Add dns client

dns/transport_base.go

@@ -0,0 +1,46 @@
+package dns
+
+import (
+	"context"
+	"net/netip"
+	"os"
+	"sync"
+
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+)
+
+type myTransportAdapter struct {
+	ctx         context.Context
+	dialer      N.Dialer
+	logger      log.Logger
+	destination M.Socksaddr
+	done        chan struct{}
+	access      sync.RWMutex
+	connection  *dnsConnection
+}
+
+func (t *myTransportAdapter) Start() error {
+	return nil
+}
+
+func (t *myTransportAdapter) Close() error {
+	select {
+	case <-t.done:
+		return os.ErrClosed
+	default:
+	}
+	close(t.done)
+	return nil
+}
+
+func (t *myTransportAdapter) Raw() bool {
+	return true
+}
+
+func (t *myTransportAdapter) Lookup(ctx context.Context, domain string, strategy C.DomainStrategy) ([]netip.Addr, error) {
+	return nil, os.ErrInvalid
+}