Do not initialize route metrics in import_control hook

During route export, the receiving protocol often initialized route
metrics to default value in its import_control hook before export filter
was executed. This is inconsistent with the expectation that an export
filter would process the same route as one in the routing table and it
breaks setting these metrics before (e.g. for static routes directly in
static protocol).

The patch removes the initialization of route metrics in import_control
hook, the default values are already handled in rt_notify hook called
after export filters.

The patch also changed the behavior of OSPF to keep metrics when a route
is reannounced between OSPF instances (to be consistent with other
protocols) and the behavior when both ospf_metric1 and ospf_metric2
are specified (to have more expected behavior).

1 files changed, 3 insertions, 9 deletions

diff --git a/proto/babel/babel.c b/proto/babel/babel.c
index ce05191c..44c6adb8 100644
--- a/proto/babel/babel.c
+++ b/proto/babel/babel.c
@@ -2087,20 +2087,14 @@ babel_prepare_attrs(struct linpool *pool, ea_list *next, uint metric, u64 router
 
 
 static int
-babel_import_control(struct proto *P, struct rte **new, struct ea_list **attrs, struct linpool *pool)
+babel_import_control(struct proto *P, struct rte **new, struct ea_list **attrs UNUSED, struct linpool *pool UNUSED)
 {
-  struct babel_proto *p = (void *) P;
-  rte *rt = *new;
+  rte *e = *new;
 
   /* Reject our own unreachable routes */
-  if ((rt->attrs->dest == RTD_UNREACHABLE) && (rt->attrs->src->proto == P))
+  if ((e->attrs->dest == RTD_UNREACHABLE) && (e->attrs->src->proto == P))
     return -1;
 
-
-  /* Prepare attributes with initial values */
-  if (rt->attrs->source != RTS_BABEL)
-    *attrs = babel_prepare_attrs(pool, NULL, 0, p->router_id);
-
   return 0;
 }