Implemented on-demand installation of the Chromoting Host on Windows.

remoting/host/plugin/daemon_installer_win.cc

+// Copyright (c) 2012 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 "remoting/host/plugin/daemon_installer_win.h"
+
+#include <windows.h>
+
+#include "base/string16.h"
+#include "base/bind.h"
+#include "base/message_loop.h"
+#include "base/process_util.h"
+#include "base/stringprintf.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
+#include "base/win/object_watcher.h"
+#include "base/win/registry.h"
+#include "base/win/scoped_bstr.h"
+#include "base/win/scoped_comptr.h"
+#include "base/win/scoped_handle.h"
+
+namespace omaha {
+#include "google_update/google_update_idl.h"
+};
+
+using base::win::ScopedBstr;
+using base::win::ScopedComPtr;
+
+namespace {
+
+// The COM elevation moniker for Omaha.
+const char kOmahaElevationMoniker[] = "Elevation:Administrator!new:"
+    "GoogleUpdate.Update3WebMachine";
+
+// The registry key where the configuration of Omaha is stored.
+const char kOmahaUpdateKeyName[] = "Software\\Google\\Update";
+
+// The name of the value where the full path to GoogleUpdate.exe is stored.
+const char kOmahaPathValueName[] = "path";
+
+// The command line format string for GoogleUpdate.exe
+const char kGoogleUpdateCommandLineFormat[] =
+    "\"%ls\" /install \"bundlename=Chromoting%%20Host&appguid=%ls&"
+    "appname=Chromoting%%20Host&needsadmin=True&lang=%ls\"";
+
+// The Omaha Appid of the host.
+const char kOmahaAppid[] = "{b210701e-ffc4-49e3-932b-370728c72662}";
+
+// TODO(alexeypa): Get the desired laungage from the web app.
+const char kOmahaLanguage[] = "en";
+
+// An empty string for optional parameters.
+const char kOmahaEmpty[] = "";
+
+// The installation status polling interval.
+const int kOmahaPollIntervalMs = 500;
+
+}  // namespace
+
+namespace remoting {
+
+// This class implements on-demand installation of the Chromoting Host via
+// per-machine Omaha instance.
+class DaemonComInstallerWin : public DaemonInstallerWin {
+ public:
+  DaemonComInstallerWin(const ScopedComPtr<omaha::IGoogleUpdate3Web>& update3);
+
+  // DaemonInstallerWin implementation.
+  virtual void Install(const CompletionCallback& done) OVERRIDE;
+
+ private:
+  // Polls the installation status performing state-specific actions (such as
+  // starting installation once download has finished).
+  void PollInstallationStatus(const CompletionCallback& done);
+
+  ScopedComPtr<omaha::IGoogleUpdate3Web> update3_;
+  ScopedComPtr<omaha::IAppBundleWeb> bundle_;
+  ScopedComPtr<omaha::IAppWeb> app_;
+};
+
+// This class implements on-demand installation of the Chromoting Host by
+// launching a per-user instance of Omaha and requesting elevation.
+class DaemonCommandLineInstallerWin
+    : public DaemonInstallerWin,
+      public base::win::ObjectWatcher::Delegate {
+public:

[Sergey Ulanov, 2012/04/07 18:09:21]

nit: indent with one space.

[alexeypa (please no reviews), 2012/04/09 20:24:11]

Done.

+  DaemonCommandLineInstallerWin();
+
+  // DaemonInstallerWin implementation.
+  virtual void Install(const CompletionCallback& done) OVERRIDE;
+
+  // base::win::ObjectWatcher::Delegate implementation.
+  virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
+
+ private:
+  CompletionCallback done_;
+
+  // Handle of the launched process.
+  base::win::ScopedHandle process_;
+
+  // Used to determine when the launched process terminates.
+  base::win::ObjectWatcher process_watcher_;
+};
+
+DaemonComInstallerWin::DaemonComInstallerWin(
+    const ScopedComPtr<omaha::IGoogleUpdate3Web>& update3)
+    : update3_(update3) {
+}
+
+void DaemonComInstallerWin::Install(const CompletionCallback& done) {
+  // Create an app bundle.
+  ScopedComPtr<IDispatch> dispatch;
+  HRESULT hr = update3_->createAppBundleWeb(dispatch.Receive());
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  hr = dispatch.QueryInterface(omaha::IID_IAppBundleWeb,
+                               bundle_.ReceiveVoid());
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  hr = bundle_->initialize();
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  // Add Chromoting Host to the bundle.
+  ScopedBstr appid(ASCIIToUTF16(kOmahaAppid).c_str());
+  ScopedBstr empty(ASCIIToUTF16(kOmahaEmpty).c_str());

[Sergey Ulanov, 2012/04/07 18:09:21]

Do we need to convert and empty string? Can this be empty(L"")?

[alexeypa (please no reviews), 2012/04/09 20:24:11]

This was needed because of the presubmit check frowning at wchar_t and L"". I
found a way around it using char16 and TO_L_STRING macro.

+  ScopedBstr language(ASCIIToUTF16(kOmahaLanguage).c_str());
+  hr = bundle_->createApp(appid, empty, language, empty);
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  hr = bundle_->checkForUpdate();
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  dispatch.Release();
+  hr = bundle_->get_appWeb(0, dispatch.Receive());
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  hr = dispatch.QueryInterface(omaha::IID_IAppWeb,
+                               app_.ReceiveVoid());
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  // Now poll for the installation status.
+  PollInstallationStatus(done);
+}
+
+void DaemonComInstallerWin::PollInstallationStatus(
+    const CompletionCallback& done) {
+  // Get the current application installation state.
+  // N.B. The object underlying the ICurrentState interface has static data that
+  // does not get updated as the server state changes. To get the most "current"
+  // state, the currentState property needs to be queried again.
+  ScopedComPtr<IDispatch> dispatch;
+  HRESULT hr = app_->get_currentState(dispatch.Receive());
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  ScopedComPtr<omaha::ICurrentState> current_state;
+  hr = dispatch.QueryInterface(omaha::IID_ICurrentState,
+                               current_state.ReceiveVoid());
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  LONG state;
+  hr = current_state->get_stateValue(&state);
+  if (FAILED(hr)) {
+    done.Run(hr);
+    return;
+  }
+
+  // Perform state-specific actions.
+  switch (state) {
+    case omaha::STATE_INIT:
+    case omaha::STATE_WAITING_TO_CHECK_FOR_UPDATE:
+    case omaha::STATE_CHECKING_FOR_UPDATE:
+    case omaha::STATE_WAITING_TO_DOWNLOAD:
+    case omaha::STATE_RETRYING_DOWNLOAD:
+    case omaha::STATE_DOWNLOADING:
+    case omaha::STATE_WAITING_TO_INSTALL:
+    case omaha::STATE_INSTALLING:
+    case omaha::STATE_PAUSED:
+      break;
+
+    case omaha::STATE_UPDATE_AVAILABLE:
+      hr = bundle_->download();
+      if (FAILED(hr)) {
+        done.Run(hr);
+        return;
+      }
+      break;
+
+    case omaha::STATE_DOWNLOAD_COMPLETE:
+    case omaha::STATE_EXTRACTING:
+    case omaha::STATE_APPLYING_DIFFERENTIAL_PATCH:
+    case omaha::STATE_READY_TO_INSTALL:
+      hr = bundle_->install();
+      if (FAILED(hr)) {
+        done.Run(hr);
+        return;
+      }
+      break;
+
+    case omaha::STATE_INSTALL_COMPLETE:
+    case omaha::STATE_NO_UPDATE:
+      // Installation complete or not required. Report success.
+      done.Run(S_OK);
+      return;
+
+    case omaha::STATE_ERROR: {
+      HRESULT error_code;
+      hr = current_state->get_errorCode(&error_code);
+      if (FAILED(hr)) {
+        error_code = hr;
+      }
+      done.Run(error_code);
+      return;
+    }
+
+    default:
+      LOG(ERROR) << "Unknown bundle state: " << state << ".";
+      done.Run(E_FAIL);
+      return;
+  }
+
+  // Keep polling.
+  MessageLoop::current()->PostDelayedTask(

[Sergey Ulanov, 2012/04/07 18:09:21]

use base::RepeatingTimer instead of posting repeated tasks

[alexeypa (please no reviews), 2012/04/09 20:24:11]

Done.

+      FROM_HERE,
+      base::Bind(&DaemonComInstallerWin::PollInstallationStatus,
+                 base::Unretained(this), done),

[Sergey Ulanov, 2012/04/07 18:09:21]

not sure if base::Unretained() is safe here. This can be fixed by using
RepeatingTimer

[alexeypa (please no reviews), 2012/04/09 20:24:11]

Done.

+      base::TimeDelta::FromMilliseconds(kOmahaPollIntervalMs));
+}
+
+DaemonCommandLineInstallerWin::DaemonCommandLineInstallerWin() {
+  process_watcher_.StopWatching();
+}
+
+void DaemonCommandLineInstallerWin::Install(const CompletionCallback& done) {
+  // Get the full path to GoogleUpdate.exe from the registry.
+  base::win::RegKey update_key;
+  LONG result = update_key.Open(HKEY_CURRENT_USER,
+                                ASCIIToUTF16(kOmahaUpdateKeyName).c_str(),
+                                KEY_READ);
+  if (result != ERROR_SUCCESS) {
+    done.Run(HRESULT_FROM_WIN32(result));
+    return;
+  }
+
+  string16 google_update;
+  result = update_key.ReadValue(ASCIIToUTF16(kOmahaPathValueName).c_str(),
+                                &google_update);
+  if (result != ERROR_SUCCESS) {
+    done.Run(HRESULT_FROM_WIN32(result));
+    return;
+  }
+
+  // Launch the updater process and wait for its termination.
+  string16 command_line =
+      StringPrintf(ASCIIToUTF16(kGoogleUpdateCommandLineFormat).c_str(),
+                   google_update.c_str(),
+                   ASCIIToUTF16(kOmahaAppid).c_str(),
+                   ASCIIToUTF16(kOmahaLanguage).c_str());
+
+  base::LaunchOptions options;
+  if (!base::LaunchProcess(command_line, options, process_.Receive())) {
+    result = GetLastError();
+    done.Run(HRESULT_FROM_WIN32(result));
+    return;
+  }
+
+  if (!process_watcher_.StartWatching(process_.Get(), this)) {
+    result = GetLastError();
+    done.Run(HRESULT_FROM_WIN32(result));
+    return;
+  }
+
+  done_ = done;
+}
+
+void DaemonCommandLineInstallerWin::OnObjectSignaled(HANDLE object) {
+  // Check if the updater process returned success.
+  DWORD exit_code;
+  if (GetExitCodeProcess(process_.Get(), &exit_code) && exit_code == 0) {
+    done_.Run(S_OK);
+  } else {
+    done_.Run(E_FAIL);
+  }
+}
+
+DaemonInstallerWin::DaemonInstallerWin() {
+}
+
+DaemonInstallerWin::~DaemonInstallerWin() {
+}
+
+// static
+HRESULT DaemonInstallerWin::Create(
+    scoped_ptr<DaemonInstallerWin>* installer_out) {
+  // Check if the machine instance of Omaha is available.
+  BIND_OPTS3 bind_options;
+  memset(&bind_options, 0, sizeof(bind_options));
+  bind_options.cbStruct = sizeof(bind_options);
+  bind_options.hwnd = NULL;
+  bind_options.dwClassContext  = CLSCTX_LOCAL_SERVER;
+
+  ScopedComPtr<omaha::IGoogleUpdate3Web> update3;
+  HRESULT hr = ::CoGetObject(
+      ASCIIToUTF16(kOmahaElevationMoniker).c_str(),
+      &bind_options,
+      omaha::IID_IGoogleUpdate3Web,
+      update3.ReceiveVoid());
+  if (SUCCEEDED(hr)) {
+    // The machine instance of Omaha is available and we successfully passed
+    // the UAC prompt.
+    *installer_out =
+        scoped_ptr<DaemonInstallerWin>(new DaemonComInstallerWin(update3));
+    return S_OK;
+  } else if (hr == CO_E_CLASSSTRING) {
+    // The machine instance of Omaha is not available so we will have to run
+    // GoogleUpdate.exe manually passing "needsadmin=True". This will cause
+    // Omaha to install the machine instance first and then install Chromoting
+    // Host.
+    *installer_out =
+        scoped_ptr<DaemonInstallerWin>(new DaemonCommandLineInstallerWin());
+    return S_OK;
+  } else {
+    // The user declined the UAC prompt or some other error occured.
+    return hr;
+  }
+}
+
+}  // namespace remoting