mirror of
https://github.com/genuinetools/reg.git
synced 2024-08-21 14:20:23 -04:00
297 lines
9.1 KiB
Go
297 lines
9.1 KiB
Go
package system // import "github.com/docker/docker/pkg/system"
|
|
|
|
import (
|
|
"os"
|
|
"path/filepath"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
"sync"
|
|
"syscall"
|
|
"time"
|
|
"unsafe"
|
|
|
|
winio "github.com/Microsoft/go-winio"
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
const (
|
|
// SddlAdministratorsLocalSystem is local administrators plus NT AUTHORITY\System
|
|
SddlAdministratorsLocalSystem = "D:P(A;OICI;GA;;;BA)(A;OICI;GA;;;SY)"
|
|
// SddlNtvmAdministratorsLocalSystem is NT VIRTUAL MACHINE\Virtual Machines plus local administrators plus NT AUTHORITY\System
|
|
SddlNtvmAdministratorsLocalSystem = "D:P(A;OICI;GA;;;S-1-5-83-0)(A;OICI;GA;;;BA)(A;OICI;GA;;;SY)"
|
|
)
|
|
|
|
// MkdirAllWithACL is a wrapper for MkdirAll that creates a directory
|
|
// with an appropriate SDDL defined ACL.
|
|
func MkdirAllWithACL(path string, perm os.FileMode, sddl string) error {
|
|
return mkdirall(path, true, sddl)
|
|
}
|
|
|
|
// MkdirAll implementation that is volume path aware for Windows.
|
|
func MkdirAll(path string, _ os.FileMode, sddl string) error {
|
|
return mkdirall(path, false, sddl)
|
|
}
|
|
|
|
// mkdirall is a custom version of os.MkdirAll modified for use on Windows
|
|
// so that it is both volume path aware, and can create a directory with
|
|
// a DACL.
|
|
func mkdirall(path string, applyACL bool, sddl string) error {
|
|
if re := regexp.MustCompile(`^\\\\\?\\Volume{[a-z0-9-]+}$`); re.MatchString(path) {
|
|
return nil
|
|
}
|
|
|
|
// The rest of this method is largely copied from os.MkdirAll and should be kept
|
|
// as-is to ensure compatibility.
|
|
|
|
// Fast path: if we can tell whether path is a directory or file, stop with success or error.
|
|
dir, err := os.Stat(path)
|
|
if err == nil {
|
|
if dir.IsDir() {
|
|
return nil
|
|
}
|
|
return &os.PathError{
|
|
Op: "mkdir",
|
|
Path: path,
|
|
Err: syscall.ENOTDIR,
|
|
}
|
|
}
|
|
|
|
// Slow path: make sure parent exists and then call Mkdir for path.
|
|
i := len(path)
|
|
for i > 0 && os.IsPathSeparator(path[i-1]) { // Skip trailing path separator.
|
|
i--
|
|
}
|
|
|
|
j := i
|
|
for j > 0 && !os.IsPathSeparator(path[j-1]) { // Scan backward over element.
|
|
j--
|
|
}
|
|
|
|
if j > 1 {
|
|
// Create parent
|
|
err = mkdirall(path[0:j-1], false, sddl)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Parent now exists; invoke os.Mkdir or mkdirWithACL and use its result.
|
|
if applyACL {
|
|
err = mkdirWithACL(path, sddl)
|
|
} else {
|
|
err = os.Mkdir(path, 0)
|
|
}
|
|
|
|
if err != nil {
|
|
// Handle arguments like "foo/." by
|
|
// double-checking that directory doesn't exist.
|
|
dir, err1 := os.Lstat(path)
|
|
if err1 == nil && dir.IsDir() {
|
|
return nil
|
|
}
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// mkdirWithACL creates a new directory. If there is an error, it will be of
|
|
// type *PathError. .
|
|
//
|
|
// This is a modified and combined version of os.Mkdir and windows.Mkdir
|
|
// in golang to cater for creating a directory am ACL permitting full
|
|
// access, with inheritance, to any subfolder/file for Built-in Administrators
|
|
// and Local System.
|
|
func mkdirWithACL(name string, sddl string) error {
|
|
sa := windows.SecurityAttributes{Length: 0}
|
|
sd, err := winio.SddlToSecurityDescriptor(sddl)
|
|
if err != nil {
|
|
return &os.PathError{Op: "mkdir", Path: name, Err: err}
|
|
}
|
|
sa.Length = uint32(unsafe.Sizeof(sa))
|
|
sa.InheritHandle = 1
|
|
sa.SecurityDescriptor = uintptr(unsafe.Pointer(&sd[0]))
|
|
|
|
namep, err := windows.UTF16PtrFromString(name)
|
|
if err != nil {
|
|
return &os.PathError{Op: "mkdir", Path: name, Err: err}
|
|
}
|
|
|
|
e := windows.CreateDirectory(namep, &sa)
|
|
if e != nil {
|
|
return &os.PathError{Op: "mkdir", Path: name, Err: e}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// IsAbs is a platform-specific wrapper for filepath.IsAbs. On Windows,
|
|
// golang filepath.IsAbs does not consider a path \windows\system32 as absolute
|
|
// as it doesn't start with a drive-letter/colon combination. However, in
|
|
// docker we need to verify things such as WORKDIR /windows/system32 in
|
|
// a Dockerfile (which gets translated to \windows\system32 when being processed
|
|
// by the daemon. This SHOULD be treated as absolute from a docker processing
|
|
// perspective.
|
|
func IsAbs(path string) bool {
|
|
if !filepath.IsAbs(path) {
|
|
if !strings.HasPrefix(path, string(os.PathSeparator)) {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
// The origin of the functions below here are the golang OS and windows packages,
|
|
// slightly modified to only cope with files, not directories due to the
|
|
// specific use case.
|
|
//
|
|
// The alteration is to allow a file on Windows to be opened with
|
|
// FILE_FLAG_SEQUENTIAL_SCAN (particular for docker load), to avoid eating
|
|
// the standby list, particularly when accessing large files such as layer.tar.
|
|
|
|
// CreateSequential creates the named file with mode 0666 (before umask), truncating
|
|
// it if it already exists. If successful, methods on the returned
|
|
// File can be used for I/O; the associated file descriptor has mode
|
|
// O_RDWR.
|
|
// If there is an error, it will be of type *PathError.
|
|
func CreateSequential(name string) (*os.File, error) {
|
|
return OpenFileSequential(name, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0)
|
|
}
|
|
|
|
// OpenSequential opens the named file for reading. If successful, methods on
|
|
// the returned file can be used for reading; the associated file
|
|
// descriptor has mode O_RDONLY.
|
|
// If there is an error, it will be of type *PathError.
|
|
func OpenSequential(name string) (*os.File, error) {
|
|
return OpenFileSequential(name, os.O_RDONLY, 0)
|
|
}
|
|
|
|
// OpenFileSequential is the generalized open call; most users will use Open
|
|
// or Create instead.
|
|
// If there is an error, it will be of type *PathError.
|
|
func OpenFileSequential(name string, flag int, _ os.FileMode) (*os.File, error) {
|
|
if name == "" {
|
|
return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOENT}
|
|
}
|
|
r, errf := windowsOpenFileSequential(name, flag, 0)
|
|
if errf == nil {
|
|
return r, nil
|
|
}
|
|
return nil, &os.PathError{Op: "open", Path: name, Err: errf}
|
|
}
|
|
|
|
func windowsOpenFileSequential(name string, flag int, _ os.FileMode) (file *os.File, err error) {
|
|
r, e := windowsOpenSequential(name, flag|windows.O_CLOEXEC, 0)
|
|
if e != nil {
|
|
return nil, e
|
|
}
|
|
return os.NewFile(uintptr(r), name), nil
|
|
}
|
|
|
|
func makeInheritSa() *windows.SecurityAttributes {
|
|
var sa windows.SecurityAttributes
|
|
sa.Length = uint32(unsafe.Sizeof(sa))
|
|
sa.InheritHandle = 1
|
|
return &sa
|
|
}
|
|
|
|
func windowsOpenSequential(path string, mode int, _ uint32) (fd windows.Handle, err error) {
|
|
if len(path) == 0 {
|
|
return windows.InvalidHandle, windows.ERROR_FILE_NOT_FOUND
|
|
}
|
|
pathp, err := windows.UTF16PtrFromString(path)
|
|
if err != nil {
|
|
return windows.InvalidHandle, err
|
|
}
|
|
var access uint32
|
|
switch mode & (windows.O_RDONLY | windows.O_WRONLY | windows.O_RDWR) {
|
|
case windows.O_RDONLY:
|
|
access = windows.GENERIC_READ
|
|
case windows.O_WRONLY:
|
|
access = windows.GENERIC_WRITE
|
|
case windows.O_RDWR:
|
|
access = windows.GENERIC_READ | windows.GENERIC_WRITE
|
|
}
|
|
if mode&windows.O_CREAT != 0 {
|
|
access |= windows.GENERIC_WRITE
|
|
}
|
|
if mode&windows.O_APPEND != 0 {
|
|
access &^= windows.GENERIC_WRITE
|
|
access |= windows.FILE_APPEND_DATA
|
|
}
|
|
sharemode := uint32(windows.FILE_SHARE_READ | windows.FILE_SHARE_WRITE)
|
|
var sa *windows.SecurityAttributes
|
|
if mode&windows.O_CLOEXEC == 0 {
|
|
sa = makeInheritSa()
|
|
}
|
|
var createmode uint32
|
|
switch {
|
|
case mode&(windows.O_CREAT|windows.O_EXCL) == (windows.O_CREAT | windows.O_EXCL):
|
|
createmode = windows.CREATE_NEW
|
|
case mode&(windows.O_CREAT|windows.O_TRUNC) == (windows.O_CREAT | windows.O_TRUNC):
|
|
createmode = windows.CREATE_ALWAYS
|
|
case mode&windows.O_CREAT == windows.O_CREAT:
|
|
createmode = windows.OPEN_ALWAYS
|
|
case mode&windows.O_TRUNC == windows.O_TRUNC:
|
|
createmode = windows.TRUNCATE_EXISTING
|
|
default:
|
|
createmode = windows.OPEN_EXISTING
|
|
}
|
|
// Use FILE_FLAG_SEQUENTIAL_SCAN rather than FILE_ATTRIBUTE_NORMAL as implemented in golang.
|
|
//https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858(v=vs.85).aspx
|
|
const fileFlagSequentialScan = 0x08000000 // FILE_FLAG_SEQUENTIAL_SCAN
|
|
h, e := windows.CreateFile(pathp, access, sharemode, sa, createmode, fileFlagSequentialScan, 0)
|
|
return h, e
|
|
}
|
|
|
|
// Helpers for TempFileSequential
|
|
var rand uint32
|
|
var randmu sync.Mutex
|
|
|
|
func reseed() uint32 {
|
|
return uint32(time.Now().UnixNano() + int64(os.Getpid()))
|
|
}
|
|
func nextSuffix() string {
|
|
randmu.Lock()
|
|
r := rand
|
|
if r == 0 {
|
|
r = reseed()
|
|
}
|
|
r = r*1664525 + 1013904223 // constants from Numerical Recipes
|
|
rand = r
|
|
randmu.Unlock()
|
|
return strconv.Itoa(int(1e9 + r%1e9))[1:]
|
|
}
|
|
|
|
// TempFileSequential is a copy of ioutil.TempFile, modified to use sequential
|
|
// file access. Below is the original comment from golang:
|
|
// TempFile creates a new temporary file in the directory dir
|
|
// with a name beginning with prefix, opens the file for reading
|
|
// and writing, and returns the resulting *os.File.
|
|
// If dir is the empty string, TempFile uses the default directory
|
|
// for temporary files (see os.TempDir).
|
|
// Multiple programs calling TempFile simultaneously
|
|
// will not choose the same file. The caller can use f.Name()
|
|
// to find the pathname of the file. It is the caller's responsibility
|
|
// to remove the file when no longer needed.
|
|
func TempFileSequential(dir, prefix string) (f *os.File, err error) {
|
|
if dir == "" {
|
|
dir = os.TempDir()
|
|
}
|
|
|
|
nconflict := 0
|
|
for i := 0; i < 10000; i++ {
|
|
name := filepath.Join(dir, prefix+nextSuffix())
|
|
f, err = OpenFileSequential(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
|
|
if os.IsExist(err) {
|
|
if nconflict++; nconflict > 10 {
|
|
randmu.Lock()
|
|
rand = reseed()
|
|
randmu.Unlock()
|
|
}
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
return
|
|
}
|