Initial

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

vendor/github.com/Microsoft/hcsshim/internal/wclayer/activatelayer.go

@@ -0,0 +1,32 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// ActivateLayer will find the layer with the given id and mount it's filesystem.
+// For a read/write layer, the mounted filesystem will appear as a volume on the
+// host, while a read-only layer is generally expected to be a no-op.
+// An activated layer must later be deactivated via DeactivateLayer.
+func ActivateLayer(path string) (err error) {
+	title := "hcsshim::ActivateLayer"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = activateLayer(&stdDriverInfo, path)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/baselayer.go

@@ -0,0 +1,173 @@
+package wclayer
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/Microsoft/hcsshim/internal/safefile"
+)
+
+type baseLayerWriter struct {
+	root         *os.File
+	f            *os.File
+	bw           *winio.BackupFileWriter
+	err          error
+	hasUtilityVM bool
+	dirInfo      []dirInfo
+}
+
+type dirInfo struct {
+	path     string
+	fileInfo winio.FileBasicInfo
+}
+
+// reapplyDirectoryTimes reapplies directory modification, creation, etc. times
+// after processing of the directory tree has completed. The times are expected
+// to be ordered such that parent directories come before child directories.
+func reapplyDirectoryTimes(root *os.File, dis []dirInfo) error {
+	for i := range dis {
+		di := &dis[len(dis)-i-1] // reverse order: process child directories first
+		f, err := safefile.OpenRelative(di.path, root, syscall.GENERIC_READ|syscall.GENERIC_WRITE, syscall.FILE_SHARE_READ, safefile.FILE_OPEN, safefile.FILE_DIRECTORY_FILE)
+		if err != nil {
+			return err
+		}
+
+		err = winio.SetFileBasicInfo(f, &di.fileInfo)
+		f.Close()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (w *baseLayerWriter) closeCurrentFile() error {
+	if w.f != nil {
+		err := w.bw.Close()
+		err2 := w.f.Close()
+		w.f = nil
+		w.bw = nil
+		if err != nil {
+			return err
+		}
+		if err2 != nil {
+			return err2
+		}
+	}
+	return nil
+}
+
+func (w *baseLayerWriter) Add(name string, fileInfo *winio.FileBasicInfo) (err error) {
+	defer func() {
+		if err != nil {
+			w.err = err
+		}
+	}()
+
+	err = w.closeCurrentFile()
+	if err != nil {
+		return err
+	}
+
+	if filepath.ToSlash(name) == `UtilityVM/Files` {
+		w.hasUtilityVM = true
+	}
+
+	var f *os.File
+	defer func() {
+		if f != nil {
+			f.Close()
+		}
+	}()
+
+	extraFlags := uint32(0)
+	if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
+		extraFlags |= safefile.FILE_DIRECTORY_FILE
+		if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT == 0 {
+			w.dirInfo = append(w.dirInfo, dirInfo{name, *fileInfo})
+		}
+	}
+
+	mode := uint32(syscall.GENERIC_READ | syscall.GENERIC_WRITE | winio.WRITE_DAC | winio.WRITE_OWNER | winio.ACCESS_SYSTEM_SECURITY)
+	f, err = safefile.OpenRelative(name, w.root, mode, syscall.FILE_SHARE_READ, safefile.FILE_CREATE, extraFlags)
+	if err != nil {
+		return hcserror.New(err, "Failed to safefile.OpenRelative", name)
+	}
+
+	err = winio.SetFileBasicInfo(f, fileInfo)
+	if err != nil {
+		return hcserror.New(err, "Failed to SetFileBasicInfo", name)
+	}
+
+	w.f = f
+	w.bw = winio.NewBackupFileWriter(f, true)
+	f = nil
+	return nil
+}
+
+func (w *baseLayerWriter) AddLink(name string, target string) (err error) {
+	defer func() {
+		if err != nil {
+			w.err = err
+		}
+	}()
+
+	err = w.closeCurrentFile()
+	if err != nil {
+		return err
+	}
+
+	return safefile.LinkRelative(target, w.root, name, w.root)
+}
+
+func (w *baseLayerWriter) Remove(name string) error {
+	return errors.New("base layer cannot have tombstones")
+}
+
+func (w *baseLayerWriter) Write(b []byte) (int, error) {
+	n, err := w.bw.Write(b)
+	if err != nil {
+		w.err = err
+	}
+	return n, err
+}
+
+func (w *baseLayerWriter) Close() error {
+	defer func() {
+		w.root.Close()
+		w.root = nil
+	}()
+	err := w.closeCurrentFile()
+	if err != nil {
+		return err
+	}
+	if w.err == nil {
+		// Restore the file times of all the directories, since they may have
+		// been modified by creating child directories.
+		err = reapplyDirectoryTimes(w.root, w.dirInfo)
+		if err != nil {
+			return err
+		}
+
+		err = ProcessBaseLayer(w.root.Name())
+		if err != nil {
+			return err
+		}
+
+		if w.hasUtilityVM {
+			err := safefile.EnsureNotReparsePointRelative("UtilityVM", w.root)
+			if err != nil {
+				return err
+			}
+			err = ProcessUtilityVMImage(filepath.Join(w.root.Name(), "UtilityVM"))
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return w.err
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/createlayer.go

@@ -0,0 +1,31 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// CreateLayer creates a new, empty, read-only layer on the filesystem based on
+// the parent layer provided.
+func CreateLayer(path, parent string) (err error) {
+	title := "hcsshim::CreateLayer"
+	fields := logrus.Fields{
+		"parent": parent,
+		"path":   path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = createLayer(&stdDriverInfo, path, parent)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/createscratchlayer.go

@@ -0,0 +1,38 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// CreateScratchLayer creates and populates new read-write layer for use by a container.
+// This requires both the id of the direct parent layer, as well as the full list
+// of paths to all parent layers up to the base (and including the direct parent
+// whose id was provided).
+func CreateScratchLayer(path string, parentLayerPaths []string) (err error) {
+	title := "hcsshim::CreateScratchLayer"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	// Generate layer descriptors
+	layers, err := layerPathsToDescriptors(parentLayerPaths)
+	if err != nil {
+		return err
+	}
+
+	err = createSandboxLayer(&stdDriverInfo, path, 0, layers)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/deactivatelayer.go

@@ -0,0 +1,29 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// DeactivateLayer will dismount a layer that was mounted via ActivateLayer.
+func DeactivateLayer(path string) (err error) {
+	title := "hcsshim::DeactivateLayer"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = deactivateLayer(&stdDriverInfo, path)
+	if err != nil {
+		return hcserror.New(err, title+"- failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/destroylayer.go

@@ -0,0 +1,30 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// DestroyLayer will remove the on-disk files representing the layer with the given
+// path, including that layer's containing folder, if any.
+func DestroyLayer(path string) (err error) {
+	title := "hcsshim::DestroyLayer"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = destroyLayer(&stdDriverInfo, path)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/expandscratchsize.go

@@ -0,0 +1,30 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// ExpandScratchSize expands the size of a layer to at least size bytes.
+func ExpandScratchSize(path string, size uint64) (err error) {
+	title := "hcsshim::ExpandScratchSize"
+	fields := logrus.Fields{
+		"path": path,
+		"size": size,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = expandSandboxSize(&stdDriverInfo, path, size)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go

@@ -0,0 +1,76 @@
+package wclayer
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// ExportLayer will create a folder at exportFolderPath and fill that folder with
+// the transport format version of the layer identified by layerId. This transport
+// format includes any metadata required for later importing the layer (using
+// ImportLayer), and requires the full list of parent layer paths in order to
+// perform the export.
+func ExportLayer(path string, exportFolderPath string, parentLayerPaths []string) (err error) {
+	title := "hcsshim::ExportLayer"
+	fields := logrus.Fields{
+		"path":             path,
+		"exportFolderPath": exportFolderPath,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	// Generate layer descriptors
+	layers, err := layerPathsToDescriptors(parentLayerPaths)
+	if err != nil {
+		return err
+	}
+
+	err = exportLayer(&stdDriverInfo, path, exportFolderPath, layers)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}
+
+type LayerReader interface {
+	Next() (string, int64, *winio.FileBasicInfo, error)
+	Read(b []byte) (int, error)
+	Close() error
+}
+
+// NewLayerReader returns a new layer reader for reading the contents of an on-disk layer.
+// The caller must have taken the SeBackupPrivilege privilege
+// to call this and any methods on the resulting LayerReader.
+func NewLayerReader(path string, parentLayerPaths []string) (LayerReader, error) {
+	exportPath, err := ioutil.TempDir("", "hcs")
+	if err != nil {
+		return nil, err
+	}
+	err = ExportLayer(path, exportPath, parentLayerPaths)
+	if err != nil {
+		os.RemoveAll(exportPath)
+		return nil, err
+	}
+	return &legacyLayerReaderWrapper{newLegacyLayerReader(exportPath)}, nil
+}
+
+type legacyLayerReaderWrapper struct {
+	*legacyLayerReader
+}
+
+func (r *legacyLayerReaderWrapper) Close() error {
+	err := r.legacyLayerReader.Close()
+	os.RemoveAll(r.root)
+	return err
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/getlayermountpath.go

@@ -0,0 +1,56 @@
+package wclayer
+
+import (
+	"syscall"
+
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// GetLayerMountPath will look for a mounted layer with the given path and return
+// the path at which that layer can be accessed.  This path may be a volume path
+// if the layer is a mounted read-write layer, otherwise it is expected to be the
+// folder path at which the layer is stored.
+func GetLayerMountPath(path string) (_ string, err error) {
+	title := "hcsshim::GetLayerMountPath"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	var mountPathLength uintptr
+	mountPathLength = 0
+
+	// Call the procedure itself.
+	logrus.WithFields(fields).Debug("Calling proc (1)")
+	err = getLayerMountPath(&stdDriverInfo, path, &mountPathLength, nil)
+	if err != nil {
+		return "", hcserror.New(err, title+" - failed", "(first call)")
+	}
+
+	// Allocate a mount path of the returned length.
+	if mountPathLength == 0 {
+		return "", nil
+	}
+	mountPathp := make([]uint16, mountPathLength)
+	mountPathp[0] = 0
+
+	// Call the procedure again
+	logrus.WithFields(fields).Debug("Calling proc (2)")
+	err = getLayerMountPath(&stdDriverInfo, path, &mountPathLength, &mountPathp[0])
+	if err != nil {
+		return "", hcserror.New(err, title+" - failed", "(second call)")
+	}
+
+	mountPath := syscall.UTF16ToString(mountPathp[0:])
+	fields["mountPath"] = mountPath
+	return mountPath, nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/getsharedbaseimages.go

@@ -0,0 +1,29 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/Microsoft/hcsshim/internal/interop"
+	"github.com/sirupsen/logrus"
+)
+
+// GetSharedBaseImages will enumerate the images stored in the common central
+// image store and return descriptive info about those images for the purpose
+// of registering them with the graphdriver, graph, and tagstore.
+func GetSharedBaseImages() (imageData string, err error) {
+	title := "hcsshim::GetSharedBaseImages"
+	logrus.Debug(title)
+	defer func() {
+		if err != nil {
+			logrus.WithError(err).Error(err)
+		} else {
+			logrus.WithField("imageData", imageData).Debug(title + " - succeeded")
+		}
+	}()
+
+	var buffer *uint16
+	err = getBaseImages(&buffer)
+	if err != nil {
+		return "", hcserror.New(err, title+" - failed", "")
+	}
+	return interop.ConvertAndFreeCoTaskMemString(buffer), nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/grantvmaccess.go

@@ -0,0 +1,30 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// GrantVmAccess adds access to a file for a given VM
+func GrantVmAccess(vmid string, filepath string) (err error) {
+	title := "hcsshim::GrantVmAccess"
+	fields := logrus.Fields{
+		"vm-id": vmid,
+		"path":  filepath,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = grantVmAccess(vmid, filepath)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/importlayer.go

@@ -0,0 +1,135 @@
+package wclayer
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/Microsoft/hcsshim/internal/safefile"
+	"github.com/sirupsen/logrus"
+)
+
+// ImportLayer will take the contents of the folder at importFolderPath and import
+// that into a layer with the id layerId.  Note that in order to correctly populate
+// the layer and interperet the transport format, all parent layers must already
+// be present on the system at the paths provided in parentLayerPaths.
+func ImportLayer(path string, importFolderPath string, parentLayerPaths []string) (err error) {
+	title := "hcsshim::ImportLayer"
+	fields := logrus.Fields{
+		"path":             path,
+		"importFolderPath": importFolderPath,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	// Generate layer descriptors
+	layers, err := layerPathsToDescriptors(parentLayerPaths)
+	if err != nil {
+		return err
+	}
+
+	err = importLayer(&stdDriverInfo, path, importFolderPath, layers)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}
+
+// LayerWriter is an interface that supports writing a new container image layer.
+type LayerWriter interface {
+	// Add adds a file to the layer with given metadata.
+	Add(name string, fileInfo *winio.FileBasicInfo) error
+	// AddLink adds a hard link to the layer. The target must already have been added.
+	AddLink(name string, target string) error
+	// Remove removes a file that was present in a parent layer from the layer.
+	Remove(name string) error
+	// Write writes data to the current file. The data must be in the format of a Win32
+	// backup stream.
+	Write(b []byte) (int, error)
+	// Close finishes the layer writing process and releases any resources.
+	Close() error
+}
+
+type legacyLayerWriterWrapper struct {
+	*legacyLayerWriter
+	path             string
+	parentLayerPaths []string
+}
+
+func (r *legacyLayerWriterWrapper) Close() error {
+	defer os.RemoveAll(r.root.Name())
+	defer r.legacyLayerWriter.CloseRoots()
+	err := r.legacyLayerWriter.Close()
+	if err != nil {
+		return err
+	}
+
+	if err = ImportLayer(r.destRoot.Name(), r.path, r.parentLayerPaths); err != nil {
+		return err
+	}
+	for _, name := range r.Tombstones {
+		if err = safefile.RemoveRelative(name, r.destRoot); err != nil && !os.IsNotExist(err) {
+			return err
+		}
+	}
+	// Add any hard links that were collected.
+	for _, lnk := range r.PendingLinks {
+		if err = safefile.RemoveRelative(lnk.Path, r.destRoot); err != nil && !os.IsNotExist(err) {
+			return err
+		}
+		if err = safefile.LinkRelative(lnk.Target, lnk.TargetRoot, lnk.Path, r.destRoot); err != nil {
+			return err
+		}
+	}
+	// Prepare the utility VM for use if one is present in the layer.
+	if r.HasUtilityVM {
+		err := safefile.EnsureNotReparsePointRelative("UtilityVM", r.destRoot)
+		if err != nil {
+			return err
+		}
+		err = ProcessUtilityVMImage(filepath.Join(r.destRoot.Name(), "UtilityVM"))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// NewLayerWriter returns a new layer writer for creating a layer on disk.
+// The caller must have taken the SeBackupPrivilege and SeRestorePrivilege privileges
+// to call this and any methods on the resulting LayerWriter.
+func NewLayerWriter(path string, parentLayerPaths []string) (LayerWriter, error) {
+	if len(parentLayerPaths) == 0 {
+		// This is a base layer. It gets imported differently.
+		f, err := safefile.OpenRoot(path)
+		if err != nil {
+			return nil, err
+		}
+		return &baseLayerWriter{
+			root: f,
+		}, nil
+	}
+
+	importPath, err := ioutil.TempDir("", "hcs")
+	if err != nil {
+		return nil, err
+	}
+	w, err := newLegacyLayerWriter(importPath, parentLayerPaths, path)
+	if err != nil {
+		return nil, err
+	}
+	return &legacyLayerWriterWrapper{
+		legacyLayerWriter: w,
+		path:              importPath,
+		parentLayerPaths:  parentLayerPaths,
+	}, nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/layerexists.go

@@ -0,0 +1,33 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// LayerExists will return true if a layer with the given id exists and is known
+// to the system.
+func LayerExists(path string) (_ bool, err error) {
+	title := "hcsshim::LayerExists"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	// Call the procedure itself.
+	var exists uint32
+	err = layerExists(&stdDriverInfo, path, &exists)
+	if err != nil {
+		return false, hcserror.New(err, title+" - failed", "")
+	}
+	fields["layer-exists"] = exists != 0
+	return exists != 0, nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/layerid.go

@@ -0,0 +1,13 @@
+package wclayer
+
+import (
+	"path/filepath"
+
+	"github.com/Microsoft/go-winio/pkg/guid"
+)
+
+// LayerID returns the layer ID of a layer on disk.
+func LayerID(path string) (guid.GUID, error) {
+	_, file := filepath.Split(path)
+	return NameToGuid(file)
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/layerutils.go

@@ -0,0 +1,96 @@
+package wclayer
+
+// This file contains utility functions to support storage (graph) related
+// functionality.
+
+import (
+	"syscall"
+
+	"github.com/Microsoft/go-winio/pkg/guid"
+	"github.com/sirupsen/logrus"
+)
+
+/* To pass into syscall, we need a struct matching the following:
+enum GraphDriverType
+{
+    DiffDriver,
+    FilterDriver
+};
+
+struct DriverInfo {
+    GraphDriverType Flavour;
+    LPCWSTR HomeDir;
+};
+*/
+
+type driverInfo struct {
+	Flavour  int
+	HomeDirp *uint16
+}
+
+var (
+	utf16EmptyString uint16
+	stdDriverInfo    = driverInfo{1, &utf16EmptyString}
+)
+
+/* To pass into syscall, we need a struct matching the following:
+typedef struct _WC_LAYER_DESCRIPTOR {
+
+    //
+    // The ID of the layer
+    //
+
+    GUID LayerId;
+
+    //
+    // Additional flags
+    //
+
+    union {
+        struct {
+            ULONG Reserved : 31;
+            ULONG Dirty : 1;    // Created from sandbox as a result of snapshot
+        };
+        ULONG Value;
+    } Flags;
+
+    //
+    // Path to the layer root directory, null-terminated
+    //
+
+    PCWSTR Path;
+
+} WC_LAYER_DESCRIPTOR, *PWC_LAYER_DESCRIPTOR;
+*/
+type WC_LAYER_DESCRIPTOR struct {
+	LayerId guid.GUID
+	Flags   uint32
+	Pathp   *uint16
+}
+
+func layerPathsToDescriptors(parentLayerPaths []string) ([]WC_LAYER_DESCRIPTOR, error) {
+	// Array of descriptors that gets constructed.
+	var layers []WC_LAYER_DESCRIPTOR
+
+	for i := 0; i < len(parentLayerPaths); i++ {
+		g, err := LayerID(parentLayerPaths[i])
+		if err != nil {
+			logrus.WithError(err).Debug("Failed to convert name to guid")
+			return nil, err
+		}
+
+		p, err := syscall.UTF16PtrFromString(parentLayerPaths[i])
+		if err != nil {
+			logrus.WithError(err).Debug("Failed conversion of parentLayerPath to pointer")
+			return nil, err
+		}
+
+		layers = append(layers, WC_LAYER_DESCRIPTOR{
+			LayerId: g,
+			Flags:   0,
+			Pathp:   p,
+		})
+	}
+
+	return layers, nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/legacy.go

@@ -0,0 +1,815 @@
+package wclayer
+
+import (
+	"bufio"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim/internal/longpath"
+	"github.com/Microsoft/hcsshim/internal/safefile"
+)
+
+var errorIterationCanceled = errors.New("")
+
+var mutatedUtilityVMFiles = map[string]bool{
+	`EFI\Microsoft\Boot\BCD`:      true,
+	`EFI\Microsoft\Boot\BCD.LOG`:  true,
+	`EFI\Microsoft\Boot\BCD.LOG1`: true,
+	`EFI\Microsoft\Boot\BCD.LOG2`: true,
+}
+
+const (
+	filesPath          = `Files`
+	hivesPath          = `Hives`
+	utilityVMPath      = `UtilityVM`
+	utilityVMFilesPath = `UtilityVM\Files`
+)
+
+func openFileOrDir(path string, mode uint32, createDisposition uint32) (file *os.File, err error) {
+	return winio.OpenForBackup(path, mode, syscall.FILE_SHARE_READ, createDisposition)
+}
+
+func hasPathPrefix(p, prefix string) bool {
+	return strings.HasPrefix(p, prefix) && len(p) > len(prefix) && p[len(prefix)] == '\\'
+}
+
+type fileEntry struct {
+	path string
+	fi   os.FileInfo
+	err  error
+}
+
+type legacyLayerReader struct {
+	root         string
+	result       chan *fileEntry
+	proceed      chan bool
+	currentFile  *os.File
+	backupReader *winio.BackupFileReader
+}
+
+// newLegacyLayerReader returns a new LayerReader that can read the Windows
+// container layer transport format from disk.
+func newLegacyLayerReader(root string) *legacyLayerReader {
+	r := &legacyLayerReader{
+		root:    root,
+		result:  make(chan *fileEntry),
+		proceed: make(chan bool),
+	}
+	go r.walk()
+	return r
+}
+
+func readTombstones(path string) (map[string]([]string), error) {
+	tf, err := os.Open(filepath.Join(path, "tombstones.txt"))
+	if err != nil {
+		return nil, err
+	}
+	defer tf.Close()
+	s := bufio.NewScanner(tf)
+	if !s.Scan() || s.Text() != "\xef\xbb\xbfVersion 1.0" {
+		return nil, errors.New("Invalid tombstones file")
+	}
+
+	ts := make(map[string]([]string))
+	for s.Scan() {
+		t := filepath.Join(filesPath, s.Text()[1:]) // skip leading `\`
+		dir := filepath.Dir(t)
+		ts[dir] = append(ts[dir], t)
+	}
+	if err = s.Err(); err != nil {
+		return nil, err
+	}
+
+	return ts, nil
+}
+
+func (r *legacyLayerReader) walkUntilCancelled() error {
+	root, err := longpath.LongAbs(r.root)
+	if err != nil {
+		return err
+	}
+
+	r.root = root
+	ts, err := readTombstones(r.root)
+	if err != nil {
+		return err
+	}
+
+	err = filepath.Walk(r.root, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Indirect fix for https://github.com/moby/moby/issues/32838#issuecomment-343610048.
+		// Handle failure from what may be a golang bug in the conversion of
+		// UTF16 to UTF8 in files which are left in the recycle bin. Os.Lstat
+		// which is called by filepath.Walk will fail when a filename contains
+		// unicode characters. Skip the recycle bin regardless which is goodness.
+		if strings.EqualFold(path, filepath.Join(r.root, `Files\$Recycle.Bin`)) && info.IsDir() {
+			return filepath.SkipDir
+		}
+
+		if path == r.root || path == filepath.Join(r.root, "tombstones.txt") || strings.HasSuffix(path, ".$wcidirs$") {
+			return nil
+		}
+
+		r.result <- &fileEntry{path, info, nil}
+		if !<-r.proceed {
+			return errorIterationCanceled
+		}
+
+		// List all the tombstones.
+		if info.IsDir() {
+			relPath, err := filepath.Rel(r.root, path)
+			if err != nil {
+				return err
+			}
+			if dts, ok := ts[relPath]; ok {
+				for _, t := range dts {
+					r.result <- &fileEntry{filepath.Join(r.root, t), nil, nil}
+					if !<-r.proceed {
+						return errorIterationCanceled
+					}
+				}
+			}
+		}
+		return nil
+	})
+	if err == errorIterationCanceled {
+		return nil
+	}
+	if err == nil {
+		return io.EOF
+	}
+	return err
+}
+
+func (r *legacyLayerReader) walk() {
+	defer close(r.result)
+	if !<-r.proceed {
+		return
+	}
+
+	err := r.walkUntilCancelled()
+	if err != nil {
+		for {
+			r.result <- &fileEntry{err: err}
+			if !<-r.proceed {
+				return
+			}
+		}
+	}
+}
+
+func (r *legacyLayerReader) reset() {
+	if r.backupReader != nil {
+		r.backupReader.Close()
+		r.backupReader = nil
+	}
+	if r.currentFile != nil {
+		r.currentFile.Close()
+		r.currentFile = nil
+	}
+}
+
+func findBackupStreamSize(r io.Reader) (int64, error) {
+	br := winio.NewBackupStreamReader(r)
+	for {
+		hdr, err := br.Next()
+		if err != nil {
+			if err == io.EOF {
+				err = nil
+			}
+			return 0, err
+		}
+		if hdr.Id == winio.BackupData {
+			return hdr.Size, nil
+		}
+	}
+}
+
+func (r *legacyLayerReader) Next() (path string, size int64, fileInfo *winio.FileBasicInfo, err error) {
+	r.reset()
+	r.proceed <- true
+	fe := <-r.result
+	if fe == nil {
+		err = errors.New("LegacyLayerReader closed")
+		return
+	}
+	if fe.err != nil {
+		err = fe.err
+		return
+	}
+
+	path, err = filepath.Rel(r.root, fe.path)
+	if err != nil {
+		return
+	}
+
+	if fe.fi == nil {
+		// This is a tombstone. Return a nil fileInfo.
+		return
+	}
+
+	if fe.fi.IsDir() && hasPathPrefix(path, filesPath) {
+		fe.path += ".$wcidirs$"
+	}
+
+	f, err := openFileOrDir(fe.path, syscall.GENERIC_READ, syscall.OPEN_EXISTING)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if f != nil {
+			f.Close()
+		}
+	}()
+
+	fileInfo, err = winio.GetFileBasicInfo(f)
+	if err != nil {
+		return
+	}
+
+	if !hasPathPrefix(path, filesPath) {
+		size = fe.fi.Size()
+		r.backupReader = winio.NewBackupFileReader(f, false)
+		if path == hivesPath || path == filesPath {
+			// The Hives directory has a non-deterministic file time because of the
+			// nature of the import process. Use the times from System_Delta.
+			var g *os.File
+			g, err = os.Open(filepath.Join(r.root, hivesPath, `System_Delta`))
+			if err != nil {
+				return
+			}
+			attr := fileInfo.FileAttributes
+			fileInfo, err = winio.GetFileBasicInfo(g)
+			g.Close()
+			if err != nil {
+				return
+			}
+			fileInfo.FileAttributes = attr
+		}
+
+		// The creation time and access time get reset for files outside of the Files path.
+		fileInfo.CreationTime = fileInfo.LastWriteTime
+		fileInfo.LastAccessTime = fileInfo.LastWriteTime
+
+	} else {
+		// The file attributes are written before the backup stream.
+		var attr uint32
+		err = binary.Read(f, binary.LittleEndian, &attr)
+		if err != nil {
+			return
+		}
+		fileInfo.FileAttributes = attr
+		beginning := int64(4)
+
+		// Find the accurate file size.
+		if !fe.fi.IsDir() {
+			size, err = findBackupStreamSize(f)
+			if err != nil {
+				err = &os.PathError{Op: "findBackupStreamSize", Path: fe.path, Err: err}
+				return
+			}
+		}
+
+		// Return back to the beginning of the backup stream.
+		_, err = f.Seek(beginning, 0)
+		if err != nil {
+			return
+		}
+	}
+
+	r.currentFile = f
+	f = nil
+	return
+}
+
+func (r *legacyLayerReader) Read(b []byte) (int, error) {
+	if r.backupReader == nil {
+		if r.currentFile == nil {
+			return 0, io.EOF
+		}
+		return r.currentFile.Read(b)
+	}
+	return r.backupReader.Read(b)
+}
+
+func (r *legacyLayerReader) Seek(offset int64, whence int) (int64, error) {
+	if r.backupReader == nil {
+		if r.currentFile == nil {
+			return 0, errors.New("no current file")
+		}
+		return r.currentFile.Seek(offset, whence)
+	}
+	return 0, errors.New("seek not supported on this stream")
+}
+
+func (r *legacyLayerReader) Close() error {
+	r.proceed <- false
+	<-r.result
+	r.reset()
+	return nil
+}
+
+type pendingLink struct {
+	Path, Target string
+	TargetRoot   *os.File
+}
+
+type pendingDir struct {
+	Path string
+	Root *os.File
+}
+
+type legacyLayerWriter struct {
+	root            *os.File
+	destRoot        *os.File
+	parentRoots     []*os.File
+	currentFile     *os.File
+	bufWriter       *bufio.Writer
+	currentFileName string
+	currentFileRoot *os.File
+	backupWriter    *winio.BackupFileWriter
+	Tombstones      []string
+	HasUtilityVM    bool
+	uvmDi           []dirInfo
+	addedFiles      map[string]bool
+	PendingLinks    []pendingLink
+	pendingDirs     []pendingDir
+	currentIsDir    bool
+}
+
+// newLegacyLayerWriter returns a LayerWriter that can write the contaler layer
+// transport format to disk.
+func newLegacyLayerWriter(root string, parentRoots []string, destRoot string) (w *legacyLayerWriter, err error) {
+	w = &legacyLayerWriter{
+		addedFiles: make(map[string]bool),
+	}
+	defer func() {
+		if err != nil {
+			w.CloseRoots()
+			w = nil
+		}
+	}()
+	w.root, err = safefile.OpenRoot(root)
+	if err != nil {
+		return
+	}
+	w.destRoot, err = safefile.OpenRoot(destRoot)
+	if err != nil {
+		return
+	}
+	for _, r := range parentRoots {
+		f, err := safefile.OpenRoot(r)
+		if err != nil {
+			return w, err
+		}
+		w.parentRoots = append(w.parentRoots, f)
+	}
+	w.bufWriter = bufio.NewWriterSize(ioutil.Discard, 65536)
+	return
+}
+
+func (w *legacyLayerWriter) CloseRoots() {
+	if w.root != nil {
+		w.root.Close()
+		w.root = nil
+	}
+	if w.destRoot != nil {
+		w.destRoot.Close()
+		w.destRoot = nil
+	}
+	for i := range w.parentRoots {
+		w.parentRoots[i].Close()
+	}
+	w.parentRoots = nil
+}
+
+func (w *legacyLayerWriter) initUtilityVM() error {
+	if !w.HasUtilityVM {
+		err := safefile.MkdirRelative(utilityVMPath, w.destRoot)
+		if err != nil {
+			return err
+		}
+		// Server 2016 does not support multiple layers for the utility VM, so
+		// clone the utility VM from the parent layer into this layer. Use hard
+		// links to avoid unnecessary copying, since most of the files are
+		// immutable.
+		err = cloneTree(w.parentRoots[0], w.destRoot, utilityVMFilesPath, mutatedUtilityVMFiles)
+		if err != nil {
+			return fmt.Errorf("cloning the parent utility VM image failed: %s", err)
+		}
+		w.HasUtilityVM = true
+	}
+	return nil
+}
+
+func (w *legacyLayerWriter) reset() error {
+	err := w.bufWriter.Flush()
+	if err != nil {
+		return err
+	}
+	w.bufWriter.Reset(ioutil.Discard)
+	if w.currentIsDir {
+		r := w.currentFile
+		br := winio.NewBackupStreamReader(r)
+		// Seek to the beginning of the backup stream, skipping the fileattrs
+		if _, err := r.Seek(4, io.SeekStart); err != nil {
+			return err
+		}
+
+		for {
+			bhdr, err := br.Next()
+			if err == io.EOF {
+				// end of backupstream data
+				break
+			}
+			if err != nil {
+				return err
+			}
+			switch bhdr.Id {
+			case winio.BackupReparseData:
+				// The current file is a `.$wcidirs$` metadata file that
+				// describes a directory reparse point. Delete the placeholder
+				// directory to prevent future files being added into the
+				// destination of the reparse point during the ImportLayer call
+				if err := safefile.RemoveRelative(w.currentFileName, w.currentFileRoot); err != nil {
+					return err
+				}
+				w.pendingDirs = append(w.pendingDirs, pendingDir{Path: w.currentFileName, Root: w.currentFileRoot})
+			default:
+				// ignore all other stream types, as we only care about directory reparse points
+			}
+		}
+		w.currentIsDir = false
+	}
+	if w.backupWriter != nil {
+		w.backupWriter.Close()
+		w.backupWriter = nil
+	}
+	if w.currentFile != nil {
+		w.currentFile.Close()
+		w.currentFile = nil
+		w.currentFileName = ""
+		w.currentFileRoot = nil
+	}
+	return nil
+}
+
+// copyFileWithMetadata copies a file using the backup/restore APIs in order to preserve metadata
+func copyFileWithMetadata(srcRoot, destRoot *os.File, subPath string, isDir bool) (fileInfo *winio.FileBasicInfo, err error) {
+	src, err := safefile.OpenRelative(
+		subPath,
+		srcRoot,
+		syscall.GENERIC_READ|winio.ACCESS_SYSTEM_SECURITY,
+		syscall.FILE_SHARE_READ,
+		safefile.FILE_OPEN,
+		safefile.FILE_OPEN_REPARSE_POINT)
+	if err != nil {
+		return nil, err
+	}
+	defer src.Close()
+	srcr := winio.NewBackupFileReader(src, true)
+	defer srcr.Close()
+
+	fileInfo, err = winio.GetFileBasicInfo(src)
+	if err != nil {
+		return nil, err
+	}
+
+	extraFlags := uint32(0)
+	if isDir {
+		extraFlags |= safefile.FILE_DIRECTORY_FILE
+	}
+	dest, err := safefile.OpenRelative(
+		subPath,
+		destRoot,
+		syscall.GENERIC_READ|syscall.GENERIC_WRITE|winio.WRITE_DAC|winio.WRITE_OWNER|winio.ACCESS_SYSTEM_SECURITY,
+		syscall.FILE_SHARE_READ,
+		safefile.FILE_CREATE,
+		extraFlags)
+	if err != nil {
+		return nil, err
+	}
+	defer dest.Close()
+
+	err = winio.SetFileBasicInfo(dest, fileInfo)
+	if err != nil {
+		return nil, err
+	}
+
+	destw := winio.NewBackupFileWriter(dest, true)
+	defer func() {
+		cerr := destw.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
+
+	_, err = io.Copy(destw, srcr)
+	if err != nil {
+		return nil, err
+	}
+
+	return fileInfo, nil
+}
+
+// cloneTree clones a directory tree using hard links. It skips hard links for
+// the file names in the provided map and just copies those files.
+func cloneTree(srcRoot *os.File, destRoot *os.File, subPath string, mutatedFiles map[string]bool) error {
+	var di []dirInfo
+	err := safefile.EnsureNotReparsePointRelative(subPath, srcRoot)
+	if err != nil {
+		return err
+	}
+	err = filepath.Walk(filepath.Join(srcRoot.Name(), subPath), func(srcFilePath string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		relPath, err := filepath.Rel(srcRoot.Name(), srcFilePath)
+		if err != nil {
+			return err
+		}
+
+		fileAttributes := info.Sys().(*syscall.Win32FileAttributeData).FileAttributes
+		// Directories, reparse points, and files that will be mutated during
+		// utility VM import must be copied. All other files can be hard linked.
+		isReparsePoint := fileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT != 0
+		// In go1.9, FileInfo.IsDir() returns false if the directory is also a symlink.
+		// See: https://github.com/golang/go/commit/1989921aef60c83e6f9127a8448fb5ede10e9acc
+		// Fixes the problem by checking syscall.FILE_ATTRIBUTE_DIRECTORY directly
+		isDir := fileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0
+
+		if isDir || isReparsePoint || mutatedFiles[relPath] {
+			fi, err := copyFileWithMetadata(srcRoot, destRoot, relPath, isDir)
+			if err != nil {
+				return err
+			}
+			if isDir && !isReparsePoint {
+				di = append(di, dirInfo{path: relPath, fileInfo: *fi})
+			}
+		} else {
+			err = safefile.LinkRelative(relPath, srcRoot, relPath, destRoot)
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	return reapplyDirectoryTimes(destRoot, di)
+}
+
+func (w *legacyLayerWriter) Add(name string, fileInfo *winio.FileBasicInfo) error {
+	if err := w.reset(); err != nil {
+		return err
+	}
+
+	if name == utilityVMPath {
+		return w.initUtilityVM()
+	}
+
+	name = filepath.Clean(name)
+	if hasPathPrefix(name, utilityVMPath) {
+		if !w.HasUtilityVM {
+			return errors.New("missing UtilityVM directory")
+		}
+		if !hasPathPrefix(name, utilityVMFilesPath) && name != utilityVMFilesPath {
+			return errors.New("invalid UtilityVM layer")
+		}
+		createDisposition := uint32(safefile.FILE_OPEN)
+		if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 {
+			st, err := safefile.LstatRelative(name, w.destRoot)
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			if st != nil {
+				// Delete the existing file/directory if it is not the same type as this directory.
+				existingAttr := st.Sys().(*syscall.Win32FileAttributeData).FileAttributes
+				if (uint32(fileInfo.FileAttributes)^existingAttr)&(syscall.FILE_ATTRIBUTE_DIRECTORY|syscall.FILE_ATTRIBUTE_REPARSE_POINT) != 0 {
+					if err = safefile.RemoveAllRelative(name, w.destRoot); err != nil {
+						return err
+					}
+					st = nil
+				}
+			}
+			if st == nil {
+				if err = safefile.MkdirRelative(name, w.destRoot); err != nil {
+					return err
+				}
+			}
+			if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT == 0 {
+				w.uvmDi = append(w.uvmDi, dirInfo{path: name, fileInfo: *fileInfo})
+			}
+		} else {
+			// Overwrite any existing hard link.
+			err := safefile.RemoveRelative(name, w.destRoot)
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			createDisposition = safefile.FILE_CREATE
+		}
+
+		f, err := safefile.OpenRelative(
+			name,
+			w.destRoot,
+			syscall.GENERIC_READ|syscall.GENERIC_WRITE|winio.WRITE_DAC|winio.WRITE_OWNER|winio.ACCESS_SYSTEM_SECURITY,
+			syscall.FILE_SHARE_READ,
+			createDisposition,
+			safefile.FILE_OPEN_REPARSE_POINT,
+		)
+		if err != nil {
+			return err
+		}
+		defer func() {
+			if f != nil {
+				f.Close()
+				safefile.RemoveRelative(name, w.destRoot)
+			}
+		}()
+
+		err = winio.SetFileBasicInfo(f, fileInfo)
+		if err != nil {
+			return err
+		}
+
+		w.backupWriter = winio.NewBackupFileWriter(f, true)
+		w.bufWriter.Reset(w.backupWriter)
+		w.currentFile = f
+		w.currentFileName = name
+		w.currentFileRoot = w.destRoot
+		w.addedFiles[name] = true
+		f = nil
+		return nil
+	}
+
+	fname := name
+	if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 {
+		err := safefile.MkdirRelative(name, w.root)
+		if err != nil {
+			return err
+		}
+		fname += ".$wcidirs$"
+		w.currentIsDir = true
+	}
+
+	f, err := safefile.OpenRelative(fname, w.root, syscall.GENERIC_READ|syscall.GENERIC_WRITE, syscall.FILE_SHARE_READ, safefile.FILE_CREATE, 0)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if f != nil {
+			f.Close()
+			safefile.RemoveRelative(fname, w.root)
+		}
+	}()
+
+	strippedFi := *fileInfo
+	strippedFi.FileAttributes = 0
+	err = winio.SetFileBasicInfo(f, &strippedFi)
+	if err != nil {
+		return err
+	}
+
+	if hasPathPrefix(name, hivesPath) {
+		w.backupWriter = winio.NewBackupFileWriter(f, false)
+		w.bufWriter.Reset(w.backupWriter)
+	} else {
+		w.bufWriter.Reset(f)
+		// The file attributes are written before the stream.
+		err = binary.Write(w.bufWriter, binary.LittleEndian, uint32(fileInfo.FileAttributes))
+		if err != nil {
+			w.bufWriter.Reset(ioutil.Discard)
+			return err
+		}
+	}
+
+	w.currentFile = f
+	w.currentFileName = name
+	w.currentFileRoot = w.root
+	w.addedFiles[name] = true
+	f = nil
+	return nil
+}
+
+func (w *legacyLayerWriter) AddLink(name string, target string) error {
+	if err := w.reset(); err != nil {
+		return err
+	}
+
+	target = filepath.Clean(target)
+	var roots []*os.File
+	if hasPathPrefix(target, filesPath) {
+		// Look for cross-layer hard link targets in the parent layers, since
+		// nothing is in the destination path yet.
+		roots = w.parentRoots
+	} else if hasPathPrefix(target, utilityVMFilesPath) {
+		// Since the utility VM is fully cloned into the destination path
+		// already, look for cross-layer hard link targets directly in the
+		// destination path.
+		roots = []*os.File{w.destRoot}
+	}
+
+	if roots == nil || (!hasPathPrefix(name, filesPath) && !hasPathPrefix(name, utilityVMFilesPath)) {
+		return errors.New("invalid hard link in layer")
+	}
+
+	// Find to try the target of the link in a previously added file. If that
+	// fails, search in parent layers.
+	var selectedRoot *os.File
+	if _, ok := w.addedFiles[target]; ok {
+		selectedRoot = w.destRoot
+	} else {
+		for _, r := range roots {
+			if _, err := safefile.LstatRelative(target, r); err != nil {
+				if !os.IsNotExist(err) {
+					return err
+				}
+			} else {
+				selectedRoot = r
+				break
+			}
+		}
+		if selectedRoot == nil {
+			return fmt.Errorf("failed to find link target for '%s' -> '%s'", name, target)
+		}
+	}
+
+	// The link can't be written until after the ImportLayer call.
+	w.PendingLinks = append(w.PendingLinks, pendingLink{
+		Path:       name,
+		Target:     target,
+		TargetRoot: selectedRoot,
+	})
+	w.addedFiles[name] = true
+	return nil
+}
+
+func (w *legacyLayerWriter) Remove(name string) error {
+	name = filepath.Clean(name)
+	if hasPathPrefix(name, filesPath) {
+		w.Tombstones = append(w.Tombstones, name)
+	} else if hasPathPrefix(name, utilityVMFilesPath) {
+		err := w.initUtilityVM()
+		if err != nil {
+			return err
+		}
+		// Make sure the path exists; os.RemoveAll will not fail if the file is
+		// already gone, and this needs to be a fatal error for diagnostics
+		// purposes.
+		if _, err := safefile.LstatRelative(name, w.destRoot); err != nil {
+			return err
+		}
+		err = safefile.RemoveAllRelative(name, w.destRoot)
+		if err != nil {
+			return err
+		}
+	} else {
+		return fmt.Errorf("invalid tombstone %s", name)
+	}
+
+	return nil
+}
+
+func (w *legacyLayerWriter) Write(b []byte) (int, error) {
+	if w.backupWriter == nil && w.currentFile == nil {
+		return 0, errors.New("closed")
+	}
+	return w.bufWriter.Write(b)
+}
+
+func (w *legacyLayerWriter) Close() error {
+	if err := w.reset(); err != nil {
+		return err
+	}
+	if err := safefile.RemoveRelative("tombstones.txt", w.root); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	for _, pd := range w.pendingDirs {
+		err := safefile.MkdirRelative(pd.Path, pd.Root)
+		if err != nil {
+			return err
+		}
+	}
+	if w.HasUtilityVM {
+		err := reapplyDirectoryTimes(w.destRoot, w.uvmDi)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/nametoguid.go

@@ -0,0 +1,34 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/go-winio/pkg/guid"
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// NameToGuid converts the given string into a GUID using the algorithm in the
+// Host Compute Service, ensuring GUIDs generated with the same string are common
+// across all clients.
+func NameToGuid(name string) (id guid.GUID, err error) {
+	title := "hcsshim::NameToGuid"
+	fields := logrus.Fields{
+		"name": name,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = nameToGuid(name, &id)
+	if err != nil {
+		err = hcserror.New(err, title+" - failed", "")
+		return
+	}
+	fields["guid"] = id.String()
+	return
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/preparelayer.go

@@ -0,0 +1,47 @@
+package wclayer
+
+import (
+	"sync"
+
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+var prepareLayerLock sync.Mutex
+
+// PrepareLayer finds a mounted read-write layer matching path and enables the
+// the filesystem filter for use on that layer.  This requires the paths to all
+// parent layers, and is necessary in order to view or interact with the layer
+// as an actual filesystem (reading and writing files, creating directories, etc).
+// Disabling the filter must be done via UnprepareLayer.
+func PrepareLayer(path string, parentLayerPaths []string) (err error) {
+	title := "hcsshim::PrepareLayer"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	// Generate layer descriptors
+	layers, err := layerPathsToDescriptors(parentLayerPaths)
+	if err != nil {
+		return err
+	}
+
+	// This lock is a temporary workaround for a Windows bug. Only allowing one
+	// call to prepareLayer at a time vastly reduces the chance of a timeout.
+	prepareLayerLock.Lock()
+	defer prepareLayerLock.Unlock()
+	err = prepareLayer(&stdDriverInfo, path, layers)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/processimage.go

@@ -0,0 +1,23 @@
+package wclayer
+
+import "os"
+
+// ProcessBaseLayer post-processes a base layer that has had its files extracted.
+// The files should have been extracted to <path>\Files.
+func ProcessBaseLayer(path string) error {
+	err := processBaseImage(path)
+	if err != nil {
+		return &os.PathError{Op: "ProcessBaseLayer", Path: path, Err: err}
+	}
+	return nil
+}
+
+// ProcessUtilityVMImage post-processes a utility VM image that has had its files extracted.
+// The files should have been extracted to <path>\Files.
+func ProcessUtilityVMImage(path string) error {
+	err := processUtilityImage(path)
+	if err != nil {
+		return &os.PathError{Op: "ProcessUtilityVMImage", Path: path, Err: err}
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/unpreparelayer.go

@@ -0,0 +1,30 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// UnprepareLayer disables the filesystem filter for the read-write layer with
+// the given id.
+func UnprepareLayer(path string) (err error) {
+	title := "hcsshim::UnprepareLayer"
+	fields := logrus.Fields{
+		"path": path,
+	}
+	logrus.WithFields(fields).Debug(title)
+	defer func() {
+		if err != nil {
+			fields[logrus.ErrorKey] = err
+			logrus.WithFields(fields).Error(err)
+		} else {
+			logrus.WithFields(fields).Debug(title + " - succeeded")
+		}
+	}()
+
+	err = unprepareLayer(&stdDriverInfo, path)
+	if err != nil {
+		return hcserror.New(err, title+" - failed", "")
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/wclayer/wclayer.go

@@ -0,0 +1,27 @@
+package wclayer
+
+import "github.com/Microsoft/go-winio/pkg/guid"
+
+//go:generate go run ../../mksyscall_windows.go -output zsyscall_windows.go wclayer.go
+
+//sys activateLayer(info *driverInfo, id string) (hr error) = vmcompute.ActivateLayer?
+//sys copyLayer(info *driverInfo, srcId string, dstId string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) = vmcompute.CopyLayer?
+//sys createLayer(info *driverInfo, id string, parent string) (hr error) = vmcompute.CreateLayer?
+//sys createSandboxLayer(info *driverInfo, id string, parent uintptr, descriptors []WC_LAYER_DESCRIPTOR) (hr error) = vmcompute.CreateSandboxLayer?
+//sys expandSandboxSize(info *driverInfo, id string, size uint64) (hr error) = vmcompute.ExpandSandboxSize?
+//sys deactivateLayer(info *driverInfo, id string) (hr error) = vmcompute.DeactivateLayer?
+//sys destroyLayer(info *driverInfo, id string) (hr error) = vmcompute.DestroyLayer?
+//sys exportLayer(info *driverInfo, id string, path string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) = vmcompute.ExportLayer?
+//sys getLayerMountPath(info *driverInfo, id string, length *uintptr, buffer *uint16) (hr error) = vmcompute.GetLayerMountPath?
+//sys getBaseImages(buffer **uint16) (hr error) = vmcompute.GetBaseImages?
+//sys importLayer(info *driverInfo, id string, path string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) = vmcompute.ImportLayer?
+//sys layerExists(info *driverInfo, id string, exists *uint32) (hr error) = vmcompute.LayerExists?
+//sys nameToGuid(name string, guid *_guid) (hr error) = vmcompute.NameToGuid?
+//sys prepareLayer(info *driverInfo, id string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) = vmcompute.PrepareLayer?
+//sys unprepareLayer(info *driverInfo, id string) (hr error) = vmcompute.UnprepareLayer?
+//sys processBaseImage(path string) (hr error) = vmcompute.ProcessBaseImage?
+//sys processUtilityImage(path string) (hr error) = vmcompute.ProcessUtilityImage?
+
+//sys grantVmAccess(vmid string, filepath string) (hr error) = vmcompute.GrantVmAccess?
+
+type _guid = guid.GUID

vendor/github.com/Microsoft/hcsshim/internal/wclayer/zsyscall_windows.go

@@ -0,0 +1,510 @@
+// Code generated mksyscall_windows.exe DO NOT EDIT
+
+package wclayer
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return nil
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modvmcompute = windows.NewLazySystemDLL("vmcompute.dll")
+
+	procActivateLayer       = modvmcompute.NewProc("ActivateLayer")
+	procCopyLayer           = modvmcompute.NewProc("CopyLayer")
+	procCreateLayer         = modvmcompute.NewProc("CreateLayer")
+	procCreateSandboxLayer  = modvmcompute.NewProc("CreateSandboxLayer")
+	procExpandSandboxSize   = modvmcompute.NewProc("ExpandSandboxSize")
+	procDeactivateLayer     = modvmcompute.NewProc("DeactivateLayer")
+	procDestroyLayer        = modvmcompute.NewProc("DestroyLayer")
+	procExportLayer         = modvmcompute.NewProc("ExportLayer")
+	procGetLayerMountPath   = modvmcompute.NewProc("GetLayerMountPath")
+	procGetBaseImages       = modvmcompute.NewProc("GetBaseImages")
+	procImportLayer         = modvmcompute.NewProc("ImportLayer")
+	procLayerExists         = modvmcompute.NewProc("LayerExists")
+	procNameToGuid          = modvmcompute.NewProc("NameToGuid")
+	procPrepareLayer        = modvmcompute.NewProc("PrepareLayer")
+	procUnprepareLayer      = modvmcompute.NewProc("UnprepareLayer")
+	procProcessBaseImage    = modvmcompute.NewProc("ProcessBaseImage")
+	procProcessUtilityImage = modvmcompute.NewProc("ProcessUtilityImage")
+	procGrantVmAccess       = modvmcompute.NewProc("GrantVmAccess")
+)
+
+func activateLayer(info *driverInfo, id string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _activateLayer(info, _p0)
+}
+
+func _activateLayer(info *driverInfo, id *uint16) (hr error) {
+	if hr = procActivateLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procActivateLayer.Addr(), 2, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func copyLayer(info *driverInfo, srcId string, dstId string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(srcId)
+	if hr != nil {
+		return
+	}
+	var _p1 *uint16
+	_p1, hr = syscall.UTF16PtrFromString(dstId)
+	if hr != nil {
+		return
+	}
+	return _copyLayer(info, _p0, _p1, descriptors)
+}
+
+func _copyLayer(info *driverInfo, srcId *uint16, dstId *uint16, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p2 *WC_LAYER_DESCRIPTOR
+	if len(descriptors) > 0 {
+		_p2 = &descriptors[0]
+	}
+	if hr = procCopyLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall6(procCopyLayer.Addr(), 5, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(srcId)), uintptr(unsafe.Pointer(dstId)), uintptr(unsafe.Pointer(_p2)), uintptr(len(descriptors)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func createLayer(info *driverInfo, id string, parent string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	var _p1 *uint16
+	_p1, hr = syscall.UTF16PtrFromString(parent)
+	if hr != nil {
+		return
+	}
+	return _createLayer(info, _p0, _p1)
+}
+
+func _createLayer(info *driverInfo, id *uint16, parent *uint16) (hr error) {
+	if hr = procCreateLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procCreateLayer.Addr(), 3, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(unsafe.Pointer(parent)))
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func createSandboxLayer(info *driverInfo, id string, parent uintptr, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _createSandboxLayer(info, _p0, parent, descriptors)
+}
+
+func _createSandboxLayer(info *driverInfo, id *uint16, parent uintptr, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p1 *WC_LAYER_DESCRIPTOR
+	if len(descriptors) > 0 {
+		_p1 = &descriptors[0]
+	}
+	if hr = procCreateSandboxLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall6(procCreateSandboxLayer.Addr(), 5, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(parent), uintptr(unsafe.Pointer(_p1)), uintptr(len(descriptors)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func expandSandboxSize(info *driverInfo, id string, size uint64) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _expandSandboxSize(info, _p0, size)
+}
+
+func _expandSandboxSize(info *driverInfo, id *uint16, size uint64) (hr error) {
+	if hr = procExpandSandboxSize.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procExpandSandboxSize.Addr(), 3, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(size))
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func deactivateLayer(info *driverInfo, id string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _deactivateLayer(info, _p0)
+}
+
+func _deactivateLayer(info *driverInfo, id *uint16) (hr error) {
+	if hr = procDeactivateLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procDeactivateLayer.Addr(), 2, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func destroyLayer(info *driverInfo, id string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _destroyLayer(info, _p0)
+}
+
+func _destroyLayer(info *driverInfo, id *uint16) (hr error) {
+	if hr = procDestroyLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procDestroyLayer.Addr(), 2, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func exportLayer(info *driverInfo, id string, path string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	var _p1 *uint16
+	_p1, hr = syscall.UTF16PtrFromString(path)
+	if hr != nil {
+		return
+	}
+	return _exportLayer(info, _p0, _p1, descriptors)
+}
+
+func _exportLayer(info *driverInfo, id *uint16, path *uint16, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p2 *WC_LAYER_DESCRIPTOR
+	if len(descriptors) > 0 {
+		_p2 = &descriptors[0]
+	}
+	if hr = procExportLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall6(procExportLayer.Addr(), 5, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(_p2)), uintptr(len(descriptors)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func getLayerMountPath(info *driverInfo, id string, length *uintptr, buffer *uint16) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _getLayerMountPath(info, _p0, length, buffer)
+}
+
+func _getLayerMountPath(info *driverInfo, id *uint16, length *uintptr, buffer *uint16) (hr error) {
+	if hr = procGetLayerMountPath.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall6(procGetLayerMountPath.Addr(), 4, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(unsafe.Pointer(length)), uintptr(unsafe.Pointer(buffer)), 0, 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func getBaseImages(buffer **uint16) (hr error) {
+	if hr = procGetBaseImages.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procGetBaseImages.Addr(), 1, uintptr(unsafe.Pointer(buffer)), 0, 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func importLayer(info *driverInfo, id string, path string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	var _p1 *uint16
+	_p1, hr = syscall.UTF16PtrFromString(path)
+	if hr != nil {
+		return
+	}
+	return _importLayer(info, _p0, _p1, descriptors)
+}
+
+func _importLayer(info *driverInfo, id *uint16, path *uint16, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p2 *WC_LAYER_DESCRIPTOR
+	if len(descriptors) > 0 {
+		_p2 = &descriptors[0]
+	}
+	if hr = procImportLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall6(procImportLayer.Addr(), 5, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(_p2)), uintptr(len(descriptors)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func layerExists(info *driverInfo, id string, exists *uint32) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _layerExists(info, _p0, exists)
+}
+
+func _layerExists(info *driverInfo, id *uint16, exists *uint32) (hr error) {
+	if hr = procLayerExists.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procLayerExists.Addr(), 3, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(unsafe.Pointer(exists)))
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func nameToGuid(name string, guid *_guid) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(name)
+	if hr != nil {
+		return
+	}
+	return _nameToGuid(_p0, guid)
+}
+
+func _nameToGuid(name *uint16, guid *_guid) (hr error) {
+	if hr = procNameToGuid.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procNameToGuid.Addr(), 2, uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(guid)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func prepareLayer(info *driverInfo, id string, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _prepareLayer(info, _p0, descriptors)
+}
+
+func _prepareLayer(info *driverInfo, id *uint16, descriptors []WC_LAYER_DESCRIPTOR) (hr error) {
+	var _p1 *WC_LAYER_DESCRIPTOR
+	if len(descriptors) > 0 {
+		_p1 = &descriptors[0]
+	}
+	if hr = procPrepareLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall6(procPrepareLayer.Addr(), 4, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), uintptr(unsafe.Pointer(_p1)), uintptr(len(descriptors)), 0, 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func unprepareLayer(info *driverInfo, id string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(id)
+	if hr != nil {
+		return
+	}
+	return _unprepareLayer(info, _p0)
+}
+
+func _unprepareLayer(info *driverInfo, id *uint16) (hr error) {
+	if hr = procUnprepareLayer.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procUnprepareLayer.Addr(), 2, uintptr(unsafe.Pointer(info)), uintptr(unsafe.Pointer(id)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func processBaseImage(path string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(path)
+	if hr != nil {
+		return
+	}
+	return _processBaseImage(_p0)
+}
+
+func _processBaseImage(path *uint16) (hr error) {
+	if hr = procProcessBaseImage.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procProcessBaseImage.Addr(), 1, uintptr(unsafe.Pointer(path)), 0, 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func processUtilityImage(path string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(path)
+	if hr != nil {
+		return
+	}
+	return _processUtilityImage(_p0)
+}
+
+func _processUtilityImage(path *uint16) (hr error) {
+	if hr = procProcessUtilityImage.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procProcessUtilityImage.Addr(), 1, uintptr(unsafe.Pointer(path)), 0, 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}
+
+func grantVmAccess(vmid string, filepath string) (hr error) {
+	var _p0 *uint16
+	_p0, hr = syscall.UTF16PtrFromString(vmid)
+	if hr != nil {
+		return
+	}
+	var _p1 *uint16
+	_p1, hr = syscall.UTF16PtrFromString(filepath)
+	if hr != nil {
+		return
+	}
+	return _grantVmAccess(_p0, _p1)
+}
+
+func _grantVmAccess(vmid *uint16, filepath *uint16) (hr error) {
+	if hr = procGrantVmAccess.Find(); hr != nil {
+		return
+	}
+	r0, _, _ := syscall.Syscall(procGrantVmAccess.Addr(), 2, uintptr(unsafe.Pointer(vmid)), uintptr(unsafe.Pointer(filepath)), 0)
+	if int32(r0) < 0 {
+		if r0&0x1fff0000 == 0x00070000 {
+			r0 &= 0xffff
+		}
+		hr = syscall.Errno(r0)
+	}
+	return
+}