NAME

       IPTables::Parse - Perl extension for parsing iptables and ip6tables policies

SYNOPSIS

         use IPTables::Parse;

         my $ipt_bin = '/sbin/iptables'; # can set this to /sbin/ip6tables

         my %opts = (
             'iptables' => $ipt_bin,
             'debug'    => 0,
             'verbose'  => 0
         );

         my $ipt_obj = new IPTables::Parse(%opts)
             or die "[*] Could not acquire IPTables::Parse object";

         my $rv = 0;

         my $table = 'filter';
         my $chain = 'INPUT';

         my ($ipt_hr, $rv) = $ipt_obj->default_drop($table, $chain);
         if ($rv) {
             if (defined $ipt_hr->{'all'}) {
                 print "The INPUT chain has a default DROP rule for all protocols.\n";
             } else {
                 for my $proto (qw/tcp udp icmp/) {
                     if (defined $ipt_hr->{$proto}) {
                         print "The INPUT chain drops $proto by default.\n";
                     }
                 }
             }
         } else {
             print "[-] Could not parse $ipt_obj->{'_ipt_bin_name'} policy\n";
         }

         ($ipt_hr, $rv) = $ipt_obj->default_log($table, $chain);
         if ($rv) {
             if (defined $ipt_hr->{'all'}) {
                 print "The INPUT chain has a default LOG rule for all protocols.\n";
             } else {
                 for my $proto (qw/tcp udp icmp/) {
                     if (defined $ipt_hr->{$proto}) {
                         print "The INPUT chain logs $proto by default.\n";
                     }
                 }
             }
         } else {
             print "[-] Could not parse $ipt_obj->{'_ipt_bin_name'} policy\n";
         }

DESCRIPTION

       The "IPTables::Parse" package provides an interface to parse iptables or ip6tables rules
       on Linux systems through the direct execution of iptables/ip6tables commands, or from
       parsing a file that contains an iptables/ip6tables policy listing.  You can get the
       current policy applied to a table/chain, look for a specific user-defined chain, check for
       a default DROP policy, or determing whether or not logging rules exist.

FUNCTIONS

       The IPTables::Parse extension provides an object interface to the following functions:

       chain_policy($table, $chain)
           This function returns the policy (e.g. 'DROP', 'ACCEPT', etc.) for the specified table
           and chain:

             print "INPUT policy: ", $ipt_obj->chain_policy('filter', 'INPUT'), "\n";

       chain_rules($table, $chain)
           This function parses the specified chain and table and returns an array reference for
           all rules in the chain.  Each element in the array reference is a hash with the
           following keys (that contain values depending on the rule): "src", "dst", "protocol",
           "s_port", "d_port", "target", "packets", "bytes", "intf_in", "intf_out", "to_ip",
           "to_port", "state", "raw", and "extended".  The "extended" element contains the rule
           output past the protocol information, and the "raw" element contains the complete rule
           itself as reported by iptables or ip6tables.

       default_drop($table, $chain)
           This function parses the running iptables or ip6tables policy in order to determine if
           the specified chain contains a default DROP rule.  Two values are returned, a hash
           reference whose keys are the protocols that are dropped by default if a global ACCEPT
           rule has not accepted matching packets first, along with a return value that tells the
           caller if parsing the iptables or ip6tables policy was successful.  Note that if all
           protocols are dropped by default, then the hash key 'all' will be defined.

             ($ipt_hr, $rv) = $ipt_obj->default_drop('filter', 'INPUT');

       default_log($table, $chain)
           This function parses the running iptables or ip6tables policy in order to determine if
           the specified chain contains a default LOG rule.  Two values are returned, a hash
           reference whose keys are the protocols that are logged by default if a global ACCEPT
           rule has not accepted matching packets first, along with a return value that tells the
           caller if parsing the iptables or ip6tables policy was successful.  Note that if all
           protocols are logged by default, then the hash key 'all' will be defined.  An example
           invocation is:

             ($ipt_hr, $rv) = $ipt_obj->default_log('filter', 'INPUT');

AUTHOR

       Michael Rash, <mbr@cipherdyne.org>

SEE ALSO

       The IPTables::Parse is used by the IPTables::ChainMgr extension in support of the psad and
       fwsnort projects to parse iptables or ip6tables policies (see the psad(8), and fwsnort(8)
       man pages).  As always, the iptables(8) and ip6tables(8) man pages provide the best
       information on command line execution and theory behind iptables and ip6tables.

       Although there is no mailing that is devoted specifically to the IPTables::Parse
       extension, questions about the extension will be answered on the following lists:

         The psad mailing list: http://lists.sourceforge.net/lists/listinfo/psad-discuss
         The fwsnort mailing list: http://lists.sourceforge.net/lists/listinfo/fwsnort-discuss

       The latest version of the IPTables::Parse extension can be found on CPAN and also here:

         http://www.cipherdyne.org/modules/

       Source control is provided by git:

         http://www.cipherdyne.org/git/IPTables-Parse.git
         http://www.cipherdyne.org/cgi-bin/gitweb.cgi?p=IPTables-Parse.git;a=summary

CREDITS

       Thanks to the following people:

         Franck Joncourt <franck.mail@dthconnex.com>
         Grant Ferley

AUTHOR

       The IPTables::Parse extension was written by Michael Rash <mbr@cipherdyne.org> to support
       the psad and fwsnort projects.  Please send email to this address if there are any
       questions, comments, or bug reports.

COPYRIGHT AND LICENSE

       Copyright (C) 2005-2012 Michael Rash.  All rights reserved.

       This module is free software.  You can redistribute it and/or modify it under the terms of
       the Artistic License 2.0.  More information can be found here:
       http://www.perl.com/perl/misc/Artistic.html

       This program is distributed "as is" in the hope that it will be useful, but without any
       warranty; without even the implied warranty of merchantability or fitness for a particular
       purpose.