BFD-FIB interactions

- single-hop BFD: attach a delegate to the appropriate adjacency
- multi-hop BFD [not supported yet]: attach a delegate to the FIB entry.

adjacency/fib_entry state tracks the BFD session state. when the state is down the object does not contribute forwarding hence and hence dependent objects will not use it.
For example, if a route is ECMP via two adjacencies and one of them is BFD down, then only the other is used to forward (i.e. we don't drop half the traffic).

Change-Id: I0ef53e20e73b067001a132cd0a3045408811a822
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 34 insertions, 16 deletions

diff --git a/src/vnet/fib/fib_entry.c b/src/vnet/fib/fib_entry.c
index 6ac5461d76c..dac1fce995f 100644
--- a/src/vnet/fib/fib_entry.c
+++ b/src/vnet/fib/fib_entry.c
@@ -99,7 +99,6 @@ format_fib_entry (u8 * s, va_list * args)
     fib_entry_src_t *src;
     fib_node_index_t fei;
     fib_source_t source;
-    u32 n_covered;
     int level;
 
     fei = va_arg (*args, fib_node_index_t);
@@ -143,14 +142,6 @@ format_fib_entry (u8 * s, va_list * args)
 	    }
 	}));
     
-	n_covered = fib_entry_cover_get_size(fib_entry);
-	if (n_covered > 0) {
-	    s = format(s, "\n tracking %d covered: ", n_covered);
-	    s = fib_entry_cover_list_format(fib_entry, s);
-	}
-	s = fib_ae_import_format(fib_entry, s);
-	s = fib_ae_export_format(fib_entry, s);
-
 	s = format (s, "\n forwarding: ");
     }
     else
@@ -179,20 +170,17 @@ format_fib_entry (u8 * s, va_list * args)
             fib_entry_delegate_type_t fdt;
             fib_entry_delegate_t *fed;
 
-            FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+            s = format (s, " Delegates:\n");
+            FOR_EACH_DELEGATE(fib_entry, fdt, fed,
             {
-                s = format(s, "  %U-chain\n  %U",
-                           format_fib_forw_chain_type,
-                           fib_entry_delegate_type_to_chain_type(fdt),
-                           format_dpo_id, &fed->fd_dpo, 2);
-                s = format(s, "\n");
+                s = format(s, "  %U\n", format_fib_entry_deletegate, fed);
             });
         }
     }
 
     if (level >= FIB_ENTRY_FORMAT_DETAIL2)
     {
-        s = format(s, "\nchildren:");
+        s = format(s, " Children:");
         s = fib_node_children_format(fib_entry->fe_node.fn_children, s);
     }
 
@@ -1339,6 +1327,36 @@ fib_entry_get_best_source (fib_node_index_t entry_index)
     return (fib_entry_src_get_source(bsrc));
 }
 
+/**
+ * Return !0 is the entry is reoslved, i.e. will return a valid forwarding
+ * chain
+ */
+int
+fib_entry_is_resolved (fib_node_index_t fib_entry_index)
+{
+    fib_entry_delegate_t *fed;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fed = fib_entry_delegate_get(fib_entry, FIB_ENTRY_DELEGATE_BFD);
+
+    if (NULL == fed)
+    {
+        /*
+         * no BFD tracking - resolved
+         */
+        return (!0);
+    }
+    else
+    {
+        /*
+         * defer to the state of the BFD tracking
+         */
+        return (FIB_BFD_STATE_UP == fed->fd_bfd_state);
+    }
+}
+
 static int
 fib_ip4_address_compare (const ip4_address_t * a1,
                          const ip4_address_t * a2)