Changes to support communication with a privileged process

This change allows the chrome-login code to talk back to a privileged process and ask it to emit upstart signals and such.  Eventually, this IPC will be changed to use DBus, probably when cryptohomed lands.
Review URL: http://codereview.chromium.org/518086

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35813 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 62 insertions, 31 deletions

diff --git a/chrome/browser/chromeos/ipc_message.h b/chrome/browser/chromeos/ipc_message.h
new file mode 100644
index 0000000..e92c066
--- /dev/null
+++ b/chrome/browser/chromeos/ipc_message.h
@@ -0,0 +1,15 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_IPC_MESSAGE_H_
+#define CHROME_BROWSER_CHROMEOS_IPC_MESSAGE_H_
+
+enum IpcMessage {
+  EMIT_LOGIN = 'a',
+  START_SESSION = 'b',
+  STOP_SESSION = 'c',
+  FAILED = 'f',
+};
+
+#endif  // CHROME_BROWSER_CHROMEOS_IPC_MESSAGE_H_
diff --git a/chrome/browser/chromeos/login_manager_view.cc b/chrome/browser/chromeos/login_manager_view.cc
index 89f6098..6a48513 100644
--- a/chrome/browser/chromeos/login_manager_view.cc
+++ b/chrome/browser/chromeos/login_manager_view.cc
@@ -4,11 +4,16 @@
 
 #include "chrome/browser/chromeos/login_manager_view.h"
 
+#include <signal.h>
+#include <sys/types.h>
+
 #include "app/resource_bundle.h"
+#include "base/file_path.h"
 #include "base/keyboard_codes.h"
 #include "base/logging.h"
 #include "base/process_util.h"
 #include "chrome/browser/chromeos/image_background.h"
+#include "chrome/browser/chromeos/ipc_message.h"
 #include "chrome/common/chrome_switches.h"
 #include "grit/theme_resources.h"
 #include "views/controls/label.h"
@@ -36,15 +41,6 @@ const int kBottomPadding = 112;
 
 namespace browser {
 
-bool EmitLoginPromptReady() {
-  base::ProcessHandle handle;
-  std::vector<std::string> argv;
-  argv.push_back("/opt/google/chrome/emit_login_prompt_ready");
-  base::environment_vector no_env;
-  base::file_handle_mapping_vector no_files;
-  return base::LaunchApp(argv, no_env, no_files, false, &handle);
-}
-
 // Acts as a frame view with no UI.
 class LoginManagerNonClientFrameView : public views::NonClientFrameView {
  public:
@@ -76,8 +72,10 @@ class LoginManagerNonClientFrameView : public views::NonClientFrameView {
 // Subclass of WindowGtk, for use as the top level login window.
 class LoginManagerWindow : public views::WindowGtk {
  public:
-  static LoginManagerWindow* CreateLoginManagerWindow() {
-    LoginManagerWindow* login_manager_window = new LoginManagerWindow();
+  static LoginManagerWindow* CreateLoginManagerWindow(
+      const FilePath& pipe_name) {
+    LoginManagerWindow* login_manager_window =
+        new LoginManagerWindow(pipe_name);
     login_manager_window->GetNonClientView()->SetFrameView(
         new LoginManagerNonClientFrameView());
     login_manager_window->Init(NULL, gfx::Rect());
@@ -85,16 +83,18 @@ class LoginManagerWindow : public views::WindowGtk {
   }
 
  private:
-  explicit LoginManagerWindow() : views::WindowGtk(new LoginManagerView()) {}
+  explicit LoginManagerWindow(const FilePath& pipe_name)
+      : views::WindowGtk(new LoginManagerView(pipe_name)) {
+  }
 
   DISALLOW_COPY_AND_ASSIGN(LoginManagerWindow);
 };
 
 // Declared in browser_dialogs.h so that others don't need to depend on our .h.
-void ShowLoginManager() {
-  views::WindowGtk* window = LoginManagerWindow::CreateLoginManagerWindow();
+void ShowLoginManager(const FilePath& pipe_name) {
+  views::WindowGtk* window =
+      LoginManagerWindow::CreateLoginManagerWindow(pipe_name);
   window->Show();
-  EmitLoginPromptReady();
   bool old_state = MessageLoop::current()->NestableTasksAllowed();
   MessageLoop::current()->SetNestableTasksAllowed(true);
   MessageLoop::current()->Run();
@@ -102,11 +102,14 @@ void ShowLoginManager() {
 }
 }  // namespace browser
 
-LoginManagerView::LoginManagerView() {
+LoginManagerView::LoginManagerView(const FilePath& pipe_name)
+      : pipe_(fopen(pipe_name.value().c_str(), "w")) {
   Init();
 }
 
 LoginManagerView::~LoginManagerView() {
+  if (pipe_)
+    fclose(pipe_);
   MessageLoop::current()->Quit();
 }
 
@@ -189,6 +192,7 @@ void LoginManagerView::BuildWindow() {
   }
 
   layout->AddPaddingRow(1, 0);
+  EmitLoginPromptReady();
 }
 
 views::View* LoginManagerView::GetContentsView() {
@@ -212,18 +216,23 @@ bool LoginManagerView::Authenticate(const std::string& username,
          child_exit_code == 0;
 }
 
-bool LoginManagerView::RunWindowManager(const std::string& username) {
-  base::ProcessHandle handle;
-  std::vector<std::string> argv;
-  // TODO(cmasone): we'll want this to be configurable.
-  argv.push_back("/etc/init.d/start_wm.sh");
-  base::environment_vector env;
+bool LoginManagerView::Send(IpcMessage outgoing) {
+  if (pipe_) {
+    if (fwrite(&outgoing, sizeof(IpcMessage), 1, pipe_) == 1) {
+      // since we're only writing 1 "member", fwrite will return 1 on success
+      // and 0 on failure.  On success, we want to flush the buffer.
+      return fflush(pipe_) != EOF;
+    }
+  }
+  return false;
+}
 
-  // TODO(cmasone): This is a legacy way of communication the logged in user's
-  //                email to xscreensaver.  Figure out a better way.
-  env.push_back(std::pair<std::string, std::string>("CHROMEOS_USER", username));
-  base::file_handle_mapping_vector no_files;
-  return base::LaunchApp(argv, env, no_files, false, &handle);
+bool LoginManagerView::EmitLoginPromptReady() {
+  return Send(EMIT_LOGIN);
+}
+
+bool LoginManagerView::RunWindowManager(const std::string& username) {
+  return Send(START_SESSION);
 }
 
 void LoginManagerView::SetupSession(const std::string& username) {
@@ -270,5 +279,3 @@ bool LoginManagerView::HandleKeystroke(views::Textfield* s,
   // Return false so that processing does not end
   return false;
 }
-
-
diff --git a/chrome/browser/chromeos/login_manager_view.h b/chrome/browser/chromeos/login_manager_view.h
index 2ac687b..b6c8b52 100644
--- a/chrome/browser/chromeos/login_manager_view.h
+++ b/chrome/browser/chromeos/login_manager_view.h
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include <string>
+#include "chrome/browser/chromeos/ipc_message.h"
 #include "views/accelerator.h"
 #include "views/controls/textfield/textfield.h"
 #include "views/view.h"
@@ -12,11 +13,13 @@
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_MANAGER_VIEW_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_MANAGER_VIEW_H_
 
+class FilePath;
+
 class LoginManagerView : public views::View,
                          public views::WindowDelegate,
                          public views::Textfield::Controller {
  public:
-  LoginManagerView();
+  LoginManagerView(const FilePath& pipe_name);
   virtual ~LoginManagerView();
 
   // Initialize the controls on the dialog.
@@ -39,6 +42,8 @@ class LoginManagerView : public views::View,
 
   // Creates all examples and start UI event loop.
  private:
+  FILE* pipe_;
+
   views::Textfield* username_field_;
   views::Textfield* password_field_;
 
@@ -57,6 +62,11 @@ class LoginManagerView : public views::View,
   bool Authenticate(const std::string& username,
                     const std::string& password);
 
+  bool Send(IpcMessage outgoing);
+
+  // Asynchronously emits the login-prompt-ready upstart signal.
+  bool EmitLoginPromptReady();
+
   // Asynchronously launches the Chrome OS window manager.
   bool RunWindowManager(const std::string& username);
 
@@ -72,4 +82,3 @@ class LoginManagerView : public views::View,
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_MANAGER_VIEW_H_
-