From d42354ab192ac8634fc7cd42660f7f2c6ffe5ee5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Tue, 3 May 2022 16:23:34 +0800
Subject: [PATCH] Fixes

---
 cli/portal/portal-v2board/main.go             |  16 +--
 cli/ss-local/main.go                          |  18 +--
 cli/trojan-local/main.go                      |  16 +--
 cli/trojan-server/main.go                     |  14 +--
 common/cache/cache.go                         | 106 ------------------
 common/cache/cache_test.go                    |  70 ------------
 common/cache/lrucache.go                      |  68 +++++++++--
 common/exceptions/error.go                    |   9 +-
 common/geosite/matcher.go                     |   2 +-
 common/metadata/addr.go                       |   8 +-
 common/udpnat/service.go                      |  27 ++++-
 go.mod                                        |  21 ++--
 go.sum                                        |  36 +++---
 protocol/shadowsocks/none.go                  |   2 +-
 protocol/shadowsocks/shadowaead/service.go    |  12 +-
 .../shadowsocks/shadowaead_2022/service.go    |  19 ++--
 protocol/socks/conn.go                        |   2 +-
 protocol/socks/protocol.go                    |   4 +-
 transport/mixed/listener.go                   |   2 +-
 19 files changed, 159 insertions(+), 293 deletions(-)
 delete mode 100644 common/cache/cache.go
 delete mode 100644 common/cache/cache_test.go

diff --git a/cli/portal/portal-v2board/main.go b/cli/portal/portal-v2board/main.go
index c7f14af..c13ca27 100644
--- a/cli/portal/portal-v2board/main.go
+++ b/cli/portal/portal-v2board/main.go
@@ -130,7 +130,7 @@ func (i *TrojanInstance) Start() error {
 
 	trojanConfig, err := i.GetTrojanConfig(context.Background())
 	if err != nil {
-		return E.CauseF(err, i.id, ": read trojan config")
+		return E.Cause(err, i.id, ": read trojan config")
 	}
 
 	if trojanConfig.SNI != "" {
@@ -140,7 +140,7 @@ func (i *TrojanInstance) Start() error {
 	if acmeManager != nil {
 		certificate, err := acmeManager.GetKeyPair(i.domain)
 		if err != nil {
-			return E.CauseF(err, i.id, ": generate certificate")
+			return E.Cause(err, i.id, ": generate certificate")
 		}
 		i.tlsConfig.Certificates = []tls.Certificate{*certificate}
 		acmeManager.RegisterUpdateListener(i.domain, func(certificate *tls.Certificate) {
@@ -152,7 +152,7 @@ func (i *TrojanInstance) Start() error {
 		Port: int(trojanConfig.LocalPort),
 	})
 	if err != nil {
-		return E.CauseF(err, i.id, ": listen at tcp:", trojanConfig.LocalPort, ", check server configuration!")
+		return E.Cause(err, i.id, ": listen at tcp:", trojanConfig.LocalPort, ", check server configuration!")
 	}
 
 	if common.IsEmpty(i.tlsConfig.Certificates) {
@@ -199,7 +199,7 @@ func (i *TrojanInstance) loopRequests() {
 	for {
 		conn, err := i.listener.Accept()
 		if err != nil {
-			logrus.Debug(E.CauseF(err, i.id, ": listener exited"))
+			logrus.Debug(E.Cause(err, i.id, ": listener exited"))
 			return
 		}
 		go func() {
@@ -218,13 +218,13 @@ func (i *TrojanInstance) loopReload() {
 	for range i.reloadTicker.C {
 		err := i.reloadUsers()
 		if err != nil {
-			i.HandleError(E.CauseF(err, "reload user"))
+			i.HandleError(E.Cause(err, "reload user"))
 		}
 		traffics := i.user.ReadTraffics()
 		if len(traffics) > 0 {
 			err = i.ReportTrojanTraffic(context.Background(), traffics)
 			if err != nil {
-				i.HandleError(E.CauseF(err, "report traffic"))
+				i.HandleError(E.Cause(err, "report traffic"))
 			}
 		}
 	}
@@ -234,7 +234,7 @@ func (i *TrojanInstance) reloadUsers() error {
 	logrus.Debug(i.id, ": fetching users...")
 	userList, err := i.GetTrojanUserList(context.Background())
 	if err != nil {
-		return E.CauseF(err, i.id, ": get user list")
+		return E.Cause(err, i.id, ": get user list")
 	}
 	if len(userList.Users) == 0 {
 		logrus.Warn(i.id, ": empty users")
@@ -244,7 +244,7 @@ func (i *TrojanInstance) reloadUsers() error {
 	for id, password := range userList.Users {
 		err = i.service.AddUser(id, password)
 		if err != nil {
-			logrus.Warn(E.CauseF(err, i.id, ": add user"))
+			logrus.Warn(E.Cause(err, i.id, ": add user"))
 		}
 	}
 
diff --git a/cli/ss-local/main.go b/cli/ss-local/main.go
index ee66599..0a72171 100644
--- a/cli/ss-local/main.go
+++ b/cli/ss-local/main.go
@@ -69,24 +69,24 @@ func main() {
 		},
 	}
 
-	command.Flags().StringVarP(&f.Server, "server", "s", "", "Set the server’s hostname or IP.")
-	command.Flags().Uint16VarP(&f.ServerPort, "server-port", "p", 0, "Set the server’s port number.")
-	command.Flags().StringVarP(&f.Bind, "local-address", "b", "", "Set the local address.")
-	command.Flags().Uint16VarP(&f.LocalPort, "local-port", "l", 0, "Set the local port number.")
-	command.Flags().StringVarP(&f.Password, "password", "k", "", "Set the password. The server and the client should use the same password.")
-	command.Flags().StringVar(&f.Key, "key", "", "Set the key directly. The key should be encoded with URL-safe Base64.")
+	command.Flags().StringVarP(&f.Server, "server", "s", "", "Store the server’s hostname or IP.")
+	command.Flags().Uint16VarP(&f.ServerPort, "server-port", "p", 0, "Store the server’s port number.")
+	command.Flags().StringVarP(&f.Bind, "local-address", "b", "", "Store the local address.")
+	command.Flags().Uint16VarP(&f.LocalPort, "local-port", "l", 0, "Store the local port number.")
+	command.Flags().StringVarP(&f.Password, "password", "k", "", "Store the password. The server and the client should use the same password.")
+	command.Flags().StringVar(&f.Key, "key", "", "Store the key directly. The key should be encoded with URL-safe Base64.")
 
 	var supportedCiphers []string
 	supportedCiphers = append(supportedCiphers, shadowsocks.MethodNone)
 	supportedCiphers = append(supportedCiphers, shadowaead_2022.List...)
 	supportedCiphers = append(supportedCiphers, shadowaead.List...)
 
-	command.Flags().StringVarP(&f.Method, "encrypt-method", "m", "", "Set the cipher.\n\nSupported ciphers:\n\n"+strings.Join(supportedCiphers, "\n"))
+	command.Flags().StringVarP(&f.Method, "encrypt-method", "m", "", "Store the cipher.\n\nSupported ciphers:\n\n"+strings.Join(supportedCiphers, "\n"))
 	command.Flags().BoolVar(&f.TCPFastOpen, "fast-open", false, `Enable TCP fast open.
 Only available with Linux kernel > 3.7.0.`)
 	command.Flags().StringVarP(&f.Transproxy, "transproxy", "t", "", "Enable transparent proxy support. [possible values: redirect, tproxy]")
-	command.Flags().IntVar(&f.FWMark, "fwmark", 0, "Set outbound socket mark.")
-	command.Flags().StringVar(&f.Bypass, "bypass", "", "Set bypass country.")
+	command.Flags().IntVar(&f.FWMark, "fwmark", 0, "Store outbound socket mark.")
+	command.Flags().StringVar(&f.Bypass, "bypass", "", "Store bypass country.")
 	command.Flags().StringVarP(&f.ConfigFile, "config", "c", "", "Use a configuration file.")
 	command.Flags().BoolVarP(&f.Verbose, "verbose", "v", false, "Enable verbose mode.")
 	command.Flags().BoolVar(&f.UseSystemRNG, "use-system-rng", false, "Use system random number generator.")
diff --git a/cli/trojan-local/main.go b/cli/trojan-local/main.go
index 73b92e5..50de22a 100644
--- a/cli/trojan-local/main.go
+++ b/cli/trojan-local/main.go
@@ -54,15 +54,15 @@ func main() {
 		},
 	}
 
-	command.Flags().StringVarP(&f.Server, "server", "s", "", "Set the server’s hostname or IP.")
-	command.Flags().Uint16VarP(&f.ServerPort, "server-port", "p", 0, "Set the server’s port number.")
-	command.Flags().StringVarP(&f.ServerName, "server-name", "n", "", "Set the server name.")
-	command.Flags().StringVarP(&f.Bind, "local-address", "b", "", "Set the local address.")
-	command.Flags().Uint16VarP(&f.LocalPort, "local-port", "l", 0, "Set the local port number.")
-	command.Flags().StringVarP(&f.Password, "password", "k", "", "Set the password. The server and the client should use the same password.")
-	command.Flags().BoolVarP(&f.Insecure, "insecure", "i", false, "Set insecure.")
+	command.Flags().StringVarP(&f.Server, "server", "s", "", "Store the server’s hostname or IP.")
+	command.Flags().Uint16VarP(&f.ServerPort, "server-port", "p", 0, "Store the server’s port number.")
+	command.Flags().StringVarP(&f.ServerName, "server-name", "n", "", "Store the server name.")
+	command.Flags().StringVarP(&f.Bind, "local-address", "b", "", "Store the local address.")
+	command.Flags().Uint16VarP(&f.LocalPort, "local-port", "l", 0, "Store the local port number.")
+	command.Flags().StringVarP(&f.Password, "password", "k", "", "Store the password. The server and the client should use the same password.")
+	command.Flags().BoolVarP(&f.Insecure, "insecure", "i", false, "Store insecure.")
 	command.Flags().StringVarP(&f.ConfigFile, "config", "c", "", "Use a configuration file.")
-	command.Flags().BoolVarP(&f.Verbose, "verbose", "v", false, "Set verbose mode.")
+	command.Flags().BoolVarP(&f.Verbose, "verbose", "v", false, "Store verbose mode.")
 
 	err := command.Execute()
 	if err != nil {
diff --git a/cli/trojan-server/main.go b/cli/trojan-server/main.go
index 3776714..6cd3d15 100644
--- a/cli/trojan-server/main.go
+++ b/cli/trojan-server/main.go
@@ -54,14 +54,14 @@ func main() {
 		},
 	}
 
-	command.Flags().StringVarP(&f.Server, "server", "s", "", "Set the server’s hostname or IP.")
-	command.Flags().Uint16VarP(&f.ServerPort, "server-port", "p", 0, "Set the server’s port number.")
-	command.Flags().StringVarP(&f.Bind, "local-address", "b", "", "Set the local address.")
-	command.Flags().Uint16VarP(&f.LocalPort, "local-port", "l", 0, "Set the local port number.")
-	command.Flags().StringVarP(&f.Password, "password", "k", "", "Set the password. The server and the client should use the same password.")
-	command.Flags().BoolVarP(&f.Insecure, "insecure", "i", false, "Set insecure.")
+	command.Flags().StringVarP(&f.Server, "server", "s", "", "Store the server’s hostname or IP.")
+	command.Flags().Uint16VarP(&f.ServerPort, "server-port", "p", 0, "Store the server’s port number.")
+	command.Flags().StringVarP(&f.Bind, "local-address", "b", "", "Store the local address.")
+	command.Flags().Uint16VarP(&f.LocalPort, "local-port", "l", 0, "Store the local port number.")
+	command.Flags().StringVarP(&f.Password, "password", "k", "", "Store the password. The server and the client should use the same password.")
+	command.Flags().BoolVarP(&f.Insecure, "insecure", "i", false, "Store insecure.")
 	command.Flags().StringVarP(&f.ConfigFile, "config", "c", "", "Use a configuration file.")
-	command.Flags().BoolVarP(&f.Verbose, "verbose", "v", false, "Set verbose mode.")
+	command.Flags().BoolVarP(&f.Verbose, "verbose", "v", false, "Store verbose mode.")
 
 	err := command.Execute()
 	if err != nil {
diff --git a/common/cache/cache.go b/common/cache/cache.go
deleted file mode 100644
index 6b252c2..0000000
--- a/common/cache/cache.go
+++ /dev/null
@@ -1,106 +0,0 @@
-package cache
-
-import (
-	"runtime"
-	"sync"
-	"time"
-)
-
-// Cache store element with a expired time
-type Cache struct {
-	*cache
-}
-
-type cache struct {
-	mapping sync.Map
-	janitor *janitor
-}
-
-type element struct {
-	Expired time.Time
-	Payload interface{}
-}
-
-// Put element in Cache with its ttl
-func (c *cache) Put(key interface{}, payload interface{}, ttl time.Duration) {
-	c.mapping.Store(key, &element{
-		Payload: payload,
-		Expired: time.Now().Add(ttl),
-	})
-}
-
-// Get element in Cache, and drop when it expired
-func (c *cache) Get(key interface{}) interface{} {
-	item, exist := c.mapping.Load(key)
-	if !exist {
-		return nil
-	}
-	elm := item.(*element)
-	// expired
-	if time.Since(elm.Expired) > 0 {
-		c.mapping.Delete(key)
-		return nil
-	}
-	return elm.Payload
-}
-
-// GetWithExpire element in Cache with Expire Time
-func (c *cache) GetWithExpire(key interface{}) (payload interface{}, expired time.Time) {
-	item, exist := c.mapping.Load(key)
-	if !exist {
-		return
-	}
-	elm := item.(*element)
-	// expired
-	if time.Since(elm.Expired) > 0 {
-		c.mapping.Delete(key)
-		return
-	}
-	return elm.Payload, elm.Expired
-}
-
-func (c *cache) cleanup() {
-	c.mapping.Range(func(k, v interface{}) bool {
-		key := k.(string)
-		elm := v.(*element)
-		if time.Since(elm.Expired) > 0 {
-			c.mapping.Delete(key)
-		}
-		return true
-	})
-}
-
-type janitor struct {
-	interval time.Duration
-	stop     chan struct{}
-}
-
-func (j *janitor) process(c *cache) {
-	ticker := time.NewTicker(j.interval)
-	for {
-		select {
-		case <-ticker.C:
-			c.cleanup()
-		case <-j.stop:
-			ticker.Stop()
-			return
-		}
-	}
-}
-
-func stopJanitor(c *Cache) {
-	c.janitor.stop <- struct{}{}
-}
-
-// New return *Cache
-func New(interval time.Duration) *Cache {
-	j := &janitor{
-		interval: interval,
-		stop:     make(chan struct{}),
-	}
-	c := &cache{janitor: j}
-	go j.process(c)
-	C := &Cache{c}
-	runtime.SetFinalizer(C, stopJanitor)
-	return C
-}
diff --git a/common/cache/cache_test.go b/common/cache/cache_test.go
deleted file mode 100644
index cf4a391..0000000
--- a/common/cache/cache_test.go
+++ /dev/null
@@ -1,70 +0,0 @@
-package cache
-
-import (
-	"runtime"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestCache_Basic(t *testing.T) {
-	interval := 200 * time.Millisecond
-	ttl := 20 * time.Millisecond
-	c := New(interval)
-	c.Put("int", 1, ttl)
-	c.Put("string", "a", ttl)
-
-	i := c.Get("int")
-	assert.Equal(t, i.(int), 1, "should recv 1")
-
-	s := c.Get("string")
-	assert.Equal(t, s.(string), "a", "should recv 'a'")
-}
-
-func TestCache_TTL(t *testing.T) {
-	interval := 200 * time.Millisecond
-	ttl := 20 * time.Millisecond
-	now := time.Now()
-	c := New(interval)
-	c.Put("int", 1, ttl)
-	c.Put("int2", 2, ttl)
-
-	i := c.Get("int")
-	_, expired := c.GetWithExpire("int2")
-	assert.Equal(t, i.(int), 1, "should recv 1")
-	assert.True(t, now.Before(expired))
-
-	time.Sleep(ttl * 2)
-	i = c.Get("int")
-	j, _ := c.GetWithExpire("int2")
-	assert.Nil(t, i, "should recv nil")
-	assert.Nil(t, j, "should recv nil")
-}
-
-func TestCache_AutoCleanup(t *testing.T) {
-	interval := 10 * time.Millisecond
-	ttl := 15 * time.Millisecond
-	c := New(interval)
-	c.Put("int", 1, ttl)
-
-	time.Sleep(ttl * 2)
-	i := c.Get("int")
-	j, _ := c.GetWithExpire("int")
-	assert.Nil(t, i, "should recv nil")
-	assert.Nil(t, j, "should recv nil")
-}
-
-func TestCache_AutoGC(t *testing.T) {
-	sign := make(chan struct{})
-	go func() {
-		interval := 10 * time.Millisecond
-		ttl := 15 * time.Millisecond
-		c := New(interval)
-		c.Put("int", 1, ttl)
-		sign <- struct{}{}
-	}()
-
-	<-sign
-	runtime.GC()
-}
diff --git a/common/cache/lrucache.go b/common/cache/lrucache.go
index 454a410..45a8f8b 100644
--- a/common/cache/lrucache.go
+++ b/common/cache/lrucache.go
@@ -9,19 +9,58 @@ import (
 	"github.com/sagernet/sing/common/list"
 )
 
+type Option[K comparable, V any] func(*LruCache[K, V])
+
+type EvictCallback[K comparable, V any] func(key K, value V)
+
+func WithEvict[K comparable, V any](cb EvictCallback[K, V]) Option[K, V] {
+	return func(l *LruCache[K, V]) {
+		l.onEvict = cb
+	}
+}
+
+func WithUpdateAgeOnGet[K comparable, V any]() Option[K, V] {
+	return func(l *LruCache[K, V]) {
+		l.updateAgeOnGet = true
+	}
+}
+
+func WithAge[K comparable, V any](maxAge int64) Option[K, V] {
+	return func(l *LruCache[K, V]) {
+		l.maxAge = maxAge
+	}
+}
+
+func WithSize[K comparable, V any](maxSize int) Option[K, V] {
+	return func(l *LruCache[K, V]) {
+		l.maxSize = maxSize
+	}
+}
+
+func WithStale[K comparable, V any](stale bool) Option[K, V] {
+	return func(l *LruCache[K, V]) {
+		l.staleReturn = stale
+	}
+}
+
 type LruCache[K comparable, V any] struct {
 	maxAge         int64
+	maxSize        int
 	mu             sync.Mutex
 	cache          map[K]*list.Element[*entry[K, V]]
 	lru            list.List[*entry[K, V]] // Front is least-recent
 	updateAgeOnGet bool
+	staleReturn    bool
+	onEvict        EvictCallback[K, V]
 }
 
-func NewLRU[K comparable, V any](maxAge int64, updateAgeOnGet bool) LruCache[K, V] {
-	lc := LruCache[K, V]{
-		maxAge:         maxAge,
-		updateAgeOnGet: updateAgeOnGet,
-		cache:          make(map[K]*list.Element[*entry[K, V]]),
+func New[K comparable, V any](options ...Option[K, V]) *LruCache[K, V] {
+	lc := &LruCache[K, V]{
+		cache: make(map[K]*list.Element[*entry[K, V]]),
+	}
+
+	for _, option := range options {
+		option(lc)
 	}
 
 	return lc
@@ -111,6 +150,12 @@ func (c *LruCache[K, V]) StoreWithExpire(key K, value V, expires time.Time) {
 	} else {
 		e := &entry[K, V]{key: key, value: value, expires: expires.Unix()}
 		c.cache[key] = c.lru.PushBack(e)
+
+		if c.maxSize > 0 {
+			if len := c.lru.Len(); len > c.maxSize {
+				c.deleteElement(c.lru.Front())
+			}
+		}
 	}
 
 	c.maybeDeleteOldest()
@@ -141,7 +186,7 @@ func (c *LruCache[K, V]) get(key K) *entry[K, V] {
 		return nil
 	}
 
-	if c.maxAge > 0 && le.Value.expires <= time.Now().Unix() {
+	if !c.staleReturn && c.maxAge > 0 && le.Value.expires <= time.Now().Unix() {
 		c.deleteElement(le)
 		c.maybeDeleteOldest()
 
@@ -168,9 +213,11 @@ func (c *LruCache[K, V]) Delete(key K) {
 }
 
 func (c *LruCache[K, V]) maybeDeleteOldest() {
-	now := time.Now().Unix()
-	for le := c.lru.Front(); le != nil && le.Value.expires <= now; le = c.lru.Front() {
-		c.deleteElement(le)
+	if !c.staleReturn && c.maxAge > 0 {
+		now := time.Now().Unix()
+		for le := c.lru.Front(); le != nil && le.Value.expires <= now; le = c.lru.Front() {
+			c.deleteElement(le)
+		}
 	}
 }
 
@@ -178,6 +225,9 @@ func (c *LruCache[K, V]) deleteElement(le *list.Element[*entry[K, V]]) {
 	c.lru.Remove(le)
 	e := le.Value
 	delete(c.cache, e.key)
+	if c.onEvict != nil {
+		c.onEvict(e.key, e.value)
+	}
 }
 
 type entry[K comparable, V any] struct {
diff --git a/common/exceptions/error.go b/common/exceptions/error.go
index 95c0cb6..6c86d1a 100644
--- a/common/exceptions/error.go
+++ b/common/exceptions/error.go
@@ -42,14 +42,7 @@ func New(message ...any) error {
 	return errors.New(fmt.Sprint(message...))
 }
 
-func Cause(cause error, message string) Exception {
-	if cause == nil {
-		return nil
-	}
-	return exception{message, cause}
-}
-
-func CauseF(cause error, message ...any) Exception {
+func Cause(cause error, message ...any) Exception {
 	return exception{fmt.Sprint(message), cause}
 }
 
diff --git a/common/geosite/matcher.go b/common/geosite/matcher.go
index 50cd330..e5c402d 100644
--- a/common/geosite/matcher.go
+++ b/common/geosite/matcher.go
@@ -37,7 +37,7 @@ func NewMatcher(domains []string) (*Matcher, error) {
 			domain = domain[7:]
 			pattern, err := regexp.Compile(domain)
 			if err != nil {
-				return nil, E.CauseF(err, "compile regex rule ", domain)
+				return nil, E.Cause(err, "compile regex rule ", domain)
 			}
 			regex = append(regex, pattern)
 		}
diff --git a/common/metadata/addr.go b/common/metadata/addr.go
index c0575ca..9b930f6 100644
--- a/common/metadata/addr.go
+++ b/common/metadata/addr.go
@@ -107,7 +107,7 @@ func AddrPortFromNetAddr(netAddr net.Addr) *AddrPort {
 
 func AddrFromIP(ip net.IP) Addr {
 	addr, _ := netip.AddrFromSlice(ip)
-	if addr.Is4() {
+	if addr.Is4() || addr.Is4In6() {
 		return Addr4(addr.As4())
 	} else {
 		return Addr16(addr.As16())
@@ -115,7 +115,7 @@ func AddrFromIP(ip net.IP) Addr {
 }
 
 func AddrFromAddr(addr netip.Addr) Addr {
-	if addr.Is4() {
+	if addr.Is4() && addr.Is4In6() {
 		return Addr4(addr.As4())
 	} else {
 		return Addr16(addr.As16())
@@ -145,7 +145,7 @@ func (a Addr4) Fqdn() string {
 }
 
 func (a Addr4) String() string {
-	return net.IP(a[:]).String()
+	return netip.AddrFrom4(a).String()
 }
 
 type Addr16 [16]byte
@@ -163,7 +163,7 @@ func (a Addr16) Fqdn() string {
 }
 
 func (a Addr16) String() string {
-	return net.IP(a[:]).String()
+	return netip.AddrFrom16(a).String()
 }
 
 type AddrFqdn string
diff --git a/common/udpnat/service.go b/common/udpnat/service.go
index 0bc05a5..34f30ea 100644
--- a/common/udpnat/service.go
+++ b/common/udpnat/service.go
@@ -5,6 +5,7 @@ import (
 	"io"
 	"net"
 	"os"
+	"sync"
 	"time"
 
 	"github.com/sagernet/sing/common"
@@ -21,13 +22,16 @@ type Handler interface {
 }
 
 type Service[K comparable] struct {
-	nat     cache.LruCache[K, *conn]
+	nat     *cache.LruCache[K, *conn]
 	handler Handler
 }
 
-func New[K comparable](maxAge int64, handler Handler) Service[K] {
-	return Service[K]{
-		nat:     cache.NewLRU[K, *conn](maxAge, true),
+func New[K comparable](maxAge int64, handler Handler) *Service[K] {
+	return &Service[K]{
+		nat: cache.New(
+			cache.WithAge[K, *conn](maxAge),
+			cache.WithUpdateAgeOnGet[K, *conn](),
+		),
 		handler: handler,
 	}
 }
@@ -52,8 +56,17 @@ func (s *Service[T]) NewContextPacket(ctx context.Context, key T, writer func()
 			if err != nil {
 				s.handler.HandleError(err)
 			}
+			c.Close()
+			s.nat.Delete(key)
 		}()
 	}
+	c.access.Lock()
+	if common.Done(c.ctx) {
+		s.nat.Delete(key)
+		c.access.Unlock()
+		s.NewContextPacket(ctx, key, writer, buffer, metadata)
+		return
+	}
 	ctx, done := context.WithCancel(c.ctx)
 	p := packet{
 		done:        done,
@@ -61,6 +74,7 @@ func (s *Service[T]) NewContextPacket(ctx context.Context, key T, writer func()
 		destination: metadata.Destination,
 	}
 	c.data <- p
+	c.access.Unlock()
 	<-ctx.Done()
 }
 
@@ -71,6 +85,7 @@ type packet struct {
 }
 
 type conn struct {
+	access     sync.Mutex
 	ctx        context.Context
 	cancel     context.CancelFunc
 	data       chan packet
@@ -96,7 +111,11 @@ func (c *conn) WritePacket(buffer *buf.Buffer, destination *M.AddrPort) error {
 }
 
 func (c *conn) Close() error {
+	c.access.Lock()
+	defer c.access.Unlock()
+
 	c.cancel()
+	common.Close(c.source)
 	select {
 	case <-c.data:
 		return os.ErrClosed
diff --git a/go.mod b/go.mod
index 96ca220..1896a97 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/sagernet/sing
 go 1.18
 
 require (
-	github.com/cloudflare/cloudflare-go v0.30.0
+	github.com/cloudflare/cloudflare-go v0.38.0
 	github.com/go-acme/lego/v4 v4.6.0
 	github.com/go-resty/resty/v2 v2.7.0
 	github.com/openacid/low v0.1.21
@@ -12,41 +12,36 @@ require (
 	github.com/seiflotfy/cuckoofilter v0.0.0-20220411075957-e3b120b3f5fb
 	github.com/sirupsen/logrus v1.8.1
 	github.com/spf13/cobra v1.4.0
-	github.com/stretchr/testify v1.7.1
 	github.com/ulikunitz/xz v0.5.10
 	github.com/v2fly/ss-bloomring v0.0.0-20210312155135-28617310f63e
-	github.com/v2fly/v2ray-core/v5 v5.0.3
+	github.com/v2fly/v2ray-core/v5 v5.0.5
 	github.com/vishvananda/netlink v1.1.0
 	golang.org/x/crypto v0.0.0-20220427172511-eb4f295cb31f
 	golang.org/x/net v0.0.0-20220425223048-2871e0cb64e4
-	golang.org/x/sys v0.0.0-20220429233432-b5fbb4746d32
+	golang.org/x/sys v0.0.0-20220502124256-b6088ccd6cba
 	golang.zx2c4.com/wireguard v0.0.0-20220407013110-ef5c587f782d
 	google.golang.org/protobuf v1.28.0
 	lukechampine.com/blake3 v1.1.7
 )
 
 require (
+	github.com/adrg/xdg v0.4.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.1.1 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dgryski/go-metro v0.0.0-20211217172704-adc40b04c140 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/klauspost/cpuid/v2 v2.0.12 // indirect
-	github.com/kr/text v0.2.0 // indirect
-	github.com/miekg/dns v1.1.45 // indirect
-	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/miekg/dns v1.1.48 // indirect
 	github.com/oschwald/maxminddb-golang v1.9.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/riobard/go-bloom v0.0.0-20200614022211-cdc8013cb5b3 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74 // indirect
-	golang.org/x/mod v0.4.2 // indirect
+	golang.org/x/mod v0.6.0-dev.0.20211013180041-c96bc1413d57 // indirect
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/time v0.0.0-20220411224347-583f2d630306 // indirect
-	golang.org/x/tools v0.1.6-0.20210726203631-07bc1bf47fb2 // indirect
+	golang.org/x/tools v0.1.9 // indirect
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
-	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
 	gopkg.in/square/go-jose.v2 v2.6.0 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )
diff --git a/go.sum b/go.sum
index 7f995eb..197ab62 100644
--- a/go.sum
+++ b/go.sum
@@ -42,6 +42,8 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/OpenDNS/vegadns2client v0.0.0-20180418235048-a3fa4a771d87/go.mod h1:iGLljf5n9GjT6kc0HBvyI1nOKnGQbNB66VzSNbK5iks=
+github.com/adrg/xdg v0.4.0 h1:RzRqFcjH4nE5C6oTAxhBtoE2IRyjBSa62SCbyPidvls=
+github.com/adrg/xdg v0.4.0/go.mod h1:N6ag73EX4wyxeaoeHctc1mas01KZgsj5tYiAIwqJE/E=
 github.com/akamai/AkamaiOPEN-edgegrid-golang v1.1.1/go.mod h1:kX6YddBkXqqywAe8c9LyvgTCyFuZCTMF4cRPQhc3Fy8=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
@@ -67,8 +69,8 @@ github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5P
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cloudflare/cloudflare-go v0.20.0/go.mod h1:sPWL/lIC6biLEdyGZwBQ1rGQKF1FhM7N60fuNiFdYTI=
-github.com/cloudflare/cloudflare-go v0.30.0 h1:ho2ObQ1iZfjMqP9RcovvT1Jwp/ZW4Ji5baWVwl2T//A=
-github.com/cloudflare/cloudflare-go v0.30.0/go.mod h1:B55yGpU9NdzhWPYu0CDq8smftKrqB/PSDQAdIBEKApw=
+github.com/cloudflare/cloudflare-go v0.38.0 h1:Qf/oVlDmQgb4RfCxqkR0hJoEUQKHvDE4A09MHWssa/w=
+github.com/cloudflare/cloudflare-go v0.38.0/go.mod h1:tWDVF03nA9VS9TvFRTrOeY78uSFQzS+n429EcBZszzg=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
@@ -78,7 +80,6 @@ github.com/cpu/goacmedns v0.1.1/go.mod h1:MuaouqEhPAHxsbqjgnck5zeghuwBP1dLnPoobe
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/cyberdelia/templates v0.0.0-20141128023046-ca7fffd4298c/go.mod h1:GyV+0YP4qX0UQ7r2MoYZ+AvYDp12OF5yg4q8rGnyNh4=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -159,9 +160,10 @@ github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-github/v32 v32.1.0/go.mod h1:rIEpZD9CTDQwDK9GDrtMTycQNA4JU3qBsCizh3q2WCI=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
+github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
 github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
@@ -241,8 +243,6 @@ github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFB
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/labbsr0x/bindman-dns-webhook v1.0.2/go.mod h1:p6b+VCXIR8NYKpDr8/dg1HKfQoRHCdcsROXKvmoehKA=
 github.com/labbsr0x/goh v1.0.1/go.mod h1:8K2UhVoaWXcCU7Lxoa2omWnC8gyW8px7/lmO61c027w=
 github.com/labstack/echo/v4 v4.2.1/go.mod h1:AA49e0DZ8kk5jTOOCKNuPR6oTnBS0dYiM4FW1e6jwpg=
@@ -275,8 +275,8 @@ github.com/mattn/go-tty v0.0.3/go.mod h1:ihxohKRERHTVzN+aSVRwACLCeqIoZAWpoICkkvr
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/miekg/dns v1.1.43/go.mod h1:+evo5L0630/F6ca/Z9+GAqzhjGyn8/c+TBaOyfEl0V4=
-github.com/miekg/dns v1.1.45 h1:g5fRIhm9nx7g8osrAvgb16QJfmyMsyOCb+J7LSv+Qzk=
-github.com/miekg/dns v1.1.45/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
+github.com/miekg/dns v1.1.48 h1:Ucfr7IIVyMBz4lRE8qmGUuZ4Wt3/ZGu9hmcMT3Uu4tQ=
+github.com/miekg/dns v1.1.48/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
 github.com/mitchellh/go-homedir v1.0.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
@@ -295,8 +295,6 @@ github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3Rllmb
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/namedotcom/go v0.0.0-20180403034216-08470befbe04/go.mod h1:5sN+Lt1CaY4wsPvgQH/jsuJi4XO2ssZbdsIizr4CVC8=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/nrdcg/auroradns v1.0.1/go.mod h1:y4pc0i9QXYlFCWrhWrUSIETnZgrf4KuwjDIWmmXo3JI=
 github.com/nrdcg/desec v0.6.0/go.mod h1:wybWg5cRrNmtXLYpUCPCLvz4jfFNEGZQEnoUiX9WqcY=
 github.com/nrdcg/dnspod-go v0.4.0/go.mod h1:vZSoFSFeQVm2gWLMkyX61LZ8HI3BaqtHZWgPTGKr6KQ=
@@ -410,7 +408,6 @@ github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common v1.0.287/go.mod h1:7sCQWVkxcsR38nffDW057DRGk8mUjK1Ing/EFOK8s8Y=
 github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/dnspod v1.0.287/go.mod h1:CuOaLxOQr477GhMWAQPYQFUJrsZbW+ZqkAgP2uHDZXg=
@@ -423,8 +420,8 @@ github.com/urfave/cli v1.22.5/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtX
 github.com/urfave/cli/v2 v2.3.0/go.mod h1:LJmUH05zAU44vOAcrfzZQKsZbVcdbOG8rtL3/XcUArI=
 github.com/v2fly/ss-bloomring v0.0.0-20210312155135-28617310f63e h1:5QefA066A1tF8gHIiADmOVOV5LS43gt3ONnlEl3xkwI=
 github.com/v2fly/ss-bloomring v0.0.0-20210312155135-28617310f63e/go.mod h1:5t19P9LBIrNamL6AcMQOncg/r10y3Pc01AbHeMhwlpU=
-github.com/v2fly/v2ray-core/v5 v5.0.3 h1:2rnJ9vZbBQ7V4upWsoUVYGoqZl4grrx8SxOReKx+jjc=
-github.com/v2fly/v2ray-core/v5 v5.0.3/go.mod h1:zhDdsUJcNE8LcLRA3l7fEQ6QLuveD4/OLbQM2CceSHM=
+github.com/v2fly/v2ray-core/v5 v5.0.5 h1:S9K9F1t9HMzrW3fzVYUu3cAVXArlkrkOnMresObncP0=
+github.com/v2fly/v2ray-core/v5 v5.0.5/go.mod h1:Rv8eq9KRQWZt177euFJb7i2MOqrzfokVmuHGhlfo/zw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
 github.com/valyala/fasttemplate v1.2.1/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
@@ -500,8 +497,9 @@ golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzB
 golang.org/x/mod v0.1.1-0.20191107180719-034126e5016b/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.4.2 h1:Gz96sIWK3OalVv/I/qNygP42zyoKp3xptRVCWRFEBvo=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.6.0-dev.0.20211013180041-c96bc1413d57 h1:LQmS1nU0twXLA96Kt7U9qtHJEbBk3z6Q0V4UXjZkpr4=
+golang.org/x/mod v0.6.0-dev.0.20211013180041-c96bc1413d57/go.mod h1:3p9vT2HGsQu2K1YbXdKPJLVgG5VJdoTa1poYQBtP1AY=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -605,8 +603,9 @@ golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220429233432-b5fbb4746d32 h1:Js08h5hqB5xyWR789+QqueR6sDE8mk+YvpETZ+F6X9Y=
-golang.org/x/sys v0.0.0-20220429233432-b5fbb4746d32/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220502124256-b6088ccd6cba h1:AyHWHCBVlIYI5rgEM3o+1PLd0sLPcIAoaUckGQMaWtw=
+golang.org/x/sys v0.0.0-20220502124256-b6088ccd6cba/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -662,8 +661,9 @@ golang.org/x/tools v0.0.0-20200224181240-023911ca70b2/go.mod h1:TB2adYChydJhpapK
 golang.org/x/tools v0.0.0-20200304193943-95d2e580d8eb/go.mod h1:o4KQGtdN14AW+yjsvvwRTJJuXz8XRtIHtEnmAXLyFUw=
 golang.org/x/tools v0.0.0-20200410194907-79a7a3126eef/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
-golang.org/x/tools v0.1.6-0.20210726203631-07bc1bf47fb2 h1:BonxutuHCTL0rBDnZlKjpGIQFTjyUVTexFOdWkB6Fg0=
 golang.org/x/tools v0.1.6-0.20210726203631-07bc1bf47fb2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/tools v0.1.9 h1:j9KsMiaP1c3B0OTQGth0/k+miLGTgLsAFUCrF2vLcF8=
+golang.org/x/tools v0.1.9/go.mod h1:nABZi5QlRsZVlzPpHl034qft6wpY4eDcsTt5AaioBiU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
@@ -725,8 +725,6 @@ gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLks
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/h2non/gock.v1 v1.0.15/go.mod h1:sX4zAkdYX1TRGJ2JY156cFspQn4yRWn6p9EMdODlynE=
diff --git a/protocol/shadowsocks/none.go b/protocol/shadowsocks/none.go
index 7abd9a5..fa33a1f 100644
--- a/protocol/shadowsocks/none.go
+++ b/protocol/shadowsocks/none.go
@@ -155,7 +155,7 @@ func (c *nonePacketConn) WritePacket(buffer *buf.Buffer, addrPort *M.AddrPort) e
 
 type NoneService struct {
 	handler Handler
-	udp     udpnat.Service[netip.AddrPort]
+	udp     *udpnat.Service[netip.AddrPort]
 }
 
 func NewNoneService(udpTimeout int64, handler Handler) Service {
diff --git a/protocol/shadowsocks/shadowaead/service.go b/protocol/shadowsocks/shadowaead/service.go
index 0d929d7..608542b 100644
--- a/protocol/shadowsocks/shadowaead/service.go
+++ b/protocol/shadowsocks/shadowaead/service.go
@@ -27,8 +27,8 @@ type Service struct {
 	key           []byte
 	secureRNG     io.Reader
 	replayFilter  replay.Filter
-	udpNat        udpnat.Service[netip.AddrPort]
 	handler       shadowsocks.Handler
+	udpNat        *udpnat.Service[netip.AddrPort]
 }
 
 func NewService(method string, key []byte, password []byte, secureRNG io.Reader, replayFilter bool, udpTimeout int64, handler shadowsocks.Handler) (shadowsocks.Service, error) {
@@ -36,8 +36,8 @@ func NewService(method string, key []byte, password []byte, secureRNG io.Reader,
 		name:      method,
 		secureRNG: secureRNG,
 		handler:   handler,
+		udpNat:    udpnat.New[netip.AddrPort](udpTimeout, handler),
 	}
-	s.udpNat = udpnat.New[netip.AddrPort](udpTimeout, s)
 	if replayFilter {
 		s.replayFilter = replay.NewBloomRing()
 	}
@@ -244,11 +244,3 @@ func (w *serverPacketWriter) WritePacket(buffer *buf.Buffer, destination *M.Addr
 	buffer.Extend(c.Overhead())
 	return w.PacketConn.WritePacket(buffer, w.source)
 }
-
-func (s *Service) NewPacketConnection(ctx context.Context, conn socks.PacketConn, metadata M.Metadata) error {
-	return s.handler.NewPacketConnection(ctx, conn, metadata)
-}
-
-func (s *Service) HandleError(err error) {
-	s.handler.HandleError(err)
-}
diff --git a/protocol/shadowsocks/shadowaead_2022/service.go b/protocol/shadowsocks/shadowaead_2022/service.go
index 04bbf90..c973f1c 100644
--- a/protocol/shadowsocks/shadowaead_2022/service.go
+++ b/protocol/shadowsocks/shadowaead_2022/service.go
@@ -38,8 +38,8 @@ type Service struct {
 	psk              [KeySaltSize]byte
 	replayFilter     replay.Filter
 	handler          shadowsocks.Handler
-	udpNat           udpnat.Service[uint64]
-	sessions         cache.LruCache[uint64, *serverUDPSession]
+	udpNat           *udpnat.Service[uint64]
+	sessions         *cache.LruCache[uint64, *serverUDPSession]
 }
 
 func NewService(method string, psk [KeySaltSize]byte, secureRNG io.Reader, udpTimeout int64, handler shadowsocks.Handler) (shadowsocks.Service, error) {
@@ -49,7 +49,11 @@ func NewService(method string, psk [KeySaltSize]byte, secureRNG io.Reader, udpTi
 		secureRNG:    secureRNG,
 		replayFilter: replay.NewCuckoo(60),
 		handler:      handler,
-		sessions:     cache.NewLRU[uint64, *serverUDPSession](udpTimeout, true),
+		udpNat:       udpnat.New[uint64](udpTimeout, handler),
+		sessions: cache.New[uint64, *serverUDPSession](
+			cache.WithAge[uint64, *serverUDPSession](udpTimeout),
+			cache.WithUpdateAgeOnGet[uint64, *serverUDPSession](),
+		),
 	}
 
 	switch method {
@@ -69,7 +73,6 @@ func NewService(method string, psk [KeySaltSize]byte, secureRNG io.Reader, udpTi
 		s.udpCipher = newXChacha20Poly1305(s.psk[:])
 	}
 
-	s.udpNat = udpnat.New[uint64](udpTimeout, s)
 	return s, nil
 }
 
@@ -445,11 +448,3 @@ func (m *Service) newUDPSession() *serverUDPSession {
 	}
 	return session
 }
-
-func (s *Service) NewPacketConnection(ctx context.Context, conn socks.PacketConn, metadata M.Metadata) error {
-	return s.handler.NewPacketConnection(ctx, conn, metadata)
-}
-
-func (s *Service) HandleError(err error) {
-	s.handler.HandleError(err)
-}
diff --git a/protocol/socks/conn.go b/protocol/socks/conn.go
index 63591f4..ba6f5c6 100644
--- a/protocol/socks/conn.go
+++ b/protocol/socks/conn.go
@@ -15,7 +15,7 @@ type AssociateConn struct {
 	dest *M.AddrPort
 }
 
-func NewAssociateConn(conn net.Conn, packetConn net.Conn, destination *M.AddrPort) net.PacketConn {
+func NewAssociateConn(conn net.Conn, packetConn net.Conn, destination *M.AddrPort) *AssociateConn {
 	return &AssociateConn{
 		Conn: packetConn,
 		conn: conn,
diff --git a/protocol/socks/protocol.go b/protocol/socks/protocol.go
index e466df3..08f2ded 100644
--- a/protocol/socks/protocol.go
+++ b/protocol/socks/protocol.go
@@ -49,7 +49,7 @@ func ReadAuthRequest(reader io.Reader) (*AuthRequest, error) {
 	}
 	methods, err := rw.ReadBytes(reader, int(methodLen))
 	if err != nil {
-		return nil, E.CauseF(err, "read socks auth methods, length ", methodLen)
+		return nil, E.Cause(err, "read socks auth methods, length ", methodLen)
 	}
 	request := &AuthRequest{
 		version,
@@ -65,7 +65,7 @@ func ReadAuthRequest0(reader io.Reader) (*AuthRequest, error) {
 	}
 	methods, err := rw.ReadBytes(reader, int(methodLen))
 	if err != nil {
-		return nil, E.CauseF(err, "read socks auth methods, length ", methodLen)
+		return nil, E.Cause(err, "read socks auth methods, length ", methodLen)
 	}
 	request := &AuthRequest{
 		Version5,
diff --git a/transport/mixed/listener.go b/transport/mixed/listener.go
index 819ecec..ad11f9a 100644
--- a/transport/mixed/listener.go
+++ b/transport/mixed/listener.go
@@ -34,7 +34,7 @@ type Listener struct {
 	bindAddr      netip.Addr
 	handler       Handler
 	authenticator auth.Authenticator
-	udpNat        udpnat.Service[netip.AddrPort]
+	udpNat        *udpnat.Service[netip.AddrPort]
 }
 
 func NewListener(bind netip.AddrPort, authenticator auth.Authenticator, transproxy redir.TransproxyMode, udpTimeout int64, handler Handler) *Listener {