shorewall_code/Shorewall6/manpages/shorewall6-conntrack.xml
Tom Eastep acd921cd08 Don't require a helper for ctevents and expevents
Signed-off-by: Tom Eastep <teastep@shorewall.net>
2015-05-16 13:40:40 -07:00

578 lines
23 KiB
XML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?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>shorewall6-conntrack</refentrytitle>
<manvolnum>5</manvolnum>
<refmiscinfo>Configuration Files</refmiscinfo>
</refmeta>
<refnamediv>
<refname>conntrack</refname>
<refpurpose>shorewall6 conntrack file</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>/etc/shorewall6/conntrack</command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>The original intent of the <emphasis role="bold">notrack</emphasis>
file was to exempt certain traffic from Netfilter connection tracking.
Traffic matching entries in the file were not to be tracked.</para>
<para>The role of the file was expanded in Shorewall 4.4.27 to include all
rules that can be added in the Netfilter <emphasis
role="bold">raw</emphasis> table. In 4.5.7, the file's name was changed to
<emphasis role="bold">conntrack</emphasis>.</para>
<para>The file supports two different column layouts: FORMAT 1, FORMAT 2,
and FORMAT 3, FORMAT 1 being the default. The three differ as
follows:</para>
<itemizedlist>
<listitem>
<para>in FORMAT 2 and 3, there is an additional leading ACTION
column.</para>
</listitem>
<listitem>
<para>in FORMAT 3, the SOURCE column accepts no zone name; rather the
ACTION column allows a SUFFIX that determines the chain(s) that the
generated rule will be added to.</para>
</listitem>
</itemizedlist>
<para>When an entry in the following form is encountered, the format of
the following entries are assumed to be of the specified
<replaceable>format</replaceable>.</para>
<simplelist>
<member><emphasis role="bold">[?]FORMAT</emphasis>
<replaceable>format</replaceable></member>
</simplelist>
<para>where <replaceable>format</replaceable> is either <emphasis
role="bold">1</emphasis>,<emphasis role="bold">2</emphasis> or <emphasis
role="bold">3</emphasis>.</para>
<para>Format 3 was introduced in Shorewall 4.5.10. The optional '?' was
introduced in Shorewall 4.5.11 and ?FORMAT is the preferred form; the form
without the '?' is deprecated.</para>
<para>Comments may be attached to Netfilter rules generated from entries
in this file through the use of COMMENT lines. These lines begin with the
word COMMENT; the remainder of the line is treated as a comment which is
attached to subsequent rules until another COMMENT line is found or until
the end of the file is reached. To stop adding comments to rules, use a
line with only the word COMMENT.</para>
<note>
<para>Beginning with Shorewall 4.5.11, ?COMMENT is a synonym for COMMENT
and is preferred.</para>
</note>
<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> - {<emphasis
role="bold">NOTRACK</emphasis>|<emphasis
role="bold">CT</emphasis>:<emphasis
role="bold">helper</emphasis>:<replaceable>name</replaceable>[(<replaceable>arg</replaceable>=<replaceable>val</replaceable>[,...])|<emphasis
role="bold">CT:ctevents:<replaceable>event</replaceable>[,...]|CT:expevents:new|notrack</emphasis>|DROP|LOG|NFLOG(<replaceable>nflog-parameters</replaceable>)|IP6TABLES(<replaceable>target</replaceable>)}[:<replaceable>log-level</replaceable>[:<replaceable>log-tag</replaceable>]][:<replaceable>chain-designator</replaceable>]</term>
<listitem>
<para>This column is only present when FORMAT &gt;= 2. Values other
than NOTRACK require <firstterm>CT Target </firstterm>support in
your iptables and kernel.</para>
<itemizedlist>
<listitem>
<para><option>NOTRACK</option> or
<option>CT:notrack</option></para>
<para>Disables connection tracking for this packet. If a
<replaceable>log-level</replaceable> is specified, the packet
will also be logged at that level.</para>
</listitem>
<listitem>
<para><option>helper</option>:<replaceable>name</replaceable></para>
<para>Attach the helper identified by the
<replaceable>name</replaceable> to this connection. This is more
flexible than loading the conntrack helper with preset ports. If
a <replaceable>log-level</replaceable> is specified, the packet
will also be logged at that level.</para>
<para>At this writing, the available helpers are:</para>
<variablelist>
<varlistentry>
<term>amanda</term>
<listitem>
<para>Requires that the amanda netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>ftp</term>
<listitem>
<para>Requires that the FTP netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>irc</term>
<listitem>
<para>Requires that the IRC netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>netbios-ns</term>
<listitem>
<para>Requires that the netbios_ns (sic) helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>RAS and Q.931</term>
<listitem>
<para>These require that the H323 netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>pptp</term>
<listitem>
<para>Requires that the pptp netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>sane</term>
<listitem>
<para>Requires that the SANE netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>sip</term>
<listitem>
<para>Requires that the SIP netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>snmp</term>
<listitem>
<para>Requires that the SNMP netfilter helper is
present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>tftp</term>
<listitem>
<para>Requires that the TFTP netfilter helper is
present.</para>
</listitem>
</varlistentry>
</variablelist>
<para>May be followed by an option list of
<replaceable>arg</replaceable>=<replaceable>val</replaceable>
pairs in parentheses:</para>
<itemizedlist>
<listitem>
<para><option>ctevents</option>=<replaceable>event</replaceable>[,...]</para>
<para>Only generate the specified conntrack events for this
connection. Possible event types are: <emphasis
role="bold">new</emphasis>, <emphasis
role="bold">related</emphasis>, <emphasis
role="bold">destroy</emphasis>, <emphasis
role="bold">reply</emphasis>, <emphasis
role="bold">assured</emphasis>, <emphasis
role="bold">protoinfo</emphasis>, <emphasis
role="bold">helper</emphasis>, <emphasis
role="bold">mark</emphasis> (this is connection mark, not
packet mark), <emphasis role="bold">natseqinfo</emphasis>,
and <emphasis role="bold">secmark</emphasis>. If more than
one <emphasis>event</emphasis> is listed, the
<replaceable>event</replaceable> list must be enclosed in
parentheses (e.g., ctevents=(new,related)).</para>
</listitem>
<listitem>
<para><option>expevents</option><option>=new</option></para>
<para>Only generate <emphasis role="bold">new</emphasis>
expectation events for this connection.</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>ctevents:<replaceable>event</replaceable>[,...]</para>
<para>Added in Shorewall 4.6.10. Only generate the specified
conntrack events for this connection. Possible event types are:
<emphasis role="bold">new</emphasis>, <emphasis
role="bold">related</emphasis>, <emphasis
role="bold">destroy</emphasis>, <emphasis
role="bold">reply</emphasis>, <emphasis
role="bold">assured</emphasis>, <emphasis
role="bold">protoinfo</emphasis>, <emphasis
role="bold">helper</emphasis>, <emphasis
role="bold">mark</emphasis> (this is connection mark, not packet
mark), <emphasis role="bold">natseqinfo</emphasis>, and
<emphasis role="bold">secmark</emphasis>.</para>
</listitem>
<listitem>
<para>expevents=new</para>
<para>Added in Shorewall 4.6.10. Only generate <emphasis
role="bold">new</emphasis> expectation events for this
connection.</para>
</listitem>
<listitem>
<para><option>DROP</option></para>
<para>Added in Shorewall 4.5.10. Silently discard the packet. If
a <replaceable>log-level</replaceable> is specified, the packet
will also be logged at that level.</para>
</listitem>
<listitem>
<para><option>IP6TABLES</option>(<replaceable>target</replaceable>)</para>
<para>Added in Shorewall 4.6.0. Allows you to specify any
iptables <replaceable>target</replaceable> with target options
(e.g., "IP6TABLES(AUDIT --type drop)"). 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
<replaceable>target</replaceable> as a builtin action in <ulink
url="/manpages6/shorewall6-actions.html">shorewall6-actions(5)</ulink>.</para>
</listitem>
<listitem>
<para><option>LOG</option></para>
<para>Added in Shoreawll 4.6.0. Logs the packet using the
specified <replaceable>log-level</replaceable> and<replaceable>
log-tag </replaceable>(if any). If no log-level is specified,
then 'info' is assumed.</para>
</listitem>
<listitem>
<para><option>NFLOG</option></para>
<para>Added in Shoreawll 4.6.0. Queues the packet to a backend
logging daemon using the NFLOG netfilter target with the
specified <replaceable>nflog-parameters</replaceable>.</para>
</listitem>
</itemizedlist>
<para>When FORMAT = 1, this column is not present and the rule is
processed as if NOTRACK had been entered in this column.</para>
<para>Beginning with Shorewall 4.5.10, when FORMAT = 3, this column
can end with a colon followed by a
<replaceable>chain-designator</replaceable>. The
<replaceable>chain-designator</replaceable> can be one of the
following:</para>
<variablelist>
<varlistentry>
<term>P</term>
<listitem>
<para>The rule is added to the raw table PREROUTING chain.
This is the default if no
<replaceable>chain-designator</replaceable> is present.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>O</term>
<listitem>
<para>The rule is added to the raw table OUTPUT chain.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PO or OP</term>
<listitem>
<para>The rule is added to the raw table PREROUTING and OUTPUT
chains.</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
</varlistentry>
<varlistentry>
<term>SOURCE (formats 1 and 2)
<emphasis>zone</emphasis>[:<emphasis>interface</emphasis>][:<emphasis>address-list</emphasis>]</term>
<listitem>
<para>where <replaceable>zone</replaceable> is the name of a zone,
<replaceable>interface</replaceable> is an interface to that zone,
and <replaceable>address-list</replaceable> is a comma-separated
list of addresses (may contain exclusion - see <ulink
url="/manpages6/shorewall6-exclusion.html">shorewall6-exclusion</ulink>
(5)).</para>
<para>Beginning with Shorewall 4.5.7, <option>all</option> can be
used as the <replaceable>zone</replaceable> name to mean
<firstterm>all zones</firstterm>.</para>
<para>Beginning with Shorewall 4.5.10, <option>all-</option> can be
used as the <replaceable>zone</replaceable> name to mean all
<firstterm>off-firewall zone</firstterm>s.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>SOURCE (format 3)
{-|<emphasis>interface</emphasis>[:<emphasis>address-list</emphasis>]|<replaceable>address-list</replaceable>}</term>
<listitem>
<para>Where <replaceable>interface</replaceable> is an interface to
that zone, and <replaceable>address-list</replaceable> is a
comma-separated list of addresses (may contain exclusion - see
<ulink
url="/manpages6/shorewall6-exclusion.html">shorewall6-exclusion</ulink>
(5)).</para>
<para>COMMENT is only allowed in format 1; the remainder of the line
is treated as a comment that will be associated with the generated
rule(s).</para>
</listitem>
</varlistentry>
<varlistentry>
<term>DEST
{-|<emphasis>interface</emphasis>[:<emphasis>address-list</emphasis>]|<replaceable>address-list</replaceable>}</term>
<listitem>
<para>where <replaceable>address-list</replaceable> is a
comma-separated list of addresses (may contain exclusion - see
<ulink
url="/manpages6/shorewall6-exclusion.html">shorewall6-exclusion</ulink>
(5)).</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PROTO
<replaceable>protocol-name-or-number</replaceable>[,...]</term>
<listitem>
<para>A protocol name from <filename>/etc/protocols</filename> or a
protocol number.</para>
<para>Beginning with Shorewall 4.5.12, this column can accept a
comma-separated list of protocols.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>DEST PORT(S) (dport) -
{-|<replaceable>port-number/service-name-list</replaceable>|+<replaceable>ipset</replaceable>}</term>
<listitem>
<para>A comma-separated list of port numbers and/or service names
from <filename>/etc/services</filename>. May also include port
ranges of the form
<replaceable>low-port</replaceable>:<replaceable>high-port</replaceable>
if your kernel and iptables include port range support.</para>
<para>Beginning with Shorewall 4.6.0, an ipset name can be specified
in this column. This is intended to be used with
<firstterm>bitmap:port</firstterm> ipsets.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>SOURCE PORT(S) (sport) -
{-|<replaceable>port-number/service-name-list</replaceable>|+<replaceable>ipset</replaceable>}</term>
<listitem>
<para>A comma-separated list of port numbers and/or service names
from <filename>/etc/services</filename>. May also include port
ranges of the form
<replaceable>low-port</replaceable>:<replaceable>high-port</replaceable>
if your kernel and iptables include port range support.</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).</para>
<para>Beginning with Shorewall 4.6.0, an ipset name can be specified
in this column. This is intended to be used with
<firstterm>bitmap:port</firstterm> ipsets.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>USER/GROUP (user)
[<replaceable>user</replaceable>][:<replaceable>group</replaceable>]</term>
<listitem>
<para>May only be specified if the SOURCE
<replaceable>zone</replaceable> is $FW. Specifies the effective user
id and or group id of the process sending the traffic.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis role="bold">SWITCH -
[!]<replaceable>switch-name</replaceable>[={0|1}]</emphasis></term>
<listitem>
<para>Added in Shorewall6 4.5.10 and allows enabling and disabling
the rule without requiring <command>shorewall6
restart</command>.</para>
<para>Enables the rule if the value stored in
<filename>/proc/net/nf_condition/<replaceable>switch-name</replaceable></filename>
is 1. Disables the rule if that file contains 0 (the default). If
'!' is supplied, the test is inverted such that the rule is enabled
if the file contains 0.</para>
<para>Within the <replaceable>switch-name</replaceable>, '@0' and
'@{0}' are replaced by the name of the chain to which the rule is a
added. The <replaceable>switch-name</replaceable> (after '@...'
expansion) must begin with a letter and be composed of letters,
decimal digits, underscores or hyphens. Switch names must be 30
characters or less in length.</para>
<para>Switches are normally <emphasis role="bold">off</emphasis>. To
turn a switch <emphasis role="bold">on</emphasis>:</para>
<simplelist>
<member><command>echo 1 &gt;
/proc/net/nf_condition/<replaceable>switch-name</replaceable></command></member>
</simplelist>
<para>To turn it <emphasis role="bold">off</emphasis> again:</para>
<simplelist>
<member><command>echo 0 &gt;
/proc/net/nf_condition/<replaceable>switch-name</replaceable></command></member>
</simplelist>
<para>Switch settings are retained over <command>shorewall6
restart</command>.</para>
<para>When the <replaceable>switch-name</replaceable> is followed by
<option>=0</option> or <option>=1</option>, then the switch is
initialized to off or on respectively by the
<command>start</command> command. Other commands do not affect the
switch setting.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>EXAMPLES</title>
<para>Example 1:</para>
<para>Use the FTP helper for TCP port 21 connections from the firewall
itself.</para>
<programlisting>FORMAT 2
#ACTION SOURCE DEST PROTO DEST SOURCE USER/GROUP
# PORT(S) PORT(S)
CT:helper:ftp(expevents=new) fw - tcp 21 </programlisting>
<para>Example 2 (Shorewall 4.5.10 or later):</para>
<para>Drop traffic to/from all zones to IP address 2001:1.2.3::4</para>
<programlisting>FORMAT 2
#ACTION SOURCE DEST PROTO DEST SOURCE USER/GROUP
# PORT(S) PORT(S)
DROP all-:2001:1.2.3::4 -
DROP all 2001:1.2.3::4
</programlisting>
<para>or<programlisting>FORMAT 3
#ACTION SOURCE DEST PROTO DEST SOURCE USER/GROUP
# PORT(S) PORT(S)
DROP:P 2001:1.2.3::4 -
DROP:PO - 2001:1.2.3::4
</programlisting></para>
</refsect1>
<refsect1>
<title>FILES</title>
<para>/etc/shorewall6/notrack</para>
</refsect1>
<refsect1>
<title>See ALSO</title>
<para><ulink
url="/configuration_file_basics.htm#Pairs">http://www.shorewall.net/configuration_file_basics.htm#Pairs</ulink></para>
<para>shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5),
shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5),
shorewall6-ipsec(5), shorewall6-netmap(5),shorewall6-params(5),
shorewall6-policy(5), shorewall6-providers(5), shorewall6-proxyarp(5),
shorewall6-rtrules(5), shorewall6-routestopped(5), shorewall6-rules(5),
shorewall6.conf(5), shorewall6-secmarks(5), shorewall6-tcclasses(5),
shorewall6-tcdevices(5), shorewall6-mangle(5), shorewall6-tos(5),
shorewall6-tunnels(5), shorewall-zones(5)</para>
</refsect1>
</refentry>