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<?php
/**
* PHP script to stream out an image thumbnail.
*
* 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
* @ingroup Media
*/
define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
require __DIR__ . '/includes/WebStart.php';
// Don't use fancy mime detection, just check the file extension for jpg/gif/png
$wgTrivialMimeDetection = true;
if ( defined( 'THUMB_HANDLER' ) ) {
// Called from thumb_handler.php via 404; extract params from the URI...
wfThumbHandle404();
} else {
// Called directly, use $_GET params
wfThumbHandleRequest();
}
wfLogProfilingData();
// Commit and close up!
$factory = wfGetLBFactory();
$factory->commitMasterChanges();
$factory->shutdown();
//--------------------------------------------------------------------------
/**
* Handle a thumbnail request via query parameters
*
* @return void
*/
function wfThumbHandleRequest() {
$params = get_magic_quotes_gpc()
? array_map( 'stripslashes', $_GET )
: $_GET;
wfStreamThumb( $params ); // stream the thumbnail
}
/**
* Handle a thumbnail request via thumbnail file URL
*
* @return void
*/
function wfThumbHandle404() {
global $wgArticlePath;
# Set action base paths so that WebRequest::getPathInfo()
# recognizes the "X" as the 'title' in ../thumb_handler.php/X urls.
# Note: If Custom per-extension repo paths are set, this may break.
$repo = RepoGroup::singleton()->getLocalRepo();
$oldArticlePath = $wgArticlePath;
$wgArticlePath = $repo->getZoneUrl( 'thumb' ) . '/$1';
$matches = WebRequest::getPathInfo();
$wgArticlePath = $oldArticlePath;
if ( !isset( $matches['title'] ) ) {
wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
return;
}
$params = wfExtractThumbRequestInfo( $matches['title'] ); // basic wiki URL param extracting
if ( $params == null ) {
wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
return;
}
wfStreamThumb( $params ); // stream the thumbnail
}
/**
* Stream a thumbnail specified by parameters
*
* @param $params Array List of thumbnailing parameters. In addition to parameters
* passed to the MediaHandler, this may also includes the keys:
* f (for filename), archived (if archived file), temp (if temp file),
* w (alias for width), p (alias for page), r (ignored; historical),
* rel404 (path for render on 404 to verify hash path correct),
* thumbName (thumbnail name to potentially extract more parameters from
* e.g. 'lossy-page1-120px-Foo.tiff' would add page, lossy and width
* to the parameters)
* @return void
*/
function wfStreamThumb( array $params ) {
global $wgVaryOnXFP;
$section = new ProfileSection( __METHOD__ );
$headers = array(); // HTTP headers to send
$fileName = isset( $params['f'] ) ? $params['f'] : '';
// Backwards compatibility parameters
if ( isset( $params['w'] ) ) {
$params['width'] = $params['w'];
unset( $params['w'] );
}
if ( isset( $params['p'] ) ) {
$params['page'] = $params['p'];
}
// Is this a thumb of an archived file?
$isOld = ( isset( $params['archived'] ) && $params['archived'] );
unset( $params['archived'] ); // handlers don't care
// Is this a thumb of a temp file?
$isTemp = ( isset( $params['temp'] ) && $params['temp'] );
unset( $params['temp'] ); // handlers don't care
// Some basic input validation
$fileName = strtr( $fileName, '\\/', '__' );
// Actually fetch the image. Method depends on whether it is archived or not.
if ( $isTemp ) {
$repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
$img = new UnregisteredLocalFile( null, $repo,
# Temp files are hashed based on the name without the timestamp.
# The thumbnails will be hashed based on the entire name however.
# @todo fix this convention to actually be reasonable.
$repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
);
} elseif ( $isOld ) {
// Format is <timestamp>!<name>
$bits = explode( '!', $fileName, 2 );
if ( count( $bits ) != 2 ) {
wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
return;
}
$title = Title::makeTitleSafe( NS_FILE, $bits[1] );
if ( !$title ) {
wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
return;
}
$img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
} else {
$img = wfLocalFile( $fileName );
}
// Check the source file title
if ( !$img ) {
wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
return;
}
// Check permissions if there are read restrictions
$varyHeader = array();
if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
wfThumbError( 403, 'Access denied. You do not have permission to access ' .
'the source file.' );
return;
}
$headers[] = 'Cache-Control: private';
$varyHeader[] = 'Cookie';
}
// Do rendering parameters extraction from thumbnail name.
if ( isset( $params['thumbName'] ) ) {
$params = wfExtractThumbParams( $img, $params );
}
if ( $params == null ) {
wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
return;
}
// Check the source file storage path
if ( !$img->exists() ) {
$redirectedLocation = false;
if ( !$isTemp ) {
// Check for file redirect
// Since redirects are associated with pages, not versions of files,
// we look for the most current version to see if its a redirect.
$possRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $img->getName() );
if ( $possRedirFile && !is_null( $possRedirFile->getRedirected() ) ) {
$redirTarget = $possRedirFile->getName();
$targetFile = wfLocalFile( Title::makeTitleSafe( NS_FILE, $redirTarget ) );
if ( $targetFile->exists() ) {
$newThumbName = $targetFile->thumbName( $params );
if ( $isOld ) {
$newThumbUrl = $targetFile->getArchiveThumbUrl(
$bits[0] . '!' . $targetFile->getName(), $newThumbName );
} else {
$newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
}
$redirectedLocation = wfExpandUrl( $newThumbUrl, PROTO_CURRENT );
}
}
}
if ( $redirectedLocation ) {
// File has been moved. Give redirect.
$response = RequestContext::getMain()->getRequest()->response();
$response->header( "HTTP/1.1 302 " . HttpStatus::getMessage( 302 ) );
$response->header( 'Location: ' . $redirectedLocation );
$response->header( 'Expires: ' .
gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT' );
if ( $wgVaryOnXFP ) {
$varyHeader[] = 'X-Forwarded-Proto';
}
if ( count( $varyHeader ) ) {
$response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
}
return;
}
// If its not a redirect that has a target as a local file, give 404.
wfThumbError( 404, "The source file '$fileName' does not exist." );
return;
} elseif ( $img->getPath() === false ) {
wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
return;
}
// Check IMS against the source file
// This means that clients can keep a cached copy even after it has been deleted on the server
if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
// Fix IE brokenness
$imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
// Calculate time
wfSuppressWarnings();
$imsUnix = strtotime( $imsString );
wfRestoreWarnings();
if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
header( 'HTTP/1.1 304 Not Modified' );
return;
}
}
unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
unset( $params['f'] ); // We're done with 'f' parameter.
// Get the normalized thumbnail name from the parameters...
try {
$thumbName = $img->thumbName( $params );
if ( !strlen( $thumbName ) ) { // invalid params?
wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
return;
}
$thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
} catch ( MWException $e ) {
wfThumbError( 500, $e->getHTML() );
return;
}
// For 404 handled thumbnails, we only use the the base name of the URI
// for the thumb params and the parent directory for the source file name.
// Check that the zone relative path matches up so squid caches won't pick
// up thumbs that would not be purged on source file deletion (bug 34231).
if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
if ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
// Request for the canonical thumbnail name
} elseif ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
// Request for the "long" thumbnail name; redirect to canonical name
$response = RequestContext::getMain()->getRequest()->response();
$response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
$response->header( 'Location: ' .
wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
$response->header( 'Expires: ' .
gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
if ( $wgVaryOnXFP ) {
$varyHeader[] = 'X-Forwarded-Proto';
}
if ( count( $varyHeader ) ) {
$response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
}
return;
} else {
wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
rawurldecode( $params['rel404'] ) . "'." );
return;
}
}
$dispositionType = isset( $params['download'] ) ? 'attachment' : 'inline';
// Suggest a good name for users downloading this thumbnail
$headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName, $dispositionType )}";
if ( count( $varyHeader ) ) {
$headers[] = 'Vary: ' . implode( ', ', $varyHeader );
}
// Stream the file if it exists already...
$thumbPath = $img->getThumbPath( $thumbName );
if ( $img->getRepo()->fileExists( $thumbPath ) ) {
$img->getRepo()->streamFile( $thumbPath, $headers );
return;
}
$user = RequestContext::getMain()->getUser();
if ( $user->pingLimiter( 'renderfile' ) ) {
wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
return;
} elseif ( wfThumbIsAttemptThrottled( $img, $thumbName, 5 ) ) {
wfThumbError( 500, wfMessage( 'thumbnail_image-failure-limit', 5 ) );
return;
}
// Thumbnail isn't already there, so create the new thumbnail...
try {
$thumb = $img->transform( $params, File::RENDER_NOW );
} catch ( Exception $ex ) {
// Tried to select a page on a non-paged file?
$thumb = false;
}
// Check for thumbnail generation errors...
$errorMsg = false;
$msg = wfMessage( 'thumbnail_error' );
if ( !$thumb ) {
$errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
} elseif ( $thumb->isError() ) {
$errorMsg = $thumb->getHtmlMsg();
} elseif ( !$thumb->hasFile() ) {
$errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
} elseif ( $thumb->fileIsSource() ) {
$errorMsg = $msg->
rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
}
if ( $errorMsg !== false ) {
wfThumbIncrAttemptFailures( $img, $thumbName );
wfThumbError( 500, $errorMsg );
} else {
// Stream the file if there were no errors
$thumb->streamFile( $headers );
}
}
/**
* @param File $img
* @param string $thumbName
* @param int $limit
* @return int|bool
*/
function wfThumbIsAttemptThrottled( File $img, $thumbName, $limit ) {
global $wgMemc;
return ( $wgMemc->get( wfThumbAttemptKey( $img, $thumbName ) ) >= $limit );
}
/**
* @param File $img
* @param string $thumbName
*/
function wfThumbIncrAttemptFailures( File $img, $thumbName ) {
global $wgMemc;
$key = wfThumbAttemptKey( $img, $thumbName );
if ( !$wgMemc->incr( $key, 1 ) ) {
if ( !$wgMemc->add( $key, 1, 3600 ) ) {
$wgMemc->incr( $key, 1 );
}
}
}
/**
* @param File $img
* @param string $thumbName
* @return string
*/
function wfThumbAttemptKey( File $img, $thumbName ) {
global $wgAttemptFailureEpoch;
return wfMemcKey( 'attempt-failures', $wgAttemptFailureEpoch,
$img->getRepo()->getName(), md5( $img->getName() ), md5( $thumbName ) );
}
/**
* Convert pathinfo type parameter, into normal request parameters
*
* So for example, if the request was redirected from
* /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
* of this function would be set to "a/ab/Foo.png/120px-Foo.png".
* This method is responsible for turning that into an array
* with the folowing keys:
* * f => the filename (Foo.png)
* * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
* * archived => 1 (If the request is for an archived thumb)
* * temp => 1 (If the file is in the "temporary" zone)
* * thumbName => the thumbnail name, including parameters (120px-Foo.png)
*
* Transform specific parameters are set later via wfExtractThumbParams().
*
* @param $thumbRel String Thumbnail path relative to the thumb zone
* @return Array|null associative params array or null
*/
function wfExtractThumbRequestInfo( $thumbRel ) {
$repo = RepoGroup::singleton()->getLocalRepo();
$hashDirReg = $subdirReg = '';
for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
$subdirReg .= '[0-9a-f]';
$hashDirReg .= "$subdirReg/";
}
// Check if this is a thumbnail of an original in the local file repo
if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
// Check if this is a thumbnail of an temp file in the local file repo
} elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
} else {
return null; // not a valid looking thumbnail request
}
$params = array( 'f' => $filename, 'rel404' => $rel );
if ( $archOrTemp === 'archive/' ) {
$params['archived'] = 1;
} elseif ( $archOrTemp === 'temp/' ) {
$params['temp'] = 1;
}
$params['thumbName'] = $thumbname;
return $params;
}
/**
* Convert a thumbnail name (122px-foo.png) to parameters, using
* file handler.
*
* @param File $file File object for file in question.
* @param $param Array Array of parameters so far.
* @return Array parameters array with more parameters.
*/
function wfExtractThumbParams( $file, $params ) {
if ( !isset( $params['thumbName'] ) ) {
throw new MWException( "No thumbnail name passed to wfExtractThumbParams" );
}
$thumbname = $params['thumbName'];
unset( $params['thumbName'] );
// Do the hook first for older extensions that rely on it.
if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
// Check hooks if parameters can be extracted
// Hooks return false if they manage to *resolve* the parameters
// This hook should be considered deprecated
wfDeprecated( 'ExtractThumbParameters', '1.22' );
return $params; // valid thumbnail URL (via extension or config)
}
// FIXME: Files in the temp zone don't set a mime type, which means
// they don't have a handler. Which means we can't parse the param
// string. However, not a big issue as what good is a param string
// if you have no handler to make use of the param string and
// actually generate the thumbnail.
$handler = $file->getHandler();
// Based on UploadStash::parseKey
$fileNamePos = strrpos( $thumbname, $params['f'] );
if ( $fileNamePos === false ) {
// Maybe using a short filename? (see FileRepo::nameForThumb)
$fileNamePos = strrpos( $thumbname, 'thumbnail' );
}
if ( $handler && $fileNamePos !== false ) {
$paramString = substr( $thumbname, 0, $fileNamePos - 1 );
$extraParams = $handler->parseParamString( $paramString );
if ( $extraParams !== false ) {
return $params + $extraParams;
}
}
// As a last ditch fallback, use the traditional common parameters
if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
list( /* all */, $pagefull, $pagenum, $size ) = $matches;
$params['width'] = $size;
if ( $pagenum ) {
$params['page'] = $pagenum;
}
return $params; // valid thumbnail URL
}
return null;
}
/**
* Output a thumbnail generation error message
*
* @param $status integer
* @param $msg string
* @return void
*/
function wfThumbError( $status, $msg ) {
global $wgShowHostnames;
header( 'Cache-Control: no-cache' );
header( 'Content-Type: text/html; charset=utf-8' );
if ( $status == 404 ) {
header( 'HTTP/1.1 404 Not found' );
} elseif ( $status == 403 ) {
header( 'HTTP/1.1 403 Forbidden' );
header( 'Vary: Cookie' );
} else {
header( 'HTTP/1.1 500 Internal server error' );
}
if ( $wgShowHostnames ) {
header( 'X-MW-Thumbnail-Renderer: ' . wfHostname() );
$url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
$hostname = htmlspecialchars( wfHostname() );
$debug = "<!-- $url -->\n<!-- $hostname -->\n";
} else {
$debug = '';
}
echo <<<EOT
<html><head><title>Error generating thumbnail</title></head>
<body>
<h1>Error generating thumbnail</h1>
<p>
$msg
</p>
$debug
</body>
</html>
EOT;
}