c - NtFsControlFile函数错误

Question

我有这个代码:

// page1.h

NTSTATUS (__stdcall *NtFsControlFile)( 
                    HANDLE FileHandle,
                    HANDLE Event,                   
                    PIO_APC_ROUTINE ApcRoutine,     
                    PVOID ApcContext,               
                    PIO_STATUS_BLOCK IoStatusBlock, 
                    ULONG FsControlCode,
                    PVOID InputBuffer,              
                    ULONG InputBufferLength,
                    PVOID OutputBuffer,     
                    ULONG OutputBufferLength
            );


ULONG (__stdcall *RtlNtStatusToDosError) (
        IN NTSTATUS Status
        );

然后在page2.cpp:

page2.cpp
VOID LocateNativeEntryPoints()
{
    //
    // If we're on Win9x, just return
    //
    if( GetVersion() >= 0x80000000) return;

    //
    // Load the NTDLL entry point we need
    //
    if( !(NtFsControlFile = (void *) GetProcAddress( GetModuleHandle(TEXT("ntdll.dll")),
            "NtFsControlFile" )) ) {

        _tprintf(TEXT("\nCould not find NtFsControlFile entry point in NTDLL.DLL\n"));
        exit(1);
    }
    if( !(RtlNtStatusToDosError = (void *) GetProcAddress( GetModuleHandle(TEXT("ntdll.dll")),
                            "RtlNtStatusToDosError" )) ) {

        _tprintf(TEXT("\nCould not find RtlNtStatusToDosError entry point in NTDLL.DLL\n"));
        exit(1);
    }
}

我在 if(!NtFsControlFile = 和 if( !(RtlNtStatusToDosError =,

error C2440: '=' : cannot convert from 'void *' to 'NTSTATUS (__stdcall *)(HANDLE,HANDLE,PIO_APC_ROUTINE,PVOID,PIO_STATUS_BLOCK,ULONG,PVOID,ULONG,PVOID,ULONG)'
         Conversion from 'void*' to pointer to non-'void' requires an explicit cast

error C2440: '=' : cannot convert from 'void *' to 'ULONG (__stdcall *)(NTSTATUS)'
         Conversion from 'void*' to pointer to non-'void' requires an explicit cast

原来的page2是C语言文件。我需要转换它以及如何做到这一点或者如何解决问题。

非常感谢。

似乎有效的解决方案(不像 C 语言那样自动转换):

     // a typedef to make casting easier

    typedef NTSTATUS (__stdcall *NtFsControlFilePtr)(
        HANDLE FileHandle,
        HANDLE Event,
        PIO_APC_ROUTINE ApcRoutine,
        PVOID ApcContext,
        PIO_STATUS_BLOCK IoStatusBlock,
        ULONG FsControlCode,
        PVOID InputBuffer,
        ULONG InputBufferLength,
        PVOID OutputBuffer,
        ULONG OutputBufferLength);

// the actual pointer to function

NtFsControlFilePtr NtFsControlFile;

// and the GetProcAddress call

    if( !(NtFsControlFile = reinterpret_cast<NtFsControlFilePtr>( GetProcAddress( GetModuleHandle(TEXT("ntdll.dll")),
            "NtFsControlFile" ))) ) {

        _tprintf(TEXT("\nCould not find NtFsControlFile entry point in NTDLL.DLL\n"));
        exit(1);
    }

此解决方案有效，但您会得到:

C4191:“reinterpret_cast”:不安全转换

与/WALL

避免警告:

if( !(NtFsControlFile = reinterpret_cast<NtFsControlFilePtr>( reinterpret_cast< void* >( GetProcAddress( GetModuleHandle(TEXT("ntdll.dll")), 
        "NtFsControlFile" )))))  {

        _tprintf(TEXT("\nCould not find NtFsControlFile entry point in NTDLL.DLL\n"));
        exit(1);
    }

   if( !(RtlNtStatusToDosError = reinterpret_cast<RtlNtStatusToDosErrorPtr>( reinterpret_cast< void* >( GetProcAddress( GetModuleHandle(TEXT("ntdll.dll")), 
        "NtFsControlFile" )))))  {

        _tprintf(TEXT("\nCould not find NtFsControlFile entry point in NTDLL.DLL\n"));
        exit(1);
    }

Answer 1

如果你有纯c代码，你可以稍微改变一下类型转换，我的意思是:

1. 声明变量:

   typedef NTSTATUS (__stdcall *NT_FS_CONTROL_FILE)(IN HANDLE FileHandle,
                         IN  HANDLE Event, IN PIO_APC_ROUTINE  ApcRoutine,
                         IN PVOID ApcContext, OUT PIO_STATUS_BLOCKIoStatusBlock,
                         IN ULONG FsControlCode, IN PVOID InputBuffer,
                         IN ULONG InputBufferLength, OUT  PVOID OutputBuffer,
                         IN ULONG OutputBufferLength);
   NT_FS_CONTROL_FILE nt_fs_control_file;
   

   那么你需要

   nt_fs_control_file = GetProcAddress(
   

   或

   nt_fs_control_file = (NT_FS_CONTROL_FILE)GetProcAddress
   

2. 调用您的函数:

   NTSTATUS status = nt_fs_control_file(....);