network protocol

Greetings,



How do I create a protocol that caches all the traffic, the incomming before any other protocol, and outgoing before going to the lower layer?

Why do I need this? because I want to modify the packets,

For example:
 add vlan tags to incomming packets so my vlan aware linux handles them and remove them on the way out so my non vlan aware pc can handle the packet.

I created a module using dev_add_pack, it works well as a sniffer but it does not prevent the other protocols from getting the packet.

As a test after the "sniffing" I called netif_rx insted of destroying the packet, I endeed up in a loop where I get one packet, sended to process and get back again ( at least that is how I understand it).

Any idea of how to do this?

I am hoping to achieve this without patching the kernel.
 
BR,
AUGUSTO SALAZAR