Re: (Lack of) specification for RX n-tuple filtering

["Vladislav Zolotarov" <vladz@broadcom.com>]

> > The
> > semantics for a specification of the steam is also quite different. For
> > instance, how do u define a rule to drop all packets with source IP
> > address 192.168.10.200 by means of RXNFC?
> 
> Something like this, I think:
> 
> struct ethtool_rxnfc insert_rule = {
> 	.cmd = ETHTOOL_SRXCLSRLINS,
> 	.flow_type = IP_USER_SPEC,
> 	.fs = {
> 		.flow_type = IP_USER_SPEC,
> 		.h_u.usr_ip4_spec = {
> 			.ip4src = inet_aton("192.168.10.200"),
> 			.ip_ver = ETH_RX_NFC_IP4
> 		},
> 		.m_u.usr_ip4_spec = {
> 			.ip4dst = 0xffffffff,
> 			.l4_4_bytes = 0xffffffff,
> 			.tos = 0xff,
> 			.proto = 0xff
> 		},
> 		.ring_cookie = RX_CLS_FLOW_DISC,
> 		.location = 0,
> 	}
> };
> 

Aha. Ok. From the remarks in the upstream ethtool.h I see now that
ethtool_rxnfc has quite wide configuration possibilities (including the
above). I missed it before. ;)

Ben, could u, pls., explain me then what's the difference between
defining the rule as u wrote above on top of -N option (nfc) and
defining the rule doing the same thing on top on -U (n-tuple) option and
when I as a user should prefer one option to another? Are they expected
to be implemented differently from FW/HW perspective?

thanks,
vlad

P.S. I see that ethtool.h from the 2.6.36 tree already has the
ethtool_rxnfc that would allow such a filtering definition however from
the man page of the 2.6.36 version of the ethtool package it's unclear
what should be a command line for such a configuration. Is it supported
with the current ethtool version or maybe I'm missing something in a man
page?