includes/ProxyTools.php

   1 <?php
   2 if ( ! defined( 'MEDIAWIKI' ) )
   3         die();
   4 /**
   5  * Functions for dealing with proxies
   6  * @package MediaWiki
   7  */
   8
   9 function wfGetForwardedFor() {
  10         if( function_exists( 'apache_request_headers' ) ) {
  11                 // More reliable than $_SERVER due to case and -/_ folding
  12                 $set = apache_request_headers();
  13                 $index = 'X-Forwarded-For';
  14         } else {
  15                 // Subject to spoofing with headers like X_Forwarded_For
  16                 $set = $_SERVER;
  17                 $index = 'HTTP_X_FORWARDED_FOR';
  18         }
  19         if( isset( $set[$index] ) ) {
  20                 return $set[$index];
  21         } else {
  22                 return null;
  23         }
  24 }
  25
  26 /** Work out the IP address based on various globals */
  27 function wfGetIP() {
  28         global $wgSquidServers, $wgSquidServersNoPurge, $wgIP;
  29
  30         # Return cached result
  31         if ( !empty( $wgIP ) ) {
  32                 return $wgIP;
  33         }
  34
  35         /* collect the originating ips */
  36         # Client connecting to this webserver
  37         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
  38                 $ipchain = array( $_SERVER['REMOTE_ADDR'] );
  39         } else {
  40                 # Running on CLI?
  41                 $ipchain = array( '127.0.0.1' );
  42         }
  43         $ip = $ipchain[0];
  44
  45         # Get list of trusted proxies
  46         # Flipped for quicker access
  47         $trustedProxies = array_flip( array_merge( $wgSquidServers, $wgSquidServersNoPurge ) );
  48         if ( count( $trustedProxies ) ) {
  49                 # Append XFF on to $ipchain
  50                 $forwardedFor = wfGetForwardedFor();
  51                 if ( isset( $forwardedFor ) ) {
  52                         $xff = array_map( 'trim', explode( ',', $forwardedFor ) );
  53                         $xff = array_reverse( $xff );
  54                         $ipchain = array_merge( $ipchain, $xff );
  55                 }
  56                 # Step through XFF list and find the last address in the list which is a trusted server
  57                 # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
  58                 foreach ( $ipchain as $i => $curIP ) {
  59                         if ( array_key_exists( $curIP, $trustedProxies ) ) {
  60                                 if ( isset( $ipchain[$i + 1] ) && wfIsIPPublic( $ipchain[$i + 1] ) ) {
  61                                         $ip = $ipchain[$i + 1];
  62                                 }
  63                         } else {
  64                                 break;
  65                         }
  66                 }
  67         }
  68
  69         wfDebug( "IP: $ip\n" );
  70         $wgIP = $ip;
  71         return $ip;
  72 }
  73
  74 /**
  75  * Given an IP address in dotted-quad notation, returns an unsigned integer.
  76  * Like ip2long() except that it actually works and has a consistent error return value.
  77  */
  78 function wfIP2Unsigned( $ip ) {
  79         $n = ip2long( $ip );
  80         if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
  81                 $n = false;
  82         } elseif ( $n < 0 ) {
  83                 $n += pow( 2, 32 );
  84         }
  85         return $n;
  86 }
  87
  88 /**
  89  * Return a zero-padded hexadecimal representation of an IP address
  90  */
  91 function wfIP2Hex( $ip ) {
  92         $n = wfIP2Unsigned( $ip );
  93         if ( $n !== false ) {
  94                 $n = sprintf( '%08X', $n );
  95         }
  96         return $n;
  97 }
  98
  99 /**
 100  * Determine if an IP address really is an IP address, and if it is public,
 101  * i.e. not RFC 1918 or similar
 102  */
 103 function wfIsIPPublic( $ip ) {
 104         $n = wfIP2Unsigned( $ip );
 105         if ( !$n ) {
 106                 return false;
 107         }
 108
 109         static $privateRanges = false;
 110         if ( !$privateRanges ) {
 111                 $privateRanges = array(
 112                         array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 113                         array( '172.16.0.0',  '172.31.255.255' ),   #     "
 114                         array( '192.168.0.0', '192.168.255.255' ),  #     "
 115                         array( '0.0.0.0',     '0.255.255.255' ),    # this network
 116                         array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 117                 );
 118         }
 119
 120         foreach ( $privateRanges as $r ) {
 121                 $start = wfIP2Unsigned( $r[0] );
 122                 $end = wfIP2Unsigned( $r[1] );
 123                 if ( $n >= $start && $n <= $end ) {
 124                         return false;
 125                 }
 126         }
 127         return true;
 128 }
 129
 130 /**
 131  * Forks processes to scan the originating IP for an open proxy server
 132  * MemCached can be used to skip IPs that have already been scanned
 133  */
 134 function wfProxyCheck() {
 135         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
 136         global $wgUseMemCached, $wgMemc, $wgDBname, $wgProxyMemcExpiry;
 137
 138         if ( !$wgBlockOpenProxies ) {
 139                 return;
 140         }
 141
 142         $ip = wfGetIP();
 143
 144         # Get MemCached key
 145         $skip = false;
 146         if ( $wgUseMemCached ) {
 147                 $mcKey = "$wgDBname: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 = Title::makeTitle( NS_SPECIAL, '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         $parts = explode( '/', $range, 2 );
 181         if ( count( $parts ) != 2 ) {
 182                 return array( false, false );
 183         }
 184         $network = wfIP2Unsigned( $parts[0] );
 185         if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 186                 $bits = $parts[1];
 187         } else {
 188                 $network = false;
 189                 $bits = false;
 190         }
 191         return array( $network, $bits );
 192 }
 193
 194 /**
 195  * Check if an IP address is in the local proxy list
 196  */
 197 function wfIsLocallyBlockedProxy( $ip ) {
 198         global $wgProxyList;
 199         $fname = 'wfIsLocallyBlockedProxy';
 200
 201         if ( !$wgProxyList ) {
 202                 return false;
 203         }
 204         wfProfileIn( $fname );
 205
 206         if ( !is_array( $wgProxyList ) ) {
 207                 # Load from the specified file
 208                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 209         }
 210
 211         if ( !is_array( $wgProxyList ) ) {
 212                 $ret = false;
 213         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 214                 $ret = true;
 215         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 216                 # Old-style flipped proxy list
 217                 $ret = true;
 218         } else {
 219                 $ret = false;
 220         }
 221         wfProfileOut( $fname );
 222         return $ret;
 223 }
 224
 225
 226
 227
 228 ?>