[PATCH v2] mbuf: add new ptype for slow protocols

[Stephen Hemminger]

On Mon, 7 Jul 2025 14:47:17 +0200
Morten Brørup <mb at smartsharesystems.com> wrote:

> > From: Mario Kuka [mailto:kuka at cesnet.cz]
> > Sent: Monday, 7 July 2025 09.51
> > 
> > Introduce a new ptype for identifying slow protocol packets.
> > 
> > Signed-off-by: Mario Kuka <kuka at cesnet.cz>  
> 
> >   * <'ether type'=[0x8847|0x8848]>
> >   */
> >  #define RTE_PTYPE_L2_ETHER_MPLS             0x0000000a
> > +/**
> > + * Ethernet packet type for Slow Protocols.
> > + *
> > + * Packet format:
> > + * <'destination mac'=01-80-C2-00-00-02, 'ether type'=0x8809>
> > + */
> > +#define RTE_PTYPE_L2_ETHER_SLOW             0x0000000b  
> 
> I'm not sure that we want to register individual packet types for Layer 2 control protocol type packets, where the packet rate is very low.
> 
> Consider the endless list of vendor proprietary Layer 2 control protocols, such as Cicso Link Layer Protocols, Realtek Layer 2 Protocols, MikroTik RoMON, etc. The list would explode if we started adding these.
> 
> IMO, only data carrying packet types (IPv4, IPv6, PPPoE, etc.) should be registered as individual packet types. The rest should be sorted manually by the application.
> 

The original purpose of ptype was to handle cases where hardware has offload
capability to identify these packets (like IPv4, IPv6, etc). It doesn't make sense
to me to have all the possible protocols there.