Re: [PATCH wpan-next 06/11] mac802154: Handle disassociations

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Alexander,

aahringo@redhat.com wrote on Sat, 3 Jun 2023 07:30:05 -0400:

> Hi,
> 
> On Thu, Jun 1, 2023 at 11:50 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> >
> > Devices may decide to disassociate from their coordinator for different
> > reasons (device turning off, coordinator signal strength too low, etc),
> > the MAC layer just has to send a disassociation notification.
> >
> > If the ack of the disassociation notification is not received, the
> > device may consider itself disassociated anyway.
> >
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> >  net/ieee802154/pan.c         |   2 +
> >  net/mac802154/cfg.c          | 102 +++++++++++++++++++++++++++++++++++
> >  net/mac802154/ieee802154_i.h |   4 ++
> >  net/mac802154/scan.c         |  60 +++++++++++++++++++++
> >  4 files changed, 168 insertions(+)
> >
> > diff --git a/net/ieee802154/pan.c b/net/ieee802154/pan.c
> > index e2a12a42ba2b..477e8dad0cf0 100644
> > --- a/net/ieee802154/pan.c
> > +++ b/net/ieee802154/pan.c
> > @@ -49,6 +49,7 @@ bool cfg802154_device_is_parent(struct wpan_dev *wpan_dev,
> >
> >         return false;
> >  }
> > +EXPORT_SYMBOL_GPL(cfg802154_device_is_parent);
> >
> >  struct ieee802154_pan_device *
> >  cfg802154_device_is_child(struct wpan_dev *wpan_dev,
> > @@ -64,3 +65,4 @@ cfg802154_device_is_child(struct wpan_dev *wpan_dev,
> >
> >         return NULL;
> >  }
> > +EXPORT_SYMBOL_GPL(cfg802154_device_is_child);
> > diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
> > index 89112d2bcee7..c27c05e825ff 100644
> > --- a/net/mac802154/cfg.c
> > +++ b/net/mac802154/cfg.c
> > @@ -386,6 +386,107 @@ static int mac802154_associate(struct wpan_phy *wpan_phy,
> >         return ret;
> >  }
> >
> > +static int mac802154_disassociate_from_parent(struct wpan_phy *wpan_phy,
> > +                                             struct wpan_dev *wpan_dev)
> > +{
> > +       struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
> > +       struct ieee802154_pan_device *child, *tmp;
> > +       struct ieee802154_sub_if_data *sdata;
> > +       u64 eaddr;
> > +       int ret;
> > +
> > +       sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(wpan_dev);
> > +
> > +       /* Start by disassociating all the children and preventing new ones to
> > +        * attempt associations.
> > +        */
> > +       list_for_each_entry_safe(child, tmp, &wpan_dev->children, node) {
> > +               ret = mac802154_send_disassociation_notif(sdata, child,
> > +                                                         IEEE802154_COORD_WISHES_DEVICE_TO_LEAVE);
> > +               if (ret) {
> > +                       eaddr = swab64((__force u64)child->extended_addr);  
> 
> Does this pass sparse? I think this needs to be le64_to_cpu()?

I never feel comfortable with sparse given the dozens (hundreds) of
lines it outputs, but I think yes, parse does not seem to complain. To
be honest I think we should keep it this way just because I copy-pasted
it from other locations in the core:

$ git grep -c "swab64((__force u64)" -- net/ieee802154/ net/mac802154/
net/ieee802154/nl-mac.c:1
net/mac802154/cfg.c:4
net/mac802154/llsec.c:1
net/mac802154/rx.c:2
net/mac802154/scan.c:6

So if we ever want to change that, we could easily find them all and
replace them all in one go?

Thanks,
Miquèl