c++ - 在 C++ 中使用 Win32_Process.GetOwner

Question

我正在尝试使用 WMI 类 Win32_Process 来获取正在运行的进程的列表以及作为每个进程所有者的用户。使用 MSDN (MSDN) 中的枚举示例并简单地将 Win32_OperatingSystem 更改为 Win32_Process，在 C++ 中使用 Win32_Process 枚举进程并不困难。我发现通过使用 Win32_Process 的 GetOwner 方法我可以获得进程所有者的用户和域。在 VB ( MSDN ) 中有一个很好的例子，它表明我可以使用枚举器对象调用 GetOwner 的特定实例以获取枚举中任何给定点的进程信息。

我试图使用“调用提供者方法”的代码示例 ( MSDN ) 来弄清楚如何调用 GetOwner 方法，但我不知道如何让它工作。我不断遇到障碍。通常我得到无效的方法参数。采取以下代码块

        BSTR MethodName = SysAllocString(L"GetOwner");
        BSTR ClassName = SysAllocString(L"Win32_Process");

        IWbemClassObject* pClass = NULL;
        hres = pSvc->GetObject(ClassName, 0, NULL, &pClass, NULL);
        printf("[1] hres = %08x\n", hres);

        IWbemClassObject* pInParamsDefinition = NULL;
        IWbemClassObject* pOutParams = NULL;
        hres = pClass->GetMethod(MethodName, 0, &pInParamsDefinition, &pOutParams);
        printf("[2] hres = %08x (%08x, %08x)\n", hres, pInParamsDefinition, pOutParams);

        // Execute Method
        hres = pSvc->ExecMethod(L"Win32_Process", MethodName, 0, NULL, NULL, &pOutParams, NULL);

        VARIANT varReturnValue;
        hres = pOutParams->Get(_bstr_t(L"ReturnValue"), 0,
            &varReturnValue, NULL, 0);
        wprintf(L"The command is: %s\n", V_BSTR(&varReturnValue));

GetOwner 没有输入参数，当我调用 GetMethod 时，pInParamsDefinition 总是返回 NULL，而 pOutParams 返回一个 ptr。由于没有返回到 pInParamsDefinition 的指针，我无法提供输入，因此我不知道如何解决无效方法参数问题。显然 WMI 编程不是我的强项:)

我在这里错过了什么？

Answer 1

断断续续折腾了一段时间后，我终于找到了自己问题的答案。问题是您需要指定要针对哪个对象执行该方法。为此，您调用 GetObject("__PATH", ...) 以获取当前正在枚举的对象的路径，并将 GetObject(一个 BSTR)的结果作为第一个参数传递给 ExecMethod。这告诉方法，在我的例子中是 GetOwner，你试图针对什么执行。这是我编写的一个示例程序，它转储当前的进程列表及其所有者。

#define _WIN32_DCOM
#include <iostream>
using namespace std;
#include <comdef.h>
#include <Wbemidl.h>

#pragma comment(lib, "wbemuuid.lib")

int main(int argc, char **argv)
{
	HRESULT hres;

	// Step 1: --------------------------------------------------
	// Initialize COM. ------------------------------------------

	hres = CoInitializeEx(0, COINIT_MULTITHREADED);
	if (FAILED(hres))
	{
		cout << "Failed to initialize COM library. Error code = 0x"
			<< hex << hres << endl;
		return 1;                  // Program has failed.
	}

	// Step 2: --------------------------------------------------
	// Set general COM security levels --------------------------

	hres = CoInitializeSecurity(
		NULL,
		-1,                          // COM authentication
		NULL,                        // Authentication services
		NULL,                        // Reserved
		RPC_C_AUTHN_LEVEL_DEFAULT,   // Default authentication 
		RPC_C_IMP_LEVEL_IMPERSONATE, // Default Impersonation  
		NULL,                        // Authentication info
		EOAC_NONE,                   // Additional capabilities 
		NULL                         // Reserved
		);


	if (FAILED(hres))
	{
		cout << "Failed to initialize security. Error code = 0x"
			<< hex << hres << endl;
		CoUninitialize();
		return 1;                    // Program has failed.
	}

	// Step 3: ---------------------------------------------------
	// Obtain the initial locator to WMI -------------------------

	IWbemLocator *pLoc = NULL;

	hres = CoCreateInstance(
		CLSID_WbemLocator,
		0,
		CLSCTX_INPROC_SERVER,
		IID_IWbemLocator, (LPVOID *)&pLoc);

	if (FAILED(hres))
	{
		cout << "Failed to create IWbemLocator object."
			<< " Err code = 0x"
			<< hex << hres << endl;
		CoUninitialize();
		return 1;                 // Program has failed.
	}

	// Step 4: -----------------------------------------------------
	// Connect to WMI through the IWbemLocator::ConnectServer method

	IWbemServices *pSvc = NULL;

	// Connect to the root\cimv2 namespace with
	// the current user and obtain pointer pSvc
	// to make IWbemServices calls.
	hres = pLoc->ConnectServer(
		_bstr_t(L"ROOT\\CIMV2"), // Object path of WMI namespace
		NULL,                    // User name. NULL = current user
		NULL,                    // User password. NULL = current
		0,                       // Locale. NULL indicates current
		NULL,                    // Security flags.
		0,                       // Authority (for example, Kerberos)
		0,                       // Context object 
		&pSvc                    // pointer to IWbemServices proxy
		);

	if (FAILED(hres))
	{
		cout << "Could not connect. Error code = 0x"
			<< hex << hres << endl;
		pLoc->Release();
		CoUninitialize();
		return 1;                // Program has failed.
	}

	cout << "Connected to ROOT\\CIMV2 WMI namespace" << endl;


	// Step 5: --------------------------------------------------
	// Set security levels on the proxy -------------------------

	hres = CoSetProxyBlanket(
		pSvc,                        // Indicates the proxy to set
		RPC_C_AUTHN_WINNT,           // RPC_C_AUTHN_xxx
		RPC_C_AUTHZ_NONE,            // RPC_C_AUTHZ_xxx
		NULL,                        // Server principal name 
		RPC_C_AUTHN_LEVEL_CALL,      // RPC_C_AUTHN_LEVEL_xxx 
		RPC_C_IMP_LEVEL_IMPERSONATE, // RPC_C_IMP_LEVEL_xxx
		NULL,                        // client identity
		EOAC_NONE                    // proxy capabilities 
		);

	if (FAILED(hres))
	{
		cout << "Could not set proxy blanket. Error code = 0x"
			<< hex << hres << endl;
		pSvc->Release();
		pLoc->Release();
		CoUninitialize();
		return 1;               // Program has failed.
	}

	BSTR MethodName = SysAllocString(L"GetOwner");
	BSTR ClassName = SysAllocString(L"Win32_Process");

	// get the object containing our desired method
	IWbemClassObject* pClass = NULL;
	hres = pSvc->GetObject(ClassName, 0, NULL, &pClass, NULL);
	if (FAILED(hres))
	{
		printf("GetObject hres = %08x\n", hres);
		pSvc->Release();
		pLoc->Release();
		CoUninitialize();
		return 1;
	}
	
	// get the desired method
	// in our case, we only need pmethodGetOwner since GetOwner really only has output
	IWbemClassObject* pmethodGetOwner = NULL;
	hres = pClass->GetMethod(MethodName, 0, NULL, &pmethodGetOwner);
	if (FAILED(hres))
	{
		printf("GetMethod hres = %08x\n", hres);
		pSvc->Release();
		pLoc->Release();
		CoUninitialize();
		return 1;
	}

	// spawn the instance of the method
	IWbemClassObject* pInInst = NULL;
	hres = pmethodGetOwner->SpawnInstance(0, &pInInst);
	if (FAILED(hres))
	{
		printf("SpawnInstance hres = %08x\n", hres);
		pSvc->Release();
		pLoc->Release();
		CoUninitialize();
		return 1;
	}

	// Step 6: --------------------------------------------------
	// Use the IWbemServices pointer to make requests of WMI ----

	// For example, get the name of the operating system
	IEnumWbemClassObject* pEnumerator = NULL;
	hres = pSvc->ExecQuery(
		bstr_t("WQL"),
		bstr_t("SELECT * FROM Win32_Process"),
		WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
		NULL,
		&pEnumerator);

	if (FAILED(hres))
	{
		cout << "Query for operating system name failed."
			<< " Error code = 0x"
			<< hex << hres << endl;
		pSvc->Release();
		pLoc->Release();
		CoUninitialize();
		return 1;               // Program has failed.
	}

	// Step 7: -------------------------------------------------
	// Get the data from the query in step 6 -------------------

	IWbemClassObject *pclsObj = NULL;
	ULONG uReturn = 0;

	while (pEnumerator)
	{
		HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1, &pclsObj, &uReturn);

		if (0 == uReturn)
		{
			break;
		}

		VARIANT vtProp;
		VARIANT vtProcName;
		VARIANT vtDomain;
		VARIANT vtUsername;

		// Get the value of the Name property
		hr = pclsObj->Get(L"Name", 0, &vtProcName, 0, 0);
		if (FAILED(hres))
		{
			printf("Failed to get the process's name\n");
			pclsObj->Release();
			continue;
		}

		// Get the PATH to the object in question
		// the result in vtProp is similar to '\\name_of_computer\ROOT\CIMV2:Win32_Process.Handle="pid_of_process"'
		hr = pclsObj->Get(L"__PATH", 0, &vtProp, 0, 0);
		if (FAILED(hres))
		{
			printf("Failed to get the path to the object\n");
			pclsObj->Release();
			continue;
		}

		// Execute Method against the object defined by the __PATH variable
		hres = pSvc->ExecMethod(vtProp.bstrVal, MethodName, 0, NULL, NULL, &pmethodGetOwner, NULL);
		if (FAILED(hres))
		{
			wprintf(L"Failed to execute the method against %s\n", vtProp.bstrVal);
			pclsObj->Release();
			continue;
		}

		// extract the results
		hres = pmethodGetOwner->Get(L"User", 0, &vtUsername, NULL, 0);
		if (FAILED(hres))
		{
			printf("Failed to get the owner's name\n");
			pclsObj->Release();
			continue;
		}

		pmethodGetOwner->Get(L"Domain", 0, &vtDomain, NULL, 0);
		if (FAILED(hres))
		{
			printf("Failed to get the owner's domain\n");
			pclsObj->Release();
			continue;
		}

		// print the output to screen
		wprintf(L"Process: %s. Domain\\User: %s\\%s\n", V_BSTR(&vtProcName), V_BSTR(&vtDomain), V_BSTR(&vtUsername));

		// release/cleanup resources we used this go around
		VariantClear(&vtProcName);
		VariantClear(&vtProp);
		VariantClear(&vtDomain);
		VariantClear(&vtUsername);
		pclsObj->Release();

	}

	// Cleanup
	// ========

	pSvc->Release();
	pLoc->Release();
	pEnumerator->Release();
	CoUninitialize();

	return 0;   // Program successfully completed.

}

多亏了 2002 年在 google 群组上的随机发帖 ( "Here is a WBem WMI C++ example" )，我才能够弄清楚这一切。

我希望这对以后的其他人有帮助。