From: Florian Westphal <fw@strlen.de>
To: Jack Ma <Jack.Ma@alliedtelesis.co.nz>
Cc: Florian Westphal <fw@strlen.de>,
"netfilter-devel@vger.kernel.org"
<netfilter-devel@vger.kernel.org>
Subject: Re: shift by n bits while performing '--restore-mark'
Date: Wed, 7 Feb 2018 00:53:57 +0100 [thread overview]
Message-ID: <20180206235357.GB14261@breakpoint.cc> (raw)
In-Reply-To: <1517960766867.47573@alliedtelesis.co.nz>
Jack Ma <Jack.Ma@alliedtelesis.co.nz> wrote:
> Our current condition is:
>
> 1) only 0xfff00000 (three F available in skb->mark), but 0xfffff000 (five F available in ct->mark)
>
> We wish to copy either 0xfff00000 or 0x00fff000 from ct->mark into skb->mark,
>
>
> What about '-j CONNMARK --restore-mark --mask 0xfffff000 << 8 ( left shift 2 F)'
>
> This will result in skb->mark = ct->mark << 8
>
> if ct->mark = 0xabcde000, now skb->mark is changed to: skb->mark = 0xcde00000.
>
> Does this make sense :) ?
Yes it does.
AFAICS with nftables you could already do this but I can understand if
you need to use iptables for this.
So feel free to send a patch from xt_connmark.
Thanks for explaining this.
next prev parent reply other threads:[~2018-02-06 23:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-16 2:26 conntrack enhancement Jack Ma
2018-01-16 14:17 ` Florian Westphal
2018-01-23 1:16 ` Jack Ma
2018-01-25 2:34 ` Jack Ma
[not found] ` <20180125062211.GE14192@breakpoint.cc>
2018-01-25 21:31 ` Jack Ma
2018-02-06 23:46 ` shift by n bits while performing '--restore-mark' Jack Ma
2018-02-06 23:53 ` Florian Westphal [this message]
2018-02-15 4:13 ` Jack Ma
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=20180206235357.GB14261@breakpoint.cc \
--to=fw@strlen.de \
--cc=Jack.Ma@alliedtelesis.co.nz \
--cc=netfilter-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).