Add support for setupapi.SetupDiClassGuidsFromNameEx()

Signed-off-by: Simon Rozman <simon@rozman.si>

setupapi/setupapi_windows.go

@@ -14,6 +14,7 @@ import (
 )
 
 //sys	setupDiClassNameFromGuidEx(ClassGUID *windows.GUID, ClassName *uint16, ClassNameSize uint32, RequiredSize *uint32, MachineName *uint16, Reserved uintptr) (err error) = setupapi.SetupDiClassNameFromGuidExW
+//sys	setupDiClassGuidsFromNameEx(ClassName *uint16, ClassGuidList *windows.GUID, ClassGuidListSize uint32, RequiredSize *uint32, MachineName *uint16, Reserved uintptr) (err error) = setupapi.SetupDiClassGuidsFromNameExW
 //sys	setupDiGetClassDevsEx(ClassGUID *windows.GUID, Enumerator *uint16, hwndParent uintptr, Flags DIGCF, DeviceInfoSet DevInfo, MachineName *uint16, reserved uintptr) (handle DevInfo, err error) [failretval==DevInfo(windows.InvalidHandle)] = setupapi.SetupDiGetClassDevsExW
 //sys	SetupDiDestroyDeviceInfoList(DeviceInfoSet DevInfo) (err error) = setupapi.SetupDiDestroyDeviceInfoList
 //sys	setupDiGetDeviceInfoListDetail(DeviceInfoSet DevInfo, DeviceInfoSetDetailData *_SP_DEVINFO_LIST_DETAIL_DATA) (err error) = setupapi.SetupDiGetDeviceInfoListDetailW
@@ -46,6 +47,42 @@ func SetupDiClassNameFromGuidEx(ClassGUID *windows.GUID, MachineName string) (Cl
 	return
 }
 
+// SetupDiClassGuidsFromNameEx function retrieves the GUIDs associated with the specified class name. This resulting list contains the classes currently installed on a local or remote computer.
+func SetupDiClassGuidsFromNameEx(ClassName string, MachineName string) (ClassGuidList []windows.GUID, err error) {
+	_p0, err := syscall.UTF16PtrFromString(ClassName)
+	if err != nil {
+		return
+	}
+
+	var _p1 [4]windows.GUID
+	var _p1reqSize uint32
+
+	var _p2 *uint16
+	if MachineName != "" {
+		_p2, err = syscall.UTF16PtrFromString(MachineName)
+		if err != nil {
+			return
+		}
+	}
+
+	err = setupDiClassGuidsFromNameEx(_p0, &_p1[0], 4, &_p1reqSize, _p2, 0)
+	if err == nil {
+		// The GUID array was sufficiently big. Return its slice.
+		return _p1[:_p1reqSize], nil
+	}
+
+	if errWin, ok := err.(syscall.Errno); ok && errWin == windows.ERROR_INSUFFICIENT_BUFFER {
+		// The GUID array was too small. Now that we got the required size, create another one big enough and retry.
+		_p1 := make([]windows.GUID, _p1reqSize)
+		err = setupDiClassGuidsFromNameEx(_p0, &_p1[0], _p1reqSize, &_p1reqSize, _p2, 0)
+		if err == nil {
+			return _p1[:_p1reqSize], nil
+		}
+	}
+
+	return
+}
+
 // SetupDiGetClassDevsEx function returns a handle to a device information set that contains requested device information elements for a local or a remote computer.
 func SetupDiGetClassDevsEx(ClassGUID *windows.GUID, Enumerator string, hwndParent uintptr, Flags DIGCF, DeviceInfoSet DevInfo, MachineName string) (handle DevInfo, err error) {
 	var _p0 *uint16

setupapi/setupapi_windows_test.go

@@ -45,6 +45,31 @@ func TestSetupDiClassNameFromGuidEx(t *testing.T) {
 	}
 }
 
+func TestSetupDiClassGuidsFromNameEx(t *testing.T) {
+	ClassGUIDs, err := SetupDiClassGuidsFromNameEx("Net", "")
+	if err != nil {
+		t.Errorf("Error calling SetupDiClassGuidsFromNameEx: %s", err.Error())
+	} else {
+		found := false
+		for i := range ClassGUIDs {
+			if ClassGUIDs[i] == deviceClassNetGUID {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Errorf("SetupDiClassGuidsFromNameEx(\"Net\") should return %x", deviceClassNetGUID)
+		}
+	}
+
+	ClassGUIDs, err = SetupDiClassGuidsFromNameEx("foobar-34274a51-a6e6-45f0-80d6-c62be96dd5fe", computerName)
+	if err != nil {
+		t.Errorf("Error calling SetupDiClassGuidsFromNameEx: %s", err.Error())
+	} else if len(ClassGUIDs) != 0 {
+		t.Errorf("SetupDiClassGuidsFromNameEx(\"foobar-34274a51-a6e6-45f0-80d6-c62be96dd5fe\") should return an empty GUID set")
+	}
+}
+
 func TestSetupDiGetClassDevsEx(t *testing.T) {
 	devInfoList, err := SetupDiGetClassDevsEx(&deviceClassNetGUID, "PCI", 0, DIGCF_PRESENT, DevInfo(0), computerName)
 	if err == nil {

setupapi/zsetupapi_windows.go

@@ -40,6 +40,7 @@ var (
 	modsetupapi = windows.NewLazySystemDLL("setupapi.dll")
 
 	procSetupDiClassNameFromGuidExW     = modsetupapi.NewProc("SetupDiClassNameFromGuidExW")
+	procSetupDiClassGuidsFromNameExW    = modsetupapi.NewProc("SetupDiClassGuidsFromNameExW")
 	procSetupDiGetClassDevsExW          = modsetupapi.NewProc("SetupDiGetClassDevsExW")
 	procSetupDiDestroyDeviceInfoList    = modsetupapi.NewProc("SetupDiDestroyDeviceInfoList")
 	procSetupDiGetDeviceInfoListDetailW = modsetupapi.NewProc("SetupDiGetDeviceInfoListDetailW")
@@ -64,6 +65,18 @@ func setupDiClassNameFromGuidEx(ClassGUID *windows.GUID, ClassName *uint16, Clas
 	return
 }
 
+func setupDiClassGuidsFromNameEx(ClassName *uint16, ClassGuidList *windows.GUID, ClassGuidListSize uint32, RequiredSize *uint32, MachineName *uint16, Reserved uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall6(procSetupDiClassGuidsFromNameExW.Addr(), 6, uintptr(unsafe.Pointer(ClassName)), uintptr(unsafe.Pointer(ClassGuidList)), uintptr(ClassGuidListSize), uintptr(unsafe.Pointer(RequiredSize)), uintptr(unsafe.Pointer(MachineName)), uintptr(Reserved))
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
 func setupDiGetClassDevsEx(ClassGUID *windows.GUID, Enumerator *uint16, hwndParent uintptr, Flags DIGCF, DeviceInfoSet DevInfo, MachineName *uint16, reserved uintptr) (handle DevInfo, err error) {
 	r0, _, e1 := syscall.Syscall9(procSetupDiGetClassDevsExW.Addr(), 7, uintptr(unsafe.Pointer(ClassGUID)), uintptr(unsafe.Pointer(Enumerator)), uintptr(hwndParent), uintptr(Flags), uintptr(DeviceInfoSet), uintptr(unsafe.Pointer(MachineName)), uintptr(reserved), 0, 0)
 	handle = DevInfo(r0)