Re: [PATCH wpan-next v3 00/11] ieee802154: Associations between devices

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

miquel.raynal@bootlin.com wrote on Mon, 18 Sep 2023 17:07:58 +0200:

> Hello,
> 
> [I know we are in the middle of the merge window, I don't think it
> matters on the wpan side, so as the wpan subsystem did not evolve
> much since the previous merge window I figured I would not delay the
> sending of this series given the fact that I should have send it at the
> beginning of the summer...]

Of course this is outdated, but the following still stands :)

Cheers,
Miquèl

> Now that we can discover our peer coordinators or make ourselves
> dynamically discoverable, we may use the information about surrounding
> devices to create PANs dynamically. This involves of course:
> * Requesting an association to a coordinator, waiting for the response
> * Sending a disassociation notification to a coordinator
> * Receiving an association request when we are coordinator, answering
>   the request (for now all devices are accepted up to a limit, to be
>   refined)
> * Sending a disassociation notification to a child
> * Users may request the list of associated devices (the parent and the
>   children).
> 
> Here are a few example of userspace calls that can be made:
> iwpan dev <dev> associate pan_id 2 coord $COORD
> iwpan dev <dev> list_associations
> iwpan dev <dev> disassociate ext_addr $COORD
> 
> I used a small using hwsim to scan for a coordinator, associate with
> it, look at the associations on both sides, disassociate from it and
> check the associations again:
> ./assoc-demo
> *** Scan ***
> PAN 0x0002 (on wpan1)
> 	coordinator 0x060f3b35169a498f
> 	page 0
> 	channel 13
> 	preamble code 0
> 	mean prf 0
> 	superframe spec. 0xcf11
> 	LQI ff
> *** End of scan ***
> Associating wpan1 with coord0 0x060f3b35169a498f...
> Dumping coord0 assoc:
> child : 0x0b6f / 0xba7633ae47ccfb21
> Dumping wpan1 assoc:
> parent: 0xffff / 0x060f3b35169a498f
> Disassociating from wpan1
> Dumping coord0 assoc:
> Dumping wpan1 assoc:
> 
> I could also successfully interact with a smaller device running Zephir,
> using its command line interface to associate and then disassociate from
> the Linux coordinator.
> 
> Thanks!
> Miquèl
> 
> Changes in v3:
> * Clarify a helper which compares if two devices seem to be identical by
>   adding two comments. This is a static function that is only used by
>   the PAN management core to operate or not an
>   association/disassociation request. In this helper, a new check is
>   introduced to be sure we compare fields which have been populated.
> * Dropped the "association_generation" counter and all its uses along
>   the code. I tried to mimic some other counter but I agree it is not
>   super useful and could be dropped anyway.
> * Dropped a faulty sequence number hardcoded to 10. This had no impact
>   because a few lines later the same entry was set to a valid value.
> 
> Changes in v2:
> * Drop the misleading IEEE802154_ADDR_LONG_BROADCAST definition and its
>   only use which was useless anyway.
> * Clarified how devices are defined when the user requests to associate
>   with a coordinator: for now only the extended address of the
>   coordinator is relevant so this is the only address we care about.
> * Drop a useless NULL check before a kfree() call.
> * Add a check when allocating a child short address: it must be
>   different than ours.
> * Rebased on top of v6.5.
> 
> Miquel Raynal (11):
>   ieee802154: Let PAN IDs be reset
>   ieee802154: Internal PAN management
>   ieee802154: Add support for user association requests
>   mac802154: Handle associating
>   ieee802154: Add support for user disassociation requests
>   mac802154: Handle disassociations
>   mac802154: Handle association requests from peers
>   ieee802154: Add support for limiting the number of associated devices
>   mac802154: Follow the number of associated devices
>   mac802154: Handle disassociation notifications from peers
>   ieee802154: Give the user the association list
> 
>  include/net/cfg802154.h         |  69 ++++++
>  include/net/ieee802154_netdev.h |  60 +++++
>  include/net/nl802154.h          |  22 +-
>  net/ieee802154/Makefile         |   2 +-
>  net/ieee802154/core.c           |  24 ++
>  net/ieee802154/nl802154.c       | 223 +++++++++++++++++-
>  net/ieee802154/pan.c            | 115 +++++++++
>  net/ieee802154/rdev-ops.h       |  30 +++
>  net/ieee802154/trace.h          |  38 +++
>  net/mac802154/cfg.c             | 170 ++++++++++++++
>  net/mac802154/ieee802154_i.h    |  27 +++
>  net/mac802154/main.c            |   2 +
>  net/mac802154/rx.c              |  25 ++
>  net/mac802154/scan.c            | 397 ++++++++++++++++++++++++++++++++
>  14 files changed, 1191 insertions(+), 13 deletions(-)
>  create mode 100644 net/ieee802154/pan.c
>