lacp: passive mode support [VPP-1551]

By definition, passive mode means the node does not start sending lacp pdu until
it first hears from the partner or remote.

- Rename ptx machine's BEGIN state to NO_PERIODIC state.
- Put periodic machine in NO_PERIDOIC state when the interface is enabled for
lacp. ptx machine will transition out of NO_PERIODIC state when the local node
hears from the remote or when the local node is configured for active mode.
- Also add send and receive statistics for debugging.

Change-Id: I747953b9595ed31328b2f4f3e7a8d15d01e04d7f
Signed-off-by: Steven Luong <sluong@cisco.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/src/plugins/lacp/rx_machine.c b/src/plugins/lacp/rx_machine.c
index fd65aa3ae8e..070b9089cd2 100644
--- a/src/plugins/lacp/rx_machine.c
+++ b/src/plugins/lacp/rx_machine.c
@@ -206,11 +206,15 @@ lacp_compare_partner (slave_if_t * sif)
 }
 
 static void
-lacp_record_pdu (slave_if_t * sif)
+lacp_record_pdu (vlib_main_t * vm, slave_if_t * sif)
 {
   lacp_pdu_t *lacpdu = (lacp_pdu_t *) sif->last_rx_pkt;
   u8 match;
 
+  /* Transition PTX out of NO_PERIODIC if needed */
+  if (!(sif->partner.state & LACP_STATE_LACP_ACTIVITY) &&
+      (lacpdu->actor.port_info.state & LACP_STATE_LACP_ACTIVITY))
+    lacp_ptx_post_short_timeout_event (vm, sif);
   match = lacp_compare_partner (sif);
   sif->partner = lacpdu->actor.port_info;
   sif->actor.state &= ~LACP_STATE_DEFAULTED;
@@ -285,8 +289,7 @@ lacp_rx_action_expired (void *p1, void *p2)
 
   sif->partner.state &= ~LACP_STATE_SYNCHRONIZATION;
   sif->partner.state |= LACP_STATE_LACP_TIMEOUT;
-  lacp_machine_dispatch (&lacp_ptx_machine, vm, sif,
-			 LACP_PTX_EVENT_SHORT_TIMEOUT, &sif->ptx_state);
+  lacp_ptx_post_short_timeout_event (vm, sif);
   if (lacp_timer_is_running (sif->current_while_timer) &&
       lacp_timer_is_expired (lm->vlib_main, sif->current_while_timer))
     timer_expired = 1;
@@ -324,6 +327,7 @@ lacp_rx_action_defaulted (void *p1, void *p2)
   vlib_main_t *vm = (vlib_main_t *) p1;
   slave_if_t *sif = (slave_if_t *) p2;
 
+  lacp_stop_timer (&sif->current_while_timer);
   lacp_update_default_selected (vm, sif);
   lacp_record_default (sif);
   sif->actor.state &= ~LACP_STATE_EXPIRED;
@@ -365,7 +369,7 @@ lacp_rx_action_current (void *p1, void *p2)
 
   lacp_update_selected (vm, sif);
   lacp_update_ntt (vm, sif);
-  lacp_record_pdu (sif);
+  lacp_record_pdu (vm, sif);
   lacp_start_current_while_timer (lm->vlib_main, sif, sif->ttl_in_seconds);
   sif->actor.state &= ~LACP_STATE_EXPIRED;
   if (lacp_port_is_moved (vm, sif))