#!/usr/bin/perl
#
# usage:
#
# IPv6-DNS.pl  -file   < filename >
#              -domain < domain name >
#              -server < primary name server hostname >
#              -prefix < ipv6 prefix address >
#
#
# IPv6-DNS.pl -- This perl script takes an IPv6 hosts file ( perhaps /etc/hosts )
#                and creates the necessary DNS records ( AAAA and ptr )
#
#             -- Note: the file format must be consistent with that of /etc/hosts
#              
#                2001:db8:baad::feed::1		myhostname
#                 
#             -- The domain name may be specified on the command line
#             -- The primary name server's hostname
#
# Dependencies --
#
#  Net::IP       -- http://www.cpan.org/modules/by-module/Net/Net-IP-1.25.tar.gz
#  Math::BigInt  -- http://www.cpan.org/modules/by-module/Math/Math-BigInt-1.87.tar.gz
#
# created on Thursday, July 5, 2007 by Mark Leighty ( mleighty@harfordtechnology.com )
#
# Copyright (2007) Harford Technology Corporation With the exception of commercial 
# resale, lease, license or other commercial transactions, permission is granted to 
# use, copy, modify, and distribute this software. By exercising this permission you
# agree, that this Notice will accompany this software at all times.
#
# Harford Technology Corporation MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND
# CONCERNING THIS SOFTWARE OR USE THEREOF.
#
#---------------------------- Revision Log ----------------------------------#

$Version = 0.01;                               # mleighty@harfordtechnology.com

# Currently "pre-production" however as features get added and we get some data
# it should achieve basic functionality.

$Version = 0.03;                               # mleighty@harfordtechnology.com

# Resoloved issues with calculating the prefix name/number for file naming.  Also
# resolved many issues with comments in the source/hosts file.


$Version = 0.04									# mleighty@harfordtechnology.com

# Fixed a semantical error that prevented the db files from being constructed properly
# when a prefix beyond a /32 was specified.


#-------------------------- End Revision Log --------------------------------#

#
# Include the standard and specialized perl libraries
#

use Getopt::Long;						# Processes command line arguments
use Net::IP qw(:PROC);					# Processes Address Operations ( v4/v6 )

#
# Evaluate the command line arguments as gracefully as possible via the Getopt::Long library
#

sub Arguments {

   my $length = @ARGV;						# Should be 3 with the supported Options
  
   if ( $length < 3 ) {

      &Usage;
 
   }

} # End "sub Arguments" ----- 


#
# Create a standard usage message.  This will allow us to fail in a reasonably 
# graceful manner if the script is not invoked with the correct options.
#

sub Usage {

   my $definition = shift;

   print "\n";
   print "\n";
   print "Usage:\n";
   print "\n";
   print "IPv6-DNS.pl -file < filename > -domain < domainname> -server <server host name> -prefix < domain ipv6 prefix address >";
   print "\n";
   print "\n";
   print "\n";
   print "Example:\n";
   print "\n";
   print "./IPv6-DNS.pl -file ./IPv6-hosts -domain ipv6-inc.com -server thunder -prefix ./2001:0db8::/32";
   print "\n";
   print "\n";
   print "\n";
   print "\n";
   print "IPv6-DNS.pl .................................... http://www.harfordtechnology.com\n";
   print "\n";

   exit(0)												# Punch out if we've reached this point
 
} # End "sub Usage" -----




#
# -- Begin Main Program Block 
#
# -------------------------------------------------------------------------------------
#
#

&Arguments;												# Check the command line arguments

$result = &GetOptions ( "file=s", "domain=s", "server=s", "prefix=s" );	# utilize the Getoptions routine to process the command line

#
# Arrange varibles from GetOptions for easier manipulation
#

$file   = $opt_file;
$domain = $opt_domain;
$server = $opt_server;
$prefix = $opt_prefix;

( $prefix_number, $prefix_bits ) = split /::/, $prefix;	# extract prefix number and bits for contextual operation


( $prefix_name = $prefix_number ) =~ s/:/-/g;			# modify the prefix such that we can use it as a filename.

$SOURCE_INFO  = $file;
$DB_DOMAIN    = "./db.$domain";
$DB_PREFIX    = "./db.$prefix_name";
$DB_LOCALHOST = "./db.v6localhost";

#
# Process Source Information and normalize IP addresses
#

open SOURCE_INFO or die "can't open $file";

LINE: while ( $line = <SOURCE_INFO> ) {
 											
   next LINE if $line =~/^#|^\n/;					# eliminate any comments or blank lines
   chop $line;										# avoid last "\n' in field
   ( $address, $host ) = split(" ", $line);			# split the logical record into address/host elements
   $address = ip_expand_address($address,6);		# Expand IPv6 address to standard/full form
   $name{$address} .= $host;						# Build array to contain information

}

close SOURCE_INFO;									# close SOURCE_INFO as we now have everything dynamically


#
# handle special case of loopback address in IPv6
#
#  ------------------------------------------------------------------------------
#

$v6_loopback = ip_expand_address("::1",6);			# generate the standard/full form of the IPv6 loopback address

#
# Create the zone file for the localhost ( i.e.; ::1/128 )
#
# This will generate the zone file for the localhost .... generally named 
# db.localhost or in this case db.v6localhost
#
#

open (DB_LOCALHOST, ">$DB_LOCALHOST") or die "can't open $DB_LOCALHOST";	# open the filehandle for the db.v6loclhost file

#
# Print the necessary DNS directives to to the file as specified
#

print DB_LOCALHOST "; Zone file for 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa ( Loopback Interface )\n";
print DB_LOCALHOST "\$TTL 3h\n";
print DB_LOCALHOST ip_reverse($v6_loopback)," IN SOA $server.$domain. hostmaster.$domain. (\n";
print DB_LOCALHOST "\t\t\t\t01\t\t; Serial Number -- Suggest format of YYMMddHHMM\n";
print DB_LOCALHOST "\t\t\t\t3h\t\t; Refresh after 3 hours\n";
print DB_LOCALHOST "\t\t\t\t1h\t\t; Retry after 1 hour\n";
print DB_LOCALHOST "\t\t\t\t1w\t\t; Expire after 1 week\n";
print DB_LOCALHOST "\t\t\t\t1h )\t\t; negative caching ttl of 1 hour\n";
print DB_LOCALHOST "\n";
print DB_LOCALHOST ";\n";
print DB_LOCALHOST "; Name Server Records ( NS )\n";
print DB_LOCALHOST ";\n";
print DB_LOCALHOST ip_reverse($v6_loopback),"\tIN NS\t$server.$domain.\n";
print DB_LOCALHOST "\n";
print DB_LOCALHOST ip_reverse($v6_loopback),"\tIN PTR\tlocalhost.\n";
print DB_LOCALHOST "\n";

close DB_LOCALHOST;									# close db.v6localhost

#
#  ------------------------------------------------------------------------------
#

#
# This section handles the forward lookup for the hosts specified
#
#  ------------------------------------------------------------------------------
#


#
# Create the zone file for the domain ( i.e.; ipv6-inc.com )
#
# This will generate the zone file for the domain .... generally named db.zone or in this case db.ipv6-inc.com
#
#

open (DB_DOMAIN, ">$DB_DOMAIN") or die "can't open $DB_DOMAIN";	# open the filehandle for the db.domain file

print DB_DOMAIN "; Zone file for $domain\n";
print DB_DOMAIN "\$TTL 3h\n";
print DB_DOMAIN "$domain. IN SOA $server.$domain. hostmaster.$domain. (\n";
print DB_DOMAIN "\t\t\t\t\t\t01\t\t; Serial Number -- Suggest format of YYMMddHHMM\n";
print DB_DOMAIN "\t\t\t\t\t\t3h\t\t; Refresh after 3 hours\n";
print DB_DOMAIN "\t\t\t\t\t\t1h\t\t; Retry after 1 hour\n";
print DB_DOMAIN "\t\t\t\t\t\t1w\t\t; Expire after 1 week\n";
print DB_DOMAIN "\t\t\t\t\t\t1h )\t\t; negative caching ttl of 1 hour\n";
print DB_DOMAIN "\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN "; Name Server Records ( NS )\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN "$domain.\t\t\t\t\tIN\tNS\t$server.$domain.\n";
print DB_DOMAIN "\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN "; Special Case for the loopback as always\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN "localhost.$domain.\t\t\t\tIN\tAAAA\t$v6_loopback\n";
print DB_DOMAIN "\n";

print DB_DOMAIN ";\n";
print DB_DOMAIN "; IPv6 Address Records ( AAAA )\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN "\n";

foreach $address ( sort keys %name ) {

   $column = 47;									# arbitrary value to better format the file/table
  
   $entry = $name{$address}.".".$domain.".";		# needed for the array operation
   @test_array = split(//, $entry );				# place the variable into an array to ...
   $width = @test_array + 0;						# get the string length
   
   print DB_DOMAIN "$name{$address}."."$domain.";	
   
   while ( $width <= $column ) {
 
      print DB_DOMAIN " ";							# pad the entry based on the column entry above
      $width++;
   }
  
   $address = ip_expand_address($address,6); 
   print DB_DOMAIN "IN\tAAAA\t$address\n";
  
}

print DB_DOMAIN "\n";
print DB_DOMAIN "\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN "; You may wish to add alias entries ( CNAME ) here\n";
print DB_DOMAIN ";\n";
print DB_DOMAIN ";somehost.$domain.\t\t\t\tIN\tCNAME\tsomeotherhost.$domain.\n";
print DB_DOMAIN "\n";


close DB_DOMAIN;									# close db.$domain

#
#  ------------------------------------------------------------------------------
#

#
# This section handles the reverse lookup for the hosts specified
#
#  ------------------------------------------------------------------------------
#


#
# Create the zone file for the reverse lookup ( i.e.; 2001:db8)
#
# This will generate the zone file for ipv6.arpa .... generally named db.address or in this case db.2001-0db8
#
#

open (DB_PREFIX, ">$DB_PREFIX") or die "can't open $DB_PREFIX";	# open the filehandle for the db.domain file

print DB_PREFIX "; Zone file for ", ip_reverse(ip_expand_address($prefix_number."::",6)),"\n";
print DB_PREFIX "\$TTL 3h\n";
print DB_PREFIX  ip_reverse(ip_expand_address($prefix_number,6)),"\t IN SOA $server.$domain. hostmaster.$domain. (\n";
print DB_PREFIX "\t\t\t\t\t01\t\t; Serial Number -- Suggest format of YYMMddHHMM\n";
print DB_PREFIX "\t\t\t\t\t3h\t\t; Refresh after 3 hours\n";
print DB_PREFIX "\t\t\t\t\t1h\t\t; Retry after 1 hour\n";
print DB_PREFIX "\t\t\t\t\t1w\t\t; Expire after 1 week\n";
print DB_PREFIX "\t\t\t\t\t1h )\t\t; negative caching ttl of 1 hour\n";
print DB_PREFIX "\n";
print DB_PREFIX ";\n";
print DB_PREFIX "; Name Server Records ( NS )\n";
print DB_PREFIX ";\n";
print DB_PREFIX "\n";
print DB_PREFIX ip_reverse(ip_expand_address($prefix_number,6)),"\t\t\t\tIN\tNS\t$server.$domain.\n";
print DB_PREFIX "\n";
print DB_PREFIX ";\n";
print DB_PREFIX "; IPv6 Pointer Records ( PTR ) NOTE - ip6.arpa configuration\n";
print DB_PREFIX ";\n";
print DB_PREFIX "\n";


foreach $address ( sort keys %name ) {
 
   print DB_PREFIX ip_reverse($address), "\tIN\tPTR\t$name{$address}.$domain.\n";
  
}

print DB_PREFIX "\n";


close DB_PREFIX;									# close db.$domain

#
#  ------------------------------------------------------------------------------
#