XIP Class: Analyze remote IP, Proxy detection,Blacklist check

 XIP Class - Proxy Detection and IP Functions class for PHP - File Name: class.XIP.php
 Copyright (C) 2004-2006 Volkan Küçükçakar. All Rights Reserved.
 (Volkan Kucukcakar)
 http://www.developera.com

 You are requested to retain this copyright notice in order to use
 this software.

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the  Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA



Info
=====

 Name          : XIP Class
 Version       : 0.3.00
 Date          : 2006.08.21
 File          : class.XIP.php
 Author        : Volkan Küçükçakar
                (Volkan Kucukcakar)
 EMail         : volkank@developera.com
 Home Page     : http://www.developera.com
 Description   : XIP Class

           ***** Proxy Detection and IP Functions class for PHP


                 Features:
                 =========

                 -Very easy to integrate and use
                 -Enhanced smart "Proxy" and "Client IP" detection using header analysis
                 -Detects Proxy by looking for more than 40 standard and non-standard headers and hostname
                 -Retrieves the real Client IP address !!!
                 -IP BLACKLIST, WHITELIST check !!!
                 -IP[/Mask] format (IP range) compatible
                 -IP validate
                 -IP public/private check
                 -Expandable proxy detection structure by using arrays and regular expressions
                 -Guess for unknown  headers using regular expressions


History
========

 v0.1.0 (2004)           : Foundation. "Proxy","Client IP","Proxy Type" detection.
 v0.2.0 (2005)           : -Enhanced smart Header analysis techniques
                           -Expandable structure by using arrays
                           -Regular expression compatible
                           -IP Validation Function added
                           -Added function to check if IP is local
                           -Invalid and Local IP adresses are ignored if reported as client ip
 v0.2.1 (2005)           : -search REMOTE_HOST (for words "proxy", "cache")
 v0.2.23(2006.02.16)     : First and public release
                           -Well commented
 v0.2.24(2006.03.12)     : -Fixed some notice level error reporting
                           -Fixed Normal Private IP List
                           -Added some comments
 v0.2.30(2006.04.25)     : -Fixed a bug in NetCheck() function relevant to a undefined variable
                           -NetCheck() function is deprecated, parameter order changed in new CheckNet() function
                           -More easily blacklist check with new CheckNet() function 
				   ($ip parameter became optional and refers to client IP by default)
                           -Fixed a potential bug (Added IP Validation check) in isPublic() function
                           -Changed some comments and explanations
 v0.2.40(2006.07.05)     : -Fixed IP octet pattern
                           -Fixed Normal Private IP List
                           -Added some security advice
                           -Added/Changed some comments and explanations
 v0.2.41(2006.07.07)     : -Added/Changed some comments and explanations
 v0.3.00(2006.08.21)     : -Bug Fixed in IP octet pattern
                           -Added Example 3: Blacklist (Local) - Another local blacklist example using an external flat text file
                           -Added Example 4: IP Log  - IP Log example using a flat text file (with exclusive file lock support via flock and semaphore files)
                           -Added Example 5: Blacklist (Check RBL) - Checking the existance of visitor's IP in RBL (Real-Time Blackhole List) using 3rd party services

Files
=====
class.XIP.php		      : Main project file, Proxy Detection and IP Functions class for PHP
License.txt                   : License, GNU General Public License (GPL)
Readme.txt                    : This file
Examples/index.php            : File simply calls Example 1
Examples/proxydetect.php      : Example 1 - Proxy type, proxy info, client IP detection
Examples/ipfunctions.php      : Example 2 - IP Functions, IP validate, public/private IP check, network check, local blacklist
Examples/blacklist_local.php  : Example 3 - Blacklist (Local) - Another local blacklist example using an external flat text file
Examples/blacklist.txt        : File needed by blacklist_local.php
Examples/iplog.php            : Example 4 - IP Log  - IP Log example using a flat text file (with exclusive file lock support via flock and semaphore files)
Examples/log/iplog.txt        : File needed by iplog.php
Examples/log/iplog.txt.lck    : File needed by iplog.php
Examples/CheckRBL.php         : Example 5 - Blacklist (Check RBL) - Checking the existance of visitor's IP in RBL (Real-Time Blackhole List) using 3rd party services


Known bugs
==========

   

Notes
=====
There is an Extended Private IP List (BOGON IP list) in variable $Private_IP_Extended
You can always download the latest version of list into a file from http://www.cymru.com/Documents/bogon-bn-nonagg.txt
Usage of this list may be disabled by default, see comments in file.
Thanks to "Team Cymru Web Site"


Examples of most common usage
=============================

1)
echo $XIP->IP['client'];
will always write the reported client IP if available or will write Proxy IP if client IP not available.
You can usually use $XIP->IP['client'] instead of $_SERVER['REMOTE_ADDR'] or $REMOTE_ADDR in your project however;

* Do not forget that client IP is always reported by gateway (or client unfortinately)
  By the way, this is a property of http proxy connection; not a weakness of XIP Class.
* You can separately use/save $_SERVER['REMOTE_ADDR'] (or $XIP->IP['proxy']) in your logs for security. (See EXAMPLE 4 - iplog.php)
* To increase security, you can use $XIP->IP['client'] in conjunction with $XIP->IP['proxy'] (equals to $_SERVER['REMOTE_ADDR']),
  or you can do something with $XIP->IP['all']

2)
if ($XIP->isValid('127.0.0.1')) echo "ip is valid"; //will output "ip is valid"

3)
if ($XIP->isPrivate('172.25.66.7')) echo "ip belongs to local netwok"; //will output "ip belongs to local netwok"

4)
if ($XIP->CheckNet('127.0.0.0/255.255.255.0','127.0.0.5')) echo "IP belongs to given network"; //will output "ip belongs to given network"

5) 
* IP Range Check examples *:

//If you want to check if IP is in range of 192.168.2.0 to 192.168.2.255
if ($XIP->CheckNet('192.168.2.0/255.255.255.0')) echo "YES IN RANGE"; //check the client IP
if ($XIP->CheckNet('192.168.2.0/255.255.255.0',$ip)) echo "YES IN RANGE"; //check the given IP

//If you want to check if IP is in range of 192.168.0.0 to 192.168.255.255
if ($XIP->CheckNet('192.168.2.0/255.255.0.0')) echo "YES IN RANGE"; //check the client IP
if ($XIP->CheckNet('192.168.2.0/255.255.0.0',$ip)) echo "YES IN RANGE"; //check the given IP

6) 
* IP BLACKLIST, WHITELIST examples *:

$blacklist="10.0.5.0, 10.0.5.1, 10.0.5.2, 10.0.4.0/24, 10.0.3.0/255.255.255.0";
if ($XIP->CheckNet($blacklist)) echo "IP is in BLACKLIST"; //check the client IP