mlxsw: spectrum_router: Offload decap only for up tunnels

When a new local route is added, an IPIP entry is looked up to determine
whether the route should be offloaded as a tunnel decap or as a trap.
That decision should take into account whether the tunnel netdevice in
question is actually IFF_UP, and only install a decap offload if it is.

Fixes: 0063587d ("mlxsw: spectrum: Support decap-only IP-in-IP tunnels")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -3996,7 +3996,7 @@ mlxsw_sp_fib4_entry_type_set(struct mlxsw_sp *mlxsw_sp,
 	case RTN_LOCAL:
 		ipip_entry = mlxsw_sp_ipip_entry_find_by_decap(mlxsw_sp, dev,
 						 MLXSW_SP_L3_PROTO_IPV4, dip);
-		if (ipip_entry) {
+		if (ipip_entry && ipip_entry->ol_dev->flags & IFF_UP) {
 			fib_entry->type = MLXSW_SP_FIB_ENTRY_TYPE_IPIP_DECAP;
 			return mlxsw_sp_fib_entry_decap_init(mlxsw_sp,
 							     fib_entry,