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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 <stdexcept>
#include <zen/win.h> //includes "windows.h"
#include <zen/dll.h>
#include <zen/win_ver.h>
#include <zen/assert_static.h>
#include <zen/long_path_prefix.h>
#include <zen/symlink_target.h>
#include "ShadowCopy/shadow.h"
#include <zen/scope_guard.h>
using namespace zen;
using namespace shadow;
namespace
{
bool runningWOW64() //test if process is running under WOW64 (reference http://msdn.microsoft.com/en-us/library/ms684139(VS.85).aspx)
{
typedef BOOL (WINAPI* IsWow64ProcessFun)(HANDLE hProcess, PBOOL Wow64Process);
const SysDllFun<IsWow64ProcessFun> isWow64Process(L"kernel32.dll", "IsWow64Process");
if (isWow64Process)
{
BOOL isWow64 = FALSE;
if (isWow64Process(::GetCurrentProcess(), &isWow64))
return isWow64 != FALSE;
}
return false;
}
const bool wereVistaOrLater = vistaOrLater(); //thread-safety: init at startup
}
//#############################################################################################################
class ShadowCopy::ShadowVolume
{
public:
ShadowVolume(const Zstring& volumeNamePf) : //throw FileError
createShadowCopy (getDllName(), funName_createShadowCopy),
releaseShadowCopy(getDllName(), funName_releaseShadowCopy),
getShadowVolume (getDllName(), funName_getShadowVolume),
getLastError (getDllName(), funName_getLastError),
backupHandle(nullptr)
{
//VSS does not support running under WOW64 except for Windows XP and Windows Server 2003
//reference: http://msdn.microsoft.com/en-us/library/aa384627(VS.85).aspx
if (runningWOW64())
throw FileError(_("Cannot access the Volume Shadow Copy Service."),
_("Please use FreeFileSync 64-bit version to create shadow copies on this system."));
//check if shadow copy dll was loaded correctly
if (!createShadowCopy || !releaseShadowCopy || !getShadowVolume || !getLastError)
throw FileError(_("Cannot access the Volume Shadow Copy Service."),
replaceCpy(_("Cannot load file %x."), L"%x", fmtFileName(getDllName())));
//---------------------------------------------------------------------------------------------------------
//start volume shadow copy service:
backupHandle = createShadowCopy(volumeNamePf.c_str());
if (!backupHandle)
throw FileError(_("Cannot access the Volume Shadow Copy Service."),
getLastError() + std::wstring(L" Volume: ") + fmtFileName(volumeNamePf));
shadowVolPf = appendSeparator(getShadowVolume(backupHandle)); //shadowVolName NEVER has a trailing backslash
}
~ShadowVolume() { releaseShadowCopy(backupHandle); } //fast! no performance optimization necessary
Zstring geNamePf() const { return shadowVolPf; } //with trailing path separator
private:
ShadowVolume(const ShadowVolume&);
ShadowVolume& operator=(const ShadowVolume&);
const DllFun<FunType_createShadowCopy> createShadowCopy;
const DllFun<FunType_releaseShadowCopy> releaseShadowCopy;
const DllFun<FunType_getShadowVolume> getShadowVolume;
const DllFun<FunType_getLastError> getLastError;
Zstring shadowVolPf;
ShadowHandle backupHandle;
};
//#############################################################################################################
Zstring ShadowCopy::makeShadowCopy(const Zstring& inputFile, const std::function<void(const Zstring&)>& onBeforeMakeVolumeCopy)
{
Zstring filenameFinal = inputFile;
//try to resolve symlinks and junctions:
//1. symlinks: we need to retrieve the target path, else we would just return a symlink on a VSS volume while the target outside were still locked!
//2. junctions: C:\Users\<username> is a junction that may link to e.g. D:\Users\<username>, so GetVolumePathName() returns "D:\" => "Volume name %x not part of file name %y."
if (wereVistaOrLater)
filenameFinal = getResolvedFilePath(inputFile); //throw FileError; requires Vista or later!
//-> returns paths with \\?\ prefix! => make sure to avoid duplicate shadow copies for volume paths with/without prefix
DWORD bufferSize = 10000;
std::vector<wchar_t> volBuffer(bufferSize);
if (!::GetVolumePathName(filenameFinal.c_str(), //__in LPCTSTR lpszFileName,
&volBuffer[0], //__out LPTSTR lpszVolumePathName,
bufferSize)) //__in DWORD cchBufferLength
throw FileError(replaceCpy(_("Cannot determine volume name for %x."), L"%x", fmtFileName(filenameFinal)), formatSystemError(L"GetVolumePathName", ::GetLastError()));
const Zstring volumeNamePf = appendSeparator(&volBuffer[0]); //msdn: if buffer is 1 char too short, GetVolumePathName() may skip last separator without error!
//input file is always absolute! directory formatting takes care of this! Therefore volume name can always be found.
const size_t pos = filenameFinal.find(volumeNamePf); //filenameFinal needs NOT to begin with volumeNamePf: consider \\?\ prefix!
if (pos == Zstring::npos)
throw FileError(replaceCpy(replaceCpy(_("Volume name %x is not part of file path %y."),
L"%x", fmtFileName(volumeNamePf)),
L"%y", fmtFileName(filenameFinal)));
//get or create instance of shadow volume
auto it = shadowVol.find(volumeNamePf);
if (it == shadowVol.end())
{
onBeforeMakeVolumeCopy(volumeNamePf); //notify client before (potentially) blocking some time
auto newEntry = std::make_shared<ShadowVolume>(volumeNamePf); //throw FileError
it = shadowVol.insert(std::make_pair(volumeNamePf, newEntry)).first;
}
//return filename alias on shadow copy volume
return it->second->geNamePf() + Zstring(filenameFinal.c_str() + pos + volumeNamePf.length());
}
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