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