Re: [dpdk-dev] [RFC] ethdev: add sanity packet checks

[Ori Kam <orika@nvidia.com>]

Hi 

PSB

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Thomas Monjalon
> Sent: Sunday, February 28, 2021 10:14 PM
> 
> 28/02/2021 20:48, Ori Kam:
> > Currently, DPDK application can offload the checksum check,
> > and report it in the mbuf.
> >
> > However, this approach doesn't work if the traffic
> > is offloaded and should not arrive to the application.
> >
> > This commit introduces rte flow item that enables
> 
> s/rte flow/rte_flow/
> 

Sure

> > matching on the checksum of the L3 and L4 layers,
> > in addition to other checks that can determine if
> > the packet is valid.
> > some of those tests can be packet len, data len,
> > unsupported flags, and so on.
> >
> > The full check is HW dependent.
> 
> What is the "full check"?
> How much it is HW dependent?
> 

This also relates to your other comments,
Each HW may run different set of checks on the packet,
for example one PMD can just check the tcp flags while
a different PMD will also check the option.

> 
> > + * RTE_FLOW_ITEM_TYPE_SANITY_CHECKS
> > + *
> > + * Enable matching on packet validity based on HW checks for the L3 and L4
> > + * layers.
> > + */
> > +struct rte_flow_item_sanity_checks {
> > +	uint32_t level;
> > +	/**< Packet encapsulation level the item should apply to.
> > +	 * @see rte_flow_action_rss
> > +	 */
> > +RTE_STD_C11
> > +	union {
> > +		struct {
> 
> Why there is no L2 check?
> 
Our HW doesn't support it.
If other HW support it, it should be added.

> > +			uint32_t l3_ok:1;
> > +			/**< L3 layer is valid after passing all HW checking. */
> > +			uint32_t l4_ok:1;
> > +			/**< L4 layer is valid after passing all HW checking. */
> 
> l3_ok and l4_ok looks vague.
> What does it cover exactly?
> 
It depends on the HW in question.
In our case it checks in case of L3
the header len, and the version.
For L4 checking the len.

> > +			uint32_t l3_ok_csum:1;
> > +			/**< L3 layer checksum is valid. */
> > +			uint32_t l4_ok_csum:1;
> > +			/**< L4 layer checksum is valid. */
> > +			uint32_t reserved:28;
> > +		};
> > +		uint32_t  value;
> > +	};
> > +};
> 
> 

Best,
Ori