/libbpfgo

eBPF library for Go. Powered by libbpf.

Primary LanguageGoApache License 2.0Apache-2.0

libbpfgo

GitHub release (latest by date) Go Report Card License

libbpfgo is a Go library for Linux's eBPF project. It was created for Tracee, our open source Runtime Security, and eBPF tracing tool, written in Go. If you are interested in eBPF and its applications, check out Tracee at Github: https://github.com/aquasecurity/tracee.

libbpfgo is built around libbpf - the standard library for interacting with eBPF programs from userspace - which is a C library maintained in Linux upstream. We have created libbpfgo as a thin Go wrapper around the libbpf project.

Installing

libbpfgo uses CGO to interop with libbpf and will expect to be linked with libbpf at run or link time. Simply importing libbpfgo is not enough to get started, and you will need to fulfill the required dependency in one of the following ways:

  1. Install libbpf as a shared object in the system. Libbpf may already be packaged for your distribution and, if not, you can build and install from source. More info here.
  2. Embed libbpf into your Go project as a vendored dependency. This means that the libbpf code is statically linked into the resulting binary, and there are no runtime dependencies. Tracee takes this approach.

Building

Currently you will find the following GNU Makefile rules:

Makefile Rule Description
all builds libbpfgo (dynamic)
clean cleans entire tree
selftest builds all selftests (static)
selftest-run runs all selftests (static)
helpers-test-run runs all helpers tests (static)
  • libbpf dynamically linked (libbpf from OS)
Makefile Rule Description
libbpfgo-dynamic builds dynamic libbpfgo (libbpf)
libbpfgo-dynamic-test 'go test' with dynamic libbpfgo
selftest-dynamic build tests with dynamic libbpfgo
selftest-dynamic-run run tests using dynamic libbpfgo
helpers-test-dynamic-run run helpers package unit tests using dynamic libbpfgo
  • statically compiled (libbpf submodule)
Makefile Rule Description
libbpfgo-static builds static libbpfgo (libbpf)
libbpfgo-static-test 'go test' with static libbpfgo
selftest-static build tests with static libbpfgo
selftest-static-run run tests using static libbpfgo
helpers-test-static-run run helpers package unit tests using static libbpfgo
  • examples
$ make libbpfgo-static => libbpfgo statically linked with libbpf
$ make -C selftest/perfbuffers => single selftest build (static libbpf)
$ make -C selftest/perfbuffers run-dynamic => single selftest run (dynamic libbpf)
$ make selftest-static-run => will build & run all static selftests

Note 01: dynamic builds need your OS to have a recent enough libbpf package (and its headers) installed. Sometimes, recent features might require the use of backported OS packages in order for your OS to contain latest libbpf features (sometimes required by libbpfgo). Note 02: static builds need git submodule init first. Make sure to sync the libbpf git submodule before trying to statically compile or test the libbpfgo repository.

Concepts

libbpfgo tries to make it natural for Go developers to use, by abstracting away C technicalities. For example, it will translate low level return codes into Go error, it will organize functionality around Go struct, and it will use channel as to let you consume events.

In a high level, this is a typical workflow for working with the library:

  1. Compile your bpf program into an object file.
  2. Initialize a Module struct - that is a unit of BPF functionality around your compiled object file.
  3. Load bpf programs from the object file using the BPFProg struct.
  4. Attach BPFProg to system facilities, for example to "raw tracepoints" or "kprobes" using the BPFProg's associated functions.
  5. Instantiate and manipulate BPF Maps via the BPFMap struct and it's associated methods.
  6. Instantiate and manipulate Perf Buffer for communicating events from your BPF program to the driving userspace program, using the RingBuffer struct and it's associated objects.

Example

// initializing
import bpf "github.com/aquasecurity/libbpfgo"
...
bpfModule := bpf.NewModuleFromFile(bpfObjectPath)
bpfModule.BPFLoadObject()

// maps
mymap, _ := bpfModule.GetMap("mymap")
mymap.Update(key, value)

// ring buffer
rb, _ := bpfModule.InitRingBuffer("events", eventsChannel, buffSize)
rb.Start()
e := <-eventsChannel

Releases

libbpfgo does not yet have a regular schedule for cutting releases. There has not yet been a major release but API backwards compatibility will be maintained for all releases with the same major release number. Milestones are created when preparing for release.

  • Major releases are cut when backwards compatibility is broken or major milestones are completed, such as reaching parity with libbpf's API.
  • Minor releases are cut to incorporate new support for libbpf APIs.
  • Patch releases are cut to incorporate important individual or groupings of bug fixes.
  • libbpf support numbering indicates the minimum required libbpf version that must be linked in order to ensure libbpfgo compatibility. For example, v0.2.1-libbpf-0.4.0 means that version 0.2.1 of libbpfgo requires v0.4.0 or newer of libbpf.

Note: some distributions might have local changes to their libbpf package and their version might include backports and/or fixes differently than upstream versions. In those cases we recommend that libbpfgo is used statically compiled.

Contributing

To better receive you, libbpfgo makes available GNU Makefile rules for vagrant machines (amd64/arm64) that can be used to compile and test on Linux and Darwin hosts:

Makefile Rule Description
vagrant-up starts and provisions the vagrant environment
vagrant-ssh connects to machine via SSH
vagrant-halt stops the vagrant machine
vagrant-destroy stops and deletes all traces of the vagrant machine

Once connected to the vagrant box you are ready to build libbpfgo (e.g. make libbpfgo-static).

For further information, check Vagrantfile.md.

Learn more

Please check our github milestones for an idea of the project roadmap. The general goal is to fully implement/expose libbpf's API in Go as seamlessly as possible.