【转帖】Ndis中间层驱动自己发包的实现(经典问题)

太过爱你忘了你带给我的痛 2022-08-23 15:58 173阅读 0赞

这个问题，大部分学习Ndis中间层的人都会去思考，算是一个比较经典的问题了。

到论坛上问，别人只会告诉你大概的方法和步骤，这里贴出具体的代码，希望对研究Ndis中间层的哥们有些帮助：

NDIS\_STATUS  
MySendPacket (  
NDIS\_HANDLE NdisBindingHandle,  
NDIS\_HANDLE NdisSendPacketPool,  
PVOID pBuffer,  
ULONG dwBufferLength  
)  
\{  
NDIS\_STATUS status;  
PNDIS\_PACKET pSendPacket = NULL;  
PNDIS\_BUFFER pSendPacketBuffer = NULL;  
PUCHAR pSendBuffer = NULL;  
ULONG dwSendBufferLength;  
NDIS\_PHYSICAL\_ADDRESS HighestAcceptableAddress;  
PSEND\_RSVD SendRsvd = NULL;  
  
if (!NdisBindingHandle)  
return NDIS\_STATUS\_FAILURE;  
  
if (!pBuffer)  
return NDIS\_STATUS\_FAILURE;  
  
if (dwBufferLength > ETH\_MAX\_PACKET\_SIZE)  
return NDIS\_STATUS\_FAILURE;  
  
HighestAcceptableAddress.QuadPart = -1;  
dwSendBufferLength = max(dwBufferLength, ETH\_MIN\_PACKET\_SIZE);  
  
status = NdisAllocateMemory(&pSendBuffer, dwSendBufferLength, 0, HighestAcceptableAddress);  
if (status != NDIS\_STATUS\_SUCCESS)  
\{  
return status;  
\}  
  
RtlZeroMemory(pSendBuffer, dwSendBufferLength);  
RtlMoveMemory(pSendBuffer, pBuffer, dwSendBufferLength);  
  
NdisAllocatePacket(&status, &pSendPacket, NdisSendPacketPool);  
if (status != NDIS\_STATUS\_SUCCESS)  
\{  
NdisFreeMemory(pSendBuffer, dwSendBufferLength, 0);  
  
return status;  
\}  
  
NdisAllocateBuffer( &status,  
&pSendPacketBuffer,  
NdisSendPacketPool,  
pSendBuffer,  
dwSendBufferLength );  
if (status != NDIS\_STATUS\_SUCCESS)  
\{  
NdisFreeMemory(pSendBuffer, dwSendBufferLength, 0);  
NdisDprFreePacket(pSendPacket);  
  
return status;  
\}  
  
NdisChainBufferAtFront(pSendPacket, pSendPacketBuffer);  
  
SendRsvd = (PSEND\_RSVD)(pSendPacket->ProtocolReserved);  
SendRsvd->OriginalPkt = NULL; //注意这里  
  
pSendPacket->Private.Head->Next=NULL;  
pSendPacket->Private.Tail=NULL;  
  
//NDIS\_SET\_PACKET\_HEADER\_SIZE(pSendPacket, 14);  
NdisSetPacketFlags(pSendPacket, NDIS\_FLAGS\_DONT\_LOOPBACK);  
  
NdisSend(&status, NdisBindingHandle, pSendPacket);  
if (status != STATUS\_PENDING)  
\{  
NdisUnchainBufferAtFront(pSendPacket ,&pSendPacketBuffer);  
NdisQueryBufferSafe( pSendPacketBuffer,  
(PVOID \*)&pSendBuffer,  
&dwSendBufferLength,  
HighPagePriority );  
NdisFreeBuffer(pSendPacketBuffer);  
NdisFreeMemory(pSendBuffer, dwSendBufferLength, 0);  
NdisDprFreePacket(pSendPacket);  
\}  
  
return status;  
\}

注意：NdisSend如果是立刻完成，没有Pending的话，你需要在NdisSend返回后释放掉刚才分配的资源，否则是Pending的话，我们就要等发生包这个事件真正完成是的Complete例程里面去释放分配的资源。  
  
在函数PtSendComplete中：  
PSEND\_RSVD SendRsvd;  
SendRsvd = (PSEND\_RSVD)(Packet->ProtocolReserved);  
Pkt = SendRsvd->OriginalPkt;  
// ProtocolReserved是个可以自己放自己数据的地方, passthru用这个存放原始包的地址, 而我们自己构造包的时候把SendRsvd->OriginalPkt设为了NULL,所以很容易判断出那个已完成发送的包是passtru的,哪些是我们构造的

if (!Pkt )  
\{  
NdisUnchainBufferAtFront(Packet, &pMySendPacketBuffer);  
  
if (pMySendPacketBuffer)  
\{  
NdisQueryBufferSafe( pMySendPacketBuffer,  
(PVOID \*)&pMySendBuffer,  
&dwMySendBufferLength,  
HighPagePriority );  
if (pMySendBuffer && dwMySendBufferLength)  
\{  
NdisFreeMemory(pMySendBuffer, dwMySendBufferLength, 0);  
\}  
  
NdisFreeBuffer( pMySendPacketBuffer );  
\}  
  
NdisDprFreePacket(Packet);