mlxsw: spectrum_router: Return an error for non-default FIB rules

Since commit 9776d325 ("net: Move call_fib_rule_notifiers up in
fib_nl_newrule") it is possible to forbid the installation of
unsupported FIB rules.

Have mlxsw return an error for non-default FIB rules in addition to the
existing extack message.

Example:
# ip rule add from 198.51.100.1 table 10
Error: mlxsw_spectrum: FIB rules not supported.

Note that offload is only aborted when non-default FIB rules are already
installed and merely replayed during module initialization.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -5882,24 +5882,24 @@ static int mlxsw_sp_router_fib_rule_event(unsigned long event,
 	switch (info->family) {
 	case AF_INET:
 		if (!fib4_rule_default(rule) && !rule->l3mdev)
-			err = -1;
+			err = -EOPNOTSUPP;
 		break;
 	case AF_INET6:
 		if (!fib6_rule_default(rule) && !rule->l3mdev)
-			err = -1;
+			err = -EOPNOTSUPP;
 		break;
 	case RTNL_FAMILY_IPMR:
 		if (!ipmr_rule_default(rule) && !rule->l3mdev)
-			err = -1;
+			err = -EOPNOTSUPP;
 		break;
 	case RTNL_FAMILY_IP6MR:
 		if (!ip6mr_rule_default(rule) && !rule->l3mdev)
-			err = -1;
+			err = -EOPNOTSUPP;
 		break;
 	}
 
 	if (err < 0)
-		NL_SET_ERR_MSG_MOD(extack, "FIB rules not supported. Aborting offload");
+		NL_SET_ERR_MSG_MOD(extack, "FIB rules not supported");
 
 	return err;
 }
@@ -5926,8 +5926,8 @@ static int mlxsw_sp_router_fib_event(struct notifier_block *nb,
 	case FIB_EVENT_RULE_DEL:
 		err = mlxsw_sp_router_fib_rule_event(event, info,
 						     router->mlxsw_sp);
-		if (!err)
-			return NOTIFY_DONE;
+		if (!err || info->extack)
+			return notifier_from_errno(err);
 	}
 
 	fib_work = kzalloc(sizeof(*fib_work), GFP_ATOMIC);