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 static int open_count;
  56
  57 static struct header_ops lowpan_header_ops = {
  58         .create = lowpan_header_create,
  59 };
  60
  61 static struct lock_class_key lowpan_tx_busylock;
  62 static struct lock_class_key lowpan_netdev_xmit_lock_key;
  63
  64 static void lowpan_set_lockdep_class_one(struct net_device *ldev,
  65                                          struct netdev_queue *txq,
  66                                          void *_unused)
  67 {
  68         lockdep_set_class(&txq->_xmit_lock,
  69                           &lowpan_netdev_xmit_lock_key);
  70 }
  71
  72 static int lowpan_dev_init(struct net_device *ldev)
  73 {
  74         netdev_for_each_tx_queue(ldev, lowpan_set_lockdep_class_one, NULL);
  75         ldev->qdisc_tx_busylock = &lowpan_tx_busylock;
  76         return 0;
  77 }
  78
  79 static int lowpan_open(struct net_device *dev)
  80 {
  81         if (!open_count)
  82                 lowpan_rx_init();
  83         open_count++;
  84         return 0;
  85 }
  86
  87 static int lowpan_stop(struct net_device *dev)
  88 {
  89         open_count--;
  90         if (!open_count)
  91                 lowpan_rx_exit();
  92         return 0;
  93 }
  94
  95 static const struct net_device_ops lowpan_netdev_ops = {
  96         .ndo_init               = lowpan_dev_init,
  97         .ndo_start_xmit         = lowpan_xmit,
  98         .ndo_open               = lowpan_open,
  99         .ndo_stop               = lowpan_stop,
 100 };
 101
 102 static void lowpan_setup(struct net_device *ldev)
 103 {
 104         memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN);
 105         /* We need an ipv6hdr as minimum len when calling xmit */
 106         ldev->hard_header_len   = sizeof(struct ipv6hdr);
 107         ldev->flags             = IFF_BROADCAST | IFF_MULTICAST;
 108
 109         ldev->netdev_ops        = &lowpan_netdev_ops;
 110         ldev->header_ops        = &lowpan_header_ops;
 111         ldev->destructor        = free_netdev;
 112         ldev->features          |= NETIF_F_NETNS_LOCAL;
 113 }
 114
 115 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 116 {
 117         if (tb[IFLA_ADDRESS]) {
 118                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
 119                         return -EINVAL;
 120         }
 121         return 0;
 122 }
 123
 124 static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
 125                           struct nlattr *tb[], struct nlattr *data[])
 126 {
 127         struct net_device *wdev;
 128         int ret;
 129
 130         ASSERT_RTNL();
 131
 132         pr_debug("adding new link\n");
 133
 134         if (!tb[IFLA_LINK] ||
 135             !net_eq(dev_net(ldev), &init_net))
 136                 return -EINVAL;
 137         /* find and hold wpan device */
 138         wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
 139         if (!wdev)
 140                 return -ENODEV;
 141         if (wdev->type != ARPHRD_IEEE802154) {
 142                 dev_put(wdev);
 143                 return -EINVAL;
 144         }
 145
 146         if (wdev->ieee802154_ptr->lowpan_dev) {
 147                 dev_put(wdev);
 148                 return -EBUSY;
 149         }
 150
 151         lowpan_dev_info(ldev)->wdev = wdev;
 152         /* Set the lowpan hardware address to the wpan hardware address. */
 153         memcpy(ldev->dev_addr, wdev->dev_addr, IEEE802154_ADDR_LEN);
 154         /* We need headroom for possible wpan_dev_hard_header call and tailroom
 155          * for encryption/fcs handling. The lowpan interface will replace
 156          * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN
 157          * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6
 158          * header.
 159          */
 160         ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN +
 161                                 wdev->needed_headroom;
 162         ldev->needed_tailroom = wdev->needed_tailroom;
 163
 164         ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
 165         if (ret < 0) {
 166                 dev_put(wdev);
 167                 return ret;
 168         }
 169
 170         wdev->ieee802154_ptr->lowpan_dev = ldev;
 171         return 0;
 172 }
 173
 174 static void lowpan_dellink(struct net_device *ldev, struct list_head *head)
 175 {
 176         struct net_device *wdev = lowpan_dev_info(ldev)->wdev;
 177
 178         ASSERT_RTNL();
 179
 180         wdev->ieee802154_ptr->lowpan_dev = NULL;
 181         lowpan_unregister_netdevice(ldev);
 182         dev_put(wdev);
 183 }
 184
 185 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 186         .kind           = "lowpan",
 187         .priv_size      = LOWPAN_PRIV_SIZE(sizeof(struct lowpan_dev_info)),
 188         .setup          = lowpan_setup,
 189         .newlink        = lowpan_newlink,
 190         .dellink        = lowpan_dellink,
 191         .validate       = lowpan_validate,
 192 };
 193
 194 static inline int __init lowpan_netlink_init(void)
 195 {
 196         return rtnl_link_register(&lowpan_link_ops);
 197 }
 198
 199 static inline void lowpan_netlink_fini(void)
 200 {
 201         rtnl_link_unregister(&lowpan_link_ops);
 202 }
 203
 204 static int lowpan_device_event(struct notifier_block *unused,
 205                                unsigned long event, void *ptr)
 206 {
 207         struct net_device *wdev = netdev_notifier_info_to_dev(ptr);
 208
 209         if (wdev->type != ARPHRD_IEEE802154)
 210                 return NOTIFY_DONE;
 211
 212         switch (event) {
 213         case NETDEV_UNREGISTER:
 214                 /* Check if wpan interface is unregistered that we
 215                  * also delete possible lowpan interfaces which belongs
 216                  * to the wpan interface.
 217                  */
 218                 if (wdev->ieee802154_ptr->lowpan_dev)
 219                         lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL);
 220                 break;
 221         default:
 222                 return NOTIFY_DONE;
 223         }
 224
 225         return NOTIFY_OK;
 226 }
 227
 228 static struct notifier_block lowpan_dev_notifier = {
 229         .notifier_call = lowpan_device_event,
 230 };
 231
 232 static int __init lowpan_init_module(void)
 233 {
 234         int err = 0;
 235
 236         err = lowpan_net_frag_init();
 237         if (err < 0)
 238                 goto out;
 239
 240         err = lowpan_netlink_init();
 241         if (err < 0)
 242                 goto out_frag;
 243
 244         err = register_netdevice_notifier(&lowpan_dev_notifier);
 245         if (err < 0)
 246                 goto out_pack;
 247
 248         return 0;
 249
 250 out_pack:
 251         lowpan_netlink_fini();
 252 out_frag:
 253         lowpan_net_frag_exit();
 254 out:
 255         return err;
 256 }
 257
 258 static void __exit lowpan_cleanup_module(void)
 259 {
 260         lowpan_netlink_fini();
 261
 262         lowpan_net_frag_exit();
 263
 264         unregister_netdevice_notifier(&lowpan_dev_notifier);
 265 }
 266
 267 module_init(lowpan_init_module);
 268 module_exit(lowpan_cleanup_module);
 269 MODULE_LICENSE("GPL");
 270 MODULE_ALIAS_RTNL_LINK("lowpan");