1 files changed, 96 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/cgroups/v3/cgroup2/ebpf.go b/vendor/github.com/containerd/cgroups/v3/cgroup2/ebpf.go
new file mode 100644
index 000000000..503a147bb
--- /dev/null
+++ b/vendor/github.com/containerd/cgroups/v3/cgroup2/ebpf.go
@@ -0,0 +1,96 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package cgroup2
+
+import (
+	"fmt"
+
+	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/asm"
+	"github.com/cilium/ebpf/link"
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"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
+	}
+	spec := &ebpf.ProgramSpec{
+		Type:         ebpf.CGroupDevice,
+		Instructions: insts,
+		License:      license,
+	}
+	prog, err := ebpf.NewProgram(spec)
+	if err != nil {
+		return nilCloser, err
+	}
+	err = link.RawAttachProgram(link.RawAttachProgramOptions{
+		Target:  dirFD,
+		Program: prog,
+		Attach:  ebpf.AttachCGroupDevice,
+		Flags:   unix.BPF_F_ALLOW_MULTI,
+	})
+	if err != nil {
+		return nilCloser, fmt.Errorf("failed to call BPF_PROG_ATTACH (BPF_CGROUP_DEVICE, BPF_F_ALLOW_MULTI): %w", err)
+	}
+	closer := func() error {
+		err = link.RawDetachProgram(link.RawDetachProgramOptions{
+			Target:  dirFD,
+			Program: prog,
+			Attach:  ebpf.AttachCGroupDevice,
+		})
+		if err != nil {
+			return fmt.Errorf("failed to call BPF_PROG_DETACH (BPF_CGROUP_DEVICE): %w", err)
+		}
+		return nil
+	}
+	return closer, nil
+}
+
+func isRWM(cgroupPermissions string) bool {
+	r := false
+	w := false
+	m := false
+	for _, rn := range cgroupPermissions {
+		switch rn {
+		case 'r':
+			r = true
+		case 'w':
+			w = true
+		case 'm':
+			m = true
+		}
+	}
+	return r && w && m
+}
+
+// the logic is from runc
+// https://github.com/opencontainers/runc/blob/master/libcontainer/cgroups/fs/devices_v2.go#L44
+func canSkipEBPFError(devices []specs.LinuxDeviceCgroup) bool {
+	for _, dev := range devices {
+		if dev.Allow || !isRWM(dev.Access) {
+			return false
+		}
+	}
+	return true
+}