<?php

class NetworkAddressIPv4
{
  var $Address;
  var $Prefix;
  
  function __construct()
  {
    $this->Address = 0;
    $this->Prefix = 0;
  }
  
  function GetNetMask()
  {
    return(0xffffffff ^ ((1 << (32 - $this->Prefix)) - 1));
  }

  function AddressToString()
  {
   return(implode('.', array(($this->Address >> 24) & 255, ($this->Address >> 16) & 255, ($this->Address >> 8) & 255, ($this->Address & 255))));
  }
  
  function AddressFromString($Value)
  {
    $Parts = explode('.', $Value);
    $this->Address = ($Parts[0] << 24) | ($Parts[1] << 16) | ($Parts[2] << 8) | $Parts[3];
  }
  
  function GetRange()
  {
    $From = new NetworkAddressIPv4();
    $From->Address = $this->Address;
    $From->Prefix = 32;
    $HostMask = 0xffffffff ^ $this->GetNetMask();
    $To = new NetworkAddressIPv4();
    $To->Address = $From->Address + $HostMask;
    $To->Prefix = 32;
    return(array('From' => $From, 'To' => $To));    
  }

  function ChangePrefix($NewPrefix)
  {
    $this->Prefix = $NewPrefix;
    if($this->Prefix > 32) $this->Prefix = 32;
    if($this->Prefix < 0) $this->Prefix = 0;
    $this->Address = $this->Address & $this->GetNetMask();
  }

  function Contain($Address)
  {    
    $UpperNetmask = $this->GetNetMask();
    if(($this->Prefix < $Address->Prefix) and (($Address->Address & $UpperNetmask) == ($this->Address & $UpperNetmask))) $Result = true;
      else $Result = false;
    //echo($Address->AddressToString().'/'.$Address->Prefix.' in '.$this->AddressToString().'/'.$this->Prefix.' '.$Result."\n");
    return($Result);
  }
}