includes/ProxyTools.php

   1 <?php
   2 /**
   3  * Functions for dealing with proxies
   4  * @package MediaWiki
   5  */
   6
   7 function wfGetForwardedFor() {
   8         if( function_exists( 'apache_request_headers' ) ) {
   9                 // More reliable than $_SERVER due to case and -/_ folding
  10                 $set = apache_request_headers();
  11                 $index = 'X-Forwarded-For';
  12         } else {
  13                 // Subject to spoofing with headers like X_Forwarded_For
  14                 $set = $_SERVER;
  15                 $index = 'HTTP_X_FORWARDED_FOR';
  16         }
  17         if( isset( $set[$index] ) ) {
  18                 return $set[$index];
  19         } else {
  20                 return null;
  21         }
  22 }
  23
  24 /** Work out the IP address based on various globals */
  25 function wfGetIP() {
  26         global $wgSquidServers, $wgSquidServersNoPurge, $wgIP;
  27
  28         # Return cached result
  29         if ( !empty( $wgIP ) ) {
  30                 return $wgIP;
  31         }
  32
  33         /* collect the originating ips */
  34         # Client connecting to this webserver
  35         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
  36                 $ipchain = array( $_SERVER['REMOTE_ADDR'] );
  37         } else {
  38                 # Running on CLI?
  39                 $ipchain = array( '127.0.0.1' );
  40         }
  41         $ip = $ipchain[0];
  42
  43         # Get list of trusted proxies
  44         # Flipped for quicker access
  45         $trustedProxies = array_flip( array_merge( $wgSquidServers, $wgSquidServersNoPurge ) );
  46         if ( count( $trustedProxies ) ) {
  47                 # Append XFF on to $ipchain
  48                 $forwardedFor = wfGetForwardedFor();
  49                 if ( isset( $forwardedFor ) ) {
  50                         $xff = array_map( 'trim', explode( ',', $forwardedFor ) );
  51                         $xff = array_reverse( $xff );
  52                         $ipchain = array_merge( $ipchain, $xff );
  53                 }
  54                 # Step through XFF list and find the last address in the list which is a trusted server
  55                 # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
  56                 foreach ( $ipchain as $i => $curIP ) {
  57                         if ( array_key_exists( $curIP, $trustedProxies ) ) {
  58                                 if ( isset( $ipchain[$i + 1] ) && wfIsIPPublic( $ipchain[$i + 1] ) ) {
  59                                         $ip = $ipchain[$i + 1];
  60                                 }
  61                         } else {
  62                                 break;
  63                         }
  64                 }
  65         }
  66
  67         wfDebug( "IP: $ip\n" );
  68         $wgIP = $ip;
  69         return $ip;
  70 }
  71
  72 /**
  73  * Given an IP address in dotted-quad notation, returns an unsigned integer.
  74  * Like ip2long() except that it actually works and has a consistent error return value.
  75  */
  76 function wfIP2Unsigned( $ip ) {
  77         $n = ip2long( $ip );
  78         if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
  79                 $n = false;
  80         } elseif ( $n < 0 ) {
  81                 $n += pow( 2, 32 );
  82         }
  83         return $n;
  84 }
  85
  86 /**
  87  * Return a zero-padded hexadecimal representation of an IP address
  88  */
  89 function wfIP2Hex( $ip ) {
  90         $n = wfIP2Unsigned( $ip );
  91         if ( $n !== false ) {
  92                 $n = sprintf( '%08X', $n );
  93         }
  94         return $n;
  95 }
  96
  97 /**
  98  * Determine if an IP address really is an IP address, and if it is public,
  99  * i.e. not RFC 1918 or similar
 100  */
 101 function wfIsIPPublic( $ip ) {
 102         $n = wfIP2Unsigned( $ip );
 103         if ( !$n ) {
 104                 return false;
 105         }
 106
 107         // ip2long accepts incomplete addresses, as well as some addresses
 108         // followed by garbage characters. Check that it's really valid.
 109         if( $ip != long2ip( $n ) ) {
 110                 return false;
 111         }
 112
 113         static $privateRanges = false;
 114         if ( !$privateRanges ) {
 115                 $privateRanges = array(
 116                         array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 117                         array( '172.16.0.0',  '172.31.255.255' ),   #     "
 118                         array( '192.168.0.0', '192.168.255.255' ),  #     "
 119                         array( '0.0.0.0',     '0.255.255.255' ),    # this network
 120                         array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 121                 );
 122         }
 123
 124         foreach ( $privateRanges as $r ) {
 125                 $start = wfIP2Unsigned( $r[0] );
 126                 $end = wfIP2Unsigned( $r[1] );
 127                 if ( $n >= $start && $n <= $end ) {
 128                         return false;
 129                 }
 130         }
 131         return true;
 132 }
 133
 134 /**
 135  * Forks processes to scan the originating IP for an open proxy server
 136  * MemCached can be used to skip IPs that have already been scanned
 137  */
 138 function wfProxyCheck() {
 139         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
 140         global $wgUseMemCached, $wgMemc, $wgDBname, $wgProxyMemcExpiry;
 141         global $wgProxyKey;
 142
 143         if ( !$wgBlockOpenProxies ) {
 144                 return;
 145         }
 146
 147         $ip = wfGetIP();
 148
 149         # Get MemCached key
 150         $skip = false;
 151         if ( $wgUseMemCached ) {
 152                 $mcKey = "$wgDBname:proxy:ip:$ip";
 153                 $mcValue = $wgMemc->get( $mcKey );
 154                 if ( $mcValue ) {
 155                         $skip = true;
 156                 }
 157         }
 158
 159         # Fork the processes
 160         if ( !$skip ) {
 161                 $title = Title::makeTitle( NS_SPECIAL, 'Blockme' );
 162                 $iphash = md5( $ip . $wgProxyKey );
 163                 $url = $title->getFullURL( 'ip='.$iphash );
 164
 165                 foreach ( $wgProxyPorts as $port ) {
 166                         $params = implode( ' ', array(
 167                                                 escapeshellarg( $wgProxyScriptPath ),
 168                                                 escapeshellarg( $ip ),
 169                                                 escapeshellarg( $port ),
 170                                                 escapeshellarg( $url )
 171                                                 ));
 172                         exec( "php $params &>/dev/null &" );
 173                 }
 174                 # Set MemCached key
 175                 if ( $wgUseMemCached ) {
 176                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 177                 }
 178         }
 179 }
 180
 181 /**
 182  * Convert a network specification in CIDR notation to an integer network and a number of bits
 183  */
 184 function wfParseCIDR( $range ) {
 185         $parts = explode( '/', $range, 2 );
 186         if ( count( $parts ) != 2 ) {
 187                 return array( false, false );
 188         }
 189         $network = wfIP2Unsigned( $parts[0] );
 190         if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 191                 $bits = $parts[1];
 192         } else {
 193                 $network = false;
 194                 $bits = false;
 195         }
 196         return array( $network, $bits );
 197 }
 198
 199 /**
 200  * Check if an IP address is in the local proxy list
 201  */
 202 function wfIsLocallyBlockedProxy( $ip ) {
 203         global $wgProxyList;
 204         $fname = 'wfIsLocallyBlockedProxy';
 205
 206         if ( !$wgProxyList ) {
 207                 return false;
 208         }
 209         wfProfileIn( $fname );
 210
 211         if ( !is_array( $wgProxyList ) ) {
 212                 # Load from the specified file
 213                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 214         }
 215
 216         if ( !is_array( $wgProxyList ) ) {
 217                 $ret = false;
 218         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 219                 $ret = true;
 220         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 221                 # Old-style flipped proxy list
 222                 $ret = true;
 223         } else {
 224                 $ret = false;
 225         }
 226         wfProfileOut( $fname );
 227         return $ret;
 228 }
 229
 230
 231
 232
 233 ?>