Compile libbpf

git submodule update --init --remote --recursive
cd external/libbpf
OBJDIR=build DESTDIR=install-dir make -C src install

Bypassing the TCP/IP stack for local connections

Instead of using the loopback interface to forward packets from one local socket to another, we can use eBPF to redirect packets to the destination socket before they traverse the TCP/IP stack in the kernel, and gain a slight performance benefit.

First, compile the tcp-bypasser by running make in the /tcp-bypasser directory. Then, you can run an experiment with:

sudo ./evaluate/test-bypasser.sh

This experiment establishes a connection between a client and a server, and then sends 250,000 requests (1024 bytes) from the client and receives an echoed response from the server. The average round trip time is then calculated as the sum of the time it took to send/receive each request and response, divided by the number of requests (250,000). It repeats the experiment after loading in the eBPF program.

I'm running the experiment on a virtual machine running Ubuntu 24.10 (ARM) and get the following results:

Average RTT (without bypasser): 42.721052 microseconds
Average RTT (with bypasser): 39.326267 microseconds

Which means roughly an 8% decrease in latency with the bypasser