/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>

#include <algorithm>
#include <functional>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <memory>
#include <sstream>
#include <string>
#include <thread>
#include <vector>

#include <gflags/gflags.h>
#include <glog/logging.h>

#include "common/libs/fs/shared_fd.h"
#include "common/libs/fs/shared_select.h"
#include "common/libs/strings/str_split.h"
#include "common/libs/utils/environment.h"
#include "common/libs/utils/files.h"
#include "common/libs/utils/subprocess.h"
#include "common/libs/utils/size_utils.h"
#include "common/vsoc/lib/vsoc_memory.h"
#include "common/vsoc/shm/screen_layout.h"
#include "host/commands/launch/boot_image_unpacker.h"
#include "host/commands/launch/data_image.h"
#include "host/commands/launch/launch.h"
#include "host/commands/launch/launcher_defs.h"
#include "host/commands/launch/pre_launch_initializers.h"
#include "host/commands/launch/process_monitor.h"
#include "host/commands/launch/vsoc_shared_memory.h"
#include "host/libs/config/cuttlefish_config.h"
#include "host/commands/kernel_log_monitor/kernel_log_server.h"
#include "host/libs/vm_manager/vm_manager.h"
#include "host/libs/vm_manager/qemu_manager.h"

using vsoc::GetPerInstanceDefault;
using cvd::LauncherExitCodes;

DEFINE_string(
    system_image, "",
    "Path to the system image, if empty it is assumed to be a file named "
    "system.img in the directory specified by -system_image_dir");
DEFINE_string(cache_image, "", "Location of the cache partition image.");
DEFINE_int32(cpus, 2, "Virtual CPU count.");
DEFINE_string(data_image, "", "Location of the data partition image.");
DEFINE_string(data_policy, "use_existing", "How to handle userdata partition."
            " Either 'use_existing', 'create_if_missing', 'resize_up_to', or "
            "'always_create'.");
DEFINE_int32(blank_data_image_mb, 0,
             "The size of the blank data image to generate, MB.");
DEFINE_string(blank_data_image_fmt, "ext4",
              "The fs format for the blank data image. Used with mkfs.");
DEFINE_string(qemu_gdb, "",
              "Debug flag to pass to qemu. e.g. --qemu_gdb=tcp::1234");

DEFINE_int32(x_res, 720, "Width of the screen in pixels");
DEFINE_int32(y_res, 1280, "Height of the screen in pixels");
DEFINE_int32(dpi, 160, "Pixels per inch for the screen");
DEFINE_int32(refresh_rate_hz, 60, "Screen refresh rate in Hertz");
DEFINE_int32(num_screen_buffers, 3, "The number of screen buffers");
DEFINE_string(kernel_path, "",
              "Path to the kernel. Overrides the one from the boot image");
DEFINE_string(extra_kernel_cmdline, "",
              "Additional flags to put on the kernel command line");
DEFINE_int32(loop_max_part, 7, "Maximum number of loop partitions");
DEFINE_string(console, "ttyS0", "Console device for the guest kernel.");
DEFINE_string(androidboot_console, "ttyS1",
              "Console device for the Android framework");
DEFINE_string(hardware_name, "vsoc",
              "The codename of the device's hardware");
DEFINE_string(guest_security, "selinux",
              "The security module to use in the guest");
DEFINE_bool(guest_enforce_security, false,
            "Whether to run in enforcing mode (non permissive). Ignored if "
            "-guest_security is empty.");
DEFINE_bool(guest_audit_security, true,
            "Whether to log security audits.");
DEFINE_string(boot_image, "", "Location of cuttlefish boot image.");
DEFINE_int32(memory_mb, 2048,
             "Total amount of memory available for guest, MB.");
std::string g_default_mempath{vsoc::GetDefaultMempath()};
DEFINE_string(mempath, g_default_mempath.c_str(),
              "Target location for the shmem file.");
DEFINE_string(mobile_interface, "", // default handled on ParseCommandLine
              "Network interface to use for mobile networking");
DEFINE_string(mobile_tap_name, "", // default handled on ParseCommandLine
              "The name of the tap interface to use for mobile");
std::string g_default_serial_number{GetPerInstanceDefault("CUTTLEFISHCVD")};
DEFINE_string(serial_number, g_default_serial_number.c_str(),
              "Serial number to use for the device");
DEFINE_string(instance_dir, "", // default handled on ParseCommandLine
              "A directory to put all instance specific files");
DEFINE_string(
    vm_manager, vm_manager::QemuManager::name(),
    "What virtual machine manager to use, one of {qemu_cli}");
DEFINE_string(system_image_dir, vsoc::DefaultGuestImagePath(""),
              "Location of the system partition images.");
DEFINE_string(vendor_image, "", "Location of the vendor partition image.");

DEFINE_bool(deprecated_boot_completed, false, "Log boot completed message to"
            " host kernel. This is only used during transition of our clients."
            " Will be deprecated soon.");
DEFINE_bool(start_vnc_server, true, "Whether to start the vnc server process.");
DEFINE_string(vnc_server_binary,
              vsoc::DefaultHostArtifactsPath("bin/vnc_server"),
              "Location of the vnc server binary.");
DEFINE_bool(start_stream_audio, true,
            "Whether to start the stream audio process.");
DEFINE_string(stream_audio_binary,
              vsoc::DefaultHostArtifactsPath("bin/stream_audio"),
              "Location of the stream_audio binary.");
DEFINE_string(virtual_usb_manager_binary,
              vsoc::DefaultHostArtifactsPath("bin/virtual_usb_manager"),
              "Location of the virtual usb manager binary.");
DEFINE_string(kernel_log_monitor_binary,
              vsoc::DefaultHostArtifactsPath("bin/kernel_log_monitor"),
              "Location of the log monitor binary.");
DEFINE_string(ivserver_binary,
              vsoc::DefaultHostArtifactsPath("bin/ivserver"),
              "Location of the ivshmem server binary.");
DEFINE_int32(vnc_server_port, GetPerInstanceDefault(6444),
             "The port on which the vnc server should listen");
DEFINE_int32(stream_audio_port, GetPerInstanceDefault(7444),
             "The port on which stream_audio should listen.");
DEFINE_string(socket_forward_proxy_binary,
              vsoc::DefaultHostArtifactsPath("bin/socket_forward_proxy"),
              "Location of the socket_forward_proxy binary.");
DEFINE_string(socket_vsock_proxy_binary,
              vsoc::DefaultHostArtifactsPath("bin/socket_vsock_proxy"),
              "Location of the socket_vsock_proxy binary.");
DEFINE_string(adb_mode, "tunnel",
              "Mode for adb connection. Can be 'usb' for usb forwarding, "
              "'tunnel' for tcp connection, 'vsock_tunnel' for vsock tcp,"
              "or a comma separated list of types as in 'usb,tunnel'");
DEFINE_bool(run_adb_connector, true,
            "Maintain adb connection by sending 'adb connect' commands to the "
            "server. Only relevant with --adb_mode=tunnel or vsock_tunnel");
DEFINE_string(adb_connector_binary,
              vsoc::DefaultHostArtifactsPath("bin/adb_connector"),
              "Location of the adb_connector binary. Only relevant if "
              "--run_adb_connector is true");
DEFINE_int32(vhci_port, GetPerInstanceDefault(0), "VHCI port to use for usb");
DEFINE_string(guest_mac_address,
              GetPerInstanceDefault("00:43:56:44:80:"), // 00:43:56:44:80:0x
              "MAC address of the wifi interface to be created on the guest.");
DEFINE_string(host_mac_address,
              "42:00:00:00:00:00",
              "MAC address of the wifi interface running on the host.");
DEFINE_string(wifi_interface, "", // default handled on ParseCommandLine
              "Network interface to use for wifi");
DEFINE_string(wifi_tap_name, "", // default handled on ParseCommandLine
              "The name of the tap interface to use for wifi");
DEFINE_int32(vsock_guest_cid,
             vsoc::GetDefaultPerInstanceVsockCid(),
             "Guest identifier for vsock. Disabled if under 3.");

// TODO(b/72969289) This should be generated
DEFINE_string(dtb, "", "Path to the cuttlefish.dtb file");

DEFINE_string(uuid, vsoc::GetPerInstanceDefault(vsoc::kDefaultUuidPrefix),
              "UUID to use for the device. Random if not specified");
DEFINE_bool(daemon, false,
            "Run cuttlefish in background, the launcher exits on boot "
            "completed/failed");

DEFINE_string(device_title, "", "Human readable name for the instance, "
              "used by the vnc_server for its server title");
DEFINE_string(setupwizard_mode, "DISABLED",
            "One of DISABLED,OPTIONAL,REQUIRED");

DEFINE_string(qemu_binary,
              "/usr/bin/qemu-system-x86_64",
              "The qemu binary to use");
DEFINE_bool(restart_subprocesses, true, "Restart any crashed host process");
DEFINE_bool(run_e2e_test, true, "Run e2e test after device launches");
DEFINE_string(e2e_test_binary,
              vsoc::DefaultHostArtifactsPath("bin/host_region_e2e_test"),
              "Location of the region end to end test binary");

namespace {

std::string GetConfigFilePath(const vsoc::CuttlefishConfig& config) {
  return config.PerInstancePath("cuttlefish_config.json");
}

cvd::OnSocketReadyCb GetOnSubprocessExitCallback(
    const vsoc::CuttlefishConfig& config) {
  if (config.restart_subprocesses()) {
    return cvd::ProcessMonitor::RestartOnExitCb;
  } else {
    return cvd::ProcessMonitor::DoNotMonitorCb;
  }
}

// Maintains the state of the boot process, once a final state is reached
// (success or failure) it sends the appropriate exit code to the foreground
// launcher process
class CvdBootStateMachine {
 public:
  CvdBootStateMachine(cvd::SharedFD fg_launcher_pipe)
      : fg_launcher_pipe_(fg_launcher_pipe), state_(kBootStarted) {}

  // Returns true if the machine is left in a final state
  bool OnBootEvtReceived(cvd::SharedFD boot_events_pipe) {
    monitor::BootEvent evt;
    auto bytes_read = boot_events_pipe->Read(&evt, sizeof(evt));
    if (bytes_read != sizeof(evt)) {
      LOG(ERROR) << "Fail to read a complete event, read " << bytes_read
                 << " bytes only instead of the expected " << sizeof(evt);
      state_ |= kGuestBootFailed;
    } else if (evt == monitor::BootEvent::BootCompleted) {
      LOG(INFO) << "Virtual device booted successfully";
      state_ |= kGuestBootCompleted;
    } else if (evt == monitor::BootEvent::BootFailed) {
      LOG(ERROR) << "Virtual device failed to boot";
      state_ |= kGuestBootFailed;
    }  // Ignore the other signals

    return MaybeWriteToForegroundLauncher();
  }

  bool  OnE2eTestCompleted(int exit_code) {
    if (exit_code != 0) {
      LOG(ERROR) << "VSoC e2e test failed";
      state_ |= kE2eTestFailed;
    } else {
      LOG(INFO) << "VSoC e2e test passed";
      state_ |= kE2eTestPassed;
    }
    return MaybeWriteToForegroundLauncher();
  }

  bool BootCompleted() const {
    return state_ == (kGuestBootCompleted | kE2eTestPassed);
  }

  bool BootFailed() const {
    return state_ & (kGuestBootFailed | kE2eTestFailed);
  }

 private:
  void SendExitCode(cvd::LauncherExitCodes exit_code) {
    fg_launcher_pipe_->Write(&exit_code, sizeof(exit_code));
    // The foreground process will exit after receiving the exit code, if we try
    // to write again we'll get a SIGPIPE
    fg_launcher_pipe_->Close();
  }
  bool MaybeWriteToForegroundLauncher() {
    if (fg_launcher_pipe_->IsOpen()) {
      if (BootCompleted()) {
        SendExitCode(cvd::LauncherExitCodes::kSuccess);
      } else if (state_ & kGuestBootFailed) {
        SendExitCode(cvd::LauncherExitCodes::kVirtualDeviceBootFailed);
      } else if (state_ & kE2eTestFailed) {
        SendExitCode(cvd::LauncherExitCodes::kE2eTestFailed);
      } else {
        // No final state was reached
        return false;
      }
    }
    // Either we sent the code before or just sent it, in any case the state is
    // final
    return true;
  }

  cvd::SharedFD fg_launcher_pipe_;
  int state_;
  static const int kBootStarted = 0;
  static const int kGuestBootCompleted = 1 << 0;
  static const int kGuestBootFailed = 1 << 1;
  static const int kE2eTestPassed = 1 << 2;
  static const int kE2eTestFailed = 1 << 3;
};

// Abuse the process monitor to make it call us back when boot events are ready
void SetUpHandlingOfBootEvents(
    cvd::ProcessMonitor* process_monitor, cvd::SharedFD boot_events_pipe,
    std::shared_ptr<CvdBootStateMachine> state_machine) {
  process_monitor->MonitorExistingSubprocess(
      // A dummy command, so logs are desciptive
      cvd::Command("boot_events_listener"),
      // A dummy subprocess, with the boot events pipe as control socket
      cvd::Subprocess(-1, boot_events_pipe),
      [boot_events_pipe, state_machine](cvd::MonitorEntry*) {
        auto sent_code = state_machine->OnBootEvtReceived(boot_events_pipe);
        return !sent_code;
      });
}

void LaunchE2eTest(cvd::ProcessMonitor* process_monitor,
                   std::shared_ptr<CvdBootStateMachine> state_machine,
                   const vsoc::CuttlefishConfig& config) {
  // Run a command that always succeeds if we are not running e2e tests
  std::string e2e_test_cmd =
      config.run_e2e_test() ? config.e2e_test_binary() : "/bin/true";
  process_monitor->StartSubprocess(
      cvd::Command(e2e_test_cmd),
      [state_machine](cvd::MonitorEntry* entry) {
        auto test_result = entry->proc->Wait();
        state_machine->OnE2eTestCompleted(test_result);
        return false;
      });
}

bool ResolveInstanceFiles() {
  if (FLAGS_system_image_dir.empty()) {
    LOG(ERROR) << "--system_image_dir must be specified.";
    return false;
  }

  // If user did not specify location of either of these files, expect them to
  // be placed in --system_image_dir location.
  std::string default_system_image = FLAGS_system_image_dir + "/system.img";
  SetCommandLineOptionWithMode("system_image", default_system_image.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  std::string default_boot_image = FLAGS_system_image_dir + "/boot.img";
  SetCommandLineOptionWithMode("boot_image", default_boot_image.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  std::string default_cache_image = FLAGS_system_image_dir + "/cache.img";
  SetCommandLineOptionWithMode("cache_image", default_cache_image.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  std::string default_data_image = FLAGS_system_image_dir + "/userdata.img";
  SetCommandLineOptionWithMode("data_image", default_data_image.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  std::string default_vendor_image = FLAGS_system_image_dir + "/vendor.img";
  SetCommandLineOptionWithMode("vendor_image", default_vendor_image.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);

  // Create data if necessary
  if (!ApplyDataImagePolicy(FLAGS_data_image.c_str(),
                            FLAGS_data_policy,
                            FLAGS_blank_data_image_mb,
                            FLAGS_blank_data_image_fmt)) {
    return false;
  }

  // Check that the files exist
  for (const auto& file :
       {FLAGS_system_image, FLAGS_vendor_image, FLAGS_cache_image,
        FLAGS_data_image, FLAGS_boot_image}) {
    if (!cvd::FileHasContent(file.c_str())) {
      LOG(ERROR) << "File not found: " << file;
      return false;
    }
  }
  return true;
}

template<typename S, typename T>
static std::string concat(const S& s, const T& t) {
  std::ostringstream os;
  os << s << t;
  return os.str();
}

std::string GetCuttlefishEnvPath() {
  return cvd::StringFromEnv("HOME", ".") + "/.cuttlefish.sh";
}

// Initializes the config object and saves it to file. It doesn't return it, all
// further uses of the config should happen through the singleton
bool InitializeCuttlefishConfiguration(
    const cvd::BootImageUnpacker& boot_image_unpacker) {
  vsoc::CuttlefishConfig tmp_config_obj;
  auto& memory_layout = *vsoc::VSoCMemoryLayout::Get();
  // Set this first so that calls to PerInstancePath below are correct
  tmp_config_obj.set_instance_dir(FLAGS_instance_dir);
  if (!vm_manager::VmManager::IsValidName(FLAGS_vm_manager)) {
    LOG(ERROR) << "Invalid vm_manager: " << FLAGS_vm_manager;
    return false;
  }
  tmp_config_obj.set_vm_manager(FLAGS_vm_manager);

  tmp_config_obj.set_serial_number(FLAGS_serial_number);

  tmp_config_obj.set_cpus(FLAGS_cpus);
  tmp_config_obj.set_memory_mb(FLAGS_memory_mb);

  tmp_config_obj.set_dpi(FLAGS_dpi);
  tmp_config_obj.set_setupwizard_mode(FLAGS_setupwizard_mode);
  tmp_config_obj.set_x_res(FLAGS_x_res);
  tmp_config_obj.set_y_res(FLAGS_y_res);
  tmp_config_obj.set_num_screen_buffers(FLAGS_num_screen_buffers);
  tmp_config_obj.set_refresh_rate_hz(FLAGS_refresh_rate_hz);
  tmp_config_obj.set_gdb_flag(FLAGS_qemu_gdb);
  tmp_config_obj.set_adb_mode(FLAGS_adb_mode);
  tmp_config_obj.set_adb_ip_and_port("127.0.0.1:" + std::to_string(GetHostPort()));

  tmp_config_obj.set_device_title(FLAGS_device_title);
  if (FLAGS_kernel_path.size()) {
    tmp_config_obj.set_kernel_image_path(FLAGS_kernel_path);
    tmp_config_obj.set_use_unpacked_kernel(false);
  } else {
    tmp_config_obj.set_kernel_image_path(
        tmp_config_obj.PerInstancePath("kernel"));
    tmp_config_obj.set_use_unpacked_kernel(true);
  }

  auto ramdisk_path = tmp_config_obj.PerInstancePath("ramdisk.img");
  bool use_ramdisk = boot_image_unpacker.HasRamdiskImage();
  if (!use_ramdisk) {
    LOG(INFO) << "No ramdisk present; assuming system-as-root build";
    ramdisk_path = "";
  }

  // This needs to be done here because the dtb path depends on the presence of
  // the ramdisk
  if (FLAGS_dtb.empty()) {
    if (use_ramdisk) {
      FLAGS_dtb = vsoc::DefaultHostArtifactsPath("config/initrd-root.dtb");
    } else {
      FLAGS_dtb = vsoc::DefaultHostArtifactsPath("config/system-root.dtb");
    }
  }

  tmp_config_obj.add_kernel_cmdline(boot_image_unpacker.kernel_cmdline());
  if (!use_ramdisk) {
    tmp_config_obj.add_kernel_cmdline("root=/dev/vda");
  }
  tmp_config_obj.add_kernel_cmdline("init=/init");
  tmp_config_obj.add_kernel_cmdline(
      concat("androidboot.serialno=", FLAGS_serial_number));
  tmp_config_obj.add_kernel_cmdline("mac80211_hwsim.radios=0");
  tmp_config_obj.add_kernel_cmdline(concat("androidboot.lcd_density=", FLAGS_dpi));
  tmp_config_obj.add_kernel_cmdline(
      concat("androidboot.setupwizard_mode=", FLAGS_setupwizard_mode));
  tmp_config_obj.add_kernel_cmdline(concat("loop.max_part=", FLAGS_loop_max_part));
  if (!FLAGS_console.empty()) {
    tmp_config_obj.add_kernel_cmdline(concat("console=", FLAGS_console));
  }
  if (!FLAGS_androidboot_console.empty()) {
    tmp_config_obj.add_kernel_cmdline(
        concat("androidboot.console=", FLAGS_androidboot_console));
  }
  if (!FLAGS_hardware_name.empty()) {
    tmp_config_obj.add_kernel_cmdline(
        concat("androidboot.hardware=", FLAGS_hardware_name));
  }
  if (!FLAGS_guest_security.empty()) {
    tmp_config_obj.add_kernel_cmdline(concat("security=", FLAGS_guest_security));
    if (FLAGS_guest_enforce_security) {
      tmp_config_obj.add_kernel_cmdline("enforcing=1");
    } else {
      tmp_config_obj.add_kernel_cmdline("enforcing=0");
      tmp_config_obj.add_kernel_cmdline("androidboot.selinux=permissive");
    }
    if (FLAGS_guest_audit_security) {
      tmp_config_obj.add_kernel_cmdline("audit=1");
    } else {
      tmp_config_obj.add_kernel_cmdline("audit=0");
    }
  }
  if (FLAGS_run_e2e_test) {
    tmp_config_obj.add_kernel_cmdline("androidboot.vsoc_e2e_test=1");
  }
  if (FLAGS_extra_kernel_cmdline.size()) {
    tmp_config_obj.add_kernel_cmdline(FLAGS_extra_kernel_cmdline);
  }

  tmp_config_obj.set_ramdisk_image_path(ramdisk_path);
  tmp_config_obj.set_system_image_path(FLAGS_system_image);
  tmp_config_obj.set_cache_image_path(FLAGS_cache_image);
  tmp_config_obj.set_data_image_path(FLAGS_data_image);
  tmp_config_obj.set_vendor_image_path(FLAGS_vendor_image);
  tmp_config_obj.set_dtb_path(FLAGS_dtb);

  tmp_config_obj.set_mempath(FLAGS_mempath);
  tmp_config_obj.set_ivshmem_qemu_socket_path(
      tmp_config_obj.PerInstancePath("ivshmem_socket_qemu"));
  tmp_config_obj.set_ivshmem_client_socket_path(
      tmp_config_obj.PerInstancePath("ivshmem_socket_client"));
  tmp_config_obj.set_ivshmem_vector_count(memory_layout.GetRegions().size());

  if (AdbUsbEnabled(tmp_config_obj)) {
    tmp_config_obj.set_usb_v1_socket_name(tmp_config_obj.PerInstancePath("usb-v1"));
    tmp_config_obj.set_vhci_port(FLAGS_vhci_port);
    tmp_config_obj.set_usb_ip_socket_name(tmp_config_obj.PerInstancePath("usb-ip"));
  }

  tmp_config_obj.set_kernel_log_socket_name(tmp_config_obj.PerInstancePath("kernel-log"));
  tmp_config_obj.set_deprecated_boot_completed(FLAGS_deprecated_boot_completed);
  tmp_config_obj.set_console_path(tmp_config_obj.PerInstancePath("console"));
  tmp_config_obj.set_logcat_path(tmp_config_obj.PerInstancePath("logcat"));
  tmp_config_obj.set_launcher_log_path(tmp_config_obj.PerInstancePath("launcher.log"));
  tmp_config_obj.set_launcher_monitor_socket_path(
      tmp_config_obj.PerInstancePath("launcher_monitor.sock"));

  tmp_config_obj.set_mobile_bridge_name(FLAGS_mobile_interface);
  tmp_config_obj.set_mobile_tap_name(FLAGS_mobile_tap_name);

  tmp_config_obj.set_wifi_bridge_name(FLAGS_wifi_interface);
  tmp_config_obj.set_wifi_tap_name(FLAGS_wifi_tap_name);

  tmp_config_obj.set_wifi_guest_mac_addr(FLAGS_guest_mac_address);
  tmp_config_obj.set_wifi_host_mac_addr(FLAGS_host_mac_address);

  tmp_config_obj.set_vsock_guest_cid(FLAGS_vsock_guest_cid);

  tmp_config_obj.set_entropy_source("/dev/urandom");
  tmp_config_obj.set_uuid(FLAGS_uuid);

  tmp_config_obj.set_qemu_binary(FLAGS_qemu_binary);
  tmp_config_obj.set_ivserver_binary(FLAGS_ivserver_binary);
  tmp_config_obj.set_kernel_log_monitor_binary(FLAGS_kernel_log_monitor_binary);

  tmp_config_obj.set_enable_vnc_server(FLAGS_start_vnc_server);
  tmp_config_obj.set_vnc_server_binary(FLAGS_vnc_server_binary);
  tmp_config_obj.set_vnc_server_port(FLAGS_vnc_server_port);

  tmp_config_obj.set_enable_stream_audio(FLAGS_start_stream_audio);
  tmp_config_obj.set_stream_audio_binary(FLAGS_stream_audio_binary);
  tmp_config_obj.set_stream_audio_port(FLAGS_stream_audio_port);

  tmp_config_obj.set_restart_subprocesses(FLAGS_restart_subprocesses);
  tmp_config_obj.set_run_adb_connector(FLAGS_run_adb_connector);
  tmp_config_obj.set_adb_connector_binary(FLAGS_adb_connector_binary);
  tmp_config_obj.set_virtual_usb_manager_binary(
      FLAGS_virtual_usb_manager_binary);
  tmp_config_obj.set_socket_forward_proxy_binary(
      FLAGS_socket_forward_proxy_binary);
  tmp_config_obj.set_socket_vsock_proxy_binary(FLAGS_socket_vsock_proxy_binary);
  tmp_config_obj.set_run_as_daemon(FLAGS_daemon);
  tmp_config_obj.set_run_e2e_test(FLAGS_run_e2e_test);
  tmp_config_obj.set_e2e_test_binary(FLAGS_e2e_test_binary);

  if(!AdbUsbEnabled(tmp_config_obj)) {
    tmp_config_obj.disable_usb_adb();
  }

  tmp_config_obj.set_cuttlefish_env_path(GetCuttlefishEnvPath());

  auto config_file = GetConfigFilePath(tmp_config_obj);
  auto config_link = vsoc::GetGlobalConfigFileLink();
  // Save the config object before starting any host process
  if (!tmp_config_obj.SaveToFile(config_file)) {
    LOG(ERROR) << "Unable to save config object";
    return false;
  }
  setenv(vsoc::kCuttlefishConfigEnvVarName, config_file.c_str(), true);
  if (symlink(config_file.c_str(), config_link.c_str()) != 0) {
    LOG(ERROR) << "Failed to create symlink to config file at " << config_link
               << ": " << strerror(errno);
    return false;
  }

  return true;
}

void SetDefaultFlagsForQemu() {
  auto default_mobile_interface = GetPerInstanceDefault("cvd-mbr-");
  SetCommandLineOptionWithMode("mobile_interface",
                               default_mobile_interface.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  auto default_mobile_tap_name = GetPerInstanceDefault("cvd-mtap-");
  SetCommandLineOptionWithMode("mobile_tap_name",
                               default_mobile_tap_name.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  auto default_wifi_interface = GetPerInstanceDefault("cvd-wbr-");
  SetCommandLineOptionWithMode("wifi_interface",
                               default_wifi_interface.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  auto default_wifi_tap_name = GetPerInstanceDefault("cvd-wtap-");
  SetCommandLineOptionWithMode("wifi_tap_name",
                               default_wifi_tap_name.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
  auto default_instance_dir =
      cvd::StringFromEnv("HOME", ".") + "/cuttlefish_runtime";
  SetCommandLineOptionWithMode("instance_dir",
                               default_instance_dir.c_str(),
                               google::FlagSettingMode::SET_FLAGS_DEFAULT);
}

bool ParseCommandLineFlags(int* argc, char*** argv) {
  // The config_file is created by the launcher, so the launcher is the only
  // host process that doesn't use the flag.
  // Set the default to empty.
  google::SetCommandLineOptionWithMode("config_file", "",
                                       gflags::SET_FLAGS_DEFAULT);
  google::ParseCommandLineNonHelpFlags(argc, argv, true);
  bool invalid_manager = false;
  if (FLAGS_vm_manager == vm_manager::QemuManager::name()) {
    SetDefaultFlagsForQemu();
  } else {
    std::cerr << "Unknown Virtual Machine Manager: " << FLAGS_vm_manager
              << std::endl;
    invalid_manager = true;
  }
  google::HandleCommandLineHelpFlags();
  if (invalid_manager) {
    return false;
  }
  // Set the env variable to empty (in case the caller passed a value for it).
  unsetenv(vsoc::kCuttlefishConfigEnvVarName);

  return ResolveInstanceFiles();
}

bool CleanPriorFiles() {
  // Everything on the instance directory
  std::string prior_files = FLAGS_instance_dir + "/*";
  // The shared memory file
  prior_files += " " + FLAGS_mempath;
  // The environment file
  prior_files += " " + GetCuttlefishEnvPath();
  // The global link to the config file
  prior_files += " " + vsoc::GetGlobalConfigFileLink();
  LOG(INFO) << "Assuming prior files of " << prior_files;
  std::string fuser_cmd = "fuser " + prior_files + " 2> /dev/null";
  int rval = std::system(fuser_cmd.c_str());
  // fuser returns 0 if any of the files are open
  if (WEXITSTATUS(rval) == 0) {
    LOG(ERROR) << "Clean aborted: files are in use";
    return false;
  }
  std::string clean_command = "rm -rf " + prior_files;
  rval = std::system(clean_command.c_str());
  if (WEXITSTATUS(rval) != 0) {
    LOG(ERROR) << "Remove of files failed";
    return false;
  }
  return true;
}

bool WriteCuttlefishEnvironment(const vsoc::CuttlefishConfig& config) {
  auto env = cvd::SharedFD::Open(config.cuttlefish_env_path().c_str(),
                                 O_CREAT | O_RDWR, 0755);
  if (!env->IsOpen()) {
    LOG(ERROR) << "Unable to create cuttlefish.env file";
    return false;
  }
  std::string config_env = "export CUTTLEFISH_PER_INSTANCE_PATH=\"" +
                           config.PerInstancePath(".") + "\"\n";
  config_env += "export ANDROID_SERIAL=";
  if (AdbUsbEnabled(config)) {
    config_env += config.serial_number();
  } else {
    config_env += "127.0.0.1:" + std::to_string(GetHostPort());
  }
  config_env += "\n";
  env->Write(config_env.c_str(), config_env.size());
  return true;
}

// Forks and returns the write end of a pipe to the child process. The parent
// process waits for boot events to come through the pipe and exits accordingly.
cvd::SharedFD DaemonizeLauncher(const vsoc::CuttlefishConfig& config) {
  cvd::SharedFD read_end, write_end;
  if (!cvd::SharedFD::Pipe(&read_end, &write_end)) {
    LOG(ERROR) << "Unable to create pipe";
    return cvd::SharedFD(); // a closed FD
  }
  auto pid = fork();
  if (pid) {
    // Explicitly close here, otherwise we may end up reading forever if the
    // child process dies.
    write_end->Close();
    LauncherExitCodes exit_code;
    auto bytes_read = read_end->Read(&exit_code, sizeof(exit_code));
    if (bytes_read != sizeof(exit_code)) {
      LOG(ERROR) << "Failed to read a complete exit code, read " << bytes_read
                 << " bytes only instead of the expected " << sizeof(exit_code);
      exit_code = LauncherExitCodes::kPipeIOError;
    } else if (exit_code == LauncherExitCodes::kSuccess) {
      LOG(INFO) << "Virtual device booted successfully";
    } else if (exit_code == LauncherExitCodes::kVirtualDeviceBootFailed) {
      LOG(ERROR) << "Virtual device failed to boot";
    } else if (exit_code == LauncherExitCodes::kE2eTestFailed) {
      LOG(ERROR) << "Host VSoC region end to end test failed";
    } else {
      LOG(ERROR) << "Unexpected exit code: " << exit_code;
    }
    std::exit(exit_code);
  } else {
    // The child returns the write end of the pipe
    if (daemon(/*nochdir*/ 1, /*noclose*/ 1) != 0) {
      LOG(ERROR) << "Failed to daemonize child process: " << strerror(errno);
      std::exit(LauncherExitCodes::kDaemonizationError);
    }
    // Redirect standard I/O
    auto log_path = config.launcher_log_path();
    auto log =
        cvd::SharedFD::Open(log_path.c_str(), O_CREAT | O_WRONLY | O_TRUNC,
                            S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
    if (!log->IsOpen()) {
      LOG(ERROR) << "Failed to create launcher log file: " << log->StrError();
      std::exit(LauncherExitCodes::kDaemonizationError);
    }
    auto dev_null = cvd::SharedFD::Open("/dev/null", O_RDONLY);
    if (!dev_null->IsOpen()) {
      LOG(ERROR) << "Failed to open /dev/null: " << dev_null->StrError();
      std::exit(LauncherExitCodes::kDaemonizationError);
    }
    if (dev_null->UNMANAGED_Dup2(0) < 0) {
      LOG(ERROR) << "Failed dup2 stdin: " << dev_null->StrError();
      std::exit(LauncherExitCodes::kDaemonizationError);
    }
    if (log->UNMANAGED_Dup2(1) < 0) {
      LOG(ERROR) << "Failed dup2 stdout: " << log->StrError();
      std::exit(LauncherExitCodes::kDaemonizationError);
    }
    if (log->UNMANAGED_Dup2(2) < 0) {
      LOG(ERROR) << "Failed dup2 seterr: " << log->StrError();
      std::exit(LauncherExitCodes::kDaemonizationError);
    }

    read_end->Close();
    return write_end;
  }
}

// Stops the device. If this function is successful it returns on a child of the
// launcher (after it killed the laucher) and it should exit immediately
bool StopCvd(vm_manager::VmManager* vm_manager) {
  vm_manager->Stop();
  auto pgid = getpgid(0);
  auto child_pid = fork();
  if (child_pid > 0) {
    // The parent just waits for the child to kill it.
    int wstatus;
    waitpid(child_pid, &wstatus, 0);
    LOG(ERROR) << "The forked child exited before delivering signal with "
                  "status: "
               << wstatus;
    // If waitpid returns it means the child exited before the signal was
    // delivered, notify the client of the error and continue serving
    return false;
  } else if (child_pid == 0) {
    // The child makes sure it is in a different process group before
    // killing everyone on its parent's
    // This call should never fail (see SETPGID(2))
    if (setpgid(0, 0) != 0) {
      LOG(ERROR) << "setpgid failed (" << strerror(errno)
                 << ") the launcher's child is about to kill itself";
    }
    killpg(pgid, SIGKILL);
    return true;
  } else {
    // The fork failed, the system is in pretty bad shape
    LOG(FATAL) << "Unable to fork before on Stop: " << strerror(errno);
    return false;
  }
}

void ServerLoop(cvd::SharedFD server,
                vm_manager::VmManager* vm_manager) {
  while (true) {
    // TODO: use select to handle simultaneous connections.
    auto client = cvd::SharedFD::Accept(*server);
    cvd::LauncherAction action;
    while (client->IsOpen() && client->Read(&action, sizeof(action)) > 0) {
      switch (action) {
        case cvd::LauncherAction::kStop:
          if (StopCvd(vm_manager)) {
            auto response = cvd::LauncherResponse::kSuccess;
            client->Write(&response, sizeof(response));
            std::exit(0);
          } else {
            auto response = cvd::LauncherResponse::kError;
            client->Write(&response, sizeof(response));
          }
          break;
        default:
          LOG(ERROR) << "Unrecognized launcher action: "
                     << static_cast<char>(action);
          auto response = cvd::LauncherResponse::kError;
          client->Write(&response, sizeof(response));
      }
    }
  }
}
}  // namespace

int main(int argc, char** argv) {
  ::android::base::InitLogging(argv, android::base::StderrLogger);
  if (!ParseCommandLineFlags(&argc, &argv)) {
    LOG(ERROR) << "Failed to parse command arguments";
    return LauncherExitCodes::kArgumentParsingError;
  }

  // Clean up prior files before saving the config file (doing it after would
  // delete it)
  if (!CleanPriorFiles()) {
    LOG(ERROR) << "Failed to clean prior files";
    return LauncherExitCodes::kPrioFilesCleanupError;
  }
  // Create instance directory if it doesn't exist.
  if (!cvd::DirectoryExists(FLAGS_instance_dir.c_str())) {
    LOG(INFO) << "Setting up " << FLAGS_instance_dir;
    if (mkdir(FLAGS_instance_dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0) {
      LOG(ERROR) << "Failed to create instance directory: "
                 << FLAGS_instance_dir << ". Error: " << errno;
      return LauncherExitCodes::kInstanceDirCreationError;
    }
  }

  auto boot_img_unpacker = cvd::BootImageUnpacker::FromImage(FLAGS_boot_image);

  if (!InitializeCuttlefishConfiguration(*boot_img_unpacker)) {
    LOG(ERROR) << "Failed to initialize configuration";
    return LauncherExitCodes::kCuttlefishConfigurationInitError;
  }
  // Do this early so that the config object is ready for anything that needs it
  auto config = vsoc::CuttlefishConfig::Get();
  if (!config) {
    LOG(ERROR) << "Failed to obtain config singleton";
    return LauncherExitCodes::kCuttlefishConfigurationInitError;
  }

  ValidateAdbModeFlag(*config);

  auto vm_manager = vm_manager::VmManager::Get(config->vm_manager(), config);

  // Check host configuration
  std::vector<std::string> config_commands;
  if (!vm_manager->ValidateHostConfiguration(&config_commands)) {
    LOG(ERROR) << "Validation of user configuration failed";
    std::cout << "Execute the following to correctly configure:" << std::endl;
    for (auto& command : config_commands) {
      std::cout << "  " << command << std::endl;
    }
    std::cout << "You may need to logout for the changes to take effect"
              << std::endl;
    return LauncherExitCodes::kInvalidHostConfiguration;
  }

  if (!boot_img_unpacker->Unpack(config->ramdisk_image_path(),
                                 config->use_unpacked_kernel()
                                     ? config->kernel_image_path()
                                     : "")) {
    LOG(ERROR) << "Failed to unpack boot image";
    return LauncherExitCodes::kBootImageUnpackError;
  }

  if (!WriteCuttlefishEnvironment(*config)) {
    LOG(ERROR) << "Unable to write cuttlefish environment file";
  }

  LOG(INFO) << "The following files contain useful debugging information:";
  if (config->run_as_daemon()) {
    LOG(INFO) << "  Launcher log: " << config->launcher_log_path();
  }
  LOG(INFO) << "  Android's logcat output: " << config->logcat_path();
  LOG(INFO) << "  Kernel log: " << config->PerInstancePath("kernel.log");
  LOG(INFO) << "  Instance configuration: " << GetConfigFilePath(*config);
  LOG(INFO) << "  Instance environment: " << config->cuttlefish_env_path();
  LOG(INFO) << "To access the console run: socat file:$(tty),raw,echo=0 "
            << config->console_path();

  auto launcher_monitor_path = config->launcher_monitor_socket_path();
  auto launcher_monitor_socket = cvd::SharedFD::SocketLocalServer(
      launcher_monitor_path.c_str(), false, SOCK_STREAM, 0666);
  if (!launcher_monitor_socket->IsOpen()) {
    LOG(ERROR) << "Error when opening launcher server: "
               << launcher_monitor_socket->StrError();
    return cvd::LauncherExitCodes::kMonitorCreationFailed;
  }
  cvd::SharedFD foreground_launcher_pipe;
  if (config->run_as_daemon()) {
    foreground_launcher_pipe = DaemonizeLauncher(*config);
    if (!foreground_launcher_pipe->IsOpen()) {
      return LauncherExitCodes::kDaemonizationError;
    }
  } else {
    // Make sure the launcher runs in its own process group even when running in
    // foreground
    if (getsid(0) != getpid()) {
      int retval = setpgid(0, 0);
      if (retval) {
        LOG(ERROR) << "Failed to create new process group: " << strerror(errno);
        std::exit(LauncherExitCodes::kProcessGroupError);
      }
    }
  }

  auto boot_state_machine =
      std::make_shared<CvdBootStateMachine>(foreground_launcher_pipe);

  // Monitor and restart host processes supporting the CVD
  cvd::ProcessMonitor process_monitor;

  cvd::SharedFD boot_events_pipe;
  // Only subscribe to boot events if running as daemon
  process_monitor.StartSubprocess(
      GetKernelLogMonitorCommand(*config,
                                 config->run_as_daemon()
                                   ? &boot_events_pipe
                                   : nullptr),
      GetOnSubprocessExitCallback(*config));

  SetUpHandlingOfBootEvents(&process_monitor, boot_events_pipe,
                            boot_state_machine);

  LaunchUsbServerIfEnabled(*config, &process_monitor);

  process_monitor.StartSubprocess(
      GetIvServerCommand(*config),
      GetOnSubprocessExitCallback(*config));

  // Initialize the regions that require so before the VM starts.
  PreLaunchInitializers::Initialize(*config);

  // Launch the e2e test after the shared memory is initialized
  LaunchE2eTest(&process_monitor, boot_state_machine, *config);

  // Start the guest VM
  process_monitor.StartSubprocess(vm_manager->StartCommand(),
                                  GetOnSubprocessExitCallback(*config));

  // Start other host processes
  LaunchSocketForwardProxyIfEnabled(&process_monitor, *config);
  LaunchSocketVsockProxyIfEnabled(&process_monitor, *config);
  LaunchVNCServerIfEnabled(*config, &process_monitor,
                           GetOnSubprocessExitCallback(*config));
  LaunchStreamAudioIfEnabled(*config, &process_monitor,
                             GetOnSubprocessExitCallback(*config));
  LaunchAdbConnectorIfEnabled(&process_monitor, *config);

  ServerLoop(launcher_monitor_socket, vm_manager); // Should not return
  LOG(ERROR) << "The server loop returned, it should never happen!!";
  return cvd::LauncherExitCodes::kServerError;
}