netdev - Re: [RFC PATCH 2/3] netdev: kernel-only IFF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 4 Apr 2018 11:21:54 -0600
From:   David Ahern <dsahern@...il.com>
To:     Siwei Liu <loseweigh@...il.com>
Cc:     Jiri Pirko <jiri@...nulli.us>, Si-Wei Liu <si-wei.liu@...cle.com>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Stephen Hemminger <stephen@...workplumber.org>,
        Alexander Duyck <alexander.h.duyck@...el.com>,
        David Miller <davem@...emloft.net>,
        "Brandeburg, Jesse" <jesse.brandeburg@...el.com>,
        Jakub Kicinski <kubakici@...pl>,
        Jason Wang <jasowang@...hat.com>,
        "Samudrala, Sridhar" <sridhar.samudrala@...el.com>,
        Netdev <netdev@...r.kernel.org>,
        virtualization@...ts.linux-foundation.org,
        virtio-dev@...ts.oasis-open.org
Subject: Re: [RFC PATCH 2/3] netdev: kernel-only IFF_HIDDEN netdevice

On 4/4/18 1:36 AM, Siwei Liu wrote:
> On Tue, Apr 3, 2018 at 6:04 PM, David Ahern <dsahern@...il.com> wrote:
>> On 4/3/18 9:42 AM, Jiri Pirko wrote:
>>>>
>>>> There are other use cases that want to hide a device from userspace. I
>>>
>>> What usecases do you have in mind?
>>
>> As mentioned in a previous response some kernel drivers create control
>> netdevs. Just as in this case users should not be mucking with it, and
>> S/W like lldpd should ignore it.
>>
>>>
>>>> would prefer a better solution than playing games with name prefixes and
>>>> one that includes an API for users to list all devices -- even ones
>>>> hidden by default.
>>>
>>> Netdevice hiding feels a bit scarry for me. This smells like a workaround
>>> for userspace issues. Why can't the netdevice be visible always and
>>> userspace would know what is it and what should it do with it?
>>>
>>> Once we start with hiding, there are other things related to that which
>>> appear. Like who can see what, levels of visibility etc...
>>>
>>
>> I would not advocate for any API that does not allow users to have full
>> introspection. The intent is to hide the netdev by default but have an
>> option to see it.
> 
> I'm fine with having a link dump API to inspect the hidden netdev. As
> said, the name for hidden netdevs should be in a separate device
> namespace, and we did not even get closer to what it should look like
> as I don't want to make it just an option for ip link. Perhaps a new
> set of sub-commands of, say, 'ip device'.

It is a netdev so there is no reason to have a separate ip command to
inspect it. 'ip link' is the right place.