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-rw-r--r--ipc/namedpipe/namedpipe.go485
1 files changed, 485 insertions, 0 deletions
diff --git a/ipc/namedpipe/namedpipe.go b/ipc/namedpipe/namedpipe.go
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+++ b/ipc/namedpipe/namedpipe.go
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+// Copyright 2021 The Go Authors. All rights reserved.
+// Copyright 2015 Microsoft
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+// Package namedpipe implements a net.Conn and net.Listener around Windows named pipes.
+package namedpipe
+
+import (
+ "context"
+ "io"
+ "net"
+ "os"
+ "runtime"
+ "sync/atomic"
+ "time"
+ "unsafe"
+
+ "golang.org/x/sys/windows"
+)
+
+type pipe struct {
+ *file
+ path string
+}
+
+type messageBytePipe struct {
+ pipe
+ writeClosed atomic.Bool
+ readEOF bool
+}
+
+type pipeAddress string
+
+func (f *pipe) LocalAddr() net.Addr {
+ return pipeAddress(f.path)
+}
+
+func (f *pipe) RemoteAddr() net.Addr {
+ return pipeAddress(f.path)
+}
+
+func (f *pipe) SetDeadline(t time.Time) error {
+ f.SetReadDeadline(t)
+ f.SetWriteDeadline(t)
+ return nil
+}
+
+// CloseWrite closes the write side of a message pipe in byte mode.
+func (f *messageBytePipe) CloseWrite() error {
+ if !f.writeClosed.CompareAndSwap(false, true) {
+ return io.ErrClosedPipe
+ }
+ err := f.file.Flush()
+ if err != nil {
+ f.writeClosed.Store(false)
+ return err
+ }
+ _, err = f.file.Write(nil)
+ if err != nil {
+ f.writeClosed.Store(false)
+ return err
+ }
+ 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.Load() {
+ return 0, io.ErrClosedPipe
+ }
+ if len(b) == 0 {
+ return 0, nil
+ }
+ return f.file.Write(b)
+}
+
+// Read reads bytes from a message pipe in byte mode. A read of a zero-byte message on a message
+// mode pipe will return io.EOF, as will all subsequent reads.
+func (f *messageBytePipe) Read(b []byte) (int, error) {
+ if f.readEOF {
+ return 0, io.EOF
+ }
+ n, err := f.file.Read(b)
+ if err == io.EOF {
+ // If this was the result of a zero-byte read, then
+ // it is possible that the read was due to a zero-size
+ // message. Since we are simulating CloseWrite with a
+ // zero-byte message, ensure that all future Read calls
+ // also return EOF.
+ f.readEOF = true
+ } else if err == windows.ERROR_MORE_DATA {
+ // ERROR_MORE_DATA indicates that the pipe's read mode is message mode
+ // and the message still has more bytes. Treat this as a success, since
+ // this package presents all named pipes as byte streams.
+ err = nil
+ }
+ return n, err
+}
+
+func (f *pipe) Handle() windows.Handle {
+ return f.handle
+}
+
+func (s pipeAddress) Network() string {
+ return "pipe"
+}
+
+func (s pipeAddress) String() string {
+ return string(s)
+}
+
+// tryDialPipe attempts to dial the specified pipe until cancellation or timeout.
+func tryDialPipe(ctx context.Context, path *string) (windows.Handle, error) {
+ for {
+ select {
+ case <-ctx.Done():
+ return 0, ctx.Err()
+ default:
+ path16, err := windows.UTF16PtrFromString(*path)
+ if err != nil {
+ return 0, err
+ }
+ h, err := windows.CreateFile(path16, windows.GENERIC_READ|windows.GENERIC_WRITE, 0, nil, windows.OPEN_EXISTING, windows.FILE_FLAG_OVERLAPPED|windows.SECURITY_SQOS_PRESENT|windows.SECURITY_ANONYMOUS, 0)
+ if err == nil {
+ return h, nil
+ }
+ if err != windows.ERROR_PIPE_BUSY {
+ return h, &os.PathError{Err: err, Op: "open", Path: *path}
+ }
+ // Wait 10 msec and try again. This is a rather simplistic
+ // view, as we always try each 10 milliseconds.
+ time.Sleep(10 * time.Millisecond)
+ }
+ }
+}
+
+// DialConfig exposes various options for use in Dial and DialContext.
+type DialConfig struct {
+ ExpectedOwner *windows.SID // If non-nil, the pipe is verified to be owned by this SID.
+}
+
+// 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 := 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.
+func (config *DialConfig) DialContext(ctx context.Context, path string) (net.Conn, error) {
+ var err error
+ var h windows.Handle
+ h, err = tryDialPipe(ctx, &path)
+ if err != nil {
+ return nil, err
+ }
+
+ if config.ExpectedOwner != nil {
+ sd, err := windows.GetSecurityInfo(h, windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+ if err != nil {
+ windows.Close(h)
+ return nil, err
+ }
+ realOwner, _, err := sd.Owner()
+ if err != nil {
+ windows.Close(h)
+ return nil, err
+ }
+ if !realOwner.Equals(config.ExpectedOwner) {
+ windows.Close(h)
+ return nil, windows.ERROR_ACCESS_DENIED
+ }
+ }
+
+ var flags uint32
+ err = windows.GetNamedPipeInfo(h, &flags, nil, nil, nil)
+ if err != nil {
+ windows.Close(h)
+ return nil, err
+ }
+
+ f, err := makeFile(h)
+ if err != nil {
+ windows.Close(h)
+ return nil, err
+ }
+
+ // If the pipe is in message mode, return a message byte pipe, which
+ // supports CloseWrite.
+ if flags&windows.PIPE_TYPE_MESSAGE != 0 {
+ return &messageBytePipe{
+ pipe: pipe{file: f, path: path},
+ }, nil
+ }
+ 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
+}
+
+type pipeListener struct {
+ firstHandle windows.Handle
+ path string
+ config ListenConfig
+ acceptCh chan chan acceptResponse
+ closeCh chan int
+ doneCh chan int
+}
+
+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}
+ }
+
+ var oa windows.OBJECT_ATTRIBUTES
+ oa.Length = uint32(unsafe.Sizeof(oa))
+
+ var ntPath windows.NTUnicodeString
+ if err := windows.RtlDosPathNameToNtPathName(path16, &ntPath, nil, nil); err != nil {
+ if ntstatus, ok := err.(windows.NTStatus); ok {
+ err = ntstatus.Errno()
+ }
+ return 0, &os.PathError{Op: "open", Path: path, Err: err}
+ }
+ defer windows.LocalFree(windows.Handle(unsafe.Pointer(ntPath.Buffer)))
+ oa.ObjectName = &ntPath
+
+ // The security descriptor is only needed for the first pipe.
+ if isFirstPipe {
+ if sd != nil {
+ oa.SecurityDescriptor = sd
+ } else {
+ // Construct the default named pipe security descriptor.
+ var acl *windows.ACL
+ if err := windows.RtlDefaultNpAcl(&acl); err != nil {
+ return 0, err
+ }
+ defer windows.LocalFree(windows.Handle(unsafe.Pointer(acl)))
+ sd, err = windows.NewSecurityDescriptor()
+ if err != nil {
+ return 0, err
+ }
+ if err = sd.SetDACL(acl, true, false); err != nil {
+ return 0, err
+ }
+ oa.SecurityDescriptor = sd
+ }
+ }
+
+ typ := uint32(windows.FILE_PIPE_REJECT_REMOTE_CLIENTS)
+ if c.MessageMode {
+ typ |= windows.FILE_PIPE_MESSAGE_TYPE
+ }
+
+ disposition := uint32(windows.FILE_OPEN)
+ access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE | windows.SYNCHRONIZE)
+ 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 isFirstPipe == false.
+ access = windows.SYNCHRONIZE
+ }
+
+ timeout := int64(-50 * 10000) // 50ms
+
+ var (
+ h windows.Handle
+ iosb windows.IO_STATUS_BLOCK
+ )
+ err = windows.NtCreateNamedPipeFile(&h, access, &oa, &iosb, windows.FILE_SHARE_READ|windows.FILE_SHARE_WRITE, disposition, 0, typ, 0, 0, 0xffffffff, uint32(c.InputBufferSize), uint32(c.OutputBufferSize), &timeout)
+ if err != nil {
+ if ntstatus, ok := err.(windows.NTStatus); ok {
+ err = ntstatus.Errno()
+ }
+ return 0, &os.PathError{Op: "open", Path: path, Err: err}
+ }
+
+ runtime.KeepAlive(ntPath)
+ return h, nil
+}
+
+func (l *pipeListener) makeServerPipe() (*file, error) {
+ h, err := makeServerPipeHandle(l.path, nil, &l.config, false)
+ if err != nil {
+ return nil, err
+ }
+ f, err := makeFile(h)
+ if err != nil {
+ windows.Close(h)
+ return nil, err
+ }
+ return f, nil
+}
+
+func (l *pipeListener) makeConnectedServerPipe() (*file, error) {
+ p, err := l.makeServerPipe()
+ if err != nil {
+ return nil, err
+ }
+
+ // Wait for the client to connect.
+ ch := make(chan error)
+ go func(p *file) {
+ ch <- connectPipe(p)
+ }(p)
+
+ select {
+ case err = <-ch:
+ if err != nil {
+ p.Close()
+ p = nil
+ }
+ case <-l.closeCh:
+ // Abort the connect request by closing the handle.
+ p.Close()
+ p = nil
+ err = <-ch
+ if err == nil || err == os.ErrClosed {
+ err = net.ErrClosed
+ }
+ }
+ return p, err
+}
+
+func (l *pipeListener) listenerRoutine() {
+ closed := false
+ for !closed {
+ select {
+ case <-l.closeCh:
+ closed = true
+ case responseCh := <-l.acceptCh:
+ var (
+ p *file
+ err error
+ )
+ for {
+ p, err = l.makeConnectedServerPipe()
+ // If the connection was immediately closed by the client, try
+ // again.
+ if err != windows.ERROR_NO_DATA {
+ break
+ }
+ }
+ responseCh <- acceptResponse{p, err}
+ closed = err == net.ErrClosed
+ }
+ }
+ windows.Close(l.firstHandle)
+ l.firstHandle = 0
+ // Notify Close and Accept callers that the handle has been closed.
+ close(l.doneCh)
+}
+
+// ListenConfig contains configuration for the pipe listener.
+type ListenConfig struct {
+ // SecurityDescriptor contains a Windows security descriptor. If nil, the default from RtlDefaultNpAcl is used.
+ SecurityDescriptor *windows.SECURITY_DESCRIPTOR
+
+ // MessageMode determines whether the pipe is in byte or message mode. In either
+ // case the pipe is read in byte mode by default. The only practical difference in
+ // this implementation is that CloseWrite is only supported for message mode pipes;
+ // CloseWrite is implemented as a zero-byte write, but zero-byte writes are only
+ // transferred to the reader (and returned as io.EOF in this implementation)
+ // when the pipe is in message mode.
+ MessageMode bool
+
+ // InputBufferSize specifies the initial size of the input buffer, in bytes, which the OS will grow as needed.
+ InputBufferSize int32
+
+ // OutputBufferSize specifies the initial size of the output buffer, in bytes, which the OS will grow as needed.
+ OutputBufferSize int32
+}
+
+// Listen creates a listener on a Windows named pipe path,such as \\.\pipe\mypipe.
+// The pipe must not already exist.
+func (c *ListenConfig) Listen(path string) (net.Listener, error) {
+ h, err := makeServerPipeHandle(path, c.SecurityDescriptor, c, true)
+ if err != nil {
+ return nil, err
+ }
+ l := &pipeListener{
+ firstHandle: h,
+ path: path,
+ config: *c,
+ 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, 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)
+ if err == nil {
+ windows.CloseHandle(h)
+ }
+ }
+ }
+ go l.listenerRoutine()
+ return l, nil
+}
+
+var defaultListener ListenConfig
+
+// Listen calls ListenConfig.Listen using an empty configuration.
+func Listen(path string) (net.Listener, error) {
+ return defaultListener.Listen(path)
+}
+
+func connectPipe(p *file) error {
+ c, err := p.prepareIo()
+ if err != nil {
+ return err
+ }
+ defer p.wg.Done()
+
+ err = windows.ConnectNamedPipe(p.handle, &c.o)
+ _, err = p.asyncIo(c, nil, 0, err)
+ if err != nil && err != windows.ERROR_PIPE_CONNECTED {
+ return err
+ }
+ return nil
+}
+
+func (l *pipeListener) Accept() (net.Conn, error) {
+ ch := make(chan acceptResponse)
+ select {
+ case l.acceptCh <- ch:
+ response := <-ch
+ err := response.err
+ if err != nil {
+ return nil, err
+ }
+ if l.config.MessageMode {
+ return &messageBytePipe{
+ pipe: pipe{file: response.f, path: l.path},
+ }, nil
+ }
+ return &pipe{file: response.f, path: l.path}, nil
+ case <-l.doneCh:
+ return nil, net.ErrClosed
+ }
+}
+
+func (l *pipeListener) Close() error {
+ select {
+ case l.closeCh <- 1:
+ <-l.doneCh
+ case <-l.doneCh:
+ }
+ return nil
+}
+
+func (l *pipeListener) Addr() net.Addr {
+ return pipeAddress(l.path)
+}