Fix system stack

stack_system.go

@@ -322,13 +322,6 @@ func (s *System) acceptLoop(listener net.Listener) {
 		if err != nil {
 			return
 		}
-		err = acceptConn(conn)
-		if err != nil {
-			s.logger.Error("set buffer for conn: ", err)
-			_ = conn.Close()
-			listener.Close()
-			return
-		}
 		connPort := M.SocksaddrFromNet(conn.RemoteAddr()).Port
 		session := s.tcpNat.LookupBack(connPort)
 		if session == nil {

stack_system_unix.go

@@ -1,26 +0,0 @@
-//go:build !windows
-
-package tun
-
-import (
-	"net"
-
-	"github.com/sagernet/sing/common/control"
-
-	"golang.org/x/sys/unix"
-)
-
-func acceptConn(conn net.Conn) error {
-	return control.Conn(conn.(*net.TCPConn), func(fd uintptr) error {
-		const bufferSize = 1024 * 1024
-		oErr := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_RCVBUF, bufferSize)
-		if oErr != nil {
-			return oErr
-		}
-		oErr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_SNDBUF, bufferSize)
-		if oErr != nil {
-			return oErr
-		}
-		return nil
-	})
-}

stack_system_windows.go

@@ -2,7 +2,6 @@ package tun
 
 import (
 	"errors"
-	"net"
 	"os"
 	"path/filepath"
 
@@ -32,7 +31,3 @@ func fixWindowsFirewall() error {
 func retryableListenError(err error) bool {
 	return errors.Is(err, windows.WSAEADDRNOTAVAIL)
 }
-
-func acceptConn(conn net.Conn) error {
-	return nil
-}