Add optimistic DNS cache

adapter/dns.go

@@ -3,6 +3,7 @@ package adapter
 import (
 	"context"
 	"net/netip"
+	"time"
 
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/log"
@@ -31,12 +32,13 @@ type DNSClient interface {
 }
 
 type DNSQueryOptions struct {
-	Transport      DNSTransport
+	Transport              DNSTransport
-	Strategy       C.DomainStrategy
+	Strategy               C.DomainStrategy
-	LookupStrategy C.DomainStrategy
+	LookupStrategy         C.DomainStrategy
-	DisableCache   bool
+	DisableCache           bool
-	RewriteTTL     *uint32
+	DisableOptimisticCache bool
-	ClientSubnet   netip.Prefix
+	RewriteTTL             *uint32
+	ClientSubnet           netip.Prefix
 }
 
 func DNSQueryOptionsFrom(ctx context.Context, options *option.DomainResolveOptions) (*DNSQueryOptions, error) {
@@ -49,11 +51,12 @@ func DNSQueryOptionsFrom(ctx context.Context, options *option.DomainResolveOptio
 		return nil, E.New("domain resolver not found: " + options.Server)
 	}
 	return &DNSQueryOptions{
-		Transport:    transport,
+		Transport:              transport,
-		Strategy:     C.DomainStrategy(options.Strategy),
+		Strategy:               C.DomainStrategy(options.Strategy),
-		DisableCache: options.DisableCache,
+		DisableCache:           options.DisableCache,
-		RewriteTTL:   options.RewriteTTL,
+		DisableOptimisticCache: options.DisableOptimisticCache,
-		ClientSubnet: options.ClientSubnet.Build(netip.Prefix{}),
+		RewriteTTL:             options.RewriteTTL,
+		ClientSubnet:           options.ClientSubnet.Build(netip.Prefix{}),
 	}, nil
 }
 
@@ -63,6 +66,13 @@ type RDRCStore interface {
 	SaveRDRCAsync(transportName string, qName string, qType uint16, logger logger.Logger)
 }
 
+type DNSCacheStore interface {
+	LoadDNSCache(transportName string, qName string, qType uint16) (rawMessage []byte, expireAt time.Time, loaded bool)
+	SaveDNSCache(transportName string, qName string, qType uint16, rawMessage []byte, expireAt time.Time) error
+	SaveDNSCacheAsync(transportName string, qName string, qType uint16, rawMessage []byte, expireAt time.Time, logger logger.Logger)
+	ClearDNSCache() error
+}
+
 type DNSTransport interface {
 	Lifecycle
 	Type() string

adapter/experimental.go

@@ -48,6 +48,12 @@ type CacheFile interface {
 	StoreRDRC() bool
 	RDRCStore
 
+	StoreDNS() bool
+	DNSCacheStore
+
+	SetDisableExpire(disableExpire bool)
+	SetOptimisticTimeout(timeout time.Duration)
+
 	LoadMode() string
 	StoreMode(mode string) error
 	LoadSelected(group string) string

box.go

@@ -196,7 +196,10 @@ func New(options Options) (*Box, error) {
 	service.MustRegister[adapter.DNSTransportManager](ctx, dnsTransportManager)
 	service.MustRegister[adapter.ServiceManager](ctx, serviceManager)
 	service.MustRegister[adapter.CertificateProviderManager](ctx, certificateProviderManager)
-	dnsRouter := dns.NewRouter(ctx, logFactory, dnsOptions)
+	dnsRouter, err := dns.NewRouter(ctx, logFactory, dnsOptions)
+	if err != nil {
+		return nil, E.Cause(err, "initialize DNS router")
+	}
 	service.MustRegister[adapter.DNSRouter](ctx, dnsRouter)
 	service.MustRegister[adapter.DNSRuleSetUpdateValidator](ctx, dnsRouter)
 	networkManager, err := route.NewNetworkManager(ctx, logFactory.NewLogger("network"), routeOptions, dnsOptions)
@@ -372,7 +375,7 @@ func New(options Options) (*Box, error) {
 		}
 	}
 	if needCacheFile {
-		cacheFile := cachefile.New(ctx, common.PtrValueOrDefault(experimentalOptions.CacheFile))
+		cacheFile := cachefile.New(ctx, logFactory.NewLogger("cache-file"), common.PtrValueOrDefault(experimentalOptions.CacheFile))
 		service.MustRegister[adapter.CacheFile](ctx, cacheFile)
 		internalServices = append(internalServices, cacheFile)
 	}

common/dialer/dialer.go

@@ -87,11 +87,12 @@ func NewWithOptions(options Options) (N.Dialer, error) {
 			}
 			server = dialOptions.DomainResolver.Server
 			dnsQueryOptions = adapter.DNSQueryOptions{
-				Transport:    transport,
+				Transport:              transport,
-				Strategy:     strategy,
+				Strategy:               strategy,
-				DisableCache: dialOptions.DomainResolver.DisableCache,
+				DisableCache:           dialOptions.DomainResolver.DisableCache,
-				RewriteTTL:   dialOptions.DomainResolver.RewriteTTL,
+				DisableOptimisticCache: dialOptions.DomainResolver.DisableOptimisticCache,
-				ClientSubnet: dialOptions.DomainResolver.ClientSubnet.Build(netip.Prefix{}),
+				RewriteTTL:             dialOptions.DomainResolver.RewriteTTL,
+				ClientSubnet:           dialOptions.DomainResolver.ClientSubnet.Build(netip.Prefix{}),
 			}
 			resolveFallbackDelay = time.Duration(dialOptions.FallbackDelay)
 		} else if options.DirectResolver {

dns/client.go

@@ -30,56 +30,63 @@ var (
 var _ adapter.DNSClient = (*Client)(nil)
 
 type Client struct {
-	timeout            time.Duration
+	ctx               context.Context
-	disableCache       bool
+	timeout           time.Duration
-	disableExpire      bool
+	disableCache      bool
-	independentCache   bool
+	disableExpire     bool
-	clientSubnet       netip.Prefix
+	optimisticTimeout time.Duration
-	rdrc               adapter.RDRCStore
+	cacheCapacity     uint32
-	initRDRCFunc       func() adapter.RDRCStore
+	clientSubnet      netip.Prefix
-	logger             logger.ContextLogger
+	rdrc              adapter.RDRCStore
-	cache              freelru.Cache[dns.Question, *dns.Msg]
+	initRDRCFunc      func() adapter.RDRCStore
-	cacheLock          compatible.Map[transportCacheKey, chan struct{}]
+	dnsCache          adapter.DNSCacheStore
-	transportCache     freelru.Cache[transportCacheKey, *dns.Msg]
+	initDNSCacheFunc  func() adapter.DNSCacheStore
-	transportCacheLock compatible.Map[transportCacheKey, chan struct{}]
+	logger            logger.ContextLogger
+	cache             freelru.Cache[dnsCacheKey, *dns.Msg]
+	cacheLock         compatible.Map[dnsCacheKey, chan struct{}]
+	backgroundRefresh compatible.Map[dnsCacheKey, struct{}]
 }
 
 type ClientOptions struct {
-	Timeout          time.Duration
+	Context           context.Context
-	DisableCache     bool
+	Timeout           time.Duration
-	DisableExpire    bool
+	DisableCache      bool
-	IndependentCache bool
+	DisableExpire     bool
-	CacheCapacity    uint32
+	OptimisticTimeout time.Duration
-	ClientSubnet     netip.Prefix
+	CacheCapacity     uint32
-	RDRC             func() adapter.RDRCStore
+	ClientSubnet      netip.Prefix
-	Logger           logger.ContextLogger
+	RDRC              func() adapter.RDRCStore
+	DNSCache          func() adapter.DNSCacheStore
+	Logger            logger.ContextLogger
 }
 
 func NewClient(options ClientOptions) *Client {
+	cacheCapacity := options.CacheCapacity
+	if cacheCapacity < 1024 {
+		cacheCapacity = 1024
+	}
 	client := &Client{
-		timeout:          options.Timeout,
+		ctx:               options.Context,
-		disableCache:     options.DisableCache,
+		timeout:           options.Timeout,
-		disableExpire:    options.DisableExpire,
+		disableCache:      options.DisableCache,
-		independentCache: options.IndependentCache,
+		disableExpire:     options.DisableExpire,
-		clientSubnet:     options.ClientSubnet,
+		optimisticTimeout: options.OptimisticTimeout,
-		initRDRCFunc:     options.RDRC,
+		cacheCapacity:     cacheCapacity,
-		logger:           options.Logger,
+		clientSubnet:      options.ClientSubnet,
+		initRDRCFunc:      options.RDRC,
+		initDNSCacheFunc:  options.DNSCache,
+		logger:            options.Logger,
 	}
 	if client.timeout == 0 {
 		client.timeout = C.DNSTimeout
 	}
-	cacheCapacity := max(options.CacheCapacity, 1024)
+	if !client.disableCache && client.initDNSCacheFunc == nil {
-	if !client.disableCache {
+		client.initializeMemoryCache()
-		if !client.independentCache {
-			client.cache = common.Must1(freelru.NewSharded[dns.Question, *dns.Msg](cacheCapacity, maphash.NewHasher[dns.Question]().Hash32))
-		} else {
-			client.transportCache = common.Must1(freelru.NewSharded[transportCacheKey, *dns.Msg](cacheCapacity, maphash.NewHasher[transportCacheKey]().Hash32))
-		}
 	}
 	return client
 }
 
-type transportCacheKey struct {
+type dnsCacheKey struct {
 	dns.Question
 	transportTag string
 }
@@ -88,6 +95,19 @@ func (c *Client) Start() {
 	if c.initRDRCFunc != nil {
 		c.rdrc = c.initRDRCFunc()
 	}
+	if c.initDNSCacheFunc != nil {
+		c.dnsCache = c.initDNSCacheFunc()
+	}
+	if c.dnsCache == nil {
+		c.initializeMemoryCache()
+	}
+}
+
+func (c *Client) initializeMemoryCache() {
+	if c.disableCache || c.cache != nil {
+		return
+	}
+	c.cache = common.Must1(freelru.NewSharded[dnsCacheKey, *dns.Msg](c.cacheCapacity, maphash.NewHasher[dnsCacheKey]().Hash32))
 }
 
 func extractNegativeTTL(response *dns.Msg) (uint32, bool) {
@@ -104,6 +124,37 @@ func extractNegativeTTL(response *dns.Msg) (uint32, bool) {
 	return 0, false
 }
 
+func computeTimeToLive(response *dns.Msg) uint32 {
+	var timeToLive uint32
+	if len(response.Answer) == 0 {
+		if soaTTL, hasSOA := extractNegativeTTL(response); hasSOA {
+			return soaTTL
+		}
+	}
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			if record.Header().Rrtype == dns.TypeOPT {
+				continue
+			}
+			if timeToLive == 0 || record.Header().Ttl > 0 && record.Header().Ttl < timeToLive {
+				timeToLive = record.Header().Ttl
+			}
+		}
+	}
+	return timeToLive
+}
+
+func normalizeTTL(response *dns.Msg, timeToLive uint32) {
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			if record.Header().Rrtype == dns.TypeOPT {
+				continue
+			}
+			record.Header().Ttl = timeToLive
+		}
+	}
+}
+
 func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, message *dns.Msg, options adapter.DNSQueryOptions, responseChecker func(response *dns.Msg) bool) (*dns.Msg, error) {
 	if len(message.Question) == 0 {
 		if c.logger != nil {
@@ -118,13 +169,7 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 		}
 		return FixedResponseStatus(message, dns.RcodeSuccess), nil
 	}
-	clientSubnet := options.ClientSubnet
+	message = c.prepareExchangeMessage(message, options)
-	if !clientSubnet.IsValid() {
-		clientSubnet = c.clientSubnet
-	}
-	if clientSubnet.IsValid() {
-		message = SetClientSubnet(message, clientSubnet)
-	}
 
 	isSimpleRequest := len(message.Question) == 1 &&
 		len(message.Ns) == 0 &&
@@ -136,41 +181,32 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 		!options.ClientSubnet.IsValid()
 	disableCache := !isSimpleRequest || c.disableCache || options.DisableCache
 	if !disableCache {
-		cacheKey := transportCacheKey{Question: question, transportTag: transport.Tag()}
+		cacheKey := dnsCacheKey{Question: question, transportTag: transport.Tag()}
-		if c.cache != nil {
+		cond, loaded := c.cacheLock.LoadOrStore(cacheKey, make(chan struct{}))
-			cond, loaded := c.cacheLock.LoadOrStore(cacheKey, make(chan struct{}))
+		if loaded {
-			if loaded {
+			select {
-				select {
+			case <-cond:
-				case <-cond:
+			case <-ctx.Done():
-				case <-ctx.Done():
+				return nil, ctx.Err()
-					return nil, ctx.Err()
-				}
-			} else {
-				defer func() {
-					c.cacheLock.Delete(cacheKey)
-					close(cond)
-				}()
-			}
-		} else if c.transportCache != nil {
-			cond, loaded := c.transportCacheLock.LoadOrStore(cacheKey, make(chan struct{}))
-			if loaded {
-				select {
-				case <-cond:
-				case <-ctx.Done():
-					return nil, ctx.Err()
-				}
-			} else {
-				defer func() {
-					c.transportCacheLock.Delete(cacheKey)
-					close(cond)
-				}()
 			}
+		} else {
+			defer func() {
+				c.cacheLock.Delete(cacheKey)
+				close(cond)
+			}()
 		}
-		response, ttl := c.loadResponse(question, transport)
+		response, ttl, isStale := c.loadResponse(question, transport)
 		if response != nil {
-			logCachedResponse(c.logger, ctx, response, ttl)
+			if isStale && !options.DisableOptimisticCache {
-			response.Id = message.Id
+				c.backgroundRefreshDNS(transport, question, message.Copy(), options, responseChecker)
-			return response, nil
+				logOptimisticResponse(c.logger, ctx, response)
+				response.Id = message.Id
+				return response, nil
+			} else if !isStale {
+				logCachedResponse(c.logger, ctx, response, ttl)
+				response.Id = message.Id
+				return response, nil
+			}
 		}
 	}
 
@@ -186,52 +222,10 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 			return nil, ErrResponseRejectedCached
 		}
 	}
-	ctx, cancel := context.WithTimeout(ctx, c.timeout)
+	response, err := c.exchangeToTransport(ctx, transport, message)
-	response, err := transport.Exchange(ctx, message)
-	cancel()
 	if err != nil {
-		var rcodeError RcodeError
+		return nil, err
-		if errors.As(err, &rcodeError) {
-			response = FixedResponseStatus(message, int(rcodeError))
-		} else {
-			return nil, err
-		}
 	}
-	/*if question.Qtype == dns.TypeA || question.Qtype == dns.TypeAAAA {
-		validResponse := response
-	loop:
-		for {
-			var (
-				addresses  int
-				queryCNAME string
-			)
-			for _, rawRR := range validResponse.Answer {
-				switch rr := rawRR.(type) {
-				case *dns.A:
-					break loop
-				case *dns.AAAA:
-					break loop
-				case *dns.CNAME:
-					queryCNAME = rr.Target
-				}
-			}
-			if queryCNAME == "" {
-				break
-			}
-			exMessage := *message
-			exMessage.Question = []dns.Question{{
-				Name:  queryCNAME,
-				Qtype: question.Qtype,
-			}}
-			validResponse, err = c.Exchange(ctx, transport, &exMessage, options, responseChecker)
-			if err != nil {
-				return nil, err
-			}
-		}
-		if validResponse != response {
-			response.Answer = append(response.Answer, validResponse.Answer...)
-		}
-	}*/
 	disableCache = disableCache || (response.Rcode != dns.RcodeSuccess && response.Rcode != dns.RcodeNameError)
 	if responseChecker != nil {
 		var rejected bool
@@ -248,54 +242,7 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 			return response, ErrResponseRejected
 		}
 	}
-	if question.Qtype == dns.TypeHTTPS {
+	timeToLive := applyResponseOptions(question, response, options)
-		if options.Strategy == C.DomainStrategyIPv4Only || options.Strategy == C.DomainStrategyIPv6Only {
-			for _, rr := range response.Answer {
-				https, isHTTPS := rr.(*dns.HTTPS)
-				if !isHTTPS {
-					continue
-				}
-				content := https.SVCB
-				content.Value = common.Filter(content.Value, func(it dns.SVCBKeyValue) bool {
-					if options.Strategy == C.DomainStrategyIPv4Only {
-						return it.Key() != dns.SVCB_IPV6HINT
-					} else {
-						return it.Key() != dns.SVCB_IPV4HINT
-					}
-				})
-				https.SVCB = content
-			}
-		}
-	}
-	var timeToLive uint32
-	if len(response.Answer) == 0 {
-		if soaTTL, hasSOA := extractNegativeTTL(response); hasSOA {
-			timeToLive = soaTTL
-		}
-	}
-	if timeToLive == 0 {
-		for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-			for _, record := range recordList {
-				if record.Header().Rrtype == dns.TypeOPT {
-					continue
-				}
-				if timeToLive == 0 || record.Header().Ttl > 0 && record.Header().Ttl < timeToLive {
-					timeToLive = record.Header().Ttl
-				}
-			}
-		}
-	}
-	if options.RewriteTTL != nil {
-		timeToLive = *options.RewriteTTL
-	}
-	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-		for _, record := range recordList {
-			if record.Header().Rrtype == dns.TypeOPT {
-				continue
-			}
-			record.Header().Ttl = timeToLive
-		}
-	}
 	if !disableCache {
 		c.storeCache(transport, question, response, timeToLive)
 	}
@@ -362,8 +309,12 @@ func (c *Client) Lookup(ctx context.Context, transport adapter.DNSTransport, dom
 func (c *Client) ClearCache() {
 	if c.cache != nil {
 		c.cache.Purge()
-	} else if c.transportCache != nil {
+	}
-		c.transportCache.Purge()
+	if c.dnsCache != nil {
+		err := c.dnsCache.ClearDNSCache()
+		if err != nil && c.logger != nil {
+			c.logger.Warn("clear DNS cache: ", err)
+		}
 	}
 }
 
@@ -379,24 +330,22 @@ func (c *Client) storeCache(transport adapter.DNSTransport, question dns.Questio
 	if timeToLive == 0 {
 		return
 	}
+	if c.dnsCache != nil {
+		packed, err := message.Pack()
+		if err == nil {
+			expireAt := time.Now().Add(time.Second * time.Duration(timeToLive))
+			c.dnsCache.SaveDNSCacheAsync(transport.Tag(), question.Name, question.Qtype, packed, expireAt, c.logger)
+		}
+		return
+	}
+	if c.cache == nil {
+		return
+	}
+	key := dnsCacheKey{Question: question, transportTag: transport.Tag()}
 	if c.disableExpire {
-		if !c.independentCache {
+		c.cache.Add(key, message.Copy())
-			c.cache.Add(question, message.Copy())
-		} else {
-			c.transportCache.Add(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			}, message.Copy())
-		}
 	} else {
-		if !c.independentCache {
+		c.cache.AddWithLifetime(key, message.Copy(), time.Second*time.Duration(timeToLive))
-			c.cache.AddWithLifetime(question, message.Copy(), time.Second*time.Duration(timeToLive))
-		} else {
-			c.transportCache.AddWithLifetime(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			}, message.Copy(), time.Second*time.Duration(timeToLive))
-		}
 	}
 }
 
@@ -406,19 +355,19 @@ func (c *Client) lookupToExchange(ctx context.Context, transport adapter.DNSTran
 		Qtype:  qType,
 		Qclass: dns.ClassINET,
 	}
-	disableCache := c.disableCache || options.DisableCache
-	if !disableCache {
-		cachedAddresses, err := c.questionCache(question, transport)
-		if err != ErrNotCached {
-			return cachedAddresses, err
-		}
-	}
 	message := dns.Msg{
 		MsgHdr: dns.MsgHdr{
 			RecursionDesired: true,
 		},
 		Question: []dns.Question{question},
 	}
+	disableCache := c.disableCache || options.DisableCache
+	if !disableCache {
+		cachedAddresses, err := c.questionCache(ctx, transport, &message, options, responseChecker)
+		if err != ErrNotCached {
+			return cachedAddresses, err
+		}
+	}
 	response, err := c.Exchange(ctx, transport, &message, options, responseChecker)
 	if err != nil {
 		return nil, err
@@ -429,95 +378,174 @@ func (c *Client) lookupToExchange(ctx context.Context, transport adapter.DNSTran
 	return MessageToAddresses(response), nil
 }
 
-func (c *Client) questionCache(question dns.Question, transport adapter.DNSTransport) ([]netip.Addr, error) {
+func (c *Client) questionCache(ctx context.Context, transport adapter.DNSTransport, message *dns.Msg, options adapter.DNSQueryOptions, responseChecker func(response *dns.Msg) bool) ([]netip.Addr, error) {
-	response, _ := c.loadResponse(question, transport)
+	question := message.Question[0]
+	response, _, isStale := c.loadResponse(question, transport)
 	if response == nil {
 		return nil, ErrNotCached
 	}
+	if isStale {
+		if options.DisableOptimisticCache {
+			return nil, ErrNotCached
+		}
+		c.backgroundRefreshDNS(transport, question, c.prepareExchangeMessage(message.Copy(), options), options, responseChecker)
+		logOptimisticResponse(c.logger, ctx, response)
+	}
 	if response.Rcode != dns.RcodeSuccess {
 		return nil, RcodeError(response.Rcode)
 	}
 	return MessageToAddresses(response), nil
 }
 
-func (c *Client) loadResponse(question dns.Question, transport adapter.DNSTransport) (*dns.Msg, int) {
+func (c *Client) loadResponse(question dns.Question, transport adapter.DNSTransport) (*dns.Msg, int, bool) {
-	var (
+	if c.dnsCache != nil {
-		response *dns.Msg
+		return c.loadPersistentResponse(question, transport)
-		loaded   bool
-	)
-	if c.disableExpire {
-		if !c.independentCache {
-			response, loaded = c.cache.Get(question)
-		} else {
-			response, loaded = c.transportCache.Get(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			})
-		}
-		if !loaded {
-			return nil, 0
-		}
-		return response.Copy(), 0
-	} else {
-		var expireAt time.Time
-		if !c.independentCache {
-			response, expireAt, loaded = c.cache.GetWithLifetime(question)
-		} else {
-			response, expireAt, loaded = c.transportCache.GetWithLifetime(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			})
-		}
-		if !loaded {
-			return nil, 0
-		}
-		timeNow := time.Now()
-		if timeNow.After(expireAt) {
-			if !c.independentCache {
-				c.cache.Remove(question)
-			} else {
-				c.transportCache.Remove(transportCacheKey{
-					Question:     question,
-					transportTag: transport.Tag(),
-				})
-			}
-			return nil, 0
-		}
-		var originTTL int
-		for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-			for _, record := range recordList {
-				if record.Header().Rrtype == dns.TypeOPT {
-					continue
-				}
-				if originTTL == 0 || record.Header().Ttl > 0 && int(record.Header().Ttl) < originTTL {
-					originTTL = int(record.Header().Ttl)
-				}
-			}
-		}
-		nowTTL := max(int(expireAt.Sub(timeNow).Seconds()), 0)
-		response = response.Copy()
-		if originTTL > 0 {
-			duration := uint32(originTTL - nowTTL)
-			for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-				for _, record := range recordList {
-					if record.Header().Rrtype == dns.TypeOPT {
-						continue
-					}
-					record.Header().Ttl = record.Header().Ttl - duration
-				}
-			}
-		} else {
-			for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-				for _, record := range recordList {
-					if record.Header().Rrtype == dns.TypeOPT {
-						continue
-					}
-					record.Header().Ttl = uint32(nowTTL)
-				}
-			}
-		}
-		return response, nowTTL
 	}
+	if c.cache == nil {
+		return nil, 0, false
+	}
+	key := dnsCacheKey{Question: question, transportTag: transport.Tag()}
+	if c.disableExpire {
+		response, loaded := c.cache.Get(key)
+		if !loaded {
+			return nil, 0, false
+		}
+		return response.Copy(), 0, false
+	}
+	response, expireAt, loaded := c.cache.GetWithLifetimeNoExpire(key)
+	if !loaded {
+		return nil, 0, false
+	}
+	timeNow := time.Now()
+	if timeNow.After(expireAt) {
+		if c.optimisticTimeout > 0 && timeNow.Before(expireAt.Add(c.optimisticTimeout)) {
+			response = response.Copy()
+			normalizeTTL(response, 1)
+			return response, 0, true
+		}
+		c.cache.Remove(key)
+		return nil, 0, false
+	}
+	nowTTL := int(expireAt.Sub(timeNow).Seconds())
+	if nowTTL < 0 {
+		nowTTL = 0
+	}
+	response = response.Copy()
+	normalizeTTL(response, uint32(nowTTL))
+	return response, nowTTL, false
+}
+
+func (c *Client) loadPersistentResponse(question dns.Question, transport adapter.DNSTransport) (*dns.Msg, int, bool) {
+	rawMessage, expireAt, loaded := c.dnsCache.LoadDNSCache(transport.Tag(), question.Name, question.Qtype)
+	if !loaded {
+		return nil, 0, false
+	}
+	response := new(dns.Msg)
+	err := response.Unpack(rawMessage)
+	if err != nil {
+		return nil, 0, false
+	}
+	if c.disableExpire {
+		return response, 0, false
+	}
+	timeNow := time.Now()
+	if timeNow.After(expireAt) {
+		if c.optimisticTimeout > 0 && timeNow.Before(expireAt.Add(c.optimisticTimeout)) {
+			normalizeTTL(response, 1)
+			return response, 0, true
+		}
+		return nil, 0, false
+	}
+	nowTTL := max(int(expireAt.Sub(timeNow).Seconds()), 0)
+	normalizeTTL(response, uint32(nowTTL))
+	return response, nowTTL, false
+}
+
+func applyResponseOptions(question dns.Question, response *dns.Msg, options adapter.DNSQueryOptions) uint32 {
+	if question.Qtype == dns.TypeHTTPS && (options.Strategy == C.DomainStrategyIPv4Only || options.Strategy == C.DomainStrategyIPv6Only) {
+		for _, rr := range response.Answer {
+			https, isHTTPS := rr.(*dns.HTTPS)
+			if !isHTTPS {
+				continue
+			}
+			content := https.SVCB
+			content.Value = common.Filter(content.Value, func(it dns.SVCBKeyValue) bool {
+				if options.Strategy == C.DomainStrategyIPv4Only {
+					return it.Key() != dns.SVCB_IPV6HINT
+				}
+				return it.Key() != dns.SVCB_IPV4HINT
+			})
+			https.SVCB = content
+		}
+	}
+	timeToLive := computeTimeToLive(response)
+	if options.RewriteTTL != nil {
+		timeToLive = *options.RewriteTTL
+	}
+	normalizeTTL(response, timeToLive)
+	return timeToLive
+}
+
+func (c *Client) backgroundRefreshDNS(transport adapter.DNSTransport, question dns.Question, message *dns.Msg, options adapter.DNSQueryOptions, responseChecker func(response *dns.Msg) bool) {
+	key := dnsCacheKey{Question: question, transportTag: transport.Tag()}
+	_, loaded := c.backgroundRefresh.LoadOrStore(key, struct{}{})
+	if loaded {
+		return
+	}
+	go func() {
+		defer c.backgroundRefresh.Delete(key)
+		ctx := contextWithTransportTag(c.ctx, transport.Tag())
+		response, err := c.exchangeToTransport(ctx, transport, message)
+		if err != nil {
+			if c.logger != nil {
+				c.logger.Debug("optimistic refresh failed for ", FqdnToDomain(question.Name), ": ", err)
+			}
+			return
+		}
+		if responseChecker != nil {
+			var rejected bool
+			if response.Rcode != dns.RcodeSuccess && response.Rcode != dns.RcodeNameError {
+				rejected = true
+			} else {
+				rejected = !responseChecker(response)
+			}
+			if rejected {
+				if c.rdrc != nil {
+					c.rdrc.SaveRDRCAsync(transport.Tag(), question.Name, question.Qtype, c.logger)
+				}
+				return
+			}
+		} else if response.Rcode != dns.RcodeSuccess && response.Rcode != dns.RcodeNameError {
+			return
+		}
+		timeToLive := applyResponseOptions(question, response, options)
+		c.storeCache(transport, question, response, timeToLive)
+	}()
+}
+
+func (c *Client) prepareExchangeMessage(message *dns.Msg, options adapter.DNSQueryOptions) *dns.Msg {
+	clientSubnet := options.ClientSubnet
+	if !clientSubnet.IsValid() {
+		clientSubnet = c.clientSubnet
+	}
+	if clientSubnet.IsValid() {
+		message = SetClientSubnet(message, clientSubnet)
+	}
+	return message
+}
+
+func (c *Client) exchangeToTransport(ctx context.Context, transport adapter.DNSTransport, message *dns.Msg) (*dns.Msg, error) {
+	ctx, cancel := context.WithTimeout(ctx, c.timeout)
+	defer cancel()
+	response, err := transport.Exchange(ctx, message)
+	if err == nil {
+		return response, nil
+	}
+	var rcodeError RcodeError
+	if errors.As(err, &rcodeError) {
+		return FixedResponseStatus(message, int(rcodeError)), nil
+	}
+	return nil, err
 }
 
 func MessageToAddresses(response *dns.Msg) []netip.Addr {

dns/client_log.go

@@ -22,6 +22,19 @@ func logCachedResponse(logger logger.ContextLogger, ctx context.Context, respons
 	}
 }
 
+func logOptimisticResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg) {
+	if logger == nil || len(response.Question) == 0 {
+		return
+	}
+	domain := FqdnToDomain(response.Question[0].Name)
+	logger.DebugContext(ctx, "optimistic ", domain, " ", dns.RcodeToString[response.Rcode])
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			logger.InfoContext(ctx, "optimistic ", dns.Type(record.Header().Rrtype).String(), " ", FormatQuestion(record.String()))
+		}
+	}
+}
+
 func logExchangedResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg, ttl uint32) {
 	if logger == nil || len(response.Question) == 0 {
 		return

dns/router.go

@@ -51,7 +51,7 @@ type Router struct {
 	closing               bool
 }
 
-func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOptions) *Router {
+func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOptions) (*Router, error) {
 	router := &Router{
 		ctx:                   ctx,
 		logger:                logFactory.NewLogger("dns"),
@@ -61,12 +61,30 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOp
 		rules:                 make([]adapter.DNSRule, 0, len(options.Rules)),
 		defaultDomainStrategy: C.DomainStrategy(options.Strategy),
 	}
+	if options.DNSClientOptions.IndependentCache {
+		deprecated.Report(ctx, deprecated.OptionIndependentDNSCache)
+	}
+	var optimisticTimeout time.Duration
+	optimisticOptions := common.PtrValueOrDefault(options.DNSClientOptions.Optimistic)
+	if optimisticOptions.Enabled {
+		if options.DNSClientOptions.DisableCache {
+			return nil, E.New("`optimistic` is conflict with `disable_cache`")
+		}
+		if options.DNSClientOptions.DisableExpire {
+			return nil, E.New("`optimistic` is conflict with `disable_expire`")
+		}
+		optimisticTimeout = time.Duration(optimisticOptions.Timeout)
+		if optimisticTimeout == 0 {
+			optimisticTimeout = 3 * 24 * time.Hour
+		}
+	}
 	router.client = NewClient(ClientOptions{
-		DisableCache:     options.DNSClientOptions.DisableCache,
+		Context:           ctx,
-		DisableExpire:    options.DNSClientOptions.DisableExpire,
+		DisableCache:      options.DNSClientOptions.DisableCache,
-		IndependentCache: options.DNSClientOptions.IndependentCache,
+		DisableExpire:     options.DNSClientOptions.DisableExpire,
-		CacheCapacity:    options.DNSClientOptions.CacheCapacity,
+		OptimisticTimeout: optimisticTimeout,
-		ClientSubnet:     options.DNSClientOptions.ClientSubnet.Build(netip.Prefix{}),
+		CacheCapacity:     options.DNSClientOptions.CacheCapacity,
+		ClientSubnet:      options.DNSClientOptions.ClientSubnet.Build(netip.Prefix{}),
 		RDRC: func() adapter.RDRCStore {
 			cacheFile := service.FromContext[adapter.CacheFile](ctx)
 			if cacheFile == nil {
@@ -77,12 +95,24 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOp
 			}
 			return cacheFile
 		},
+		DNSCache: func() adapter.DNSCacheStore {
+			cacheFile := service.FromContext[adapter.CacheFile](ctx)
+			if cacheFile == nil {
+				return nil
+			}
+			if !cacheFile.StoreDNS() {
+				return nil
+			}
+			cacheFile.SetDisableExpire(options.DNSClientOptions.DisableExpire)
+			cacheFile.SetOptimisticTimeout(optimisticTimeout)
+			return cacheFile
+		},
 		Logger: router.logger,
 	})
 	if options.ReverseMapping {
 		router.dnsReverseMapping = common.Must1(freelru.NewSharded[netip.Addr, string](1024, maphash.NewHasher[netip.Addr]().Hash32))
 	}
-	return router
+	return router, nil
 }
 
 func (r *Router) Initialize(rules []option.DNSRule) error {
@@ -319,6 +349,9 @@ func (r *Router) applyDNSRouteOptions(options *adapter.DNSQueryOptions, routeOpt
 	if routeOptions.DisableCache {
 		options.DisableCache = true
 	}
+	if routeOptions.DisableOptimisticCache {
+		options.DisableOptimisticCache = true
+	}
 	if routeOptions.RewriteTTL != nil {
 		options.RewriteTTL = routeOptions.RewriteTTL
 	}
@@ -907,7 +940,9 @@ func dnsRuleModeRequirementsInRule(router adapter.Router, rule option.DNSRule, m
 		return dnsRuleModeRequirementsInDefaultRule(router, rule.DefaultOptions, metadataOverrides)
 	case C.RuleTypeLogical:
 		flags := dnsRuleModeFlags{
-			disabled:           dnsRuleActionType(rule) == C.RuleActionTypeEvaluate || dnsRuleActionType(rule) == C.RuleActionTypeRespond,
+			disabled: dnsRuleActionType(rule) == C.RuleActionTypeEvaluate ||
+				dnsRuleActionType(rule) == C.RuleActionTypeRespond ||
+				dnsRuleActionDisablesLegacyDNSMode(rule.LogicalOptions.DNSRuleAction),
 			neededFromStrategy: dnsRuleActionHasStrategy(rule.LogicalOptions.DNSRuleAction),
 		}
 		flags.needed = flags.neededFromStrategy
@@ -926,7 +961,7 @@ func dnsRuleModeRequirementsInRule(router adapter.Router, rule option.DNSRule, m
 
 func dnsRuleModeRequirementsInDefaultRule(router adapter.Router, rule option.DefaultDNSRule, metadataOverrides map[string]adapter.RuleSetMetadata) (dnsRuleModeFlags, error) {
 	flags := dnsRuleModeFlags{
-		disabled:           defaultRuleDisablesLegacyDNSMode(rule),
+		disabled:           defaultRuleDisablesLegacyDNSMode(rule) || dnsRuleActionDisablesLegacyDNSMode(rule.DNSRuleAction),
 		neededFromStrategy: dnsRuleActionHasStrategy(rule.DNSRuleAction),
 	}
 	flags.needed = defaultRuleNeedsLegacyDNSModeFromAddressFilter(rule) || flags.neededFromStrategy
@@ -1063,6 +1098,17 @@ func validateLegacyDNSModeDisabledDefaultRule(rule option.DefaultDNSRule) (bool,
 	return rule.MatchResponse || rule.Action == C.RuleActionTypeRespond, nil
 }
 
+func dnsRuleActionDisablesLegacyDNSMode(action option.DNSRuleAction) bool {
+	switch action.Action {
+	case "", C.RuleActionTypeRoute, C.RuleActionTypeEvaluate:
+		return action.RouteOptions.DisableOptimisticCache
+	case C.RuleActionTypeRouteOptions:
+		return action.RouteOptionsOptions.DisableOptimisticCache
+	default:
+		return false
+	}
+}
+
 func dnsRuleActionHasStrategy(action option.DNSRuleAction) bool {
 	switch action.Action {
 	case "", C.RuleActionTypeRoute, C.RuleActionTypeEvaluate:

docs/configuration/dns/index.md

@@ -2,6 +2,11 @@
 icon: material/alert-decagram
 ---
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-delete-clock: [independent_cache](#independent_cache)  
+    :material-plus: [optimistic](#optimistic)
+
 !!! quote "Changes in sing-box 1.12.0"
 
     :material-decagram: [servers](#servers)
@@ -25,6 +30,7 @@ icon: material/alert-decagram
     "disable_expire": false,
     "independent_cache": false,
     "cache_capacity": 0,
+    "optimistic": false, // or {}
     "reverse_mapping": false,
     "client_subnet": "",
     "fakeip": {}
@@ -57,12 +63,20 @@ One of `prefer_ipv4` `prefer_ipv6` `ipv4_only` `ipv6_only`.
 
 Disable dns cache.
 
+Conflict with `optimistic`.
+
 #### disable_expire
 
 Disable dns cache expire.
 
+Conflict with `optimistic`.
+
 #### independent_cache
 
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    `independent_cache` is deprecated and will be removed in sing-box 1.14.0, check [Migration](/migration/#migrate-independent-dns-cache).
+
 Make each DNS server's cache independent for special purposes. If enabled, will slightly degrade performance.
 
 #### cache_capacity
@@ -73,6 +87,34 @@ LRU cache capacity.
 
 Value less than 1024 will be ignored.
 
+#### optimistic
+
+!!! question "Since sing-box 1.14.0"
+
+Enable optimistic DNS caching. When a cached DNS entry has expired but is still within the timeout window,
+the stale response is returned immediately while a background refresh is triggered.
+
+Conflict with `disable_cache` and `disable_expire`.
+
+Accepts a boolean or an object. When set to `true`, the default timeout of `3d` is used.
+
+```json
+{
+  "enabled": true,
+  "timeout": "3d"
+}
+```
+
+##### enabled
+
+Enable optimistic DNS caching.
+
+##### timeout
+
+The maximum time an expired cache entry can be served optimistically.
+
+`3d` is used by default.
+
 #### reverse_mapping
 
 Stores a reverse mapping of IP addresses after responding to a DNS query in order to provide domain names when routing.

docs/configuration/dns/index.zh.md

@@ -2,6 +2,11 @@
 icon: material/alert-decagram
 ---
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-delete-clock: [independent_cache](#independent_cache)  
+    :material-plus: [optimistic](#optimistic)
+
 !!! quote "sing-box 1.12.0 中的更改"
 
     :material-decagram: [servers](#servers)
@@ -25,6 +30,7 @@ icon: material/alert-decagram
     "disable_expire": false,
     "independent_cache": false,
     "cache_capacity": 0,
+    "optimistic": false, // or {}
     "reverse_mapping": false,
     "client_subnet": "",
     "fakeip": {}
@@ -56,12 +62,20 @@ icon: material/alert-decagram
 
 禁用 DNS 缓存。
 
+与 `optimistic` 冲突。
+
 #### disable_expire
 
 禁用 DNS 缓存过期。
 
+与 `optimistic` 冲突。
+
 #### independent_cache
 
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    `independent_cache` 已在 sing-box 1.14.0 废弃，且将在 sing-box 1.16.0 中被移除，参阅[迁移指南](/zh/migration/#迁移-independent-dns-cache)。
+
 使每个 DNS 服务器的缓存独立，以满足特殊目的。如果启用，将轻微降低性能。
 
 #### cache_capacity
@@ -72,6 +86,34 @@ LRU 缓存容量。
 
 小于 1024 的值将被忽略。
 
+#### optimistic
+
+!!! question "自 sing-box 1.14.0 起"
+
+启用乐观 DNS 缓存。当缓存的 DNS 条目已过期但仍在超时窗口内时，
+立即返回过期的响应，同时在后台触发刷新。
+
+与 `disable_cache` 和 `disable_expire` 冲突。
+
+接受布尔值或对象。当设置为 `true` 时，使用默认超时 `3d`。
+
+```json
+{
+  "enabled": true,
+  "timeout": "3d"
+}
+```
+
+##### enabled
+
+启用乐观 DNS 缓存。
+
+##### timeout
+
+过期缓存条目可被乐观提供的最长时间。
+
+默认使用 `3d`。
+
 #### reverse_mapping
 
 在响应 DNS 查询后存储 IP 地址的反向映射以为路由目的提供域名。

docs/configuration/dns/rule_action.md

@@ -6,7 +6,8 @@ icon: material/new-box
 
     :material-delete-clock: [strategy](#strategy)  
     :material-plus: [evaluate](#evaluate)  
-    :material-plus: [respond](#respond)
+    :material-plus: [respond](#respond)  
+    :material-plus: [disable_optimistic_cache](#disable_optimistic_cache)
 
 !!! quote "Changes in sing-box 1.12.0"
 
@@ -23,6 +24,7 @@ icon: material/new-box
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -52,6 +54,12 @@ One of `prefer_ipv4` `prefer_ipv6` `ipv4_only` `ipv6_only`.
 
 Disable cache and save cache in this query.
 
+#### disable_optimistic_cache
+
+!!! question "Since sing-box 1.14.0"
+
+Disable optimistic DNS caching in this query.
+
 #### rewrite_ttl
 
 Rewrite TTL in DNS responses.
@@ -73,6 +81,7 @@ Will override `dns.client_subnet`.
   "action": "evaluate",
   "server": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -97,6 +106,12 @@ Tag of target server.
 
 Disable cache and save cache in this query.
 
+#### disable_optimistic_cache
+
+!!! question "Since sing-box 1.14.0"
+
+Disable optimistic DNS caching in this query.
+
 #### rewrite_ttl
 
 Rewrite TTL in DNS responses.
@@ -131,6 +146,7 @@ Only allowed after a preceding top-level `evaluate` rule. If the action is reach
 {
   "action": "route-options",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }

docs/configuration/dns/rule_action.zh.md

@@ -6,7 +6,8 @@ icon: material/new-box
 
     :material-delete-clock: [strategy](#strategy)  
     :material-plus: [evaluate](#evaluate)  
-    :material-plus: [respond](#respond)
+    :material-plus: [respond](#respond)  
+    :material-plus: [disable_optimistic_cache](#disable_optimistic_cache)
 
 !!! quote "sing-box 1.12.0 中的更改"
 
@@ -23,6 +24,7 @@ icon: material/new-box
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -52,6 +54,12 @@ icon: material/new-box
 
 在此查询中禁用缓存。
 
+#### disable_optimistic_cache
+
+!!! question "自 sing-box 1.14.0 起"
+
+在此查询中禁用乐观 DNS 缓存。
+
 #### rewrite_ttl
 
 重写 DNS 回应中的 TTL。
@@ -73,6 +81,7 @@ icon: material/new-box
   "action": "evaluate",
   "server": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -95,6 +104,12 @@ icon: material/new-box
 
 在此查询中禁用缓存。
 
+#### disable_optimistic_cache
+
+!!! question "自 sing-box 1.14.0 起"
+
+在此查询中禁用乐观 DNS 缓存。
+
 #### rewrite_ttl
 
 重写 DNS 回应中的 TTL。
@@ -129,6 +144,7 @@ icon: material/new-box
 {
   "action": "route-options",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }

docs/configuration/experimental/cache-file.md

@@ -1,5 +1,10 @@
 !!! question "Since sing-box 1.8.0"
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-delete-clock: [store_rdrc](#store_rdrc)  
+    :material-plus: [store_dns](#store_dns)
+
 !!! quote "Changes in sing-box 1.9.0"
 
     :material-plus: [store_rdrc](#store_rdrc)  
@@ -14,7 +19,8 @@
   "cache_id": "",
   "store_fakeip": false,
   "store_rdrc": false,
-  "rdrc_timeout": ""
+  "rdrc_timeout": "",
+  "store_dns": false
 }
 ```
 
@@ -42,6 +48,10 @@ Store fakeip in the cache file
 
 #### store_rdrc
 
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    `store_rdrc` is deprecated and will be removed in sing-box 1.16.0, check [Migration](/migration/#migrate-store-rdrc).
+
 Store rejected DNS response cache in the cache file
 
 The check results of [Legacy Address Filter Fields](/configuration/dns/rule/#legacy-address-filter-fields)
@@ -52,3 +62,9 @@ will be cached until expiration.
 Timeout of rejected DNS response cache.
 
 `7d` is used by default.
+
+#### store_dns
+
+!!! question "Since sing-box 1.14.0"
+
+Store DNS cache in the cache file.

docs/configuration/experimental/cache-file.zh.md

@@ -1,5 +1,10 @@
 !!! question "自 sing-box 1.8.0 起"
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-delete-clock: [store_rdrc](#store_rdrc)  
+    :material-plus: [store_dns](#store_dns)
+
 !!! quote "sing-box 1.9.0 中的更改"
 
     :material-plus: [store_rdrc](#store_rdrc)  
@@ -14,7 +19,8 @@
   "cache_id": "",
   "store_fakeip": false,
   "store_rdrc": false,
-  "rdrc_timeout": ""
+  "rdrc_timeout": "",
+  "store_dns": false
 }
 ```
 
@@ -40,6 +46,10 @@
 
 #### store_rdrc
 
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    `store_rdrc` 已在 sing-box 1.14.0 废弃，且将在 sing-box 1.16.0 中被移除，参阅[迁移指南](/zh/migration/#迁移-store_rdrc)。
+
 将拒绝的 DNS 响应缓存存储在缓存文件中。
 
 [旧版地址筛选字段](/zh/configuration/dns/rule/#旧版地址筛选字段) 的检查结果将被缓存至过期。
@@ -49,3 +59,9 @@
 拒绝的 DNS 响应缓存超时。
 
 默认使用 `7d`。
+
+#### store_dns
+
+!!! question "自 sing-box 1.14.0 起"
+
+将 DNS 缓存存储在缓存文件中。

docs/configuration/route/rule_action.md

@@ -7,6 +7,10 @@ icon: material/new-box
     :material-plus: [bypass](#bypass)  
     :material-alert: [reject](#reject)
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-plus: [resolve.disable_optimistic_cache](#disable_optimistic_cache)
+
 !!! quote "Changes in sing-box 1.12.0"
 
     :material-plus: [tls_fragment](#tls_fragment)  
@@ -279,6 +283,7 @@ Timeout for sniffing.
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -302,6 +307,12 @@ DNS resolution strategy, available values are: `prefer_ipv4`, `prefer_ipv6`, `ip
 
 Disable cache and save cache in this query.
 
+#### disable_optimistic_cache
+
+!!! question "Since sing-box 1.14.0"
+
+Disable optimistic DNS caching in this query.
+
 #### rewrite_ttl
 
 !!! question "Since sing-box 1.12.0"

docs/configuration/route/rule_action.zh.md

@@ -7,6 +7,10 @@ icon: material/new-box
     :material-plus: [bypass](#bypass)  
     :material-alert: [reject](#reject)
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-plus: [resolve.disable_optimistic_cache](#disable_optimistic_cache)
+
 !!! quote "sing-box 1.12.0 中的更改"
 
     :material-plus: [tls_fragment](#tls_fragment)  
@@ -268,6 +272,7 @@ UDP 连接超时时间。
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -291,6 +296,12 @@ DNS 解析策略，可用值有：`prefer_ipv4`、`prefer_ipv6`、`ipv4_only`、
 
 在此查询中禁用缓存。
 
+#### disable_optimistic_cache
+
+!!! question "自 sing-box 1.14.0 起"
+
+在此查询中禁用乐观 DNS 缓存。
+
 #### rewrite_ttl
 
 !!! question "自 sing-box 1.12.0 起"

docs/deprecated.md

@@ -27,6 +27,21 @@ check [Migration](../migration/#migrate-address-filter-fields-to-response-matchi
 
 Old fields will be removed in sing-box 1.16.0.
 
+#### `independent_cache` DNS option
+
+`independent_cache` DNS option is deprecated.
+The DNS cache now always keys by transport, making this option unnecessary,
+check [Migration](../migration/#migrate-independent-dns-cache).
+
+Old fields will be removed in sing-box 1.16.0.
+
+#### `store_rdrc` cache file option
+
+`store_rdrc` cache file option is deprecated,
+check [Migration](../migration/#migrate-store-rdrc).
+
+Old fields will be removed in sing-box 1.16.0.
+
 #### Legacy Address Filter Fields in DNS rules
 
 Legacy Address Filter Fields (`ip_cidr`, `ip_is_private` without `match_response`)

docs/deprecated.zh.md

@@ -27,6 +27,21 @@ TLS 中的内联 ACME 选项（`tls.acme`）已废弃，
 
 旧字段将在 sing-box 1.16.0 中被移除。
 
+#### `independent_cache` DNS 选项
+
+`independent_cache` DNS 选项已废弃。
+DNS 缓存现在始终按传输分离，使此选项不再需要，
+参阅[迁移指南](/zh/migration/#迁移-independent-dns-cache)。
+
+旧字段将在 sing-box 1.16.0 中被移除。
+
+#### `store_rdrc` 缓存文件选项
+
+`store_rdrc` 缓存文件选项已废弃，
+参阅[迁移指南](/zh/migration/#迁移-store_rdrc)。
+
+旧字段将在 sing-box 1.16.0 中被移除。
+
 #### 旧版地址筛选字段 (DNS 规则)
 
 旧版地址筛选字段（不使用 `match_response` 的 `ip_cidr`、`ip_is_private`）已废弃，

docs/migration.md

@@ -137,6 +137,68 @@ to fetch a DNS response, then match against it explicitly with `match_response`.
     }
     ```
 
+### Migrate independent DNS cache
+
+The DNS cache now always keys by transport name, making `independent_cache` unnecessary.
+Simply remove the field.
+
+!!! info "References"
+
+    [DNS](/configuration/dns/)
+
+=== ":material-card-remove: Deprecated"
+
+    ```json
+    {
+      "dns": {
+        "independent_cache": true
+      }
+    }
+    ```
+
+=== ":material-card-multiple: New"
+
+    ```json
+    {
+      "dns": {}
+    }
+    ```
+
+### Migrate store_rdrc
+
+`store_rdrc` is deprecated and can be replaced by `store_dns`,
+which persists the full DNS cache to the cache file.
+
+!!! info "References"
+
+    [Cache File](/configuration/experimental/cache-file/)
+
+=== ":material-card-remove: Deprecated"
+
+    ```json
+    {
+      "experimental": {
+        "cache_file": {
+          "enabled": true,
+          "store_rdrc": true
+        }
+      }
+    }
+    ```
+
+=== ":material-card-multiple: New"
+
+    ```json
+    {
+      "experimental": {
+        "cache_file": {
+          "enabled": true,
+          "store_dns": true
+        }
+      }
+    }
+    ```
+
 ### ip_version and query_type behavior changes in DNS rules
 
 In sing-box 1.14.0, the behavior of

docs/migration.zh.md

@@ -137,6 +137,68 @@ sing-box 1.14.0 新增字段参阅 [ACME](/zh/configuration/shared/certificate-p
     }
     ```
 
+### 迁移 independent DNS cache
+
+DNS 缓存现在始终按传输名称分离，使 `independent_cache` 不再需要。
+直接移除该字段即可。
+
+!!! info "参考"
+
+    [DNS](/zh/configuration/dns/)
+
+=== ":material-card-remove: 弃用的"
+
+    ```json
+    {
+      "dns": {
+        "independent_cache": true
+      }
+    }
+    ```
+
+=== ":material-card-multiple: 新的"
+
+    ```json
+    {
+      "dns": {}
+    }
+    ```
+
+### 迁移 store_rdrc
+
+`store_rdrc` 已废弃，且可以被 `store_dns` 替代，
+后者将完整的 DNS 缓存持久化到缓存文件中。
+
+!!! info "参考"
+
+    [缓存文件](/zh/configuration/experimental/cache-file/)
+
+=== ":material-card-remove: 弃用的"
+
+    ```json
+    {
+      "experimental": {
+        "cache_file": {
+          "enabled": true,
+          "store_rdrc": true
+        }
+      }
+    }
+    ```
+
+=== ":material-card-multiple: 新的"
+
+    ```json
+    {
+      "experimental": {
+        "cache_file": {
+          "enabled": true,
+          "store_dns": true
+        }
+      }
+    }
+    ```
+
 ### DNS 规则中的 ip_version 和 query_type 行为更改
 
 在 sing-box 1.14.0 中，DNS 规则中的

experimental/cachefile/cache.go

@@ -12,9 +12,11 @@ import (
 	"github.com/sagernet/bbolt"
 	bboltErrors "github.com/sagernet/bbolt/errors"
 	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/experimental/deprecated"
 	"github.com/sagernet/sing-box/option"
 	"github.com/sagernet/sing/common"
 	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
 	"github.com/sagernet/sing/service/filemanager"
 )
 
@@ -30,6 +32,7 @@ var (
 		string(bucketMode),
 		string(bucketRuleSet),
 		string(bucketRDRC),
+		string(bucketDNSCache),
 	}
 
 	cacheIDDefault = []byte("default")
@@ -39,11 +42,15 @@ var _ adapter.CacheFile = (*CacheFile)(nil)
 
 type CacheFile struct {
 	ctx                context.Context
+	logger             logger.Logger
 	path               string
 	cacheID            []byte
 	storeFakeIP        bool
 	storeRDRC          bool
+	storeDNS           bool
+	disableExpire      bool
 	rdrcTimeout        time.Duration
+	optimisticTimeout  time.Duration
 	DB                 *bbolt.DB
 	resetAccess        sync.Mutex
 	saveMetadataAccess sync.Mutex
@@ -54,16 +61,25 @@ type CacheFile struct {
 	saveAddress4       map[string]netip.Addr
 	saveAddress6       map[string]netip.Addr
 	saveRDRCAccess     sync.RWMutex
-	saveRDRC           map[saveRDRCCacheKey]bool
+	saveRDRC           map[saveCacheKey]bool
+	saveDNSCacheAccess sync.RWMutex
+	saveDNSCache       map[saveCacheKey]saveDNSCacheEntry
 }
 
-type saveRDRCCacheKey struct {
+type saveCacheKey struct {
 	TransportName string
 	QuestionName  string
 	QType         uint16
 }
 
-func New(ctx context.Context, options option.CacheFileOptions) *CacheFile {
+type saveDNSCacheEntry struct {
+	rawMessage []byte
+	expireAt   time.Time
+	sequence   uint64
+	saving     bool
+}
+
+func New(ctx context.Context, logger logger.Logger, options option.CacheFileOptions) *CacheFile {
 	var path string
 	if options.Path != "" {
 		path = options.Path
@@ -74,6 +90,9 @@ func New(ctx context.Context, options option.CacheFileOptions) *CacheFile {
 	if options.CacheID != "" {
 		cacheIDBytes = append([]byte{0}, []byte(options.CacheID)...)
 	}
+	if options.StoreRDRC {
+		deprecated.Report(ctx, deprecated.OptionStoreRDRC)
+	}
 	var rdrcTimeout time.Duration
 	if options.StoreRDRC {
 		if options.RDRCTimeout > 0 {
@@ -84,15 +103,18 @@ func New(ctx context.Context, options option.CacheFileOptions) *CacheFile {
 	}
 	return &CacheFile{
 		ctx:          ctx,
+		logger:       logger,
 		path:         filemanager.BasePath(ctx, path),
 		cacheID:      cacheIDBytes,
 		storeFakeIP:  options.StoreFakeIP,
 		storeRDRC:    options.StoreRDRC,
+		storeDNS:     options.StoreDNS,
 		rdrcTimeout:  rdrcTimeout,
 		saveDomain:   make(map[netip.Addr]string),
 		saveAddress4: make(map[string]netip.Addr),
 		saveAddress6: make(map[string]netip.Addr),
-		saveRDRC:     make(map[saveRDRCCacheKey]bool),
+		saveRDRC:     make(map[saveCacheKey]bool),
+		saveDNSCache: make(map[saveCacheKey]saveDNSCacheEntry),
 	}
 }
 
@@ -104,10 +126,44 @@ func (c *CacheFile) Dependencies() []string {
 	return nil
 }
 
+func (c *CacheFile) SetOptimisticTimeout(timeout time.Duration) {
+	c.optimisticTimeout = timeout
+}
+
+func (c *CacheFile) SetDisableExpire(disableExpire bool) {
+	c.disableExpire = disableExpire
+}
+
 func (c *CacheFile) Start(stage adapter.StartStage) error {
-	if stage != adapter.StartStateInitialize {
+	switch stage {
-		return nil
+	case adapter.StartStateInitialize:
+		return c.start()
+	case adapter.StartStateStart:
+		c.startCacheCleanup()
 	}
+	return nil
+}
+
+func (c *CacheFile) startCacheCleanup() {
+	if c.storeDNS {
+		c.clearRDRC()
+		c.cleanupDNSCache()
+		interval := c.optimisticTimeout / 2
+		if interval <= 0 {
+			interval = time.Hour
+		}
+		go c.loopCacheCleanup(interval, c.cleanupDNSCache)
+	} else if c.storeRDRC {
+		c.cleanupRDRC()
+		interval := c.rdrcTimeout / 2
+		if interval <= 0 {
+			interval = time.Hour
+		}
+		go c.loopCacheCleanup(interval, c.cleanupRDRC)
+	}
+}
+
+func (c *CacheFile) start() error {
 	const fileMode = 0o666
 	options := bbolt.Options{Timeout: time.Second}
 	var (

experimental/cachefile/dns_cache.go

@@ -0,0 +1,299 @@
+package cachefile
+
+import (
+	"encoding/binary"
+	"time"
+
+	"github.com/sagernet/bbolt"
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/logger"
+)
+
+var bucketDNSCache = []byte("dns_cache")
+
+func (c *CacheFile) StoreDNS() bool {
+	return c.storeDNS
+}
+
+func (c *CacheFile) LoadDNSCache(transportName string, qName string, qType uint16) (rawMessage []byte, expireAt time.Time, loaded bool) {
+	c.saveDNSCacheAccess.RLock()
+	entry, cached := c.saveDNSCache[saveCacheKey{transportName, qName, qType}]
+	c.saveDNSCacheAccess.RUnlock()
+	if cached {
+		return entry.rawMessage, entry.expireAt, true
+	}
+	key := buf.Get(2 + len(qName))
+	binary.BigEndian.PutUint16(key, qType)
+	copy(key[2:], qName)
+	defer buf.Put(key)
+	err := c.view(func(tx *bbolt.Tx) error {
+		bucket := c.bucket(tx, bucketDNSCache)
+		if bucket == nil {
+			return nil
+		}
+		bucket = bucket.Bucket([]byte(transportName))
+		if bucket == nil {
+			return nil
+		}
+		content := bucket.Get(key)
+		if len(content) < 8 {
+			return nil
+		}
+		expireAt = time.Unix(int64(binary.BigEndian.Uint64(content[:8])), 0)
+		rawMessage = make([]byte, len(content)-8)
+		copy(rawMessage, content[8:])
+		loaded = true
+		return nil
+	})
+	if err != nil {
+		return nil, time.Time{}, false
+	}
+	return
+}
+
+func (c *CacheFile) SaveDNSCache(transportName string, qName string, qType uint16, rawMessage []byte, expireAt time.Time) error {
+	return c.batch(func(tx *bbolt.Tx) error {
+		bucket, err := c.createBucket(tx, bucketDNSCache)
+		if err != nil {
+			return err
+		}
+		bucket, err = bucket.CreateBucketIfNotExists([]byte(transportName))
+		if err != nil {
+			return err
+		}
+		key := buf.Get(2 + len(qName))
+		binary.BigEndian.PutUint16(key, qType)
+		copy(key[2:], qName)
+		defer buf.Put(key)
+		value := buf.Get(8 + len(rawMessage))
+		defer buf.Put(value)
+		binary.BigEndian.PutUint64(value[:8], uint64(expireAt.Unix()))
+		copy(value[8:], rawMessage)
+		return bucket.Put(key, value)
+	})
+}
+
+func (c *CacheFile) SaveDNSCacheAsync(transportName string, qName string, qType uint16, rawMessage []byte, expireAt time.Time, logger logger.Logger) {
+	saveKey := saveCacheKey{transportName, qName, qType}
+	if !c.queueDNSCacheSave(saveKey, rawMessage, expireAt) {
+		return
+	}
+	go c.flushPendingDNSCache(saveKey, logger)
+}
+
+func (c *CacheFile) queueDNSCacheSave(saveKey saveCacheKey, rawMessage []byte, expireAt time.Time) bool {
+	c.saveDNSCacheAccess.Lock()
+	defer c.saveDNSCacheAccess.Unlock()
+	entry := c.saveDNSCache[saveKey]
+	entry.rawMessage = append([]byte(nil), rawMessage...)
+	entry.expireAt = expireAt
+	entry.sequence++
+	startFlush := !entry.saving
+	entry.saving = true
+	c.saveDNSCache[saveKey] = entry
+	return startFlush
+}
+
+func (c *CacheFile) flushPendingDNSCache(saveKey saveCacheKey, logger logger.Logger) {
+	c.flushPendingDNSCacheWith(saveKey, logger, func(entry saveDNSCacheEntry) error {
+		return c.SaveDNSCache(saveKey.TransportName, saveKey.QuestionName, saveKey.QType, entry.rawMessage, entry.expireAt)
+	})
+}
+
+func (c *CacheFile) flushPendingDNSCacheWith(saveKey saveCacheKey, logger logger.Logger, save func(saveDNSCacheEntry) error) {
+	for {
+		c.saveDNSCacheAccess.RLock()
+		entry, loaded := c.saveDNSCache[saveKey]
+		c.saveDNSCacheAccess.RUnlock()
+		if !loaded {
+			return
+		}
+		err := save(entry)
+		if err != nil {
+			logger.Warn("save DNS cache: ", err)
+		}
+		c.saveDNSCacheAccess.Lock()
+		currentEntry, loaded := c.saveDNSCache[saveKey]
+		if !loaded {
+			c.saveDNSCacheAccess.Unlock()
+			return
+		}
+		if currentEntry.sequence != entry.sequence {
+			c.saveDNSCacheAccess.Unlock()
+			continue
+		}
+		delete(c.saveDNSCache, saveKey)
+		c.saveDNSCacheAccess.Unlock()
+		return
+	}
+}
+
+func (c *CacheFile) ClearDNSCache() error {
+	c.saveDNSCacheAccess.Lock()
+	clear(c.saveDNSCache)
+	c.saveDNSCacheAccess.Unlock()
+	return c.batch(func(tx *bbolt.Tx) error {
+		if c.cacheID == nil {
+			bucket := tx.Bucket(bucketDNSCache)
+			if bucket == nil {
+				return nil
+			}
+			return tx.DeleteBucket(bucketDNSCache)
+		}
+		bucket := tx.Bucket(c.cacheID)
+		if bucket == nil || bucket.Bucket(bucketDNSCache) == nil {
+			return nil
+		}
+		return bucket.DeleteBucket(bucketDNSCache)
+	})
+}
+
+func (c *CacheFile) loopCacheCleanup(interval time.Duration, cleanupFunc func()) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-c.ctx.Done():
+			return
+		case <-ticker.C:
+			cleanupFunc()
+		}
+	}
+}
+
+func (c *CacheFile) cleanupDNSCache() {
+	now := time.Now()
+	err := c.batch(func(tx *bbolt.Tx) error {
+		bucket := c.bucket(tx, bucketDNSCache)
+		if bucket == nil {
+			return nil
+		}
+		var emptyTransports [][]byte
+		err := bucket.ForEachBucket(func(transportName []byte) error {
+			transportBucket := bucket.Bucket(transportName)
+			if transportBucket == nil {
+				return nil
+			}
+			var expiredKeys [][]byte
+			err := transportBucket.ForEach(func(key, value []byte) error {
+				if len(value) < 8 {
+					expiredKeys = append(expiredKeys, append([]byte(nil), key...))
+					return nil
+				}
+				if c.disableExpire {
+					return nil
+				}
+				expireAt := time.Unix(int64(binary.BigEndian.Uint64(value[:8])), 0)
+				if now.After(expireAt.Add(c.optimisticTimeout)) {
+					expiredKeys = append(expiredKeys, append([]byte(nil), key...))
+				}
+				return nil
+			})
+			if err != nil {
+				return err
+			}
+			for _, key := range expiredKeys {
+				err = transportBucket.Delete(key)
+				if err != nil {
+					return err
+				}
+			}
+			first, _ := transportBucket.Cursor().First()
+			if first == nil {
+				emptyTransports = append(emptyTransports, append([]byte(nil), transportName...))
+			}
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+		for _, name := range emptyTransports {
+			err = bucket.DeleteBucket(name)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		c.logger.Warn("cleanup DNS cache: ", err)
+	}
+}
+
+func (c *CacheFile) clearRDRC() {
+	c.saveRDRCAccess.Lock()
+	clear(c.saveRDRC)
+	c.saveRDRCAccess.Unlock()
+	err := c.batch(func(tx *bbolt.Tx) error {
+		if c.cacheID == nil {
+			if tx.Bucket(bucketRDRC) == nil {
+				return nil
+			}
+			return tx.DeleteBucket(bucketRDRC)
+		}
+		bucket := tx.Bucket(c.cacheID)
+		if bucket == nil || bucket.Bucket(bucketRDRC) == nil {
+			return nil
+		}
+		return bucket.DeleteBucket(bucketRDRC)
+	})
+	if err != nil {
+		c.logger.Warn("clear RDRC: ", err)
+	}
+}
+
+func (c *CacheFile) cleanupRDRC() {
+	now := time.Now()
+	err := c.batch(func(tx *bbolt.Tx) error {
+		bucket := c.bucket(tx, bucketRDRC)
+		if bucket == nil {
+			return nil
+		}
+		var emptyTransports [][]byte
+		err := bucket.ForEachBucket(func(transportName []byte) error {
+			transportBucket := bucket.Bucket(transportName)
+			if transportBucket == nil {
+				return nil
+			}
+			var expiredKeys [][]byte
+			err := transportBucket.ForEach(func(key, value []byte) error {
+				if len(value) < 8 {
+					expiredKeys = append(expiredKeys, append([]byte(nil), key...))
+					return nil
+				}
+				expiresAt := time.Unix(int64(binary.BigEndian.Uint64(value)), 0)
+				if now.After(expiresAt) {
+					expiredKeys = append(expiredKeys, append([]byte(nil), key...))
+				}
+				return nil
+			})
+			if err != nil {
+				return err
+			}
+			for _, key := range expiredKeys {
+				err = transportBucket.Delete(key)
+				if err != nil {
+					return err
+				}
+			}
+			first, _ := transportBucket.Cursor().First()
+			if first == nil {
+				emptyTransports = append(emptyTransports, append([]byte(nil), transportName...))
+			}
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+		for _, name := range emptyTransports {
+			err = bucket.DeleteBucket(name)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		c.logger.Warn("cleanup RDRC: ", err)
+	}
+}

experimental/cachefile/rdrc.go

@@ -21,7 +21,7 @@ func (c *CacheFile) RDRCTimeout() time.Duration {
 
 func (c *CacheFile) LoadRDRC(transportName string, qName string, qType uint16) (rejected bool) {
 	c.saveRDRCAccess.RLock()
-	rejected, cached := c.saveRDRC[saveRDRCCacheKey{transportName, qName, qType}]
+	rejected, cached := c.saveRDRC[saveCacheKey{transportName, qName, qType}]
 	c.saveRDRCAccess.RUnlock()
 	if cached {
 		return
@@ -93,7 +93,7 @@ func (c *CacheFile) SaveRDRC(transportName string, qName string, qType uint16) e
 }
 
 func (c *CacheFile) SaveRDRCAsync(transportName string, qName string, qType uint16, logger logger.Logger) {
-	saveKey := saveRDRCCacheKey{transportName, qName, qType}
+	saveKey := saveCacheKey{transportName, qName, qType}
 	c.saveRDRCAccess.Lock()
 	c.saveRDRC[saveKey] = true
 	c.saveRDRCAccess.Unlock()

experimental/deprecated/constants.go

@@ -120,6 +120,24 @@ var OptionLegacyDNSRuleStrategy = Note{
 	MigrationLink:     "https://sing-box.sagernet.org/migration/#migrate-dns-rule-action-strategy-to-rule-items",
 }
 
+var OptionIndependentDNSCache = Note{
+	Name:              "independent-dns-cache",
+	Description:       "`independent_cache` DNS option",
+	DeprecatedVersion: "1.14.0",
+	ScheduledVersion:  "1.16.0",
+	EnvName:           "INDEPENDENT_DNS_CACHE",
+	MigrationLink:     "https://sing-box.sagernet.org/migration/#migrate-independent-dns-cache",
+}
+
+var OptionStoreRDRC = Note{
+	Name:              "store-rdrc",
+	Description:       "`store_rdrc` cache file option",
+	DeprecatedVersion: "1.14.0",
+	ScheduledVersion:  "1.16.0",
+	EnvName:           "STORE_RDRC",
+	MigrationLink:     "https://sing-box.sagernet.org/migration/#migrate-store-rdrc",
+}
+
 var Options = []Note{
 	OptionOutboundDNSRuleItem,
 	OptionMissingDomainResolver,
@@ -128,4 +146,6 @@ var Options = []Note{
 	OptionRuleSetIPCIDRAcceptEmpty,
 	OptionLegacyDNSAddressFilter,
 	OptionLegacyDNSRuleStrategy,
+	OptionIndependentDNSCache,
+	OptionStoreRDRC,
 }

option/dns.go

@@ -52,9 +52,32 @@ type DNSClientOptions struct {
 	DisableExpire    bool                  `json:"disable_expire,omitempty"`
 	IndependentCache bool                  `json:"independent_cache,omitempty"`
 	CacheCapacity    uint32                `json:"cache_capacity,omitempty"`
+	Optimistic       *OptimisticDNSOptions `json:"optimistic,omitempty"`
 	ClientSubnet     *badoption.Prefixable `json:"client_subnet,omitempty"`
 }
 
+type _OptimisticDNSOptions struct {
+	Enabled bool               `json:"enabled,omitempty"`
+	Timeout badoption.Duration `json:"timeout,omitempty"`
+}
+
+type OptimisticDNSOptions _OptimisticDNSOptions
+
+func (o OptimisticDNSOptions) MarshalJSON() ([]byte, error) {
+	if o.Timeout == 0 {
+		return json.Marshal(o.Enabled)
+	}
+	return json.Marshal((_OptimisticDNSOptions)(o))
+}
+
+func (o *OptimisticDNSOptions) UnmarshalJSON(bytes []byte) error {
+	err := json.Unmarshal(bytes, &o.Enabled)
+	if err == nil {
+		return nil
+	}
+	return json.UnmarshalDisallowUnknownFields(bytes, (*_OptimisticDNSOptions)(o))
+}
+
 type DNSTransportOptionsRegistry interface {
 	CreateOptions(transportType string) (any, bool)
 }

option/experimental.go

@@ -16,6 +16,7 @@ type CacheFileOptions struct {
 	StoreFakeIP bool               `json:"store_fakeip,omitempty"`
 	StoreRDRC   bool               `json:"store_rdrc,omitempty"`
 	RDRCTimeout badoption.Duration `json:"rdrc_timeout,omitempty"`
+	StoreDNS    bool               `json:"store_dns,omitempty"`
 }
 
 type ClashAPIOptions struct {

option/outbound.go

@@ -93,11 +93,12 @@ type DialerOptions struct {
 }
 
 type _DomainResolveOptions struct {
-	Server       string                `json:"server"`
+	Server                 string                `json:"server"`
-	Strategy     DomainStrategy        `json:"strategy,omitempty"`
+	Strategy               DomainStrategy        `json:"strategy,omitempty"`
-	DisableCache bool                  `json:"disable_cache,omitempty"`
+	DisableCache           bool                  `json:"disable_cache,omitempty"`
-	RewriteTTL   *uint32               `json:"rewrite_ttl,omitempty"`
+	DisableOptimisticCache bool                  `json:"disable_optimistic_cache,omitempty"`
-	ClientSubnet *badoption.Prefixable `json:"client_subnet,omitempty"`
+	RewriteTTL             *uint32               `json:"rewrite_ttl,omitempty"`
+	ClientSubnet           *badoption.Prefixable `json:"client_subnet,omitempty"`
 }
 
 type DomainResolveOptions _DomainResolveOptions
@@ -107,6 +108,7 @@ func (o DomainResolveOptions) MarshalJSON() ([]byte, error) {
 		return []byte("{}"), nil
 	} else if o.Strategy == DomainStrategy(C.DomainStrategyAsIS) &&
 		!o.DisableCache &&
+		!o.DisableOptimisticCache &&
 		o.RewriteTTL == nil &&
 		o.ClientSubnet == nil {
 		return json.Marshal(o.Server)

option/rule_action.go

@@ -201,18 +201,20 @@ func (r *RouteOptionsActionOptions) UnmarshalJSON(data []byte) error {
 }
 
 type DNSRouteActionOptions struct {
-	Server       string                `json:"server,omitempty"`
+	Server                 string                `json:"server,omitempty"`
-	Strategy     DomainStrategy        `json:"strategy,omitempty"`
+	Strategy               DomainStrategy        `json:"strategy,omitempty"`
-	DisableCache bool                  `json:"disable_cache,omitempty"`
+	DisableCache           bool                  `json:"disable_cache,omitempty"`
-	RewriteTTL   *uint32               `json:"rewrite_ttl,omitempty"`
+	DisableOptimisticCache bool                  `json:"disable_optimistic_cache,omitempty"`
-	ClientSubnet *badoption.Prefixable `json:"client_subnet,omitempty"`
+	RewriteTTL             *uint32               `json:"rewrite_ttl,omitempty"`
+	ClientSubnet           *badoption.Prefixable `json:"client_subnet,omitempty"`
 }
 
 type _DNSRouteOptionsActionOptions struct {
-	Strategy     DomainStrategy        `json:"strategy,omitempty"`
+	Strategy               DomainStrategy        `json:"strategy,omitempty"`
-	DisableCache bool                  `json:"disable_cache,omitempty"`
+	DisableCache           bool                  `json:"disable_cache,omitempty"`
-	RewriteTTL   *uint32               `json:"rewrite_ttl,omitempty"`
+	DisableOptimisticCache bool                  `json:"disable_optimistic_cache,omitempty"`
-	ClientSubnet *badoption.Prefixable `json:"client_subnet,omitempty"`
+	RewriteTTL             *uint32               `json:"rewrite_ttl,omitempty"`
+	ClientSubnet           *badoption.Prefixable `json:"client_subnet,omitempty"`
 }
 
 type DNSRouteOptionsActionOptions _DNSRouteOptionsActionOptions
@@ -321,11 +323,12 @@ type RouteActionSniff struct {
 }
 
 type RouteActionResolve struct {
-	Server       string                `json:"server,omitempty"`
+	Server                 string                `json:"server,omitempty"`
-	Strategy     DomainStrategy        `json:"strategy,omitempty"`
+	Strategy               DomainStrategy        `json:"strategy,omitempty"`
-	DisableCache bool                  `json:"disable_cache,omitempty"`
+	DisableCache           bool                  `json:"disable_cache,omitempty"`
-	RewriteTTL   *uint32               `json:"rewrite_ttl,omitempty"`
+	DisableOptimisticCache bool                  `json:"disable_optimistic_cache,omitempty"`
-	ClientSubnet *badoption.Prefixable `json:"client_subnet,omitempty"`
+	RewriteTTL             *uint32               `json:"rewrite_ttl,omitempty"`
+	ClientSubnet           *badoption.Prefixable `json:"client_subnet,omitempty"`
 }
 
 type DNSRouteActionPredefined struct {

route/network.go

@@ -80,10 +80,11 @@ func NewNetworkManager(ctx context.Context, logger logger.ContextLogger, options
 			RoutingMark:    uint32(options.DefaultMark),
 			DomainResolver: defaultDomainResolver.Server,
 			DomainResolveOptions: adapter.DNSQueryOptions{
-				Strategy:     C.DomainStrategy(defaultDomainResolver.Strategy),
+				Strategy:               C.DomainStrategy(defaultDomainResolver.Strategy),
-				DisableCache: defaultDomainResolver.DisableCache,
+				DisableCache:           defaultDomainResolver.DisableCache,
-				RewriteTTL:   defaultDomainResolver.RewriteTTL,
+				DisableOptimisticCache: defaultDomainResolver.DisableOptimisticCache,
-				ClientSubnet: defaultDomainResolver.ClientSubnet.Build(netip.Prefix{}),
+				RewriteTTL:             defaultDomainResolver.RewriteTTL,
+				ClientSubnet:           defaultDomainResolver.ClientSubnet.Build(netip.Prefix{}),
 			},
 			NetworkStrategy:     (*C.NetworkStrategy)(options.DefaultNetworkStrategy),
 			NetworkType:         common.Map(options.DefaultNetworkType, option.InterfaceType.Build),

route/route.go

@@ -786,11 +786,12 @@ func (r *Router) actionResolve(ctx context.Context, metadata *adapter.InboundCon
 			}
 		}
 		addresses, err := r.dns.Lookup(adapter.WithContext(ctx, metadata), metadata.Destination.Fqdn, adapter.DNSQueryOptions{
-			Transport:    transport,
+			Transport:              transport,
-			Strategy:     action.Strategy,
+			Strategy:               action.Strategy,
-			DisableCache: action.DisableCache,
+			DisableCache:           action.DisableCache,
-			RewriteTTL:   action.RewriteTTL,
+			DisableOptimisticCache: action.DisableOptimisticCache,
-			ClientSubnet: action.ClientSubnet,
+			RewriteTTL:             action.RewriteTTL,
+			ClientSubnet:           action.ClientSubnet,
 		})
 		if err != nil {
 			return err

route/rule/rule_action.go

@@ -107,11 +107,12 @@ func NewRuleAction(ctx context.Context, logger logger.ContextLogger, action opti
 		return sniffAction, sniffAction.build()
 	case C.RuleActionTypeResolve:
 		return &RuleActionResolve{
-			Server:       action.ResolveOptions.Server,
+			Server:                 action.ResolveOptions.Server,
-			Strategy:     C.DomainStrategy(action.ResolveOptions.Strategy),
+			Strategy:               C.DomainStrategy(action.ResolveOptions.Strategy),
-			DisableCache: action.ResolveOptions.DisableCache,
+			DisableCache:           action.ResolveOptions.DisableCache,
-			RewriteTTL:   action.ResolveOptions.RewriteTTL,
+			DisableOptimisticCache: action.ResolveOptions.DisableOptimisticCache,
-			ClientSubnet: action.ResolveOptions.ClientSubnet.Build(netip.Prefix{}),
+			RewriteTTL:             action.ResolveOptions.RewriteTTL,
+			ClientSubnet:           action.ResolveOptions.ClientSubnet.Build(netip.Prefix{}),
 		}, nil
 	default:
 		panic(F.ToString("unknown rule action: ", action.Action))
@@ -126,30 +127,33 @@ func NewDNSRuleAction(logger logger.ContextLogger, action option.DNSRuleAction)
 		return &RuleActionDNSRoute{
 			Server: action.RouteOptions.Server,
 			RuleActionDNSRouteOptions: RuleActionDNSRouteOptions{
-				Strategy:     C.DomainStrategy(action.RouteOptions.Strategy),
+				Strategy:               C.DomainStrategy(action.RouteOptions.Strategy),
-				DisableCache: action.RouteOptions.DisableCache,
+				DisableCache:           action.RouteOptions.DisableCache,
-				RewriteTTL:   action.RouteOptions.RewriteTTL,
+				DisableOptimisticCache: action.RouteOptions.DisableOptimisticCache,
-				ClientSubnet: netip.Prefix(common.PtrValueOrDefault(action.RouteOptions.ClientSubnet)),
+				RewriteTTL:             action.RouteOptions.RewriteTTL,
+				ClientSubnet:           netip.Prefix(common.PtrValueOrDefault(action.RouteOptions.ClientSubnet)),
 			},
 		}
 	case C.RuleActionTypeEvaluate:
 		return &RuleActionEvaluate{
 			Server: action.RouteOptions.Server,
 			RuleActionDNSRouteOptions: RuleActionDNSRouteOptions{
-				Strategy:     C.DomainStrategy(action.RouteOptions.Strategy),
+				Strategy:               C.DomainStrategy(action.RouteOptions.Strategy),
-				DisableCache: action.RouteOptions.DisableCache,
+				DisableCache:           action.RouteOptions.DisableCache,
-				RewriteTTL:   action.RouteOptions.RewriteTTL,
+				DisableOptimisticCache: action.RouteOptions.DisableOptimisticCache,
-				ClientSubnet: netip.Prefix(common.PtrValueOrDefault(action.RouteOptions.ClientSubnet)),
+				RewriteTTL:             action.RouteOptions.RewriteTTL,
+				ClientSubnet:           netip.Prefix(common.PtrValueOrDefault(action.RouteOptions.ClientSubnet)),
 			},
 		}
 	case C.RuleActionTypeRespond:
 		return &RuleActionRespond{}
 	case C.RuleActionTypeRouteOptions:
 		return &RuleActionDNSRouteOptions{
-			Strategy:     C.DomainStrategy(action.RouteOptionsOptions.Strategy),
+			Strategy:               C.DomainStrategy(action.RouteOptionsOptions.Strategy),
-			DisableCache: action.RouteOptionsOptions.DisableCache,
+			DisableCache:           action.RouteOptionsOptions.DisableCache,
-			RewriteTTL:   action.RouteOptionsOptions.RewriteTTL,
+			DisableOptimisticCache: action.RouteOptionsOptions.DisableOptimisticCache,
-			ClientSubnet: netip.Prefix(common.PtrValueOrDefault(action.RouteOptionsOptions.ClientSubnet)),
+			RewriteTTL:             action.RouteOptionsOptions.RewriteTTL,
+			ClientSubnet:           netip.Prefix(common.PtrValueOrDefault(action.RouteOptionsOptions.ClientSubnet)),
 		}
 	case C.RuleActionTypeReject:
 		return &RuleActionReject{
@@ -310,6 +314,9 @@ func formatDNSRouteAction(action string, server string, options RuleActionDNSRou
 	if options.DisableCache {
 		descriptions = append(descriptions, "disable-cache")
 	}
+	if options.DisableOptimisticCache {
+		descriptions = append(descriptions, "disable-optimistic-cache")
+	}
 	if options.RewriteTTL != nil {
 		descriptions = append(descriptions, F.ToString("rewrite-ttl=", *options.RewriteTTL))
 	}
@@ -320,10 +327,11 @@ func formatDNSRouteAction(action string, server string, options RuleActionDNSRou
 }
 
 type RuleActionDNSRouteOptions struct {
-	Strategy     C.DomainStrategy
+	Strategy               C.DomainStrategy
-	DisableCache bool
+	DisableCache           bool
-	RewriteTTL   *uint32
+	DisableOptimisticCache bool
-	ClientSubnet netip.Prefix
+	RewriteTTL             *uint32
+	ClientSubnet           netip.Prefix
 }
 
 func (r *RuleActionDNSRouteOptions) Type() string {
@@ -335,6 +343,9 @@ func (r *RuleActionDNSRouteOptions) String() string {
 	if r.DisableCache {
 		descriptions = append(descriptions, "disable-cache")
 	}
+	if r.DisableOptimisticCache {
+		descriptions = append(descriptions, "disable-optimistic-cache")
+	}
 	if r.RewriteTTL != nil {
 		descriptions = append(descriptions, F.ToString("rewrite-ttl=", *r.RewriteTTL))
 	}
@@ -510,11 +521,12 @@ func (r *RuleActionSniff) String() string {
 }
 
 type RuleActionResolve struct {
-	Server       string
+	Server                 string
-	Strategy     C.DomainStrategy
+	Strategy               C.DomainStrategy
-	DisableCache bool
+	DisableCache           bool
-	RewriteTTL   *uint32
+	DisableOptimisticCache bool
-	ClientSubnet netip.Prefix
+	RewriteTTL             *uint32
+	ClientSubnet           netip.Prefix
 }
 
 func (r *RuleActionResolve) Type() string {
@@ -532,6 +544,9 @@ func (r *RuleActionResolve) String() string {
 	if r.DisableCache {
 		options = append(options, "disable_cache")
 	}
+	if r.DisableOptimisticCache {
+		options = append(options, "disable_optimistic_cache")
+	}
 	if r.RewriteTTL != nil {
 		options = append(options, F.ToString("rewrite_ttl=", *r.RewriteTTL))
 	}