VPP-598: tcp stack initial commit

Change-Id: I49e5ce0aae6e4ff634024387ceaf7dbc432a0351
Signed-off-by: Dave Barach <dave@barachs.net>
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c
new file mode 100644
index 00000000000..856dffe4af9
--- /dev/null
+++ b/src/vnet/tcp/tcp_newreno.c
@@ -0,0 +1,93 @@
+/*
+ * 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->prev_ssthresh = tc->ssthresh;
+  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)
+    {
+      tc->cwnd += tc->snd_mss;
+    }
+  else if (ack_type == TCP_CC_PARTIALACK)
+    {
+      tc->cwnd -= tc->bytes_acked;
+      if (tc->bytes_acked > tc->snd_mss)
+	tc->bytes_acked += 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:
+ */