includes/ProxyTools.php

   1 <?php
   2 /**
   3  * Functions for dealing with proxies
   4  */
   5
   6 function wfGetForwardedFor() {
   7         if( function_exists( 'apache_request_headers' ) ) {
   8                 // More reliable than $_SERVER due to case and -/_ folding
   9                 $set = apache_request_headers();
  10                 $index = 'X-Forwarded-For';
  11                 $index2 = 'Client-ip';
  12         } else {
  13                 // Subject to spoofing with headers like X_Forwarded_For
  14                 $set = $_SERVER;
  15                 $index = 'HTTP_X_FORWARDED_FOR';
  16                 $index2 = 'CLIENT-IP';
  17         }
  18         #Try a couple of headers
  19         if( isset( $set[$index] ) ) {
  20                 return $set[$index];
  21         } else if( isset( $set[$index2] ) ) {
  22                 return $set[$index2];
  23         } else {
  24                 return null;
  25         }
  26 }
  27
  28 function wfGetLastIPfromXFF( $xff ) {
  29         if ( $xff ) {
  30         // Avoid annoyingly long xff hacks
  31                 $xff = substr( $xff, 0, 255 );
  32                 // Look for the last IP, assuming they are separated by commas or spaces
  33                 $n = ( strrpos($xff, ',') ) ? strrpos($xff, ',') : strrpos($xff, ' ');
  34                 if ( strrpos !== false ) {
  35                         $last = trim( substr( $xff, $n + 1 ) );
  36                         // Make sure it is an IP
  37                         $m = preg_match('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}#', $last, $last_ip4);
  38                         $n = preg_match('#:(:[0-9A-Fa-f]{1,4}){1,7}|[0-9A-Fa-f]{1,4}(:{1,2}[0-9A-Fa-f]{1,4}|::$){1,7}#', $last, $last_ip6);
  39                         if ( $m > 0 )
  40                                 $xff_ip = $last_ip4;
  41                         else if ( $n > 0 )
  42                                 $xff_ip = $last_ip6;
  43                         else
  44                                 $xff_ip = null;
  45                 } else {
  46                         $xff_ip = null;
  47                 }
  48         } else {
  49                 $xff_ip = null;
  50         }
  51         return $xff_ip;
  52 }
  53
  54 function wfGetAgent() {
  55         if( function_exists( 'apache_request_headers' ) ) {
  56                 // More reliable than $_SERVER due to case and -/_ folding
  57                 $set = apache_request_headers();
  58                 $index = 'User-Agent';
  59         } else {
  60                 // Subject to spoofing with headers like X_Forwarded_For
  61                 $set = $_SERVER;
  62                 $index = 'HTTP_USER_AGENT';
  63         }
  64         if( isset( $set[$index] ) ) {
  65                 return $set[$index];
  66         } else {
  67                 return '';
  68         }
  69 }
  70
  71 /** Work out the IP address based on various globals */
  72 function wfGetIP() {
  73         global $wgIP;
  74
  75         # Return cached result
  76         if ( !empty( $wgIP ) ) {
  77                 return $wgIP;
  78         }
  79
  80         /* collect the originating ips */
  81         # Client connecting to this webserver
  82         if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
  83                 $ipchain = array( IP::canonicalize( $_SERVER['REMOTE_ADDR'] ) );
  84         } else {
  85                 # Running on CLI?
  86                 $ipchain = array( '127.0.0.1' );
  87         }
  88         $ip = $ipchain[0];
  89
  90         # Append XFF on to $ipchain
  91         $forwardedFor = wfGetForwardedFor();
  92         if ( isset( $forwardedFor ) ) {
  93                 $xff = array_map( 'trim', explode( ',', $forwardedFor ) );
  94                 $xff = array_reverse( $xff );
  95                 $ipchain = array_merge( $ipchain, $xff );
  96         }
  97
  98         # Step through XFF list and find the last address in the list which is a trusted server
  99         # Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
 100         foreach ( $ipchain as $i => $curIP ) {
 101                 $curIP = IP::canonicalize( $curIP );
 102                 if ( wfIsTrustedProxy( $curIP ) ) {
 103                         if ( isset( $ipchain[$i + 1] ) && IP::isPublic( $ipchain[$i + 1] ) ) {
 104                                 $ip = $ipchain[$i + 1];
 105                         }
 106                 } else {
 107                         break;
 108                 }
 109         }
 110
 111         wfDebug( "IP: $ip\n" );
 112         $wgIP = $ip;
 113         return $ip;
 114 }
 115
 116 function wfIsTrustedProxy( $ip ) {
 117         global $wgSquidServers, $wgSquidServersNoPurge;
 118
 119         if ( in_array( $ip, $wgSquidServers ) ||
 120                 in_array( $ip, $wgSquidServersNoPurge ) ||
 121                 wfIsAOLProxy( $ip )
 122         ) {
 123                 $trusted = true;
 124         } else {
 125                 $trusted = false;
 126         }
 127         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
 128         return $trusted;
 129 }
 130
 131 /**
 132  * Forks processes to scan the originating IP for an open proxy server
 133  * MemCached can be used to skip IPs that have already been scanned
 134  */
 135 function wfProxyCheck() {
 136         global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
 137         global $wgUseMemCached, $wgMemc, $wgProxyMemcExpiry;
 138         global $wgProxyKey;
 139
 140         if ( !$wgBlockOpenProxies ) {
 141                 return;
 142         }
 143
 144         $ip = wfGetIP();
 145
 146         # Get MemCached key
 147         $skip = false;
 148         if ( $wgUseMemCached ) {
 149                 $mcKey = wfMemcKey( 'proxy', 'ip', $ip );
 150                 $mcValue = $wgMemc->get( $mcKey );
 151                 if ( $mcValue ) {
 152                         $skip = true;
 153                 }
 154         }
 155
 156         # Fork the processes
 157         if ( !$skip ) {
 158                 $title = SpecialPage::getTitleFor( 'Blockme' );
 159                 $iphash = md5( $ip . $wgProxyKey );
 160                 $url = $title->getFullURL( 'ip='.$iphash );
 161
 162                 foreach ( $wgProxyPorts as $port ) {
 163                         $params = implode( ' ', array(
 164                                                 escapeshellarg( $wgProxyScriptPath ),
 165                                                 escapeshellarg( $ip ),
 166                                                 escapeshellarg( $port ),
 167                                                 escapeshellarg( $url )
 168                                                 ));
 169                         exec( "php $params &>/dev/null &" );
 170                 }
 171                 # Set MemCached key
 172                 if ( $wgUseMemCached ) {
 173                         $wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
 174                 }
 175         }
 176 }
 177
 178 /**
 179  * Convert a network specification in CIDR notation to an integer network and a number of bits
 180  */
 181 function wfParseCIDR( $range ) {
 182         return IP::parseCIDR( $range );
 183 }
 184
 185 /**
 186  * Check if an IP address is in the local proxy list
 187  */
 188 function wfIsLocallyBlockedProxy( $ip ) {
 189         global $wgProxyList;
 190         $fname = 'wfIsLocallyBlockedProxy';
 191
 192         if ( !$wgProxyList ) {
 193                 return false;
 194         }
 195         wfProfileIn( $fname );
 196
 197         if ( !is_array( $wgProxyList ) ) {
 198                 # Load from the specified file
 199                 $wgProxyList = array_map( 'trim', file( $wgProxyList ) );
 200         }
 201
 202         if ( !is_array( $wgProxyList ) ) {
 203                 $ret = false;
 204         } elseif ( array_search( $ip, $wgProxyList ) !== false ) {
 205                 $ret = true;
 206         } elseif ( array_key_exists( $ip, $wgProxyList ) ) {
 207                 # Old-style flipped proxy list
 208                 $ret = true;
 209         } else {
 210                 $ret = false;
 211         }
 212         wfProfileOut( $fname );
 213         return $ret;
 214 }
 215
 216 /**
 217  * TODO: move this list to the database in a global IP info table incorporating
 218  * trusted ISP proxies, blocked IP addresses and open proxies.
 219  */
 220 function wfIsAOLProxy( $ip ) {
 221         $ranges = array(
 222                 '64.12.96.0/19',
 223                 '149.174.160.0/20',
 224                 '152.163.240.0/21',
 225                 '152.163.248.0/22',
 226                 '152.163.252.0/23',
 227                 '152.163.96.0/22',
 228                 '152.163.100.0/23',
 229                 '195.93.32.0/22',
 230                 '195.93.48.0/22',
 231                 '195.93.64.0/19',
 232                 '195.93.96.0/19',
 233                 '195.93.16.0/20',
 234                 '198.81.0.0/22',
 235                 '198.81.16.0/20',
 236                 '198.81.8.0/23',
 237                 '202.67.64.128/25',
 238                 '205.188.192.0/20',
 239                 '205.188.208.0/23',
 240                 '205.188.112.0/20',
 241                 '205.188.146.144/30',
 242                 '207.200.112.0/21',
 243         );
 244
 245         static $parsedRanges;
 246         if ( is_null( $parsedRanges ) ) {
 247                 $parsedRanges = array();
 248                 foreach ( $ranges as $range ) {
 249                         $parsedRanges[] =  IP::parseRange( $range );
 250                 }
 251         }
 252
 253         $hex = IP::toHex( $ip );
 254         foreach ( $parsedRanges as $range ) {
 255                 if ( $hex >= $range[0] && $hex <= $range[1] ) {
 256                         return true;
 257                 }
 258         }
 259         return false;
 260 }
 261
 262
 263
 264 ?>