Add trojan-go multiplex support for trojan inbound

transport/trojan/mux.go

@@ -0,0 +1,66 @@
+package trojan
+
+import (
+	"context"
+	"net"
+
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	"github.com/sagernet/sing/common/rw"
+	"github.com/sagernet/sing/common/task"
+	"github.com/sagernet/smux"
+)
+
+func HandleMuxConnection(ctx context.Context, conn net.Conn, metadata M.Metadata, handler Handler) error {
+	session, err := smux.Server(conn, smuxConfig())
+	if err != nil {
+		return err
+	}
+	var group task.Group
+	group.Append0(func(ctx context.Context) error {
+		var stream net.Conn
+		for {
+			stream, err = session.AcceptStream()
+			if err != nil {
+				return err
+			}
+			go newMuxConnection(ctx, stream, metadata, handler)
+		}
+	})
+	group.Cleanup(func() {
+		session.Close()
+	})
+	return group.Run(ctx)
+}
+
+func newMuxConnection(ctx context.Context, stream net.Conn, metadata M.Metadata, handler Handler) {
+	err := newMuxConnection0(ctx, stream, metadata, handler)
+	if err != nil {
+		handler.NewError(ctx, E.Cause(err, "process trojan-go multiplex connection"))
+	}
+}
+
+func newMuxConnection0(ctx context.Context, stream net.Conn, metadata M.Metadata, handler Handler) error {
+	command, err := rw.ReadByte(stream)
+	if err != nil {
+		return E.Cause(err, "read command")
+	}
+	metadata.Destination, err = M.SocksaddrSerializer.ReadAddrPort(stream)
+	if err != nil {
+		return E.Cause(err, "read destination")
+	}
+	switch command {
+	case CommandTCP:
+		return handler.NewConnection(ctx, stream, metadata)
+	case CommandUDP:
+		return handler.NewPacketConnection(ctx, &PacketConn{stream}, metadata)
+	default:
+		return E.New("unknown command ", command)
+	}
+}
+
+func smuxConfig() *smux.Config {
+	config := smux.DefaultConfig()
+	config.KeepAliveDisabled = true
+	return config
+}