1 files changed, 177 insertions, 0 deletions
diff --git a/browser/components/attribution/MacAttribution.sys.mjs b/browser/components/attribution/MacAttribution.sys.mjs
new file mode 100644
index 0000000000..cb4a8373c8
--- /dev/null
+++ b/browser/components/attribution/MacAttribution.sys.mjs
@@ -0,0 +1,177 @@
+/* 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/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+XPCOMUtils.defineLazyGetter(lazy, "log", () => {
+  let { ConsoleAPI } = ChromeUtils.importESModule(
+    "resource://gre/modules/Console.sys.mjs"
+  );
+  let consoleOptions = {
+    // tip: set maxLogLevel to "debug" and use lazy.log.debug() to create
+    // detailed messages during development. See LOG_LEVELS in Console.sys.mjs
+    // for details.
+    maxLogLevel: "error",
+    maxLogLevelPref: "browser.attribution.mac.loglevel",
+    prefix: "MacAttribution",
+  };
+  return new ConsoleAPI(consoleOptions);
+});
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Subprocess: "resource://gre/modules/Subprocess.sys.mjs",
+});
+
+/**
+ * Get the location of the user's macOS quarantine database.
+ * @return {String} path.
+ */
+function getQuarantineDatabasePath() {
+  let file = Services.dirsvc.get("Home", Ci.nsIFile);
+  file.append("Library");
+  file.append("Preferences");
+  file.append("com.apple.LaunchServices.QuarantineEventsV2");
+  return file.path;
+}
+
+/**
+ * Query given path for quarantine extended attributes.
+ * @param {String} path of the file to query.
+ * @return {[String, String]} pair of the quarantine data GUID and remaining
+ *                            quarantine data (usually, Gatekeeper flags).
+ * @throws NS_ERROR_NOT_AVAILABLE if there is no quarantine GUID for the given path.
+ * @throws NS_ERROR_UNEXPECTED if there is a quarantine GUID, but it is malformed.
+ */
+async function getQuarantineAttributes(path) {
+  let bytes = await IOUtils.getMacXAttr(path, "com.apple.quarantine");
+  if (!bytes) {
+    throw new Components.Exception(
+      `No macOS quarantine xattrs found for ${path}`,
+      Cr.NS_ERROR_NOT_AVAILABLE
+    );
+  }
+
+  let string = new TextDecoder("utf-8").decode(bytes);
+  let parts = string.split(";");
+  if (!parts.length) {
+    throw new Components.Exception(
+      `macOS quarantine data is not ; separated`,
+      Cr.NS_ERROR_UNEXPECTED
+    );
+  }
+  let guid = parts[parts.length - 1];
+  if (guid.length != 36) {
+    // Like "12345678-90AB-CDEF-1234-567890ABCDEF".
+    throw new Components.Exception(
+      `macOS quarantine data guid is not length 36: ${guid.length}`,
+      Cr.NS_ERROR_UNEXPECTED
+    );
+  }
+
+  return { guid, parts };
+}
+
+/**
+ * Invoke system SQLite binary to extract the referrer URL corresponding to
+ * the given GUID from the given macOS quarantine database.
+ * @param {String} path of the user's macOS quarantine database.
+ * @param {String} guid to query.
+ * @return {String} referrer URL.
+ */
+async function queryQuarantineDatabase(
+  guid,
+  path = getQuarantineDatabasePath()
+) {
+  let query = `SELECT COUNT(*), LSQuarantineOriginURLString
+       FROM LSQuarantineEvent
+       WHERE LSQuarantineEventIdentifier = '${guid}'
+       ORDER BY LSQuarantineTimeStamp DESC LIMIT 1`;
+
+  let proc = await lazy.Subprocess.call({
+    command: "/usr/bin/sqlite3",
+    arguments: [path, query],
+    environment: {},
+    stderr: "stdout",
+  });
+
+  let stdout = await proc.stdout.readString();
+
+  let { exitCode } = await proc.wait();
+  if (exitCode != 0) {
+    throw new Components.Exception(
+      "Failed to run sqlite3",
+      Cr.NS_ERROR_UNEXPECTED
+    );
+  }
+
+  // Output is like "integer|url".
+  let parts = stdout.split("|", 2);
+  if (parts.length != 2) {
+    throw new Components.Exception(
+      "Failed to parse sqlite3 output",
+      Cr.NS_ERROR_UNEXPECTED
+    );
+  }
+
+  if (parts[0].trim() == "0") {
+    throw new Components.Exception(
+      `Quarantine database does not contain URL for guid ${guid}`,
+      Cr.NS_ERROR_UNEXPECTED
+    );
+  }
+
+  return parts[1].trim();
+}
+
+export var MacAttribution = {
+  /**
+   * The file path to the `.app` directory.
+   */
+  get applicationPath() {
+    // On macOS, `GreD` is like "App.app/Contents/macOS".  Return "App.app".
+    return Services.dirsvc.get("GreD", Ci.nsIFile).parent.parent.path;
+  },
+
+  /**
+   * Used by the Attributions system to get the download referrer.
+   *
+   * @param {String} path to get the quarantine data from.
+   *             Usually this is a `.app` directory but can be any
+   *             (existing) file or directory.  Default: `this.applicationPath`.
+   * @return {String} referrer URL.
+   * @throws NS_ERROR_NOT_AVAILABLE if there is no quarantine GUID for the given path.
+   * @throws NS_ERROR_UNEXPECTED if there is a quarantine GUID, but no corresponding referrer URL is known.
+   */
+  async getReferrerUrl(path = this.applicationPath) {
+    lazy.log.debug(`getReferrerUrl(${JSON.stringify(path)})`);
+
+    // First, determine the quarantine GUID assigned by macOS to the given path.
+    let guid;
+    try {
+      guid = (await getQuarantineAttributes(path)).guid;
+    } catch (ex) {
+      throw new Components.Exception(
+        `No macOS quarantine GUID found for ${path}`,
+        Cr.NS_ERROR_NOT_AVAILABLE
+      );
+    }
+    lazy.log.debug(`getReferrerUrl: guid: ${guid}`);
+
+    // Second, fish the relevant record from the quarantine database.
+    let url = "";
+    try {
+      url = await queryQuarantineDatabase(guid);
+      lazy.log.debug(`getReferrerUrl: url: ${url}`);
+    } catch (ex) {
+      // This path is known to macOS but we failed to extract a referrer -- be noisy.
+      throw new Components.Exception(
+        `No macOS quarantine referrer URL found for ${path} with GUID ${guid}`,
+        Cr.NS_ERROR_UNEXPECTED
+      );
+    }
+
+    return url;
+  },
+};