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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/Microsoft/hcsshim/legacy.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/Microsoft/hcsshim/legacy.go')
-rw-r--r-- | vendor/github.com/Microsoft/hcsshim/legacy.go | 741 |
1 files changed, 741 insertions, 0 deletions
diff --git a/vendor/github.com/Microsoft/hcsshim/legacy.go b/vendor/github.com/Microsoft/hcsshim/legacy.go new file mode 100644 index 000000000..c7f6073ac --- /dev/null +++ b/vendor/github.com/Microsoft/hcsshim/legacy.go @@ -0,0 +1,741 @@ +package hcsshim + +import ( + "bufio" + "encoding/binary" + "errors" + "fmt" + "io" + "os" + "path/filepath" + "strings" + "syscall" + + "github.com/Microsoft/go-winio" +) + +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 makeLongAbsPath(path string) (string, error) { + if strings.HasPrefix(path, `\\?\`) || strings.HasPrefix(path, `\\.\`) { + return path, nil + } + if !filepath.IsAbs(path) { + absPath, err := filepath.Abs(path) + if err != nil { + return "", err + } + path = absPath + } + if strings.HasPrefix(path, `\\`) { + return `\\?\UNC\` + path[2:], nil + } + return `\\?\` + path, nil +} + +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 := makeLongAbsPath(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 + } + 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 = uintptr(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 +} + +type legacyLayerWriter struct { + root string + parentRoots []string + destRoot string + currentFile *os.File + backupWriter *winio.BackupFileWriter + tombstones []string + pathFixed bool + HasUtilityVM bool + uvmDi []dirInfo + addedFiles map[string]bool + PendingLinks []pendingLink +} + +// newLegacyLayerWriter returns a LayerWriter that can write the contaler layer +// transport format to disk. +func newLegacyLayerWriter(root string, parentRoots []string, destRoot string) *legacyLayerWriter { + return &legacyLayerWriter{ + root: root, + parentRoots: parentRoots, + destRoot: destRoot, + addedFiles: make(map[string]bool), + } +} + +func (w *legacyLayerWriter) init() error { + if !w.pathFixed { + path, err := makeLongAbsPath(w.root) + if err != nil { + return err + } + for i, p := range w.parentRoots { + w.parentRoots[i], err = makeLongAbsPath(p) + if err != nil { + return err + } + } + destPath, err := makeLongAbsPath(w.destRoot) + if err != nil { + return err + } + w.root = path + w.destRoot = destPath + w.pathFixed = true + } + return nil +} + +func (w *legacyLayerWriter) initUtilityVM() error { + if !w.HasUtilityVM { + err := os.Mkdir(filepath.Join(w.destRoot, utilityVMPath), 0) + 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(filepath.Join(w.parentRoots[0], utilityVMFilesPath), filepath.Join(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() { + if w.backupWriter != nil { + w.backupWriter.Close() + w.backupWriter = nil + } + if w.currentFile != nil { + w.currentFile.Close() + w.currentFile = nil + } +} + +// copyFileWithMetadata copies a file using the backup/restore APIs in order to preserve metadata +func copyFileWithMetadata(srcPath, destPath string, isDir bool) (fileInfo *winio.FileBasicInfo, err error) { + createDisposition := uint32(syscall.CREATE_NEW) + if isDir { + err = os.Mkdir(destPath, 0) + if err != nil { + return nil, err + } + createDisposition = syscall.OPEN_EXISTING + } + + src, err := openFileOrDir(srcPath, syscall.GENERIC_READ|winio.ACCESS_SYSTEM_SECURITY, syscall.OPEN_EXISTING) + 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 + } + + dest, err := openFileOrDir(destPath, syscall.GENERIC_READ|syscall.GENERIC_WRITE|winio.WRITE_DAC|winio.WRITE_OWNER|winio.ACCESS_SYSTEM_SECURITY, createDisposition) + 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(srcPath, destPath string, mutatedFiles map[string]bool) error { + var di []dirInfo + err := filepath.Walk(srcPath, func(srcFilePath string, info os.FileInfo, err error) error { + if err != nil { + return err + } + + relPath, err := filepath.Rel(srcPath, srcFilePath) + if err != nil { + return err + } + destFilePath := filepath.Join(destPath, relPath) + + // Directories, reparse points, and files that will be mutated during + // utility VM import must be copied. All other files can be hard linked. + isReparsePoint := info.Sys().(*syscall.Win32FileAttributeData).FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT != 0 + if info.IsDir() || isReparsePoint || mutatedFiles[relPath] { + fi, err := copyFileWithMetadata(srcFilePath, destFilePath, info.IsDir()) + if err != nil { + return err + } + if info.IsDir() && !isReparsePoint { + di = append(di, dirInfo{path: destFilePath, fileInfo: *fi}) + } + } else { + err = os.Link(srcFilePath, destFilePath) + if err != nil { + return err + } + } + + // Don't recurse on reparse points. + if info.IsDir() && isReparsePoint { + return filepath.SkipDir + } + + return nil + }) + if err != nil { + return err + } + + return reapplyDirectoryTimes(di) +} + +func (w *legacyLayerWriter) Add(name string, fileInfo *winio.FileBasicInfo) error { + w.reset() + err := w.init() + if err != nil { + return err + } + + if name == utilityVMPath { + return w.initUtilityVM() + } + + 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") + } + path := filepath.Join(w.destRoot, name) + createDisposition := uint32(syscall.OPEN_EXISTING) + if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 { + st, err := os.Lstat(path) + 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 = os.RemoveAll(path); err != nil { + return err + } + st = nil + } + } + if st == nil { + if err = os.Mkdir(path, 0); err != nil { + return err + } + } + if fileInfo.FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT == 0 { + w.uvmDi = append(w.uvmDi, dirInfo{path: path, fileInfo: *fileInfo}) + } + } else { + // Overwrite any existing hard link. + err = os.Remove(path) + if err != nil && !os.IsNotExist(err) { + return err + } + createDisposition = syscall.CREATE_NEW + } + + f, err := openFileOrDir(path, syscall.GENERIC_READ|syscall.GENERIC_WRITE|winio.WRITE_DAC|winio.WRITE_OWNER|winio.ACCESS_SYSTEM_SECURITY, createDisposition) + if err != nil { + return err + } + defer func() { + if f != nil { + f.Close() + os.Remove(path) + } + }() + + err = winio.SetFileBasicInfo(f, fileInfo) + if err != nil { + return err + } + + w.backupWriter = winio.NewBackupFileWriter(f, true) + w.currentFile = f + w.addedFiles[name] = true + f = nil + return nil + } + + path := filepath.Join(w.root, name) + if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 { + err := os.Mkdir(path, 0) + if err != nil { + return err + } + path += ".$wcidirs$" + } + + f, err := openFileOrDir(path, syscall.GENERIC_READ|syscall.GENERIC_WRITE, syscall.CREATE_NEW) + if err != nil { + return err + } + defer func() { + if f != nil { + f.Close() + os.Remove(path) + } + }() + + 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) + } else { + // The file attributes are written before the stream. + err = binary.Write(f, binary.LittleEndian, uint32(fileInfo.FileAttributes)) + if err != nil { + return err + } + } + + w.currentFile = f + w.addedFiles[name] = true + f = nil + return nil +} + +func (w *legacyLayerWriter) AddLink(name string, target string) error { + w.reset() + err := w.init() + if err != nil { + return err + } + + var roots []string + 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 = []string{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 string + if _, ok := w.addedFiles[target]; ok { + selectedRoot = w.destRoot + } else { + for _, r := range roots { + if _, err = os.Lstat(filepath.Join(r, target)); err != nil { + if !os.IsNotExist(err) { + return err + } + } else { + selectedRoot = r + break + } + } + if selectedRoot == "" { + 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: filepath.Join(w.destRoot, name), + Target: filepath.Join(selectedRoot, target), + }) + w.addedFiles[name] = true + return nil +} + +func (w *legacyLayerWriter) Remove(name string) error { + if hasPathPrefix(name, filesPath) { + w.tombstones = append(w.tombstones, name[len(filesPath)+1:]) + } 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. + path := filepath.Join(w.destRoot, name) + if _, err := os.Lstat(path); err != nil { + return err + } + err = os.RemoveAll(path) + 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 { + if w.currentFile == nil { + return 0, errors.New("closed") + } + return w.currentFile.Write(b) + } + return w.backupWriter.Write(b) +} + +func (w *legacyLayerWriter) Close() error { + w.reset() + err := w.init() + if err != nil { + return err + } + tf, err := os.Create(filepath.Join(w.root, "tombstones.txt")) + if err != nil { + return err + } + defer tf.Close() + _, err = tf.Write([]byte("\xef\xbb\xbfVersion 1.0\n")) + if err != nil { + return err + } + for _, t := range w.tombstones { + _, err = tf.Write([]byte(filepath.Join(`\`, t) + "\n")) + if err != nil { + return err + } + } + if w.HasUtilityVM { + err = reapplyDirectoryTimes(w.uvmDi) + if err != nil { + return err + } + } + return nil +} |