pan.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * IEEE 802.15.4 PAN management
  4 *
  5 * Copyright (C) 2023 Qorvo US, Inc
  6 * Authors:
  7 *   - David Girault <david.girault@qorvo.com>
  8 *   - Miquel Raynal <miquel.raynal@bootlin.com>
  9 */
 10
 11#include <linux/kernel.h>
 12#include <net/cfg802154.h>
 13#include <net/af_ieee802154.h>
 14
 15/* Checks whether a device address matches one from the PAN list.
 16 * This helper is meant to be used only during PAN management, when we expect
 17 * extended addresses to be used.
 18 */
 19static bool cfg802154_pan_device_is_matching(struct ieee802154_pan_device *pan_dev,
 20					     struct ieee802154_addr *ext_dev)
 21{
 22	if (!pan_dev || !ext_dev)
 23		return false;
 24
 25	if (ext_dev->mode == IEEE802154_ADDR_SHORT)
 26		return false;
 27
 28	return pan_dev->extended_addr == ext_dev->extended_addr;
 29}
 30
 31bool cfg802154_device_is_associated(struct wpan_dev *wpan_dev)
 32{
 33	bool is_assoc;
 34
 35	mutex_lock(&wpan_dev->association_lock);
 36	is_assoc = !list_empty(&wpan_dev->children) || wpan_dev->parent;
 37	mutex_unlock(&wpan_dev->association_lock);
 38
 39	return is_assoc;
 40}
 41
 42bool cfg802154_device_is_parent(struct wpan_dev *wpan_dev,
 43				struct ieee802154_addr *target)
 44{
 45	lockdep_assert_held(&wpan_dev->association_lock);
 46
 47	return cfg802154_pan_device_is_matching(wpan_dev->parent, target);
 48}
 49EXPORT_SYMBOL_GPL(cfg802154_device_is_parent);
 50
 51struct ieee802154_pan_device *
 52cfg802154_device_is_child(struct wpan_dev *wpan_dev,
 53			  struct ieee802154_addr *target)
 54{
 55	struct ieee802154_pan_device *child;
 56
 57	lockdep_assert_held(&wpan_dev->association_lock);
 58
 59	list_for_each_entry(child, &wpan_dev->children, node)
 60		if (cfg802154_pan_device_is_matching(child, target))
 61			return child;
 62
 63	return NULL;
 64}
 65EXPORT_SYMBOL_GPL(cfg802154_device_is_child);
 66
 67__le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev)
 68{
 69	struct ieee802154_pan_device *child;
 70	__le16 addr;
 71
 72	lockdep_assert_held(&wpan_dev->association_lock);
 73
 74	do {
 75		get_random_bytes(&addr, 2);
 76		if (addr == cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST) ||
 77		    addr == cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC))
 78			continue;
 79
 80		if (wpan_dev->short_addr == addr)
 81			continue;
 82
 83		if (wpan_dev->parent && wpan_dev->parent->short_addr == addr)
 84			continue;
 85
 86		list_for_each_entry(child, &wpan_dev->children, node)
 87			if (child->short_addr == addr)
 88				continue;
 89
 90		break;
 91	} while (1);
 92
 93	return addr;
 94}
 95EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
 96
 97unsigned int cfg802154_set_max_associations(struct wpan_dev *wpan_dev,
 98					    unsigned int max)
 99{
100	unsigned int old_max;
101
102	lockdep_assert_held(&wpan_dev->association_lock);
103
104	old_max = wpan_dev->max_associations;
105	wpan_dev->max_associations = max;
106
107	return old_max;
108}
109EXPORT_SYMBOL_GPL(cfg802154_set_max_associations);