I'm trying to run Chkdsk from WMI in C++ (I'm using Qt Framework). 'ExecMethod' returns 'Parameter is not valid'. I've set parameters according to http://msdn.microsoft.com/en-us/library/cc250766.aspx -> I'm using semisynchronously call.
I'm using MSDN Documentation (Win32_LogicalDisk, WMI C++ Application Examples, Win32_Volume,...)
I was also trying with Win32_Volume but it wasn't working as well.
Part of my code:
IWbemLocator *pLoc = NULL;
HRESULT hres = CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &pLoc);
IWbemServices *pSvc = NULL;
hres = pLoc->ConnectServer(_bstr_t(L"ROOT\\CIMV2"), NULL, NULL, 0, NULL, 0, 0, &pSvc);
BSTR MethodName = SysAllocString(L"Chkdsk");
BSTR ClassName = SysAllocString(L"Win32_LogicalDisk");
IWbemCallResult *pCallRes = 0;
hres = pSvc->ExecMethod(ClassName, MethodName, WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY, NULL, NULL, NULL, &pCallRes);
I've also tried with:
BSTR ClassName = SysAllocString(L"Win32_LogicalDisk.DeviceID='C:'");
but there is this same problem.
Any help would be welcome.
You are not passing a proper value to the classname parameter
You must use something like L"Win32_LogicalDisk.DeviceID=\"C:\""
Anyway this is a full sample console app.
#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"Chkdsk");
BSTR ClassName = SysAllocString(L"Win32_LogicalDisk");
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);
VARIANT varCommand;
// Execute Method
IWbemClassObject* pOutParams = NULL;
hres = pSvc->ExecMethod(L"Win32_LogicalDisk.DeviceID=\"C:\"", 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;
}
If you are new to the WMI and C++, you can try a tool like the WMI Delphi Code Creator which can help you to create C++ code to access the WMI.