[Chromoting] The daemon process now starts the networking process and passes the host configuration…

remoting/host/daemon_process_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/daemon_process.h"
 
+#include "base/base_switches.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/logging.h"
+#include "base/path_service.h"
 #include "base/single_thread_task_runner.h"
+#include "base/time.h"
+#include "base/timer.h"
+#include "base/utf_string_conversions.h"
 #include "base/win/scoped_handle.h"
+#include "remoting/host/constants.h"
+#include "remoting/host/win/launch_process_with_token.h"
+#include "remoting/host/win/worker_process_launcher.h"
+
+using base::win::ScopedHandle;
+using base::TimeDelta;
+
+namespace {
+
+// The minimum and maximum delays between attempts to launch the networking
+// process.
+const int kMaxLaunchDelaySeconds = 60;
+const int kMinLaunchDelaySeconds = 1;
+
+const FilePath::CharType kMe2meHostBinaryName[] =
+    FILE_PATH_LITERAL("remoting_me2me_host.exe");
+
+// The IPC channel name is passed to the networking process in the command line.
+const char kDaemonPipeSwitchName[] = "daemon-pipe";
+
+// The command line parameters that should be copied from the service's command
+// line to the network process.
+const char* kCopiedSwitchNames[] = {
+    "host-config", switches::kV, switches::kVModule };
+
+// The security descriptor of the daemon IPC endpoint. It gives full access
+// to LocalSystem and denies access by anyone else.
+const char kDaemonPipeSecurityDescriptor[] = "O:SYG:SYD:(A;;GA;;;SY)";
+
+} // namespace
 
 namespace remoting {
 
-class DaemonProcessWin : public DaemonProcess {
+class DaemonProcessWin : public DaemonProcess,
+                         public WorkerProcessLauncher::Delegate {
  public:
   DaemonProcessWin(scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
                    scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
                    const base::Closure& stopped_callback);
   virtual ~DaemonProcessWin();
 
+  virtual void OnChannelConnected() OVERRIDE;
+
+  // Sends an IPC message to the worker process. This method can be called only
+  // after successful Start() and until Stop() is called or an error occurred.
+  virtual void Send(IPC::Message* message) OVERRIDE;
+
+  // WorkerProcessLauncher::Delegate implementation.
+  virtual bool DoLaunchProcess(
+      const std::string& channel_name,
+      ScopedHandle* process_exit_event_out) OVERRIDE;
+  virtual void DoKillProcess(DWORD exit_code) OVERRIDE;
+
+ protected:
+  // Stoppable implementation.
+  virtual void DoStop() OVERRIDE;
+
   // DaemonProcess implementation.
-  virtual bool LaunchNetworkProcess() OVERRIDE;
+  virtual void LaunchNetworkProcess() OVERRIDE;
 
  private:
+  // Called when the launcher reports the worker process has stopped.
+  void OnLauncherStopped();
+
+  // True if the network process is connected to the daemon.
+  bool connected_;
+
+  // Time of the last launch attempt.
+  base::Time launch_time_;
+
+  // Current backoff delay.
+  base::TimeDelta launch_backoff_;
+
+  // Timer used to schedule the next attempt to launch the process.
+  base::OneShotTimer<DaemonProcessWin> timer_;
+
+  scoped_ptr<WorkerProcessLauncher> launcher_;
+
+  ScopedHandle network_process_;
+
   DISALLOW_COPY_AND_ASSIGN(DaemonProcessWin);
 };
 
 DaemonProcessWin::DaemonProcessWin(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
     const base::Closure& stopped_callback)
-    : DaemonProcess(main_task_runner, io_task_runner, stopped_callback) {
+    : DaemonProcess(main_task_runner, io_task_runner, stopped_callback),
+      connected_(false) {
 }
 
 DaemonProcessWin::~DaemonProcessWin() {
+  // Make sure that the object is completely stopped. The same check exists
+  // in Stoppable::~Stoppable() but this one allows us to examine the state of
+  // the object before destruction.
+  CHECK_EQ(stoppable_state(), Stoppable::kStopped);
 }
 
-bool DaemonProcessWin::LaunchNetworkProcess() {
-  NOTIMPLEMENTED();
-  return false;
+void DaemonProcessWin::LaunchNetworkProcess() {
+  DCHECK(main_task_runner()->BelongsToCurrentThread());
+  DCHECK(launcher_.get() == NULL);
+  DCHECK(!network_process_.IsValid());
+  DCHECK(!timer_.IsRunning());
+
+  launch_time_ = base::Time::Now();
+  launcher_.reset(new WorkerProcessLauncher(
+      this, this,
+      base::Bind(&DaemonProcessWin::OnLauncherStopped, base::Unretained(this)),
+      main_task_runner(),
+      io_task_runner()));
+  launcher_->Start(kDaemonPipeSecurityDescriptor);
+}
+
+void DaemonProcessWin::OnChannelConnected() {
+  connected_ = true;
+  DaemonProcess::OnChannelConnected();
+}
+
+void DaemonProcessWin::Send(IPC::Message* message) {
+  if (connected_) {
+    launcher_->Send(message);
+  } else {
+    delete message;
+  }
+}
+
+bool DaemonProcessWin::DoLaunchProcess(
+    const std::string& channel_name,
+    ScopedHandle* process_exit_event_out) {
+  DCHECK(main_task_runner()->BelongsToCurrentThread());
+  DCHECK(!network_process_.IsValid());
+
+  // Construct the host binary name.
+  FilePath dir_path;
+  if (!PathService::Get(base::DIR_EXE, &dir_path)) {
+    LOG(ERROR) << "Failed to get the executable file name.";
+    return false;
+  }
+  FilePath host_binary = dir_path.Append(kMe2meHostBinaryName);
+
+  // Create the host process command line passing the name of the IPC channel
+  // to use and copying known switches from the service's command line.
+  CommandLine command_line(host_binary);
+  command_line.AppendSwitchNative(kDaemonPipeSwitchName,
+                                  UTF8ToWide(channel_name));
+  command_line.CopySwitchesFrom(*CommandLine::ForCurrentProcess(),
+                                kCopiedSwitchNames,
+                                _countof(kCopiedSwitchNames));
+
+  ScopedHandle token;
+  if (!OpenProcessToken(GetCurrentProcess(),
+                        MAXIMUM_ALLOWED,
+                        token.Receive())) {
+    LOG_GETLASTERROR(FATAL) << "Failed to open process token";
+    return false;
+  }
+
+  // Try to launch the process and attach an object watcher to the returned
+  // handle so that we get notified when the process terminates.
+  // TODO(alexeypa): Pass a restricted process token.
+  // See http://crbug.com/134694.
+  ScopedHandle worker_thread;
+  if (!LaunchProcessWithToken(host_binary,
+                              command_line.GetCommandLineString(),
+                              token,
+                              0,
+                              &network_process_,
+                              &worker_thread)) {
+    return false;
+  }
+
+  ScopedHandle process_exit_event;
+  if (!DuplicateHandle(GetCurrentProcess(),
+                       network_process_,
+                       GetCurrentProcess(),
+                       process_exit_event.Receive(),
+                       SYNCHRONIZE,
+                       FALSE,
+                       0)) {
+    LOG_GETLASTERROR(ERROR) << "Failed to duplicate a handle";
+    DoKillProcess(CONTROL_C_EXIT);
+    return false;
+  }
+
+  *process_exit_event_out = process_exit_event.Pass();
+  return true;
+}
+
+void DaemonProcessWin::DoKillProcess(DWORD exit_code) {
+  DCHECK(main_task_runner()->BelongsToCurrentThread());
+  CHECK(network_process_.IsValid());
+
+  TerminateProcess(network_process_, exit_code);
+}
+
+void DaemonProcessWin::DoStop() {
+  DCHECK(main_task_runner()->BelongsToCurrentThread());
+
+  launch_backoff_ = base::TimeDelta();
+  timer_.Stop();
+
+  if (launcher_.get() != NULL) {
+    launcher_->Stop();
+  }
+
+  // Early exit if we're still waiting for |launcher_| to stop.
+  if (launcher_.get() != NULL) {
+    return;
+  }
+
+  DaemonProcess::DoStop();
+}
+
+void DaemonProcessWin::OnLauncherStopped() {
+  DCHECK(main_task_runner()->BelongsToCurrentThread());
+  CHECK(network_process_.IsValid());
+
+  DWORD exit_code = CONTROL_C_EXIT;
+  if (!::GetExitCodeProcess(network_process_, &exit_code)) {
+    LOG_GETLASTERROR(INFO)
+        << "Failed to query the exit code of the worker process";
+    exit_code = CONTROL_C_EXIT;
+  }
+
+  network_process_.Close();
+  connected_ = false;
+  launcher_.reset(NULL);
+
+  // Do not relaunch the network process if the caller has asked us to stop.
+  if (stoppable_state() != Stoppable::kRunning) {
+    Stop();
+    return;
+  }
+
+  // Stop trying to restart the worker process if its process exited due to
+  // misconfiguration.
+  if (kMinPermanentErrorExitCode <= exit_code &&
+      exit_code <= kMaxPermanentErrorExitCode) {
+    Stop();
+    return;
+  }
+
+  // Expand the backoff interval if the process has died quickly or reset it
+  // if it was up longer than the maximum backoff delay.
+  base::TimeDelta delta = base::Time::Now() - launch_time_;
+  if (delta < base::TimeDelta() ||
+      delta >= base::TimeDelta::FromSeconds(kMaxLaunchDelaySeconds)) {
+    launch_backoff_ = base::TimeDelta();
+  } else {
+    launch_backoff_ = std::max(
+        launch_backoff_ * 2, TimeDelta::FromSeconds(kMinLaunchDelaySeconds));
+    launch_backoff_ = std::min(
+        launch_backoff_, TimeDelta::FromSeconds(kMaxLaunchDelaySeconds));
+  }
+
+  // Try to launch the worker process.
+  timer_.Start(FROM_HERE, launch_backoff_,
+               this, &DaemonProcessWin::LaunchNetworkProcess);
 }
 
 scoped_ptr<DaemonProcess> DaemonProcess::Create(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
     const base::Closure& stopped_callback) {
   scoped_ptr<DaemonProcessWin> daemon_process(
       new DaemonProcessWin(main_task_runner, io_task_runner, stopped_callback));
   return daemon_process.PassAs<DaemonProcess>();
 }
 
 }  // namespace remoting