systemd_util.cc | Explore in Territory

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "chrome/updater/linux/systemd_util.h"

#include <fcntl.h>
#include <sys/un.h>
#include <systemd/sd-daemon.h>
#include <unistd.h>

#include <optional>
#include <utility>

#include "base/base_paths.h"
#include "base/command_line.h"
#include "base/files/file_descriptor_watcher_posix.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/files/scoped_file.h"
#include "base/functional/bind.h"
#include "base/logging.h"
#include "base/path_service.h"
#include "base/posix/eintr_wrapper.h"
#include "base/process/launch.h"
#include "base/process/process.h"
#include "base/strings/stringprintf.h"
#include "base/threading/thread_restrictions.h"
#include "chrome/updater/constants.h"
#include "chrome/updater/linux/ipc_constants.h"
#include "chrome/updater/updater_branding.h"
#include "chrome/updater/util/posix_util.h"

namespace updater {
// Allows the utility functions below to join processes. To avoid overzealously
// granting access to |base::ScopedAllowBaseSyncPrimitives|, this class must
// continue to live in a `.cc`.
class [[maybe_unused, nodiscard]] SystemctlLauncherScopedAllowBaseSyncPrimitives
    : public base::ScopedAllowBaseSyncPrimitives { … };

namespace {
// Location of system-scoped unit files.
const base::FilePath kSystemUnitDirectory("/etc/systemd/system");
// Location of user-scoped unit files relative to the user's home directory.
const base::FilePath kUserUnitRelativeDirectory(".local/share/systemd/user");
// Systemd unit names.
constexpr char kUpdaterServiceName[] = PRODUCT_FULLNAME_STRING ".service";
constexpr char kUpdaterSocketName[] = PRODUCT_FULLNAME_STRING ".socket";
// Systemd unit definition templates.
constexpr char kUpdaterServiceDefinitionTemplate[] = …;  // Ensure systemd does not kill child processes when
                         // the main process exits.
constexpr char kUpdaterSocketDefinitionTemplate[] = …;

// Returns the path to the systemd unit directory for the given scope.
std::optional<base::FilePath> GetUnitDirectory(UpdaterScope scope) { … }

// Returns the command `systemctl` with or without the `--user` flag.
base::CommandLine GetBaseSystemctlCommand(UpdaterScope scope) { … }

// Launch the given command line with stdin, stdout, and stderr remapped to
// /dev/null.
void LaunchWithRemaps(base::CommandLine command) { … }

// Runs the daemon-reload command to have systemd reload unit files.
void ReloadUnitFiles(UpdaterScope scope) { … }

// Enables the socket unit to be created and managed by systemd at boot.
void EnableSocketUnit(UpdaterScope scope) { … }

// Ensures that the update service and socket are stopped.
void StopService(UpdaterScope scope) { … }

// Writes the contents of |unit_definition| to |unit_path|. Returns true on
// success.
[[nodiscard]] bool InstallSystemdUnit(base::FilePath unit_path,
                                      std::string unit_definition) { … }

// Returns the command line which should be used to start the updater service.
std::string GetLauncherCommandLine(UpdaterScope scope,
                                   base::FilePath launcher) { … }

}  // namespace

SystemdService::SystemdService() { … }

SystemdService::~SystemdService() = default;

void SystemdService::OnSocketReadable() { … }

bool InstallSystemdUnits(UpdaterScope scope) { … }

bool UninstallSystemdUnits(UpdaterScope scope) { … }

bool SystemdUnitsInstalled(UpdaterScope scope) { … }

}  // namespace updater
chromium/chrome/updater/linux/systemd_util.cc
