net/6lowpan/core.c

   1 /* This program is free software; you can redistribute it and/or modify
   2  * it under the terms of the GNU General Public License version 2
   3  * as published by the Free Software Foundation.
   4  *
   5  * This program is distributed in the hope that it will be useful,
   6  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   7  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   8  * GNU General Public License for more details.
   9  *
  10  * Authors:
  11  * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
  12  */
  13
  14 #include <linux/module.h>
  15
  16 #include <net/6lowpan.h>
  17 #include <net/addrconf.h>
  18
  19 #include "6lowpan_i.h"
  20
  21 int lowpan_register_netdevice(struct net_device *dev,
  22                               enum lowpan_lltypes lltype)
  23 {
  24         int i, ret;
  25
  26         switch (lltype) {
  27         case LOWPAN_LLTYPE_IEEE802154:
  28                 dev->addr_len = EUI64_ADDR_LEN;
  29                 break;
  30
  31         case LOWPAN_LLTYPE_BTLE:
  32                 dev->addr_len = ETH_ALEN;
  33                 break;
  34         }
  35
  36         dev->type = ARPHRD_6LOWPAN;
  37         dev->mtu = IPV6_MIN_MTU;
  38
  39         lowpan_dev(dev)->lltype = lltype;
  40
  41         spin_lock_init(&lowpan_dev(dev)->ctx.lock);
  42         for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
  43                 lowpan_dev(dev)->ctx.table[i].id = i;
  44
  45         dev->ndisc_ops = &lowpan_ndisc_ops;
  46
  47         ret = register_netdevice(dev);
  48         if (ret < 0)
  49                 return ret;
  50
  51         ret = lowpan_dev_debugfs_init(dev);
  52         if (ret < 0)
  53                 unregister_netdevice(dev);
  54
  55         return ret;
  56 }
  57 EXPORT_SYMBOL(lowpan_register_netdevice);
  58
  59 int lowpan_register_netdev(struct net_device *dev,
  60                            enum lowpan_lltypes lltype)
  61 {
  62         int ret;
  63
  64         rtnl_lock();
  65         ret = lowpan_register_netdevice(dev, lltype);
  66         rtnl_unlock();
  67         return ret;
  68 }
  69 EXPORT_SYMBOL(lowpan_register_netdev);
  70
  71 void lowpan_unregister_netdevice(struct net_device *dev)
  72 {
  73         unregister_netdevice(dev);
  74         lowpan_dev_debugfs_exit(dev);
  75 }
  76 EXPORT_SYMBOL(lowpan_unregister_netdevice);
  77
  78 void lowpan_unregister_netdev(struct net_device *dev)
  79 {
  80         rtnl_lock();
  81         lowpan_unregister_netdevice(dev);
  82         rtnl_unlock();
  83 }
  84 EXPORT_SYMBOL(lowpan_unregister_netdev);
  85
  86 int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
  87 {
  88         struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
  89
  90         /* Set short_addr autoconfiguration if short_addr is present only */
  91         if (!lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
  92                 return -1;
  93
  94         /* For either address format, all zero addresses MUST NOT be used */
  95         if (wpan_dev->pan_id == cpu_to_le16(0x0000) &&
  96             wpan_dev->short_addr == cpu_to_le16(0x0000))
  97                 return -1;
  98
  99         /* Alternatively, if no PAN ID is known, 16 zero bits may be used */
 100         if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PAN_ID_BROADCAST))
 101                 memset(eui, 0, 2);
 102         else
 103                 ieee802154_le16_to_be16(eui, &wpan_dev->pan_id);
 104
 105         /* The "Universal/Local" (U/L) bit shall be set to zero */
 106         eui[0] &= ~2;
 107         eui[2] = 0;
 108         eui[3] = 0xFF;
 109         eui[4] = 0xFE;
 110         eui[5] = 0;
 111         ieee802154_le16_to_be16(&eui[6], &wpan_dev->short_addr);
 112         return 0;
 113 }
 114
 115 static int lowpan_event(struct notifier_block *unused,
 116                         unsigned long event, void *ptr)
 117 {
 118         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 119         struct inet6_dev *idev;
 120         struct in6_addr addr;
 121         int i;
 122
 123         if (dev->type != ARPHRD_6LOWPAN)
 124                 return NOTIFY_DONE;
 125
 126         idev = __in6_dev_get(dev);
 127         if (!idev)
 128                 return NOTIFY_DONE;
 129
 130         switch (event) {
 131         case NETDEV_UP:
 132         case NETDEV_CHANGE:
 133                 /* (802.15.4 6LoWPAN short address slaac handling */
 134                 if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) &&
 135                     addrconf_ifid_802154_6lowpan(addr.s6_addr + 8, dev) == 0) {
 136                         __ipv6_addr_set_half(&addr.s6_addr32[0],
 137                                              htonl(0xFE800000), 0);
 138                         addrconf_add_linklocal(idev, &addr, 0);
 139                 }
 140                 break;
 141         case NETDEV_DOWN:
 142                 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
 143                         clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
 144                                   &lowpan_dev(dev)->ctx.table[i].flags);
 145                 break;
 146         default:
 147                 return NOTIFY_DONE;
 148         }
 149
 150         return NOTIFY_OK;
 151 }
 152
 153 static struct notifier_block lowpan_notifier = {
 154         .notifier_call = lowpan_event,
 155 };
 156
 157 static int __init lowpan_module_init(void)
 158 {
 159         int ret;
 160
 161         ret = lowpan_debugfs_init();
 162         if (ret < 0)
 163                 return ret;
 164
 165         ret = register_netdevice_notifier(&lowpan_notifier);
 166         if (ret < 0) {
 167                 lowpan_debugfs_exit();
 168                 return ret;
 169         }
 170
 171         request_module_nowait("nhc_dest");
 172         request_module_nowait("nhc_fragment");
 173         request_module_nowait("nhc_hop");
 174         request_module_nowait("nhc_ipv6");
 175         request_module_nowait("nhc_mobility");
 176         request_module_nowait("nhc_routing");
 177         request_module_nowait("nhc_udp");
 178
 179         return 0;
 180 }
 181
 182 static void __exit lowpan_module_exit(void)
 183 {
 184         lowpan_debugfs_exit();
 185         unregister_netdevice_notifier(&lowpan_notifier);
 186 }
 187
 188 module_init(lowpan_module_init);
 189 module_exit(lowpan_module_exit);
 190
 191 MODULE_LICENSE("GPL");