thumb.php

   1 <?php
   2
   3 /**
   4  * PHP script to stream out an image thumbnail.
   5  *
   6  * @file
   7  * @ingroup Media
   8  */
   9 define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  10 if ( isset( $_SERVER['MW_COMPILED'] ) ) {
  11         require( 'phase3/includes/WebStart.php' );
  12 } else {
  13         require( dirname( __FILE__ ) . '/includes/WebStart.php' );
  14 }
  15
  16 // Don't use fancy mime detection, just check the file extension for jpg/gif/png
  17 $wgTrivialMimeDetection = true;
  18
  19 if ( defined( 'THUMB_HANDLER' ) ) {
  20         // Called from thumb_handler.php via 404; extract params from the URI...
  21         wfThumbHandle404();
  22 } else {
  23         // Called directly, use $_REQUEST params
  24         wfThumbHandleRequest();
  25 }
  26 wfLogProfilingData();
  27
  28 //--------------------------------------------------------------------------
  29
  30 /**
  31  * Handle a thumbnail request via query parameters
  32  *
  33  * @return void
  34  */
  35 function wfThumbHandleRequest() {
  36         $params = get_magic_quotes_gpc()
  37                 ? array_map( 'stripslashes', $_REQUEST )
  38                 : $_REQUEST;
  39
  40         wfStreamThumb( $params ); // stream the thumbnail
  41 }
  42
  43 /**
  44  * Handle a thumbnail request via thumbnail file URL
  45  *
  46  * @return void
  47  */
  48 function wfThumbHandle404() {
  49         # lighttpd puts the original request in REQUEST_URI, while sjs sets
  50         # that to the 404 handler, and puts the original request in REDIRECT_URL.
  51         if ( isset( $_SERVER['REDIRECT_URL'] ) ) {
  52                 # The URL is un-encoded, so put it back how it was
  53                 $uri = str_replace( "%2F", "/", urlencode( $_SERVER['REDIRECT_URL'] ) );
  54                 # Just get the URI path (REDIRECT_URL is either a full URL or a path)
  55                 if ( $uri[0] !== '/' ) {
  56                         $bits = wfParseUrl( $uri );
  57                         if ( $bits && isset( $bits['path'] ) ) {
  58                                 $uri = $bits['path'];
  59                         }
  60                 }
  61         } else {
  62                 $uri = $_SERVER['REQUEST_URI'];
  63         }
  64
  65         $params = wfExtractThumbParams( $uri ); // basic wiki URL param extracting
  66         if ( $params == null ) {
  67                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  68                 return;
  69         }
  70
  71         wfStreamThumb( $params ); // stream the thumbnail
  72 }
  73
  74 /**
  75  * Stream a thumbnail specified by parameters
  76  *
  77  * @param $params Array
  78  * @return void
  79  */
  80 function wfStreamThumb( array $params ) {
  81         wfProfileIn( __METHOD__ );
  82
  83         $headers = array(); // HTTP headers to send
  84
  85         $fileName = isset( $params['f'] ) ? $params['f'] : '';
  86         unset( $params['f'] );
  87
  88         // Backwards compatibility parameters
  89         if ( isset( $params['w'] ) ) {
  90                 $params['width'] = $params['w'];
  91                 unset( $params['w'] );
  92         }
  93         if ( isset( $params['p'] ) ) {
  94                 $params['page'] = $params['p'];
  95         }
  96         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
  97
  98         // Is this a thumb of an archived file?
  99         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 100         unset( $params['archived'] );
 101
 102         // Some basic input validation
 103         $fileName = strtr( $fileName, '\\/', '__' );
 104
 105         // Actually fetch the image. Method depends on whether it is archived or not.
 106         if ( $isOld ) {
 107                 // Format is <timestamp>!<name>
 108                 $bits = explode( '!', $fileName, 2 );
 109                 if ( count( $bits ) != 2 ) {
 110                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 111                         wfProfileOut( __METHOD__ );
 112                         return;
 113                 }
 114                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 115                 if ( !$title ) {
 116                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 117                         wfProfileOut( __METHOD__ );
 118                         return;
 119                 }
 120                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 121         } else {
 122                 $img = wfLocalFile( $fileName );
 123         }
 124
 125         // Check permissions if there are read restrictions
 126         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 127                 if ( !$img->getTitle()->userCan( 'read' ) ) {
 128                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 129                                 'the source file.' );
 130                         wfProfileOut( __METHOD__ );
 131                         return;
 132                 }
 133                 $headers[] = 'Cache-Control: private';
 134                 $headers[] = 'Vary: Cookie';
 135         }
 136
 137         // Check the source file storage path
 138         if ( !$img ) {
 139                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
 140                 wfProfileOut( __METHOD__ );
 141                 return;
 142         }
 143         if ( !$img->exists() ) {
 144                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 145                 wfProfileOut( __METHOD__ );
 146                 return;
 147         }
 148         $sourcePath = $img->getPath();
 149         if ( $sourcePath === false ) {
 150                 wfThumbError( 500, 'The source file is not locally accessible.' );
 151                 wfProfileOut( __METHOD__ );
 152                 return;
 153         }
 154
 155         // Check IMS against the source file
 156         // This means that clients can keep a cached copy even after it has been deleted on the server
 157         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 158                 // Fix IE brokenness
 159                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 160                 // Calculate time
 161                 wfSuppressWarnings();
 162                 $imsUnix = strtotime( $imsString );
 163                 wfRestoreWarnings();
 164                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 165                 if ( $sourceTsUnix <= $imsUnix ) {
 166                         header( 'HTTP/1.1 304 Not Modified' );
 167                         wfProfileOut( __METHOD__ );
 168                         return;
 169                 }
 170         }
 171
 172         // Stream the file if it exists already...
 173         try {
 174                 $thumbName = $img->thumbName( $params );
 175                 if ( strlen( $thumbName ) ) { // valid params?
 176                         $thumbPath = $img->getThumbPath( $thumbName );
 177                         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 178                                 $img->getRepo()->streamFile( $thumbPath, $headers );
 179                                 wfProfileOut( __METHOD__ );
 180                                 return;
 181                         }
 182                 }
 183         } catch ( MWException $e ) {
 184                 wfThumbError( 500, $e->getHTML() );
 185                 wfProfileOut( __METHOD__ );
 186                 return;
 187         }
 188
 189         // Thumbnail isn't already there, so create the new thumbnail...
 190         try {
 191                 $thumb = $img->transform( $params, File::RENDER_NOW );
 192         } catch ( Exception $ex ) {
 193                 // Tried to select a page on a non-paged file?
 194                 $thumb = false;
 195         }
 196
 197         // Check for thumbnail generation errors...
 198         $errorMsg = false;
 199         if ( !$thumb ) {
 200                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 201         } elseif ( $thumb->isError() ) {
 202                 $errorMsg = $thumb->getHtmlMsg();
 203         } elseif ( !$thumb->hasFile() ) {
 204                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 205         } elseif ( $thumb->fileIsSource() ) {
 206                 $errorMsg = wfMsgHtml( 'thumbnail_error',
 207                         'Image was not scaled, is the requested width bigger than the source?' );
 208         }
 209
 210         if ( $errorMsg !== false ) {
 211                 wfThumbError( 500, $errorMsg );
 212         } else {
 213                 // Stream the file if there were no errors
 214                 $thumb->streamFile( $headers );
 215         }
 216
 217         wfProfileOut( __METHOD__ );
 218 }
 219
 220 /**
 221  * Extract the required params for thumb.php from the thumbnail request URI.
 222  * At least 'width' and 'f' should be set if the result is an array.
 223  *
 224  * @param $uri String Thumbnail request URI path
 225  * @return Array|null associative params array or null
 226  */
 227 function wfExtractThumbParams( $uri ) {
 228         $repo = RepoGroup::singleton()->getLocalRepo();
 229
 230         $zoneURI = $repo->getZoneUrl( 'thumb' );
 231         if ( substr( $zoneURI, 0, 1 ) !== '/' ) {
 232                 $bits = wfParseUrl( $zoneURI );
 233                 if ( $bits && isset( $bits['path'] ) ) {
 234                         $zoneURI = $bits['path'];
 235                 } else {
 236                         return null;
 237                 }
 238         }
 239         $zoneUrlRegex = preg_quote( $zoneURI );
 240
 241         $hashDirRegex = $subdirRegex = '';
 242         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 243                 $subdirRegex .= '[0-9a-f]';
 244                 $hashDirRegex .= "$subdirRegex/";
 245         }
 246
 247         $thumbUrlRegex = "!^$zoneUrlRegex(/archive|/temp|)/$hashDirRegex([^/]*)/([^/]*)$!";
 248
 249         // Check if this is a valid looking thumbnail request...
 250         if ( preg_match( $thumbUrlRegex, $uri, $matches ) ) {
 251                 list( /* all */, $archOrTemp, $filename, $thumbname ) = $matches;
 252                 $filename = urldecode( $filename );
 253                 $thumbname = urldecode( $thumbname );
 254
 255                 $params = array( 'f' => $filename );
 256                 if ( $archOrTemp == '/archive' ) {
 257                         $params['archived'] = 1;
 258                 } elseif ( $archOrTemp == '/temp' ) {
 259                         $params['temp'] = 1;
 260                 }
 261
 262                 // Check if the parameters can be extracted from the thumbnail name...
 263                 // @TODO: remove 'page' stuff and make ProofreadPage handle it via hook.
 264                 if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 265                         list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 266                         $params['width'] = $size;
 267                         if ( $pagenum ) {
 268                                 $params['page'] = $pagenum;
 269                         }
 270                         return $params; // valid thumbnail URL
 271                 // Hooks return false if they manage to *resolve* the parameters
 272                 } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 273                         return $params; // valid thumbnail URL (via extension or config)
 274                 }
 275         }
 276
 277         return null; // not a valid thumbnail URL
 278 }
 279
 280 /**
 281  * Output a thumbnail generation error message
 282  *
 283  * @param $status integer
 284  * @param $msg string
 285  * @return void
 286  */
 287 function wfThumbError( $status, $msg ) {
 288         global $wgShowHostnames;
 289
 290         header( 'Cache-Control: no-cache' );
 291         header( 'Content-Type: text/html; charset=utf-8' );
 292         if ( $status == 404 ) {
 293                 header( 'HTTP/1.1 404 Not found' );
 294         } elseif ( $status == 403 ) {
 295                 header( 'HTTP/1.1 403 Forbidden' );
 296                 header( 'Vary: Cookie' );
 297         } else {
 298                 header( 'HTTP/1.1 500 Internal server error' );
 299         }
 300         if ( $wgShowHostnames ) {
 301                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 302                 $hostname = htmlspecialchars( wfHostname() );
 303                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 304         } else {
 305                 $debug = "";
 306         }
 307         echo <<<EOT
 308 <html><head><title>Error generating thumbnail</title></head>
 309 <body>
 310 <h1>Error generating thumbnail</h1>
 311 <p>
 312 $msg
 313 </p>
 314 $debug
 315 </body>
 316 </html>
 317
 318 EOT;
 319 }