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

[Akhil Goyal]

Hi Olivier,
> 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 at 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?

> 
> I think it is time to start thinking about how the packet_type
> mbuf API can evolve to solve this issue.
> 
> By the way, the update of *rte_get_ptype_tunnel_name() is missing.