// Copyright (c) 2009 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 "chrome/browser/utility_process_host.h"

#include "base/command_line.h"
#include "base/file_util.h"
#include "base/message_loop.h"
#include "base/path_service.h"
#include "base/process_util.h"
#include "base/string_util.h"
#include "base/task.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/render_messages.h"

#if defined(OS_WIN)
#include "chrome/browser/sandbox_policy.h"
#elif defined(OS_POSIX)
#include "base/global_descriptors_posix.h"
#include "chrome/common/chrome_descriptors.h"
#endif

UtilityProcessHost::UtilityProcessHost(ResourceDispatcherHost* rdh,
                                       Client* client,
                                       MessageLoop* client_loop)
    : ChildProcessHost(UTILITY_PROCESS, rdh),
      client_(client),
      client_loop_(client_loop) {
}

UtilityProcessHost::~UtilityProcessHost() {
}

bool UtilityProcessHost::StartExtensionUnpacker(const FilePath& extension) {
  // Grant the subprocess access to the entire subdir the extension file is
  // in, so that it can unpack to that dir.
  if (!StartProcess(extension.DirName()))
    return false;

  Send(new UtilityMsg_UnpackExtension(extension));
  return true;
}

bool UtilityProcessHost::StartWebResourceUnpacker(const std::string& data) {
  if (!StartProcess(FilePath()))
    return false;

  Send(new UtilityMsg_UnpackWebResource(data));
  return true;
}

std::wstring UtilityProcessHost::GetUtilityProcessCmd() {
  std::wstring exe_path = CommandLine::ForCurrentProcess()->GetSwitchValue(
      switches::kBrowserSubprocessPath);
  if (exe_path.empty()) {
    PathService::Get(base::FILE_EXE, &exe_path);
  }
  return exe_path;
}

bool UtilityProcessHost::StartProcess(const FilePath& exposed_dir) {
  // Name must be set or metrics_service will crash in any test which
  // launches a UtilityProcessHost.
  set_name(L"utility process");

  if (!CreateChannel())
    return false;

  std::wstring exe_path = GetUtilityProcessCmd();
  if (exe_path.empty()) {
    NOTREACHED() << "Unable to get utility process binary name.";
    return false;
  }

  CommandLine cmd_line(exe_path);
  cmd_line.AppendSwitchWithValue(switches::kProcessType,
                                 switches::kUtilityProcess);
  cmd_line.AppendSwitchWithValue(switches::kProcessChannelID,
                                 ASCIIToWide(channel_id()));

  base::ProcessHandle process;
#if defined(OS_WIN)
  if (!UseSandbox()) {
    // Don't use the sandbox during unit tests.
    base::LaunchApp(cmd_line, false, false, &process);
  } else if (exposed_dir.empty()) {
    process = sandbox::StartProcess(&cmd_line);
  } else {
    process = sandbox::StartProcessWithAccess(&cmd_line, exposed_dir);
  }
#else
  // TODO(port): Sandbox this on Linux/Mac.  Also, zygote this to work with
  // Linux updating.
  const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
  bool has_cmd_prefix = browser_command_line.HasSwitch(
      switches::kUtilityCmdPrefix);
  if (has_cmd_prefix) {
    // launch the utility child process with some prefix (usually "xterm -e gdb
    // --args").
    cmd_line.PrependWrapper(browser_command_line.GetSwitchValue(
        switches::kUtilityCmdPrefix));
  }

  // This code is duplicated with browser_render_process_host.cc and
  // plugin_process_host.cc, but there's not a good place to de-duplicate it.
  // Maybe we can merge this into sandbox::StartProcess which will set up
  // everything before calling LaunchApp?
  base::file_handle_mapping_vector fds_to_map;
  const int ipcfd = channel().GetClientFileDescriptor();
  if (ipcfd > -1)
    fds_to_map.push_back(std::pair<int, int>(
        ipcfd, kPrimaryIPCChannel + base::GlobalDescriptors::kBaseDescriptor));
  base::LaunchApp(cmd_line.argv(), fds_to_map, false, &process);
#endif
  if (!process)
    return false;
  SetHandle(process);

  return true;
}

void UtilityProcessHost::OnMessageReceived(const IPC::Message& message) {
  client_loop_->PostTask(FROM_HERE,
      NewRunnableMethod(client_.get(), &Client::OnMessageReceived, message));
}

void UtilityProcessHost::OnChannelError() {
  bool child_exited;
  bool did_crash = base::DidProcessCrash(&child_exited, handle());
  if (did_crash) {
    client_loop_->PostTask(FROM_HERE,
        NewRunnableMethod(client_.get(), &Client::OnProcessCrashed));
  }
}

void UtilityProcessHost::Client::OnMessageReceived(
    const IPC::Message& message) {
  IPC_BEGIN_MESSAGE_MAP(UtilityProcessHost, message)
    IPC_MESSAGE_HANDLER(UtilityHostMsg_UnpackExtension_Succeeded,
                        Client::OnUnpackExtensionSucceeded)
    IPC_MESSAGE_HANDLER(UtilityHostMsg_UnpackExtension_Failed,
                        Client::OnUnpackExtensionFailed)
    IPC_MESSAGE_HANDLER(UtilityHostMsg_UnpackWebResource_Succeeded,
                        Client::OnUnpackWebResourceSucceeded)
    IPC_MESSAGE_HANDLER(UtilityHostMsg_UnpackWebResource_Failed,
                        Client::OnUnpackWebResourceFailed)
  IPC_END_MESSAGE_MAP_EX()
}