Windows8内核模式下开发NDIS应用-NDIS Filter讲解

 在Win8系统下开发驱动程序，需要数字证书，还需要驱动签名认证。不能像XP下面那样疯狂滴耍流氓了。


 由于Win8系统的内核做了大幅度的修改，它和XP系统的内核起了很大的变化，最显著的就是刚才说的：需要签名和证书。  还有就是：不能随意的HOOK SSDT了。




在开发NDIS驱动程序的时候，WDK开发包提供了一个新的框架，叫着NDIS Filter
NDIS Filter是一个例子工程。
假入我把WDK安装在E盘，那么这个工程代码就在：
C:\WinDDK\8600.16385.1\src\network\ndis\filter目录下。


把这个例子工程和原来的Passthru工程代码做比较，您会发现，原来需要导出来的2种类型的回调函数MiniportXXX和ProtocolXXX 在新的框架里面被全部隐藏起来了。
微软提供了新的函数。 一起来看看，微软提供了什么。
在这里，为了方便分析， 我把函数代码都做了功能注释，请大家一起看看。
代码如下：

#pragma NDIS_INIT_FUNCTION(DriverEntry)

#define LITTLE_ENDIAN   (1)
//
// Global variables
// 
NDIS_HANDLE         FilterDriverHandle; // NDIS handle for filter driver
NDIS_HANDLE         FilterDriverObject;
NDIS_HANDLE         NdisFilterDeviceHandle = NULL;
PDEVICE_OBJECT      DeviceObject = NULL;

FILTER_LOCK         FilterListLock;
LIST_ENTRY          FilterModuleList;
PWCHAR              InstanceStrings = NULL;

NDIS_FILTER_PARTIAL_CHARACTERISTICS DefaultChars = {
{ 0, 0, 0},
      0,
      FilterSendNetBufferLists,
      FilterSendNetBufferListsComplete,
      NULL,
      FilterReceiveNetBufferLists,
      FilterReturnNetBufferLists
};    

typedef struct in_addr {
  union {
    struct { UCHAR s_b1,s_b2,s_b3,s_b4; } S_un_b;
    struct { USHORT s_w1,s_w2; } S_un_w;
    ULONG S_addr;
  } S_un;
} IN_ADDR, *PIN_ADDR, FAR *LPIN_ADDR;


#pragma push(1)
typedef struct IP_HEADER
{

#if LITTLE_ENDIAN
  unsigned char  ip_hl:4;    /* 头长度 */
  unsigned char  ip_v:4;      /* 版本号 */
#else
  unsigned char   ip_v:4;
  unsigned char   ip_hl:4;     
#endif

  unsigned char  TOS;           // 服务类型

  unsigned short   TotLen;      // 封包总长度，即整个IP包的长度
  unsigned short   ID;          // 封包标识，唯一标识发送的每一个数据报
  unsigned short   FlagOff;     // 标志
  unsigned char  TTL;           // 生存时间，就是TTL
  unsigned char  Protocol;      // 协议，可能是TCP、UDP、ICMP等
  unsigned short Checksum;      // 校验和
  struct in_addr        iaSrc;  // 源IP地址
  struct in_addr        iaDst;  // 目的PI地址

}IP_HEADER, *PIP_HEADER;


typedef struct tcp_header
{
  unsigned short src_port;    //源端口号
  unsigned short dst_port;    //目的端口号
  unsigned int   seq_no;      //序列号
  unsigned int   ack_no;      //确认号
#if LITTLE_ENDIAN
  unsigned char reserved_1:4; //保留6位中的4位首部长度
  unsigned char thl:4;    //tcp头部长度
  unsigned char flag:6;  //6位标志
  unsigned char reseverd_2:2; //保留6位中的2位
#else
  unsigned char thl:4;    //tcp头部长度
  unsigned char reserved_1:4; //保留6位中的4位首部长度
  unsigned char reseverd_2:2; //保留6位中的2位
  unsigned char flag:6;  //6位标志 
#endif
  unsigned short wnd_size;   //16位窗口大小
  unsigned short chk_sum;    //16位TCP检验和
  unsigned short urgt_p;     //16为紧急指针

}TCP_HEADER,*PTCP_HEADER;


typedef struct udp_header 
{
  USHORT srcport;   // 源端口
  USHORT dstport;   // 目的端口
  USHORT total_len; // 包括UDP报头及UDP数据的长度(单位:字节)
  USHORT chksum;    // 校验和

}UDP_HEADER,*PUDP_HEADER;
#pragma push()


#define IP_OFFSET                               0x0E

//IP 协议类型
#define PROT_ICMP                               0x01 
#define PROT_TCP                                0x06 
#define PROT_UDP                                0x11 


USHORT UTIL_htons( USHORT hostshort )
{
  PUCHAR  pBuffer;
  USHORT  nResult;

  nResult = 0;
  pBuffer = (PUCHAR )&hostshort;

  nResult = ( (pBuffer[ 0 ] << 8) & 0xFF00) | (pBuffer[ 1 ] & 0x00FF);

  return( nResult );
}


/*UTIL_ntohs把网络字节顺序转换成主机字节顺序*/
USHORT UTIL_ntohs( USHORT netshort )
{
  return( UTIL_htons( netshort ) );
}



NTSTATUS 
DriverEntry(IN  PDRIVER_OBJECT  DriverObject, IN  PUNICODE_STRING   RegistryPath)
{
    NDIS_STATUS                             Status;
    NDIS_FILTER_DRIVER_CHARACTERISTICS      FChars;
    NDIS_STRING                             ServiceName;
    NDIS_STRING                             UniqueName;
    NDIS_STRING                             FriendlyName;
    BOOLEAN                                 bFalse = FALSE;

    UNREFERENCED_PARAMETER(RegistryPath);
    
    DEBUGP(DL_TRACE,("===>DriverEntry...\n"));
   
    RtlInitUnicodeString(&ServiceName, FILTER_SERVICE_NAME);
    RtlInitUnicodeString(&FriendlyName, FILTER_FRIENDLY_NAME);
    RtlInitUnicodeString(&UniqueName, FILTER_UNIQUE_NAME);
    FilterDriverObject = DriverObject;
    
    do
    {
        NdisZeroMemory(&FChars, sizeof(NDIS_FILTER_DRIVER_CHARACTERISTICS));  

/*
大多数的NDIS6.0数据结构中包含的对象头结构的成员，即NDIS_OBJECT_HEADER结构。
对象头有三个成员：类型，大小和修改。如果头信息是不正确的，那么调用NDIS6.0函数将失败。
*/
        FChars.Header.Type =  
        NDIS_OBJECT_TYPE_FILTER_DRIVER_CHARACTERISTICS;
        FChars.Header.Size = sizeof(NDIS_FILTER_DRIVER_CHARACTERISTICS);
        FChars.Header.Revision = NDIS_FILTER_CHARACTERISTICS_REVISION_1;

        FChars.MajorNdisVersion = FILTER_MAJOR_NDIS_VERSION;
        FChars.MinorNdisVersion = FILTER_MINOR_NDIS_VERSION;
        FChars.MajorDriverVersion = 1;
        FChars.MinorDriverVersion = 0;
        FChars.Flags = 0;

        FChars.FriendlyName = FriendlyName;
        FChars.UniqueName = UniqueName;
        FChars.ServiceName = ServiceName;

            
/******************************************************
NDIS_FILTER_DRIVER_CHARACTERISTICS结构中Mandatory例程
******************************************************/
        FChars.AttachHandler = FilterAttach;
        FChars.DetachHandler = FilterDetach;
        FChars.RestartHandler = FilterRestart;
        FChars.PauseHandler = FilterPause;


/************************************************************
NDIS_FILTER_DRIVER_CHARACTERISTICS结构中Optional且不能在运行时变更的例程
*************************************************************/
        FChars.SetOptionsHandler = FilterRegisterOptions;
        FChars.SetFilterModuleOptionsHandler = FilterSetModuleOptions;
        FChars.OidRequestHandler = FilterOidRequest;
        FChars.OidRequestCompleteHandler = FilterOidRequestComplete;
        FChars.StatusHandler = FilterStatus;
       FChars.DevicePnPEventNotifyHandler = FilterDevicePnPEventNotify;
       FChars.NetPnPEventHandler = FilterNetPnPEvent;      
      FChars.CancelSendNetBufferListsHandler = FilterCancelSendNetBufferLists;



/**************************************************************
DIS_FILTER_DRIVER_CHARACTERISTICS结构中Optional且能在运行时变更的例程。
        
下面这4个例程也被定义在NDIS_FILTER_PARTIAL_CHARACTERISTICS中,这个结构指定的
例程可以在运行时的FilterSetModuleOptions例程中调用NdisSetOptionHandles来改变。
如果过滤驱动要在例程中修改自身的一个特性,那么必须提供FilterSetModuleOptions例程。
****************************************************************/
        FChars.SendNetBufferListsHandler = FilterSendNetBufferLists;  
   FChars.SendNetBufferListsCompleteHandler = FilterSendNetBufferListsComplete;
        FChars.ReturnNetBufferListsHandler = FilterReturnNetBufferLists;
        FChars.ReceiveNetBufferListsHandler = FilterReceiveNetBufferLists;

       ///
        FChars.CancelOidRequestHandler = FilterCancelOidRequest;        
      
        DriverObject->DriverUnload = FilterUnload;
    
        FilterDriverHandle = NULL;

        FILTER_INIT_LOCK(&FilterListLock);

        InitializeListHead(&FilterModuleList);
        
  // 把Filter驱动注册给NDIS
        Status = NdisFRegisterFilterDriver(DriverObject,
                                           (NDIS_HANDLE)FilterDriverObject,
                                           &FChars, 
                                           &FilterDriverHandle);
        if (Status != NDIS_STATUS_SUCCESS)
        {
            DEBUGP(DL_WARN, ("MSFilter: Register filter driver failed.\n")); 
            break;
        }
        //
        // Initilize spin locks
        //

        Status = FilterRegisterDevice();

        if (Status != NDIS_STATUS_SUCCESS)
        {
            NdisFDeregisterFilterDriver(FilterDriverHandle);
            FILTER_FREE_LOCK(&FilterListLock);
            DEBUGP(DL_WARN, ("MSFilter: Register device for the filter driver failed.\n")); 
            break;
        }

        
    } 
    while(bFalse);
    
    
    DEBUGP(DL_TRACE, ("<===DriverEntry, Status = %8x\n", Status));
    return Status;
    
}




//过滤驱动注册可选服务
NDIS_STATUS
FilterRegisterOptions(
        IN NDIS_HANDLE  NdisFilterDriverHandle, //它指向了这个过滤驱动
        IN NDIS_HANDLE  FilterDriverContext     //它是这个驱动的上下文
        )
{
    DEBUGP(DL_TRACE, ("===>FilterRegisterOptions\n"));
    
    ASSERT(NdisFilterDriverHandle == FilterDriverHandle);
    ASSERT(FilterDriverContext == (NDIS_HANDLE)FilterDriverObject);

    if ((NdisFilterDriverHandle != (NDIS_HANDLE)FilterDriverHandle) ||
        (FilterDriverContext != (NDIS_HANDLE)FilterDriverObject))
    {
        return NDIS_STATUS_INVALID_PARAMETER;
    }

    DEBUGP(DL_TRACE, ("<===FilterRegisterOptions\n"));

    return (NDIS_STATUS_SUCCESS);
}

    

/***************************************************************  
FilterAttach函数的功能:
   Attaching状态表示：一个Filter Driver正准备附加一个Filter Module到一个驱动栈上。
   一个过滤驱动进入Attaching状态下不能进行发送请求、接收指示、状态指示、OID请求操作。

   当一个过滤驱动进入Attaching状态时，它可以:
   (1)创建一个环境上下文区域并且初始化一个缓冲区池以及其Filter Module特点的资源。
  (2)用NDIS 传来给Filter Attach的NdisFilterHandle作为输入来调用NdisFSetAttributes例程。


   Attach is complete
   当Filter Module在Attaching状态下并且Filter Driver初始化了所有的Filter Module所需要的
   所有资源时,Filter Module进入Paused状态。


   参数说明：
    NdisFilterHandle     它用于所有过滤驱动中对Ndisxxx类例程的调用时引用指示这个过滤模块。
    FilterDriverContext  它由NdisFRegisterFilterDriver的FilterDriverContext来指定。
    AttachParameters     它是过滤模块的初始化参数结构体。
 **************************************************************/
NDIS_STATUS
FilterAttach(
    IN  NDIS_HANDLE                     NdisFilterHandle,
    IN  NDIS_HANDLE                     FilterDriverContext,
    IN  PNDIS_FILTER_ATTACH_PARAMETERS  AttachParameters
    )

{
    PMS_FILTER              pFilter = NULL;
    NDIS_STATUS             Status = NDIS_STATUS_SUCCESS;
    NDIS_FILTER_ATTRIBUTES  FilterAttributes;
    ULONG                   Size;
    BOOLEAN               bFalse = FALSE;
    
    DEBUGP(DL_TRACE, ("===>FilterAttach: NdisFilterHandle %p\n", NdisFilterHandle));

    do
    {
        ASSERT(FilterDriverContext == (NDIS_HANDLE)FilterDriverObject);
        if (FilterDriverContext != (NDIS_HANDLE)FilterDriverObject)
        {
            Status = NDIS_STATUS_INVALID_PARAMETER;
            break;
        }
        
        if ((AttachParameters->MiniportMediaType != NdisMedium802_3)
                && (AttachParameters->MiniportMediaType != NdisMediumWan))
        {
           DEBUGP(DL_ERROR, ("MSFilter: Doesn't support media type other than NdisMedium802_3.\n")); 
        
           Status = NDIS_STATUS_INVALID_PARAMETER;
           break;
        }
        
        Size = sizeof(MS_FILTER) + 
               AttachParameters->FilterModuleGuidName->Length + 
               AttachParameters->BaseMiniportInstanceName->Length + 
               AttachParameters->BaseMiniportName->Length;
        
        pFilter = (PMS_FILTER)FILTER_ALLOC_MEM(NdisFilterHandle, Size);
        if (pFilter == NULL)
        {
            DEBUGP(DL_WARN, ("MSFilter: Failed to allocate context structure.\n"));
            Status = NDIS_STATUS_RESOURCES;
            break;
        }
        
        NdisZeroMemory(pFilter, sizeof(MS_FILTER));

        pFilter->FilterModuleName.Length = pFilter->FilterModuleName.MaximumLength = AttachParameters->FilterModuleGuidName->Length;
        pFilter->FilterModuleName.Buffer = (PWSTR)((PUCHAR)pFilter + sizeof(MS_FILTER));

        NdisMoveMemory(pFilter->FilterModuleName.Buffer, 
                        AttachParameters->FilterModuleGuidName->Buffer,
                        pFilter->FilterModuleName.Length);

        
        pFilter->MiniportFriendlyName.Length = pFilter->MiniportFriendlyName.MaximumLength = AttachParameters->BaseMiniportInstanceName->Length;
        pFilter->MiniportFriendlyName.Buffer = (PWSTR)((PUCHAR)pFilter->FilterModuleName.Buffer + pFilter->FilterModuleName.Length);
        
  NdisMoveMemory(pFilter->MiniportFriendlyName.Buffer, 
                       AttachParameters->BaseMiniportInstanceName->Buffer,
                        pFilter->MiniportFriendlyName.Length);

        
        pFilter->MiniportName.Length = pFilter->MiniportName.MaximumLength = AttachParameters->BaseMiniportName->Length;
        pFilter->MiniportName.Buffer = (PWSTR)((PUCHAR)pFilter->MiniportFriendlyName.Buffer + 
                                                   pFilter->MiniportFriendlyName.Length);
        NdisMoveMemory(pFilter->MiniportName.Buffer, 
                        AttachParameters->BaseMiniportName->Buffer,
                        pFilter->MiniportName.Length);

        pFilter->MiniportIfIndex = AttachParameters->BaseMiniportIfIndex;
      
        pFilter->TrackReceives = TRUE;
        pFilter->TrackSends = TRUE;
        pFilter->FilterHandle = NdisFilterHandle;


        NdisZeroMemory(&FilterAttributes, sizeof(NDIS_FILTER_ATTRIBUTES));
        FilterAttributes.Header.Revision = NDIS_FILTER_ATTRIBUTES_REVISION_1;
        FilterAttributes.Header.Size = sizeof(NDIS_FILTER_ATTRIBUTES);
        FilterAttributes.Header.Type = NDIS_OBJECT_TYPE_FILTER_ATTRIBUTES;
        FilterAttributes.Flags = 0;


        Status = NdisFSetAttributes(NdisFilterHandle, 
                                    pFilter, //pFilter参数的功能是，为过滤模块指定环境上下文
                                    &FilterAttributes);

        if (Status != NDIS_STATUS_SUCCESS)
        {
            DEBUGP(DL_WARN, ("MSFilter: Failed to set attributes.\n"));
            break;
        }
        
        pFilter->State = FilterPaused;

        FILTER_ACQUIRE_LOCK(&FilterListLock, bFalse);
        InsertHeadList(&FilterModuleList, &pFilter->FilterModuleLink);
        FILTER_RELEASE_LOCK(&FilterListLock, bFalse);
        
    }
    while (bFalse);
    
    if (Status != NDIS_STATUS_SUCCESS)
    {
        if (pFilter != NULL)
        {
            FILTER_FREE_MEM(pFilter);
        }
    }
    
    DEBUGP(DL_TRACE, ("<===FilterAttach:    Status %x\n", Status));
    return Status;
}




/**************************************************************  
FilterPause函数的功能:
   Paused状态：在这种状态下，Filter Driver不能执行接收和发送操作。
   当FilterDriver执行FilterPause全程时它就进入了Pausing状态。

   Pausing状态：在这种状态下,Filter Driver要为一个Filter Module完成停止发送和接收
   处理所需要的所有准备工作。

   一个在Pausing状态的Filter Driver有如下的约束：

   (1)Filter Module不能发起任何新的接收指示,但可以传递下层驱动的接收指示。
   (2)如果有Filter Module发起的接收指示还没有完成,那么必须等到它们全部完成。有只当
      FilterReturnNetBufferLists完成所有外部接收指示后,暂停操作才能完成。
   (3)要返回任何未处理的由下层驱动引发的接收指示给NDIS,只有等到NdisFReturnNetBufferLists返回了所有未处理的接收指示后暂停操作才能完成。这里也可以排队缓冲这些未完成的接收指示。
   (4)立即用NdisFReturnNetBufferLists返回所有下层驱动新传来的接收指示,如果需要可以在返回之前制和排队这些接收指示。
   (5)不能发起任何新的发送请求。
   (6)如果有Filter Driver引的但NDIS还未完成的发送操作,必须等待它们完成。
   (8)应该在FilterSendNetBufferLists例程中立即调用NdisFSendNetBufferListsComplete返回那些新达到的发送请求。并且为每一个NET_BUFFER_LIST设置NDIS_STATUS_PAUSED返回状态。
   (8)这时可以使用NdisFIndicateStatus提供状态指示。
   (9)可以在FilterStatus中处理状态指示。
   (10)可以在FilterOidRequest里面处理OID请求。
   (11)可以发起一个OID操作。
   (12)不能释放分配的相关资源,和Filter Module相关的资源最好放在FilterDetach例程里面来释放。
   (13)如果有用于发送和接收的定时器那么要停止它。

   当成功停止发送和接收操作后就必须完成暂停操作。暂停操作的完成可以是同步的也可以是异步的。
   若返回值是NDIS_STATUS_SUCCESS则，是同步。
   若是异步，则返回NDIS_STATUS_PENDING。那么还必须调用NdisFPauseComplete函数。

   暂停操作完成了以后,Filter Module进入了Paused状态。这里它有如下的约束：

   (1)不能发起任何接收指示,但可以传递底层驱动发来的接收指示。
   (2)需要立即调用NdisFReturnNetBufferLists返回底层驱动的接收指示给NDIS,如果需要可以在返回之前复制和排队这些接收指示。
   (3)不能引发任何新的发送指示。
   (4)需要立即调用NdisFSendNetBufferListsComplete完成那些在FilterSendNetBufferLists中收到的发送请求，并为每一个NET_BUFFER_LIST设置NDIS_STATUS_PAUSED返回状态。
   (5)这时可以使用NdisFIndicateStatus发起状态指示。
   (6)可以在FilterStatus中进行状态指示处理。
   (8)可以在FilterOidRequest里面处理OID请求。
   (8)可以发起一个OID请求。


   在Filter Module进行Pausing状态时NDIS不会发起其它PnP操作，比如:附加、分离、重启。只有当Filter Module进入了Paused状态后NDIS才能对它进行分离和重启操作。
 ***************************************************************/
NDIS_STATUS
FilterPause(
        IN  NDIS_HANDLE                     FilterModuleContext,
        IN  PNDIS_FILTER_PAUSE_PARAMETERS   PauseParameters
        )

{
    PMS_FILTER          pFilter = (PMS_FILTER)(FilterModuleContext);
    NDIS_STATUS         Status;
    BOOLEAN               bFalse = FALSE;

    UNREFERENCED_PARAMETER(PauseParameters);
    
    DEBUGP(DL_TRACE, ("===>NDISLWF FilterPause: FilterInstance %p\n", FilterModuleContext));

     
    FILTER_ASSERT(pFilter->State == FilterRunning); 
    
    FILTER_ACQUIRE_LOCK(&pFilter->Lock, bFalse);
    pFilter->State = FilterPausing;
    FILTER_RELEASE_LOCK(&pFilter->Lock, bFalse);


    Status = NDIS_STATUS_SUCCESS;    

    pFilter->State = FilterPaused;
    
    DEBUGP(DL_TRACE, ("<===FilterPause:  Status %x\n", Status));
    return Status;
}




/***************************************************************
  FilterRestart函数的功能:
   在Restarting状态下,一个Filter Driver必须为一个Filter Module完成重启发送和接收数据时
   所需要的所有准备工作。

   Restart is complete
    当Filter Module在Restarting状态下并且完成所有发送和接收所需要的准备工作时,Filter Module就进入了Running状态。

要启动一个Paused状态的Filter Module,如果有FilterSetModuleOptions就先调用它,接着调用FilterRestart。

  当Filter Module在Restarting状态下,它可以:
  (1)完成任何正常的发送和接收所需要的准备工作。
  (2)可读写Filter Module的配置参数。
  (3)可以接收网络数据指示,拷贝和排队数据稍后只是给上层驱动或者丢弃数据。
  (4)不能发起任何新的接收指示。
  (5)应该立即调用NdisFSendNetBufferListsComplete例程来拒绝FilterSendNetBufferLists传来的发送的请求。应该设置每一个NET_BUFFER_LIST的完成状态为NDIS_STATUS_PAUSED
                (6)可以使用NdisFIndicateStatus例程进行状态指示。
  (8)可以控制OID请求操作。
  (8)不能发起任何新的发送请求。
  (9)应该调用NdisFReturnNetBufferLists返回所有新的接收指示。如果需要的话可以在接收指示返回之前拷贝它们。
  (10)可以制作OID请求发送给下层驱动设置或查询配置信息。
  (11)可以在FilterStatus中控制状态指示。
  (12)返回时指示 NDIS_STATUS_SUCCESS 或失败状态,如果不Filter Module不能启动返回了失败，而它又是一个Mandatory的Filter Driver 那个 NDIS将会结束这个驱动栈
在一个Filter Driver完成对发送和接收的重启后必须指示完成这个重启操作。 
Filter Driver的重启操作的完成可以是同步也可以是异步的，同步时返回 NDIS_STATUS_SUCCESS 异步时返回NDIS_STATUS_PENDING。如果返回的是 NDIS_STATUS_PENDING 就必须调用NdisFRestartComplete 例程在重启操作完成后。
在这种情况下，驱动需要传递给NdisFRestartComplete 一个固定状态(标识重启结果的成功或失败状态)。

重启操作完成Filter Module就进入了 Running状态,恢得一切正常的发送和接收外理。
在Filter Driver的FilterRestart例程执行的时候NDIS不会发起任即插即用操作,如附加,分离,暂停请求等等。Ndis可以在Filter Module进入Running状态后发起一个暂停请求。
***************************************************************/
NDIS_STATUS
FilterRestart(
    IN  NDIS_HANDLE                     FilterModuleContext,
    IN  PNDIS_FILTER_RESTART_PARAMETERS RestartParameters
    )

{
    NDIS_STATUS     Status;
    PMS_FILTER      pFilter = (PMS_FILTER)FilterModuleContext; // BUGBUG, the cast may be wrong
    NDIS_HANDLE     ConfigurationHandle = NULL;


    PNDIS_RESTART_GENERAL_ATTRIBUTES NdisGeneralAttributes;
    PNDIS_RESTART_ATTRIBUTES         NdisRestartAttributes;
    NDIS_CONFIGURATION_OBJECT        ConfigObject;
    
    DEBUGP(DL_TRACE, ("===>FilterRestart:   FilterModuleContext %p\n", FilterModuleContext));
    
    FILTER_ASSERT(pFilter->State == FilterPaused);

    ConfigObject.Header.Type = NDIS_OBJECT_TYPE_CONFIGURATION_OBJECT;
    ConfigObject.Header.Revision = NDIS_CONFIGURATION_OBJECT_REVISION_1;
    ConfigObject.Header.Size = sizeof(NDIS_CONFIGURATION_OBJECT);
    ConfigObject.NdisHandle = FilterDriverHandle;
    ConfigObject.Flags = 0;
    
    Status = NdisOpenConfigurationEx(&ConfigObject, &ConfigurationHandle);
    if (Status != NDIS_STATUS_SUCCESS)
    {        
        
#if 0
        //
        // The code is here just to demonstrate how to call NDIS to write an eventlog. If drivers need to write 
        // an event log.
        //
        PWCHAR              ErrorString = L"Ndislwf";
        
        DEBUGP(DL_WARN, ("FilterRestart: Cannot open configuration.\n"));
        NdisWriteEventLogEntry(FilterDriverObject,
                                EVENT_NDIS_DRIVER_FAILURE,
                                0,
                                1,
                                &ErrorString,
                                sizeof(Status),
                                &Status);
#endif                                
                                
    }


    if (Status == NDIS_STATUS_SUCCESS)
    {
        NdisCloseConfiguration(ConfigurationHandle);
    }

    NdisRestartAttributes = RestartParameters->RestartAttributes;

  
    if (NdisRestartAttributes != NULL)
    {
        PNDIS_RESTART_ATTRIBUTES   NextAttributes;
        
        ASSERT(NdisRestartAttributes->Oid == OID_GEN_MINIPORT_RESTART_ATTRIBUTES);
    
        NdisGeneralAttributes = (PNDIS_RESTART_GENERAL_ATTRIBUTES)NdisRestartAttributes->Data;
    
        NdisGeneralAttributes->LookaheadSize = 128;

        NextAttributes = NdisRestartAttributes->Next;

        while (NextAttributes != NULL)
        {

            NextAttributes = NextAttributes->Next;
        }
    
    }

   
    pFilter->State = FilterRunning; 


    Status = NDIS_STATUS_SUCCESS;
    
    if (Status != NDIS_STATUS_SUCCESS)
    {
        pFilter->State = FilterPaused;
    }
    
    
    DEBUGP(DL_TRACE, ("<===FilterRestart:  FilterModuleContext %p, Status %x\n", FilterModuleContext, Status));
    return Status;
}



/**************************************************************  
FilterDetach函数的功能：
   Detach状态：当Filter Driver从一个驱动栈上分离一个Filter Module时,将发生该事件。
   在驱动栈上分离一个过滤模块时,NDIS会暂停这个驱动栈。这意味着NDIS已经使过滤模块进入
   了Parse状态。即FilterPause函数先被调用了。

   在这个例程中释放和这个过滤模块相关的环境上下文和其它资源。这个过程不能失败。
   当FilterDetach函数返回以后,NDIS会重新启动被暂停的驱动栈。
   
   参数说明：
    FilterDriverContext  它由NdisFRegisterFilterDriver的FilterDriverContext来指定。
 ************************************************************/
VOID
FilterDetach(
        IN  NDIS_HANDLE     FilterModuleContext
        )

{
    PMS_FILTER                  pFilter = (PMS_FILTER)FilterModuleContext;
    BOOLEAN                      bFalse = FALSE;


    DEBUGP(DL_TRACE, ("===>FilterDetach:    FilterInstance %p\n", FilterModuleContext));

  
    FILTER_ASSERT(pFilter->State == FilterPaused);
        
   
    if (pFilter->FilterName.Buffer != NULL)
    {
        FILTER_FREE_MEM(pFilter->FilterName.Buffer);
    }


    FILTER_ACQUIRE_LOCK(&FilterListLock, bFalse);
    RemoveEntryList(&pFilter->FilterModuleLink);
    FILTER_RELEASE_LOCK(&FilterListLock, bFalse);


    FILTER_FREE_MEM(pFilter);

  
    DEBUGP(DL_TRACE, ("<===FilterDetach Successfully\n"));
    
    return;
}




/**************************************************************
 系统只会在调用FilterDetach()分离了所有和本Filter Driver相关的Filter Module以后,才会调用FilterUnload例程。
****************************************************************/
VOID
FilterUnload(
        IN  PDRIVER_OBJECT      DriverObject
        )

{
#if DBG    
    BOOLEAN               bFalse = FALSE;
#endif

    UNREFERENCED_PARAMETER(DriverObject);

    DEBUGP(DL_TRACE, ("===>FilterUnload\n"));
    
   
    FilterDeregisterDevice();
    NdisFDeregisterFilterDriver(FilterDriverHandle);
    
#if DBG    
    FILTER_ACQUIRE_LOCK(&FilterListLock, bFalse);
    ASSERT(IsListEmpty(&FilterModuleList));

    FILTER_RELEASE_LOCK(&FilterListLock, bFalse);
    
#endif    
    
    FILTER_FREE_LOCK(&FilterListLock);
    
    DEBUGP(DL_TRACE, ("<===FilterUnload\n"));

    return;
    
}



/***************************************************************
 FilterOidRequest函数的功能:
  Filter Module可以在Runnig状态、Restarting状态、Paused状态和Pauseing状态进行OID的控制和处理。
  Filter Driver可以处理上层驱动引发的OID请求,NDIS调用Filter Driver的FilterOidRequest例程来处理OID请求,Filter Driver需要调用NdisFOidRequest例程来转发请求给下层驱动。 

  Filter Driver可以从FilterOidRequest同步和异步完成一个OID请求,分别返回NDIS_STATS_SUCCESS和NDIS_STATUS_PENDING即可。FilterOidRequest可以用同步的直接完成一个OID请求并返回一个错误状态。 

  如果FilterOidRequest返回NDIS_STATUS_PENDING,就必须在OID请求完成后调用
  NdisFOidRequestComplete来通知上层驱动求请求完成。在这种情况下,请求的结果通过
  NdisFOidRequestComplete的OidRequest参数返回给上层驱动,并通过Status参数返回请求完成的最终状态。
   

  如果FilterOidRequest返回NDIS_STATUS_SUCCESS,通过FilterOidRequest的OidRequest参数返回一个查询结果到上层。这时不调用 NdisFOidRequestComplete例程。 


  要转发OID请求到下层驱动,Filter Driver必须调用NdisFOidRequest。如果一个OID请求不能被转发到下层驱动应该当立即返回。要完成一个请求且不转发可以直接返回NDIS_STATUS_SUCCESS或其它错误状态或返回 NDIS_STATUS_PENDING 后调用NdisFOidRequestComplete。 


  如果NdisFOidRequest返回NDIS_STATUS_PENDING,NDIS在OID请求完成后调用FilterOidRequestComplete来通知求请求完成在这种情况下,请求的结果通过NdisFOidRequestComplete的OidRequest参数返回给上层驱动,并通过 Status 参数返回请求完成的最终状态。
   

  如果 NdisFOidRequest返回NDIS_STATUS_SUCCESS,通过NdisFOidRequest的OidRequest参数返回一个查询结果到上层。这时不调用FilterOidRequestComplete例程。 
  一个Filter Driver可以调用NdisFOidRequest引发OID请求在Restarting、Running、Pausing和Paused 状态。 
  
  注意:Filter Driver必须跟踪这个请求确保不在FilterOidRequestComplete中调用NdisFOidRequestComplete(因为请求是自己引发的不能传到上层)。 
 ****************************************************************/
NDIS_STATUS
FilterOidRequest(IN  NDIS_HANDLE   FilterModuleContext,IN  PNDIS_OID_REQUEST   Request)

{
    PMS_FILTER              pFilter = (PMS_FILTER)FilterModuleContext;
    NDIS_STATUS             Status;
    PNDIS_OID_REQUEST       ClonedRequest=NULL;
    BOOLEAN                 bSubmitted = FALSE;
    PFILTER_REQUEST_CONTEXT Context;
    BOOLEAN               bFalse = FALSE;

    
    DEBUGP(DL_TRACE, ("===>FilterOidRequest: Request %p.\n", Request));

    do
    {
        Status = NdisAllocateCloneOidRequest(pFilter->FilterHandle,
                                            Request,
                                            FILTER_TAG,
                                            &ClonedRequest);
        if (Status != NDIS_STATUS_SUCCESS)
        {
            DEBUGP(DL_WARN, ("FilerOidRequest: Cannot Clone Request\n"));
            break;
        }

        Context = (PFILTER_REQUEST_CONTEXT)(&ClonedRequest->SourceReserved[0]);
        *Context = Request;

        bSubmitted = TRUE;

       
        ClonedRequest->RequestId = Request->RequestId;

        pFilter->PendingOidRequest = ClonedRequest;


//Filter Driver可以调用NdisFOidRequest引发一个OID查询和设置请求给下层驱动。
        Status = NdisFOidRequest(pFilter->FilterHandle, ClonedRequest);

        if (Status != NDIS_STATUS_PENDING)
        {

            FilterOidRequestComplete(pFilter, ClonedRequest, Status);
            Status = NDIS_STATUS_PENDING;
        } 

        
    }while (bFalse);

    if (bSubmitted == FALSE)
    {
        switch(Request->RequestType)
        {
            case NdisRequestMethod:
                Request->DATA.METHOD_INFORMATION.BytesRead = 0;
                Request->DATA.METHOD_INFORMATION.BytesNeeded = 0; 
                Request->DATA.METHOD_INFORMATION.BytesWritten = 0; 
                break;

            case NdisRequestSetInformation:
                Request->DATA.SET_INFORMATION.BytesRead = 0;
                Request->DATA.SET_INFORMATION.BytesNeeded = 0; 
                break;

            case NdisRequestQueryInformation:
            case NdisRequestQueryStatistics:
            default:
                Request->DATA.QUERY_INFORMATION.BytesWritten = 0;
                Request->DATA.QUERY_INFORMATION.BytesNeeded = 0; 
                break;
        }

    }
    DEBUGP(DL_TRACE, ("<===FilterOidRequest: Status %8x.\n", Status));

    return Status;

}



/*************************************************************
 FilterCancelOidRequest函数的功能:
  NDIS调用FilterCancelOidRequest来取消一个OID请求,当NDIS调用FilterCancelOidRequest时,
  Filter Driver应该尽可能快的调用NdisFCancelOidRequest。 
 *************************************************************/
VOID
FilterCancelOidRequest(
    IN  NDIS_HANDLE             FilterModuleContext,
    IN  PVOID                   RequestId
    )
{
    PMS_FILTER                          pFilter = (PMS_FILTER)FilterModuleContext;
    PNDIS_OID_REQUEST                   Request = NULL;
    PFILTER_REQUEST_CONTEXT             Context;
    PNDIS_OID_REQUEST                   OriginalRequest = NULL;
    BOOLEAN               bFalse = FALSE;
     
    FILTER_ACQUIRE_LOCK(&pFilter->Lock, bFalse);
    
    Request = pFilter->PendingOidRequest;

    if (Request != NULL)
    {
        Context = (PFILTER_REQUEST_CONTEXT)(&Request->SourceReserved[0]);
    
        OriginalRequest = (*Context);
    }

    if ((OriginalRequest != NULL) && (OriginalRequest->RequestId == RequestId))
    {
        FILTER_RELEASE_LOCK(&pFilter->Lock, bFalse);
        
        NdisFCancelOidRequest(pFilter->FilterHandle, RequestId);
    }
    else
    {
        FILTER_RELEASE_LOCK(&pFilter->Lock, bFalse);
    }
        

}

    
VOID
FilterOidRequestComplete(
        IN  NDIS_HANDLE         FilterModuleContext,
        IN  PNDIS_OID_REQUEST   Request,
        IN  NDIS_STATUS         Status
        )

{
    PMS_FILTER                          pFilter = (PMS_FILTER)FilterModuleContext;
    PNDIS_OID_REQUEST                   OriginalRequest;
    PFILTER_REQUEST_CONTEXT             Context;
    BOOLEAN               bFalse = FALSE;
    
    DEBUGP(DL_TRACE, ("===>FilterOidRequestComplete, Request %p.\n", Request));

    Context = (PFILTER_REQUEST_CONTEXT)(&Request->SourceReserved[0]);
    OriginalRequest = (*Context);

   
    if (OriginalRequest == NULL)
    {
        filterInternalRequestComplete(pFilter, Request, Status);
        return;
    }


    FILTER_ACQUIRE_LOCK(&pFilter->Lock, bFalse);
    
    ASSERT(pFilter->PendingOidRequest == Request);
    pFilter->PendingOidRequest = NULL;

    FILTER_RELEASE_LOCK(&pFilter->Lock, bFalse);

    switch(Request->RequestType)
    {
        case NdisRequestMethod:
            OriginalRequest->DATA.METHOD_INFORMATION.OutputBufferLength =  Request->DATA.METHOD_INFORMATION.OutputBufferLength;
            OriginalRequest->DATA.METHOD_INFORMATION.BytesRead = Request->DATA.METHOD_INFORMATION.BytesRead;
            OriginalRequest->DATA.METHOD_INFORMATION.BytesNeeded = Request->DATA.METHOD_INFORMATION.BytesNeeded; 
            OriginalRequest->DATA.METHOD_INFORMATION.BytesWritten = Request->DATA.METHOD_INFORMATION.BytesWritten; 
            break;

        case NdisRequestSetInformation:  
            OriginalRequest->DATA.SET_INFORMATION.BytesRead = Request->DATA.SET_INFORMATION.BytesRead;
            OriginalRequest->DATA.SET_INFORMATION.BytesNeeded = Request->DATA.SET_INFORMATION.BytesNeeded; 
            break;

        case NdisRequestQueryInformation:
        case NdisRequestQueryStatistics:
        default:     
            OriginalRequest->DATA.QUERY_INFORMATION.BytesWritten = Request->DATA.QUERY_INFORMATION.BytesWritten;
            OriginalRequest->DATA.QUERY_INFORMATION.BytesNeeded = Request->DATA.QUERY_INFORMATION.BytesNeeded;
            break;
    }


    (*Context) = NULL;

    NdisFreeCloneOidRequest(pFilter->FilterHandle, Request);


/*
如果FilterOidRequest返回NDIS_STATUS_PENDING,就必须在OID请求完成后调用NdisFOidRequestComplete 来通知上层驱动求请求完成。在这种情况下,请求的结果通过NdisFOidRequestComplete的OidRequest参数返回给上层驱动,并通过Status参数返回请求完成的最终状态。
要转发OID请求到下层驱动,Filter Driver必须调用NdisFOidRequest。
如果一个OID请求不能被转发到下层驱动应该当立即返回。
要完成一个请求且不转发可以直接返回NDIS_STATUS_SUCCESS或其它错误状态
或返回NDIS_STATUS_PENDING后调用NdisFOidRequestComplete。  
*/

    NdisFOidRequestComplete(pFilter->FilterHandle, OriginalRequest, Status);
    
    DEBUGP(DL_TRACE, ("<===FilterOidRequestComplete.\n"));
}




/*************************************************************
  FilterStatus函数的功能:
    当下层驱动报告状态的时候 NDIS会调用它。此外,Filter Driver还可以自己引发一个状态指示。

当下层驱动调用一个状态指示例程时(NdisMIndicateStatusEx或NdisFIndicateStats),NDIS
会调用Filter Driver的FilterStatus例程。

Filter Driver在FilterStatus中调用NdisFIndicateStatus传递一个状态指示给上层驱动。此外,还可以过滤状态指示(不用调用 NdisFIndicateStatus)或在调用 NdisFIndicateStatus之前修改状态信息。
  
   
Filter Driver要自己引发一个状态报告,可以在NDIS未调用 FilterStatus的情况下调用NdisFIndicateStatus。在这种情况下,Filter Driver要设置 SourceHandle 成员为 FilteAttech 参数提供的NdisFilterHandle句柄。
如果一个状态指示是一个OID请求相关的(下层请求一个 OID 下层要做相应的状态指示),那么状态的DestinationHandle和RequestId成员要设置成上层的OID请求包携带的数据。 
  

Filter Driver调用NdisFIndicateStatus后NDIS会调用相邻上层的状态指示函数(ProtocolStatusEx或FilterStatus)。 
****************************************************************/
VOID
FilterStatus(
        IN  NDIS_HANDLE             FilterModuleContext,
        IN  PNDIS_STATUS_INDICATION StatusIndication
        )

{
    PMS_FILTER              pFilter = (PMS_FILTER)FilterModuleContext;
#if DBG    
    BOOLEAN                  bFalse = FALSE;
#endif

    DEBUGP(DL_TRACE, ("===>FilterStaus, IndicateStatus = %8x.\n", StatusIndication->StatusCode));
   
#if DBG
    FILTER_ACQUIRE_LOCK(&pFilter->Lock, bFalse);
    ASSERT(pFilter->bIndicating == FALSE);
    pFilter->bIndicating = TRUE;
    FILTER_RELEASE_LOCK(&pFilter->Lock, bFalse);
#endif    
    
   
    NdisFIndicateStatus(pFilter->FilterHandle, StatusIndication);

#if DBG    
    FILTER_ACQUIRE_LOCK(&pFilter->Lock, bFalse);
    ASSERT(pFilter->bIndicating == TRUE);
    pFilter->bIndicating = FALSE;
    
    FILTER_RELEASE_LOCK(&pFilter->Lock, bFalse);


#endif
    
    DEBUGP(DL_TRACE, ("<===FilterStaus.\n"));

}




/*
Filter Driver提供FilterPnpEventNotify来接收NDIS传递的PnP和电源管理事件
*/
VOID
FilterDevicePnPEventNotify(
        IN  NDIS_HANDLE             FilterModuleContext,
        IN  PNET_DEVICE_PNP_EVENT   NetDevicePnPEvent
        )

{
    PMS_FILTER          pFilter = (PMS_FILTER)FilterModuleContext;
    NDIS_DEVICE_PNP_EVENT   DevicePnPEvent = NetDevicePnPEvent->DevicePnPEvent;
#if DBG
    BOOLEAN             bFalse = FALSE;
#endif

    DEBUGP(DL_TRACE, ("===>FilterDevicePnPEventNotify: NetPnPEvent = %p.\n", NetDevicePnPEvent));

    switch (DevicePnPEvent)
    {

        case NdisDevicePnPEventQueryRemoved: 
        case NdisDevicePnPEventRemoved:
        case NdisDevicePnPEventSurpriseRemoved:
        case NdisDevicePnPEventQueryStopped:
        case NdisDevicePnPEventStopped:
        case NdisDevicePnPEventPowerProfileChanged:
        case NdisDevicePnPEventFilterListChanged:
                
            break;
            
        default:
            DEBUGP(DL_ERROR, ("FilterDevicePnPEventNotify: Invalid event.\n"));
            FILTER_ASSERT(bFalse);
            
            break;
    }

  //Filter Driver要下层驱动转发收到的事件,转发事件要用到NdisFDevicePnPEventNotify例程
    NdisFDevicePnPEventNotify(pFilter->FilterHandle, NetDevicePnPEvent);
                              
    DEBUGP(DL_TRACE, ("<===FilterDevicePnPEventNotify\n"));

}





/*
Filter Driver提供了FilterNetPnpEvent例程来处理网络Pnp和电源管理事件通知。
*/
NDIS_STATUS
FilterNetPnPEvent(
        IN  NDIS_HANDLE             FilterModuleContext,
        IN  PNET_PNP_EVENT_NOTIFICATION NetPnPEventNotification
        )
{
    PMS_FILTER             pFilter = (PMS_FILTER)FilterModuleContext;
    NDIS_STATUS           Status = NDIS_STATUS_SUCCESS;

//Filter Driver需要转发网络PnP和电源管理事件给上层驱动。转发这些事件是通NdisFNetPnpEvent来完成的。 
    Status = NdisFNetPnPEvent(pFilter->FilterHandle, NetPnPEventNotification);
    
    return Status;
}




/**************************************************************
 FilterSendNetBufferListsComplete函数的功能:
  NDIS调用 FilterSendNetBufferListsComplete 把发送的结构和数据返还给 Filter Driver。NDIS可以收集多次NdisFSendNetBufferLists发送的结构和数据形成一个单链表传递给FilterSendNetBufferListsComplete。除非到NDIS调用FilterSendNetBufferListsComplete,否则一个发送请求的当前状态总是未知的。

  一个过滤驱动是不能在NDIS调用FilterSendNetBufferListsComplete返回结构之前对NET_BUFFER_LIST和其关联的数据做检查的。FilterSendNetBufferListsComplete要完成一个发送请求完成后的任何必要的后继处理。当NDIS调用FilterSendNetBufferListsComplete时,Filter Driver就重新获地对结构及结构相关资源的所有权。可以在 FilterSendNetBufferListsComplete中释放相关的资源和准备下一个NdisFSendNetBufferLists调用。 
 
  NDIS总是按照过滤驱动调用NdisFSendNetBufferLists提交的顺序传递给下层驱动,但是回返FilterSendNetBufferListsComplete 的顺序则是任意的。Filter Driver可以请求一个回环发送请求,只要把NdisFSendNetBufferLists的SendFlags设置成NDIS_SEND_FLAGS_CHECK_FOR_LOOPBACK就行了。NDIS会引发一个包含发送数据的接收包指示。
  
   
  一个Filter Driver应该对自己引发的发送请求保持跟踪并确保在完成时不调用NdisFSendNetBufferComplete例程。 
 **************************************************************/
VOID
FilterSendNetBufferListsComplete(
        IN  NDIS_HANDLE         FilterModuleContext,
        IN  PNET_BUFFER_LIST    NetBufferLists,
        IN  ULONG               SendCompleteFlags
        )

{
    PMS_FILTER         pFilter = (PMS_FILTER)FilterModuleContext;
    ULONG              NumOfSendCompletes = 0;
    BOOLEAN            DispatchLevel;
    PNET_BUFFER_LIST   CurrNbl;
   
    DEBUGP(DL_TRACE, ("===>SendNBLComplete, NetBufferList: %p.\n", NetBufferLists));

   
    if (pFilter->TrackSends)
    {
        CurrNbl = NetBufferLists;
        while (CurrNbl)
        {
            NumOfSendCompletes++;
            CurrNbl = NET_BUFFER_LIST_NEXT_NBL(CurrNbl);
            
        }
        DispatchLevel = NDIS_TEST_SEND_AT_DISPATCH_LEVEL(SendCompleteFlags);
        FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);
        pFilter->OutstandingSends -= NumOfSendCompletes;
        FILTER_LOG_SEND_REF(2, pFilter, PrevNbl, pFilter->OutstandingSends);        
        FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
    }

    NdisFSendNetBufferListsComplete(pFilter->FilterHandle, NetBufferLists, SendCompleteFlags);

    DEBUGP(DL_TRACE, ("<===SendNBLComplete.\n"));
}




/*************************************************************
 FilterSendNetBufferLists函数的功能:
  NDIS调用一个Filter Driver的FilterSendNetBufferLists例程来过滤上层驱动的发送请求。Filter Driver不能改变其它驱动传来的NET_BUFFER_LIST结构中的SourceHandle成员的值。它可以过滤数据并发送过滤的数据到下层驱动。
  对每一个提交到FilterSendNetBufferLists的NDIS_BUFFER_LIST，我们可做下面的操作。
   
  1)可以把缓冲区通过 NdisFSendBufferLists 传递给下层驱动,NDIS 保证上下文空间对FilterDriver的有效性。过滤驱动可以在发送前修改缓冲区的内容。可以像处理自己引发的发送请求的缓冲区一样处理这个缓冲区。   
  2)可以调用 NdisFSendNetBufferListsComplete 拒绝传递这个包 
  3)排队缓冲区内容到本地的供以后处理。例如要在一定超时后处理或要接收到特定包后才处理等。如果支持这种处理方式就要支持取消请求的操作。     
  4)可以拷贝缓冲区并引发一个发送请求。它类似自己引发一个发送请求,但必须先调用 NdisFSendNetBufferComplete返回上层驱动的缓冲区。
      
  发送请求在驱动栈继续完成,当一个微端口驱动调用NdisMSendNetBufferListsComplete完成一个发送请求时,NDIS会调用微端口
  驱动之上最近的Filter Driver的FilterSendNetBufferLists例程。
  
  在一个发送操作完成后,Filter Driver可以做在FilterSendNetBufferLists中所有修改的相反操作。FilterSendNetBufferListsComplete返回一个NET_BUFFER_LIST结构的单链表和发送请求的最终状态给上层的驱动。当最顶层的 Filter Module的FilterSendNetBufferListsComplete被调用完成后NDIS会调用引发发送请求的协议驱动的ProtocolSendNetBufferListsComplete。如果Filter Driver不提供FilterSendNetBufferLists它还是可以引发一个发送操作的,但它必须提供一个FilterSendNetBufferListsComplete并且不能在这个例程里把这个事件传递给上层驱动。

  一个Filter Driver可以传递或过滤一个上层驱动的回环请求,要传递一个回环请求,NDIS会设置FilterSendNetBufferLists的SendFlags参数为NDIS_SEND_FLAGS_CHECK_FOR_LOOPBACK,Filter Driver在调用NdisFSendNetBufferLists时把这个标记传给它即可。在回环请求的情况下NDIS会指示一个包含发送数据的接收包。

  通常情况下,如果一个Filter Driver修改的任何行为不是NDIS提供的标准服务,那么它应该当自己为NDIS提供相应的服务。例如,如果一个Filter Driver修改了一个硬件地址请求,就必须处理直接到这个新地址回环包。在这种情况下, 因为Filter Driver已经更改了地址NDIS是不能提供一个回环服务的。
  还有就是如果Filter Driver设置了混杂模式那它就不能传递额外的数据给上层接收。 
**************************************************************/

VOID
FilterSendNetBufferLists(
        IN  NDIS_HANDLE         FilterModuleContext,
        IN  PNET_BUFFER_LIST    NetBufferLists,
        IN  NDIS_PORT_NUMBER    PortNumber,
        IN  ULONG               SendFlags
        )


{
    PMS_FILTER          pFilter = (PMS_FILTER)FilterModuleContext;
    PNET_BUFFER_LIST    CurrNbl;
    BOOLEAN             DispatchLevel;
    BOOLEAN               bFalse = FALSE;
    
    DEBUGP(DL_TRACE, ("===>SendNetBufferList: NBL = %p.\n", NetBufferLists));

    do
    {

       DispatchLevel = NDIS_TEST_SEND_AT_DISPATCH_LEVEL(SendFlags);

#if DBG 
        
        FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);
        
        if (pFilter->State != FilterRunning)
        {
            FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
            
            CurrNbl = NetBufferLists;
            while (CurrNbl)
            {
                NET_BUFFER_LIST_STATUS(CurrNbl) = NDIS_STATUS_PAUSED;
                CurrNbl = NET_BUFFER_LIST_NEXT_NBL(CurrNbl);
            }
            NdisFSendNetBufferListsComplete(pFilter->FilterHandle, 
                        NetBufferLists, 
                        DispatchLevel ? NDIS_SEND_COMPLETE_FLAGS_DISPATCH_LEVEL : 0);
            break;
            
        }
        FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
#endif

/******************************************************/

             //在这里添加我们的代码

/******************************************************/

        if (pFilter->TrackSends)
        {
            FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);
            CurrNbl = NetBufferLists;
            while (CurrNbl)
            {
                pFilter->OutstandingSends++;
                FILTER_LOG_SEND_REF(1, pFilter, CurrNbl, pFilter->OutstandingSends);
                
                CurrNbl = NET_BUFFER_LIST_NEXT_NBL(CurrNbl);
            }
            FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
        }
       

        NdisFSendNetBufferLists(pFilter->FilterHandle, NetBufferLists, PortNumber, SendFlags);
        
        
    }
    while (bFalse);
    
    DEBUGP(DL_TRACE, ("<===SendNetBufferList. \n"));
}




/*************************************************************
 FilterReturnNetBufferLists函数的功能:
  如果Filter Driver设置了NdisFIndicateReceiveNetBufferLists的状态为NDIS_STATUS_SUCCESS, NDIS通过驱动的FilterReturnNetBufferLists
  返回指示数据。在这种情况下 Filter Driver失去了对NET_BUFFER_LIST的所有权,直到FilterReturnNetBufferLists被调用。

  Filter Driver调用NdisFIndicateNetBufferLists 传递接收指示给驱动栈上的上层驱动,如果上层驱动保留了对缓冲区(NET_BUFFER_LIST)的所有权,NDIS会调用Filter Driver的FilterReturnNetBufferLists 例程。
  
  在FilterReturnNetBufferLists中应该撤消在接收路径上(如在 FilterReciveNetBufferLists中做的一些处理)的操作。当最底层的Filter Module完成对缓冲区(NET_BUFFER_LIST)的处理后,NDIS把缓冲区返回给微端口驱动。如果FilterReceiveNetBufferLists的ReceiveFlags没有设置NDIS_RECEIVE_FLAGS_RESOURCES标记, FilterDriver调用NdisFReturnNetBufferList返回这个缓冲区数据,如果设置了FilterReceiveNetBufferLists直接返回时就把缓冲区返还给了下层微端口驱动。  
 ***************************************************************/
VOID
FilterReturnNetBufferLists(
        IN  NDIS_HANDLE         FilterModuleContext,
        IN  PNET_BUFFER_LIST    NetBufferLists,
        IN  ULONG               ReturnFlags
        )

{
    PMS_FILTER          pFilter = (PMS_FILTER)FilterModuleContext;
    PNET_BUFFER_LIST    CurrNbl = NULL;
    UINT                NumOfNetBufferLists = 0;
    BOOLEAN             DispatchLevel;
    ULONG               Ref;
    
    DEBUGP(DL_TRACE, ("===>ReturnNetBufferLists, NetBufferLists is %p.\n", NetBufferLists));

    if (pFilter->TrackReceives)
    {
        while (CurrNbl)
        {
            
            NumOfNetBufferLists ++;
            CurrNbl = NET_BUFFER_LIST_NEXT_NBL(CurrNbl);
        }
    }
    NdisFReturnNetBufferLists(pFilter->FilterHandle, NetBufferLists, ReturnFlags);
 
    if (pFilter->TrackReceives)
    {
        DispatchLevel = NDIS_TEST_RETURN_AT_DISPATCH_LEVEL(ReturnFlags);
        FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);

        pFilter->OutstandingRcvs -= NumOfNetBufferLists;
        Ref = pFilter->OutstandingRcvs;
        FILTER_LOG_RCV_REF(3, pFilter, NetBufferLists, Ref);
        FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
    }                


    DEBUGP(DL_TRACE, ("<===ReturnNetBufferLists.\n"));
    

}



/***************************************************************
 FilterReceiveNetBufferLists函数的功能:
  Filter Driver调用 NdisFIndicateReceiveNetBufferLists来指示发送数据。这个函数通过NET_BUFFER_LIST结构给上层驱动指示数据。Filter Driver可以从池中分配这个结构。如果Filter Driver设置了NdisFIndicateReceiveNetBufferLists的状态为 NDIS_STATUS_SUCCESS, NDIS通过驱动的FilterReturnNetBufferLists返回指示数据。在这种情况下Filter Driver失去了对NET_BUFFER_LIST的所有权直到FilterReturnNetBufferLists被调用。如果Filter Driver在调用NdisFIndicateReceiveNetBufferLists时设置ReceiveFlags为NDIS_RECEIVE_FLAGS_RESOURCES，在函数返回后Filter Driver会立即恢复对NET_BUFFER_LIST的所有权,这时Filter Driver必须立即处理这个NET_BUFFER_LIST的返回,因为NDIS在这种情况下是不会调用FilterReturnNetBufferLists返回NET_BUFFER_LIST结构的。 

  注意: 一个Filter Driver应该跟踪自己引发的接收指示确保它在FilterReturnNetBufferLists
  中不调用NdisFReturnNetBufferLists。 
 ***************************************************************/
VOID
FilterReceiveNetBufferLists(
        IN  NDIS_HANDLE         FilterModuleContext,
        IN  PNET_BUFFER_LIST    NetBufferLists,
        IN  NDIS_PORT_NUMBER    PortNumber,
        IN  ULONG               NumberOfNetBufferLists,
        IN  ULONG               ReceiveFlags
         )

{

    PMS_FILTER          pFilter = (PMS_FILTER)FilterModuleContext;
    BOOLEAN             DispatchLevel;
    ULONG               Ref;
    BOOLEAN               bFalse = FALSE;


#if DBG
    ULONG               ReturnFlags;
#endif
    
    DEBUGP(DL_TRACE, ("===>ReceiveNetBufferList: NetBufferLists = %p.\n", NetBufferLists));
    do
    {

        DispatchLevel = NDIS_TEST_RECEIVE_AT_DISPATCH_LEVEL(ReceiveFlags);
#if DBG
        FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);
 
        if (pFilter->State != FilterRunning)
        {
            FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);

            if (NDIS_TEST_RECEIVE_CAN_PEND(ReceiveFlags))
            {   
                ReturnFlags = 0;
                if (NDIS_TEST_RECEIVE_AT_DISPATCH_LEVEL(ReceiveFlags))
                {
                    NDIS_SET_RETURN_FLAG(ReturnFlags, NDIS_RETURN_FLAGS_DISPATCH_LEVEL);
                }
                
                NdisFReturnNetBufferLists(pFilter->FilterHandle, NetBufferLists, ReturnFlags);
            }
            break;
        }
        FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
#endif

        ASSERT(NumberOfNetBufferLists >= 1);


/*--------------------------------------------------------------------------------------*/          

                  //在这里添加我们的代码


/*---------------------------------------------------------------------------------------*/


        if (pFilter->TrackReceives)
        {
            FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);
            pFilter->OutstandingRcvs += NumberOfNetBufferLists;
            Ref = pFilter->OutstandingRcvs;
            
            FILTER_LOG_RCV_REF(1, pFilter, NetBufferLists, Ref);
            FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
        }


/************************************************************
调用 NdisFIndicateReceiveNetBufferLists来指示发送数据。

如果Filter Driver设置了NdisFIndicateReceiveNetBufferLists的状态为NDIS_STATUS_SUCCESS, NDIS通过驱动的FilterReturnNetBufferLists 返回指示数据。
    
如果Filter Driver设置了NdisFIndicateReceiveNetBufferLists的ReceiveFlags值为
NDIS_RECEIVE_FLAGS_RESOURCES,那么在函数返回后Filter Driver会立即恢复对
NET_BUFFER_LIST的所有权,这时Filter Driver必须立即处理这个NET_BUFFER_LIST的返回。
在这种情况下是不会调用FilterReturnNetBufferLists返回NET_BUFFER_LIST结构的。
************************************************************/
        NdisFIndicateReceiveNetBufferLists(
                   pFilter->FilterHandle,
                   NetBufferLists,
                   PortNumber, 
                   NumberOfNetBufferLists,
                   ReceiveFlags);


        if (NDIS_TEST_RECEIVE_CANNOT_PEND(ReceiveFlags) && pFilter->TrackReceives)
        {
            FILTER_ACQUIRE_LOCK(&pFilter->Lock, DispatchLevel);
            pFilter->OutstandingRcvs -= NumberOfNetBufferLists;
            Ref = pFilter->OutstandingRcvs;
            FILTER_LOG_RCV_REF(2, pFilter, NetBufferLists, Ref);
            FILTER_RELEASE_LOCK(&pFilter->Lock, DispatchLevel);
        }

    } while (bFalse);
    
    DEBUGP(DL_TRACE, ("<===ReceiveNetBufferList: Flags = %8x.\n", ReceiveFlags));
    
}



/**************************************************************
 FilterCancelSendNetBufferLists函数的功能:
 过滤驱动调用NDIS_SET_NET_BUFFER_LIST_CANCEL_ID宏为每一个NET_BUFFER_LIST标记一个取消Id。
 在为网络数据分配取消ID之前,必须先调用NdisGenratePartialCanceId获得取消ID的高字节。
 这是为了确保不是驱动不会把一个取消ID分配给两个驱动驱动通常在DriverEntry调用
 NdisGenratePartialCanceld,但是驱动可以在不同的时间多次调用它来获得多个取消ID。
 要取消被标记过取消ID且正在传输的数据,驱动可以调用NdisFCancelSendNetBufferLists例程
 来完成。要获得取消ID可以用NDIS_GET_NET_BUFFER_LIST_CANCEL_ID宏来完成。

 如果一个Filter Driver对所有发送的NET_BUFFER_LIST标记了相同的取消ID那它可以用一个 
 NdisFCancelSendNetBufferLists来取消所有的发送请求。如果把一部发送请求的NET_BUFFER_LIST标记相同的取消ID那么就可以调用一次NdisFCancelSendNetBufferLists来取消这部分发送请求。

 在实现这个功能时NDIS会调用下层驱动的取消发送功能。中断正在执行的发送任务后,下层驱动会
 调用发送完成全程(如:NdisMSendNetBufferListComplete)返回指定的NET_BUFFER_LIST结构并指定 返回状态为 NDIS_STATUS_CANCELLED, NDIS依次调用Filter Driver的FilterSendNetBufferListsComplete例程。在FilterSendNetBufferListsComplete中要用NDIS_SET_NET_BUFFER_LIST_CANCEL_ID设置取消的NET_BUFFER_LIST 
 的取消ID 为 NULL,这样是为了防止这个ID,在 NET_BUFFER_LIST被再次分配时使用。 


上层驱动在取消一个未完成的发送请求时也必须对这个发送请求的 NET_BUFFER_LIST结构设定取消ID。
 NDIS会传递给Filter Driver的FilterCancelSendNetBufferLists一个取消ID来取消发送请求的
 NET_BUFFER_LIST发送。FilterCanCelSendNetBufferLists下执行下列操作。  
  1)遍历 Filter Driver的发送队列，用 NDIS_GET_NET_BUFFER_LSIT_CANCEL_ID获得队列中NET_BUFFER_LIST的取消ID与FilterCancelSendBufferLists的取消ID比较。 
  2)移除队列中取消 ID 和 FilterCancelSentBufferLists中取消ID相同的元素。 
  3)调用 NdisFSendNetBufferListsComplete来完成这些NET_BUFFER_LIST并设定返回状
    态为NDIS_STATUS_CANCELLED。 
  4)调用NdisFCancelSendNetBufferLists传递取消发送请求给下层驱动。传递取消ID给下层驱动就Filter Driver取消自己引发的发关请求一样。 
 *************************************************************/
VOID
FilterCancelSendNetBufferLists(
    IN  NDIS_HANDLE             FilterModuleContext,
    IN  PVOID                   CancelId
    )

{
    PMS_FILTER  pFilter = (PMS_FILTER)FilterModuleContext;

    NdisFCancelSendNetBufferLists(pFilter->FilterHandle,CancelId);
}




/**************************************************************
 FilterSetModuleOptions函数的功能:
  必须要在初始化时为驱动注册FilterSetModuleOptions例程,驱动可以在这个例程中初始化
  NDIS_FILTER_PARTIAL_CHARACTERISTICS结构来调用NdisSetOptionalHandlers来完成必变。
  这个例程如果存在那么在调用Filter Driver的FilterRestart例程之前调用它。
 ***************************************************************/ 
NDIS_STATUS
FilterSetModuleOptions(
    IN  NDIS_HANDLE             FilterModuleContext
    )
{
    
   PMS_FILTER                   pFilter = (PMS_FILTER)FilterModuleContext;
   NDIS_FILTER_PARTIAL_CHARACTERISTICS      OptionalHandlers;
   NDIS_STATUS                Status = NDIS_STATUS_SUCCESS;
   BOOLEAN               bFalse = FALSE;

 
   if (bFalse)
   {
       UINT    i;

      
       pFilter->CallsRestart++;

       i = pFilter->CallsRestart % 8;

       pFilter->TrackReceives = TRUE;
       pFilter->TrackSends = TRUE;

       NdisMoveMemory(&OptionalHandlers, &DefaultChars, sizeof(OptionalHandlers));
       OptionalHandlers.Header.Type = NDIS_OBJECT_TYPE_FILTER_PARTIAL_CHARACTERISTICS;
       OptionalHandlers.Header.Size = sizeof(OptionalHandlers);
       switch (i)
       {
           
            case 0: 
                OptionalHandlers.ReceiveNetBufferListsHandler = NULL;
                pFilter->TrackReceives = FALSE;
                break;

            case 1:
                
                OptionalHandlers.ReturnNetBufferListsHandler = NULL;
                pFilter->TrackReceives = FALSE;
                break;

            case 2:
                OptionalHandlers.SendNetBufferListsHandler = NULL;
                pFilter->TrackSends = FALSE;
                break;

            case 3:
                OptionalHandlers.SendNetBufferListsCompleteHandler = NULL;
                pFilter->TrackSends = FALSE;
                break;

            case 4:
                OptionalHandlers.ReceiveNetBufferListsHandler = NULL;
                OptionalHandlers.ReturnNetBufferListsHandler = NULL;
                break;

            case 5:
                OptionalHandlers.SendNetBufferListsHandler = NULL;
                OptionalHandlers.SendNetBufferListsCompleteHandler = NULL;
                break;

            case 6:
                
                OptionalHandlers.ReceiveNetBufferListsHandler = NULL;
                OptionalHandlers.ReturnNetBufferListsHandler = NULL;
                OptionalHandlers.SendNetBufferListsHandler = NULL;
                OptionalHandlers.SendNetBufferListsCompleteHandler = NULL;
                break;
                
            case 8:
                break;
       }
       Status = NdisSetOptionalHandlers(pFilter->FilterHandle, (PNDIS_DRIVER_OPTIONAL_HANDLERS)&OptionalHandlers );
   }
   return Status;
}



NDIS_STATUS
filterDoInternalRequest(
    IN PMS_FILTER                   FilterModuleContext,
    IN NDIS_REQUEST_TYPE            RequestType,
    IN NDIS_OID                     Oid,
    IN PVOID                        InformationBuffer,
    IN ULONG                        InformationBufferLength,
    IN ULONG                        OutputBufferLength, OPTIONAL
    IN ULONG                        MethodId, OPTIONAL
    OUT PULONG                      pBytesProcessed
    )

{
    FILTER_REQUEST              FilterRequest;
    PNDIS_OID_REQUEST           NdisRequest = &FilterRequest.Request;
    NDIS_STATUS                 Status;
    BOOLEAN               bFalse;


    bFalse = FALSE;
    NdisZeroMemory(NdisRequest, sizeof(NDIS_OID_REQUEST));

    NdisInitializeEvent(&FilterRequest.ReqEvent);
    
    NdisRequest->Header.Type = NDIS_OBJECT_TYPE_OID_REQUEST;
    NdisRequest->Header.Revision = NDIS_OID_REQUEST_REVISION_1;
    NdisRequest->Header.Size = sizeof(NDIS_OID_REQUEST);
    NdisRequest->RequestType = RequestType;

    switch (RequestType)
    {
        case NdisRequestQueryInformation:
             NdisRequest->DATA.QUERY_INFORMATION.Oid = Oid;
             NdisRequest->DATA.QUERY_INFORMATION.InformationBuffer =InformationBuffer;
                                    
             NdisRequest->DATA.QUERY_INFORMATION.InformationBufferLength = InformationBufferLength;
                                   
            break;

        case NdisRequestSetInformation:
             NdisRequest->DATA.SET_INFORMATION.Oid = Oid;
             NdisRequest->DATA.SET_INFORMATION.InformationBuffer =InformationBuffer;
                                    
             NdisRequest->DATA.SET_INFORMATION.InformationBufferLength =InformationBufferLength;
                                    
            break;

        case NdisRequestMethod:
             NdisRequest->DATA.METHOD_INFORMATION.Oid = Oid;
             NdisRequest->DATA.METHOD_INFORMATION.MethodId = MethodId;
             NdisRequest->DATA.METHOD_INFORMATION.InformationBuffer = InformationBuffer;
                                    
             NdisRequest->DATA.METHOD_INFORMATION.InputBufferLength = InformationBufferLength;
                                    
             NdisRequest->DATA.METHOD_INFORMATION.OutputBufferLength = OutputBufferLength;
             break;
             
                

        default:
            FILTER_ASSERT(bFalse);
            break;
    }

    NdisRequest->RequestId = (PVOID)FILTER_REQUEST_ID;
    
    Status = NdisFOidRequest(FilterModuleContext->FilterHandle,NdisRequest);
    

    if (Status == NDIS_STATUS_PENDING)
    {
        
        NdisWaitEvent(&FilterRequest.ReqEvent, 0);
        Status = FilterRequest.Status;
    }


    if (Status == NDIS_STATUS_SUCCESS)
    {
        if (RequestType == NdisRequestSetInformation)
        {
            *pBytesProcessed = NdisRequest->DATA.SET_INFORMATION.BytesRead;
        }

        if (RequestType == NdisRequestQueryInformation)
        {
            *pBytesProcessed = NdisRequest->DATA.QUERY_INFORMATION.BytesWritten;
        }

        if (RequestType == NdisRequestMethod)
        {
            *pBytesProcessed = NdisRequest->DATA.METHOD_INFORMATION.BytesWritten;
        }
        
        if (RequestType == NdisRequestMethod)
        {
            if (*pBytesProcessed > OutputBufferLength)
            {
                *pBytesProcessed = OutputBufferLength;
            }
        }
        else
        {
            
            if (*pBytesProcessed > InformationBufferLength)
            {
                *pBytesProcessed = InformationBufferLength;
            }
        }
    }


    return (Status);
}



VOID
filterInternalRequestComplete(
    IN NDIS_HANDLE                  FilterModuleContext,
    IN PNDIS_OID_REQUEST            NdisRequest,
    IN NDIS_STATUS                  Status
    )


{
    PFILTER_REQUEST              FilterRequest;

    UNREFERENCED_PARAMETER(FilterModuleContext);
   
    FilterRequest = CONTAINING_RECORD(NdisRequest, FILTER_REQUEST, Request);

    FilterRequest->Status = Status;

    NdisSetEvent(&FilterRequest->ReqEvent);
}