This adds support for syncing extended attributes on supported filesystem on Linux, macOS, FreeBSD and NetBSD. Windows is currently excluded because the APIs seem onerous and annoying and frankly the uses cases seem few and far between. On Unixes this also covers ACLs as those are stored as extended attributes. Similar to ownership syncing this will optional & opt-in, which two settings controlling the main behavior: one to "sync" xattrs (read & write) and another one to "scan" xattrs (only read them so other devices can "sync" them, but not apply any locally). Co-authored-by: Tomasz Wilczyński <twilczynski@naver.com>
44 lines
1.0 KiB
Go
44 lines
1.0 KiB
Go
// Copyright (C) 2022 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at https://mozilla.org/MPL/2.0/.
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//go:build linux || darwin
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// +build linux darwin
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package fs
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import (
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"errors"
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"fmt"
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"sort"
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"strings"
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"golang.org/x/sys/unix"
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)
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func listXattr(path string) ([]string, error) {
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buf := make([]byte, 1024)
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size, err := unix.Llistxattr(path, buf)
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if errors.Is(err, unix.ERANGE) {
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// Buffer is too small. Try again with a zero sized buffer to get
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// the size, then allocate a buffer of the correct size.
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size, err = unix.Llistxattr(path, nil)
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if err != nil {
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return nil, fmt.Errorf("Listxattr %s: %w", path, err)
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}
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buf = make([]byte, size)
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size, err = unix.Llistxattr(path, buf)
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}
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if err != nil {
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return nil, fmt.Errorf("Listxattr %s: %w", path, err)
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}
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buf = buf[:size]
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attrs := compact(strings.Split(string(buf), "\x00"))
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sort.Strings(attrs)
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return attrs, nil
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}
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