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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant reason:default
#include "qsharedmemory.h"
#include "qsharedmemory_p.h"
#include "qsystemsemaphore.h"
#include <qdebug.h>
#include <qt_windows.h>
QT_BEGIN_NAMESPACE
using namespace Qt::StringLiterals;
#if QT_CONFIG(sharedmemory)
void QSharedMemoryPrivate::setWindowsErrorString(QLatin1StringView function)
{
DWORD windowsError = GetLastError();
if (windowsError == 0)
return;
switch (windowsError) {
case ERROR_ALREADY_EXISTS:
error = QSharedMemory::AlreadyExists;
errorString = QSharedMemory::tr("%1: already exists").arg(function);
break;
case ERROR_FILE_NOT_FOUND:
error = QSharedMemory::NotFound;
errorString = QSharedMemory::tr("%1: doesn't exist").arg(function);
break;
case ERROR_COMMITMENT_LIMIT:
error = QSharedMemory::InvalidSize;
errorString = QSharedMemory::tr("%1: invalid size").arg(function);
break;
case ERROR_NO_SYSTEM_RESOURCES:
case ERROR_NOT_ENOUGH_MEMORY:
error = QSharedMemory::OutOfResources;
errorString = QSharedMemory::tr("%1: out of resources").arg(function);
break;
case ERROR_ACCESS_DENIED:
error = QSharedMemory::PermissionDenied;
errorString = QSharedMemory::tr("%1: permission denied").arg(function);
break;
default:
errorString = QSharedMemory::tr("%1: unknown error: %2")
.arg(function, qt_error_string(windowsError));
error = QSharedMemory::UnknownError;
#if defined QSHAREDMEMORY_DEBUG
qDebug() << errorString << "key" << key;
#endif
}
}
HANDLE QSharedMemoryWin32::handle(QSharedMemoryPrivate *self)
{
if (!hand) {
const auto function = "QSharedMemory::handle"_L1;
if (self->nativeKey.isEmpty()) {
self->setError(QSharedMemory::KeyError,
QSharedMemory::tr("%1: unable to make key").arg(function));
return 0;
}
hand = OpenFileMapping(FILE_MAP_ALL_ACCESS, false,
reinterpret_cast<const wchar_t *>(self->nativeKey.nativeKey().utf16()));
if (!hand) {
self->setWindowsErrorString(function);
return 0;
}
}
return hand;
}
bool QSharedMemoryWin32::cleanHandle(QSharedMemoryPrivate *)
{
if (hand != 0 && !CloseHandle(hand)) {
hand = 0;
return false;
}
hand = 0;
return true;
}
bool QSharedMemoryWin32::create(QSharedMemoryPrivate *self, qsizetype size)
{
const auto function = "QSharedMemory::create"_L1;
if (self->nativeKey.isEmpty()) {
self->setError(QSharedMemory::KeyError,
QSharedMemory::tr("%1: key error").arg(function));
return false;
}
// Create the file mapping.
DWORD high, low;
if constexpr (sizeof(qsizetype) == 8)
high = DWORD(quint64(size) >> 32);
else
high = 0;
low = DWORD(size_t(size) & 0xffffffff);
hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, high, low,
reinterpret_cast<const wchar_t *>(self->nativeKey.nativeKey().utf16()));
self->setWindowsErrorString(function);
// hand is valid when it already exists unlike unix so explicitly check
return self->error != QSharedMemory::AlreadyExists && hand;
}
bool QSharedMemoryWin32::attach(QSharedMemoryPrivate *self, QSharedMemory::AccessMode mode)
{
// Grab a pointer to the memory block
int permissions = (mode == QSharedMemory::ReadOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS);
self->memory = (void *)MapViewOfFile(handle(self), permissions, 0, 0, 0);
if (!self->memory) {
self->setWindowsErrorString("QSharedMemory::attach"_L1);
cleanHandle(self);
return false;
}
// Grab the size of the memory we have been given (a multiple of 4K on windows)
MEMORY_BASIC_INFORMATION info;
if (!VirtualQuery(self->memory, &info, sizeof(info))) {
// Windows doesn't set an error code on this one,
// it should only be a kernel memory error.
self->setError(QSharedMemory::UnknownError,
QSharedMemory::tr("%1: size query failed")
.arg("QSharedMemory::attach: "_L1));
return false;
}
self->size = qsizetype(info.RegionSize);
return true;
}
bool QSharedMemoryWin32::detach(QSharedMemoryPrivate *self)
{
// umap memory
if (!UnmapViewOfFile(self->memory)) {
self->setWindowsErrorString("QSharedMemory::detach"_L1);
return false;
}
self->memory = 0;
self->size = 0;
// close handle
return cleanHandle(self);
}
#endif // QT_CONFIG(sharedmemory)
QT_END_NAMESPACE