考虑以下我在 Win 10 Fall Creators Update Version 10.0.16299 Build 16299 上试验的独立源代码
#include <Windows.h>
#include <iostream>
#include <string>
#include <memory>
#if !defined (REPARSE_DATA_BUFFER_HEADER_SIZE) //
// Note:
// See http://msdn.microsoft.com/en-us/library/ff552012.aspx for information about
// the following structure.
//
typedef struct _REPARSE_DATA_BUFFER
{
ULONG ReparseTag;
USHORT ReparseDataLength;
USHORT Reserved;
union
{
struct
{
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
ULONG Flags;
WCHAR PathBuffer[1];
} SymbolicLinkReparseBuffer;
struct
{
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
WCHAR PathBuffer[1];
} MountPointReparseBuffer;
struct
{
UCHAR DataBuffer[1];
} GenericReparseBuffer;
};
} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
#define REPARSE_DATA_BUFFER_HEADER_SIZE FIELD_OFFSET(REPARSE_DATA_BUFFER, GenericReparseBuffer)
#endif
#if !defined(IO_REPARSE_TAG_CLOUD_7)
#define IO_REPARSE_TAG_CLOUD_7 (0x9000701AL)
#endif
struct file_handle_close
{
void operator()(void *handle) const
{
if (static_cast<HANDLE>(handle) != INVALID_HANDLE_VALUE)
{
CloseHandle(static_cast<HANDLE>(handle));
}
}
}; // end of file_handle_close structure
typedef std::unique_ptr<void, file_handle_close> file_handle_uptr;
bool is_link(DWORD file_attrib)
{
return ((file_attrib & FILE_ATTRIBUTE_REPARSE_POINT) && !(file_attrib & FILE_ATTRIBUTE_SPARSE_FILE));
} // end of is_link()
union reparse_data_context
{
char buff[REPARSE_DATA_BUFFER_HEADER_SIZE + MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
REPARSE_DATA_BUFFER reparse_data_buff;
}; // end of reparse_data_context union
void foo(const std::string& var,const std::wstring& path_name)
{
WIN32_FILE_ATTRIBUTE_DATA attr_ctx;
if (GetFileAttributesExW(path_name.c_str(), GetFileExInfoStandard, &attr_ctx) == 0)
{
DWORD error_code(GetLastError());
std::cout << "Error occurred "<< error_code << "\n";
}
else
{
std::cout << var << '\n';
std::cout << "attr_ctx.dwFileAttributes :" << attr_ctx.dwFileAttributes << '\n';
bool islink = is_link(attr_ctx.dwFileAttributes);
if(islink)
{
file_handle_uptr handle_uptr(CreateFileW(path_name.c_str(),
FILE_READ_EA,
(FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE),
0,
OPEN_EXISTING,
(FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT),
0));
HANDLE handle(static_cast<HANDLE>(handle_uptr.get()));
if (handle == INVALID_HANDLE_VALUE)
{
std::cout << "CreateFileW failed with : "<<GetLastError()<<'\n';
return;
}
DWORD ret_len;
reparse_data_context rctx;
if(!DeviceIoControl(handle,
FSCTL_GET_REPARSE_POINT,
nullptr,
0,
rctx.buff,
sizeof(rctx),
&ret_len,
nullptr))
{
std::cout << "DeviceIoControl failed with : "<<GetLastError()<<'\n';
return;
}
else
{
ULONG reparse_tag(reinterpret_cast<const REPARSE_DATA_BUFFER*>(rctx.buff)->ReparseTag);
if (!IsReparseTagMicrosoft(reparse_tag))
{
std::cout << "Not a supported reparse tag" << std::endl;
return;
}
if (reparse_tag == IO_REPARSE_TAG_SYMLINK)
{
std::wstring target_name;
{
size_t len = static_cast<size_t>((rctx.reparse_data_buff.SymbolicLinkReparseBuffer.PrintNameLength) / sizeof(wchar_t));
const size_t another = len;
std::wcout << "Target " << std::wstring(static_cast<wchar_t*>(rctx.reparse_data_buff.SymbolicLinkReparseBuffer.PathBuffer) +
(rctx.reparse_data_buff.SymbolicLinkReparseBuffer.PrintNameOffset / sizeof(wchar_t)),
len);
}
{
size_t len = static_cast<size_t>((rctx.reparse_data_buff.SymbolicLinkReparseBuffer.SubstituteNameLength) / sizeof(wchar_t));
std::wcout << "Target " << std::wstring(static_cast<wchar_t*>(rctx.reparse_data_buff.SymbolicLinkReparseBuffer.PathBuffer) +
(rctx.reparse_data_buff.SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(wchar_t)),
len);
}
}
else if(reparse_tag == IO_REPARSE_TAG_MOUNT_POINT)
{
// Do something similar to previous block
}
else if(reparse_tag == IO_REPARSE_TAG_CLOUD_7)
{
std::cout << " this is not a valid Reparse Point"<<std::endl;
// How to resolve a target for this ?
}
}
}
else
{
std::cout << var << " is not a link or junction "<< '\n';
}
}
}
int main()
{
std::wstring path_name = L"C:\\Users\\someuser\\OneDrive";
foo("OneDrive",path_name);
return 0;
}
这是我用来解析一个驱动器的目标的代码，该驱动器被视为IO_REPARSE_TAG_CLOUD_7按GetFileAttributesExW功能处理。
我知道它_REPARSE_DATA_STRUCTURE的信息仅适用于SymbolicLinkReparseBuffer并且MountPointReparseBuffer它没有任何与重解析点相关的字段，例如 One Drive。
我检查了 Windows 驱动程序套件的（用于秋季创建者更新）ntifs.h文件，以查看结构是否已更新以支持 One Drive。然而，情况似乎并非如此。
我还尝试从第一个 if 块SymbolicLinkReparseBuffer中获取 One Drive 目标信息。MountPointReparseBuffer然而，它最终给了我垃圾。
问题：
1) 如何正确确定 REPARSE_POINTS 的目标，例如 One Drive？
2) Windows 10 Fall Creators Update SDK 添加了更多这样的 REPARSE_POINT 标签。如果一个人不能解决它的目标（例如一个驱动器），那么对待它们（即源 REPARSE_POINTS）的一般经验法则是什么？作为文件还是目录？