package link
import (
"errors"
"fmt"
"github.com/cilium/ebpf"
"github.com/cilium/ebpf/internal/sys"
)
type RawTracepointOptions struct {
// Tracepoint name.
Name string
// Program must be of type RawTracepoint*
Program *ebpf.Program
}
// AttachRawTracepoint links a BPF program to a raw_tracepoint.
//
// Requires at least Linux 4.17.
func AttachRawTracepoint(opts RawTracepointOptions) (Link, error) {
if t := opts.Program.Type(); t != ebpf.RawTracepoint && t != ebpf.RawTracepointWritable {
return nil, fmt.Errorf("invalid program type %s, expected RawTracepoint(Writable)", t)
}
if opts.Program.FD() < 0 {
return nil, fmt.Errorf("invalid program: %w", sys.ErrClosedFd)
}
fd, err := sys.RawTracepointOpen(&sys.RawTracepointOpenAttr{
Name: sys.NewStringPointer(opts.Name),
ProgFd: uint32(opts.Program.FD()),
})
if err != nil {
return nil, err
}
err = haveBPFLink()
if errors.Is(err, ErrNotSupported) {
// Prior to commit 70ed506c3bbc ("bpf: Introduce pinnable bpf_link abstraction")
// raw_tracepoints are just a plain fd.
return &simpleRawTracepoint{fd}, nil
}
if err != nil {
return nil, err
}
return &rawTracepoint{RawLink{fd: fd}}, nil
}
type simpleRawTracepoint struct {
fd *sys.FD
}
var _ Link = (*simpleRawTracepoint)(nil)
func (frt *simpleRawTracepoint) isLink() {}
func (frt *simpleRawTracepoint) Close() error {
return frt.fd.Close()
}
func (frt *simpleRawTracepoint) Update(_ *ebpf.Program) error {
return fmt.Errorf("update raw_tracepoint: %w", ErrNotSupported)
}
func (frt *simpleRawTracepoint) Pin(string) error {
return fmt.Errorf("pin raw_tracepoint: %w", ErrNotSupported)
}
func (frt *simpleRawTracepoint) Unpin() error {
return fmt.Errorf("unpin raw_tracepoint: %w", ErrNotSupported)
}
func (frt *simpleRawTracepoint) Info() (*Info, error) {
return nil, fmt.Errorf("can't get raw_tracepoint info: %w", ErrNotSupported)
}
type rawTracepoint struct {
RawLink
}
var _ Link = (*rawTracepoint)(nil)
func (rt *rawTracepoint) Update(_ *ebpf.Program) error {
return fmt.Errorf("update raw_tracepoint: %w", ErrNotSupported)
}