includes/ProxyTools.php

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