#!/usr/bin/perl -w

# Brian Masney <masneyb@ntelos.net>
# To use this script, set your base DN below. Then run 
# ./dhcpd-conf-to-ldap.pl < /path-to-dhcpd-conf/dhcpd.conf > output-file
# The output of this script will generate entries in LDIF format. You can use
# the slapadd command to add these entries into your LDAP server. You will
# definately want to double check that your LDAP entries are correct before
# you load them into LDAP.

# This script does not do much error checking. Make sure before you run this
# that the DHCP server doesn't give any errors about your config file

use Sys::Hostname;

my $basedn = "dc=ntelos, dc=net";

sub next_token
{
  local ($lowercase) = @_;
  local ($token, $newline);

  do 
    {
      if (!defined ($line) || length ($line) == 0)
        {
          $line = <>;
          return undef if !defined ($line);
          chop $line;
          $line_number++;
          $token_number = 0;
        }

      $line =~ s/#.*//;
      $line =~ s/^\s+//;
      $line =~ s/\s+$//;
    }
  while (length ($line) == 0);

  if (($token, $newline) = $line =~ /^(.*?)\s+(.*)/)
    {
      $line = $newline;
    }
  else
    {
      $token = $line;
      $line = '';
    }
  $token_number++;

  $token =~ y/[A-Z]/[a-z]/ if $lowercase;

  return ($token);
}


sub remaining_line
{
  local ($tmp, $str);

  $str = "";
  while (($tmp = next_token (0)))
    {
      $str .= ' ' if !($str eq "");
      $str .= $tmp;
      last if $tmp =~ /;\s*$/;
    }

  $str =~ s/;$//;
  return ($str);
}


sub
add_dn_to_stack
{
  local ($dn) = @_;

  $current_dn = "$dn, $current_dn";
}


sub
remove_dn_from_stack
{
  $current_dn =~ s/^.*?,\s*//;
}


sub
parse_error
{
  print "Parse error on line number $line_number at token number $token_number\n";
  exit (1);
}


sub
print_entry
{
  return if (scalar keys %curentry == 0);

  if (!defined ($curentry{'type'}))
    {
      $host = hostname ();
      $hostdn = "cn=$host, $basedn";
      print "dn: $hostdn\n";
      print "objectClass: top\n";
      print "objectClass: dhcpServer\n";
      print "cn: $host\n";
      print "dhcpServiceDN: $current_dn\n\n";

      print "dn: $current_dn\n";
      print "cn: DHCP Config\n";
      print "objectClass: top\n";
      print "objectClass: dhcpService\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }
      print "dhcpPrimaryDN: $hostdn\n";
    }
  elsif ($curentry{'type'} eq 'subnet')
    {
      print "dn: $current_dn\n";
      print "cn: " . $curentry{'ip'} . "\n";
      print "objectClass: top\n";
      print "objectClass: dhcpSubnet\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }
      
      print "dhcpNetMask: " . $curentry{'netmask'} . "\n";
      if (defined ($curentry{'range'}))
        {
          print "dhcpRange: " . $curentry{'range'} . "\n";
        }
    }
  elsif ($curentry{'type'} eq 'shared-network')
    {
      print "dn: $current_dn\n";
      print "cn: " . $curentry{'descr'} . "\n";
      print "objectClass: top\n";
      print "objectClass: dhcpSharedNetwork\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }
    }
  elsif ($curentry{'type'} eq 'group')
    {
      print "dn: $current_dn\n";
      print "cn: group\n";
      print "objectClass: top\n";
      print "objectClass: dhcpGroup\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }
    }
  elsif ($curentry{'type'} eq 'host')
    {
      print "dn: $current_dn\n";
      print "cn: " . $curentry{'host'} . "\n";
      print "objectClass: top\n";
      print "objectClass: dhcpHost\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }

      if (defined ($curentry{'hwaddress'}))
        {
          print "dhcpHWAddress: " . $curentry{'hwaddress'} . "\n";
        }
    }
  elsif ($curentry{'type'} eq 'pool')
    {
      print "dn: $current_dn\n";
      print "cn: pool\n";
      print "objectClass: top\n";
      print "objectClass: dhcpPool\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }

      if (defined ($curentry{'range'}))
        {
          print "dhcpRange: " . $curentry{'range'} . "\n";
        }
    }
  elsif ($curentry{'type'} eq 'class')
    {
      print "dn: $current_dn\n";
      print "cn: " . $curentry{'class'} . "\n";
      print "objectClass: top\n";
      print "objectClass: dhcpClass\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }
    }
  elsif ($curentry{'type'} eq 'subclass')
    {
      print "dn: $current_dn\n";
      print "cn: " . $curentry{'subclass'} . "\n";
      print "objectClass: top\n";
      print "objectClass: dhcpSubClass\n";
      if (defined ($curentry{'options'}))
        {
          print "objectClass: dhcpOptions\n";
        }
      print "dhcpClassData: " . $curentry{'class'} . "\n";
    }

  if (defined ($curentry{'statements'}))
    {
      foreach $statement (@{$curentry{'statements'}})
        {
          print "dhcpStatements: $statement\n";
        }
    }

  if (defined ($curentry{'options'}))
    {
      foreach $statement (@{$curentry{'options'}})
        {
          print "dhcpOption: $statement\n";
        }
    }

  print "\n";
  undef (%curentry);
}


sub parse_netmask
{
  local ($netmask) = @_;
  local ($i);

  if ((($a, $b, $c, $d) = $netmask =~ /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/) != 4)
    {
      parse_error ();
    }

  $num = (($a & 0xff) << 24) |
         (($b & 0xff) << 16) |
         (($c & 0xff) << 8) |
          ($d & 0xff);

  for ($i=1; $i<=32 && $num & (1 << (32 - $i)); $i++)
    {
    }
  $i--;

  return ($i);
}


sub parse_subnet
{
  local ($ip, $tmp, $netmask);

  print_entry () if %curentry;
    
  $ip = next_token (0);
  parse_error () if !defined ($ip);

  $tmp = next_token (1);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq 'netmask');

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  $netmask = parse_netmask ($tmp);

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  add_dn_to_stack ("cn=$ip");
  $curentry{'type'} = 'subnet';
  $curentry{'ip'} = $ip;
  $curentry{'netmask'} = $netmask;
}


sub parse_shared_network
{
  local ($descr, $tmp);

  print_entry () if %curentry;

  $descr = next_token (0);
  parse_error () if !defined ($descr);

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  add_dn_to_stack ("cn=$descr");
  $curentry{'type'} = 'shared-network';
  $curentry{'descr'} = $descr;
}


sub parse_host
{
  local ($descr, $tmp);

  print_entry () if %curentry;

  $host = next_token (0);
  parse_error () if !defined ($host);

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  add_dn_to_stack ("cn=$host");
  $curentry{'type'} = 'host';
  $curentry{'host'} = $host;
}


sub parse_group
{
  local ($descr, $tmp);

  print_entry () if %curentry;

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  add_dn_to_stack ("cn=group");
  $curentry{'type'} = 'group';
}


sub parse_pool
{
  local ($descr, $tmp);

  print_entry () if %curentry;

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  add_dn_to_stack ("cn=pool");
  $curentry{'type'} = 'pool';
}


sub parse_class
{
  local ($descr, $tmp);

  print_entry () if %curentry;

  $class = next_token (0);
  parse_error () if !defined ($class);

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  $class =~ s/\"//g;
  add_dn_to_stack ("cn=$class");
  $curentry{'type'} = 'class';
  $curentry{'class'} = $class;
}


sub parse_subclass
{
  local ($descr, $tmp);

  print_entry () if %curentry;

  $class = next_token (0);
  parse_error () if !defined ($class);

  $subclass = next_token (0);
  parse_error () if !defined ($subclass);

  $tmp = next_token (0);
  parse_error () if !defined ($tmp);
  parse_error () if !($tmp eq '{');

  add_dn_to_stack ("cn=$subclass");
  $curentry{'type'} = 'subclass';
  $curentry{'class'} = $class;
  $curentry{'subclass'} = $subclass;
}


sub parse_hwaddress
{
  local ($type, $hw, $tmp);

  $type = next_token (0);
  parse_error () if !defined ($type);

  $hw = next_token (0);
  parse_error () if !defined ($hw);
  $hw =~ s/;$//;

  $curentry{'hwaddress'} = "$type $hw";
}

    
sub parse_range
{
  local ($tmp, $str);

  $str = remaining_line ();

  if (!($str eq ''))
    {
      $str =~ s/;$//;
      $curentry{'range'} = $str;
    }
}


sub parse_statement
{
  local ($token) = shift;
  local ($str);

  if ($token eq 'option')
    {
      $str = remaining_line ();
      push (@{$curentry{'options'}}, $str);
    }
  else
    {
      $str = $token . " " . remaining_line ();
      push (@{$curentry{'statements'}}, $str);
    }
}


my $token;
my $token_number = 0;
my $line_number = 0;
my %curentry;

$current_dn = "cn=DHCP Config, $basedn";
$curentry{'descr'} = 'DHCP Config';
$line = '';

while (($token = next_token (1)))
  {
    if ($token eq '}')
      {
        print_entry () if %curentry;
        remove_dn_from_stack ();
      }
    elsif ($token eq 'subnet')
      {
        parse_subnet ();
        next;
      }
    elsif ($token eq 'shared-network')
      {
        parse_shared_network ();
        next;
      }
    elsif ($token eq 'class')
      {
        parse_class ();
        next;
      }
    elsif ($token eq 'subclass')
      {
        parse_subclass ();
        next;
      }
    elsif ($token eq 'pool')
      {
        parse_pool ();
        next;
      }
    elsif ($token eq 'group')
      {
        parse_group ();
        next;
      }
    elsif ($token eq 'host')
      {
        parse_host ();
        next;
      }
    elsif ($token eq 'hardware')
      {
        parse_hwaddress ();
        next;
      }
    elsif ($token eq 'range')
      {
        parse_range ();
        next;
      }
    else
      {
        parse_statement ($token);
        next;
      }
  }