Zebra: Don't resolve nexthops over default route unless explicitly allowed.

Ensure that resolution of a nexthop using a default route is not done in the
nexthop validation/update code in zebra_rib.c also. This is an addition to
the zebra-nht-no-default.patch which made the checks only in the NHT code. In
the case of scenarios like interface down, this nexthop update code will kick
in first to update the route before the NHT code comes into play; without the
additional fix, this code could incorrectly resolve the nexthop over a default
route, even when disallowed by the administrator.

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/nexthop.h b/lib/nexthop.h
index b375c55b9..e92d97262 100644
--- a/lib/nexthop.h
+++ b/lib/nexthop.h
@@ -85,6 +85,20 @@ struct nexthop
   n;                                                                    \
 })
 
+
+extern int zebra_rnh_ip_default_route;
+extern int zebra_rnh_ipv6_default_route;
+
+static inline int
+nh_resolve_via_default(int family)
+{
+  if (((family == AF_INET) && zebra_rnh_ip_default_route) ||
+      ((family == AF_INET6) && zebra_rnh_ipv6_default_route))
+    return 1;
+  else
+    return 0;
+}
+
 extern const char *nexthop_type_to_str (enum nexthop_types_t nh_type);
 extern int nexthop_same_no_recurse (struct nexthop *next1, struct nexthop *next2);