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 #include <linux/if_arp.h> 51 52 #include <net/ipv6.h> 53 54 #include "6lowpan_i.h" 55 56 static int open_count; 57 58 static const struct header_ops lowpan_header_ops = { 59 .create = lowpan_header_create, 60 }; 61 62 static int lowpan_dev_init(struct net_device *ldev) 63 { 64 netdev_lockdep_set_classes(ldev); 65 66 return 0; 67 } 68 69 static int lowpan_open(struct net_device *dev) 70 { 71 if (!open_count) 72 lowpan_rx_init(); 73 open_count++; 74 return 0; 75 } 76 77 static int lowpan_stop(struct net_device *dev) 78 { 79 open_count--; 80 if (!open_count) 81 lowpan_rx_exit(); 82 return 0; 83 } 84 85 static int lowpan_neigh_construct(struct net_device *dev, struct neighbour *n) 86 { 87 struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n)); 88 89 /* default no short_addr is available for a neighbour */ 90 neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC); 91 return 0; 92 } 93 94 static int lowpan_get_iflink(const struct net_device *dev) 95 { 96 return READ_ONCE(lowpan_802154_dev(dev)->wdev->ifindex); 97 } 98 99 static const struct net_device_ops lowpan_netdev_ops = { 100 .ndo_init = lowpan_dev_init, 101 .ndo_start_xmit = lowpan_xmit, 102 .ndo_open = lowpan_open, 103 .ndo_stop = lowpan_stop, 104 .ndo_neigh_construct = lowpan_neigh_construct, 105 .ndo_get_iflink = lowpan_get_iflink, 106 }; 107 108 static void lowpan_setup(struct net_device *ldev) 109 { 110 memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN); 111 /* We need an ipv6hdr as minimum len when calling xmit */ 112 ldev->hard_header_len = sizeof(struct ipv6hdr); 113 ldev->flags = IFF_BROADCAST | IFF_MULTICAST; 114 ldev->priv_flags |= IFF_NO_QUEUE; 115 116 ldev->netdev_ops = &lowpan_netdev_ops; 117 ldev->header_ops = &lowpan_header_ops; 118 ldev->needs_free_netdev = true; 119 ldev->netns_immutable = true; 120 } 121 122 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[], 123 struct netlink_ext_ack *extack) 124 { 125 if (tb[IFLA_ADDRESS]) { 126 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN) 127 return -EINVAL; 128 } 129 return 0; 130 } 131 132 static int lowpan_newlink(struct net_device *ldev, 133 struct rtnl_newlink_params *params, 134 struct netlink_ext_ack *extack) 135 { 136 struct nlattr **tb = params->tb; 137 struct net_device *wdev; 138 int ret; 139 140 ASSERT_RTNL(); 141 142 pr_debug("adding new link\n"); 143 144 if (!tb[IFLA_LINK]) 145 return -EINVAL; 146 if (params->link_net && !net_eq(params->link_net, dev_net(ldev))) 147 return -EINVAL; 148 /* find and hold wpan device */ 149 wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK])); 150 if (!wdev) 151 return -ENODEV; 152 if (wdev->type != ARPHRD_IEEE802154) { 153 dev_put(wdev); 154 return -EINVAL; 155 } 156 157 if (wdev->ieee802154_ptr->lowpan_dev) { 158 dev_put(wdev); 159 return -EBUSY; 160 } 161 162 lowpan_802154_dev(ldev)->wdev = wdev; 163 /* Set the lowpan hardware address to the wpan hardware address. */ 164 __dev_addr_set(ldev, wdev->dev_addr, IEEE802154_ADDR_LEN); 165 /* We need headroom for possible wpan_dev_hard_header call and tailroom 166 * for encryption/fcs handling. The lowpan interface will replace 167 * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN 168 * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6 169 * header. 170 */ 171 ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN + 172 wdev->needed_headroom; 173 ldev->needed_tailroom = wdev->needed_tailroom; 174 175 ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh); 176 177 ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154); 178 if (ret < 0) { 179 dev_put(wdev); 180 return ret; 181 } 182 183 wdev->ieee802154_ptr->lowpan_dev = ldev; 184 return 0; 185 } 186 187 static void lowpan_dellink(struct net_device *ldev, struct list_head *head) 188 { 189 struct net_device *wdev = lowpan_802154_dev(ldev)->wdev; 190 191 ASSERT_RTNL(); 192 193 wdev->ieee802154_ptr->lowpan_dev = NULL; 194 lowpan_unregister_netdevice(ldev); 195 dev_put(wdev); 196 } 197 198 static struct rtnl_link_ops lowpan_link_ops __read_mostly = { 199 .kind = "lowpan", 200 .priv_size = LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)), 201 .setup = lowpan_setup, 202 .newlink = lowpan_newlink, 203 .dellink = lowpan_dellink, 204 .validate = lowpan_validate, 205 }; 206 207 static inline int __init lowpan_netlink_init(void) 208 { 209 return rtnl_link_register(&lowpan_link_ops); 210 } 211 212 static inline void lowpan_netlink_fini(void) 213 { 214 rtnl_link_unregister(&lowpan_link_ops); 215 } 216 217 static int lowpan_device_event(struct notifier_block *unused, 218 unsigned long event, void *ptr) 219 { 220 struct net_device *ndev = netdev_notifier_info_to_dev(ptr); 221 struct wpan_dev *wpan_dev; 222 223 if (ndev->type != ARPHRD_IEEE802154) 224 return NOTIFY_DONE; 225 wpan_dev = ndev->ieee802154_ptr; 226 if (!wpan_dev) 227 return NOTIFY_DONE; 228 229 switch (event) { 230 case NETDEV_UNREGISTER: 231 /* Check if wpan interface is unregistered that we 232 * also delete possible lowpan interfaces which belongs 233 * to the wpan interface. 234 */ 235 if (wpan_dev->lowpan_dev) 236 lowpan_dellink(wpan_dev->lowpan_dev, NULL); 237 break; 238 default: 239 return NOTIFY_DONE; 240 } 241 242 return NOTIFY_OK; 243 } 244 245 static struct notifier_block lowpan_dev_notifier = { 246 .notifier_call = lowpan_device_event, 247 }; 248 249 static int __init lowpan_init_module(void) 250 { 251 int err = 0; 252 253 err = lowpan_net_frag_init(); 254 if (err < 0) 255 goto out; 256 257 err = lowpan_netlink_init(); 258 if (err < 0) 259 goto out_frag; 260 261 err = register_netdevice_notifier(&lowpan_dev_notifier); 262 if (err < 0) 263 goto out_pack; 264 265 return 0; 266 267 out_pack: 268 lowpan_netlink_fini(); 269 out_frag: 270 lowpan_net_frag_exit(); 271 out: 272 return err; 273 } 274 275 static void __exit lowpan_cleanup_module(void) 276 { 277 lowpan_netlink_fini(); 278 279 lowpan_net_frag_exit(); 280 281 unregister_netdevice_notifier(&lowpan_dev_notifier); 282 } 283 284 module_init(lowpan_init_module); 285 module_exit(lowpan_cleanup_module); 286 MODULE_DESCRIPTION("IPv6 over Low power Wireless Personal Area Network IEEE 802.15.4 core"); 287 MODULE_LICENSE("GPL"); 288 MODULE_ALIAS_RTNL_LINK("lowpan"); 289