public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Alexei Starovoitov <ast@plumgrid•com>
To: Jamal Hadi Salim <jhs@mojatatu•com>, David Miller <davem@davemloft•net>
Cc: daniel@iogearbox•net, tgraf@suug•ch, jiri@resnulli•us,
	netdev@vger•kernel.org
Subject: Re: [PATCH v3 net-next 2/2] tc: add 'needs_l2' flag to ingress qdisc
Date: Mon, 13 Apr 2015 09:13:18 -0700	[thread overview]
Message-ID: <552BEB1E.2060704@plumgrid.com> (raw)
In-Reply-To: <552BD2A8.10105@mojatatu.com>

On 4/13/15 7:28 AM, Jamal Hadi Salim wrote:
> On 04/10/15 18:35, Alexei Starovoitov wrote:
>
>>> To your "bugs" comments:
>>> - updating csum; earlier i said i was conflicted it being a
>>> useful "feature".
>>> You are repeating again that it is a bug. It is not.
>>> This action is intended to  mirror or redirect packets, period.
>>
>> without updating skb->csum act_mirred is breaking csum for
>> checksum_complete devices.
>
> Ok, could this then be checked for in dev features flags and
> only then recomputed?

that's what my v2 patch did :)
if ip_summed == checksum_complete -> recompute skb->csum

> Yes, I see your point here as reasonable dilema. But you could add an
> API call the user always make that resets and unsets the header?
> It would be a single branch failure for egress/stack source.

cannot do that from the program. skb->data and headerlen are already
cached by JITs and skb pointer itself is in some bpf registers,
so push/pull/skb_share_check is _not_ possible when program is running.
It can only be done before program starts. That's exactly what all my
patches are doing.

      reply	other threads:[~2015-04-13 16:13 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-08 23:26 [PATCH v3 net-next 1/2] net: introduce skb_postpush_rcsum() helper Alexei Starovoitov
2015-04-08 23:26 ` [PATCH v3 net-next 2/2] tc: add 'needs_l2' flag to ingress qdisc Alexei Starovoitov
2015-04-09  2:44   ` David Miller
2015-04-09  3:05     ` Alexei Starovoitov
2015-04-09  3:14       ` David Miller
2015-04-09  3:39         ` Alexei Starovoitov
2015-04-09  5:20           ` Alexei Starovoitov
2015-04-09  5:25             ` David Miller
2015-04-09 15:15             ` Daniel Borkmann
2015-04-09 15:36               ` Eric Dumazet
2015-04-09 17:20                 ` Alexei Starovoitov
2015-04-09 10:49       ` Jamal Hadi Salim
2015-04-09 11:02         ` Jamal Hadi Salim
2015-04-09 15:38         ` Daniel Borkmann
2015-04-10 11:49           ` Jamal Hadi Salim
2015-04-09 17:03         ` Alexei Starovoitov
2015-04-10 12:48           ` Jamal Hadi Salim
2015-04-10 22:35             ` Alexei Starovoitov
2015-04-13 14:28               ` Jamal Hadi Salim
2015-04-13 16:13                 ` Alexei Starovoitov [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=552BEB1E.2060704@plumgrid.com \
    --to=ast@plumgrid$(echo .)com \
    --cc=daniel@iogearbox$(echo .)net \
    --cc=davem@davemloft$(echo .)net \
    --cc=jhs@mojatatu$(echo .)com \
    --cc=jiri@resnulli$(echo .)us \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=tgraf@suug$(echo .)ch \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox