Commit b720383a authored by Miquel Raynal's avatar Miquel Raynal
Browse files

ieee802154: Avoid confusing changes after associating 



Once associated with any device, we are part of a PAN (with a specific
PAN ID), and we are expected to be present on a particular
channel. Let's avoid confusing other devices by preventing any PAN
ID/channel change once associated.

Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Acked-by: default avatarStefan Schmidt <stefan@datenfreihafen.org>
Acked-by: default avatarAlexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/linux-wpan/20231128111655.507479-5-miquel.raynal@bootlin.com
parent 95d92505

net/ieee802154/nl802154.c

+18 −12
Original line number Diff line number Diff line
@@ -1087,6 +1087,15 @@ static int nl802154_set_pan_id(struct sk_buff *skb, struct genl_info *info) 


	pan_id = nla_get_le16(info->attrs[NL802154_ATTR_PAN_ID]);



	/* Only allow changing the PAN ID when the device has no more

	 * associations ongoing to avoid confusing peers.

	 */

	if (cfg802154_device_is_associated(wpan_dev)) {

		NL_SET_ERR_MSG(info->extack,

			       "Existing associations, changing PAN ID forbidden");

		return -EINVAL;

	}



	return rdev_set_pan_id(rdev, wpan_dev, pan_id);

}
@@ -1113,20 +1122,17 @@ static int nl802154_set_short_addr(struct sk_buff *skb, struct genl_info *info) 


	short_addr = nla_get_le16(info->attrs[NL802154_ATTR_SHORT_ADDR]);



	/* TODO

	 * I am not sure about to check here on broadcast short_addr.

	 * Broadcast is a valid setting, comment from 802.15.4:

	 * A value of 0xfffe indicates that the device has

	 * associated but has not been allocated an address. A

	 * value of 0xffff indicates that the device does not

	 * have a short address.

	 *

	 * I think we should allow to set these settings but

	 * don't allow to allow socket communication with it.

	/* The short address only has a meaning when part of a PAN, after a

	 * proper association procedure. However, we want to still offer the

	 * possibility to create static networks so changing the short address

	 * is only allowed when not already associated to other devices with

	 * the official handshake.

	 */

	if (short_addr == cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC) ||

	    short_addr == cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST))

	if (cfg802154_device_is_associated(wpan_dev)) {

		NL_SET_ERR_MSG(info->extack,

			       "Existing associations, changing short address forbidden");

		return -EINVAL;

	}



	return rdev_set_short_addr(rdev, wpan_dev, short_addr);

}