includes/ProxyTools.php

   1 <?php
   2 /**
   3  * Functions for dealing with proxies
   4  */
   5
   6 /**
   7  * Extracts the XFF string from the request header
   8  * Checks first for "X-Forwarded-For", then "Client-ip"
   9  * Note: headers are spoofable
  10  * @return string
  11  */
  12 function wfGetForwardedFor() {
  13         if( function_exists( 'apache_request_headers' ) ) {
  14                 // More reliable than $_SERVER due to case and -/_ folding
  15                 $set = apache_request_headers();
  16                 $index = 'X-Forwarded-For';
  17                 $index2 = 'Client-ip';
  18         } else {
  19                 // Subject to spoofing with headers like X_Forwarded_For
  20                 $set = $_SERVER;
  21                 $index = 'HTTP_X_FORWARDED_FOR';
  22                 $index2 = 'CLIENT-IP';
  23         }
  24         #Try a couple of headers
  25         if( isset( $set[$index] ) ) {
  26                 return $set[$index];
  27         } else if( isset( $set[$index2] ) ) {
  28                 return $set[$index2];
  29         } else {
  30                 return null;
  31         }
  32 }
  33
  34 /**
  35  * @todo FUCKING DOCUMENT THIS FUCKING FUNCTION
  36  */
  37 function wfGetLastIPfromXFF( $xff ) {
  38         if ( $xff ) {
  39         // Avoid annoyingly long xff hacks
  40                 $xff = substr( $xff, 0, 255 );
  41                 // Look for the last IP, assuming they are separated by commas or spaces
  42                 $n = ( strrpos($xff, ',') ) ? strrpos($xff, ',') : strrpos($xff, ' ');
  43                 if ( $n !== false ) {
  44                         $last = trim( substr( $xff, $n + 1 ) );
  45                         // Make sure it is an IP
  46                         $m = preg_match('#^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$#', $last);
  47                         $n = preg_match('#^:(:[0-9A-Fa-f]{1,4}){1,7}|[0-9A-Fa-f]{1,4}(:{1,2}[0-9A-Fa-f]{1,4}|::$){1,7}$#', $last);
  48                         if ( $m > 0 )
  49                                 $xff_ip = $last;
  50                         else if ( $n > 0 )
  51                                 $xff_ip = $last;
  52                         else
  53                                 $xff_ip = null;
  54                 } else {
  55                         $xff_ip = null;
  56                 }
  57         } else {
  58                 $xff_ip = null;
  59         }
  60         return $xff_ip;
  61 }
  62
  63 /**
  64  * Returns the browser/OS data from the request header
  65  * Note: headers are spoofable
  66  * @return string
  67  */
  68 function wfGetAgent() {
  69         if( function_exists( 'apache_request_headers' ) ) {
  70                 // More reliable than $_SERVER due to case and -/_ folding
  71                 $set = apache_request_headers();
  72                 $index = 'User-Agent';
  73         } else {
  74                 // Subject to spoofing with headers like X_Forwarded_For
  75                 $set = $_SERVER;
  76                 $index = 'HTTP_USER_AGENT';
  77         }
  78         if( isset( $set[$index] ) ) {
  79                 return $set[$index];
  80         } else {
  81                 return '';
  82         }
  83 }
  84
  85 /**
  86  * Work out the IP address based on various globals
  87  * For trusted proxies, use the XFF client IP (first of the chain)
  88  * @return string
  89  */
  90 function wfGetIP() {
  91         global $wgIP;
  92
  93         # Return cached result
  94         if ( !empty( $wgIP ) ) {
  95                 return $wgIP;
  96         }
  97
  98         /* collect the originating ips */
  99         # Client connecting to this webserver
 100         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
 101                 $ipchain = array( IP::canonicalize( $_SERVER['REMOTE_ADDR'] ) );
 102         } else {
 103                 # Running on CLI?
 104                 $ipchain = array( '127.0.0.1' );
 105         }
 106         $ip = $ipchain[0];
 107
 108         # Append XFF on to $ipchain
 109         $forwardedFor = wfGetForwardedFor();
 110         if ( isset( $forwardedFor ) ) {
 111                 $xff = array_map( 'trim', explode( ',', $forwardedFor ) );
 112                 $xff = array_reverse( $xff );
 113                 $ipchain = array_merge( $ipchain, $xff );
 114         }
 115
 116         # Step through XFF list and find the last address in the list which is a trusted server
 117         # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
 118         foreach ( $ipchain as $i => $curIP ) {
 119                 $curIP = IP::canonicalize( $curIP );
 120                 if ( wfIsTrustedProxy( $curIP ) ) {
 121                         if ( isset( $ipchain[$i + 1] ) && IP::isPublic( $ipchain[$i + 1] ) ) {
 122                                 $ip = $ipchain[$i + 1];
 123                         }
 124                 } else {
 125                         break;
 126                 }
 127         }
 128
 129         wfDebug( "IP: $ip\n" );
 130         $wgIP = $ip;
 131         return $ip;
 132 }
 133
 134 /**
 135  * Checks if an IP is a trusted proxy providor
 136  * Useful to tell if X-Fowarded-For data is possibly bogus
 137  * Squid cache servers for the site and AOL are whitelisted
 138  * @param string $ip
 139  * @return bool
 140  */
 141 function wfIsTrustedProxy( $ip ) {
 142         global $wgSquidServers, $wgSquidServersNoPurge;
 143
 144         if ( in_array( $ip, $wgSquidServers ) ||
 145                 in_array( $ip, $wgSquidServersNoPurge ) ||
 146                 wfIsAOLProxy( $ip )
 147         ) {
 148                 $trusted = true;
 149         } else {
 150                 $trusted = false;
 151         }
 152         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
 153         return $trusted;
 154 }
 155
 156 /**
 157  * Forks processes to scan the originating IP for an open proxy server
 158  * MemCached can be used to skip IPs that have already been scanned
 159  */
 160 function wfProxyCheck() {
 161         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
 162         global $wgUseMemCached, $wgMemc, $wgProxyMemcExpiry;
 163         global $wgProxyKey;
 164
 165         if ( !$wgBlockOpenProxies ) {
 166                 return;
 167         }
 168
 169         $ip = wfGetIP();
 170
 171         # Get MemCached key
 172         $skip = false;
 173         if ( $wgUseMemCached ) {
 174                 $mcKey = wfMemcKey( 'proxy', 'ip', $ip );
 175                 $mcValue = $wgMemc->get( $mcKey );
 176                 if ( $mcValue ) {
 177                         $skip = true;
 178                 }
 179         }
 180
 181         # Fork the processes
 182         if ( !$skip ) {
 183                 $title = SpecialPage::getTitleFor( 'Blockme' );
 184                 $iphash = md5( $ip . $wgProxyKey );
 185                 $url = $title->getFullURL( 'ip='.$iphash );
 186
 187                 foreach ( $wgProxyPorts as $port ) {
 188                         $params = implode( ' ', array(
 189                                                 escapeshellarg( $wgProxyScriptPath ),
 190                                                 escapeshellarg( $ip ),
 191                                                 escapeshellarg( $port ),
 192                                                 escapeshellarg( $url )
 193                                                 ));
 194                         exec( "php $params &>/dev/null &" );
 195                 }
 196                 # Set MemCached key
 197                 if ( $wgUseMemCached ) {
 198                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 199                 }
 200         }
 201 }
 202
 203 /**
 204  * Convert a network specification in CIDR notation to an integer network and a number of bits
 205  * @return array(string, int)
 206  */
 207 function wfParseCIDR( $range ) {
 208         return IP::parseCIDR( $range );
 209 }
 210
 211 /**
 212  * Check if an IP address is in the local proxy list
 213  * @return bool
 214  */
 215 function wfIsLocallyBlockedProxy( $ip ) {
 216         global $wgProxyList;
 217         $fname = 'wfIsLocallyBlockedProxy';
 218
 219         if ( !$wgProxyList ) {
 220                 return false;
 221         }
 222         wfProfileIn( $fname );
 223
 224         if ( !is_array( $wgProxyList ) ) {
 225                 # Load from the specified file
 226                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 227         }
 228
 229         if ( !is_array( $wgProxyList ) ) {
 230                 $ret = false;
 231         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 232                 $ret = true;
 233         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 234                 # Old-style flipped proxy list
 235                 $ret = true;
 236         } else {
 237                 $ret = false;
 238         }
 239         wfProfileOut( $fname );
 240         return $ret;
 241 }
 242
 243 /**
 244  * TODO: move this list to the database in a global IP info table incorporating
 245  * trusted ISP proxies, blocked IP addresses and open proxies.
 246  * @return bool
 247  */
 248 function wfIsAOLProxy( $ip ) {
 249         $ranges = array(
 250                 '64.12.96.0/19',
 251                 '149.174.160.0/20',
 252                 '152.163.240.0/21',
 253                 '152.163.248.0/22',
 254                 '152.163.252.0/23',
 255                 '152.163.96.0/22',
 256                 '152.163.100.0/23',
 257                 '195.93.32.0/22',
 258                 '195.93.48.0/22',
 259                 '195.93.64.0/19',
 260                 '195.93.96.0/19',
 261                 '195.93.16.0/20',
 262                 '198.81.0.0/22',
 263                 '198.81.16.0/20',
 264                 '198.81.8.0/23',
 265                 '202.67.64.128/25',
 266                 '205.188.192.0/20',
 267                 '205.188.208.0/23',
 268                 '205.188.112.0/20',
 269                 '205.188.146.144/30',
 270                 '207.200.112.0/21',
 271         );
 272
 273         static $parsedRanges;
 274         if ( is_null( $parsedRanges ) ) {
 275                 $parsedRanges = array();
 276                 foreach ( $ranges as $range ) {
 277                         $parsedRanges[] =  IP::parseRange( $range );
 278                 }
 279         }
 280
 281         $hex = IP::toHex( $ip );
 282         foreach ( $parsedRanges as $range ) {
 283                 if ( $hex >= $range[0] && $hex <= $range[1] ) {
 284                         return true;
 285                 }
 286         }
 287         return false;
 288 }
 289
 290
 291
 292 ?>