#!/usr/bin/perl -w

use strict;

use Getopt::Long;
use vars qw($opt_V $opt_h $opt_i $opt_o $verbose $infile $outfile @inputfile
            $domainname $scope $numOfScopes $netmask $PROGNAME @netlist @elencomac @temp);

$PROGNAME = $0;
sub print_help ();
sub print_usage ();

# Some initializations...
$opt_o="";
$opt_i="";
@temp= ("", "", "", "", "");



# --------------------------------------------------------------------
# Data input reading and check
# --------------------------------------------------------------------
Getopt::Long::Configure('bundling');
GetOptions
        ("V"   => \$opt_V, "version"    => \$opt_V,
         "h"   => \$opt_h, "help"       => \$opt_h,
         "i=s" => \$opt_i, "InputFile=s"  => \$opt_i,
         "o=s" => \$opt_o, "OutputFile=s"  => \$opt_o);


if (($opt_V) || ($opt_h) || ("$opt_o " eq " ") || ("$opt_i " eq " ")) {
        &print_help();
        &print_usage();
        exit 1;
}


($opt_i) || ($opt_i = shift) || ($opt_i = "/tmp/dhcpd.conf.foobar");
$infile = $1 if ($opt_i =~ /([0-9\-\/a-zA-Z\.]+)/);

($opt_o) || ($opt_o = shift) || ($opt_i = "/tmp/dhcpd.temp");
$outfile = $1 if ($opt_o =~ /([0-9\-\/a-zA-Z\.]+)/);

my ($sec,$min,$hour,$mday,$mon,$year,$wday, $yday,$isdst)=localtime(time);

# --------------------------------------------------------------------
# Reading Micro$oft cfg file
# --------------------------------------------------------------------
open(INFILE,"<$infile") || die("Cannot open $infile: $!\n");
while (<INFILE>) {
    push(@inputfile, $_);
}
close(INFILE);

# --------------------------------------------------------------------
# Opening output file
# --------------------------------------------------------------------
open(OUTFILE,">$outfile") || die("Cannot open $outfile: $!\n");

@temp = &rowfind('Dhcp Server ([0-9\.]*) Set DatabaseName "(.*)"');
print OUTFILE "# DHCP Server configuration exported by $PROGNAME ";
printf OUTFILE " at %4d-%02d-%02d %02d:%02d:%02d\n#\n", $year+1900,$mon+1,$mday,$hour,$min,$sec;
print OUTFILE "# Server IP Address: $temp[0]\n";

# Ugly trick to remind me the $temp[1] value later...
$min=$temp[1];
@temp =  &rowfind('Dhcp Server ([0-9\.]*) Set DatabasePath "(.*)"');
print OUTFILE "# Configuration exported from: $temp[1]\\$min\n\n";

# ----- Main parameters
@temp = &rowfind('Dhcp Server ([0-9\.]*) add scope ([0-9\.]*) ([0-9\.]*) "([a-zA-Z0-9\ ]*)"');
my $serverip=$temp[0];
my $scope=$temp[1];
my $netmask=$temp[2];
my $descrizione=$temp[3];
print OUTFILE "ddns-update-style interim;\n";
print OUTFILE "ignore client-updates;\n\n";

# --------------------------------------------------------------------
# Reading "add scope" added subnets
@netlist = `grep -i "add scope" $infile|grep "^Dhcp Server"|sed -e "s/^.*add scope//"|sed -e "s/255.255.*//"|sed -e "s/ //g"`;

$numOfScopes = $#netlist+1;

print " $numOfScopes subnets found.\n";
if ($numOfScopes > 1) {
	print OUTFILE "shared-network $infile {\n\n";
}

# ----- Lease
@temp = &rowfind('Dhcp Server ([0-9\.]*) Add Optiondef ([0-9]*) "Lease" DWORD');
@temp = &rowfind("Dhcp Server ([0-9\.]*) Scope ([0-9\.]*) set optionvalue $temp[1] DWORD ([0-9\"]*)");
print OUTFILE "    option default-lease-time	".  &cleanstring($temp[2])/2 . ";\n";
print OUTFILE "    option max-lease-time	".  &cleanstring($temp[2]) . ";\n\n";

# ----- Domain Name
@temp = &rowfind('Dhcp Server ([0-9\.]*) Add Optiondef ([0-9]*) "Nome dominio DNS" STRING');
@temp = &rowfind("Dhcp Server ([0-9\.]*) Scope ([0-9\.]*) set optionvalue $temp[1] STRING ([a-zA-Z\-0-9\.\"]*)");
$domainname=&cleanstring($temp[2]);


foreach $scope (@netlist) {
	$scope=&cleanstring($scope);
	print $scope;
	# ----- Main parameters
	my $trg = 'Dhcp Server ([0-9\.]*) add scope ' . $scope . ' ([0-9\.]*) "([a-zA-Z0-9\ ]*)"';
print ">>>$trg<<<\n";
	@temp = &rowfind($trg);
	my $serverip=$temp[0];
	my $netmask=$temp[1];
	my $descrizione=$temp[2];
	print OUTFILE "    subnet $scope netmask $netmask { # $descrizione\n";

	# ----- Routers
	@temp = &rowfind('Dhcp Server ([0-9\.]*) Add Optiondef ([0-9]*) "Router"');
	$trg = 'Dhcp Server ([0-9\.]*) Scope ' . $scope . ' set optionvalue ' . $temp[1] . ' IPADDRESS ([0-9\.\ \"]*)';
print ">>>$trg<<<\n";
	@temp = &rowfind($trg);
	print OUTFILE "      option routers	". &cleanstring($temp[1]) . ";\n";
	print OUTFILE "      option subnet-mask   ". $netmask . ";\n";
	print OUTFILE "      option domain-name	".  $domainname . ";\n";

# ----- DNS Servers
	@temp = &rowfind('Dhcp Server ([0-9\.]*) Add Optiondef ([0-9]*) "(.*)DNS(.*)" IPADDRESS');
	$trg = 'Dhcp Server ([0-9\.]*) Scope ' . $scope . ' set optionvalue ' . $temp[1] . ' IPADDRESS ([0-9\.\ \"]*)';
print ">>>$trg<<<\n";
	@temp = &rowfind($trg);
	print OUTFILE "	     option domain-name-servers ".  &cleanstring($temp[1])  . ";\n\n";

	print OUTFILE "      range.....\n";

	print OUTFILE "\n    }\n\n";
}

print OUTFILE "# --------------------------------------------------------\n";
print OUTFILE "# Reserved IP section starts here\n";
my ($row, $myip, $mymac, $myname, $mydescr);

foreach $scope (@netlist) {
	@elencomac = `grep -i "Add reservedip" $infile|grep "^Dhcp Server $serverip Scope $scope" | sed -e "s/.*Add reservedip //i" | sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k 4,4`;

	print OUTFILE "# Subnet $scope reservation\n";
	foreach $row (@elencomac) {
		if ($row =~ /([0-9\.]*) ([0-9a-fA-F]{12}) "(.*)" "(.*)" "(.*)"/) {
			$myip=$1;
			$mymac=&addcolon($2);
			$myname=$3;
			$mydescr=$4;
			print OUTFILE "\n\t# Reservation for $mydescr\n";
			print OUTFILE "\thost $myname {\n";
			print OUTFILE "\t	hardware ethernet $mymac;\n";
			print OUTFILE "\t	fixed-address $myip;\n";
			print OUTFILE "\t}\n";
		}
	}
}

print OUTFILE "# end of Reserved IP section\n\n";
print OUTFILE "# --------------------------------------------------------\n";

if ($numOfScopes > 1) {
	print OUTFILE "}\n";
}

close(OUTFILE);

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

# --------------------------------------------------------------------
sub cleanstring() {
	my $mystring = shift;

	$mystring=~ s/\"//g;
	$mystring=~ s/ /,/g;
	$mystring=~ s/,$//;
	$mystring=~ s/\n//;
	$mystring=~ s/\r//;

	return $mystring;
}

# --------------------------------------------------------------------
sub addcolon() {
	my $macadd=shift;
	my $i;

	foreach $i (10,8,6,4,2) {
		$macadd = substr($macadd,0,$i) . ":" . substr($macadd, $i);
	} 

	return $macadd;
}


# --------------------------------------------------------------------
sub rowfind() {
	my $strtarget = shift;
	my $row;
	my @retval;

	print "Cerco nel file: $strtarget\n";

	foreach $row (@inputfile) {
		if($row=~/$strtarget/) {
			print "FOUND: $1 $2\n";
			@retval= ($1, $2, $3, $4, $5);
			return @retval;
        	}
	}
	return "NOT FOUND";
}

# --------------------------------------------------------------------
sub print_usage () {
        print "Usage: $PROGNAME -i <infile> -o <outfile> [-V] [-h]\n";
        print " E.G.: $PROGNAME -i dhcp.dump -o dhcp.conf\n";
}

# --------------------------------------------------------------------
sub print_help () {
        print "\n";
        print "This script reads the Microsoft DHCP configuration file produced by\n";
	print "  C:\\temp> netsh dhcp server \\\\dhcpserver dump > dhcp.dump\n";
        print "then it writes a DHCP configuration file for ISC DHCP, commonly used in Linux world.\n\n";
}