First Commmit

experimental/libbox/dns.go

@@ -0,0 +1,150 @@
+package libbox
+
+import (
+	"context"
+	"net/netip"
+	"strings"
+	"syscall"
+
+	"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"
+	"github.com/sagernet/sing/common/task"
+
+	mDNS "github.com/miekg/dns"
+)
+
+type LocalDNSTransport interface {
+	Raw() bool
+	Lookup(ctx *ExchangeContext, network string, domain string) error
+	Exchange(ctx *ExchangeContext, message []byte) error
+}
+
+var _ adapter.DNSTransport = (*platformTransport)(nil)
+
+type platformTransport struct {
+	dns.TransportAdapter
+	iif LocalDNSTransport
+}
+
+func newPlatformTransport(iif LocalDNSTransport, tag string, options option.LocalDNSServerOptions) *platformTransport {
+	return &platformTransport{
+		TransportAdapter: dns.NewTransportAdapterWithLocalOptions(C.DNSTypeLocal, tag, options),
+		iif:              iif,
+	}
+}
+
+func (p *platformTransport) Start(stage adapter.StartStage) error {
+	return nil
+}
+
+func (p *platformTransport) Close() error {
+	return nil
+}
+
+func (p *platformTransport) Reset() {
+}
+
+func (p *platformTransport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg, error) {
+	response := &ExchangeContext{
+		context: ctx,
+	}
+	if p.iif.Raw() {
+		messageBytes, err := message.Pack()
+		if err != nil {
+			return nil, err
+		}
+		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 nil, err
+		}
+		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:
+			return nil, E.New("only IP queries are supported by current version of Android")
+		}
+		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
+	}
+}
+
+type Func interface {
+	Invoke() error
+}
+
+type ExchangeContext struct {
+	context   context.Context
+	message   mDNS.Msg
+	addresses []netip.Addr
+	error     error
+}
+
+func (c *ExchangeContext) OnCancel(callback Func) {
+	go func() {
+		<-c.context.Done()
+		callback.Invoke()
+	}()
+}
+
+func (c *ExchangeContext) Success(result string) {
+	c.addresses = common.Map(common.Filter(strings.Split(result, "\n"), func(it string) bool {
+		return !common.IsEmpty(it)
+	}), func(it string) netip.Addr {
+		return M.ParseSocksaddrHostPort(it, 0).Unwrap().Addr
+	})
+}
+
+func (c *ExchangeContext) RawSuccess(result []byte) {
+	err := c.message.Unpack(result)
+	if err != nil {
+		c.error = E.Cause(err, "parse response")
+	}
+}
+
+func (c *ExchangeContext) ErrorCode(code int32) {
+	c.error = dns.RcodeError(code)
+}
+
+func (c *ExchangeContext) ErrnoCode(code int32) {
+	c.error = syscall.Errno(code)
+}