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