includes/ProxyTools.php

   1 <?php
   2 if ( ! defined( 'MEDIAWIKI' ) )
   3         die( -1 );
   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         global $wgProxyKey;
 138
 139         if ( !$wgBlockOpenProxies ) {
 140                 return;
 141         }
 142
 143         $ip = wfGetIP();
 144
 145         # Get MemCached key
 146         $skip = false;
 147         if ( $wgUseMemCached ) {
 148                 $mcKey = "$wgDBname:proxy:ip:$ip";
 149                 $mcValue = $wgMemc->get( $mcKey );
 150                 if ( $mcValue ) {
 151                         $skip = true;
 152                 }
 153         }
 154
 155         # Fork the processes
 156         if ( !$skip ) {
 157                 $title = Title::makeTitle( NS_SPECIAL, 'Blockme' );
 158                 $iphash = md5( $ip . $wgProxyKey );
 159                 $url = $title->getFullURL( 'ip='.$iphash );
 160
 161                 foreach ( $wgProxyPorts as $port ) {
 162                         $params = implode( ' ', array(
 163                                                 escapeshellarg( $wgProxyScriptPath ),
 164                                                 escapeshellarg( $ip ),
 165                                                 escapeshellarg( $port ),
 166                                                 escapeshellarg( $url )
 167                                                 ));
 168                         exec( "php $params &>/dev/null &" );
 169                 }
 170                 # Set MemCached key
 171                 if ( $wgUseMemCached ) {
 172                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 173                 }
 174         }
 175 }
 176
 177 /**
 178  * Convert a network specification in CIDR notation to an integer network and a number of bits
 179  */
 180 function wfParseCIDR( $range ) {
 181         $parts = explode( '/', $range, 2 );
 182         if ( count( $parts ) != 2 ) {
 183                 return array( false, false );
 184         }
 185         $network = wfIP2Unsigned( $parts[0] );
 186         if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 187                 $bits = $parts[1];
 188         } else {
 189                 $network = false;
 190                 $bits = false;
 191         }
 192         return array( $network, $bits );
 193 }
 194
 195 /**
 196  * Check if an IP address is in the local proxy list
 197  */
 198 function wfIsLocallyBlockedProxy( $ip ) {
 199         global $wgProxyList;
 200         $fname = 'wfIsLocallyBlockedProxy';
 201
 202         if ( !$wgProxyList ) {
 203                 return false;
 204         }
 205         wfProfileIn( $fname );
 206
 207         if ( !is_array( $wgProxyList ) ) {
 208                 # Load from the specified file
 209                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 210         }
 211
 212         if ( !is_array( $wgProxyList ) ) {
 213                 $ret = false;
 214         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 215                 $ret = true;
 216         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 217                 # Old-style flipped proxy list
 218                 $ret = true;
 219         } else {
 220                 $ret = false;
 221         }
 222         wfProfileOut( $fname );
 223         return $ret;
 224 }
 225
 226
 227
 228
 229 ?>