1 files changed, 236 insertions, 0 deletions
diff --git a/src/VBox/HostServices/SharedFolders/shflhandle.cpp b/src/VBox/HostServices/SharedFolders/shflhandle.cpp
new file mode 100644
index 00000000..6a449ee2
--- /dev/null
+++ b/src/VBox/HostServices/SharedFolders/shflhandle.cpp
@@ -0,0 +1,236 @@
+/* $Id: shflhandle.cpp $ */
+/** @file
+ * Shared Folders Service - Handles helper functions.
+ */
+
+/*
+ * Copyright (C) 2006-2022 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();
+}
+