feat(hicn-plugin): reuse strategy node to forward interests

Before the interest forwarding was duplicated in 2 different nodes,
the strategy_node and the interest_hitpit_node.
Reuse the strategy node so that the nexthop selection via the strategy
is done only in one place - teh strategy node.

Change-Id: I2c72ec35b1df4e6ed8ce0877e9f3e6f5c1ae68f8
Signed-off-by: Mauro Sardara <msardara@cisco.com>
(cherry picked from commit 4ec2784197db60e4f287a88b7944ecb1067bfc08)

1 files changed, 53 insertions, 29 deletions

diff --git a/hicn-plugin/src/interest_pcslookup_node.c b/hicn-plugin/src/interest_pcslookup_node.c
index a0b2ee3f0..e8aad4a83 100644
--- a/hicn-plugin/src/interest_pcslookup_node.c
+++ b/hicn-plugin/src/interest_pcslookup_node.c
@@ -80,6 +80,7 @@ hicn_interest_pcslookup_node_inline (vlib_main_t *vm,
   hicn_pcs_entry_t *pcs_entry = NULL;
   f64 tnow;
   hicn_buffer_t *hicnb0;
+  const hicn_strategy_vft_t *strategy;
 
   rt = vlib_node_get_runtime_data (vm, hicn_interest_pcslookup_node.index);
 
@@ -132,49 +133,72 @@ hicn_interest_pcslookup_node_inline (vlib_main_t *vm,
 
 	  if (ret == HICN_ERROR_NONE)
 	    {
-	      // We found an entry in the PCS. Next stage for this packet is
-	      // one of hitpit/cs nodes
-	      next0 = HICN_INTEREST_PCSLOOKUP_NEXT_INTEREST_HITPIT +
-		      hicn_pcs_entry_is_cs (pcs_entry);
-
+	      // We found an entry in the PCS.
 	      ret = hicn_store_internal_state (
 		b0, hicn_pcs_entry_get_index (rt->pitcs, pcs_entry),
 		vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 
-	      if (PREDICT_FALSE (ret != HICN_ERROR_NONE))
-		next0 = HICN_INTEREST_PCSLOOKUP_NEXT_ERROR_DROP;
-	    }
-	  else
-	    {
-	      // No entry in PCS. Let's create one now
-	      pcs_entry = hicn_pcs_entry_pit_get (
-		rt->pitcs, tnow, hicn_buffer_get_lifetime (b0));
+	      // Make sure the entry is not expired first
+	      if (tnow > hicn_pcs_entry_get_expire_time (pcs_entry))
+		{
+		  // Notify strategy
+		  strategy = hicn_dpo_get_strategy_vft (hicnb0->vft_id);
+		  strategy->hicn_on_interest_timeout (
+		    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 
-	      ret = hicn_pcs_pit_insert (rt->pitcs, pcs_entry, &name);
+		  // Release lock on entry - this MUST delete the entry
+		  hicn_pcs_entry_remove_lock (rt->pitcs, pcs_entry);
 
-	      if (PREDICT_FALSE (ret != HICN_ERROR_NONE))
+		  stats.pit_expired_count++;
+
+		  // Forward to strategy node
+		  // TODO this can be simplified by checking directly in the
+		  // pcslookup node!
+		  next0 = HICN_INTEREST_PCSLOOKUP_NEXT_STRATEGY;
+
+		  goto newentry;
+		}
+	      else
 		{
-		  next0 = HICN_INTEREST_PCSLOOKUP_NEXT_ERROR_DROP;
+		  // Next stage for this packet is one of hitpit/cs nodes
+		  next0 = HICN_INTEREST_PCSLOOKUP_NEXT_INTEREST_HITPIT +
+			  hicn_pcs_entry_is_cs (pcs_entry);
+
+		  if (PREDICT_FALSE (ret != HICN_ERROR_NONE))
+		    next0 = HICN_INTEREST_PCSLOOKUP_NEXT_ERROR_DROP;
+
 		  goto end;
 		}
+	    }
+	newentry:
+	  // No entry in PCS. Let's create one now
+	  pcs_entry = hicn_pcs_entry_pit_get (rt->pitcs, tnow,
+					      hicn_buffer_get_lifetime (b0));
 
-	      // Store internal state
-	      ret = hicn_store_internal_state (
-		b0, hicn_pcs_entry_get_index (rt->pitcs, pcs_entry),
-		vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
+	  ret = hicn_pcs_pit_insert (rt->pitcs, pcs_entry, &name);
 
-	      if (PREDICT_FALSE (ret != HICN_ERROR_NONE))
-		{
-		  hicn_pcs_entry_remove_lock (rt->pitcs, pcs_entry);
-		  drop_packet (vm, bi0, &n_left_from, &next0, &to_next,
-			       &next_index, node);
-		  continue;
-		}
+	  if (PREDICT_FALSE (ret != HICN_ERROR_NONE))
+	    {
+	      next0 = HICN_INTEREST_PCSLOOKUP_NEXT_ERROR_DROP;
+	      goto end;
+	    }
 
-	      // Add face
-	      hicn_pcs_entry_pit_add_face (pcs_entry, hicnb0->face_id);
+	  // Store internal state
+	  ret = hicn_store_internal_state (
+	    b0, hicn_pcs_entry_get_index (rt->pitcs, pcs_entry),
+	    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
+
+	  if (PREDICT_FALSE (ret != HICN_ERROR_NONE))
+	    {
+	      hicn_pcs_entry_remove_lock (rt->pitcs, pcs_entry);
+	      drop_packet (vm, bi0, &n_left_from, &next0, &to_next,
+			   &next_index, node);
+	      continue;
 	    }
 
+	  // Add face
+	  hicn_pcs_entry_pit_add_face (pcs_entry, hicnb0->face_id);
+
 	end:
 	  stats.pkts_interest_count++;