[PATCH] net: support Arista L2 headers

[Stephen Hemminger]

On Fri, 7 Feb 2025 09:07:57 +0000
"Denis  Davidoglu" <denis.davidoglu at b-ulltech.com> wrote:

> From: Thomas Monjalon <thomas at monjalon.net>
> > I'm not familiar with these headers.
> > Are they standardized?
> > Is there a RFC?  
> 
> Arista Vendor Specific Protocol is not publicly disclosed yet. However, Wireshark already includes a dissector implementetation and its source code can serve for now as a reference:
> https://gitlab.com/wireshark/wireshark/-/blob/master/epan/dissectors/packet-avsp.c
> 
> > I'm not sure about adding vendor specific protocols.
> > What should be the policy here?  
> 
> Given the large number of registered EtherType™ assignments related to IEEE 802.3™ (ISO/IEC 8802-3) standard, supporting vendor-specific protocols should be considered. Though probably not in the way I organized it, mixing RFC-standardized and proprietary protocols in the same files. ./lib/net can have a new subdirectory for keeping them separate. 
> 
> Arista timestamp is particularly valuable for stock exchanges due to efficiency. The timestamp extension is already in use at German Eurex Exchange and it needs to undergo PoC trials at Borsa İstanbul, which utilizes Nasdaq infrastructure. Some parts of it rely on DPDK and this patch will be especially useful.


The rte_net_ptype() is intended to provide a software equivalent for the packet type
matching done in many smart NIC's. It is not meant to be a general purpose L2 packet
parser.

If a user needs to do this kind of packet processing, it belongs in the application
and all the data and metadata is exposed to do this.