1 files changed, 119 insertions, 0 deletions
diff --git a/toolkit/components/extensions/child/ext-webRequest.js b/toolkit/components/extensions/child/ext-webRequest.js
new file mode 100644
index 0000000000..49bdd3f232
--- /dev/null
+++ b/toolkit/components/extensions/child/ext-webRequest.js
@@ -0,0 +1,119 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+/* 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/. */
+
+"use strict";
+
+var { ExtensionError } = ExtensionUtils;
+
+this.webRequest = class extends ExtensionAPI {
+  STREAM_FILTER_INACTIVE_STATUSES = ["closed", "disconnected", "failed"];
+
+  hasActiveStreamFilter(filtersWeakSet) {
+    const iter = ChromeUtils.nondeterministicGetWeakSetKeys(filtersWeakSet);
+    for (let filter of iter) {
+      if (!this.STREAM_FILTER_INACTIVE_STATUSES.includes(filter.status)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  watchStreamFilterSuspendCancel({
+    context,
+    filters,
+    onSuspend,
+    onSuspendCanceled,
+  }) {
+    if (
+      !context.isBackgroundContext ||
+      context.extension.persistentBackground !== false
+    ) {
+      return;
+    }
+
+    const { extension } = context;
+    const cancelSuspendOnActiveStreamFilter = () =>
+      this.hasActiveStreamFilter(filters);
+    context.callOnClose({
+      close() {
+        extension.off(
+          "internal:stream-filter-suspend-cancel",
+          cancelSuspendOnActiveStreamFilter
+        );
+        extension.off("background-script-suspend", onSuspend);
+        extension.off("background-script-suspend-canceled", onSuspend);
+      },
+    });
+    extension.on(
+      "internal:stream-filter-suspend-cancel",
+      cancelSuspendOnActiveStreamFilter
+    );
+    extension.on("background-script-suspend", onSuspend);
+    extension.on("background-script-suspend-canceled", onSuspendCanceled);
+  }
+
+  getAPI(context) {
+    let filters = new WeakSet();
+
+    context.callOnClose({
+      close() {
+        for (let filter of ChromeUtils.nondeterministicGetWeakSetKeys(
+          filters
+        )) {
+          try {
+            filter.disconnect();
+          } catch (e) {
+            // Ignore.
+          }
+        }
+      },
+    });
+
+    let isSuspending = false;
+    this.watchStreamFilterSuspendCancel({
+      context,
+      filters,
+      onSuspend: () => (isSuspending = true),
+      onSuspendCanceled: () => (isSuspending = false),
+    });
+
+    function filterResponseData(requestId) {
+      if (isSuspending) {
+        throw new ExtensionError(
+          "filterResponseData method calls forbidden while background extension global is suspending"
+        );
+      }
+      requestId = parseInt(requestId, 10);
+
+      let streamFilter = context.cloneScope.StreamFilter.create(
+        requestId,
+        context.extension.id
+      );
+
+      filters.add(streamFilter);
+      return streamFilter;
+    }
+
+    const webRequest = {};
+
+    // For extensions with manifest_version >= 3, an additional webRequestFilterResponse permission
+    // is required to get access to the webRequest.filterResponseData API method.
+    if (
+      context.extension.manifestVersion < 3 ||
+      context.extension.hasPermission("webRequestFilterResponse")
+    ) {
+      webRequest.filterResponseData = filterResponseData;
+    } else {
+      webRequest.filterResponseData = () => {
+        throw new ExtensionError(
+          'Missing required "webRequestFilterResponse" permission'
+        );
+      };
+    }
+
+    return { webRequest };
+  }
+};