chrome sandbox中的幾個有用函數

//判斷控制代碼與路徑是否是一樣的// We get a |full_path| of the form /??/c:/some/foo/bar, and the name that// we'll get from |handle| will be /device/harddiskvolume1/some/foo/bar.bool SameObject(HANDLE handle, const wchar_t* full_path) {  std::wstring path(full_path);  DCHECK(!path.empty());  // Check if it's a pipe.  if (IsPipe(path))    return true;  std::wstring actual_path;  if (!GetPathFromHandle(handle, &actual_path))    return false;  // This may end with a backslash.  const wchar_t kBackslash = '//';  if (path[path.length() - 1] == kBackslash)    path = path.substr(0, path.length() - 1);  // Perfect match (case-insesitive check).  if (0 == _wcsicmp(actual_path.c_str(), path.c_str()))    return true;  // Look for the drive letter.  size_t colon_pos = path.find(L':');  if (colon_pos == 0 || colon_pos == std::wstring::npos)    return false;  // Only one character for the drive.  if (colon_pos > 1 && path[colon_pos - 2] != kBackslash)    return false;  // We only need 3 chars, but let's alloc a buffer for four.  wchar_t drive[4] = {0};  wchar_t vol_name[MAX_PATH];  memcpy(drive, &path[colon_pos - 1], 2 * sizeof(*drive));  // We'll get a double null terminated string.  DWORD vol_length = ::QueryDosDeviceW(drive, vol_name, MAX_PATH);  if (vol_length < 2 || vol_length == MAX_PATH)    return false;  // Ignore the nulls at the end.  vol_length = static_cast(wcslen(vol_name));  // The two paths should be the same length.  if (vol_length + path.size() - (colon_pos + 1) != actual_path.size())    return false;  // Check up to the drive letter.  if (0 != _wcsnicmp(actual_path.c_str(), vol_name, vol_length))    return false;  // Check the path after the drive letter.  if (0 != _wcsicmp(&actual_path[vol_length], &path[colon_pos + 1]))    return false;  return true;}//將短路徑轉換為長路徑// Convert a short path (C:/path~1 or //??//c:/path~1) to the long version of// the path. If the path is not a valid filesystem path, the function returns// false and the output parameter is not modified.bool ConvertToLongPath(const std::wstring& short_path,                       std::wstring* long_path) {  // Check if the path is a NT path.  bool is_nt_path = false;  std::wstring path = short_path;  if (0 == path.compare(0, kNTPrefixLen, kNTPrefix)) {    path = path.substr(kNTPrefixLen);    is_nt_path = true;  }  DWORD size = MAX_PATH;  scoped_array long_path_buf(new wchar_t[size]);  DWORD return_value = ::GetLongPathName(path.c_str(), long_path_buf.get(),                                         size);  while (return_value >= size) {    size *= 2;    long_path_buf.reset(new wchar_t[size]);    return_value = ::GetLongPathName(path.c_str(), long_path_buf.get(), size);  }  DWORD last_error = ::GetLastError();  if (0 == return_value && (ERROR_FILE_NOT_FOUND == last_error ||                            ERROR_PATH_NOT_FOUND == last_error ||                            ERROR_INVALID_NAME == last_error)) {    // The file does not exist, but maybe a sub path needs to be expanded.    std::wstring::size_type last_slash = path.rfind(L'//');    if (std::wstring::npos == last_slash)      return false;    std::wstring begin = path.substr(0, last_slash);    std::wstring end = path.substr(last_slash);    if (!ConvertToLongPath(begin, &begin))      return false;    // Ok, it worked. Let's reset the return value.    path = begin + end;    return_value = 1;  } else if (0 != return_value) {    path = long_path_buf.get();  }  if (return_value != 0) {    if (is_nt_path) {      *long_path = kNTPrefix;      *long_path += path;    } else {      *long_path = path;    }    return true;  }  return false;}//根據控制代碼擷取路徑bool GetPathFromHandle(HANDLE handle, std::wstring* path) {  NtQueryObjectFunction NtQueryObject = NULL;  ResolveNTFunctionPtr("NtQueryObject", &NtQueryObject);  OBJECT_NAME_INFORMATION initial_buffer;  OBJECT_NAME_INFORMATION* name = &initial_buffer;  ULONG size = sizeof(initial_buffer);  // Query the name information a first time to get the size of the name.  NTSTATUS status = NtQueryObject(handle, ObjectNameInformation, name, size,                                  &size);  scoped_ptr name_ptr;  if (size) {    name = reinterpret_cast(new BYTE[size]);    name_ptr.reset(name);    // Query the name information a second time to get the name of the    // object referenced by the handle.    status = NtQueryObject(handle, ObjectNameInformation, name, size, &size);  }  if (STATUS_SUCCESS != status)    return false;  path->assign(name->ObjectName.Buffer, name->ObjectName.Length /                                        sizeof(name->ObjectName.Buffer[0]));  return true;}//將win32類型的路徑轉換為Native(Nt)類型的path//http://stackoverflow.com/questions/4445108/how-can-i-convert-a-native-nt-pathname-into-a-win32-path-name//http://pdh11.blogspot.com/2009/05/pathcanonicalize-versus-what-it-says-on.html// Resolves a win32 path to an nt path using GetPathFromHandle. The path must// exist. Returs true if the translation was succesful.bool GetNtPathFromWin32Path(const std::wstring& path, std::wstring* nt_path) {  HANDLE file = ::CreateFileW(path.c_str(), 0,    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,    OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);  if (file == INVALID_HANDLE_VALUE)    return false;  bool rv = GetPathFromHandle(file, nt_path);  ::CloseHandle(file);  return rv;}

檔案路徑：D:/project/chrome/src/src/sandbox/src/win_utils.cc