtz</term>

              <listitem>
                <para>Times are expressed in Local Civil Time
                (default).</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>weekdays=ddd[,ddd]...</term>

              <listitem>
                <para>where <replaceable>ddd</replaceable> is one of
                <option>Mon</option>, <option>Tue</option>,
                <option>Wed</option>, <option>Thu</option>,
                <option>Fri</option>, <option>Sat</option> or
                <option>Sun</option></para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>monthdays=dd[,dd],...</term>

              <listitem>
                <para>where <replaceable>dd</replaceable> is an ordinal day of
                the month</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>datestart=<replaceable>yyyy</replaceable>[-<replaceable>mm</replaceable>[-<replaceable>dd</replaceable>[<option>T</option><replaceable>hh</replaceable>[:<replaceable>mm</replaceable>[:<replaceable>ss</replaceable>]]]]]</term>

              <listitem>
                <para>Defines the starting date and time.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term>datestop=<replaceable>yyyy</replaceable>[-<replaceable>mm</replaceable>[-<replaceable>dd</replaceable>[<option>T</option><replaceable>hh</replaceable>[:<replaceable>mm</replaceable>[:<replaceable>ss</replaceable>]]]]]</term>

              <listitem>
                <para>Defines the ending date and time.</para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">HEADERS -
        [!][any:|exactly:]</emphasis><replaceable>header-list
        </replaceable>(Optional - Added in Shorewall 4.4.15)</term>

        <listitem>
          <para>The <replaceable>header-list</replaceable> consists of a
          comma-separated list of headers from the following list.</para>

          <variablelist>
            <varlistentry>
              <term><emphasis role="bold">auth</emphasis>, <emphasis
              role="bold">ah</emphasis>, or <emphasis
              role="bold">51</emphasis></term>

              <listitem>
                <para><firstterm>Authentication Headers</firstterm> extension
                header.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">esp</emphasis>, or <emphasis
              role="bold">50</emphasis></term>

              <listitem>
                <para><firstterm>Encrypted Security Payload</firstterm>
                extension header.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">hop</emphasis>, <emphasis
              role="bold">hop-by-hop</emphasis> or <emphasis
              role="bold">0</emphasis></term>

              <listitem>
                <para>Hop-by-hop options extension header.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">route</emphasis>, <emphasis
              role="bold">ipv6-route</emphasis> or <emphasis
              role="bold">41</emphasis></term>

              <listitem>
                <para>IPv6 Route extension header.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">frag</emphasis>, <emphasis
              role="bold">ipv6-frag</emphasis> or <emphasis
              role="bold">44</emphasis></term>

              <listitem>
                <para>IPv6 fragmentation extension header.</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">none</emphasis>, <emphasis
              role="bold">ipv6-nonxt</emphasis> or <emphasis
              role="bold">59</emphasis></term>

              <listitem>
                <para>No next header</para>
              </listitem>
            </varlistentry>

            <varlistentry>
              <term><emphasis role="bold">proto</emphasis>, <emphasis
              role="bold">protocol</emphasis> or <emphasis
              role="bold">255</emphasis></term>

              <listitem>
                <para>Any protocol header.</para>
              </listitem>
            </varlistentry>
          </variablelist>

          <para>If <emphasis role="bold">any:</emphasis> is specified, the
          rule will match if any of the listed headers are present. If
          <emphasis role="bold">exactly:</emphasis> is specified, the will
          match packets that exactly include all specified headers. If neither
          is given, <emphasis role="bold">any:</emphasis> is assumed.</para>

          <para>If <emphasis role="bold">!</emphasis> is entered, the rule
          will match those packets which would not be matched when <emphasis
          role="bold">!</emphasis> is omitted.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><emphasis role="bold">SWITCH -
        [!]<replaceable>switch-name</replaceable></emphasis></term>

        <listitem>
          <para>Added in Shorewall6 4.4.24 and allows enabling and disabling
          the rule without requiring <command>shorewall6
          restart</command>.</para>

          <para>Enables the rule if the value stored in
          <filename>/proc/net/nf_condition/<replaceable>switch-name</replaceable></filename>
          is 1. Disables the rule if that file contains 0 (the default). If
          '!' is supplied, the test is inverted such that the rule is enabled
          if the file contains 0. The <replaceable>switch-name</replaceable>
          must begin with a letter and be composed of letters, decimal digits,
          underscores or hyphens. Switch names must be 30 characters or less
          in length.</para>

          <para>Switches are normally <emphasis role="bold">off</emphasis>. To
          turn a switch <emphasis role="bold">on</emphasis>:</para>

          <simplelist>
            <member><command>echo 1 &gt;
            /proc/net/nf_condition/<replaceable>switch-name</replaceable></command></member>
          </simplelist>

          <para>To turn it <emphasis role="bold">off</emphasis> again:</para>

          <simplelist>
            <member><command>echo 0 &gt;
            /proc/net/nf_condition/<replaceable>switch-name</replaceable></command></member>
          </simplelist>

          <para>Switch settings are retained over <command>shorewall6
          restart</command>.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Example</title>

    <variablelist>
      <varlistentry>
        <term>Example 1:</term>

        <listitem>
          <para>Accept SMTP requests from the DMZ to the internet</para>

          <programlisting>         #ACTION SOURCE  DEST PROTO      DEST    SOURCE  ORIGINAL
         #                               PORT    PORT(S) DEST
         ACCEPT  dmz     net       tcp   smtp</programlisting>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>Example 4:</term>

        <listitem>
          <para>You want to accept SSH connections to your firewall only from
          internet IP addresses 2002:ce7c::92b4:1::2 and
          2002:ce7c::92b4:1::22</para>

          <programlisting>        #ACTION  SOURCE DEST            PROTO   DEST    SOURCE  ORIGINAL
        #                                       PORT    PORT(S) DEST
        ACCEPT   net:&lt;2002:ce7c::92b4:1::2,2002:ce7c::92b4:1::22&gt; \
                        $FW              tcp     22</programlisting>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>Example 5:</term>

        <listitem>
          <para>You wish to limit SSH connections from remote systems to 1/min
          with a burst of three (to allow for limited retry):</para>

          <programlisting>        #ACTION     SOURCE          DEST       PROTO       DEST         SOURCE    ORIGINAL         RATE
        #                                                  PORT(S)      PORT(S)   DEST             LIMIT
        SSH(ACCEPT) net             all        -           -            -         -                s:1/min:3</programlisting>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>Example 6:</term>

        <listitem>
          <para>Forward port 80 to dmz host $BACKUP if switch 'primary_down'
          is set.</para>

          <programlisting>        #ACTION     SOURCE          DEST        PROTO       DEST         SOURCE    ORIGINAL   RATE      USER/     MARK    CONNLIMIT     TIME     HEADERS    SWITCH
        #                                                   PORT(S)      PORT(S)   DEST       LIMIT     GROUP
        DNAT        net             dmz:$BACKUP tcp         80           -         -          -         -         -       -             -        -          primary_down</programlisting>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <para>/etc/shorewall6/rules</para>
  </refsect1>

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

    <para><ulink
    url="http://shorewall.net/configuration_file_basics.htm#Pairs">http://shorewall.net/configuration_file_basics.htm#Pairs</ulink></para>

    <para>shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5),
    shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5),
    shorewall6-maclist(5), shoewall6-netmap(5),shorewall6-params(5),
    shorewall6-policy(5), shorewall6-providers(5), shorewall6-route_rules(5),
    shorewall6-routestopped(5), shorewall6.conf(5), shorewall6-secmarks(5),
    shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5),
    shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)</para>
  </refsect1>
</refentry>