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https://github.com/octoleo/syncthing.git
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105 lines
3.1 KiB
Go
105 lines
3.1 KiB
Go
// Copyright (C) 2015 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 windows
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// +build windows
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package fs
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import (
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"fmt"
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"go/version"
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"os"
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"runtime"
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"syscall"
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"unsafe"
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"golang.org/x/sys/windows"
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)
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func readReparseTag(path string) (uint32, error) {
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namep, err := syscall.UTF16PtrFromString(path)
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if err != nil {
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return 0, fmt.Errorf("syscall.UTF16PtrFromString failed with: %s", err)
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}
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attrs := uint32(syscall.FILE_FLAG_BACKUP_SEMANTICS | syscall.FILE_FLAG_OPEN_REPARSE_POINT)
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h, err := syscall.CreateFile(namep, 0, 0, nil, syscall.OPEN_EXISTING, attrs, 0)
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if err != nil {
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return 0, fmt.Errorf("syscall.CreateFile failed with: %s", err)
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}
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defer syscall.CloseHandle(h)
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//https://docs.microsoft.com/windows/win32/api/winbase/ns-winbase-file_attribute_tag_info
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const fileAttributeTagInfo = 9
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type FILE_ATTRIBUTE_TAG_INFO struct {
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FileAttributes uint32
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ReparseTag uint32
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}
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var ti FILE_ATTRIBUTE_TAG_INFO
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err = windows.GetFileInformationByHandleEx(windows.Handle(h), fileAttributeTagInfo, (*byte)(unsafe.Pointer(&ti)), uint32(unsafe.Sizeof(ti)))
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if err != nil {
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if errno, ok := err.(syscall.Errno); ok && errno == windows.ERROR_INVALID_PARAMETER {
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// It appears calling GetFileInformationByHandleEx with
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// FILE_ATTRIBUTE_TAG_INFO fails on FAT file system with
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// ERROR_INVALID_PARAMETER. Clear ti.ReparseTag in that
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// instance to indicate no symlinks are possible.
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ti.ReparseTag = 0
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} else {
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return 0, fmt.Errorf("windows.GetFileInformationByHandleEx failed with: %s", err)
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}
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}
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return ti.ReparseTag, nil
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}
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func isDirectoryJunction(reparseTag uint32) bool {
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return reparseTag == windows.IO_REPARSE_TAG_MOUNT_POINT
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}
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type dirJunctFileInfo struct {
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os.FileInfo
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}
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func (fi *dirJunctFileInfo) Mode() os.FileMode {
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// Simulate a directory and not a symlink; also set the execute
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// bits so the directory can be traversed Unix-side.
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return fi.FileInfo.Mode() ^ junctionPointModeMask | os.ModeDir | 0111
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}
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func (fi *dirJunctFileInfo) IsDir() bool {
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return true
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}
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var junctionPointModeMask os.FileMode
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func init() {
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junctionPointModeMask = os.ModeSymlink
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if version.Compare(runtime.Version(), "go1.23") >= 0 {
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// if GODEBUG=winsymlink=0, then we are in g1.22 mode so let's check for
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// os.ModeSymlink as well, as it can't hurt.
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junctionPointModeMask |= os.ModeIrregular
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}
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}
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func (f *BasicFilesystem) underlyingLstat(name string) (os.FileInfo, error) {
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var fi, err = os.Lstat(name)
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// There are cases where files are tagged as symlink, but they end up being
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// something else. Make sure we properly handle those types.
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if err == nil {
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// NTFS directory junctions can be treated as ordinary directories,
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// see https://forum.syncthing.net/t/option-to-follow-directory-junctions-symbolic-links/14750
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if fi.Mode()&junctionPointModeMask != 0 && f.junctionsAsDirs {
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if reparseTag, reparseErr := readReparseTag(name); reparseErr == nil && isDirectoryJunction(reparseTag) {
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return &dirJunctFileInfo{fi}, nil
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}
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}
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}
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return fi, err
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}
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