MSDN说使用ReadDirectoryChangesW意味着调用进程具有备份和恢复权限。使用ReadDirectoryChangesW是否需要管理员权限?
这是否表示只有在管理员帐户下启动的进程才能正常工作?
我试过下面的代码,它在作为受限用户运行时无法启用所需的特权。
void enablePrivileges()
{
enablePrivilege(SE_BACKUP_NAME);
enablePrivilege(SE_RESTORE_NAME);
}
void enablePrivilege(LPCTSTR name)
{
HANDLE hToken;
DWORD status;
if (::OpenProcessToken(::GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES, &hToken))
{
TOKEN_PRIVILEGES tp = { 1 };
if(::LookupPrivilegeValue(NULL, name, &tp.Privileges[0].Luid))
{
tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
BOOL result = ::AdjustTokenPrivileges(hToken, FALSE, &tp, 0, NULL, NULL);
verify (result != FALSE);
status = ::GetLastError();
}
::CloseHandle(hToken);
}
}
我做错了什么?是否有任何解决方法从非管理员用户帐户使用ReadDirectoryChangesW?似乎.NET的FileSystemWatcher可以做到这一点。谢谢!
更新:这是阶级的全码:
class DirectoryChangesWatcher
{
public:
DirectoryChangesWatcher(wstring directory)
{
enablePrivileges();
hDir = ::CreateFile(directory.c_str(),
FILE_LIST_DIRECTORY | FILE_FLAG_OVERLAPPED,
FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS, NULL);
ensure (hDir != INVALID_HANDLE_VALUE, err::SystemException);
::ZeroMemory(&overlapped, sizeof(OVERLAPPED));
overlapped.hEvent = dirChangedEvent.getHandle();
}
~DirectoryChangesWatcher() { ::CloseHandle(hDir); }
public:
Event& getEvent() { return dirChangedEvent; }
FILE_NOTIFY_INFORMATION* getBuffer() { return buffer; }
public:
void startAsyncWatch()
{
DWORD bytesReturned;
const BOOL res = ::ReadDirectoryChangesW(
hDir,
&buffer,
sizeof(buffer),
TRUE,
FILE_NOTIFY_CHANGE_LAST_WRITE | FILE_NOTIFY_CHANGE_SIZE,
&bytesReturned,
&overlapped,
NULL);
ensure(res != FALSE, err::SystemException);
}
private:
void enablePrivileges()
{
enablePrivilege(SE_BACKUP_NAME);
enablePrivilege(SE_RESTORE_NAME);
}
void enablePrivilege(LPCTSTR name)
{
HANDLE hToken;
DWORD status;
if (::OpenProcessToken(::GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES, &hToken))
{
TOKEN_PRIVILEGES tp = { 1 };
if(::LookupPrivilegeValue(NULL, name, &tp.Privileges[0].Luid))
{
tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
BOOL result = ::AdjustTokenPrivileges(hToken, FALSE, &tp, 0, NULL, NULL);
verify (result != FALSE);
status = ::GetLastError();
}
::CloseHandle(hToken);
}
}
private:
HANDLE hDir;
OVERLAPPED overlapped;
Event dirChangedEvent;
FILE_NOTIFY_INFORMATION buffer[1024];
};
}
更新:好消息!事实证明,问题确实发生在CreateFile调用中的FILE_SHARE_WRITE标志中。除非我是管理员,否则通知不会到来。当我删除此标志时,所有内容现在都在非管理员帐户上工作。
你打电话给ReadDirectoryChangesW?随着驱动器的根目录或文件夹? – MSN 2010-04-14 20:07:29
MSDN在哪里说完全? – avakar 2010-04-14 20:08:49
我在文件夹上使用它。但AdjustTokenPrivileges之后的GetLastError返回ERROR_NOT_ALL_ASSIGNED。 – 2010-04-14 20:16:01