FIB Interpose Source

The interpose source allows the source/provider to insert/interpose
a DPO in the forwarding chain of the FIB entry ahead of the forwarding
provided by the next best source. For example if the API source (i.e
the 'control plane') has provided an adjacency for forwarding, then
an interpose source (e.g. a monitoring service) couold interpose a
replicatte DPO to copy the traffic to another location AND forward
using the API's adjacency.
To use the interose feature an existing source (i.e FIB_SOURCE_PLUGIN_HI)
cn specifiy as a flag FIB_ENTRY_FLAG_INTERPOSE and provide a DPO to
interpose. One might also consider using interpose in conjunction with
FIB_ENTRY_FLAG_COVER_INHERIT to ensure the interpose object affects
all prefixes in the sub-tree.

Change-Id: I8b2737b985f8f7c08123406d0491881def347b52
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 62 insertions, 64 deletions

diff --git a/src/vnet/fib/fib_entry_src_mpls.c b/src/vnet/fib/fib_entry_src_mpls.c
index f80d42afbb0..32a620de713 100644
--- a/src/vnet/fib/fib_entry_src_mpls.c
+++ b/src/vnet/fib/fib_entry_src_mpls.c
@@ -22,7 +22,7 @@
 #include <vnet/fib/mpls_fib.h>
 
 /**
- * Source initialisation Function 
+ * Source initialisation Function
  */
 static void
 fib_entry_src_mpls_init (fib_entry_src_t *src)
@@ -30,16 +30,16 @@ fib_entry_src_mpls_init (fib_entry_src_t *src)
     mpls_eos_bit_t eos;
 
     src->fes_flags = FIB_ENTRY_SRC_FLAG_NONE;
-    src->mpls.fesm_label = MPLS_LABEL_INVALID;
+    src->u.mpls.fesm_label = MPLS_LABEL_INVALID;
 
     FOR_EACH_MPLS_EOS_BIT(eos)
     {
-	src->mpls.fesm_lfes[eos] = FIB_NODE_INDEX_INVALID;
+        src->u.mpls.fesm_lfes[eos] = FIB_NODE_INDEX_INVALID;
     }
 }
 
 /**
- * Source deinitialisation Function 
+ * Source deinitialisation Function
  */
 static void
 fib_entry_src_mpls_deinit (fib_entry_src_t *src)
@@ -50,7 +50,7 @@ static void
 fib_entry_src_mpls_remove (fib_entry_src_t *src)
 {
     src->fes_pl = FIB_NODE_INDEX_INVALID;
-    src->mpls.fesm_label = MPLS_LABEL_INVALID;
+    src->u.mpls.fesm_label = MPLS_LABEL_INVALID;
 }
 
 static void
@@ -61,9 +61,9 @@ fib_entry_src_mpls_add (fib_entry_src_t *src,
                         const dpo_id_t *dpo)
 {
     src->fes_pl =
-	fib_path_list_create_special(proto,
-				     FIB_PATH_LIST_FLAG_DROP,
-				     drop_dpo_get(proto));
+        fib_path_list_create_special(proto,
+                                     FIB_PATH_LIST_FLAG_DROP,
+                                     drop_dpo_get(proto));
 }
 
 static void
@@ -91,71 +91,71 @@ fib_entry_src_mpls_set_data (fib_entry_src_t *src,
          */
         FOR_EACH_MPLS_EOS_BIT(eos)
         {
-	    fib_table_entry_delete_index(src->mpls.fesm_lfes[eos],
-					 FIB_SOURCE_SPECIAL);
+            fib_table_entry_delete_index(src->u.mpls.fesm_lfes[eos],
+                                         FIB_SOURCE_SPECIAL);
         }
         fib_table_unlock(MPLS_FIB_DEFAULT_TABLE_ID,
                          FIB_PROTOCOL_MPLS,
                          FIB_SOURCE_MPLS);
-        src->mpls.fesm_label = label;
+        src->u.mpls.fesm_label = label;
     }
     else
     {
-	fib_prefix_t prefix = {
-	    .fp_proto = FIB_PROTOCOL_MPLS,
-	    .fp_label = label,
-	};
-	fib_node_index_t fib_index;
-	dpo_id_t dpo = DPO_INVALID;
+        fib_prefix_t prefix = {
+            .fp_proto = FIB_PROTOCOL_MPLS,
+            .fp_label = label,
+        };
+        fib_node_index_t fib_index;
+        dpo_id_t dpo = DPO_INVALID;
 
         /*
          * adding a new local label. make sure the MPLS fib exists.
          */
-        if (MPLS_LABEL_INVALID == src->mpls.fesm_label)
+        if (MPLS_LABEL_INVALID == src->u.mpls.fesm_label)
         {
             fib_index =
-		fib_table_find_or_create_and_lock(FIB_PROTOCOL_MPLS,
-						  MPLS_FIB_DEFAULT_TABLE_ID,
+                fib_table_find_or_create_and_lock(FIB_PROTOCOL_MPLS,
+                                                  MPLS_FIB_DEFAULT_TABLE_ID,
                                                   FIB_SOURCE_MPLS);
         }
-	else
-	{
-	    fib_index = mpls_fib_index_from_table_id(MPLS_FIB_DEFAULT_TABLE_ID);
-
-	    /*
-	     * if this is a change in label, reomve the old one first
-	     */
-	    if (src->mpls.fesm_label != label)
-	    {
-		FOR_EACH_MPLS_EOS_BIT(eos)
-		{
-		    ASSERT(FIB_NODE_INDEX_INVALID != src->mpls.fesm_lfes[eos]);
-		    fib_table_entry_delete_index(src->mpls.fesm_lfes[eos],
-						 FIB_SOURCE_SPECIAL);
-		}
-	    }
-	}
-
-        src->mpls.fesm_label = label;
-
-	FOR_EACH_MPLS_EOS_BIT(eos)
-	{
-	    prefix.fp_eos = eos;
-	    prefix.fp_payload_proto = fib_proto_to_dpo(payload_proto);
-
-	    fib_entry_contribute_forwarding(fei,
-					    (eos ?
-					     FIB_FORW_CHAIN_TYPE_MPLS_EOS :
-					     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS),
-					    &dpo);
-	    src->mpls.fesm_lfes[eos] = 
-		fib_table_entry_special_dpo_add(fib_index,
-						&prefix,
-						FIB_SOURCE_SPECIAL,
-						FIB_ENTRY_FLAG_EXCLUSIVE,
-						&dpo);
-	    dpo_reset(&dpo);
-	}
+        else
+        {
+            fib_index = mpls_fib_index_from_table_id(MPLS_FIB_DEFAULT_TABLE_ID);
+
+            /*
+             * if this is a change in label, reomve the old one first
+             */
+            if (src->u.mpls.fesm_label != label)
+            {
+                FOR_EACH_MPLS_EOS_BIT(eos)
+                {
+                    ASSERT(FIB_NODE_INDEX_INVALID != src->u.mpls.fesm_lfes[eos]);
+                    fib_table_entry_delete_index(src->u.mpls.fesm_lfes[eos],
+                                                 FIB_SOURCE_SPECIAL);
+                }
+            }
+        }
+
+        src->u.mpls.fesm_label = label;
+
+        FOR_EACH_MPLS_EOS_BIT(eos)
+        {
+            prefix.fp_eos = eos;
+            prefix.fp_payload_proto = fib_proto_to_dpo(payload_proto);
+
+            fib_entry_contribute_forwarding(fei,
+                                            (eos ?
+                                             FIB_FORW_CHAIN_TYPE_MPLS_EOS :
+                                             FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS),
+                                            &dpo);
+            src->u.mpls.fesm_lfes[eos] =
+                fib_table_entry_special_dpo_add(fib_index,
+                                                &prefix,
+                                                FIB_SOURCE_SPECIAL,
+                                                FIB_ENTRY_FLAG_EXCLUSIVE,
+                                                &dpo);
+            dpo_reset(&dpo);
+        }
     }
 }
 
@@ -163,14 +163,14 @@ static const void *
 fib_entry_src_mpls_get_data (fib_entry_src_t *src,
                              const fib_entry_t *entry)
 {
-    return (&(src->mpls.fesm_label));
+    return (&(src->u.mpls.fesm_label));
 }
 
 static u8*
 fib_entry_src_mpls_format (fib_entry_src_t *src,
-			   u8* s)
+                           u8* s)
 {
-    return (format(s, " local-label:%d", src->mpls.fesm_label));
+    return (format(s, " local-label:%d", src->u.mpls.fesm_label));
 }
 
 const static fib_entry_src_vft_t mpls_src_vft = {
@@ -193,7 +193,5 @@ const static fib_entry_src_vft_t mpls_src_vft = {
 void
 fib_entry_src_mpls_register (void)
 {
-    fib_entry_src_register(FIB_SOURCE_MPLS, &mpls_src_vft);    
+    fib_entry_src_register(FIB_SOURCE_MPLS, &mpls_src_vft);
 }
-
-