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/* $Id: shflhandle.cpp $ */
/** @file
* Shared Folders Service - Handles helper functions.
*/
/*
* Copyright (C) 2006-2023 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
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#define LOG_GROUP LOG_GROUP_SHARED_FOLDERS
#include "shflhandle.h"
#include <iprt/alloc.h>
#include <iprt/assert.h>
#include <iprt/critsect.h>
/*********************************************************************************************************************************
* Structures and Typedefs *
*********************************************************************************************************************************/
/**
* Very basic and primitive handle management. Should be sufficient for our needs.
* Handle allocation can be rather slow, but at least lookup is fast.
*/
typedef struct
{
uint32_t uFlags;
uintptr_t pvUserData;
PSHFLCLIENTDATA pClient;
} SHFLINTHANDLE, *PSHFLINTHANDLE;
/*********************************************************************************************************************************
* Global Variables *
*********************************************************************************************************************************/
static SHFLINTHANDLE *g_pHandles = NULL;
static int32_t gLastHandleIndex = 0;
static RTCRITSECT gLock;
int vbsfInitHandleTable()
{
g_pHandles = (SHFLINTHANDLE *)RTMemAllocZ (sizeof (SHFLINTHANDLE) * SHFLHANDLE_MAX);
if (!g_pHandles)
{
AssertFailed();
return VERR_NO_MEMORY;
}
/* Never return handle 0 */
g_pHandles[0].uFlags = SHFL_HF_TYPE_DONTUSE;
gLastHandleIndex = 1;
return RTCritSectInit(&gLock);
}
int vbsfFreeHandleTable()
{
if (g_pHandles)
RTMemFree(g_pHandles);
g_pHandles = NULL;
if (RTCritSectIsInitialized(&gLock))
RTCritSectDelete(&gLock);
return VINF_SUCCESS;
}
SHFLHANDLE vbsfAllocHandle(PSHFLCLIENTDATA pClient, uint32_t uType,
uintptr_t pvUserData)
{
SHFLHANDLE handle;
Assert((uType & SHFL_HF_TYPE_MASK) != 0 && pvUserData);
RTCritSectEnter(&gLock);
/* Find next free handle */
if (gLastHandleIndex >= SHFLHANDLE_MAX-1)
gLastHandleIndex = 1;
/* Nice linear search */
for(handle=gLastHandleIndex;handle<SHFLHANDLE_MAX;handle++)
{
if (g_pHandles[handle].pvUserData == 0)
{
gLastHandleIndex = handle;
break;
}
}
if (handle == SHFLHANDLE_MAX)
{
/* Try once more from the start */
for(handle=1;handle<SHFLHANDLE_MAX;handle++)
{
if (g_pHandles[handle].pvUserData == 0)
{
gLastHandleIndex = handle;
break;
}
}
if (handle == SHFLHANDLE_MAX)
{
/* Out of handles */
RTCritSectLeave(&gLock);
AssertFailed();
return SHFL_HANDLE_NIL;
}
}
g_pHandles[handle].uFlags = (uType & SHFL_HF_TYPE_MASK) | SHFL_HF_VALID;
g_pHandles[handle].pvUserData = pvUserData;
g_pHandles[handle].pClient = pClient;
gLastHandleIndex++;
RTCritSectLeave(&gLock);
return handle;
}
static int vbsfFreeHandle(PSHFLCLIENTDATA pClient, SHFLHANDLE handle)
{
if ( handle < SHFLHANDLE_MAX
&& (g_pHandles[handle].uFlags & SHFL_HF_VALID)
&& g_pHandles[handle].pClient == pClient)
{
g_pHandles[handle].uFlags = 0;
g_pHandles[handle].pvUserData = 0;
g_pHandles[handle].pClient = 0;
return VINF_SUCCESS;
}
return VERR_INVALID_HANDLE;
}
uintptr_t vbsfQueryHandle(PSHFLCLIENTDATA pClient, SHFLHANDLE handle,
uint32_t uType)
{
if ( handle < SHFLHANDLE_MAX
&& (g_pHandles[handle].uFlags & SHFL_HF_VALID)
&& g_pHandles[handle].pClient == pClient)
{
Assert((uType & SHFL_HF_TYPE_MASK) != 0);
if (g_pHandles[handle].uFlags & uType)
return g_pHandles[handle].pvUserData;
}
return 0;
}
SHFLFILEHANDLE *vbsfQueryFileHandle(PSHFLCLIENTDATA pClient, SHFLHANDLE handle)
{
return (SHFLFILEHANDLE *)vbsfQueryHandle(pClient, handle,
SHFL_HF_TYPE_FILE);
}
SHFLFILEHANDLE *vbsfQueryDirHandle(PSHFLCLIENTDATA pClient, SHFLHANDLE handle)
{
return (SHFLFILEHANDLE *)vbsfQueryHandle(pClient, handle,
SHFL_HF_TYPE_DIR);
}
uint32_t vbsfQueryHandleType(PSHFLCLIENTDATA pClient, SHFLHANDLE handle)
{
if ( handle < SHFLHANDLE_MAX
&& (g_pHandles[handle].uFlags & SHFL_HF_VALID)
&& g_pHandles[handle].pClient == pClient)
return g_pHandles[handle].uFlags & SHFL_HF_TYPE_MASK;
return 0;
}
SHFLHANDLE vbsfAllocDirHandle(PSHFLCLIENTDATA pClient)
{
SHFLFILEHANDLE *pHandle = (SHFLFILEHANDLE *)RTMemAllocZ (sizeof (SHFLFILEHANDLE));
if (pHandle)
{
pHandle->Header.u32Flags = SHFL_HF_TYPE_DIR;
return vbsfAllocHandle(pClient, pHandle->Header.u32Flags,
(uintptr_t)pHandle);
}
return SHFL_HANDLE_NIL;
}
SHFLHANDLE vbsfAllocFileHandle(PSHFLCLIENTDATA pClient)
{
SHFLFILEHANDLE *pHandle = (SHFLFILEHANDLE *)RTMemAllocZ (sizeof (SHFLFILEHANDLE));
if (pHandle)
{
pHandle->Header.u32Flags = SHFL_HF_TYPE_FILE;
return vbsfAllocHandle(pClient, pHandle->Header.u32Flags,
(uintptr_t)pHandle);
}
return SHFL_HANDLE_NIL;
}
void vbsfFreeFileHandle(PSHFLCLIENTDATA pClient, SHFLHANDLE hHandle)
{
SHFLFILEHANDLE *pHandle = (SHFLFILEHANDLE *)vbsfQueryHandle(pClient,
hHandle, SHFL_HF_TYPE_DIR|SHFL_HF_TYPE_FILE);
if (pHandle)
{
vbsfFreeHandle(pClient, hHandle);
RTMemFree (pHandle);
}
else
AssertFailed();
}
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