From: ebiederm@xmission•com (Eric W. Biederman)
To: David Lamparter <equinox@diac24•net>
Cc: Alex Bligh <alex@alex•org.uk>,
linux-arch@vger•kernel.org, netdev@vger•kernel.org,
linux-kernel@vger•kernel.org,
Linux Containers <containers@lists•osdl.org>,
linux-fsdevel@vger•kernel.org
Subject: Re: [PATCH 0/7] Network namespace manipulation with file descriptors
Date: Tue, 17 May 2011 07:33:18 -0700 [thread overview]
Message-ID: <m1mxil9z2p.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20110517111148.GA3762520@jupiter.n2.diac24.net> (David Lamparter's message of "Tue, 17 May 2011 13:11:48 +0200")
David Lamparter <equinox@diac24•net> writes:
> On Sat, May 07, 2011 at 07:18:44AM -0700, Eric W. Biederman wrote:
>> You can read the processes network namespace by opening
>> /proc/<pid>/ns/net. Unfortunately comparing the network
>> namespaces for identity is another matter. You will probably
>> be better off simply forcing the routing daemon to start
>> in the desired network namespace in it's initscript.
>>
>> For purposes of clarity please have a look at my work in
>> progress patch for iproute2. This demonstrates how I expect
>> userspace to work in a multi-network namespace world.
>>
> [...]
>> Subject: [PATCH] iproute2: Add processless netnwork namespace support.
> [...]
>> Configuration specific to a network namespace that
>> would ordinarily be stored under /etc/ is stored under
>> /etc/netns/<name>. For example if the dns server
>> configuration is different for your vpn you would
>> create a file /etc/netns/myvpn/resolv.conf.
>>
>> File descriptors that can be used to manipulate a
>> network namespace can be created by opening
>> /var/run/netns/<NAME>.
>>
>> This adds the following commands to iproute.
>> ip netns add NAME
>> ip netns delete NAME
>> ip netns monitor
>> ip netns list
>> ip netns exec NAME cmd ....
>> ip link set DEV netns NAME
>
> funny, this is almost exactly what my code does - though you're probably
> doing it better and have more features ;)
Well if it has more features it is only because I have managed to keep
everything simple enough that adding features was easy. I ignored all
of the hard bits.
> http://git.spaceboyz.net/equinox/vrf-tools.git/
> git://spaceboyz.net/equinox/vrf-tools.git
>
> It currently forks off a daemon to keep the namespace open; attaching is
> not possible yet, but opening a socket in a different namespace is.
I went the round of keeping a daemon open, saw how much code that
takes and how fragile that can be in the corner cases and decided to
patch the kernel to make the interfaces better.
> Most of the actual management (mounting things & co.) I offloaded to
> some shell scripts; I use it together with GNU screen (which makes it
> very nice to grab one of the namespaces and start/stop/manage/...
> things).
That does sound like a nice way of doing the management.
> I also have patches for OpenVPN and pptpd floating around that make it
> possible to 'cross' namespace boundaries, i.e. the VPN servers listen in
> one namespace and have their devices in another.
For openvpn I have managed to get away with simply using an up script.
Mostly the script is:
ip netns add $NSNAME || true
ip netns exec $NSNAME ip link set lo up
ip link set $dev netns $NSNAME
ip netns exec $NSNAME ip link set $dev up
ip netns exec $NSNAME ifconfig $dev $ifconfig_local netmask $ifconfig_netmask broadcast $ifconfig_broadcast
With a few extra bits for dns options and routes. If I had an openvpn
built with the iproute option I expect I could get away by just wrapping
iproute. Not that I would mind a patched openvpn.
Personally I think using a vpn in a network namespace seems like a
killer feature.
Eric
next prev parent reply other threads:[~2011-05-17 14:33 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-07 2:23 [PATCH 0/7] Network namespace manipulation with file descriptors Eric W. Biederman
2011-05-07 2:24 ` [PATCH 1/7] ns: proc files for namespace naming policy Eric W. Biederman
2011-05-07 2:24 ` [PATCH 3/7] ns proc: Add support for the network namespace Eric W. Biederman
2011-05-07 22:41 ` Daniel Lezcano
2011-05-11 19:21 ` Nathan Lynch
2011-05-11 21:34 ` Eric W. Biederman
2011-05-11 21:42 ` Nathan Lynch
2011-05-07 2:24 ` [PATCH 4/7] ns proc: Add support for the uts namespace Eric W. Biederman
2011-05-07 22:42 ` Daniel Lezcano
2011-05-07 2:24 ` [PATCH 5/7] ns proc: Add support for the ipc namespace Eric W. Biederman
2011-05-07 22:44 ` Daniel Lezcano
[not found] ` <1304735101-1824-1-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2011-05-07 2:24 ` [PATCH 2/7] ns: Introduce the setns syscall Eric W. Biederman
[not found] ` <1304735101-1824-2-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2011-05-07 8:01 ` Rémi Denis-Courmont
2011-05-07 13:57 ` Eric W. Biederman
2011-05-07 22:39 ` Daniel Lezcano
2011-05-08 3:51 ` Matt Helsley
2011-05-11 19:21 ` Nathan Lynch
2011-05-11 20:33 ` Eric W. Biederman
2011-05-07 2:25 ` [PATCH 6/7] net: Allow setting the network namespace by fd Eric W. Biederman
2011-05-07 22:46 ` Daniel Lezcano
2011-05-07 2:25 ` [PATCH 7/7] ns: Wire up the setns system call Eric W. Biederman
2011-05-07 8:27 ` Geert Uytterhoeven
2011-05-07 14:09 ` Eric W. Biederman
2011-05-07 18:22 ` Geert Uytterhoeven
2011-05-07 13:59 ` Mike Frysinger
2011-05-07 20:06 ` James Bottomley
2011-05-08 2:19 ` Eric W. Biederman
2011-05-08 4:02 ` James Bottomley
2011-05-07 22:37 ` [PATCH 1/7] ns: proc files for namespace naming policy Daniel Lezcano
2011-05-11 19:20 ` Nathan Lynch
2011-05-11 22:52 ` Eric W. Biederman
[not found] ` <m1tyd7p7tq.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2011-05-07 6:58 ` [PATCH 0/7] Network namespace manipulation with file descriptors Alex Bligh
2011-05-07 14:18 ` Eric W. Biederman
2011-05-08 12:31 ` Alex Bligh
[not found] ` <m1fwoqoapn.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2011-05-17 11:11 ` David Lamparter
2011-05-17 14:33 ` Eric W. Biederman [this message]
2011-05-17 15:35 ` David Lamparter
2011-05-22 4:19 ` Renato Westphal
2011-05-09 19:04 ` David Miller
2011-05-09 19:59 ` Eric W. Biederman
2011-05-09 20:40 ` David Miller
2011-05-09 20:54 ` Eric W. Biederman
2011-05-09 20:55 ` David Miller
2011-05-10 21:56 ` Luck, Tony
2011-05-10 23:02 ` Eric W. Biederman
2011-05-18 12:43 ` Identifying network namespaces (was: Network namespace manipulation with file descriptors) David Lamparter
2011-05-18 13:03 ` Alexey Dobriyan
[not found] ` <BANLkTikmrC86hk=W84UBwhJLe_uGAN4w9w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-05-18 13:33 ` David Lamparter
2011-05-18 14:13 ` Alexey Dobriyan
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