From: James Prestwood <prestwoj@gmail.com>
To: Johannes Berg <johannes@sipsolutions.net>,
linux-wireless@vger.kernel.org
Subject: Re: [PATCH 1/2] nl80211: Add LIVE_ADDR_CHANGE feature
Date: Tue, 08 Oct 2019 15:13:30 -0700 [thread overview]
Message-ID: <cedf5016a59f313c073e1549961317b8fcf0ceab.camel@gmail.com> (raw)
In-Reply-To: <83bde7f521e636903b6b386faaa31b73479add8b.camel@sipsolutions.net>
Hi Johannes,
On Tue, 2019-10-01 at 11:14 +0200, Johannes Berg wrote:
> Hi,
>
> > > > Because userspace needs to know if this is supported?
> > > > IFF_LIVE_ADDR_CHANGE is a private flag... AFAIK userspace has
> > > > no
> > > > way of
> > > > obtaining this.
> > >
> > > Oh, annoying.
> > >
> > > But that doesn't really mean that nl80211 is an appropriate place
> > > to
> > > advertise it, IMHO?
> >
> > The intention of the flag was not soley related to
> > CMD_CONNECT/CMD_AUTHENTICATE. Its an indication that the
> > hardware/driver supports a live address change. If you don't want
> > it
> > here could you suggest a better location for it?
>
> I guess RTNL would be the right place? This can hardly be specific to
> wireless, the flag comes from elsewhere.
I do see where your coming from, and maybe the answer is both RTNL and
NL80211?
In this context a NL80211 flag would mean something different than only
putting a flag into RTNL.
The NL80211 flag means this device supports changing the MAC while
running and not offchannel/scanning. Which is what -EBUSY would mean in
this context. Managing the offchannel/scanning work is only possible
with a NL80211 application.
An RTNL only application has no idea about scanning/offchannel work, so
it has no way of knowing what -EBUSY means in the wireless device
context, or a way to prevent this from happening (stopping scanning or
offchannel before changing the MAC).
Now, another example would be an RTNL application that only cares about
non-wireless devices (like ethernet), and in this case it could benefit
from some type of RTNL specific flag and not care about a NL80211 flag.
Since there is no such application that cares about this RTNL flag
(since it doesn't exist) I would say that adding NL80211 flag is the
way to go. If someone wants to add an RTNL flag I would say that is
appropriate too. But in terms of this feature, a NL80211 flag is really
what fits best since the changes are wireless specific.
Thanks,
James
>
> johannes
>
prev parent reply other threads:[~2019-10-08 22:16 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-13 19:59 [PATCH 1/2] nl80211: Add LIVE_ADDR_CHANGE feature James Prestwood
2019-09-13 19:59 ` [PATCH 2/2] mac80211: Support LIVE_ADDRESS_CHANGE feature James Prestwood
2019-10-04 11:56 ` Johannes Berg
2019-10-04 16:25 ` James Prestwood
2019-10-04 16:42 ` James Prestwood
2019-10-07 21:16 ` Johannes Berg
2019-10-08 15:37 ` Denis Kenzior
2019-10-08 15:52 ` Johannes Berg
2019-10-08 15:53 ` Denis Kenzior
2019-10-08 16:24 ` Johannes Berg
2019-10-08 16:23 ` Denis Kenzior
2019-10-08 17:08 ` Johannes Berg
2019-10-08 18:50 ` Denis Kenzior
2019-10-08 20:16 ` Johannes Berg
2019-10-08 20:55 ` Denis Kenzior
2019-10-10 15:18 ` Johannes Berg
2019-10-07 21:11 ` Johannes Berg
2019-10-08 15:28 ` Denis Kenzior
2019-10-08 15:49 ` Johannes Berg
2019-09-13 20:48 ` [PATCH 1/2] nl80211: Add LIVE_ADDR_CHANGE feature Johannes Berg
2019-09-13 20:56 ` James Prestwood
2019-09-13 21:01 ` Johannes Berg
2019-09-13 21:14 ` James Prestwood
2019-09-17 20:09 ` James Prestwood
2019-10-01 9:14 ` Johannes Berg
2019-10-08 22:13 ` James Prestwood [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=cedf5016a59f313c073e1549961317b8fcf0ceab.camel@gmail.com \
--to=prestwoj@gmail.com \
--cc=johannes@sipsolutions.net \
--cc=linux-wireless@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).