How to know ipv4 or ipv6 from NDIS packet buffer?

Question

I am getting packets from NDIS filter SendnetBufferList routine . Inside that I am accepting the buffer after filtering that buffer .

In case of NdisMedium802_3 medium , getting packet with Ethernet header (Ethernet frames) . So i can easily analyze ipv4 & ipv6 using Ethernet header .

PPF_ETHERNET_HEADER pEthHeader = (PPF_ETHERNET_HEADER) pBuffer;

filter.nEthProto = pEthHeader->nProto;

System::MCopyMemory(&filter.aSrcMac, &pEthHeader->aSrcMac, 
sizeof(ETH_MAC_ADDRESS));

System::MCopyMemory(&filter.aDstMac, &pEthHeader->aDstMac, 
sizeof(ETH_MAC_ADDRESS));

if (filter.nEthProto == ETH_PROTO_IPV4) {

PPF_IPV4_HEADER pIpHeader = (PPF_IPV4_HEADER) (pBuffer + 
sizeof(PF_ETHERNET_HEADER));

/* IPV4 operations */

}

else if (filter.nEthProto == ETH_PROTO_IPV6)
{

PPF_IPV6_HEADER pIpHeader = (PPF_IPV6_HEADER) (pBuffer + 
sizeof(PF_ETHERNET_HEADER));

/* IPV6 operations */
}

This is working fine . Next i am attaching NdisMediumWirelessWan / NdisMediumIP medium . This is sending RAW IP frames with out Ethernet header .

My questions is how can i check NDIS buffer contain ipv4 or ipv6 with out Ethernet header ? and also how can i set Mac address ?

Answer 1

You can easily obtain protocol information from the NET_BUFFER_LIST:

filter.nEthProto = (USHORT)NET_BUFFER_LIST_INFO(pNBList, NetBufferListFrameType);