Wire things altogether

proxy/middle.go

@@ -0,0 +1,60 @@
+package proxy
+
+import (
+	"sync"
+
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/conntypes"
+	"github.com/9seconds/mtg/protocol"
+	"github.com/9seconds/mtg/wrappers/packetack"
+)
+
+func middleConnection(request *protocol.TelegramRequest) error {
+	telegramConn := packetack.NewProxy(request)
+	defer telegramConn.Close()
+
+	var clientConn conntypes.PacketAckFullReadWriteCloser
+	switch request.ClientProtocol.ConnectionType() {
+	case conntypes.ConnectionTypeAbridged:
+		clientConn = packetack.NewClientAbridged(request.ClientConn)
+	case conntypes.ConnectionTypeIntermediate:
+		clientConn = packetack.NewClientIntermediate(request.ClientConn)
+	case conntypes.ConnectionTypeSecure:
+		clientConn = packetack.NewClientIntermediateSecure(request.ClientConn)
+	default:
+		panic("unknown connection type")
+	}
+
+	wg := &sync.WaitGroup{}
+	wg.Add(2)
+
+	go middlePipe(telegramConn, clientConn, wg, request.Logger)
+	go middlePipe(clientConn, telegramConn, wg, request.Logger)
+
+	<-request.Ctx.Done()
+	wg.Wait()
+
+	return request.Ctx.Err()
+}
+
+func middlePipe(dst conntypes.PacketAckWriter,
+	src conntypes.PacketAckReader,
+	wg *sync.WaitGroup,
+	logger *zap.SugaredLogger) {
+	defer wg.Done()
+
+	for {
+		acks := conntypes.ConnectionAcks{}
+		packet, err := src.Read(&acks)
+		if err != nil {
+			logger.Debugw("Cannot read packet", "error", err)
+			return
+		}
+
+		if err = dst.Write(packet, &acks); err != nil {
+			logger.Debugw("Cannot send packet", "error", err)
+			return
+		}
+	}
+}