Commit f4356947 authored May 29, 2023 by Ido Schimmel Committed by Jakub Kicinski May 30, 2023

flow_offload: Reject matching on layer 2 miss



Adjust drivers that support the 'FLOW_DISSECTOR_KEY_META' key to reject
filters that try to match on the newly added layer 2 miss field. Add an
extack message to clearly communicate the failure reason to user space.

The following users were not patched:

1. mtk_flow_offload_replace(): Only checks that the key is present, but
   does not do anything with it.
2. mlx5_tc_ct_set_tuple_match(): Used as part of netfilter offload,
   which does not make use of the new field, unlike tc.
3. get_netdev_from_rule() in nfp: Likewise.

Example:

 # tc filter add dev swp1 egress pref 1 proto all flower skip_sw l2_miss true action drop
 Error: mlxsw_spectrum: Can't match on "l2_miss".
 We have an error talking to the kernel

Acked-by: Elad Nachman <enachman@marvell.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 1a432018

drivers/net/ethernet/marvell/prestera/prestera_flower.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -148,6 +148,12 @@ static int prestera_flower_parse_meta(struct prestera_acl_rule *rule,
		__be16 key, mask;

		flow_rule_match_meta(f_rule, &match);

		if (match.mask->l2_miss) {
		NL_SET_ERR_MSG_MOD(f->common.extack, "Can't match on \"l2_miss\"");
		return -EOPNOTSUPP;
		}

		if (match.mask->ingress_ifindex != 0xFFFFFFFF) {
		NL_SET_ERR_MSG_MOD(f->common.extack,
		"Unsupported ingress ifindex mask");

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -2587,6 +2587,12 @@ static int mlx5e_flower_parse_meta(struct net_device *filter_dev,
		return 0;

		flow_rule_match_meta(rule, &match);

		if (match.mask->l2_miss) {
		NL_SET_ERR_MSG_MOD(f->common.extack, "Can't match on \"l2_miss\"");
		return -EOPNOTSUPP;
		}

		if (!match.mask->ingress_ifindex)
		return 0;

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

+6 −0

Original line number	Diff line number	Diff line
		@@ -294,6 +294,12 @@ static int mlxsw_sp_flower_parse_meta(struct mlxsw_sp_acl_rule_info *rulei,
		return 0;

		flow_rule_match_meta(rule, &match);

		if (match.mask->l2_miss) {
		NL_SET_ERR_MSG_MOD(f->common.extack, "Can't match on \"l2_miss\"");
		return -EOPNOTSUPP;
		}

		if (match.mask->ingress_ifindex != 0xFFFFFFFF) {
		NL_SET_ERR_MSG_MOD(f->common.extack, "Unsupported ingress ifindex mask");
		return -EINVAL;

drivers/net/ethernet/mscc/ocelot_flower.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -592,6 +592,16 @@ ocelot_flower_parse_key(struct ocelot *ocelot, int port, bool ingress,
		return -EOPNOTSUPP;
		}

		if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_META)) {
		struct flow_match_meta match;

		flow_rule_match_meta(rule, &match);
		if (match.mask->l2_miss) {
		NL_SET_ERR_MSG_MOD(extack, "Can't match on \"l2_miss\"");
		return -EOPNOTSUPP;
		}
		}

		/* For VCAP ES0 (egress rewriter) we can match on the ingress port */
		if (!ingress) {
		ret = ocelot_flower_parse_indev(ocelot, port, f, filter);