shorewall_code/manpages/shorewall-tcrules.xml
2006-11-22 03:51:39 +00:00

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<?xml version="1.0" encoding="UTF-8"?>
<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/</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 shorewall-rules(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
http://shorewall.net/MultiISP.html.</para>
</important>
<para>The columns in the file are as follows.</para>
<variablelist>
<varlistentry>
<term><emphasis role="bold">MARK/CLASSIFY</emphasis></term>
<listitem>
<orderedlist numeration="loweralpha">
<listitem>
<para>A mark value 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>If HIGH_ROUTE_MARKS=Yes in shorewall.conf 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">:F</emphasis> or you have set
MARK_IN_FORWARD_CHAIN=Yes in shorewall conf and have not
followed the value with :P) or the OUTPUT chain (SOURCE is
<emphasis role="bold">$FW</emphasis>).</para>
<para>May optionally be followed by <emphasis
role="bold">:P</emphasis> or <emphasis role="bold">:F</emphasis>
where<emphasis role="bold"> :P</emphasis> indicates that marking
should occur in the PREROUTING chain and <emphasis
role="bold">:F</emphasis> indicates that marking should occur in
the FORWARD chain. If neither <emphasis
role="bold">:P</emphasis> nor <emphasis
role="bold">:F</emphasis> follow the mark value then the chain
is determined by the setting of MARK_IN_FORWARD_CHAIN in
shorewall.conf(5).</para>
<para>If your kernel and iptables include CONNMARK support then
you can also mark the connection rather than the packet.</para>
<para>The mark value may be optionally followed by "/" and a
mask value (used to determine those bits of the connection mark
to actually be set). The mark and optional mask are then
followed by one of:</para>
<variablelist>
<varlistentry>
<term><emphasis role="bold">C</emphasis></term>
<listitem>
<para>Mark the connection in the chain determined by the
setting of MARK_IN_FORWARD_CHAIN</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CF</emphasis></term>
<listitem>
<para>Mark the connection in the FORWARD chain</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">CP</emphasis></term>
<listitem>
<para>Mark the connection in the PREROUTING chain.</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
<listitem>
<para>A classification (classid) of the form
<emphasis>major</emphasis>:<emphasis>minor</emphasis> where
<emphasis>major</emphasis> and <emphasis>minor</emphasis> are
integers. Corresponds to the 'class' specification in these
traffic shaping modules:</para>
<programlisting> atm
cbq
dsmark
pfifo_fast
htb
prio</programlisting>
<para>Classification occurs in the POSTROUTING chain except when
the <emphasis role="bold">SOURCE</emphasis> is <emphasis
role="bold">$FW</emphasis>[:<emphasis>address</emphasis>] in
which case marking occurs in the OUTPUT chain.</para>
</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 a) 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 a) 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 a) above, may be followed by <emphasis
role="bold">:P</emphasis> or <emphasis
role="bold">:F</emphasis></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>
</orderedlist>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SOURCE</emphasis></term>
<listitem>
<para>Source of the packet. A comma-separated list of interface
names, IP addresses, MAC addresses and/or subnets for packets being
routed through a common path. List elements may also consist of an
interface name followed by ":" and an address (e.g.,
eth1:192.168.1.0/24). For example, all packets for connections
masqueraded to eth0 from other interfaces can be matched in a single
rule with several alternative SOURCE criteria. However, a connection
whose packets gets to eth0 in a different way, e.g., direct from the
firewall itself, needs a different rule.</para>
<para>Accordingly, use $<emphasis role="bold">FW</emphasis> in its
own separate rule for packets originating on the firewall. In such a
rule, the MARK column may NOT specify either <emphasis
role="bold">:P</emphasis> or <emphasis role="bold">:F</emphasis>
because marking for firewall-originated packets always occurs in the
OUTPUT chain.</para>
<para>MAC addresses must be prefixed with "~" and use "-" as a
separator.</para>
<para>Example: ~00-A0-C9-15-39-78</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">DEST</emphasis></term>
<listitem>
<para>Destination of the packet. Comma separated list of IP
addresses and/or subnets. If your kernel and iptables include
iprange match support, IP address ranges are also allowed. List
elements may also consist of an interface name followed by ":" and
an address (e.g., eth1:192.168.1.0/24). If the <emphasis
role="bold">MARK</emphasis> column specificies a classification of
the form <emphasis>major</emphasis>:<emphasis>minor</emphasis> then
this column may also contain an interface name.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">PROTO</emphasis></term>
<listitem>
<para>Protocol - Must be <emphasis role="bold">tcp</emphasis>,
<emphasis role="bold">udp</emphasis>, <emphasis
role="bold">icmp</emphasis>, <emphasis
role="bold">ipp2p</emphasis>,<emphasis role="bold">
ipp2p:udp</emphasis>, <emphasis role="bold">ipp2p:all</emphasis> a
<emphasis>number</emphasis>, or <emphasis
role="bold">all</emphasis>. <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></term>
<listitem>
<para>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).</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>This column is ignored if PROTOCOL = all but must be entered
if any of the following field is supplied. In that case, it is
suggested that this field contain "-"</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SOURCE PORT(S)</emphasis>
(Optional)</term>
<listitem>
<para>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>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">USER</emphasis></term>
<listitem>
<para>This column may only be non-empty if the SOURCE is the
firewall itself.</para>
<para>The column may contain:</para>
<para>[!][<emphasis>user name or number</emphasis>][:<emphasis>group
name or number</emphasis>][+<emphasis>program
name</emphasis>]</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>TEST</term>
<listitem>
<para>Defines a test on the existing packet or connection mark. The
rule will match only if the test returns true. Tests have the
format</para>
<para>[<emphasis
role="bold">!</emphasis>]<emphasis>value</emphasis>[/<emphasis>mask</emphasis>][<emphasis
role="bold">:C</emphasis>]</para>
<para>Where:</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>
<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>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">LENGTH</emphasis> (Optional)</term>
<listitem>
<para>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></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>
</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> #MARK/ SOURCE DEST PROTO PORT(S) SOURCE USER TEST
#CLASSIFY PORT(S)
1 0.0.0.0/0 0.0.0.0/0 icmp echo-request
1 0.0.0.0/0 0.0.0.0/0 icmp echo-reply
RESTORE 0.0.0.0/0 0.0.0.0/0 all - - - 0
CONTINUE 0.0.0.0/0 0.0.0.0/0 all - - - !0
4 0.0.0.0/0 0.0.0.0/0 ipp2p:all
SAVE 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>shorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-hosts(5), shorewall-interfaces(5),
shorewall-ipsec(5), shorewall-maclist(5), shorewall-masq(5),
shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5),
shorewall-route_rules(5), shorewall-routestopped(5), shorewall-rules(5),
shorewall.conf(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)</para>
</refsect1>
</refentry>