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