How do we determine IP Address of interface the packet arrived on

[Maninder Singh]

Hi,

Each time a packet arrives at a router in a subnet during transit, I
need to determine the IP address of the incoming interface of the
router for that packet. I have a netfilter kernel module running at
each router but I dont understand which data structure will give me
thw IP address. Can someone please suggest how shall I get that?


Thanks
Maninder