Split out xattr and flags routines to new files

src/duplicacy_xattr_linux.go

@@ -0,0 +1,207 @@
+// 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"
+	"fmt"
+	"os"
+	"unsafe"
+
+	"github.com/pkg/xattr"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	linux_FS_SECRM_FL        = 0x00000001 /* Secure deletion */
+	linux_FS_UNRM_FL         = 0x00000002 /* Undelete */
+	linux_FS_COMPR_FL        = 0x00000004 /* Compress file */
+	linux_FS_SYNC_FL         = 0x00000008 /* Synchronous updates */
+	linux_FS_IMMUTABLE_FL    = 0x00000010 /* Immutable file */
+	linux_FS_APPEND_FL       = 0x00000020 /* writes to file may only append */
+	linux_FS_NODUMP_FL       = 0x00000040 /* do not dump file */
+	linux_FS_NOATIME_FL      = 0x00000080 /* do not update atime */
+	linux_FS_NOCOMP_FL       = 0x00000400 /* Don't compress */
+	linux_FS_JOURNAL_DATA_FL = 0x00004000 /* Reserved for ext3 */
+	linux_FS_NOTAIL_FL       = 0x00008000 /* file tail should not be merged */
+	linux_FS_DIRSYNC_FL      = 0x00010000 /* dirsync behaviour (directories only) */
+	linux_FS_TOPDIR_FL       = 0x00020000 /* Top of directory hierarchies*/
+	linux_FS_NOCOW_FL        = 0x00800000 /* Do not cow file */
+	linux_FS_PROJINHERIT_FL  = 0x20000000 /* Create with parents projid */
+
+	linux_FS_IOC_GETFLAGS uintptr = 0x80086601
+	linux_FS_IOC_SETFLAGS uintptr = 0x40086602
+
+	linuxIocFlagsFileEarly = linux_FS_SECRM_FL | linux_FS_UNRM_FL | linux_FS_COMPR_FL | linux_FS_NODUMP_FL | linux_FS_NOATIME_FL | linux_FS_NOCOMP_FL | linux_FS_JOURNAL_DATA_FL | linux_FS_NOTAIL_FL | linux_FS_NOCOW_FL
+	linuxIocFlagsDirEarly  = linux_FS_TOPDIR_FL | linux_FS_PROJINHERIT_FL
+	linuxIocFlagsLate      = linux_FS_SYNC_FL | linux_FS_IMMUTABLE_FL | linux_FS_APPEND_FL | linux_FS_DIRSYNC_FL
+
+	linuxFileFlagsKey = "\x00lf"
+)
+
+func ioctl(f *os.File, request uintptr, attrp *uint32) error {
+	argp := uintptr(unsafe.Pointer(attrp))
+
+	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, f.Fd(), request, argp); errno != 0 {
+		return os.NewSyscallError("ioctl", errno)
+	}
+	return nil
+}
+
+func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
+	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 {
+	if !(entry.IsFile() || entry.IsDir()) {
+		return nil
+	}
+
+	f, err := os.OpenFile(fullPath, os.O_RDONLY|unix.O_NOFOLLOW, 0)
+	if err != nil {
+		return err
+	}
+
+	var flags uint32
+
+	err = ioctl(f, linux_FS_IOC_GETFLAGS, &flags)
+	f.Close()
+	if err != nil {
+		return err
+	}
+
+	if flags != 0 {
+		if entry.Attributes == nil {
+			entry.Attributes = &map[string][]byte{}
+		}
+		v := make([]byte, 4)
+		binary.LittleEndian.PutUint32(v, flags)
+		(*entry.Attributes)[linuxFileFlagsKey] = v
+	}
+	return nil
+}
+
+func (entry *Entry) SetAttributesToFile(fullPath string) error {
+	if entry.Attributes == nil || len(*entry.Attributes) == 0 {
+		return nil
+	}
+	attributes := *entry.Attributes
+
+	if _, haveFlags := attributes[linuxFileFlagsKey]; haveFlags && len(attributes) <= 1 {
+		return nil
+	}
+
+	names, err := xattr.LList(fullPath)
+	if err != nil {
+		return err
+	}
+	for _, name := range names {
+		newAttribute, found := (*entry.Attributes)[name]
+		if found {
+			oldAttribute, _ := xattr.LGet(fullPath, name)
+			if !bytes.Equal(oldAttribute, newAttribute) {
+				err = errors.Join(err, xattr.LSet(fullPath, name, newAttribute))
+			}
+			delete(*entry.Attributes, name)
+		} else {
+			err = errors.Join(err, xattr.LRemove(fullPath, name))
+		}
+	}
+
+	for name, attribute := range *entry.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 {
+	if entry.Attributes == nil {
+		return nil
+	}
+	var flags uint32
+
+	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v) & linuxIocFlagsDirEarly & ^mask
+	}
+
+	if flags != 0 {
+		f, err := os.OpenFile(fullPath, os.O_RDONLY|unix.O_DIRECTORY, 0)
+		if err != nil {
+			return err
+		}
+		err = ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		f.Close()
+		if err != nil {
+			return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
+		}
+	}
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File, mask uint32) error {
+	if entry.Attributes == nil {
+		return nil
+	}
+	var flags uint32
+
+	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v) & linuxIocFlagsFileEarly & ^mask
+	}
+
+	if flags != 0 {
+		err := ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		if err != nil {
+			return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
+		}
+	}
+	return nil
+}
+
+func (entry *Entry) RestoreLateFileFlags(fullPath string, fileInfo os.FileInfo, mask uint32) error {
+	if entry.IsLink() || entry.Attributes == nil {
+		return nil
+	}
+	var flags uint32
+
+	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v) & (linuxIocFlagsFileEarly | linuxIocFlagsDirEarly | linuxIocFlagsLate) & ^mask
+	}
+
+	if flags != 0 {
+		f, err := os.OpenFile(fullPath, os.O_RDONLY|unix.O_NOFOLLOW, 0)
+		if err != nil {
+			return err
+		}
+		err = ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		f.Close()
+		if err != nil {
+			return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
+		}
+	}
+	return nil
+}