From b720383ab1cfd584c8c0d9fc7b8cc541ed76dba5 Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Tue, 28 Nov 2023 12:16:54 +0100 Subject: [PATCH] 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 Acked-by: Stefan Schmidt Acked-by: Alexander Aring Link: https://lore.kernel.org/linux-wpan/20231128111655.507479-5-miquel.raynal@bootlin.com --- 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 822cf025120a..7eb37de3add2 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); }