Adding a SW reporter component updater

chrome/browser/component_updater/sw_reporter_installer_win.cc

+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/component_updater/sw_reporter_installer_win.h"
+
+#include <string>
+#include <vector>
+
+#include "base/base_paths.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/command_line.h"
+#include "base/file_util.h"
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
+#include "base/path_service.h"
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/pref_service.h"
+#include "base/process/kill.h"
+#include "base/process/launch.h"
+#include "base/task_runner_util.h"
+#include "base/threading/worker_pool.h"
+#include "base/win/registry.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/component_updater/component_updater_service.h"
+#include "chrome/browser/component_updater/component_updater_utils.h"
+#include "chrome/browser/component_updater/default_component_installer.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/pref_names.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace component_updater {
+
+namespace {
+
+// These values are used to send UMA information and are replicated in the
+// histograms.xml file, so the order MUST NOT CHANGE.
+enum SwReporterUmaValue {
+  SW_REPORTER_EXPLICIT_REQUEST = 0,
+  SW_REPORTER_STARTUP_RETRY = 1,
+  SW_REPORTER_RETRIED_TOO_MANY_TIMES = 2,
+  SW_REPORTER_START_EXECUTION = 3,
+  SW_REPORTER_FAILED_TO_START = 4,
+  SW_REPORTER_REGISTRY_EXIT_CODE = 5,
+  SW_REPORTER_MAX,
+};
+
+// The maximum number of times to retry a download on startup.
+const int kMaxRetry = 7;
+
+// CRX hash. The extension id is: gkmgaooipdjhmangpemjhigmamcehddo. The hash was
+// generated in Python with something like this:
+// hashlib.sha256().update(open("<file>.crx").read()[16:16+294]).digest().
+const uint8 kSha256Hash[] = {0x6a, 0xc6, 0x0e, 0xe8, 0xf3, 0x97, 0xc0, 0xd6,
+                             0xf4, 0xc9, 0x78, 0x6c, 0x0c, 0x24, 0x73, 0x3e,
+                             0x05, 0xa5, 0x62, 0x4b, 0x2e, 0xc7, 0xb7, 0x1c,
+                             0x5f, 0xea, 0xf0, 0x88, 0xf6, 0x97, 0x9b, 0xc7};
+
+const base::FilePath::CharType kSwReporterExeName[] =
+    FILE_PATH_LITERAL("software_reporter_tool.exe");
+
+// Where to fetch the reporter exit code in the registry.
+const wchar_t kSoftwareRemovalToolRegistryKey[] =
+    L"Software\\Google\\Software Removal Tool";
+const wchar_t kExitCodeRegistryValueName[] = L"ExitCode";
+
+void ReportUmaStep(SwReporterUmaValue value) {
+  UMA_HISTOGRAM_ENUMERATION("SoftwareReporter.Step", value, SW_REPORTER_MAX);
+}
+
+// This function is called on the UI thread to report the SwReporter exit code
+// and then clear it from the registry as well as clear the execution state
+// from the local state. This could be called from an interruptible worker
+// thread so should be resilient to unexpected shutdown.
+void ReportAndClearExitCode(int exit_code) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("SoftwareReporter.ExitCode", exit_code);
+
+  base::win::RegKey srt_key(
+      HKEY_CURRENT_USER, kSoftwareRemovalToolRegistryKey, KEY_WRITE);
+  srt_key.DeleteValue(kExitCodeRegistryValueName);
+
+  // Now that we are done we can reset the try count.
+  g_browser_process->local_state()->SetInteger(
+      prefs::kSwReporterExecuteTryCount, 0);
+}
+
+// This function is called from a worker thread to launch the SwReporter and
+// wait for termination to collect its exit code. This task could be interrupted
+// by a shutdown at anytime, so it shouldn't depend on anything external that
+// could be shutdown beforehand.
+void LaunchAndWaitForExit(const base::FilePath& exe_path) {
+  const base::CommandLine reporter_command_line(exe_path);
+  base::ProcessHandle scan_reporter_process = base::kNullProcessHandle;
+  if (!base::LaunchProcess(reporter_command_line,
+                           base::LaunchOptions(),
+                           &scan_reporter_process)) {
+    ReportUmaStep(SW_REPORTER_FAILED_TO_START);
+    return;
+  }
+  ReportUmaStep(SW_REPORTER_START_EXECUTION);
+
+  int exit_code = -1;
+  bool success = base::WaitForExitCode(scan_reporter_process, &exit_code);
+  DCHECK(success);
+  base::CloseProcessHandle(scan_reporter_process);
+  scan_reporter_process = base::kNullProcessHandle;
+  // It's OK if this doesn't complete, the work will continue on next startup.
+  BrowserThread::PostTask(BrowserThread::UI,
+                          FROM_HERE,
+                          base::Bind(&ReportAndClearExitCode, exit_code));
+}
+
+void ExecuteReporter(const base::FilePath& install_dir) {
+  base::WorkerPool::PostTask(
+      FROM_HERE,
+      base::Bind(&LaunchAndWaitForExit, install_dir.Append(kSwReporterExeName)),
+      true);
+}
+
+class SwReporterInstallerTraits : public ComponentInstallerTraits {
+ public:
+  explicit SwReporterInstallerTraits(PrefService* prefs) : prefs_(prefs) {
+    pending_registration_ = true;
+  }
+
+  virtual ~SwReporterInstallerTraits() {}
+
+  virtual bool VerifyInstallation(const base::FilePath& dir) const {
+    return base::PathExists(dir.Append(kSwReporterExeName));
+  }
+
+  virtual bool CanAutoUpdate() const { return true; }
+
+  virtual bool OnCustomInstall(const base::DictionaryValue& manifest,
+                               const base::FilePath& install_dir) {
+    return true;
+  }
+
+  virtual void ComponentReady(const base::Version& version,
+                              const base::FilePath& install_dir,
+                              scoped_ptr<base::DictionaryValue> manifest) {
+    wcsncpy_s(version_dir_,
+              _MAX_PATH,
+              install_dir.value().c_str(),
+              install_dir.value().size());
+    // Only execute the reporter if there is still a pending request for it..

[Sorin Jianu, 2014/06/20 05:09:58]

extra . at the end.

[MAD, 2014/06/20 14:40:14]

Done.

+    if (prefs_->GetInteger(prefs::kSwReporterExecuteTryCount))
+      ExecuteReporter(install_dir);
+  }
+
+  virtual base::FilePath GetBaseDirectory() const { return install_dir(); }
+
+  virtual void GetHash(std::vector<uint8>* hash) const { GetPkHash(hash); }
+
+  virtual std::string GetName() const { return "Software Reporter Tool"; }
+
+  static const base::FilePath install_dir() {
+    // The base directory on windows looks like:
+    // <profile>\AppData\Local\Google\Chrome\User Data\SwReporter\.
+    base::FilePath result;
+    PathService::Get(chrome::DIR_USER_DATA, &result);
+    return result.Append(FILE_PATH_LITERAL("SwReporter"));
+  }
+
+  static const std::string ID() {
+    CrxComponent component;
+    component.version = Version("0.0.0.0");
+    GetPkHash(&component.pk_hash);
+    return component_updater::GetCrxComponentID(component);
+  }
+
+  static bool pending_registration() { return pending_registration_; }
+  static const base::FilePath VersionPath() {
+    return base::FilePath(version_dir_);
+  }
+
+ private:
+  static void GetPkHash(std::vector<uint8>* hash) {
+    DCHECK(hash);
+    hash->assign(kSha256Hash, kSha256Hash + sizeof(kSha256Hash));
+  }
+
+  PrefService* prefs_;
+  static bool pending_registration_;
+  static wchar_t version_dir_[_MAX_PATH];
+};
+
+bool SwReporterInstallerTraits::pending_registration_ = false;
+wchar_t SwReporterInstallerTraits::version_dir_[] = {};
+
+void RegisterComponent(ComponentUpdateService* cus, PrefService* prefs) {
+  scoped_ptr<ComponentInstallerTraits> traits(
+      new SwReporterInstallerTraits(prefs));
+  // |cus| will take ownership of |installer| during installer->Register(cus).
+  DefaultComponentInstaller* installer =
+      new DefaultComponentInstaller(traits.Pass());
+  installer->Register(cus);
+}
+
+bool IsComponentInstalled() {
+  return base::PathExists(
+      SwReporterInstallerTraits::VersionPath().Append(kSwReporterExeName));
+}
+
+void ExecuteAndOrRegisterReporter(ComponentUpdateService* cus,
+                                  PrefService* prefs,
+                                  bool execute) {
+  if (!SwReporterInstallerTraits::pending_registration())

[Sorin Jianu, 2014/06/20 05:09:58]

Fore readability sake, we could get rid of ! and swap the branches.

[MAD, 2014/06/20 14:40:14]

Pending registration is gone...

+    RegisterComponent(cus, prefs);
+  else if (execute)
+    ExecuteReporter(SwReporterInstallerTraits::VersionPath());
+}
+
+}  // namespace
+
+void ExecuteSwReporter(ComponentUpdateService* cus, PrefService* prefs) {
+  // This is an explicit call, so let's forget about previous incomplete
+  // execution attempts and start from scratch.
+  prefs->SetInteger(prefs::kSwReporterExecuteTryCount, kMaxRetry);
+  ReportUmaStep(SW_REPORTER_EXPLICIT_REQUEST);
+  base::PostTaskAndReplyWithResult(
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
+      FROM_HERE,
+      base::Bind(&IsComponentInstalled),
+      base::Bind(&ExecuteAndOrRegisterReporter, cus, prefs));
+}
+
+void ExecutePendingSwReporter(ComponentUpdateService* cus, PrefService* prefs) {
+  // Only continue registration / execute if we have a pending execution.
+  int execute_try_count = prefs->GetInteger(prefs::kSwReporterExecuteTryCount);
+  if (execute_try_count) {

[Sorin Jianu, 2014/06/20 05:09:58]

Might want to use > 0, to avoid some potential integer arithmetic problems
(someone will find a way to code a bug and make execute_try_count negative).

[MAD, 2014/06/20 14:40:14]

Done.

+    // We have a pending execution, let's check if it completed or not.
+    base::win::RegKey srt_key(
+        HKEY_CURRENT_USER, kSoftwareRemovalToolRegistryKey, KEY_READ);
+    DWORD exit_code = -1;
+    if (srt_key.Valid() &&
+        srt_key.ReadValueDW(kExitCodeRegistryValueName, &exit_code) ==
+            ERROR_SUCCESS) {
+      ReportUmaStep(SW_REPORTER_REGISTRY_EXIT_CODE);
+      ReportAndClearExitCode(exit_code);
+      return;

[Sorin Jianu, 2014/06/20 05:09:58]

My thinking is that we want to register all the time for updates. So this
function should only run the reporter if execute_try_count > 0. We must always
register for updates.

[MAD, 2014/06/20 14:40:14]

This doesn't run the reporter, just looks to see if it ran before and completed
while Chrome wasn't listening. We just read the exit code value from the
registry, and report it... OK?

+    }
+
+    // If it didn't complete, let's make sure we didn't go beyond the maximum
+    // retry count yet.
+    prefs->SetInteger(prefs::kSwReporterExecuteTryCount, --execute_try_count);
+    if (!execute_try_count)

[Sorin Jianu, 2014/06/20 05:09:58]

could use > instead of !, see above.

[MAD, 2014/06/20 14:40:14]

Done.

+      ReportUmaStep(SW_REPORTER_RETRIED_TOO_MANY_TIMES);
+    else
+      ReportUmaStep(SW_REPORTER_STARTUP_RETRY);
+  }
+  // If we already have an install dir, we need to register to get updates.

[Sorin Jianu, 2014/06/20 05:09:58]

Let's assume that SWR is installed and nothing is pending to be reported. I
understand this function is called when the browser is booting up. In that case,
VersionPath() will be empty, since CUS has not called us yet (we are not
registered at this point) Also, execute_try_count  == 0 (we don't have work to
do). In this case, we still want to register for updates.

[MAD, 2014/06/20 14:40:14]

Ho, right I meant to check the root dir of the component, good catch.

+  if (base::PathExists(SwReporterInstallerTraits::VersionPath()) ||
+      execute_try_count) {
+    base::PostTaskAndReplyWithResult(
+        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
+        FROM_HERE,
+        base::Bind(&IsComponentInstalled),
+        base::Bind(&ExecuteAndOrRegisterReporter, cus, prefs));
+  }
+}
+
+void RegisterPrefsForSwReporter(PrefRegistrySimple* registry) {
+  registry->RegisterIntegerPref(prefs::kSwReporterExecuteTryCount, 0);
+}
+
+}  // namespace component_updater