How can i calculate rss hash value from c++ code, to reassemble packet and send them to the same process . Packet that have the same ip + port arrive to the same queue. If some packet are ip fragmented packet arrive to different process. It is a problem

Infrastructure & Networking Software And Drivers
1

I am using Mellanox Technologies MT27800 Family [ConnectX-5], using dpdk multi rx queue with rss “ETH_RSS_IP | ETH_RSS_UDP | ETH_RSS_TCP”

I analyzer traffic and need all packet of same session to arrive to the same process ( session for now can be ip+port)

So Packet that have the same ip + port arrive to the same queue.

But If some packet are ip fragmented, packet arrive to different process. It is a problem!

How can i calculate the hash value in the c++ code, like it is done in the card, so i can reassemble packets and send them to the same process like the non fragmented packets

2

Hi Yaron,

In MLX5 poll mode driver, RSS hash for fragmented packets is not supported.

The RSS offload types supported in DPDK & ConnectX family are the types mentioned in dpdk.org - MLX5 poll mode driver section.

Which are:

IPv4, IPv6, TCPv4, TCPv6, UDPv4 and UDPv6 RSS on any number of queues.

RSS using different combinations of fields: L3 only, L4 only or both, and source only, destination only or both.

Regards,

Chen