6cac308bcd
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>
72 lines
2.4 KiB
Go
72 lines
2.4 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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package fs
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import (
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"fmt"
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"github.com/syncthing/syncthing/lib/protocol"
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"golang.org/x/sys/windows"
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)
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func (f *BasicFilesystem) PlatformData(name string, scanOwnership, _ bool, _ XattrFilter) (protocol.PlatformData, error) {
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if !scanOwnership {
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// That's the only thing we do, currently
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return protocol.PlatformData{}, nil
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}
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rootedName, err := f.rooted(name)
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if err != nil {
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return protocol.PlatformData{}, fmt.Errorf("rooted for %s: %w", name, err)
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}
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hdl, err := openReadOnlyWithBackupSemantics(rootedName)
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if err != nil {
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return protocol.PlatformData{}, fmt.Errorf("open %s: %w", rootedName, err)
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}
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defer windows.Close(hdl)
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// GetSecurityInfo returns an owner SID.
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sd, err := windows.GetSecurityInfo(hdl, windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
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if err != nil {
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return protocol.PlatformData{}, fmt.Errorf("get security info for %s: %w", rootedName, err)
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}
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owner, _, err := sd.Owner()
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if err != nil {
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return protocol.PlatformData{}, fmt.Errorf("get owner for %s: %w", rootedName, err)
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}
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pd := &protocol.WindowsData{}
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if us := f.userCache.lookup(owner.String()); us != nil {
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pd.OwnerName = us.Username
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} else if gr := f.groupCache.lookup(owner.String()); gr != nil {
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pd.OwnerName = gr.Name
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pd.OwnerIsGroup = true
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} else {
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l.Debugf("Failed to resolve owner for %s: %v", rootedName, err)
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}
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return protocol.PlatformData{Windows: pd}, nil
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}
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func openReadOnlyWithBackupSemantics(path string) (fd windows.Handle, err error) {
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// This is windows.Open but simplified to read-only only, and adding
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// FILE_FLAG_BACKUP_SEMANTICS which is required to open directories.
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if len(path) == 0 {
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return windows.InvalidHandle, windows.ERROR_FILE_NOT_FOUND
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}
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pathp, err := windows.UTF16PtrFromString(path)
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if err != nil {
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return windows.InvalidHandle, err
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}
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var access uint32 = windows.GENERIC_READ
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var sharemode uint32 = windows.FILE_SHARE_READ | windows.FILE_SHARE_WRITE
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var sa *windows.SecurityAttributes
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var createmode uint32 = windows.OPEN_EXISTING
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var attrs uint32 = windows.FILE_ATTRIBUTE_READONLY | windows.FILE_FLAG_BACKUP_SEMANTICS
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return windows.CreateFile(pathp, access, sharemode, sa, createmode, attrs, 0)
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}
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