Merge branch 'stable/1710' of https://gerrit.fd.io/r/vpp into 17101710

1 files changed, 107 insertions, 0 deletions

diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c
new file mode 100644
index 00000000..103fea4c
--- /dev/null
+++ b/src/vnet/tcp/tcp_newreno.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/tcp/tcp.h>
+
+void
+newreno_congestion (tcp_connection_t * tc)
+{
+  tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss);
+}
+
+void
+newreno_recovered (tcp_connection_t * tc)
+{
+  tc->cwnd = tc->ssthresh;
+}
+
+void
+newreno_rcv_ack (tcp_connection_t * tc)
+{
+  if (tcp_in_slowstart (tc))
+    {
+      tc->cwnd += clib_min (tc->snd_mss, tc->bytes_acked);
+    }
+  else
+    {
+      /* Round up to 1 if needed */
+      tc->cwnd += clib_max ((tc->snd_mss * tc->snd_mss) / tc->cwnd, 1);
+    }
+}
+
+void
+newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type)
+{
+  if (ack_type == TCP_CC_DUPACK)
+    {
+      if (!tcp_opts_sack_permitted (tc))
+	tc->cwnd += tc->snd_mss;
+    }
+  else if (ack_type == TCP_CC_PARTIALACK)
+    {
+      /* RFC 6582 Sec. 3.2 */
+      if (!tcp_opts_sack_permitted (&tc->rcv_opts))
+	{
+	  /* Deflate the congestion window by the amount of new data
+	   * acknowledged by the Cumulative Acknowledgment field.
+	   * If the partial ACK acknowledges at least one SMSS of new data,
+	   * then add back SMSS bytes to the congestion window. This
+	   * artificially inflates the congestion window in order to reflect
+	   * the additional segment that has left the network. This "partial
+	   * window deflation" attempts to ensure that, when fast recovery
+	   * eventually ends, approximately ssthresh amount of data will be
+	   * outstanding in the network.*/
+	  tc->cwnd = (tc->cwnd > tc->bytes_acked + tc->snd_mss) ?
+	    tc->cwnd - tc->bytes_acked : tc->snd_mss;
+	  if (tc->bytes_acked > tc->snd_mss)
+	    tc->cwnd += tc->snd_mss;
+	}
+    }
+}
+
+void
+newreno_conn_init (tcp_connection_t * tc)
+{
+  tc->ssthresh = tc->snd_wnd;
+  tc->cwnd = tcp_initial_cwnd (tc);
+}
+
+const static tcp_cc_algorithm_t tcp_newreno = {
+  .congestion = newreno_congestion,
+  .recovered = newreno_recovered,
+  .rcv_ack = newreno_rcv_ack,
+  .rcv_cong_ack = newreno_rcv_cong_ack,
+  .init = newreno_conn_init
+};
+
+clib_error_t *
+newreno_init (vlib_main_t * vm)
+{
+  clib_error_t *error = 0;
+
+  tcp_cc_algo_register (TCP_CC_NEWRENO, &tcp_newreno);
+
+  return error;
+}
+
+VLIB_INIT_FUNCTION (newreno_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */