diff mbox series

[net-next,3/5] flow_offload: Reject matching on layer 2 miss

Message ID 20230518113328.1952135-4-idosch@nvidia.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Add layer 2 miss indication and filtering | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 1 maintainers not CCed: linux-rdma@vger.kernel.org
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 83 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Ido Schimmel May 18, 2023, 11:33 a.m. UTC 
Adjust drivers that support the 'FLOW_DISSECTOR_KEY_META' key to reject
filters that try to match on the newly added layer 2 miss option. Add an
extack message to clearly communicate the failure reason to user space.

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>
---
 .../net/ethernet/marvell/prestera/prestera_flower.c    |  6 ++++++
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c        |  6 ++++++
 drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c  |  6 ++++++
 drivers/net/ethernet/mscc/ocelot_flower.c              | 10 ++++++++++
 4 files changed, 28 insertions(+)

Comments

Simon Horman May 19, 2023, 11:33 a.m. UTC | #1 
On Thu, May 18, 2023 at 02:33:26PM +0300, Ido Schimmel wrote:
> Adjust drivers that support the 'FLOW_DISSECTOR_KEY_META' key to reject
> filters that try to match on the newly added layer 2 miss option. Add an
> extack message to clearly communicate the failure reason to user space.

Hi Ido,

FLOW_DISSECTOR_KEY_META is also used in the following.
Perhaps they don't need updating. But perhaps it is worth mentioning why.

 * drivers/net/ethernet/mediatek/mtk_ppe_offload.c
 * drivers/net/ethernet/netronome/nfp/flower/conntrack.c

> 
> 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>

...
Ido Schimmel May 19, 2023, 2:10 p.m. UTC | #2 
On Fri, May 19, 2023 at 01:33:00PM +0200, Simon Horman wrote:
> On Thu, May 18, 2023 at 02:33:26PM +0300, Ido Schimmel wrote:
> > Adjust drivers that support the 'FLOW_DISSECTOR_KEY_META' key to reject
> > filters that try to match on the newly added layer 2 miss option. Add an
> > extack message to clearly communicate the failure reason to user space.
> 
> Hi Ido,
> 
> FLOW_DISSECTOR_KEY_META is also used in the following.
> Perhaps they don't need updating. But perhaps it is worth mentioning why.

Good point.

> 
>  * drivers/net/ethernet/mediatek/mtk_ppe_offload.c

This driver does not seem to do anything with this key. TBH, I'm not
sure what is the purpose of this hunk:

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

	flow_rule_match_meta(rule, &match);
} else {
	return -EOPNOTSUPP;
}

Felix, can you comment?
Original patch:
https://lore.kernel.org/netdev/20230518113328.1952135-4-idosch@nvidia.com/

>  * drivers/net/ethernet/netronome/nfp/flower/conntrack.c

My understanding is that this code is for netfilter offload (not tc)
which does not use the new bit. Adding a check would therefore be dead
code. I don't mind adding a check or mentioning in the commit message
why I didn't add one. Let me know what you prefer.

Thanks
Simon Horman May 19, 2023, 2:15 p.m. UTC | #3 
On Fri, May 19, 2023 at 05:10:58PM +0300, Ido Schimmel wrote:
> On Fri, May 19, 2023 at 01:33:00PM +0200, Simon Horman wrote:
> > On Thu, May 18, 2023 at 02:33:26PM +0300, Ido Schimmel wrote:
> > > Adjust drivers that support the 'FLOW_DISSECTOR_KEY_META' key to reject
> > > filters that try to match on the newly added layer 2 miss option. Add an
> > > extack message to clearly communicate the failure reason to user space.
> > 
> > Hi Ido,
> > 
> > FLOW_DISSECTOR_KEY_META is also used in the following.
> > Perhaps they don't need updating. But perhaps it is worth mentioning why.
> 
> Good point.
> 
> > 
> >  * drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> 
> This driver does not seem to do anything with this key. TBH, I'm not
> sure what is the purpose of this hunk:
> 
> if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_META)) {
> 	struct flow_match_meta match;
> 
> 	flow_rule_match_meta(rule, &match);
> } else {
> 	return -EOPNOTSUPP;
> }
> 
> Felix, can you comment?
> Original patch:
> https://lore.kernel.org/netdev/20230518113328.1952135-4-idosch@nvidia.com/

FWIIW, I agree with your analysis here.

> >  * drivers/net/ethernet/netronome/nfp/flower/conntrack.c
> 
> My understanding is that this code is for netfilter offload (not tc)
> which does not use the new bit. Adding a check would therefore be dead
> code. I don't mind adding a check or mentioning in the commit message
> why I didn't add one. Let me know what you prefer.

Let's go with a comment in the commit message.
Thanks.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_flower.c b/drivers/net/ethernet/marvell/prestera/prestera_flower.c
index 91a478b75cbf..3e20e71b0f81 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_flower.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_flower.c
@@ -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");
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 728b82ce4031..516653568330 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2586,6 +2586,12 @@  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;
 
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
index 594cdcb90b3d..6fec9223250b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
@@ -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;
diff --git a/drivers/net/ethernet/mscc/ocelot_flower.c b/drivers/net/ethernet/mscc/ocelot_flower.c
index ee052404eb55..e0916afcddfb 100644
--- a/drivers/net/ethernet/mscc/ocelot_flower.c
+++ b/drivers/net/ethernet/mscc/ocelot_flower.c
@@ -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);