querying WMI in dlang over COM

dlang_wmi.d

// https://forum.dlang.org/post/dmmfzotxhlghialrsvyw@forum.dlang.org
//
// warning: this is not what you would consider good code, you want
// to make a proper library for the COM classes and types and make sure
// really all resources are freed. I mostly try to do so with all the
// scope(exit) expressions here but for example the VARIANT usage is
// actually wrong and should use proper types.

import core.stdc.config;
import core.stdc.stdio;
import core.sys.windows.com;
import core.sys.windows.oaidl;
import core.sys.windows.objidl;
import core.sys.windows.windows;
import core.sys.windows.wtypes;

void main(string[] args)
{
	// port of https://docs.microsoft.com/en-us/windows/win32/wmisdk/example-creating-a-wmi-application

	CoInitializeEx(null, COINIT.COINIT_MULTITHREADED)
		.validateHResult("CoInitializeEx");
	scope (exit)
		CoUninitialize();

	CoInitializeSecurity(null, // security descriptor
			-1, // COM negotiates service                  
			null, // Authentication services
			null, // Reserved
			RPC_C_AUTHN_LEVEL_DEFAULT, // authentication
			RPC_C_IMP_LEVEL_IMPERSONATE, // Impersonation
			null, // Authentication info 
			EOLE_AUTHENTICATION_CAPABILITIES.EOAC_NONE, // Additional capabilities
			null  // Reserved
			).validateHResult("CoInitializeSecurity");

	IWbemLocator loc;
	CoCreateInstance(&CLSID_WbemLocator, null, CLSCTX_INPROC_SERVER,
			&IID_IWbemLocator, cast(void**)&loc).validateHResult(
			"CoCreateInstance WbemLocator");
	scope (exit)
		loc.Release();

	IWbemServices svc;
	loc.ConnectServer("ROOT\\CIMV2", // WMI namespace
			null, // username
			null, // password
			null, // locale
			0, // security flags
			null, // authority
			null, // context object
			&svc // IWbemServices proxy
			).validateHResult("ConnectServer");
	scope (exit)
		svc.Release();

	// Set the IWbemServices proxy so that impersonation
	// of the user (client) occurs.

	// WARNING V wrong D definition (wants IUnknown* instead of IUnknown which is already a reference type, cast overrides this)
	CoSetProxyBlanket(cast(IUnknown*) svc, // the proxy to set
			RPC_C_AUTHN_WINNT, // authentication service
			RPC_C_AUTHZ_NONE, // authorization service
			NULL, // Server principal name
			RPC_C_AUTHN_LEVEL_CALL, // authentication level
			RPC_C_IMP_LEVEL_IMPERSONATE, // impersonation level
			NULL, // client identity 
			EOLE_AUTHENTICATION_CAPABILITIES.EOAC_NONE // proxy capabilities
			).validateHResult("CoSetProxyBlanket");

	IEnumWbemClassObject enumerator;
	svc.ExecQuery("WQL", "SELECT * FROM Win32_PnPEntity",
			WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
			null, &enumerator).validateHResult("ExecQuery");
	scope (exit)
		enumerator.Release();

	IWbemClassObject clsobj;
	ULONG ureturn;
	while (true)
	{
		enumerator.Next(WBEM_INFINITE,
				1, &clsobj, &ureturn);
		if (!ureturn)
			break;
		scope (exit)
			clsobj.Release();

		BSTR name;
		VARIANT vtProp;
		printf("\nEntry:\n");
		clsobj.BeginEnumeration(0);
		while (true)
		{
			enum WBEM_S_NO_MORE_DATA = 0x40005;
			if (clsobj.Next(0, &name, &vtProp, null,
					null) == WBEM_S_NO_MORE_DATA)
				break;
			printf("\t%ls: ", name);
			SysFreeString(name);
			
			// TODO: variant code suck
			// check https://docs.microsoft.com/en-us/windows/win32/api/oaidl/ns-oaidl-variant
			// and https://docs.microsoft.com/en-us/windows/win32/api/propidlbase/ns-propidlbase-propvariant
			// to make this better
			switch (vtProp.vt)
			{
			case VARENUM.VT_EMPTY:
				printf("<empty>\n");
				break;
			case VARENUM.VT_NULL:
				printf("null\n");
				break;
			case VARENUM.VT_VOID:
				printf("void\n");
				break;
			case VARENUM.VT_I1:
				printf("byte: %d\n",
						cast(int) vtProp.bVal);
				break;
			case VARENUM.VT_UI1:
				printf("ubyte: %d\n",
						cast(int) vtProp.bVal);
				break;
			case VARENUM.VT_UI2:
				printf("ushort: %d\n",
						cast(int) vtProp.iVal);
				break;
			case VARENUM.VT_UI4:
			case VARENUM.VT_UINT:
				printf("uint: %u\n",
						cast(uint) vtProp.intVal);
				break;
			case VARENUM.VT_I8:
				printf("long: %ld\n",
						cast(long) vtProp.llVal);
				break;
			case VARENUM.VT_UI8:
				printf("ulong: %lu\n",
						cast(ulong) vtProp.llVal);
				break;
			case VARENUM.VT_I2:
				printf("short: %d\n",
						cast(int) vtProp.iVal);
				break;
			case VARENUM.VT_I4:
			case VARENUM.VT_INT:
				printf("int: %d\n", vtProp.intVal);
				break;
			case VARENUM.VT_R4:
				printf("float: %f\n", vtProp.fltVal);
				break;
			case VARENUM.VT_R8:
				printf("double: %f\n", vtProp.dblVal);
				break;
			case VARENUM.VT_CY:
				printf("currency: %ld\n",
						vtProp.cyVal.int64);
				break;
			case VARENUM.VT_DATE:
				printf("date: %lf\n", vtProp.date);
				break;
			case VARENUM.VT_BSTR:
				printf("bstr: %ls\n", vtProp.bstrVal);
				break;
			case VARENUM.VT_BOOL:
				if (vtProp.boolVal)
					printf("true\n");
				else
					printf("false\n");
				break;
			default:
				printf("<type %d>\n", vtProp.vt);
				break;
			}
			VariantClear(&vtProp);
		}
	}
}

// type definitions, might as well move them to a library...

HRESULT validateHResult(HRESULT result, string what)
{
	if (!FAILED(result))
		return result;
	else
		throw new HResultException(result, what);
}

class HResultException : Exception
{
	this(HRESULT hresult, string what,
			string file = __FILE__, size_t line = __LINE__)
	{
		import std.conv : to;

		code = hresult;
		if (hresult == S_OK)
		{
			super("Nothing wrong (S_OK)", file, line);
			return;
		}

		string error = "HRESULT Fail for " ~ what ~ ": ";
		wstring info = windowsMessage;
		if (info.length)
			error ~= info.to!string ~ " ";
		super(error ~ "Code 0x" ~ hresult.to!string(16),
				file, line);
	}

	wstring windowsMessage()
	{
		import std.string : strip;

		wchar* message;
		auto len = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER
				| FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
				null, code, MAKELANGID(LANG_NEUTRAL,
					SUBLANG_DEFAULT),
				cast(wchar*)&message, 0, null);
		wstring ret = message[0 .. len].strip.idup;
		LocalFree(message);
		return ret;
	}

	HRESULT code;
}

// COM interface defintions (see C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\um\WbemCli.Idl)

// [object, restricted, local, uuid(dc12a687-737f-11cf-884d-00aa004b2e24),
//     pointer_default(unique)]
//dfmt off
interface IWbemLocator  : IUnknown
{
	HRESULT ConnectServer(
		const BSTR strNetworkResource,
		const BSTR strUser,
		const BSTR strPassword,
		const BSTR strLocale,
		c_long lSecurityFlags,
		const BSTR strAuthority,
		IWbemContext pCtx,
		IWbemServices* ppNamespace
	);
}


// [object, restricted, local, uuid(44aca674-e8fc-11d0-a07c-00c04fb68820)]
interface IWbemContext : IUnknown
{
	HRESULT Clone(IWbemContext* ppNewCopy);

	HRESULT GetNames(
		c_long lFlags,
		BSTR* pNames
	);

	HRESULT BeginEnumeration(c_long lFlags);

	HRESULT Next(
		c_long lFlags,
		BSTR* pstrName,
		VARIANT* pValue
	);

	HRESULT EndEnumeration();


	HRESULT SetValue(
		LPCWSTR wszName,
		c_long lFlags,
		VARIANT* pValue
	);

	HRESULT GetValue(
		LPCWSTR wszName,
		c_long lFlags,
		VARIANT* pValue
	);

	HRESULT DeleteValue(
		LPCWSTR wszName,
		c_long lFlags
	);

	HRESULT DeleteAll();
};

// [object, restricted, uuid(9556dc99-828c-11cf-a37e-00aa003240c7),
// 		pointer_default(unique)]
interface IWbemServices : IUnknown
{
	// Context.
	// ========
	HRESULT OpenNamespace(
		const BSTR strNamespace,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemServices* ppWorkingNamespace,
		IWbemCallResult* ppResult
	);

	HRESULT CancelAsyncCall(
		IWbemObjectSink pSink
	);

	HRESULT QueryObjectSink(
		c_long lFlags,
		IWbemObjectSink* ppResponseHandler
	);

	// Classes and instances.
	// ======================

	HRESULT GetObject(
		const BSTR strObjectPath,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemClassObject* ppObject,
		IWbemCallResult* ppCallResult
	);

	HRESULT GetObjectAsync(
		const BSTR strObjectPath,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	// Class manipulation.
	// ===================

	HRESULT PutClass(
		IWbemClassObject pObject,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemCallResult* ppCallResult
	);

	HRESULT PutClassAsync(
		IWbemClassObject pObject,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	HRESULT DeleteClass(
		const BSTR strClass,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemCallResult* ppCallResult
	);

	HRESULT DeleteClassAsync(
		const BSTR strClass,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	HRESULT CreateClassEnum(
		const BSTR strSuperclass,
		c_long lFlags,
		IWbemContext pCtx,
		IEnumWbemClassObject* ppEnum
	);

	HRESULT CreateClassEnumAsync(
		const BSTR strSuperclass,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	// Instances.
	// ==========

	HRESULT PutInstance(
		IWbemClassObject pInst,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemCallResult* ppCallResult
	);

	HRESULT PutInstanceAsync(
		IWbemClassObject pInst,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	HRESULT DeleteInstance(
		const BSTR strObjectPath,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemCallResult* ppCallResult
	);

	HRESULT DeleteInstanceAsync(
		const BSTR strObjectPath,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
		);

	HRESULT CreateInstanceEnum(
		const BSTR strFilter,          // allow more things than a class name
		c_long lFlags,
		IWbemContext pCtx,
		IEnumWbemClassObject* ppEnum
	);

	HRESULT CreateInstanceEnumAsync(
		const BSTR strFilter,          // allow more things than a class name
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	// Queries.
	// ========

	HRESULT ExecQuery(
		const BSTR strQueryLanguage,
		const BSTR strQuery,
		c_long lFlags,
		IWbemContext pCtx,
		IEnumWbemClassObject* ppEnum
	);

	HRESULT ExecQueryAsync(
		const BSTR strQueryLanguage,
		const BSTR strQuery,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);


	HRESULT ExecNotificationQuery(
		const BSTR strQueryLanguage,
		const BSTR strQuery,
		c_long lFlags,
		IWbemContext pCtx,
		IEnumWbemClassObject* ppEnum
		);

	HRESULT ExecNotificationQueryAsync(
		const BSTR strQueryLanguage,
		const BSTR strQuery,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemObjectSink pResponseHandler
	);

	// Methods
	// =======

	HRESULT ExecMethod(
		const BSTR strObjectPath,
		const BSTR strMethodName,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemClassObject pInParams,
		IWbemClassObject* ppOutParams,
		IWbemCallResult* ppCallResult
	);

	HRESULT ExecMethodAsync(
		const BSTR strObjectPath,
		const BSTR strMethodName,
		c_long lFlags,
		IWbemContext pCtx,
		IWbemClassObject pInParams,
		IWbemObjectSink pResponseHandler
	);
}


// [object, restricted, uuid(44aca675-e8fc-11d0-a07c-00c04fb68820)]
interface IWbemCallResult : IUnknown
{
	HRESULT GetResultObject(
		c_long lTimeout,
		IWbemClassObject* ppResultObject
	);

	HRESULT GetResultString(
		c_long lTimeout,
		BSTR* pstrResultString
	);

	HRESULT GetResultServices(
		c_long lTimeout,
		IWbemServices* ppServices
		);

	HRESULT GetCallStatus(
		c_long lTimeout,
		c_long* plStatus
	);
}

// [object, restricted, uuid(7c857801-7381-11cf-884d-00aa004b2e24)]
interface IWbemObjectSink : IUnknown
{
	HRESULT Indicate(
		c_long lObjectCount,
		IWbemClassObject* apObjArray
	);


	HRESULT SetStatus(
		c_long lFlags,
		HRESULT hResult,
		BSTR strParam,
		IWbemClassObject pObjParam
	);
}

// [local, restricted, object, uuid(dc12a681-737f-11cf-884d-00aa004b2e24)]
interface IWbemClassObject : IUnknown
{
	HRESULT GetQualifierSet(
		IWbemQualifierSet* ppQualSet
	);

	HRESULT Get(
		LPCWSTR wszName,
		c_long lFlags,
		VARIANT* pVal,
		CIMTYPE* pType,
		c_long* plFlavor
	);

	HRESULT Put(
		LPCWSTR wszName,
		c_long lFlags,
		VARIANT* pVal,
		CIMTYPE Type
	);

	HRESULT Delete(
		LPCWSTR wszName
	);

	HRESULT GetNames(
		LPCWSTR wszQualifierName,
		c_long lFlags,
		VARIANT* pQualifierVal,
		BSTR* pNames
	);

	HRESULT BeginEnumeration(c_long lEnumFlags);

	HRESULT Next(
		c_long lFlags,
		BSTR* strName,
		VARIANT* pVal,
		CIMTYPE* pType,
		c_long* plFlavor
	);

	HRESULT EndEnumeration();

	HRESULT GetPropertyQualifierSet(
		LPCWSTR wszProperty,
		IWbemQualifierSet* ppQualSet
	);

	HRESULT Clone(
		IWbemClassObject* ppCopy
	);

	HRESULT GetObjectText(
		c_long lFlags,
		BSTR* pstrObjectText
	);

	HRESULT SpawnDerivedClass(
		c_long lFlags,
		IWbemClassObject* ppNewClass
	);

	HRESULT SpawnInstance(
		c_long lFlags,
		IWbemClassObject* ppNewInstance
	);

	HRESULT CompareTo(
		c_long lFlags,
		IWbemClassObject pCompareTo
	);

	HRESULT GetPropertyOrigin(
		LPCWSTR wszName,
		BSTR* pstrClassName
	);

	HRESULT InheritsFrom(
		LPCWSTR strAncestor
	);

	// Method manipulation.
	// ====================

	HRESULT GetMethod(
		LPCWSTR wszName,
		c_long lFlags,
		IWbemClassObject* ppInSignature,
		IWbemClassObject* ppOutSignature
		);

	HRESULT PutMethod(
		LPCWSTR wszName,
		c_long lFlags,
		IWbemClassObject pInSignature,
		IWbemClassObject pOutSignature
	);

	HRESULT DeleteMethod(
		LPCWSTR wszName
	);

	HRESULT BeginMethodEnumeration(c_long lEnumFlags);

	HRESULT NextMethod(
		c_long lFlags,
		BSTR* pstrName,
		IWbemClassObject* ppInSignature,
		IWbemClassObject* ppOutSignature
	);

	HRESULT EndMethodEnumeration();

	HRESULT GetMethodQualifierSet(
		LPCWSTR wszMethod,
		IWbemQualifierSet* ppQualSet
	);

	HRESULT GetMethodOrigin(
		LPCWSTR wszMethodName,
		BSTR* pstrClassName
	);
}

// [object, restricted, uuid(027947e1-d731-11ce-a357-000000000001)]
interface IEnumWbemClassObject : IUnknown
{
	HRESULT Reset();

	HRESULT Next(
		c_long lTimeout,
		ULONG uCount,
		IWbemClassObject* apObjects,
		ULONG* puReturned
	);

	HRESULT NextAsync(
		ULONG uCount,
		IWbemObjectSink pSink
	);

	HRESULT Clone(
		IEnumWbemClassObject* ppEnum
	);

	HRESULT Skip(
		c_long lTimeout,
		ULONG nCount
	);
}

// [object, restricted, local, uuid(dc12a680-737f-11cf-884d-00aa004b2e24)]
interface IWbemQualifierSet : IUnknown
{
	HRESULT Get(
		LPCWSTR wszName,
		c_long lFlags,
		VARIANT* pVal,
		c_long* plFlavor
	);

	HRESULT Put(
		LPCWSTR wszName,
		VARIANT* pVal,
		c_long lFlavor
	);

	HRESULT Delete(
		LPCWSTR wszName
	);

	HRESULT GetNames(
		c_long lFlags,
		BSTR* pNames
	);

	HRESULT BeginEnumeration(
		c_long lFlags
	);

	HRESULT Next(
		c_long lFlags,
		BSTR* pstrName,
		VARIANT* pVal,
		c_long* plFlavor
	);

	HRESULT EndEnumeration();
}
//dfmt on

enum CIMTYPE : c_long
{
	CIM_ILLEGAL = 0xfff,
	CIM_EMPTY = 0,

	CIM_SINT8 = 16,
	CIM_UINT8 = 17,
	CIM_SINT16 = 2,
	CIM_UINT16 = 18,
	CIM_SINT32 = 3,
	CIM_UINT32 = 19,
	CIM_SINT64 = 20,
	CIM_UINT64 = 21,
	CIM_REAL32 = 4,
	CIM_REAL64 = 5,
	CIM_BOOLEAN = 11,
	CIM_STRING = 8,
	CIM_DATETIME = 101,
	CIM_REFERENCE = 102,
	CIM_CHAR16 = 103,
	CIM_OBJECT = 13,

	CIM_FLAG_ARRAY = 0x2000
}

enum WBEM_FLAG_RETURN_IMMEDIATELY = 0x10;
enum WBEM_FLAG_RETURN_WBEM_COMPLETE = 0;
enum WBEM_FLAG_BIDIRECTIONAL = 0;
enum WBEM_FLAG_FORWARD_ONLY = 0x20;
enum WBEM_FLAG_NO_ERROR_OBJECT = 0x40;
enum WBEM_FLAG_RETURN_ERROR_OBJECT = 0;
enum WBEM_FLAG_SEND_STATUS = 0x80;
enum WBEM_FLAG_DONT_SEND_STATUS = 0;
enum WBEM_FLAG_ENSURE_LOCATABLE = 0x100;
enum WBEM_FLAG_DIRECT_READ = 0x200;
enum WBEM_FLAG_SEND_ONLY_SELECTED = 0;

// backward-compatibility
enum WBEM_RETURN_WHEN_COMPLETE = 0;
enum WBEM_RETURN_IMMEDIATELY = 0x10;

// these bits are reserved!!
enum WBEM_MASK_RESERVED_FLAGS = 0x1F000;

enum WBEM_FLAG_USE_AMENDED_QUALIFIERS = 0x20000;
// If used, the context object must have one or more of the following
//  BOOL "INCLUDE_OWNER"
//  BOOL "INCLUDE_DACL"
//  BOOL "INCLUDE_SACL"
//  BOOL "INCLUDE_GROUP"

enum WBEM_FLAG_STRONG_VALIDATION = 0x100000;

enum WBEM_NO_WAIT = 0;
enum WBEM_INFINITE = 0xFFFFFFFF;