[HICN-475] Adding multihoming in case the producer is facing the producer

Change-Id: I9ec9d43083379ed8961532f2b9d20f03fd1fa45e
Signed-off-by: Alberto Compagno <acompagn+fdio@cisco.com>

5 files changed, 49 insertions, 8 deletions

diff --git a/hicn-plugin/src/mapme.h b/hicn-plugin/src/mapme.h
index d5e77f641..5b89e5709 100644
--- a/hicn-plugin/src/mapme.h
+++ b/hicn-plugin/src/mapme.h
@@ -122,6 +122,28 @@ hicn_mapme_tfib_add (hicn_mapme_tfib_t * tfib, dpo_id_t * face_id)
 }
 
 static_always_inline int
+hicn_mapme_tfib_clear (hicn_mapme_tfib_t * tfib)
+{
+  dpo_id_t invalid = NEXT_HOP_INVALID;
+  /*
+   * We need to do a linear scan of TFIB entries to find the one to
+   * remove
+   */
+  u8 start_pos = HICN_PARAM_FIB_ENTRY_NHOPS_MAX - tfib->tfib_entry_count;
+  u8 pos = ~0;
+  for (pos = start_pos; pos < HICN_PARAM_FIB_ENTRY_NHOPS_MAX; pos++)
+      {
+	hicn_face_unlock (&tfib->next_hops[pos]);
+	tfib->next_hops[pos] = invalid;
+	break;
+      }
+
+  tfib->tfib_entry_count = 0;
+
+  return 0;
+}
+
+static_always_inline int
 hicn_mapme_tfib_del (hicn_mapme_tfib_t * tfib, dpo_id_t * face_id)
 {
   dpo_id_t invalid = NEXT_HOP_INVALID;
diff --git a/hicn-plugin/src/mapme_ctrl_node.c b/hicn-plugin/src/mapme_ctrl_node.c
index 22a50d49e..57f63dbe1 100644
--- a/hicn-plugin/src/mapme_ctrl_node.c
+++ b/hicn-plugin/src/mapme_ctrl_node.c
@@ -152,7 +152,11 @@ hicn_mapme_process_ctrl (vlib_main_t * vm, vlib_buffer_t * b,
       for (u8 pos = 0; pos < tfib->entry_count; pos++)
 	{
 	  if (dpo_cmp (&tfib->next_hops[pos], in_face) == 0)
-	    continue;
+	    {
+	      tfib->entry_count = 0;
+	      break;
+	    }
+	  DEBUG ("Adding nexthop to the tfib, dpo index in_face %d, dpo index tfib %d", in_face->dpoi_index, tfib->next_hops[pos].dpoi_index);
 	  hicn_mapme_tfib_add (tfib, &tfib->next_hops[pos]);
 	}
 
diff --git a/hicn-plugin/src/mapme_eventmgr.c b/hicn-plugin/src/mapme_eventmgr.c
index ce9c0a4b4..93168d059 100644
--- a/hicn-plugin/src/mapme_eventmgr.c
+++ b/hicn-plugin/src/mapme_eventmgr.c
@@ -322,6 +322,7 @@ hicn_mapme_eventmgr_process (vlib_main_t * vm,
   u8 idle = 0;
 
   retx_t retx_array[NUM_RETX_SLOT][NUM_RETX_ENTRIES];
+  memset(retx_array, 0, NUM_RETX_SLOT*NUM_RETX_ENTRIES);
   u8 retx_len[NUM_RETX_SLOT] = { 0 };
   u8 cur = 0;			/* current slot */
 
@@ -415,6 +416,7 @@ hicn_mapme_eventmgr_process (vlib_main_t * vm,
 		 */
 		retx_t *retx = (retx_t *) & retx_events[i];
 
+		retx->rtx_count = 0;
 		/*
 		 * Transmit IU for all TFIB entries with latest seqno (we have
 		 * at least one for sure!)
@@ -510,12 +512,21 @@ hicn_mapme_eventmgr_process (vlib_main_t * vm,
 
 	      hicn_mapme_send_updates (vm, &retx->prefix, retx->dpo, true);
 
-	      /*
-	       * We did some retransmissions, so let's reschedule a check in the
-	       * next slot
-	       */
-	      NXT[NXTLEN++] = CUR[pos];
-	      idle = 0;
+	      retx->rtx_count++;
+	      // If we exceed the numver of retransmittion it means that all tfib entries have seens at least HICN_PARAM_RTX_MAX of retransmission
+	      if (retx->rtx_count < HICN_PARAM_RTX_MAX)
+		{
+		/*
+		 * We did some retransmissions, so let's reschedule a check in the
+		 * next slot
+		 */
+		  NXT[NXTLEN++] = CUR[pos];
+		  idle = 0;
+		}
+	      else
+		{
+		  hicn_mapme_tfib_clear(tfib);
+		}
 	    }
 
 	  /* Reset events in this slot and prepare for next one */
diff --git a/hicn-plugin/src/mapme_eventmgr.h b/hicn-plugin/src/mapme_eventmgr.h
index 2f8106d6c..338915d63 100644
--- a/hicn-plugin/src/mapme_eventmgr.h
+++ b/hicn-plugin/src/mapme_eventmgr.h
@@ -15,7 +15,7 @@
 
 #include <vlib/vlib.h>		// vlib_node_registration_t (vlib/node.h)
 
-/* 
+/*
  * Structure carrying all necessary information for managing Special Interest
  * (re)transmissions.
  */
@@ -23,6 +23,7 @@ typedef struct
 {
   hicn_prefix_t prefix;
   dpo_id_t dpo;
+  u8 rtx_count; // Number of retransmissions since last tfib addition
 } retx_t;
 
 #define HASH32(x) ((u16)x ^ (x << 16))
diff --git a/hicn-plugin/src/params.h b/hicn-plugin/src/params.h
index a484d076a..56aff30b6 100644
--- a/hicn-plugin/src/params.h
+++ b/hicn-plugin/src/params.h
@@ -62,6 +62,9 @@ STATIC_ASSERT ((ceil (log2 ((HICN_PARAM_PIT_ENTRY_PHOPS_MAX - 4)))) ==
 STATIC_ASSERT ((HICN_PARAM_PIT_ENTRY_PHOPS_MAX <= HICN_PARAM_FACES_MAX),
 	       "HICN_PARAM_PIT_ENTRY_PHOP_MAX must be <= than HICN_PARAM_FACES_MAX");
 
+//tFIB parameters
+#define HICN_PARAM_RTX_MAX 10
+
 // PIT lifetime limits on API override this(in seconds, integer type)
 #define HICN_PARAM_PIT_LIFETIME_BOUND_MIN_SEC   0
 #define HICN_PARAM_PIT_LIFETIME_BOUND_MAX_SEC  200