From: Florian Westphal <fw@strlen.de>
To: Phil Sutter <phil@nwl.cc>,
Pablo Neira Ayuso <pablo@netfilter.org>,
netfilter-devel@vger.kernel.org
Subject: Re: [conntrack-tools PATCH] conntrack: Fix CIDR to mask conversion on Big Endian
Date: Wed, 4 Sep 2019 10:21:28 +0200 [thread overview]
Message-ID: <20190904082128.GG13660@breakpoint.cc> (raw)
In-Reply-To: <20190904065356.GF25650@orbyte.nwl.cc>
Phil Sutter <phil@nwl.cc> wrote:
> What we need in b is 'ff ff ff 00' for a prefix length of 24. Your
> suggested alternative does not compile, so I tried both options for the
> closing brace:
>
> | htonl((1 << 24) - 1)
>
> This turns into '00 ff ff ff' for both LE and BE, the opposite of what
> we need.
>
> | htonl((1 << 24)) - 1
>
> This turns into '00 00 00 00' on LE and '00 ff ff ff' on BE.
>
> My code leads to correct result on either architecture and I don't see a
> simpler way of doing it.
htonl(~0u << (32 - i)) would work, assuming i > 0 and <= 32.
next prev parent reply other threads:[~2019-09-04 8:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-02 16:44 [conntrack-tools PATCH] conntrack: Fix CIDR to mask conversion on Big Endian Phil Sutter
2019-09-03 20:34 ` Pablo Neira Ayuso
2019-09-04 6:53 ` Phil Sutter
2019-09-04 8:21 ` Florian Westphal [this message]
2019-09-04 9:31 ` Phil Sutter
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=20190904082128.GG13660@breakpoint.cc \
--to=fw@strlen.de \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=phil@nwl.cc \
/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).