C++ coding with Enable/disable methods of WIN32_NetworkAdapter

Question

I'm trying to enable/disable my network ethernet interface using C++ and WIN32_NetworkAdapter class of WMI. But unfortunately i did not found how the methods of the class may be invoked. thanks in advance...

Answer 1

The code RRUZ posted won't work as is because WIN32_NetworkAdapter's Disable() (and Enable()) methods for have no input parameters. In the call to ExecMethod(), you need to pass in a null in place of pClassInstance (obviously, don't call SpawnInstance() on the null pInParamsDefinition). Note, however, that this doesn't necessarily apply to all cases where there seem to be no input parameters; see the discussion at http://microsoft.public.win32.programmer.wmi.narkive.com/Pxy4mfTi/calling-method-with-no-input-params-in-c

Answer 2

To execute the WMI methods you must use the ExecMethod method of the IWbemServices class. On this case you must pass the Index of the Network adapter to Enable/Disble methods.

Btw if you are new using the WMI and C++ you can use the WDCC Tool , which can help you generate code to access the WMI from C++.

Try this sample code.

#include "stdafx.h"
#define _WIN32_DCOM
#include <iostream>
using namespace std;
#include <comdef.h>
#include <Wbemidl.h>
# pragma comment(lib, "wbemuuid.lib")

//CREDENTIAL structure
//http://msdn.microsoft.com/en-us/library/windows/desktop/aa374788%28v=vs.85%29.aspx
#define CRED_MAX_USERNAME_LENGTH            513
#define CRED_MAX_CREDENTIAL_BLOB_SIZE       512
#define CREDUI_MAX_USERNAME_LENGTH CRED_MAX_USERNAME_LENGTH
#define CREDUI_MAX_PASSWORD_LENGTH (CRED_MAX_CREDENTIAL_BLOB_SIZE / 2)


#pragma argsused
int main(int argc, char* argv[])
{
    wchar_t pszName[CREDUI_MAX_USERNAME_LENGTH+1] = L"user";
    wchar_t pszPwd[CREDUI_MAX_PASSWORD_LENGTH+1]  = L"password";
    BSTR strNetworkResource;
    //To use a WMI remote connection set localconn to false and configure the values of the pszName, pszPwd and the name of the remote machine in strNetworkResource
    bool localconn = true;  
    strNetworkResource = localconn ?  L"\\\\.\\root\\CIMV2" : L"\\\\remote--machine\\root\\CIMV2";

    COAUTHIDENTITY *userAcct =  NULL ;
    COAUTHIDENTITY authIdent;
    HRESULT hres;

    // Initialize COM. ------------------------------------------

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

    // Set general COM security levels --------------------------
    if (localconn)
        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
            );
    else
        hres =  CoInitializeSecurity(
            NULL,
            -1,                          // COM authentication
            NULL,                        // Authentication services
            NULL,                        // Reserved
            RPC_C_AUTHN_LEVEL_DEFAULT,   // Default authentication
            RPC_C_IMP_LEVEL_IDENTIFY,    // 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;
        cout << _com_error(hres).ErrorMessage() << endl;
        CoUninitialize();
        cout << "press enter to exit" << endl;
        cin.get();          
        return 1;                      // Program has failed.
    }

    // 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;
        cout << _com_error(hres).ErrorMessage() << endl;
        CoUninitialize();
        cout << "press enter to exit" << endl;
        cin.get();              
        return 1;                 // Program has failed.
    }

    // Connect to WMI through the IWbemLocator::ConnectServer method

    IWbemServices *pSvc = NULL;

    // Connect to the root\\CIMV2 namespace
    // and obtain pointer pSvc to make IWbemServices calls.
    if (localconn)  
        hres = pLoc->ConnectServer(
             _bstr_t(strNetworkResource),      // 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 (e.g. Kerberos)
             0,                       // Context object
             &pSvc                    // pointer to IWbemServices proxy
             );
    else
        hres = pLoc->ConnectServer(
            _bstr_t(strNetworkResource),  // Object path of WMI namespace
            _bstr_t(pszName),             // User name
            _bstr_t(pszPwd),              // User password
            NULL,                // Locale
            NULL,                // Security flags
            NULL,                // Authority
            NULL,                // Context object
            &pSvc                // IWbemServices proxy
            );


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

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

    // Set security levels on the proxy -------------------------
    if (localconn)
        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
        );
    else
    {
        // Create COAUTHIDENTITY that can be used for setting security on proxy
        memset(&authIdent, 0, sizeof(COAUTHIDENTITY));
        authIdent.PasswordLength = wcslen (pszPwd);
        authIdent.Password = (USHORT*)pszPwd;
        authIdent.User = (USHORT*)pszName;
        authIdent.UserLength = wcslen(pszName);
        authIdent.Domain = 0;
        authIdent.DomainLength = 0;
        authIdent.Flags = SEC_WINNT_AUTH_IDENTITY_UNICODE;
        userAcct = &authIdent;

        hres = CoSetProxyBlanket(
           pSvc,                           // Indicates the proxy to set
           RPC_C_AUTHN_DEFAULT,            // RPC_C_AUTHN_xxx
           RPC_C_AUTHZ_DEFAULT,            // RPC_C_AUTHZ_xxx
           COLE_DEFAULT_PRINCIPAL,         // Server principal name
           RPC_C_AUTHN_LEVEL_PKT_PRIVACY,  // RPC_C_AUTHN_LEVEL_xxx
           RPC_C_IMP_LEVEL_IMPERSONATE,    // RPC_C_IMP_LEVEL_xxx
           userAcct,                       // client identity
           EOAC_NONE                       // proxy capabilities
        );
    }


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

    // Use the IWbemServices pointer to make requests of WMI ----

    BSTR MethodName = SysAllocString(L"Disable");
    BSTR ClassName = SysAllocString(L"Win32_NetworkAdapter");

    IWbemClassObject* pClass = NULL;
    hres = pSvc->GetObject(ClassName, 0, NULL, &pClass, NULL);

    IWbemClassObject* pInParamsDefinition = NULL;
    hres = pClass->GetMethod(MethodName, 0, &pInParamsDefinition, NULL);

    IWbemClassObject* pClassInstance = NULL;
    hres = pInParamsDefinition->SpawnInstance(0, &pClassInstance);



    // Execute Method
    IWbemClassObject* pOutParams = NULL;
    hres = pSvc->ExecMethod(L"Win32_NetworkAdapter.DeviceID=\"0\"", MethodName, 0,
    NULL, pClassInstance, &pOutParams, NULL);

    if (FAILED(hres))
    {
        cout << "Could not execute method. Error code = 0x" << hex << hres << endl;
        cout << _com_error(hres).ErrorMessage() << endl;        
        SysFreeString(ClassName);
        SysFreeString(MethodName);
        if (pClass) pClass->Release();
        if (pInParamsDefinition) pInParamsDefinition->Release();
        if (pOutParams) pOutParams->Release();
        if (pSvc) pSvc->Release();
        if (pLoc) pLoc->Release();     
        CoUninitialize();
        cout << "press enter to exit" << endl;
        cin.get();          
        return 1;               // Program has failed.
    }


    VARIANT varReturnValue;
    hres = pOutParams->Get(L"ReturnValue", 0, &varReturnValue, NULL, 0);
    if (!FAILED(hres))
    wcout << "ReturnValue " << varReturnValue.intVal << endl;
    VariantClear(&varReturnValue);


    // Clean up    
    SysFreeString(ClassName);
    SysFreeString(MethodName);  
    if (pClass) pClass->Release();
    if (pInParamsDefinition) pInParamsDefinition->Release();
    if (pOutParams) pOutParams->Release();
    if (pLoc) pLoc->Release();
    if (pSvc) pSvc->Release();
    CoUninitialize();
    cout << "press enter to exit" << endl;
    cin.get();  
    return 0;
}