详解C语言内核中的链表与结构体

2024-04-02 19:55

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Windows内核中是无法使用vector容器等数据结构的，当我们需要保存一个结构体数组时，就需要使用内核中提供的专用链表结构LIST_ENTRY通过一些列链表操作函数对结构体进行装入弹出等操作，如下代码是本人总结的内核中使用链表存储多个结构体的通用案例。

首先实现一个枚举用户进程功能，将枚举到的进程存储到链表结构体内。

#include <ntifs.h>
#include <windef.h>

extern PVOID PsGetProcessPeb(_In_ PEPROCESS Process);
NTKERNELAPI NTSTATUS PsLookupProcessByProcessId(HANDLE ProcessId, PEPROCESS *Process);
extern NTKERNELAPI PVOID PsGetProcessWow64Process(_In_ PEPROCESS Process);
extern NTKERNELAPI UCHAR* PsGetProcessImageFileName(IN PEPROCESS Process);
extern NTKERNELAPI HANDLE PsGetProcessInheritedFromUniqueProcessId(IN PEPROCESS Process);

typedef struct
{
	DWORD Pid;
	UCHAR ProcessName[2048];
	DWORD Handle;
	LIST_ENTRY ListEntry;
}ProcessList;

// 根据进程ID返回进程EPROCESS结构体失败返回NULL
PEPROCESS LookupProcess(HANDLE Pid)
{
	PEPROCESS eprocess = NULL;
	NTSTATUS Status = STATUS_UNSUCCESSFUL;
	Status = PsLookupProcessByProcessId(Pid, &eprocess);
	if (NT_SUCCESS(Status))
	{
		return eprocess;
	}
	return NULL;
}

// 内核链表操作
// By: LyShark
BOOLEAN GetAllProcess()
{
	PEPROCESS eproc = NULL;
	LIST_ENTRY linkListHead;

	// 初始化链表头部
	InitializeListHead(&linkListHead);
	ProcessList *pData = NULL;

	for (int temp = 0; temp < 100000; temp += 4)
	{
		eproc = LookupProcess((HANDLE)temp);
		if (eproc != NULL)
		{
			STRING nowProcessnameString = { 0 };
			RtlInitString(&nowProcessnameString, PsGetProcessImageFileName(eproc));

			// DbgPrint("进程名: %s --> 进程PID = %d --> 父进程PPID = %d\r\n", 
			// PsGetProcessImageFileName(eproc), PsGetProcessId(eproc), PsGetProcessInheritedFromUniqueProcessId(eproc));

			// 分配内核堆空间
			pData = (ProcessList *)ExAllocatePool(PagedPool, sizeof(ProcessList));
			RtlZeroMemory(pData, sizeof(ProcessList));

			// 设置变量
			pData->Pid = (DWORD)PsGetProcessId(eproc);
			RtlCopyMemory(pData->ProcessName, PsGetProcessImageFileName(eproc), strlen(PsGetProcessImageFileName(eproc)) * 2);
			pData->Handle = (DWORD)PsGetProcessInheritedFromUniqueProcessId(eproc);

			// 插入元素到
			InsertTailList(&linkListHead, &pData->ListEntry);
			ObDereferenceObject(eproc);
		}
	}

	// 输出链表内的数据
	while (!IsListEmpty(&linkListHead))
	{
		LIST_ENTRY *pEntry = RemoveHeadList(&linkListHead);
		pData = CONTAINING_RECORD(pEntry, ProcessList, ListEntry);

		DbgPrint("%d \n", pData->Pid);
		DbgPrint("%s \n", pData->ProcessName);
		DbgPrint("%d \n", pData->Handle);
		ExFreePool(pData);
	}
	return TRUE;
}

VOID UnDriver(PDRIVER_OBJECT driver)
{
	DbgPrint(("Uninstall Driver Is OK \n"));
}

NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
	DbgPrint("hello lyshark.com \n");

	GetAllProcess();

	Driver->DriverUnload = UnDriver;
	return STATUS_SUCCESS;
}

运行后将可以在DbgView中看到输出的进程信息：

如果需要返回一个结构体，则可以这样来写代码。

#include <ntifs.h>
#include <windef.h>

typedef struct
{
	int count;
	char username[256];
	char password[256];
}MyData;

// 模拟返回一个结构
BOOLEAN GetProcess(PVOID OutPut)
{
	RtlZeroMemory(OutPut, sizeof(MyData));
	MyData *data = OutPut;

	data->count = 100;
	RtlCopyMemory(data->username, "lyshark.com", sizeof("lyshark.com"));
	RtlCopyMemory(data->password, "https://www.cnblogs.com/lyshark", sizeof("https://www.cnblogs.com/lyshark"));
	return TRUE;
}

VOID UnDriver(PDRIVER_OBJECT driver)
{
	DbgPrint(("Uninstall Driver Is OK \n"));
}

NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
	DbgPrint("hello lyshark.com \n");
	PVOID Ptr = (PVOID)ExAllocatePool(NonPagedPool, sizeof(MyData));


	GetProcess(Ptr);

	MyData *data = (MyData *)Ptr;

	DbgPrint("count = %d \n", data->count);
	DbgPrint("username = %s \n", data->username);
	DbgPrint("password = %s \n", data->password);

	Driver->DriverUnload = UnDriver;
	return STATUS_SUCCESS;
}

输出效果如下：