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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 SysError
{
ComPtr<IVssBackupComponents> backupComp;
{
HRESULT hr = ::CreateVssBackupComponents(backupComp.init());
if (FAILED(hr))
{
if (hr == E_ACCESSDENIED)
throw SysError(formatComError(L"The caller does not have sufficient backup privileges or is not an administrator.", hr));
throw SysError(formatComError(L"Error calling \"CreateVssBackupComponents\".", hr));
}
}
ZEN_COM_CHECK(backupComp->InitializeForBackup()); //throw SysError
//SetContext() only required if different than the default, VSS_CTX_BACKUP; not implemented on XP!!!
//ZEN_COM_CHECK(backupComp->SetContext(VSS_CTX_BACKUP)); //throw SysError
ZEN_COM_CHECK(backupComp->SetBackupState(false, false, VSS_BT_FULL)); //throw SysError
//the Shadow Copy Optimization Writer removes items it considers non-essential,
//http://msdn.microsoft.com/en-US/library/bb968827#shadow_copy_optimization_writer
//like the exclusions in HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\BackupRestore\FilesNotToSnapshot
//http://msdn.microsoft.com/en-us/library/aa819132%28v=vs.85%29.aspx
//Outlook *.ost files in particular:
//https://sourceforge.net/p/freefilesync/discussion/help/thread/722dcbfb
const VSS_ID disabledWriters[] = { { 0x4dc3bdd4, 0xab48, 0x4d07, { 0xad, 0xb0, 0x3b, 0xee, 0x29, 0x26, 0xfd, 0x7f } } }; //Shadow Copy Optimization Writer
{
HRESULT hr = backupComp->DisableWriterClasses(disabledWriters, 1);
if (FAILED(hr) && hr != E_NOTIMPL) //DisableWriterClasses() is not implemented on Windows XP, although MSDN documented otherwise!
throw SysError(formatComError(L"Error calling \"backupComp->DisableWriterClasses\".", hr));
}
auto waitForComFuture = [](IVssAsync& fut)
{
ZEN_COM_CHECK(fut.Wait());
HRESULT hr = S_OK;
ZEN_COM_CHECK(fut.QueryStatus(&hr, nullptr)); //check if the async operation succeeded...
if (FAILED(hr))
throw SysError(formatComError(L"Error calling \"fut->QueryStatus\".", hr));
};
ComPtr<IVssAsync> gatherAsync;
ZEN_COM_CHECK(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_COM_CHECK(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 SysError(L"Volume Shadow Copy Service is not supported on this volume!");
const std::wstring vssError = formatVssError(hr);
if (!vssError.empty())
throw SysError(L"Error calling \"backupComp->AddToSnapshotSet\": " + vssError);
else
throw SysError(formatComError(L"Error calling \"backupComp->AddToSnapshotSet\".", hr));
}
}
ComPtr<IVssAsync> prepareAsync;
ZEN_COM_CHECK(backupComp->PrepareForBackup(prepareAsync.init()));
waitForComFuture(*prepareAsync);
ComPtr<IVssAsync> snapshotAsync;
ZEN_COM_CHECK(backupComp->DoSnapshotSet(snapshotAsync.init()));
guardSnapShot.dismiss();
waitForComFuture(*snapshotAsync);
VSS_SNAPSHOT_PROP props = {};
ZEN_COM_CHECK(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 SysError
return new ShadowData(result); //shadow handle owned by caller! std::bad_alloc?
}
catch (const zen::SysError& 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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