static int vbglR3DnDCreateDropDir(char* pszDropDir, size_t cbSize)
{
    /* Validate input */
    AssertPtrReturn(pszDropDir, VERR_INVALID_POINTER);
    AssertReturn(cbSize,        VERR_INVALID_PARAMETER);

    /* Get the users document directory (usually $HOME/Documents). */
    int rc = RTPathUserDocuments(pszDropDir, cbSize);
    if (RT_FAILURE(rc))
        return rc;
    /* Append our base drop directory. */
    rc = RTPathAppend(pszDropDir, cbSize, "VirtualBox Dropped Files");
    if (RT_FAILURE(rc))
        return rc;
    /* Create it when necessary. */
    if (!RTDirExists(pszDropDir))
    {
        rc = RTDirCreateFullPath(pszDropDir, RTFS_UNIX_IRWXU);
        if (RT_FAILURE(rc))
            return rc;
    }
    /* The actually drop directory consist of the current time stamp and a
     * unique number when necessary. */
    char pszTime[64];
    RTTIMESPEC time;
    if (!RTTimeSpecToString(RTTimeNow(&time), pszTime, sizeof(pszTime)))
        return VERR_BUFFER_OVERFLOW;
    rc = RTPathAppend(pszDropDir, cbSize, pszTime);
    if (RT_FAILURE(rc))
        return rc;

    /* Create it (only accessible by the current user) */
    return RTDirCreateUniqueNumbered(pszDropDir, cbSize, RTFS_UNIX_IRWXU, 3, '-');
}
int GetVBoxUserHomeDirectory(char *aDir, size_t aDirLen)
{
    AssertReturn(aDir, VERR_INVALID_POINTER);
    AssertReturn(aDirLen > 0, VERR_BUFFER_OVERFLOW);

    /* start with null */
    *aDir = 0;

    char szTmp[RTPATH_MAX];
    int vrc = RTEnvGetEx(RTENV_DEFAULT, "VBOX_USER_HOME", szTmp, sizeof(szTmp), NULL);
    if (RT_SUCCESS(vrc) || vrc == VERR_ENV_VAR_NOT_FOUND)
    {
        if (RT_SUCCESS(vrc))
        {
            /* get the full path name */
            vrc = RTPathAbs(szTmp, aDir, aDirLen);
        }
        else
        {
            /* compose the config directory (full path) */
            /** @todo r=bird: RTPathUserHome doesn't necessarily return a full (abs) path
             *        like the comment above seems to indicate. */
            vrc = RTPathUserHome(aDir, aDirLen);
            if (RT_SUCCESS(vrc))
                vrc = RTPathAppend(aDir, aDirLen, VBOX_USER_HOME_SUFFIX);
        }

        /* ensure the home directory exists */
        if (RT_SUCCESS(vrc))
            if (!RTDirExists(aDir))
                vrc = RTDirCreateFullPath(aDir, 0700);
    }

    return vrc;
}
static RTEXITCODE rtZipUnzipCmdExtractCallback(PRTZIPUNZIPCMDOPS pOpts, RTVFSOBJ hVfsObj,
                                               const char *pszName, RTEXITCODE rcExit, PRTFOFF pcBytes)
{
    if (pOpts->fVerbose)
        RTPrintf("%s\n", pszName);

    /*
     * Query all the information.
     */
    RTFSOBJINFO UnixInfo;
    int rc = RTVfsObjQueryInfo(hVfsObj, &UnixInfo, RTFSOBJATTRADD_UNIX);
    if (RT_FAILURE(rc))
        return RTMsgErrorExit(RTEXITCODE_FAILURE, "RTVfsObjQueryInfo returned %Rrc on '%s'", rc, pszName);

    *pcBytes = UnixInfo.cbObject;

    char szDst[RTPATH_MAX];
    rc = RTPathJoin(szDst, sizeof(szDst), pOpts->pszDirectory ? pOpts->pszDirectory : ".", pszName);
    if (RT_FAILURE(rc))
        return RTMsgErrorExit(RTEXITCODE_FAILURE, "%s: Failed to construct destination path for: %Rrc", pszName, rc);

    /*
     * Extract according to the type.
     */
    switch (UnixInfo.Attr.fMode & RTFS_TYPE_MASK)
    {
        case RTFS_TYPE_FILE:
            return rtZipUnzipCmdExtractFile(pOpts, hVfsObj, rcExit, szDst, &UnixInfo);

        case RTFS_TYPE_DIRECTORY:
            rc = RTDirCreateFullPath(szDst, UnixInfo.Attr.fMode & RTFS_UNIX_ALL_ACCESS_PERMS);
            if (RT_FAILURE(rc))
                return RTMsgErrorExit(RTEXITCODE_FAILURE, "%s: Error creating directory: %Rrc", szDst, rc);
            break;

        default:
            return RTMsgErrorExit(RTEXITCODE_FAILURE, "%s: Unknown file type.", pszName);
    }

    if (!pOpts->fNoModTimeDirectories)
    {
        rc = RTPathSetTimesEx(szDst, NULL, &UnixInfo.ModificationTime, NULL, NULL, RTPATH_F_ON_LINK);
        if (RT_FAILURE(rc) && rc != VERR_NOT_SUPPORTED && rc != VERR_NS_SYMLINK_SET_TIME)
            rcExit = RTMsgErrorExit(RTEXITCODE_FAILURE, "%s: Error changing modification time: %Rrc.", pszName, rc);
    }

    return rcExit;
}
static int VBoxServiceAutoMountPrepareMountPoint(const char *pszMountPoint, const char *pszShareName,
                                                 vbsf_mount_opts *pOpts)
{
    AssertPtrReturn(pOpts, VERR_INVALID_PARAMETER);
    AssertPtrReturn(pszMountPoint, VERR_INVALID_PARAMETER);
    AssertPtrReturn(pszShareName, VERR_INVALID_PARAMETER);

    RTFMODE fMode = RTFS_UNIX_IRWXU | RTFS_UNIX_IRWXG; /* Owner (=root) and the group (=vboxsf) have full access. */
    int rc = RTDirCreateFullPath(pszMountPoint, fMode);
    if (RT_SUCCESS(rc))
    {
        rc = RTPathSetOwnerEx(pszMountPoint, NIL_RTUID /* Owner, unchanged */, pOpts->gid, RTPATH_F_ON_LINK);
        if (RT_SUCCESS(rc))
        {
            rc = RTPathSetMode(pszMountPoint, fMode);
            if (RT_FAILURE(rc))
            {
                if (rc == VERR_WRITE_PROTECT)
                {
                    VBoxServiceVerbose(3, "VBoxServiceAutoMountPrepareMountPoint: Mount directory \"%s\" already is used/mounted\n", pszMountPoint);
                    rc = VINF_SUCCESS;
                }
                else
                    VBoxServiceError("VBoxServiceAutoMountPrepareMountPoint: Could not set mode %RTfmode for mount directory \"%s\", rc = %Rrc\n",
                                     fMode, pszMountPoint, rc);
            }
        }
        else
            VBoxServiceError("VBoxServiceAutoMountPrepareMountPoint: Could not set permissions for mount directory \"%s\", rc = %Rrc\n",
                             pszMountPoint, rc);
    }
    else
        VBoxServiceError("VBoxServiceAutoMountPrepareMountPoint: Could not create mount directory \"%s\" with mode %RTfmode, rc = %Rrc\n",
                         pszMountPoint, fMode, rc);
    return rc;
}