includes/ProxyTools.php

   1 <?php
   2 /**
   3  * Functions for dealing with proxies
   4  * @package MediaWiki
   5  */
   6
   7 function wfGetForwardedFor() {
   8         if( function_exists( 'apache_request_headers' ) ) {
   9                 // More reliable than $_SERVER due to case and -/_ folding
  10                 $set = apache_request_headers();
  11                 $index = 'X-Forwarded-For';
  12         } else {
  13                 // Subject to spoofing with headers like X_Forwarded_For
  14                 $set = $_SERVER;
  15                 $index = 'HTTP_X_FORWARDED_FOR';
  16         }
  17         if( isset( $set[$index] ) ) {
  18                 return $set[$index];
  19         } else {
  20                 return null;
  21         }
  22 }
  23
  24 /** Work out the IP address based on various globals */
  25 function wfGetIP() {
  26         global $wgIP;
  27
  28         # Return cached result
  29         if ( !empty( $wgIP ) ) {
  30                 return $wgIP;
  31         }
  32
  33         /* collect the originating ips */
  34         # Client connecting to this webserver
  35         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
  36                 $ipchain = array( IP::canonicalize( $_SERVER['REMOTE_ADDR'] ) );
  37         } else {
  38                 # Running on CLI?
  39                 $ipchain = array( '127.0.0.1' );
  40         }
  41         $ip = $ipchain[0];
  42
  43         # Append XFF on to $ipchain
  44         $forwardedFor = wfGetForwardedFor();
  45         if ( isset( $forwardedFor ) ) {
  46                 $xff = array_map( 'trim', explode( ',', $forwardedFor ) );
  47                 $xff = array_reverse( $xff );
  48                 $ipchain = array_merge( $ipchain, $xff );
  49         }
  50
  51         # Step through XFF list and find the last address in the list which is a trusted server
  52         # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
  53         foreach ( $ipchain as $i => $curIP ) {
  54                 $curIP = IP::canonicalize( $curIP );
  55                 if ( wfIsTrustedProxy( $curIP ) ) {
  56                         if ( isset( $ipchain[$i + 1] ) && IP::isPublic( $ipchain[$i + 1] ) ) {
  57                                 $ip = $ipchain[$i + 1];
  58                         }
  59                 } else {
  60                         break;
  61                 }
  62         }
  63
  64         wfDebug( "IP: $ip\n" );
  65         $wgIP = $ip;
  66         return $ip;
  67 }
  68
  69 function wfIsTrustedProxy( $ip ) {
  70         global $wgSquidServers, $wgSquidServersNoPurge;
  71
  72         if ( in_array( $ip, $wgSquidServers ) ||
  73                 in_array( $ip, $wgSquidServersNoPurge ) ||
  74                 wfIsAOLProxy( $ip )
  75         ) {
  76                 $trusted = true;
  77         } else {
  78                 $trusted = false;
  79         }
  80         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
  81         return $trusted;
  82 }
  83
  84 /**
  85  * Forks processes to scan the originating IP for an open proxy server
  86  * MemCached can be used to skip IPs that have already been scanned
  87  */
  88 function wfProxyCheck() {
  89         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
  90         global $wgUseMemCached, $wgMemc, $wgProxyMemcExpiry;
  91         global $wgProxyKey;
  92
  93         if ( !$wgBlockOpenProxies ) {
  94                 return;
  95         }
  96
  97         $ip = wfGetIP();
  98
  99         # Get MemCached key
 100         $skip = false;
 101         if ( $wgUseMemCached ) {
 102                 $mcKey = wfMemcKey( 'proxy', 'ip', $ip );
 103                 $mcValue = $wgMemc->get( $mcKey );
 104                 if ( $mcValue ) {
 105                         $skip = true;
 106                 }
 107         }
 108
 109         # Fork the processes
 110         if ( !$skip ) {
 111                 $title = SpecialPage::getTitleFor( 'Blockme' );
 112                 $iphash = md5( $ip . $wgProxyKey );
 113                 $url = $title->getFullURL( 'ip='.$iphash );
 114
 115                 foreach ( $wgProxyPorts as $port ) {
 116                         $params = implode( ' ', array(
 117                                                 escapeshellarg( $wgProxyScriptPath ),
 118                                                 escapeshellarg( $ip ),
 119                                                 escapeshellarg( $port ),
 120                                                 escapeshellarg( $url )
 121                                                 ));
 122                         exec( "php $params &>/dev/null &" );
 123                 }
 124                 # Set MemCached key
 125                 if ( $wgUseMemCached ) {
 126                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 127                 }
 128         }
 129 }
 130
 131 /**
 132  * Convert a network specification in CIDR notation to an integer network and a number of bits
 133  */
 134 function wfParseCIDR( $range ) {
 135         return IP::parseCIDR( $range );
 136 }
 137
 138 /**
 139  * Check if an IP address is in the local proxy list
 140  */
 141 function wfIsLocallyBlockedProxy( $ip ) {
 142         global $wgProxyList;
 143         $fname = 'wfIsLocallyBlockedProxy';
 144
 145         if ( !$wgProxyList ) {
 146                 return false;
 147         }
 148         wfProfileIn( $fname );
 149
 150         if ( !is_array( $wgProxyList ) ) {
 151                 # Load from the specified file
 152                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 153         }
 154
 155         if ( !is_array( $wgProxyList ) ) {
 156                 $ret = false;
 157         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 158                 $ret = true;
 159         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 160                 # Old-style flipped proxy list
 161                 $ret = true;
 162         } else {
 163                 $ret = false;
 164         }
 165         wfProfileOut( $fname );
 166         return $ret;
 167 }
 168
 169 /**
 170  * TODO: move this list to the database in a global IP info table incorporating
 171  * trusted ISP proxies, blocked IP addresses and open proxies.
 172  */
 173 function wfIsAOLProxy( $ip ) {
 174         $ranges = array(
 175                 '64.12.96.0/19',
 176                 '149.174.160.0/20',
 177                 '152.163.240.0/21',
 178                 '152.163.248.0/22',
 179                 '152.163.252.0/23',
 180                 '152.163.96.0/22',
 181                 '152.163.100.0/23',
 182                 '195.93.32.0/22',
 183                 '195.93.48.0/22',
 184                 '195.93.64.0/19',
 185                 '195.93.96.0/19',
 186                 '195.93.16.0/20',
 187                 '198.81.0.0/22',
 188                 '198.81.16.0/20',
 189                 '198.81.8.0/23',
 190                 '202.67.64.128/25',
 191                 '205.188.192.0/20',
 192                 '205.188.208.0/23',
 193                 '205.188.112.0/20',
 194                 '205.188.146.144/30',
 195                 '207.200.112.0/21',
 196         );
 197
 198         static $parsedRanges;
 199         if ( is_null( $parsedRanges ) ) {
 200                 $parsedRanges = array();
 201                 foreach ( $ranges as $range ) {
 202                         $parsedRanges[] =  IP::parseRange( $range );
 203                 }
 204         }
 205
 206         $hex = IP::toHex( $ip );
 207         foreach ( $parsedRanges as $range ) {
 208                 if ( $hex >= $range[0] && $hex <= $range[1] ) {
 209                         return true;
 210                 }
 211         }
 212         return false;
 213 }
 214
 215
 216
 217 ?>