Re: [dpdk-dev] [RFC] ethdev: allow multiple security sessions to use one rte flow

[Anoob Joseph <anoobj@marvell.com>]

Hi Konstantin,

Please see inline.

Thanks,
Anoob

> -----Original Message-----
> From: Ananyev, Konstantin <konstantin.ananyev@intel.com>
> Sent: Thursday, August 15, 2019 3:18 PM
> To: Anoob Joseph <anoobj@marvell.com>; Akhil Goyal
> <akhil.goyal@nxp.com>; Adrien Mazarguil <adrien.mazarguil@6wind.com>;
> Doherty, Declan <declan.doherty@intel.com>; De Lara Guarch, Pablo
> <pablo.de.lara.guarch@intel.com>; Thomas Monjalon
> <thomas@monjalon.net>
> Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Narayana Prasad Raju
> Athreya <pathreya@marvell.com>; Ankur Dwivedi
> <adwivedi@marvell.com>; Shahaf Shuler <shahafs@mellanox.com>;
> Hemant Agrawal <hemant.agrawal@nxp.com>; Matan Azrad
> <matan@mellanox.com>; Yongseok Koh <yskoh@mellanox.com>; Lu,
> Wenzhuo <wenzhuo.lu@intel.com>; Nicolau, Radu
> <radu.nicolau@intel.com>; dev@dpdk.org
> Subject: RE: [RFC] ethdev: allow multiple security sessions to use one rte
> flow
> 
> Hi Anoob,
> 
> >
> > > > > >
> > > > > > The rte_security API which enables inline protocol/crypto
> > > > > > feature mandates that for every security session an rte_flow is
> created.
> > > > > > This would internally translate to a rule in the hardware
> > > > > > which would do packet
> > > > > classification.
> > > > > >
> > > > > > In rte_securty, one SA would be one security session. And if
> > > > > > an rte_flow need to be created for every session, the number
> > > > > > of SAs supported by an inline implementation would be limited
> > > > > > by the number of rte_flows the PMD would be able to support.
> > > > > >
> > > > > > If the fields SPI & IP addresses are allowed to be a range,
> > > > > > then this limitation can be overcome. Multiple flows will be
> > > > > > able to use one rule for SECURITY processing. In this case,
> > > > > > the security session provided as
> > > > > conf would be NULL.
> > >
> > > SPI values are normally used to uniquely identify the SA that need
> > > to be applied on a particular flow.
> > > I believe SPI value should not be a range for applying a particular
> > > SA or session.
> > >
> > > Plain packet IP addresses can be a range. That is not an issue.
> > > Multiple plain packet flows can use the same session/SA.
> > >
> > > Why do you feel that security session provided should be NULL to
> > > support multiple flows.
> > > How will the keys and other SA related info will be passed to the
> driver/HW.
> >
> > [Anoob] The SA configuration would be done via rte_security session.
> > The proposal here only changes the 1:1 dependency of rte_flow and
> rte_security session.
> >
> > The h/w could use SPI field in the received packet to identify SA(ie,
> > rte_security session). If the h/w allows to index into a table which
> > holds SA information, then per SPI rte_flow is not required. This is in fact
> our case. And for PMDs which doesn't do it this way, rte_flow_validate()
> would fail and then per SPI rte_flow would require to be created.
> >
> > In the present model, a security session is created, and then rte_flow
> > will connect ESP packets with one SPI to one security session.
> > Instead, when we create the security session, h/w can populate entries in a
> DB that would be accessed during data path handling. And the rte_flow could
> say, all SPI in some range gets inline processed with the security session
> identified with its SPI.
> >
> > Our PMD supports limited number of flow entries but our h/w can do SA
> > lookup without flow entries(using SPI instead). So the current approach of
> one flow per session is creating an artificial limit to the number of SAs that
> can be supported.
> 
> QQ: Would that change be accompanied with real implementation for some
> particular PMD?
> Konstantin

[Anoob] Yes. This will be implemented as part of the rte_security additions in net_octeontx2 PMD, which will be upstreamed this release cycle.

> 
> 
> >
> > >
> > > > > >
> > > > > > Application should do an rte_flow_validate() to make sure the
> > > > > > flow is supported on the PMD.
> > > > > >
> > > > > > Signed-off-by: Anoob Joseph <anoobj@marvell.com>
> > > > > > ---
> > > > > >  lib/librte_ethdev/rte_flow.h | 6 ++++++
> > > > > >  1 file changed, 6 insertions(+)
> > > > > >
> > > > > > diff --git a/lib/librte_ethdev/rte_flow.h
> > > > > > b/lib/librte_ethdev/rte_flow.h index f3a8fb1..4977d3c 100644
> > > > > > --- a/lib/librte_ethdev/rte_flow.h
> > > > > > +++ b/lib/librte_ethdev/rte_flow.h
> > > > > > @@ -1879,6 +1879,12 @@ struct rte_flow_action_meter {
> > > > > >   * direction.
> > > > > >   *
> > > > > >   * Multiple flows can be configured to use the same security
> session.
> > > > > > + *
> > > > > > + * The NULL value is allowed for security session. If
> > > > > > + security session is NULL,
> > > > > > + * then SPI field in ESP flow item and IP addresses in flow
> > > > > > + items 'IPv4' and
> > > > > > + * 'IPv6' will be allowed to be a range. The rule thus
> > > > > > + created can enable
> > > > > > + * SECURITY processing on multiple flows.
> > > > > > + *
> > > > > >   */
> > > > > >  struct rte_flow_action_security {
> > > > > >  	void *security_session; /**< Pointer to security session
> structure.
> > > > > > */
> > > > > > --
> > > > > > 2.7.4