devicelist.cpp

Programming the Microsoft Windows Driver Model(2nd)

// DeviceList.cpp - Implemementation of CDeviceList class
// Copyright (C) 1999 by Walter Oney
// All rights reserved

#include "stdafx.h"
#include <setupapi.h>
#include <regstr.h>
#include "DeviceList.h"

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

CDeviceList::CDeviceList(const GUID& guid)
	{							// CDeviceList::CDeviceList
	m_guid = guid;
	}							// CDeviceList::CDeviceList

CDeviceList::~CDeviceList()
	{							// CDeviceList::~CDeviceList
	}							// CDeviceList::~CDeviceList

///////////////////////////////////////////////////////////////////////////////

int CDeviceList::Initialize()
	{							// CDeviceList::Initialize

	// Open an enumeration handle so we can locate all devices of our
	// own class

	HDEVINFO info = SetupDiGetClassDevs(&m_guid, NULL, NULL, DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);
	if (info == INVALID_HANDLE_VALUE)
		return 0;

	// Enumerate all devices of our class. For each one, create a
	// CDeviceEntryList object. Then determine the friendly name of the
	// device by reading the registry.

	SP_DEVICE_INTERFACE_DATA ifdata;
	ifdata.cbSize = sizeof(ifdata);
	DWORD devindex;
	for (devindex = 0; SetupDiEnumDeviceInterfaces(info, NULL, &m_guid, devindex, &ifdata); ++devindex)
		{						// for each device

		// Determine the symbolic link name for this device instance. Since
		// this is variable in length, make an initial call to determine
		// the required length.

		DWORD needed;
		SetupDiGetDeviceInterfaceDetail(info, &ifdata, NULL, 0, &needed, NULL);

		PSP_INTERFACE_DEVICE_DETAIL_DATA detail = (PSP_INTERFACE_DEVICE_DETAIL_DATA) malloc(needed);
		SP_DEVINFO_DATA did = {sizeof(SP_DEVINFO_DATA)};
		detail->cbSize = sizeof(SP_INTERFACE_DEVICE_DETAIL_DATA);
		if (!SetupDiGetDeviceInterfaceDetail(info, &ifdata, detail, needed, NULL, &did))
			{						// can't get detail info
			free((PVOID) detail);
			continue;
			}						// can't get detail info

		// Determine the device's friendly name

		TCHAR fname[256];
		memset(fname, 0, sizeof(fname));
		if (!SetupDiGetDeviceRegistryProperty(info, &did, SPDRP_FRIENDLYNAME, NULL, (PBYTE) fname, sizeof(fname), NULL)
			&& !SetupDiGetDeviceRegistryProperty(info, &did, SPDRP_DEVICEDESC, NULL, (PBYTE) fname, sizeof(fname), NULL))
			_tcsncpy(fname, detail->DevicePath, 256);

		CDeviceListEntry e(detail->DevicePath, fname);
		free((PVOID) detail);

		m_list.Add(e);
		}						// for each device

	SetupDiDestroyDeviceInfoList(info);

	// Return the number of entries in the list

	return m_list.GetSize();
	}							// CDeviceList::Initialize

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

CDeviceListEntry::CDeviceListEntry(LPCTSTR linkname, LPCTSTR friendlyname)
	{							// CDeviceListEntry::CDeviceListEntry
	m_linkname = linkname;
	m_friendlyname = friendlyname;
	}							// CDeviceListEntry::CDeviceListEntry

///////////////////////////////////////////////////////////////////////////////

CString CDeviceListEntry::GetProperty(enum DEVPROP prop)
	{							// CDeviceListEntry::GetProperty

	TCHAR propval[256] = "";

	// Create a device info object describing this device.

	HDEVINFO info = SetupDiCreateDeviceInfoList(NULL, NULL);
	if (info != INVALID_HANDLE_VALUE)
		{						// opened info list okay

		SP_DEVICE_INTERFACE_DATA ifdata = {sizeof(SP_DEVICE_INTERFACE_DATA)};
		SP_DEVINFO_DATA devdata = {sizeof(SP_DEVINFO_DATA)};

		// Open the device interface using the device's symbolic link name, then request
		// detailed information about the interface. What we want here is an SP_DEVINFO_DATA
		// structure that we can use to get properties from the registry. Note the obscure
		// fact that the get-detail call will fail with ERROR_INSUFFICIENT_BUFFER because
		// we're not supplying a detail structure even though it returns the SP_DEVINFO_DATA (!)

		if (SetupDiOpenDeviceInterface(info, m_linkname, 0, &ifdata)
			&& (SetupDiGetDeviceInterfaceDetail(info, &ifdata, NULL, 0, NULL, &devdata)
			|| GetLastError() == ERROR_INSUFFICIENT_BUFFER))
			{					// got device info
			static DWORD propcode[] = {
				SPDRP_DEVICEDESC,
				SPDRP_HARDWAREID,
				SPDRP_COMPATIBLEIDS,
				SPDRP_SERVICE,
				SPDRP_CLASS,
				SPDRP_CLASSGUID,
				SPDRP_DRIVER,
				SPDRP_MFG,
				SPDRP_FRIENDLYNAME,
				SPDRP_ENUMERATOR_NAME,
				};

			// Fetch the desired property from the registry

			SetupDiGetDeviceRegistryProperty(info, &devdata, propcode[prop], NULL, (PBYTE) propval,
				sizeof(propval), NULL);
			}					// got device info

		SetupDiDestroyDeviceInfoList(info);
		}						// opened info list okay

	return propval;
	}							// CDeviceListEntry::GetProperty