Re: [PATCH net] macvlan: don't touch promisc without passthrough

[John Fastabend]

On 06/12/2013 06:56 AM, Sergei Shtylyov wrote:
> Hello.
>
> On 12-06-2013 15:34, Michael S. Tsirkin wrote:
>
> > commit df8ef8f3aaa6692970a436204c4429210addb23a in linux 3.5 added a way
>
>     Please also specify that commit's summary line in parens.
>
> > to control NOPROMISC macvlan flag through netlink.
>
> > However, with a non passthrough device we don't set promisc on open or
> > clear it on stop, even if NOPROMISC is off.  As a result:
>
> > If userspace clears NOPROMISC on open, then does not clear it on a
> > netlink command, promisc counter is not decremented on stop and there
> > will be no way to clear it once macvlan is detached.
>
> > If userspace does not clear NOPROMISC on open, then sets NOPROMISC on a
> > netlink command, promisc counter will be decremented from 0 and overflow
> > to fffffffff with no way to clear promisc afterwards.
>
> > To fix, simply ignore NOPROMISC flag in a netlink command for
> > non-passthrough devices, same as we do at open/stop.
>
> > While at it - since we touch this code anyway - check
> > dev_set_promiscuity return code and pass it to users (though an error
> > here is unlikely).
>
> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> > CC: Roopa Prabhu <roprabhu@xxxxxxxxx>
> > Cc: John Fastabend <john.r.fastabend@xxxxxxxxx>
> > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> > ---
>
> > Please review, and consider for 3.10 and -stable.

Other than those few nits looks good to me thanks!

Reviewed-by: John Fastabend <john.r.fastabend@xxxxxxxxx>

--
John Fastabend         Intel Corporation
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