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, 22 insertions, 20 deletions

diff --git a/src/vnet/fib/fib_entry_src_rr.c b/src/vnet/fib/fib_entry_src_rr.c
index b6f4bc3ba45..8e477362374 100644
--- a/src/vnet/fib/fib_entry_src_rr.c
+++ b/src/vnet/fib/fib_entry_src_rr.c
@@ -20,6 +20,7 @@
 #include <vnet/dpo/drop_dpo.h>
 
 #include "fib_entry_src.h"
+#include "fib_entry_src_rr.h"
 #include "fib_entry_cover.h"
 #include "fib_entry.h"
 #include "fib_table.h"
@@ -29,7 +30,7 @@
  *
  * Resolve via a connected cover.
  */
-static void
+void
 fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
 					const fib_entry_t *fib_entry,
 					const fib_entry_t *cover)
@@ -53,7 +54,8 @@ fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
      * shortly to over-rule this RR source.
      */
     src->fes_pl = fib_path_list_create(FIB_PATH_LIST_FLAG_NONE, paths);
-    src->fes_entry_flags = fib_entry_get_flags(fib_entry_get_index(cover));
+    src->fes_entry_flags |= (fib_entry_get_flags(fib_entry_get_index(cover)) &
+                             FIB_ENTRY_FLAGS_RR_INHERITED);
 
     vec_free(paths);
 }
@@ -65,8 +67,8 @@ fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
 static void
 fib_entry_src_rr_init (fib_entry_src_t *src)
 {
-    src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
-    src->rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
+    src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
+    src->u.rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
 }
 
 
@@ -84,7 +86,7 @@ fib_entry_src_rr_init (fib_entry_src_t *src)
  * the loop will break when the cover changes, and this function
  * will be called again when that happens.
  */
-static void
+void
 fib_entry_src_rr_use_covers_pl (fib_entry_src_t *src,
                                 const fib_entry_t *fib_entry,
                                 const fib_entry_t *cover)
@@ -132,14 +134,14 @@ fib_entry_src_rr_activate (fib_entry_src_t *src,
 	return (!0);
     }
 
-    src->rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
+    src->u.rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
 						     &fib_entry->fe_prefix);
 
-    ASSERT(FIB_NODE_INDEX_INVALID != src->rr.fesr_cover);
+    ASSERT(FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover);
 
-    cover = fib_entry_get(src->rr.fesr_cover);
+    cover = fib_entry_get(src->u.rr.fesr_cover);
 
-    src->rr.fesr_sibling =
+    src->u.rr.fesr_sibling =
 	fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
 
     /*
@@ -175,11 +177,11 @@ fib_entry_src_rr_deactivate (fib_entry_src_t *src,
     /*
      * remove the depednecy on the covering entry
      */
-    if (FIB_NODE_INDEX_INVALID != src->rr.fesr_cover)
+    if (FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover)
     {
-	cover = fib_entry_get(src->rr.fesr_cover);
-	fib_entry_cover_untrack(cover, src->rr.fesr_sibling);
-	src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
+	cover = fib_entry_get(src->u.rr.fesr_cover);
+	fib_entry_cover_untrack(cover, src->u.rr.fesr_sibling);
+	src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
     }
 
     fib_path_list_unlock(src->fes_pl);
@@ -187,7 +189,7 @@ fib_entry_src_rr_deactivate (fib_entry_src_t *src,
     src->fes_entry_flags = FIB_ENTRY_FLAG_NONE;
 }
 
-static fib_entry_src_cover_res_t
+fib_entry_src_cover_res_t
 fib_entry_src_rr_cover_change (fib_entry_src_t *src,
 			       const fib_entry_t *fib_entry)
 {
@@ -196,7 +198,7 @@ fib_entry_src_rr_cover_change (fib_entry_src_t *src,
 	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
     };
 
-    if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
+    if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
     {
 	/*
 	 * the source may be added, but it is not active
@@ -210,7 +212,7 @@ fib_entry_src_rr_cover_change (fib_entry_src_t *src,
      * entry inserted benaeth it. That does not necessarily mean that this
      * entry is covered by the new prefix. check that
      */
-    if (src->rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
+    if (src->u.rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
 							  &fib_entry->fe_prefix))
     {
 	fib_entry_src_rr_deactivate(src, fib_entry);
@@ -230,7 +232,7 @@ fib_entry_src_rr_cover_change (fib_entry_src_t *src,
  * This entry's cover has updated its forwarding info. This entry
  * will need to re-inheret.
  */
-static fib_entry_src_cover_res_t
+fib_entry_src_cover_res_t
 fib_entry_src_rr_cover_update (fib_entry_src_t *src,
 			       const fib_entry_t *fib_entry)
 {
@@ -241,7 +243,7 @@ fib_entry_src_rr_cover_update (fib_entry_src_t *src,
     fib_node_index_t old_path_list;
     fib_entry_t *cover;
 
-    if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
+    if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
     {
 	/*
 	 * the source may be added, but it is not active
@@ -250,7 +252,7 @@ fib_entry_src_rr_cover_update (fib_entry_src_t *src,
 	return (res);
     }
 
-    cover = fib_entry_get(src->rr.fesr_cover);
+    cover = fib_entry_get(src->u.rr.fesr_cover);
     old_path_list = src->fes_pl;
 
     /*
@@ -280,7 +282,7 @@ static u8*
 fib_entry_src_rr_format (fib_entry_src_t *src,
 			 u8* s)
 {
-    return (format(s, " cover:%d", src->rr.fesr_cover));
+    return (format(s, " cover:%d", src->u.rr.fesr_cover));
 }
 
 const static fib_entry_src_vft_t rr_src_vft = {