Re: [PATCH net-next] net: qede: flower: validate control flags

[Jiri Pirko <jiri@resnulli.us>]

Wed, Apr 24, 2024 at 03:42:48PM CEST, ast@fiberby.net wrote:
>This driver currently doesn't support any flower control flags.
>
>Implement check for control flags, such as can be set through
>`tc flower ... ip_flags frag`.
>
>Since qede_parse_flow_attr() are called by both qede_add_tc_flower_fltr()
>and qede_flow_spec_to_rule(), as the latter doesn't having access to
>extack, then flow_rule_*_control_flags() can't be used in this driver.

Why? You can pass null.

>
>This patch therefore re-implements flow_rule_match_has_control_flags(),
>but with error messaging via DP_NOTICE, instead of NL_SET_ERR_MSG_FMT_MOD.
>
>So in case any control flags are masked, we call DP_NOTICE() and
>return -EOPNOTSUPP.
>
>Only compile-tested.
>
>Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
>---
>
>This is AFAICT the last driver which didn't validate these flags.
>
>$ git grep FLOW_DISSECTOR_KEY_CONTROL drivers/
>$ git grep 'flow_rule_.*_control_flags' drivers/
>
> drivers/net/ethernet/qlogic/qede/qede_filter.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
>diff --git a/drivers/net/ethernet/qlogic/qede/qede_filter.c b/drivers/net/ethernet/qlogic/qede/qede_filter.c
>index a5ac21a0ee33..40f72e700d8e 100644
>--- a/drivers/net/ethernet/qlogic/qede/qede_filter.c
>+++ b/drivers/net/ethernet/qlogic/qede/qede_filter.c
>@@ -1843,6 +1843,19 @@ qede_parse_flow_attr(struct qede_dev *edev, __be16 proto,
> 		return -EPROTONOSUPPORT;
> 	}
> 
>+	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_CONTROL)) {
>+		struct flow_match_control match;
>+
>+		flow_rule_match_control(rule, &match);
>+
>+		if (match.mask->flags) {
>+			DP_NOTICE(edev,
>+				  "Unsupported match on control.flags %#x",
>+				  match.mask->flags);
>+			return -EOPNOTSUPP;
>+		}
>+	}
>+
> 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC)) {
> 		struct flow_match_basic match;
> 
>-- 
>2.43.0
>
>