IP Multicast FIB (mfib)

 - IPv[46] mfib tables with support for (*,G/m), (*,G) and (S,G) exact and longest prefix match
 - Replication represented via a new replicate DPO.
 - RPF configuration and data-plane checking
 - data-plane signals sent to listening control planes.

The functions of multicast forwarding entries differ from their unicast conterparts, so we introduce a new mfib_table_t and mfib_entry_t objects. However, we re-use the fib_path_list to resolve and build the entry's output list. the fib_path_list provides the service to construct a replicate DPO for multicast.

'make tests' is added to with two new suites; TEST=mfib, this is invocation of the CLI command 'test mfib' which deals with many path add/remove, flag set/unset scenarios, TEST=ip-mcast, data-plane forwarding tests.

Updated applications to use the new MIFB functions;
  - IPv6 NS/RA.
  - DHCPv6
 unit tests for these are undated accordingly.

Change-Id: I49ec37b01f1b170335a5697541c8fd30e6d3a961
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 34 insertions, 9 deletions

diff --git a/src/vnet/ip/ip6_input.c b/src/vnet/ip/ip6_input.c
index bbc2cebaa39..20306088611 100644
--- a/src/vnet/ip/ip6_input.c
+++ b/src/vnet/ip/ip6_input.c
@@ -64,6 +64,7 @@ typedef enum
 {
   IP6_INPUT_NEXT_DROP,
   IP6_INPUT_NEXT_LOOKUP,
+  IP6_INPUT_NEXT_LOOKUP_MULTICAST,
   IP6_INPUT_NEXT_ICMP_ERROR,
   IP6_INPUT_N_NEXT,
 } ip6_input_next_t;
@@ -142,12 +143,27 @@ ip6_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 	  sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 	  sw_if_index1 = vnet_buffer (p1)->sw_if_index[VLIB_RX];
 
-	  arc0 =
-	    ip6_address_is_multicast (&ip0->dst_address) ?
-	    lm->mcast_feature_arc_index : lm->ucast_feature_arc_index;
-	  arc1 =
-	    ip6_address_is_multicast (&ip1->dst_address) ?
-	    lm->mcast_feature_arc_index : lm->ucast_feature_arc_index;
+	  if (PREDICT_FALSE (ip6_address_is_multicast (&ip0->dst_address)))
+	    {
+	      arc0 = lm->mcast_feature_arc_index;
+	      next0 = IP6_INPUT_NEXT_LOOKUP_MULTICAST;
+	    }
+	  else
+	    {
+	      arc0 = lm->ucast_feature_arc_index;
+	      next0 = IP6_INPUT_NEXT_LOOKUP;
+	    }
+
+	  if (PREDICT_FALSE (ip6_address_is_multicast (&ip1->dst_address)))
+	    {
+	      arc1 = lm->mcast_feature_arc_index;
+	      next1 = IP6_INPUT_NEXT_LOOKUP_MULTICAST;
+	    }
+	  else
+	    {
+	      arc1 = lm->ucast_feature_arc_index;
+	      next1 = IP6_INPUT_NEXT_LOOKUP;
+	    }
 
 	  vnet_buffer (p0)->ip.adj_index[VLIB_RX] = ~0;
 	  vnet_buffer (p1)->ip.adj_index[VLIB_RX] = ~0;
@@ -240,9 +256,17 @@ ip6_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 	  ip0 = vlib_buffer_get_current (p0);
 
 	  sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
-	  arc0 =
-	    ip6_address_is_multicast (&ip0->dst_address) ?
-	    lm->mcast_feature_arc_index : lm->ucast_feature_arc_index;
+	  if (PREDICT_FALSE (ip6_address_is_multicast (&ip0->dst_address)))
+	    {
+	      arc0 = lm->mcast_feature_arc_index;
+	      next0 = IP6_INPUT_NEXT_LOOKUP_MULTICAST;
+	    }
+	  else
+	    {
+	      arc0 = lm->ucast_feature_arc_index;
+	      next0 = IP6_INPUT_NEXT_LOOKUP;
+	    }
+
 	  vnet_buffer (p0)->ip.adj_index[VLIB_RX] = ~0;
 	  vnet_feature_arc_start (arc0, sw_if_index0, &next0, p0);
 
@@ -313,6 +337,7 @@ VLIB_REGISTER_NODE (ip6_input_node) = {
     [IP6_INPUT_NEXT_DROP] = "error-drop",
     [IP6_INPUT_NEXT_LOOKUP] = "ip6-lookup",
     [IP6_INPUT_NEXT_ICMP_ERROR] = "ip6-icmp-error",
+    [IP6_INPUT_NEXT_LOOKUP_MULTICAST] = "ip6-mfib-forward-lookup",
   },
 
   .format_buffer = format_ip6_header,