eBPF: A Revolutionary Kernel Technology for Networking, Observability, and Security

eBPF is a revolutionary kernel technology that allows developers to write custom code that can be dynamically loaded into the kernel, changing its behavior. This enables users to create new generations of high-performance networking, observability, and security tools. The ability to customize functionality through dynamic changes to kernel behavior is incredibly powerful, and as such, eBPF is driving a new wave of technological innovation in multiple fields.

Based on Liz Rice's 'Learning eBPF', this article provides a detailed introduction to eBPF's basic concepts, toolchain, kernel API, security, network, and performance analysis. It begins with a brief overview of eBPF's history and application scenarios, followed by an in-depth analysis of the entire process from development to compilation to loading and running eBPF code. This includes eBPF's instruction set and registers, BPF system calls and helper functions, program loading and unloading, eBPF map usage, CO-RE and BTF principles, eBPF verifier, and how user-space programs can collaborate with kernel-space eBPF programs. Finally, the article introduces various eBPF program types, what functionalities they can achieve, and their practical applications in networking and security.