Improve error handling and setting of xattr and file flags

- Improve error handling of file flags and xattrs. You now get warnings
- file flags on *BSD/Darwin use a mask and combine with the user/superuser
mask to prevent spurious warnings. The mask is not yet implemented as
a preference
- error handling/report for reading special files
- bump to go 1.20 for errors.Join
This commit is contained in:
2023-10-05 21:43:02 -05:00
parent 7df1ba5d82
commit 42ee20a9e1
9 changed files with 382 additions and 284 deletions

View File

@@ -7,8 +7,9 @@ package duplicacy
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"os"
"path/filepath"
"syscall"
"unsafe"
@@ -51,125 +52,55 @@ func ioctl(f *os.File, request uintptr, attrp *uint32) error {
return nil
}
type xattrHandle struct {
f *os.File
fullPath string
func excludedByAttribute(attributes map[string][]byte) bool {
_, excluded := attributes["user.duplicacy_exclude"]
if !excluded {
flags, ok := attributes[linuxFileFlagsKey]
excluded = ok && (binary.LittleEndian.Uint32(flags)&linux_FS_NODUMP_FL) != 0
}
return excluded
}
func (x xattrHandle) list() ([]string, error) {
if x.f != nil {
return xattr.FList(x.f)
} else {
return xattr.LList(x.fullPath)
func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
attributes, err := xattr.LList(fullPath)
if err != nil {
return err
}
}
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{}
}
var allErrors error
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 excludedByAttribute(attributes map[string][]byte) bool {
_, ok := attributes["user.duplicacy_exclude"]
return ok
}
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)
value, err := xattr.LGet(fullPath, name)
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)
allErrors = errors.Join(allErrors, err)
} else {
x.remove(name)
(*entry.Attributes)[name] = value
}
}
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()
return allErrors
}
func (entry *Entry) readFileFlags(f *os.File) error {
var flags uint32
if err := ioctl(f, linux_FS_IOC_GETFLAGS, &flags); err != nil {
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|syscall.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{}
@@ -177,49 +108,109 @@ func (entry *Entry) readFileFlags(f *os.File) error {
v := make([]byte, 4)
binary.LittleEndian.PutUint32(v, flags)
(*entry.Attributes)[linuxFileFlagsKey] = v
LOG_DEBUG("ATTR_READ", "Read flags 0x%x for %s", flags, entry.Path)
}
return nil
}
func (entry *Entry) RestoreEarlyDirFlags(path string) error {
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
f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_DIRECTORY, 0)
flags = binary.LittleEndian.Uint32(v) & linuxIocFlagsDirEarly & ^mask
}
if flags != 0 {
f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_DIRECTORY, 0)
if err != nil {
return err
}
LOG_DEBUG("ATTR_RESTORE", "Restore dir flags (early) 0x%x for %s", flags, entry.Path)
err = ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
f.Close()
return err
if err != nil {
return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
}
}
return nil
}
func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
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
LOG_DEBUG("ATTR_RESTORE", "Restore flags (early) 0x%x for %s", flags, entry.Path)
return ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
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(f *os.File) error {
if entry.Attributes == 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)
LOG_DEBUG("ATTR_RESTORE", "Restore flags (late) 0x%x for %s", flags, entry.Path)
return ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
flags = binary.LittleEndian.Uint32(v) & (linuxIocFlagsFileEarly | linuxIocFlagsDirEarly | linuxIocFlagsLate) & ^mask
}
if flags != 0 {
f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.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
}