Adding a SW reporter component updater

chrome/browser/component_updater/sw_reporter_component_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_component_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_enumerator.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/threading/worker_pool.h"
+#include "base/values.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/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_START_DOWNLOAD = 0,
+  SW_REPORTER_RETRYING_DOWNLOAD = 1,
+  SW_REPORTER_RETRIED_TOO_MANY_DOWNLOADS = 2,
+  SW_REPORTER_START_EXECUTION = 3,
+  SW_REPORTER_RETRYING_EXECUTION = 4,
+  SW_REPORTER_RETRIED_TOO_MANY_EXECUTIONS = 5,
+  SW_REPORTER_FAILED_TO_LAUNCH_REPORTER = 6,
+  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 ReportSwReporterStep(SwReporterUmaValue value) {
+  UMA_HISTOGRAM_ENUMERATION(
+      "ComponentUpdater.SwReporterStep", value, SW_REPORTER_MAX);
+}
+
+// This function is called on the UI thread to report the SwReporter exit code
+// and then to 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 ReportAndClearSwReporterExitCode(int exit_code) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("ComponentUpdater.SwReporterExitCode", 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::kSwReporterComponentExecuteTryCount, 0);
+}
+
+// This function is called from a worker thread to wait for the SwReporter to
+// complete and then 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 LaunchProcessAndWaitForTermination(const base::FilePath& exe_path) {
+  base::CommandLine reporter_command_line(exe_path);
+  base::ProcessHandle scan_reporter_process = NULL;
+  if (!base::LaunchProcess(reporter_command_line,
+                           base::LaunchOptions(),
+                           &scan_reporter_process)) {
+    ReportSwReporterStep(SW_REPORTER_FAILED_TO_LAUNCH_REPORTER);
+    return;
+  }
+
+  int exit_code = -1;
+  bool success = base::WaitForExitCode(scan_reporter_process, &exit_code);
+  DCHECK(success);
+  ::CloseHandle(scan_reporter_process);
+  scan_reporter_process = NULL;
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ReportAndClearSwReporterExitCode, exit_code));
+}
+
+void SwReporterExecutionUITask(const base::FilePath& executable_path,
+                               PrefService* prefs) {
+  // If we get here without a register or an execute try count, this means that
+  // the component have been silently updated to a new version, so we don't want
+  // to execute.
+  int execute_try_count =
+      prefs->GetInteger(prefs::kSwReporterComponentExecuteTryCount);
+  if (execute_try_count == 0 &&
+      prefs->GetInteger(prefs::kSwReporterComponentRegisterTryCount) == 0) {
+    return;
+  }
+
+  // If we get here, we're done with the registration so clear the number of
+  // retries, and add one more try at execution.
+  prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount, 0);
+  ReportSwReporterStep(execute_try_count ? SW_REPORTER_RETRYING_EXECUTION
+                                         : SW_REPORTER_START_EXECUTION);
+  prefs->SetInteger(prefs::kSwReporterComponentExecuteTryCount,
+                    execute_try_count + 1);
+
+  // Now execute the reporter from a worker thread.
+  base::WorkerPool::PostTask(
+      FROM_HERE,
+      base::Bind(&LaunchProcessAndWaitForTermination,
+                 executable_path.Append(kSwReporterExeName)),
+      true);
+}
+
+// The base directory on windows looks like:
+// <profile>\AppData\Local\Google\Chrome\User Data\SwReporter\.
+base::FilePath GetSwReporterBaseDirectory() {
+  base::FilePath result;
+  PathService::Get(chrome::DIR_USER_DATA, &result);
+  return result.Append(FILE_PATH_LITERAL("SwReporter"));
+}
+
+// Enumerate the version directories to find the latest one. On success,
+// latest_version_path is set to something like:
+// [user-data-dir]\SwReporter\<ver>.
+bool GetLatestSwReporterDirectory(base::FilePath* latest_version_path) {
+  base::FilePath base_dir = GetSwReporterBaseDirectory();
+  bool found = false;
+  base::FileEnumerator file_enumerator(
+      base_dir, false, base::FileEnumerator::DIRECTORIES);
+  Version latest_version("0.0.0.0");
+  for (base::FilePath path = file_enumerator.Next(); !path.value().empty();
+       path = file_enumerator.Next()) {
+    Version version(path.BaseName().MaybeAsASCII());
+    if (!version.IsValid())
+      continue;
+    if (version.CompareTo(latest_version) > 0 &&
+        base::PathExists(path.Append(kSwReporterExeName))) {
+      *latest_version_path = path;
+      latest_version = version;
+      found = true;
+    }
+  }
+  return found;
+}
+
+class SwReporterComponentInstallerTraits : public ComponentInstallerTraits {
+ public:
+  explicit SwReporterComponentInstallerTraits(PrefService* prefs)
+      : prefs_(prefs) {}
+
+  virtual ~SwReporterComponentInstallerTraits() {}
+
+  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) {
+    // Installation is over, now check if we have a pending execution.
+    SwReporterExecutionUITask(install_dir, prefs_);
+  }
+
+  virtual base::FilePath GetBaseDirectory() const {
+    return GetSwReporterBaseDirectory();
+  }
+
+  virtual void GetHash(std::vector<uint8>* hash) const {
+    DCHECK(hash);
+    hash->assign(kSha256Hash, &kSha256Hash[sizeof(kSha256Hash)]);
+  }
+
+  virtual std::string GetName() const { return "Software Reporter Tool"; }
+
+ private:
+  PrefService* prefs_;
+};
+
+void FindSwReporterComponentOnFileThread(ComponentUpdateService* cus,
+                                         PrefService* prefs) {
+  base::FilePath latest_version_path;
+  if (!GetLatestSwReporterDirectory(&latest_version_path)) {
+    scoped_ptr<ComponentInstallerTraits> traits(
+        new SwReporterComponentInstallerTraits(prefs));
+    // |cus| will take ownership of |installer| during installer->Register(cus).
+    DefaultComponentInstaller* installer =
+        new DefaultComponentInstaller(traits.Pass());
+    installer->Register(cus);
+  } else {
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&SwReporterExecutionUITask, latest_version_path, prefs));
+  }
+}
+
+void ExecuteSwReporterComponentImpl(ComponentUpdateService* cus,
+                                    PrefService* prefs,
+                                    int register_try_count) {
+  if (register_try_count > kMaxRetry) {
+    ReportSwReporterStep(SW_REPORTER_RETRIED_TOO_MANY_DOWNLOADS);
+    // Let's forget about this attempt.
+    prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount, 0);
+    return;
+  }
+
+  ReportSwReporterStep(register_try_count ? SW_REPORTER_RETRYING_DOWNLOAD
+                                          : SW_REPORTER_START_DOWNLOAD);
+  prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount,
+                    register_try_count + 1);
+  BrowserThread::PostTask(
+      BrowserThread::FILE,
+      FROM_HERE,
+      base::Bind(&FindSwReporterComponentOnFileThread, cus, prefs));
+}
+
+}  // namespace
+
+void ExecuteSwReporterComponent(ComponentUpdateService* cus,
+                                PrefService* prefs) {
+  // This is an explicit call, so let's forget about previous incomplete
+  // attempts and start from scratch.
+  prefs->SetInteger(prefs::kSwReporterComponentExecuteTryCount, 0);
+  prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount, 0);
+  ExecuteSwReporterComponentImpl(cus, prefs, 0);
+}
+
+void ExecutePendingSwReporterComponent(ComponentUpdateService* cus,
+                                       PrefService* prefs) {
+  // Only register / execute if we have a pending registration / execution.
+  int register_try_count =
+      prefs->GetInteger(prefs::kSwReporterComponentRegisterTryCount);
+  int execute_try_count =
+      prefs->GetInteger(prefs::kSwReporterComponentExecuteTryCount);
+  if (register_try_count == 0) {
+    if (execute_try_count == 0)
+      return;
+    // 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) {
+      ReportAndClearSwReporterExitCode(exit_code);
+      return;
+    }
+
+    // If it didn't complete, let's make sure we didn't go beyond the maximum
+    // retry count yet.
+    if (execute_try_count > kMaxRetry) {
+      ReportSwReporterStep(SW_REPORTER_RETRIED_TOO_MANY_EXECUTIONS);
+      // Let's forget about this attempt.
+      prefs->SetInteger(prefs::kSwReporterComponentExecuteTryCount, 0);
+      return;
+    }
+  }
+
+  ExecuteSwReporterComponentImpl(cus, prefs, register_try_count);
+}
+
+void RegisterPrefsForSwReporterComponent(PrefRegistrySimple* registry) {
+  registry->RegisterIntegerPref(prefs::kSwReporterComponentRegisterTryCount, 0);
+  registry->RegisterIntegerPref(prefs::kSwReporterComponentExecuteTryCount, 0);
+}
+
+}  // namespace component_updater