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/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,
+  SW_REPORTER_RETRIED_TOO_MANY_DOWNLOADS,
+  SW_REPORTER_START_EXECUTION,
+  SW_REPORTER_RETRYING_EXECUTION,
+  SW_REPORTER_RETRIED_TOO_MANY_EXECUTIONS,
+  SW_REPORTER_COMPONENT_UPDATE_ERROR,
+  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.
+// hashlib.sha256().update(open(".crx").read()[16:16+294]).digest().
+const uint8 kSha2Hash[] = {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 char kSwReporterManifestName[] = "Software Reporter Tool";
+
+const base::FilePath::CharType kSwReporterExeName[] =
+    FILE_PATH_LITERAL("software_reporter_tool.exe");
+const base::FilePath::CharType kSwReporterBaseDirectory[] =
+    FILE_PATH_LITERAL("SwReporter");
+
+// If we don't have a SwReporter component, this is the version we claim.
+const char kNullVersion[] = "0.0.0.0";
+
+// 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.
+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 it's exit code to be sent to
+// ReportAndClearSwReporterExitCode on the UI thread.
+void WaitForProcessTermination(base::ProcessHandle process_handle,
+                               const base::FilePath& reporter_exe_full_path) {
+  int exit_code = -1;
+  bool success = base::WaitForExitCode(process_handle, &exit_code);
+  DCHECK(success);
+  ::CloseHandle(process_handle);

[Sorin Jianu, 2014/06/19 19:08:48]

Consider using base::CloseProcessHandle instead since we are using the related
functions from base?

+  process_handle = NULL;

[Sorin Jianu, 2014/06/19 19:08:48]

base::kNullProcessHandle ?

+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ReportAndClearSwReporterExitCode, exit_code));
+
+  // The software reporter must be deleted so that the component updater will
+  // fetch it again the next time we need it. This is because the updater
+  // doesn't let us know when no new version is available and so we can't tell
+  // if we should run the currently installed version or wait for the update.
+  success = base::DeleteFile(base::FilePath(reporter_exe_full_path), false);
+  DCHECK(success);
+}
+
+// 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(kSwReporterBaseDirectory);
+}
+
+// SwReporter has version encoded in the path itself so we need to enumerate the
+// directories to find the full path. On success it returns something like:
+// <profile>\AppData\Local\Google\Chrome\User Data\SwReporter\1.0.1.5\.
+void GetLatestSwReporterDirectory(base::FilePath* result,
+                                  Version* latest,
+                                  std::vector<base::FilePath>* older_dirs) {
+  base::FilePath base_dir = GetSwReporterBaseDirectory();
+  bool found = false;
+  base::FileEnumerator file_enumerator(
+      base_dir, false, base::FileEnumerator::DIRECTORIES);
+  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) > 0 &&
+        base::PathExists(path.Append(kSwReporterExeName))) {
+      if (found && older_dirs)
+        older_dirs->push_back(*result);
+      *latest = version;
+      *result = path;
+      found = true;
+    } else {
+      if (older_dirs)
+        older_dirs->push_back(path);
+    }
+  }
+}
+
+class SwReporterComponentInstaller : public ComponentInstaller {

[waffles, 2014/06/17 23:30:11]

I think you might be able to reduce the amount of code here if you use the
DefaultComponentInstaller, and provide a DefaultComponentInstallerTraits object
instead of subclassing ComponentInstaller - see
widevine_cdm_component_installer.cc for an example.

[MAD, 2014/06/18 01:38:49]

Done.

+ public:
+  explicit SwReporterComponentInstaller(const Version& version,

[Sorin Jianu, 2014/06/19 19:08:48]

explicit makes sense with one-param ctor unless you meant it to be explicit for
C++ 11 initializers.

+                                        PrefService* prefs);
+  virtual ~SwReporterComponentInstaller() {}
+
+  // ComponentInstaller overrides.
+  virtual void OnUpdateError(int error) OVERRIDE;
+  virtual bool Install(const base::DictionaryValue& manifest,
+                       const base::FilePath& unpack_path) OVERRIDE;
+  virtual bool GetInstalledFile(const std::string& file,
+                                base::FilePath* installed_file) OVERRIDE;
+
+ private:
+  void UpdateInstallPrefsOnUIThread();
+
+  Version current_version_;
+  PrefService* prefs_;
+};
+
+SwReporterComponentInstaller::SwReporterComponentInstaller(
+    const Version& version,
+    PrefService* prefs)
+    : current_version_(version), prefs_(prefs) {
+  DCHECK(version.IsValid());
+  DCHECK(prefs_);
+}
+
+void SwReporterComponentInstaller::OnUpdateError(int error) {
+  ReportSwReporterStep(SW_REPORTER_COMPONENT_UPDATE_ERROR);
+  NOTREACHED() << "SwReporter update error: " << error;
+}
+
+bool SwReporterComponentInstaller::Install(
+    const base::DictionaryValue& manifest,
+    const base::FilePath& unpack_path) {
+  std::string name;
+  manifest.GetStringASCII("name", &name);
+  if (name != kSwReporterManifestName)
+    return false;
+
+  std::string proposed_version;
+  manifest.GetStringASCII("version", &proposed_version);
+  Version new_version(proposed_version.c_str());
+  if (!new_version.IsValid())
+    return false;
+
+  base::FilePath sw_reporter_path(GetSwReporterBaseDirectory());
+  base::FilePath new_version_path(
+      sw_reporter_path.AppendASCII(proposed_version));
+  if (current_version_.CompareTo(new_version) < 0) {
+    // If the latest version identified is current_version_, then
+    // new_version_path should not exist.
+    DCHECK(!base::PathExists(new_version_path));
+    if (!base::PathExists(unpack_path.Append(kSwReporterExeName)) ||
+        !base::Move(unpack_path, new_version_path)) {
+      PLOG(ERROR) << "Couldn't move files to new_version_path.\n"
+                  << unpack_path.value() << " -> " << new_version_path.value();
+      return false;
+    }
+  } else {
+    // We should never get an older version than the current one.
+    DCHECK(current_version_.CompareTo(new_version) == 0);
+    if (!base::PathExists(new_version_path.Append(kSwReporterExeName))) {
+      PLOG(INFO) << "existing version_path doesn't contain file.";
+      return false;
+    }
+  }
+
+  // Passed the basic tests, update the prefs on the UI thread.
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&SwReporterComponentInstaller::UpdateInstallPrefsOnUIThread,
+                 base::Unretained(this)));
+
+  // Installation is done. Now execute the reporter.
+  base::FilePath reporter_exe_full_path(
+      new_version_path.Append(kSwReporterExeName));
+  base::CommandLine reporter_command_line(reporter_exe_full_path);
+  base::ProcessHandle scan_reporter_process = NULL;
+  bool success = base::LaunchProcess(
+      reporter_command_line, base::LaunchOptions(), &scan_reporter_process);
+  if (success) {
+    base::WorkerPool::PostTask(FROM_HERE,
+                               base::Bind(&WaitForProcessTermination,
+                                          scan_reporter_process,
+                                          reporter_exe_full_path),
+                               true);
+    // WaitForProcessTermination will close the handle.
+    scan_reporter_process = NULL;
+    return true;
+  }
+  return false;
+}
+
+bool SwReporterComponentInstaller::GetInstalledFile(
+    const std::string& file,
+    base::FilePath* installed_file) {
+  return false;
+}
+
+void SwReporterComponentInstaller::UpdateInstallPrefsOnUIThread() {
+  // We're done with the registration so clean the number of retries,
+  prefs_->SetInteger(prefs::kSwReporterComponentRegisterTryCount, 0);
+
+  int tries = prefs_->GetInteger(prefs::kSwReporterComponentExecuteTryCount);
+  ReportSwReporterStep(tries ? SW_REPORTER_RETRYING_EXECUTION
+                             : SW_REPORTER_START_EXECUTION);
+  prefs_->SetInteger(prefs::kSwReporterComponentExecuteTryCount, tries + 1);
+}
+
+// Complete the registration of the component on the UI thread...
+void FinishSwReporterUpdateRegistration(ComponentUpdateService* cus,
+                                        const Version& version,
+                                        PrefService* prefs) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  CrxComponent SwReporter;
+  SwReporter.name = "SwReporter";
+  SwReporter.installer = new SwReporterComponentInstaller(version, prefs);
+  SwReporter.version = version;
+  SwReporter.pk_hash.assign(kSha2Hash, &kSha2Hash[sizeof(kSha2Hash)]);
+  if (cus->RegisterComponent(SwReporter) == ComponentUpdateService::kError)
+    NOTREACHED() << "SwReporter component registration fail";
+}
+
+// Check if there already is a version of SwReporter installed, and if so
+// register it.
+void RegisterSwReporterComponentOnFileThread(ComponentUpdateService* cus,
+                                             PrefService* prefs) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  base::FilePath path = GetSwReporterBaseDirectory();
+  if (!base::PathExists(path)) {
+    if (!base::CreateDirectory(path)) {
+      NOTREACHED() << "Could not create SwReporter directory.";
+      return;
+    }
+  }
+
+  Version version(kNullVersion);
+  std::vector<base::FilePath> older_dirs;
+  GetLatestSwReporterDirectory(&path, &version, &older_dirs);
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&FinishSwReporterUpdateRegistration, cus, version, prefs));
+
+  // Remove older versions of SwReporter.
+  for (std::vector<base::FilePath>::iterator iter = older_dirs.begin();
+       iter != older_dirs.end();
+       ++iter) {
+    base::DeleteFile(*iter, true);
+  }
+}
+
+}  // namespace
+
+void RegisterSwReporterComponent(ComponentUpdateService* cus,
+                                 PrefService* prefs) {
+  int tries = prefs->GetInteger(prefs::kSwReporterComponentRegisterTryCount);
+  if (tries > kMaxRetry) {
+    ReportSwReporterStep(SW_REPORTER_RETRIED_TOO_MANY_DOWNLOADS);
+    // Let's forget about this attempt.
+    prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount, 0);
+    return;
+  }
+
+  ReportSwReporterStep(tries ? SW_REPORTER_RETRYING_DOWNLOAD
+                             : SW_REPORTER_START_DOWNLOAD);
+  prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount, tries + 1);
+  BrowserThread::PostTask(
+      BrowserThread::FILE,
+      FROM_HERE,
+      base::Bind(&RegisterSwReporterComponentOnFileThread, cus, prefs));
+}
+
+void MaybeRegisterSwReporterComponent(ComponentUpdateService* cus,
+                                      PrefService* prefs) {
+  // Only register if we have a pending registration / execution.
+  if (prefs->GetInteger(prefs::kSwReporterComponentRegisterTryCount) == 0) {
+    if (prefs->GetInteger(prefs::kSwReporterComponentExecuteTryCount) == 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 (prefs->GetInteger(prefs::kSwReporterComponentExecuteTryCount) >
+        kMaxRetry) {
+      ReportSwReporterStep(SW_REPORTER_RETRIED_TOO_MANY_EXECUTIONS);
+      // Let's forget about this attempt.
+      prefs->SetInteger(prefs::kSwReporterComponentExecuteTryCount, 0);
+      return;
+    }
+  }
+
+  RegisterSwReporterComponent(cus, prefs);
+}
+
+void RegisterPrefsForSwReporterComponent(PrefRegistrySimple* registry) {
+  registry->RegisterIntegerPref(prefs::kSwReporterComponentRegisterTryCount, 0);
+  registry->RegisterIntegerPref(prefs::kSwReporterComponentExecuteTryCount, 0);
+}
+
+}  // namespace component_updater