修复DNS逻辑错误的问题

adapter/dns.go

@@ -39,13 +39,42 @@ type DNSQueryOptions struct {
 	ClientSubnet   netip.Prefix
 }
 
+func LookupDNSTransport(manager DNSTransportManager, reference string) (DNSTransport, bool, bool) {
+	transport, loaded := manager.Transport(reference)
+	if loaded {
+		return transport, true, false
+	}
+	switch reference {
+	case C.DNSTypeLocal, C.DNSTypeFakeIP:
+	default:
+		return nil, false, false
+	}
+	var matchedTransport DNSTransport
+	for _, transport := range manager.Transports() {
+		if transport.Type() != reference {
+			continue
+		}
+		if matchedTransport != nil {
+			return nil, false, true
+		}
+		matchedTransport = transport
+	}
+	if matchedTransport != nil {
+		return matchedTransport, true, false
+	}
+	return nil, false, false
+}
+
 func DNSQueryOptionsFrom(ctx context.Context, options *option.DomainResolveOptions) (*DNSQueryOptions, error) {
 	if options == nil {
 		return &DNSQueryOptions{}, nil
 	}
 	transportManager := service.FromContext[DNSTransportManager](ctx)
-	transport, loaded := transportManager.Transport(options.Server)
+	transport, loaded, ambiguous := LookupDNSTransport(transportManager, options.Server)
 	if !loaded {
+		if ambiguous {
+			return nil, E.New("domain resolver is ambiguous: " + options.Server)
+		}
 		return nil, E.New("domain resolver not found: " + options.Server)
 	}
 	return &DNSQueryOptions{

adapter/dns.go.834007539997830043

@@ -0,0 +1,122 @@
+package adapter
+
+import (
+	"context"
+	"net/netip"
+
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	"github.com/sagernet/sing/service"
+
+	"github.com/miekg/dns"
+)
+
+type DNSRouter interface {
+	Lifecycle
+	Exchange(ctx context.Context, message *dns.Msg, options DNSQueryOptions) (*dns.Msg, error)
+	Lookup(ctx context.Context, domain string, options DNSQueryOptions) ([]netip.Addr, error)
+	ClearCache()
+	LookupReverseMapping(ip netip.Addr) (string, bool)
+	ResetNetwork()
+}
+
+type DNSClient interface {
+	Start()
+	Exchange(ctx context.Context, transport DNSTransport, message *dns.Msg, options DNSQueryOptions, responseChecker func(responseAddrs []netip.Addr) bool) (*dns.Msg, error)
+	Lookup(ctx context.Context, transport DNSTransport, domain string, options DNSQueryOptions, responseChecker func(responseAddrs []netip.Addr) bool) ([]netip.Addr, error)
+	ClearCache()
+}
+
+type DNSQueryOptions struct {
+	Transport      DNSTransport
+	Strategy       C.DomainStrategy
+	LookupStrategy C.DomainStrategy
+	DisableCache   bool
+	RewriteTTL     *uint32
+	ClientSubnet   netip.Prefix
+}
+
+func LookupDNSTransport(manager DNSTransportManager, reference string) (DNSTransport, bool, bool) {
+	transport, loaded := manager.Transport(reference)
+	if loaded {
+		return transport, true, false
+	}
+	switch reference {
+	case C.DNSTypeLocal, C.DNSTypeFakeIP:
+	default:
+		return nil, false, false
+	}
+	var matchedTransport DNSTransport
+	for _, transport := range manager.Transports() {
+		if transport.Type() != reference {
+			continue
+		}
+		if matchedTransport != nil {
+			return nil, false, true
+		}
+		matchedTransport = transport
+	}
+	if matchedTransport != nil {
+		return matchedTransport, true, false
+	}
+	return nil, false, false
+}
+
+func DNSQueryOptionsFrom(ctx context.Context, options *option.DomainResolveOptions) (*DNSQueryOptions, error) {
+	if options == nil {
+		return &DNSQueryOptions{}, nil
+	}
+	transportManager := service.FromContext[DNSTransportManager](ctx)
+	transport, loaded, ambiguous := LookupDNSTransport(transportManager, options.Server)
+	if !loaded {
+		if ambiguous {
+			return nil, E.New("domain resolver is ambiguous: " + options.Server)
+		}
+		return nil, E.New("domain resolver not found: " + options.Server)
+	}
+	return &DNSQueryOptions{
+		Transport:    transport,
+		Strategy:     C.DomainStrategy(options.Strategy),
+		DisableCache: options.DisableCache,
+		RewriteTTL:   options.RewriteTTL,
+		ClientSubnet: options.ClientSubnet.Build(netip.Prefix{}),
+	}, nil
+}
+
+type RDRCStore interface {
+	LoadRDRC(transportName string, qName string, qType uint16) (rejected bool)
+	SaveRDRC(transportName string, qName string, qType uint16) error
+	SaveRDRCAsync(transportName string, qName string, qType uint16, logger logger.Logger)
+}
+
+type DNSTransport interface {
+	Lifecycle
+	Type() string
+	Tag() string
+	Dependencies() []string
+	Reset()
+	Exchange(ctx context.Context, message *dns.Msg) (*dns.Msg, error)
+}
+
+type LegacyDNSTransport interface {
+	LegacyStrategy() C.DomainStrategy
+	LegacyClientSubnet() netip.Prefix
+}
+
+type DNSTransportRegistry interface {
+	option.DNSTransportOptionsRegistry
+	CreateDNSTransport(ctx context.Context, logger log.ContextLogger, tag string, transportType string, options any) (DNSTransport, error)
+}
+
+type DNSTransportManager interface {
+	Lifecycle
+	Transports() []DNSTransport
+	Transport(tag string) (DNSTransport, bool)
+	Default() DNSTransport
+	FakeIP() FakeIPTransport
+	Remove(tag string) error
+	Create(ctx context.Context, logger log.ContextLogger, tag string, outboundType string, options any) error
+}

adapter/dns_test.go

@@ -0,0 +1,137 @@
+package adapter
+
+import (
+	"context"
+	"testing"
+
+	"github.com/sagernet/sing-box/log"
+	"github.com/stretchr/testify/require"
+
+	mDNS "github.com/miekg/dns"
+)
+
+type testDNSTransport struct {
+	transportType string
+	tag           string
+}
+
+func (t *testDNSTransport) Start(stage StartStage) error {
+	return nil
+}
+
+func (t *testDNSTransport) Close() error {
+	return nil
+}
+
+func (t *testDNSTransport) Type() string {
+	return t.transportType
+}
+
+func (t *testDNSTransport) Tag() string {
+	return t.tag
+}
+
+func (t *testDNSTransport) Dependencies() []string {
+	return nil
+}
+
+func (t *testDNSTransport) Reset() {
+}
+
+func (t *testDNSTransport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg, error) {
+	return nil, nil
+}
+
+type testDNSTransportManager struct {
+	transports      []DNSTransport
+	transportByTag  map[string]DNSTransport
+	fakeIPTransport FakeIPTransport
+}
+
+func newTestDNSTransportManager(transports ...DNSTransport) *testDNSTransportManager {
+	manager := &testDNSTransportManager{
+		transports:     transports,
+		transportByTag: make(map[string]DNSTransport),
+	}
+	for _, transport := range transports {
+		manager.transportByTag[transport.Tag()] = transport
+	}
+	return manager
+}
+
+func (m *testDNSTransportManager) Start(stage StartStage) error {
+	return nil
+}
+
+func (m *testDNSTransportManager) Close() error {
+	return nil
+}
+
+func (m *testDNSTransportManager) Transports() []DNSTransport {
+	return m.transports
+}
+
+func (m *testDNSTransportManager) Transport(tag string) (DNSTransport, bool) {
+	transport, loaded := m.transportByTag[tag]
+	return transport, loaded
+}
+
+func (m *testDNSTransportManager) Default() DNSTransport {
+	return nil
+}
+
+func (m *testDNSTransportManager) FakeIP() FakeIPTransport {
+	return m.fakeIPTransport
+}
+
+func (m *testDNSTransportManager) Remove(tag string) error {
+	return nil
+}
+
+func (m *testDNSTransportManager) Create(ctx context.Context, logger log.ContextLogger, tag string, outboundType string, options any) error {
+	return nil
+}
+
+func TestLookupDNSTransportLocalAlias(t *testing.T) {
+	t.Parallel()
+
+	localTransport := &testDNSTransport{
+		transportType: "local",
+		tag:           "dns-local",
+	}
+	manager := newTestDNSTransportManager(localTransport)
+
+	transport, loaded, ambiguous := LookupDNSTransport(manager, "local")
+	require.True(t, loaded)
+	require.False(t, ambiguous)
+	require.Same(t, localTransport, transport)
+}
+
+func TestLookupDNSTransportExactTagPreferred(t *testing.T) {
+	t.Parallel()
+
+	localTransport := &testDNSTransport{
+		transportType: "local",
+		tag:           "local",
+	}
+	manager := newTestDNSTransportManager(localTransport)
+
+	transport, loaded, ambiguous := LookupDNSTransport(manager, "local")
+	require.True(t, loaded)
+	require.False(t, ambiguous)
+	require.Same(t, localTransport, transport)
+}
+
+func TestLookupDNSTransportLocalAliasAmbiguous(t *testing.T) {
+	t.Parallel()
+
+	manager := newTestDNSTransportManager(
+		&testDNSTransport{transportType: "local", tag: "dns-local-a"},
+		&testDNSTransport{transportType: "local", tag: "dns-local-b"},
+	)
+
+	transport, loaded, ambiguous := LookupDNSTransport(manager, "local")
+	require.Nil(t, transport)
+	require.False(t, loaded)
+	require.True(t, ambiguous)
+}

dns/router.go

@@ -145,9 +145,13 @@ func (r *Router) matchDNS(ctx context.Context, allowFakeIP bool, ruleIndex int,
 			}
 			switch action := currentRule.Action().(type) {
 			case *R.RuleActionDNSRoute:
-				transport, loaded := r.transport.Transport(action.Server)
+				transport, loaded, ambiguous := adapter.LookupDNSTransport(r.transport, action.Server)
 				if !loaded {
-					r.logger.ErrorContext(ctx, "transport not found: ", action.Server)
+					if ambiguous {
+						r.logger.ErrorContext(ctx, "transport is ambiguous: ", action.Server)
+					} else {
+						r.logger.ErrorContext(ctx, "transport not found: ", action.Server)
+					}
 					continue
 				}
 				isFakeIP := transport.Type() == C.DNSTypeFakeIP

dns/router.go.7853130561294400935

@@ -0,0 +1,464 @@
+package dns
+
+import (
+	"context"
+	"errors"
+	"net/netip"
+	"strings"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/taskmonitor"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	R "github.com/sagernet/sing-box/route/rule"
+	"github.com/sagernet/sing-tun"
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+	F "github.com/sagernet/sing/common/format"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	"github.com/sagernet/sing/contrab/freelru"
+	"github.com/sagernet/sing/contrab/maphash"
+	"github.com/sagernet/sing/service"
+
+	mDNS "github.com/miekg/dns"
+)
+
+var _ adapter.DNSRouter = (*Router)(nil)
+
+type Router struct {
+	ctx                   context.Context
+	logger                logger.ContextLogger
+	transport             adapter.DNSTransportManager
+	outbound              adapter.OutboundManager
+	client                adapter.DNSClient
+	rules                 []adapter.DNSRule
+	defaultDomainStrategy C.DomainStrategy
+	dnsReverseMapping     freelru.Cache[netip.Addr, string]
+	platformInterface     adapter.PlatformInterface
+}
+
+func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOptions) *Router {
+	router := &Router{
+		ctx:                   ctx,
+		logger:                logFactory.NewLogger("dns"),
+		transport:             service.FromContext[adapter.DNSTransportManager](ctx),
+		outbound:              service.FromContext[adapter.OutboundManager](ctx),
+		rules:                 make([]adapter.DNSRule, 0, len(options.Rules)),
+		defaultDomainStrategy: C.DomainStrategy(options.Strategy),
+	}
+	router.client = NewClient(ClientOptions{
+		DisableCache:     options.DNSClientOptions.DisableCache,
+		DisableExpire:    options.DNSClientOptions.DisableExpire,
+		IndependentCache: options.DNSClientOptions.IndependentCache,
+		CacheCapacity:    options.DNSClientOptions.CacheCapacity,
+		ClientSubnet:     options.DNSClientOptions.ClientSubnet.Build(netip.Prefix{}),
+		RDRC: func() adapter.RDRCStore {
+			cacheFile := service.FromContext[adapter.CacheFile](ctx)
+			if cacheFile == nil {
+				return nil
+			}
+			if !cacheFile.StoreRDRC() {
+				return nil
+			}
+			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
+}
+
+func (r *Router) Initialize(rules []option.DNSRule) error {
+	for i, ruleOptions := range rules {
+		dnsRule, err := R.NewDNSRule(r.ctx, r.logger, ruleOptions, true)
+		if err != nil {
+			return E.Cause(err, "parse dns rule[", i, "]")
+		}
+		r.rules = append(r.rules, dnsRule)
+	}
+	return nil
+}
+
+func (r *Router) Start(stage adapter.StartStage) error {
+	monitor := taskmonitor.New(r.logger, C.StartTimeout)
+	switch stage {
+	case adapter.StartStateStart:
+		monitor.Start("initialize DNS client")
+		r.client.Start()
+		monitor.Finish()
+
+		for i, rule := range r.rules {
+			monitor.Start("initialize DNS rule[", i, "]")
+			err := rule.Start()
+			monitor.Finish()
+			if err != nil {
+				return E.Cause(err, "initialize DNS rule[", i, "]")
+			}
+		}
+	}
+	return nil
+}
+
+func (r *Router) Close() error {
+	monitor := taskmonitor.New(r.logger, C.StopTimeout)
+	var err error
+	for i, rule := range r.rules {
+		monitor.Start("close dns rule[", i, "]")
+		err = E.Append(err, rule.Close(), func(err error) error {
+			return E.Cause(err, "close dns rule[", i, "]")
+		})
+		monitor.Finish()
+	}
+	return err
+}
+
+func (r *Router) matchDNS(ctx context.Context, allowFakeIP bool, ruleIndex int, isAddressQuery bool, options *adapter.DNSQueryOptions) (adapter.DNSTransport, adapter.DNSRule, int) {
+	metadata := adapter.ContextFrom(ctx)
+	if metadata == nil {
+		panic("no context")
+	}
+	var currentRuleIndex int
+	if ruleIndex != -1 {
+		currentRuleIndex = ruleIndex + 1
+	}
+	for ; currentRuleIndex < len(r.rules); currentRuleIndex++ {
+		currentRule := r.rules[currentRuleIndex]
+		if currentRule.WithAddressLimit() && !isAddressQuery {
+			continue
+		}
+		metadata.ResetRuleCache()
+		if currentRule.Match(metadata) {
+			displayRuleIndex := currentRuleIndex
+			if displayRuleIndex != -1 {
+				displayRuleIndex += displayRuleIndex + 1
+			}
+			ruleDescription := currentRule.String()
+			if ruleDescription != "" {
+				r.logger.DebugContext(ctx, "match[", displayRuleIndex, "] ", currentRule, " => ", currentRule.Action())
+			} else {
+				r.logger.DebugContext(ctx, "match[", displayRuleIndex, "] => ", currentRule.Action())
+			}
+			switch action := currentRule.Action().(type) {
+			case *R.RuleActionDNSRoute:
+				transport, loaded, ambiguous := adapter.LookupDNSTransport(r.transport, action.Server)
+				if !loaded {
+					if ambiguous {
+						r.logger.ErrorContext(ctx, "transport is ambiguous: ", action.Server)
+					} else {
+						r.logger.ErrorContext(ctx, "transport not found: ", action.Server)
+					}
+					continue
+				}
+				isFakeIP := transport.Type() == C.DNSTypeFakeIP
+				if isFakeIP && !allowFakeIP {
+					continue
+				}
+				if action.Strategy != C.DomainStrategyAsIS {
+					options.Strategy = action.Strategy
+				}
+				if isFakeIP || action.DisableCache {
+					options.DisableCache = true
+				}
+				if action.RewriteTTL != nil {
+					options.RewriteTTL = action.RewriteTTL
+				}
+				if action.ClientSubnet.IsValid() {
+					options.ClientSubnet = action.ClientSubnet
+				}
+				if legacyTransport, isLegacy := transport.(adapter.LegacyDNSTransport); isLegacy {
+					if options.Strategy == C.DomainStrategyAsIS {
+						options.Strategy = legacyTransport.LegacyStrategy()
+					}
+					if !options.ClientSubnet.IsValid() {
+						options.ClientSubnet = legacyTransport.LegacyClientSubnet()
+					}
+				}
+				return transport, currentRule, currentRuleIndex
+			case *R.RuleActionDNSRouteOptions:
+				if action.Strategy != C.DomainStrategyAsIS {
+					options.Strategy = action.Strategy
+				}
+				if action.DisableCache {
+					options.DisableCache = true
+				}
+				if action.RewriteTTL != nil {
+					options.RewriteTTL = action.RewriteTTL
+				}
+				if action.ClientSubnet.IsValid() {
+					options.ClientSubnet = action.ClientSubnet
+				}
+			case *R.RuleActionReject:
+				return nil, currentRule, currentRuleIndex
+			case *R.RuleActionPredefined:
+				return nil, currentRule, currentRuleIndex
+			}
+		}
+	}
+	transport := r.transport.Default()
+	if legacyTransport, isLegacy := transport.(adapter.LegacyDNSTransport); isLegacy {
+		if options.Strategy == C.DomainStrategyAsIS {
+			options.Strategy = legacyTransport.LegacyStrategy()
+		}
+		if !options.ClientSubnet.IsValid() {
+			options.ClientSubnet = legacyTransport.LegacyClientSubnet()
+		}
+	}
+	return transport, nil, -1
+}
+
+func (r *Router) Exchange(ctx context.Context, message *mDNS.Msg, options adapter.DNSQueryOptions) (*mDNS.Msg, error) {
+	if len(message.Question) != 1 {
+		r.logger.WarnContext(ctx, "bad question size: ", len(message.Question))
+		responseMessage := mDNS.Msg{
+			MsgHdr: mDNS.MsgHdr{
+				Id:       message.Id,
+				Response: true,
+				Rcode:    mDNS.RcodeFormatError,
+			},
+			Question: message.Question,
+		}
+		return &responseMessage, nil
+	}
+	r.logger.DebugContext(ctx, "exchange ", FormatQuestion(message.Question[0].String()))
+	var (
+		response  *mDNS.Msg
+		transport adapter.DNSTransport
+		err       error
+	)
+	var metadata *adapter.InboundContext
+	ctx, metadata = adapter.ExtendContext(ctx)
+	metadata.Destination = M.Socksaddr{}
+	metadata.QueryType = message.Question[0].Qtype
+	switch metadata.QueryType {
+	case mDNS.TypeA:
+		metadata.IPVersion = 4
+	case mDNS.TypeAAAA:
+		metadata.IPVersion = 6
+	}
+	metadata.Domain = FqdnToDomain(message.Question[0].Name)
+	if options.Transport != nil {
+		transport = options.Transport
+		if legacyTransport, isLegacy := transport.(adapter.LegacyDNSTransport); isLegacy {
+			if options.Strategy == C.DomainStrategyAsIS {
+				options.Strategy = legacyTransport.LegacyStrategy()
+			}
+			if !options.ClientSubnet.IsValid() {
+				options.ClientSubnet = legacyTransport.LegacyClientSubnet()
+			}
+		}
+		if options.Strategy == C.DomainStrategyAsIS {
+			options.Strategy = r.defaultDomainStrategy
+		}
+		response, err = r.client.Exchange(ctx, transport, message, options, nil)
+	} else {
+		var (
+			rule      adapter.DNSRule
+			ruleIndex int
+		)
+		ruleIndex = -1
+		for {
+			dnsCtx := adapter.OverrideContext(ctx)
+			dnsOptions := options
+			transport, rule, ruleIndex = r.matchDNS(ctx, true, ruleIndex, isAddressQuery(message), &dnsOptions)
+			if rule != nil {
+				switch action := rule.Action().(type) {
+				case *R.RuleActionReject:
+					switch action.Method {
+					case C.RuleActionRejectMethodDefault:
+						return &mDNS.Msg{
+							MsgHdr: mDNS.MsgHdr{
+								Id:       message.Id,
+								Rcode:    mDNS.RcodeRefused,
+								Response: true,
+							},
+							Question: []mDNS.Question{message.Question[0]},
+						}, nil
+					case C.RuleActionRejectMethodDrop:
+						return nil, tun.ErrDrop
+					}
+				case *R.RuleActionPredefined:
+					return action.Response(message), nil
+				}
+			}
+			responseCheck := addressLimitResponseCheck(rule, metadata)
+			if dnsOptions.Strategy == C.DomainStrategyAsIS {
+				dnsOptions.Strategy = r.defaultDomainStrategy
+			}
+			response, err = r.client.Exchange(dnsCtx, transport, message, dnsOptions, responseCheck)
+			var rejected bool
+			if err != nil {
+				if errors.Is(err, ErrResponseRejectedCached) {
+					rejected = true
+					r.logger.DebugContext(ctx, E.Cause(err, "response rejected for ", FormatQuestion(message.Question[0].String())), " (cached)")
+				} else if errors.Is(err, ErrResponseRejected) {
+					rejected = true
+					r.logger.DebugContext(ctx, E.Cause(err, "response rejected for ", FormatQuestion(message.Question[0].String())))
+				} else if len(message.Question) > 0 {
+					r.logger.ErrorContext(ctx, E.Cause(err, "exchange failed for ", FormatQuestion(message.Question[0].String())))
+				} else {
+					r.logger.ErrorContext(ctx, E.Cause(err, "exchange failed for <empty query>"))
+				}
+			}
+			if responseCheck != nil && rejected {
+				continue
+			}
+			break
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+	if r.dnsReverseMapping != nil && len(message.Question) > 0 && response != nil && len(response.Answer) > 0 {
+		if transport == nil || transport.Type() != C.DNSTypeFakeIP {
+			for _, answer := range response.Answer {
+				switch record := answer.(type) {
+				case *mDNS.A:
+					r.dnsReverseMapping.AddWithLifetime(M.AddrFromIP(record.A), FqdnToDomain(record.Hdr.Name), time.Duration(record.Hdr.Ttl)*time.Second)
+				case *mDNS.AAAA:
+					r.dnsReverseMapping.AddWithLifetime(M.AddrFromIP(record.AAAA), FqdnToDomain(record.Hdr.Name), time.Duration(record.Hdr.Ttl)*time.Second)
+				}
+			}
+		}
+	}
+	return response, nil
+}
+
+func (r *Router) Lookup(ctx context.Context, domain string, options adapter.DNSQueryOptions) ([]netip.Addr, error) {
+	var (
+		responseAddrs []netip.Addr
+		err           error
+	)
+	printResult := func() {
+		if err == nil && len(responseAddrs) == 0 {
+			err = E.New("empty result")
+		}
+		if err != nil {
+			if errors.Is(err, ErrResponseRejectedCached) {
+				r.logger.DebugContext(ctx, "response rejected for ", domain, " (cached)")
+			} else if errors.Is(err, ErrResponseRejected) {
+				r.logger.DebugContext(ctx, "response rejected for ", domain)
+			} else {
+				r.logger.ErrorContext(ctx, E.Cause(err, "lookup failed for ", domain))
+			}
+		}
+		if err != nil {
+			err = E.Cause(err, "lookup ", domain)
+		}
+	}
+	r.logger.DebugContext(ctx, "lookup domain ", domain)
+	ctx, metadata := adapter.ExtendContext(ctx)
+	metadata.Destination = M.Socksaddr{}
+	metadata.Domain = FqdnToDomain(domain)
+	if options.Transport != nil {
+		transport := options.Transport
+		if legacyTransport, isLegacy := transport.(adapter.LegacyDNSTransport); isLegacy {
+			if options.Strategy == C.DomainStrategyAsIS {
+				options.Strategy = legacyTransport.LegacyStrategy()
+			}
+			if !options.ClientSubnet.IsValid() {
+				options.ClientSubnet = legacyTransport.LegacyClientSubnet()
+			}
+		}
+		if options.Strategy == C.DomainStrategyAsIS {
+			options.Strategy = r.defaultDomainStrategy
+		}
+		responseAddrs, err = r.client.Lookup(ctx, transport, domain, options, nil)
+	} else {
+		var (
+			transport adapter.DNSTransport
+			rule      adapter.DNSRule
+			ruleIndex int
+		)
+		ruleIndex = -1
+		for {
+			dnsCtx := adapter.OverrideContext(ctx)
+			dnsOptions := options
+			transport, rule, ruleIndex = r.matchDNS(ctx, false, ruleIndex, true, &dnsOptions)
+			if rule != nil {
+				switch action := rule.Action().(type) {
+				case *R.RuleActionReject:
+					return nil, &R.RejectedError{Cause: action.Error(ctx)}
+				case *R.RuleActionPredefined:
+					responseAddrs = nil
+					if action.Rcode != mDNS.RcodeSuccess {
+						err = RcodeError(action.Rcode)
+					} else {
+						err = nil
+						for _, answer := range action.Answer {
+							switch record := answer.(type) {
+							case *mDNS.A:
+								responseAddrs = append(responseAddrs, M.AddrFromIP(record.A))
+							case *mDNS.AAAA:
+								responseAddrs = append(responseAddrs, M.AddrFromIP(record.AAAA))
+							}
+						}
+					}
+					goto response
+				}
+			}
+			responseCheck := addressLimitResponseCheck(rule, metadata)
+			if dnsOptions.Strategy == C.DomainStrategyAsIS {
+				dnsOptions.Strategy = r.defaultDomainStrategy
+			}
+			responseAddrs, err = r.client.Lookup(dnsCtx, transport, domain, dnsOptions, responseCheck)
+			if responseCheck == nil || err == nil {
+				break
+			}
+			printResult()
+		}
+	}
+response:
+	printResult()
+	if len(responseAddrs) > 0 {
+		r.logger.InfoContext(ctx, "lookup succeed for ", domain, ": ", strings.Join(F.MapToString(responseAddrs), " "))
+	}
+	return responseAddrs, err
+}
+
+func isAddressQuery(message *mDNS.Msg) bool {
+	for _, question := range message.Question {
+		if question.Qtype == mDNS.TypeA || question.Qtype == mDNS.TypeAAAA || question.Qtype == mDNS.TypeHTTPS {
+			return true
+		}
+	}
+	return false
+}
+
+func addressLimitResponseCheck(rule adapter.DNSRule, metadata *adapter.InboundContext) func(responseAddrs []netip.Addr) bool {
+	if rule == nil || !rule.WithAddressLimit() {
+		return nil
+	}
+	responseMetadata := *metadata
+	return func(responseAddrs []netip.Addr) bool {
+		checkMetadata := responseMetadata
+		checkMetadata.DestinationAddresses = responseAddrs
+		return rule.MatchAddressLimit(&checkMetadata)
+	}
+}
+
+func (r *Router) ClearCache() {
+	r.client.ClearCache()
+	if r.platformInterface != nil {
+		r.platformInterface.ClearDNSCache()
+	}
+}
+
+func (r *Router) LookupReverseMapping(ip netip.Addr) (string, bool) {
+	if r.dnsReverseMapping == nil {
+		return "", false
+	}
+	domain, loaded := r.dnsReverseMapping.Get(ip)
+	return domain, loaded
+}
+
+func (r *Router) ResetNetwork() {
+	r.ClearCache()
+	for _, transport := range r.transport.Transports() {
+		transport.Reset()
+	}
+}

dns/transport_dialer.go

@@ -33,8 +33,11 @@ func NewRemoteDialer(ctx context.Context, options option.RemoteDNSServerOptions)
 		transportDialer := dialer.NewDefaultOutbound(ctx)
 		if options.LegacyAddressResolver != "" {
 			transport := service.FromContext[adapter.DNSTransportManager](ctx)
-			resolverTransport, loaded := transport.Transport(options.LegacyAddressResolver)
+			resolverTransport, loaded, ambiguous := adapter.LookupDNSTransport(transport, options.LegacyAddressResolver)
 			if !loaded {
+				if ambiguous {
+					return nil, E.New("address resolver is ambiguous: ", options.LegacyAddressResolver)
+				}
 				return nil, E.New("address resolver not found: ", options.LegacyAddressResolver)
 			}
 			transportDialer = newTransportDialer(transportDialer, service.FromContext[adapter.DNSRouter](ctx), resolverTransport, C.DomainStrategy(options.LegacyAddressStrategy), time.Duration(options.LegacyAddressFallbackDelay))

dns/transport_dialer.go.6124520021629164267

@@ -0,0 +1,108 @@
+package dns
+
+import (
+	"context"
+	"net"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/dialer"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/service"
+)
+
+func NewLocalDialer(ctx context.Context, options option.LocalDNSServerOptions) (N.Dialer, error) {
+	if options.LegacyDefaultDialer {
+		return dialer.NewDefaultOutbound(ctx), nil
+	} else {
+		return dialer.NewWithOptions(dialer.Options{
+			Context:         ctx,
+			Options:         options.DialerOptions,
+			DirectResolver:  true,
+			LegacyDNSDialer: options.Legacy,
+		})
+	}
+}
+
+func NewRemoteDialer(ctx context.Context, options option.RemoteDNSServerOptions) (N.Dialer, error) {
+	if options.LegacyDefaultDialer {
+		transportDialer := dialer.NewDefaultOutbound(ctx)
+		if options.LegacyAddressResolver != "" {
+			transport := service.FromContext[adapter.DNSTransportManager](ctx)
+			resolverTransport, loaded, ambiguous := adapter.LookupDNSTransport(transport, options.LegacyAddressResolver)
+			if !loaded {
+				if ambiguous {
+					return nil, E.New("address resolver is ambiguous: ", options.LegacyAddressResolver)
+				}
+				return nil, E.New("address resolver not found: ", options.LegacyAddressResolver)
+			}
+			transportDialer = newTransportDialer(transportDialer, service.FromContext[adapter.DNSRouter](ctx), resolverTransport, C.DomainStrategy(options.LegacyAddressStrategy), time.Duration(options.LegacyAddressFallbackDelay))
+		} else if options.ServerIsDomain() {
+			return nil, E.New("missing address resolver for server: ", options.Server)
+		}
+		return transportDialer, nil
+	} else {
+		return dialer.NewWithOptions(dialer.Options{
+			Context:         ctx,
+			Options:         options.DialerOptions,
+			RemoteIsDomain:  options.ServerIsDomain(),
+			DirectResolver:  true,
+			LegacyDNSDialer: options.Legacy,
+		})
+	}
+}
+
+type legacyTransportDialer struct {
+	dialer        N.Dialer
+	dnsRouter     adapter.DNSRouter
+	transport     adapter.DNSTransport
+	strategy      C.DomainStrategy
+	fallbackDelay time.Duration
+}
+
+func newTransportDialer(dialer N.Dialer, dnsRouter adapter.DNSRouter, transport adapter.DNSTransport, strategy C.DomainStrategy, fallbackDelay time.Duration) *legacyTransportDialer {
+	return &legacyTransportDialer{
+		dialer,
+		dnsRouter,
+		transport,
+		strategy,
+		fallbackDelay,
+	}
+}
+
+func (d *legacyTransportDialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	if destination.IsIP() {
+		return d.dialer.DialContext(ctx, network, destination)
+	}
+	addresses, err := d.dnsRouter.Lookup(ctx, destination.Fqdn, adapter.DNSQueryOptions{
+		Transport: d.transport,
+		Strategy:  d.strategy,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return N.DialParallel(ctx, d.dialer, network, destination, addresses, d.strategy == C.DomainStrategyPreferIPv6, d.fallbackDelay)
+}
+
+func (d *legacyTransportDialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	if destination.IsIP() {
+		return d.dialer.ListenPacket(ctx, destination)
+	}
+	addresses, err := d.dnsRouter.Lookup(ctx, destination.Fqdn, adapter.DNSQueryOptions{
+		Transport: d.transport,
+		Strategy:  d.strategy,
+	})
+	if err != nil {
+		return nil, err
+	}
+	conn, _, err := N.ListenSerial(ctx, d.dialer, destination, addresses)
+	return conn, err
+}
+
+func (d *legacyTransportDialer) Upstream() any {
+	return d.dialer
+}

route/route.go

@@ -792,9 +792,15 @@ func (r *Router) actionResolve(ctx context.Context, metadata *adapter.InboundCon
 	if metadata.Destination.IsDomain() {
 		var transport adapter.DNSTransport
 		if action.Server != "" {
-			var loaded bool
+			var (
-			transport, loaded = r.dnsTransport.Transport(action.Server)
+				loaded    bool
+				ambiguous bool
+			)
+			transport, loaded, ambiguous = adapter.LookupDNSTransport(r.dnsTransport, action.Server)
 			if !loaded {
+				if ambiguous {
+					return E.New("DNS server is ambiguous: ", action.Server)
+				}
 				return E.New("DNS server not found: ", action.Server)
 			}
 		}

route/route.go.3955832358233176917

@@ -0,0 +1,821 @@
+package route
+
+import (
+	"context"
+	"errors"
+	"net"
+	"net/netip"
+	"strings"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/sniff"
+	C "github.com/sagernet/sing-box/constant"
+	R "github.com/sagernet/sing-box/route/rule"
+	"github.com/sagernet/sing-mux"
+	"github.com/sagernet/sing-tun"
+	"github.com/sagernet/sing-tun/ping"
+	"github.com/sagernet/sing-vmess"
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	"github.com/sagernet/sing/common/bufio/deadline"
+	E "github.com/sagernet/sing/common/exceptions"
+	F "github.com/sagernet/sing/common/format"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/common/uot"
+
+	"golang.org/x/exp/slices"
+)
+
+// Deprecated: use RouteConnectionEx instead.
+func (r *Router) RouteConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
+	done := make(chan interface{})
+	err := r.routeConnection(ctx, conn, metadata, N.OnceClose(func(it error) {
+		close(done)
+	}))
+	if err != nil {
+		return err
+	}
+	select {
+	case <-done:
+	case <-r.ctx.Done():
+	}
+	return nil
+}
+
+func (r *Router) RouteConnectionEx(ctx context.Context, conn net.Conn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) {
+	err := r.routeConnection(ctx, conn, metadata, onClose)
+	if err != nil {
+		N.CloseOnHandshakeFailure(conn, onClose, err)
+		if E.IsClosedOrCanceled(err) || R.IsRejected(err) {
+			r.logger.DebugContext(ctx, "connection closed: ", err)
+		} else {
+			r.logger.ErrorContext(ctx, err)
+		}
+	}
+}
+
+func (r *Router) routeConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) error {
+	//nolint:staticcheck
+	if metadata.InboundDetour != "" {
+		if metadata.LastInbound == metadata.InboundDetour {
+			return E.New("routing loop on detour: ", metadata.InboundDetour)
+		}
+		detour, loaded := r.inbound.Get(metadata.InboundDetour)
+		if !loaded {
+			return E.New("inbound detour not found: ", metadata.InboundDetour)
+		}
+		injectable, isInjectable := detour.(adapter.TCPInjectableInbound)
+		if !isInjectable {
+			return E.New("inbound detour is not TCP injectable: ", metadata.InboundDetour)
+		}
+		metadata.LastInbound = metadata.Inbound
+		metadata.Inbound = metadata.InboundDetour
+		metadata.InboundDetour = ""
+		injectable.NewConnectionEx(ctx, conn, metadata, onClose)
+		return nil
+	}
+	metadata.Network = N.NetworkTCP
+	switch metadata.Destination.Fqdn {
+	case mux.Destination.Fqdn:
+		return E.New("global multiplex is deprecated since sing-box v1.7.0, enable multiplex in Inbound fields instead.")
+	case vmess.MuxDestination.Fqdn:
+		return E.New("global multiplex (v2ray legacy) not supported since sing-box v1.7.0.")
+	case uot.MagicAddress:
+		return E.New("global UoT not supported since sing-box v1.7.0.")
+	case uot.LegacyMagicAddress:
+		return E.New("global UoT (legacy) not supported since sing-box v1.7.0.")
+	}
+	if deadline.NeedAdditionalReadDeadline(conn) {
+		conn = deadline.NewConn(conn)
+	}
+	selectedRule, _, buffers, _, err := r.matchRule(ctx, &metadata, false, false, conn, nil)
+	if err != nil {
+		return err
+	}
+	var selectedOutbound adapter.Outbound
+	if selectedRule != nil {
+		switch action := selectedRule.Action().(type) {
+		case *R.RuleActionRoute:
+			var loaded bool
+			selectedOutbound, loaded = r.outbound.Outbound(action.Outbound)
+			if !loaded {
+				buf.ReleaseMulti(buffers)
+				return E.New("outbound not found: ", action.Outbound)
+			}
+			if !common.Contains(selectedOutbound.Network(), N.NetworkTCP) {
+				buf.ReleaseMulti(buffers)
+				return E.New("TCP is not supported by outbound: ", selectedOutbound.Tag())
+			}
+		case *R.RuleActionBypass:
+			if action.Outbound == "" {
+				break
+			}
+			var loaded bool
+			selectedOutbound, loaded = r.outbound.Outbound(action.Outbound)
+			if !loaded {
+				buf.ReleaseMulti(buffers)
+				return E.New("outbound not found: ", action.Outbound)
+			}
+			if !common.Contains(selectedOutbound.Network(), N.NetworkTCP) {
+				buf.ReleaseMulti(buffers)
+				return E.New("TCP is not supported by outbound: ", selectedOutbound.Tag())
+			}
+		case *R.RuleActionReject:
+			buf.ReleaseMulti(buffers)
+			if action.Method == C.RuleActionRejectMethodReply {
+				return E.New("reject method `reply` is not supported for TCP connections")
+			}
+			return action.Error(ctx)
+		case *R.RuleActionHijackDNS:
+			for _, buffer := range buffers {
+				conn = bufio.NewCachedConn(conn, buffer)
+			}
+			N.CloseOnHandshakeFailure(conn, onClose, r.hijackDNSStream(ctx, conn, metadata))
+			return nil
+		}
+	}
+	if selectedRule == nil {
+		defaultOutbound := r.outbound.Default()
+		if !common.Contains(defaultOutbound.Network(), N.NetworkTCP) {
+			buf.ReleaseMulti(buffers)
+			return E.New("TCP is not supported by default outbound: ", defaultOutbound.Tag())
+		}
+		selectedOutbound = defaultOutbound
+	}
+
+	for _, buffer := range buffers {
+		conn = bufio.NewCachedConn(conn, buffer)
+	}
+	for _, tracker := range r.trackers {
+		conn = tracker.RoutedConnection(ctx, conn, metadata, selectedRule, selectedOutbound)
+	}
+	if outboundHandler, isHandler := selectedOutbound.(adapter.ConnectionHandlerEx); isHandler {
+		outboundHandler.NewConnectionEx(ctx, conn, metadata, onClose)
+	} else {
+		r.connection.NewConnection(ctx, selectedOutbound, conn, metadata, onClose)
+	}
+	return nil
+}
+
+func (r *Router) RoutePacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
+	done := make(chan interface{})
+	err := r.routePacketConnection(ctx, conn, metadata, N.OnceClose(func(it error) {
+		close(done)
+	}))
+	if err != nil {
+		conn.Close()
+		if E.IsClosedOrCanceled(err) || R.IsRejected(err) {
+			r.logger.DebugContext(ctx, "connection closed: ", err)
+		} else {
+			r.logger.ErrorContext(ctx, err)
+		}
+	}
+	select {
+	case <-done:
+	case <-r.ctx.Done():
+	}
+	return nil
+}
+
+func (r *Router) RoutePacketConnectionEx(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) {
+	err := r.routePacketConnection(ctx, conn, metadata, onClose)
+	if err != nil {
+		N.CloseOnHandshakeFailure(conn, onClose, err)
+		if E.IsClosedOrCanceled(err) || R.IsRejected(err) {
+			r.logger.DebugContext(ctx, "connection closed: ", err)
+		} else {
+			r.logger.ErrorContext(ctx, err)
+		}
+	}
+}
+
+func (r *Router) routePacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext, onClose N.CloseHandlerFunc) error {
+	//nolint:staticcheck
+	if metadata.InboundDetour != "" {
+		if metadata.LastInbound == metadata.InboundDetour {
+			return E.New("routing loop on detour: ", metadata.InboundDetour)
+		}
+		detour, loaded := r.inbound.Get(metadata.InboundDetour)
+		if !loaded {
+			return E.New("inbound detour not found: ", metadata.InboundDetour)
+		}
+		injectable, isInjectable := detour.(adapter.UDPInjectableInbound)
+		if !isInjectable {
+			return E.New("inbound detour is not UDP injectable: ", metadata.InboundDetour)
+		}
+		metadata.LastInbound = metadata.Inbound
+		metadata.Inbound = metadata.InboundDetour
+		metadata.InboundDetour = ""
+		injectable.NewPacketConnectionEx(ctx, conn, metadata, onClose)
+		return nil
+	}
+	// TODO: move to UoT
+	metadata.Network = N.NetworkUDP
+
+	// Currently we don't have deadline usages for UDP connections
+	/*if deadline.NeedAdditionalReadDeadline(conn) {
+		conn = deadline.NewPacketConn(bufio.NewNetPacketConn(conn))
+	}*/
+
+	selectedRule, _, _, packetBuffers, err := r.matchRule(ctx, &metadata, false, false, nil, conn)
+	if err != nil {
+		return err
+	}
+	var selectedOutbound adapter.Outbound
+	var selectReturn bool
+	if selectedRule != nil {
+		switch action := selectedRule.Action().(type) {
+		case *R.RuleActionRoute:
+			var loaded bool
+			selectedOutbound, loaded = r.outbound.Outbound(action.Outbound)
+			if !loaded {
+				N.ReleaseMultiPacketBuffer(packetBuffers)
+				return E.New("outbound not found: ", action.Outbound)
+			}
+			if !common.Contains(selectedOutbound.Network(), N.NetworkUDP) {
+				N.ReleaseMultiPacketBuffer(packetBuffers)
+				return E.New("UDP is not supported by outbound: ", selectedOutbound.Tag())
+			}
+		case *R.RuleActionBypass:
+			if action.Outbound == "" {
+				break
+			}
+			var loaded bool
+			selectedOutbound, loaded = r.outbound.Outbound(action.Outbound)
+			if !loaded {
+				N.ReleaseMultiPacketBuffer(packetBuffers)
+				return E.New("outbound not found: ", action.Outbound)
+			}
+			if !common.Contains(selectedOutbound.Network(), N.NetworkUDP) {
+				N.ReleaseMultiPacketBuffer(packetBuffers)
+				return E.New("UDP is not supported by outbound: ", selectedOutbound.Tag())
+			}
+		case *R.RuleActionReject:
+			N.ReleaseMultiPacketBuffer(packetBuffers)
+			if action.Method == C.RuleActionRejectMethodReply {
+				return E.New("reject method `reply` is not supported for UDP connections")
+			}
+			return action.Error(ctx)
+		case *R.RuleActionHijackDNS:
+			return r.hijackDNSPacket(ctx, conn, packetBuffers, metadata, onClose)
+		}
+	}
+	if selectedRule == nil || selectReturn {
+		defaultOutbound := r.outbound.Default()
+		if !common.Contains(defaultOutbound.Network(), N.NetworkUDP) {
+			N.ReleaseMultiPacketBuffer(packetBuffers)
+			return E.New("UDP is not supported by outbound: ", defaultOutbound.Tag())
+		}
+		selectedOutbound = defaultOutbound
+	}
+	for _, buffer := range packetBuffers {
+		conn = bufio.NewCachedPacketConn(conn, buffer.Buffer, buffer.Destination)
+		N.PutPacketBuffer(buffer)
+	}
+	for _, tracker := range r.trackers {
+		conn = tracker.RoutedPacketConnection(ctx, conn, metadata, selectedRule, selectedOutbound)
+	}
+	if metadata.FakeIP {
+		conn = bufio.NewNATPacketConn(bufio.NewNetPacketConn(conn), metadata.OriginDestination, metadata.Destination)
+	}
+	if outboundHandler, isHandler := selectedOutbound.(adapter.PacketConnectionHandlerEx); isHandler {
+		outboundHandler.NewPacketConnectionEx(ctx, conn, metadata, onClose)
+	} else {
+		r.connection.NewPacketConnection(ctx, selectedOutbound, conn, metadata, onClose)
+	}
+	return nil
+}
+
+func (r *Router) PreMatch(metadata adapter.InboundContext, routeContext tun.DirectRouteContext, timeout time.Duration, supportBypass bool) (tun.DirectRouteDestination, error) {
+	selectedRule, _, _, _, err := r.matchRule(r.ctx, &metadata, true, supportBypass, nil, nil)
+	if err != nil {
+		return nil, err
+	}
+	var directRouteOutbound adapter.DirectRouteOutbound
+	if selectedRule != nil {
+		switch action := selectedRule.Action().(type) {
+		case *R.RuleActionReject:
+			switch metadata.Network {
+			case N.NetworkTCP:
+				if action.Method == C.RuleActionRejectMethodReply {
+					return nil, E.New("reject method `reply` is not supported for TCP connections")
+				}
+			case N.NetworkUDP:
+				if action.Method == C.RuleActionRejectMethodReply {
+					return nil, E.New("reject method `reply` is not supported for UDP connections")
+				}
+			}
+			return nil, action.Error(context.Background())
+		case *R.RuleActionBypass:
+			if supportBypass {
+				return nil, &R.BypassedError{Cause: tun.ErrBypass}
+			}
+			if routeContext == nil {
+				return nil, nil
+			}
+			outbound, loaded := r.outbound.Outbound(action.Outbound)
+			if !loaded {
+				return nil, E.New("outbound not found: ", action.Outbound)
+			}
+			if !common.Contains(outbound.Network(), metadata.Network) {
+				return nil, E.New(metadata.Network, " is not supported by outbound: ", action.Outbound)
+			}
+			directRouteOutbound = outbound.(adapter.DirectRouteOutbound)
+		case *R.RuleActionRoute:
+			if routeContext == nil {
+				return nil, nil
+			}
+			outbound, loaded := r.outbound.Outbound(action.Outbound)
+			if !loaded {
+				return nil, E.New("outbound not found: ", action.Outbound)
+			}
+			if !common.Contains(outbound.Network(), metadata.Network) {
+				return nil, E.New(metadata.Network, " is not supported by outbound: ", action.Outbound)
+			}
+			directRouteOutbound = outbound.(adapter.DirectRouteOutbound)
+		}
+	}
+	if directRouteOutbound == nil {
+		if selectedRule != nil || metadata.Network != N.NetworkICMP {
+			return nil, nil
+		}
+		defaultOutbound := r.outbound.Default()
+		if !common.Contains(defaultOutbound.Network(), metadata.Network) {
+			return nil, E.New(metadata.Network, " is not supported by default outbound: ", defaultOutbound.Tag())
+		}
+		directRouteOutbound = defaultOutbound.(adapter.DirectRouteOutbound)
+	}
+	if metadata.Destination.IsDomain() {
+		if len(metadata.DestinationAddresses) == 0 {
+			var strategy C.DomainStrategy
+			if metadata.Source.IsIPv4() {
+				strategy = C.DomainStrategyIPv4Only
+			} else {
+				strategy = C.DomainStrategyIPv6Only
+			}
+			err = r.actionResolve(r.ctx, &metadata, &R.RuleActionResolve{
+				Strategy: strategy,
+			})
+			if err != nil {
+				return nil, err
+			}
+		}
+		var newDestination netip.Addr
+		if metadata.Source.IsIPv4() {
+			for _, address := range metadata.DestinationAddresses {
+				if address.Is4() {
+					newDestination = address
+					break
+				}
+			}
+		} else {
+			for _, address := range metadata.DestinationAddresses {
+				if address.Is6() {
+					newDestination = address
+					break
+				}
+			}
+		}
+		if !newDestination.IsValid() {
+			if metadata.Source.IsIPv4() {
+				return nil, E.New("no IPv4 address found for domain: ", metadata.Destination.Fqdn)
+			} else {
+				return nil, E.New("no IPv6 address found for domain: ", metadata.Destination.Fqdn)
+			}
+		}
+		metadata.Destination = M.Socksaddr{
+			Addr: newDestination,
+		}
+		routeContext = ping.NewContextDestinationWriter(routeContext, metadata.OriginDestination.Addr)
+		var routeDestination tun.DirectRouteDestination
+		routeDestination, err = directRouteOutbound.NewDirectRouteConnection(metadata, routeContext, timeout)
+		if err != nil {
+			return nil, err
+		}
+		return ping.NewDestinationWriter(routeDestination, newDestination), nil
+	}
+	return directRouteOutbound.NewDirectRouteConnection(metadata, routeContext, timeout)
+}
+
+func (r *Router) matchRule(
+	ctx context.Context, metadata *adapter.InboundContext, preMatch bool, supportBypass bool,
+	inputConn net.Conn, inputPacketConn N.PacketConn,
+) (
+	selectedRule adapter.Rule, selectedRuleIndex int,
+	buffers []*buf.Buffer, packetBuffers []*N.PacketBuffer, fatalErr error,
+) {
+	if r.processSearcher != nil && metadata.ProcessInfo == nil {
+		var originDestination netip.AddrPort
+		if metadata.OriginDestination.IsValid() {
+			originDestination = metadata.OriginDestination.AddrPort()
+		} else if metadata.Destination.IsIP() {
+			originDestination = metadata.Destination.AddrPort()
+		}
+		processInfo, fErr := r.findProcessInfoCached(ctx, metadata.Network, metadata.Source.AddrPort(), originDestination)
+		if fErr != nil {
+			r.logger.InfoContext(ctx, "failed to search process: ", fErr)
+		} else {
+			if processInfo.ProcessPath != "" {
+				if processInfo.UserName != "" {
+					r.logger.InfoContext(ctx, "found process path: ", processInfo.ProcessPath, ", user: ", processInfo.UserName)
+				} else if processInfo.UserId != -1 {
+					r.logger.InfoContext(ctx, "found process path: ", processInfo.ProcessPath, ", user id: ", processInfo.UserId)
+				} else {
+					r.logger.InfoContext(ctx, "found process path: ", processInfo.ProcessPath)
+				}
+			} else if len(processInfo.AndroidPackageNames) > 0 {
+				r.logger.InfoContext(ctx, "found package name: ", strings.Join(processInfo.AndroidPackageNames, ", "))
+			} else if processInfo.UserId != -1 {
+				if processInfo.UserName != "" {
+					r.logger.InfoContext(ctx, "found user: ", processInfo.UserName)
+				} else {
+					r.logger.InfoContext(ctx, "found user id: ", processInfo.UserId)
+				}
+			}
+			metadata.ProcessInfo = processInfo
+		}
+	}
+	if metadata.Destination.Addr.IsValid() && r.dnsTransport.FakeIP() != nil && r.dnsTransport.FakeIP().Store().Contains(metadata.Destination.Addr) {
+		domain, loaded := r.dnsTransport.FakeIP().Store().Lookup(metadata.Destination.Addr)
+		if !loaded {
+			fatalErr = E.New("missing fakeip record, try enable `experimental.cache_file`")
+			return
+		}
+		if domain != "" {
+			metadata.OriginDestination = metadata.Destination
+			metadata.Destination = M.Socksaddr{
+				Fqdn: domain,
+				Port: metadata.Destination.Port,
+			}
+			metadata.FakeIP = true
+			r.logger.DebugContext(ctx, "found fakeip domain: ", domain)
+		}
+	} else if metadata.Domain == "" {
+		domain, loaded := r.dns.LookupReverseMapping(metadata.Destination.Addr)
+		if loaded {
+			metadata.Domain = domain
+			r.logger.DebugContext(ctx, "found reserve mapped domain: ", metadata.Domain)
+		}
+	}
+	if metadata.Destination.IsIPv4() {
+		metadata.IPVersion = 4
+	} else if metadata.Destination.IsIPv6() {
+		metadata.IPVersion = 6
+	}
+
+match:
+	for currentRuleIndex, currentRule := range r.rules {
+		metadata.ResetRuleCache()
+		if !currentRule.Match(metadata) {
+			continue
+		}
+		if !preMatch {
+			ruleDescription := currentRule.String()
+			if ruleDescription != "" {
+				r.logger.DebugContext(ctx, "match[", currentRuleIndex, "] ", currentRule, " => ", currentRule.Action())
+			} else {
+				r.logger.DebugContext(ctx, "match[", currentRuleIndex, "] => ", currentRule.Action())
+			}
+		} else {
+			switch currentRule.Action().Type() {
+			case C.RuleActionTypeReject:
+				ruleDescription := currentRule.String()
+				if ruleDescription != "" {
+					r.logger.DebugContext(ctx, "pre-match[", currentRuleIndex, "] ", currentRule, " => ", currentRule.Action())
+				} else {
+					r.logger.DebugContext(ctx, "pre-match[", currentRuleIndex, "] => ", currentRule.Action())
+				}
+			}
+		}
+		var routeOptions *R.RuleActionRouteOptions
+		switch action := currentRule.Action().(type) {
+		case *R.RuleActionRoute:
+			routeOptions = &action.RuleActionRouteOptions
+		case *R.RuleActionRouteOptions:
+			routeOptions = action
+		}
+		if routeOptions != nil {
+			// TODO: add nat
+			if (routeOptions.OverrideAddress.IsValid() || routeOptions.OverridePort > 0) && !metadata.RouteOriginalDestination.IsValid() {
+				metadata.RouteOriginalDestination = metadata.Destination
+			}
+			if routeOptions.OverrideAddress.IsValid() {
+				metadata.Destination = M.Socksaddr{
+					Addr: routeOptions.OverrideAddress.Addr,
+					Port: metadata.Destination.Port,
+					Fqdn: routeOptions.OverrideAddress.Fqdn,
+				}
+				metadata.DestinationAddresses = nil
+			}
+			if routeOptions.OverridePort > 0 {
+				metadata.Destination = M.Socksaddr{
+					Addr: metadata.Destination.Addr,
+					Port: routeOptions.OverridePort,
+					Fqdn: metadata.Destination.Fqdn,
+				}
+			}
+			if routeOptions.NetworkStrategy != nil {
+				metadata.NetworkStrategy = routeOptions.NetworkStrategy
+			}
+			if len(routeOptions.NetworkType) > 0 {
+				metadata.NetworkType = routeOptions.NetworkType
+			}
+			if len(routeOptions.FallbackNetworkType) > 0 {
+				metadata.FallbackNetworkType = routeOptions.FallbackNetworkType
+			}
+			if routeOptions.FallbackDelay != 0 {
+				metadata.FallbackDelay = routeOptions.FallbackDelay
+			}
+			if routeOptions.UDPDisableDomainUnmapping {
+				metadata.UDPDisableDomainUnmapping = true
+			}
+			if routeOptions.UDPConnect {
+				metadata.UDPConnect = true
+			}
+			if routeOptions.UDPTimeout > 0 {
+				metadata.UDPTimeout = routeOptions.UDPTimeout
+			}
+			if routeOptions.TLSFragment {
+				metadata.TLSFragment = true
+				metadata.TLSFragmentFallbackDelay = routeOptions.TLSFragmentFallbackDelay
+			}
+			if routeOptions.TLSRecordFragment {
+				metadata.TLSRecordFragment = true
+			}
+		}
+		switch action := currentRule.Action().(type) {
+		case *R.RuleActionSniff:
+			if !preMatch {
+				newBuffer, newPacketBuffers, newErr := r.actionSniff(ctx, metadata, action, inputConn, inputPacketConn, buffers, packetBuffers)
+				if newBuffer != nil {
+					buffers = append(buffers, newBuffer)
+				} else if len(newPacketBuffers) > 0 {
+					packetBuffers = append(packetBuffers, newPacketBuffers...)
+				}
+				if newErr != nil {
+					fatalErr = newErr
+					return
+				}
+			} else if metadata.Network != N.NetworkICMP {
+				selectedRule = currentRule
+				selectedRuleIndex = currentRuleIndex
+				break match
+			}
+		case *R.RuleActionResolve:
+			fatalErr = r.actionResolve(ctx, metadata, action)
+			if fatalErr != nil {
+				return
+			}
+		}
+		actionType := currentRule.Action().Type()
+		if actionType == C.RuleActionTypeRoute ||
+			actionType == C.RuleActionTypeReject ||
+			actionType == C.RuleActionTypeHijackDNS {
+			selectedRule = currentRule
+			selectedRuleIndex = currentRuleIndex
+			break match
+		}
+		if actionType == C.RuleActionTypeBypass {
+			bypassAction := currentRule.Action().(*R.RuleActionBypass)
+			if !supportBypass && bypassAction.Outbound == "" {
+				continue match
+			}
+			selectedRule = currentRule
+			selectedRuleIndex = currentRuleIndex
+			break match
+		}
+	}
+	return
+}
+
+func (r *Router) actionSniff(
+	ctx context.Context, metadata *adapter.InboundContext, action *R.RuleActionSniff,
+	inputConn net.Conn, inputPacketConn N.PacketConn, inputBuffers []*buf.Buffer, inputPacketBuffers []*N.PacketBuffer,
+) (buffer *buf.Buffer, packetBuffers []*N.PacketBuffer, fatalErr error) {
+	if sniff.Skip(metadata) {
+		r.logger.DebugContext(ctx, "sniff skipped due to port considered as server-first")
+		return
+	} else if metadata.Protocol != "" {
+		r.logger.DebugContext(ctx, "duplicate sniff skipped")
+		return
+	}
+	if inputConn != nil {
+		if len(action.StreamSniffers) == 0 && len(action.PacketSniffers) > 0 {
+			return
+		} else if slices.Equal(metadata.SnifferNames, action.SnifferNames) && metadata.SniffError != nil && !errors.Is(metadata.SniffError, sniff.ErrNeedMoreData) {
+			r.logger.DebugContext(ctx, "packet sniff skipped due to previous error: ", metadata.SniffError)
+			return
+		}
+		var streamSniffers []sniff.StreamSniffer
+		if len(action.StreamSniffers) > 0 {
+			streamSniffers = action.StreamSniffers
+		} else {
+			streamSniffers = []sniff.StreamSniffer{
+				sniff.TLSClientHello,
+				sniff.HTTPHost,
+				sniff.StreamDomainNameQuery,
+				sniff.BitTorrent,
+				sniff.SSH,
+				sniff.RDP,
+			}
+		}
+		sniffBuffer := buf.NewPacket()
+		err := sniff.PeekStream(
+			ctx,
+			metadata,
+			inputConn,
+			inputBuffers,
+			sniffBuffer,
+			action.Timeout,
+			streamSniffers...,
+		)
+		metadata.SnifferNames = action.SnifferNames
+		metadata.SniffError = err
+		if err == nil {
+			//goland:noinspection GoDeprecation
+			if action.OverrideDestination && M.IsDomainName(metadata.Domain) {
+				metadata.Destination = M.Socksaddr{
+					Fqdn: metadata.Domain,
+					Port: metadata.Destination.Port,
+				}
+			}
+			if metadata.Domain != "" && metadata.Client != "" {
+				r.logger.DebugContext(ctx, "sniffed protocol: ", metadata.Protocol, ", domain: ", metadata.Domain, ", client: ", metadata.Client)
+			} else if metadata.Domain != "" {
+				r.logger.DebugContext(ctx, "sniffed protocol: ", metadata.Protocol, ", domain: ", metadata.Domain)
+			} else {
+				r.logger.DebugContext(ctx, "sniffed protocol: ", metadata.Protocol)
+			}
+		}
+		if !sniffBuffer.IsEmpty() {
+			buffer = sniffBuffer
+		} else {
+			sniffBuffer.Release()
+		}
+	} else if inputPacketConn != nil {
+		if len(action.PacketSniffers) == 0 && len(action.StreamSniffers) > 0 {
+			return
+		} else if slices.Equal(metadata.SnifferNames, action.SnifferNames) && metadata.SniffError != nil && !errors.Is(metadata.SniffError, sniff.ErrNeedMoreData) {
+			r.logger.DebugContext(ctx, "packet sniff skipped due to previous error: ", metadata.SniffError)
+			return
+		}
+		quicMoreData := func() bool {
+			return slices.Equal(metadata.SnifferNames, action.SnifferNames) && errors.Is(metadata.SniffError, sniff.ErrNeedMoreData)
+		}
+		var packetSniffers []sniff.PacketSniffer
+		if len(action.PacketSniffers) > 0 {
+			packetSniffers = action.PacketSniffers
+		} else {
+			packetSniffers = []sniff.PacketSniffer{
+				sniff.DomainNameQuery,
+				sniff.QUICClientHello,
+				sniff.STUNMessage,
+				sniff.UTP,
+				sniff.UDPTracker,
+				sniff.DTLSRecord,
+				sniff.NTP,
+			}
+		}
+		var err error
+		for _, packetBuffer := range inputPacketBuffers {
+			if quicMoreData() {
+				err = sniff.PeekPacket(
+					ctx,
+					metadata,
+					packetBuffer.Buffer.Bytes(),
+					sniff.QUICClientHello,
+				)
+			} else {
+				err = sniff.PeekPacket(
+					ctx, metadata,
+					packetBuffer.Buffer.Bytes(),
+					packetSniffers...,
+				)
+			}
+			metadata.SnifferNames = action.SnifferNames
+			metadata.SniffError = err
+			if errors.Is(err, sniff.ErrNeedMoreData) {
+				// TODO: replace with generic message when there are more multi-packet protocols
+				r.logger.DebugContext(ctx, "attempt to sniff fragmented QUIC client hello")
+				continue
+			}
+			goto finally
+		}
+		packetBuffers = inputPacketBuffers
+		for {
+			var (
+				sniffBuffer = buf.NewPacket()
+				destination M.Socksaddr
+				done        = make(chan struct{})
+			)
+			go func() {
+				sniffTimeout := C.ReadPayloadTimeout
+				if action.Timeout > 0 {
+					sniffTimeout = action.Timeout
+				}
+				inputPacketConn.SetReadDeadline(time.Now().Add(sniffTimeout))
+				destination, err = inputPacketConn.ReadPacket(sniffBuffer)
+				inputPacketConn.SetReadDeadline(time.Time{})
+				close(done)
+			}()
+			select {
+			case <-done:
+			case <-ctx.Done():
+				inputPacketConn.Close()
+				fatalErr = ctx.Err()
+				return
+			}
+			if err != nil {
+				sniffBuffer.Release()
+				if !errors.Is(err, context.DeadlineExceeded) {
+					fatalErr = err
+					return
+				}
+			} else {
+				if quicMoreData() {
+					err = sniff.PeekPacket(
+						ctx,
+						metadata,
+						sniffBuffer.Bytes(),
+						sniff.QUICClientHello,
+					)
+				} else {
+					err = sniff.PeekPacket(
+						ctx, metadata,
+						sniffBuffer.Bytes(),
+						packetSniffers...,
+					)
+				}
+				packetBuffer := N.NewPacketBuffer()
+				*packetBuffer = N.PacketBuffer{
+					Buffer:      sniffBuffer,
+					Destination: destination,
+				}
+				packetBuffers = append(packetBuffers, packetBuffer)
+				metadata.SnifferNames = action.SnifferNames
+				metadata.SniffError = err
+				if errors.Is(err, sniff.ErrNeedMoreData) {
+					// TODO: replace with generic message when there are more multi-packet protocols
+					r.logger.DebugContext(ctx, "attempt to sniff fragmented QUIC client hello")
+					continue
+				}
+			}
+			goto finally
+		}
+	finally:
+		if err == nil {
+			//goland:noinspection GoDeprecation
+			if action.OverrideDestination && M.IsDomainName(metadata.Domain) {
+				metadata.Destination = M.Socksaddr{
+					Fqdn: metadata.Domain,
+					Port: metadata.Destination.Port,
+				}
+			}
+			if metadata.Domain != "" && metadata.Client != "" {
+				r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol, ", domain: ", metadata.Domain, ", client: ", metadata.Client)
+			} else if metadata.Domain != "" {
+				r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol, ", domain: ", metadata.Domain)
+			} else if metadata.Client != "" {
+				r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol, ", client: ", metadata.Client)
+			} else {
+				r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol)
+			}
+		}
+	}
+	return
+}
+
+func (r *Router) actionResolve(ctx context.Context, metadata *adapter.InboundContext, action *R.RuleActionResolve) error {
+	if metadata.Destination.IsDomain() {
+		var transport adapter.DNSTransport
+		if action.Server != "" {
+			var (
+				loaded    bool
+				ambiguous bool
+			)
+			transport, loaded, ambiguous = adapter.LookupDNSTransport(r.dnsTransport, action.Server)
+			if !loaded {
+				if ambiguous {
+					return E.New("DNS server is ambiguous: ", action.Server)
+				}
+				return E.New("DNS server not found: ", action.Server)
+			}
+		}
+		addresses, err := r.dns.Lookup(adapter.WithContext(ctx, metadata), metadata.Destination.Fqdn, adapter.DNSQueryOptions{
+			Transport:    transport,
+			Strategy:     action.Strategy,
+			DisableCache: action.DisableCache,
+			RewriteTTL:   action.RewriteTTL,
+			ClientSubnet: action.ClientSubnet,
+		})
+		if err != nil {
+			return err
+		}
+		metadata.DestinationAddresses = addresses
+		r.logger.DebugContext(ctx, "resolved [", strings.Join(F.MapToString(metadata.DestinationAddresses), " "), "]")
+	}
+	return nil
+}