net/ieee802154/6lowpan_rtnl.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/bitops.h>
  48 #include <linux/if_arp.h>
  49 #include <linux/module.h>
  50 #include <linux/moduleparam.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/ieee802154.h>
  53 #include <net/af_ieee802154.h>
  54 #include <net/ieee802154_netdev.h>
  55 #include <net/6lowpan.h>
  56 #include <net/ipv6.h>
  57
  58 #include "reassembly.h"
  59
  60 static LIST_HEAD(lowpan_devices);
  61 static int lowpan_open_count;
  62
  63 /* private device info */
  64 struct lowpan_dev_info {
  65         struct net_device       *real_dev; /* real WPAN device ptr */
  66         struct mutex            dev_list_mtx; /* mutex for list ops */
  67         u16                     fragment_tag;
  68 };
  69
  70 struct lowpan_dev_record {
  71         struct net_device *ldev;
  72         struct list_head list;
  73 };
  74
  75 /* don't save pan id, it's intra pan */
  76 struct lowpan_addr {
  77         u8 mode;
  78         union {
  79                 /* IPv6 needs big endian here */
  80                 __be64 extended_addr;
  81                 __be16 short_addr;
  82         } u;
  83 };
  84
  85 struct lowpan_addr_info {
  86         struct lowpan_addr daddr;
  87         struct lowpan_addr saddr;
  88 };
  89
  90 static inline struct
  91 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
  92 {
  93         return netdev_priv(dev);
  94 }
  95
  96 static inline struct
  97 lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
  98 {
  99         WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
 100         return (struct lowpan_addr_info *)(skb->data -
 101                         sizeof(struct lowpan_addr_info));
 102 }
 103
 104 static int lowpan_header_create(struct sk_buff *skb, struct net_device *dev,
 105                                 unsigned short type, const void *_daddr,
 106                                 const void *_saddr, unsigned int len)
 107 {
 108         const u8 *saddr = _saddr;
 109         const u8 *daddr = _daddr;
 110         struct lowpan_addr_info *info;
 111
 112         /* TODO:
 113          * if this package isn't ipv6 one, where should it be routed?
 114          */
 115         if (type != ETH_P_IPV6)
 116                 return 0;
 117
 118         if (!saddr)
 119                 saddr = dev->dev_addr;
 120
 121         raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
 122         raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 123
 124         info = lowpan_skb_priv(skb);
 125
 126         /* TODO: Currently we only support extended_addr */
 127         info->daddr.mode = IEEE802154_ADDR_LONG;
 128         memcpy(&info->daddr.u.extended_addr, daddr,
 129                sizeof(info->daddr.u.extended_addr));
 130         info->saddr.mode = IEEE802154_ADDR_LONG;
 131         memcpy(&info->saddr.u.extended_addr, saddr,
 132                sizeof(info->daddr.u.extended_addr));
 133
 134         return 0;
 135 }
 136
 137 static int lowpan_give_skb_to_devices(struct sk_buff *skb,
 138                                       struct net_device *dev)
 139 {
 140         struct lowpan_dev_record *entry;
 141         struct sk_buff *skb_cp;
 142         int stat = NET_RX_SUCCESS;
 143
 144         skb->protocol = htons(ETH_P_IPV6);
 145         skb->pkt_type = PACKET_HOST;
 146
 147         rcu_read_lock();
 148         list_for_each_entry_rcu(entry, &lowpan_devices, list)
 149                 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
 150                         skb_cp = skb_copy(skb, GFP_ATOMIC);
 151                         if (!skb_cp) {
 152                                 kfree_skb(skb);
 153                                 rcu_read_unlock();
 154                                 return NET_RX_DROP;
 155                         }
 156
 157                         skb_cp->dev = entry->ldev;
 158                         stat = netif_rx(skb_cp);
 159                         if (stat == NET_RX_DROP)
 160                                 break;
 161                 }
 162         rcu_read_unlock();
 163
 164         consume_skb(skb);
 165
 166         return stat;
 167 }
 168
 169 static int
 170 iphc_decompress(struct sk_buff *skb, const struct ieee802154_hdr *hdr)
 171 {
 172         u8 iphc0, iphc1;
 173         struct ieee802154_addr_sa sa, da;
 174         void *sap, *dap;
 175
 176         raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
 177         /* at least two bytes will be used for the encoding */
 178         if (skb->len < 2)
 179                 goto drop;
 180
 181         if (lowpan_fetch_skb_u8(skb, &iphc0))
 182                 goto drop;
 183
 184         if (lowpan_fetch_skb_u8(skb, &iphc1))
 185                 goto drop;
 186
 187         ieee802154_addr_to_sa(&sa, &hdr->source);
 188         ieee802154_addr_to_sa(&da, &hdr->dest);
 189
 190         if (sa.addr_type == IEEE802154_ADDR_SHORT)
 191                 sap = &sa.short_addr;
 192         else
 193                 sap = &sa.hwaddr;
 194
 195         if (da.addr_type == IEEE802154_ADDR_SHORT)
 196                 dap = &da.short_addr;
 197         else
 198                 dap = &da.hwaddr;
 199
 200         return lowpan_header_decompress(skb, skb->dev, sap, sa.addr_type,
 201                                         IEEE802154_ADDR_LEN, dap, da.addr_type,
 202                                         IEEE802154_ADDR_LEN, iphc0, iphc1);
 203
 204 drop:
 205         kfree_skb(skb);
 206         return -EINVAL;
 207 }
 208
 209 static int lowpan_set_address(struct net_device *dev, void *p)
 210 {
 211         struct sockaddr *sa = p;
 212
 213         if (netif_running(dev))
 214                 return -EBUSY;
 215
 216         /* TODO: validate addr */
 217         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 218
 219         return 0;
 220 }
 221
 222 static struct sk_buff*
 223 lowpan_alloc_frag(struct sk_buff *skb, int size,
 224                   const struct ieee802154_hdr *master_hdr)
 225 {
 226         struct net_device *real_dev = lowpan_dev_info(skb->dev)->real_dev;
 227         struct sk_buff *frag;
 228         int rc;
 229
 230         frag = alloc_skb(real_dev->hard_header_len +
 231                          real_dev->needed_tailroom + size,
 232                          GFP_ATOMIC);
 233
 234         if (likely(frag)) {
 235                 frag->dev = real_dev;
 236                 frag->priority = skb->priority;
 237                 skb_reserve(frag, real_dev->hard_header_len);
 238                 skb_reset_network_header(frag);
 239                 *mac_cb(frag) = *mac_cb(skb);
 240
 241                 rc = dev_hard_header(frag, real_dev, 0, &master_hdr->dest,
 242                                      &master_hdr->source, size);
 243                 if (rc < 0) {
 244                         kfree_skb(frag);
 245                         return ERR_PTR(rc);
 246                 }
 247         } else {
 248                 frag = ERR_PTR(-ENOMEM);
 249         }
 250
 251         return frag;
 252 }
 253
 254 static int
 255 lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
 256                      u8 *frag_hdr, int frag_hdrlen,
 257                      int offset, int len)
 258 {
 259         struct sk_buff *frag;
 260
 261         raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
 262
 263         frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr);
 264         if (IS_ERR(frag))
 265                 return -PTR_ERR(frag);
 266
 267         memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
 268         memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);
 269
 270         raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
 271
 272         return dev_queue_xmit(frag);
 273 }
 274
 275 static int
 276 lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *dev,
 277                        const struct ieee802154_hdr *wpan_hdr)
 278 {
 279         u16 dgram_size, dgram_offset;
 280         __be16 frag_tag;
 281         u8 frag_hdr[5];
 282         int frag_cap, frag_len, payload_cap, rc;
 283         int skb_unprocessed, skb_offset;
 284
 285         dgram_size = lowpan_uncompress_size(skb, &dgram_offset) -
 286                      skb->mac_len;
 287         frag_tag = htons(lowpan_dev_info(dev)->fragment_tag);
 288         lowpan_dev_info(dev)->fragment_tag++;
 289
 290         frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
 291         frag_hdr[1] = dgram_size & 0xff;
 292         memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
 293
 294         payload_cap = ieee802154_max_payload(wpan_hdr);
 295
 296         frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
 297                               skb_network_header_len(skb), 8);
 298
 299         skb_offset = skb_network_header_len(skb);
 300         skb_unprocessed = skb->len - skb->mac_len - skb_offset;
 301
 302         rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
 303                                   LOWPAN_FRAG1_HEAD_SIZE, 0,
 304                                   frag_len + skb_network_header_len(skb));
 305         if (rc) {
 306                 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
 307                          __func__, ntohs(frag_tag));
 308                 goto err;
 309         }
 310
 311         frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
 312         frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
 313         frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
 314
 315         do {
 316                 dgram_offset += frag_len;
 317                 skb_offset += frag_len;
 318                 skb_unprocessed -= frag_len;
 319                 frag_len = min(frag_cap, skb_unprocessed);
 320
 321                 frag_hdr[4] = dgram_offset >> 3;
 322
 323                 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
 324                                           LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
 325                                           frag_len);
 326                 if (rc) {
 327                         pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
 328                                  __func__, ntohs(frag_tag), skb_offset);
 329                         goto err;
 330                 }
 331         } while (skb_unprocessed > frag_cap);
 332
 333         consume_skb(skb);
 334         return NET_XMIT_SUCCESS;
 335
 336 err:
 337         kfree_skb(skb);
 338         return rc;
 339 }
 340
 341 static int lowpan_header(struct sk_buff *skb, struct net_device *dev)
 342 {
 343         struct ieee802154_addr sa, da;
 344         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 345         struct lowpan_addr_info info;
 346         void *daddr, *saddr;
 347
 348         memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
 349
 350         /* TODO: Currently we only support extended_addr */
 351         daddr = &info.daddr.u.extended_addr;
 352         saddr = &info.saddr.u.extended_addr;
 353
 354         lowpan_header_compress(skb, dev, ETH_P_IPV6, daddr, saddr, skb->len);
 355
 356         cb->type = IEEE802154_FC_TYPE_DATA;
 357
 358         /* prepare wpan address data */
 359         sa.mode = IEEE802154_ADDR_LONG;
 360         sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 361         sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
 362
 363         /* intra-PAN communications */
 364         da.pan_id = sa.pan_id;
 365
 366         /* if the destination address is the broadcast address, use the
 367          * corresponding short address
 368          */
 369         if (lowpan_is_addr_broadcast((const u8 *)daddr)) {
 370                 da.mode = IEEE802154_ADDR_SHORT;
 371                 da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
 372                 cb->ackreq = false;
 373         } else {
 374                 da.mode = IEEE802154_ADDR_LONG;
 375                 da.extended_addr = ieee802154_devaddr_from_raw(daddr);
 376                 cb->ackreq = true;
 377         }
 378
 379         return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 380                         ETH_P_IPV6, (void *)&da, (void *)&sa, 0);
 381 }
 382
 383 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
 384 {
 385         struct ieee802154_hdr wpan_hdr;
 386         int max_single, ret;
 387
 388         pr_debug("package xmit\n");
 389
 390         /* We must take a copy of the skb before we modify/replace the ipv6
 391          * header as the header could be used elsewhere
 392          */
 393         skb = skb_unshare(skb, GFP_ATOMIC);
 394         if (!skb)
 395                 return NET_XMIT_DROP;
 396
 397         ret = lowpan_header(skb, dev);
 398         if (ret < 0) {
 399                 kfree_skb(skb);
 400                 return NET_XMIT_DROP;
 401         }
 402
 403         if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
 404                 kfree_skb(skb);
 405                 return NET_XMIT_DROP;
 406         }
 407
 408         max_single = ieee802154_max_payload(&wpan_hdr);
 409
 410         if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
 411                 skb->dev = lowpan_dev_info(dev)->real_dev;
 412                 return dev_queue_xmit(skb);
 413         } else {
 414                 netdev_tx_t rc;
 415
 416                 pr_debug("frame is too big, fragmentation is needed\n");
 417                 rc = lowpan_xmit_fragmented(skb, dev, &wpan_hdr);
 418
 419                 return rc < 0 ? NET_XMIT_DROP : rc;
 420         }
 421 }
 422
 423 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
 424 {
 425         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 426
 427         return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
 428 }
 429
 430 static __le16 lowpan_get_pan_id(const struct net_device *dev)
 431 {
 432         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 433
 434         return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
 435 }
 436
 437 static __le16 lowpan_get_short_addr(const struct net_device *dev)
 438 {
 439         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 440
 441         return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
 442 }
 443
 444 static u8 lowpan_get_dsn(const struct net_device *dev)
 445 {
 446         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 447
 448         return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
 449 }
 450
 451 static struct header_ops lowpan_header_ops = {
 452         .create = lowpan_header_create,
 453 };
 454
 455 static struct lock_class_key lowpan_tx_busylock;
 456 static struct lock_class_key lowpan_netdev_xmit_lock_key;
 457
 458 static void lowpan_set_lockdep_class_one(struct net_device *dev,
 459                                          struct netdev_queue *txq,
 460                                          void *_unused)
 461 {
 462         lockdep_set_class(&txq->_xmit_lock,
 463                           &lowpan_netdev_xmit_lock_key);
 464 }
 465
 466
 467 static int lowpan_dev_init(struct net_device *dev)
 468 {
 469         netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL);
 470         dev->qdisc_tx_busylock = &lowpan_tx_busylock;
 471         return 0;
 472 }
 473
 474 static const struct net_device_ops lowpan_netdev_ops = {
 475         .ndo_init               = lowpan_dev_init,
 476         .ndo_start_xmit         = lowpan_xmit,
 477         .ndo_set_mac_address    = lowpan_set_address,
 478 };
 479
 480 static struct ieee802154_mlme_ops lowpan_mlme = {
 481         .get_pan_id = lowpan_get_pan_id,
 482         .get_phy = lowpan_get_phy,
 483         .get_short_addr = lowpan_get_short_addr,
 484         .get_dsn = lowpan_get_dsn,
 485 };
 486
 487 static void lowpan_setup(struct net_device *dev)
 488 {
 489         dev->addr_len           = IEEE802154_ADDR_LEN;
 490         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
 491         dev->type               = ARPHRD_IEEE802154;
 492         /* Frame Control + Sequence Number + Address fields + Security Header */
 493         dev->hard_header_len    = 2 + 1 + 20 + 14;
 494         dev->needed_tailroom    = 2; /* FCS */
 495         dev->mtu                = IPV6_MIN_MTU;
 496         dev->tx_queue_len       = 0;
 497         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
 498         dev->watchdog_timeo     = 0;
 499
 500         dev->netdev_ops         = &lowpan_netdev_ops;
 501         dev->header_ops         = &lowpan_header_ops;
 502         dev->ml_priv            = &lowpan_mlme;
 503         dev->destructor         = free_netdev;
 504 }
 505
 506 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 507 {
 508         if (tb[IFLA_ADDRESS]) {
 509                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
 510                         return -EINVAL;
 511         }
 512         return 0;
 513 }
 514
 515 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 516                       struct packet_type *pt, struct net_device *orig_dev)
 517 {
 518         struct ieee802154_hdr hdr;
 519         int ret;
 520
 521         skb = skb_share_check(skb, GFP_ATOMIC);
 522         if (!skb)
 523                 goto drop;
 524
 525         if (!netif_running(dev))
 526                 goto drop_skb;
 527
 528         if (skb->pkt_type == PACKET_OTHERHOST)
 529                 goto drop_skb;
 530
 531         if (dev->type != ARPHRD_IEEE802154)
 532                 goto drop_skb;
 533
 534         if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
 535                 goto drop_skb;
 536
 537         /* check that it's our buffer */
 538         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
 539                 /* Pull off the 1-byte of 6lowpan header. */
 540                 skb_pull(skb, 1);
 541                 return lowpan_give_skb_to_devices(skb, NULL);
 542         } else {
 543                 switch (skb->data[0] & 0xe0) {
 544                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
 545                         ret = iphc_decompress(skb, &hdr);
 546                         if (ret < 0)
 547                                 goto drop;
 548
 549                         return lowpan_give_skb_to_devices(skb, NULL);
 550                 case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
 551                         ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1);
 552                         if (ret == 1) {
 553                                 ret = iphc_decompress(skb, &hdr);
 554                                 if (ret < 0)
 555                                         goto drop;
 556
 557                                 return lowpan_give_skb_to_devices(skb, NULL);
 558                         } else if (ret == -1) {
 559                                 return NET_RX_DROP;
 560                         } else {
 561                                 return NET_RX_SUCCESS;
 562                         }
 563                 case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
 564                         ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN);
 565                         if (ret == 1) {
 566                                 ret = iphc_decompress(skb, &hdr);
 567                                 if (ret < 0)
 568                                         goto drop;
 569
 570                                 return lowpan_give_skb_to_devices(skb, NULL);
 571                         } else if (ret == -1) {
 572                                 return NET_RX_DROP;
 573                         } else {
 574                                 return NET_RX_SUCCESS;
 575                         }
 576                 default:
 577                         break;
 578                 }
 579         }
 580
 581 drop_skb:
 582         kfree_skb(skb);
 583 drop:
 584         return NET_RX_DROP;
 585 }
 586
 587 static struct packet_type lowpan_packet_type = {
 588         .type = htons(ETH_P_IEEE802154),
 589         .func = lowpan_rcv,
 590 };
 591
 592 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
 593                           struct nlattr *tb[], struct nlattr *data[])
 594 {
 595         struct net_device *real_dev;
 596         struct lowpan_dev_record *entry;
 597         int ret;
 598
 599         ASSERT_RTNL();
 600
 601         pr_debug("adding new link\n");
 602
 603         if (!tb[IFLA_LINK])
 604                 return -EINVAL;
 605         /* find and hold real wpan device */
 606         real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
 607         if (!real_dev)
 608                 return -ENODEV;
 609         if (real_dev->type != ARPHRD_IEEE802154) {
 610                 dev_put(real_dev);
 611                 return -EINVAL;
 612         }
 613
 614         lowpan_dev_info(dev)->real_dev = real_dev;
 615         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
 616
 617         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 618         if (!entry) {
 619                 dev_put(real_dev);
 620                 lowpan_dev_info(dev)->real_dev = NULL;
 621                 return -ENOMEM;
 622         }
 623
 624         entry->ldev = dev;
 625
 626         /* Set the lowpan harware address to the wpan hardware address. */
 627         memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
 628
 629         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 630         INIT_LIST_HEAD(&entry->list);
 631         list_add_tail(&entry->list, &lowpan_devices);
 632         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 633
 634         ret = register_netdevice(dev);
 635         if (ret >= 0) {
 636                 if (!lowpan_open_count)
 637                         dev_add_pack(&lowpan_packet_type);
 638                 lowpan_open_count++;
 639         }
 640
 641         return ret;
 642 }
 643
 644 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
 645 {
 646         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
 647         struct net_device *real_dev = lowpan_dev->real_dev;
 648         struct lowpan_dev_record *entry, *tmp;
 649
 650         ASSERT_RTNL();
 651
 652         lowpan_open_count--;
 653         if (!lowpan_open_count)
 654                 dev_remove_pack(&lowpan_packet_type);
 655
 656         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 657         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 658                 if (entry->ldev == dev) {
 659                         list_del(&entry->list);
 660                         kfree(entry);
 661                 }
 662         }
 663         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 664
 665         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
 666
 667         unregister_netdevice_queue(dev, head);
 668
 669         dev_put(real_dev);
 670 }
 671
 672 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 673         .kind           = "lowpan",
 674         .priv_size      = sizeof(struct lowpan_dev_info),
 675         .setup          = lowpan_setup,
 676         .newlink        = lowpan_newlink,
 677         .dellink        = lowpan_dellink,
 678         .validate       = lowpan_validate,
 679 };
 680
 681 static inline int __init lowpan_netlink_init(void)
 682 {
 683         return rtnl_link_register(&lowpan_link_ops);
 684 }
 685
 686 static inline void lowpan_netlink_fini(void)
 687 {
 688         rtnl_link_unregister(&lowpan_link_ops);
 689 }
 690
 691 static int lowpan_device_event(struct notifier_block *unused,
 692                                unsigned long event, void *ptr)
 693 {
 694         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 695         LIST_HEAD(del_list);
 696         struct lowpan_dev_record *entry, *tmp;
 697
 698         if (dev->type != ARPHRD_IEEE802154)
 699                 goto out;
 700
 701         if (event == NETDEV_UNREGISTER) {
 702                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 703                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
 704                                 lowpan_dellink(entry->ldev, &del_list);
 705                 }
 706
 707                 unregister_netdevice_many(&del_list);
 708         }
 709
 710 out:
 711         return NOTIFY_DONE;
 712 }
 713
 714 static struct notifier_block lowpan_dev_notifier = {
 715         .notifier_call = lowpan_device_event,
 716 };
 717
 718 static int __init lowpan_init_module(void)
 719 {
 720         int err = 0;
 721
 722         err = lowpan_net_frag_init();
 723         if (err < 0)
 724                 goto out;
 725
 726         err = lowpan_netlink_init();
 727         if (err < 0)
 728                 goto out_frag;
 729
 730         err = register_netdevice_notifier(&lowpan_dev_notifier);
 731         if (err < 0)
 732                 goto out_pack;
 733
 734         return 0;
 735
 736 out_pack:
 737         lowpan_netlink_fini();
 738 out_frag:
 739         lowpan_net_frag_exit();
 740 out:
 741         return err;
 742 }
 743
 744 static void __exit lowpan_cleanup_module(void)
 745 {
 746         lowpan_netlink_fini();
 747
 748         lowpan_net_frag_exit();
 749
 750         unregister_netdevice_notifier(&lowpan_dev_notifier);
 751 }
 752
 753 module_init(lowpan_init_module);
 754 module_exit(lowpan_cleanup_module);
 755 MODULE_LICENSE("GPL");
 756 MODULE_ALIAS_RTNL_LINK("lowpan");