import: introduce importMaxFileSize setting. Defaults to 50 MB

From Etherpad 1.8.3 onwards, the maximum allowed size for a single imported
file will always be bounded.

The maximum allowed size can be configured via importMaxFileSize.

settings.json.docker

@@ -408,6 +408,14 @@
   "indentationOnNewLine": false,
   */
 
+  /*
+   * From Etherpad 1.8.3 onwards, the maximum allowed size for a single imported
+   * file is always bounded.
+   *
+   * File size is specified in bytes. Default is 50 MB.
+   */
+  "importMaxFileSize": 52428800, // 50 * 1024 * 1024
+
   /*
    * Toolbar buttons configuration.
    *

settings.json.template

@@ -413,6 +413,14 @@
   "indentationOnNewLine": false,
   */
 
+  /*
+   * From Etherpad 1.8.3 onwards, the maximum allowed size for a single imported
+   * file is always bounded.
+   *
+   * File size is specified in bytes. Default is 50 MB.
+   */
+  "importMaxFileSize": 52428800, // 50 * 1024 * 1024
+
   /*
    * Toolbar buttons configuration.
    *

src/node/handler/ImportHandler.js

@@ -72,6 +72,7 @@ async function doImport(req, res, padId)
   let form = new formidable.IncomingForm();
   form.keepExtensions = true;
   form.uploadDir = tmpDirectory;
+  form.maxFileSize = settings.importMaxFileSize;
 
   // locally wrapped Promise, since form.parse requires a callback
   let srcFile = await new Promise((resolve, reject) => {

src/node/utils/Settings.js

@@ -305,6 +305,14 @@ exports.scrollWhenFocusLineIsOutOfViewport = {
  */
 exports.exposeVersion = false;
 
+/*
+ * From Etherpad 1.8.3 onwards, the maximum allowed size for a single imported
+ * file is always bounded.
+ *
+ * File size is specified in bytes. Default is 50 MB.
+ */
+exports.importMaxFileSize = 50 * 1024 * 1024;
+
 // checks if abiword is avaiable
 exports.abiwordAvailable = function()
 {