includes/ProxyTools.php

   1 <?php
   2 /**
   3  * Functions for dealing with proxies
   4  */
   5
   6 /**
   7  * Extracts the XFF string from the request header
   8  * Checks first for "X-Forwarded-For", then "Client-ip"
   9  * Note: headers are spoofable
  10  * @return string
  11  */
  12 function wfGetForwardedFor() {
  13         if( function_exists( 'apache_request_headers' ) ) {
  14                 // More reliable than $_SERVER due to case and -/_ folding
  15                 $set = apache_request_headers();
  16                 $index = 'X-Forwarded-For';
  17                 $index2 = 'Client-ip';
  18         } else {
  19                 // Subject to spoofing with headers like X_Forwarded_For
  20                 $set = $_SERVER;
  21                 $index = 'HTTP_X_FORWARDED_FOR';
  22                 $index2 = 'CLIENT-IP';
  23         }
  24         #Try a couple of headers
  25         if( isset( $set[$index] ) ) {
  26                 return $set[$index];
  27         } else if( isset( $set[$index2] ) ) {
  28                 return $set[$index2];
  29         } else {
  30                 return null;
  31         }
  32 }
  33
  34 /**
  35  * Returns the browser/OS data from the request header
  36  * Note: headers are spoofable
  37  * @return string
  38  */
  39 function wfGetAgent() {
  40         if( function_exists( 'apache_request_headers' ) ) {
  41                 // More reliable than $_SERVER due to case and -/_ folding
  42                 $set = apache_request_headers();
  43                 $index = 'User-Agent';
  44         } else {
  45                 // Subject to spoofing with headers like X_Forwarded_For
  46                 $set = $_SERVER;
  47                 $index = 'HTTP_USER_AGENT';
  48         }
  49         if( isset( $set[$index] ) ) {
  50                 return $set[$index];
  51         } else {
  52                 return '';
  53         }
  54 }
  55
  56 /**
  57  * Work out the IP address based on various globals
  58  * For trusted proxies, use the XFF client IP (first of the chain)
  59  * @return string
  60  */
  61 function wfGetIP() {
  62         global $wgIP;
  63
  64         # Return cached result
  65         if ( !empty( $wgIP ) ) {
  66                 return $wgIP;
  67         }
  68
  69         /* collect the originating ips */
  70         # Client connecting to this webserver
  71         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
  72                 $ipchain = array( IP::canonicalize( $_SERVER['REMOTE_ADDR'] ) );
  73         } else {
  74                 # Running on CLI?
  75                 $ipchain = array( '127.0.0.1' );
  76         }
  77         $ip = $ipchain[0];
  78
  79         # Append XFF on to $ipchain
  80         $forwardedFor = wfGetForwardedFor();
  81         if ( isset( $forwardedFor ) ) {
  82                 $xff = array_map( 'trim', explode( ',', $forwardedFor ) );
  83                 $xff = array_reverse( $xff );
  84                 $ipchain = array_merge( $ipchain, $xff );
  85         }
  86
  87         # Step through XFF list and find the last address in the list which is a trusted server
  88         # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
  89         foreach ( $ipchain as $i => $curIP ) {
  90                 $curIP = IP::canonicalize( $curIP );
  91                 if ( wfIsTrustedProxy( $curIP ) ) {
  92                         if ( isset( $ipchain[$i + 1] ) && IP::isPublic( $ipchain[$i + 1] ) ) {
  93                                 $ip = $ipchain[$i + 1];
  94                         }
  95                 } else {
  96                         break;
  97                 }
  98         }
  99
 100         wfDebug( "IP: $ip\n" );
 101         $wgIP = $ip;
 102         return $ip;
 103 }
 104
 105 /**
 106  * Checks if an IP is a trusted proxy providor
 107  * Useful to tell if X-Fowarded-For data is possibly bogus
 108  * Squid cache servers for the site and AOL are whitelisted
 109  * @param string $ip
 110  * @return bool
 111  */
 112 function wfIsTrustedProxy( $ip ) {
 113         global $wgSquidServers, $wgSquidServersNoPurge;
 114
 115         if ( in_array( $ip, $wgSquidServers ) ||
 116                 in_array( $ip, $wgSquidServersNoPurge ) ||
 117                 wfIsAOLProxy( $ip )
 118         ) {
 119                 $trusted = true;
 120         } else {
 121                 $trusted = false;
 122         }
 123         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
 124         return $trusted;
 125 }
 126
 127 /**
 128  * Forks processes to scan the originating IP for an open proxy server
 129  * MemCached can be used to skip IPs that have already been scanned
 130  */
 131 function wfProxyCheck() {
 132         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
 133         global $wgUseMemCached, $wgMemc, $wgProxyMemcExpiry;
 134         global $wgProxyKey;
 135
 136         if ( !$wgBlockOpenProxies ) {
 137                 return;
 138         }
 139
 140         $ip = wfGetIP();
 141
 142         # Get MemCached key
 143         $skip = false;
 144         if ( $wgUseMemCached ) {
 145                 $mcKey = wfMemcKey( 'proxy', 'ip', $ip );
 146                 $mcValue = $wgMemc->get( $mcKey );
 147                 if ( $mcValue ) {
 148                         $skip = true;
 149                 }
 150         }
 151
 152         # Fork the processes
 153         if ( !$skip ) {
 154                 $title = SpecialPage::getTitleFor( 'Blockme' );
 155                 $iphash = md5( $ip . $wgProxyKey );
 156                 $url = $title->getFullURL( 'ip='.$iphash );
 157
 158                 foreach ( $wgProxyPorts as $port ) {
 159                         $params = implode( ' ', array(
 160                                                 escapeshellarg( $wgProxyScriptPath ),
 161                                                 escapeshellarg( $ip ),
 162                                                 escapeshellarg( $port ),
 163                                                 escapeshellarg( $url )
 164                                                 ));
 165                         exec( "php $params &>/dev/null &" );
 166                 }
 167                 # Set MemCached key
 168                 if ( $wgUseMemCached ) {
 169                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 170                 }
 171         }
 172 }
 173
 174 /**
 175  * Convert a network specification in CIDR notation to an integer network and a number of bits
 176  * @return array(string, int)
 177  */
 178 function wfParseCIDR( $range ) {
 179         return IP::parseCIDR( $range );
 180 }
 181
 182 /**
 183  * Check if an IP address is in the local proxy list
 184  * @return bool
 185  */
 186 function wfIsLocallyBlockedProxy( $ip ) {
 187         global $wgProxyList;
 188         $fname = 'wfIsLocallyBlockedProxy';
 189
 190         if ( !$wgProxyList ) {
 191                 return false;
 192         }
 193         wfProfileIn( $fname );
 194
 195         if ( !is_array( $wgProxyList ) ) {
 196                 # Load from the specified file
 197                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 198         }
 199
 200         if ( !is_array( $wgProxyList ) ) {
 201                 $ret = false;
 202         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 203                 $ret = true;
 204         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 205                 # Old-style flipped proxy list
 206                 $ret = true;
 207         } else {
 208                 $ret = false;
 209         }
 210         wfProfileOut( $fname );
 211         return $ret;
 212 }
 213
 214 /**
 215  * TODO: move this list to the database in a global IP info table incorporating
 216  * trusted ISP proxies, blocked IP addresses and open proxies.
 217  * @return bool
 218  */
 219 function wfIsAOLProxy( $ip ) {
 220         $ranges = array(
 221                 '64.12.96.0/19',
 222                 '149.174.160.0/20',
 223                 '152.163.240.0/21',
 224                 '152.163.248.0/22',
 225                 '152.163.252.0/23',
 226                 '152.163.96.0/22',
 227                 '152.163.100.0/23',
 228                 '195.93.32.0/22',
 229                 '195.93.48.0/22',
 230                 '195.93.64.0/19',
 231                 '195.93.96.0/19',
 232                 '195.93.16.0/20',
 233                 '198.81.0.0/22',
 234                 '198.81.16.0/20',
 235                 '198.81.8.0/23',
 236                 '202.67.64.128/25',
 237                 '205.188.192.0/20',
 238                 '205.188.208.0/23',
 239                 '205.188.112.0/20',
 240                 '205.188.146.144/30',
 241                 '207.200.112.0/21',
 242         );
 243
 244         static $parsedRanges;
 245         if ( is_null( $parsedRanges ) ) {
 246                 $parsedRanges = array();
 247                 foreach ( $ranges as $range ) {
 248                         $parsedRanges[] =  IP::parseRange( $range );
 249                 }
 250         }
 251
 252         $hex = IP::toHex( $ip );
 253         foreach ( $parsedRanges as $range ) {
 254                 if ( $hex >= $range[0] && $hex <= $range[1] ) {
 255                         return true;
 256                 }
 257         }
 258         return false;
 259 }
 260
 261
 262
 263