/* $Id: HostVideoInputDeviceImpl.cpp $ */
/** @file
 * Host video capture device implementation.
 */

/*
 * Copyright (C) 2013-2023 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, in version 3 of the
 * License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses>.
 *
 * SPDX-License-Identifier: GPL-3.0-only
 */

#define LOG_GROUP LOG_GROUP_MAIN_HOSTVIDEOINPUTDEVICE
#include "HostVideoInputDeviceImpl.h"
#include "LoggingNew.h"
#include "VirtualBoxImpl.h"
#ifdef VBOX_WITH_EXTPACK
# include "ExtPackManagerImpl.h"
#endif

#include <iprt/err.h>
#include <iprt/ldr.h>
#include <iprt/path.h>

#include <VBox/sup.h>

/*
 * HostVideoInputDevice implementation.
 */
DEFINE_EMPTY_CTOR_DTOR(HostVideoInputDevice)

HRESULT HostVideoInputDevice::FinalConstruct()
{
    return BaseFinalConstruct();
}

void HostVideoInputDevice::FinalRelease()
{
    uninit();

    BaseFinalRelease();
}

/*
 * Initializes the instance.
 */
HRESULT HostVideoInputDevice::init(const com::Utf8Str &name, const com::Utf8Str &path, const com::Utf8Str &alias)
{
    LogFlowThisFunc(("\n"));

    /* Enclose the state transition NotReady->InInit->Ready */
    AutoInitSpan autoInitSpan(this);
    AssertReturn(autoInitSpan.isOk(), E_FAIL);

    m.name = name;
    m.path = path;
    m.alias = alias;

    /* Confirm a successful initialization */
    autoInitSpan.setSucceeded();

    return S_OK;
}

/*
 * Uninitializes the instance.
 * Called either from FinalRelease() or by the parent when it gets destroyed.
 */
void HostVideoInputDevice::uninit()
{
    LogFlowThisFunc(("\n"));

    /* Enclose the state transition Ready->InUninit->NotReady */
    AutoUninitSpan autoUninitSpan(this);
    if (autoUninitSpan.uninitDone())
        return;

    m.name.setNull();
    m.path.setNull();
    m.alias.setNull();
}

static HRESULT hostVideoInputDeviceAdd(HostVideoInputDeviceList *pList,
                                       const com::Utf8Str &name,
                                       const com::Utf8Str &path,
                                       const com::Utf8Str &alias)
{
    ComObjPtr<HostVideoInputDevice> obj;
    HRESULT hrc = obj.createObject();
    if (SUCCEEDED(hrc))
    {
        hrc = obj->init(name, path, alias);
        if (SUCCEEDED(hrc))
            pList->push_back(obj);
    }
    return hrc;
}

static DECLCALLBACK(int) hostWebcamAdd(void *pvUser,
                                       const char *pszName,
                                       const char *pszPath,
                                       const char *pszAlias,
                                       uint64_t *pu64Result)
{
    HostVideoInputDeviceList *pList = (HostVideoInputDeviceList *)pvUser;
    HRESULT hrc = hostVideoInputDeviceAdd(pList, pszName, pszPath, pszAlias);
    if (FAILED(hrc))
    {
        *pu64Result = (uint64_t)hrc;
        return VERR_NOT_SUPPORTED;
    }
    return VINF_SUCCESS;
}

/** @todo These typedefs must be in a header. */
typedef DECLCALLBACKTYPE(int, FNVBOXHOSTWEBCAMADD,(void *pvUser,
                                                   const char *pszName,
                                                   const char *pszPath,
                                                   const char *pszAlias,
                                                   uint64_t *pu64Result));
typedef FNVBOXHOSTWEBCAMADD *PFNVBOXHOSTWEBCAMADD;

typedef DECLCALLBACKTYPE(int, FNVBOXHOSTWEBCAMLIST,(PFNVBOXHOSTWEBCAMADD pfnWebcamAdd,
                                                    void *pvUser,
                                                    uint64_t *pu64WebcamAddResult));
typedef FNVBOXHOSTWEBCAMLIST *PFNVBOXHOSTWEBCAMLIST;


/*
 * Work around clang being unhappy about PFNVBOXHOSTWEBCAMLIST
 * ("exception specifications are not allowed beyond a single level of
 * indirection").  The original comment for 13.0 check said: "assuming
 * this issue will be fixed eventually".  Well, 13.0 is now out, and
 * it was not.
 */
#define CLANG_EXCEPTION_SPEC_HACK (RT_CLANG_PREREQ(11, 0) /* && !RT_CLANG_PREREQ(13, 0) */)

#if CLANG_EXCEPTION_SPEC_HACK
static int loadHostWebcamLibrary(const char *pszPath, RTLDRMOD *phmod, void **ppfn)
#else
static int loadHostWebcamLibrary(const char *pszPath, RTLDRMOD *phmod, PFNVBOXHOSTWEBCAMLIST *ppfn)
#endif
{
    int vrc;
    if (RTPathHavePath(pszPath))
    {
        RTLDRMOD hmod = NIL_RTLDRMOD;
        RTERRINFOSTATIC ErrInfo;
        vrc = SUPR3HardenedLdrLoadPlugIn(pszPath, &hmod, RTErrInfoInitStatic(&ErrInfo));
        if (RT_SUCCESS(vrc))
        {
            static const char s_szSymbol[] = "VBoxHostWebcamList";
            vrc = RTLdrGetSymbol(hmod, s_szSymbol, (void **)ppfn);
            if (RT_SUCCESS(vrc))
                *phmod = hmod;
            else
            {
                if (vrc != VERR_SYMBOL_NOT_FOUND)
                    LogRel(("Resolving symbol '%s': %Rrc\n", s_szSymbol, vrc));
                RTLdrClose(hmod);
                hmod = NIL_RTLDRMOD;
            }
        }
        else
        {
            LogRel(("Loading the library '%s': %Rrc\n", pszPath, vrc));
            if (RTErrInfoIsSet(&ErrInfo.Core))
                LogRel(("  %s\n", ErrInfo.Core.pszMsg));
        }
    }
    else
    {
        LogRel(("Loading the library '%s': No path! Refusing to try loading it!\n", pszPath));
        vrc = VERR_INVALID_PARAMETER;
    }
    return vrc;
}


static HRESULT fillDeviceList(VirtualBox *pVirtualBox, HostVideoInputDeviceList *pList)
{
    Utf8Str strLibrary;
#ifdef VBOX_WITH_EXTPACK
    ExtPackManager *pExtPackMgr = pVirtualBox->i_getExtPackManager();
    HRESULT hrc = pExtPackMgr->i_getLibraryPathForExtPack("VBoxHostWebcam", ORACLE_PUEL_EXTPACK_NAME, &strLibrary);
#else
    HRESULT hrc = E_NOTIMPL;
#endif

    if (SUCCEEDED(hrc))
    {
        PFNVBOXHOSTWEBCAMLIST pfn = NULL;
        RTLDRMOD hmod = NIL_RTLDRMOD;
#if CLANG_EXCEPTION_SPEC_HACK
        int vrc = loadHostWebcamLibrary(strLibrary.c_str(), &hmod, (void **)&pfn);
#else
        int vrc = loadHostWebcamLibrary(strLibrary.c_str(), &hmod, &pfn);
#endif

        LogRel(("Load [%s] vrc=%Rrc\n", strLibrary.c_str(), vrc));

        if (RT_SUCCESS(vrc))
        {
            uint64_t u64Result = S_OK;
            vrc = pfn(hostWebcamAdd, pList, &u64Result);
            Log(("VBoxHostWebcamList vrc %Rrc, result 0x%08RX64\n", vrc, u64Result));
            if (RT_FAILURE(vrc))
                hrc = (HRESULT)u64Result;

            RTLdrClose(hmod);
            hmod = NIL_RTLDRMOD;
        }

        if (SUCCEEDED(hrc))
        {
            if (RT_FAILURE(vrc))
                hrc = pVirtualBox->setErrorBoth(VBOX_E_IPRT_ERROR, vrc,
                                                HostVideoInputDevice::tr("Failed to get webcam list: %Rrc"), vrc);
        }
    }

    return hrc;
}

/* static */ HRESULT HostVideoInputDevice::queryHostDevices(VirtualBox *pVirtualBox, HostVideoInputDeviceList *pList)
{
    HRESULT hrc = fillDeviceList(pVirtualBox, pList);
    if (FAILED(hrc))
        pList->clear();
    return hrc;
}

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