What is eBPF and why you should know about it

eBPF (extended Berkeley Packet Filter) is a technology built into the Linux kernel that allows developers to write custom programs that run inside the kernel. This allows for better monitoring, debugging, and control of system resources, without requiring modifications to the kernel itself.

At a high level, eBPF programs are written in C and compiled into bytecode that can be loaded into the kernel. These programs can be attached to a variety of events, such as network packets, system calls, and file system activity. When an event occurs, the eBPF program is executed, allowing it to capture data and perform analysis.

The eBPF technology was first introduced in version 3.18 of the Linux kernel, which was released in December 2014. However, the eBPF implementation has been continuously improved and expanded since then, with new features and capabilities being added in subsequent kernel releases. It’s worth noting that some features of eBPF may require a more recent kernel version, so it’s recommended to check the specific requirements of any tools or solutions that make use of eBPF.

One of the key benefits of eBPF is that it allows for low-overhead monitoring and analysis of system activity. For example, eBPF can be used to monitor network traffic and identify performance bottlenecks, without adding significant overhead to the system. Additionally, eBPF programs can be loaded and unloaded dynamically, making it easy to experiment with different monitoring and analysis solutions.

One tool that makes extensive use of eBPF is Falco. Falco is an open-source intrusion detection system that uses eBPF to monitor system calls and file system activity. Falco is designed to detect unusual behavior on a system, such as privilege escalation, file tampering, or network scanning.

Falco works by running eBPF programs that are attached to system calls and file system activity. When unusual behavior is detected, Falco generates an alert, which can be logged or sent to an external system for further analysis. By using eBPF in this way, Falco is able to provide real-time monitoring and detection of potential security threats.

Other tools that make use of eBPF include BCC (BPF Compiler Collection), which provides a collection of tools for tracing and profiling system activity, and Cilium, which uses eBPF to provide network security and policy enforcement for containerized environments.

Overall, eBPF is a powerful technology that allows for low-overhead monitoring and analysis of system activity. By attaching eBPF programs to events like network packets, system calls, and file system activity, developers can create custom solutions to monitor and analyze system activity. Tools like Falco and BCC demonstrate the potential of eBPF for security and performance monitoring in production environments. As more developers become familiar with eBPF, we can expect to see even more powerful tools and solutions developed in the future.