diff --git a/ping/socket_linux_unprivileged.go b/ping/socket_linux_unprivileged.go
index 78d1026..efaf11f 100644
--- a/ping/socket_linux_unprivileged.go
+++ b/ping/socket_linux_unprivileged.go
@@ -18,14 +18,14 @@ import (
 )
 
 type UnprivilegedConn struct {
-	ctx          context.Context
-	cancel       context.CancelFunc
-	controlFunc  control.Func
-	destination  netip.Addr
-	receiveChan  chan *unprivilegedResponse
-	readDeadline pipe.Deadline
-	natMap       map[uint16]net.Conn
-	natMapMutex  sync.Mutex
+	ctx           context.Context
+	cancel        context.CancelFunc
+	controlFunc   control.Func
+	destination   netip.Addr
+	receiveChan   chan *unprivilegedResponse
+	readDeadline  pipe.Deadline
+	mappingAccess sync.Mutex
+	mapping       map[uint16]net.Conn
 }
 
 type unprivilegedResponse struct {
@@ -48,7 +48,7 @@ func newUnprivilegedConn(ctx context.Context, controlFunc control.Func, destinat
 		destination:  destination,
 		receiveChan:  make(chan *unprivilegedResponse),
 		readDeadline: pipe.MakeDeadline(),
-		natMap:       make(map[uint16]net.Conn),
+		mapping:      make(map[uint16]net.Conn),
 	}, nil
 }
 
@@ -59,10 +59,10 @@ func (c *UnprivilegedConn) Read(b []byte) (n int, err error) {
 		packet.Buffer.Release()
 		packet.Cmsg.Release()
 		return
-	case <-c.ctx.Done():
-		return 0, os.ErrClosed
 	case <-c.readDeadline.Wait():
 		return 0, os.ErrDeadlineExceeded
+	case <-c.ctx.Done():
+		return 0, os.ErrClosed
 	}
 }
 
@@ -75,10 +75,10 @@ func (c *UnprivilegedConn) ReadMsg(b []byte, oob []byte) (n, oobn int, addr neti
 		packet.Buffer.Release()
 		packet.Cmsg.Release()
 		return
-	case <-c.ctx.Done():
-		return 0, 0, netip.Addr{}, os.ErrClosed
 	case <-c.readDeadline.Wait():
 		return 0, 0, netip.Addr{}, os.ErrDeadlineExceeded
+	case <-c.ctx.Done():
+		return 0, 0, netip.Addr{}, os.ErrClosed
 	}
 }
 
@@ -92,26 +92,23 @@ func (c *UnprivilegedConn) Write(b []byte) (n int, err error) {
 		identifier = icmpHdr.Ident()
 	}
 
-	c.natMapMutex.Lock()
-	if err = c.ctx.Err(); err != nil {
-		c.natMapMutex.Unlock()
-		return 0, err
+	c.mappingAccess.Lock()
+	if c.ctx.Err() != nil {
+		return 0, c.ctx.Err()
 	}
-	conn, ok := c.natMap[identifier]
-	if !ok {
+	conn, loaded := c.mapping[identifier]
+	if !loaded {
 		conn, err = connect(false, c.controlFunc, c.destination)
 		if err != nil {
-			c.natMapMutex.Unlock()
-			return 0, err
+			c.mappingAccess.Unlock()
+			return
 		}
 		go c.fetchResponse(conn.(*net.UDPConn), identifier)
 	}
-	c.natMapMutex.Unlock()
-
+	c.mappingAccess.Unlock()
 	n, err = conn.Write(b)
 	if err != nil {
 		c.removeConn(conn.(*net.UDPConn), identifier)
-		return
 	}
 	return
 }
@@ -154,22 +151,20 @@ func (c *UnprivilegedConn) fetchResponse(conn *net.UDPConn, identifier uint16) {
 }
 
 func (c *UnprivilegedConn) removeConn(conn *net.UDPConn, identifier uint16) {
-	c.natMapMutex.Lock()
+	c.mappingAccess.Lock()
+	defer c.mappingAccess.Unlock()
 	_ = conn.Close()
-	if c.natMap[identifier] == conn {
-		delete(c.natMap, identifier)
-	}
-	c.natMapMutex.Unlock()
+	delete(c.mapping, identifier)
 }
 
 func (c *UnprivilegedConn) Close() error {
-	c.natMapMutex.Lock()
+	c.mappingAccess.Lock()
+	defer c.mappingAccess.Unlock()
 	c.cancel()
-	for _, conn := range c.natMap {
+	for _, conn := range c.mapping {
 		_ = conn.Close()
 	}
-	common.ClearMap(c.natMap)
-	c.natMapMutex.Unlock()
+	common.ClearMap(c.mapping)
 	return nil
 }
 
@@ -182,7 +177,7 @@ func (c *UnprivilegedConn) RemoteAddr() net.Addr {
 }
 
 func (c *UnprivilegedConn) SetDeadline(t time.Time) error {
-	return c.SetReadDeadline(t)
+	return os.ErrInvalid
 }
 
 func (c *UnprivilegedConn) SetReadDeadline(t time.Time) error {
@@ -191,5 +186,5 @@ func (c *UnprivilegedConn) SetReadDeadline(t time.Time) error {
 }
 
 func (c *UnprivilegedConn) SetWriteDeadline(t time.Time) error {
-	return nil
+	return os.ErrInvalid
 }