Commit ce93b937 authored by Miquel Raynal's avatar Miquel Raynal
Browse files

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: 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/20230927181214.129346-9-miquel.raynal@bootlin.com
parent 601f160b

include/net/cfg802154.h

+8 −0
Original line number Diff line number Diff line
@@ -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

include/net/nl802154.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

net/ieee802154/core.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

net/ieee802154/nl802154.c

+28 −0
Original line number Diff line number Diff line
@@ -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,

net/ieee802154/pan.c

+8 −0
Original line number Diff line number Diff line
@@ -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);