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shorewall_code/Shorewall/manpages/shorewall-tcrules.xml
Tom Eastep cb7fc31f0b Restore 4.5.3 compatibility 
Signed-off-by: Tom Eastep <teastep@shorewall.net>
2012-05-10 14:23:33 -07:00

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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-tcrules</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>tcrules</refname>
<refpurpose>Shorewall Packet Marking rules file</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>/etc/shorewall/tcrules</command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<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="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="http://shorewall.net/MultiISP.html">http://shorewall.net/MultiISP.html</ulink>.</para>
</important>
<para>Beginning with Shorewall 4.5.4, the tcrules file supports two
different formats:</para>
<variablelist>
<varlistentry>
<term>FORMAT 1 (default - deprecated)</term>
<listitem>
<para>The older limited-function version of TPROXY is
supported.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>FORMAT 2</term>
<listitem>
<para>The newer version of TPROXY is supported.</para>
</listitem>
</varlistentry>
</variablelist>
<para>The format is specified by a line as follows:</para>
<blockquote>
<para><emphasis role="bold">FORMAT {1|2}</emphasis></para>
</blockquote>
<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> (mark) -
<replaceable>mark</replaceable></term>
<listitem>
<para>Where <replaceable>mark</replaceable> may assume one of the
following values.</para>
<orderedlist numeration="arabic">
<listitem>
<para>A mark <emphasis>value</emphasis> which is an integer in
the range 1-255.</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; neither may be used with connection
marks (see below).</para>
<para>May optionally be followed by <emphasis
role="bold">:P</emphasis>, <emphasis
role="bold">:F</emphasis>,<emphasis role="bold">:T</emphasis> or
<emphasis role="bold">:I</emphasis> where<emphasis role="bold">
:P</emphasis> indicates that marking should occur in the
PREROUTING chain, <emphasis role="bold">:F</emphasis> indicates
that marking should occur in the FORWARD chain, <emphasis
role="bold">:I </emphasis>indicates that marking should occur in
the INPUT chain (added in Shorewall 4.4.13), and <emphasis
role="bold">:T</emphasis> indicates that marking should occur in
the POSTROUTING chain. If neither <emphasis
role="bold">:P</emphasis>, <emphasis role="bold">:F</emphasis>
nor <emphasis role="bold">:T</emphasis> follow the mark value
then the chain is determined as follows:</para>
<para>- If the SOURCE is <emphasis
role="bold">$FW</emphasis>[<emphasis
role="bold">:</emphasis><emphasis>address-or-range</emphasis>[,<emphasis>address-or-range</emphasis>]...],
then the rule is inserted into the OUTPUT chain. When
HIGH_ROUTE_MARKS=Yes, only high mark values may be assigned
there. Packet marking rules for traffic shaping of packets
originating on the firewall must be coded in the POSTROUTING
chain (see below).</para>
<para>- Otherwise, the chain is determined by the setting of
MARK_IN_FORWARD_CHAIN in <ulink
url="shorewall.conf.html">shorewall.conf</ulink>(5).</para>
<para>Please note that <emphasis role="bold">:I</emphasis> is
included for completeness and affects neither traffic shaping
nor policy routing.</para>
<para>If your kernel and iptables include CONNMARK support then
you can also mark the connection rather than the packet.</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). The mark and optional mask are then
followed by one of:</para>
<variablelist>
<varlistentry>
<term><emphasis role="bold">C</emphasis></term>
<listitem>
<para>Mark the connection in the chain determined by the
setting of MARK_IN_FORWARD_CHAIN</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CF</emphasis></term>
<listitem>
<para>Mark the connection in the FORWARD chain</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CP</emphasis></term>
<listitem>
<para>Mark the connection in the PREROUTING chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>CT</term>
<listitem>
<para>Mark the connecdtion in the POSTROUTING chain</para>
</listitem>
</varlistentry>
<varlistentry>
<term>CI</term>
<listitem>
<para>Mark the connection in the INPUT chain. This option
is included for completeness and has no applicability to
traffic shaping or policy routing.</para>
</listitem>
</varlistentry>
</variablelist>
<para><emphasis role="bold">Special considerations for If
HIGH_ROUTE_MARKS=Yes in <ulink
url="shorewall.conf.html">shorewall.conf</ulink>(5</emphasis>).</para>
<para>If HIGH_ROUTE_MARKS=Yes, then you may also specify a value
in the range 0x0100-0xFF00 with the low-order byte being zero.
Such values may only be used in the PREROUTING chain (value
followed by <emphasis role="bold">:P</emphasis> or you have set
MARK_IN_FORWARD_CHAIN=No in <ulink
url="shorewall.conf.html">shorewall.conf</ulink>(5) and have not
followed the value with <option>:F</option>) or the OUTPUT chain
(SOURCE is <emphasis role="bold">$FW</emphasis>). With
HIGH_ROUTE_MARKS=Yes, non-zero mark values less that 256 are not
permitted. Shorewall prohibits non-zero mark values less that
256 in the OUTPUT chain when HIGH_ROUTE_MARKS=Yes. While earlier
versions allow such values in the OUTPUT chain, it is strongly
recommended that with HIGH_ROUTE_MARKS=Yes, you use the
POSTROUTING chain to apply traffic shaping
marks/classification.</para>
</listitem>
<listitem>
<para>A classification Id (classid) 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="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="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>
<para>Beginning with Shorewall 4.4.27, the classid may be
optionally followed by ':' and a capital letter designating the
chain where classification is to occur.</para>
<variablelist>
<varlistentry>
<term>F</term>
<listitem>
<para>FORWARD chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>T</term>
<listitem>
<para>POSTROUTING chain (default).</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
<listitem>
<para><emphasis
role="bold">RESTORE</emphasis>[/<emphasis>mask</emphasis>] --
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>
<para>As in 1) above, may be followed by <emphasis
role="bold">:P</emphasis> or <emphasis
role="bold">:F</emphasis></para>
</listitem>
<listitem>
<para><emphasis
role="bold">SAVE</emphasis>[/<emphasis>mask</emphasis>] -- 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>
<para>As in 1) above, may be followed by <emphasis
role="bold">:P</emphasis> or <emphasis
role="bold">:F</emphasis></para>
</listitem>
<listitem>
<para><emphasis role="bold">CONTINUE</emphasis> Don't process
any more marking rules ‒in the table.</para>
<para>As in 1) above, may be followed by <emphasis
role="bold">:P</emphasis> or <emphasis
role="bold">:F</emphasis>. 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>
<listitem>
<para><emphasis role="bold">SAME</emphasis> 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>
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 five
minutes 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>
<listitem>
<para><emphasis role="bold">COMMENT</emphasis> -- 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>
<listitem>
<para><emphasis role="bold">IPMARK</emphasis> ‒ 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
chose instent 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>
<listitem>
<para><emphasis role="bold">DIVERT</emphasis></para>
<para>Added in Shorewall 4.5.4 and only available when FORMAT is
2. Two DIVERT rule should preceed 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>
<listitem>
<para><emphasis
role="bold">TPROXY</emphasis>(<replaceable>mark</replaceable>[,[<replaceable>port</replaceable>][,[<replaceable>address</replaceable>]]])
-- FORMAT 1</para>
<para>Transparently redirects a packet without altering the IP
header. Requires a local provider to be defined in <ulink
url="shorewall-providers.html">shorewall-providers</ulink>(5).</para>
<para>There are three parameters to TPROXY - only the first
(mark) is required:</para>
<itemizedlist>
<listitem>
<para><replaceable>mark</replaceable> - the MARK value
corresponding to the local provider in <ulink
url="shorewall-providers.html">shorewall-providers</ulink>(5).</para>
</listitem>
<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>
<listitem>
<para><emphasis
role="bold">TPROXY</emphasis>([<replaceable>port</replaceable>][,<replaceable>address</replaceable>])
-- FORMAT 2</para>
<para>Transparently redirects a packet without altering the IP
header. Requires a tproxy provider to be defined in <ulink
url="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>
<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. May be option followed by
<emphasis role="bold">:F</emphasis> but the resulting rule is
always added to the FORWARD chain. 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>
<listitem>
<para><emphasis
role="bold">IMQ</emphasis>(<replaceable>number</replaceable>)</para>
<para>Added in Shorewall 4.5.1. 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>
<listitem>
<para><emphasis
role="bold">DSCP</emphasis>(<replaceable>dscp</replaceable>)</para>
<para>Added in Shorewall 4.5.1. 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>May be optionally followed by ':' and a capital letter
designating the chain where classification is to occur.</para>
<variablelist>
<varlistentry>
<term>F</term>
<listitem>
<para>FORWARD chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>T</term>
<listitem>
<para>POSTROUTING chain (default).</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
<listitem>
<para><emphasis
role="bold">TOS</emphasis>(<replaceable>tos</replaceable>[/<replaceable>mask</replaceable>])</para>
<para>Added in Shorewall 4.5.1. 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>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>
<para>May be optionally followed by ':' and a capital letter
designating the chain where classification is to occur.</para>
<variablelist>
<varlistentry>
<term>F</term>
<listitem>
<para>FORWARD chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>T</term>
<listitem>
<para>POSTROUTING chain.</para>
</listitem>
</varlistentry>
</variablelist>
</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="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="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>
</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>]...]</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 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>.</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>
</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>]...]</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>
</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 Length. This field, if present allow you to
match the length of a packet 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 Netfiler 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. You can also append "-" and a port
number to the helper module name (e.g., <emphasis
role="bold">ftp-21</emphasis>) to specify the port number that the
original connection was made on.</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>
</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)
1:T 0.0.0.0/0 0.0.0.0/0 icmp echo-request
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
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 classifed (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>
</variablelist>
</refsect1>
<refsect1>
<title>FILES</title>
<para>/etc/shorewall/tcrules</para>
</refsect1>
<refsect1>
<title>See ALSO</title>
<para><ulink
url="http://shorewall.net/traffic_shaping.htm">http://shorewall.net/traffic_shaping.htm</ulink></para>
<para><ulink
url="http://shorewall.net/MultiISP.html">http://shorewall.net/MultiISP.html</ulink></para>
<para><ulink
url="http://shorewall.net/PacketMarking.html">http://shorewall.net/PacketMarking.html</ulink></para>
<para><ulink
url="http://shorewall.net/configuration_file_basics.htm#Pairs">http://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>
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