tcp: cleanup connection/session fixes

- Cleanup session state after last ack and avoid using a cleanup timer.
- Change session cleanup to free the session as opposed to waiting for
delete notify.
- When in close-wait, postpone sending the fin on close until all
outstanding data has been sent.
- Don't flush rx fifo unless in closed state

Change-Id: Ic2a4f0d5568b65c83f4b55b6c469a7b24b947f39
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 16 insertions, 13 deletions

diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c
index 15ac7d37edc..2a696f19d22 100644
--- a/src/vnet/tcp/tcp.c
+++ b/src/vnet/tcp/tcp.c
@@ -277,19 +277,19 @@ tcp_connection_reset (tcp_connection_t * tc)
       tcp_connection_cleanup (tc);
       break;
     case TCP_STATE_ESTABLISHED:
+      tcp_connection_timers_reset (tc);
+      /* Set the cleanup timer, in case the session layer/app don't
+       * cleanly close the connection */
+      tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
       stream_session_reset_notify (&tc->connection);
-      /* fall through */
+      break;
     case TCP_STATE_CLOSE_WAIT:
     case TCP_STATE_FIN_WAIT_1:
     case TCP_STATE_FIN_WAIT_2:
     case TCP_STATE_CLOSING:
       tc->state = TCP_STATE_CLOSED;
       TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc);
-
-      /* Make sure all timers are cleared */
       tcp_connection_timers_reset (tc);
-
-      /* Wait for cleanup from session layer but not forever */
       tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
       break;
     case TCP_STATE_CLOSED:
@@ -326,17 +326,22 @@ tcp_connection_close (tcp_connection_t * tc)
       tc->state = TCP_STATE_FIN_WAIT_1;
       break;
     case TCP_STATE_ESTABLISHED:
-      if (!stream_session_tx_fifo_max_dequeue (&tc->connection))
+      if (!session_tx_fifo_max_dequeue (&tc->connection))
 	tcp_send_fin (tc);
       else
 	tc->flags |= TCP_CONN_FINPNDG;
       tc->state = TCP_STATE_FIN_WAIT_1;
       break;
     case TCP_STATE_CLOSE_WAIT:
-      tcp_send_fin (tc);
-      tcp_connection_timers_reset (tc);
-      tc->state = TCP_STATE_LAST_ACK;
-      tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
+      if (!session_tx_fifo_max_dequeue (&tc->connection))
+	{
+	  tcp_send_fin (tc);
+	  tcp_connection_timers_reset (tc);
+	  tc->state = TCP_STATE_LAST_ACK;
+	  tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
+	}
+      else
+	tc->flags |= TCP_CONN_FINPNDG;
       break;
     case TCP_STATE_FIN_WAIT_1:
       tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
@@ -367,11 +372,9 @@ tcp_session_cleanup (u32 conn_index, u32 thread_index)
   tcp_connection_t *tc;
   tc = tcp_connection_get (conn_index, thread_index);
   tcp_connection_timers_reset (tc);
-
-  /* Wait for the session tx events to clear */
   tc->state = TCP_STATE_CLOSED;
   TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc);
-  tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
+  tcp_connection_cleanup (tc);
 }
 
 /**