gofmt some files

Also, don't attempt xattr ops on special files on the BSD likes.

TODO: Should have a way to allow restore without special files,
otherwise very cumbersome for a regular user.

src/duplicacy_backupmanager.go

@@ -187,7 +187,7 @@ func (manager *BackupManager) Backup(top string, quickMode bool, threads int, ta
 
 	// If the listing operation is fast and this is an initial backup, list all chunks and
 	// put them in the cache.
-	if (manager.storage.IsFastListing() && remoteSnapshot.Revision == 0) {
+	if manager.storage.IsFastListing() && remoteSnapshot.Revision == 0 {
 		LOG_INFO("BACKUP_LIST", "Listing all chunks")
 		allChunks, _ := manager.SnapshotManager.ListAllFiles(manager.storage, "chunks/")
 
@@ -705,11 +705,34 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 
 	type hardLinkEntry struct {
 		entry     *Entry
-		willDownload bool
+		willExist bool
 	}
 	var hardLinkTable []hardLinkEntry
 	var hardLinks []*Entry
 
+	restoreHardlink := func(entry *Entry, fullPath string) bool {
+		if entry.IsHardlinkRoot() {
+			hardLinkTable[len(hardLinkTable)-1].willExist = true
+		} else if entry.IsHardlinkedFrom() {
+			i, err := entry.GetHardlinkId()
+			if err != nil {
+				LOG_ERROR("RESTORE_HARDLINK", "Decode error for hardlinked entry %s, %v", entry.Path, err)
+				return false
+			}
+			if !hardLinkTable[i].willExist {
+				hardLinkTable[i] = hardLinkEntry{entry, true}
+			} else {
+				sourcePath := joinPath(top, hardLinkTable[i].entry.Path)
+				LOG_INFO("RESTORE_HARDLINK", "Hard linking %s to %s", fullPath, sourcePath)
+				if err := MakeHardlink(sourcePath, fullPath); err != nil {
+					LOG_ERROR("RESTORE_HARDLINK", "Failed to create hard link %s to %s %v", fullPath, sourcePath, err)
+				}
+				return true
+			}
+		}
+		return false
+	}
+
 	for remoteEntry := range remoteListingChannel {
 
 		if remoteEntry.IsHardlinkRoot() {
@@ -752,26 +775,39 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 		}
 
 		fullPath := joinPath(top, remoteEntry.Path)
+
 		if remoteEntry.IsLink() {
-			stat, err := os.Lstat(fullPath)
-			if stat != nil {
+			if stat, _ := os.Lstat(fullPath); stat != nil {
 				if stat.Mode()&os.ModeSymlink != 0 {
 					isRegular, link, err := Readlink(fullPath)
 					if err == nil && link == remoteEntry.Link && !isRegular {
 						remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
+						if remoteEntry.IsHardlinkRoot() {
+							hardLinkTable[len(hardLinkTable)-1].willExist = true
+						}
 						continue
 					}
 				}
 
+				if !overwrite {
+					LOG_WERROR(allowFailures, "DOWNLOAD_OVERWRITE",
+						"File %s already exists.  Please specify the -overwrite option to overwrite", remoteEntry.Path)
+					continue
+				}
+
 				os.Remove(fullPath)
 			}
 
-			err = os.Symlink(remoteEntry.Link, fullPath)
-			if err != nil {
+			if restoreHardlink(remoteEntry, fullPath) {
+				continue
+			}
+
+			if err := os.Symlink(remoteEntry.Link, fullPath); err != nil {
 				LOG_ERROR("RESTORE_SYMLINK", "Can't create symlink %s: %v", remoteEntry.Path, err)
 				return 0
 			}
 			remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
+
 			LOG_TRACE("DOWNLOAD_DONE", "Symlink %s updated", remoteEntry.Path)
 		} else if remoteEntry.IsDir() {
 
@@ -793,22 +829,48 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 			}
 			remoteEntry.RestoreEarlyDirFlags(fullPath)
 			directoryEntries = append(directoryEntries, remoteEntry)
-		} else {
+		} else if remoteEntry.IsSpecial() {
+			if stat, _ := os.Lstat(fullPath); stat != nil {
+				if remoteEntry.IsSameSpecial(stat) {
+					remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
 					if remoteEntry.IsHardlinkRoot() {
-				hardLinkTable[len(hardLinkTable)-1] = hardLinkEntry{remoteEntry, true}
-			} else if remoteEntry.IsHardlinkedFrom() {
-				i, err := strconv.ParseUint(remoteEntry.Link, 16, 64)
-				if err !=  nil {
-					LOG_ERROR("RESTORE_HARDLINK", "Decode error in hardlink entry, expected hex int, got %s", remoteEntry.Link)
+						hardLinkTable[len(hardLinkTable)-1].willExist = true
+					}
+				}
+				if !overwrite {
+					LOG_WERROR(allowFailures, "DOWNLOAD_OVERWRITE",
+						"File %s already exists.  Please specify the -overwrite option to overwrite", remoteEntry.Path)
+					continue
+				}
+				os.Remove(fullPath)
+			}
+
+			if restoreHardlink(remoteEntry, fullPath) {
+				continue
+			}
+
+			if err := remoteEntry.RestoreSpecial(fullPath); err != nil {
+				LOG_ERROR("RESTORE_SPECIAL", "Unable to restore special file %s: %v", remoteEntry.Path, err)
 				return 0
 			}
-				if !hardLinkTable[i].willDownload {
+			remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
+		} else {
+			if remoteEntry.IsHardlinkRoot() {
+				hardLinkTable[len(hardLinkTable)-1].willExist = true
+			} else if remoteEntry.IsHardlinkedFrom() {
+				i, err := remoteEntry.GetHardlinkId()
+				if err != nil {
+					LOG_ERROR("RESTORE_HARDLINK", "Decode error for hardlinked entry %s, %v", remoteEntry.Path, err)
+					return 0
+				}
+				if !hardLinkTable[i].willExist {
 					hardLinkTable[i] = hardLinkEntry{remoteEntry, true}
 				} else {
 					hardLinks = append(hardLinks, remoteEntry)
 					continue
 				}
 			}
+
 			// We can't download files here since fileEntries needs to be sorted
 			fileEntries = append(fileEntries, remoteEntry)
 			totalFileSize += remoteEntry.Size
@@ -929,11 +991,32 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 	}
 
 	for _, linkEntry := range hardLinks {
-		i, _ := strconv.ParseUint(linkEntry.Link, 16, 64)
+
+		i, _ := linkEntry.GetHardlinkId()
 		sourcePath := joinPath(top, hardLinkTable[i].entry.Path)
 		fullPath := joinPath(top, linkEntry.Path)
-		LOG_INFO("RESTORE_HARDLINK", "Hard linking %s to %s", fullPath, sourcePath)
-		if err := os.Link(sourcePath, fullPath); err != nil {
+
+		if stat, _ := os.Lstat(fullPath); stat != nil {
+			sourceStat, _ := os.Lstat(sourcePath)
+			if os.SameFile(stat, sourceStat) {
+				continue
+			}
+
+			if sourceStat == nil {
+				LOG_WERROR(allowFailures, "RESTORE_HARDLINK",
+					"Target %s for hardlink %s is missing", sourcePath, linkEntry.Path)
+				continue
+			}
+			if !overwrite {
+				LOG_WERROR(allowFailures, "DOWNLOAD_OVERWRITE",
+					"File %s already exists.  Please specify the -overwrite option to overwrite", linkEntry.Path)
+				continue
+			}
+			os.Remove(fullPath)
+		}
+
+		LOG_DEBUG("RESTORE_HARDLINK", "Hard linking %s to %s", fullPath, sourcePath)
+		if err := MakeHardlink(sourcePath, fullPath); err != nil {
 			LOG_ERROR("RESTORE_HARDLINK", "Failed to create hard link %s to %s", fullPath, sourcePath)
 			return 0
 		}
@@ -1123,10 +1206,10 @@ func (manager *BackupManager) UploadSnapshot(chunkOperator *ChunkOperator, top s
 			entry.StartChunk -= lastEndChunk
 			lastEndChunk = entry.EndChunk
 			entry.EndChunk = delta
-		} else if entry.IsHardlinkedFrom() {
-			i, err := strconv.ParseUint(entry.Link, 16, 64)
+		} else if entry.IsHardlinkedFrom() && !entry.IsLink() {
+			i, err := entry.GetHardlinkId()
 			if err != nil {
-				LOG_ERROR("SNAPSHOT_UPLOAD", "Decode error in hardlink entry, expected hex int, got %s", entry.Link)
+				LOG_ERROR("SNAPSHOT_UPLOAD", "Decode error for hardlinked entry %s, %v", entry.Link, err)
 				return err
 			}
 
@@ -1215,6 +1298,7 @@ func (manager *BackupManager) UploadSnapshot(chunkOperator *ChunkOperator, top s
 // file under the .duplicacy directory and then replaces the existing one.  Otherwise, the existing file will be
 // overwritten directly.
 // Return: true, nil:    Restored file;
+//
 //	false, nil:   Skipped file;
 //	false, error: Failure to restore file (only if allowFailures == true)
 func (manager *BackupManager) RestoreFile(chunkDownloader *ChunkDownloader, chunkMaker *ChunkMaker, entry *Entry, top string, inPlace bool, overwrite bool,

src/duplicacy_entry.go

@@ -8,6 +8,7 @@ import (
 	"crypto/sha256"
 	"encoding/base64"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -23,6 +24,11 @@ import (
 	"github.com/vmihailenco/msgpack"
 )
 
+const (
+	entrySymHardLinkRootChunkMarker   = -72
+	entrySymHardLinkTargetChunkMarker = -73
+)
+
 // This is the hidden directory in the repository for storing various files.
 var DUPLICACY_DIRECTORY = ".duplicacy"
 var DUPLICACY_FILE = ".duplicacy"
@@ -509,16 +515,36 @@ func (entry *Entry) IsLink() bool {
 	return entry.Mode&uint32(os.ModeSymlink) != 0
 }
 
+func (entry *Entry) IsSpecial() bool {
+	return entry.Mode&uint32(os.ModeNamedPipe|os.ModeDevice|os.ModeCharDevice) != 0
+}
+
+func (entry *Entry) IsFileOrSpecial() bool {
+	return entry.Mode&uint32(os.ModeDir|os.ModeSymlink|os.ModeIrregular) == 0
+}
+
 func (entry *Entry) IsComplete() bool {
 	return entry.Size >= 0
 }
 
 func (entry *Entry) IsHardlinkedFrom() bool {
-	return entry.IsFile() && len(entry.Link) > 0 && entry.Link != "/"
+	return (entry.IsFileOrSpecial() && len(entry.Link) > 0 && entry.Link != "/") || (entry.IsLink() && entry.StartChunk == entrySymHardLinkTargetChunkMarker)
 }
 
 func (entry *Entry) IsHardlinkRoot() bool {
-	return entry.IsFile() && entry.Link == "/"
+	return (entry.IsFileOrSpecial() && entry.Link == "/") || (entry.IsLink() && entry.StartChunk == entrySymHardLinkRootChunkMarker)
+}
+
+func (entry *Entry) GetHardlinkId() (int, error) {
+	if entry.IsLink() {
+		if entry.StartChunk != entrySymHardLinkTargetChunkMarker {
+			return 0, errors.New("Symlink entry not marked as hardlinked")
+		}
+		return entry.StartOffset, nil
+	} else {
+		i, err := strconv.ParseUint(entry.Link, 16, 64)
+		return int(i), err
+	}
 }
 
 func (entry *Entry) GetPermissions() os.FileMode {
@@ -579,6 +605,10 @@ func (entry *Entry) RestoreMetadata(fullPath string, fileInfo *os.FileInfo, setO
 		}
 	}
 
+	if entry.Attributes != nil && len(*entry.Attributes) > 0 {
+		entry.SetAttributesToFile(fullPath)
+	}
+
 	// Only set the time if the file is not a symlink
 	if !entry.IsLink() && (*fileInfo).ModTime().Unix() != entry.Time {
 		modifiedTime := time.Unix(entry.Time, 0)
@@ -589,10 +619,6 @@ func (entry *Entry) RestoreMetadata(fullPath string, fileInfo *os.FileInfo, setO
 		}
 	}
 
-	if entry.Attributes != nil && len(*entry.Attributes) > 0 {
-		entry.SetAttributesToFile(fullPath)
-	}
-
 	return true
 }
 
@@ -781,10 +807,44 @@ func ListEntries(top string, path string, patterns []string, nobackupFile string
 		if f.Name() == DUPLICACY_DIRECTORY {
 			continue
 		}
+		if f.Mode()&os.ModeSocket != 0 {
+			continue
+		}
+
 		entry := CreateEntryFromFileInfo(f, normalizedPath)
 		if len(patterns) > 0 && !MatchPath(entry.Path, patterns) {
 			continue
 		}
+
+		var linkKey *listEntryLinkKey
+
+		if runtime.GOOS != "windows" && !entry.IsDir() {
+			if stat := f.Sys().(*syscall.Stat_t); stat != nil && stat.Nlink > 1 {
+				k := listEntryLinkKey{dev: uint64(stat.Dev), ino: uint64(stat.Ino)}
+				if linkIndex, seen := listingState.linkTable[k]; seen {
+					if linkIndex == -1 {
+						LOG_DEBUG("LIST_EXCLUDE", "%s is excluded by attribute (hardlink)", entry.Path)
+						continue
+					}
+					entry.Size = 0
+					if entry.IsLink() {
+						entry.StartChunk = entrySymHardLinkTargetChunkMarker
+						entry.StartOffset = linkIndex
+					} else {
+						entry.Link = strconv.FormatInt(int64(linkIndex), 16)
+					}
+				} else {
+					if entry.IsLink() {
+						entry.StartChunk = entrySymHardLinkRootChunkMarker
+					} else {
+						entry.Link = "/"
+					}
+					listingState.linkTable[k] = -1
+					linkKey = &k
+				}
+			}
+		}
+
 		if entry.IsLink() {
 			isRegular := false
 			isRegular, entry.Link, err = Readlink(joinPath(top, entry.Path))
@@ -815,30 +875,12 @@ func ListEntries(top string, path string, patterns []string, nobackupFile string
 				}
 				entry = newEntry
 			}
-		}
-
-		if f.Mode()&(os.ModeNamedPipe|os.ModeSocket|os.ModeDevice) != 0 {
-			LOG_WARN("LIST_SKIP", "Skipped non-regular file %s", entry.Path)
+		} else if entry.IsSpecial() {
+			if !entry.ReadSpecial(f) {
+				LOG_WARN("LIST_DEV", "Failed to save device node %s", entry.Path)
 				skippedFiles = append(skippedFiles, entry.Path)
 				continue
 			}
-
-		var linkKey *listEntryLinkKey
-
-		if stat, ok := f.Sys().(*syscall.Stat_t); entry.IsFile() && ok && stat != nil && stat.Nlink > 1 {
-			k := listEntryLinkKey{dev: uint64(stat.Dev), ino: uint64(stat.Ino)}
-			if linkIndex, seen := listingState.linkTable[k]; seen {
-				if linkIndex == -1 {
-					LOG_DEBUG("LIST_EXCLUDE", "%s is excluded by attribute (hardlink)", entry.Path)
-					continue
-				}
-				entry.Size = 0
-				entry.Link = strconv.FormatInt(int64(linkIndex), 16)
-			} else {
-				entry.Link = "/"
-				listingState.linkTable[k] = -1
-				linkKey = &k
-			}
 		}
 
 		entry.ReadAttributes(top)

src/duplicacy_entrylist.go

@@ -111,12 +111,12 @@ func (entryList *EntryList)createOnDiskFile() error {
 // Add an entry to the entry list
 func (entryList *EntryList)AddEntry(entry *Entry) error {
 
-	if !entry.IsDir() && !entry.IsLink() {
+	if entry.IsFile() {
 		entryList.NumberOfEntries++
 	}
 
 	if !entry.IsComplete() {
-		if entry.IsDir() || entry.IsLink() {
+		if !entry.IsFile() {
 			entry.Size = 0
 		} else {
 			modifiedEntry := ModifiedEntry {

src/duplicacy_utils.go

@@ -7,14 +7,15 @@ package duplicacy
 import (
 	"bufio"
 	"crypto/sha256"
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
 	"regexp"
+	"runtime"
 	"strconv"
 	"strings"
 	"time"
-	"runtime"
 
 	"github.com/gilbertchen/gopass"
 	"golang.org/x/crypto/pbkdf2"
@@ -275,7 +276,6 @@ func SavePassword(preference Preference, passwordType string, password string) {
 // The following code was modified from the online article  'Matching Wildcards: An Algorithm', by Kirk J. Krauss,
 // Dr. Dobb's, August 26, 2008. However, the version in the article doesn't handle cases like matching 'abcccd'
 // against '*ccd', and the version here fixed that issue.
-//
 func matchPattern(text string, pattern string) bool {
 
 	textLength := len(text)
@@ -474,3 +474,34 @@ func PrintMemoryUsage() {
 		time.Sleep(time.Second)
 	}
 }
+
+func (entry *Entry) dump() map[string]interface{} {
+
+	object := make(map[string]interface{})
+
+	object["path"] = entry.Path
+	object["size"] = entry.Size
+	object["time"] = entry.Time
+	object["mode"] = entry.Mode
+	object["hash"] = entry.Hash
+	object["link"] = entry.Link
+
+	object["content"] = fmt.Sprintf("%d:%d:%d:%d",
+		entry.StartChunk, entry.StartOffset, entry.EndChunk, entry.EndOffset)
+
+	if entry.UID != -1 && entry.GID != -1 {
+		object["uid"] = entry.UID
+		object["gid"] = entry.GID
+	}
+
+	if entry.Attributes != nil && len(*entry.Attributes) > 0 {
+		object["attributes"] = entry.Attributes
+	}
+
+	return object
+}
+
+func (entry *Entry) dumpString() string {
+	data, _ := json.Marshal(entry.dump())
+	return string(data)
+}

src/duplicacy_utils_bsd.go

@@ -1,53 +0,0 @@
-// Copyright (c) Acrosync LLC. All rights reserved.
-// Free for personal use and commercial trial
-// Commercial use requires per-user licenses available from https://duplicacy.com
-
-//go:build freebsd || netbsd || darwin
-// +build freebsd netbsd darwin
-
-package duplicacy
-
-import (
-	"encoding/binary"
-	"os"
-	"syscall"
-)
-
-const bsdFileFlagsKey = "\x00bf"
-
-func (entry *Entry) ReadFileFlags(f *os.File) error {
-	fileInfo, err := f.Stat()
-	if err != nil {
-		return err
-	}
-	stat, ok := fileInfo.Sys().(*syscall.Stat_t)
-	if ok && stat.Flags != 0 {
-		if entry.Attributes == nil {
-			entry.Attributes = &map[string][]byte{}
-		}
-		v := make([]byte, 4)
-		binary.LittleEndian.PutUint32(v, stat.Flags)
-		(*entry.Attributes)[bsdFileFlagsKey] = v
-		LOG_DEBUG("ATTR_READ", "Read flags 0x%x for %s", stat.Flags, entry.Path)
-	}
-	return nil
-}
-
-func (entry *Entry) RestoreEarlyDirFlags(path string) error {
-	return nil
-}
-
-func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
-	return nil
-}
-
-func (entry *Entry) RestoreLateFileFlags(f *os.File) error {
-	if entry.Attributes == nil {
-		return nil
-	}
-	if v, have := (*entry.Attributes)[bsdFileFlagsKey]; have {
-		LOG_DEBUG("ATTR_RESTORE", "Restore flags 0x%x for %s", binary.LittleEndian.Uint32(v), entry.Path)
-		return syscall.Fchflags(int(f.Fd()), int(binary.LittleEndian.Uint32(v)))
-	}
-	return nil
-}

src/duplicacy_utils_bsd_common.go

@@ -0,0 +1,94 @@
+// Copyright (c) Acrosync LLC. All rights reserved.
+// Free for personal use and commercial trial
+// Commercial use requires per-user licenses available from https://duplicacy.com
+
+//go:build freebsd || netbsd || darwin
+// +build freebsd netbsd darwin
+
+package duplicacy
+
+import (
+	"bytes"
+	"encoding/binary"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/pkg/xattr"
+)
+
+const bsdFileFlagsKey = "\x00bf"
+
+func (entry *Entry) ReadAttributes(top string) {
+	fullPath := filepath.Join(top, entry.Path)
+	fileInfo, err := os.Lstat(fullPath)
+	if err != nil {
+		return
+	}
+
+	if !entry.IsSpecial() {
+		attributes, _ := xattr.LList(fullPath)
+		if len(attributes) > 0 {
+			entry.Attributes = &map[string][]byte{}
+			for _, name := range attributes {
+				attribute, err := xattr.LGet(fullPath, name)
+				if err == nil {
+					(*entry.Attributes)[name] = attribute
+				}
+			}
+		}
+	}
+	if err := entry.readFileFlags(fileInfo); err != nil {
+		LOG_INFO("ATTR_BACKUP", "Could not backup flags for file %s: %v", fullPath, err)
+	}
+}
+
+func (entry *Entry) SetAttributesToFile(fullPath string) {
+	if !entry.IsSpecial() {
+		names, _ := xattr.LList(fullPath)
+		for _, name := range names {
+			newAttribute, found := (*entry.Attributes)[name]
+			if found {
+				oldAttribute, _ := xattr.LGet(fullPath, name)
+				if !bytes.Equal(oldAttribute, newAttribute) {
+					xattr.LSet(fullPath, name, newAttribute)
+				}
+				delete(*entry.Attributes, name)
+			} else {
+				xattr.LRemove(fullPath, name)
+			}
+		}
+
+		for name, attribute := range *entry.Attributes {
+			if len(name) > 0 && name[0] == '\x00' {
+				continue
+			}
+			xattr.LSet(fullPath, name, attribute)
+		}
+	}
+	if err := entry.restoreLateFileFlags(fullPath); err != nil {
+		LOG_DEBUG("ATTR_RESTORE", "Could not restore flags for file %s: %v", fullPath, err)
+	}
+}
+
+func (entry *Entry) readFileFlags(fileInfo os.FileInfo) error {
+	stat, ok := fileInfo.Sys().(*syscall.Stat_t)
+	if ok && stat.Flags != 0 {
+		if entry.Attributes == nil {
+			entry.Attributes = &map[string][]byte{}
+		}
+		v := make([]byte, 4)
+		binary.LittleEndian.PutUint32(v, stat.Flags)
+		(*entry.Attributes)[bsdFileFlagsKey] = v
+		LOG_DEBUG("ATTR_READ", "Read flags 0x%x for %s", stat.Flags, entry.Path)
+	}
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyDirFlags(path string) error {
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
+	return nil
+}

src/duplicacy_utils_darwin.go

@@ -5,10 +5,29 @@
 package duplicacy
 
 import (
+	"encoding/binary"
+	"os"
 	"strings"
+	"syscall"
 )
 
 func excludedByAttribute(attributes map[string][]byte) bool {
 	value, ok := attributes["com.apple.metadata:com_apple_backup_excludeItem"]
 	return ok && strings.Contains(string(value), "com.apple.backupd")
 }
+
+func (entry *Entry) restoreLateFileFlags(path string) error {
+	if entry.Attributes == nil {
+		return nil
+	}
+	if v, have := (*entry.Attributes)[bsdFileFlagsKey]; have {
+		f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_SYMLINK, 0)
+		if err != nil {
+			return err
+		}
+		err = syscall.Fchflags(int(f.Fd()), int(binary.LittleEndian.Uint32(v)))
+		f.Close()
+		return err
+	}
+	return nil
+}

src/duplicacy_utils_linux.go

@@ -5,10 +5,14 @@
 package duplicacy
 
 import (
+	"bytes"
 	"encoding/binary"
 	"os"
+	"path/filepath"
 	"syscall"
 	"unsafe"
+
+	"github.com/pkg/xattr"
 )
 
 const (
@@ -47,7 +51,116 @@ func ioctl(f *os.File, request uintptr, attrp *uint32) error {
 	return nil
 }
 
-func (entry *Entry) ReadFileFlags(f *os.File) error {
+type xattrHandle struct {
+	f        *os.File
+	fullPath string
+}
+
+func (x xattrHandle) list() ([]string, error) {
+	if x.f != nil {
+		return xattr.FList(x.f)
+	} else {
+		return xattr.LList(x.fullPath)
+	}
+}
+
+func (x xattrHandle) get(name string) ([]byte, error) {
+	if x.f != nil {
+		return xattr.FGet(x.f, name)
+	} else {
+		return xattr.LGet(x.fullPath, name)
+	}
+}
+
+func (x xattrHandle) set(name string, value []byte) error {
+	if x.f != nil {
+		return xattr.FSet(x.f, name, value)
+	} else {
+		return xattr.LSet(x.fullPath, name, value)
+	}
+}
+
+func (x xattrHandle) remove(name string) error {
+	if x.f != nil {
+		return xattr.FRemove(x.f, name)
+	} else {
+		return xattr.LRemove(x.fullPath, name)
+	}
+}
+
+func (entry *Entry) ReadAttributes(top string) {
+	fullPath := filepath.Join(top, entry.Path)
+	x := xattrHandle{nil, fullPath}
+
+	if !entry.IsLink() {
+		var err error
+		x.f, err = os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
+		if err != nil {
+			// FIXME: We really should return errors for failure to read
+			return
+		}
+	}
+
+	attributes, _ := x.list()
+
+	if len(attributes) > 0 {
+		entry.Attributes = &map[string][]byte{}
+	}
+	for _, name := range attributes {
+		attribute, err := x.get(name)
+		if err == nil {
+			(*entry.Attributes)[name] = attribute
+		}
+	}
+
+	if entry.IsFile() || entry.IsDir() {
+		if err := entry.readFileFlags(x.f); err != nil {
+			LOG_INFO("ATTR_BACKUP", "Could not backup flags for file %s: %v", fullPath, err)
+		}
+	}
+	x.f.Close()
+}
+
+func (entry *Entry) SetAttributesToFile(fullPath string) {
+	x := xattrHandle{nil, fullPath}
+	if !entry.IsLink() {
+		var err error
+		x.f, err = os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW, 0)
+		if err != nil {
+			return
+		}
+	}
+
+	names, _ := x.list()
+
+	for _, name := range names {
+		newAttribute, found := (*entry.Attributes)[name]
+		if found {
+			oldAttribute, _ := x.get(name)
+			if !bytes.Equal(oldAttribute, newAttribute) {
+				x.set(name, newAttribute)
+			}
+			delete(*entry.Attributes, name)
+		} else {
+			x.remove(name)
+		}
+	}
+
+	for name, attribute := range *entry.Attributes {
+		if len(name) > 0 && name[0] == '\x00' {
+			continue
+		}
+		x.set(name, attribute)
+	}
+	if entry.IsFile() || entry.IsDir() {
+		if err := entry.restoreLateFileFlags(x.f); err != nil {
+			LOG_DEBUG("ATTR_RESTORE", "Could not restore flags for file %s: %v", fullPath, err)
+		}
+	}
+	x.f.Close()
+}
+
+func (entry *Entry) readFileFlags(f *os.File) error {
 	var flags uint32
 	if err := ioctl(f, linux_FS_IOC_GETFLAGS, &flags); err != nil {
 		return err
@@ -94,7 +207,7 @@ func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
 	return nil
 }
 
-func (entry *Entry) RestoreLateFileFlags(f *os.File) error {
+func (entry *Entry) restoreLateFileFlags(f *os.File) error {
 	if entry.Attributes == nil {
 		return nil
 	}

src/duplicacy_utils_others.go

@@ -2,18 +2,17 @@
 // Free for personal use and commercial trial
 // Commercial use requires per-user licenses available from https://duplicacy.com
 
+//go:build !windows
 // +build !windows
 
 package duplicacy
 
 import (
-	"bytes"
 	"os"
 	"path"
-	"path/filepath"
 	"syscall"
 
-	"github.com/pkg/xattr"
+	"golang.org/x/sys/unix"
 )
 
 func Readlink(path string) (isRegular bool, s string, err error) {
@@ -47,58 +46,50 @@ func SetOwner(fullPath string, entry *Entry, fileInfo *os.FileInfo) bool {
 	return true
 }
 
-func (entry *Entry) ReadAttributes(top string) {
-	fullPath := filepath.Join(top, entry.Path)
-	f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW, 0)
-	if err != nil {
-		return
+func (entry *Entry) ReadSpecial(fileInfo os.FileInfo) bool {
+	if fileInfo.Mode()&(os.ModeDevice|os.ModeCharDevice) == 0 {
+		return true
 	}
-	attributes, _ := xattr.FList(f)
-	if len(attributes) > 0 {
-		entry.Attributes = &map[string][]byte{}
-		for _, name := range attributes {
-			attribute, err := xattr.Get(fullPath, name)
-			if err == nil {
-				(*entry.Attributes)[name] = attribute
+	stat := fileInfo.Sys().(*syscall.Stat_t)
+	if stat == nil {
+		return false
 	}
-		}
-	}
-	if err := entry.ReadFileFlags(f); err != nil {
-		LOG_INFO("ATTR_BACKUP", "Could not backup flags for file %s: %v", fullPath, err)
-	}
-	f.Close()
+	entry.Size = 0
+	rdev := uint64(stat.Rdev)
+	entry.StartChunk = int(rdev & 0xFFFFFFFF)
+	entry.StartOffset = int(rdev >> 32)
+	return true
 }
 
-func (entry *Entry) SetAttributesToFile(fullPath string) {
-	f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW, 0)
-	if err != nil {
-		return
+func (entry *Entry) GetRdev() uint64 {
+	return uint64(entry.StartChunk) | uint64(entry.StartOffset)<<32
 }
 
-	names, _ := xattr.FList(f)
-	for _, name := range names {
-		newAttribute, found := (*entry.Attributes)[name]
-		if found {
-			oldAttribute, _ := xattr.FGet(f, name)
-			if !bytes.Equal(oldAttribute, newAttribute) {
-				xattr.FSet(f, name, newAttribute)
-			}
-			delete(*entry.Attributes, name)
+func (entry *Entry) RestoreSpecial(fullPath string) error {
+	mode := entry.Mode & uint32(fileModeMask)
+
+	if entry.Mode&uint32(os.ModeNamedPipe) != 0 {
+		mode |= syscall.S_IFIFO
+	} else if entry.Mode&uint32(os.ModeCharDevice) != 0 {
+		mode |= syscall.S_IFCHR
+	} else if entry.Mode&uint32(os.ModeDevice) != 0 {
+		mode |= syscall.S_IFBLK
 	} else {
-			xattr.FRemove(f, name)
+		return nil
 	}
+	return syscall.Mknod(fullPath, mode, int(entry.GetRdev()))
 }
 
-	for name, attribute := range *entry.Attributes {
-		if len(name) > 0 && name[0] == '\x00' {
-			continue
+func (entry *Entry) IsSameSpecial(fileInfo os.FileInfo) bool {
+	stat := fileInfo.Sys().(*syscall.Stat_t)
+	if stat == nil {
+		return false
 	}
-		xattr.FSet(f, name, attribute)
+	return (uint32(fileInfo.Mode()) == entry.Mode) && (uint64(stat.Rdev) == entry.GetRdev())
 }
-	if err := entry.RestoreLateFileFlags(f); err != nil {
-		LOG_DEBUG("ATTR_RESTORE", "Could not restore flags for file %s: %v", fullPath, err)
-	}
-	f.Close()
+
+func MakeHardlink(source string, target string) error {
+	return unix.Linkat(unix.AT_FDCWD, source, unix.AT_FDCWD, target, 0)
 }
 
 func joinPath(components ...string) string {

src/duplicacy_utils_windows.go

@@ -117,6 +117,18 @@ func (entry *Entry) SetAttributesToFile(fullPath string) {
 
 }
 
+func (entry *Entry) ReadDeviceNode(fileInfo os.FileInfo) bool {
+	return nil
+}
+
+func (entry *Entry) RestoreSpecial(fullPath string) error {
+	return nil
+}
+
+func MakeHardlink(source string, target string) error {
+	return os.Link(source, target)
+}
+
 func joinPath(components ...string) string {
 
 	combinedPath := `\\?\` + filepath.Join(components...)

src/duplicacy_utils_xbsd.go

@@ -0,0 +1,30 @@
+// Copyright (c) Acrosync LLC. All rights reserved.
+// Free for personal use and commercial trial
+// Commercial use requires per-user licenses available from https://duplicacy.com
+
+//go:build freebsd || netbsd
+// +build freebsd netbsd
+
+package duplicacy
+
+import (
+	"bytes"
+	"encoding/binary"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/pkg/xattr"
+)
+
+func (entry *Entry) restoreLateFileFlags(path string) error {
+	if entry.Attributes == nil {
+		return nil
+	}
+	if v, have := (*entry.Attributes)[bsdFileFlagsKey]; have {
+		if _, _, errno := syscall.Syscall(syscall.SYS_LCHFLAGS, uintptr(unsafe.Pointer(syscall.StringBytePtr(path))), uintptr(v), 0); errno != 0 {
+			return os.NewSyscallError("lchflags", errno)
+		}
+	}
+	return nil
+}