mirror of
https://github.com/tailscale/tailscale.git
synced 2024-12-04 23:45:34 +00:00
f95785f22b
Fixes #13182 Signed-off-by: Aaron Klotz <aaron@tailscale.com>
320 lines
10 KiB
Go
320 lines
10 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
|
|
// SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
package winutil
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"os"
|
|
"slices"
|
|
"unsafe"
|
|
|
|
"github.com/dblohm7/wingoes"
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
var (
|
|
// ErrAlreadyResolved is returned by (*StartupInfoBuilder).Resolve when the
|
|
// StartupInfoBuilder has already been resolved.
|
|
ErrAlreadyResolved = errors.New("StartupInfo already resolved")
|
|
// ErrAlreadySet is returned by StartupInfoBuilder setters if the value
|
|
// has already been set.
|
|
ErrAlreadySet = errors.New("StartupInfoBuilder value already set")
|
|
// ErrTooManyMitigationPolicyArguments is returned by
|
|
// (*StartupInfoBuilder).AddMitigationPolicyFlags if more arguments are
|
|
// passed than are supported by the current version of Windows. This error
|
|
// may be wrapped with additional information, so use [errors.Is] to check for it.
|
|
ErrTooManyMitigationPolicyArguments = errors.New("too many mitigation policy arguments for current Windows version")
|
|
)
|
|
|
|
// Attribute IDs not yet present in x/sys/windows
|
|
const (
|
|
_PROC_THREAD_ATTRIBUTE_JOB_LIST = 0x0002000D
|
|
)
|
|
|
|
// Mitigation flags from the Win32 SDK
|
|
const (
|
|
PROCESS_CREATION_MITIGATION_POLICY_EXTENSION_POINT_DISABLE_ALWAYS_ON = (1 << 32)
|
|
PROCESS_CREATION_MITIGATION_POLICY_BLOCK_NON_MICROSOFT_BINARIES_ALWAYS_ON = (1 << 44)
|
|
PROCESS_CREATION_MITIGATION_POLICY_IMAGE_LOAD_NO_REMOTE_ALWAYS_ON = (1 << 52)
|
|
PROCESS_CREATION_MITIGATION_POLICY_IMAGE_LOAD_NO_LOW_LABEL_ALWAYS_ON = (1 << 56)
|
|
PROCESS_CREATION_MITIGATION_POLICY_IMAGE_LOAD_PREFER_SYSTEM32_ALWAYS_ON = (1 << 60)
|
|
)
|
|
|
|
// StartupInfoBuilder constructs a Windows STARTUPINFOEX and optional
|
|
// process/thread attribute list for use with the CreateProcess family of APIs.
|
|
type StartupInfoBuilder struct {
|
|
siex windows.StartupInfoEx
|
|
attrs map[uintptr]any // attr -> value
|
|
attrContainer *windows.ProcThreadAttributeListContainer
|
|
}
|
|
|
|
func (sib *StartupInfoBuilder) Close() error {
|
|
si := &sib.siex.StartupInfo
|
|
if (si.Flags & windows.STARTF_USESTDHANDLES) != 0 {
|
|
for _, h := range []windows.Handle{si.StdInput, si.StdOutput, si.StdErr} {
|
|
if canBeInherited(h) {
|
|
windows.CloseHandle(h)
|
|
}
|
|
}
|
|
}
|
|
|
|
sib.siex = windows.StartupInfoEx{}
|
|
if sib.attrContainer != nil {
|
|
sib.attrContainer.Delete()
|
|
sib.attrContainer = nil
|
|
}
|
|
|
|
sib.attrs = nil
|
|
return nil
|
|
}
|
|
|
|
// Resolve causes all settings and attributes stored within sib to be processed
|
|
// and formatted into valid arguments for use by CreateProcess* APIs.
|
|
// The returned values will not be altered any further by sib, so the caller
|
|
// is free to make additional customizations to the returned values prior to
|
|
// passing them into CreateProcess.
|
|
func (sib *StartupInfoBuilder) Resolve() (startupInfo *windows.StartupInfo, inheritHandles bool, createProcessFlags uint32, err error) {
|
|
if sib.siex.StartupInfo.Cb != 0 {
|
|
return nil, false, 0, ErrAlreadyResolved
|
|
}
|
|
|
|
// Always create a Unicode environment.
|
|
createProcessFlags = windows.CREATE_UNICODE_ENVIRONMENT
|
|
|
|
if l := uint32(len(sib.attrs)); l > 0 {
|
|
attrCont, err := windows.NewProcThreadAttributeList(l)
|
|
if err != nil {
|
|
return nil, false, 0, err
|
|
}
|
|
defer func() {
|
|
if err != nil {
|
|
attrCont.Delete()
|
|
}
|
|
}()
|
|
|
|
for attr, val := range sib.attrs {
|
|
var pval unsafe.Pointer
|
|
var sval uintptr
|
|
switch v := val.(type) {
|
|
case windows.Handle:
|
|
// An individual handle is pointer-width and is thus passed by value.
|
|
pval = unsafe.Pointer(v)
|
|
sval = unsafe.Sizeof(v)
|
|
case []uint64:
|
|
pval = unsafe.Pointer(unsafe.SliceData(v))
|
|
sval = unsafe.Sizeof(v[0]) * uintptr(len(v))
|
|
case []windows.Handle:
|
|
pval = unsafe.Pointer(unsafe.SliceData(v))
|
|
sval = unsafe.Sizeof(v[0]) * uintptr(len(v))
|
|
default:
|
|
panic("unsupported data type")
|
|
}
|
|
|
|
// Note that pointer keepalives are managed by attrCont.
|
|
if err := attrCont.Update(attr, pval, sval); err != nil {
|
|
return nil, false, 0, err
|
|
}
|
|
|
|
if attr == windows.PROC_THREAD_ATTRIBUTE_HANDLE_LIST {
|
|
inheritHandles = true
|
|
}
|
|
}
|
|
|
|
sib.attrContainer = attrCont
|
|
sib.siex.ProcThreadAttributeList = attrCont.List()
|
|
sib.siex.StartupInfo.Cb = uint32(unsafe.Sizeof(sib.siex))
|
|
createProcessFlags |= windows.EXTENDED_STARTUPINFO_PRESENT
|
|
} else {
|
|
sib.siex.StartupInfo.Cb = uint32(unsafe.Sizeof(sib.siex.StartupInfo))
|
|
}
|
|
|
|
return &sib.siex.StartupInfo, inheritHandles, createProcessFlags, nil
|
|
}
|
|
|
|
func canBeInherited(h windows.Handle) bool {
|
|
if h == 0 || h == windows.InvalidHandle {
|
|
return false
|
|
}
|
|
|
|
ft, _ := windows.GetFileType(h)
|
|
switch ft {
|
|
case windows.FILE_TYPE_DISK, windows.FILE_TYPE_PIPE:
|
|
return true
|
|
case windows.FILE_TYPE_CHAR:
|
|
// Console handles are treated differently from other character devices.
|
|
// In particular, they should not be set up to be inherited like other
|
|
// kernel handles. We determine whether h is a console handle by attempting
|
|
// to retrieve its console mode. If this call fails then h is not a console.
|
|
var mode uint32
|
|
return windows.GetConsoleMode(h, &mode) != nil
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// SetStdHandles sets the StdInput, StdOutput, and StdErr handles and configures
|
|
// their inheritability as needed. When the handles are valid, non-console
|
|
// kernel objects, sib takes ownership of of them. All three handles may be set
|
|
// to zero to indicate that the parent's std handles should not be implicitly
|
|
// inherited.
|
|
//
|
|
// It returns ErrAlreadySet if the handles have already been set by a previous call.
|
|
func (sib *StartupInfoBuilder) SetStdHandles(stdin, stdout, stderr windows.Handle) error {
|
|
if (sib.siex.StartupInfo.Flags & windows.STARTF_USESTDHANDLES) != 0 {
|
|
return ErrAlreadySet
|
|
}
|
|
|
|
toInherit := make([]windows.Handle, 0, 3)
|
|
for _, h := range []windows.Handle{stdin, stdout, stderr} {
|
|
if !canBeInherited(h) {
|
|
continue
|
|
}
|
|
|
|
toInherit = append(toInherit, h)
|
|
}
|
|
|
|
if err := sib.InheritHandles(toInherit...); err != nil {
|
|
return err
|
|
}
|
|
|
|
sib.siex.StartupInfo.Flags |= windows.STARTF_USESTDHANDLES
|
|
sib.siex.StartupInfo.StdInput = stdin
|
|
sib.siex.StartupInfo.StdOutput = stdout
|
|
sib.siex.StartupInfo.StdErr = stderr
|
|
return nil
|
|
}
|
|
|
|
func (sib *StartupInfoBuilder) makeAttrs() {
|
|
if sib.attrs == nil {
|
|
// The size of this map should correspond to the number of distinct
|
|
// attribute values supported by the StartupInfoBuilder API. Currently
|
|
// we support four:
|
|
// * Inheritable handle list;
|
|
// * Pseudoconsole;
|
|
// * Mitigation policy;
|
|
// * Job list
|
|
sib.attrs = make(map[uintptr]any, 4)
|
|
}
|
|
}
|
|
|
|
func (sib *StartupInfoBuilder) getAttr(attr uintptr) any {
|
|
sib.makeAttrs()
|
|
return sib.attrs[attr]
|
|
}
|
|
|
|
// InheritHandles configures each handle in handles to be inheritable and adds
|
|
// it to the inheritable handle list proc/thread attribute. handles must consist
|
|
// entirely of kernel objects (handles that are closed via windows.CloseHandle).
|
|
// InheritHandles may be called multiple times; each successive call accumulates
|
|
// handles into an internal list maintained by sib.
|
|
func (sib *StartupInfoBuilder) InheritHandles(handles ...windows.Handle) error {
|
|
if len(handles) == 0 {
|
|
return nil
|
|
}
|
|
|
|
newHandles := make([]windows.Handle, 0, len(handles))
|
|
for _, h := range handles {
|
|
if h == 0 || h == windows.InvalidHandle || slices.Contains(newHandles, h) {
|
|
continue
|
|
}
|
|
|
|
if err := windows.SetHandleInformation(h, windows.HANDLE_FLAG_INHERIT, windows.HANDLE_FLAG_INHERIT); err != nil {
|
|
return err
|
|
}
|
|
|
|
newHandles = append(newHandles, h)
|
|
}
|
|
|
|
if len(newHandles) == 0 {
|
|
return nil
|
|
}
|
|
|
|
var handleList []windows.Handle
|
|
if attrv := sib.getAttr(windows.PROC_THREAD_ATTRIBUTE_HANDLE_LIST); attrv != nil {
|
|
handleList = attrv.([]windows.Handle)
|
|
}
|
|
|
|
sib.attrs[windows.PROC_THREAD_ATTRIBUTE_HANDLE_LIST] = append(handleList, newHandles...)
|
|
return nil
|
|
}
|
|
|
|
// AddMitigationPolicyFlags sets the process mitigation policy flags in newFlags
|
|
// on the mitigation policy proc/thread attribute. It accepts a different
|
|
// number of arguments depending on the current Windows version. If the
|
|
// current Windows version is Windows 10 build 1703 or newer, it accepts up to
|
|
// two arguments. It only accepts one argument on older versions of Windows 10.
|
|
// If too many arguments are supplied, AddMitigationPolicyFlags returns
|
|
// ErrTooManyMitigationPolicyArguments wrapped with additional information;
|
|
// use errors.Is to check for this error.
|
|
// AddMitigationPolicyFlags may be called multiple times; each successive call
|
|
// accumulates additional flags into the mitigation policy.
|
|
func (sib *StartupInfoBuilder) AddMitigationPolicyFlags(newFlags ...uint64) error {
|
|
if len(newFlags) == 0 {
|
|
return nil
|
|
}
|
|
|
|
supportedLen := 1
|
|
if wingoes.IsWin10BuildOrGreater(wingoes.Win10Build1703) {
|
|
supportedLen++
|
|
}
|
|
|
|
if len(newFlags) > supportedLen {
|
|
return fmt.Errorf("%w: no more than %d allowed", ErrTooManyMitigationPolicyArguments, supportedLen)
|
|
}
|
|
|
|
attrv := sib.getAttr(windows.PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY)
|
|
switch v := attrv.(type) {
|
|
case nil:
|
|
sib.attrs[windows.PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY] = newFlags
|
|
case []uint64:
|
|
if newElems := len(newFlags) - len(v); newElems > 0 {
|
|
v = append(v, make([]uint64, newElems)...)
|
|
sib.attrs[windows.PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY] = v
|
|
}
|
|
for i := range v {
|
|
v[i] |= newFlags[i]
|
|
}
|
|
default:
|
|
panic("unexpected attribute type")
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// SetPseudoConsole sets pty as the pseudoconsole proc/thread attribute.
|
|
// pty must be a conpty handle. It returns ErrAlreadySet if the pty has already
|
|
// been successfully set by a previous call.
|
|
func (sib *StartupInfoBuilder) SetPseudoConsole(pty windows.Handle) error {
|
|
if pty == 0 {
|
|
return os.ErrInvalid
|
|
}
|
|
|
|
if attrv := sib.getAttr(windows.PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE); attrv != nil {
|
|
return ErrAlreadySet
|
|
}
|
|
|
|
sib.attrs[windows.PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE] = pty
|
|
return nil
|
|
}
|
|
|
|
// AssignToJob assigns the process created by sib to job. AssignToJob may be
|
|
// called multiple times to assign the process to multiple jobs.
|
|
func (sib *StartupInfoBuilder) AssignToJob(job windows.Handle) error {
|
|
if job == 0 {
|
|
return os.ErrInvalid
|
|
}
|
|
|
|
var jobList []windows.Handle
|
|
if attrv := sib.getAttr(_PROC_THREAD_ATTRIBUTE_JOB_LIST); attrv != nil {
|
|
jobList = attrv.([]windows.Handle)
|
|
}
|
|
if slices.Contains(jobList, job) {
|
|
return nil
|
|
}
|
|
|
|
sib.attrs[_PROC_THREAD_ATTRIBUTE_JOB_LIST] = append(jobList, job)
|
|
return nil
|
|
}
|