public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Russell King <rmk@arm.linux.org.uk>
To: erich@uruk.org
Cc: Julian Anastasov <ja@ssi.bg>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Szekeres Bela <szekeres@lhsystems.hu>,
	Daniel Gryniewicz <dang@fprintf.net>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	netdev@oss.sgi.com
Subject: Re: Network Security hole (was -> Re: arp bug )
Date: Sun, 3 Mar 2002 00:33:51 +0000	[thread overview]
Message-ID: <20020303003351.B6120@flint.arm.linux.org.uk> (raw)
In-Reply-To: <Pine.LNX.4.44.0203030035030.9147-100000@u.domain.uli> <E16hJki-0000rY-00@trillium-hollow.org>
In-Reply-To: <E16hJki-0000rY-00@trillium-hollow.org>; from erich@uruk.org on Sat, Mar 02, 2002 at 04:21:24PM -0800

On Sat, Mar 02, 2002 at 04:21:24PM -0800, erich@uruk.org wrote:
> The fact that the routing layer and application layers of Linux's
> TCP/IP stack are one and the same is a difficulty here which the
> IP firewalling code in Linux does not fix.  I.e. if I wanted to
> have routing as well, but not accept any packets internally *not*
> destined for my interface, I'm not sure how to specify it without
> something like TCP wrappers, as sleazy as they can be, and they
> don't offer this kind of capability in general as is.

Linux 2.4 netfilter:

Incoming                                                 Outgoing
interface                                                interface
  ----+------------------- FORWARD -----------------+------->
      |                                             ^
      v                                             |
    INPUT -------------> Application -----------> OUTPUT

The names in capitals are the names of the tables.  You can control
packets that the local machine sees completely independently of what
gets routed through the machine with a kernel supporting iptables
by adding the appropriate rules to the input and forward tables.

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html


  reply	other threads:[~2002-03-03  0:34 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-01-08 23:33 arp bug Julian Anastasov
2002-03-02 18:42 ` Network Security hole (was -> Re: arp bug ) erich
2002-03-02 19:14   ` Alan Cox
2002-03-02 19:58     ` erich
2002-03-02 20:22       ` Alan Cox
2002-03-02 20:31         ` erich
2002-03-02 20:52           ` Alan Cox
2002-03-02 21:14             ` erich
2002-03-02 23:31           ` Andrew Pimlott
2002-03-03  1:00             ` erich
2002-03-03  3:21           ` David Ford
     [not found]       ` <Your message of "Sat, 02 Mar 2002 19:14:55 GMT." <E16hEy7-000875-00@the-village.bc.nu>
2002-03-03  0:50         ` Stevie O
2002-03-02 21:52   ` Julian Anastasov
2002-03-02 20:23     ` Alan Cox
2002-03-02 20:26       ` Ben Greear
2002-03-02 23:23       ` Karl
2002-03-03  0:20       ` Julian Anastasov
2002-03-02 22:40         ` Alan Cox
2002-03-03  0:46           ` Julian Anastasov
2002-03-02 23:27             ` Alan Cox
2002-03-03  2:38               ` Julian Anastasov
2002-03-03  0:21             ` erich
2002-03-03  0:33               ` Russell King [this message]
2002-03-03  0:43                 ` erich
2002-03-03  0:49                   ` erich
     [not found]                     ` <Your message of "Sat, 02 Mar 2002 16:43:23 PST." <E16hK5z-0000vI-00@trillium-hollow.org>
2002-03-03  1:05                       ` Stevie O
2002-03-04 18:14                         ` Paul Jakma

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=20020303003351.B6120@flint.arm.linux.org.uk \
    --to=rmk@arm.linux.org.uk \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=dang@fprintf.net \
    --cc=erich@uruk.org \
    --cc=ja@ssi.bg \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@oss.sgi.com \
    --cc=szekeres@lhsystems.hu \
    /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