if i have two or more adapter connect to the Internet

[Vadim Smirnov]

With WinpkFilter you can capture packets from any amount of adapters (using dedicated for each with WaitForSingleObject, or using single thread for all adapters with WaitForMultiplyObjects).

Another question is how to determine wich adapters are of your interest (connected to the Internet). There is no universal way to do it. If default Internet connection can be determined as the default route (0.0.0.0 mask 0.0.0.0) then other Internet connections look similar to LAN connections.

[PLY]

Can you give me an example for WaitForMultiplyObjects? i can’t create thread for each adapter because it waste my time for recreate the whole system.

[Vadim Smirnov]

An example, it can be done like in the code below (I’m sorry C code only)

TCP_AdapterList		AdList;

CNdisApi			api;

ETH_REQUEST			Request;

INTERMEDIATE_BUFFER PacketBuffer;

HANDLE				hEvent[32];

DWORD				dwAdapterCount;



int InitHandles()

{

api.GetTcpipBoundAdaptersInfo ( &AdList );



ADAPTER_MODE Mode;



Mode.dwFlags = MSTCP_FLAG_SENT_TUNNEL|MSTCP_FLAG_RECV_TUNNEL;



dwAdapterCount	=	AdList.m_nAdapterCount ;



// Create notification events

for(int nCount = 0; nCount < dwAdapterCount; nCount++)

{

hEvent[nCount] = CreateEvent(NULL, TRUE, FALSE, NULL);



Mode.hAdapterHandle = (HANDLE)AdList.m_nAdapterHandle[nCount];



// Set event for helper driver

if ((!hEvent[nCount])||(!api.SetPacketEvent((HANDLE)AdList.m_nAdapterHandle[nCount], hEvent[nCount])))

{

printf ("Failed to create notification event or set it for driver.n");

return 0;

}



api.SetAdapterMode(&Mode);

}



return 1;

}



void ReleaseHandles()

{

// This function releases packets in the adapter queue and stops listening the interface

ADAPTER_MODE Mode;



for(int nCount = 0; nCount < dwAdapterCount; nCount++)

{

Mode.dwFlags = 0;

Mode.hAdapterHandle = (HANDLE)AdList.m_nAdapterHandle[nCount];



// Set NULL event to release previously set event object

api.SetPacketEvent(AdList.m_nAdapterHandle[nCount], NULL);



// Close Event

if (hEvent[nCount])

CloseHandle ( hEvent[nCount+1] );



// Set default adapter mode

api.SetAdapterMode(&Mode);



// Empty adapter packets queue

api.FlushAdapterPacketQueue (AdList.m_nAdapterHandle[nCount]);

}



}



int main(int argc, char* argv[])

{

ether_header*			pEthHeader = NULL;

iphdr*				pIpHeader = NULL;

DWORD				dwEvent;



.............



if(!api.IsDriverLoaded())

{

printf ("Driver not installed on this system of failed to load.n");

return 0;

}



InitHandles();



atexit (ReleaseHandles);





while (TRUE)

{

dwEvent = WaitForMultipleObjects (dwAdapterCount, hEvent, FALSE, INFINITE );



ResetEvent(hEvent[dwEvent]);



// Initialize Request

ZeroMemory ( &Request, sizeof(ETH_REQUEST) );

ZeroMemory ( &PacketBuffer, sizeof(INTERMEDIATE_BUFFER) );

Request.EthPacket.Buffer = &PacketBuffer;

Request.hAdapterHandle = (HANDLE)AdList.m_nAdapterHandle[dwEvent-1];





while(api.ReadPacket(&Request))

{



pEthHeader = (ether_header*)PacketBuffer.m_IBuffer;

pIpHeader = (iphdr*)(PacketBuffer.m_IBuffer + ETHER_HEADER_LENGTH);



if (PacketBuffer.m_dwDeviceFlags == PACKET_FLAG_ON_SEND)

{

// Place packet on the network interface

api.SendPacketToAdapter(&Request);

}

else

{

// Indicate packet to MSTCP

api.SendPacketToMstcp(&Request);

}







}



}



return 0;

}

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