.. index:: pair: group; Rx classification rule and AF_XDP socket
.. _doxid-group__rss-af__xdp__rx__rule:

Rx classification rule and AF_XDP socket
========================================

.. toctree::
	:hidden:

Check that a packet directed to Rx queue by Rx classification rule can be received and replied by AF_XDP socket.

#. Create UDP socket on Tester, bind it to **tst_addr**.

#. From IUT TA pin XSK BPF map of **rxq_stats** XDP program to a file. From IUT RPC server open that file to obtain file descriptor of the map.

#. Find out which Rx queue on IUT will be used for packets sent from **tst_addr** to **iut_addr** according to RSS indirection table.

#. Choose a different Rx queue **rule_queue** on IUT.

#. Create Rx classification rule on IUT redirecting packets sent from **tst_addr** to **iut_addr** to Rx queue **rule_queue**.

#. Configure **rxq_stats** XDP program on IUT to process only packets going from **tst_addr** to **iut_addr**.

#. Create AF_XDP socket on IUT bound to **rule_queue**. Set corresponding record of XSK map of **rxq_stats** program to its file descriptor.

#. Send a packet from the Tester UDP socket. Check that the AF_XDP socket gets that packet on IUT. Construct a reply by inverting addresses and ports of the received packet. Send it back to Tester over the AF_XDP socket. Check that the Tester socket gets it and its payload is the same as in the previously sent packet.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- env

		- 
		  Testing environment:
		  
		  * :ref:`env.peer2peer <doxid-group__env-peer2peer>`
		  
		  * :ref:`env.peer2peer_ipv6 <doxid-group__env-peer2peer__ipv6>`

	*
		- copy_mode

		- 
		  XDP copy mode:
		  
		  * ``none`` (kernel tries zero-copy, falls back to copy mode if it fails)
		  
		  * ``copy``
		  
		  * ``zerocopy``