BIER disposition default route

Change-Id: I7196ad8bf6afaf356674789c05e23ac000bc038e
Signed-off-by: Neale Ranns <nranns@cisco.com>

3 files changed, 20 insertions, 8 deletions

diff --git a/src/vnet/bier/bier.api b/src/vnet/bier/bier.api
index f7a13e4705b..6f88732aba9 100644
--- a/src/vnet/bier/bier.api
+++ b/src/vnet/bier/bier.api
@@ -221,7 +221,8 @@ define bier_disp_table_details
 /** \brief BIER Disposition Entry Add / del
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
-    @param bde_bp - The Bit-position value for the entry
+    @param bde_bp - The Bit-position value for the entry, i.e. the sender's
+                    Use 0 for the default (match any source) entry.
     @param bde_tbl_id - The BIER dispositiontable-id the route is added in
     @param bde_next_hop_sw_if_index - the nextop interface
     @param bde_is_add - Is this a route add or delete
diff --git a/src/vnet/bier/bier_api.c b/src/vnet/bier/bier_api.c
index 67c70462540..002ea0b051a 100644
--- a/src/vnet/bier/bier_api.c
+++ b/src/vnet/bier/bier_api.c
@@ -496,7 +496,10 @@ vl_api_bier_disp_entry_add_del_t_handler (vl_api_bier_disp_entry_add_del_t * mp)
     table_id = ntohl(mp->bde_tbl_id);
     bp = ntohs(mp->bde_bp);
 
-    if (0 == bp || bp > 0xffff)
+    /*
+     * BP=0 is the default route
+     */
+    if (bp > 0xffff)
     {
         rv = -1;
         goto done;
diff --git a/src/vnet/bier/bier_disp_lookup_node.c b/src/vnet/bier/bier_disp_lookup_node.c
index 15515f467ca..1e1ea99557f 100644
--- a/src/vnet/bier/bier_disp_lookup_node.c
+++ b/src/vnet/bier/bier_disp_lookup_node.c
@@ -63,6 +63,7 @@ bier_disp_lookup_inline (vlib_main_t * vm,
         while (n_left_from > 0 && n_left_to_next > 0)
         {
             const bier_hdr_t *hdr0;
+            bier_hdr_src_id_t src0;
             vlib_buffer_t * b0;
             u32 bdei0, bdti0;
             u32 next0, bi0;
@@ -82,15 +83,22 @@ bier_disp_lookup_inline (vlib_main_t * vm,
             /*
              * lookup - source is in network order.
              */
-            bdei0 = bier_disp_table_lookup(bdti0, bier_hdr_get_src_id(hdr0));
+            src0 = bier_hdr_get_src_id(hdr0);
+            next0 = BIER_DISP_LOOKUP_NEXT_DISPATCH;
+
+            bdei0 = bier_disp_table_lookup(bdti0, src0);
 
             if (PREDICT_FALSE(INDEX_INVALID == bdei0))
             {
-                next0 = BIER_DISP_LOOKUP_NEXT_DROP;
-            }
-            else
-            {
-                next0 = BIER_DISP_LOOKUP_NEXT_DISPATCH;
+                /*
+                 * if a specific match misses, try the default
+                 */
+                bdei0 = bier_disp_table_lookup(bdti0, 0);
+
+                if (PREDICT_FALSE(INDEX_INVALID == bdei0))
+                {
+                    next0 = BIER_DISP_LOOKUP_NEXT_DROP;
+                }
             }
 
             vnet_buffer(b0)->ip.adj_index[VLIB_TX] = bdei0;