[Chromoting] Adding uiAccess='true' to the remoting_me2me_host.exe's manifest as it is required to …

remoting/host/win/wts_session_process_launcher.cc

Index: remoting/host/win/wts_session_process_launcher.cc
diff --git a/remoting/host/win/wts_session_process_launcher.cc b/remoting/host/win/wts_session_process_launcher.cc
index e57d37c93e03cd573d8db8ddb0e28543c9353256..6c35aa2b860a608a237c1918ef72ad0849cd3448 100644
--- a/remoting/host/win/wts_session_process_launcher.cc
+++ b/remoting/host/win/wts_session_process_launcher.cc
@@ -47,9 +47,14 @@ const int kMinLaunchDelaySeconds = 1;
 const FilePath::CharType kMe2meHostBinaryName[] =
     FILE_PATH_LITERAL("remoting_me2me_host.exe");
 
+const FilePath::CharType kMe2meServiceBinaryName[] =
+    FILE_PATH_LITERAL("remoting_service.exe");
+
 // The IPC channel name is passed to the host in the command line.
 const char kChromotingIpcSwitchName[] = "chromoting-ipc";
 
+const char kElevateSwitchName[] = "elevate";
+
 // The command line parameters that should be copied from the service's command
 // line to the host process.
 const char* kCopiedSwitchNames[] = {
@@ -72,8 +77,17 @@ WtsSessionProcessLauncher::WtsSessionProcessLauncher(
       attached_(false),
       main_message_loop_(main_message_loop),
       ipc_message_loop_(ipc_message_loop),
-      monitor_(monitor) {
+      monitor_(monitor),
+      sandbox_state_(kSandboxUninitialized) {
   monitor_->AddWtsConsoleObserver(this);
+
+  process_exit_event_.Set(CreateEvent(NULL, TRUE, FALSE, NULL));
+  CHECK(process_exit_event_.IsValid());
+
+  // Sandbox initalization has to be performed on the I/O thread.
+  ipc_message_loop_->PostTask(FROM_HERE, base::Bind(
+      &WtsSessionProcessLauncher::InitializeSandbox,
+      base::Unretained(this)));
 }
 
 WtsSessionProcessLauncher::~WtsSessionProcessLauncher() {
@@ -103,19 +117,22 @@ void WtsSessionProcessLauncher::LaunchProcess() {
 void WtsSessionProcessLauncher::OnLauncherStopped() {
   DCHECK(main_message_loop_->BelongsToCurrentThread());
 
-  DWORD exit_code;
-  if (!::GetExitCodeProcess(worker_process_, &exit_code)) {
-    LOG_GETLASTERROR(INFO)
-        << "Failed to query the exit code of the worker process";
-    exit_code = CONTROL_C_EXIT;
+  DWORD exit_code = CONTROL_C_EXIT;
+  if (worker_process_.IsValid()) {
+    if (!::GetExitCodeProcess(worker_process_, &exit_code)) {
+      LOG_GETLASTERROR(INFO)
+          << "Failed to query the exit code of the worker process";
+      exit_code = CONTROL_C_EXIT;
+    }
+
+    worker_process_.Close();
   }
 
   launcher_.reset(NULL);
-  worker_process_.Close();
 
   // Do not relaunch the worker process if the caller has asked us to stop.
   if (stoppable_state() != Stoppable::kRunning) {
-    CompleteStopping();
+    Stop();
     return;
   }
 
@@ -148,12 +165,34 @@ void WtsSessionProcessLauncher::OnLauncherStopped() {
   }
 }
 
+void WtsSessionProcessLauncher::OnIOCompleted(
+    base::MessagePumpForIO::IOContext* context,
+    DWORD bytes_transfered,
+    DWORD error) {
+  DCHECK(ipc_message_loop_->BelongsToCurrentThread());
+
+  // |bytes_transfered| is repurposed by the job object notifications to be
+  // the message ID.
+  BOOL result;
+  switch (bytes_transfered) {
+    case JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO:
+      result = SetEvent(process_exit_event_);
+      CHECK(result);
+      break;
+  }
+}
+
 bool WtsSessionProcessLauncher::DoLaunchProcess(
     const std::string& channel_name,
     ScopedHandle* process_exit_event_out) {
   DCHECK(main_message_loop_->BelongsToCurrentThread());
   DCHECK(!worker_process_.IsValid());
 
+  // Wait until the sandbox is ready.
+  if (!job_.IsValid()) {
+    return false;
+  }
+
   // Construct the host binary name.
   FilePath dir_path;
   if (!PathService::Get(base::DIR_EXE, &dir_path)) {
@@ -161,28 +200,49 @@ bool WtsSessionProcessLauncher::DoLaunchProcess(
     return false;
   }
   FilePath host_binary = dir_path.Append(kMe2meHostBinaryName);
+  FilePath service_binary = dir_path.Append(kMe2meServiceBinaryName);
 
   // 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);
+  CommandLine command_line(service_binary);
+  command_line.AppendSwitchPath(kElevateSwitchName, host_binary);
   command_line.AppendSwitchNative(kChromotingIpcSwitchName,
                                   UTF8ToWide(channel_name));
   command_line.CopySwitchesFrom(*CommandLine::ForCurrentProcess(),
                                 kCopiedSwitchNames,
                                 _countof(kCopiedSwitchNames));
 
+  BOOL result = ResetEvent(process_exit_event_);
+  CHECK(result);
+
   // Try to launch the process and attach an object watcher to the returned
   // handle so that we get notified when the process terminates.
-  if (!LaunchProcessWithToken(host_binary,
+  base::win::ScopedHandle worker_process;
+  base::win::ScopedHandle worker_thread;
+  if (!LaunchProcessWithToken(service_binary,
                               command_line.GetCommandLineString(),
                               session_token_,
-                              &worker_process_)) {
+                              CREATE_SUSPENDED,
+                              &worker_process,
+                              &worker_thread)) {
+    return false;
+  }
+
+  if (!AssignProcessToJobObject(job_, worker_process)) {
+    LOG_GETLASTERROR(ERROR) << "Failed to assign the worker to the job object";
+    TerminateProcess(worker_process, CONTROL_C_EXIT);
+    return false;
+  }
+
+  if (!ResumeThread(worker_thread)) {
+    LOG_GETLASTERROR(ERROR) << "Failed to resume the worker thread";
+    DoKillProcess(CONTROL_C_EXIT);
     return false;
   }
 
   ScopedHandle process_exit_event;
   if (!DuplicateHandle(GetCurrentProcess(),
-                       worker_process_,
+                       process_exit_event_,
                        GetCurrentProcess(),
                        process_exit_event.Receive(),
                        SYNCHRONIZE,
@@ -200,21 +260,21 @@ bool WtsSessionProcessLauncher::DoLaunchProcess(
 void WtsSessionProcessLauncher::DoKillProcess(DWORD exit_code) {
   DCHECK(main_message_loop_->BelongsToCurrentThread());
 
-  if (worker_process_.IsValid()) {
-    TerminateProcess(worker_process_, exit_code);
+  if (job_.IsValid()) {
+    TerminateJobObject(job_, exit_code);
   }
 }
 
 void WtsSessionProcessLauncher::OnChannelConnected(DWORD peer_pid) {
   DCHECK(main_message_loop_->BelongsToCurrentThread());
 
-  DWORD expected_pid = GetProcessId(worker_process_);
-  if (peer_pid != expected_pid) {
-    LOG(ERROR)
-        << "Unexpected client connected: expected=" << expected_pid
-        << ", actual=" << peer_pid;
-    Stop();
-  }
+  // Nothing to validate. Only processes running as SYSTEM can connect to
+  // the pipe, so if it was a malicious process the game would be over already.
+
+  // Get a handle to the peer process so we could query its exit code later.
+  // Ignore the error. If the processes cannot be open the error code is generic
+  // |CONTROL_C_EXIT|.
+  worker_process_.Set(OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, peer_pid));
 }
 
 bool WtsSessionProcessLauncher::OnMessageReceived(const IPC::Message& message) {
@@ -284,8 +344,105 @@ void WtsSessionProcessLauncher::DoStop() {
     OnSessionDetached();
   }
 
-  if (launcher_.get() == NULL) {
-    CompleteStopping();
+  job_.Close();
+
+  // Drain the completion queue to make sure all job object notification have
+  // been received.
+  if (sandbox_state_ > kSandboxUninitialized) {
+    DCHECK_EQ(sandbox_state_, kSandboxRunning);
+    sandbox_state_ = kSandboxStopping;
+    ipc_message_loop_->PostTask(FROM_HERE, base::Bind(
+        &WtsSessionProcessLauncher::DrainSandboxNotifications,
+        base::Unretained(this)));
+  }
+
+  // Wait for |launcher_| to be completely stopped.
+  if (launcher_.get() != NULL) {
+    return;
+  }
+
+  // Wait for the completion queue to be drained.
+  if (sandbox_state_ != kSandboxUninitialized &&
+      sandbox_state_ != kSandboxStopped) {
+    return;
+  }
+
+  CompleteStopping();
+}
+
+void WtsSessionProcessLauncher::DrainSandboxNotifications() {
+  DCHECK(ipc_message_loop_->BelongsToCurrentThread());
+
+  // DrainSandboxNotifications() is posted after the job object is destroyed, so
+  // by this time all notifications from the job object have been processed
+  // already. Let the main thread know that the queue has been drained.
+  main_message_loop_->PostTask(FROM_HERE, base::Bind(
+      &WtsSessionProcessLauncher::DrainSandboxNotificationsCompleted,
+      base::Unretained(this)));
+}
+
+void WtsSessionProcessLauncher::DrainSandboxNotificationsCompleted() {
+  DCHECK(main_message_loop_->BelongsToCurrentThread());
+  DCHECK_EQ(sandbox_state_, kSandboxStopping);
+
+  sandbox_state_ = kSandboxStopped;
+  Stop();
+}
+
+void WtsSessionProcessLauncher::InitializeSandbox() {
+  DCHECK(ipc_message_loop_->BelongsToCurrentThread());
+
+  ScopedHandle job;
+  job.Set(CreateJobObject(NULL, NULL));
+  if (!job.IsValid()) {
+    LOG_GETLASTERROR(ERROR) << "Failed to create a job object";
+    return;
+  }
+
+  // Limit number of active processes in the job to two (the process performing
+  // elevation and the host) and make sure that all processes will be killed
+  // once the job object is destroyed.
+  JOBOBJECT_EXTENDED_LIMIT_INFORMATION info;
+  memset(&info, 0, sizeof(info));
+  info.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_ACTIVE_PROCESS |
+      JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
+  info.BasicLimitInformation.ActiveProcessLimit = 2;
+  if (!SetInformationJobObject(job,
+                               JobObjectExtendedLimitInformation,
+                               &info,
+                               sizeof(info))) {
+    LOG_GETLASTERROR(ERROR) << "Failed to set limits on the job object";
+    return;
+  }
+
+  // Register the job object with the completion port in the I/O thread to
+  // receive job notifications.
+  if (!MessageLoopForIO::current()->RegisterJobObject(job, this)) {
+    LOG_GETLASTERROR(ERROR)
+        << "Failed to associate the job object with a completion port";
+    return;
+  }
+
+  // ScopedHandle is not compatible with base::Passed, so we wrap it to a scoped
+  // pointer.
+  scoped_ptr<ScopedHandle> job_wrapper(new ScopedHandle());
+  *job_wrapper = job.Pass();
+
+  // Let the main thread know that initialization is complete.
+  main_message_loop_->PostTask(FROM_HERE, base::Bind(
+      &WtsSessionProcessLauncher::InitializeSandboxCompleted,
+      base::Unretained(this), base::Passed(&job_wrapper)));
+}
+
+void WtsSessionProcessLauncher::InitializeSandboxCompleted(
+    scoped_ptr<ScopedHandle> job) {
+  DCHECK(main_message_loop_->BelongsToCurrentThread());
+  DCHECK(!job_.IsValid());
+  DCHECK_EQ(sandbox_state_, kSandboxUninitialized);
+
+  if (stoppable_state() == Stoppable::kRunning) {
+    job_ = job->Pass();
+    sandbox_state_ = kSandboxRunning;
   }
 }