A transparent proxy, also known as an inline proxy, intercepts client requests and redirects them without modifying the request or requiring client-side configuration. It operates invisibly to users, meaning they are unaware of its presence and do not need to adjust their network settings. This technology is invaluable for network management, security policy enforcement, traffic monitoring, and optimization. Transparent proxies can execute a range of functions, including content filtering, cache acceleration, traffic control, and load balancing. Commonly used technologies for implementing transparent proxies include TPROXY, NAT, and others.
In this repository, I implementated Transparent proxy using eBPF. Specifically, I utilize Golang alongside the ebpf-go package.
First build and run the eBPF program:
go generate
go build
sudo ./proxy
Now let's verify it works as expected:
-
Run the HTTP Server from
/testdirectorygo run main.go -
From another shell, run
curl http://localhost:8000
You can then inspect eBPF logs using sudo cat /sys/kernel/debug/tracing/trace_pipe to verify transparent proxy indeed intercepts the network traffic.