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

[Olivier Matz <olivier.matz@6wind.com>]

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.

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.