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https://github.com/dropbox/goebpf
Library to work with eBPF programs from Go
https://github.com/dropbox/goebpf
bpf cats cats-effect ebpf go golang golang-library perfevents xdp xdpdump
Last synced: 20 days ago
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Library to work with eBPF programs from Go
- Host: GitHub
- URL: https://github.com/dropbox/goebpf
- Owner: dropbox
- License: other
- Created: 2019-01-24T23:51:24.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2024-03-19T15:37:38.000Z (8 months ago)
- Last Synced: 2024-10-01T22:24:36.656Z (about 1 month ago)
- Topics: bpf, cats, cats-effect, ebpf, go, golang, golang-library, perfevents, xdp, xdpdump
- Language: Go
- Homepage:
- Size: 1.72 MB
- Stars: 1,132
- Watchers: 34
- Forks: 86
- Open Issues: 15
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-list - goebpf
- awesome-golang-repositories - goebpf
README
# Go eBPF
[](https://github.com/dropbox/goebpf/actions?query=branch%3Amaster)
[](https://goreportcard.com/report/github.com/dropbox/goebpf)
[](http://godoc.org/github.com/dropbox/goebpf)
A nice and convenient way to work with `eBPF` programs / perf events from Go.
## Requirements
- Go 1.11+
- Linux Kernel 4.15+
## Supported eBPF features
- eBPF programs
- `SocketFilter`
- `XDP`
- `Kprobe` / `Kretprobe`
- `tc-cls` (`tc-act` is partially implemented, currently)
- Perf Events
Support for other program types / features can be added in future.
Meanwhile your contributions are warmly welcomed.. :)
## Installation
```bash
# Main library
go get github.com/dropbox/goebpf
# Mock version (if needed)
go get github.com/dropbox/goebpf/goebpf_mock
```
## Quick start
Consider very simple example of Read / Load / Attach
```go
// In order to be simple this examples does not handle errors
bpf := goebpf.NewDefaultEbpfSystem()
// Read clang compiled binary
bpf.LoadElf("test.elf")
// Load XDP program into kernel (name matches function name in C)
xdp := bpf.GetProgramByName("xdp_test")
xdp.Load()
// Attach to interface
xdp.Attach("eth0")
defer xdp.Detach()
// Work with maps
test := bpf.GetMapByName("test")
value, _ := test.LookupInt(0)
fmt.Printf("Value at index 0 of map 'test': %d\n", value)
```
Like it? Check our [examples](https://github.com/dropbox/goebpf/tree/master/examples/)
## Perf Events
Currently library has support for one, most popular use case of perf_events: where `eBPF` map key maps to `cpu_id`.
So `eBPF` and `go` parts actually bind `cpu_id` to map index. It maybe as simple as:
```c
// Define special, perf_events map where key maps to CPU_ID
BPF_MAP_DEF(perfmap) = {
.map_type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.max_entries = 128, // Max supported CPUs
};
BPF_MAP_ADD(perfmap);
// ...
// Emit perf event with "data" to map "perfmap" where index is current CPU_ID
bpf_perf_event_output(ctx, &perfmap, BPF_F_CURRENT_CPU, &data, sizeof(data));
```
And the `go` part:
```go
perf, err := goebpf.NewPerfEvents("perfmap")
// 4096 is ring buffer size
perfEvents, err := perf.StartForAllProcessesAndCPUs(4096)
defer perf.Stop()
for {
select {
case data := <-perfEvents:
fmt.Println(data)
}
}
```
Looks simple? Check our [full XDP dump example](https://github.com/dropbox/goebpf/tree/master/examples/xdp/xdp_dump)
## Kprobes
Library currently has support for `kprobes` and `kretprobes`.
It can be as simple as:
```c
// kprobe handler function
SEC("kprobe/guess_execve")
int execve_entry(struct pt_regs *ctx) {
// ...
buf_perf_output(ctx);
return 0;
}
```
And the `go` part:
```go
// Cleanup old probes
err := goebpf.CleanupProbes()
// Attach all probe programs
for _, prog := range bpf.GetPrograms() {
err := prog.Attach(nil)
}
// Create perf events
eventsMap := p.bpf.GetMapByName("events")
p.pe, err = goebpf.NewPerfEvents(eventsMap)
events, err := p.pe.StartForAllProcessesAndCPUs(4096)
defer events.Stop()
for {
select {
case data := <-events:
fmt.Println(data) // kProbe event
}
}
```
Simple? Check [exec dump example](https://github.com/dropbox/goebpf/tree/master/examples/kprobe/exec_dump)
## Good readings
- [XDP Tutorials](https://github.com/xdp-project/xdp-tutorial)
- [Cilium BPF and XDP Reference Guide](https://docs.cilium.io/en/latest/bpf/)
- [Prototype Kernel: XDP](https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/index.html)
- [AF_XDP: Accelerating networking](https://lwn.net/Articles/750845/)
- [eBPF, part 1: Past, Present, and Future](https://ferrisellis.com/posts/ebpf_past_present_future/)
- [eBPF, part 2: Syscall and Map Types](https://ferrisellis.com/posts/ebpf_syscall_and_maps/)
- [Oracle Blog: A Tour of eBPF Program Types](https://blogs.oracle.com/linux/notes-on-bpf-1)
- [Oracle Blog: eBPF Helper Functions](https://blogs.oracle.com/linux/notes-on-bpf-2)
- [Oracle Blog: Communicating with Userspace](https://blogs.oracle.com/linux/notes-on-bpf-3)