Re: [dpdk-dev] [PATCH] ethdev: add packet integrity checks

[Jerin Jacob <jerinjacobk@gmail.com>]

On Wed, Apr 7, 2021 at 4:02 PM Ori Kam <orika@nvidia.com> wrote:
>
> Hi Jerin,

Hi Ori,


>
> > -----Original Message-----
> > From: Jerin Jacob <jerinjacobk@gmail.com>
> > Sent: Tuesday, April 6, 2021 10:40 AM
> > To: Ori Kam <orika@nvidia.com>
> > Subject: Re: [dpdk-dev] [PATCH] ethdev: add packet integrity checks
> >
> > On Mon, Apr 5, 2021 at 11:35 PM Ori Kam <orika@nvidia.com> wrote:
> > >
> > > Currently, DPDK application can offload the checksum check,
> > > and report it in the mbuf.
> > >
> > > However, as more and more applications are offloading some or all
> > > logic and action to the HW, there is a need to check the packet
> > > integrity so the right decision can be taken.
> > >
> > > The application logic can be positive meaning if the packet is
> > > valid jump / do  actions, or negative if packet is not valid
> > > jump to SW / do actions (like drop)  a, and add default flow
> > > (match all in low priority) that will direct the miss packet
> > > to the miss path.
> > >
> > > Since currenlty rte_flow works in positive way the assumtion is
> > > that the postive way will be the common way in this case also.
> > >
> > > When thinking what is the best API to implement such feature,
> > > we need to considure the following (in no specific order):
> > > 1. API breakage.
> > > 2. Simplicity.
> > > 3. Performance.
> > > 4. HW capabilities.
> > > 5. rte_flow limitation.
> > > 6. Flexability.
> >
> >
> > Alteast in Marvell HW integrity checks are functions of the Ethdev Rx
> > queue attribute.
> > Not sure about other Vendor HW.
>
> I'm not sure what do you mean?

What I meant is, What will be the preferred way to configure the feature?
ie. Is it as ethdev Rx offload or rte_flow?

I think, in order to decide that, we need to know, how most of the
other HW express this feature?


> This is the idea of the patch, to allow application to route the packet
> before getting to the Rx,
> In any case all items support is dependent on HW capabilities.




>
>
> >
> >
> > >
> > > First option: Add integrity flags to each of the items.
> > > For example add checksum_ok to ipv4 item.
> > >
> > > Pros:
> > > 1. No new rte_flow item.
> > > 2. Simple in the way that on each item the app can see
> > > what checks are available.
> > >
> > > Cons:
> > > 1. API breakage.
> > > 2. increase number of flows, since app can't add global rule and
> > >    must have dedicated flow for each of the flow combinations, for example
> > >    matching on icmp traffic or UDP/TCP  traffic with IPv4 / IPv6 will
> > >    result in 5 flows.
> > >
> > > Second option: dedicated item
> > >
> > > Pros:
> > > 1. No API breakage, and there will be no for some time due to having
> > >    extra space. (by using bits)
> > > 2. Just one flow to support the icmp or UDP/TCP traffic with IPv4 /
> > >    IPv6.
> > > 3. Simplicity application can just look at one place to see all possible
> > >    checks.
> > > 4. Allow future support for more tests.
> > >
> > > Cons:
> > > 1. New item, that holds number of fields from different items.
> > >
> > > For starter the following bits are suggested:
> > > 1. packet_ok - means that all HW checks depending on packet layer have
> > >    passed. This may mean that in some HW such flow should be splited to
> > >    number of flows or fail.
> > > 2. l2_ok - all check flor layer 2 have passed.
> > > 3. l3_ok - all check flor layer 2 have passed. If packet doens't have
> > >    l3 layer this check shoudl fail.
> > > 4. l4_ok - all check flor layer 2 have passed. If packet doesn't
> > >    have l4 layer this check should fail.
> > > 5. l2_crc_ok - the layer 2 crc is O.K. it is possible that the crc will
> > >    be O.K. but the l3_ok will be 0. it is not possible that l2_crc_ok will
> > >    be 0 and the l3_ok will be 0.
> > > 6. ipv4_csum_ok - IPv4 checksum is O.K.
> > > 7. l4_csum_ok - layer 4 checksum is O.K.
> > > 8. l3_len_OK - check that the reported layer 3 len is smaller than the
> > >    packet len.
> > >
> > > Example of usage:
> > > 1. check packets from all possible layers for integrity.
> > >    flow create integrity spec packet_ok = 1 mask packet_ok = 1 .....
> > >
> > > 2. Check only packet with layer 4 (UDP / TCP)
> > >    flow create integrity spec l3_ok = 1, l4_ok = 1 mask l3_ok = 1 l4_ok = 1
> > >
> > > Signed-off-by: Ori Kam <orika@nvidia.com>
> > > ---
> > >  doc/guides/prog_guide/rte_flow.rst | 19 ++++++++++++++++
> > >  lib/librte_ethdev/rte_flow.h       | 46
> > ++++++++++++++++++++++++++++++++++++++
> > >  2 files changed, 65 insertions(+)
> > >
> > > diff --git a/doc/guides/prog_guide/rte_flow.rst
> > b/doc/guides/prog_guide/rte_flow.rst
> > > index aec2ba1..58b116e 100644
> > > --- a/doc/guides/prog_guide/rte_flow.rst
> > > +++ b/doc/guides/prog_guide/rte_flow.rst
> > > @@ -1398,6 +1398,25 @@ Matches a eCPRI header.
> > >  - ``hdr``: eCPRI header definition (``rte_ecpri.h``).
> > >  - Default ``mask`` matches nothing, for all eCPRI messages.
> > >
> > > +Item: ``PACKET_INTEGRITY_CHECKS``
> > > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > +
> > > +Matches packet integrity.
> > > +
> > > +- ``level``: the encapsulation level that should be checked. level 0 means the
> > > +  default PMD mode (Can be inner most / outermost). value of 1 means
> > outermost
> > > +  and higher value means inner header. See also RSS level.
> > > +- ``packet_ok``: All HW packet integrity checks have passed based on the
> > max
> > > +  layer of the packet.
> > > +  layer of the packet.
> > > +- ``l2_ok``: all layer 2 HW integrity checks passed.
> > > +- ``l3_ok``: all layer 3 HW integrity checks passed.
> > > +- ``l4_ok``: all layer 3 HW integrity checks passed.
> > > +- ``l2_crc_ok``: layer 2 crc check passed.
> > > +- ``ipv4_csum_ok``: ipv4 checksum check passed.
> > > +- ``l4_csum_ok``: layer 4 checksum check passed.
> > > +- ``l3_len_ok``: the layer 3 len is smaller than the packet len.
> > > +
> > >  Actions
> > >  ~~~~~~~
> > >
> > > diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> > > index 6cc5713..f6888a1 100644
> > > --- a/lib/librte_ethdev/rte_flow.h
> > > +++ b/lib/librte_ethdev/rte_flow.h
> > > @@ -551,6 +551,15 @@ enum rte_flow_item_type {
> > >          * See struct rte_flow_item_geneve_opt
> > >          */
> > >         RTE_FLOW_ITEM_TYPE_GENEVE_OPT,
> > > +
> > > +       /**
> > > +        * [META]
> > > +        *
> > > +        * Matches on packet integrity.
> > > +        *
> > > +        * See struct rte_flow_item_packet_integrity_checks.
> > > +        */
> > > +       RTE_FLOW_ITEM_TYPE_PACKET_INTEGRITY_CHECKS,
> > >  };
> > >
> > >  /**
> > > @@ -1685,6 +1694,43 @@ struct rte_flow_item_geneve_opt {
> > >  };
> > >  #endif
> > >
> > > +struct rte_flow_item_packet_integrity_checks {
> > > +       uint32_t level;
> > > +       /**< Packet encapsulation level the item should apply to.
> > > +        * @see rte_flow_action_rss
> > > +        */
> > > +RTE_STD_C11
> > > +       union {
> > > +               struct {
> > > +                       uint64_t packet_ok:1;
> > > +                       /** The packet is valid after passing all HW checks. */
> > > +                       uint64_t l2_ok:1;
> > > +                       /**< L2 layer is valid after passing all HW checks. */
> > > +                       uint64_t l3_ok:1;
> > > +                       /**< L3 layer is valid after passing all HW checks. */
> > > +                       uint64_t l4_ok:1;
> > > +                       /**< L4 layer is valid after passing all HW checks. */
> > > +                       uint64_t l2_crc_ok:1;
> > > +                       /**< L2 layer checksum is valid. */
> > > +                       uint64_t ipv4_csum_ok:1;
> > > +                       /**< L3 layer checksum is valid. */
> > > +                       uint64_t l4_csum_ok:1;
> > > +                       /**< L4 layer checksum is valid. */
> > > +                       uint64_t l3_len_ok:1;
> > > +                       /**< The l3 len is smaller than the packet len. */
> > > +                       uint64_t reserved:56;
> > > +               };
> > > +               uint64_t  value;
> > > +       };
> > > +};
> > > +
> > > +#ifndef __cplusplus
> > > +static const struct rte_flow_item_sanity_checks
> > > +       rte_flow_item_sanity_checks_mask = {
> > > +               .value = 0,
> > > +};
> > > +#endif
> > > +
> > >  /**
> > >   * Matching pattern item definition.
> > >   *
> > > --
> > > 1.8.3.1
> > >
>
> Best,
> Ori