public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Nikolay Aleksandrov <nikolay@cumulusnetworks•com>
To: Stephen Hemminger <stephen@networkplumber•org>
Cc: netdev@vger•kernel.org, bridge@lists•linux-foundation.org,
	davem@davemloft•net
Subject: Re: [PATCH net-next] bridge: mdb: add vlan support for user entries
Date: Tue, 21 Jul 2015 00:53:09 +0200	[thread overview]
Message-ID: <55AD7BD5.4090505@cumulusnetworks.com> (raw)
In-Reply-To: <20150720152817.4c2f5c73@urahara>

On 07/21/2015 12:28 AM, Stephen Hemminger wrote:
> On Fri, 10 Jul 2015 08:02:08 -0700
> Nikolay Aleksandrov <nikolay@cumulusnetworks•com> wrote:
> 
>> diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
>> index eaaea6208b42..3635b7797508 100644
>> --- a/include/uapi/linux/if_bridge.h
>> +++ b/include/uapi/linux/if_bridge.h
>> @@ -182,6 +182,7 @@ struct br_mdb_entry {
>>  #define MDB_TEMPORARY 0
>>  #define MDB_PERMANENT 1
>>  	__u8 state;
>> +	__u16 vid;
>>  	struct {
>>  		union {
>>  			__be32	ip4;
> 
> You added a new field into an unused hole in a data
> structure shared as part of API with user space.
> 
> This seems like it might break when newer iproute
> is run on older kernels. The vid would always be 0
> on show and ignored when adding entries.
> 

I thought it'd be fine because the vid was 0 anyway and 
when it's 0 it's not shown i.e. no vid so the show command
will have the same output. And when set - it'll be ignored
which is again as the behaviour before when it couldn't be
specified.

Here's the new iproute2 on an older kernel:
# ./bridge/bridge mdb add dev virbr0 port vnet1 grp 239.0.0.1 permanent vid 200
# ./bridge/bridge mdb
dev virbr0 port vnet1 grp 239.0.0.1 permanent

      reply	other threads:[~2015-07-20 22:53 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-10 15:02 [PATCH net-next] bridge: mdb: add vlan support for user entries Nikolay Aleksandrov
2015-07-13 21:41 ` David Miller
2015-07-20 22:28 ` Stephen Hemminger
2015-07-20 22:53   ` Nikolay Aleksandrov [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=55AD7BD5.4090505@cumulusnetworks.com \
    --to=nikolay@cumulusnetworks$(echo .)com \
    --cc=bridge@lists$(echo .)linux-foundation.org \
    --cc=davem@davemloft$(echo .)net \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=stephen@networkplumber$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox