修复DNS逻辑错误的问题

2026-04-16 21:40:39 +08:00
parent 830944682f
commit 95b664a772
9 changed files with 1700 additions and 6 deletions
--- a/dns/router.go
+++ b/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
--- a/dns/router.go.7853130561294400935
+++ b/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()
+	}
+}
--- a/dns/transport_dialer.go
+++ b/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))
--- a/dns/transport_dialer.go.6124520021629164267
+++ b/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
+}