内核模式下获取SSDT服务索引代码

ULONG 
GetDllFunctionIndex(
                                        IN CONST char* lpFunctionName
                                        )
{
        HANDLE                                hSection                = NULL;
        HANDLE                                hFile                        = NULL; 
        HANDLE                                hMod                        = NULL;
        IMAGE_DOS_HEADER*        dosheader                = NULL;
        IMAGE_OPTIONAL_HEADER* opthdr                = NULL;
        IMAGE_EXPORT_DIRECTORY* pExportTable = NULL;
        ULONG*                                arrayOfFunctionAddresses = NULL;
        ULONG*                                arrayOfFunctionNames = NULL;
        USHORT*                                arrayOfFunctionOrdinals = NULL;
        ULONG                                functionOrdinal = 0;
        ULONG                                Base                        = 0;
        ULONG                                x                                = 0;
        ULONG_PTR                        functionAddress = 0;
        char*                                functionName        = NULL;
        STRING                                ntFunctionName        = {0};
        STRING                                ntFunctionNameSearch = {0};
        PVOID                                BaseAddress                = NULL;
        SIZE_T                                size                        = 0;
        OBJECT_ATTRIBUTES        oa                                = {0};// = {sizeof oa, 0, pDllName, OBJ_CASE_INSENSITIVE};
        IO_STATUS_BLOCK                iosb                        = {0};
        NTSTATUS                        status                        = STATUS_SUCCESS;
        ULONG                                uIndex                        = -1;
        UNICODE_STRING                pDllName                = {0};


        RtlInitUnicodeString(&pDllName,L"\\SystemRoot\\system32\\ntdll.dll");
        InitializeObjectAttributes ( &oa, &pDllName, OBJ_KERNEL_HANDLE|OBJ_CASE_INSENSITIVE, NULL, NULL);

        status=ZwOpenFile(&hFile, FILE_EXECUTE | SYNCHRONIZE, &oa, &iosb, FILE_SHARE_READ, FILE_SYNCHRONOUS_IO_NONALERT);
        if(status!=STATUS_SUCCESS)
        {
                //FILE_SUPERSEDED
                KdPrint(("ZwOpenFile Error:0x%x,0x%x",status,iosb.Information));
                return 0;
        }

        oa.ObjectName = 0;
        status=ZwCreateSection(&hSection, SECTION_ALL_ACCESS, &oa, 0,PAGE_EXECUTE, 0x01000000, hFile);
        if(status!=STATUS_SUCCESS)
        {
                KdPrint(("ZwCreateSection Error"));
                ZwClose(hFile);
                return 0;
        }

        ZwMapViewOfSection(hSection, NtCurrentProcess(), &BaseAddress, 0, 1000, 0, &size, (SECTION_INHERIT)1, MEM_TOP_DOWN, PAGE_READWRITE);

        ZwClose(hFile);

        hMod                        = BaseAddress;
        dosheader                = (IMAGE_DOS_HEADER *)hMod;
        opthdr                        = (IMAGE_OPTIONAL_HEADER *) ((unsigned char*)hMod+dosheader->e_lfanew+24);
        pExportTable        = (IMAGE_EXPORT_DIRECTORY*)((unsigned char*) hMod + opthdr->DataDirectory[ IMAGE_DIRECTORY_ENTRY_EXPORT]. VirtualAddress);

        arrayOfFunctionAddresses        = (ULONG*)( (unsigned char*)hMod + pExportTable->AddressOfFunctions);
        arrayOfFunctionNames                = (ULONG*)( (unsigned char*)hMod + pExportTable->AddressOfNames);
        arrayOfFunctionOrdinals                = (USHORT*)( (unsigned char*)hMod + pExportTable->AddressOfNameOrdinals);
        Base                                                = pExportTable->Base;

        RtlInitString(&ntFunctionNameSearch, lpFunctionName);
        for(x = 0; x < pExportTable->NumberOfFunctions; x++)
        {
                functionName = (char*)( (unsigned char*)hMod + arrayOfFunctionNames[x]);

                RtlInitString(&ntFunctionName, functionName);        

                if (RtlCompareString(&ntFunctionName, &ntFunctionNameSearch, TRUE) == 0)
                {
                        functionOrdinal = arrayOfFunctionOrdinals[x] + Base - 1;
                        functionAddress = (ULONG_PTR)( (unsigned char*)hMod + arrayOfFunctionAddresses[functionOrdinal]);

#ifdef _AMD64_
                        uIndex=*(PULONG)((PUCHAR)functionAddress+4);
#else
                        uIndex=*(PULONG)((PUCHAR)functionAddress+1);
#endif

                        break;
                }
        }

        ZwClose(hSection);
        ZwUnmapViewOfSection(NtCurrentProcess(),BaseAddress);
        return uIndex;
}