How to change packages using Netfilter in linux?

Question

linux

I understand that it is necessary to write a kernel module. From the searches, I realized that we are forcing iptables all FORWARD packets to go to our proxy, and there you can already do anything with the packets.
Who has examples or articles, books where methods for this task are described?
The point is to write your own network balancer.

Answer 1

What exactly do you want to balance?