fix: handling for error

pkg/socks5/auth.go

@@ -42,7 +42,7 @@ func (a NoAuthAuthenticator) GetCode() uint8 {
 	return NoAuth
 }
 
-func (a NoAuthAuthenticator) Authenticate(reader io.Reader, writer io.Writer) (*AuthContext, error) {
+func (a NoAuthAuthenticator) Authenticate(_ io.Reader, writer io.Writer) (*AuthContext, error) {
 	_, err := writer.Write([]byte{socks5Version, NoAuth})
 	return &AuthContext{NoAuth, nil}, err
 }
@@ -131,7 +131,10 @@ func (s *Server) authenticate(conn io.Writer, bufConn io.Reader) (*AuthContext,
 // noAcceptableAuth is used to handle when we have no eligible
 // authentication mechanism
 func noAcceptableAuth(conn io.Writer) error {
-	conn.Write([]byte{socks5Version, noAcceptable})
+	_, err := conn.Write([]byte{socks5Version, noAcceptable})
+	if err != nil {
+		return err
+	}
 	return NoSupportedAuth
 }
 

pkg/socks5/request.go

@@ -197,7 +197,9 @@ func (s *Server) handleConnect(ctx context.Context, conn conn, req *Request) err
 		}
 		return fmt.Errorf("connect to %v failed: %v", req.DestAddr, err)
 	}
-	defer target.Close()
+	defer func(target net.Conn) {
+		_ = target.Close()
+	}(target)
 
 	// Send success
 	local := target.LocalAddr().(*net.TCPAddr)
@@ -367,7 +369,7 @@ type closeWriter interface {
 func proxy(dst io.Writer, src io.Reader, errCh chan error) {
 	_, err := io.Copy(dst, src)
 	if tcpConn, ok := dst.(closeWriter); ok {
-		tcpConn.CloseWrite()
+		_ = tcpConn.CloseWrite()
 	}
 	errCh <- err
 }

pkg/socks5/socks5.go

@@ -120,7 +120,12 @@ func (s *Server) Serve(l net.Listener) error {
 
 // ServeConn is used to serve a single connection.
 func (s *Server) ServeConn(conn net.Conn) {
-	defer conn.Close()
+	defer func(conn net.Conn) {
+		err := conn.Close()
+		if err != nil {
+			s.config.Logger.Err(err).Msg("failed to close connection")
+		}
+	}(conn)
 	bufConn := bufio.NewReader(conn)
 
 	// Read the version byte