mlxsw: spectrum_router: Allow appending to dev-only routes

Commit f34436a4 ("net/ipv6: Simplify route replace and appending
into multipath route") changed the IPv6 route append logic so that
dev-only routes can be appended and not only gatewayed routes.

Align mlxsw with the new behaviour.

Fixes: f34436a4 ("net/ipv6: Simplify route replace and appending into multipath route")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -4771,11 +4771,11 @@ mlxsw_sp_fib6_entry_rt(const struct mlxsw_sp_fib6_entry *fib6_entry)
 
 static struct mlxsw_sp_fib6_entry *
 mlxsw_sp_fib6_node_mp_entry_find(const struct mlxsw_sp_fib_node *fib_node,
-				 const struct fib6_info *nrt, bool replace)
+				 const struct fib6_info *nrt, bool append)
 {
 	struct mlxsw_sp_fib6_entry *fib6_entry;
 
-	if (!mlxsw_sp_fib6_rt_can_mp(nrt) || replace)
+	if (!append)
 		return NULL;
 
 	list_for_each_entry(fib6_entry, &fib_node->entry_list, common.list) {
@@ -4790,8 +4790,7 @@ mlxsw_sp_fib6_node_mp_entry_find(const struct mlxsw_sp_fib_node *fib_node,
 			break;
 		if (rt->fib6_metric < nrt->fib6_metric)
 			continue;
-		if (rt->fib6_metric == nrt->fib6_metric &&
-		    mlxsw_sp_fib6_rt_can_mp(rt))
+		if (rt->fib6_metric == nrt->fib6_metric)
 			return fib6_entry;
 		if (rt->fib6_metric > nrt->fib6_metric)
 			break;
@@ -5316,7 +5315,8 @@ static void mlxsw_sp_fib6_entry_replace(struct mlxsw_sp *mlxsw_sp,
 }
 
 static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
-				    struct fib6_info *rt, bool replace)
+				    struct fib6_info *rt, bool replace,
+				    bool append)
 {
 	struct mlxsw_sp_fib6_entry *fib6_entry;
 	struct mlxsw_sp_fib_node *fib_node;
@@ -5342,7 +5342,7 @@ static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
 	/* Before creating a new entry, try to append route to an existing
 	 * multipath entry.
 	 */
-	fib6_entry = mlxsw_sp_fib6_node_mp_entry_find(fib_node, rt, replace);
+	fib6_entry = mlxsw_sp_fib6_node_mp_entry_find(fib_node, rt, append);
 	if (fib6_entry) {
 		err = mlxsw_sp_fib6_entry_nexthop_add(mlxsw_sp, fib6_entry, rt);
 		if (err)
@@ -5350,6 +5350,14 @@ static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
 		return 0;
 	}
 
+	/* We received an append event, yet did not find any route to
+	 * append to.
+	 */
+	if (WARN_ON(append)) {
+		err = -EINVAL;
+		goto err_fib6_entry_append;
+	}
+
 	fib6_entry = mlxsw_sp_fib6_entry_create(mlxsw_sp, fib_node, rt);
 	if (IS_ERR(fib6_entry)) {
 		err = PTR_ERR(fib6_entry);
@@ -5367,6 +5375,7 @@ static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
 err_fib6_node_entry_link:
 	mlxsw_sp_fib6_entry_destroy(mlxsw_sp, fib6_entry);
 err_fib6_entry_create:
+err_fib6_entry_append:
 err_fib6_entry_nexthop_add:
 	mlxsw_sp_fib_node_put(mlxsw_sp, fib_node);
 	return err;
@@ -5717,7 +5726,7 @@ static void mlxsw_sp_router_fib6_event_work(struct work_struct *work)
 	struct mlxsw_sp_fib_event_work *fib_work =
 		container_of(work, struct mlxsw_sp_fib_event_work, work);
 	struct mlxsw_sp *mlxsw_sp = fib_work->mlxsw_sp;
-	bool replace;
+	bool replace, append;
 	int err;
 
 	rtnl_lock();
@@ -5728,8 +5737,10 @@ static void mlxsw_sp_router_fib6_event_work(struct work_struct *work)
 	case FIB_EVENT_ENTRY_APPEND: /* fall through */
 	case FIB_EVENT_ENTRY_ADD:
 		replace = fib_work->event == FIB_EVENT_ENTRY_REPLACE;
+		append = fib_work->event == FIB_EVENT_ENTRY_APPEND;
 		err = mlxsw_sp_router_fib6_add(mlxsw_sp,
-					       fib_work->fen6_info.rt, replace);
+					       fib_work->fen6_info.rt, replace,
+					       append);
 		if (err)
 			mlxsw_sp_router_fib_abort(mlxsw_sp);
 		mlxsw_sp_rt6_release(fib_work->fen6_info.rt);