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