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"); 273