Fix ss-server close

common/cond.go

@@ -145,10 +145,8 @@ func Close(closers ...any) error {
 			err = c.Close()
 		}
 		switch c := closer.(type) {
-		case ReaderWithUpstream:
+		case WithUpstream:
-			err = Close(c.UpstreamReader())
+			err = Close(c.Upstream())
-		case WriterWithUpstream:
-			err = Close(c.UpstreamWriter())
 		}
 		if err != nil {
 			retErr = err

common/flush.go

@@ -1,95 +0,0 @@
-package common
-
-import (
-	"io"
-)
-
-type Flusher interface {
-	Flush() error
-}
-
-func Flush(writer io.Writer) error {
-	writerBack := writer
-	for {
-		if f, ok := writer.(Flusher); ok {
-			err := f.Flush()
-			if err != nil {
-				return err
-			}
-		}
-		if u, ok := writer.(WriterWithUpstream); ok {
-			if u.WriterReplaceable() {
-				if writerBack == writer {
-				} else if setter, hasSetter := u.UpstreamWriter().(UpstreamWriterSetter); hasSetter {
-					setter.SetWriter(writerBack)
-					writer = u.UpstreamWriter()
-					continue
-				}
-			}
-			writerBack = writer
-			writer = u.UpstreamWriter()
-		} else {
-			break
-		}
-	}
-	return nil
-}
-
-func FlushVar(writerP *io.Writer) error {
-	writer := *writerP
-	writerBack := writer
-	for {
-		if f, ok := writer.(Flusher); ok {
-			err := f.Flush()
-			if err != nil {
-				return err
-			}
-		}
-		if u, ok := writer.(WriterWithUpstream); ok {
-			if u.WriterReplaceable() {
-				if writerBack == writer {
-					writer = u.UpstreamWriter()
-					writerBack = writer
-					*writerP = writer
-					continue
-				} else if setter, hasSetter := writerBack.(UpstreamWriterSetter); hasSetter {
-					setter.SetWriter(u.UpstreamWriter())
-					writer = u.UpstreamWriter()
-					continue
-				}
-			}
-			writerBack = writer
-			writer = u.UpstreamWriter()
-		} else {
-			break
-		}
-	}
-	return nil
-}
-
-type FlushOnceWriter struct {
-	io.Writer
-	flushed bool
-}
-
-func (w *FlushOnceWriter) UpstreamWriter() io.Writer {
-	return w.Writer
-}
-
-func (w *FlushOnceWriter) WriterReplaceable() bool {
-	return w.flushed
-}
-
-func (w *FlushOnceWriter) Write(p []byte) (n int, err error) {
-	if w.flushed {
-		return w.Writer.Write(p)
-	}
-	n, err = w.Writer.Write(p)
-	if n > 0 {
-		err = FlushVar(&w.Writer)
-	}
-	if err == nil {
-		w.flushed = true
-	}
-	return
-}

common/rw/buffer.go

@@ -10,7 +10,6 @@ import (
 )
 
 type CachedReader interface {
-	common.ReaderWithUpstream
 	ReadCached() *buf.Buffer
 }
 
@@ -62,22 +61,10 @@ func (c *BufferedConn) ReadFrom(r io.Reader) (n int64, err error) {
 	return Copy(c.Conn, r)
 }
 
-func (c *BufferedConn) UpstreamReader() io.Reader {
+func (c *BufferedConn) Upstream() any {
 	return c.Conn
 }
 
-func (c *BufferedConn) ReaderReplaceable() bool {
-	return c.Buffer == nil
-}
-
-func (c *BufferedConn) UpstreamWriter() io.Writer {
-	return c.Conn
-}
-
-func (c *BufferedConn) WriterReplaceable() bool {
-	return true
-}
-
 type BufferedReader struct {
 	Reader io.Reader
 	Buffer *buf.Buffer
@@ -114,27 +101,19 @@ func (r *BufferedReader) WriteTo(w io.Writer) (n int64, err error) {
 	return
 }
 
-func (w *BufferedReader) UpstreamReader() io.Reader {
+func (w *BufferedReader) Upstream() any {
 	return w.Reader
 }
 
-func (w *BufferedReader) ReaderReplaceable() bool {
-	return w.Buffer == nil
-}
-
 type BufferedWriter struct {
 	Writer io.Writer
 	Buffer *buf.Buffer
 }
 
-func (w *BufferedWriter) UpstreamWriter() io.Writer {
+func (w *BufferedWriter) Upstream() any {
 	return w.Writer
 }
 
-func (w *BufferedWriter) WriterReplaceable() bool {
-	return w.Buffer == nil
-}
-
 func (w *BufferedWriter) Write(p []byte) (n int, err error) {
 	if w.Buffer == nil {
 		return w.Writer.Write(p)
@@ -200,14 +179,10 @@ type HeaderWriter struct {
 	Header *buf.Buffer
 }
 
-func (w *HeaderWriter) UpstreamWriter() io.Writer {
+func (w *HeaderWriter) Upstream() any {
 	return w.Writer
 }
 
-func (w *HeaderWriter) WriterReplaceable() bool {
-	return w.Header == nil
-}
-
 func (w *HeaderWriter) Write(p []byte) (n int, err error) {
 	if w.Header == nil {
 		return w.Writer.Write(p)

common/rw/copy.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"io"
 	"net"
-	"os"
 	"runtime"
 
 	"github.com/sagernet/sing/common"
@@ -12,35 +11,6 @@ import (
 	"github.com/sagernet/sing/common/task"
 )
 
-func ReadFromVar(writerVar *io.Writer, reader io.Reader) (int64, error) {
-	writer := *writerVar
-	writerBack := writer
-	for {
-		if w, ok := writer.(io.ReaderFrom); ok {
-			return w.ReadFrom(reader)
-		}
-		if f, ok := writer.(common.Flusher); ok {
-			err := f.Flush()
-			if err != nil {
-				return 0, err
-			}
-		}
-		if u, ok := writer.(common.WriterWithUpstream); ok {
-			if u.WriterReplaceable() && writerBack == writer {
-				writer = u.UpstreamWriter()
-				writerBack = writer
-				writerVar = &writer
-				continue
-			}
-			writer = u.UpstreamWriter()
-			writerBack = writer
-		} else {
-			break
-		}
-	}
-	return 0, os.ErrInvalid
-}
-
 func CopyConn(ctx context.Context, conn net.Conn, dest net.Conn) error {
 	if pc, inPc := conn.(net.PacketConn); inPc {
 		if destPc, outPc := dest.(net.PacketConn); outPc {

common/rw/duplex.go

@@ -13,31 +13,15 @@ type WriteCloser interface {
 }
 
 func CloseRead(reader any) error {
-	r := reader
+	if c, ok := common.Cast[ReadCloser](reader); ok {
-	for {
+		return c.CloseRead()
-		if closer, ok := r.(ReadCloser); ok {
-			return closer.CloseRead()
-		}
-		if u, ok := r.(common.ReaderWithUpstream); ok {
-			r = u.UpstreamReader()
-			continue
-		}
-		break
 	}
 	return common.Close(reader)
 }
 
 func CloseWrite(writer any) error {
-	w := writer
+	if c, ok := common.Cast[WriteCloser](writer); ok {
-	for {
+		return c.CloseWrite()
-		if closer, ok := w.(WriteCloser); ok {
-			return closer.CloseWrite()
-		}
-		if u, ok := w.(common.WriterWithUpstream); ok {
-			w = u.UpstreamWriter()
-			continue
-		}
-		break
 	}
 	return common.Close(writer)
 }

common/upstream.go

@@ -1,23 +1,16 @@
 package common
 
-import (
+type WithUpstream interface {
-	"io"
+	Upstream() any
-)
-
-type ReaderWithUpstream interface {
-	UpstreamReader() io.Reader
-	ReaderReplaceable() bool
 }
 
-type UpstreamReaderSetter interface {
+func Cast[T any](obj any) (T, bool) {
-	SetReader(reader io.Reader)
+	if c, ok := obj.(T); ok {
-}
+		return c, true
-
+	}
-type WriterWithUpstream interface {
+	if u, ok := obj.(WithUpstream); ok {
-	UpstreamWriter() io.Writer
+		return Cast[T](u.Upstream())
-	WriterReplaceable() bool
+	}
-}
+	var defaultValue T
-
+	return defaultValue, false
-type UpstreamWriterSetter interface {
-	SetWriter(writer io.Writer)
 }

protocol/shadowsocks/service.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net"
 
+	"github.com/sagernet/sing/common"
 	E "github.com/sagernet/sing/common/exceptions"
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
@@ -33,8 +34,8 @@ type ServerConnError struct {
 }
 
 func (e *ServerConnError) Close() error {
-	if tcpConn, ok := e.Conn.(*net.TCPConn); ok {
+	if conn, ok := common.Cast[*net.TCPConn](e.Conn); ok {
-		tcpConn.SetLinger(0)
+		conn.SetLinger(0)
 	}
 	return e.Conn.Close()
 }

protocol/shadowsocks/shadowaead/aead.go

@@ -53,18 +53,10 @@ func NewRawReader(upstream io.Reader, cipher cipher.AEAD, buffer []byte, nonce [
 	}
 }
 
-func (r *Reader) UpstreamReader() io.Reader {
+func (r *Reader) Upstream() any {
 	return r.upstream
 }
 
-func (r *Reader) ReaderReplaceable() bool {
-	return false
-}
-
-func (r *Reader) SetReader(reader io.Reader) {
-	r.upstream = reader
-}
-
 func (r *Reader) WriteTo(writer io.Writer) (n int64, err error) {
 	if r.cached > 0 {
 		writeN, writeErr := writer.Write(r.buffer[r.index : r.index+r.cached])
@@ -295,18 +287,10 @@ func NewRawWriter(upstream io.Writer, cipher cipher.AEAD, maxPacketSize int, buf
 	}
 }
 
-func (w *Writer) UpstreamWriter() io.Writer {
+func (w *Writer) Upstream() any {
 	return w.upstream
 }
 
-func (w *Writer) WriterReplaceable() bool {
-	return false
-}
-
-func (w *Writer) SetWriter(writer io.Writer) {
-	w.upstream = writer
-}
-
 func (w *Writer) ReadFrom(r io.Reader) (n int64, err error) {
 	for {
 		offset := Overhead + PacketLengthBufferSize

protocol/shadowsocks/shadowaead/protocol.go

@@ -279,26 +279,8 @@ func (c *clientConn) ReadFrom(r io.Reader) (n int64, err error) {
 	return c.writer.ReadFrom(r)
 }
 
-func (c *clientConn) UpstreamReader() io.Reader {
+func (c *clientConn) Upstream() any {
-	if c.reader == nil {
+	return c.Conn
-		return c.Conn
-	}
-	return c.reader
-}
-
-func (c *clientConn) ReaderReplaceable() bool {
-	return c.reader != nil
-}
-
-func (c *clientConn) UpstreamWriter() io.Writer {
-	if c.writer == nil {
-		return c.Conn
-	}
-	return c.writer
-}
-
-func (c *clientConn) WriterReplaceable() bool {
-	return c.writer != nil
 }
 
 type clientPacketConn struct {
@@ -375,18 +357,6 @@ func (c *clientPacketConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
 	return len(p), nil
 }
 
-func (c *clientPacketConn) UpstreamReader() io.Reader {
+func (c *clientPacketConn) Upstream() any {
 	return c.Conn
 }
-
-func (c *clientPacketConn) ReaderReplaceable() bool {
-	return false
-}
-
-func (c *clientPacketConn) UpstreamWriter() io.Writer {
-	return c.Conn
-}
-
-func (c *clientPacketConn) WriterReplaceable() bool {
-	return false
-}

protocol/shadowsocks/shadowaead/service.go

@@ -186,26 +186,8 @@ func (c *serverConn) WriteTo(w io.Writer) (n int64, err error) {
 	return c.reader.WriteTo(w)
 }
 
-func (c *serverConn) UpstreamReader() io.Reader {
+func (c *serverConn) Upstream() any {
-	if c.reader == nil {
+	return c.Conn
-		return c.Conn
-	}
-	return c.reader
-}
-
-func (c *serverConn) ReaderReplaceable() bool {
-	return c.reader != nil
-}
-
-func (c *serverConn) UpstreamWriter() io.Writer {
-	if c.writer == nil {
-		return c.Conn
-	}
-	return c.writer
-}
-
-func (c *serverConn) WriterReplaceable() bool {
-	return c.writer != nil
 }
 
 func (s *Service) NewPacket(conn N.PacketConn, buffer *buf.Buffer, metadata M.Metadata) error {

protocol/shadowsocks/shadowaead_2022/protocol.go

@@ -394,26 +394,8 @@ func (c *clientConn) ReadFrom(r io.Reader) (n int64, err error) {
 	return c.writer.ReadFrom(r)
 }
 
-func (c *clientConn) UpstreamReader() io.Reader {
+func (c *clientConn) Upstream() any {
-	if c.reader == nil {
+	return c.Conn
-		return c.Conn
-	}
-	return c.reader
-}
-
-func (c *clientConn) ReaderReplaceable() bool {
-	return c.reader != nil
-}
-
-func (c *clientConn) UpstreamWriter() io.Writer {
-	if c.writer == nil {
-		return c.Conn
-	}
-	return c.writer
-}
-
-func (c *clientConn) WriterReplaceable() bool {
-	return c.writer != nil
 }
 
 type clientPacketConn struct {
@@ -732,18 +714,6 @@ func (m *Method) newUDPSession() *udpSession {
 	return session
 }
 
-func (c *clientPacketConn) UpstreamReader() io.Reader {
+func (c *clientPacketConn) Upstream() any {
 	return c.Conn
 }
-
-func (c *clientPacketConn) ReaderReplaceable() bool {
-	return false
-}
-
-func (c *clientPacketConn) UpstreamWriter() io.Writer {
-	return c.Conn
-}
-
-func (c *clientPacketConn) WriterReplaceable() bool {
-	return false
-}

protocol/shadowsocks/shadowaead_2022/service.go

@@ -279,26 +279,8 @@ func (c *serverConn) WriteTo(w io.Writer) (n int64, err error) {
 	return c.reader.WriteTo(w)
 }
 
-func (c *serverConn) UpstreamReader() io.Reader {
+func (c *serverConn) Upstream() any {
-	if c.reader == nil {
+	return c.Conn
-		return c.Conn
-	}
-	return c.reader
-}
-
-func (c *serverConn) ReaderReplaceable() bool {
-	return c.reader != nil
-}
-
-func (c *serverConn) UpstreamWriter() io.Writer {
-	if c.writer == nil {
-		return c.Conn
-	}
-	return c.writer
-}
-
-func (c *serverConn) WriterReplaceable() bool {
-	return c.writer != nil
 }
 
 func (s *Service) NewPacket(conn N.PacketConn, buffer *buf.Buffer, metadata M.Metadata) error {

protocol/shadowsocks/shadowstream/protocol.go

@@ -303,22 +303,10 @@ func (c *clientConn) Write(p []byte) (n int, err error) {
 	return c.Conn.Write(p)
 }
 
-func (c *clientConn) UpstreamReader() io.Reader {
+func (c *clientConn) Upstream() any {
 	return c.Conn
 }
 
-func (c *clientConn) ReaderReplaceable() bool {
-	return false
-}
-
-func (c *clientConn) UpstreamWriter() io.Writer {
-	return c.Conn
-}
-
-func (c *clientConn) WriterReplaceable() bool {
-	return false
-}
-
 type clientPacketConn struct {
 	*Method
 	net.Conn
@@ -400,18 +388,6 @@ func (c *clientPacketConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
 	return len(p), nil
 }
 
-func (c *clientPacketConn) UpstreamReader() io.Reader {
+func (c *clientPacketConn) Upstream() any {
 	return c.Conn
 }
-
-func (c *clientPacketConn) ReaderReplaceable() bool {
-	return false
-}
-
-func (c *clientPacketConn) UpstreamWriter() io.Writer {
-	return c.Conn
-}
-
-func (c *clientPacketConn) WriterReplaceable() bool {
-	return false
-}

transport/tcp/listener.go

@@ -25,23 +25,6 @@ type Listener struct {
 	*net.TCPListener
 }
 
-type Error struct {
-	Conn  net.Conn
-	Cause error
-}
-
-func (e *Error) Error() string {
-	return e.Cause.Error()
-}
-
-func (e *Error) Unwrap() error {
-	return e.Cause
-}
-
-func (e *Error) Close() error {
-	return common.Close(e.Conn)
-}
-
 func NewTCPListener(listen netip.AddrPort, handler Handler, options ...Option) *Listener {
 	listener := &Listener{
 		bind:    listen,
@@ -112,9 +95,26 @@ func (l *Listener) loop() {
 			metadata.Protocol = "tcp"
 			hErr := l.handler.NewConnection(context.Background(), tcpConn, metadata)
 			if hErr != nil {
-				l.handler.HandleError(&Error{Conn: tcpConn, Cause: hErr})
+				l.handler.HandleError(hErr)
 			}
 			debug.Free()
 		}()
 	}
 }
+
+type Error struct {
+	Conn  net.Conn
+	Cause error
+}
+
+func (e *Error) Error() string {
+	return e.Cause.Error()
+}
+
+func (e *Error) Unwrap() error {
+	return e.Cause
+}
+
+func (e *Error) Close() error {
+	return common.Close(e.Conn)
+}