Support tighter rate limiting for "non-standard" thumbnails

* Also avoid passing some junk params to File::thumbName()

Change-Id: I7e89f72ade47be7fcc7bf33f0afb970183aac936

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 663098f..bdcee15 100644 (file)
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -4772,6 +4772,13 @@ $wgRateLimits = array(
                'ip' => null,
                'subnet' => null,
        ),
+       'renderfile-nonstandard' => array( // same as above but for non-standard thumbnails
+               'anon' => null,
+               'user' => null,
+               'newbie' => null,
+               'ip' => null,
+               'subnet' => null,
+       ),
 );
 
 /**

diff --git a/thumb.php b/thumb.php
index 3f8e0d3..f2e3017 100644 (file)
--- a/thumb.php
+++ b/thumb.php
@@ -243,8 +243,10 @@ function wfStreamThumb( array $params ) {
                }
        }
 
+       $rel404 = isset( $params['rel404'] ) ? $params['rel404'] : null;
        unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
        unset( $params['f'] ); // We're done with 'f' parameter.
+       unset( $params['rel404'] ); // moved to $rel404
 
        // Get the normalized thumbnail name from the parameters...
        try {
@@ -263,10 +265,10 @@ function wfStreamThumb( array $params ) {
        // 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 ) ) {
+       if ( $rel404 !== null ) { // thumbnail was handled via 404
+               if ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName ) ) {
                        // Request for the canonical thumbnail name
-               } elseif ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
+               } elseif ( rawurldecode( $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 ) );
@@ -284,7 +286,7 @@ function wfStreamThumb( array $params ) {
                } else {
                        wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
                                expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
-                               rawurldecode( $params['rel404'] ) . "'." );
+                               rawurldecode( $rel404 ) . "'." );
                        return;
                }
        }
@@ -306,7 +308,10 @@ function wfStreamThumb( array $params ) {
        }
 
        $user = RequestContext::getMain()->getUser();
-       if ( $user->pingLimiter( 'renderfile' ) ) {
+       if ( !wfThumbIsStandard( $img, $params ) && $user->pingLimiter( 'renderfile-nonstandard' ) ) {
+               wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
+               return;
+       } elseif ( $user->pingLimiter( 'renderfile' ) ) {
                wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
                return;
        } elseif ( wfThumbIsAttemptThrottled( $img, $thumbName, 5 ) ) {
@@ -345,6 +350,37 @@ function wfStreamThumb( array $params ) {
        }
 }
 
+/**
+ * Returns true if this thumbnail is one that MediaWiki generates
+ * links to on file description pages and possibly parser output.
+ *
+ * $params is considered non-standard if they involve a non-standard
+ * width or any parameter aside from width and page number. The number
+ * of possible files with standard parameters is far less than that of all
+ * possible combinations; rate-limiting for them can thus be more generious.
+ *
+ * @param File $img
+ * @param array $params
+ * @return bool
+ */
+function wfThumbIsStandard( File $img, array $params ) {
+       global $wgThumbLimits, $wgImageLimits;
+       // @TODO: use polymorphism with media handler here
+       if ( array_diff( array_keys( $params ), array( 'width', 'page' ) ) ) {
+               return false; // extra parameters present
+       }
+       if ( isset( $params['width'] ) ) {
+               $widths = $wgThumbLimits;
+               foreach ( $wgImageLimits as $pair ) {
+                       $widths[] = $pair[0];
+               }
+               if ( !in_array( $params['width'], $widths ) ) {
+                       return false;
+               }
+       }
+       return true;
+}
+
 /**
  * @param File $img
  * @param string $thumbName