Commit 80f8bf9a authored by Miquel Raynal's avatar Miquel Raynal
Browse files

mac802154: Follow the number of associated devices 



Track the count of associated devices. Limit the number of associations
using the value provided by the user if any. If we reach the maximum
number of associations, we tell the device we are at capacity. If the
user do not want to accept any more associations, it may specify the
value 0 to the maximum number of associations, which will lead to an
access denied error status returned to the peers trying to associate.

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/20230927181214.129346-10-miquel.raynal@bootlin.com
parent ce93b937

include/net/cfg802154.h

+1 −0
Original line number Diff line number Diff line
@@ -507,6 +507,7 @@ struct wpan_dev { 
	struct ieee802154_pan_device *parent;

	struct list_head children;

	unsigned int max_associations;

	unsigned int nchildren;

};



#define to_phy(_dev)	container_of(_dev, struct wpan_phy, dev)

net/ieee802154/core.c

+2 −0
Original line number Diff line number Diff line
@@ -212,6 +212,8 @@ static void cfg802154_free_peer_structures(struct wpan_dev *wpan_dev) 
		kfree(child);

	}



	wpan_dev->nchildren = 0;



	mutex_unlock(&wpan_dev->association_lock);

}

net/mac802154/cfg.c

+1 −0
Original line number Diff line number Diff line
@@ -454,6 +454,7 @@ static int mac802154_disassociate_child(struct wpan_phy *wpan_phy, 
		return ret;



	list_del(&child->node);

	wpan_dev->nchildren--;

	kfree(child);



	return 0;

net/mac802154/scan.c

+23 −10
Original line number Diff line number Diff line
@@ -800,6 +800,17 @@ int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata, 
	child->mode = IEEE802154_EXTENDED_ADDRESSING;

	ceaddr = swab64((__force u64)child->extended_addr);



	if (wpan_dev->nchildren >= wpan_dev->max_associations) {

		if (!wpan_dev->max_associations)

			assoc_resp_pl.status = IEEE802154_PAN_ACCESS_DENIED;

		else

			assoc_resp_pl.status = IEEE802154_PAN_AT_CAPACITY;

		assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST);

		dev_dbg(&sdata->dev->dev,

			"Refusing ASSOC REQ from child %8phC, %s\n", &ceaddr,

			assoc_resp_pl.status == IEEE802154_PAN_ACCESS_DENIED ?

			"access denied" : "too many children");

	} else {

		assoc_resp_pl.status = IEEE802154_ASSOCIATION_SUCCESSFUL;

		if (assoc_req_pl.alloc_addr) {

			assoc_resp_pl.short_addr = cfg802154_get_free_short_addr(wpan_dev);
@@ -811,9 +822,10 @@ int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata, 
		dev_dbg(&sdata->dev->dev,

			"Accepting ASSOC REQ from child %8phC, providing short address 0x%04x\n",

			&ceaddr, le16_to_cpu(child->short_addr));

	}



	ret = mac802154_send_association_resp_locked(sdata, child, &assoc_resp_pl);

	if (ret) {

	if (ret || assoc_resp_pl.status != IEEE802154_ASSOCIATION_SUCCESSFUL) {

		kfree(child);

		goto unlock;

	}
@@ -834,6 +846,7 @@ int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata, 
	}



	list_add(&child->node, &wpan_dev->children);

	wpan_dev->nchildren++;



unlock:

	mutex_unlock(&wpan_dev->association_lock);