Re: [dpdk-dev] [EXT] Re: [PATCH v3 2/4] mbuf: add packet type for UDP-ESP tunnel packets

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

Hi Akhil,

> 
>  Hi Olivier/ Konstantin,
> > > On Thu, Apr 08, 2021 at 01:47:18PM +0530, Tejasree Kondoj wrote:
> > > > Adding new mbuf packet type for UDP encapsulated
> > > > ESP packets.
> > > >
> > > > Signed-off-by: Tejasree Kondoj <ktejasree@marvell.com>
> > > > ---
> > > >  doc/guides/rel_notes/release_21_05.rst |  5 +++++
> > > >  lib/librte_mbuf/rte_mbuf_ptype.h       | 21 +++++++++++++++++++++
> > > >  2 files changed, 26 insertions(+)
> > > >
> > > > diff --git a/doc/guides/rel_notes/release_21_05.rst
> > > b/doc/guides/rel_notes/release_21_05.rst
> > > > index 5565c7637c..c9e9e2ec22 100644
> > > > --- a/doc/guides/rel_notes/release_21_05.rst
> > > > +++ b/doc/guides/rel_notes/release_21_05.rst
> > > > @@ -55,6 +55,11 @@ New Features
> > > >       Also, make sure to start the actual text at the margin.
> > > >       =======================================================
> > > >
> > > > +* **Added new packet type for UDP-ESP packets in mbuf.**
> > > > +
> > > > +  Added new packet type ``RTE_PTYPE_TUNNEL_ESP_IN_UDP`` which can
> > > be
> > > > +  used to identify UDP encapsulated ESP packets.
> > > > +
> > > >  * **Enhanced ethdev representor syntax.**
> > > >
> > > >    * Introduced representor type of VF, SF and PF.
> > > > diff --git a/lib/librte_mbuf/rte_mbuf_ptype.h
> > > b/lib/librte_mbuf/rte_mbuf_ptype.h
> > > > index 17a2dd3576..bf92ce0c1a 100644
> > > > --- a/lib/librte_mbuf/rte_mbuf_ptype.h
> > > > +++ b/lib/librte_mbuf/rte_mbuf_ptype.h
> > > > @@ -491,6 +491,27 @@ extern "C" {
> > > >   * | 'destination port'=6635>
> > > >   */
> > > >  #define RTE_PTYPE_TUNNEL_MPLS_IN_UDP      0x0000d000
> > > > +/**
> > > > + * ESP-in-UDP tunneling packet type (RFC 3948).
> > > > + *
> > > > + * Packet format:
> > > > + * <'ether type'=0x0800
> > > > + * | 'version'=4, 'protocol'=17
> > > > + * | 'destination port'=4500>
> > > > + * or,
> > > > + * <'ether type'=0x86DD
> > > > + * | 'version'=6, 'next header'=17
> > > > + * | 'destination port'=4500>
> > > > + * or,
> > > > + * <'ether type'=0x0800
> > > > + * | 'version'=4, 'protocol'=17
> > > > + * | 'source port'=4500>
> > > > + * or,
> > > > + * <'ether type'=0x86DD
> > > > + * | 'version'=6, 'next header'=17
> > > > + * | 'source port'=4500>
> > > > + */
> > > > +#define RTE_PTYPE_TUNNEL_ESP_IN_UDP       0x0000e000
> > > >  /**
> > > >   * Mask of tunneling packet types.
> > > >   */
> > >
> > > We arrive at the end of the values in packet type tunnel types,
> > > and there is another pending patch that needs another tunnel type.
> > >
> > > As there is already a RTE_PTYPE_TUNNEL_ESP, what would you think about
> > > trying to reuse it, and differentiate IP/ESP from IP/UDP/ESP by using
> > > the L4 layer type (unknown vs udp)? Or maybe add RTE_PTYPE_L4_NONE.
> > >
> > > It is sensible, because it can be considered as an API change for
> > > current users of RTE_PTYPE_TUNNEL_ESP. I don't really know how this
> > > type is used by applications.
> >
> > It is OK to use combination of these two but with an assumption
> > that a normal - IP-UDP packet when encrypted will be an IP-ESP packet
> > And L4 types are reset from the mbuf->packet_type by the driver.
> > @Konstantin Ananyev: Are you OK with this assumption?
> >
> > And, if we choose this path, then also we may need a macro in this file,
> > So that application doesn't have to combine that explicitly for a standard use
> > case.
> > #define RTE_PTYPE_TUNNEL_ESP_IN_UDP       RTE_PTYPE_TUNNEL_ESP |
> > RTE_PTYPE_L4_UDP
> >
> > Will this be fine?
> >
> Can we proceed with this approach?

I think we can safely use such combination inside ipsec-secgw app.
About making it a new generic type - I am not so sure. 
As Olivier already pointed out - it looks like an API/behaviour breakage to me. 

> Regards,
> Akhil
> 
> > >
> > > I think it is time to start thinking about how the packet_type
> > > mbuf API can evolve to solve this issue.

+1
Might be it needs to be reworked completely.

> > >
> > > By the way, the update of *rte_get_ptype_tunnel_name() is missing.