WIP: prepare for testing

backend_udp.go

@@ -119,7 +119,7 @@ func (b *backendUDP) createRelSend(clientAddr string, buf []byte) (udpRel, error
 		return rel, fmt.Errorf("create udp relation and send message: dial udp: %w", err)
 	}
 
-	if n, err = udpConn.Write(buf); err != nil && n == 0 {
+	if n, err = udpConn.WriteTo(buf, b.cfg.BackendAddr()); err != nil && n == 0 {
 		_ = udpConn.Close()
 		return rel, fmt.Errorf("create udp relation and send message: write udp: %w", err)
 	}
@@ -130,6 +130,23 @@ func (b *backendUDP) createRelSend(clientAddr string, buf []byte) (udpRel, error
 	return rel, nil
 }
 
+func (b *backendUDP) relSend(rel udpRel, buf []byte) error {
+	var (
+		n   int
+		err error
+	)
+
+	if n, err = rel.backend.WriteTo(buf, b.cfg.BackendAddr()); err != nil && n == 0 {
+		return fmt.Errorf("relSend: %w", err)
+	}
+
+	if len(buf) != n {
+		log.Error().Msg("relSend mismatch size")
+	}
+
+	return nil
+}
+
 func (b *backendUDP) handle(wg *sync.WaitGroup, ctx context.Context, msg udpMessage) {
 	var (
 		rel udpRel
@@ -139,9 +156,15 @@ func (b *backendUDP) handle(wg *sync.WaitGroup, ctx context.Context, msg udpMess
 
 	if rel, ok = b.findRel(msg.addr); !ok {
 		if rel, err = b.createRelSend(msg.addr, msg.buf.Bytes()); err != nil {
+			msg.buf.Reset()
+			b.bufPool.Put(msg.buf)
 			log.Error().Err(err).Str(DIRECTION, CLIENT_TO_BACKEND).Msg("establish relation with udp backend")
+			return
 		}
 
+		msg.buf.Reset()
+		b.bufPool.Put(msg.buf)
+
 		rel.ctx, rel.ctxCancel = context.WithCancel(ctx)
 		b.addUpdateRel(msg.addr, rel)
 
@@ -150,9 +173,18 @@ func (b *backendUDP) handle(wg *sync.WaitGroup, ctx context.Context, msg udpMess
 		return
 	}
 
-	_ = rel
-	//TODO: handle existing valid client
+	if err = b.relSend(rel, msg.buf.Bytes()); err != nil {
+		msg.buf.Reset()
+		b.bufPool.Put(msg.buf)
+		log.Error().Err(err).Msg("handle: send for existing relation")
+		return
+	}
 
+	msg.buf.Reset()
+	b.bufPool.Put(msg.buf)
+
+	rel.expiry = time.Now().Add(b.cfg.Timeout())
+	b.addUpdateRel(rel.clientAddr, rel)
 }
 
 func (b *backendUDP) Send(ctx context.Context, addr string, p []byte) error {