#!/usr/bin/perl

use strict;

#####################################################
# Update MAC-IP pairings for all registered devices #
#####################################################

my %devices;
my $dhcpdconf;

# Open dhcpd.conf and initialize the %devices hash with all
# registered modems and cpes
open (DHCPDCONF, "dhcpd.conf");
foreach my $line (<DHCPDCONF>)
{
	$devices{lc($1)} = ''
	  if ($line =~ /#.*#.*#.*# Modem MAC: (\w+:\w+:\w+:\w+:\w+:\w+)/
	   	  or $line =~ /subclass ".*" 1:(\w+:\w+:\w+:\w+:\w+:\w+)/);
	
	# read dhcpd.conf into a variable for later substitutions		 
	$dhcpdconf .= $line; # <-- This is the line causing trouble...
						 #     the script does not hang up later when
						 #     this line is commented out.
}
close DHCPDCONF;

# open leases file and match mac addresses in %devices with active ips
open (LEASES, "dhcpd.leases");
my ($current_ip, $state);
foreach my $line (<LEASES>)
{

	$current_ip = $1 and next if
				  $line =~ /^\s*lease (\d+.\d+.\d+.\d+)/;
				  
	$state = $1 and next if $line =~ /^\s*binding state (\w+)/;
	
	$devices{lc($1)} = $current_ip and
	print lc($1) . " - " . $devices{lc($1)} . "\n" and next if
		($line =~ /^\s*hardware ethernet (\w+:\w+:\w+:\w+:\w+:\w+)/
		 and $state eq 'active' and exists $devices{lc($1)});	
}
# <- Hangs up inside the loop, never makes it to Marker 1
print "Marker 1\n";
close LEASES;

# alternative method of reading dhcpd.conf
#$dhcpdconf = `cat dhcpd.conf`; 

print "Marker 2\n";
# <--- hangs up right here with `cat dhcpd.conf` method.

# substitute old ip with current value
foreach my $device (keys %devices)
{
	print ".";
	$dhcpdconf =~ s/(#.*#.*# Modem IP: ).*( # Modem MAC: $device)/$1$devices{$device}$2/ig;


}
print "Marker 3\n";
open (DHCPDCONF, ">dhcpd.conf") or die;
print DHCPDCONF "$dhcpdconf";
close DHCPDCONF;


######## Update LDAP database

# not implemented yet.