netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Phil Sutter <phil@nwl.cc>
To: netdev@vger.kernel.org
Subject: netstat and dual stack sockets
Date: Mon, 15 Jun 2015 22:54:21 +0200	[thread overview]
Message-ID: <20150615205421.GA22616@orbit.nwl.cc> (raw)

Hi,

A socket listening on any AF_INET6 address will receive IPv4 traffic as
well, as long as it does not set IPV6_V6ONLY (or sysctl
net.ipv6.bindv6only is set). Apache APR e.g. explicitly disables
IPV6_V6ONLY for listening sockets.

As I see it, a user has no way of detecting the listening socket in this
address family: it does not show in /proc/net/{tcp,udp} nor do
'netstat', 'ss' or 'lsof' print any additional information about those
sockets over pure IPv6 ones.

Is this correct? If so, are there any intentions to export the missing
information to userspace?

Phil

             reply	other threads:[~2015-06-15 21:00 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-15 20:54 Phil Sutter [this message]
2015-06-15 21:36 ` netstat and dual stack sockets Hagen Paul Pfeifer
2015-06-16  1:25   ` Phil Sutter
2015-06-19 12:15 ` [PATCH] net: inet_diag: export IPV6_V6ONLY sockopt Phil Sutter
2015-06-19 13:52   ` Eric Dumazet
2015-06-21  1:47     ` Phil Sutter
2015-06-21  8:52       ` Eric Dumazet

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=20150615205421.GA22616@orbit.nwl.cc \
    --to=phil@nwl.cc \
    --cc=netdev@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).