isisd: give precedence to new-style TLVs when generating routes

When both old and new-style TLVs exist for a particular prefix, give
precedence to the new-style TLV (like JUNOS does) when generating
routes from the SPT. This changes the current behavior which is to
generate a route for both TLVs, whereas the first is overwritten by
the second in a non-deterministic order (i.e. either the old-style
or the new-style TLV can "win" depending on how the SPF TENTative
list is arranged).

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index 39a1c9ebe97e4f3931eb8ed6326f9567715dfe22..138095fa0cd0fa641e3de8810c5f42c61ae04b40 100644 (file)
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -1222,8 +1222,9 @@ static void isis_spf_build_adj_list(struct isis_spftree *spftree,
 static void add_to_paths(struct isis_spftree *spftree,
                         struct isis_vertex *vertex)
 {
-       struct isis_area *area = spftree->area;
+#ifdef EXTREME_DEBUG
        char buff[VID2STR_BUFFER];
+#endif /* EXTREME_DEBUG */
 
        if (isis_find_vertex(&spftree->paths, &vertex->N, vertex->type))
                return;
@@ -1235,6 +1236,24 @@ static void add_to_paths(struct isis_spftree *spftree,
                   vid2string(vertex, buff, sizeof(buff)), vertex->depth,
                   vertex->d_N);
 #endif /* EXTREME_DEBUG */
+}
+
+static void init_spt(struct isis_spftree *spftree, int mtid)
+{
+       /* Clear data from previous run. */
+       isis_spf_node_list_clear(&spftree->adj_nodes);
+       list_delete_all_node(spftree->sadj_list);
+       isis_vertex_queue_clear(&spftree->tents);
+       isis_vertex_queue_clear(&spftree->paths);
+
+       spftree->mtid = mtid;
+}
+
+static void spf_path_process(struct isis_spftree *spftree,
+                            struct isis_vertex *vertex)
+{
+       struct isis_area *area = spftree->area;
+       char buff[VID2STR_BUFFER];
 
        if (VTYPE_IS(vertex->type)
            && !CHECK_FLAG(spftree->flags, F_SPFTREE_NO_ADJACENCIES)) {
@@ -1281,19 +1300,6 @@ static void add_to_paths(struct isis_spftree *spftree,
                                vid2string(vertex, buff, sizeof(buff)),
                                vertex->depth, vertex->d_N);
        }
-
-       return;
-}
-
-static void init_spt(struct isis_spftree *spftree, int mtid)
-{
-       /* Clear data from previous run. */
-       isis_spf_node_list_clear(&spftree->adj_nodes);
-       list_delete_all_node(spftree->sadj_list);
-       isis_vertex_queue_clear(&spftree->tents);
-       isis_vertex_queue_clear(&spftree->paths);
-
-       spftree->mtid = mtid;
 }
 
 static void isis_spf_loop(struct isis_spftree *spftree,
@@ -1301,6 +1307,7 @@ static void isis_spf_loop(struct isis_spftree *spftree,
 {
        struct isis_vertex *vertex;
        struct isis_lsp *lsp;
+       struct listnode *node;
 
        while (isis_vertex_queue_count(&spftree->tents)) {
                vertex = isis_vertex_queue_pop(&spftree->tents);
@@ -1327,6 +1334,23 @@ static void isis_spf_loop(struct isis_spftree *spftree,
                isis_spf_process_lsp(spftree, lsp, vertex->d_N, vertex->depth,
                                     root_sysid, vertex);
        }
+
+       /* Generate routes once the SPT is formed. */
+       for (ALL_QUEUE_ELEMENTS_RO(&spftree->paths, node, vertex)) {
+               /* New-style TLVs take precedence over the old-style TLVs. */
+               switch (vertex->type) {
+               case VTYPE_IPREACH_INTERNAL:
+               case VTYPE_IPREACH_EXTERNAL:
+                       if (isis_find_vertex(&spftree->paths, &vertex->N,
+                                            VTYPE_IPREACH_TE))
+                               continue;
+                       break;
+               default:
+                       break;
+               }
+
+               spf_path_process(spftree, vertex);
+       }
 }
 
 struct isis_spftree *isis_run_hopcount_spf(struct isis_area *area,