eBPF tc demo

This is a testing demo that implements a simple DNAT with eBPF TC(Traffic control). It will switch the network packet destination IP addr from 10.0.2.11 to 10.6.183.22.

Note: This project is an extension by ArthurChiao eBPF learning, you can check ArthurChiao's blog

Preparation

Start a nginx in 10.6.183.22 Node with port 6666.

You can use docker to start up a nginx container and map the port.

docker run --rm -d -p 6666:80 --name my_nginx nginx

How to run

1. compile dnat-demo.c with clang:

   clang -O2 -Wall -c dnat-demo.c -target bpf -o dnat-demo.o
   

2. add tc queuing discipline (egress and ingress buffer) for NIC ens160:

   tc qdisc del dev ens160 clsact 2>&1 >/dev/null
   tc qdisc add dev ens160 clsact
   

3. load bpf code into the tc egress and ingress hook respectively:

   tc filter add dev ens160 egress bpf da obj dnat-demo.o sec egress
   tc filter add dev ens160 ingress bpf da obj dnat-demo.o sec ingress
   

4. show info:

   tc filter show dev ens160 egress
   tc filter show dev ens160 ingress
   

5. test run:

   curl 10.0.2.11:6666
   

6. clean up:

   tc qdisc del dev ens160 clsact 2>&1 >/dev/null
   

7. check the logs:

   cat /sys/kernel/debug/tracing/trace_pipe