From: Daniel Borkmann <daniel@iogearbox.net>
To: David Miller <davem@davemloft.net>, cernekee@chromium.org
Cc: johannes.berg@intel.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] netlink: Add netns check on taps
Date: Wed, 6 Dec 2017 21:51:44 +0100 [thread overview]
Message-ID: <6de61b79-9015-a445-0d95-a0f3ed823213@iogearbox.net> (raw)
In-Reply-To: <20171206.144003.2119311447846512879.davem@davemloft.net>
On 12/06/2017 08:40 PM, David Miller wrote:
> From: Kevin Cernekee <cernekee@chromium.org>
> Date: Tue, 5 Dec 2017 14:46:22 -0800
>
>> Currently, a nlmon link inside a child namespace can observe systemwide
>> netlink activity. Filter the traffic so that in a non-init netns,
>> nlmon can only sniff netlink messages from its own netns.
>>
>> Test case:
>>
>> vpnns -- bash -c "ip link add nlmon0 type nlmon; \
>> ip link set nlmon0 up; \
>> tcpdump -i nlmon0 -q -w /tmp/nlmon.pcap -U" &
>> sudo ip xfrm state add src 10.1.1.1 dst 10.1.1.2 proto esp \
>> spi 0x1 mode transport \
>> auth sha1 0x6162633132330000000000000000000000000000 \
>> enc aes 0x00000000000000000000000000000000
>> grep abc123 /tmp/nlmon.pcap
>>
>> Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
>
> Daniel, what behavior did you intend this to have?
>
> Taps can see their own namespace only, or init_net is special
> and can see all netlink activity.
>
> I think letting init_net see everything could be confusing,
> because there is no way to distinguish netlink events by
> namespace just by looking at the messages that arrive at
> the tap right?
Yeah, only snooping from own netns makes sense, lets limit
it to this.
prev parent reply other threads:[~2017-12-06 20:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-05 22:46 [PATCH] netlink: Add netns check on taps Kevin Cernekee
2017-12-06 2:19 ` David Ahern
2017-12-06 3:14 ` Kevin Cernekee
2017-12-06 19:40 ` David Miller
2017-12-06 20:51 ` Daniel Borkmann [this message]
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