/******************************************************************************
* *
* Function: zbx_wmi_get_variant *
* *
* Purpose: retrieves WMI value and stores it in the provided memory location *
* *
* Parameters: wmi_namespace [IN] - object path of the WMI namespace (UTF-8) *
* wmi_query [IN] - WQL query (UTF-8) *
* vtProp [OUT] - pointer to memory for the queried value *
* *
* Return value: SYSINFO_RET_OK - *vtProp contains the retrieved WMI value *
* SYSINFO_RET_FAIL - retreiving WMI value failed *
* *
* Comments: *vtProp must be initialized with VariantInit(), *
* wmi_* must not be NULL. The callers must convert value to the *
* intended format using VariantChangeType() *
* *
******************************************************************************/
extern "C" int zbx_wmi_get_variant(const char *wmi_namespace, const char *wmi_query, VARIANT *vtProp)
{
IWbemLocator *pLoc = 0;
IWbemServices *pService = 0;
IEnumWbemClassObject *pEnumerator = 0;
IWbemClassObject *pclsObj = 0;
ULONG uReturn = 0;
int ret = SYSINFO_RET_FAIL;
HRESULT hres;
wchar_t *wmi_namespace_wide;
wchar_t *wmi_query_wide;
/* obtain the initial locator to Windows Management on a particular host computer */
hres = CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &pLoc);
if (FAILED(hres))
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot obtain WMI locator service");
goto out;
}
wmi_namespace_wide = zbx_utf8_to_unicode(wmi_namespace);
hres = pLoc->ConnectServer(_bstr_t(wmi_namespace_wide), NULL, NULL, 0, NULL, 0, 0, &pService);
zbx_free(wmi_namespace_wide);
if (FAILED(hres))
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot obtain %s WMI service", wmi_namespace);
goto out;
}
/* set the IWbemServices proxy so that impersonation of the user (client) occurs */
hres = CoSetProxyBlanket(pService, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE, NULL, RPC_C_AUTHN_LEVEL_CALL,
RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE);
if (FAILED(hres))
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot set IWbemServices proxy");
goto out;
}
wmi_query_wide = zbx_utf8_to_unicode(wmi_query);
hres = pService->ExecQuery(_bstr_t("WQL"), _bstr_t(wmi_query_wide),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY, NULL, &pEnumerator);
zbx_free(wmi_query_wide);
if (FAILED(hres))
{
zabbix_log(LOG_LEVEL_DEBUG, "failed to execute WMI query %s", wmi_query);
goto out;
}
hres = pEnumerator->Next(WBEM_INFINITE, 1, &pclsObj, &uReturn);
if (0 == uReturn)
goto out;
hres = pclsObj->BeginEnumeration(WBEM_FLAG_NONSYSTEM_ONLY);
if (FAILED(hres))
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot start WMI query result enumeration");
goto out;
}
hres = pclsObj->Next(0, NULL, vtProp, 0, 0);
pclsObj->EndEnumeration();
if (FAILED(hres) || hres == WBEM_S_NO_MORE_DATA)
goto out;
ret = SYSINFO_RET_OK;
out:
if (0 != pclsObj)
pclsObj->Release();
if (0 != pEnumerator)
pEnumerator->Release();
if (0 != pService)
pService->Release();
if (0 != pLoc)
pLoc->Release();
return ret;
}
