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// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
// **************************************************************************
#include "shadow.h"
#include <algorithm>
#include <string>
#include <zen/com_ptr.h>
#include <zen/com_error.h>
#include <zen/scope_guard.h>
#include <boost/thread/tss.hpp>
#ifdef USE_SHADOW_XP
#include "xp/inc/vss.h"
#include "xp/inc/vswriter.h"
#include "xp/inc/vsbackup.h"
#elif defined USE_SHADOW_2003
#include "Server 2003/inc/vss.h"
#include "Server 2003/inc/vswriter.h"
#include "Server 2003/inc/vsbackup.h"
#elif defined USE_SHADOW_WINDOWS7
#include <vss.h> //
#include <vswriter.h> //part of Windows SDK for Windows 7
#include <vsbackup.h> //
#pragma comment(lib, "VssApi.lib")
#else
#error adapt!
#endif
using namespace zen;
struct shadow::ShadowData
{
ShadowData(const ComPtr<IVssBackupComponents>& backupComp,
const std::wstring& shadowVolume) : backupComp_(backupComp), shadowVolume_(shadowVolume) {}
ComPtr<IVssBackupComponents> backupComp_;
std::wstring shadowVolume_;
};
namespace
{
std::wstring formatVssError(HRESULT hr) //at least the one's from IVssBackupComponents::AddToSnapshotSet; return empty if no format found
{
switch (hr)
{
case VSS_E_BAD_STATE:
return L"VSS_E_BAD_STATE";
case VSS_E_MAXIMUM_NUMBER_OF_VOLUMES_REACHED:
return L"VSS_E_MAXIMUM_NUMBER_OF_VOLUMES_REACHED";
case VSS_E_MAXIMUM_NUMBER_OF_SNAPSHOTS_REACHED:
return L"VSS_E_MAXIMUM_NUMBER_OF_SNAPSHOTS_REACHED";
case VSS_E_OBJECT_NOT_FOUND:
return L"VSS_E_OBJECT_NOT_FOUND";
case VSS_E_PROVIDER_NOT_REGISTERED:
return L"VSS_E_PROVIDER_NOT_REGISTERED";
case VSS_E_PROVIDER_VETO:
return L"VSS_E_PROVIDER_VETO";
case VSS_E_VOLUME_NOT_SUPPORTED:
return L"VSS_E_VOLUME_NOT_SUPPORTED";
case VSS_E_VOLUME_NOT_SUPPORTED_BY_PROVIDER:
return L"VSS_E_VOLUME_NOT_SUPPORTED_BY_PROVIDER";
case VSS_E_UNEXPECTED_PROVIDER_ERROR:
return L"VSS_E_UNEXPECTED_PROVIDER_ERROR";
default:
return std::wstring();
}
}
shadow::ShadowData createShadowCopy(const wchar_t* volumeName) //throw ComError
{
ComPtr<IVssBackupComponents> backupComp;
{
HRESULT hr = ::CreateVssBackupComponents(backupComp.init());
if (FAILED(hr))
{
if (hr == E_ACCESSDENIED)
throw ComError(L"The caller does not have sufficient backup privileges or is not an administrator.", hr);
throw ComError(L"Error calling \"CreateVssBackupComponents\".", hr);
}
}
ZEN_CHECK_COM(backupComp->InitializeForBackup()); //throw ComError
ZEN_CHECK_COM(backupComp->SetBackupState(false, false, VSS_BT_FULL)); //throw ComError
auto waitForComFuture = [](IVssAsync& fut)
{
ZEN_CHECK_COM(fut.Wait());
HRESULT hr = S_OK;
ZEN_CHECK_COM(fut.QueryStatus(&hr, nullptr)); //check if the async operation succeeded...
if (FAILED(hr))
throw ComError(L"Error calling \"fut->QueryStatus\".", hr);
};
ComPtr<IVssAsync> gatherAsync;
ZEN_CHECK_COM(backupComp->GatherWriterMetadata(gatherAsync.init()));
waitForComFuture(*gatherAsync); //failure can happen if XP-version of VSS is used on Windows Vista (which needs at least VSS-Server2003 build)
VSS_ID snapshotSetId = {};
ZEN_CHECK_COM(backupComp->StartSnapshotSet(&snapshotSetId));
ScopeGuard guardSnapShot = makeGuard([&] { backupComp->AbortBackup(); });
//Quote: "This method must be called if a backup operation terminates after the creation of a
//shadow copy set with "StartSnapshotSet" and before "DoSnapshotSet" returns."
VSS_ID SnapShotId = {};
{
HRESULT hr = backupComp->AddToSnapshotSet(const_cast<wchar_t*>(volumeName), GUID_NULL, &SnapShotId);
if (FAILED(hr))
{
if (hr == VSS_E_VOLUME_NOT_SUPPORTED)
throw ComError(L"Volume Shadow Copy Service is not supported on this volume!");
const std::wstring vssError = formatVssError(hr);
if (!vssError.empty())
throw ComError(L"Error calling \"backupComp->AddToSnapshotSet\": " + vssError);
else
throw ComError(L"Error calling \"backupComp->AddToSnapshotSet\".", hr);
}
}
ComPtr<IVssAsync> prepareAsync;
ZEN_CHECK_COM(backupComp->PrepareForBackup(prepareAsync.init()));
waitForComFuture(*prepareAsync);
ComPtr<IVssAsync> snapshotAsync;
ZEN_CHECK_COM(backupComp->DoSnapshotSet(snapshotAsync.init()));
guardSnapShot.dismiss();
waitForComFuture(*snapshotAsync);
VSS_SNAPSHOT_PROP props = {};
ZEN_CHECK_COM(backupComp->GetSnapshotProperties(SnapShotId, &props));
ZEN_ON_SCOPE_EXIT(::VssFreeSnapshotProperties(&props));
//finally: write volume name of newly created shadow copy
return shadow::ShadowData(backupComp, props.m_pwszSnapshotDeviceObject);
}
boost::thread_specific_ptr<std::wstring> lastErrorMessage; //use "thread_local" in C++11
}
shadow::ShadowHandle shadow::createShadowCopy(const wchar_t* volumeName)
{
try
{
ShadowData result = ::createShadowCopy(volumeName); //throw ComError
return new ShadowData(result); //shadow handle owned by caller! std::bad_alloc?
}
catch (const zen::ComError& e)
{
lastErrorMessage.reset(new std::wstring(e.toString()));
return nullptr;
}
}
const wchar_t* shadow::getShadowVolume(shadow::ShadowHandle handle)
{
return handle ? handle->shadowVolume_.c_str() : nullptr; //better fail in client code than here!
}
void shadow::releaseShadowCopy(ShadowHandle handle)
{
delete handle;
}
const wchar_t* shadow::getLastError()
{
return !lastErrorMessage.get() ? L"" : lastErrorMessage->c_str();
}
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