Split out xattr and flags routines to new files

src/duplicacy_xattr_darwin.go

@@ -0,0 +1,142 @@
+// 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
+
+package duplicacy
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"os"
+	"syscall"
+
+	"github.com/pkg/xattr"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	darwinFileFlagsKey = "\x00bf"
+)
+
+var darwinIsSuperUser bool
+
+func init() {
+	darwinIsSuperUser = unix.Geteuid() == 0
+}
+
+func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
+	if entry.IsSpecial() {
+		return nil
+	}
+
+	attributes, err := xattr.LList(fullPath)
+	if err != nil {
+		return err
+	}
+
+	if len(attributes) > 0 {
+		entry.Attributes = &map[string][]byte{}
+	}
+	var allErrors error
+	for _, name := range attributes {
+		value, err := xattr.LGet(fullPath, name)
+		if err != nil {
+			allErrors = errors.Join(allErrors, err)
+		} else {
+			(*entry.Attributes)[name] = value
+		}
+	}
+
+	return allErrors
+}
+
+func (entry *Entry) ReadFileFlags(fullPath string, fileInfo os.FileInfo) error {
+	stat := fileInfo.Sys().(*syscall.Stat_t)
+	if stat.Flags != 0 {
+		if entry.Attributes == nil {
+			entry.Attributes = &map[string][]byte{}
+		}
+		v := make([]byte, 4)
+		binary.LittleEndian.PutUint32(v, stat.Flags)
+		(*entry.Attributes)[darwinFileFlagsKey] = v
+	}
+	return nil
+}
+
+func (entry *Entry) SetAttributesToFile(fullPath string) error {
+	if entry.Attributes == nil || len(*entry.Attributes) == 0 || entry.IsSpecial() {
+		return nil
+	}
+	attributes := *entry.Attributes
+
+	if _, haveFlags := attributes[darwinFileFlagsKey]; haveFlags && len(attributes) <= 1 {
+		return nil
+	}
+
+	names, err := xattr.LList(fullPath)
+	if err != nil {
+		return err
+	}
+	for _, name := range names {
+		newAttribute, found := attributes[name]
+		if found {
+			oldAttribute, _ := xattr.LGet(fullPath, name)
+			if !bytes.Equal(oldAttribute, newAttribute) {
+				err = errors.Join(err, xattr.LSet(fullPath, name, newAttribute))
+			}
+			delete(attributes, name)
+		} else {
+			err = errors.Join(err, xattr.LRemove(fullPath, name))
+		}
+	}
+
+	for name, attribute := range attributes {
+		if len(name) > 0 && name[0] == '\x00' {
+			continue
+		}
+		err = errors.Join(err, xattr.LSet(fullPath, name, attribute))
+	}
+	return err
+}
+
+func (entry *Entry) RestoreEarlyDirFlags(fullPath string, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreLateFileFlags(fullPath string, fileInfo os.FileInfo, mask uint32) error {
+	if entry.Attributes == nil {
+		return nil
+	}
+
+	if darwinIsSuperUser {
+		mask |= ^uint32(unix.UF_SETTABLE | unix.SF_SETTABLE)
+	} else {
+		mask |= ^uint32(unix.UF_SETTABLE)
+	}
+
+	var flags uint32
+
+	if v, have := (*entry.Attributes)[darwinFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v)
+	}
+
+	stat := fileInfo.Sys().(*syscall.Stat_t)
+
+	flags = (flags & ^mask) | (stat.Flags & mask)
+
+	if flags != stat.Flags {
+		f, err := os.OpenFile(fullPath, os.O_RDONLY|unix.O_SYMLINK, 0)
+		if err != nil {
+			return err
+		}
+		err = unix.Fchflags(int(f.Fd()), int(flags))
+		f.Close()
+		return err
+	}
+	return nil
+}