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/if_arp.h>
   9 #include <linux/module.h>
  10
  11 #include <net/6lowpan.h>
  12 #include <net/addrconf.h>
  13
  14 #include "6lowpan_i.h"
  15
  16 int lowpan_register_netdevice(struct net_device *dev,
  17                               enum lowpan_lltypes lltype)
  18 {
  19         int i, ret;
  20
  21         switch (lltype) {
  22         case LOWPAN_LLTYPE_IEEE802154:
  23                 dev->addr_len = EUI64_ADDR_LEN;
  24                 break;
  25
  26         case LOWPAN_LLTYPE_BTLE:
  27                 dev->addr_len = ETH_ALEN;
  28                 break;
  29         }
  30
  31         dev->type = ARPHRD_6LOWPAN;
  32         dev->mtu = IPV6_MIN_MTU;
  33
  34         lowpan_dev(dev)->lltype = lltype;
  35
  36         spin_lock_init(&lowpan_dev(dev)->ctx.lock);
  37         for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
  38                 lowpan_dev(dev)->ctx.table[i].id = i;
  39
  40         dev->ndisc_ops = &lowpan_ndisc_ops;
  41
  42         ret = register_netdevice(dev);
  43         if (ret < 0)
  44                 return ret;
  45
  46         lowpan_dev_debugfs_init(dev);
  47
  48         return ret;
  49 }
  50 EXPORT_SYMBOL(lowpan_register_netdevice);
  51
  52 int lowpan_register_netdev(struct net_device *dev,
  53                            enum lowpan_lltypes lltype)
  54 {
  55         int ret;
  56
  57         rtnl_lock();
  58         ret = lowpan_register_netdevice(dev, lltype);
  59         rtnl_unlock();
  60         return ret;
  61 }
  62 EXPORT_SYMBOL(lowpan_register_netdev);
  63
  64 void lowpan_unregister_netdevice(struct net_device *dev)
  65 {
  66         unregister_netdevice(dev);
  67         lowpan_dev_debugfs_exit(dev);
  68 }
  69 EXPORT_SYMBOL(lowpan_unregister_netdevice);
  70
  71 void lowpan_unregister_netdev(struct net_device *dev)
  72 {
  73         rtnl_lock();
  74         lowpan_unregister_netdevice(dev);
  75         rtnl_unlock();
  76 }
  77 EXPORT_SYMBOL(lowpan_unregister_netdev);
  78
  79 int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
  80 {
  81         struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
  82
  83         /* Set short_addr autoconfiguration if short_addr is present only */
  84         if (!lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
  85                 return -1;
  86
  87         /* For either address format, all zero addresses MUST NOT be used */
  88         if (wpan_dev->pan_id == cpu_to_le16(0x0000) &&
  89             wpan_dev->short_addr == cpu_to_le16(0x0000))
  90                 return -1;
  91
  92         /* Alternatively, if no PAN ID is known, 16 zero bits may be used */
  93         if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PAN_ID_BROADCAST))
  94                 memset(eui, 0, 2);
  95         else
  96                 ieee802154_le16_to_be16(eui, &wpan_dev->pan_id);
  97
  98         /* The "Universal/Local" (U/L) bit shall be set to zero */
  99         eui[0] &= ~2;
 100         eui[2] = 0;
 101         eui[3] = 0xFF;
 102         eui[4] = 0xFE;
 103         eui[5] = 0;
 104         ieee802154_le16_to_be16(&eui[6], &wpan_dev->short_addr);
 105         return 0;
 106 }
 107
 108 static int lowpan_event(struct notifier_block *unused,
 109                         unsigned long event, void *ptr)
 110 {
 111         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 112         struct inet6_dev *idev;
 113         struct in6_addr addr;
 114         int i;
 115
 116         if (dev->type != ARPHRD_6LOWPAN)
 117                 return NOTIFY_DONE;
 118
 119         idev = __in6_dev_get(dev);
 120         if (!idev)
 121                 return NOTIFY_DONE;
 122
 123         switch (event) {
 124         case NETDEV_UP:
 125         case NETDEV_CHANGE:
 126                 /* (802.15.4 6LoWPAN short address slaac handling */
 127                 if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) &&
 128                     addrconf_ifid_802154_6lowpan(addr.s6_addr + 8, dev) == 0) {
 129                         __ipv6_addr_set_half(&addr.s6_addr32[0],
 130                                              htonl(0xFE800000), 0);
 131                         addrconf_add_linklocal(idev, &addr, 0);
 132                 }
 133                 break;
 134         case NETDEV_DOWN:
 135                 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
 136                         clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
 137                                   &lowpan_dev(dev)->ctx.table[i].flags);
 138                 break;
 139         default:
 140                 return NOTIFY_DONE;
 141         }
 142
 143         return NOTIFY_OK;
 144 }
 145
 146 static struct notifier_block lowpan_notifier = {
 147         .notifier_call = lowpan_event,
 148 };
 149
 150 static int __init lowpan_module_init(void)
 151 {
 152         int ret;
 153
 154         lowpan_debugfs_init();
 155
 156         ret = register_netdevice_notifier(&lowpan_notifier);
 157         if (ret < 0) {
 158                 lowpan_debugfs_exit();
 159                 return ret;
 160         }
 161
 162         request_module_nowait("nhc_dest");
 163         request_module_nowait("nhc_fragment");
 164         request_module_nowait("nhc_hop");
 165         request_module_nowait("nhc_ipv6");
 166         request_module_nowait("nhc_mobility");
 167         request_module_nowait("nhc_routing");
 168         request_module_nowait("nhc_udp");
 169
 170         return 0;
 171 }
 172
 173 static void __exit lowpan_module_exit(void)
 174 {
 175         lowpan_debugfs_exit();
 176         unregister_netdevice_notifier(&lowpan_notifier);
 177 }
 178
 179 module_init(lowpan_module_init);
 180 module_exit(lowpan_module_exit);
 181
 182 MODULE_DESCRIPTION("IPv6 over Low-Power Wireless Personal Area Network core module");
 183 MODULE_LICENSE("GPL");