experiment : 字符串分解 on drv

需求:  分解字符串, 提取分隔符之间的内容

字符串输入: \\MY-DEV2\MyShareDir\test.txt

分解成3部分: MY-DEV2 + MyShareDir + test.txt

    switch(ulCtrlCode)
    {
    case IO_CTRL_CODE_UNC_QUERY:
        DbgPrint("IO_CTRL_CODE_UNC_QUERY\r\n");
        sRc = fnUncFileQuery(pInputBuffer, ulinputSize, &UncFileQueryInfo);
        pIrp->IoStatus.Status = sRc;
        pIrp->IoStatus.Information = (STATUS_SUCCESS == sRc) ? sizeof(TAG_UNC_FILE_QUERY_INFO) : 0;
        if (STATUS_SUCCESS == sRc)
        {
            if (*pulOutputSize >= sizeof(TAG_UNC_FILE_QUERY_INFO))
            {
                RtlCopyMemory(pOutputBuffer, (PVOID)(&UncFileQueryInfo), sizeof(TAG_UNC_FILE_QUERY_INFO));
            }
            else
            {
                pIrp->IoStatus.Status = STATUS_BUFFER_TOO_SMALL;
                pIrp->IoStatus.Information = 0;
            }
        }
        break;
    default:
        DbgPrint("Unknown ulCtrlCode\r\n");
        pIrp->IoStatus.Status = STATUS_SUCCESS;
        pIrp->IoStatus.Information = 0;
        break;
    }

NTSTATUS fnUncFileQuery(PVOID pcUncPathName, ULONG ulLenUncPathName, TAG_UNC_FILE_QUERY_INFO * pUncFileQueryInfo)
{
    /// ulLenUncPathName 是字节长度

    ULONG   dwRc    =   E_SUCCESS;

    if (PASSIVE_LEVEL != KeGetCurrentIrql())
    {
        DbgPrint("PASSIVE_LEVEL != KeGetCurrentIrql()\r\n");
        return KfRaiseIrql(PASSIVE_LEVEL);
    }

    if (
        (NULL == pcUncPathName)
        || (NULL == pUncFileQueryInfo)
        || (ulLenUncPathName <= 0))
    {
        return STATUS_INVALID_PARAMETER;
    }

    /// 从UncPathName中取出 主机名, 共享文件夹名称, 剩下的内容(共享文件中的子文件夹+共享文件名称)
    dwRc = fnParseUncPathName((wchar_t *)pcUncPathName, pUncFileQueryInfo);
    if (E_SUCCESS != dwRc)
    {
        DbgPrint("fnParseUncPathName(%S) = %d\r\n", pcUncPathName, dwRc);
        return STATUS_INVALID_PARAMETER;
    }

    /// 判断主机名是否是本机

    /// 判断共享文件夹 是否为本地的共享文件夹

    /// 重组UNC文件全路径名 => 实际的文件名, 写入输出参数

    return STATUS_SUCCESS;
}

DWORD fnParseUncPathName(wchar_t * pszUncPathName, TAG_UNC_FILE_QUERY_INFO * pUncFileQueryInfo)
{
    //     \\MY-DEV2\MyShareDir\test.txt		///< \\主机名称\共享文件夹名称\共享子文件夹\共享文件名称
    //     \\Localhost\MyShareDir\test.txt		///< \\Localhost\共享文件夹名称\共享子文件夹\共享文件名称
    //     \\192.168.1.60\MyShareDir\test.txt	///< \\IP地址\共享文件夹名称\共享子文件夹\共享文件名称
    
    ULONG       dwRc            =   E_SUCCESS;
    wchar_t *   pszFindBegin    =   NULL;
    wchar_t *   pszFindEnd      =   NULL;

    const wchar_t * pszUncFileNameHead      =   L"\\\\";    ///< UNC 文件名以 L"\\\\" 起头
    const wchar_t * pszUncFileNameSeparator =   L"\\";    ///< UNC 文件名 元素间的分隔符

    if (PASSIVE_LEVEL != KeGetCurrentIrql())
    {
        DbgPrint("PASSIVE_LEVEL != KeGetCurrentIrql()\r\n");
        return KfRaiseIrql(PASSIVE_LEVEL);
    }

    RtlZeroMemory(pUncFileQueryInfo, sizeof(TAG_UNC_FILE_QUERY_INFO));

    DbgPrint("pszUncPathName = %S\r\n", pszUncPathName);
    RtlCopyMemory(pUncFileQueryInfo->szUncFilePathName, 
        pszUncPathName, 
        wcslen(pszUncPathName) * sizeof(wchar_t));

    /// 查找主机名称
    pszFindBegin = wcsstr(pUncFileQueryInfo->szUncFilePathName, pszUncFileNameHead);
    if ((NULL == pszFindBegin)
        || (pszFindBegin != pUncFileQueryInfo->szUncFilePathName))  ///< 字符串开头就是引导符号
    {
        return E_PARAM;
    }

    pszFindBegin += wcslen(pszUncFileNameHead);   ///< 指向引导符号后的字符串
    pszFindEnd = wcsstr(pszFindBegin, pszUncFileNameSeparator);
    if (NULL == pszFindEnd)
    {
        return E_PARAM;
    }

    RtlCopyMemory(pUncFileQueryInfo->szHostName, 
        pszFindBegin, 
        (pszFindEnd - pszFindBegin) * sizeof(wchar_t));

    /// 查找共享文件夹名称
    pszFindBegin = pszFindEnd + 1;
    pszFindEnd = wcsstr(pszFindBegin, pszUncFileNameSeparator);
    if (NULL == pszFindEnd)
    {
        return E_PARAM;
    }

    RtlCopyMemory(pUncFileQueryInfo->szShareDir, 
        pszFindBegin, 
        (pszFindEnd - pszFindBegin) * sizeof(wchar_t));

    /// 查找 共享文件名, 包含子文件夹
    pszFindBegin = pszFindEnd + 1;
    RtlCopyMemory(pUncFileQueryInfo->szShareFileName, 
        pszFindBegin, 
        wcslen(pszFindBegin) * sizeof(wchar_t));

    return  dwRc;
}