winpipe: update with latest changes from CL299009

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 39 insertions, 31 deletions

diff --git a/ipc/winpipe/winpipe.go b/ipc/winpipe/winpipe.go
index e3719d6..d34ba82 100644
--- a/ipc/winpipe/winpipe.go
+++ b/ipc/winpipe/winpipe.go
@@ -1,11 +1,11 @@
-//go:build windows
-
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2005 Microsoft
  * Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2015 Microsoft
  */
 
+//go:build windows
+
 // Package winpipe implements a net.Conn and net.Listener around Windows named pipes.
 package winpipe
 
@@ -15,6 +15,7 @@ import (
 	"net"
 	"os"
 	"runtime"
+	"sync/atomic"
 	"time"
 	"unsafe"
 
@@ -28,7 +29,7 @@ type pipe struct {
 
 type messageBytePipe struct {
 	pipe
-	writeClosed bool
+	writeClosed int32
 	readEOF     bool
 }
 
@@ -50,25 +51,26 @@ func (f *pipe) SetDeadline(t time.Time) error {
 
 // CloseWrite closes the write side of a message pipe in byte mode.
 func (f *messageBytePipe) CloseWrite() error {
-	if f.writeClosed {
+	if !atomic.CompareAndSwapInt32(&f.writeClosed, 0, 1) {
 		return io.ErrClosedPipe
 	}
 	err := f.file.Flush()
 	if err != nil {
+		atomic.StoreInt32(&f.writeClosed, 0)
 		return err
 	}
 	_, err = f.file.Write(nil)
 	if err != nil {
+		atomic.StoreInt32(&f.writeClosed, 0)
 		return err
 	}
-	f.writeClosed = true
 	return nil
 }
 
 // Write writes bytes to a message pipe in byte mode. Zero-byte writes are ignored, since
 // they are used to implement CloseWrite.
 func (f *messageBytePipe) Write(b []byte) (int, error) {
-	if f.writeClosed {
+	if atomic.LoadInt32(&f.writeClosed) != 0 {
 		return 0, io.ErrClosedPipe
 	}
 	if len(b) == 0 {
@@ -142,30 +144,24 @@ type DialConfig struct {
 	ExpectedOwner *windows.SID // If non-nil, the pipe is verified to be owned by this SID.
 }
 
-// Dial connects to the specified named pipe by path, timing out if the connection
-// takes longer than the specified duration. If timeout is nil, then we use
-// a default timeout of 2 seconds.
-func Dial(path string, timeout *time.Duration, config *DialConfig) (net.Conn, error) {
-	var absTimeout time.Time
-	if timeout != nil {
-		absTimeout = time.Now().Add(*timeout)
-	} else {
-		absTimeout = time.Now().Add(2 * time.Second)
+// DialTimeout connects to the specified named pipe by path, timing out if the
+// connection  takes longer than the specified duration. If timeout is zero, then
+// we use a default timeout of 2 seconds.
+func (config *DialConfig) DialTimeout(path string, timeout time.Duration) (net.Conn, error) {
+	if timeout == 0 {
+		timeout = time.Second * 2
 	}
+	absTimeout := time.Now().Add(timeout)
 	ctx, _ := context.WithDeadline(context.Background(), absTimeout)
-	conn, err := DialContext(ctx, path, config)
+	conn, err := config.DialContext(ctx, path)
 	if err == context.DeadlineExceeded {
 		return nil, os.ErrDeadlineExceeded
 	}
 	return conn, err
 }
 
-// DialContext attempts to connect to the specified named pipe by path
-// cancellation or timeout.
-func DialContext(ctx context.Context, path string, config *DialConfig) (net.Conn, error) {
-	if config == nil {
-		config = &DialConfig{}
-	}
+// DialContext attempts to connect to the specified named pipe by path.
+func (config *DialConfig) DialContext(ctx context.Context, path string) (net.Conn, error) {
 	var err error
 	var h windows.Handle
 	h, err = tryDialPipe(ctx, &path)
@@ -213,6 +209,18 @@ func DialContext(ctx context.Context, path string, config *DialConfig) (net.Conn
 	return &pipe{file: f, path: path}, nil
 }
 
+var defaultDialer DialConfig
+
+// DialTimeout calls DialConfig.DialTimeout using an empty configuration.
+func DialTimeout(path string, timeout time.Duration) (net.Conn, error) {
+	return defaultDialer.DialTimeout(path, timeout)
+}
+
+// DialContext calls DialConfig.DialContext using an empty configuration.
+func DialContext(ctx context.Context, path string) (net.Conn, error) {
+	return defaultDialer.DialContext(ctx, path)
+}
+
 type acceptResponse struct {
 	f   *file
 	err error
@@ -222,12 +230,12 @@ type pipeListener struct {
 	firstHandle windows.Handle
 	path        string
 	config      ListenConfig
-	acceptCh    chan (chan acceptResponse)
+	acceptCh    chan chan acceptResponse
 	closeCh     chan int
 	doneCh      chan int
 }
 
-func makeServerPipeHandle(path string, sd *windows.SECURITY_DESCRIPTOR, c *ListenConfig, first bool) (windows.Handle, error) {
+func makeServerPipeHandle(path string, sd *windows.SECURITY_DESCRIPTOR, c *ListenConfig, isFirstPipe bool) (windows.Handle, error) {
 	path16, err := windows.UTF16PtrFromString(path)
 	if err != nil {
 		return 0, &os.PathError{Op: "open", Path: path, Err: err}
@@ -247,7 +255,7 @@ func makeServerPipeHandle(path string, sd *windows.SECURITY_DESCRIPTOR, c *Liste
 	oa.ObjectName = &ntPath
 
 	// The security descriptor is only needed for the first pipe.
-	if first {
+	if isFirstPipe {
 		if sd != nil {
 			oa.SecurityDescriptor = sd
 		} else {
@@ -257,7 +265,7 @@ func makeServerPipeHandle(path string, sd *windows.SECURITY_DESCRIPTOR, c *Liste
 				return 0, err
 			}
 			defer windows.LocalFree(windows.Handle(unsafe.Pointer(acl)))
-			sd, err := windows.NewSecurityDescriptor()
+			sd, err = windows.NewSecurityDescriptor()
 			if err != nil {
 				return 0, err
 			}
@@ -275,11 +283,11 @@ func makeServerPipeHandle(path string, sd *windows.SECURITY_DESCRIPTOR, c *Liste
 
 	disposition := uint32(windows.FILE_OPEN)
 	access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE | windows.SYNCHRONIZE)
-	if first {
+	if isFirstPipe {
 		disposition = windows.FILE_CREATE
 		// By not asking for read or write access, the named pipe file system
 		// will put this pipe into an initially disconnected state, blocking
-		// client connections until the next call with first == false.
+		// client connections until the next call with isFirstPipe == false.
 		access = windows.SYNCHRONIZE
 	}
 
@@ -407,12 +415,12 @@ func Listen(path string, c *ListenConfig) (net.Listener, error) {
 		firstHandle: h,
 		path:        path,
 		config:      *c,
-		acceptCh:    make(chan (chan acceptResponse)),
+		acceptCh:    make(chan chan acceptResponse),
 		closeCh:     make(chan int),
 		doneCh:      make(chan int),
 	}
 	// The first connection is swallowed on Windows 7 & 8, so synthesize it.
-	if maj, _, _ := windows.RtlGetNtVersionNumbers(); maj <= 8 {
+	if maj, min, _ := windows.RtlGetNtVersionNumbers(); maj < 6 || (maj == 6 && min < 4) {
 		path16, err := windows.UTF16PtrFromString(path)
 		if err == nil {
 			h, err = windows.CreateFile(path16, 0, 0, nil, windows.OPEN_EXISTING, windows.SECURITY_SQOS_PRESENT|windows.SECURITY_ANONYMOUS, 0)