tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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NetworkOverride.sys.mjs (2380B)

      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 /**
      6 * This modules focuses on redirecting requests to a particular local file.
      7 */
      8 
      9 import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
     10 
     11 import { NetUtil } from "resource://gre/modules/NetUtil.sys.mjs";
     12 
     13 const lazy = {};
     14 
     15 ChromeUtils.defineESModuleGetters(lazy, {
     16  FileUtils: "resource://gre/modules/FileUtils.sys.mjs",
     17 });
     18 
     19 XPCOMUtils.defineLazyServiceGetter(
     20  lazy,
     21  "mimeService",
     22  "@mozilla.org/mime;1",
     23  Ci.nsIMIMEService
     24 );
     25 
     26 function readFile(file) {
     27  const fstream = Cc["@mozilla.org/network/file-input-stream;1"].createInstance(
     28    Ci.nsIFileInputStream
     29  );
     30  fstream.init(file, -1, 0, 0);
     31  const data = NetUtil.readInputStreamToString(fstream, fstream.available());
     32  fstream.close();
     33  return data;
     34 }
     35 
     36 /**
     37 * Given an in-flight channel, we will force to replace the content of this request
     38 * with the content of a local file.
     39 *
     40 * @param {nsIHttpChannel} channel
     41 *        The request to replace content for.
     42 * @param {string} path
     43 *        The absolute path to the local file to read content from.
     44 */
     45 function overrideChannelWithFilePath(channel, path) {
     46  // For JS it isn't important, but for HTML we ought to set the right content type on the data URI.
     47  let mimeType = "";
     48  try {
     49    // getTypeFromURI will throw if there is no extension at the end of the URI
     50    mimeType = lazy.mimeService.getTypeFromURI(channel.URI);
     51  } catch (e) {}
     52 
     53  // Create a new response.
     54  const replacedHttpResponse = Cc[
     55    "@mozilla.org/network/replaced-http-response;1"
     56  ].createInstance(Ci.nsIReplacedHttpResponse);
     57 
     58  replacedHttpResponse.responseStatus = 200;
     59  replacedHttpResponse.responseStatusText = "OK";
     60  const file = lazy.FileUtils.File(path);
     61  replacedHttpResponse.responseBody = readFile(file);
     62  if (mimeType) {
     63    replacedHttpResponse.setResponseHeader("Content-Type", mimeType, false);
     64  }
     65 
     66  // Allow all cross origin requests for overrides.
     67  replacedHttpResponse.setResponseHeader(
     68    "Access-Control-Allow-Origin",
     69    "*",
     70    false
     71  );
     72 
     73  channel
     74    .QueryInterface(Ci.nsIHttpChannelInternal)
     75    .setResponseOverride(replacedHttpResponse);
     76 }
     77 
     78 export const NetworkOverride = {
     79  overrideChannelWithFilePath,
     80 };