All of lore.kernel.org
 help / color / mirror / Atom feed
From: Florian Westphal <fw@strlen.de>
To: Eric Garver <eric@garver.life>, Florian Westphal <fw@strlen.de>,
	netfilter-devel@vger.kernel.org, Phil Sutter <phil@nwl.cc>
Subject: Re: [PATCH nf] netfilter: nat: force port remap to prevent shadowing well-known ports
Date: Mon, 29 Nov 2021 23:02:54 +0100	[thread overview]
Message-ID: <20211129220254.GA17540@breakpoint.cc> (raw)
In-Reply-To: <YaU2gndowxjvV+zn@egarver.remote.csb>

Eric Garver <eric@garver.life> wrote:
> On Mon, Nov 29, 2021 at 03:42:18PM +0100, Florian Westphal wrote:
> > If destination port is above 32k and source port below 16k
> > assume this might cause 'port shadowing' where a 'new' inbound
> > connection matches an existing one, e.g.
> 
> How did you arrive at 16k?

I had to pick some number.  1k is too low since some administrative
portals (or openvpn for that matter) are on ports above that.

I wanted to pick something that would not kick in for most cases.
16k just seemed like a good compromise, thats all.

  reply	other threads:[~2021-11-29 22:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-29 14:42 [PATCH nf] netfilter: nat: force port remap to prevent shadowing well-known ports Florian Westphal
2021-11-29 20:22 ` Eric Garver
2021-11-29 22:02   ` Florian Westphal [this message]
2021-11-30 14:34     ` Eric Garver
2021-12-08  0:28 ` Pablo Neira Ayuso
2021-12-08 10:47   ` Florian Westphal

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=20211129220254.GA17540@breakpoint.cc \
    --to=fw@strlen.de \
    --cc=eric@garver.life \
    --cc=netfilter-devel@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.