On 3/27/19 3:08 AM, Ido Schimmel wrote:

On Tue, Mar 26, 2019 at 08:29:36PM -0700, David Ahern wrote:

quoted

@@ -989,8 +989,11 @@ static void ip6_rt_copy_init(struct rt6_info *rt, struct fib6_info *ort)
 
 	rt->rt6i_dst = ort->fib6_dst;
 	rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
-	rt->rt6i_gateway = ort->fib6_nh.nh_gw;
 	rt->rt6i_flags = ort->fib6_flags;
+	if (ort->fib6_nh.fib_nh_has_gw) {
+		rt->rt6i_gateway = ort->fib6_nh.nh_gw;
+		rt->rt6i_flags |= RTF_GATEWAY;

Not sure I understand why this line is needed. Can you explain?

The RTF_GATEWAY flag in an rt6_info still has many users.

quoted

+	}
 	rt6_set_from(rt, ort);
 #ifdef CONFIG_IPV6_SUBTREES
 	rt->rt6i_src = ort->fib6_src;

@@ -1870,7 +1873,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,

...

quoted

@@ -3134,7 +3138,7 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
 	} else
 		rt->fib6_prefsrc.plen = 0;
 
-	rt->fib6_flags = cfg->fc_flags;
+	rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;

This is going to break mlxsw. See:

mlxsw_sp_fib6_rt_can_mp()
mlxsw_sp_rt6_is_gateway()

hmmm... not sure how I missed those. Will rescan the code for any other
missed checks on a fib6_info.