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, 6 insertions, 4 deletions

diff --git a/src/vnet/dpo/replicate_dpo.h b/src/vnet/dpo/replicate_dpo.h
index 7383184a2ea..ccb25630e16 100644
--- a/src/vnet/dpo/replicate_dpo.h
+++ b/src/vnet/dpo/replicate_dpo.h
@@ -53,7 +53,7 @@ extern replicate_main_t replicate_main;
  */
 typedef struct replicate_t_ {
     /**
-     * number of buckets in the load-balance. always a power of 2.
+     * number of buckets in the replicate.
      */
     u16 rep_n_buckets;
 
@@ -104,15 +104,17 @@ extern void replicate_multipath_update(
     load_balance_path_t *next_hops);
 
 extern void replicate_set_bucket(index_t repi,
-				    u32 bucket,
-				    const dpo_id_t *next);
+                                 u32 bucket,
+                                 const dpo_id_t *next);
 
 extern u8* format_replicate(u8 * s, va_list * args);
 
 extern const dpo_id_t *replicate_get_bucket(index_t repi,
-					       u32 bucket);
+                                            u32 bucket);
 extern int replicate_is_drop(const dpo_id_t *dpo);
 
+extern u16 replicate_n_buckets(index_t repi);
+
 /**
  * The encapsulation breakages are for fast DP access
  */