mirror of https://github.com/k3s-io/k3s
46 lines
1.5 KiB
Go
46 lines
1.5 KiB
Go
|
package ebpf
|
||
|
|
|
||
|
|
import (
|
||
|
|
"github.com/cilium/ebpf"
|
||
|
|
"github.com/cilium/ebpf/asm"
|
||
|
|
"github.com/pkg/errors"
|
||
|
|
"golang.org/x/sys/unix"
|
||
|
|
)
|
||
|
|
|
||
|
|
// LoadAttachCgroupDeviceFilter installs eBPF device filter program to /sys/fs/cgroup/<foo> directory.
|
||
|
|
//
|
||
|
|
// Requires the system to be running in cgroup2 unified-mode with kernel >= 4.15 .
|
||
|
|
//
|
||
|
|
// https://github.com/torvalds/linux/commit/ebc614f687369f9df99828572b1d85a7c2de3d92
|
||
|
|
func LoadAttachCgroupDeviceFilter(insts asm.Instructions, license string, dirFD int) (func() error, error) {
|
||
|
|
nilCloser := func() error {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
// Increase `ulimit -l` limit to avoid BPF_PROG_LOAD error (#2167).
|
||
|
|
// This limit is not inherited into the container.
|
||
|
|
memlockLimit := &unix.Rlimit{
|
||
|
|
Cur: unix.RLIM_INFINITY,
|
||
|
|
Max: unix.RLIM_INFINITY,
|
||
|
|
}
|
||
|
|
_ = unix.Setrlimit(unix.RLIMIT_MEMLOCK, memlockLimit)
|
||
|
|
spec := &ebpf.ProgramSpec{
|
||
|
|
Type: ebpf.CGroupDevice,
|
||
|
|
Instructions: insts,
|
||
|
|
License: license,
|
||
|
|
}
|
||
|
|
prog, err := ebpf.NewProgram(spec)
|
||
|
|
if err != nil {
|
||
|
|
return nilCloser, err
|
||
|
|
}
|
||
|
|
if err := prog.Attach(dirFD, ebpf.AttachCGroupDevice, unix.BPF_F_ALLOW_MULTI); err != nil {
|
||
|
|
return nilCloser, errors.Wrap(err, "failed to call BPF_PROG_ATTACH (BPF_CGROUP_DEVICE, BPF_F_ALLOW_MULTI)")
|
||
|
|
}
|
||
|
|
closer := func() error {
|
||
|
|
if err := prog.Detach(dirFD, ebpf.AttachCGroupDevice, unix.BPF_F_ALLOW_MULTI); err != nil {
|
||
|
|
return errors.Wrap(err, "failed to call BPF_PROG_DETACH (BPF_CGROUP_DEVICE, BPF_F_ALLOW_MULTI)")
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
return closer, nil
|
||
|
|
}
|