logging_installer.cc

// Copyright 2011 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/installer/util/logging_installer.h"

#include <windows.h>

#include <shlobj.h>
#include <stdint.h>

#include <optional>
#include <tuple>

#include "base/command_line.h"
#include "base/containers/heap_array.h"
#include "base/files/file.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/logging_win.h"
#include "base/path_service.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/scoped_handle.h"
#include "build/branding_buildflags.h"
#include "chrome/installer/util/initial_preferences.h"
#include "chrome/installer/util/initial_preferences_constants.h"
#include "chrome/installer/util/util_constants.h"

// {93BCE0BF-3FAF-43b1-9E28-BEB6FAB5ECE7}
static const GUID kSetupTraceProvider = {
    0x93bce0bf,
    0x3faf,
    0x43b1,
    {0x9e, 0x28, 0xbe, 0xb6, 0xfa, 0xb5, 0xec, 0xe7}};

namespace installer {

// This should be true for the period between the end of
// InitInstallerLogging() and the beginning of EndInstallerLogging().
bool installer_logging_ = false;

TruncateResult TruncateLogFileIfNeeded(const base::FilePath& log_file) {
  TruncateResult result = LOGFILE_UNTOUCHED;

  std::optional<int64_t> log_size = base::GetFileSize(log_file);
  if (log_size.has_value() && log_size.value() > kMaxInstallerLogFileSize) {
    // Cause the old log file to be deleted when we are done with it.
    uint32_t file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ |
                          base::File::FLAG_WIN_SHARE_DELETE |
                          base::File::FLAG_DELETE_ON_CLOSE;
    base::File old_log_file(log_file, file_flags);

    if (old_log_file.IsValid()) {
      result = LOGFILE_DELETED;
      base::FilePath tmp_log(log_file.value() + FILE_PATH_LITERAL(".tmp"));
      // Note that base::Move will attempt to replace existing files.
      if (base::Move(log_file, tmp_log)) {
        int64_t offset = log_size.value() - kTruncatedInstallerLogFileSize;
        auto old_log_data =
            base::HeapArray<uint8_t>::Uninit(kTruncatedInstallerLogFileSize);
        std::optional<size_t> bytes_read =
            old_log_file.Read(offset, old_log_data);
        if (bytes_read.value_or(0) > 0 &&
            (base::WriteFile(log_file, old_log_data.subspan(0, *bytes_read)) ||
             base::PathExists(log_file))) {
          result = LOGFILE_TRUNCATED;
        }
      }
    } else if (base::DeleteFile(log_file)) {
      // Couldn't get sufficient access to the log file, optimistically try to
      // delete it.
      result = LOGFILE_DELETED;
    }
  }

  return result;
}

void InitInstallerLogging(const installer::InitialPreferences& prefs) {
  if (installer_logging_)
    return;

  installer_logging_ = true;

  bool value = false;
  if (prefs.GetBool(installer::initial_preferences::kDisableLogging, &value) &&
      value) {
    return;
  }

  base::FilePath log_file_path(GetLogFilePath(prefs));
  TruncateLogFileIfNeeded(log_file_path);

  logging::LoggingSettings settings;
  settings.logging_dest = logging::LOG_TO_FILE;
  settings.log_file_path = log_file_path.value().c_str();
  logging::InitLogging(settings);

  if (prefs.GetBool(installer::initial_preferences::kVerboseLogging, &value) &&
      value) {
    logging::SetMinLogLevel(logging::LOGGING_VERBOSE);
  } else {
    logging::SetMinLogLevel(logging::LOGGING_ERROR);
  }

  // Enable ETW logging.
  logging::LogEventProvider::Initialize(kSetupTraceProvider);
}

void EndInstallerLogging() {
  logging::CloseLogFile();

  installer_logging_ = false;
}

base::FilePath GetLogFilePath(const installer::InitialPreferences& prefs) {
  std::string path;
  prefs.GetString(installer::initial_preferences::kLogFile, &path);
  if (!path.empty())
    return base::FilePath(base::UTF8ToWide(path));

  static const base::FilePath::CharType kLogFilename[] =
#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
      FILE_PATH_LITERAL("chrome_installer.log");
#else  // BUILDFLAG(CHROMIUM_BRANDING)
      FILE_PATH_LITERAL("chromium_installer.log");
#endif

  // Fallback to current directory if getting the secure or temp directory
  // fails.
  base::FilePath tmp_path;
  std::ignore = ::IsUserAnAdmin()
                    ? base::PathService::Get(base::DIR_SYSTEM_TEMP, &tmp_path)
                    : base::PathService::Get(base::DIR_TEMP, &tmp_path);
  return tmp_path.Append(kLogFilename);
}

}  // namespace installer