Index: php/upload.php
===================================================================
--- php/upload.php	(revision 64249d67d46154f425d75b148c215f53466b90e0)
+++ php/upload.php	(revision 64249d67d46154f425d75b148c215f53466b90e0)
@@ -0,0 +1,18 @@
+<?php
+
+header('content-type: application/json');
+header('Access-Control-Allow-Origin: *');
+
+if($_FILES['file']['name'] == 'err.html') {
+  http_response_code(404);
+
+  echo json_encode([
+    'status' => 'error',
+    'file' => $_FILES['file']['name']
+  ]);
+}
+else
+  echo json_encode([
+    'status' => 'ok',
+    'file' => $_FILES['file']['name']
+  ]);