tcp: req app deq notification on fifo full

If fifo full, default to requesting an app deq notification and forcing
an ack (window update) if zero rcv window sent is still active.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Iade7e1722503da149c62c465c472edbb0a5599f7
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 928e824..dac50b5 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -463,7 +463,10 @@
   vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
 
   if (wnd == 0)
-    tcp_zero_rwnd_sent_on (tc);
+    {
+      transport_rx_fifo_req_deq_ntf (&tc->connection);
+      tcp_zero_rwnd_sent_on (tc);
+    }
   else
     tcp_zero_rwnd_sent_off (tc);
 }