TCP/session improvements

- Added svm fifo flag for tracking fifo dequeue events (replaces event
  length). Updated all code to switch to the new scheme.
- More session debugging
- Fix peek index wrap
- Add a trivial socket test client
- Fast retransmit/cc fixes
- tx and rx SACK fixes and unit testing
- SRTT computation fix
- remove dupack/ack burst filters
- improve ack rx
- improved segment rx
- builtin client test code

Change-Id: Ic4eb2d5ca446eb2260ccd3ccbcdaa73c64e7f4e1
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Barach <dbarach@cisco.com>

2 files changed, 44 insertions, 32 deletions

diff --git a/src/vnet/udp/builtin_server.c b/src/vnet/udp/builtin_server.c
index 46c8e734b3a..57f774c5954 100644
--- a/src/vnet/udp/builtin_server.c
+++ b/src/vnet/udp/builtin_server.c
@@ -39,10 +39,10 @@ builtin_session_disconnect_callback (stream_session_t * s)
 }
 
 static int
-builtin_server_rx_callback (stream_session_t * s, session_fifo_event_t * ep)
+builtin_server_rx_callback (stream_session_t * s)
 {
   svm_fifo_t *rx_fifo, *tx_fifo;
-  u32 this_transfer;
+  u32 this_transfer, max_deq, max_enq;
   int actual_transfer;
   u8 *my_copy_buffer;
   session_fifo_event_t evt;
@@ -52,9 +52,9 @@ builtin_server_rx_callback (stream_session_t * s, session_fifo_event_t * ep)
   rx_fifo = s->server_rx_fifo;
   tx_fifo = s->server_tx_fifo;
 
-  this_transfer = svm_fifo_max_enqueue (tx_fifo)
-    < svm_fifo_max_dequeue (rx_fifo) ?
-    svm_fifo_max_enqueue (tx_fifo) : svm_fifo_max_dequeue (rx_fifo);
+  max_deq = svm_fifo_max_dequeue (rx_fifo);
+  max_enq = svm_fifo_max_enqueue (tx_fifo);
+  this_transfer = max_enq < max_deq ? max_enq : max_deq;
 
   vec_validate (my_copy_buffer, this_transfer - 1);
   _vec_len (my_copy_buffer) = this_transfer;
@@ -64,17 +64,20 @@ builtin_server_rx_callback (stream_session_t * s, session_fifo_event_t * ep)
   ASSERT (actual_transfer == this_transfer);
   actual_transfer = svm_fifo_enqueue_nowait (tx_fifo, 0, this_transfer,
 					     my_copy_buffer);
+  ASSERT (actual_transfer == this_transfer);
 
   copy_buffers[s->thread_index] = my_copy_buffer;
 
-  /* Fabricate TX event, send to ourselves */
-  evt.fifo = tx_fifo;
-  evt.event_type = FIFO_EVENT_SERVER_TX;
-  /* $$$$ for event logging */
-  evt.enqueue_length = actual_transfer;
-  evt.event_id = 0;
-  q = session_manager_get_vpp_event_queue (s->thread_index);
-  unix_shared_memory_queue_add (q, (u8 *) & evt, 0 /* do wait for mutex */ );
+  if (svm_fifo_set_event (tx_fifo))
+    {
+      /* Fabricate TX event, send to ourselves */
+      evt.fifo = tx_fifo;
+      evt.event_type = FIFO_EVENT_SERVER_TX;
+      evt.event_id = 0;
+      q = session_manager_get_vpp_event_queue (s->thread_index);
+      unix_shared_memory_queue_add (q, (u8 *) & evt,
+				    0 /* do wait for mutex */ );
+    }
 
   return 0;
 }
diff --git a/src/vnet/udp/udp_input.c b/src/vnet/udp/udp_input.c
index 88278735b55..4b22109bc71 100644
--- a/src/vnet/udp/udp_input.c
+++ b/src/vnet/udp/udp_input.c
@@ -244,44 +244,53 @@ udp4_uri_input_node_fn (vlib_main_t * vm,
       /* Get session's server */
       server0 = application_get (s0->app_index);
 
-      /* Fabricate event */
-      evt.fifo = s0->server_rx_fifo;
-      evt.event_type = FIFO_EVENT_SERVER_RX;
-      evt.event_id = serial_number++;
-      evt.enqueue_length = svm_fifo_max_dequeue (s0->server_rx_fifo);
-
       /* Built-in server? Deliver the goods... */
       if (server0->cb_fns.builtin_server_rx_callback)
 	{
-	  server0->cb_fns.builtin_server_rx_callback (s0, &evt);
+	  server0->cb_fns.builtin_server_rx_callback (s0);
 	  continue;
 	}
 
-      /* Add event to server's event queue */
-      q = server0->event_queue;
-
-      /* Don't block for lack of space */
-      if (PREDICT_TRUE (q->cursize < q->maxsize))
-	unix_shared_memory_queue_add (server0->event_queue, (u8 *) & evt,
-				      0 /* do wait for mutex */ );
-      else
+      if (svm_fifo_set_event (s0->server_rx_fifo))
 	{
-	  vlib_node_increment_counter (vm, udp4_uri_input_node.index,
-				       SESSION_ERROR_FIFO_FULL, 1);
+	  /* Fabricate event */
+	  evt.fifo = s0->server_rx_fifo;
+	  evt.event_type = FIFO_EVENT_SERVER_RX;
+	  evt.event_id = serial_number++;
+
+	  /* Add event to server's event queue */
+	  q = server0->event_queue;
+
+	  /* Don't block for lack of space */
+	  if (PREDICT_TRUE (q->cursize < q->maxsize))
+	    {
+	      unix_shared_memory_queue_add (server0->event_queue,
+					    (u8 *) & evt,
+					    0 /* do wait for mutex */ );
+	    }
+	  else
+	    {
+	      vlib_node_increment_counter (vm, udp4_uri_input_node.index,
+					   SESSION_ERROR_FIFO_FULL, 1);
+	    }
 	}
+      /* *INDENT-OFF* */
       if (1)
 	{
 	  ELOG_TYPE_DECLARE (e) =
 	  {
-	  .format = "evt-enqueue: id %d length %d",.format_args = "i4i4",};
+	      .format = "evt-enqueue: id %d length %d",
+	      .format_args = "i4i4",};
 	  struct
 	  {
 	    u32 data[2];
 	  } *ed;
 	  ed = ELOG_DATA (&vlib_global_main.elog_main, e);
 	  ed->data[0] = evt.event_id;
-	  ed->data[1] = evt.enqueue_length;
+	  ed->data[1] = svm_fifo_max_dequeue (s0->server_rx_fifo);
 	}
+      /* *INDENT-ON* */
+
     }
 
   vec_reset_length (session_indices_to_enqueue);