eBPF, or Extended Berkeley Packet Filter, is a recent addition to the Linux kernel, fully available since the Linux 4.4 release.
It is a highly efficient, sandboxed virtual machine within the Linux kernel that allows for the kernel to be programmable at native execution speed.
This means that you can extend the capabilities of the kernel without having to modify the kernel’s source code, making it a powerful tool for developers and system administrators.
For example, when a read system call event occurs, you can run a BPF program. This allows for a high degree of customization and control over system behavior.
eBPF has a wide range of use cases, including:
- Security: eBPF can be used to implement advanced security mechanisms, such as intrusion detection systems or firewalls. It can monitor system calls, network packets, and other events for suspicious activity.
- Networking Tracing: eBPF can trace network packets as they pass through the various layers of the network stack, providing detailed information about network behavior and performance.
- Profiling: eBPF can be used to profile system performance, helping to identify bottlenecks and optimize system behavior.
- Observability: eBPF provides a powerful tool for system observability, allowing for detailed monitoring of system events and behavior.
- Monitoring: eBPF can be used to implement advanced system monitoring tools, providing real-time information about system performance and behavior.
Major companies like Google, Facebook, and Netflix have already implemented eBPF for various use cases in their production systems, demonstrating the power and flexibility of this technology.
In the context of Kubernetes, the open-source network plugin Cilium uses BPF for Kubernetes networking, providing advanced networking features and performance enhancements.
Furthermore, the Linux kernel development community has announced bpfilter, which will replace the in-kernel iptables implementation with a high-performance, Linux-based BPF network filtering mechanism. This represents a significant advancement in Linux networking technology.
In conclusion, eBPF is a powerful and flexible technology that can greatly enhance the capabilities of the Linux kernel. Whether you’re a developer, a system administrator, or just a tech enthusiast, understanding and utilizing eBPF can provide significant benefits.
BPF Learning resources
[1]. Getting Started With eBPF [2]. How to Make Linux Microservice-Aware with Cilium and eBPF — [[Video] [3]. Brendan Gregg, Senior Performance Engineer, Netflix Performance and OS Team, explores the past, present and future of BPF, and describes use cases. [4]. BPF Comes to Firewall [5]. How companies like Facebook and Google use BPF to patch 0-day exploits [6] Cloudflare Production ready eBPF [7]. Replacing iptables with eBPF in Kubernetes with Cilium [8]. Cilium Kubernetes Network Plugin [9]. eBPF: exploring use case of BPF kernel infrastructure [10]. BPF – the forgotten bytecode