tcp: make newreno byte instead of acks dependent

Should be more resilient to ack losses

Change-Id: Icec3b93c1d290dec437fcc4e6fe5171906c9ba8a
Signed-off-by: Florin Coras <fcoras@cisco.com>

4 files changed, 28 insertions, 3 deletions

diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h
index 9606a0e1d15..8a6f74ab13a 100644
--- a/src/vnet/tcp/tcp.h
+++ b/src/vnet/tcp/tcp.h
@@ -283,6 +283,7 @@ typedef struct _tcp_connection
 
   /* Congestion control */
   u32 cwnd;		/**< Congestion window */
+  u32 cwnd_acc_bytes;	/**< Bytes accumulated for cwnd increment */
   u32 ssthresh;		/**< Slow-start threshold */
   u32 prev_ssthresh;	/**< ssthresh before congestion */
   u32 prev_cwnd;	/**< ssthresh before congestion */
diff --git a/src/vnet/tcp/tcp_debug.h b/src/vnet/tcp/tcp_debug.h
index e37b3cd9a9b..d35691173c1 100755
--- a/src/vnet/tcp/tcp_debug.h
+++ b/src/vnet/tcp/tcp_debug.h
@@ -721,7 +721,7 @@ if (_tc->c_cc_stat_tstamp + STATS_INTERVAL < tcp_time_now())		\
 {									\
   ELOG_TYPE_DECLARE (_e) =						\
   {									\
-    .format = "rto_stat: rto %u srtt %u rttvar %u ",			\
+    .format = "rcv_stat: rto %u srtt %u rttvar %u ",			\
     .format_args = "i4i4i4",						\
   };									\
   DECLARE_ETD(_tc, _e, 3);						\
@@ -730,6 +730,23 @@ if (_tc->c_cc_stat_tstamp + STATS_INTERVAL < tcp_time_now())		\
   ed->data[2] = _tc->rttvar;						\
 }									\
 }
+#define TCP_EVT_CC_SND_STAT_HANDLER(_tc, ...)				\
+{									\
+if (_tc->c_cc_stat_tstamp + STATS_INTERVAL < tcp_time_now())		\
+{									\
+  ELOG_TYPE_DECLARE (_e) =						\
+  {									\
+    .format = "snd_stat: dack %u sacked %u lost %u out %u rxt %u",	\
+    .format_args = "i4i4i4i4i4",					\
+  };									\
+  DECLARE_ETD(_tc, _e, 5);						\
+  ed->data[0] = _tc->rcv_dupacks;					\
+  ed->data[1] = _tc->sack_sb.sacked_bytes;				\
+  ed->data[2] = _tc->sack_sb.lost_bytes;				\
+  ed->data[3] = tcp_bytes_out (_tc);					\
+  ed->data[3] = _tc->snd_rxt_bytes;					\
+}									\
+}
 
 #define TCP_EVT_CC_STAT_HANDLER(_tc, ...)				\
 {									\
diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index 5a1e84f3569..a1cdc76c626 100644
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -941,6 +941,7 @@ tcp_cc_init_congestion (tcp_connection_t * tc)
 {
   tcp_fastrecovery_on (tc);
   tc->snd_congestion = tc->snd_una_max;
+  tc->cwnd_acc_bytes = 0;
   tc->cc_algo->congestion (tc);
   TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
 }
diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c
index 103fea4c194..7ae7f484b56 100644
--- a/src/vnet/tcp/tcp_newreno.c
+++ b/src/vnet/tcp/tcp_newreno.c
@@ -36,8 +36,14 @@ newreno_rcv_ack (tcp_connection_t * tc)
     }
   else
     {
-      /* Round up to 1 if needed */
-      tc->cwnd += clib_max ((tc->snd_mss * tc->snd_mss) / tc->cwnd, 1);
+      /* tc->cwnd += clib_max ((tc->snd_mss * tc->snd_mss) / tc->cwnd, 1); */
+      tc->cwnd_acc_bytes += tc->bytes_acked;
+      if (tc->cwnd_acc_bytes >= tc->cwnd)
+	{
+	  u32 inc = tc->cwnd_acc_bytes / tc->cwnd;
+	  tc->cwnd += inc * tc->snd_mss;
+	  tc->cwnd_acc_bytes -= inc * tc->cwnd;
+	}
     }
 }