Re: [PATCH] Revert "wireless: Support of IFLA_INFO_KIND rtnl attribute"

[Dan Williams <dcbw@redhat.com>]

On Mon, 2015-01-19 at 15:09 -0600, Dan Williams wrote:
> On Mon, 2015-01-19 at 13:22 -0600, Dan Williams wrote:
> > On Mon, 2015-01-19 at 18:52 +0100, Johannes Berg wrote:
> > > From: Johannes Berg <johannes.berg@intel.com>
> > > 
> > > This reverts commit ba1debdfed974f25aa598c283567878657b292ee.
> > > 
> > > Oliver reported that it breaks network-manager, for some reason with
> > > this patch NM decides that the device isn't wireless but "generic"
> > > (ethernet), sees no carrier (as expected with wifi) and fails to do
> > > anything else with it.
> > 
> > Hmm, which NM version?  NM uses either DEVTYPE (from 'uevent' in sysfs),
> > the phy80211 link in sysfs, or (if enabled) WEXT to figure out whether a
> > network interface with arptype=1 is WiFi or not.  I can't think of why
> > IFLA_INFO_KIND would break that...  what are the userspace visible
> > effects of the patch before reversion?
> 
> So with the patch, libnl will return 'wlan' from rtnl_link_get_type().
> NetworkManager was relying on the fact that this would return NULL for
> WiFi devices and was not falling back to alternate WiFi detection
> mechanisms (sysfs, DEVTYPE, etc) when an unknown IFLA_INFO_KIND was
> found.
> 
> NM 0.9.10+ have this bug.
> 
> I'll submit a patch upstream for review, which will get backported to
> 0.9.10 and later when approved.

https://bugzilla.gnome.org/show_bug.cgi?id=743209

Dan

> Dan
> 
> > Dan
> > 
> > > Revert this to unbreak userspace.
> > > 
> > > Reported-by: Oliver Hartkopp <socketcan@hartkopp.net>
> > > Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
> > > Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> > > ---
> > >  net/wireless/core.c | 6 ------
> > >  1 file changed, 6 deletions(-)
> > > 
> > > diff --git a/net/wireless/core.c b/net/wireless/core.c
> > > index 456e4c38c279..3af0ecf1cc16 100644
> > > --- a/net/wireless/core.c
> > > +++ b/net/wireless/core.c
> > > @@ -21,7 +21,6 @@
> > >  #include <linux/sched.h>
> > >  #include <net/genetlink.h>
> > >  #include <net/cfg80211.h>
> > > -#include <net/rtnetlink.h>
> > >  #include "nl80211.h"
> > >  #include "core.h"
> > >  #include "sysfs.h"
> > > @@ -964,10 +963,6 @@ void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
> > >  }
> > >  EXPORT_SYMBOL(cfg80211_stop_iface);
> > >  
> > > -static const struct rtnl_link_ops wireless_link_ops = {
> > > -	.kind = "wlan",
> > > -};
> > > -
> > >  static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
> > >  					 unsigned long state, void *ptr)
> > >  {
> > > @@ -986,7 +981,6 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
> > >  	switch (state) {
> > >  	case NETDEV_POST_INIT:
> > >  		SET_NETDEV_DEVTYPE(dev, &wiphy_type);
> > > -		dev->rtnl_link_ops = &wireless_link_ops;
> > >  		break;
> > >  	case NETDEV_REGISTER:
> > >  		/*
> > 
> > 
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> 
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