Refactor read waiter interface

common/bufio/bind.go

@@ -8,51 +8,76 @@ import (
 	N "github.com/sagernet/sing/common/network"
 )
 
-type BindPacketConn struct {
+type BindPacketConn interface {
 	N.NetPacketConn
-	Addr net.Addr
+	net.Conn
 }
 
-func NewBindPacketConn(conn net.PacketConn, addr net.Addr) *BindPacketConn {
-	return &BindPacketConn{
+type bindPacketConn struct {
+	N.NetPacketConn
+	addr net.Addr
+}
+
+func NewBindPacketConn(conn net.PacketConn, addr net.Addr) BindPacketConn {
+	return &bindPacketConn{
 		NewPacketConn(conn),
 		addr,
 	}
 }
 
-func (c *BindPacketConn) Read(b []byte) (n int, err error) {
+func (c *bindPacketConn) Read(b []byte) (n int, err error) {
 	n, _, err = c.ReadFrom(b)
 	return
 }
 
-func (c *BindPacketConn) Write(b []byte) (n int, err error) {
-	return c.WriteTo(b, c.Addr)
+func (c *bindPacketConn) Write(b []byte) (n int, err error) {
+	return c.WriteTo(b, c.addr)
 }
 
-func (c *BindPacketConn) RemoteAddr() net.Addr {
-	return c.Addr
+func (c *bindPacketConn) CreateReadWaiter() (N.ReadWaiter, bool) {
+	readWaiter, isReadWaiter := CreatePacketReadWaiter(c.NetPacketConn)
+	if !isReadWaiter {
+		return nil, false
+	}
+	return &BindPacketReadWaiter{readWaiter}, true
 }
 
-func (c *BindPacketConn) Upstream() any {
+func (c *bindPacketConn) RemoteAddr() net.Addr {
+	return c.addr
+}
+
+func (c *bindPacketConn) Upstream() any {
 	return c.NetPacketConn
 }
 
+var (
+	_ N.NetPacketConn         = (*UnbindPacketConn)(nil)
+	_ N.PacketReadWaitCreator = (*UnbindPacketConn)(nil)
+)
+
 type UnbindPacketConn struct {
 	N.ExtendedConn
-	Addr M.Socksaddr
+	addr M.Socksaddr
 }
 
-func NewUnbindPacketConn(conn net.Conn) *UnbindPacketConn {
+func NewUnbindPacketConn(conn net.Conn) N.NetPacketConn {
 	return &UnbindPacketConn{
 		NewExtendedConn(conn),
 		M.SocksaddrFromNet(conn.RemoteAddr()),
 	}
 }
 
+func NewUnbindPacketConnWithAddr(conn net.Conn, addr M.Socksaddr) N.NetPacketConn {
+	return &UnbindPacketConn{
+		NewExtendedConn(conn),
+		addr,
+	}
+}
+
 func (c *UnbindPacketConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
 	n, err = c.ExtendedConn.Read(p)
 	if err == nil {
-		addr = c.Addr.UDPAddr()
+		addr = c.addr.UDPAddr()
 	}
 	return
 }
@@ -66,7 +91,7 @@ func (c *UnbindPacketConn) ReadPacket(buffer *buf.Buffer) (destination M.Socksad
 	if err != nil {
 		return
 	}
-	destination = c.Addr
+	destination = c.addr
 	return
 }
 
@@ -74,6 +99,14 @@ func (c *UnbindPacketConn) WritePacket(buffer *buf.Buffer, _ M.Socksaddr) error
 	return c.ExtendedConn.WriteBuffer(buffer)
 }
 
+func (c *UnbindPacketConn) CreateReadWaiter() (N.PacketReadWaiter, bool) {
+	readWaiter, isReadWaiter := CreateReadWaiter(c.ExtendedConn)
+	if !isReadWaiter {
+		return nil, false
+	}
+	return &UnbindPacketReadWaiter{readWaiter, c.addr}, true
+}
+
 func (c *UnbindPacketConn) Upstream() any {
 	return c.ExtendedConn
 }

common/bufio/bind_wait.go

@@ -0,0 +1,42 @@
+package bufio
+
+import (
+	"github.com/sagernet/sing/common/buf"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+var _ N.ReadWaiter = (*BindPacketReadWaiter)(nil)
+
+type BindPacketReadWaiter struct {
+	readWaiter N.PacketReadWaiter
+}
+
+func (w *BindPacketReadWaiter) InitializeReadWaiter(newBuffer func() *buf.Buffer) {
+	w.readWaiter.InitializeReadWaiter(newBuffer)
+}
+
+func (w *BindPacketReadWaiter) WaitReadBuffer() (buffer *buf.Buffer, err error) {
+	buffer, _, err = w.readWaiter.WaitReadPacket()
+	return
+}
+
+var _ N.PacketReadWaiter = (*UnbindPacketReadWaiter)(nil)
+
+type UnbindPacketReadWaiter struct {
+	readWaiter N.ReadWaiter
+	addr       M.Socksaddr
+}
+
+func (w *UnbindPacketReadWaiter) InitializeReadWaiter(newBuffer func() *buf.Buffer) {
+	w.readWaiter.InitializeReadWaiter(newBuffer)
+}
+
+func (w *UnbindPacketReadWaiter) WaitReadPacket() (buffer *buf.Buffer, destination M.Socksaddr, err error) {
+	buffer, err = w.readWaiter.WaitReadBuffer()
+	if err != nil {
+		return
+	}
+	destination = w.addr
+	return
+}

common/bufio/copy_direct_posix.go

@@ -39,7 +39,7 @@ func copyWaitWithPool(originSource io.Reader, destination N.ExtendedWriter, sour
 	})
 	defer source.InitializeReadWaiter(nil)
 	for {
-		err = source.WaitReadBuffer()
+		_, err = source.WaitReadBuffer()
 		if err != nil {
 			if errors.Is(err, io.EOF) {
 				err = nil
@@ -92,7 +92,7 @@ func copyPacketWaitWithPool(originSource N.PacketReader, destinationConn N.Packe
 	})
 	defer source.InitializeReadWaiter(nil)
 	for {
-		destination, err = source.WaitReadPacket()
+		_, destination, err = source.WaitReadPacket()
 		if err != nil {
 			return
 		}
@@ -123,6 +123,7 @@ type syscallReadWaiter struct {
 	rawConn  syscall.RawConn
 	readErr  error
 	readFunc func(fd uintptr) (done bool)
+	buffer   *buf.Buffer
 }
 
 func createSyscallReadWaiter(reader any) (*syscallReadWaiter, bool) {
@@ -156,26 +157,29 @@ func (w *syscallReadWaiter) InitializeReadWaiter(newBuffer func() *buf.Buffer) {
 			if readN == 0 {
 				w.readErr = io.EOF
 			}
+			w.buffer = buffer
 			return true
 		}
 	}
 }
 
-func (w *syscallReadWaiter) WaitReadBuffer() error {
+func (w *syscallReadWaiter) WaitReadBuffer() (buffer *buf.Buffer, err error) {
 	if w.readFunc == nil {
-		return os.ErrInvalid
+		return nil, os.ErrInvalid
 	}
-	err := w.rawConn.Read(w.readFunc)
+	err = w.rawConn.Read(w.readFunc)
 	if err != nil {
-		return err
+		return
 	}
 	if w.readErr != nil {
 		if w.readErr == io.EOF {
-			return io.EOF
+			return nil, io.EOF
 		}
-		return E.Cause(w.readErr, "raw read")
+		return nil, E.Cause(w.readErr, "raw read")
 	}
-	return nil
+	buffer = w.buffer
+	w.buffer = nil
+	return
 }
 
 var _ N.PacketReadWaiter = (*syscallPacketReadWaiter)(nil)
@@ -185,6 +189,7 @@ type syscallPacketReadWaiter struct {
 	readErr  error
 	readFrom M.Socksaddr
 	readFunc func(fd uintptr) (done bool)
+	buffer   *buf.Buffer
 }
 
 func createSyscallPacketReadWaiter(reader any) (*syscallPacketReadWaiter, bool) {
@@ -225,14 +230,15 @@ func (w *syscallPacketReadWaiter) InitializeReadWaiter(newBuffer func() *buf.Buf
 					w.readFrom = M.SocksaddrFrom(netip.AddrFrom16(fromAddr.Addr), uint16(fromAddr.Port)).Unwrap()
 				}
 			}
+			w.buffer = buffer
 			return true
 		}
 	}
 }
 
-func (w *syscallPacketReadWaiter) WaitReadPacket() (destination M.Socksaddr, err error) {
+func (w *syscallPacketReadWaiter) WaitReadPacket() (buffer *buf.Buffer, destination M.Socksaddr, err error) {
 	if w.readFunc == nil {
-		return M.Socksaddr{}, os.ErrInvalid
+		return nil, M.Socksaddr{}, os.ErrInvalid
 	}
 	err = w.rawConn.Read(w.readFunc)
 	if err != nil {
@@ -242,6 +248,8 @@ func (w *syscallPacketReadWaiter) WaitReadPacket() (destination M.Socksaddr, err
 		err = E.Cause(w.readErr, "raw read")
 		return
 	}
+	buffer = w.buffer
+	w.buffer = nil
 	destination = w.readFrom
 	return
 }

common/network/direct.go

@@ -7,7 +7,7 @@ import (
 
 type ReadWaiter interface {
 	InitializeReadWaiter(newBuffer func() *buf.Buffer)
-	WaitReadBuffer() error
+	WaitReadBuffer() (buffer *buf.Buffer, err error)
 }
 
 type ReadWaitCreator interface {
@@ -16,7 +16,7 @@ type ReadWaitCreator interface {
 
 type PacketReadWaiter interface {
 	InitializeReadWaiter(newBuffer func() *buf.Buffer)
-	WaitReadPacket() (destination M.Socksaddr, err error)
+	WaitReadPacket() (buffer *buf.Buffer, destination M.Socksaddr, err error)
 }
 
 type PacketReadWaitCreator interface {