zebra: trust directly connected kernel/system routes

We made the decision to explicitly trust kernel and system routes
of every other type with 058c16b7e239f1c50a1d4b4376a6aff6b8dad959.

So, we should trust directly connected routes the same way, assuming
the interface exists.

Old Behavior:

K   2.2.2.1/32 [0/0] is directly connected, unknown inactive, 00:00:39

New Behavior:

K>* 2.2.2.1/32 [0/0] is directly connected, test1, 00:00:03

As a bonus, this fixes the issues we were seeing with not removing
directly connected routes of certain interface types when
those interfaces go down/are deleted.

Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>

diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
index 7f81e530fb858e40a14057700e7106592a522119..8088b78a93aa1d0751633b7adec8e656038a2c6d 100644 (file)
--- a/zebra/zebra_nhg.c
+++ b/zebra/zebra_nhg.c
@@ -1637,7 +1637,16 @@ static unsigned nexthop_active_check(struct route_node *rn,
        switch (nexthop->type) {
        case NEXTHOP_TYPE_IFINDEX:
                ifp = if_lookup_by_index(nexthop->ifindex, nexthop->vrf_id);
-               if (ifp && if_is_operative(ifp))
+               /*
+                * If the interface exists and its operative or its a kernel
+                * route and interface is up, its active. We trust kernel routes
+                * to be good.
+                */
+               if (ifp
+                   && (if_is_operative(ifp)
+                       || (if_is_up(ifp)
+                           && (re->type == ZEBRA_ROUTE_KERNEL
+                               || re->type == ZEBRA_ROUTE_SYSTEM))))
                        SET_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE);
                else
                        UNSET_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE);