net/6lowpan/core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *
   4  * Authors:
   5  * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
   6  */
   7
   8 #include <linux/module.h>
   9
  10 #include <net/6lowpan.h>
  11 #include <net/addrconf.h>
  12
  13 #include "6lowpan_i.h"
  14
  15 int lowpan_register_netdevice(struct net_device *dev,
  16                               enum lowpan_lltypes lltype)
  17 {
  18         int i, ret;
  19
  20         switch (lltype) {
  21         case LOWPAN_LLTYPE_IEEE802154:
  22                 dev->addr_len = EUI64_ADDR_LEN;
  23                 break;
  24
  25         case LOWPAN_LLTYPE_BTLE:
  26                 dev->addr_len = ETH_ALEN;
  27                 break;
  28         }
  29
  30         dev->type = ARPHRD_6LOWPAN;
  31         dev->mtu = IPV6_MIN_MTU;
  32
  33         lowpan_dev(dev)->lltype = lltype;
  34
  35         spin_lock_init(&lowpan_dev(dev)->ctx.lock);
  36         for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
  37                 lowpan_dev(dev)->ctx.table[i].id = i;
  38
  39         dev->ndisc_ops = &lowpan_ndisc_ops;
  40
  41         ret = register_netdevice(dev);
  42         if (ret < 0)
  43                 return ret;
  44
  45         ret = lowpan_dev_debugfs_init(dev);
  46         if (ret < 0)
  47                 unregister_netdevice(dev);
  48
  49         return ret;
  50 }
  51 EXPORT_SYMBOL(lowpan_register_netdevice);
  52
  53 int lowpan_register_netdev(struct net_device *dev,
  54                            enum lowpan_lltypes lltype)
  55 {
  56         int ret;
  57
  58         rtnl_lock();
  59         ret = lowpan_register_netdevice(dev, lltype);
  60         rtnl_unlock();
  61         return ret;
  62 }
  63 EXPORT_SYMBOL(lowpan_register_netdev);
  64
  65 void lowpan_unregister_netdevice(struct net_device *dev)
  66 {
  67         unregister_netdevice(dev);
  68         lowpan_dev_debugfs_exit(dev);
  69 }
  70 EXPORT_SYMBOL(lowpan_unregister_netdevice);
  71
  72 void lowpan_unregister_netdev(struct net_device *dev)
  73 {
  74         rtnl_lock();
  75         lowpan_unregister_netdevice(dev);
  76         rtnl_unlock();
  77 }
  78 EXPORT_SYMBOL(lowpan_unregister_netdev);
  79
  80 int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
  81 {
  82         struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
  83
  84         /* Set short_addr autoconfiguration if short_addr is present only */
  85         if (!lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
  86                 return -1;
  87
  88         /* For either address format, all zero addresses MUST NOT be used */
  89         if (wpan_dev->pan_id == cpu_to_le16(0x0000) &&
  90             wpan_dev->short_addr == cpu_to_le16(0x0000))
  91                 return -1;
  92
  93         /* Alternatively, if no PAN ID is known, 16 zero bits may be used */
  94         if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PAN_ID_BROADCAST))
  95                 memset(eui, 0, 2);
  96         else
  97                 ieee802154_le16_to_be16(eui, &wpan_dev->pan_id);
  98
  99         /* The "Universal/Local" (U/L) bit shall be set to zero */
 100         eui[0] &= ~2;
 101         eui[2] = 0;
 102         eui[3] = 0xFF;
 103         eui[4] = 0xFE;
 104         eui[5] = 0;
 105         ieee802154_le16_to_be16(&eui[6], &wpan_dev->short_addr);
 106         return 0;
 107 }
 108
 109 static int lowpan_event(struct notifier_block *unused,
 110                         unsigned long event, void *ptr)
 111 {
 112         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 113         struct inet6_dev *idev;
 114         struct in6_addr addr;
 115         int i;
 116
 117         if (dev->type != ARPHRD_6LOWPAN)
 118                 return NOTIFY_DONE;
 119
 120         idev = __in6_dev_get(dev);
 121         if (!idev)
 122                 return NOTIFY_DONE;
 123
 124         switch (event) {
 125         case NETDEV_UP:
 126         case NETDEV_CHANGE:
 127                 /* (802.15.4 6LoWPAN short address slaac handling */
 128                 if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) &&
 129                     addrconf_ifid_802154_6lowpan(addr.s6_addr + 8, dev) == 0) {
 130                         __ipv6_addr_set_half(&addr.s6_addr32[0],
 131                                              htonl(0xFE800000), 0);
 132                         addrconf_add_linklocal(idev, &addr, 0);
 133                 }
 134                 break;
 135         case NETDEV_DOWN:
 136                 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
 137                         clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
 138                                   &lowpan_dev(dev)->ctx.table[i].flags);
 139                 break;
 140         default:
 141                 return NOTIFY_DONE;
 142         }
 143
 144         return NOTIFY_OK;
 145 }
 146
 147 static struct notifier_block lowpan_notifier = {
 148         .notifier_call = lowpan_event,
 149 };
 150
 151 static int __init lowpan_module_init(void)
 152 {
 153         int ret;
 154
 155         ret = lowpan_debugfs_init();
 156         if (ret < 0)
 157                 return ret;
 158
 159         ret = register_netdevice_notifier(&lowpan_notifier);
 160         if (ret < 0) {
 161                 lowpan_debugfs_exit();
 162                 return ret;
 163         }
 164
 165         request_module_nowait("nhc_dest");
 166         request_module_nowait("nhc_fragment");
 167         request_module_nowait("nhc_hop");
 168         request_module_nowait("nhc_ipv6");
 169         request_module_nowait("nhc_mobility");
 170         request_module_nowait("nhc_routing");
 171         request_module_nowait("nhc_udp");
 172
 173         return 0;
 174 }
 175
 176 static void __exit lowpan_module_exit(void)
 177 {
 178         lowpan_debugfs_exit();
 179         unregister_netdevice_notifier(&lowpan_notifier);
 180 }
 181
 182 module_init(lowpan_module_init);
 183 module_exit(lowpan_module_exit);
 184
 185 MODULE_LICENSE("GPL");