Re: [dpdk-dev] [RFC 01/17] mbuf: add definitions of unified packet types

[Neil Horman <nhorman@tuxdriver.com>]

On Mon, Jan 19, 2015 at 11:23:07AM +0800, Helin Zhang wrote:
> As there are only 6 bit flags in ol_flags for indicating packet types,
> which is not enough to describe all the possible packet types hardware
> can recognize. For example, i40e hardware can recognize more than 150
> packet types. Unified packet type is composed of tunnel type, L3 type,
> L4 type and inner L3 type fields, and can be stored in 16 bits mbuf
> field of 'packet_type'.
> 
> Signed-off-by: Helin Zhang <helin.zhang@intel.com>
> Signed-off-by: Cunming Liang <cunming.liang@intel.com>
> Signed-off-by: Jijiang Liu <jijiang.liu@intel.com>
> ---
>  lib/librte_mbuf/rte_mbuf.h | 68 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index 16059c6..94eb38f 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -165,6 +165,74 @@ extern "C" {
>  /* Use final bit of flags to indicate a control mbuf */
>  #define CTRL_MBUF_FLAG       (1ULL << 63) /**< Mbuf contains control data */
>  
> +/*
> + * Sixteen bits are divided into several fields to mark packet types. Note that
> + * each field is indexical.
> + * - Bit 3:0 is for tunnel types.
> + * - Bit 7:4 is for L3 or outer L3 (for tunneling case) types.
> + * - Bit 10:8 is for L4 types. It can also be used for inner L4 types for
> + *   tunneling packets.
This seems a bit sparse, in that the protocol field is 8 bits wide in a packet.
There are several common protocls that you don't have listed, and you've already
exhausted your namespace with the list you have.
Neil