refactor: DNS

experimental/libbox/dns.go

@@ -6,7 +6,10 @@ import (
 	"strings"
 	"syscall"
 
-	"github.com/sagernet/sing-dns"
+	"github.com/sagernet/sing-box/adapter"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/dns"
+	"github.com/sagernet/sing-box/option"
 	"github.com/sagernet/sing/common"
 	E "github.com/sagernet/sing/common/exceptions"
 	M "github.com/sagernet/sing/common/metadata"
@@ -21,118 +24,80 @@ type LocalDNSTransport interface {
 	Exchange(ctx *ExchangeContext, message []byte) error
 }
 
-func RegisterLocalDNSTransport(transport LocalDNSTransport) {
-	if transport == nil {
-		dns.RegisterTransport([]string{"local"}, func(options dns.TransportOptions) (dns.Transport, error) {
-			return dns.NewLocalTransport(options), nil
-		})
-	} else {
-		dns.RegisterTransport([]string{"local"}, func(options dns.TransportOptions) (dns.Transport, error) {
-			return &platformLocalDNSTransport{
-				iif: transport,
-			}, nil
-		})
-	}
-}
+var _ adapter.DNSTransport = (*platformTransport)(nil)
 
-var _ dns.Transport = (*platformLocalDNSTransport)(nil)
-
-type platformLocalDNSTransport struct {
+type platformTransport struct {
+	dns.TransportAdapter
 	iif LocalDNSTransport
 }
 
-func (p *platformLocalDNSTransport) Name() string {
-	return "local"
-}
-
-func (p *platformLocalDNSTransport) Start() error {
-	return nil
-}
-
-func (p *platformLocalDNSTransport) Reset() {
-}
-
-func (p *platformLocalDNSTransport) Close() error {
-	return nil
-}
-
-func (p *platformLocalDNSTransport) Raw() bool {
-	return p.iif.Raw()
-}
-
-func (p *platformLocalDNSTransport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg, error) {
-	messageBytes, err := message.Pack()
-	if err != nil {
-		return nil, err
+func newPlatformTransport(iif LocalDNSTransport, tag string, options option.LocalDNSServerOptions) *platformTransport {
+	return &platformTransport{
+		TransportAdapter: dns.NewTransportAdapterWithLocalOptions(C.DNSTypeLocal, tag, options),
+		iif:              iif,
 	}
+}
+
+func (p *platformTransport) Reset() {
+}
+
+func (p *platformTransport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg, error) {
 	response := &ExchangeContext{
 		context: ctx,
 	}
-	var responseMessage *mDNS.Msg
-	var group task.Group
-	group.Append0(func(ctx context.Context) error {
-		err = p.iif.Exchange(response, messageBytes)
+	if p.iif.Raw() {
+		messageBytes, err := message.Pack()
 		if err != nil {
-			return err
+			return nil, err
 		}
-		if response.error != nil {
-			return response.error
-		}
-		responseMessage = &response.message
-		return nil
-	})
-	err = group.Run(ctx)
-	if err != nil {
-		return nil, err
-	}
-	return responseMessage, nil
-}
-
-func (p *platformLocalDNSTransport) Lookup(ctx context.Context, domain string, strategy dns.DomainStrategy) ([]netip.Addr, error) {
-	var network string
-	switch strategy {
-	case dns.DomainStrategyUseIPv4:
-		network = "ip4"
-	case dns.DomainStrategyPreferIPv6:
-		network = "ip6"
-	default:
-		network = "ip"
-	}
-	response := &ExchangeContext{
-		context: ctx,
-	}
-	var responseAddr []netip.Addr
-	var group task.Group
-	group.Append0(func(ctx context.Context) error {
-		err := p.iif.Lookup(response, network, domain)
+		var responseMessage *mDNS.Msg
+		var group task.Group
+		group.Append0(func(ctx context.Context) error {
+			err = p.iif.Exchange(response, messageBytes)
+			if err != nil {
+				return err
+			}
+			if response.error != nil {
+				return response.error
+			}
+			responseMessage = &response.message
+			return nil
+		})
+		err = group.Run(ctx)
 		if err != nil {
-			return err
+			return nil, err
 		}
-		if response.error != nil {
-			return response.error
-		}
-		switch strategy {
-		case dns.DomainStrategyUseIPv4:
-			responseAddr = common.Filter(response.addresses, func(it netip.Addr) bool {
-				return it.Is4()
-			})
-		case dns.DomainStrategyPreferIPv6:
-			responseAddr = common.Filter(response.addresses, func(it netip.Addr) bool {
-				return it.Is6()
-			})
+		return responseMessage, nil
+	} else {
+		question := message.Question[0]
+		var network string
+		switch question.Qtype {
+		case mDNS.TypeA:
+			network = "ip4"
+		case mDNS.TypeAAAA:
+			network = "ip6"
 		default:
-			responseAddr = response.addresses
+			return nil, E.New("only IP queries are supported by current version of Android")
 		}
-		/*if len(responseAddr) == 0 {
-			response.error = dns.RCodeSuccess
-		}*/
-		return nil
-	})
-	err := group.Run(ctx)
-	if err != nil {
-		return nil, err
+		var responseAddrs []netip.Addr
+		var group task.Group
+		group.Append0(func(ctx context.Context) error {
+			err := p.iif.Lookup(response, network, question.Name)
+			if err != nil {
+				return err
+			}
+			if response.error != nil {
+				return response.error
+			}
+			responseAddrs = response.addresses
+			return nil
+		})
+		err := group.Run(ctx)
+		if err != nil {
+			return nil, err
+		}
+		return dns.FixedResponse(message.Id, question, responseAddrs, C.DefaultDNSTTL), nil
 	}
-	return responseAddr, nil
 }
 
 type Func interface {