thumb.php

   1 <?php
   2 /**
   3  * PHP script to stream out an image thumbnail.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23
  24 define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  25 require __DIR__ . '/includes/WebStart.php';
  26
  27 // Don't use fancy mime detection, just check the file extension for jpg/gif/png
  28 $wgTrivialMimeDetection = true;
  29
  30 if ( defined( 'THUMB_HANDLER' ) ) {
  31         // Called from thumb_handler.php via 404; extract params from the URI...
  32         wfThumbHandle404();
  33 } else {
  34         // Called directly, use $_GET params
  35         wfThumbHandleRequest();
  36 }
  37
  38 wfLogProfilingData();
  39
  40 //--------------------------------------------------------------------------
  41
  42 /**
  43  * Handle a thumbnail request via query parameters
  44  *
  45  * @return void
  46  */
  47 function wfThumbHandleRequest() {
  48         $params = get_magic_quotes_gpc()
  49                 ? array_map( 'stripslashes', $_GET )
  50                 : $_GET;
  51
  52         wfStreamThumb( $params ); // stream the thumbnail
  53 }
  54
  55 /**
  56  * Handle a thumbnail request via thumbnail file URL
  57  *
  58  * @return void
  59  */
  60 function wfThumbHandle404() {
  61         global $wgArticlePath;
  62
  63         # Set action base paths so that WebRequest::getPathInfo()
  64         # recognizes the "X" as the 'title' in ../thumb_handler.php/X urls.
  65         # Note: If Custom per-extension repo paths are set, this may break.
  66         $repo = RepoGroup::singleton()->getLocalRepo();
  67         $oldArticlePath = $wgArticlePath;
  68         $wgArticlePath = $repo->getZoneUrl( 'thumb' ) . '/$1';
  69
  70         $matches = WebRequest::getPathInfo();
  71
  72         $wgArticlePath = $oldArticlePath;
  73
  74         if ( !isset( $matches['title'] ) ) {
  75                 wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
  76                 return;
  77         }
  78
  79         $params = wfExtractThumbParams( $matches['title'] ); // basic wiki URL param extracting
  80         if ( $params == null ) {
  81                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
  82                 return;
  83         }
  84
  85         wfStreamThumb( $params ); // stream the thumbnail
  86 }
  87
  88 /**
  89  * Stream a thumbnail specified by parameters
  90  *
  91  * @param $params Array
  92  * @return void
  93  */
  94 function wfStreamThumb( array $params ) {
  95         global $wgVaryOnXFP;
  96
  97         $section = new ProfileSection( __METHOD__ );
  98
  99         $headers = array(); // HTTP headers to send
 100
 101         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 102         unset( $params['f'] );
 103
 104         // Backwards compatibility parameters
 105         if ( isset( $params['w'] ) ) {
 106                 $params['width'] = $params['w'];
 107                 unset( $params['w'] );
 108         }
 109         if ( isset( $params['p'] ) ) {
 110                 $params['page'] = $params['p'];
 111         }
 112         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 113
 114         // Is this a thumb of an archived file?
 115         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 116         unset( $params['archived'] ); // handlers don't care
 117
 118         // Is this a thumb of a temp file?
 119         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 120         unset( $params['temp'] ); // handlers don't care
 121
 122         // Some basic input validation
 123         $fileName = strtr( $fileName, '\\/', '__' );
 124
 125         // Actually fetch the image. Method depends on whether it is archived or not.
 126         if ( $isTemp ) {
 127                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 128                 $img = new UnregisteredLocalFile( null, $repo,
 129                         # Temp files are hashed based on the name without the timestamp.
 130                         # The thumbnails will be hashed based on the entire name however.
 131                         # @todo fix this convention to actually be reasonable.
 132                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 133                 );
 134         } elseif ( $isOld ) {
 135                 // Format is <timestamp>!<name>
 136                 $bits = explode( '!', $fileName, 2 );
 137                 if ( count( $bits ) != 2 ) {
 138                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 139                         return;
 140                 }
 141                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 142                 if ( !$title ) {
 143                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 144                         return;
 145                 }
 146                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 147         } else {
 148                 $img = wfLocalFile( $fileName );
 149         }
 150
 151         // Check the source file title
 152         if ( !$img ) {
 153                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 154                 return;
 155         }
 156
 157         // Check permissions if there are read restrictions
 158         $varyHeader = array();
 159         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 160                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 161                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 162                                 'the source file.' );
 163                         return;
 164                 }
 165                 $headers[] = 'Cache-Control: private';
 166                 $varyHeader[] = 'Cookie';
 167         }
 168
 169         // Check the source file storage path
 170         if ( !$img->exists() ) {
 171                 wfThumbError( 404, "The source file '$fileName' does not exist." );
 172                 return;
 173         } elseif ( $img->getPath() === false ) {
 174                 wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
 175                 return;
 176         }
 177
 178         // Check IMS against the source file
 179         // This means that clients can keep a cached copy even after it has been deleted on the server
 180         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 181                 // Fix IE brokenness
 182                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 183                 // Calculate time
 184                 wfSuppressWarnings();
 185                 $imsUnix = strtotime( $imsString );
 186                 wfRestoreWarnings();
 187                 if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 188                         header( 'HTTP/1.1 304 Not Modified' );
 189                         return;
 190                 }
 191         }
 192
 193         // Get the normalized thumbnail name from the parameters...
 194         try {
 195                 $thumbName = $img->thumbName( $params );
 196                 if ( !strlen( $thumbName ) ) { // invalid params?
 197                         wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 198                         return;
 199                 }
 200                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 201         } catch ( MWException $e ) {
 202                 wfThumbError( 500, $e->getHTML() );
 203                 return;
 204         }
 205
 206         // For 404 handled thumbnails, we only use the the base name of the URI
 207         // for the thumb params and the parent directory for the source file name.
 208         // Check that the zone relative path matches up so squid caches won't pick
 209         // up thumbs that would not be purged on source file deletion (bug 34231).
 210         if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 211                 if ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 212                         // Request for the canonical thumbnail name
 213                 } elseif ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 214                         // Request for the "long" thumbnail name; redirect to canonical name
 215                         $response = RequestContext::getMain()->getRequest()->response();
 216                         $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 217                         $response->header( 'Location: ' .
 218                                 wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 219                         $response->header( 'Expires: ' .
 220                                 gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
 221                         if ( $wgVaryOnXFP ) {
 222                                 $varyHeader[] = 'X-Forwarded-Proto';
 223                         }
 224                         if ( count( $varyHeader ) ) {
 225                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 226                         }
 227                         return;
 228                 } else {
 229                         wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 230                                 expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 231                                 rawurldecode( $params['rel404'] ) . "'." );
 232                         return;
 233                 }
 234         }
 235
 236         // Suggest a good name for users downloading this thumbnail
 237         $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName )}";
 238
 239         if ( count( $varyHeader ) ) {
 240                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 241         }
 242
 243         // Stream the file if it exists already...
 244         $thumbPath = $img->getThumbPath( $thumbName );
 245         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 246                 $img->getRepo()->streamFile( $thumbPath, $headers );
 247                 return;
 248         }
 249
 250         // Thumbnail isn't already there, so create the new thumbnail...
 251         try {
 252                 $thumb = $img->transform( $params, File::RENDER_NOW );
 253         } catch ( Exception $ex ) {
 254                 // Tried to select a page on a non-paged file?
 255                 $thumb = false;
 256         }
 257
 258         // Check for thumbnail generation errors...
 259         $errorMsg = false;
 260         $msg = wfMessage( 'thumbnail_error' );
 261         if ( !$thumb ) {
 262                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 263         } elseif ( $thumb->isError() ) {
 264                 $errorMsg = $thumb->getHtmlMsg();
 265         } elseif ( !$thumb->hasFile() ) {
 266                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 267         } elseif ( $thumb->fileIsSource() ) {
 268                 $errorMsg = $msg->
 269                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 270         }
 271
 272         if ( $errorMsg !== false ) {
 273                 wfThumbError( 500, $errorMsg );
 274         } else {
 275                 // Stream the file if there were no errors
 276                 $thumb->streamFile( $headers );
 277         }
 278 }
 279
 280 /**
 281  * Extract the required params for thumb.php from the thumbnail request URI.
 282  * At least 'width' and 'f' should be set if the result is an array.
 283  *
 284  * @param $thumbRel String Thumbnail path relative to the thumb zone
 285  * @return Array|null associative params array or null
 286  */
 287 function wfExtractThumbParams( $thumbRel ) {
 288         $repo = RepoGroup::singleton()->getLocalRepo();
 289
 290         $hashDirReg = $subdirReg = '';
 291         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 292                 $subdirReg .= '[0-9a-f]';
 293                 $hashDirReg .= "$subdirReg/";
 294         }
 295
 296         // Check if this is a thumbnail of an original in the local file repo
 297         if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 298                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 299         // Check if this is a thumbnail of an temp file in the local file repo
 300         } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 301                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 302         } else {
 303                 return null; // not a valid looking thumbnail request
 304         }
 305
 306         $params = array( 'f' => $filename, 'rel404' => $rel );
 307         if ( $archOrTemp === 'archive/' ) {
 308                 $params['archived'] = 1;
 309         } elseif ( $archOrTemp === 'temp/' ) {
 310                 $params['temp'] = 1;
 311         }
 312
 313         // Check hooks if parameters can be extracted
 314         // Hooks return false if they manage to *resolve* the parameters
 315         if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 316                 return $params; // valid thumbnail URL (via extension or config)
 317         // Check if the parameters can be extracted from the thumbnail name...
 318         } elseif ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 319                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 320                 $params['width'] = $size;
 321                 if ( $pagenum ) {
 322                         $params['page'] = $pagenum;
 323                 }
 324                 return $params; // valid thumbnail URL
 325         }
 326
 327         return null; // not a valid thumbnail URL
 328 }
 329
 330 /**
 331  * Output a thumbnail generation error message
 332  *
 333  * @param $status integer
 334  * @param $msg string
 335  * @return void
 336  */
 337 function wfThumbError( $status, $msg ) {
 338         global $wgShowHostnames;
 339
 340         header( 'Cache-Control: no-cache' );
 341         header( 'Content-Type: text/html; charset=utf-8' );
 342         if ( $status == 404 ) {
 343                 header( 'HTTP/1.1 404 Not found' );
 344         } elseif ( $status == 403 ) {
 345                 header( 'HTTP/1.1 403 Forbidden' );
 346                 header( 'Vary: Cookie' );
 347         } else {
 348                 header( 'HTTP/1.1 500 Internal server error' );
 349         }
 350         if ( $wgShowHostnames ) {
 351                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 352                 $hostname = htmlspecialchars( wfHostname() );
 353                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 354         } else {
 355                 $debug = '';
 356         }
 357         echo <<<EOT
 358 <html><head><title>Error generating thumbnail</title></head>
 359 <body>
 360 <h1>Error generating thumbnail</h1>
 361 <p>
 362 $msg
 363 </p>
 364 $debug
 365 </body>
 366 </html>
 367
 368 EOT;
 369 }