From dfd980fcffacc2bed90e53b9da669eac53025bb2 Mon Sep 17 00:00:00 2001
From: Florin Coras <fcoras@cisco.com>
Date: Thu, 26 Mar 2020 02:45:39 +0000
Subject: [PATCH] tcp: count zero wnd enqueue attempts

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: If22bad96a9102bc4058d52fc8565bd6a14c3c66c
---
 src/vnet/tcp/tcp_input.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index bc11461b521..86158b9d6c6 100755
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -1942,6 +1942,10 @@ tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
     }
   else
     {
+      /* Packet made it through for ack processing */
+      if (tc->rcv_wnd < tc->snd_mss)
+	return TCP_ERROR_ZERO_RWND;
+
       return TCP_ERROR_FIFO_FULL;
     }
 
-- 
2.16.6