Merge "rest: Return a 400 for invalid render IDs"

[mediawiki.git] / includes / specials / SpecialUploadStash.php

<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

namespace MediaWiki\Specials;

use Exception;
use File;
use HttpError;
use LocalRepo;
use MediaWiki\Html\Html;
use MediaWiki\HTMLForm\HTMLForm;
use MediaWiki\Http\HttpRequestFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\Pager\UploadStashPager;
use MediaWiki\SpecialPage\UnlistedSpecialPage;
use MediaWiki\Status\Status;
use MediaWiki\Utils\UrlUtils;
use RepoGroup;
use SpecialUploadStashTooLargeException;
use UnregisteredLocalFile;
use UploadStash;
use UploadStashBadPathException;
use UploadStashFileNotFoundException;
use Wikimedia\Rdbms\IConnectionProvider;

/**
 * Web access for files temporarily stored by UploadStash.
 *
 * For example -- files that were uploaded with the UploadWizard extension are stored temporarily
 * before committing them to the db. But we want to see their thumbnails and get other information
 * about them.
 *
 * Since this is based on the user's session, in effect this creates a private temporary file area.
 * However, the URLs for the files cannot be shared.
 *
 * @ingroup SpecialPage
 * @ingroup Upload
 */
class SpecialUploadStash extends UnlistedSpecialPage {
        /** @var UploadStash|null */
        private $stash;

        private LocalRepo $localRepo;
        private HttpRequestFactory $httpRequestFactory;
        private UrlUtils $urlUtils;
        private IConnectionProvider $dbProvider;

        /**
         * Since we are directly writing the file to STDOUT,
         * we should not be reading in really big files and serving them out.
         *
         * We also don't want people using this as a file drop, even if they
         * share credentials.
         *
         * This service is really for thumbnails and other such previews while
         * uploading.
         */
        private const MAX_SERVE_BYTES = 1_048_576; // 1 MiB

        /**
         * @param RepoGroup $repoGroup
         * @param HttpRequestFactory $httpRequestFactory
         * @param UrlUtils $urlUtils
         * @param IConnectionProvider $dbProvider
         */
        public function __construct(
                RepoGroup $repoGroup,
                HttpRequestFactory $httpRequestFactory,
                UrlUtils $urlUtils,
                IConnectionProvider $dbProvider
        ) {
                parent::__construct( 'UploadStash', 'upload' );
                $this->localRepo = $repoGroup->getLocalRepo();
                $this->httpRequestFactory = $httpRequestFactory;
                $this->urlUtils = $urlUtils;
                $this->dbProvider = $dbProvider;
        }

        public function doesWrites() {
                return true;
        }

        /**
         * Execute page -- can output a file directly or show a listing of them.
         *
         * @param string|null $subPage Subpage, e.g. in
         *   https://example.com/wiki/Special:UploadStash/foo.jpg, the "foo.jpg" part
         */
        public function execute( $subPage ) {
                $this->useTransactionalTimeLimit();

                // This is not set in constructor, because the context with the user is not safe to be set
                $this->stash = $this->localRepo->getUploadStash( $this->getUser() );
                $this->checkPermissions();

                if ( $subPage === null || $subPage === '' ) {
                        $this->showUploads();
                } else {
                        $this->showUpload( $subPage );
                }
        }

        /**
         * If file available in stash, cats it out to the client as a simple HTTP response.
         * n.b. Most checking done in UploadStashLocalFile, so this is straightforward.
         *
         * @param string $key The key of a particular requested file
         * @throws HttpError
         */
        public function showUpload( $key ) {
                // prevent callers from doing standard HTML output -- we'll take it from here
                $this->getOutput()->disable();

                try {
                        $params = $this->parseKey( $key );
                        if ( $params['type'] === 'thumb' ) {
                                $this->outputThumbFromStash( $params['file'], $params['params'] );
                        } else {
                                $this->outputLocalFile( $params['file'] );
                        }
                        return;
                } catch ( UploadStashFileNotFoundException $e ) {
                        $code = 404;
                        $message = $e->getMessage();
                } catch ( Exception $e ) {
                        $code = 500;
                        $message = $e->getMessage();
                }

                throw new HttpError( $code, $message );
        }

        /**
         * Parse the key passed to the SpecialPage. Returns an array containing
         * the associated file object, the type ('file' or 'thumb') and if
         * application the transform parameters
         *
         * @param string $key
         * @throws UploadStashBadPathException
         * @return array
         */
        private function parseKey( $key ) {
                $type = strtok( $key, '/' );

                if ( $type !== 'file' && $type !== 'thumb' ) {
                        throw new UploadStashBadPathException(
                                $this->msg( 'uploadstash-bad-path-unknown-type', $type )
                        );
                }
                $fileName = strtok( '/' );
                $thumbPart = strtok( '/' );
                $file = $this->stash->getFile( $fileName );
                if ( $type === 'thumb' ) {
                        $srcNamePos = strrpos( $thumbPart, $fileName );
                        if ( $srcNamePos === false || $srcNamePos < 1 ) {
                                throw new UploadStashBadPathException(
                                        $this->msg( 'uploadstash-bad-path-unrecognized-thumb-name' )
                                );
                        }
                        $paramString = substr( $thumbPart, 0, $srcNamePos - 1 );

                        $handler = $file->getHandler();
                        if ( $handler ) {
                                $params = $handler->parseParamString( $paramString );
                                if ( $params === false ) {
                                        // The params are invalid, but still try to show a thumb
                                        $params = [];
                                }

                                return [ 'file' => $file, 'type' => $type, 'params' => $params ];
                        } else {
                                throw new UploadStashBadPathException(
                                        $this->msg( 'uploadstash-bad-path-no-handler', $file->getMimeType(), $file->getPath() )
                                );
                        }
                }

                return [ 'file' => $file, 'type' => $type ];
        }

        /**
         * Get a thumbnail for file, either generated locally or remotely, and stream it out
         *
         * @param File $file
         * @param array $params
         */
        private function outputThumbFromStash( $file, $params ) {
                // this config option, if it exists, points to a "scaler", as you might find in
                // the Wikimedia Foundation cluster. See outputRemoteScaledThumb(). This
                // is part of our horrible NFS-based system, we create a file on a mount
                // point here, but fetch the scaled file from somewhere else that
                // happens to share it over NFS.
                if ( $file->getRepo()->getThumbProxyUrl()
                        || $this->getConfig()->get( MainConfigNames::UploadStashScalerBaseUrl )
                ) {
                        $this->outputRemoteScaledThumb( $file, $params );
                } else {
                        $this->outputLocallyScaledThumb( $file, $params );
                }
        }

        /**
         * Scale a file (probably with a locally installed imagemagick, or similar)
         * and output it to STDOUT.
         * @param File $file
         * @param array $params Scaling parameters ( e.g. [ width => '50' ] );
         */
        private function outputLocallyScaledThumb( $file, $params ) {
                // n.b. this is stupid, we insist on re-transforming the file every time we are invoked. We rely
                // on HTTP caching to ensure this doesn't happen.

                $thumbnailImage = $file->transform( $params, File::RENDER_NOW );
                if ( !$thumbnailImage ) {
                        throw new UploadStashFileNotFoundException(
                                $this->msg( 'uploadstash-file-not-found-no-thumb' )
                        );
                }

                // we should have just generated it locally
                if ( !$thumbnailImage->getStoragePath() ) {
                        throw new UploadStashFileNotFoundException(
                                $this->msg( 'uploadstash-file-not-found-no-local-path' )
                        );
                }

                // now we should construct a File, so we can get MIME and other such info in a standard way
                // n.b. MIME type may be different from original (ogx original -> jpeg thumb)
                $thumbFile = new UnregisteredLocalFile( false,
                        $this->stash->repo, $thumbnailImage->getStoragePath(), false );

                $this->outputLocalFile( $thumbFile );
        }

        /**
         * Scale a file with a remote "scaler", as exists on the Wikimedia Foundation
         * cluster, and output it to STDOUT.
         * Note: Unlike the usual thumbnail process, the web client never sees the
         * cluster URL; we do the whole HTTP transaction to the scaler ourselves
         * and cat the results out.
         * Note: We rely on NFS to have propagated the file contents to the scaler.
         * However, we do not rely on the thumbnail being created in NFS and then
         * propagated back to our filesystem. Instead we take the results of the
         * HTTP request instead.
         * Note: No caching is being done here, although we are instructing the
         * client to cache it forever.
         *
         * @param File $file
         * @param array $params Scaling parameters ( e.g. [ width => '50' ] );
         */
        private function outputRemoteScaledThumb( $file, $params ) {
                // We need to use generateThumbName() instead of thumbName(), because
                // the suffix needs to match the file name for the remote thumbnailer
                // to work
                $scalerThumbName = $file->generateThumbName( $file->getName(), $params );

                // If a thumb proxy is set up for the repo, we favor that, as that will
                // keep the request internal
                $thumbProxyUrl = $file->getRepo()->getThumbProxyUrl();
                if ( strlen( $thumbProxyUrl ) ) {
                        $scalerThumbUrl = $thumbProxyUrl . 'temp/' . $file->getUrlRel() .
                                '/' . rawurlencode( $scalerThumbName );
                        $secret = $file->getRepo()->getThumbProxySecret();
                } else {
                        // This option probably looks something like
                        // '//upload.wikimedia.org/wikipedia/test/thumb/temp'. Do not use
                        // trailing slash.
                        $scalerBaseUrl = $this->getConfig()->get( MainConfigNames::UploadStashScalerBaseUrl );

                        if ( preg_match( '/^\/\//', $scalerBaseUrl ) ) {
                                // this is apparently a protocol-relative URL, which makes no sense in this context,
                                // since this is used for communication that's internal to the application.
                                // default to http.
                                $scalerBaseUrl = $this->urlUtils->expand( $scalerBaseUrl, PROTO_CANONICAL );
                        }

                        $scalerThumbUrl = $scalerBaseUrl . '/' . $file->getUrlRel() .
                                '/' . rawurlencode( $scalerThumbName );
                        $secret = false;
                }

                // make an http request based on wgUploadStashScalerBaseUrl to lazy-create
                // a thumbnail
                $httpOptions = [
                        'method' => 'GET',
                        'timeout' => 5 // T90599 attempt to time out cleanly
                ];
                $req = $this->httpRequestFactory->create( $scalerThumbUrl, $httpOptions, __METHOD__ );

                // Pass a secret key shared with the proxied service if any
                if ( strlen( $secret ) ) {
                        $req->setHeader( 'X-Swift-Secret', $secret );
                }

                $status = $req->execute();
                if ( !$status->isOK() ) {
                        throw new UploadStashFileNotFoundException(
                                $this->msg(
                                        'uploadstash-file-not-found-no-remote-thumb',
                                        $status->getMessage(),
                                        $scalerThumbUrl
                                )
                        );
                }
                $contentType = $req->getResponseHeader( "content-type" );
                if ( !$contentType ) {
                        throw new UploadStashFileNotFoundException(
                                $this->msg( 'uploadstash-file-not-found-missing-content-type' )
                        );
                }

                $this->outputContents( $req->getContent(), $contentType );
        }

        /**
         * Output HTTP response for file
         * Side effect: writes HTTP response to STDOUT.
         *
         * @param File $file File object with a local path (e.g. UnregisteredLocalFile,
         *   LocalFile. Oddly these don't share an ancestor!)
         * @throws SpecialUploadStashTooLargeException
         */
        private function outputLocalFile( File $file ) {
                if ( $file->getSize() > self::MAX_SERVE_BYTES ) {
                        throw new SpecialUploadStashTooLargeException(
                                $this->msg( 'uploadstash-file-too-large', self::MAX_SERVE_BYTES )
                        );
                }

                $file->getRepo()->streamFileWithStatus( $file->getPath(),
                        [ 'Content-Transfer-Encoding: binary',
                                'Expires: Sun, 17-Jan-2038 19:14:07 GMT' ]
                );
        }

        /**
         * Output HTTP response of raw content
         * Side effect: writes HTTP response to STDOUT.
         * @param string $content
         * @param string $contentType MIME type
         * @throws SpecialUploadStashTooLargeException
         */
        private function outputContents( $content, $contentType ) {
                $size = strlen( $content );
                if ( $size > self::MAX_SERVE_BYTES ) {
                        throw new SpecialUploadStashTooLargeException(
                                $this->msg( 'uploadstash-file-too-large', self::MAX_SERVE_BYTES )
                        );
                }
                // Cancel output buffering and gzipping if set
                wfResetOutputBuffers();
                self::outputFileHeaders( $contentType, $size );
                print $content;
        }

        /**
         * Output headers for streaming
         * @todo Unsure about encoding as binary; if we received from HTTP perhaps
         * we should use that encoding, concatenated with semicolon to `$contentType` as it
         * usually is.
         * Side effect: preps PHP to write headers to STDOUT.
         * @param string $contentType String suitable for content-type header
         * @param int $size Length in bytes
         */
        private static function outputFileHeaders( $contentType, $size ) {
                header( "Content-Type: $contentType", true );
                header( 'Content-Transfer-Encoding: binary', true );
                header( 'Expires: Sun, 17-Jan-2038 19:14:07 GMT', true );
                // T55032 - It shouldn't be a problem here, but let's be safe and not cache
                header( 'Cache-Control: private' );
                header( "Content-Length: $size", true );
        }

        /**
         * Default action when we don't have a subpage -- just show links to the uploads we have,
         * Also show a button to clear stashed files
         */
        private function showUploads() {
                // sets the title, etc.
                $this->setHeaders();
                $this->outputHeader();

                // create the form, which will also be used to execute a callback to process incoming form data
                // this design is extremely dubious, but supposedly HTMLForm is our standard now?

                $form = HTMLForm::factory( 'ooui', [
                        'Clear' => [
                                'type' => 'hidden',
                                'default' => true,
                                'name' => 'clear',
                        ]
                ], $this->getContext(), 'clearStashedUploads' );
                $form->setTitle( $this->getPageTitle() ); // Remove subpage
                $form->setSubmitDestructive();
                $form->setSubmitCallback( function ( $formData, $form ) {
                        if ( isset( $formData['Clear'] ) ) {
                                wfDebug( 'stash has: ' . print_r( $this->stash->listFiles(), true ) );

                                if ( !$this->stash->clear() ) {
                                        return Status::newFatal( 'uploadstash-errclear' );
                                }
                        }

                        return Status::newGood();
                } );
                $form->setSubmitTextMsg( 'uploadstash-clear' );

                $form->prepareForm();
                $formResult = $form->tryAuthorizedSubmit();

                // show the files + form, if there are any, or just say there are none
                $linkRenderer = $this->getLinkRenderer();
                $refreshHtml = $linkRenderer->makeKnownLink(
                        $this->getPageTitle(),
                        $this->msg( 'uploadstash-refresh' )->text()
                );
                $pager = new UploadStashPager(
                        $this->getContext(),
                        $linkRenderer,
                        $this->dbProvider,
                        $this->stash,
                        $this->localRepo
                );
                if ( $pager->getNumRows() ) {
                        $pager->getForm();
                        $this->getOutput()->addParserOutputContent( $pager->getFullOutput() );
                        $form->displayForm( $formResult );
                        $this->getOutput()->addHTML( Html::rawElement( 'p', [], $refreshHtml ) );
                } else {
                        $this->getOutput()->addHTML( Html::rawElement( 'p', [],
                                Html::element( 'span', [], $this->msg( 'uploadstash-nofiles' )->text() )
                                . ' '
                                . $refreshHtml
                        ) );
                }
        }
}

/**
 * Retain the old class name for backwards compatibility.
 * @deprecated since 1.41
 */
class_alias( SpecialUploadStash::class, 'SpecialUploadStash' );