kernel/net/ieee802154/6lowpan/core.c

   1 /* Copyright 2011, Siemens AG
   2  * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
   3  */
   4
   5 /* Based on patches from Jon Smirl <jonsmirl@gmail.com>
   6  * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 /* Jon's code is based on 6lowpan implementation for Contiki which is:
  19  * Copyright (c) 2008, Swedish Institute of Computer Science.
  20  * All rights reserved.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the above copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. Neither the name of the Institute nor the names of its contributors
  31  *    may be used to endorse or promote products derived from this software
  32  *    without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  35  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  36  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  37  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  38  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  39  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  40  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  41  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  42  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  43  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  44  * SUCH DAMAGE.
  45  */
  46
  47 #include <linux/module.h>
  48 #include <linux/netdevice.h>
  49 #include <linux/ieee802154.h>
  50
  51 #include <net/ipv6.h>
  52
  53 #include "6lowpan_i.h"
  54
  55 LIST_HEAD(lowpan_devices);
  56 static int lowpan_open_count;
  57
  58 static __le16 lowpan_get_pan_id(const struct net_device *dev)
  59 {
  60         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
  61
  62         return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
  63 }
  64
  65 static __le16 lowpan_get_short_addr(const struct net_device *dev)
  66 {
  67         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
  68
  69         return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
  70 }
  71
  72 static u8 lowpan_get_dsn(const struct net_device *dev)
  73 {
  74         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
  75
  76         return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
  77 }
  78
  79 static struct header_ops lowpan_header_ops = {
  80         .create = lowpan_header_create,
  81 };
  82
  83 static struct lock_class_key lowpan_tx_busylock;
  84 static struct lock_class_key lowpan_netdev_xmit_lock_key;
  85
  86 static void lowpan_set_lockdep_class_one(struct net_device *dev,
  87                                          struct netdev_queue *txq,
  88                                          void *_unused)
  89 {
  90         lockdep_set_class(&txq->_xmit_lock,
  91                           &lowpan_netdev_xmit_lock_key);
  92 }
  93
  94 static int lowpan_dev_init(struct net_device *dev)
  95 {
  96         netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL);
  97         dev->qdisc_tx_busylock = &lowpan_tx_busylock;
  98         return 0;
  99 }
 100
 101 static const struct net_device_ops lowpan_netdev_ops = {
 102         .ndo_init               = lowpan_dev_init,
 103         .ndo_start_xmit         = lowpan_xmit,
 104 };
 105
 106 static struct ieee802154_mlme_ops lowpan_mlme = {
 107         .get_pan_id = lowpan_get_pan_id,
 108         .get_short_addr = lowpan_get_short_addr,
 109         .get_dsn = lowpan_get_dsn,
 110 };
 111
 112 static void lowpan_setup(struct net_device *dev)
 113 {
 114         dev->addr_len           = IEEE802154_ADDR_LEN;
 115         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
 116         dev->type               = ARPHRD_6LOWPAN;
 117         /* Frame Control + Sequence Number + Address fields + Security Header */
 118         dev->hard_header_len    = 2 + 1 + 20 + 14;
 119         dev->needed_tailroom    = 2; /* FCS */
 120         dev->mtu                = IPV6_MIN_MTU;
 121         dev->tx_queue_len       = 0;
 122         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
 123         dev->watchdog_timeo     = 0;
 124
 125         dev->netdev_ops         = &lowpan_netdev_ops;
 126         dev->header_ops         = &lowpan_header_ops;
 127         dev->ml_priv            = &lowpan_mlme;
 128         dev->destructor         = free_netdev;
 129         dev->features           |= NETIF_F_NETNS_LOCAL;
 130 }
 131
 132 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 133 {
 134         if (tb[IFLA_ADDRESS]) {
 135                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
 136                         return -EINVAL;
 137         }
 138         return 0;
 139 }
 140
 141 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
 142                           struct nlattr *tb[], struct nlattr *data[])
 143 {
 144         struct net_device *real_dev;
 145         struct lowpan_dev_record *entry;
 146         int ret;
 147
 148         ASSERT_RTNL();
 149
 150         pr_debug("adding new link\n");
 151
 152         if (!tb[IFLA_LINK] ||
 153             !net_eq(dev_net(dev), &init_net))
 154                 return -EINVAL;
 155         /* find and hold real wpan device */
 156         real_dev = dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
 157         if (!real_dev)
 158                 return -ENODEV;
 159         if (real_dev->type != ARPHRD_IEEE802154) {
 160                 dev_put(real_dev);
 161                 return -EINVAL;
 162         }
 163
 164         lowpan_dev_info(dev)->real_dev = real_dev;
 165         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
 166
 167         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 168         if (!entry) {
 169                 dev_put(real_dev);
 170                 lowpan_dev_info(dev)->real_dev = NULL;
 171                 return -ENOMEM;
 172         }
 173
 174         entry->ldev = dev;
 175
 176         /* Set the lowpan hardware address to the wpan hardware address. */
 177         memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
 178
 179         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 180         INIT_LIST_HEAD(&entry->list);
 181         list_add_tail(&entry->list, &lowpan_devices);
 182         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 183
 184         ret = register_netdevice(dev);
 185         if (ret >= 0) {
 186                 if (!lowpan_open_count)
 187                         lowpan_rx_init();
 188                 lowpan_open_count++;
 189         }
 190
 191         return ret;
 192 }
 193
 194 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
 195 {
 196         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
 197         struct net_device *real_dev = lowpan_dev->real_dev;
 198         struct lowpan_dev_record *entry, *tmp;
 199
 200         ASSERT_RTNL();
 201
 202         lowpan_open_count--;
 203         if (!lowpan_open_count)
 204                 lowpan_rx_exit();
 205
 206         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 207         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 208                 if (entry->ldev == dev) {
 209                         list_del(&entry->list);
 210                         kfree(entry);
 211                 }
 212         }
 213         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 214
 215         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
 216
 217         unregister_netdevice_queue(dev, head);
 218
 219         dev_put(real_dev);
 220 }
 221
 222 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 223         .kind           = "lowpan",
 224         .priv_size      = sizeof(struct lowpan_dev_info),
 225         .setup          = lowpan_setup,
 226         .newlink        = lowpan_newlink,
 227         .dellink        = lowpan_dellink,
 228         .validate       = lowpan_validate,
 229 };
 230
 231 static inline int __init lowpan_netlink_init(void)
 232 {
 233         return rtnl_link_register(&lowpan_link_ops);
 234 }
 235
 236 static inline void lowpan_netlink_fini(void)
 237 {
 238         rtnl_link_unregister(&lowpan_link_ops);
 239 }
 240
 241 static int lowpan_device_event(struct notifier_block *unused,
 242                                unsigned long event, void *ptr)
 243 {
 244         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 245         LIST_HEAD(del_list);
 246         struct lowpan_dev_record *entry, *tmp;
 247
 248         if (dev->type != ARPHRD_IEEE802154)
 249                 goto out;
 250
 251         if (event == NETDEV_UNREGISTER) {
 252                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 253                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
 254                                 lowpan_dellink(entry->ldev, &del_list);
 255                 }
 256
 257                 unregister_netdevice_many(&del_list);
 258         }
 259
 260 out:
 261         return NOTIFY_DONE;
 262 }
 263
 264 static struct notifier_block lowpan_dev_notifier = {
 265         .notifier_call = lowpan_device_event,
 266 };
 267
 268 static int __init lowpan_init_module(void)
 269 {
 270         int err = 0;
 271
 272         err = lowpan_net_frag_init();
 273         if (err < 0)
 274                 goto out;
 275
 276         err = lowpan_netlink_init();
 277         if (err < 0)
 278                 goto out_frag;
 279
 280         err = register_netdevice_notifier(&lowpan_dev_notifier);
 281         if (err < 0)
 282                 goto out_pack;
 283
 284         return 0;
 285
 286 out_pack:
 287         lowpan_netlink_fini();
 288 out_frag:
 289         lowpan_net_frag_exit();
 290 out:
 291         return err;
 292 }
 293
 294 static void __exit lowpan_cleanup_module(void)
 295 {
 296         lowpan_netlink_fini();
 297
 298         lowpan_net_frag_exit();
 299
 300         unregister_netdevice_notifier(&lowpan_dev_notifier);
 301 }
 302
 303 module_init(lowpan_init_module);
 304 module_exit(lowpan_cleanup_module);
 305 MODULE_LICENSE("GPL");
 306 MODULE_ALIAS_RTNL_LINK("lowpan");