58a8f05f50
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com> [Jason: ran go mod tidy.] Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
273 lines
8 KiB
Go
273 lines
8 KiB
Go
/* SPDX-License-Identifier: MIT
|
|
*
|
|
* Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
|
|
*/
|
|
|
|
package registry
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"runtime"
|
|
"strings"
|
|
"time"
|
|
"unsafe"
|
|
|
|
"golang.org/x/sys/windows"
|
|
"golang.org/x/sys/windows/registry"
|
|
)
|
|
|
|
const (
|
|
// REG_NOTIFY_CHANGE_NAME notifies the caller if a subkey is added or deleted.
|
|
REG_NOTIFY_CHANGE_NAME uint32 = 0x00000001
|
|
|
|
// REG_NOTIFY_CHANGE_ATTRIBUTES notifies the caller of changes to the attributes of the key, such as the security descriptor information.
|
|
REG_NOTIFY_CHANGE_ATTRIBUTES uint32 = 0x00000002
|
|
|
|
// REG_NOTIFY_CHANGE_LAST_SET notifies the caller of changes to a value of the key. This can include adding or deleting a value, or changing an existing value.
|
|
REG_NOTIFY_CHANGE_LAST_SET uint32 = 0x00000004
|
|
|
|
// REG_NOTIFY_CHANGE_SECURITY notifies the caller of changes to the security descriptor of the key.
|
|
REG_NOTIFY_CHANGE_SECURITY uint32 = 0x00000008
|
|
|
|
// REG_NOTIFY_THREAD_AGNOSTIC indicates that the lifetime of the registration must not be tied to the lifetime of the thread issuing the RegNotifyChangeKeyValue call. Note: This flag value is only supported in Windows 8 and later.
|
|
REG_NOTIFY_THREAD_AGNOSTIC uint32 = 0x10000000
|
|
)
|
|
|
|
//sys regNotifyChangeKeyValue(key windows.Handle, watchSubtree bool, notifyFilter uint32, event windows.Handle, asynchronous bool) (regerrno error) = advapi32.RegNotifyChangeKeyValue
|
|
|
|
func OpenKeyWait(k registry.Key, path string, access uint32, timeout time.Duration) (registry.Key, error) {
|
|
runtime.LockOSThread()
|
|
defer runtime.UnlockOSThread()
|
|
|
|
deadline := time.Now().Add(timeout)
|
|
pathSpl := strings.Split(path, "\\")
|
|
for i := 0; ; i++ {
|
|
keyName := pathSpl[i]
|
|
isLast := i+1 == len(pathSpl)
|
|
|
|
event, err := windows.CreateEvent(nil, 0, 0, nil)
|
|
if err != nil {
|
|
return 0, fmt.Errorf("Error creating event: %v", err)
|
|
}
|
|
defer windows.CloseHandle(event)
|
|
|
|
var key registry.Key
|
|
for {
|
|
err = regNotifyChangeKeyValue(windows.Handle(k), false, REG_NOTIFY_CHANGE_NAME, windows.Handle(event), true)
|
|
if err != nil {
|
|
return 0, fmt.Errorf("Setting up change notification on registry key failed: %v", err)
|
|
}
|
|
|
|
var accessFlags uint32
|
|
if isLast {
|
|
accessFlags = access
|
|
} else {
|
|
accessFlags = registry.NOTIFY
|
|
}
|
|
key, err = registry.OpenKey(k, keyName, accessFlags)
|
|
if err == windows.ERROR_FILE_NOT_FOUND || err == windows.ERROR_PATH_NOT_FOUND {
|
|
timeout := time.Until(deadline) / time.Millisecond
|
|
if timeout < 0 {
|
|
timeout = 0
|
|
}
|
|
s, err := windows.WaitForSingleObject(event, uint32(timeout))
|
|
if err != nil {
|
|
return 0, fmt.Errorf("Unable to wait on registry key: %v", err)
|
|
}
|
|
if s == uint32(windows.WAIT_TIMEOUT) { // windows.WAIT_TIMEOUT status const is misclassified as error in golang.org/x/sys/windows
|
|
return 0, errors.New("Timeout waiting for registry key")
|
|
}
|
|
} else if err != nil {
|
|
return 0, fmt.Errorf("Error opening registry key %v: %v", path, err)
|
|
} else {
|
|
if isLast {
|
|
return key, nil
|
|
}
|
|
defer key.Close()
|
|
break
|
|
}
|
|
}
|
|
|
|
k = key
|
|
}
|
|
}
|
|
|
|
func WaitForKey(k registry.Key, path string, timeout time.Duration) error {
|
|
key, err := OpenKeyWait(k, path, registry.NOTIFY, timeout)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
key.Close()
|
|
return nil
|
|
}
|
|
|
|
//
|
|
// getValue is more or less the same as windows/registry's getValue.
|
|
//
|
|
func getValue(k registry.Key, name string, buf []byte) (value []byte, valueType uint32, err error) {
|
|
var name16 *uint16
|
|
name16, err = windows.UTF16PtrFromString(name)
|
|
if err != nil {
|
|
return
|
|
}
|
|
n := uint32(len(buf))
|
|
for {
|
|
err = windows.RegQueryValueEx(windows.Handle(k), name16, nil, &valueType, (*byte)(unsafe.Pointer(&buf[0])), &n)
|
|
if err == nil {
|
|
value = buf[:n]
|
|
return
|
|
}
|
|
if err != windows.ERROR_MORE_DATA {
|
|
return
|
|
}
|
|
if n <= uint32(len(buf)) {
|
|
return
|
|
}
|
|
buf = make([]byte, n)
|
|
}
|
|
}
|
|
|
|
//
|
|
// getValueRetry function reads any value from registry. It waits for
|
|
// the registry value to become available or returns error on timeout.
|
|
//
|
|
// Key must be opened with at least QUERY_VALUE|NOTIFY access.
|
|
//
|
|
func getValueRetry(key registry.Key, name string, buf []byte, timeout time.Duration) ([]byte, uint32, error) {
|
|
runtime.LockOSThread()
|
|
defer runtime.UnlockOSThread()
|
|
|
|
event, err := windows.CreateEvent(nil, 0, 0, nil)
|
|
if err != nil {
|
|
return nil, 0, fmt.Errorf("Error creating event: %v", err)
|
|
}
|
|
defer windows.CloseHandle(event)
|
|
|
|
deadline := time.Now().Add(timeout)
|
|
for {
|
|
err := regNotifyChangeKeyValue(windows.Handle(key), false, REG_NOTIFY_CHANGE_LAST_SET, windows.Handle(event), true)
|
|
if err != nil {
|
|
return nil, 0, fmt.Errorf("Setting up change notification on registry value failed: %v", err)
|
|
}
|
|
|
|
buf, valueType, err := getValue(key, name, buf)
|
|
if err == windows.ERROR_FILE_NOT_FOUND || err == windows.ERROR_PATH_NOT_FOUND {
|
|
timeout := time.Until(deadline) / time.Millisecond
|
|
if timeout < 0 {
|
|
timeout = 0
|
|
}
|
|
s, err := windows.WaitForSingleObject(event, uint32(timeout))
|
|
if err != nil {
|
|
return nil, 0, fmt.Errorf("Unable to wait on registry value: %v", err)
|
|
}
|
|
if s == uint32(windows.WAIT_TIMEOUT) { // windows.WAIT_TIMEOUT status const is misclassified as error in golang.org/x/sys/windows
|
|
return nil, 0, errors.New("Timeout waiting for registry value")
|
|
}
|
|
} else if err != nil {
|
|
return nil, 0, fmt.Errorf("Error reading registry value %v: %v", name, err)
|
|
} else {
|
|
return buf, valueType, nil
|
|
}
|
|
}
|
|
}
|
|
|
|
func toString(buf []byte, valueType uint32, err error) (string, error) {
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
var value string
|
|
switch valueType {
|
|
case registry.SZ, registry.EXPAND_SZ, registry.MULTI_SZ:
|
|
if len(buf) == 0 {
|
|
return "", nil
|
|
}
|
|
value = windows.UTF16PtrToString((*uint16)(unsafe.Pointer(&buf[0])))
|
|
|
|
default:
|
|
return "", registry.ErrUnexpectedType
|
|
}
|
|
|
|
if valueType != registry.EXPAND_SZ {
|
|
// Value does not require expansion.
|
|
return value, nil
|
|
}
|
|
|
|
valueExp, err := registry.ExpandString(value)
|
|
if err != nil {
|
|
// Expanding failed: return original sting value.
|
|
return value, nil
|
|
}
|
|
|
|
// Return expanded value.
|
|
return valueExp, nil
|
|
}
|
|
|
|
func toInteger(buf []byte, valueType uint32, err error) (uint64, error) {
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
switch valueType {
|
|
case registry.DWORD:
|
|
if len(buf) != 4 {
|
|
return 0, errors.New("DWORD value is not 4 bytes long")
|
|
}
|
|
var val uint32
|
|
copy((*[4]byte)(unsafe.Pointer(&val))[:], buf)
|
|
return uint64(val), nil
|
|
|
|
case registry.QWORD:
|
|
if len(buf) != 8 {
|
|
return 0, errors.New("QWORD value is not 8 bytes long")
|
|
}
|
|
var val uint64
|
|
copy((*[8]byte)(unsafe.Pointer(&val))[:], buf)
|
|
return val, nil
|
|
|
|
default:
|
|
return 0, registry.ErrUnexpectedType
|
|
}
|
|
}
|
|
|
|
//
|
|
// GetStringValueWait function reads a string value from registry. It waits
|
|
// for the registry value to become available or returns error on timeout.
|
|
//
|
|
// Key must be opened with at least QUERY_VALUE|NOTIFY access.
|
|
//
|
|
// If the value type is REG_EXPAND_SZ the environment variables are expanded.
|
|
// Should expanding fail, original string value and nil error are returned.
|
|
//
|
|
// If the value type is REG_MULTI_SZ only the first string is returned.
|
|
//
|
|
func GetStringValueWait(key registry.Key, name string, timeout time.Duration) (string, error) {
|
|
return toString(getValueRetry(key, name, make([]byte, 256), timeout))
|
|
}
|
|
|
|
//
|
|
// GetStringValue function reads a string value from registry.
|
|
//
|
|
// Key must be opened with at least QUERY_VALUE access.
|
|
//
|
|
// If the value type is REG_EXPAND_SZ the environment variables are expanded.
|
|
// Should expanding fail, original string value and nil error are returned.
|
|
//
|
|
// If the value type is REG_MULTI_SZ only the first string is returned.
|
|
//
|
|
func GetStringValue(key registry.Key, name string) (string, error) {
|
|
return toString(getValue(key, name, make([]byte, 256)))
|
|
}
|
|
|
|
//
|
|
// GetIntegerValueWait function reads a DWORD32 or QWORD value from registry.
|
|
// It waits for the registry value to become available or returns error on
|
|
// timeout.
|
|
//
|
|
// Key must be opened with at least QUERY_VALUE|NOTIFY access.
|
|
//
|
|
func GetIntegerValueWait(key registry.Key, name string, timeout time.Duration) (uint64, error) {
|
|
return toInteger(getValueRetry(key, name, make([]byte, 8), timeout))
|
|
}
|