Commit b39297ae authored by Tomoki Sekiyama's avatar Tomoki Sekiyama Committed by Michael Roth
Browse files

qemu-ga: Add Windows VSS provider and requester as DLL



Adds VSS provider and requester as a qga-vss.dll, which is loaded by
Windows VSS service as well as by qemu-ga.

"provider.cpp" implements a basic stub of a software VSS provider.
Currently, this module only relays a frozen event from VSS service to the
agent, and thaw event from the agent to VSS service, to block VSS process
to keep the system frozen while snapshots are taken at the host.

To register the provider to the guest system as COM+ application, the type
library (.tlb) for qga-vss.dll is required. To build it from COM IDL (.idl),
VisualC++, MIDL and stdole2.tlb in Windows SDK are required. This patch also
adds pre-compiled .tlb file in the repository in order to enable
cross-compile qemu-ga.exe for Windows with VSS support.

"requester.cpp" provides the VSS requester to kick the VSS snapshot process.
Qemu-ga.exe works without the DLL, although fsfreeze features are disabled.

These functions are only supported in Windows 2003 or later. In older
systems, fsfreeze features are disabled.

In several versions of Windows which don't support attribute
VSS_VOLSNAP_ATTR_NO_AUTORECOVERY, DoSnapshotSet fails with error
VSS_E_OBJECT_NOT_FOUND. In this patch, we just ignore this error.
To solve this fundamentally, we need a framework to handle mount writable
snapshot on guests, which is required by VSS auto-recovery feature
(cleanup phase after a snapshot is taken).
Signed-off-by: default avatarTomoki Sekiyama <tomoki.sekiyama@hds.com>
Signed-off-by: default avatarMichael Roth <mdroth@linux.vnet.ibm.com>
parent 20840d4c
......@@ -235,7 +235,7 @@ clean:
rm -f qemu-options.def
find . -name '*.[oda]' -type f -exec rm -f {} +
find . -name '*.l[oa]' -type f -exec rm -f {} +
rm -f $(TOOLS) $(HELPERS-y) qemu-ga TAGS cscope.* *.pod *~ */*~
rm -f $(filter-out %.tlb,$(TOOLS)) $(HELPERS-y) qemu-ga TAGS cscope.* *.pod *~ */*~
rm -Rf .libs
rm -f qemu-img-cmds.h
@# May not be present in GENERATED_HEADERS
......
......@@ -109,6 +109,7 @@ version-lobj-$(CONFIG_WIN32) += $(BUILD_DIR)/version.lo
# FIXME: a few definitions from qapi-types.o/qapi-visit.o are needed
# by libqemuutil.a. These should be moved to a separate .json schema.
qga-obj-y = qga/ qapi-types.o qapi-visit.o
qga-vss-dll-obj-y = qga/
vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
......@@ -120,6 +121,7 @@ nested-vars += \
stub-obj-y \
util-obj-y \
qga-obj-y \
qga-vss-dll-obj-y \
block-obj-y \
common-obj-y
dummy := $(call unnest-vars)
......@@ -3568,8 +3568,11 @@ if test "$softmmu" = yes ; then
fi
fi
if [ "$guest_agent" != "no" ]; then
if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" ] ; then
if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" -o "$mingw32" = "yes" ] ; then
tools="qemu-ga\$(EXESUF) $tools"
if [ "$mingw32" = "yes" -a "$guest_agent_with_vss" = "yes" ]; then
tools="qga/vss-win32/qga-vss.dll qga/vss-win32/qga-vss.tlb $tools"
fi
guest_agent=yes
elif [ "$guest_agent" != yes ]; then
guest_agent=no
......
......@@ -3,3 +3,5 @@ qga-obj-$(CONFIG_POSIX) += commands-posix.o channel-posix.o
qga-obj-$(CONFIG_WIN32) += commands-win32.o channel-win32.o service-win32.o
qga-obj-y += qapi-generated/qga-qapi-types.o qapi-generated/qga-qapi-visit.o
qga-obj-y += qapi-generated/qga-qmp-marshal.o
qga-vss-dll-obj-$(CONFIG_QGA_VSS) += vss-win32/
# rules to build qga-vss.dll
qga-vss-dll-obj-y += requester.o provider.o install.o
obj-qga-vss-dll-obj-y = $(addprefix $(obj)/, $(qga-vss-dll-obj-y))
$(obj-qga-vss-dll-obj-y): QEMU_CXXFLAGS = $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls -fstack-protector-all, $(QEMU_CFLAGS)) -Wno-unknown-pragmas -Wno-delete-non-virtual-dtor
$(obj)/qga-vss.dll: LDFLAGS = -shared -Wl,--add-stdcall-alias,--enable-stdcall-fixup -lole32 -loleaut32 -lshlwapi -luuid -static
$(obj)/qga-vss.dll: $(obj-qga-vss-dll-obj-y) $(SRC_PATH)/$(obj)/qga-vss.def
$(call quiet-command,$(CXX) -o $@ $(qga-vss-dll-obj-y) $(SRC_PATH)/qga/vss-win32/qga-vss.def $(CXXFLAGS) $(LDFLAGS)," LINK $(TARGET_DIR)$@")
# rules to build qga-provider.tlb
# Currently, only native build is supported because building .tlb
# (TypeLibrary) from .idl requires WindowsSDK and MIDL (and cl.exe in VC++).
MIDL=$(WIN_SDK)/Bin/midl
$(obj)/qga-vss.tlb: $(SRC_PATH)/$(obj)/qga-vss.idl
ifeq ($(WIN_SDK),"")
$(call quiet-command,cp $(dir $<)qga-vss.tlb $@, " COPY $(TARGET_DIR)$@")
else
$(call quiet-command,$(MIDL) -tlb $@ -I $(WIN_SDK)/Include $<," MIDL $(TARGET_DIR)$@")
endif
/*
* QEMU Guest Agent win32 VSS Provider installer
*
* Copyright Hitachi Data Systems Corp. 2013
*
* Authors:
* Tomoki Sekiyama <tomoki.sekiyama@hds.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include <stdio.h>
#include <string.h>
#include "vss-common.h"
#include "inc/win2003/vscoordint.h"
#include <comadmin.h>
#include <wbemidl.h>
#include <comdef.h>
#include <comutil.h>
extern HINSTANCE g_hinstDll;
const GUID CLSID_COMAdminCatalog = { 0xF618C514, 0xDFB8, 0x11d1,
{0xA2, 0xCF, 0x00, 0x80, 0x5F, 0xC7, 0x92, 0x35} };
const GUID IID_ICOMAdminCatalog = { 0xDD662187, 0xDFC2, 0x11d1,
{0xA2, 0xCF, 0x00, 0x80, 0x5F, 0xC7, 0x92, 0x35} };
const GUID CLSID_WbemLocator = { 0x4590f811, 0x1d3a, 0x11d0,
{0x89, 0x1f, 0x00, 0xaa, 0x00, 0x4b, 0x2e, 0x24} };
const GUID IID_IWbemLocator = { 0xdc12a687, 0x737f, 0x11cf,
{0x88, 0x4d, 0x00, 0xaa, 0x00, 0x4b, 0x2e, 0x24} };
void errmsg(DWORD err, const char *text)
{
/*
* `text' contains function call statement when errmsg is called via chk().
* To make error message more readable, we cut off the text after '('.
* If text doesn't contains '(', negative precision is given, which is
* treated as though it were missing.
*/
char *msg = NULL, *nul = strchr(text, '(');
int len = nul ? nul - text : -1;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(char *)&msg, 0, NULL);
fprintf(stderr, "%.*s. (Error: %lx) %s\n", len, text, err, msg);
LocalFree(msg);
}
static void errmsg_dialog(DWORD err, const char *text, const char *opt = "")
{
char *msg, buf[512];
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(char *)&msg, 0, NULL);
snprintf(buf, sizeof(buf), "%s%s. (Error: %lx) %s", text, opt, err, msg);
MessageBox(NULL, buf, "Error from " QGA_PROVIDER_NAME, MB_OK|MB_ICONERROR);
LocalFree(msg);
}
#define _chk(hr, status, msg, err_label) \
do { \
hr = (status); \
if (FAILED(hr)) { \
errmsg(hr, msg); \
goto err_label; \
} \
} while (0)
#define chk(status) _chk(hr, status, "Failed to " #status, out)
void __stdcall _com_issue_error(HRESULT hr)
{
errmsg(hr, "Unexpected error in COM");
}
template<class T>
HRESULT put_Value(ICatalogObject *pObj, LPCWSTR name, T val)
{
return pObj->put_Value(_bstr_t(name), _variant_t(val));
}
/* Lookup Administrators group name from winmgmt */
static HRESULT GetAdminName(_bstr_t *name)
{
HRESULT hr;
COMPointer<IWbemLocator> pLoc;
COMPointer<IWbemServices> pSvc;
COMPointer<IEnumWbemClassObject> pEnum;
COMPointer<IWbemClassObject> pWobj;
ULONG returned;
_variant_t var;
chk(CoCreateInstance(CLSID_WbemLocator, NULL, CLSCTX_INPROC_SERVER,
IID_IWbemLocator, (LPVOID *)pLoc.replace()));
chk(pLoc->ConnectServer(_bstr_t(L"ROOT\\CIMV2"), NULL, NULL, NULL,
0, 0, 0, pSvc.replace()));
chk(CoSetProxyBlanket(pSvc, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE,
NULL, RPC_C_AUTHN_LEVEL_CALL,
RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE));
chk(pSvc->ExecQuery(_bstr_t(L"WQL"),
_bstr_t(L"select * from Win32_Account where "
"SID='S-1-5-32-544' and localAccount=TRUE"),
WBEM_FLAG_RETURN_IMMEDIATELY | WBEM_FLAG_FORWARD_ONLY,
NULL, pEnum.replace()));
if (!pEnum) {
hr = E_FAIL;
errmsg(hr, "Failed to query for Administrators");
goto out;
}
chk(pEnum->Next(WBEM_INFINITE, 1, pWobj.replace(), &returned));
if (returned == 0) {
hr = E_FAIL;
errmsg(hr, "No Administrators found");
goto out;
}
chk(pWobj->Get(_bstr_t(L"Name"), 0, &var, 0, 0));
try {
*name = var;
} catch(...) {
hr = E_FAIL;
errmsg(hr, "Failed to get name of Administrators");
goto out;
}
out:
return hr;
}
/* Find and iterate QGA VSS provider in COM+ Application Catalog */
static HRESULT QGAProviderFind(
HRESULT (*found)(ICatalogCollection *, int, void *), void *arg)
{
HRESULT hr;
COMInitializer initializer;
COMPointer<IUnknown> pUnknown;
COMPointer<ICOMAdminCatalog> pCatalog;
COMPointer<ICatalogCollection> pColl;
COMPointer<ICatalogObject> pObj;
_variant_t var;
long i, n;
chk(CoCreateInstance(CLSID_COMAdminCatalog, NULL, CLSCTX_INPROC_SERVER,
IID_IUnknown, (void **)pUnknown.replace()));
chk(pUnknown->QueryInterface(IID_ICOMAdminCatalog,
(void **)pCatalog.replace()));
chk(pCatalog->GetCollection(_bstr_t(L"Applications"),
(IDispatch **)pColl.replace()));
chk(pColl->Populate());
chk(pColl->get_Count(&n));
for (i = n - 1; i >= 0; i--) {
chk(pColl->get_Item(i, (IDispatch **)pObj.replace()));
chk(pObj->get_Value(_bstr_t(L"Name"), &var));
if (var == _variant_t(QGA_PROVIDER_LNAME)) {
if (FAILED(found(pColl, i, arg))) {
goto out;
}
}
}
chk(pColl->SaveChanges(&n));
out:
return hr;
}
/* Count QGA VSS provider in COM+ Application Catalog */
static HRESULT QGAProviderCount(ICatalogCollection *coll, int i, void *arg)
{
(*(int *)arg)++;
return S_OK;
}
/* Remove QGA VSS provider from COM+ Application Catalog Collection */
static HRESULT QGAProviderRemove(ICatalogCollection *coll, int i, void *arg)
{
HRESULT hr;
fprintf(stderr, "Removing COM+ Application: %s\n", QGA_PROVIDER_NAME);
chk(coll->Remove(i));
out:
return hr;
}
/* Unregister this module from COM+ Applications Catalog */
STDAPI COMUnregister(void)
{
HRESULT hr;
DllUnregisterServer();
chk(QGAProviderFind(QGAProviderRemove, NULL));
out:
return hr;
}
/* Register this module to COM+ Applications Catalog */
STDAPI COMRegister(void)
{
HRESULT hr;
COMInitializer initializer;
COMPointer<IUnknown> pUnknown;
COMPointer<ICOMAdminCatalog> pCatalog;
COMPointer<ICatalogCollection> pApps, pRoles, pUsersInRole;
COMPointer<ICatalogObject> pObj;
long n;
_bstr_t name;
_variant_t key;
CHAR dllPath[MAX_PATH], tlbPath[MAX_PATH];
bool unregisterOnFailure = false;
int count = 0;
if (!g_hinstDll) {
errmsg(E_FAIL, "Failed to initialize DLL");
return E_FAIL;
}
chk(QGAProviderFind(QGAProviderCount, (void *)&count));
if (count) {
errmsg(E_ABORT, "QGA VSS Provider is already installed");
return E_ABORT;
}
chk(CoCreateInstance(CLSID_COMAdminCatalog, NULL, CLSCTX_INPROC_SERVER,
IID_IUnknown, (void **)pUnknown.replace()));
chk(pUnknown->QueryInterface(IID_ICOMAdminCatalog,
(void **)pCatalog.replace()));
/* Install COM+ Component */
chk(pCatalog->GetCollection(_bstr_t(L"Applications"),
(IDispatch **)pApps.replace()));
chk(pApps->Populate());
chk(pApps->Add((IDispatch **)&pObj));
chk(put_Value(pObj, L"Name", QGA_PROVIDER_LNAME));
chk(put_Value(pObj, L"Description", QGA_PROVIDER_LNAME));
chk(put_Value(pObj, L"ApplicationAccessChecksEnabled", true));
chk(put_Value(pObj, L"Authentication", short(6)));
chk(put_Value(pObj, L"AuthenticationCapability", short(2)));
chk(put_Value(pObj, L"ImpersonationLevel", short(2)));
chk(pApps->SaveChanges(&n));
/* The app should be deleted if something fails after SaveChanges */
unregisterOnFailure = true;
chk(pObj->get_Key(&key));
if (!GetModuleFileName(g_hinstDll, dllPath, sizeof(dllPath))) {
hr = HRESULT_FROM_WIN32(GetLastError());
errmsg(hr, "GetModuleFileName failed");
goto out;
}
n = strlen(dllPath);
if (n < 3) {
hr = E_FAIL;
errmsg(hr, "Failed to lookup dll");
goto out;
}
strcpy(tlbPath, dllPath);
strcpy(tlbPath+n-3, "tlb");
fprintf(stderr, "Registering " QGA_PROVIDER_NAME ":\n");
fprintf(stderr, " %s\n", dllPath);
fprintf(stderr, " %s\n", tlbPath);
if (!PathFileExists(tlbPath)) {
hr = HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND);
errmsg(hr, "Failed to lookup tlb");
goto out;
}
chk(pCatalog->InstallComponent(_bstr_t(QGA_PROVIDER_LNAME),
_bstr_t(dllPath), _bstr_t(tlbPath),
_bstr_t("")));
/* Setup roles of the applicaion */
chk(pApps->GetCollection(_bstr_t(L"Roles"), key,
(IDispatch **)pRoles.replace()));
chk(pRoles->Populate());
chk(pRoles->Add((IDispatch **)pObj.replace()));
chk(put_Value(pObj, L"Name", L"Administrators"));
chk(put_Value(pObj, L"Description", L"Administrators group"));
chk(pRoles->SaveChanges(&n));
chk(pObj->get_Key(&key));
/* Setup users in the role */
chk(pRoles->GetCollection(_bstr_t(L"UsersInRole"), key,
(IDispatch **)pUsersInRole.replace()));
chk(pUsersInRole->Populate());
chk(pUsersInRole->Add((IDispatch **)pObj.replace()));
chk(GetAdminName(&name));
chk(put_Value(pObj, L"User", _bstr_t(".\\") + name));
chk(pUsersInRole->Add((IDispatch **)pObj.replace()));
chk(put_Value(pObj, L"User", L"SYSTEM"));
chk(pUsersInRole->SaveChanges(&n));
out:
if (unregisterOnFailure && FAILED(hr)) {
COMUnregister();
}
return hr;
}
static BOOL CreateRegistryKey(LPCTSTR key, LPCTSTR value, LPCTSTR data)
{
HKEY hKey;
LONG ret;
DWORD size;
ret = RegCreateKeyEx(HKEY_CLASSES_ROOT, key, 0, NULL,
REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL, &hKey, NULL);
if (ret != ERROR_SUCCESS) {
goto out;
}
if (data != NULL) {
size = strlen(data) + 1;
} else {
size = 0;
}
ret = RegSetValueEx(hKey, value, 0, REG_SZ, (LPBYTE)data, size);
RegCloseKey(hKey);
out:
if (ret != ERROR_SUCCESS) {
/* As we cannot printf within DllRegisterServer(), show a dialog. */
errmsg_dialog(ret, "Cannot add registry", key);
return FALSE;
}
return TRUE;
}
/* Register this dll as a VSS provider */
STDAPI DllRegisterServer(void)
{
COMInitializer initializer;
COMPointer<IVssAdmin> pVssAdmin;
HRESULT hr = E_FAIL;
char dllPath[MAX_PATH];
char key[256];
if (!g_hinstDll) {
errmsg_dialog(hr, "Module instance is not available");
goto out;
}
/* Add this module to registery */
sprintf(key, "CLSID\\%s", g_szClsid);
if (!CreateRegistryKey(key, NULL, g_szClsid)) {
goto out;
}
if (!GetModuleFileName(g_hinstDll, dllPath, sizeof(dllPath))) {
errmsg_dialog(GetLastError(), "GetModuleFileName failed");
goto out;
}
sprintf(key, "CLSID\\%s\\InprocServer32", g_szClsid);
if (!CreateRegistryKey(key, NULL, dllPath)) {
goto out;
}
if (!CreateRegistryKey(key, "ThreadingModel", "Apartment")) {
goto out;
}
sprintf(key, "CLSID\\%s\\ProgID", g_szClsid);
if (!CreateRegistryKey(key, NULL, g_szProgid)) {
goto out;
}
if (!CreateRegistryKey(g_szProgid, NULL, QGA_PROVIDER_NAME)) {
goto out;
}
sprintf(key, "%s\\CLSID", g_szProgid);
if (!CreateRegistryKey(key, NULL, g_szClsid)) {
goto out;
}
hr = CoCreateInstance(CLSID_VSSCoordinator, NULL, CLSCTX_ALL,
IID_IVssAdmin, (void **)pVssAdmin.replace());
if (FAILED(hr)) {
errmsg_dialog(hr, "CoCreateInstance(VSSCoordinator) failed");
goto out;
}
hr = pVssAdmin->RegisterProvider(g_gProviderId, CLSID_QGAVSSProvider,
const_cast<WCHAR*>(QGA_PROVIDER_LNAME),
VSS_PROV_SOFTWARE,
const_cast<WCHAR*>(QGA_PROVIDER_VERSION),
g_gProviderVersion);
if (FAILED(hr)) {
errmsg_dialog(hr, "RegisterProvider failed");
}
out:
if (FAILED(hr)) {
DllUnregisterServer();
}
return hr;
}
/* Unregister this VSS hardware provider from the system */
STDAPI DllUnregisterServer(void)
{
TCHAR key[256];
COMInitializer initializer;
COMPointer<IVssAdmin> pVssAdmin;
HRESULT hr = CoCreateInstance(CLSID_VSSCoordinator,
NULL, CLSCTX_ALL, IID_IVssAdmin,
(void **)pVssAdmin.replace());
if (SUCCEEDED(hr)) {
hr = pVssAdmin->UnregisterProvider(g_gProviderId);
} else {
errmsg(hr, "CoCreateInstance(VSSCoordinator) failed");
}
sprintf(key, "CLSID\\%s", g_szClsid);
SHDeleteKey(HKEY_CLASSES_ROOT, key);
SHDeleteKey(HKEY_CLASSES_ROOT, g_szProgid);
return S_OK; /* Uninstall should never fail */
}
/* Support function to convert ASCII string into BSTR (used in _bstr_t) */
namespace _com_util
{
BSTR WINAPI ConvertStringToBSTR(const char *ascii) {
int len = strlen(ascii);
BSTR bstr = SysAllocStringLen(NULL, len);
if (!bstr) {
return NULL;
}
if (mbstowcs(bstr, ascii, len) == (size_t)-1) {
fprintf(stderr, "Failed to convert string '%s' into BSTR", ascii);
bstr[0] = 0;
}
return bstr;
}
}
/*
* QEMU Guest Agent win32 VSS Provider implementations
*
* Copyright Hitachi Data Systems Corp. 2013
*
* Authors:
* Tomoki Sekiyama <tomoki.sekiyama@hds.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include <stdio.h>
#include "vss-common.h"
#include "inc/win2003/vscoordint.h"
#include "inc/win2003/vsprov.h"
#define VSS_TIMEOUT_MSEC (60*1000)
static long g_nComObjsInUse;
HINSTANCE g_hinstDll;
/* VSS common GUID's */
const CLSID CLSID_VSSCoordinator = { 0xE579AB5F, 0x1CC4, 0x44b4,
{0xBE, 0xD9, 0xDE, 0x09, 0x91, 0xFF, 0x06, 0x23} };
const IID IID_IVssAdmin = { 0x77ED5996, 0x2F63, 0x11d3,
{0x8A, 0x39, 0x00, 0xC0, 0x4F, 0x72, 0xD8, 0xE3} };
const IID IID_IVssHardwareSnapshotProvider = { 0x9593A157, 0x44E9, 0x4344,
{0xBB, 0xEB, 0x44, 0xFB, 0xF9, 0xB0, 0x6B, 0x10} };
const IID IID_IVssSoftwareSnapshotProvider = { 0x609e123e, 0x2c5a, 0x44d3,
{0x8f, 0x01, 0x0b, 0x1d, 0x9a, 0x47, 0xd1, 0xff} };
const IID IID_IVssProviderCreateSnapshotSet = { 0x5F894E5B, 0x1E39, 0x4778,
{0x8E, 0x23, 0x9A, 0xBA, 0xD9, 0xF0, 0xE0, 0x8C} };
const IID IID_IVssProviderNotifications = { 0xE561901F, 0x03A5, 0x4afe,
{0x86, 0xD0, 0x72, 0xBA, 0xEE, 0xCE, 0x70, 0x04} };
const IID IID_IVssEnumObject = { 0xAE1C7110, 0x2F60, 0x11d3,
{0x8A, 0x39, 0x00, 0xC0, 0x4F, 0x72, 0xD8, 0xE3} };
void LockModule(BOOL lock)
{
if (lock) {
InterlockedIncrement(&g_nComObjsInUse);
} else {
InterlockedDecrement(&g_nComObjsInUse);
}
}
/* Empty enumerator for VssObject */
class CQGAVSSEnumObject : public IVssEnumObject
{
public:
STDMETHODIMP QueryInterface(REFIID riid, void **ppObj);
STDMETHODIMP_(ULONG) AddRef();
STDMETHODIMP_(ULONG) Release();
/* IVssEnumObject Methods */
STDMETHODIMP Next(
ULONG celt, VSS_OBJECT_PROP *rgelt, ULONG *pceltFetched);
STDMETHODIMP Skip(ULONG celt);
STDMETHODIMP Reset(void);
STDMETHODIMP Clone(IVssEnumObject **ppenum);
/* CQGAVSSEnumObject Methods */
CQGAVSSEnumObject();
~CQGAVSSEnumObject();
private:
long m_nRefCount;
};
CQGAVSSEnumObject::CQGAVSSEnumObject()
{