shorewall_code/Shorewall/manpages/shorewall-mangle.xml

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
<refentry>
<refmeta>
<refentrytitle>shorewall-mangle</refentrytitle>
<manvolnum>5</manvolnum>
<refmiscinfo>Configuration Files</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mangle</refname>
<refpurpose>Shorewall Packet marking/mangling rules file</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>/etc/shorewall/mangle</command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>This file was introduced in Shorewall 4.6.0 and is intended to
replace <ulink
url="/manpages/shorewall-tcrules.html">shorewall-tcrules(5)</ulink>. This
file is only processed by the compiler if:</para>
<orderedlist numeration="loweralpha">
<listitem>
<para>No file named 'tcrules' exists on the current CONFIG_PATH (see
<ulink url="/manpages/shorewall.conf.html">shorewall.conf(5)</ulink>);
or</para>
</listitem>
<listitem>
<para>The first file named 'tcrules' found on the CONFIG_PATH contains
no non-commentary entries.</para>
</listitem>
</orderedlist>
<para>Entries in this file cause packets to be marked as a means of
classifying them for traffic control or policy routing.</para>
<important>
<para>Unlike rules in the <ulink
url="/manpages/shorewall-rules.html">shorewall-rules</ulink>(5) file,
evaluation of rules in this file will continue after a match. So the
final mark for each packet will be the one assigned by the LAST tcrule
that matches.</para>
<para>If you use multiple internet providers with the 'track' option, in
/etc/shorewall/providers be sure to read the restrictions at <ulink
url="/MultiISP.html">http://www.shorewall.net/MultiISP.html</ulink>.</para>
</important>
<para>The columns in the file are as follows (where the column name is
followed by a different name in parentheses, the different name is used in
the alternate specification syntax).</para>
<variablelist>
<varlistentry>
<term><emphasis role="bold">ACTION</emphasis> -
<replaceable>command</replaceable>[(<replaceable>parameters</replaceable>)][:<replaceable>chain-designator</replaceable>]</term>
<listitem>
<para>The chain-specifier indicates the Netfilter chain that the
entry applies to and may be one of the following:</para>
<variablelist>
<varlistentry>
<term>P</term>
<listitem>
<para>PREROUTING chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>F</term>
<listitem>
<para>FORWARD chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>T</term>
<listitem>
<para>POSTROUTING chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>I</term>
<listitem>
<para>INPUT chain.</para>
</listitem>
</varlistentry>
</variablelist>
<para>Unless otherwise specified for the particular
<replaceable>command</replaceable>, the default chain is PREROUTING
when MARK_IN_FORWARD_CHAIN=No in <ulink
url="/manpages/shorewall.conf.html">shorewall.conf(5)</ulink>, and
FORWARD when MARK_IN_FORWARD_CHAIN=Yes.</para>
<para>A chain-designator may not be specified if the SOURCE or DEST
columns begin with '$FW'. When the SOURCE is $FW, the generated rule
is always placed in the OUTPUT chain. If DEST is '$FW', then the
rule is placed in the INPUT chain.</para>
<para>Where a command takes parameters, those parameters are
enclosed in parentheses ("(....)") and separated by commas.</para>
<para>The <replaceable>command</replaceable> may be one of the
following.</para>
<variablelist>
<varlistentry>
<term><emphasis
role="bold">ADD(<replaceable>ipset</replaceable>:<replaceable>flags</replaceable>)</emphasis></term>
<listitem>
<para>Added in Shorewall 4.6.7. Causes addresses and/or port
numbers to be added to the named
<replaceable>ipset</replaceable>. The
<replaceable>flags</replaceable> specify the address or tuple
to be added to the set and must match the type of ipset
involved. For example, for an iphash ipset, either the SOURCE
or DESTINATION address can be added using
<replaceable>flags</replaceable> <emphasis
role="bold">src</emphasis> or <emphasis
role="bold">dst</emphasis> respectively (see the -A command in
ipset (8)).</para>
<para>ADD is non-terminating. Even if a packet matches the
rule, it is passed on to the next rule.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CHECKSUM</emphasis></term>
<listitem>
<para>Compute and fill in the checksum in a packet that lacks
a checksum. This is particularly useful if you need to work
around old applications, such as dhcp clients, that do not
work well with checksum offloads, but you don't want to
disable checksum offload in your device.</para>
<para>Requires 'Checksum Target' support in your kernel and
iptables.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">CLASSIFY(<replaceable>classid</replaceable>)</emphasis></term>
<listitem>
<para>A classification Id (classid) is of the form
<emphasis>major</emphasis>:<emphasis>minor</emphasis> where
<emphasis>major</emphasis> and <emphasis>minor</emphasis> are
integers. Corresponds to the 'class' specification in these
traffic shaping modules:</para>
<programlisting> atm
cbq
dsmark
pfifo_fast
htb
prio</programlisting>
<para>Classification occurs in the POSTROUTING chain except
when the <emphasis role="bold">SOURCE</emphasis> is <emphasis
role="bold">$FW</emphasis>[:<emphasis>address</emphasis>] in
which case classification occurs in the OUTPUT chain.</para>
<para>When using Shorewall's built-in traffic shaping tool,
the <emphasis>major</emphasis> class is the device number (the
first device in <ulink
url="/manpages/shorewall-tcdevices.html">shorewall-tcdevices</ulink>(5)
is major class 1, the second device is major class 2, and so
on) and the <emphasis>minor</emphasis> class is the class's
MARK value in <ulink
url="/manpages/shorewall-tcclasses.html">shorewall-tcclasses</ulink>(5)
preceded by the number 1 (MARK 1 corresponds to minor class
11, MARK 5 corresponds to minor class 15, MARK 22 corresponds
to minor class 122, etc.).</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
<command>shorewall show mangle</command></para>
<para>To stop the comment from being attached to further
rules, simply include COMMENT on a line by itself.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">CONMARK({mark|range})</emphasis></term>
<listitem>
<para>Identical to MARK with the exception that the mark is
assigned to connection to which the packet belongs is marked
rather than to the packet itself.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CONTINUE</emphasis></term>
<listitem>
<para>Don't process any more marking rules in the
table.</para>
<para>Currently, CONTINUE may not be used with
<emphasis>exclusion</emphasis> (see the SOURCE and DEST
columns below); that restriction will be removed when
iptables/Netfilter provides the necessary support.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">DEL(<replaceable>ipset</replaceable>:<replaceable>flags</replaceable>)</emphasis></term>
<listitem>
<para>Added in Shorewall 4.6.7. Causes an entry to be deleted
from the named <replaceable>ipset</replaceable>. The
<replaceable>flags</replaceable> specify the address or tuple
to be deleted from the set and must match the type of ipset
involved. For example, for an iphash ipset, either the SOURCE
or DESTINATION address can be deleted using
<replaceable>flags</replaceable> <emphasis
role="bold">src</emphasis> or <emphasis
role="bold">dst</emphasis> respectively (see the -D command in
ipset (8)).</para>
<para>DEL is non-terminating. Even if a packet matches the
rule, it is passed on to the next rule.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DIVERT</emphasis></term>
<listitem>
<para>Two DIVERT rule should precede the TPROXY rule and
should select DEST PORT tcp 80 and SOURCE PORT tcp 80
respectively (assuming that tcp port 80 is being proxied).
DIVERT avoids sending packets to the TPROXY target once a
socket connection to Squid3 has been established by TPROXY.
DIVERT marks the packet with a unique mark and exempts it from
any rules that follow.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DROP</emphasis></term>
<listitem>
<para>Causes matching packets to be discarded.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">DSCP</emphasis>(<replaceable>dscp</replaceable>)</term>
<listitem>
<para>Sets the <firstterm>Differentiated Services Code
Point</firstterm> field in the IP header. The
<replaceable>dscp</replaceable> value may be given as an even
number (hex or decimal) or as the name of a DSCP class. Valid
class names and their associated hex numeric values
are:</para>
<programlisting> CS0 =&gt; 0x00
CS1 =&gt; 0x08
CS2 =&gt; 0x10
CS3 =&gt; 0x18
CS4 =&gt; 0x20
CS5 =&gt; 0x28
CS6 =&gt; 0x30
CS7 =&gt; 0x38
BE =&gt; 0x00
AF11 =&gt; 0x0a
AF12 =&gt; 0x0c
AF13 =&gt; 0x0e
AF21 =&gt; 0x12
AF22 =&gt; 0x14
AF23 =&gt; 0x16
AF31 =&gt; 0x1a
AF32 =&gt; 0x1c
AF33 =&gt; 0x1e
AF41 =&gt; 0x22
AF42 =&gt; 0x24
AF43 =&gt; 0x26
EF =&gt; 0x2e</programlisting>
<para>To indicate more than one class, add their hex values
together and specify the result.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">IMQ</emphasis>(<replaceable>number</replaceable>)</term>
<listitem>
<para>Specifies that the packet should be passed to the IMQ
identified by <replaceable>number</replaceable>. Requires IMQ
Target support in your kernel and iptables.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">INLINE</emphasis>[(<replaceable>action</replaceable>)]</term>
<listitem>
<para>Allows you to place your own ip[6]tables matches at the
end of the line following a semicolon (";"). If an
<replaceable>action</replaceable> is specified, the compiler
procedes as if that <replaceable>action</replaceable> had been
specified in this column. If no action is specified, then you
may include your own jump ("-j
<replaceable>target</replaceable>
[<replaceable>option</replaceable>] ...") after any matches
specified at the end of the rule. If the target is not one
known to Shorewall, then it must be defined as a builtin
action in <ulink
url="/manpages/shorewall-actions.html">shorewall-actions</ulink>
(5).</para>
<para>The following rules are equivalent:</para>
<programlisting>2:P eth0 - tcp 22
INLINE(MARK(2)):P eth0 - tcp 22
INLINE(MARK(2)):P eth0 - ; -p tcp
INLINE eth0 - tcp 22 ; -j MARK --set-mark 2
INLINE eth0 - ; -p tcp -j MARK --set-mark 2
</programlisting>
<para>If INLINE_MATCHES=Yes in <ulink
url="/manpages/shorewall.conf.html">shorewall6.conf(5)</ulink>
then the third rule above can be specified as follows:</para>
<programlisting>MARK(2):P eth0 - ; -p tcp</programlisting>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">IPMARK</emphasis></term>
<listitem>
<para>Assigns a mark to each matching packet based on the
either the source or destination IP address. By default, it
assigns a mark value equal to the low-order 8 bits of the
source address. Default values are:</para>
<simplelist>
<member>src</member>
<member><emphasis>mask1</emphasis> = 0xFF</member>
<member><emphasis>mask2</emphasis> = 0x00</member>
<member><emphasis>shift</emphasis> = 0</member>
</simplelist>
<para>'src' and 'dst' specify whether the mark is to be based
on the source or destination address respectively. The
selected address is first shifted to the right by
<emphasis>shift</emphasis> bits. The result is then LANDed
with <emphasis>mask1</emphasis> then LORed with
<emphasis>ma<emphasis>s</emphasis>k2</emphasis>.</para>
<para>In a sense, the IPMARK target is more like an IPCLASSIFY
target in that the mark value is later interpreted as a class
ID. A packet mark is 32 bits wide; so is a class ID. The
&lt;major&gt; class occupies the high-order 16 bits and the
&lt;minor&gt; class occupies the low-order 16 bits. So the
class ID 1:4ff (remember that class IDs are always in hex) is
equivalent to a mark value of 0x104ff. Remember that Shorewall
uses the interface number as the &lt;major&gt; number where
the first interface in tcdevices has &lt;major&gt; number 1,
the second has &lt;major&gt; number 2, and so on.</para>
<para>The IPMARK target assigns a mark to each matching packet
based on the either the source or destination IP address. By
default, it assigns a mark value equal to the low-order 8 bits
of the source address. The syntax is as follows:</para>
<blockquote>
<para><option>IPMARK</option>[([{<option>src</option>|<option>dst</option>}][,[<replaceable>mask1</replaceable>][,[<replaceable>mask2</replaceable>][,[<replaceable>shift</replaceable>]]]])]</para>
</blockquote>
<para>Default values are:</para>
<simplelist>
<member><option>src</option></member>
<member><replaceable>mask1</replaceable> = 0xFF</member>
<member><replaceable>mask2</replaceable> = 0x00</member>
<member><replaceable>shift</replaceable> = 0</member>
</simplelist>
<para><option>src</option> and <option>dst</option> specify
whether the mark is to be based on the source or destination
address respectively. The selected address is first shifted
right by <replaceable>shift</replaceable>, then LANDed with
<replaceable>mask1</replaceable> and then LORed with
<replaceable>mask2</replaceable>. The
<replaceable>shift</replaceable> argument is intended to be
used primarily with IPv6 addresses.</para>
<para>Example:</para>
<blockquote>
<para>IPMARK(src,0xff,0x10100)</para>
<simplelist>
<member>Suppose that the source IP address is 192.168.4.3
= 0xc0a80403; then</member>
<member>0xc0a80403 &gt;&gt; 0 = 0xc0a80403</member>
<member>0xc0a80403 LAND 0xFF = 0x03</member>
<member>0x03 LOR 0x0x10100 = 0x10103 or class ID
1:103</member>
</simplelist>
</blockquote>
<para>It is important to realize that, while class IDs are
composed of a <replaceable>major</replaceable> and a
<replaceable>minor</replaceable> value, the set of values must
be unique. That is, the same numeric value cannot be used as
both a <replaceable>major</replaceable> and a
<replaceable>minor</replaceable> number for the same interface
unless class nesting occurs (which is not currently possible
with Shorewall). You should keep this in mind when deciding
how to map IP addresses to class IDs.</para>
<para>For example, suppose that your internal network is
192.168.1.0/29 (host IP addresses 192.168.1.1 - 192.168.1.6).
Your first notion might be to use IPMARK(src,0xFF,0x10000) so
as to produce class IDs 1:1 through 1:6. But 1:1 is an invalid
class ID since the <replaceable>major</replaceable> and
<replaceable>minor</replaceable> classes are equal. So you
might choose instead to use IPMARK(src,0xFF,0x10100) as in the
example above so that all of your
<replaceable>minor</replaceable> classes will have a value
&gt; 256.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">IPTABLES({<replaceable>target</replaceable>
[<replaceable>option</replaceable> ...])</emphasis></term>
<listitem>
<para>This action allows you to specify an iptables target
with options (e.g., 'IPTABLES(MARK --set-xmark 0x01/0xff)'. If
the target is not one recognized by Shorewall, the following
error message will be issued:</para>
<simplelist>
<member>ERROR: Unknown target
(<replaceable>target</replaceable>)</member>
</simplelist>
<para>This error message may be eliminated by adding the
<replaceable>target</replaceable> as a builtin action in
<ulink
url="/manpages/shorewall-actions.html">shorewall-actions(5)</ulink>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">MARK({<replaceable>mark</replaceable>|<replaceable>range</replaceable>})</emphasis></term>
<listitem>
<para>where <replaceable>mark</replaceable> is a packet mark
value.</para>
<para>Normally will set the mark value. If preceded by a
vertical bar ("|"), the mark value will be logically ORed with
the current mark value to produce a new mark value. If
preceded by an ampersand ("&amp;"), will be logically ANDed
with the current mark value to produce a new mark
value.</para>
<para>Both "|" and "&amp;" require Extended MARK Target
support in your kernel and iptables.</para>
<para>The mark value may be optionally followed by "/" and a
mask value (used to determine those bits of the connection
mark to actually be set). When a mask is specified, the result
of logically ANDing the mark value with the mask must be the
same as the mark value.</para>
<para>A mark <replaceable>range</replaceable> is a pair of
integers separated by a dash ("-").</para>
<para>May be optionally followed by a slash ("/") and a mask
and requires the <firstterm>Statistics Match</firstterm>
capability in iptables and kernel. Marks in the specified
range are assigned to packets on a round-robin fashion.</para>
<para>When a mask is specified, the result of logically ANDing
each mark value with the mask must be the same as the mark
value. The least significant bit in the mask is used as an
increment. For example, if '0x200-0x400/0xff00' is specified,
then the assigned mark values are 0x200, 0x300 and 0x400 in
equal proportions. If no mask is specified, then ( 2 **
MASK_BITS ) - 1 is assumed (MASK_BITS is set in <ulink
url="/manpages/shorewall.conf.html">shorewall.conf</ulink>(5)).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">RESTORE</emphasis>[(<emphasis>mask</emphasis>)]</term>
<listitem>
<para>Restore the packet's mark from the connection's mark
using the supplied mask if any. Your kernel and iptables must
include CONNMARK support.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">SAME[(<replaceable>timeout</replaceable>)]</emphasis></term>
<listitem>
<para>Some websites run applications that require multiple
connections from a client browser. Where multiple 'balanced'
providers are configured, this can lead to problems when some
of the connections are routed through one provider and some
through another. The SAME target allows you to work around
that problem. SAME may be used in the PREROUTING and OUTPUT
chains. When used in PREROUTING, it causes matching
connections from an individual local system to all use the
same provider. For example: <programlisting>#ACTION SOURCE DEST PROTO DEST
# PORT(S)
SAME:P 192.168.1.0/24 0.0.0.0/0 tcp 80,443</programlisting>
If a host in 192.168.1.0/24 attempts a connection on TCP port
80 or 443 and it has sent a packet on either of those ports in
the last five minutes then the new connection will use the
same provider as the connection over which that last packet
was sent.</para>
<para>When used in the OUTPUT chain, it causes all matching
connections to an individual remote system to all use the same
provider. For example:<programlisting>#ACTION SOURCE DEST PROTO DEST
# PORT(S)
SAME $FW 0.0.0.0/0 tcp 80,443</programlisting>The
optional <replaceable>timeout</replaceable> parameter was
added in Shorewall 4.6.7 and specifies a number of seconds .
When not specified, a value of 300 seconds (5 minutes) is
assumed. If the firewall attempts a connection on TCP port 80
or 443 and it has sent a packet on either of those ports in
the last <replaceable>timeout</replaceable> seconds to the
same remote system then the new connection will use the same
provider as the connection over which that last packet was
sent.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">SAVE[(<emphasis><replaceable>mask</replaceable>)</emphasis>]
</emphasis></term>
<listitem>
<para>Save the packet's mark to the connection's mark using
the supplied mask if any. Your kernel and iptables must
include CONNMARK support.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">TOS</emphasis>(<replaceable>tos</replaceable>[/<replaceable>mask</replaceable>])</term>
<listitem>
<para>Sets the <firstterm>Type of Service</firstterm> field in
the IP header. The <replaceable>tos</replaceable> value may be
given as an number (hex or decimal) or as the name of a TOS
type. Valid type names and their associated hex numeric values
are:</para>
<programlisting>Minimize-Delay =&gt; 0x10,
Maximize-Throughput =&gt; 0x08,
Maximize-Reliability =&gt; 0x04,
Minimize-Cost =&gt; 0x02,
Normal-Service =&gt; 0x00</programlisting>
<para>To indicate more than one class, add their hex values
together and specify the result.</para>
<para>When <replaceable>tos</replaceable> is given as a
number, it may be optionally followed by '/' and a
<replaceable>mask</replaceable>. When no
<replaceable>mask</replaceable> is given, the value 0xff is
assumed. When <replaceable>tos</replaceable> is given as a
type name, the <replaceable>mask</replaceable> 0x3f is
assumed.</para>
<para>The action performed is to zero out the bits specified
by the <replaceable>mask</replaceable>, then set the bits
specified by <replaceable>tos</replaceable>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis
role="bold">TPROXY</emphasis>([<replaceable>port</replaceable>][,<replaceable>address</replaceable>])</term>
<listitem>
<para>Transparently redirects a packet without altering the IP
header. Requires a tproxy provider to be defined in <ulink
url="/manpages/shorewall-providers.html">shorewall-providers</ulink>(5).</para>
<para>There are three parameters to TPROXY - neither is
required:</para>
<itemizedlist>
<listitem>
<para><replaceable>port</replaceable> - the port on which
the proxy server is listening. If omitted, the original
destination port.</para>
</listitem>
<listitem>
<para><replaceable>address</replaceable> - a local (to the
firewall) IP address on which the proxy server is
listening. If omitted, the IP address of the interface on
which the request arrives.</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">TTL</emphasis>([<emphasis
role="bold">-</emphasis>|<emphasis
role="bold">+</emphasis>]<replaceable>number</replaceable>)</term>
<listitem>
<para>If <emphasis role="bold">+</emphasis> is included,
packets matching the rule will have their TTL incremented by
<replaceable>number</replaceable>. Similarly, if <emphasis
role="bold">-</emphasis> is included, matching packets have
their TTL decremented by <replaceable>number</replaceable>. If
neither <emphasis role="bold">+</emphasis> nor <emphasis
role="bold">-</emphasis> is given, the TTL of matching packets
is set to <replaceable>number</replaceable>. The valid range
of values for <replaceable>number</replaceable> is
1-255.</para>
</listitem>
</varlistentry>
</variablelist>
<orderedlist numeration="arabic">
<listitem>
<para><emphasis role="bold">TTL</emphasis>([<emphasis
role="bold">-</emphasis>|<emphasis
role="bold">+</emphasis>]<replaceable>number</replaceable>)</para>
<para>Added in Shorewall 4.4.24.</para>
<para>Prior to Shorewall 4.5.7.2, may be optionally followed by
<emphasis role="bold">:F</emphasis> but the resulting rule is
always added to the FORWARD chain. Beginning with Shorewall
4.5.7.s, it may be optionally followed by <emphasis
role="bold">:P</emphasis>, in which case the rule is added to
the PREROUTING chain.</para>
<para>If <emphasis role="bold">+</emphasis> is included, packets
matching the rule will have their TTL incremented by
<replaceable>number</replaceable>. Similarly, if <emphasis
role="bold">-</emphasis> is included, matching packets have
their TTL decremented by <replaceable>number</replaceable>. If
neither <emphasis role="bold">+</emphasis> nor <emphasis
role="bold">-</emphasis> is given, the TTL of matching packets
is set to <replaceable>number</replaceable>. The valid range of
values for <replaceable>number</replaceable> is 1-255.</para>
</listitem>
</orderedlist>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SOURCE</emphasis> - {<emphasis
role="bold">-</emphasis>|{<emphasis>interface</emphasis>|<emphasis
role="bold">$FW</emphasis>}|[{<emphasis>interface</emphasis>|<emphasis
role="bold">$FW</emphasis>}:]<emphasis>address-or-range</emphasis>[<emphasis
role="bold">,</emphasis><emphasis>address-or-range</emphasis>]...}[<emphasis>exclusion</emphasis>]</term>
<listitem>
<para>May be:</para>
<orderedlist>
<listitem>
<para>An interface name - matches traffic entering the firewall
on the specified interface. May not be used in classify rules or
in rules using the :T chain qualifier.</para>
</listitem>
<listitem>
<para>A comma-separated list of host or network IP addresses or
MAC addresses. <emphasis role="bold">This form will not match
traffic that originates on the firewall itself unless either
&lt;major&gt;&lt;minor&gt; or the :T chain qualifier is used in
the ACTION column.</emphasis></para>
<para>Examples:<simplelist>
<member>0.0.0.0/0</member>
</simplelist></para>
<para><simplelist>
<member>192.168.1.0/24, 172.20.4.0/24</member>
</simplelist></para>
</listitem>
<listitem>
<para>An interface name followed by a colon (":") followed by a
comma-separated list of host or network IP addresses or MAC
addresses. May not be used in classify rules or in rules using
the :T chain qualifier.</para>
</listitem>
<listitem>
<para>$FW optionally followed by a colon (":") and a
comma-separated list of host or network IP addresses. Matches
packets originating on the firewall. May not be used with a
chain qualifier (:P, :F, etc.) in the ACTION column.</para>
</listitem>
</orderedlist>
<para>MAC addresses must be prefixed with "~" and use "-" as a
separator.</para>
<para>Example: ~00-A0-C9-15-39-78</para>
<para>You may exclude certain hosts from the set already defined
through use of an <emphasis>exclusion</emphasis> (see <ulink
url="/manpages/shorewall-exclusion.html">shorewall-exclusion</ulink>(5)).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DEST</emphasis> - {<emphasis
role="bold">-</emphasis>|{<emphasis>interface</emphasis>|$FW}|[<emphasis>{interface</emphasis>|$FW}:]<emphasis>address-or-range</emphasis>[<emphasis
role="bold">,</emphasis><emphasis>address-or-range</emphasis>]...}[<emphasis>exclusion</emphasis>]</term>
<listitem>
<para>May be:</para>
<orderedlist>
<listitem>
<para>An interface name. May not be used in the PREROUTING chain
(:P in the mark column or no chain qualifier and
MARK_IN_FORWARD_CHAIN=No in <ulink
url="manpages/shorewall.conf">shorewall.conf</ulink> (5)). The
interface name may be optionally followed by a colon (":") and
an IP address list.</para>
</listitem>
<listitem>
<para>A comma-separated list of host or network IP addresses.
The list may include ip address ranges if your kernel and
iptables include iprange support.</para>
</listitem>
<listitem>
<para>Beginning with Shorewall 4.4.13, $FW may be specified by
itself or qualified by an address list. This causes marking to
occur in the INPUT chain.</para>
</listitem>
</orderedlist>
<para>You may exclude certain hosts from the set already defined
through use of an <emphasis>exclusion</emphasis> (see <ulink
url="/manpages/shorewall-exclusion.html">shorewall-exclusion</ulink>(5)).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">PROTO</emphasis> - {<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 iptables.</para>
<para>Beginning with Shorewall 4.5.12, this column can accept a
comma-separated list of protocols.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">PORT(S)</emphasis> (dport) - {<emphasis
role="bold">-</emphasis>|<emphasis>port-name-number-or-range</emphasis>[<emphasis
role="bold">,</emphasis><emphasis>port-name-number-or-range</emphasis>]...|+<replaceable>ipset</replaceable>}</term>
<listitem>
<para>Optional destination Ports. A comma-separated list of Port
names (from services(5)), <emphasis>port number</emphasis>s or
<emphasis>port range</emphasis>s; 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 numeric type and code separated by a slash (e.g., 3/4), or a
typename. See <ulink
url="/configuration_file_basics.htm#ICMP">http://www.shorewall.net/configuration_file_basics.htm#ICMP</ulink>.</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>An entry in this field requires that the PROTO column specify
icmp (1), tcp (6), udp (17), sctp (132) or udplite (136). Use '-' if
any of the following field is supplied.</para>
<para>Beginning with Shorewall 4.6.0, an
<replaceable>ipset</replaceable> name can be specified in this
column. This is intended to be used with
<firstterm>bitmap:port</firstterm> ipsets.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SOURCE PORT(S)</emphasis> (sport) -
{<emphasis
role="bold">-</emphasis>|<emphasis>port-name-number-or-range</emphasis>[<emphasis
role="bold">,</emphasis><emphasis>port-name-number-or-range</emphasis>]...|+<replaceable>ipset</replaceable>}</term>
<listitem>
<para>Optional source port(s). If omitted, any source port is
acceptable. Specified as a comma-separated list of port names, port
numbers or port ranges.</para>
<para>An entry in this field requires that the PROTO column specify
tcp (6), udp (17), sctp (132) or udplite (136). Use '-' if any of
the following fields is supplied.</para>
<para>Beginning with Shorewall 4.5.15, you may place '=' in this
column, provided that the DEST PORT(S) column is non-empty. This
causes the rule to match when either the source port or the
destination port in a packet matches one of the ports specified in
DEST PORTS(S). Use of '=' requires multi-port match in your iptables
and kernel.</para>
<para>Beginning with Shorewall 4.6.0, an
<replaceable>ipset</replaceable> name can be specified in this
column. This is intended to be used with
<firstterm>bitmap:port</firstterm> ipsets.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">USER</emphasis> - [<emphasis
role="bold">!</emphasis>][<emphasis>user-name-or-number</emphasis>][<emphasis
role="bold">:</emphasis><emphasis>group-name-or-number</emphasis>][<emphasis
role="bold">+</emphasis><emphasis>program-name</emphasis>]</term>
<listitem>
<para>This optional 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>
<varlistentry>
<term>+upnpd</term>
<listitem>
<para>#program named upnpd</para>
<important>
<para>The ability to specify a program name was removed from
Netfilter in kernel version 2.6.14.</para>
</important>
</listitem>
</varlistentry>
</variablelist>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">TEST</emphasis> - [<emphasis
role="bold">!</emphasis>]<emphasis>value</emphasis>[/<emphasis>mask</emphasis>][<emphasis
role="bold">:C</emphasis>]</term>
<listitem>
<para>Optional - 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">LENGTH</emphasis> -
[<emphasis>length</emphasis>|[<emphasis>min</emphasis>]<emphasis
role="bold">:</emphasis>[<emphasis>max</emphasis>]]</term>
<listitem>
<para>Optional - packet payload length. This field, if present allow
you to match the length of a packet payload (Layer 4 data ) against
a specific value or range of values. You must have iptables length
support for this to work. A range is specified in the form
<emphasis>min</emphasis>:<emphasis>max</emphasis> where either
<emphasis>min</emphasis> or <emphasis>max</emphasis> (but not both)
may be omitted. If <emphasis>min</emphasis> is omitted, then 0 is
assumed; if <emphasis>max</emphasis> is omitted, than any packet
that is <emphasis>min</emphasis> or longer will match.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">TOS</emphasis> -
<emphasis>tos</emphasis></term>
<listitem>
<para>Type of service. Either a standard name, or a numeric value to
match.</para>
<programlisting> <emphasis role="bold">Minimize-Delay</emphasis> (16)
<emphasis role="bold">Maximize-Throughput</emphasis> (8)
<emphasis role="bold">Maximize-Reliability</emphasis> (4)
<emphasis role="bold">Minimize-Cost</emphasis> (2)
<emphasis role="bold">Normal-Service</emphasis> (0)</programlisting>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CONNBYTES</emphasis> -
[!]<emphasis>min</emphasis>:[<emphasis>max</emphasis>[:{<emphasis
role="bold">O</emphasis>|<emphasis role="bold">R</emphasis>|<emphasis
role="bold">B</emphasis>}[:{<emphasis
role="bold">B</emphasis>|<emphasis role="bold">P</emphasis>|<emphasis
role="bold">A</emphasis>}]]]</term>
<listitem>
<para>Optional connection Bytes; defines a byte or packet range that
the connection must fall within in order for the rule to
match.</para>
<para>A packet matches if the the packet/byte count is within the
range defined by <emphasis>min</emphasis> and
<emphasis>max</emphasis> (unless ! is given in which case, a packet
matches if the packet/byte count is not within the range).
<emphasis>min</emphasis> is an integer which defines the beginning
of the byte/packet range. <emphasis>max</emphasis> is an integer
which defines the end of the byte/packet range; if omitted, only the
beginning of the range is checked. The first letter gives the
direction which the range refers to:<blockquote>
<para><emphasis role="bold">O</emphasis> - The original
direction of the connection.</para>
<para>- The opposite direction from the original
connection.</para>
<para><emphasis role="bold">B</emphasis> - The total of both
directions.</para>
</blockquote></para>
<para>If omitted, <emphasis role="bold">B</emphasis> is
assumed.</para>
<para>The second letter determines what the range refers
to.<blockquote>
<para><emphasis role="bold">B</emphasis> - Bytes</para>
<para><emphasis role="bold">P</emphasis> - Packets</para>
<para><emphasis role="bold">A</emphasis> - Average packet
size.</para>
</blockquote>If omitted, <emphasis role="bold">B</emphasis> is
assumed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">HELPER -
</emphasis><emphasis>helper</emphasis></term>
<listitem>
<para>Names a Netfilter protocol <firstterm>helper</firstterm>
module such as <option>ftp</option>, <option>sip</option>,
<option>amanda</option>, etc. A packet will match if it was accepted
by the named helper module.</para>
<para>Example: Mark all FTP data connections with mark
4:<programlisting>#ACTION SOURCE DEST PROTO PORT(S) SOURCE USER TEST LENGTH TOS CONNBYTES HELPER
# PORT(S)
4:T 0.0.0.0/0 0.0.0.0/0 TCP - - - - - - - ftp</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">PROBABILITY</emphasis> -
[<replaceable>probability</replaceable>]</term>
<listitem>
<para>Added in Shorewall 4.5.0. When non-empty, requires the
<firstterm>Statistics Match</firstterm> capability in your kernel
and ip6tables and causes the rule to match randomly but with the
given <replaceable>probability</replaceable>. The
<replaceable>probability</replaceable> is a number 0 &lt;
<replaceable>probability</replaceable> &lt;= 1 and may be expressed
at up to 8 decimal points of precision.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DSCP -</emphasis>
[[!]<replaceable>dscp</replaceable>]</term>
<listitem>
<para>Added in Shorewall 4.5.1. When non-empty, match packets whose
<firstterm>Differentiated Service Code Point</firstterm> field
matches the supplied value (when '!' is given, the rule matches
packets whose DSCP field does not match the supplied value). The
<replaceable>dscp</replaceable> value may be given as an even number
(hex or decimal) or as the name of a DSCP class. Valid class names
and their associated hex numeric values are:</para>
<programlisting> CS0 =&gt; 0x00
CS1 =&gt; 0x08
CS2 =&gt; 0x10
CS3 =&gt; 0x18
CS4 =&gt; 0x20
CS5 =&gt; 0x28
CS6 =&gt; 0x30
CS7 =&gt; 0x38
BE =&gt; 0x00
AF11 =&gt; 0x0a
AF12 =&gt; 0x0c
AF13 =&gt; 0x0e
AF21 =&gt; 0x12
AF22 =&gt; 0x14
AF23 =&gt; 0x16
AF31 =&gt; 0x1a
AF32 =&gt; 0x1c
AF33 =&gt; 0x1e
AF41 =&gt; 0x22
AF42 =&gt; 0x24
AF43 =&gt; 0x26
EF =&gt; 0x2e</programlisting>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">STATE</emphasis> -- {<emphasis
role="bold">NEW</emphasis>|<emphasis
role="bold">RELATED</emphasis>|<emphasis
role="bold">ESTABLISHED</emphasis>|<emphasis
role="bold">INVALID</emphasis>} [,...]</term>
<listitem>
<para>The rule will only match if the packet's connection is in one
of the listed states.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">TIME</emphasis> -
<emphasis>timeelement</emphasis>[&amp;<emphasis>timeelement</emphasis>...]</term>
<listitem>
<para>Added in Shorewall 4.6.2.</para>
<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>Deprecated by the Netfilter team in favor of <emphasis
role="bold">kerneltz</emphasis>. Times are expressed in Local
Civil Time (default).</para>
</listitem>
</varlistentry>
<varlistentry>
<term>kerneltz</term>
<listitem>
<para>Added in Shorewall 4.5.2. Times are expressed in Local
Kernel Time (requires iptables 1.4.12 or later).</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>
</variablelist>
</refsect1>
<refsect1>
<title>Example</title>
<variablelist>
<varlistentry>
<term>Example 1:</term>
<listitem>
<para>Mark all ICMP echo traffic with packet mark 1. Mark all peer
to peer traffic with packet mark 4.</para>
<para>This is a little more complex than otherwise expected. Since
the ipp2p module is unable to determine all packets in a connection
are P2P packets, we mark the entire connection as P2P if any of the
packets are determined to match.</para>
<para>We assume packet/connection mark 0 means unclassified.</para>
<programlisting> #ACTION SOURCE DEST PROTO PORT(S) SOURCE USER TEST
# PORT(S)
MARK(1):T 0.0.0.0/0 0.0.0.0/0 icmp echo-request
MARK(1):T 0.0.0.0/0 0.0.0.0/0 icmp echo-reply
RESTORE:T 0.0.0.0/0 0.0.0.0/0 all - - - 0
CONTINUE:T 0.0.0.0/0 0.0.0.0/0 all - - - !0
MARK(4):T 0.0.0.0/0 0.0.0.0/0 ipp2p:all
SAVE:T 0.0.0.0/0 0.0.0.0/0 all - - - !0</programlisting>
<para>If a packet hasn't been classified (packet mark is 0), copy
the connection mark to the packet mark. If the packet mark is set,
we're done. If the packet is P2P, set the packet mark to 4. If the
packet mark has been set, save it to the connection mark.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example 2:</term>
<listitem>
<para>SNAT outgoing connections on eth0 from 192.168.1.0/24 in
round-robin fashion between addresses 1.1.1.1, 1.1.1.3, and 1.1.1.9
(Shorewall 4.5.9 and later).</para>
<programlisting>/etc/shorewall/tcrules:
#ACTION SOURCE DEST PROTO PORT(S) SOURCE USER TEST
# PORT(S)
CONNMARK(1-3):F 192.168.1.0/24 eth0 ; state=NEW
/etc/shorewall/masq:
#INTERFACE SOURCE ADDRESS ...
eth0 192.168.1.0/24 1.1.1.1 ; mark=1:C
eth0 192.168.1.0/24 1.1.1.3 ; mark=2:C
eth0 192.168.1.0/24 1.1.1.4 ; mark=3:C</programlisting>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>FILES</title>
<para>/etc/shorewall/mangle</para>
</refsect1>
<refsect1>
<title>See ALSO</title>
<para><ulink
url="/traffic_shaping.htm">http://www.shorewall.net/traffic_shaping.htm</ulink></para>
<para><ulink
url="/MultiISP.html">http://www.shorewall.net/MultiISP.html</ulink></para>
<para><ulink
url="/PacketMarking.html">http://www.shorewall.net/PacketMarking.html</ulink></para>
<para><ulink
url="/configuration_file_basics.htm#Pairs">http://www.shorewall.net/configuration_file_basics.htm#Pairs</ulink></para>
<para>shorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-ecn(5), shorewall-exclusion(5),
shorewall-hosts(5), shorewall_interfaces(5), shorewall-ipsets(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-rtrules(5),
shorewall-routestopped(5), shorewall-rules(5), shorewall.conf(5),
shorewall-secmarks(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)</para>
</refsect1>
</refentry>