1 files changed, 138 insertions, 0 deletions
diff --git a/toolkit/components/url-classifier/UrlClassifierRemoteSettingsService.sys.mjs b/toolkit/components/url-classifier/UrlClassifierRemoteSettingsService.sys.mjs
new file mode 100644
index 0000000000..e20e31b7b1
--- /dev/null
+++ b/toolkit/components/url-classifier/UrlClassifierRemoteSettingsService.sys.mjs
@@ -0,0 +1,138 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+ChromeUtils.defineESModuleGetters(lazy, {
+  RemoteSettings: "resource://services-settings/remote-settings.sys.mjs",
+});
+
+const COLLECTION_NAME = "tracking-protection-lists";
+
+// SafeBrowsing protocol parameters.
+export const SBRS_UPDATE_MINIMUM_DELAY = 21600; // Minimum delay before polling again in seconds
+
+export function UrlClassifierRemoteSettingsService() {}
+UrlClassifierRemoteSettingsService.prototype = {
+  classID: Components.ID("{1980624c-c50b-4b46-a91c-dfaba7792706}"),
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIUrlClassifierRemoteSettingsService",
+  ]),
+
+  _initialized: false,
+
+  // Entries that are retrieved from RemoteSettings.get(). keyed by the table name.
+  _entries: {},
+
+  async lazyInit() {
+    if (this._initialized) {
+      return;
+    }
+
+    let rs = lazy.RemoteSettings(COLLECTION_NAME);
+    // Bug 1750191: Notify listmanager to trigger an update instead
+    // of polling data periodically.
+    rs.on("sync", async event => {
+      let {
+        data: { current },
+      } = event;
+      this._onUpdateEntries(current);
+    });
+
+    this._initialized = true;
+
+    let entries;
+    try {
+      entries = await rs.get();
+    } catch (e) {}
+
+    this._onUpdateEntries(entries || []);
+  },
+
+  _onUpdateEntries(aEntries) {
+    aEntries.map(entry => {
+      this._entries[entry.Name] = entry;
+    });
+  },
+
+  // Parse the update request. See UrlClassifierListManager.jsm makeUpdateRequest
+  // for more details about how we build the update request.
+  //
+  // @param aRequest the request payload of the update request
+  // @return array The array of requested tables. Each item in the array is composed
+  //               with [table name, chunk numner]
+  _parseRequest(aRequest) {
+    let lines = aRequest.split("\n");
+    let requests = [];
+    for (let line of lines) {
+      let fields = line.split(";");
+      let chunkNum = fields[1]?.match(/(?<=a:).*/);
+      requests.push([fields[0], chunkNum]);
+    }
+    return requests;
+  },
+
+  async _getLists(aRequest, aListener) {
+    await this.lazyInit();
+
+    let rs = lazy.RemoteSettings(COLLECTION_NAME);
+    let payload = "n:" + SBRS_UPDATE_MINIMUM_DELAY + "\n";
+
+    let requests = this._parseRequest(aRequest);
+    for (let request of requests) {
+      let [reqTableName, reqChunkNum] = request;
+      let entry = this._entries[reqTableName];
+      if (!entry?.attachment) {
+        continue;
+      }
+
+      // If the request version is the same as what we have in Remote Settings,
+      // we are up-to-date now.
+      if (entry.Version == reqChunkNum) {
+        continue;
+      }
+
+      let downloadError = false;
+      try {
+        // SafeBrowsing maintains its own files, so we can remove the downloaded
+        // files after SafeBrowsing processes the data.
+        let buffer = await rs.attachments.downloadAsBytes(entry);
+        let bytes = new Uint8Array(buffer);
+        let strData = String.fromCharCode.apply(String, bytes);
+
+        // Construct the payload
+        payload += "i:" + reqTableName + "\n";
+        payload += strData;
+      } catch (e) {
+        downloadError = true;
+      }
+
+      if (downloadError) {
+        try {
+          aListener.onStartRequest(null);
+          aListener.onStopRequest(null, Cr.NS_ERROR_FAILURE);
+        } catch (e) {}
+        return;
+      }
+    }
+
+    // Send the update response over stream listener interface
+    let stream = Cc["@mozilla.org/io/string-input-stream;1"].createInstance(
+      Ci.nsIStringInputStream
+    );
+    stream.setData(payload, payload.length);
+
+    aListener.onStartRequest(null);
+    aListener.onDataAvailable(null, stream, 0, payload.length);
+    aListener.onStopRequest(null, Cr.NS_OK);
+  },
+
+  fetchList(aPayload, aListener) {
+    this._getLists(aPayload, aListener);
+  },
+
+  clear() {
+    this._initialized = false;
+    this._entries = {};
+  },
+};