How to use netmap for DDoS protection?

Question

linux

Hello!
Perhaps someone had a similar task. Initial data:
We have a server with two cards, one 10Gbps, the second 1Gbps, netmap and the ixgbe driver are installed.
The question is how to use netmap to repel all sorts of attacks like Syn-flood without using the kernel, purely netmap capabilities, transfer pure traffic through the kernel, and send appropriately processed traffic through the 1Gbps card. Perhaps there is already ready-made software for this, which I don’t know about, or do you still need to write your own, based on the netmap documentation?