extern/shorewall_code
1
0
Fork 1
mirror of https://gitlab.com/shorewall/code.git synced 2024-11-22 23:53:30 +01:00
Code Issues Packages Projects Releases Wiki Activity

Add explanation of maximum zone length

Browse Source 
Signed-off-by: Tom Eastep <teastep@shorewall.net>

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@9690 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
This commit is contained in:
teastep 2009-03-15 15:54:29 +00:00
parent 8dd7895609
commit fc3a2fc386
3 changed files with 85 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Shorewall/Perl/Shorewall/Config.pm
View File

@ -281,7 +281,8 @@ our %validlevels;
# initialize() function does globals initialization for this
# module and is called from an INIT block below. The function is
# also called by Shorewall::Compiler::compiler at the beginning of
# the second and subsequent calls to that function.
# the second and subsequent calls to that function and when compiling
# for IPv6.
#
sub initialize( $ ) {
$family = shift;

42
manpages/shorewall-zones.xml
View File

@ -1,4 +1,6 @@
<?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-zones</refentrytitle>
@ -44,6 +46,46 @@
default LOGFORMAT, zone names can be at most 5 characters
long.</para>
<blockquote>
<para>The maximum length of an iptables log prefix is 29 bytes. As
explained in <ulink
url="shorewall.conf.html">shorewall.conf</ulink> (5), the default
LOGPREFIX formatting string is “Shorewall:%s:%s:” where the first
%s is replaced by the chain name and the second is replaced by the
disposition.</para>
<itemizedlist>
<listitem>
<para>The default formatting string has 12 fixed characters
("Shorewall" and three colons).</para>
</listitem>
<listitem>
<para>The longest of the standard dispositions are ACCEPT and
REJECT which have 6 characters each.</para>
</listitem>
<listitem>
<para>The canonical name for the chain containing the rules
for traffic going from zone 1 to zone 2 is "&lt;zone
1&gt;2&lt;zone 2&gt;".</para>
</listitem>
<listitem>
<para>So if M is the maximum zone name length, such chains can
have length 2*M + 1.</para>
<simplelist>
<member>12 + 6 + 2*M + 1 = 29 which reduces to</member>
<member>2*M = 29 - 12 - 6 = 11 or</member>
<member>M = 5</member>
</simplelist>
</listitem>
</itemizedlist>
</blockquote>
<para>The order in which Shorewall matches addresses from packets to
zones is determined by the order of zone declarations. Where a zone
is nested in one or more other zones, you may either ensure that the

40
manpages6/shorewall6-zones.xml
View File

@ -46,6 +46,46 @@
default LOGFORMAT, zone names can be at most 5 characters
long.</para>
<blockquote>
<para>The maximum length of an iptables log prefix is 29 bytes. As
explained in <ulink
url="shorewall.conf.html">shorewall6.conf</ulink> (5), the default
LOGPREFIX formatting string is “Shorewall:%s:%s:” where the first
%s is replaced by the chain name and the second is replaced by the
disposition.</para>
<itemizedlist>
<listitem>
<para>The default formatting string has 12 fixed characters
("Shorewall" and three colons).</para>
</listitem>
<listitem>
<para>The longest of the standard dispositions are ACCEPT and
REJECT which have 6 characters each.</para>
</listitem>
<listitem>
<para>The canonical name for the chain containing the rules
for traffic going from zone 1 to zone 2 is "&lt;zone
1&gt;2&lt;zone 2&gt;".</para>
</listitem>
<listitem>
<para>So if M is the maximum zone name length, such chains can
have length 2*M + 1.</para>
<simplelist>
<member>12 + 6 + 2*M + 1 = 29 which reduces to</member>
<member>2*M = 29 - 12 - 6 = 11 or</member>
<member>M = 5</member>
</simplelist>
</listitem>
</itemizedlist>
</blockquote>
<para>The order in which Shorewall6 matches addresses from packets
to zones is determined by the order of zone declarations. Where a
zone is nested in one or more other zones, you may either ensure