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 */
19 static 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
31 bool 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
42 bool 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 }
49 EXPORT_SYMBOL_GPL(cfg802154_device_is_parent);
50
51 struct ieee802154_pan_device *
52 cfg802154_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 }
65 EXPORT_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 }
95 EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
96
97 unsigned 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 }
109 EXPORT_SYMBOL_GPL(cfg802154_set_max_associations);
110
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