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: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/linux-wpan/20231128111655.507479-5-miquel.raynal@bootlin.com
This commit is contained in:
Miquel Raynal 2023-11-28 12:16:54 +01:00
parent 95d92505b6
commit b720383ab1

View File

@ -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);
}