You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
tailscale/tempfork/registry/value.go

387 lines
11 KiB
Go

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build windows
package registry
import (
"errors"
"io"
"syscall"
"unicode/utf16"
"unsafe"
)
const (
// Registry value types.
NONE = 0
SZ = 1
EXPAND_SZ = 2
BINARY = 3
DWORD = 4
DWORD_BIG_ENDIAN = 5
LINK = 6
MULTI_SZ = 7
RESOURCE_LIST = 8
FULL_RESOURCE_DESCRIPTOR = 9
RESOURCE_REQUIREMENTS_LIST = 10
QWORD = 11
)
var (
// ErrShortBuffer is returned when the buffer was too short for the operation.
ErrShortBuffer = syscall.ERROR_MORE_DATA
// ErrNotExist is returned when a registry key or value does not exist.
ErrNotExist = syscall.ERROR_FILE_NOT_FOUND
// ErrUnexpectedType is returned by Get*Value when the value's type was unexpected.
ErrUnexpectedType = errors.New("unexpected key value type")
)
// GetValue retrieves the type and data for the specified value associated
// with an open key k. It fills up buffer buf and returns the retrieved
// byte count n. If buf is too small to fit the stored value it returns
// ErrShortBuffer error along with the required buffer size n.
// If no buffer is provided, it returns true and actual buffer size n.
// If no buffer is provided, GetValue returns the value's type only.
// If the value does not exist, the error returned is ErrNotExist.
//
// GetValue is a low level function. If value's type is known, use the appropriate
// Get*Value function instead.
func (k Key) GetValue(name string, buf []byte) (n int, valtype uint32, err error) {
pname, err := syscall.UTF16PtrFromString(name)
if err != nil {
return 0, 0, err
}
var pbuf *byte
if len(buf) > 0 {
pbuf = (*byte)(unsafe.Pointer(&buf[0]))
}
l := uint32(len(buf))
err = syscall.RegQueryValueEx(syscall.Handle(k), pname, nil, &valtype, pbuf, &l)
if err != nil {
return int(l), valtype, err
}
return int(l), valtype, nil
}
func (k Key) getValue(name string, buf []byte) (data []byte, valtype uint32, err error) {
p, err := syscall.UTF16PtrFromString(name)
if err != nil {
return nil, 0, err
}
var t uint32
n := uint32(len(buf))
for {
err = syscall.RegQueryValueEx(syscall.Handle(k), p, nil, &t, (*byte)(unsafe.Pointer(&buf[0])), &n)
if err == nil {
return buf[:n], t, nil
}
if err != syscall.ERROR_MORE_DATA {
return nil, 0, err
}
if n <= uint32(len(buf)) {
return nil, 0, err
}
buf = make([]byte, n)
}
}
// GetStringValue retrieves the string value for the specified
// value name associated with an open key k. It also returns the value's type.
// If value does not exist, GetStringValue returns ErrNotExist.
// If value is not SZ or EXPAND_SZ, it will return the correct value
// type and ErrUnexpectedType.
func (k Key) GetStringValue(name string) (val string, valtype uint32, err error) {
data, typ, err2 := k.getValue(name, make([]byte, 64))
if err2 != nil {
return "", typ, err2
}
switch typ {
case SZ, EXPAND_SZ:
default:
return "", typ, ErrUnexpectedType
}
if len(data) == 0 {
return "", typ, nil
}
u := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2]
return syscall.UTF16ToString(u), typ, nil
}
// GetMUIStringValue retrieves the localized string value for
// the specified value name associated with an open key k.
// If the value name doesn't exist or the localized string value
// can't be resolved, GetMUIStringValue returns ErrNotExist.
// GetMUIStringValue panics if the system doesn't support
// regLoadMUIString; use LoadRegLoadMUIString to check if
// regLoadMUIString is supported before calling this function.
func (k Key) GetMUIStringValue(name string) (string, error) {
pname, err := syscall.UTF16PtrFromString(name)
if err != nil {
return "", err
}
buf := make([]uint16, 1024)
var buflen uint32
var pdir *uint16
err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir)
if err == syscall.ERROR_FILE_NOT_FOUND { // Try fallback path
// Try to resolve the string value using the system directory as
// a DLL search path; this assumes the string value is of the form
// @[path]\dllname,-strID but with no path given, e.g. @tzres.dll,-320.
// This approach works with tzres.dll but may have to be revised
// in the future to allow callers to provide custom search paths.
var s string
s, err = ExpandString("%SystemRoot%\\system32\\")
if err != nil {
return "", err
}
pdir, err = syscall.UTF16PtrFromString(s)
if err != nil {
return "", err
}
err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir)
}
for err == syscall.ERROR_MORE_DATA { // Grow buffer if needed
if buflen <= uint32(len(buf)) {
break // Buffer not growing, assume race; break
}
buf = make([]uint16, buflen)
err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir)
}
if err != nil {
return "", err
}
return syscall.UTF16ToString(buf), nil
}
// ExpandString expands environment-variable strings and replaces
// them with the values defined for the current user.
// Use ExpandString to expand EXPAND_SZ strings.
func ExpandString(value string) (string, error) {
if value == "" {
return "", nil
}
p, err := syscall.UTF16PtrFromString(value)
if err != nil {
return "", err
}
r := make([]uint16, 100)
for {
n, err := expandEnvironmentStrings(p, &r[0], uint32(len(r)))
if err != nil {
return "", err
}
if n <= uint32(len(r)) {
return syscall.UTF16ToString(r[:n]), nil
}
r = make([]uint16, n)
}
}
// GetStringsValue retrieves the []string value for the specified
// value name associated with an open key k. It also returns the value's type.
// If value does not exist, GetStringsValue returns ErrNotExist.
// If value is not MULTI_SZ, it will return the correct value
// type and ErrUnexpectedType.
func (k Key) GetStringsValue(name string) (val []string, valtype uint32, err error) {
data, typ, err2 := k.getValue(name, make([]byte, 64))
if err2 != nil {
return nil, typ, err2
}
if typ != MULTI_SZ {
return nil, typ, ErrUnexpectedType
}
if len(data) == 0 {
return nil, typ, nil
}
p := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2]
if len(p) == 0 {
return nil, typ, nil
}
if p[len(p)-1] == 0 {
p = p[:len(p)-1] // remove terminating null
}
val = make([]string, 0, 5)
from := 0
for i, c := range p {
if c == 0 {
val = append(val, string(utf16.Decode(p[from:i])))
from = i + 1
}
}
return val, typ, nil
}
// GetIntegerValue retrieves the integer value for the specified
// value name associated with an open key k. It also returns the value's type.
// If value does not exist, GetIntegerValue returns ErrNotExist.
// If value is not DWORD or QWORD, it will return the correct value
// type and ErrUnexpectedType.
func (k Key) GetIntegerValue(name string) (val uint64, valtype uint32, err error) {
data, typ, err2 := k.getValue(name, make([]byte, 8))
if err2 != nil {
return 0, typ, err2
}
switch typ {
case DWORD:
if len(data) != 4 {
return 0, typ, errors.New("DWORD value is not 4 bytes long")
}
var val32 uint32
copy((*[4]byte)(unsafe.Pointer(&val32))[:], data)
return uint64(val32), DWORD, nil
case QWORD:
if len(data) != 8 {
return 0, typ, errors.New("QWORD value is not 8 bytes long")
}
copy((*[8]byte)(unsafe.Pointer(&val))[:], data)
return val, QWORD, nil
default:
return 0, typ, ErrUnexpectedType
}
}
// GetBinaryValue retrieves the binary value for the specified
// value name associated with an open key k. It also returns the value's type.
// If value does not exist, GetBinaryValue returns ErrNotExist.
// If value is not BINARY, it will return the correct value
// type and ErrUnexpectedType.
func (k Key) GetBinaryValue(name string) (val []byte, valtype uint32, err error) {
data, typ, err2 := k.getValue(name, make([]byte, 64))
if err2 != nil {
return nil, typ, err2
}
if typ != BINARY {
return nil, typ, ErrUnexpectedType
}
return data, typ, nil
}
func (k Key) setValue(name string, valtype uint32, data []byte) error {
p, err := syscall.UTF16PtrFromString(name)
if err != nil {
return err
}
if len(data) == 0 {
return regSetValueEx(syscall.Handle(k), p, 0, valtype, nil, 0)
}
return regSetValueEx(syscall.Handle(k), p, 0, valtype, &data[0], uint32(len(data)))
}
// SetDWordValue sets the data and type of a name value
// under key k to value and DWORD.
func (k Key) SetDWordValue(name string, value uint32) error {
return k.setValue(name, DWORD, (*[4]byte)(unsafe.Pointer(&value))[:])
}
// SetQWordValue sets the data and type of a name value
// under key k to value and QWORD.
func (k Key) SetQWordValue(name string, value uint64) error {
return k.setValue(name, QWORD, (*[8]byte)(unsafe.Pointer(&value))[:])
}
func (k Key) setStringValue(name string, valtype uint32, value string) error {
v, err := syscall.UTF16FromString(value)
if err != nil {
return err
}
buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2]
return k.setValue(name, valtype, buf)
}
// SetStringValue sets the data and type of a name value
// under key k to value and SZ. The value must not contain a zero byte.
func (k Key) SetStringValue(name, value string) error {
return k.setStringValue(name, SZ, value)
}
// SetExpandStringValue sets the data and type of a name value
// under key k to value and EXPAND_SZ. The value must not contain a zero byte.
func (k Key) SetExpandStringValue(name, value string) error {
return k.setStringValue(name, EXPAND_SZ, value)
}
// SetStringsValue sets the data and type of a name value
// under key k to value and MULTI_SZ. The value strings
// must not contain a zero byte.
func (k Key) SetStringsValue(name string, value []string) error {
ss := ""
for _, s := range value {
for i := 0; i < len(s); i++ {
if s[i] == 0 {
return errors.New("string cannot have 0 inside")
}
}
ss += s + "\x00"
}
v := utf16.Encode([]rune(ss + "\x00"))
buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2]
return k.setValue(name, MULTI_SZ, buf)
}
// SetBinaryValue sets the data and type of a name value
// under key k to value and BINARY.
func (k Key) SetBinaryValue(name string, value []byte) error {
return k.setValue(name, BINARY, value)
}
// DeleteValue removes a named value from the key k.
func (k Key) DeleteValue(name string) error {
return regDeleteValue(syscall.Handle(k), syscall.StringToUTF16Ptr(name))
}
// ReadValueNames returns the value names of key k.
// The parameter n controls the number of returned names,
// analogous to the way os.File.Readdirnames works.
func (k Key) ReadValueNames(n int) ([]string, error) {
ki, err := k.Stat()
if err != nil {
return nil, err
}
names := make([]string, 0, ki.ValueCount)
buf := make([]uint16, ki.MaxValueNameLen+1) // extra room for terminating null character
loopItems:
for i := uint32(0); ; i++ {
if n > 0 {
if len(names) == n {
return names, nil
}
}
l := uint32(len(buf))
for {
err := regEnumValue(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
if err == nil {
break
}
if err == syscall.ERROR_MORE_DATA {
// Double buffer size and try again.
l = uint32(2 * len(buf))
buf = make([]uint16, l)
continue
}
if err == _ERROR_NO_MORE_ITEMS {
break loopItems
}
return names, err
}
names = append(names, syscall.UTF16ToString(buf[:l]))
}
if n > len(names) {
return names, io.EOF
}
return names, nil
}