includes/ProxyTools.php

   1 <?php
   2 /**
   3  * Functions for dealing with proxies
   4  * @package MediaWiki
   5  */
   6
   7 if ( !defined( 'MEDIAWIKI' ) ) {
   8         die();
   9 }
  10
  11 /** Work out the IP address based on various globals */
  12 function wfGetIP() {
  13         global $wgSquidServers, $wgSquidServersNoPurge, $wgIP;
  14
  15         # Return cached result
  16         if ( !empty( $wgIP ) ) {
  17                 return $wgIP;
  18         }
  19
  20         /* collect the originating ips */
  21         # Client connecting to this webserver
  22         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
  23                 $ipchain = array( $_SERVER['REMOTE_ADDR'] );
  24         } else {
  25                 # Running on CLI?
  26                 $ipchain = array( '127.0.0.1' );
  27         }
  28         $ip = $ipchain[0];
  29
  30         # Get list of trusted proxies
  31         # Flipped for quicker access
  32         $trustedProxies = array_flip( array_merge( $wgSquidServers, $wgSquidServersNoPurge ) );
  33         if ( count( $trustedProxies ) ) {
  34                 # Append XFF on to $ipchain
  35                 if ( isset( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
  36                         $xff = array_map( 'trim', explode( ',', $_SERVER['HTTP_X_FORWARDED_FOR'] ) );
  37                         $xff = array_reverse( $xff );
  38                         $ipchain = array_merge( $ipchain, $xff );
  39                 }
  40                 # Step through XFF list and find the last address in the list which is a trusted server
  41                 # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
  42                 foreach ( $ipchain as $i => $curIP ) {
  43                         if ( array_key_exists( $curIP, $trustedProxies ) ) {
  44                                 if ( isset( $ipchain[$i + 1] ) && wfIsIPPublic( $ipchain[$i + 1] ) ) {
  45                                         $ip = $ipchain[$i + 1];
  46                                 }
  47                         } else {
  48                                 break;
  49                         }
  50                 }
  51         }
  52
  53         wfDebug( "IP: $ip\n" );
  54         $wgIP = $ip;
  55         return $ip;
  56 }
  57
  58 /**
  59  * Given an IP address in dotted-quad notation, returns an unsigned integer.
  60  * Like ip2long() except that it actually works and has a consistent error return value.
  61  */
  62 function wfIP2Unsigned( $ip ) {
  63         $n = ip2long( $ip );
  64         if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
  65                 $n = false;
  66         } elseif ( $n < 0 ) {
  67                 $n += pow( 2, 32 );
  68         }
  69         return $n;
  70 }
  71
  72 /**
  73  * Return a zero-padded hexadecimal representation of an IP address
  74  */
  75 function wfIP2Hex( $ip ) {
  76         $n = wfIP2Unsigned( $ip );
  77         if ( $n !== false ) {
  78                 $n = sprintf( '%08X', $n );
  79         }
  80         return $n;
  81 }
  82
  83 /**
  84  * Determine if an IP address really is an IP address, and if it is public,
  85  * i.e. not RFC 1918 or similar
  86  */
  87 function wfIsIPPublic( $ip ) {
  88         $n = wfIP2Unsigned( $ip );
  89         if ( !$n ) {
  90                 return false;
  91         }
  92
  93         static $privateRanges = false;
  94         if ( !$privateRanges ) {
  95                 $privateRanges = array(
  96                         array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
  97                         array( '172.16.0.0',  '172.31.255.255' ),   #     "
  98                         array( '192.168.0.0', '192.168.255.255' ),  #     "
  99                         array( '0.0.0.0',     '0.255.255.255' ),    # this network
 100                         array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 101                 );
 102         }
 103
 104         foreach ( $privateRanges as $r ) {
 105                 $start = wfIP2Unsigned( $r[0] );
 106                 $end = wfIP2Unsigned( $r[1] );
 107                 if ( $n >= $start && $n <= $end ) {
 108                         return false;
 109                 }
 110         }
 111         return true;
 112 }
 113
 114 /**
 115  * Forks processes to scan the originating IP for an open proxy server
 116  * MemCached can be used to skip IPs that have already been scanned
 117  */
 118 function wfProxyCheck() {
 119         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
 120         global $wgUseMemCached, $wgMemc, $wgDBname, $wgProxyMemcExpiry;
 121
 122         if ( !$wgBlockOpenProxies ) {
 123                 return;
 124         }
 125
 126         $ip = wfGetIP();
 127
 128         # Get MemCached key
 129         $skip = false;
 130         if ( $wgUseMemCached ) {
 131                 $mcKey = "$wgDBname:proxy:ip:$ip";
 132                 $mcValue = $wgMemc->get( $mcKey );
 133                 if ( $mcValue ) {
 134                         $skip = true;
 135                 }
 136         }
 137
 138         # Fork the processes
 139         if ( !$skip ) {
 140                 $title = Title::makeTitle( NS_SPECIAL, 'Blockme' );
 141                 $iphash = md5( $ip . $wgProxyKey );
 142                 $url = $title->getFullURL( 'ip='.$iphash );
 143
 144                 foreach ( $wgProxyPorts as $port ) {
 145                         $params = implode( ' ', array(
 146                                                 escapeshellarg( $wgProxyScriptPath ),
 147                                                 escapeshellarg( $ip ),
 148                                                 escapeshellarg( $port ),
 149                                                 escapeshellarg( $url )
 150                                                 ));
 151                         exec( "php $params &>/dev/null &" );
 152                 }
 153                 # Set MemCached key
 154                 if ( $wgUseMemCached ) {
 155                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 156                 }
 157         }
 158 }
 159
 160 /**
 161  * Convert a network specification in CIDR notation to an integer network and a number of bits
 162  */
 163 function wfParseCIDR( $range ) {
 164         $parts = explode( '/', $range, 2 );
 165         if ( count( $parts ) != 2 ) {
 166                 return array( false, false );
 167         }
 168         $network = wfIP2Unsigned( $parts[0] );
 169         if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 170                 $bits = $parts[1];
 171         } else {
 172                 $network = false;
 173                 $bits = false;
 174         }
 175         return array( $network, $bits );
 176 }
 177
 178 /**
 179  * Check if an IP address is in the local proxy list
 180  */
 181 function wfIsLocallyBlockedProxy( $ip ) {
 182         global $wgProxyList;
 183         $fname = 'wfIsLocallyBlockedProxy';
 184
 185         if ( !$wgProxyList ) {
 186                 return false;
 187         }
 188         wfProfileIn( $fname );
 189
 190         if ( !is_array( $wgProxyList ) ) {
 191                 # Load from the specified file
 192                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 193         }
 194
 195         if ( !is_array( $wgProxyList ) ) {
 196                 $ret = false;
 197         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 198                 $ret = true;
 199         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 200                 # Old-style flipped proxy list
 201                 $ret = true;
 202         } else {
 203                 $ret = false;
 204         }
 205         wfProfileOut( $fname );
 206         return $ret;
 207 }
 208
 209
 210
 211
 212 ?>