From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [RFC] nftables: reverse path filtering for nft
Date: Mon, 12 Sep 2016 21:14:38 +0200 [thread overview]
Message-ID: <20160912191438.GA11229@salvia> (raw)
In-Reply-To: <20160912190025.GB11685@breakpoint.cc>
On Mon, Sep 12, 2016 at 09:00:25PM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > fib lookup ip daddr . oif
> >
> > As you are basically looking for the route based on IPv4 address and
> > the output interface, so this boils down to:
> >
> > fib lookup $expr $flags
>
> How would the kernel disentangle the register data?
What I'm proposing is to represent this as a concatenation, since this
represents the tuple that you use to look up for route.
> (i.e., how do i know where in the sreg e.g. the daddr is
> that i need to stuff in the flowi struct?)
You can iterate over the concatenation compound from the
netlink_linearize path, it is just a list of expressions. Then, you
can set the NFTA_FIB_* netlink attribute using them.
>From the evaluation step, you would need to validate that the
expressions that we're using in the concatenation fit into flowi
struct, otherwise tell the user that they are not supported.
We cannot not actually support every tuple, as we are constrained by
flowi.
next prev parent reply other threads:[~2016-09-12 19:14 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-10 20:01 [RFC] nftables: reverse path filtering for nft Florian Westphal
2016-09-12 12:04 ` Pablo Neira Ayuso
2016-09-12 12:21 ` Florian Westphal
2016-09-12 18:52 ` Pablo Neira Ayuso
2016-09-12 19:00 ` Florian Westphal
2016-09-12 19:14 ` Pablo Neira Ayuso [this message]
2016-09-12 19:19 ` Florian Westphal
2016-09-12 22:46 ` Florian Westphal
2016-09-14 17:45 ` Florian Westphal
2016-09-14 18:23 ` Arturo Borrero Gonzalez
2016-09-14 21:13 ` Florian Westphal
2016-09-14 22:00 ` Florian Westphal
2016-09-15 8:24 ` Arturo Borrero Gonzalez
2016-09-15 8:27 ` Arturo Borrero Gonzalez
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=20160912191438.GA11229@salvia \
--to=pablo@netfilter.org \
--cc=fw@strlen.de \
--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).