1 files changed, 99 insertions, 0 deletions
diff --git a/vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs2/defaultpath.go b/vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs2/defaultpath.go
new file mode 100644
index 000000000..9c949c91f
--- /dev/null
+++ b/vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs2/defaultpath.go
@@ -0,0 +1,99 @@
+/*
+   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 fs2
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/opencontainers/runc/libcontainer/configs"
+	"github.com/opencontainers/runc/libcontainer/utils"
+)
+
+const UnifiedMountpoint = "/sys/fs/cgroup"
+
+func defaultDirPath(c *configs.Cgroup) (string, error) {
+	if (c.Name != "" || c.Parent != "") && c.Path != "" {
+		return "", fmt.Errorf("cgroup: either Path or Name and Parent should be used, got %+v", c)
+	}
+
+	return _defaultDirPath(UnifiedMountpoint, c.Path, c.Parent, c.Name)
+}
+
+func _defaultDirPath(root, cgPath, cgParent, cgName string) (string, error) {
+	if (cgName != "" || cgParent != "") && cgPath != "" {
+		return "", errors.New("cgroup: either Path or Name and Parent should be used")
+	}
+
+	// XXX: Do not remove CleanPath. Path safety is important! -- cyphar
+	innerPath := utils.CleanPath(cgPath)
+	if innerPath == "" {
+		cgParent := utils.CleanPath(cgParent)
+		cgName := utils.CleanPath(cgName)
+		innerPath = filepath.Join(cgParent, cgName)
+	}
+	if filepath.IsAbs(innerPath) {
+		return filepath.Join(root, innerPath), nil
+	}
+
+	ownCgroup, err := parseCgroupFile("/proc/self/cgroup")
+	if err != nil {
+		return "", err
+	}
+	// The current user scope most probably has tasks in it already,
+	// making it impossible to enable controllers for its sub-cgroup.
+	// A parent cgroup (with no tasks in it) is what we need.
+	ownCgroup = filepath.Dir(ownCgroup)
+
+	return filepath.Join(root, ownCgroup, innerPath), nil
+}
+
+// parseCgroupFile parses /proc/PID/cgroup file and return string
+func parseCgroupFile(path string) (string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	return parseCgroupFromReader(f)
+}
+
+func parseCgroupFromReader(r io.Reader) (string, error) {
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		var (
+			text  = s.Text()
+			parts = strings.SplitN(text, ":", 3)
+		)
+		if len(parts) < 3 {
+			return "", fmt.Errorf("invalid cgroup entry: %q", text)
+		}
+		// text is like "0::/user.slice/user-1001.slice/session-1.scope"
+		if parts[0] == "0" && parts[1] == "" {
+			return parts[2], nil
+		}
+	}
+	if err := s.Err(); err != nil {
+		return "", err
+	}
+	return "", errors.New("cgroup path not found")
+}