linux/net/ieee802154/pan.c
Miquel Raynal 2373699560 mac802154: Avoid new associations while disassociating
While disassociating from a PAN ourselves, let's set the maximum number
of associations temporarily to zero to be sure no new device tries to
associate with us.

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/20231128111655.507479-6-miquel.raynal@bootlin.com
2023-12-15 11:14:57 +01:00

110 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* IEEE 802.15.4 PAN management
*
* Copyright (C) 2023 Qorvo US, Inc
* Authors:
* - David Girault <david.girault@qorvo.com>
* - Miquel Raynal <miquel.raynal@bootlin.com>
*/
#include <linux/kernel.h>
#include <net/cfg802154.h>
#include <net/af_ieee802154.h>
/* Checks whether a device address matches one from the PAN list.
* This helper is meant to be used only during PAN management, when we expect
* extended addresses to be used.
*/
static bool cfg802154_pan_device_is_matching(struct ieee802154_pan_device *pan_dev,
struct ieee802154_addr *ext_dev)
{
if (!pan_dev || !ext_dev)
return false;
if (ext_dev->mode == IEEE802154_ADDR_SHORT)
return false;
return pan_dev->extended_addr == ext_dev->extended_addr;
}
bool cfg802154_device_is_associated(struct wpan_dev *wpan_dev)
{
bool is_assoc;
mutex_lock(&wpan_dev->association_lock);
is_assoc = !list_empty(&wpan_dev->children) || wpan_dev->parent;
mutex_unlock(&wpan_dev->association_lock);
return is_assoc;
}
bool cfg802154_device_is_parent(struct wpan_dev *wpan_dev,
struct ieee802154_addr *target)
{
lockdep_assert_held(&wpan_dev->association_lock);
return cfg802154_pan_device_is_matching(wpan_dev->parent, target);
}
EXPORT_SYMBOL_GPL(cfg802154_device_is_parent);
struct ieee802154_pan_device *
cfg802154_device_is_child(struct wpan_dev *wpan_dev,
struct ieee802154_addr *target)
{
struct ieee802154_pan_device *child;
lockdep_assert_held(&wpan_dev->association_lock);
list_for_each_entry(child, &wpan_dev->children, node)
if (cfg802154_pan_device_is_matching(child, target))
return child;
return NULL;
}
EXPORT_SYMBOL_GPL(cfg802154_device_is_child);
__le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev)
{
struct ieee802154_pan_device *child;
__le16 addr;
lockdep_assert_held(&wpan_dev->association_lock);
do {
get_random_bytes(&addr, 2);
if (addr == cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST) ||
addr == cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC))
continue;
if (wpan_dev->short_addr == addr)
continue;
if (wpan_dev->parent && wpan_dev->parent->short_addr == addr)
continue;
list_for_each_entry(child, &wpan_dev->children, node)
if (child->short_addr == addr)
continue;
break;
} while (1);
return addr;
}
EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
unsigned int cfg802154_set_max_associations(struct wpan_dev *wpan_dev,
unsigned int max)
{
unsigned int old_max;
lockdep_assert_held(&wpan_dev->association_lock);
old_max = wpan_dev->max_associations;
wpan_dev->max_associations = max;
return old_max;
}
EXPORT_SYMBOL_GPL(cfg802154_set_max_associations);