NAME
iptables2dot - turn iptables-save output into graphs for GraphViz
SYNOPSIS
iptables2dot [options] [iptables-save-output-file]
OPTIONS
--help Print a brief help message and exit.
--manual
Print the manual page and exit.
--add-optdef optdef
Provide an option definition for an iptables option that is
unknown to the rule parser from App::Iptables2Dot.
If the program dies with the message *unknown argument in rule:
--unknown-opt arg*, you could run it like this:
iptables2dot --add-optdef unknown-opt=s iptables-save-output
This may allow you to finish your analysis of
iptables-save-output-file without having to modify the module
source in *lib/App/Iptables2Dot.pm*. Look at App::Iptables2Dot
for further information.
--edgelabel
Provide labels at the edge showing the input or output device
for a jump rule.
--omittargets targetlist
Omit some jump targets in the *dot* graph when given together
with "--showrules". Multiple targets are separated by comma.
--showrules/--noshowrules
Show/don't show the rules for the chains. Default is
"--showrules".
--showunusednodes/--noshowunusednodes
Show/don't show chains without jumps to other chains. Default is
"--noshowunusednodes".
--tables tablelist
Only print the tables given in *tablelist*. The tables in
*tablelist* are separated by comma.
Possible tables are "nat", "raw", "mangle" and "filter".
Defaults to table "filter".
DESCRIPTION
This program takes the output from the command "iptables-save" on Linux
and turns into input suitable for the "dot" program from GraphViz.
It takes the output form "iptables-save" either from standard input
(STDIN) or from a text file whose name was given on the command line.
It writes the graph description for the "dot" program to standard output
(STDOUT).
The main purpose of this program is to get an overview of a given
iptables configuration and understand the possible jumps between
different chains in the tables. I usually make a printout of the graph
for the different tables and have it at hand when studying the rules.
The typical workflow is:
$ sudo iptables-save \
| iptables2dot -noshowrules -table filter \
> iptables-filter-overview.dot
$ dot -Tpdf iptables-filter-overview.dot -o iptables-filter-overview.pdf
Although it is possible to make a detailed graph of an iptables
configuration containing all rules, I wouldn't recommend this in most
cases.
In those configurations, where you would need the graph to comprehend
the rules, the resulting graph would be a mess.
When the graph looks neat and is legible on A4 paper, you would probably
understand the configuration without it. But it could be handy to
explain the rules to someone else, following them with a pencil or your
finger.
You would do this to get a detailed graph:
$ sudo iptables-save \
| iptables2dot -edgelabel -table filter \
> iptables-filter.dot
$ dot -Tpdf iptables-filter.dot -o iptables-filter.pdf
DIAGNOSTICS
"unknown argument in rule: %s"
The program will die with this message showing the rule for
*iptables-save* that contained an unknown option.
Since the rules are parsed by "GetOptionsFromString()" from module
*Getopt::Long*, you may workaround this by adding the unknown option
to the array @optdefs at the top of Apt/Iptables2Dot.pm. After that
please file a bug at <
https://rt.cpan.org/> or send me a notice at
[email protected] to have it fixed in one of the next releases of this
distribution.
Alternatively you may want to use the program like this
iptables2dot --add-optdef unknown-opt=s ...
if the program dies with message *unknown argument in rule:
--unknown-opt arg ...* and you don't want to touch the library file
*Apt/Iptables2Dot.pm*.
AUTHOR
Mathias Weidner <
[email protected]>
