#!/usr/bin/perl

#  

#  This script uses the named D-BUS support, which must be enabled in

#  the running named with the named '-D' option, to get and print the

#  list of forwarding zones in the running server.

#

#  It accepts an optional <zone> first argument which is the DNS name

#  of the zone whose forwarders (if any) will be retrieved.

#

#  If no zone argument is specified, all forwarding zones will be listed.

#

#  Usage: GetForwarders [-n -r] [ <zone> ]

#    -n : output forward zone statements for named.conf

#    -r : output in resolv.conf format

#       : no -r or -n: just list the forwarders

#

#  Copyright(C) Jason Vas Dias<jvdias@redhat.com> Red Hat Inc. 2005

#

#  This program is free software; you can redistribute it and/or modify

#  it under the terms of the GNU General Public License as published by

#  the Free Software Foundation at

#           http://www.fsf.org/licensing/licenses/gpl.txt

#  and included in this software distribution as the "LICENSE" file.

#

#  This program is distributed 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.  See the

#  GNU General Public License for more details.

#

use Getopt::Std;

%opts=();

getopts("rn",\%opts);

$zone = '';

if ( $#ARGV >= 0 )

{

    $zone = "string:'". join("' string:'",@ARGV)."'";

};

@dn=(); 

open(DNS,

     '/usr/bin/dbus-send --system --type=method_call --print-reply --reply-timeout=20000 '

    .'--dest=com.redhat.named /com/redhat/named com.redhat.named.text.GetForwarders '

    .$zone .'|'

    ) || die("dbus-send failed: $?: $!");

while(<DNS>)

{ 

    $_=~s/[\s\r\n]+$//;

    if ( /(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/ )

    { # nameserver address

	push @{${$dn[-1]}{'s'}}, { 'a' => "$1.$2.$3.$4" }; 

    }elsif

       ( /\"(\d+)\"$/ )      

    { # port

	if ( $1 != 53 )

	{

	    ${@{${$dn[-1]}{'s'}}[-1]}{'p'} = $1;

	};

    }elsif

       ( /string\s+\"([^\"]+)\"$/ )

    { 

	if ( ($1 eq 'first') || ($1 eq 'only') )

	{ # policy

	    if( $1 eq 'only' )

	    { # not default

		${$dn[-1]}{'o'} = 1;

	    }

	}else

	{ # new DN - "zone"

	    push @dn, {'n'=>$1,'s'=>[]}; 

	};

    }; 

};

close(DNS);

if( exists($opts{'r'}) )

{ # resolv.conf style:

    my %svrs=();

    print 'search ', 

          join( ' ', 

		grep { !( $_ =~ /\.in-addr\.arpa$/) }

		map  { ${$_}{'n'} }

		@dn

	      ),"\n",

          'nameserver ',

	  join( "\nnameserver ",

		grep { exists ( $svrs{ $_ } ) ? undef : { $svrs{$_}=$_ } } 

		map  { ${$_}{'a'} }

		map  { @{${$_}{'s'}} } @dn			     

	      ),"\n";

}elsif( exists($opts{'n'}) )

{ # named.conf style:

    foreach $d (@dn)

    {

	print 'zone "',${$d}{'n'},'." IN { type forward; forwarders { ',

	      join("; ",

		   map { exists( ${$_}{'p'} ) 

			 ? ${$_}{'a'} . ' port ' . ${$_}{'p'}  

			 : ${$_}{'a'}

		       } @{${$d}{'s'}}

		  ),

	      '; }; ',

	      exists(${$d}{'o'}) ? ' forward only; ' : '',

              "};\n";

    };

}else

{ # just list:

    foreach $d (@dn)

    {

	print  ${$d}{'n'}, "\n\t", 

	       (exists(${$d}{'o'}) ? "forward only\n\t" : ''),

	       join( "\n\t",	

		     map { exists( ${$_}{'p'} )

			   ? ${$_}{'a'} . ':' . ${$_}{'p'} 

			   : ${$_}{'a'}

		         } @{${$d}{'s'}}

		   ),"\n";

    };

};