ieee802154: Add support for limiting the number of associated devices

Coordinators may refuse associations. We need a user input for
that. Let's add a new netlink command which can provide a maximum number
of devices we accept to associate with as a first step. Later, we could
also forward the request to userspace and check whether the association
should be accepted or not.

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/20230927181214.129346-9-miquel.raynal@bootlin.com
This commit is contained in:
Miquel Raynal 2023-09-27 20:12:11 +02:00
parent 601f160b61
commit ce93b9378c
5 changed files with 47 additions and 0 deletions

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@ -506,6 +506,7 @@ struct wpan_dev {
struct mutex association_lock;
struct ieee802154_pan_device *parent;
struct list_head children;
unsigned int max_associations;
};
#define to_phy(_dev) container_of(_dev, struct wpan_phy, dev)
@ -583,6 +584,13 @@ struct ieee802154_pan_device *
cfg802154_device_is_child(struct wpan_dev *wpan_dev,
struct ieee802154_addr *target);
/**
* cfg802154_set_max_associations - Limit the number of future associations
* @wpan_dev: the wpan device
* @max: the maximum number of devices we accept to associate
*/
void cfg802154_set_max_associations(struct wpan_dev *wpan_dev, unsigned int max);
/**
* cfg802154_get_free_short_addr - Get a free address among the known devices
* @wpan_dev: the wpan device

View File

@ -80,6 +80,7 @@ enum nl802154_commands {
NL802154_CMD_STOP_BEACONS,
NL802154_CMD_ASSOCIATE,
NL802154_CMD_DISASSOCIATE,
NL802154_CMD_SET_MAX_ASSOCIATIONS,
/* add new commands above here */
@ -149,6 +150,7 @@ enum nl802154_attrs {
NL802154_ATTR_SCAN_DURATION,
NL802154_ATTR_SCAN_DONE_REASON,
NL802154_ATTR_BEACON_INTERVAL,
NL802154_ATTR_MAX_ASSOCIATIONS,
/* add attributes here, update the policy in nl802154.c */

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@ -295,6 +295,7 @@ static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
rdev->devlist_generation++;
mutex_init(&wpan_dev->association_lock);
INIT_LIST_HEAD(&wpan_dev->children);
wpan_dev->max_associations = SZ_16K;
wpan_dev->netdev = dev;
break;

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@ -234,6 +234,7 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
NL802154_SCAN_DONE_REASON_ABORTED),
[NL802154_ATTR_BEACON_INTERVAL] =
NLA_POLICY_MAX(NLA_U8, IEEE802154_ACTIVE_SCAN_DURATION),
[NL802154_ATTR_MAX_ASSOCIATIONS] = { .type = NLA_U32 },
#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
[NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },
@ -1696,6 +1697,26 @@ static int nl802154_disassociate(struct sk_buff *skb, struct genl_info *info)
return 0;
}
static int nl802154_set_max_associations(struct sk_buff *skb, struct genl_info *info)
{
struct net_device *dev = info->user_ptr[1];
struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
unsigned int max_assoc;
if (!info->attrs[NL802154_ATTR_MAX_ASSOCIATIONS]) {
NL_SET_ERR_MSG(info->extack, "No maximum number of association given");
return -EINVAL;
}
max_assoc = nla_get_u32(info->attrs[NL802154_ATTR_MAX_ASSOCIATIONS]);
mutex_lock(&wpan_dev->association_lock);
cfg802154_set_max_associations(wpan_dev, max_assoc);
mutex_unlock(&wpan_dev->association_lock);
return 0;
}
#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
static const struct nla_policy nl802154_dev_addr_policy[NL802154_DEV_ADDR_ATTR_MAX + 1] = {
[NL802154_DEV_ADDR_ATTR_PAN_ID] = { .type = NLA_U16 },
@ -2833,6 +2854,13 @@ static const struct genl_ops nl802154_ops[] = {
NL802154_FLAG_CHECK_NETDEV_UP |
NL802154_FLAG_NEED_RTNL,
},
{
.cmd = NL802154_CMD_SET_MAX_ASSOCIATIONS,
.doit = nl802154_set_max_associations,
.flags = GENL_ADMIN_PERM,
.internal_flags = NL802154_FLAG_NEED_NETDEV |
NL802154_FLAG_NEED_RTNL,
},
#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
{
.cmd = NL802154_CMD_SET_SEC_PARAMS,

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@ -93,3 +93,11 @@ __le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev)
return addr;
}
EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
void cfg802154_set_max_associations(struct wpan_dev *wpan_dev, unsigned int max)
{
lockdep_assert_held(&wpan_dev->association_lock);
wpan_dev->max_associations = max;
}
EXPORT_SYMBOL_GPL(cfg802154_set_max_associations);