net/ieee802154/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  */
  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);