From c30318da220953610820a2e7cd957da7046eaf4b Mon Sep 17 00:00:00 2001
From: Sergey Ivanushkin <sergey.ivanushkin@enea.com>
Date: Thu, 17 Oct 2019 10:16:27 +0100
Subject: tcp: Init cwnd from ssthresh.

Set high ssthresh out of the box and make configurable

Type: fix

Signed-off-by: Sergey Ivanushkin <sergey.ivanushkin@enea.com>
Change-Id: Iba1549b4ee55e51468ad0b28ef3d26a85fa9cae0
---
 src/vnet/tcp/tcp_cubic.c   |  8 +++++++-
 src/vnet/tcp/tcp_newreno.c | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/src/vnet/tcp/tcp_cubic.c b/src/vnet/tcp/tcp_cubic.c
index 17f7932ea2e..b79ef8342d3 100644
--- a/src/vnet/tcp/tcp_cubic.c
+++ b/src/vnet/tcp/tcp_cubic.c
@@ -23,10 +23,12 @@
 typedef struct cubic_cfg_
 {
   u8 fast_convergence;
+  u32 ssthresh;
 } cubic_cfg_t;
 
 static cubic_cfg_t cubic_cfg = {
   .fast_convergence = 1,
+  .ssthresh = 0x7FFFFFFFU,
 };
 
 typedef struct cubic_data_
@@ -200,7 +202,7 @@ static void
 cubic_conn_init (tcp_connection_t * tc)
 {
   cubic_data_t *cd = (cubic_data_t *) tcp_cc_data (tc);
-  tc->ssthresh = tc->snd_wnd;
+  tc->ssthresh = cubic_cfg.ssthresh;
   tc->cwnd = tcp_initial_cwnd (tc);
   cd->w_max = 0;
   cd->K = 0;
@@ -210,6 +212,8 @@ cubic_conn_init (tcp_connection_t * tc)
 static uword
 cubic_unformat_config (unformat_input_t * input)
 {
+  u32 ssthresh = 0x7FFFFFFFU;
+
   if (!input)
     return 0;
 
@@ -219,6 +223,8 @@ cubic_unformat_config (unformat_input_t * input)
     {
       if (unformat (input, "no-fast-convergence"))
 	cubic_cfg.fast_convergence = 0;
+      else if (unformat (input, "ssthresh %u", &ssthresh))
+	cubic_cfg.ssthresh = ssthresh;
       else
 	return 0;
     }
diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c
index e9213a2e6d9..69dd2247132 100644
--- a/src/vnet/tcp/tcp_newreno.c
+++ b/src/vnet/tcp/tcp_newreno.c
@@ -15,6 +15,15 @@
 
 #include <vnet/tcp/tcp.h>
 
+typedef struct nwreno_cfg_
+{
+  u32 ssthresh;
+} newreno_cfg_t;
+
+static newreno_cfg_t newreno_cfg = {
+  .ssthresh = 0x7FFFFFFFU,
+};
+
 static void
 newreno_congestion (tcp_connection_t * tc)
 {
@@ -82,12 +91,33 @@ newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type,
 static void
 newreno_conn_init (tcp_connection_t * tc)
 {
-  tc->ssthresh = tc->snd_wnd;
+  tc->ssthresh = newreno_cfg.ssthresh;
   tc->cwnd = tcp_initial_cwnd (tc);
 }
 
+static uword
+newreno_unformat_config (unformat_input_t * input)
+{
+  u32 ssthresh = 0x7FFFFFFFU;
+
+  if (!input)
+    return 0;
+
+  unformat_skip_white_space (input);
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "ssthresh %u", &ssthresh))
+	newreno_cfg.ssthresh = ssthresh;
+      else
+	return 0;
+    }
+  return 1;
+}
+
 const static tcp_cc_algorithm_t tcp_newreno = {
   .name = "newreno",
+  .unformat_cfg = newreno_unformat_config,
   .congestion = newreno_congestion,
   .loss = newreno_loss,
   .recovered = newreno_recovered,
-- 
cgit 1.2.3-korg