Hello.
On 28.11.23 12:16, Miquel Raynal wrote:
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@xxxxxxxxxxx>
---
net/ieee802154/nl802154.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index e4d290d0e0a0..5c73b5fcadc0 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -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);
}
Acked-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
regards
Stefan Schmidt
