Fix HandshakeFailure usages

common/network/dialer.go

@@ -13,10 +13,6 @@ type Dialer interface {
 	ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error)
 }
 
-type PayloadDialer interface {
-	DialPayloadContext(ctx context.Context, network string, destination M.Socksaddr, payload [][]byte) (net.Conn, error)
-}
-
 type ParallelDialer interface {
 	Dialer
 	DialParallel(ctx context.Context, network string, destination M.Socksaddr, destinationAddresses []netip.Addr) (net.Conn, error)

common/network/handshake.go

@@ -36,7 +36,13 @@ func ReportHandshakeFailure(reporter any, err error) error {
 func CloseOnHandshakeFailure(reporter any, onClose CloseHandlerFunc, err error) error {
 	if err != nil {
 		if handshakeConn, isHandshakeConn := common.Cast[HandshakeFailure](reporter); isHandshakeConn {
-			err = E.Append(err, handshakeConn.HandshakeFailure(err), func(err error) error {
+			hErr := handshakeConn.HandshakeFailure(err)
+			err = E.Append(err, hErr, func(err error) error {
+				if closer, isCloser := reporter.(io.Closer); isCloser {
+					err = E.Append(err, closer.Close(), func(err error) error {
+						return E.Cause(err, "close")
+					})
+				}
 				return E.Cause(err, "write handshake failure")
 			})
 		} else {

protocol/socks/lazy.go

@@ -2,6 +2,7 @@ package socks
 
 import (
 	"net"
+	"os"
 
 	"github.com/sagernet/sing/common/buf"
 	"github.com/sagernet/sing/common/bufio"
@@ -48,7 +49,7 @@ func (c *LazyConn) ConnHandshakeSuccess(conn net.Conn) error {
 
 func (c *LazyConn) HandshakeFailure(err error) error {
 	if c.responseWritten {
-		return nil
+		return os.ErrInvalid
 	}
 	defer func() {
 		c.responseWritten = true
@@ -130,7 +131,7 @@ func (c *LazyAssociatePacketConn) HandshakeSuccess() error {
 
 func (c *LazyAssociatePacketConn) HandshakeFailure(err error) error {
 	if c.responseWritten {
-		return nil
+		return os.ErrInvalid
 	}
 	defer func() {
 		c.responseWritten = true