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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "DynamicallyLinkedFunctionPtr.h"
#include "mozilla/mscom/EnsureMTA.h"
#include "mozilla/mscom/ProxyStream.h"
#include "mozilla/mscom/Utils.h"
#include "mozilla/Move.h"
#include <windows.h>
#include <objbase.h>
#include <shlwapi.h>
namespace mozilla {
namespace mscom {
ProxyStream::ProxyStream()
: mGlobalLockedBuf(nullptr)
, mHGlobal(nullptr)
, mBufSize(0)
{
}
// GetBuffer() fails with this variant, but that's okay because we're just
// reconstructing the stream from a buffer anyway.
ProxyStream::ProxyStream(const BYTE* aInitBuf, const int aInitBufSize)
: mStream(InitStream(aInitBuf, static_cast<const UINT>(aInitBufSize)))
, mGlobalLockedBuf(nullptr)
, mHGlobal(nullptr)
, mBufSize(aInitBufSize)
{
if (!aInitBufSize) {
// We marshaled a nullptr. Nothing else to do here.
return;
}
// NB: We can't check for a null mStream until after we have checked for
// the zero aInitBufSize above. This is because InitStream will also fail
// in that case, even though marshaling a nullptr is allowable.
MOZ_ASSERT(mStream);
if (!mStream) {
return;
}
// We need to convert to an interface here otherwise we mess up const
// correctness with IPDL. We'll request an IUnknown and then QI the
// actual interface later.
auto marshalFn = [&]() -> void
{
IUnknown* rawUnmarshaledProxy = nullptr;
// OK to forget mStream when calling into this function because the stream
// gets released even if the unmarshaling part fails.
DebugOnly<HRESULT> hr =
::CoGetInterfaceAndReleaseStream(mStream.forget().take(), IID_IUnknown,
(void**)&rawUnmarshaledProxy);
MOZ_ASSERT(SUCCEEDED(hr));
mUnmarshaledProxy.reset(rawUnmarshaledProxy);
};
if (XRE_IsParentProcess()) {
// We'll marshal this stuff directly using the current thread, therefore its
// proxy will reside in the same apartment as the current thread.
marshalFn();
} else {
// When marshaling in child processes, we want to force the MTA.
EnsureMTA mta(marshalFn);
}
}
already_AddRefed<IStream>
ProxyStream::InitStream(const BYTE* aInitBuf, const UINT aInitBufSize)
{
// Need to link to this as ordinal 12 for Windows XP
static DynamicallyLinkedFunctionPtr<decltype(&::SHCreateMemStream)>
pSHCreateMemStream(L"shlwapi.dll", reinterpret_cast<const char*>(12));
if (!pSHCreateMemStream) {
return nullptr;
}
return already_AddRefed<IStream>(pSHCreateMemStream(aInitBuf, aInitBufSize));
}
ProxyStream::ProxyStream(ProxyStream&& aOther)
{
*this = mozilla::Move(aOther);
}
ProxyStream&
ProxyStream::operator=(ProxyStream&& aOther)
{
mStream = mozilla::Move(aOther.mStream);
mGlobalLockedBuf = aOther.mGlobalLockedBuf;
aOther.mGlobalLockedBuf = nullptr;
mHGlobal = aOther.mHGlobal;
aOther.mHGlobal = nullptr;
mBufSize = aOther.mBufSize;
aOther.mBufSize = 0;
return *this;
}
ProxyStream::~ProxyStream()
{
if (mHGlobal && mGlobalLockedBuf) {
DebugOnly<BOOL> result = ::GlobalUnlock(mHGlobal);
MOZ_ASSERT(!result && ::GetLastError() == NO_ERROR);
// ::GlobalFree() is called implicitly when mStream is released
}
}
const BYTE*
ProxyStream::GetBuffer(int& aReturnedBufSize) const
{
aReturnedBufSize = 0;
if (!mStream) {
return nullptr;
}
if (!mGlobalLockedBuf) {
return nullptr;
}
aReturnedBufSize = mBufSize;
return mGlobalLockedBuf;
}
bool
ProxyStream::GetInterface(REFIID aIID, void** aOutInterface) const
{
// We should not have a locked buffer on this side
MOZ_ASSERT(!mGlobalLockedBuf);
MOZ_ASSERT(aOutInterface);
if (!aOutInterface) {
return false;
}
if (!mUnmarshaledProxy) {
*aOutInterface = nullptr;
return true;
}
HRESULT hr = E_UNEXPECTED;
auto qiFn = [&]() -> void
{
hr = mUnmarshaledProxy->QueryInterface(aIID, aOutInterface);
};
if (XRE_IsParentProcess()) {
qiFn();
} else {
// mUnmarshaledProxy requires that we execute this in the MTA
EnsureMTA mta(qiFn);
}
return SUCCEEDED(hr);
}
ProxyStream::ProxyStream(REFIID aIID, IUnknown* aObject)
: mGlobalLockedBuf(nullptr)
, mHGlobal(nullptr)
, mBufSize(0)
{
RefPtr<IStream> stream;
HGLOBAL hglobal = NULL;
auto marshalFn = [&]() -> void
{
HRESULT hr = ::CreateStreamOnHGlobal(nullptr, TRUE, getter_AddRefs(stream));
if (FAILED(hr)) {
return;
}
hr = ::CoMarshalInterface(stream, aIID, aObject, MSHCTX_LOCAL, nullptr,
MSHLFLAGS_NORMAL);
if (FAILED(hr)) {
return;
}
hr = ::GetHGlobalFromStream(stream, &hglobal);
MOZ_ASSERT(SUCCEEDED(hr));
};
if (XRE_IsParentProcess()) {
// We'll marshal this stuff directly using the current thread, therefore its
// stub will reside in the same apartment as the current thread.
marshalFn();
} else {
// When marshaling in child processes, we want to force the MTA.
EnsureMTA mta(marshalFn);
}
mStream = mozilla::Move(stream);
if (hglobal) {
mGlobalLockedBuf = reinterpret_cast<BYTE*>(::GlobalLock(hglobal));
mHGlobal = hglobal;
mBufSize = static_cast<int>(::GlobalSize(hglobal));
}
}
} // namespace mscom
} // namespace mozilla
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