Add dns client

adapter/dns.go

@@ -0,0 +1,22 @@
+package adapter
+
+import (
+	"context"
+	"net/netip"
+
+	C "github.com/sagernet/sing-box/constant"
+
+	"golang.org/x/net/dns/dnsmessage"
+)
+
+type DNSClient interface {
+	Exchange(ctx context.Context, transport DNSTransport, message *dnsmessage.Message) (*dnsmessage.Message, error)
+	Lookup(ctx context.Context, transport DNSTransport, domain string, strategy C.DomainStrategy) ([]netip.Addr, error)
+}
+
+type DNSTransport interface {
+	Service
+	Raw() bool
+	Exchange(ctx context.Context, message *dnsmessage.Message) (*dnsmessage.Message, error)
+	Lookup(ctx context.Context, domain string, strategy C.DomainStrategy) ([]netip.Addr, error)
+}

adapter/router.go

@@ -13,6 +13,7 @@ import (
 type Router interface {
 	Service
 	Outbound(tag string) (Outbound, bool)
+	DefaultOutbound(network string) Outbound
 	RouteConnection(ctx context.Context, conn net.Conn, metadata InboundContext) error
 	RoutePacketConnection(ctx context.Context, conn N.PacketConn, metadata InboundContext) error
 	GeoIPReader() *geoip.Reader