rebase: update replaced k8s.io modules to v0.33.0

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/github.com/opencontainers/cgroups/file.go

@@ -0,0 +1,216 @@
+package cgroups
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// OpenFile opens a cgroup file in a given dir with given flags.
+// It is supposed to be used for cgroup files only, and returns
+// an error if the file is not a cgroup file.
+//
+// Arguments dir and file are joined together to form an absolute path
+// to a file being opened.
+func OpenFile(dir, file string, flags int) (*os.File, error) {
+	if dir == "" {
+		return nil, fmt.Errorf("no directory specified for %s", file)
+	}
+	return openFile(dir, file, flags)
+}
+
+// ReadFile reads data from a cgroup file in dir.
+// It is supposed to be used for cgroup files only.
+func ReadFile(dir, file string) (string, error) {
+	fd, err := OpenFile(dir, file, unix.O_RDONLY)
+	if err != nil {
+		return "", err
+	}
+	defer fd.Close()
+	var buf bytes.Buffer
+
+	_, err = buf.ReadFrom(fd)
+	return buf.String(), err
+}
+
+// WriteFile writes data to a cgroup file in dir.
+// It is supposed to be used for cgroup files only.
+func WriteFile(dir, file, data string) error {
+	fd, err := OpenFile(dir, file, unix.O_WRONLY)
+	if err != nil {
+		return err
+	}
+	defer fd.Close()
+	if _, err := fd.WriteString(data); err != nil {
+		// Having data in the error message helps in debugging.
+		return fmt.Errorf("failed to write %q: %w", data, err)
+	}
+	return nil
+}
+
+// WriteFileByLine is the same as WriteFile, except if data contains newlines,
+// it is written line by line.
+func WriteFileByLine(dir, file, data string) error {
+	i := strings.Index(data, "\n")
+	if i == -1 {
+		return WriteFile(dir, file, data)
+	}
+
+	fd, err := OpenFile(dir, file, unix.O_WRONLY)
+	if err != nil {
+		return err
+	}
+	defer fd.Close()
+	start := 0
+	for {
+		var line string
+		if i == -1 {
+			line = data[start:]
+		} else {
+			line = data[start : start+i+1]
+		}
+		_, err := fd.WriteString(line)
+		if err != nil {
+			return fmt.Errorf("failed to write %q: %w", line, err)
+		}
+		if i == -1 {
+			break
+		}
+		start += i + 1
+		i = strings.Index(data[start:], "\n")
+	}
+	return nil
+}
+
+const (
+	cgroupfsDir    = "/sys/fs/cgroup"
+	cgroupfsPrefix = cgroupfsDir + "/"
+)
+
+var (
+	// TestMode is set to true by unit tests that need "fake" cgroupfs.
+	TestMode bool
+
+	cgroupRootHandle *os.File
+	prepOnce         sync.Once
+	prepErr          error
+	resolveFlags     uint64
+)
+
+func prepareOpenat2() error {
+	prepOnce.Do(func() {
+		fd, err := unix.Openat2(-1, cgroupfsDir, &unix.OpenHow{
+			Flags: unix.O_DIRECTORY | unix.O_PATH | unix.O_CLOEXEC,
+		})
+		if err != nil {
+			prepErr = &os.PathError{Op: "openat2", Path: cgroupfsDir, Err: err}
+			if err != unix.ENOSYS {
+				logrus.Warnf("falling back to securejoin: %s", prepErr)
+			} else {
+				logrus.Debug("openat2 not available, falling back to securejoin")
+			}
+			return
+		}
+		file := os.NewFile(uintptr(fd), cgroupfsDir)
+
+		var st unix.Statfs_t
+		if err := unix.Fstatfs(int(file.Fd()), &st); err != nil {
+			prepErr = &os.PathError{Op: "statfs", Path: cgroupfsDir, Err: err}
+			logrus.Warnf("falling back to securejoin: %s", prepErr)
+			return
+		}
+
+		cgroupRootHandle = file
+		resolveFlags = unix.RESOLVE_BENEATH | unix.RESOLVE_NO_MAGICLINKS
+		if st.Type == unix.CGROUP2_SUPER_MAGIC {
+			// cgroupv2 has a single mountpoint and no "cpu,cpuacct" symlinks
+			resolveFlags |= unix.RESOLVE_NO_XDEV | unix.RESOLVE_NO_SYMLINKS
+		}
+	})
+
+	return prepErr
+}
+
+func openFile(dir, file string, flags int) (*os.File, error) {
+	mode := os.FileMode(0)
+	if TestMode && flags&os.O_WRONLY != 0 {
+		// "emulate" cgroup fs for unit tests
+		flags |= os.O_TRUNC | os.O_CREATE
+		mode = 0o600
+	}
+	// NOTE it is important to use filepath.Clean("/"+file) here
+	// (see https://github.com/opencontainers/runc/issues/4103)!
+	path := filepath.Join(dir, filepath.Clean("/"+file))
+
+	if prepareOpenat2() != nil {
+		return openFallback(path, flags, mode)
+	}
+	relPath, ok := strings.CutPrefix(path, cgroupfsPrefix)
+	if !ok { // Non-standard path, old system?
+		return openFallback(path, flags, mode)
+	}
+
+	fd, err := unix.Openat2(int(cgroupRootHandle.Fd()), relPath,
+		&unix.OpenHow{
+			Resolve: resolveFlags,
+			Flags:   uint64(flags) | unix.O_CLOEXEC,
+			Mode:    uint64(mode),
+		})
+	if err != nil {
+		err = &os.PathError{Op: "openat2", Path: path, Err: err}
+		// Check if cgroupRootHandle is still opened to cgroupfsDir
+		// (happens when this package is incorrectly used
+		// across the chroot/pivot_root/mntns boundary, or
+		// when /sys/fs/cgroup is remounted).
+		//
+		// TODO: if such usage will ever be common, amend this
+		// to reopen cgroupRootHandle and retry openat2.
+		fdDest, fdErr := os.Readlink("/proc/thread-self/fd/" + strconv.Itoa(int(cgroupRootHandle.Fd())))
+		if fdErr == nil && fdDest != cgroupfsDir {
+			// Wrap the error so it is clear that cgroupRootHandle
+			// is opened to an unexpected/wrong directory.
+			err = fmt.Errorf("cgroupRootHandle %d unexpectedly opened to %s != %s: %w",
+				cgroupRootHandle.Fd(), fdDest, cgroupfsDir, err)
+		}
+		return nil, err
+	}
+
+	return os.NewFile(uintptr(fd), path), nil
+}
+
+var errNotCgroupfs = errors.New("not a cgroup file")
+
+// Can be changed by unit tests.
+var openFallback = openAndCheck
+
+// openAndCheck is used when openat2(2) is not available. It checks the opened
+// file is on cgroupfs, returning an error otherwise.
+func openAndCheck(path string, flags int, mode os.FileMode) (*os.File, error) {
+	fd, err := os.OpenFile(path, flags, mode)
+	if err != nil {
+		return nil, err
+	}
+	if TestMode {
+		return fd, nil
+	}
+	// Check this is a cgroupfs file.
+	var st unix.Statfs_t
+	if err := unix.Fstatfs(int(fd.Fd()), &st); err != nil {
+		_ = fd.Close()
+		return nil, &os.PathError{Op: "statfs", Path: path, Err: err}
+	}
+	if st.Type != unix.CGROUP_SUPER_MAGIC && st.Type != unix.CGROUP2_SUPER_MAGIC {
+		_ = fd.Close()
+		return nil, &os.PathError{Op: "open", Path: path, Err: errNotCgroupfs}
+	}
+
+	return fd, nil
+}