lkml.org 
[lkml]   [2021]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] net: add net namespace inode for all net_dev events
On Wed, Mar 10, 2021 at 09:22:34AM +0000, Lorenz Bauer wrote:
> On Tue, 9 Mar 2021 at 20:12, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> >
> > On 3/9/21 5:43 AM, Tony Lu wrote:
> > > There are lots of net namespaces on the host runs containers like k8s.
> > > It is very common to see the same interface names among different net
> > > namespaces, such as eth0. It is not possible to distinguish them without
> > > net namespace inode.
> > >
> > > This adds net namespace inode for all net_dev events, help us
> > > distinguish between different net devices.
> > >
> > > Output:
> > > <idle>-0 [006] ..s. 133.306989: net_dev_xmit: net_inum=4026531992 dev=eth0 skbaddr=0000000011a87c68 len=54 rc=0
> > >
> > > Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
> > > ---
> > >
> >
> > There was a proposal from Lorenz to use netns cookies (SO_NETNS_COOKIE) instead.
> >
> > They have a guarantee of being not reused.
> >
> > After 3d368ab87cf6681f9 ("net: initialize net->net_cookie at netns setup")
> > net->net_cookie is directly available.
>
> The patch set is at
> https://lore.kernel.org/bpf/20210219154330.93615-1-lmb@cloudflare.com/
> but I decided to abandon it. I can work around my issue by comparing
> the netns inode of two processes, which is "good enough" for now.

Without the patch set, it is impossible to get net_cookie from
userspace, except bpf prog. AFAIK, netns inode has been widely used to
distinguish different netns, it is easy to use for docker
(/proc/${container_pid}/ns/net). It would be better to provide a unified
approach to do so.


Cheers,
Tony Lu

>
> --
> Lorenz Bauer | Systems Engineer
> 6th Floor, County Hall/The Riverside Building, SE1 7PB, UK
>
> www.cloudflare.com

\
 
 \ /
  Last update: 2021-03-10 13:03    [W:0.045 / U:1.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site