index.rst

BPF Documentation

This directory contains documentation for the BPF (Berkeley Packet Filter) facility, with a focus on the extended BPF version (eBPF).

This kernel side documentation is still work in progress. The main textual documentation is (for historical reasons) described in :ref:`networking-filter`, which describe both classical and extended BPF instruction-set. The Cilium project also maintains a BPF and XDP Reference Guide that goes into great technical depth about the BPF Architecture.

libbpf

Documentation/bpf/libbpf/libbpf.rst is a userspace library for loading and interacting with bpf programs.

BPF Type Format (BTF)

.. toctree::
   :maxdepth: 1

   btf

Frequently asked questions (FAQ)

Two sets of Questions and Answers (Q&A) are maintained.

.. toctree::
   :maxdepth: 1

   bpf_design_QA
   bpf_devel_QA

Syscall API

The primary info for the bpf syscall is available in the man-pages for bpf(2). For more information about the userspace API, see Documentation/userspace-api/ebpf/index.rst.

Helper functions

• bpf-helpers(7) maintains a list of helpers available to eBPF programs.

Program types

.. toctree::
   :maxdepth: 1

   prog_cgroup_sockopt
   prog_cgroup_sysctl
   prog_flow_dissector
   bpf_lsm
   prog_sk_lookup

Map types

.. toctree::
   :maxdepth: 1

   map_cgroup_storage

Testing and debugging BPF

.. toctree::
   :maxdepth: 1

   drgn
   s390

Other

.. toctree::
   :maxdepth: 1

   ringbuf
   llvm_reloc