Subject: Re: [PATCH net-next] ethtool: Drop check for vlan etype and vlan tci when parsing flow_rule

From: Maxime Chevallier <[email-masked]>
Date: Wed, 29 May 2019 17:07:25 +0200

On Wed, 29 May 2019 16:10:44 +0200
Maxime Chevallier <[email-masked]> wrote:

>When parsing an ethtool flow spec to build a flow_rule, the code checks
>if both the vlan etype and the vlan tci are specified by the user to add
>a FLOW_DISSECTOR_KEY_VLAN match.
>
>However, when the user only specified a vlan etype or a vlan tci, this
>check silently ignores these parameters.
>
>For example, the following rule :
>
>ethtool -N eth0 flow-type udp4 vlan 0x0010 action -1 loc 0
>
>will result in no error being issued, but the equivalent rule will be
>created and passed to the NIC driver :
>
>ethtool -N eth0 flow-type udp4 action -1 loc 0
>
>In the end, neither the NIC driver using the rule nor the end user have
>a way to know that these keys were dropped along the way, or that
>incorrect parameters were entered.
>
>This kind of check should be left to either the driver, or the ethtool
>flow spec layer.
>
>This commit makes so that ethtool parameters are forwarded as-is to the
>NIC driver.
>
>Since none of the users of ethtool_rx_flow_rule_create are using the
>VLAN dissector, I don't think this qualifies as a regression.
>
>Signed-off-by: Maxime Chevallier <[email-masked]>

I should have targeted this to -net, and provided a Fixes tag.
Let me resend that to the proper tree.

Sorry about the noise,

Maxime