Implement archive.Apply on Windows

Signed-off-by: Darren Stahl <darst@microsoft.com>

archive/strconv.go

@@ -0,0 +1,52 @@
+// +build windows
+
+package archive
+
+import (
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/dmcgowan/go-tar"
+)
+
+// Forked from https://github.com/golang/go/blob/master/src/archive/tar/strconv.go
+// as archive/tar doesn't support CreationTime, but does handle PAX time parsing,
+// and there's no need to re-invent the wheel.
+
+// parsePAXTime takes a string of the form %d.%d as described in the PAX
+// specification. Note that this implementation allows for negative timestamps,
+// which is allowed for by the PAX specification, but not always portable.
+func parsePAXTime(s string) (time.Time, error) {
+	const maxNanoSecondDigits = 9
+
+	// Split string into seconds and sub-seconds parts.
+	ss, sn := s, ""
+	if pos := strings.IndexByte(s, '.'); pos >= 0 {
+		ss, sn = s[:pos], s[pos+1:]
+	}
+
+	// Parse the seconds.
+	secs, err := strconv.ParseInt(ss, 10, 64)
+	if err != nil {
+		return time.Time{}, tar.ErrHeader
+	}
+	if len(sn) == 0 {
+		return time.Unix(secs, 0), nil // No sub-second values
+	}
+
+	// Parse the nanoseconds.
+	if strings.Trim(sn, "0123456789") != "" {
+		return time.Time{}, tar.ErrHeader
+	}
+	if len(sn) < maxNanoSecondDigits {
+		sn += strings.Repeat("0", maxNanoSecondDigits-len(sn)) // Right pad
+	} else {
+		sn = sn[:maxNanoSecondDigits] // Right truncate
+	}
+	nsecs, _ := strconv.ParseInt(sn, 10, 64) // Must succeed
+	if len(ss) > 0 && ss[0] == '-' {
+		return time.Unix(secs, -1*int64(nsecs)), nil // Negative correction
+	}
+	return time.Unix(secs, int64(nsecs)), nil
+}

archive/tar.go

@@ -87,12 +87,23 @@ const (
 
 // Apply applies a tar stream of an OCI style diff tar.
 // See https://github.com/opencontainers/image-spec/blob/master/layer.md#applying-changesets
-func Apply(ctx context.Context, root string, r io.Reader) (int64, error) {
+func Apply(ctx context.Context, root string, r io.Reader, opts ...ApplyOpt) (int64, error) {
 	root = filepath.Clean(root)
 
+	var options ApplyOptions
+	for _, opt := range opts {
+		if err := opt(&options); err != nil {
+			return 0, errors.Wrap(err, "failed to apply option")
+		}
+	}
+
+	return apply(ctx, root, tar.NewReader(r), options)
+}
+
+// applyNaive applies a tar stream of an OCI style diff tar.
+// See https://github.com/opencontainers/image-spec/blob/master/layer.md#applying-changesets
+func applyNaive(ctx context.Context, root string, tr *tar.Reader, options ApplyOptions) (size int64, err error) {
 	var (
-		tr   = tar.NewReader(r)
-		size int64
 		dirs []*tar.Header
 
 		// Used for handling opaque directory markers which
@@ -285,6 +296,99 @@ func Apply(ctx context.Context, root string, r io.Reader) (int64, error) {
 	return size, nil
 }
 
+func createTarFile(ctx context.Context, path, extractDir string, hdr *tar.Header, reader io.Reader) error {
+	// hdr.Mode is in linux format, which we can use for syscalls,
+	// but for os.Foo() calls we need the mode converted to os.FileMode,
+	// so use hdrInfo.Mode() (they differ for e.g. setuid bits)
+	hdrInfo := hdr.FileInfo()
+
+	switch hdr.Typeflag {
+	case tar.TypeDir:
+		// Create directory unless it exists as a directory already.
+		// In that case we just want to merge the two
+		if fi, err := os.Lstat(path); !(err == nil && fi.IsDir()) {
+			if err := mkdir(path, hdrInfo.Mode()); err != nil {
+				return err
+			}
+		}
+
+	case tar.TypeReg, tar.TypeRegA:
+		file, err := openFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, hdrInfo.Mode())
+		if err != nil {
+			return err
+		}
+
+		_, err = copyBuffered(ctx, file, reader)
+		if err1 := file.Close(); err == nil {
+			err = err1
+		}
+		if err != nil {
+			return err
+		}
+
+	case tar.TypeBlock, tar.TypeChar:
+		// Handle this is an OS-specific way
+		if err := handleTarTypeBlockCharFifo(hdr, path); err != nil {
+			return err
+		}
+
+	case tar.TypeFifo:
+		// Handle this is an OS-specific way
+		if err := handleTarTypeBlockCharFifo(hdr, path); err != nil {
+			return err
+		}
+
+	case tar.TypeLink:
+		targetPath, err := fs.RootPath(extractDir, hdr.Linkname)
+		if err != nil {
+			return err
+		}
+		if err := os.Link(targetPath, path); err != nil {
+			return err
+		}
+
+	case tar.TypeSymlink:
+		if err := os.Symlink(hdr.Linkname, path); err != nil {
+			return err
+		}
+
+	case tar.TypeXGlobalHeader:
+		log.G(ctx).Debug("PAX Global Extended Headers found and ignored")
+		return nil
+
+	default:
+		return errors.Errorf("unhandled tar header type %d\n", hdr.Typeflag)
+	}
+
+	// Lchown is not supported on Windows.
+	if runtime.GOOS != "windows" {
+		if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil {
+			return err
+		}
+	}
+
+	for key, value := range hdr.PAXRecords {
+		if strings.HasPrefix(key, paxSchilyXattr) {
+			key = key[len(paxSchilyXattr):]
+			if err := setxattr(path, key, value); err != nil {
+				if errors.Cause(err) == syscall.ENOTSUP {
+					log.G(ctx).WithError(err).Warnf("ignored xattr %s in archive", key)
+					continue
+				}
+				return err
+			}
+		}
+	}
+
+	// There is no LChmod, so ignore mode for symlink. Also, this
+	// must happen after chown, as that can modify the file mode
+	if err := handleLChmod(hdr, path, hdrInfo); err != nil {
+		return err
+	}
+
+	return chtimes(path, boundTime(latestTime(hdr.AccessTime, hdr.ModTime)), boundTime(hdr.ModTime))
+}
+
 type changeWriter struct {
 	tw        *tar.Writer
 	source    string
@@ -440,99 +544,6 @@ func (cw *changeWriter) Close() error {
 	return nil
 }
 
-func createTarFile(ctx context.Context, path, extractDir string, hdr *tar.Header, reader io.Reader) error {
-	// hdr.Mode is in linux format, which we can use for syscalls,
-	// but for os.Foo() calls we need the mode converted to os.FileMode,
-	// so use hdrInfo.Mode() (they differ for e.g. setuid bits)
-	hdrInfo := hdr.FileInfo()
-
-	switch hdr.Typeflag {
-	case tar.TypeDir:
-		// Create directory unless it exists as a directory already.
-		// In that case we just want to merge the two
-		if fi, err := os.Lstat(path); !(err == nil && fi.IsDir()) {
-			if err := mkdir(path, hdrInfo.Mode()); err != nil {
-				return err
-			}
-		}
-
-	case tar.TypeReg, tar.TypeRegA:
-		file, err := openFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, hdrInfo.Mode())
-		if err != nil {
-			return err
-		}
-
-		_, err = copyBuffered(ctx, file, reader)
-		if err1 := file.Close(); err == nil {
-			err = err1
-		}
-		if err != nil {
-			return err
-		}
-
-	case tar.TypeBlock, tar.TypeChar:
-		// Handle this is an OS-specific way
-		if err := handleTarTypeBlockCharFifo(hdr, path); err != nil {
-			return err
-		}
-
-	case tar.TypeFifo:
-		// Handle this is an OS-specific way
-		if err := handleTarTypeBlockCharFifo(hdr, path); err != nil {
-			return err
-		}
-
-	case tar.TypeLink:
-		targetPath, err := fs.RootPath(extractDir, hdr.Linkname)
-		if err != nil {
-			return err
-		}
-		if err := os.Link(targetPath, path); err != nil {
-			return err
-		}
-
-	case tar.TypeSymlink:
-		if err := os.Symlink(hdr.Linkname, path); err != nil {
-			return err
-		}
-
-	case tar.TypeXGlobalHeader:
-		log.G(ctx).Debug("PAX Global Extended Headers found and ignored")
-		return nil
-
-	default:
-		return errors.Errorf("unhandled tar header type %d\n", hdr.Typeflag)
-	}
-
-	// Lchown is not supported on Windows.
-	if runtime.GOOS != "windows" {
-		if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil {
-			return err
-		}
-	}
-
-	for key, value := range hdr.PAXRecords {
-		if strings.HasPrefix(key, paxSchilyXattr) {
-			key = key[len(paxSchilyXattr):]
-			if err := setxattr(path, key, value); err != nil {
-				if errors.Cause(err) == syscall.ENOTSUP {
-					log.G(ctx).WithError(err).Warnf("ignored xattr %s in archive", key)
-					continue
-				}
-				return err
-			}
-		}
-	}
-
-	// There is no LChmod, so ignore mode for symlink. Also, this
-	// must happen after chown, as that can modify the file mode
-	if err := handleLChmod(hdr, path, hdrInfo); err != nil {
-		return err
-	}
-
-	return chtimes(path, boundTime(latestTime(hdr.AccessTime, hdr.ModTime)), boundTime(hdr.ModTime))
-}
-
 func copyBuffered(ctx context.Context, dst io.Writer, src io.Reader) (written int64, err error) {
 	buf := bufferPool.Get().(*[]byte)
 	defer bufferPool.Put(buf)

archive/tar_opts.go

@@ -0,0 +1,4 @@
+package archive
+
+// ApplyOpt allows setting mutable archive apply properties on creation
+type ApplyOpt func(options *ApplyOptions) error

archive/tar_opts_unix.go

@@ -0,0 +1,7 @@
+// +build !windows
+
+package archive
+
+// ApplyOptions provides additional options for an Apply operation
+type ApplyOptions struct {
+}

archive/tar_opts_windows.go

@@ -0,0 +1,28 @@
+// +build windows
+
+package archive
+
+// ApplyOptions provides additional options for an Apply operation
+type ApplyOptions struct {
+	ParentLayerPaths        []string // Parent layer paths used for Windows layer apply
+	IsWindowsContainerLayer bool     // True if the tar stream to be applied is a Windows Container Layer
+}
+
+// WithParentLayers adds parent layers to the apply process this is required
+// for all Windows layers except the base layer.
+func WithParentLayers(parentPaths []string) ApplyOpt {
+	return func(options *ApplyOptions) error {
+		options.ParentLayerPaths = parentPaths
+		return nil
+	}
+}
+
+// AsWindowsContainerLayer indicates that the tar stream to apply is that of
+// a Windows Container Layer. The caller must be holding SeBackupPrivilege and
+// SeRestorePrivilege.
+func AsWindowsContainerLayer() ApplyOpt {
+	return func(options *ApplyOptions) error {
+		options.IsWindowsContainerLayer = true
+		return nil
+	}
+}

archive/tar_unix.go

@@ -3,6 +3,7 @@
 package archive
 
 import (
+	"context"
 	"os"
 	"sync"
 	"syscall"
@@ -128,3 +129,9 @@ func getxattr(path, attr string) ([]byte, error) {
 func setxattr(path, key, value string) error {
 	return sysx.LSetxattr(path, key, []byte(value), 0)
 }
+
+// apply applies a tar stream of an OCI style diff tar.
+// See https://github.com/opencontainers/image-spec/blob/master/layer.md#applying-changesets
+func apply(ctx context.Context, root string, tr *tar.Reader, options ApplyOptions) (size int64, err error) {
+	return applyNaive(ctx, root, tr, options)
+}

archive/tar_windows.go

@@ -1,15 +1,55 @@
+// +build windows
+
 package archive
 
 import (
+	"bufio"
+	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
+	"io"
 	"os"
+	"path"
+	"path/filepath"
+	"strconv"
 	"strings"
+	"syscall"
 
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim"
+	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/sys"
 	"github.com/dmcgowan/go-tar"
 )
 
+const (
+	// MSWINDOWS pax vendor extensions
+	hdrMSWindowsPrefix = "MSWINDOWS."
+
+	hdrFileAttributes        = hdrMSWindowsPrefix + "fileattr"
+	hdrSecurityDescriptor    = hdrMSWindowsPrefix + "sd"
+	hdrRawSecurityDescriptor = hdrMSWindowsPrefix + "rawsd"
+	hdrMountPoint            = hdrMSWindowsPrefix + "mountpoint"
+	hdrEaPrefix              = hdrMSWindowsPrefix + "xattr."
+
+	// LIBARCHIVE pax vendor extensions
+	hdrLibArchivePrefix = "LIBARCHIVE."
+
+	hdrCreateTime = hdrLibArchivePrefix + "creationtime"
+)
+
+var (
+	// mutatedFiles is a list of files that are mutated by the import process
+	// and must be backed up and restored.
+	mutatedFiles = map[string]string{
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD":      "bcd.bak",
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD.LOG":  "bcd.log.bak",
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD.LOG1": "bcd.log1.bak",
+		"UtilityVM/Files/EFI/Microsoft/Boot/BCD.LOG2": "bcd.log2.bak",
+	}
+)
+
 // tarName returns platform-specific filepath
 // to canonical posix-style path for tar archival. p is relative
 // path.
@@ -101,3 +141,286 @@ func setxattr(path, key, value string) error {
 	// since xattrs should not exist in windows diff archives
 	return errors.New("xattrs not supported on Windows")
 }
+
+// apply applies a tar stream of an OCI style diff tar of a Windows layer.
+// See https://github.com/opencontainers/image-spec/blob/master/layer.md#applying-changesets
+func apply(ctx context.Context, root string, tr *tar.Reader, options ApplyOptions) (size int64, err error) {
+	if options.IsWindowsContainerLayer {
+		return applyWindowsLayer(ctx, root, tr, options)
+	}
+	return applyNaive(ctx, root, tr, options)
+}
+
+// applyWindowsLayer applies a tar stream of an OCI style diff tar of a Windows layer.
+// See https://github.com/opencontainers/image-spec/blob/master/layer.md#applying-changesets
+func applyWindowsLayer(ctx context.Context, root string, tr *tar.Reader, options ApplyOptions) (size int64, err error) {
+	home, id := filepath.Split(root)
+	info := hcsshim.DriverInfo{
+		HomeDir: home,
+	}
+
+	w, err := hcsshim.NewLayerWriter(info, id, options.ParentLayerPaths)
+	if err != nil {
+		return 0, err
+	}
+	defer func() {
+		if err := w.Close(); err != nil {
+			log.G(ctx).Errorf("failed to close layer writer: %v", err)
+		}
+	}()
+
+	buf := bufio.NewWriter(nil)
+	hdr, nextErr := tr.Next()
+	// Iterate through the files in the archive.
+	for {
+		select {
+		case <-ctx.Done():
+			return 0, ctx.Err()
+		default:
+		}
+
+		if nextErr == io.EOF {
+			// end of tar archive
+			break
+		}
+		if nextErr != nil {
+			return 0, nextErr
+		}
+
+		// Note: path is used instead of filepath to prevent OS specific handling
+		// of the tar path
+		base := path.Base(hdr.Name)
+		if strings.HasPrefix(base, whiteoutPrefix) {
+			dir := path.Dir(hdr.Name)
+			originalBase := base[len(whiteoutPrefix):]
+			originalPath := path.Join(dir, originalBase)
+			if err := w.Remove(filepath.FromSlash(originalPath)); err != nil {
+				return 0, err
+			}
+			hdr, nextErr = tr.Next()
+		} else if hdr.Typeflag == tar.TypeLink {
+			err := w.AddLink(filepath.FromSlash(hdr.Name), filepath.FromSlash(hdr.Linkname))
+			if err != nil {
+				return 0, err
+			}
+			hdr, nextErr = tr.Next()
+		} else {
+			name, fileSize, fileInfo, err := fileInfoFromHeader(hdr)
+			if err != nil {
+				return 0, err
+			}
+			if err := w.Add(filepath.FromSlash(name), fileInfo); err != nil {
+				return 0, err
+			}
+			size += fileSize
+			hdr, nextErr = tarToBackupStreamWithMutatedFiles(buf, w, tr, hdr, root)
+		}
+	}
+
+	return
+}
+
+// fileInfoFromHeader retrieves basic Win32 file information from a tar header, using the additional metadata written by
+// WriteTarFileFromBackupStream.
+func fileInfoFromHeader(hdr *tar.Header) (name string, size int64, fileInfo *winio.FileBasicInfo, err error) {
+	name = hdr.Name
+	if hdr.Typeflag == tar.TypeReg || hdr.Typeflag == tar.TypeRegA {
+		size = hdr.Size
+	}
+	fileInfo = &winio.FileBasicInfo{
+		LastAccessTime: syscall.NsecToFiletime(hdr.AccessTime.UnixNano()),
+		LastWriteTime:  syscall.NsecToFiletime(hdr.ModTime.UnixNano()),
+		ChangeTime:     syscall.NsecToFiletime(hdr.ChangeTime.UnixNano()),
+
+		// Default CreationTime to ModTime, updated below if MSWINDOWS.createtime exists
+		CreationTime: syscall.NsecToFiletime(hdr.ModTime.UnixNano()),
+	}
+	if attrStr, ok := hdr.PAXRecords[hdrFileAttributes]; ok {
+		attr, err := strconv.ParseUint(attrStr, 10, 32)
+		if err != nil {
+			return "", 0, nil, err
+		}
+		fileInfo.FileAttributes = uintptr(attr)
+	} else {
+		if hdr.Typeflag == tar.TypeDir {
+			fileInfo.FileAttributes |= syscall.FILE_ATTRIBUTE_DIRECTORY
+		}
+	}
+	if createStr, ok := hdr.PAXRecords[hdrCreateTime]; ok {
+		createTime, err := parsePAXTime(createStr)
+		if err != nil {
+			return "", 0, nil, err
+		}
+		fileInfo.CreationTime = syscall.NsecToFiletime(createTime.UnixNano())
+	}
+	return
+}
+
+// tarToBackupStreamWithMutatedFiles reads data from a tar stream and
+// writes it to a backup stream, and also saves any files that will be mutated
+// by the import layer process to a backup location.
+func tarToBackupStreamWithMutatedFiles(buf *bufio.Writer, w io.Writer, t *tar.Reader, hdr *tar.Header, root string) (nextHdr *tar.Header, err error) {
+	var (
+		bcdBackup       *os.File
+		bcdBackupWriter *winio.BackupFileWriter
+	)
+	if backupPath, ok := mutatedFiles[hdr.Name]; ok {
+		bcdBackup, err = os.Create(filepath.Join(root, backupPath))
+		if err != nil {
+			return nil, err
+		}
+		defer func() {
+			cerr := bcdBackup.Close()
+			if err == nil {
+				err = cerr
+			}
+		}()
+
+		bcdBackupWriter = winio.NewBackupFileWriter(bcdBackup, false)
+		defer func() {
+			cerr := bcdBackupWriter.Close()
+			if err == nil {
+				err = cerr
+			}
+		}()
+
+		buf.Reset(io.MultiWriter(w, bcdBackupWriter))
+	} else {
+		buf.Reset(w)
+	}
+
+	defer func() {
+		ferr := buf.Flush()
+		if err == nil {
+			err = ferr
+		}
+	}()
+
+	return writeBackupStreamFromTarFile(buf, t, hdr)
+}
+
+// writeBackupStreamFromTarFile writes a Win32 backup stream from the current tar file. Since this function may process multiple
+// tar file entries in order to collect all the alternate data streams for the file, it returns the next
+// tar file that was not processed, or io.EOF is there are no more.
+func writeBackupStreamFromTarFile(w io.Writer, t *tar.Reader, hdr *tar.Header) (*tar.Header, error) {
+	bw := winio.NewBackupStreamWriter(w)
+	var sd []byte
+	var err error
+	// Maintaining old SDDL-based behavior for backward compatibility.  All new tar headers written
+	// by this library will have raw binary for the security descriptor.
+	if sddl, ok := hdr.PAXRecords[hdrSecurityDescriptor]; ok {
+		sd, err = winio.SddlToSecurityDescriptor(sddl)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if sdraw, ok := hdr.PAXRecords[hdrRawSecurityDescriptor]; ok {
+		sd, err = base64.StdEncoding.DecodeString(sdraw)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if len(sd) != 0 {
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupSecurity,
+			Size: int64(len(sd)),
+		}
+		err := bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = bw.Write(sd)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var eas []winio.ExtendedAttribute
+	for k, v := range hdr.PAXRecords {
+		if !strings.HasPrefix(k, hdrEaPrefix) {
+			continue
+		}
+		data, err := base64.StdEncoding.DecodeString(v)
+		if err != nil {
+			return nil, err
+		}
+		eas = append(eas, winio.ExtendedAttribute{
+			Name:  k[len(hdrEaPrefix):],
+			Value: data,
+		})
+	}
+	if len(eas) != 0 {
+		eadata, err := winio.EncodeExtendedAttributes(eas)
+		if err != nil {
+			return nil, err
+		}
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupEaData,
+			Size: int64(len(eadata)),
+		}
+		err = bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = bw.Write(eadata)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if hdr.Typeflag == tar.TypeSymlink {
+		_, isMountPoint := hdr.PAXRecords[hdrMountPoint]
+		rp := winio.ReparsePoint{
+			Target:       filepath.FromSlash(hdr.Linkname),
+			IsMountPoint: isMountPoint,
+		}
+		reparse := winio.EncodeReparsePoint(&rp)
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupReparseData,
+			Size: int64(len(reparse)),
+		}
+		err := bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = bw.Write(reparse)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if hdr.Typeflag == tar.TypeReg || hdr.Typeflag == tar.TypeRegA {
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupData,
+			Size: hdr.Size,
+		}
+		err := bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = io.Copy(bw, t)
+		if err != nil {
+			return nil, err
+		}
+	}
+	// Copy all the alternate data streams and return the next non-ADS header.
+	for {
+		ahdr, err := t.Next()
+		if err != nil {
+			return nil, err
+		}
+		if ahdr.Typeflag != tar.TypeReg || !strings.HasPrefix(ahdr.Name, hdr.Name+":") {
+			return ahdr, nil
+		}
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupAlternateData,
+			Size: ahdr.Size,
+			Name: ahdr.Name[len(hdr.Name):] + ":$DATA",
+		}
+		err = bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = io.Copy(bw, t)
+		if err != nil {
+			return nil, err
+		}
+	}
+}