fib: Decouple source from priority and behaviour

Type: feature

the fib_source_t enum alone no longer defines the priority and
behaviour, instead each source must be allocated these attributes.
This allows the creation of other sources by the plugins (and
soon over the API).

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I890ee820fbc16079ee417ea1fbc163192806e853

1 files changed, 26 insertions, 34 deletions

diff --git a/src/vnet/fib/fib_entry.c b/src/vnet/fib/fib_entry.c
index fd69db989f2..0e5482840bf 100644
--- a/src/vnet/fib/fib_entry.c
+++ b/src/vnet/fib/fib_entry.c
@@ -34,7 +34,6 @@
 /*
  * Array of strings/names for the FIB sources
  */
-static const char *fib_source_names[] = FIB_SOURCES;
 static const char *fib_attribute_names[] = FIB_ENTRY_ATTRIBUTES;
 static const char *fib_src_attribute_names[] = FIB_ENTRY_SRC_ATTRIBUTES;
 
@@ -98,16 +97,6 @@ fib_entry_get_default_chain_type (const fib_entry_t *fib_entry)
 }
 
 u8 *
-format_fib_source (u8 * s, va_list * args)
-{
-    fib_source_t source = va_arg (*args, int);
-
-    s = format (s, "src:%s", fib_source_names[source]);
-
-    return (s);
-}
-
-u8 *
 format_fib_entry_flags (u8 *s, va_list *args)
 {
     fib_entry_attribute_t attr;
@@ -285,7 +274,7 @@ fib_entry_src_get_source (const fib_entry_src_t *esrc)
     {
 	return (esrc->fes_src);
     }
-    return (FIB_SOURCE_MAX);
+    return (FIB_SOURCE_INVALID);
 }
 
 static fib_entry_flag_t
@@ -836,16 +825,17 @@ fib_entry_source_change_w_flags (fib_entry_t *fib_entry,
                                  fib_entry_flag_t old_flags,
                                  fib_source_t new_source)
 {
-    if (new_source < old_source)
+    switch (fib_source_cmp(new_source, old_source))
     {
+    case FIB_SOURCE_CMP_BETTER:
 	/*
 	 * we have a new winning source.
 	 */
 	fib_entry_src_action_deactivate(fib_entry, old_source);
 	fib_entry_src_action_activate(fib_entry, new_source);
-    }
-    else if (new_source > old_source)
-    {
+        break;
+
+    case FIB_SOURCE_CMP_WORSE:
         /*
          * the new source loses. Re-activate the winning sources
          * in case it is an interposer and hence relied on the losing
@@ -853,15 +843,15 @@ fib_entry_source_change_w_flags (fib_entry_t *fib_entry,
          */
         fib_entry_src_action_reactivate(fib_entry, old_source);
         return;
-    }
-    else
-    {
+
+    case FIB_SOURCE_CMP_EQUAL:
 	/*
 	 * the new source is one this entry already has.
 	 * But the path-list was updated, which will contribute new forwarding,
 	 * so install it.
 	 */
         fib_entry_src_action_reactivate(fib_entry, new_source);
+        break;
     }
 
     fib_entry_post_update_actions(fib_entry, new_source, old_flags);
@@ -984,7 +974,7 @@ fib_entry_source_removed (fib_entry_t *fib_entry,
     bsrc = fib_entry_get_best_src_i(fib_entry);
     best_source = fib_entry_src_get_source(bsrc);
 
-    if (FIB_SOURCE_MAX == best_source)
+    if (FIB_SOURCE_INVALID == best_source)
     {
         /*
          * no more sources left. this entry is toast.
@@ -1040,16 +1030,16 @@ fib_entry_path_remove (fib_node_index_t fib_entry_index,
      * then we need to create a new one. else we are updating
      * an existing.
      */
-    if (source < best_source)
+    switch (fib_source_cmp(source, best_source))
     {
+    case FIB_SOURCE_CMP_BETTER:
 	/*
 	 * Que! removing a path from a source that is better than the
 	 * one this entry is using.
 	 */
 	ASSERT(0);
-    }
-    else if (source > best_source )
-    {
+        break;
+    case FIB_SOURCE_CMP_WORSE:
 	/*
 	 * the source is not the best. no need to update forwarding
 	 */
@@ -1067,10 +1057,9 @@ fib_entry_path_remove (fib_node_index_t fib_entry_index,
              * that remain are non-inherited
              */
             return (fib_entry_src_burn_only_inherited(fib_entry));
-       }
-    }
-    else
-    {
+        }
+        break;
+    case FIB_SOURCE_CMP_EQUAL:
 	/*
 	 * removing a path from the path-list we were using.
 	 */
@@ -1089,6 +1078,7 @@ fib_entry_path_remove (fib_node_index_t fib_entry_index,
 	     */
 	    fib_entry_src_action_reactivate(fib_entry, source);
 	}
+        break;
     }
 
     fib_entry_post_update_actions(fib_entry, source, bflags);
@@ -1131,16 +1121,17 @@ fib_entry_special_remove (fib_node_index_t fib_entry_index,
      * then we need to create a new one. else we are updating
      * an existing.
      */
-    if (source < best_source )
+    switch (fib_source_cmp(source, best_source))
     {
+    case FIB_SOURCE_CMP_BETTER:
 	/*
 	 * Que! removing a path from a source that is better than the
 	 * one this entry is using. This can only mean it is a source
          * this prefix does not have.
 	 */
         return (FIB_ENTRY_SRC_FLAG_ADDED);
-    }
-    else if (source > best_source ) {
+
+    case FIB_SOURCE_CMP_WORSE:
 	/*
 	 * the source is not the best. no need to update forwarding
 	 */
@@ -1174,9 +1165,9 @@ fib_entry_special_remove (fib_node_index_t fib_entry_index,
 
             return (FIB_ENTRY_SRC_FLAG_ADDED);
         }
-    }
-    else
-    {
+        break;
+
+    case FIB_SOURCE_CMP_EQUAL:
 	if (!(FIB_ENTRY_SRC_FLAG_ADDED & sflag))
 	{
 	    /*
@@ -1191,6 +1182,7 @@ fib_entry_special_remove (fib_node_index_t fib_entry_index,
 	     */
 	    fib_entry_src_action_reactivate(fib_entry, source);
 	}
+        break;
     }
 
     fib_entry_post_update_actions(fib_entry, source, bflags);