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