tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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Sniffer.sys.mjs (2045B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 
      5 import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
      6 
      7 const gPrefs = {};
      8 
      9 XPCOMUtils.defineLazyPreferenceGetter(
     10  gPrefs,
     11  "gEnabled",
     12  "devtools.jsonview.enabled"
     13 );
     14 
     15 const JSON_VIEW_MIME_TYPE = "application/vnd.mozilla.json.view";
     16 
     17 function getContentDisposition(channel) {
     18  try {
     19    return channel.contentDisposition;
     20  } catch (e) {
     21    // Channel doesn't support content dispositions
     22    return null;
     23  }
     24 }
     25 
     26 /**
     27 * This component represents a sniffer (implements nsIContentSniffer
     28 * interface) responsible for changing top level 'application/json'
     29 * document types to: 'application/vnd.mozilla.json.view'.
     30 *
     31 * This internal type is consequently rendered by JSON View component
     32 * that represents the JSON through a viewer interface.
     33 *
     34 * This is done in the .js file rather than a .jsm to avoid creating
     35 * a compartment at startup when no JSON is being viewed.
     36 */
     37 export class Sniffer {
     38  getMIMETypeFromContent(request) {
     39    if (request instanceof Ci.nsIChannel) {
     40      // JSON View is enabled only for top level loads only.
     41      if (
     42        gPrefs.gEnabled &&
     43        request.loadInfo?.isTopLevelLoad &&
     44        request.loadFlags & Ci.nsIChannel.LOAD_DOCUMENT_URI &&
     45        getContentDisposition(request) != Ci.nsIChannel.DISPOSITION_ATTACHMENT
     46      ) {
     47        // Check the response content type and if it's a valid type
     48        // such as application/json or application/manifest+json
     49        // change it to new internal type consumed by JSON View.
     50        if (/^application\/(?:.+\+)?json$/.test(request.contentType)) {
     51          return JSON_VIEW_MIME_TYPE;
     52        }
     53      } else if (request.contentType === JSON_VIEW_MIME_TYPE) {
     54        return "application/json";
     55      }
     56    }
     57 
     58    return "";
     59  }
     60 }
     61 
     62 Sniffer.prototype.QueryInterface = ChromeUtils.generateQI([
     63  "nsIContentSniffer",
     64 ]);