帮忙解释ddk中前视缓冲区的含义

在读ddk中前视缓冲区是什莫含义，有什莫作用？谢谢

在读ddk中前视缓冲区是什莫含义，有什莫作用？谢谢
 

lookaheadbuffer??

这个缓冲区是给协议一段packet的内容，让协议来决定是否接受这个报文。

[quote]在读ddk中前视缓冲区是什莫含义，有什莫作用？谢谢
 

lookaheadbuffer??

这个缓冲区是给协议一段packet的内容，让协议来决定是否接受这个报文。 [/quote]

谢谢斑竹，那莫你所说的**给协议一段packet内容**是怎莫控制的，到底要给那一段内容，有什莫规则要遵循？是不是这些都是由函数来执行的，我们只需要调用就可以了？

这个是有miniport驱动来决定究竟那个lookaheadbuffer的大小的，这个缓冲区是从报文的ip头开始的一段缓冲区，也有可能是包含了整个的ip报文，这个时候lookaheadbuffersize＝packetsize了，
如果lookaheadbuffersiz<Packetsize,而这个时候协议驱动还要接受整个报文，那就调用ndistransferdata来获得整个的报文。

谢谢斑竹，给分了

这个是有miniport驱动来决定究竟那个lookaheadbuffer的大小的，这个缓冲区是从报文的ip头开始的一段缓冲区，也有可能是包含了整个的ip报文，这个时候lookaheadbuffersize＝packetsize了，
如果lookaheadbuffersiz<Packetsize,而这个时候协议驱动还要接受整个报文，那就调用ndistransferdata来获得整个的报文。

斑竹解释得我好像是明白了，可一看到程序就不知道什莫意思了？
斑竹能给解释一下下面的程序吗，谢谢！

if(LookaheadBufferSize!=PacketSize){
  IndicateBuffer=TransferBuffer-HeaderBufferSize-LookaheadBufferSize;
  NdisMoveMemory( IndicateBuffer, HeaderBuffer, HeaderBufferSize);
  NdisMoveMemory( IndicateBuffer+HeaderBufferSize, LookaheadBuffer, Lookahea
dBufferSize);
  NdisTransferData(
     &ReturnStatus,
     *((PUINT)NdisBindingContext+1),
     MacReceiveContext,
     LookaheadBufferSize, // ByteOffset,
     PacketSize-LookaheadBufferSize, //BytesToTransfer,
     RcvTransferPacket,
     &BytesTransfered
     );
  HeaderBuffer=IndicateBuffer;
  LookaheadBuffer=IndicateBuffer+HeaderBufferSize;
  LookaheadBufferSize = PacketSize;
 }  
else  
{
  IndicateBuffer=HeaderBuffer;
 }

斑竹解释得我好像是明白了，可一看到程序就不知道什莫意思了？
斑竹能给解释一下下面的程序吗，谢谢！

if(LookaheadBufferSize!=PacketSize){
//不等于就是小于，lookaheadbuffersize不应该会大于packetsize
  IndicateBuffer=TransferBuffer-HeaderBufferSize-LookaheadBufferSize;
//TransferBuffer在前面应该有声明和初始化的地方吧，这里把指针向前移动了headbuffersize＋lookaheadbuffersize长的距离，他是不是把这个缓冲区chain到下面的那个RcvTransferPacket上了？这样在ndistransferdata之后整个报文的数据都在一快连续的缓冲区里面了。IndicateBuffer是要向协议提交的缓冲区的指针了
  NdisMoveMemory( IndicateBuffer, HeaderBuffer, HeaderBufferSize);
  NdisMoveMemory( IndicateBuffer+HeaderBufferSize, LookaheadBuffer, Lookahea
dBufferSize);
  NdisTransferData(
     &ReturnStatus,
     *((PUINT)NdisBindingContext+1),
     MacReceiveContext,
     LookaheadBufferSize, // ByteOffset,
     PacketSize-LookaheadBufferSize, //BytesToTransfer,
     RcvTransferPacket,
     &BytesTransfered
     );

    //这里应该判断一下ReturnStatus的状态，如果不是success，那就要到transferdatacomplete里面去处理了。
  HeaderBuffer=IndicateBuffer;
  LookaheadBuffer=IndicateBuffer+HeaderBufferSize;
  LookaheadBufferSize = PacketSize;
 }  
else  
{
  IndicateBuffer=HeaderBuffer;
 }
 

这段程序就是判断lookaheadbuffersize是否等于packetsize，如果等于那就直接提交，如果不等于，就调用ndistranferdata来把剩余的数据都取上来，然后在一起提交。

谢谢斑竹，还有点小问题：
1 我不太明白HeaderBufferSize和LookaheadBufferSize大小是不是要重叠的？还有HeaderBuffer和LookaheadBuffer所代表的缓冲区的表示符是不是同指一个地址，假如要是重叠或是相同下面的两个NdisMoveMemory复制数据值就有重复了吧？
2 还有NdisTransferData中参数 *((PUINT)NdisBindingContext+1) 不明白什莫意思

1 headbuffer和lookaheadbuffer上不重叠的，指向的不是同以地址，packetsize是不包括headbuffer的大小的，headbuffer一般是以太网的头
2 *((PUINT)NdisBindingContext+1)这个你要看那个NdisBindingContext的声明了，指针向前挪了一个，应该是一个NDIS_HANDLE的指针，就是ndistransferdata的第二个参数。

mikeluo :
     lookaheadbuffersize > packetsize 的情况下， 难道也要调用ndistransferdata 来获得 整个 数据吗 ？？
     呵呵。 先谢 了。

mikeluo :
     lookaheadbuffersize > packetsize 的情况下， 难道也要调用ndistransferdata 来获得 整个 数据吗 ？？
     呵呵。 先谢 了。
 

真的有这个时候？应该不会出现的。
那个判断其实应该是判断if(lookaheadbuffersize<packetsize)
那直接从lookaheadbuffer里面copy出来packetsize大小的数据就ok了啊。

1 headbuffer和lookaheadbuffer上不重叠的，指向的不是同以地址，packetsize是不包括headbuffer的大小的，headbuffer一般是以太网的头
2 *((PUINT)NdisBindingContext+1)这个你要看那个NdisBindingContext的声明了，指针向前挪了一个，应该是一个NDIS_HANDLE的指针，就是ndistransferdata的第二个参数。
 

谢谢斑竹！
第一个问题明白了，可第二个问题还有些不懂，我在ddk中查到ndistransferdata的第二个参数的意思是：
Specifies the handle returned by NdisOpenAdapter that identifies the target NIC or the virtual adapter of the next-lower driver to which the caller is bound.
不明白为慎莫要加一呢，是不是要指向另一个the target NIC or the virtual adapter？ 而且加一我认为是指针向后挪了一个？
 

你在看谁的代码？他那个NdisBindingContext是怎么声明的？如何赋值的？

你在看谁的代码？他那个NdisBindingContext是怎么声明的？如何赋值的？

可能是胡老大的帖子吧
发信人: Immortal1015 (1015), 信区: WinDDK        
标  题: 一个win95下的VPN SOURCE
发信站: BBS 水木清华站 (Fri Mar 16 15:00:46 2001)

转自白云黄鹤站系统内核版

发信人: huyuguang (不再困惑), 信区: SysInternals ;32mWWW-POSTm
标  题: win9x vpn source
发信站: 武汉白云黄鹤站 (Tue Aug  8 20:53:58 2000) , 站内信件
这个代码是17（oneseven)写的，我和他是源代码共享的，
由于前面友人向我要win9x下的vpn源代码，我相信肯定有
人看了我前面的简介还是不太明白，干脆贴在下面。
下文来自17的毕业论文，别的东西不好都贴上来，毕竟还有
点军队背景。
为了免得大家看的麻烦，我就不分成几块了，其实我是很喜欢
灌水的;-)
垫片模块的源程序：
1．Ndisshim.h，C语言头文件。
/***************************************************************************
*
*                                                                            
*
* THIS CODE AND INFORMATION IS PROVIDED \"AS IS\" WITHOUT WARRANTY OF ANY      
*
* KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE        
*
* IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR      
*
* PURPOSE.                                                                  
*
*                                                                            
*
****************************************************************************
/
#define WANTVXDWRAPS
#include <basedef.h>
#include <vmm.h>
#include <shell.h>
#include <debug.h>
#include <vxdwraps.h>
#include <vwin32.h>
#include <winerror.h>
#include <ndis.h>
MAKE_HEADER(DWORD,_stdcall,VKD_Filter_Keyboard_Input, (VOID))
MAKE_HEADER(VOID,_cdecl,Ndis_Hook, ())
MAKE_HEADER(DWORD,_cdecl,_SHELL_PostMessage,(DWORD,DWORD,DWORD,DWORD,DWORD,D
WORD))
MAKE_HEADER(USHORT,_cdecl,Encrypt_reg,(PUCHAR,USHORT,USHORT))
MAKE_HEADER(USHORT,_cdecl,Decrypt_reg,(PUCHAR,USHORT,USHORT))
#define Ndis_Hook      PREPEND(Ndis_Hook)
#define _SHELL_PostMessage               PREPEND(_SHELL_PostMessage)
#define Encrypt_reg      PREPEND(Encrypt_reg)
#define Decrypt_reg      PREPEND(Decrypt_reg)
#define WM_NSHIM_NEW       3002
#define  IP_PROTOCOL    0x0008
#define  IP_HEADER_LEN   20
#define  MAC_HEADER_LEN  14
#define NSHIM_VERSION 0x400
#define NSHIM_V86_FUNCTION1 1
#define NSHIM_V86_FUNCTION2 2
#define NSHIM_PM_FUNCTION1  1
#define NSHIM_PM_FUNCTION2  2
#define MAX_NSHIM_W32_API (sizeof(NSHIM_W32_Proc)/sizeof(DWORD))
#define MAX_SEND_BUF_LIST        10
#define MAX_SEND_PKT_LIST        10
#define MAX_SEND_APPEND_LEN      21
#define MAX_ADAPTER_NUM          5
#define PACKET_REFUSE   0
#define PACKET_MUD      1
#define PACKET_CLEAR    2
#define PACKET_D_REFUSE   3
#define PACKET_D_QUERY    4
#define PACKET_D_CLEAR    5
#define QUERY_SEND_PACKET  0
#define QUERY_RCV_PACKET   1
/*#define ENCRYPT_Service  Declare_Service
#define ENCRYPT_DEVICE_ID  0x1800
Begin_Service_Table(ENCRYPT)
ENCRYPT_Service(Encrypt_reg)
ENCRYPT_Service(Decrypt_reg)
End_Service_Table(ENCRYPT)*/
typedef DIOCPARAMETERS *LPDIOC;
typedef struct _MAC_HEADER{
   UCHAR  MAC_DA[6];
   UCHAR  MAC_SA[6];
   USHORT ProtocolType;
} MAC_HEADER, *PMAC_HEADER;
typedef struct _IP_HEADER{
   UCHAR  Ver;
   UCHAR  Service;
   UCHAR  LengthU;
   UCHAR  LengthL;
   USHORT Identification;
   USHORT FragmentOffset;
   UCHAR  LiveTime;
   UCHAR  Protocol;
   USHORT HeaderCRC;
   ULONG  IP_SA;
   ULONG  IP_DA;
} IP_HEADER, *PIP_HEADER;
typedef struct _AC_ITEM
{
 ULONG ip;
 ULONG net_mask;
 USHORT access;
 USHORT sndkeyno;
} AC_ITEM, *PAC_ITEM;
typedef struct _EXCP_ITEM
{
 ULONG ip;
 USHORT tcp_port;
} EXCP_ITEM, *PEXCP_ITEM;
typedef struct _BINDING_INFO{
   NDIS_HANDLE BindingHandle;
   UCHAR CtrlActived;
   NDIS_STRING Name;
} BINDING_INFO, *PBINDING_INFO;
typedef struct _PENDING_INFO{
   NDIS_HANDLE ProtocolBindingContext;
   PNDIS_HANDLE NdisBindingHandle;
   NDIS_STRING Name;
} PENDING_INFO, *PPENDING_INFO;
DWORD _stdcall NSHIM_W32_DeviceIOControl(DWORD, DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_CleanUp(void);
DWORD _stdcall NSHIM_W32_OpenWnd(DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_W32_CloseWnd(DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_W32_GetAdapterInfo(DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_W32_SetAdapterState(DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_W32_SetACState(DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_W32_LoadAccList(DWORD, DWORD, LPDIOC);
DWORD _stdcall NSHIM_W32_LoadExcpList(DWORD, DWORD, LPDIOC);
VOID  _stdcall NSHIM_Send(PNDIS_STATUS, NDIS_HANDLE, PNDIS_PACKET);
VOID  _stdcall NSHIM_Request(
  OUT PNDIS_STATUS Status,
  IN NDIS_HANDLE NdisBindingHandle,
  IN PNDIS_REQUEST Request
  );
VOID NDIS_API
NSHIM_RegisterProtocol(
    OUT PNDIS_STATUS Status,
    OUT PNDIS_HANDLE NdisProtocolHandle,
    IN PNDIS_PROTOCOL_CHARACTERISTICS ProtocolCharacteristics,
    IN UINT CharacteristicsLength
    );
NDIS_STATUS NDIS_API
NSHIM_IPReceive(
  IN NDIS_HANDLE NdisBindingContext,
  IN NDIS_HANDLE MacReceiveContext,
  IN PVOID HeaderBuffer,
  IN UINT HeaderBufferSize,
  IN PVOID LookaheadBuffer,
  IN UINT LookaheadBufferSize,
  IN UINT PacketSize
  );
VOID NDIS_API
NSHIM_IPSendComplete(
    IN NDIS_HANDLE NdisBindingContext,
    IN PNDIS_PACKET Packet,
    IN NDIS_STATUS Status
    );
VOID NDIS_API
NSHIM_IPOpenAdapterComplete(
  IN NDIS_HANDLE  ProtocolBindingContext,
  IN NDIS_STATUS  Status,
  IN NDIS_STATUS  OpenErrorStatus
  );
UINT
CopyPacketToBuffer(
  IN OUT PUCHAR Buf,              // destination
  IN PNDIS_PACKET Packet,         // source packet
  IN UINT Offset,                 // offset in packet
  IN UINT Length                  // number of bytes to copy
  );
VOID
CopyNdisString( PNDIS_STRING D_string,
      PNDIS_STRING S_string
      );
extern USHORT In_cksum( unsigned char *buf,
               int  len);
/*USHORT Encrypt_reg(PUCHAR buffer,
       USHORT buflen,
       USHORT sndkeyno
       );
USHORT Decrypt_reg(PUCHAR buffer,
       USHORT buflen,
       USHORT sndkeyno
       );*/
UCHAR QueryAccessList(PIP_HEADER Ip_header,
       UCHAR QueryType,
       PUSHORT  sndkeyno
       );
UCHAR LoadAccessList(PUCHAR buffer,
      ULONG buflen
      );
UCHAR LoadExceptList(PUCHAR buffer,
      ULONG buflen
      );
VOID  UnloadLists();
extern DWORD  NdisIndicateReceiveAddr;
extern DWORD  NdisRequestAddr;
extern DWORD  NdisCompleteSendAddr;
//extern DWORD  NdisRegisterProtocolAddr;
extern DWORD  IPReceiveAddr;
extern DWORD  IPSendCompleteAddr;
extern PUCHAR RcvBuffer;
extern PUCHAR IndicateBuffer;
extern PUCHAR TransferBuffer;
extern NDIS_HANDLE RcvPacketPoolHandle;
extern PNDIS_PACKET RcvTransferPacket;
extern NDIS_HANDLE RcvBufferPoolHandle;
extern PNDIS_BUFFER RcvPacketBuffer;
extern PMAC_HEADER RcvMACHeader;
extern PIP_HEADER  RcvIPHeader;
extern PUCHAR SendBuffer;
extern PUCHAR CurSendBuffer;
extern PMAC_HEADER SendMACHeader;
extern PIP_HEADER  SendIPHeader;
extern NDIS_HANDLE SendBufferPoolHandle;
extern NDIS_HANDLE SendPacketPoolHandle;
extern PNDIS_PACKET SendPktList[MAX_SEND_PKT_LIST];
extern CHAR SendPktListHead;
extern CHAR SendPktListTail;
extern PNDIS_PACKET ReservedPkt[MAX_SEND_PKT_LIST];
extern NDIS_STATUS ReturnStatus;
extern PNDIS_BUFFER BUFFER;
extern DWORD  CopiedLen;
extern UINT   BytesTransfered;
extern USHORT Old_cksum,New_cksum;
extern DWORD  ViewHandle;
extern BINDING_INFO BindingAdapterInfo[MAX_ADAPTER_NUM];
extern UCHAR BindingAdapterNum;
2．Nshim.c 垫片的C语言程序
#include \"ndisshim.h\"
UINT CurSendPktLen;
UINT MaxSendPktLen;
DWORD  NdisIndicateReceiveAddr;
DWORD  NdisRequestAddr;
DWORD  NdisCompleteSendAddr;
//DWORD  NdisRegisterProtocolAddr;
DWORD  IPReceiveAddr;
DWORD  IPSendCompleteAddr;
DWORD  IPOpenAdapterCompleteAddr;
VOID (NDIS_API *NdisSendAddr )( PNDIS_STATUS, NDIS_HANDLE, PNDIS_PACKET);
VOID (NDIS_API *NdisOpenAdapterAddr)(
      PNDIS_STATUS ,
      PNDIS_STATUS ,
      PNDIS_HANDLE ,
      PUINT ,
      PNDIS_MEDIUM ,
      UINT ,
      NDIS_HANDLE ,
      NDIS_HANDLE ,
      PNDIS_STRING ,
      UINT ,
      PSTRING
      );
VOID (NDIS_API *NdisRegisterProtocolAddr)(
      PNDIS_STATUS ,
      PNDIS_HANDLE ,
      PNDIS_PROTOCOL_CHARACTERISTICS ,
      UINT
      );
/*VOID (NDIS_API *NdisRegisterMacAddr)( PNDIS_STATUS ,
          PNDIS_HANDLE,
          NDIS_HANDLE ,
          NDIS_HANDLE ,
          PNDIS_MAC_CHARACTERISTICS,
          UINT
         );*/
PUCHAR RcvBuffer;
PUCHAR IndicateBuffer;
PUCHAR TransferBuffer;
NDIS_HANDLE RcvPacketPoolHandle;
PNDIS_PACKET RcvTransferPacket;
NDIS_HANDLE RcvBufferPoolHandle;
PNDIS_BUFFER RcvPacketBuffer;
PMAC_HEADER RcvMACHeader;
PIP_HEADER  RcvIPHeader;
PUCHAR SendBuffer;
PUCHAR CurSendBuffer;
PMAC_HEADER SendMACHeader;
PIP_HEADER  SendIPHeader;
NDIS_HANDLE SendBufferPoolHandle;
NDIS_HANDLE SendPacketPoolHandle;
PNDIS_PACKET SendPktList[MAX_SEND_PKT_LIST];
CHAR SendPktListHead;
CHAR SendPktListTail;
PNDIS_PACKET ReservedPkt[MAX_SEND_PKT_LIST];
NDIS_STATUS ReturnStatus;
PNDIS_BUFFER BUFFER;
DWORD  CopiedLen;
UINT   BytesTransfered;
UCHAR  ReadInfoOK=0;
NDIS_HANDLE IPHandle;
UCHAR AdapterNameBuf[2*MAX_ADAPTER_NUM][10];
BINDING_INFO BindingAdapterInfo[MAX_ADAPTER_NUM];
PENDING_INFO PendingOpenAdapter[MAX_ADAPTER_NUM];
UCHAR BindingAdapterNum = 0;
UCHAR PendOpenNum = 0;
NDIS_STRING TcpName = NDIS_STRING_CONST(\"MSTCP\");
//NDIS_HANDLE MacHandle;
//NDIS_HANDLE WrapperHandle;
//NDIS_HANDLE MacContext;
USHORT Old_cksum,New_cksum;
VOID _stdcall NSHIM_Send(
    OUT PNDIS_STATUS Status,
    IN  NDIS_HANDLE  NdisBindingHandle,
    IN  PNDIS_PACKET Packet
    )
{
 USHORT sndkeyno;
 UCHAR i;
 for(i=0;i<BindingAdapterNum;i++){
  if(BindingAdapterInfo.BindingHandle==NdisBindingHandle&& BindingAdapter
Info.CtrlActived)
   break;
 }
 if(i==BindingAdapterNum) goto forward;
 NdisQueryPacket(Packet, NULL, NULL, NULL, &CurSendPktLen);
 if(CurSendPktLen>MaxSendPktLen) MaxSendPktLen=CurSendPktLen;
 if(SendBuffer!=NULL){
  CurSendBuffer=SendBuffer+1500*SendPktListHead;
  SendMACHeader=(PMAC_HEADER)CurSendBuffer;
  SendIPHeader=(PIP_HEADER)(CurSendBuffer+MAC_HEADER_LEN);
  CopiedLen=CopyPacketToBuffer(
     CurSendBuffer,
     Packet,
     0,
     MAC_HEADER_LEN  //+IP_HEADER_LEN
     );
  if(SendMACHeader->ProtocolType==IP_PROTOCOL){
   CopiedLen = CopyPacketToBuffer(
     CurSendBuffer+MAC_HEADER_LEN,//+IP_HEADER_LEN,
     Packet,
     MAC_HEADER_LEN, //+IP_HEADER_LEN,
     CurSendPktLen-MAC_HEADER_LEN  //-IP_HEADER_LEN
     );
   switch( QueryAccessList(SendIPHeader,QUERY_SEND_PACKET,&sndkeyno) ){
   case PACKET_REFUSE :
    *Status=NDIS_STATUS_SUCCESS;
    return;
   case PACKET_CLEAR :
    break;
   case PACKET_MUD :
    CurSendPktLen = Encrypt_reg(
         (PUCHAR)SendIPHeader+IP_HEADER_LEN,
         CurSendPktLen-MAC_HEADER_LEN-IP_HEADER_LEN,
         sndkeyno
         );
    CurSendPktLen += (MAC_HEADER_LEN+IP_HEADER_LEN);
    Old_cksum = SendIPHeader->HeaderCRC;
    SendIPHeader->HeaderCRC = 0;
    SendIPHeader->LengthL = (CurSendPktLen-MAC_HEADER_LEN)&0xff;
    SendIPHeader->LengthU = ((CurSendPktLen-MAC_HEADER_LEN)&0xff00)>>8;
    New_cksum = In_cksum((PUCHAR)SendIPHeader,20);
    SendIPHeader->HeaderCRC = New_cksum;
    break;
   }
   NdisQueryPacket(SendPktList[SendPktListHead], NULL, NULL, &BUFFER, NULL);

   if(BUFFER!=NULL){
    NdisUnchainBufferAtBack( SendPktList[SendPktListHead],&BUFFER);
    NdisFreeBuffer(BUFFER);
   }
   NdisAllocateBuffer(
      &ReturnStatus,
      &BUFFER,
      SendBufferPoolHandle,
      CurSendBuffer, //VirtualAddress,
      CurSendPktLen   //Length
      );
   NdisChainBufferAtBack( SendPktList[SendPktListHead],BUFFER);
   SendPktList[SendPktListHead]->ProtocolReserved[0]=SendPktListHead;
   ReservedPkt[SendPktListHead]=Packet;
   NdisSendAddr( Status,
      NdisBindingHandle,
      SendPktList[SendPktListHead]
      );
   if(*Status!=NDIS_STATUS_SUCCESS){
    SendPktListHead++;
    if(SendPktListHead==MAX_SEND_PKT_LIST)
     SendPktListHead=0;
   }
   return;
  }
 }
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 //_asm pop ebp
 _asm leave
 _asm jmp [NdisSendAddr]
}
VOID NDIS_API
NSHIM_IPSendComplete(
    IN NDIS_HANDLE NdisBindingContext,
    IN PNDIS_PACKET Packet,
    IN NDIS_STATUS Status
    )
{
 UCHAR i;
 for(i=0;i<BindingAdapterNum;i++){
  if(BindingAdapterInfo.BindingHandle==(*((PUINT)NdisBindingContext+1)) &
&
     BindingAdapterInfo.CtrlActived)
   break;
 }
 if(i==BindingAdapterNum) goto forward;
 if(SendBuffer!= NULL){
  CurSendBuffer = SendBuffer+SendPktListHead*1500;
  SendMACHeader = (PMAC_HEADER)CurSendBuffer;
  CopiedLen = CopyPacketToBuffer(
      CurSendBuffer,
      Packet,
      0,
      MAC_HEADER_LEN  //+IP_HEADER_LEN
      );
  if(SendMACHeader->ProtocolType==IP_PROTOCOL){
   Packet=ReservedPkt[Packet->ProtocolReserved[0]];
  }
 }
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 _asm leave
 _asm jmp [IPSendCompleteAddr]
}
VOID NDIS_API
NSHIM_Request(
    OUT PNDIS_STATUS Status,
    IN NDIS_HANDLE NdisBindingHandle,
    IN PNDIS_REQUEST Request
    )
{
 UCHAR i;
 for(i=0;i<BindingAdapterNum;i++){
  if(BindingAdapterInfo.BindingHandle==NdisBindingHandle )
   break;
 }
 if(i==BindingAdapterNum) goto forward;
 if( Request->RequestType == NdisRequestQueryInformation){
  switch ( Request->DATA.QUERY_INFORMATION.Oid ){
  case OID_GEN_MAXIMUM_FRAME_SIZE:
   *(PULONG)Request->DATA.QUERY_INFORMATION.InformationBuffer=1024-14;
   break;
  case OID_GEN_MAXIMUM_TOTAL_SIZE:
   *(PULONG)Request->DATA.QUERY_INFORMATION.InformationBuffer=1024;
   break;
  default:
   goto forward;
  }
  Request->DATA.QUERY_INFORMATION.BytesWritten=4;
  Request->DATA.QUERY_INFORMATION.BytesNeeded=4;
  *Status=NDIS_STATUS_SUCCESS;
  return;
 }
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 _asm leave
 _asm jmp [NdisRequestAddr]
}
VOID NDIS_API
NSHIM_RegisterProtocol(
    OUT PNDIS_STATUS Status,
    OUT PNDIS_HANDLE NdisProtocolHandle,
    IN PNDIS_PROTOCOL_CHARACTERISTICS ProtocolCharacteristics,
    IN UINT CharacteristicsLength
    )
{
 if( !(NdisEqualString(
     &TcpName,
     &ProtocolCharacteristics->Name,
     FALSE
     )) )
  goto forward;
 IPReceiveAddr = ProtocolCharacteristics->ReceiveHandler;
 ProtocolCharacteristics->ReceiveHandler = NSHIM_IPReceive;
 IPSendCompleteAddr = ProtocolCharacteristics->SendCompleteHandler;
 ProtocolCharacteristics->SendCompleteHandler = NSHIM_IPSendComplete;
 IPOpenAdapterCompleteAddr = ProtocolCharacteristics->OpenAdapterCompleteHan
dler;
 ProtocolCharacteristics->OpenAdapterCompleteHandler = NSHIM_IPOpenAdapterCo
mplete;
 NdisRegisterProtocolAddr(
      Status,
      NdisProtocolHandle,
      ProtocolCharacteristics,
      CharacteristicsLength
      );
 if( *Status==NDIS_STATUS_SUCCESS)
  IPHandle = *NdisProtocolHandle;
 return;
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 _asm leave
 _asm jmp [NdisRegisterProtocolAddr]
}
VOID NDIS_API
NSHIM_OpenAdapter(
    OUT PNDIS_STATUS Status,
    OUT PNDIS_STATUS OpenErrorStatus,
    OUT PNDIS_HANDLE NdisBindingHandle,
    OUT PUINT SelectedMediumIndex,
    IN PNDIS_MEDIUM MediumArray,
    IN UINT MediumArraySize,
    IN NDIS_HANDLE NdisProtocolHandle,
    IN NDIS_HANDLE ProtocolBindingContext,
    IN PNDIS_STRING AdapterName,
    IN UINT OpenOptions,
    IN PSTRING AddressingInformation OPTIONAL
    )
{
 if( NdisProtocolHandle!=IPHandle ) goto forward;
 PendingOpenAdapter[PendOpenNum].ProtocolBindingContext = ProtocolBindingCon
text;
 PendingOpenAdapter[PendOpenNum].NdisBindingHandle = NdisBindingHandle;
 PendingOpenAdapter[PendOpenNum].Name.Buffer = AdapterNameBuf
[PendOpenNum+MA
X_ADAPTER_NUM];
 CopyNdisString(
   &PendingOpenAdapter[PendOpenNum].Name,
   AdapterName
   );
 PendOpenNum++;
 NdisOpenAdapterAddr(
    Status,
    OpenErrorStatus,
    NdisBindingHandle,
    SelectedMediumIndex,
    MediumArray,
    MediumArraySize,
    NdisProtocolHandle,
    ProtocolBindingContext,
    AdapterName,
    OpenOptions,
    AddressingInformation
    );
 if(*Status==NDIS_STATUS_SUCCESS){
  BindingAdapterInfo[BindingAdapterNum].BindingHandle = *NdisBindingHandle;
  BindingAdapterInfo[BindingAdapterNum].Name.Buffer = AdapterNameBuf
[Binding
AdapterNum];
  CopyNdisString(
   &BindingAdapterInfo[BindingAdapterNum].Name,
   AdapterName
   );
  BindingAdapterNum++;
 }
 return;
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 _asm leave
 _asm jmp [NdisOpenAdapterAddr]
}
VOID NDIS_API
NSHIM_IPOpenAdapterComplete(
  IN NDIS_HANDLE  ProtocolBindingContext,
  IN NDIS_STATUS  Status,
  IN NDIS_STATUS  OpenErrorStatus
  )
{
 UCHAR i;
 for(i=0;i<PendOpenNum;i++){
  if(PendingOpenAdapter.ProtocolBindingContext==ProtocolBindingContext)
   break;
 }
 if(i==PendOpenNum) goto forward;
 if(Status==NDIS_STATUS_SUCCESS){
  BindingAdapterInfo[BindingAdapterNum].BindingHandle = *PendingOpenAdapter
[
i].NdisBindingHandle;
  BindingAdapterInfo[BindingAdapterNum].Name.Buffer = AdapterNameBuf
[Binding
AdapterNum];
  CopyNdisString(
   &BindingAdapterInfo[BindingAdapterNum].Name,
   &PendingOpenAdapter.Name
   );
  BindingAdapterNum++;
 }
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 _asm leave
 _asm jmp [IPOpenAdapterCompleteAddr]
}
NDIS_STATUS NDIS_API
NSHIM_IPReceive(
  IN NDIS_HANDLE NdisBindingContext,
  IN NDIS_HANDLE MacReceiveContext,
  IN PVOID HeaderBuffer,
  IN UINT HeaderBufferSize,
  IN PVOID LookaheadBuffer,
  IN UINT LookaheadBufferSize,
  IN UINT PacketSize
  )
{
 USHORT sndkeyno;
 UCHAR i;
 for(i=0;i<BindingAdapterNum;i++){
  if(BindingAdapterInfo.BindingHandle==(*((PUINT)NdisBindingContext+1)) &
&
   BindingAdapterInfo.CtrlActived)
   break;
 }
 if(i==BindingAdapterNum) goto forward;
 if(LookaheadBufferSize!=PacketSize){
  IndicateBuffer=TransferBuffer-HeaderBufferSize-LookaheadBufferSize;
  NdisMoveMemory( IndicateBuffer, HeaderBuffer, HeaderBufferSize);
  NdisMoveMemory( IndicateBuffer+HeaderBufferSize, LookaheadBuffer, Lookahea
dBufferSize);
  NdisTransferData(
     &ReturnStatus,
     *((PUINT)NdisBindingContext+1),
     MacReceiveContext,
     LookaheadBufferSize, // ByteOffset,
     PacketSize-LookaheadBufferSize, //BytesToTransfer,
     RcvTransferPacket,
     &BytesTransfered
     );
  HeaderBuffer=IndicateBuffer;
  LookaheadBuffer=IndicateBuffer+HeaderBufferSize;
  LookaheadBufferSize = PacketSize;
 }else{
  IndicateBuffer=HeaderBuffer;
 }
 RcvMACHeader=(PMAC_HEADER)IndicateBuffer;
 if(RcvMACHeader->ProtocolType==IP_PROTOCOL){
  RcvIPHeader=(PIP_HEADER)(IndicateBuffer+MAC_HEADER_LEN);
  switch( QueryAccessList(RcvIPHeader,QUERY_RCV_PACKET,&sndkeyno) ){
  case PACKET_REFUSE:
   return NDIS_STATUS_SUCCESS;
  case PACKET_CLEAR:
   goto forward;
  case PACKET_MUD:
   PacketSize = Decrypt_reg(
        (PUCHAR)RcvIPHeader+IP_HEADER_LEN,
        (USHORT)PacketSize-IP_HEADER_LEN,
        sndkeyno
        );
   PacketSize += IP_HEADER_LEN;
   Old_cksum = RcvIPHeader->HeaderCRC;
   RcvIPHeader->HeaderCRC = 0;
   RcvIPHeader->LengthL = (USHORT)(PacketSize)&0x00ff;
   RcvIPHeader->LengthU = ((USHORT)(PacketSize)&0xff00)>>8;
   New_cksum=In_cksum((PUCHAR)RcvIPHeader,IP_HEADER_LEN);
   RcvIPHeader->HeaderCRC=New_cksum;
   LookaheadBufferSize=PacketSize;
   break;
  }
 }
forward:
 _asm pop edi
 _asm pop esi
 _asm pop ebx
 _asm leave
 _asm jmp [IPReceiveAddr]
}
/*VOID NDIS_API
NSHIM_RegisterMac(
    OUT PNDIS_STATUS Status,
    OUT PNDIS_HANDLE NdisMacHandle,
    IN NDIS_HANDLE NdisWrapperHandle,
    IN NDIS_HANDLE MacMacContext,
    IN PNDIS_MAC_CHARACTERISTICS MacCharacteristics,
    IN UINT CharacteristicsLength
    )
{
 WrapperHandle = NdisWrapperHandle;
 MacContext = MacMacContext;
 NdisRegisterMacAddr(
     Status,
     NdisMacHandle,
     NdisWrapperHandle,
     MacMacContext,
     MacCharacteristics,
     CharacteristicsLength
     );
 if(*Status==NDIS_STATUS_SUCCESS){
  MacHandle = *NdisMacHandle;
 }
 return;
}*/
UINT
CopyPacketToBuffer(
    IN OUT PUCHAR Buf,                 // destination
    IN PNDIS_PACKET Packet,         // source packet
    IN UINT Offset,                 // offset in packet
    IN UINT Length                  // number of bytes to copy
    )
/*++
Routine Description:
    Copies bytes from a packet into a buffer. Used to copy data
    out of a packet during loopback indications.
Arguments:
    Buf - the destination buffer
    Packet - the source packet
    Offset - the offset in the packet to start copying at
    Length - the number of bytes to copy
Return Value:
    The actual number of bytes copied; will be less than Length if
    the packet length is less than Offset+Length.
--*/
{
    PNDIS_BUFFER CurBuffer;
    UINT BytesCopied;
    PUCHAR BufVA;
    UINT BufLen;
    UINT ToCopy;
    UINT CurOffset;
    BytesCopied = 0;
    //
    // First find a spot Offset bytes into the packet.
    //
    CurOffset = 0;
    NdisQueryPacket(Packet, NULL, NULL, &CurBuffer, NULL);
    while (CurBuffer != (PNDIS_BUFFER)NULL) {
        NdisQueryBuffer(CurBuffer, (PVOID *)&BufVA, &BufLen);
        if (CurOffset + BufLen > Offset) {
            break;
        }
        CurOffset += BufLen;
        NdisGetNextBuffer(CurBuffer, &CurBuffer);
    }
    //
    // See if the end of the packet has already been passed.
    //
    if (CurBuffer == (PNDIS_BUFFER)NULL) {
        return 0;
    }
    //
    // Now copy over Length bytes.
    //
    BufVA += (Offset - CurOffset);
    BufLen -= (Offset - CurOffset);
    for (;;) {
        ToCopy = (BytesCopied+BufLen > Length) ? Length - BytesCopied : BufL
en;
        NdisMoveMemory(Buf+BytesCopied, BufVA, ToCopy);
        BytesCopied += ToCopy;
        if (BytesCopied == Length) {
            return BytesCopied;
        }
        NdisGetNextBuffer(CurBuffer, &CurBuffer);
        if (CurBuffer == (PNDIS_BUFFER)NULL) {
            break;
        }
        NdisQueryBuffer(CurBuffer, (PVOID *)&BufVA, &BufLen);
    }
    return BytesCopied;
}
VOID
CopyNdisString( PNDIS_STRING D_string,
      PNDIS_STRING S_string
      )
{
 D_string->Length = S_string->Length;
 D_string->MaximumLength = S_string->MaximumLength;
 NdisMoveMemory( D_string->Buffer, S_string->Buffer, S_string->Length);
 return;
}
#pragma VxD_ICODE_SEG
#pragma VxD_IDATA_SEG
DWORD _stdcall NSHIM_Device_Init(void)
{
    Out_Debug_String(\"NSHIMSAMP: Dynamic Init\\n\\r\");
 return(VXD_SUCCESS);
}
DWORD _stdcall NSHIM_Sys_Crit_Init(void)
{
 UCHAR i;
 Ndis_Hook();
 if((SendBuffer=(PUCHAR)_HeapAllocate(15000,HEAPLOCKEDIFDP|HEAPZEROINIT))!=N
ULL){
//  SendMACHeader=(PMAC_HEADER)SendBuffer;
//  SendIPHeader =(PIP_HEADER)(SendBuffer+14);
  NdisAllocateBufferPool(
      &ReturnStatus,
      &SendBufferPoolHandle,
      MAX_SEND_BUF_LIST  //* NumberOfDescriptors
      );
  if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  NdisAllocatePacketPool(
      &ReturnStatus,
      &SendPacketPoolHandle,
      MAX_SEND_PKT_LIST, //NumberOfDescriptors,
      1 //ProtocolReservedLength
      );
  if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  for(i=0;i<MAX_SEND_PKT_LIST;i++){
   NdisAllocatePacket(
      &ReturnStatus,
      &SendPktList,
      SendPacketPoolHandle
      );
   if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  }
  SendPktListHead=SendPktListTail=0;
 }
 if((RcvBuffer=(PUCHAR)_HeapAllocate(2000,HEAPLOCKEDIFDP|HEAPZEROINIT))!=NUL
L){
  TransferBuffer=RcvBuffer+500;
  NdisAllocatePacketPool(
      &ReturnStatus,
      &RcvPacketPoolHandle,
      1, //NumberOfDescriptors,
      0 //ProtocolReservedLength
      );
  if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  NdisAllocatePacket(
      &ReturnStatus,
      &RcvTransferPacket,
      RcvPacketPoolHandle
      );
  if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  NdisAllocateBufferPool(
      &ReturnStatus,
      &RcvBufferPoolHandle,
      1  //* NumberOfDescriptors
      );
  if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  NdisAllocateBuffer(
      &ReturnStatus,
      &RcvPacketBuffer,
      RcvBufferPoolHandle,
      TransferBuffer, //VirtualAddress,
      1500   //Length
      );
  if(ReturnStatus!=NDIS_STATUS_SUCCESS){}
  NdisChainBufferAtBack(
      RcvTransferPacket,
      RcvPacketBuffer
      );
 }
// InitAccessList();
}

是17的那个代码。
他那个NdisBindingContext相当于passthru里面的那个padapter结构，是一个自定义的结构，里面保存有那些handle什么的信息。
NdisBindingContext＋1应该是那个NdisBindingHandle的位置。

是17的那个代码。
他那个NdisBindingContext相当于passthru里面的那个padapter结构，是一个自定义的结构，里面保存有那些handle什么的信息。
NdisBindingContext＋1应该是那个NdisBindingHandle的位置。

 

NdisBindingContext在原码中的定义好像都是函数的形式参数来定义的如：
NDIS_STATUS NDIS_API
NSHIM_IPReceive(
  IN NDIS_HANDLE NdisBindingContext,
  IN NDIS_HANDLE MacReceiveContext,
。。。。。。。。
}
从表面上看只能算是个句柄，+1还是不明白？
即使像您所说的那样，+1我认为是指向下一个adapter的地址,但是为什莫要指向下一个呢？
还有这个原码是不是不全啊?

在17的那个代码中有一段函数是这样声明的
VOID (NDIS_API *NdisRegisterProtocolAddr)(  
      PNDIS_STATUS ,
      PNDIS_HANDLE ,
      PNDIS_PROTOCOL_CHARACTERISTICS ,
      UINT
      );
问题是在语法上这种函数声明形式不大明白，NDIS_API在这里是什莫作用？这个问题挺弱的，请不要见笑！！！

那个代码显然是不完全的。

NdisBindingContext相当于passthru里面的padapter，你看看passthru里面是如何使用的padapter结构就应该明白了。这里面NdisBindingContext指向的也应该是他的结构，＋1的位置是保存ndisbindhandle的地方，这个指针上ndisopenadapter的时候返回的。
VOID (NDIS_API *NdisRegisterProtocolAddr)(
PNDIS_STATUS ,
PNDIS_HANDLE ,
PNDIS_PROTOCOL_CHARACTERISTICS ,
UINT
);
声明的是函数指针，NDIS_API指明函数的调用方式，也就是参数入栈的次序。

那个代码显然是不完全的。

NdisBindingContext相当于passthru里面的padapter，你看看passthru里面是如何使用的padapter结构就应该明白了。这里面NdisBindingContext指向的也应该是他的结构，＋1的位置是保存ndisbindhandle的地方，这个指针上ndisopenadapter的时候返回的。
VOID (NDIS_API *NdisRegisterProtocolAddr)(
PNDIS_STATUS ,
PNDIS_HANDLE ,
PNDIS_PROTOCOL_CHARACTERISTICS ,
UINT
);
声明的是函数指针，NDIS_API指明函数的调用方式，也就是参数入栈的次序。
 

passthru的adapter结构我看了，里面有三个定义：
PADAPT pPrimaryAdapt;                  // Pointer to the primary
PADAPT pSecondaryAdapt;                        // Pointer to Secondary\'s structure
PADAPT Next;
是不是与上面的定义有关吧，总之要是知道NdisBindingContext结构就清楚了，谢谢
我现在在做windows下的vpn的客户端，不知道17的那段代码能给我带来什莫帮助，也就是说什莫地方是可取的，你给提示一下好吗？
当然我会努力的把这段代码搞懂，谢谢你的帮助！！

17的代码是98下vxd hook的代码，如果你在2k下做的话还是直接看passthru吧。