Unifying ChildProcessLauncher across platforms.

content/browser/child_process_launcher_mac.cc

+// Copyright 2016 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 "base/memory/ptr_util.h"
+#include "base/posix/global_descriptors.h"
+#include "content/browser/bootstrap_sandbox_manager_mac.h"
+#include "content/browser/child_process_launcher.h"
+#include "content/browser/child_process_launcher_posix.h"
+#include "content/browser/mach_broker_mac.h"
+#include "content/public/common/result_codes.h"
+#include "content/public/common/sandboxed_process_launcher_delegate.h"
+#include "mojo/edk/embedder/scoped_platform_handle.h"
+#include "sandbox/mac/bootstrap_sandbox.h"
+#include "sandbox/mac/pre_exec_delegate.h"
+
+namespace content {
+
+mojo::edk::ScopedPlatformHandle
+ChildProcessLauncher::Helper::PrepareMojoPipeHandlesOnClientThread() {
+  DCHECK_CURRENTLY_ON(client_thread_id_);
+  return mojo::edk::ScopedPlatformHandle();
+}
+
+void ChildProcessLauncher::Helper::BeforeLaunchOnClientThread() {
+  DCHECK_CURRENTLY_ON(client_thread_id_);
+}
+
+bool ChildProcessLauncher::Helper::ShouldForkAsZygote() {
+  return false;
+}
+
+ZygoteHandle ChildProcessLauncher::Helper::ForkAsZygote(
+    std::unique_ptr<FileMappedForLaunch> files_to_register,
+    base::Process* process) {
+  NOTREACHED();
+  return nullptr;
+}
+
+std::unique_ptr<FileDescriptorInfo>
+ChildProcessLauncher::Helper::GetFilesToMap() {
+  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
+  return CreateDefaultPosixFilesToMap(*command_line(), child_process_id(),
+                                      mojo_client_handle());
+}
+
+void ChildProcessLauncher::Helper::BeforeLaunchOnLauncherThread(
+    const FileMappedForLaunch& files_to_register,
+    base::LaunchOptions* options) {
+  // Convert FD mapping to FileHandleMappingVector.
+  std::unique_ptr<base::FileHandleMappingVector> fds_to_map =
+      files_to_register.GetMappingWithIDAdjustment(
+          base::GlobalDescriptors::kBaseDescriptor);
+
+  options->environ = delegate_->GetEnvironment();
+  // fds_to_remap will de deleted in AfterLaunchOnLauncherThread() below.
+  options->fds_to_remap = fds_to_map.release();
+
+  // Hold the MachBroker lock for the duration of LaunchProcess. The child will
+  // send its task port to the parent almost immediately after startup. The Mach
+  // message will be delivered to the parent, but updating the record of the
+  // launch will wait until after the placeholder PID is inserted below. This
+  // ensures that while the child process may send its port to the parent prior
+  // to the parent leaving LaunchProcess, the order in which the record in
+  // MachBroker is updated is correct.
+  MachBroker* broker = MachBroker::GetInstance();
+  broker->GetLock().Acquire();
+
+  // Make sure the MachBroker is running, and inform it to expect a check-in
+  // from the new process.
+  broker->EnsureRunning();
+
+  const SandboxType sandbox_type = delegate_->GetSandboxType();
+  std::unique_ptr<sandbox::PreExecDelegate> pre_exec_delegate;
+  if (BootstrapSandboxManager::ShouldEnable()) {
+    BootstrapSandboxManager* sandbox_manager =
+        BootstrapSandboxManager::GetInstance();
+    if (sandbox_manager->EnabledForSandbox(sandbox_type)) {
+      pre_exec_delegate = sandbox_manager->sandbox()->NewClient(sandbox_type);
+    }
+  }
+  // options now owns the pre_exec_delegate which will be delete on
+  // AfterLaunchOnLauncherThread below.
+  options->pre_exec_delegate = pre_exec_delegate.release();
+}
+
+base::Process ChildProcessLauncher::Helper::LaunchProcessOnLauncherThread(
+    const base::LaunchOptions& options,
+    FileDescriptorInfo* files_to_register,
+    bool* is_synchronous_launch,
+    int* launch_result) {
+  *is_synchronous_launch = true;
+  base::Process process = base::LaunchProcess(*command_line(), options);
+  *launch_result = process.IsValid() ? LAUNCH_RESULT_SUCCESS
+                                     : LAUNCH_RESULT_FAILURE;
+  return process;
+}
+
+void ChildProcessLauncher::Helper::AfterLaunchOnLauncherThread(
+    const base::Process& process,
+    const base::LaunchOptions& options) {
+  delete options.fds_to_remap;
+
+  std::unique_ptr<sandbox::PreExecDelegate> pre_exec_delegate =
+    base::WrapUnique(static_cast<sandbox::PreExecDelegate*>(
+        options.pre_exec_delegate));
+
+  MachBroker* broker = MachBroker::GetInstance();
+  if (process.IsValid()) {
+    broker->AddPlaceholderForPid(process.Pid(), child_process_id());
+  } else {
+    if (pre_exec_delegate) {
+      BootstrapSandboxManager::GetInstance()->sandbox()->RevokeToken(
+          pre_exec_delegate->sandbox_token());
+    }
+  }
+
+  // After updating the broker, release the lock and let the child's message be
+  // processed on the broker's thread.
+  broker->GetLock().Release();
+}
+
+void ChildProcessLauncher::UpdateTerminationStatus(bool known_dead) {
+  DCHECK(CalledOnValidThread());
+  if (known_dead) {
+    termination_status_ =
+        base::GetKnownDeadTerminationStatus(process_.Handle(), &exit_code_);
+  } else {
+    termination_status_ =
+      base::GetTerminationStatus(process_.Handle(), &exit_code_);
+  }
+}
+
+// static
+bool ChildProcessLauncher::TerminateProcess(
+    const base::Process& process, int exit_code, bool wait) {
+  return process.Terminate(exit_code, wait);
+}
+
+// static
+void ChildProcessLauncher::TerminateOnLauncherThread(
+    ZygoteHandle zygote, base::Process process) {
+  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
+  // Client has gone away, so just kill the process.  Using exit code 0 means
+  // that UMA won't treat this as a crash.
+  process.Terminate(RESULT_CODE_NORMAL_EXIT, false);
+  base::EnsureProcessTerminated(std::move(process));
+}
+
+// static
+void ChildProcessLauncher::SetProcessBackgroundedOnLauncherThread(
+      base::Process process, bool background) {
+  if (process.CanBackgroundProcesses())
+    process.SetProcessBackgrounded(MachBroker::GetInstance(), background);
+}
+
+}  // namespace content