refactor: Modular inbounds/outbounds

protocol/dns/outbound.go

@@ -0,0 +1,61 @@
+package dns
+
+import (
+	"context"
+	"net"
+	"os"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/adapter/outbound"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func RegisterOutbound(registry *outbound.Registry) {
+	outbound.Register[option.StubOptions](registry, C.TypeDNS, NewOutbound)
+}
+
+type Outbound struct {
+	outbound.Adapter
+	router adapter.Router
+	logger logger.ContextLogger
+}
+
+func NewOutbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.StubOptions) (adapter.Outbound, error) {
+	return &Outbound{
+		Adapter: outbound.NewAdapter(C.TypeDNS, []string{N.NetworkTCP, N.NetworkUDP}, tag, nil),
+		router:  router,
+		logger:  logger,
+	}, nil
+}
+
+func (d *Outbound) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	return nil, os.ErrInvalid
+}
+
+func (d *Outbound) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	return nil, os.ErrInvalid
+}
+
+// Deprecated
+func (d *Outbound) NewConnection(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
+	metadata.Destination = M.Socksaddr{}
+	defer conn.Close()
+	for {
+		conn.SetReadDeadline(time.Now().Add(C.DNSTimeout))
+		err := HandleStreamDNSRequest(ctx, d.router, conn, metadata)
+		if err != nil {
+			return err
+		}
+	}
+}
+
+// Deprecated
+func (d *Outbound) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata adapter.InboundContext) error {
+	return NewDNSPacketConnection(ctx, d.router, conn, nil, metadata)
+}