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 const struct header_ops lowpan_header_ops = {
  58         .create = lowpan_header_create,
  59 };
  60
  61 static int lowpan_dev_init(struct net_device *ldev)
  62 {
  63         netdev_lockdep_set_classes(ldev);
  64
  65         return 0;
  66 }
  67
  68 static int lowpan_open(struct net_device *dev)
  69 {
  70         if (!open_count)
  71                 lowpan_rx_init();
  72         open_count++;
  73         return 0;
  74 }
  75
  76 static int lowpan_stop(struct net_device *dev)
  77 {
  78         open_count--;
  79         if (!open_count)
  80                 lowpan_rx_exit();
  81         return 0;
  82 }
  83
  84 static int lowpan_neigh_construct(struct net_device *dev, struct neighbour *n)
  85 {
  86         struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
  87
  88         /* default no short_addr is available for a neighbour */
  89         neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
  90         return 0;
  91 }
  92
  93 static const struct net_device_ops lowpan_netdev_ops = {
  94         .ndo_init               = lowpan_dev_init,
  95         .ndo_start_xmit         = lowpan_xmit,
  96         .ndo_open               = lowpan_open,
  97         .ndo_stop               = lowpan_stop,
  98         .ndo_neigh_construct    = lowpan_neigh_construct,
  99 };
 100
 101 static void lowpan_setup(struct net_device *ldev)
 102 {
 103         memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN);
 104         /* We need an ipv6hdr as minimum len when calling xmit */
 105         ldev->hard_header_len   = sizeof(struct ipv6hdr);
 106         ldev->flags             = IFF_BROADCAST | IFF_MULTICAST;
 107
 108         ldev->netdev_ops        = &lowpan_netdev_ops;
 109         ldev->header_ops        = &lowpan_header_ops;
 110         ldev->needs_free_netdev = true;
 111         ldev->features          |= NETIF_F_NETNS_LOCAL;
 112 }
 113
 114 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
 115                            struct netlink_ext_ack *extack)
 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                           struct netlink_ext_ack *extack)
 127 {
 128         struct net_device *wdev;
 129         int ret;
 130
 131         ASSERT_RTNL();
 132
 133         pr_debug("adding new link\n");
 134
 135         if (!tb[IFLA_LINK])
 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_802154_dev(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         ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh);
 165
 166         ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
 167         if (ret < 0) {
 168                 dev_put(wdev);
 169                 return ret;
 170         }
 171
 172         wdev->ieee802154_ptr->lowpan_dev = ldev;
 173         return 0;
 174 }
 175
 176 static void lowpan_dellink(struct net_device *ldev, struct list_head *head)
 177 {
 178         struct net_device *wdev = lowpan_802154_dev(ldev)->wdev;
 179
 180         ASSERT_RTNL();
 181
 182         wdev->ieee802154_ptr->lowpan_dev = NULL;
 183         lowpan_unregister_netdevice(ldev);
 184         dev_put(wdev);
 185 }
 186
 187 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 188         .kind           = "lowpan",
 189         .priv_size      = LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)),
 190         .setup          = lowpan_setup,
 191         .newlink        = lowpan_newlink,
 192         .dellink        = lowpan_dellink,
 193         .validate       = lowpan_validate,
 194 };
 195
 196 static inline int __init lowpan_netlink_init(void)
 197 {
 198         return rtnl_link_register(&lowpan_link_ops);
 199 }
 200
 201 static inline void lowpan_netlink_fini(void)
 202 {
 203         rtnl_link_unregister(&lowpan_link_ops);
 204 }
 205
 206 static int lowpan_device_event(struct notifier_block *unused,
 207                                unsigned long event, void *ptr)
 208 {
 209         struct net_device *wdev = netdev_notifier_info_to_dev(ptr);
 210
 211         if (wdev->type != ARPHRD_IEEE802154)
 212                 return NOTIFY_DONE;
 213
 214         switch (event) {
 215         case NETDEV_UNREGISTER:
 216                 /* Check if wpan interface is unregistered that we
 217                  * also delete possible lowpan interfaces which belongs
 218                  * to the wpan interface.
 219                  */
 220                 if (wdev->ieee802154_ptr->lowpan_dev)
 221                         lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL);
 222                 break;
 223         default:
 224                 return NOTIFY_DONE;
 225         }
 226
 227         return NOTIFY_OK;
 228 }
 229
 230 static struct notifier_block lowpan_dev_notifier = {
 231         .notifier_call = lowpan_device_event,
 232 };
 233
 234 static int __init lowpan_init_module(void)
 235 {
 236         int err = 0;
 237
 238         err = lowpan_net_frag_init();
 239         if (err < 0)
 240                 goto out;
 241
 242         err = lowpan_netlink_init();
 243         if (err < 0)
 244                 goto out_frag;
 245
 246         err = register_netdevice_notifier(&lowpan_dev_notifier);
 247         if (err < 0)
 248                 goto out_pack;
 249
 250         return 0;
 251
 252 out_pack:
 253         lowpan_netlink_fini();
 254 out_frag:
 255         lowpan_net_frag_exit();
 256 out:
 257         return err;
 258 }
 259
 260 static void __exit lowpan_cleanup_module(void)
 261 {
 262         lowpan_netlink_fini();
 263
 264         lowpan_net_frag_exit();
 265
 266         unregister_netdevice_notifier(&lowpan_dev_notifier);
 267 }
 268
 269 module_init(lowpan_init_module);
 270 module_exit(lowpan_cleanup_module);
 271 MODULE_LICENSE("GPL");
 272 MODULE_ALIAS_RTNL_LINK("lowpan");