From: Cong Wang <xiyou.wangcong@gmail.com>
To: John Hurley <john.hurley@netronome.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
David Miller <davem@davemloft.net>,
Jiri Pirko <jiri@mellanox.com>,
Davide Caratti <dcaratti@redhat.com>,
Simon Horman <simon.horman@netronome.com>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
oss-drivers@netronome.com
Subject: Re: [PATCH net-next v2 1/3] net: sched: add mpls manipulation actions to TC
Date: Mon, 17 Jun 2019 14:18:01 -0700 [thread overview]
Message-ID: <CAM_iQpW+bnMG+43cyMJuLYCqEKM4jk5LbxGtsHFOFY=Ha7nZfA@mail.gmail.com> (raw)
In-Reply-To: <CAK+XE=mXVW84MXE5bDYyGhK5XrC_q3ECiaj5=WsXFV0FXBk+eA@mail.gmail.com>
On Fri, Jun 14, 2019 at 3:56 PM John Hurley <john.hurley@netronome.com> wrote:
>
> On Fri, Jun 14, 2019 at 5:59 PM Cong Wang <xiyou.wangcong@gmail.com> wrote:
> >
> > On Thu, Jun 13, 2019 at 10:44 AM John Hurley <john.hurley@netronome.com> wrote:
> > > +static inline void tcf_mpls_set_eth_type(struct sk_buff *skb, __be16 ethertype)
> > > +{
> > > + struct ethhdr *hdr = eth_hdr(skb);
> > > +
> > > + skb_postpull_rcsum(skb, &hdr->h_proto, ETH_TLEN);
> > > + hdr->h_proto = ethertype;
> > > + skb_postpush_rcsum(skb, &hdr->h_proto, ETH_TLEN);
> >
> > So you just want to adjust the checksum with the new ->h_proto
> > value. please use a right csum API, rather than skb_post*_rcsum().
> >
>
> Hi Cong,
> Yes, I'm trying to maintain the checksum value if checksum complete
> has been set.
> The function above pulls the old eth type out of the checksum value
> (if it is checksum complete), updates the eth type, and pushes the new
> eth type into the checksum.
> This passes my tests on the checksum.
> I couldn't see an appropriate function to do this other than
> recalculating the whole thing.
> Maybe I missed something?
I never say it is wrong, I mean to say using a csum API is more
clear. Please look into checksum API's, there are many options
for different scenarios, there must be one serves your purpose.
Thanks.
next prev parent reply other threads:[~2019-06-17 21:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 17:43 [PATCH net-next v2 0/3] Add MPLS actions to TC John Hurley
2019-06-13 17:43 ` [PATCH net-next v2 1/3] net: sched: add mpls manipulation " John Hurley
2019-06-14 8:10 ` Jiri Pirko
2019-06-14 11:59 ` John Hurley
2019-06-14 16:59 ` Cong Wang
2019-06-14 22:56 ` John Hurley
2019-06-17 21:18 ` Cong Wang [this message]
2019-06-17 22:09 ` John Hurley
2019-06-13 17:43 ` [PATCH net-next v2 2/3] net: sched: include mpls actions in hardware intermediate representation John Hurley
2019-06-14 8:11 ` Jiri Pirko
2019-06-13 17:43 ` [PATCH net-next v2 3/3] selftests: tc-tests: actions: add MPLS tests John Hurley
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