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 struct header_ops lowpan_header_ops = {
  59         .create = lowpan_header_create,
  60 };
  61
  62 static struct lock_class_key lowpan_tx_busylock;
  63 static struct lock_class_key lowpan_netdev_xmit_lock_key;
  64
  65 static void lowpan_set_lockdep_class_one(struct net_device *dev,
  66                                          struct netdev_queue *txq,
  67                                          void *_unused)
  68 {
  69         lockdep_set_class(&txq->_xmit_lock,
  70                           &lowpan_netdev_xmit_lock_key);
  71 }
  72
  73 static int lowpan_dev_init(struct net_device *dev)
  74 {
  75         netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL);
  76         dev->qdisc_tx_busylock = &lowpan_tx_busylock;
  77         return 0;
  78 }
  79
  80 static const struct net_device_ops lowpan_netdev_ops = {
  81         .ndo_init               = lowpan_dev_init,
  82         .ndo_start_xmit         = lowpan_xmit,
  83 };
  84
  85 static void lowpan_setup(struct net_device *dev)
  86 {
  87         dev->addr_len           = IEEE802154_ADDR_LEN;
  88         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
  89         dev->type               = ARPHRD_6LOWPAN;
  90         /* Frame Control + Sequence Number + Address fields + Security Header */
  91         dev->hard_header_len    = 2 + 1 + 20 + 14;
  92         dev->needed_tailroom    = 2; /* FCS */
  93         dev->mtu                = IPV6_MIN_MTU;
  94         dev->tx_queue_len       = 0;
  95         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
  96         dev->watchdog_timeo     = 0;
  97
  98         dev->netdev_ops         = &lowpan_netdev_ops;
  99         dev->header_ops         = &lowpan_header_ops;
 100         dev->destructor         = free_netdev;
 101         dev->features           |= NETIF_F_NETNS_LOCAL;
 102 }
 103
 104 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 105 {
 106         if (tb[IFLA_ADDRESS]) {
 107                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
 108                         return -EINVAL;
 109         }
 110         return 0;
 111 }
 112
 113 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
 114                           struct nlattr *tb[], struct nlattr *data[])
 115 {
 116         struct net_device *real_dev;
 117         struct lowpan_dev_record *entry;
 118         int ret;
 119
 120         ASSERT_RTNL();
 121
 122         pr_debug("adding new link\n");
 123
 124         if (!tb[IFLA_LINK] ||
 125             !net_eq(dev_net(dev), &init_net))
 126                 return -EINVAL;
 127         /* find and hold real wpan device */
 128         real_dev = dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
 129         if (!real_dev)
 130                 return -ENODEV;
 131         if (real_dev->type != ARPHRD_IEEE802154) {
 132                 dev_put(real_dev);
 133                 return -EINVAL;
 134         }
 135
 136         lowpan_dev_info(dev)->real_dev = real_dev;
 137         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
 138
 139         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 140         if (!entry) {
 141                 dev_put(real_dev);
 142                 lowpan_dev_info(dev)->real_dev = NULL;
 143                 return -ENOMEM;
 144         }
 145
 146         entry->ldev = dev;
 147
 148         /* Set the lowpan hardware address to the wpan hardware address. */
 149         memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
 150
 151         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 152         INIT_LIST_HEAD(&entry->list);
 153         list_add_tail(&entry->list, &lowpan_devices);
 154         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 155
 156         ret = register_netdevice(dev);
 157         if (ret >= 0) {
 158                 if (!lowpan_open_count)
 159                         lowpan_rx_init();
 160                 lowpan_open_count++;
 161         }
 162
 163         return ret;
 164 }
 165
 166 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
 167 {
 168         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
 169         struct net_device *real_dev = lowpan_dev->real_dev;
 170         struct lowpan_dev_record *entry, *tmp;
 171
 172         ASSERT_RTNL();
 173
 174         lowpan_open_count--;
 175         if (!lowpan_open_count)
 176                 lowpan_rx_exit();
 177
 178         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 179         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 180                 if (entry->ldev == dev) {
 181                         list_del(&entry->list);
 182                         kfree(entry);
 183                 }
 184         }
 185         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 186
 187         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
 188
 189         unregister_netdevice_queue(dev, head);
 190
 191         dev_put(real_dev);
 192 }
 193
 194 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 195         .kind           = "lowpan",
 196         .priv_size      = sizeof(struct lowpan_dev_info),
 197         .setup          = lowpan_setup,
 198         .newlink        = lowpan_newlink,
 199         .dellink        = lowpan_dellink,
 200         .validate       = lowpan_validate,
 201 };
 202
 203 static inline int __init lowpan_netlink_init(void)
 204 {
 205         return rtnl_link_register(&lowpan_link_ops);
 206 }
 207
 208 static inline void lowpan_netlink_fini(void)
 209 {
 210         rtnl_link_unregister(&lowpan_link_ops);
 211 }
 212
 213 static int lowpan_device_event(struct notifier_block *unused,
 214                                unsigned long event, void *ptr)
 215 {
 216         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 217         LIST_HEAD(del_list);
 218         struct lowpan_dev_record *entry, *tmp;
 219
 220         if (dev->type != ARPHRD_IEEE802154)
 221                 goto out;
 222
 223         if (event == NETDEV_UNREGISTER) {
 224                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 225                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
 226                                 lowpan_dellink(entry->ldev, &del_list);
 227                 }
 228
 229                 unregister_netdevice_many(&del_list);
 230         }
 231
 232 out:
 233         return NOTIFY_DONE;
 234 }
 235
 236 static struct notifier_block lowpan_dev_notifier = {
 237         .notifier_call = lowpan_device_event,
 238 };
 239
 240 static int __init lowpan_init_module(void)
 241 {
 242         int err = 0;
 243
 244         err = lowpan_net_frag_init();
 245         if (err < 0)
 246                 goto out;
 247
 248         err = lowpan_netlink_init();
 249         if (err < 0)
 250                 goto out_frag;
 251
 252         err = register_netdevice_notifier(&lowpan_dev_notifier);
 253         if (err < 0)
 254                 goto out_pack;
 255
 256         return 0;
 257
 258 out_pack:
 259         lowpan_netlink_fini();
 260 out_frag:
 261         lowpan_net_frag_exit();
 262 out:
 263         return err;
 264 }
 265
 266 static void __exit lowpan_cleanup_module(void)
 267 {
 268         lowpan_netlink_fini();
 269
 270         lowpan_net_frag_exit();
 271
 272         unregister_netdevice_notifier(&lowpan_dev_notifier);
 273 }
 274
 275 module_init(lowpan_init_module);
 276 module_exit(lowpan_cleanup_module);
 277 MODULE_LICENSE("GPL");
 278 MODULE_ALIAS_RTNL_LINK("lowpan");