fib: add invalid source type and fix debug log

Add the FIB_SOURCE_INVALID fib source type. This allows to spot
uninitialized fib source more easily (0 no longer means special) and we
can use it as placeholder when no source is present.
Use it to fix FIB_ENTRY_DBG() which was accessing the 1st source, even
when no sources were present.

Type: fix
Fixes: 710071bf0e

Change-Id: I980b6a6a07616d4a8d6f2db166a1dd335721c74d
Signed-off-by: Benoît Ganne <bganne@cisco.com>

1 files changed, 12 insertions, 17 deletions

diff --git a/src/vnet/fib/fib_entry_src.c b/src/vnet/fib/fib_entry_src.c
index 067733f0a8d..6ed13a328bd 100644
--- a/src/vnet/fib/fib_entry_src.c
+++ b/src/vnet/fib/fib_entry_src.c
@@ -1827,27 +1827,22 @@ fib_entry_get_flags_for_source (fib_node_index_t entry_index,
     return (FIB_ENTRY_FLAG_NONE);
 }
 
+fib_source_t
+fib_entry_get_source_i (const fib_entry_t *fib_entry)
+{
+    /* the vector of sources is deliberately arranged in priority order */
+    if (0 == vec_len(fib_entry->fe_srcs))
+        return (FIB_SOURCE_INVALID);
+    return (vec_elt(fib_entry->fe_srcs, 0).fes_src);
+}
+
 fib_entry_flag_t
 fib_entry_get_flags_i (const fib_entry_t *fib_entry)
 {
-    fib_entry_flag_t flags;
-
-    /*
-     * the vector of sources is deliberately arranged in priority order
-     */
+    /* the vector of sources is deliberately arranged in priority order */
     if (0 == vec_len(fib_entry->fe_srcs))
-    {
-	flags = FIB_ENTRY_FLAG_NONE;
-    }
-    else
-    {
-	fib_entry_src_t *esrc;
-
-	esrc = vec_elt_at_index(fib_entry->fe_srcs, 0);
-	flags = esrc->fes_entry_flags;
-    }
-
-    return (flags);
+        return (FIB_ENTRY_FLAG_NONE);
+    return (vec_elt(fib_entry->fe_srcs, 0).fes_entry_flags);
 }
 
 void