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 ldev->priv_flags |= IFF_NO_QUEUE; 108 109 ldev->netdev_ops = &lowpan_netdev_ops; 110 ldev->header_ops = &lowpan_header_ops; 111 ldev->needs_free_netdev = true; 112 ldev->features |= NETIF_F_NETNS_LOCAL; 113 } 114 115 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[], 116 struct netlink_ext_ack *extack) 117 { 118 if (tb[IFLA_ADDRESS]) { 119 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN) 120 return -EINVAL; 121 } 122 return 0; 123 } 124 125 static int lowpan_newlink(struct net *src_net, struct net_device *ldev, 126 struct nlattr *tb[], struct nlattr *data[], 127 struct netlink_ext_ack *extack) 128 { 129 struct net_device *wdev; 130 int ret; 131 132 ASSERT_RTNL(); 133 134 pr_debug("adding new link\n"); 135 136 if (!tb[IFLA_LINK]) 137 return -EINVAL; 138 /* find and hold wpan device */ 139 wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK])); 140 if (!wdev) 141 return -ENODEV; 142 if (wdev->type != ARPHRD_IEEE802154) { 143 dev_put(wdev); 144 return -EINVAL; 145 } 146 147 if (wdev->ieee802154_ptr->lowpan_dev) { 148 dev_put(wdev); 149 return -EBUSY; 150 } 151 152 lowpan_802154_dev(ldev)->wdev = wdev; 153 /* Set the lowpan hardware address to the wpan hardware address. */ 154 memcpy(ldev->dev_addr, wdev->dev_addr, IEEE802154_ADDR_LEN); 155 /* We need headroom for possible wpan_dev_hard_header call and tailroom 156 * for encryption/fcs handling. The lowpan interface will replace 157 * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN 158 * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6 159 * header. 160 */ 161 ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN + 162 wdev->needed_headroom; 163 ldev->needed_tailroom = wdev->needed_tailroom; 164 165 ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh); 166 167 ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154); 168 if (ret < 0) { 169 dev_put(wdev); 170 return ret; 171 } 172 173 wdev->ieee802154_ptr->lowpan_dev = ldev; 174 return 0; 175 } 176 177 static void lowpan_dellink(struct net_device *ldev, struct list_head *head) 178 { 179 struct net_device *wdev = lowpan_802154_dev(ldev)->wdev; 180 181 ASSERT_RTNL(); 182 183 wdev->ieee802154_ptr->lowpan_dev = NULL; 184 lowpan_unregister_netdevice(ldev); 185 dev_put(wdev); 186 } 187 188 static struct rtnl_link_ops lowpan_link_ops __read_mostly = { 189 .kind = "lowpan", 190 .priv_size = LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)), 191 .setup = lowpan_setup, 192 .newlink = lowpan_newlink, 193 .dellink = lowpan_dellink, 194 .validate = lowpan_validate, 195 }; 196 197 static inline int __init lowpan_netlink_init(void) 198 { 199 return rtnl_link_register(&lowpan_link_ops); 200 } 201 202 static inline void lowpan_netlink_fini(void) 203 { 204 rtnl_link_unregister(&lowpan_link_ops); 205 } 206 207 static int lowpan_device_event(struct notifier_block *unused, 208 unsigned long event, void *ptr) 209 { 210 struct net_device *ndev = netdev_notifier_info_to_dev(ptr); 211 struct wpan_dev *wpan_dev; 212 213 if (ndev->type != ARPHRD_IEEE802154) 214 return NOTIFY_DONE; 215 wpan_dev = ndev->ieee802154_ptr; 216 if (!wpan_dev) 217 return NOTIFY_DONE; 218 219 switch (event) { 220 case NETDEV_UNREGISTER: 221 /* Check if wpan interface is unregistered that we 222 * also delete possible lowpan interfaces which belongs 223 * to the wpan interface. 224 */ 225 if (wpan_dev->lowpan_dev) 226 lowpan_dellink(wpan_dev->lowpan_dev, NULL); 227 break; 228 default: 229 return NOTIFY_DONE; 230 } 231 232 return NOTIFY_OK; 233 } 234 235 static struct notifier_block lowpan_dev_notifier = { 236 .notifier_call = lowpan_device_event, 237 }; 238 239 static int __init lowpan_init_module(void) 240 { 241 int err = 0; 242 243 err = lowpan_net_frag_init(); 244 if (err < 0) 245 goto out; 246 247 err = lowpan_netlink_init(); 248 if (err < 0) 249 goto out_frag; 250 251 err = register_netdevice_notifier(&lowpan_dev_notifier); 252 if (err < 0) 253 goto out_pack; 254 255 return 0; 256 257 out_pack: 258 lowpan_netlink_fini(); 259 out_frag: 260 lowpan_net_frag_exit(); 261 out: 262 return err; 263 } 264 265 static void __exit lowpan_cleanup_module(void) 266 { 267 lowpan_netlink_fini(); 268 269 lowpan_net_frag_exit(); 270 271 unregister_netdevice_notifier(&lowpan_dev_notifier); 272 } 273 274 module_init(lowpan_init_module); 275 module_exit(lowpan_cleanup_module); 276 MODULE_LICENSE("GPL"); 277 MODULE_ALIAS_RTNL_LINK("lowpan"); 278