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/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 {
+
+// UMA identifiers.
+const char kSwReporterComponentHistogramName[] = "ComponentUpdater.SwReporter";
+const char kSwReporterComponentExiCodeHistogramName[] =
+    "ComponentUpdater.SwReporterExitCode";
+const int kMaxSwReporterExitCodeUMAValue = 100;
+
+enum {

[Alexei Svitkine (slow), 2014/06/16 21:50:05]

Name this enum.

[MAD, 2014/06/17 01:03:37]

Done.

+  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,
+};

[Alexei Svitkine (slow), 2014/06/16 21:50:05]

Add a comment that these are used in an UMA histogram and entries shouldn't
re-ordered or deleted.

[MAD, 2014/06/17 01:03:37]

Done.

+
+// 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";
+
+// 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) {
+  DCHECK(exit_code < kMaxSwReporterExitCodeUMAValue);
+  UMA_HISTOGRAM_ENUMERATION(kSwReporterComponentExiCodeHistogramName,

[Alexei Svitkine (slow), 2014/06/16 21:50:05]

Use UMA_HISTOGRAM_SPARSE_SLOWLY() here, then you don't need
kMaxSwReporterExitCodeUMAValue.

[MAD, 2014/06/17 01:03:37]

Done.

+                            exit_code,
+                            kMaxSwReporterExitCodeUMAValue);
+
+  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) {
+  int exit_code = -1;
+  bool success = base::WaitForExitCode(process_handle, &exit_code);
+  DCHECK(success);
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ReportAndClearSwReporterExitCode, exit_code));
+}
+
+// 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 {
+ public:
+  explicit SwReporterComponentInstaller(const Version& version,
+                                        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) {
+  UMA_HISTOGRAM_ENUMERATION(kSwReporterComponentHistogramName,
+                            SW_REPORTER_COMPONENT_UPDATE_ERROR,
+                            SW_REPORTER_MAX);
+  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::CommandLine reporter_command_line(
+      new_version_path.Append(kSwReporterExeName));
+  base::ProcessHandle scan_reporter_process = NULL;
+  bool success = base::LaunchProcess(
+      reporter_command_line, base::LaunchOptions(), &scan_reporter_process);
+  if (success) {
+    base::WorkerPool::PostTask(

[Alexei Svitkine (slow), 2014/06/16 21:50:05]

Nit: Consider using PostTaskAndReplyWithResult() here so that
WaitForProcessTermination() doesn't need to post its own task. (If you do that,
change WaitForProcessTermination() to return the exit code).

[MAD, 2014/06/17 01:03:37]

But this would only work if the tasked posted from within
WaitForProcessTermination was sent to the FILE thread (where this code is run
from), which is not the case. Right?

[Alexei Svitkine (slow), 2014/06/17 15:01:52]

You're right, sorry for the bad suggestion.

+        FROM_HERE,
+        base::Bind(&WaitForProcessTermination, scan_reporter_process),
+        true);
+    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);
+  UMA_HISTOGRAM_ENUMERATION(
+      kSwReporterComponentHistogramName,
+      tries ? SW_REPORTER_RETRYING_EXECUTION : SW_REPORTER_START_EXECUTION,
+      SW_REPORTER_MAX);
+  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) {
+    UMA_HISTOGRAM_ENUMERATION(kSwReporterComponentHistogramName,
+                              SW_REPORTER_RETRIED_TOO_MANY_DOWNLOADS,
+                              SW_REPORTER_MAX);
+    // Let's forget about this attempt.
+    prefs->SetInteger(prefs::kSwReporterComponentRegisterTryCount, 0);
+    return;
+  }
+
+  UMA_HISTOGRAM_ENUMERATION(
+      kSwReporterComponentHistogramName,
+      tries ? SW_REPORTER_RETRYING_DOWNLOAD : SW_REPORTER_START_DOWNLOAD,
+      SW_REPORTER_MAX);
+  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) {
+      UMA_HISTOGRAM_ENUMERATION(kSwReporterComponentHistogramName,
+                                SW_REPORTER_RETRIED_TOO_MANY_EXECUTIONS,
+                                SW_REPORTER_MAX);

[Alexei Svitkine (slow), 2014/06/16 21:50:05]

Nit: Make a function in the anon namespace that logs
kSwReporterComponentHistogramName and just takes the enum. Each UMA macro
invocation expands to a large chunk of machine code, so not repeating them
reduces bloat. Then, since kSwReporterComponentHistogramName will only be used
from that function, you can inline the string literal and remove the constant
var.

[MAD, 2014/06/17 01:03:37]

Done.

+      // 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