includes/specials/SpecialUploadStash.php

   1 <?php
   2 /**
   3  * Implements Special:UploadStash.
   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 SpecialPage
  22  * @ingroup Upload
  23  */
  24
  25 /**
  26  * Web access for files temporarily stored by UploadStash.
  27  *
  28  * For example -- files that were uploaded with the UploadWizard extension are stored temporarily
  29  * before committing them to the db. But we want to see their thumbnails and get other information
  30  * about them.
  31  *
  32  * Since this is based on the user's session, in effect this creates a private temporary file area.
  33  * However, the URLs for the files cannot be shared.
  34  */
  35 class SpecialUploadStash extends UnlistedSpecialPage {
  36         // UploadStash
  37         private $stash;
  38
  39         /**
  40          * Since we are directly writing the file to STDOUT,
  41          * we should not be reading in really big files and serving them out.
  42          *
  43          * We also don't want people using this as a file drop, even if they
  44          * share credentials.
  45          *
  46          * This service is really for thumbnails and other such previews while
  47          * uploading.
  48          */
  49         const MAX_SERVE_BYTES = 1048576; // 1MB
  50
  51         public function __construct() {
  52                 parent::__construct( 'UploadStash', 'upload' );
  53         }
  54
  55         public function doesWrites() {
  56                 return true;
  57         }
  58
  59         /**
  60          * Execute page -- can output a file directly or show a listing of them.
  61          *
  62          * @param string $subPage Subpage, e.g. in
  63          *   https://example.com/wiki/Special:UploadStash/foo.jpg, the "foo.jpg" part
  64          * @return bool Success
  65          */
  66         public function execute( $subPage ) {
  67                 $this->useTransactionalTimeLimit();
  68
  69                 $this->stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $this->getUser() );
  70                 $this->checkPermissions();
  71
  72                 if ( $subPage === null || $subPage === '' ) {
  73                         return $this->showUploads();
  74                 }
  75
  76                 return $this->showUpload( $subPage );
  77         }
  78
  79         /**
  80          * If file available in stash, cats it out to the client as a simple HTTP response.
  81          * n.b. Most sanity checking done in UploadStashLocalFile, so this is straightforward.
  82          *
  83          * @param string $key The key of a particular requested file
  84          * @throws HttpError
  85          * @return bool
  86          */
  87         public function showUpload( $key ) {
  88                 // prevent callers from doing standard HTML output -- we'll take it from here
  89                 $this->getOutput()->disable();
  90
  91                 try {
  92                         $params = $this->parseKey( $key );
  93                         if ( $params['type'] === 'thumb' ) {
  94                                 return $this->outputThumbFromStash( $params['file'], $params['params'] );
  95                         } else {
  96                                 return $this->outputLocalFile( $params['file'] );
  97                         }
  98                 } catch ( UploadStashFileNotFoundException $e ) {
  99                         $code = 404;
 100                         $message = $e->getMessage();
 101                 } catch ( UploadStashZeroLengthFileException $e ) {
 102                         $code = 500;
 103                         $message = $e->getMessage();
 104                 } catch ( UploadStashBadPathException $e ) {
 105                         $code = 500;
 106                         $message = $e->getMessage();
 107                 } catch ( SpecialUploadStashTooLargeException $e ) {
 108                         $code = 500;
 109                         $message = 'Cannot serve a file larger than ' . self::MAX_SERVE_BYTES .
 110                                 ' bytes. ' . $e->getMessage();
 111                 } catch ( Exception $e ) {
 112                         $code = 500;
 113                         $message = $e->getMessage();
 114                 }
 115
 116                 throw new HttpError( $code, $message );
 117         }
 118
 119         /**
 120          * Parse the key passed to the SpecialPage. Returns an array containing
 121          * the associated file object, the type ('file' or 'thumb') and if
 122          * application the transform parameters
 123          *
 124          * @param string $key
 125          * @throws UploadStashBadPathException
 126          * @return array
 127          */
 128         private function parseKey( $key ) {
 129                 $type = strtok( $key, '/' );
 130
 131                 if ( $type !== 'file' && $type !== 'thumb' ) {
 132                         throw new UploadStashBadPathException( "Unknown type '$type'" );
 133                 }
 134                 $fileName = strtok( '/' );
 135                 $thumbPart = strtok( '/' );
 136                 $file = $this->stash->getFile( $fileName );
 137                 if ( $type === 'thumb' ) {
 138                         $srcNamePos = strrpos( $thumbPart, $fileName );
 139                         if ( $srcNamePos === false || $srcNamePos < 1 ) {
 140                                 throw new UploadStashBadPathException( 'Unrecognized thumb name' );
 141                         }
 142                         $paramString = substr( $thumbPart, 0, $srcNamePos - 1 );
 143
 144                         $handler = $file->getHandler();
 145                         if ( $handler ) {
 146                                 $params = $handler->parseParamString( $paramString );
 147
 148                                 return [ 'file' => $file, 'type' => $type, 'params' => $params ];
 149                         } else {
 150                                 throw new UploadStashBadPathException( 'No handler found for ' .
 151                                         "mime {$file->getMimeType()} of file {$file->getPath()}" );
 152                         }
 153                 }
 154
 155                 return [ 'file' => $file, 'type' => $type ];
 156         }
 157
 158         /**
 159          * Get a thumbnail for file, either generated locally or remotely, and stream it out
 160          *
 161          * @param File $file
 162          * @param array $params
 163          *
 164          * @return bool Success
 165          */
 166         private function outputThumbFromStash( $file, $params ) {
 167                 $flags = 0;
 168                 // this config option, if it exists, points to a "scaler", as you might find in
 169                 // the Wikimedia Foundation cluster. See outputRemoteScaledThumb(). This
 170                 // is part of our horrible NFS-based system, we create a file on a mount
 171                 // point here, but fetch the scaled file from somewhere else that
 172                 // happens to share it over NFS.
 173                 if ( $this->getConfig()->get( 'UploadStashScalerBaseUrl' ) ) {
 174                         $this->outputRemoteScaledThumb( $file, $params, $flags );
 175                 } else {
 176                         $this->outputLocallyScaledThumb( $file, $params, $flags );
 177                 }
 178         }
 179
 180         /**
 181          * Scale a file (probably with a locally installed imagemagick, or similar)
 182          * and output it to STDOUT.
 183          * @param File $file
 184          * @param array $params Scaling parameters ( e.g. [ width => '50' ] );
 185          * @param int $flags Scaling flags ( see File:: constants )
 186          * @throws MWException|UploadStashFileNotFoundException
 187          * @return bool Success
 188          */
 189         private function outputLocallyScaledThumb( $file, $params, $flags ) {
 190                 // n.b. this is stupid, we insist on re-transforming the file every time we are invoked. We rely
 191                 // on HTTP caching to ensure this doesn't happen.
 192
 193                 $flags |= File::RENDER_NOW;
 194
 195                 $thumbnailImage = $file->transform( $params, $flags );
 196                 if ( !$thumbnailImage ) {
 197                         throw new MWException( 'Could not obtain thumbnail' );
 198                 }
 199
 200                 // we should have just generated it locally
 201                 if ( !$thumbnailImage->getStoragePath() ) {
 202                         throw new UploadStashFileNotFoundException( "no local path for scaled item" );
 203                 }
 204
 205                 // now we should construct a File, so we can get MIME and other such info in a standard way
 206                 // n.b. MIME type may be different from original (ogx original -> jpeg thumb)
 207                 $thumbFile = new UnregisteredLocalFile( false,
 208                         $this->stash->repo, $thumbnailImage->getStoragePath(), false );
 209                 if ( !$thumbFile ) {
 210                         throw new UploadStashFileNotFoundException( "couldn't create local file object for thumbnail" );
 211                 }
 212
 213                 return $this->outputLocalFile( $thumbFile );
 214         }
 215
 216         /**
 217          * Scale a file with a remote "scaler", as exists on the Wikimedia Foundation
 218          * cluster, and output it to STDOUT.
 219          * Note: Unlike the usual thumbnail process, the web client never sees the
 220          * cluster URL; we do the whole HTTP transaction to the scaler ourselves
 221          * and cat the results out.
 222          * Note: We rely on NFS to have propagated the file contents to the scaler.
 223          * However, we do not rely on the thumbnail being created in NFS and then
 224          * propagated back to our filesystem. Instead we take the results of the
 225          * HTTP request instead.
 226          * Note: No caching is being done here, although we are instructing the
 227          * client to cache it forever.
 228          *
 229          * @param File $file
 230          * @param array $params Scaling parameters ( e.g. [ width => '50' ] );
 231          * @param int $flags Scaling flags ( see File:: constants )
 232          * @throws MWException
 233          * @return bool Success
 234          */
 235         private function outputRemoteScaledThumb( $file, $params, $flags ) {
 236                 // This option probably looks something like
 237                 // '//upload.wikimedia.org/wikipedia/test/thumb/temp'. Do not use
 238                 // trailing slash.
 239                 $scalerBaseUrl = $this->getConfig()->get( 'UploadStashScalerBaseUrl' );
 240
 241                 if ( preg_match( '/^\/\//', $scalerBaseUrl ) ) {
 242                         // this is apparently a protocol-relative URL, which makes no sense in this context,
 243                         // since this is used for communication that's internal to the application.
 244                         // default to http.
 245                         $scalerBaseUrl = wfExpandUrl( $scalerBaseUrl, PROTO_CANONICAL );
 246                 }
 247
 248                 // We need to use generateThumbName() instead of thumbName(), because
 249                 // the suffix needs to match the file name for the remote thumbnailer
 250                 // to work
 251                 $scalerThumbName = $file->generateThumbName( $file->getName(), $params );
 252                 $scalerThumbUrl = $scalerBaseUrl . '/' . $file->getUrlRel() .
 253                         '/' . rawurlencode( $scalerThumbName );
 254
 255                 // make a curl call to the scaler to create a thumbnail
 256                 $httpOptions = [
 257                         'method' => 'GET',
 258                         'timeout' => 5 // T90599 attempt to time out cleanly
 259                 ];
 260                 $req = MWHttpRequest::factory( $scalerThumbUrl, $httpOptions, __METHOD__ );
 261                 $status = $req->execute();
 262                 if ( !$status->isOK() ) {
 263                         $errors = $status->getErrorsArray();
 264                         $errorStr = "Fetching thumbnail failed: " . print_r( $errors, 1 );
 265                         $errorStr .= "\nurl = $scalerThumbUrl\n";
 266                         throw new MWException( $errorStr );
 267                 }
 268                 $contentType = $req->getResponseHeader( "content-type" );
 269                 if ( !$contentType ) {
 270                         throw new MWException( "Missing content-type header" );
 271                 }
 272
 273                 return $this->outputContents( $req->getContent(), $contentType );
 274         }
 275
 276         /**
 277          * Output HTTP response for file
 278          * Side effect: writes HTTP response to STDOUT.
 279          *
 280          * @param File $file File object with a local path (e.g. UnregisteredLocalFile,
 281          *   LocalFile. Oddly these don't share an ancestor!)
 282          * @throws SpecialUploadStashTooLargeException
 283          * @return bool
 284          */
 285         private function outputLocalFile( File $file ) {
 286                 if ( $file->getSize() > self::MAX_SERVE_BYTES ) {
 287                         throw new SpecialUploadStashTooLargeException();
 288                 }
 289
 290                 return $file->getRepo()->streamFile( $file->getPath(),
 291                         [ 'Content-Transfer-Encoding: binary',
 292                                 'Expires: Sun, 17-Jan-2038 19:14:07 GMT' ]
 293                 );
 294         }
 295
 296         /**
 297          * Output HTTP response of raw content
 298          * Side effect: writes HTTP response to STDOUT.
 299          * @param string $content Content
 300          * @param string $contentType MIME type
 301          * @throws SpecialUploadStashTooLargeException
 302          * @return bool
 303          */
 304         private function outputContents( $content, $contentType ) {
 305                 $size = strlen( $content );
 306                 if ( $size > self::MAX_SERVE_BYTES ) {
 307                         throw new SpecialUploadStashTooLargeException();
 308                 }
 309                 // Cancel output buffering and gzipping if set
 310                 wfResetOutputBuffers();
 311                 self::outputFileHeaders( $contentType, $size );
 312                 print $content;
 313
 314                 return true;
 315         }
 316
 317         /**
 318          * Output headers for streaming
 319          * @todo Unsure about encoding as binary; if we received from HTTP perhaps
 320          * we should use that encoding, concatenated with semicolon to `$contentType` as it
 321          * usually is.
 322          * Side effect: preps PHP to write headers to STDOUT.
 323          * @param string $contentType String suitable for content-type header
 324          * @param string $size Length in bytes
 325          */
 326         private static function outputFileHeaders( $contentType, $size ) {
 327                 header( "Content-Type: $contentType", true );
 328                 header( 'Content-Transfer-Encoding: binary', true );
 329                 header( 'Expires: Sun, 17-Jan-2038 19:14:07 GMT', true );
 330                 // T55032 - It shouldn't be a problem here, but let's be safe and not cache
 331                 header( 'Cache-Control: private' );
 332                 header( "Content-Length: $size", true );
 333         }
 334
 335         /**
 336          * Static callback for the HTMLForm in showUploads, to process
 337          * Note the stash has to be recreated since this is being called in a static context.
 338          * This works, because there really is only one stash per logged-in user, despite appearances.
 339          *
 340          * @param array $formData
 341          * @param HTMLForm $form
 342          * @return Status
 343          */
 344         public static function tryClearStashedUploads( $formData, $form ) {
 345                 if ( isset( $formData['Clear'] ) ) {
 346                         $stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $form->getUser() );
 347                         wfDebug( 'stash has: ' . print_r( $stash->listFiles(), true ) . "\n" );
 348
 349                         if ( !$stash->clear() ) {
 350                                 return Status::newFatal( 'uploadstash-errclear' );
 351                         }
 352                 }
 353
 354                 return Status::newGood();
 355         }
 356
 357         /**
 358          * Default action when we don't have a subpage -- just show links to the uploads we have,
 359          * Also show a button to clear stashed files
 360          * @return bool
 361          */
 362         private function showUploads() {
 363                 // sets the title, etc.
 364                 $this->setHeaders();
 365                 $this->outputHeader();
 366
 367                 // create the form, which will also be used to execute a callback to process incoming form data
 368                 // this design is extremely dubious, but supposedly HTMLForm is our standard now?
 369
 370                 $context = new DerivativeContext( $this->getContext() );
 371                 $context->setTitle( $this->getPageTitle() ); // Remove subpage
 372                 $form = HTMLForm::factory( 'ooui', [
 373                         'Clear' => [
 374                                 'type' => 'hidden',
 375                                 'default' => true,
 376                                 'name' => 'clear',
 377                         ]
 378                 ], $context, 'clearStashedUploads' );
 379                 $form->setSubmitDestructive();
 380                 $form->setSubmitCallback( [ __CLASS__, 'tryClearStashedUploads' ] );
 381                 $form->setSubmitTextMsg( 'uploadstash-clear' );
 382
 383                 $form->prepareForm();
 384                 $formResult = $form->tryAuthorizedSubmit();
 385
 386                 // show the files + form, if there are any, or just say there are none
 387                 $refreshHtml = Html::element( 'a',
 388                         [ 'href' => $this->getPageTitle()->getLocalURL() ],
 389                         $this->msg( 'uploadstash-refresh' )->text() );
 390                 $files = $this->stash->listFiles();
 391                 if ( $files && count( $files ) ) {
 392                         sort( $files );
 393                         $fileListItemsHtml = '';
 394                         $linkRenderer = $this->getLinkRenderer();
 395                         foreach ( $files as $file ) {
 396                                 $itemHtml = $linkRenderer->makeKnownLink(
 397                                         $this->getPageTitle( "file/$file" ),
 398                                         $file
 399                                 );
 400                                 try {
 401                                         $fileObj = $this->stash->getFile( $file );
 402                                         $thumb = $fileObj->generateThumbName( $file, [ 'width' => 220 ] );
 403                                         $itemHtml .=
 404                                                 $this->msg( 'word-separator' )->escaped() .
 405                                                 $this->msg( 'parentheses' )->rawParams(
 406                                                         $linkRenderer->makeKnownLink(
 407                                                                 $this->getPageTitle( "thumb/$file/$thumb" ),
 408                                                                 $this->msg( 'uploadstash-thumbnail' )->text()
 409                                                         )
 410                                                 )->escaped();
 411                                 } catch ( Exception $e ) {
 412                                 }
 413                                 $fileListItemsHtml .= Html::rawElement( 'li', [], $itemHtml );
 414                         }
 415                         $this->getOutput()->addHTML( Html::rawElement( 'ul', [], $fileListItemsHtml ) );
 416                         $form->displayForm( $formResult );
 417                         $this->getOutput()->addHTML( Html::rawElement( 'p', [], $refreshHtml ) );
 418                 } else {
 419                         $this->getOutput()->addHTML( Html::rawElement( 'p', [],
 420                                 Html::element( 'span', [], $this->msg( 'uploadstash-nofiles' )->text() )
 421                                 . ' '
 422                                 . $refreshHtml
 423                         ) );
 424                 }
 425
 426                 return true;
 427         }
 428 }
 429
 430 class SpecialUploadStashTooLargeException extends MWException {
 431 }