From 209c593a00408af13756a578a654cc133429e4b3 Mon Sep 17 00:00:00 2001
From: Ghostyhands <1248424-Ghostyhands@users.noreply.gitlab.com>
Date: Sun, 28 Jul 2024 19:18:27 +0000
Subject: [PATCH] tcp: (merges !2083) Consider segmentSize send limit while
 checking for cwnd rate-limit

---
 src/internet/model/tcp-socket-base.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/internet/model/tcp-socket-base.cc b/src/internet/model/tcp-socket-base.cc
index 499c716a2..874b3fdff 100644
--- a/src/internet/model/tcp-socket-base.cc
+++ b/src/internet/model/tcp-socket-base.cc
@@ -3259,7 +3259,8 @@ TcpSocketBase::SendDataPacket(SequenceNumber32 seq, uint32_t maxSize, bool withA
     // This is a simple version of Linux tcp_cwnd_validate() but following
     // the principle implemented in Linux that limits the updating of cwnd
     // (in the congestion controls) when flight size is >= cwnd
-    m_tcb->m_isCwndLimited = (BytesInFlight() >= m_tcb->m_cWnd);
+    // send will also be cwnd limited if less then one segment of cwnd is available
+    m_tcb->m_isCwndLimited = (m_tcb->m_cWnd < BytesInFlight() + m_tcb->m_segmentSize);
 
     UpdateRttHistory(seq, sz, isRetransmission);