linux/net/ieee802154/6lowpan.c
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   1/*
   2 * Copyright 2011, Siemens AG
   3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
   4 */
   5
   6/*
   7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
   8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License version 2
  12 * as published by the Free Software Foundation.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License along
  20 * with this program; if not, write to the Free Software Foundation, Inc.,
  21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22 */
  23
  24/* Jon's code is based on 6lowpan implementation for Contiki which is:
  25 * Copyright (c) 2008, Swedish Institute of Computer Science.
  26 * All rights reserved.
  27 *
  28 * Redistribution and use in source and binary forms, with or without
  29 * modification, are permitted provided that the following conditions
  30 * are met:
  31 * 1. Redistributions of source code must retain the above copyright
  32 *    notice, this list of conditions and the following disclaimer.
  33 * 2. Redistributions in binary form must reproduce the above copyright
  34 *    notice, this list of conditions and the following disclaimer in the
  35 *    documentation and/or other materials provided with the distribution.
  36 * 3. Neither the name of the Institute nor the names of its contributors
  37 *    may be used to endorse or promote products derived from this software
  38 *    without specific prior written permission.
  39 *
  40 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50 * SUCH DAMAGE.
  51 */
  52
  53#include <linux/bitops.h>
  54#include <linux/if_arp.h>
  55#include <linux/module.h>
  56#include <linux/moduleparam.h>
  57#include <linux/netdevice.h>
  58#include <net/af_ieee802154.h>
  59#include <net/ieee802154.h>
  60#include <net/ieee802154_netdev.h>
  61#include <net/ipv6.h>
  62
  63#include "6lowpan.h"
  64
  65/* TTL uncompression values */
  66static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
  67
  68static LIST_HEAD(lowpan_devices);
  69
  70/*
  71 * Uncompression of linklocal:
  72 *   0 -> 16 bytes from packet
  73 *   1 -> 2  bytes from prefix - bunch of zeroes and 8 from packet
  74 *   2 -> 2  bytes from prefix - zeroes + 2 from packet
  75 *   3 -> 2  bytes from prefix - infer 8 bytes from lladdr
  76 *
  77 *  NOTE: => the uncompress function does change 0xf to 0x10
  78 *  NOTE: 0x00 => no-autoconfig => unspecified
  79 */
  80static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20};
  81
  82/*
  83 * Uncompression of ctx-based:
  84 *   0 -> 0 bits  from packet [unspecified / reserved]
  85 *   1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet
  86 *   2 -> 8 bytes from prefix - zeroes + 2 from packet
  87 *   3 -> 8 bytes from prefix - infer 8 bytes from lladdr
  88 */
  89static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80};
  90
  91/*
  92 * Uncompression of ctx-base
  93 *   0 -> 0 bits from packet
  94 *   1 -> 2 bytes from prefix - bunch of zeroes 5 from packet
  95 *   2 -> 2 bytes from prefix - zeroes + 3 from packet
  96 *   3 -> 2 bytes from prefix - infer 1 bytes from lladdr
  97 */
  98static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
  99
 100/* Link local prefix */
 101static const u8 lowpan_llprefix[] = {0xfe, 0x80};
 102
 103/* private device info */
 104struct lowpan_dev_info {
 105        struct net_device       *real_dev; /* real WPAN device ptr */
 106        struct mutex            dev_list_mtx; /* mutex for list ops */
 107};
 108
 109struct lowpan_dev_record {
 110        struct net_device *ldev;
 111        struct list_head list;
 112};
 113
 114struct lowpan_fragment {
 115        struct sk_buff          *skb;           /* skb to be assembled */
 116        u16                     length;         /* length to be assemled */
 117        u32                     bytes_rcv;      /* bytes received */
 118        u16                     tag;            /* current fragment tag */
 119        struct timer_list       timer;          /* assembling timer */
 120        struct list_head        list;           /* fragments list */
 121};
 122
 123static unsigned short fragment_tag;
 124static LIST_HEAD(lowpan_fragments);
 125static DEFINE_SPINLOCK(flist_lock);
 126
 127static inline struct
 128lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
 129{
 130        return netdev_priv(dev);
 131}
 132
 133static inline void lowpan_address_flip(u8 *src, u8 *dest)
 134{
 135        int i;
 136        for (i = 0; i < IEEE802154_ADDR_LEN; i++)
 137                (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
 138}
 139
 140/* list of all 6lowpan devices, uses for package delivering */
 141/* print data in line */
 142static inline void lowpan_raw_dump_inline(const char *caller, char *msg,
 143                                   unsigned char *buf, int len)
 144{
 145#ifdef DEBUG
 146        if (msg)
 147                pr_debug("(%s) %s: ", caller, msg);
 148        print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE,
 149                       16, 1, buf, len, false);
 150#endif /* DEBUG */
 151}
 152
 153/*
 154 * print data in a table format:
 155 *
 156 * addr: xx xx xx xx xx xx
 157 * addr: xx xx xx xx xx xx
 158 * ...
 159 */
 160static inline void lowpan_raw_dump_table(const char *caller, char *msg,
 161                                   unsigned char *buf, int len)
 162{
 163#ifdef DEBUG
 164        if (msg)
 165                pr_debug("(%s) %s:\n", caller, msg);
 166        print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET,
 167                       16, 1, buf, len, false);
 168#endif /* DEBUG */
 169}
 170
 171static u8
 172lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const struct in6_addr *ipaddr,
 173                 const unsigned char *lladdr)
 174{
 175        u8 val = 0;
 176
 177        if (is_addr_mac_addr_based(ipaddr, lladdr))
 178                val = 3; /* 0-bits */
 179        else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
 180                /* compress IID to 16 bits xxxx::XXXX */
 181                memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
 182                *hc06_ptr += 2;
 183                val = 2; /* 16-bits */
 184        } else {
 185                /* do not compress IID => xxxx::IID */
 186                memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
 187                *hc06_ptr += 8;
 188                val = 1; /* 64-bits */
 189        }
 190
 191        return rol8(val, shift);
 192}
 193
 194static void
 195lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr)
 196{
 197        memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ADDR_LEN);
 198        /* second bit-flip (Universe/Local) is done according RFC2464 */
 199        ipaddr->s6_addr[8] ^= 0x02;
 200}
 201
 202/*
 203 * Uncompress addresses based on a prefix and a postfix with zeroes in
 204 * between. If the postfix is zero in length it will use the link address
 205 * to configure the IP address (autoconf style).
 206 * pref_post_count takes a byte where the first nibble specify prefix count
 207 * and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
 208 */
 209static int
 210lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
 211        u8 const *prefix, u8 pref_post_count, unsigned char *lladdr)
 212{
 213        u8 prefcount = pref_post_count >> 4;
 214        u8 postcount = pref_post_count & 0x0f;
 215
 216        /* full nibble 15 => 16 */
 217        prefcount = (prefcount == 15 ? 16 : prefcount);
 218        postcount = (postcount == 15 ? 16 : postcount);
 219
 220        if (lladdr)
 221                lowpan_raw_dump_inline(__func__, "linklocal address",
 222                                                lladdr, IEEE802154_ADDR_LEN);
 223        if (prefcount > 0)
 224                memcpy(ipaddr, prefix, prefcount);
 225
 226        if (prefcount + postcount < 16)
 227                memset(&ipaddr->s6_addr[prefcount], 0,
 228                                        16 - (prefcount + postcount));
 229
 230        if (postcount > 0) {
 231                memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
 232                skb_pull(skb, postcount);
 233        } else if (prefcount > 0) {
 234                if (lladdr == NULL)
 235                        return -EINVAL;
 236
 237                /* no IID based configuration if no prefix and no data */
 238                lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
 239        }
 240
 241        pr_debug("uncompressing %d + %d => ", prefcount, postcount);
 242        lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
 243
 244        return 0;
 245}
 246
 247static void
 248lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
 249{
 250        struct udphdr *uh = udp_hdr(skb);
 251
 252        if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
 253                                LOWPAN_NHC_UDP_4BIT_PORT) &&
 254            ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
 255                                LOWPAN_NHC_UDP_4BIT_PORT)) {
 256                pr_debug("UDP header: both ports compression to 4 bits\n");
 257                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
 258                **(hc06_ptr + 1) = /* subtraction is faster */
 259                   (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
 260                       ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
 261                *hc06_ptr += 2;
 262        } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
 263                        LOWPAN_NHC_UDP_8BIT_PORT) {
 264                pr_debug("UDP header: remove 8 bits of dest\n");
 265                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
 266                memcpy(*hc06_ptr + 1, &uh->source, 2);
 267                **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
 268                *hc06_ptr += 4;
 269        } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
 270                        LOWPAN_NHC_UDP_8BIT_PORT) {
 271                pr_debug("UDP header: remove 8 bits of source\n");
 272                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
 273                memcpy(*hc06_ptr + 1, &uh->dest, 2);
 274                **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
 275                *hc06_ptr += 4;
 276        } else {
 277                pr_debug("UDP header: can't compress\n");
 278                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
 279                memcpy(*hc06_ptr + 1, &uh->source, 2);
 280                memcpy(*hc06_ptr + 3, &uh->dest, 2);
 281                *hc06_ptr += 5;
 282        }
 283
 284        /* checksum is always inline */
 285        memcpy(*hc06_ptr, &uh->check, 2);
 286        *hc06_ptr += 2;
 287}
 288
 289static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 290{
 291        if (unlikely(!pskb_may_pull(skb, 1)))
 292                return -EINVAL;
 293
 294        *val = skb->data[0];
 295        skb_pull(skb, 1);
 296
 297        return 0;
 298}
 299
 300static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 301{
 302        if (unlikely(!pskb_may_pull(skb, 2)))
 303                return -EINVAL;
 304
 305        *val = (skb->data[0] << 8) | skb->data[1];
 306        skb_pull(skb, 2);
 307
 308        return 0;
 309}
 310
 311static int
 312lowpan_uncompress_udp_header(struct sk_buff *skb)
 313{
 314        struct udphdr *uh = udp_hdr(skb);
 315        u8 tmp;
 316
 317        if (!uh)
 318                goto err;
 319
 320        if (lowpan_fetch_skb_u8(skb, &tmp))
 321                goto err;
 322
 323        if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 324                pr_debug("UDP header uncompression\n");
 325                switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
 326                case LOWPAN_NHC_UDP_CS_P_00:
 327                        memcpy(&uh->source, &skb->data[0], 2);
 328                        memcpy(&uh->dest, &skb->data[2], 2);
 329                        skb_pull(skb, 4);
 330                        break;
 331                case LOWPAN_NHC_UDP_CS_P_01:
 332                        memcpy(&uh->source, &skb->data[0], 2);
 333                        uh->dest =
 334                           skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
 335                        skb_pull(skb, 3);
 336                        break;
 337                case LOWPAN_NHC_UDP_CS_P_10:
 338                        uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
 339                        memcpy(&uh->dest, &skb->data[1], 2);
 340                        skb_pull(skb, 3);
 341                        break;
 342                case LOWPAN_NHC_UDP_CS_P_11:
 343                        uh->source =
 344                           LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
 345                        uh->dest =
 346                           LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
 347                        skb_pull(skb, 1);
 348                        break;
 349                default:
 350                        pr_debug("ERROR: unknown UDP format\n");
 351                        goto err;
 352                        break;
 353                }
 354
 355                pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
 356                         uh->source, uh->dest);
 357
 358                /* copy checksum */
 359                memcpy(&uh->check, &skb->data[0], 2);
 360                skb_pull(skb, 2);
 361        } else {
 362                pr_debug("ERROR: unsupported NH format\n");
 363                goto err;
 364        }
 365
 366        return 0;
 367err:
 368        return -EINVAL;
 369}
 370
 371static int lowpan_header_create(struct sk_buff *skb,
 372                           struct net_device *dev,
 373                           unsigned short type, const void *_daddr,
 374                           const void *_saddr, unsigned int len)
 375{
 376        u8 tmp, iphc0, iphc1, *hc06_ptr;
 377        struct ipv6hdr *hdr;
 378        const u8 *saddr = _saddr;
 379        const u8 *daddr = _daddr;
 380        u8 *head;
 381        struct ieee802154_addr sa, da;
 382
 383        if (type != ETH_P_IPV6)
 384                return 0;
 385                /* TODO:
 386                 * if this package isn't ipv6 one, where should it be routed?
 387                 */
 388        head = kzalloc(100, GFP_KERNEL);
 389        if (head == NULL)
 390                return -ENOMEM;
 391
 392        hdr = ipv6_hdr(skb);
 393        hc06_ptr = head + 2;
 394
 395        pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n"
 396                 "\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version,
 397                 ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit);
 398
 399        lowpan_raw_dump_table(__func__, "raw skb network header dump",
 400                skb_network_header(skb), sizeof(struct ipv6hdr));
 401
 402        if (!saddr)
 403                saddr = dev->dev_addr;
 404
 405        lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
 406
 407        /*
 408         * As we copy some bit-length fields, in the IPHC encoding bytes,
 409         * we sometimes use |=
 410         * If the field is 0, and the current bit value in memory is 1,
 411         * this does not work. We therefore reset the IPHC encoding here
 412         */
 413        iphc0 = LOWPAN_DISPATCH_IPHC;
 414        iphc1 = 0;
 415
 416        /* TODO: context lookup */
 417
 418        lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 419
 420        /*
 421         * Traffic class, flow label
 422         * If flow label is 0, compress it. If traffic class is 0, compress it
 423         * We have to process both in the same time as the offset of traffic
 424         * class depends on the presence of version and flow label
 425         */
 426
 427        /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
 428        tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
 429        tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
 430
 431        if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
 432             (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
 433                /* flow label can be compressed */
 434                iphc0 |= LOWPAN_IPHC_FL_C;
 435                if ((hdr->priority == 0) &&
 436                   ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 437                        /* compress (elide) all */
 438                        iphc0 |= LOWPAN_IPHC_TC_C;
 439                } else {
 440                        /* compress only the flow label */
 441                        *hc06_ptr = tmp;
 442                        hc06_ptr += 1;
 443                }
 444        } else {
 445                /* Flow label cannot be compressed */
 446                if ((hdr->priority == 0) &&
 447                   ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 448                        /* compress only traffic class */
 449                        iphc0 |= LOWPAN_IPHC_TC_C;
 450                        *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
 451                        memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
 452                        hc06_ptr += 3;
 453                } else {
 454                        /* compress nothing */
 455                        memcpy(hc06_ptr, &hdr, 4);
 456                        /* replace the top byte with new ECN | DSCP format */
 457                        *hc06_ptr = tmp;
 458                        hc06_ptr += 4;
 459                }
 460        }
 461
 462        /* NOTE: payload length is always compressed */
 463
 464        /* Next Header is compress if UDP */
 465        if (hdr->nexthdr == UIP_PROTO_UDP)
 466                iphc0 |= LOWPAN_IPHC_NH_C;
 467
 468        if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 469                *hc06_ptr = hdr->nexthdr;
 470                hc06_ptr += 1;
 471        }
 472
 473        /*
 474         * Hop limit
 475         * if 1:   compress, encoding is 01
 476         * if 64:  compress, encoding is 10
 477         * if 255: compress, encoding is 11
 478         * else do not compress
 479         */
 480        switch (hdr->hop_limit) {
 481        case 1:
 482                iphc0 |= LOWPAN_IPHC_TTL_1;
 483                break;
 484        case 64:
 485                iphc0 |= LOWPAN_IPHC_TTL_64;
 486                break;
 487        case 255:
 488                iphc0 |= LOWPAN_IPHC_TTL_255;
 489                break;
 490        default:
 491                *hc06_ptr = hdr->hop_limit;
 492                hc06_ptr += 1;
 493                break;
 494        }
 495
 496        /* source address compression */
 497        if (is_addr_unspecified(&hdr->saddr)) {
 498                pr_debug("source address is unspecified, setting SAC\n");
 499                iphc1 |= LOWPAN_IPHC_SAC;
 500        /* TODO: context lookup */
 501        } else if (is_addr_link_local(&hdr->saddr)) {
 502                pr_debug("source address is link-local\n");
 503                iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 504                                LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
 505        } else {
 506                pr_debug("send the full source address\n");
 507                memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
 508                hc06_ptr += 16;
 509        }
 510
 511        /* destination address compression */
 512        if (is_addr_mcast(&hdr->daddr)) {
 513                pr_debug("destination address is multicast: ");
 514                iphc1 |= LOWPAN_IPHC_M;
 515                if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
 516                        pr_debug("compressed to 1 octet\n");
 517                        iphc1 |= LOWPAN_IPHC_DAM_11;
 518                        /* use last byte */
 519                        *hc06_ptr = hdr->daddr.s6_addr[15];
 520                        hc06_ptr += 1;
 521                } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
 522                        pr_debug("compressed to 4 octets\n");
 523                        iphc1 |= LOWPAN_IPHC_DAM_10;
 524                        /* second byte + the last three */
 525                        *hc06_ptr = hdr->daddr.s6_addr[1];
 526                        memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
 527                        hc06_ptr += 4;
 528                } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
 529                        pr_debug("compressed to 6 octets\n");
 530                        iphc1 |= LOWPAN_IPHC_DAM_01;
 531                        /* second byte + the last five */
 532                        *hc06_ptr = hdr->daddr.s6_addr[1];
 533                        memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
 534                        hc06_ptr += 6;
 535                } else {
 536                        pr_debug("using full address\n");
 537                        iphc1 |= LOWPAN_IPHC_DAM_00;
 538                        memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
 539                        hc06_ptr += 16;
 540                }
 541        } else {
 542                /* TODO: context lookup */
 543                if (is_addr_link_local(&hdr->daddr)) {
 544                        pr_debug("dest address is unicast and link-local\n");
 545                        iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 546                                LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
 547                } else {
 548                        pr_debug("dest address is unicast: using full one\n");
 549                        memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
 550                        hc06_ptr += 16;
 551                }
 552        }
 553
 554        /* UDP header compression */
 555        if (hdr->nexthdr == UIP_PROTO_UDP)
 556                lowpan_compress_udp_header(&hc06_ptr, skb);
 557
 558        head[0] = iphc0;
 559        head[1] = iphc1;
 560
 561        skb_pull(skb, sizeof(struct ipv6hdr));
 562        memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
 563
 564        kfree(head);
 565
 566        lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 567                                skb->len);
 568
 569        /*
 570         * NOTE1: I'm still unsure about the fact that compression and WPAN
 571         * header are created here and not later in the xmit. So wait for
 572         * an opinion of net maintainers.
 573         */
 574        /*
 575         * NOTE2: to be absolutely correct, we must derive PANid information
 576         * from MAC subif of the 'dev' and 'real_dev' network devices, but
 577         * this isn't implemented in mainline yet, so currently we assign 0xff
 578         */
 579        {
 580                /* prepare wpan address data */
 581                sa.addr_type = IEEE802154_ADDR_LONG;
 582                sa.pan_id = 0xff;
 583
 584                da.addr_type = IEEE802154_ADDR_LONG;
 585                da.pan_id = 0xff;
 586
 587                memcpy(&(da.hwaddr), daddr, 8);
 588                memcpy(&(sa.hwaddr), saddr, 8);
 589
 590                mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
 591
 592                return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 593                                type, (void *)&da, (void *)&sa, skb->len);
 594        }
 595}
 596
 597static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 598{
 599        struct sk_buff *new;
 600        struct lowpan_dev_record *entry;
 601        int stat = NET_RX_SUCCESS;
 602
 603        new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
 604                                                                GFP_ATOMIC);
 605        kfree_skb(skb);
 606
 607        if (!new)
 608                return -ENOMEM;
 609
 610        skb_push(new, sizeof(struct ipv6hdr));
 611        skb_reset_network_header(new);
 612        skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
 613
 614        new->protocol = htons(ETH_P_IPV6);
 615        new->pkt_type = PACKET_HOST;
 616
 617        rcu_read_lock();
 618        list_for_each_entry_rcu(entry, &lowpan_devices, list)
 619                if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) {
 620                        skb = skb_copy(new, GFP_ATOMIC);
 621                        if (!skb) {
 622                                stat = -ENOMEM;
 623                                break;
 624                        }
 625
 626                        skb->dev = entry->ldev;
 627                        stat = netif_rx(skb);
 628                }
 629        rcu_read_unlock();
 630
 631        kfree_skb(new);
 632
 633        return stat;
 634}
 635
 636static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 637{
 638        struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
 639
 640        pr_debug("timer expired for frame with tag %d\n", entry->tag);
 641
 642        list_del(&entry->list);
 643        dev_kfree_skb(entry->skb);
 644        kfree(entry);
 645}
 646
 647static struct lowpan_fragment *
 648lowpan_alloc_new_frame(struct sk_buff *skb, u8 len, u16 tag)
 649{
 650        struct lowpan_fragment *frame;
 651
 652        frame = kzalloc(sizeof(struct lowpan_fragment),
 653                        GFP_ATOMIC);
 654        if (!frame)
 655                goto frame_err;
 656
 657        INIT_LIST_HEAD(&frame->list);
 658
 659        frame->length = len;
 660        frame->tag = tag;
 661
 662        /* allocate buffer for frame assembling */
 663        frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
 664                                               sizeof(struct ipv6hdr));
 665
 666        if (!frame->skb)
 667                goto skb_err;
 668
 669        frame->skb->priority = skb->priority;
 670        frame->skb->dev = skb->dev;
 671
 672        /* reserve headroom for uncompressed ipv6 header */
 673        skb_reserve(frame->skb, sizeof(struct ipv6hdr));
 674        skb_put(frame->skb, frame->length);
 675
 676        init_timer(&frame->timer);
 677        /* time out is the same as for ipv6 - 60 sec */
 678        frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
 679        frame->timer.data = (unsigned long)frame;
 680        frame->timer.function = lowpan_fragment_timer_expired;
 681
 682        add_timer(&frame->timer);
 683
 684        list_add_tail(&frame->list, &lowpan_fragments);
 685
 686        return frame;
 687
 688skb_err:
 689        kfree(frame);
 690frame_err:
 691        return NULL;
 692}
 693
 694static int
 695lowpan_process_data(struct sk_buff *skb)
 696{
 697        struct ipv6hdr hdr;
 698        u8 tmp, iphc0, iphc1, num_context = 0;
 699        u8 *_saddr, *_daddr;
 700        int err;
 701
 702        lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 703                                skb->len);
 704        /* at least two bytes will be used for the encoding */
 705        if (skb->len < 2)
 706                goto drop;
 707
 708        if (lowpan_fetch_skb_u8(skb, &iphc0))
 709                goto drop;
 710
 711        /* fragments assembling */
 712        switch (iphc0 & LOWPAN_DISPATCH_MASK) {
 713        case LOWPAN_DISPATCH_FRAG1:
 714        case LOWPAN_DISPATCH_FRAGN:
 715        {
 716                struct lowpan_fragment *frame;
 717                /* slen stores the rightmost 8 bits of the 11 bits length */
 718                u8 slen, offset;
 719                u16 len, tag;
 720                bool found = false;
 721
 722                if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
 723                    lowpan_fetch_skb_u16(skb, &tag))  /* fragment tag */
 724                        goto drop;
 725
 726                /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 727                len = ((iphc0 & 7) << 8) | slen;
 728
 729                /*
 730                 * check if frame assembling with the same tag is
 731                 * already in progress
 732                 */
 733                spin_lock_bh(&flist_lock);
 734
 735                list_for_each_entry(frame, &lowpan_fragments, list)
 736                        if (frame->tag == tag) {
 737                                found = true;
 738                                break;
 739                        }
 740
 741                /* alloc new frame structure */
 742                if (!found) {
 743                        frame = lowpan_alloc_new_frame(skb, len, tag);
 744                        if (!frame)
 745                                goto unlock_and_drop;
 746                }
 747
 748                if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1)
 749                        goto unlock_and_drop;
 750
 751                if (lowpan_fetch_skb_u8(skb, &offset)) /* fetch offset */
 752                        goto unlock_and_drop;
 753
 754                /* if payload fits buffer, copy it */
 755                if (likely((offset * 8 + skb->len) <= frame->length))
 756                        skb_copy_to_linear_data_offset(frame->skb, offset * 8,
 757                                                        skb->data, skb->len);
 758                else
 759                        goto unlock_and_drop;
 760
 761                frame->bytes_rcv += skb->len;
 762
 763                /* frame assembling complete */
 764                if ((frame->bytes_rcv == frame->length) &&
 765                     frame->timer.expires > jiffies) {
 766                        /* if timer haven't expired - first of all delete it */
 767                        del_timer_sync(&frame->timer);
 768                        list_del(&frame->list);
 769                        spin_unlock_bh(&flist_lock);
 770
 771                        dev_kfree_skb(skb);
 772                        skb = frame->skb;
 773                        kfree(frame);
 774
 775                        if (lowpan_fetch_skb_u8(skb, &iphc0))
 776                                goto drop;
 777
 778                        break;
 779                }
 780                spin_unlock_bh(&flist_lock);
 781
 782                return kfree_skb(skb), 0;
 783        }
 784        default:
 785                break;
 786        }
 787
 788        if (lowpan_fetch_skb_u8(skb, &iphc1))
 789                goto drop;
 790
 791        _saddr = mac_cb(skb)->sa.hwaddr;
 792        _daddr = mac_cb(skb)->da.hwaddr;
 793
 794        pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
 795
 796        /* another if the CID flag is set */
 797        if (iphc1 & LOWPAN_IPHC_CID) {
 798                pr_debug("CID flag is set, increase header with one\n");
 799                if (lowpan_fetch_skb_u8(skb, &num_context))
 800                        goto drop;
 801        }
 802
 803        hdr.version = 6;
 804
 805        /* Traffic Class and Flow Label */
 806        switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 807        /*
 808         * Traffic Class and FLow Label carried in-line
 809         * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
 810         */
 811        case 0: /* 00b */
 812                if (lowpan_fetch_skb_u8(skb, &tmp))
 813                        goto drop;
 814
 815                memcpy(&hdr.flow_lbl, &skb->data[0], 3);
 816                skb_pull(skb, 3);
 817                hdr.priority = ((tmp >> 2) & 0x0f);
 818                hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
 819                                        (hdr.flow_lbl[0] & 0x0f);
 820                break;
 821        /*
 822         * Traffic class carried in-line
 823         * ECN + DSCP (1 byte), Flow Label is elided
 824         */
 825        case 1: /* 10b */
 826                if (lowpan_fetch_skb_u8(skb, &tmp))
 827                        goto drop;
 828
 829                hdr.priority = ((tmp >> 2) & 0x0f);
 830                hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
 831                hdr.flow_lbl[1] = 0;
 832                hdr.flow_lbl[2] = 0;
 833                break;
 834        /*
 835         * Flow Label carried in-line
 836         * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
 837         */
 838        case 2: /* 01b */
 839                if (lowpan_fetch_skb_u8(skb, &tmp))
 840                        goto drop;
 841
 842                hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
 843                memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
 844                skb_pull(skb, 2);
 845                break;
 846        /* Traffic Class and Flow Label are elided */
 847        case 3: /* 11b */
 848                hdr.priority = 0;
 849                hdr.flow_lbl[0] = 0;
 850                hdr.flow_lbl[1] = 0;
 851                hdr.flow_lbl[2] = 0;
 852                break;
 853        default:
 854                break;
 855        }
 856
 857        /* Next Header */
 858        if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 859                /* Next header is carried inline */
 860                if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
 861                        goto drop;
 862
 863                pr_debug("NH flag is set, next header carried inline: %02x\n",
 864                         hdr.nexthdr);
 865        }
 866
 867        /* Hop Limit */
 868        if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
 869                hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
 870        else {
 871                if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
 872                        goto drop;
 873        }
 874
 875        /* Extract SAM to the tmp variable */
 876        tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
 877
 878        /* Source address uncompression */
 879        pr_debug("source address stateless compression\n");
 880        err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
 881                                lowpan_unc_llconf[tmp], skb->data);
 882        if (err)
 883                goto drop;
 884
 885        /* Extract DAM to the tmp variable */
 886        tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
 887
 888        /* check for Multicast Compression */
 889        if (iphc1 & LOWPAN_IPHC_M) {
 890                if (iphc1 & LOWPAN_IPHC_DAC) {
 891                        pr_debug("dest: context-based mcast compression\n");
 892                        /* TODO: implement this */
 893                } else {
 894                        u8 prefix[] = {0xff, 0x02};
 895
 896                        pr_debug("dest: non context-based mcast compression\n");
 897                        if (0 < tmp && tmp < 3) {
 898                                if (lowpan_fetch_skb_u8(skb, &prefix[1]))
 899                                        goto drop;
 900                        }
 901
 902                        err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
 903                                        lowpan_unc_mxconf[tmp], NULL);
 904                        if (err)
 905                                goto drop;
 906                }
 907        } else {
 908                pr_debug("dest: stateless compression\n");
 909                err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
 910                                lowpan_unc_llconf[tmp], skb->data);
 911                if (err)
 912                        goto drop;
 913        }
 914
 915        /* UDP data uncompression */
 916        if (iphc0 & LOWPAN_IPHC_NH_C)
 917                if (lowpan_uncompress_udp_header(skb))
 918                        goto drop;
 919
 920        /* Not fragmented package */
 921        hdr.payload_len = htons(skb->len);
 922
 923        pr_debug("skb headroom size = %d, data length = %d\n",
 924                 skb_headroom(skb), skb->len);
 925
 926        pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n\t"
 927                 "nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version,
 928                 ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
 929
 930        lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
 931                                                        sizeof(hdr));
 932        return lowpan_skb_deliver(skb, &hdr);
 933
 934unlock_and_drop:
 935        spin_unlock_bh(&flist_lock);
 936drop:
 937        kfree_skb(skb);
 938        return -EINVAL;
 939}
 940
 941static int lowpan_set_address(struct net_device *dev, void *p)
 942{
 943        struct sockaddr *sa = p;
 944
 945        if (netif_running(dev))
 946                return -EBUSY;
 947
 948        /* TODO: validate addr */
 949        memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 950
 951        return 0;
 952}
 953
 954static int lowpan_get_mac_header_length(struct sk_buff *skb)
 955{
 956        /*
 957         * Currently long addressing mode is supported only, so the overall
 958         * header size is 21:
 959         * FC SeqNum DPAN DA  SA  Sec
 960         * 2  +  1  +  2 + 8 + 8 + 0  = 21
 961         */
 962        return 21;
 963}
 964
 965static int
 966lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
 967                        int mlen, int plen, int offset)
 968{
 969        struct sk_buff *frag;
 970        int hlen, ret;
 971
 972        /* if payload length is zero, therefore it's a first fragment */
 973        hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE :  LOWPAN_FRAGN_HEAD_SIZE);
 974
 975        lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
 976
 977        frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
 978        if (!frag)
 979                return -ENOMEM;
 980
 981        frag->priority = skb->priority;
 982        frag->dev = skb->dev;
 983
 984        /* copy header, MFR and payload */
 985        memcpy(skb_put(frag, mlen), skb->data, mlen);
 986        memcpy(skb_put(frag, hlen), head, hlen);
 987
 988        if (plen)
 989                skb_copy_from_linear_data_offset(skb, offset + mlen,
 990                                        skb_put(frag, plen), plen);
 991
 992        lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
 993                                                                frag->len);
 994
 995        ret = dev_queue_xmit(frag);
 996
 997        return ret;
 998}
 999
1000static int
1001lowpan_skb_fragmentation(struct sk_buff *skb)
1002{
1003        int  err, header_length, payload_length, tag, offset = 0;
1004        u8 head[5];
1005
1006        header_length = lowpan_get_mac_header_length(skb);
1007        payload_length = skb->len - header_length;
1008        tag = fragment_tag++;
1009
1010        /* first fragment header */
1011        head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
1012        head[1] = payload_length & 0xff;
1013        head[2] = tag >> 8;
1014        head[3] = tag & 0xff;
1015
1016        err = lowpan_fragment_xmit(skb, head, header_length, 0, 0);
1017
1018        /* next fragment header */
1019        head[0] &= ~LOWPAN_DISPATCH_FRAG1;
1020        head[0] |= LOWPAN_DISPATCH_FRAGN;
1021
1022        while ((payload_length - offset > 0) && (err >= 0)) {
1023                int len = LOWPAN_FRAG_SIZE;
1024
1025                head[4] = offset / 8;
1026
1027                if (payload_length - offset < len)
1028                        len = payload_length - offset;
1029
1030                err = lowpan_fragment_xmit(skb, head, header_length,
1031                                                        len, offset);
1032                offset += len;
1033        }
1034
1035        return err;
1036}
1037
1038static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
1039{
1040        int err = -1;
1041
1042        pr_debug("package xmit\n");
1043
1044        skb->dev = lowpan_dev_info(dev)->real_dev;
1045        if (skb->dev == NULL) {
1046                pr_debug("ERROR: no real wpan device found\n");
1047                goto error;
1048        }
1049
1050        if (skb->len <= IEEE802154_MTU) {
1051                err = dev_queue_xmit(skb);
1052                goto out;
1053        }
1054
1055        pr_debug("frame is too big, fragmentation is needed\n");
1056        err = lowpan_skb_fragmentation(skb);
1057error:
1058        dev_kfree_skb(skb);
1059out:
1060        if (err < 0)
1061                pr_debug("ERROR: xmit failed\n");
1062
1063        return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
1064}
1065
1066static void lowpan_dev_free(struct net_device *dev)
1067{
1068        dev_put(lowpan_dev_info(dev)->real_dev);
1069        free_netdev(dev);
1070}
1071
1072static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
1073{
1074        struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1075        return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
1076}
1077
1078static u16 lowpan_get_pan_id(const struct net_device *dev)
1079{
1080        struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1081        return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
1082}
1083
1084static u16 lowpan_get_short_addr(const struct net_device *dev)
1085{
1086        struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1087        return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
1088}
1089
1090static struct header_ops lowpan_header_ops = {
1091        .create = lowpan_header_create,
1092};
1093
1094static const struct net_device_ops lowpan_netdev_ops = {
1095        .ndo_start_xmit         = lowpan_xmit,
1096        .ndo_set_mac_address    = lowpan_set_address,
1097};
1098
1099static struct ieee802154_mlme_ops lowpan_mlme = {
1100        .get_pan_id = lowpan_get_pan_id,
1101        .get_phy = lowpan_get_phy,
1102        .get_short_addr = lowpan_get_short_addr,
1103};
1104
1105static void lowpan_setup(struct net_device *dev)
1106{
1107        dev->addr_len           = IEEE802154_ADDR_LEN;
1108        memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
1109        dev->type               = ARPHRD_IEEE802154;
1110        /* Frame Control + Sequence Number + Address fields + Security Header */
1111        dev->hard_header_len    = 2 + 1 + 20 + 14;
1112        dev->needed_tailroom    = 2; /* FCS */
1113        dev->mtu                = 1281;
1114        dev->tx_queue_len       = 0;
1115        dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
1116        dev->watchdog_timeo     = 0;
1117
1118        dev->netdev_ops         = &lowpan_netdev_ops;
1119        dev->header_ops         = &lowpan_header_ops;
1120        dev->ml_priv            = &lowpan_mlme;
1121        dev->destructor         = lowpan_dev_free;
1122}
1123
1124static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
1125{
1126        if (tb[IFLA_ADDRESS]) {
1127                if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
1128                        return -EINVAL;
1129        }
1130        return 0;
1131}
1132
1133static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
1134        struct packet_type *pt, struct net_device *orig_dev)
1135{
1136        if (!netif_running(dev))
1137                goto drop;
1138
1139        if (dev->type != ARPHRD_IEEE802154)
1140                goto drop;
1141
1142        /* check that it's our buffer */
1143        switch (skb->data[0] & 0xe0) {
1144        case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
1145        case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
1146        case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
1147                lowpan_process_data(skb);
1148                break;
1149        default:
1150                break;
1151        }
1152
1153        return NET_RX_SUCCESS;
1154
1155drop:
1156        kfree_skb(skb);
1157        return NET_RX_DROP;
1158}
1159
1160static int lowpan_newlink(struct net *src_net, struct net_device *dev,
1161                          struct nlattr *tb[], struct nlattr *data[])
1162{
1163        struct net_device *real_dev;
1164        struct lowpan_dev_record *entry;
1165
1166        pr_debug("adding new link\n");
1167
1168        if (!tb[IFLA_LINK])
1169                return -EINVAL;
1170        /* find and hold real wpan device */
1171        real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
1172        if (!real_dev)
1173                return -ENODEV;
1174
1175        lowpan_dev_info(dev)->real_dev = real_dev;
1176        mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
1177
1178        entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
1179        if (!entry) {
1180                dev_put(real_dev);
1181                lowpan_dev_info(dev)->real_dev = NULL;
1182                return -ENOMEM;
1183        }
1184
1185        entry->ldev = dev;
1186
1187        mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1188        INIT_LIST_HEAD(&entry->list);
1189        list_add_tail(&entry->list, &lowpan_devices);
1190        mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1191
1192        register_netdevice(dev);
1193
1194        return 0;
1195}
1196
1197static void lowpan_dellink(struct net_device *dev, struct list_head *head)
1198{
1199        struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
1200        struct net_device *real_dev = lowpan_dev->real_dev;
1201        struct lowpan_dev_record *entry, *tmp;
1202
1203        ASSERT_RTNL();
1204
1205        mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1206        list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1207                if (entry->ldev == dev) {
1208                        list_del(&entry->list);
1209                        kfree(entry);
1210                }
1211        }
1212        mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1213
1214        mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
1215
1216        unregister_netdevice_queue(dev, head);
1217
1218        dev_put(real_dev);
1219}
1220
1221static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
1222        .kind           = "lowpan",
1223        .priv_size      = sizeof(struct lowpan_dev_info),
1224        .setup          = lowpan_setup,
1225        .newlink        = lowpan_newlink,
1226        .dellink        = lowpan_dellink,
1227        .validate       = lowpan_validate,
1228};
1229
1230static inline int __init lowpan_netlink_init(void)
1231{
1232        return rtnl_link_register(&lowpan_link_ops);
1233}
1234
1235static inline void __init lowpan_netlink_fini(void)
1236{
1237        rtnl_link_unregister(&lowpan_link_ops);
1238}
1239
1240static struct packet_type lowpan_packet_type = {
1241        .type = __constant_htons(ETH_P_IEEE802154),
1242        .func = lowpan_rcv,
1243};
1244
1245static int __init lowpan_init_module(void)
1246{
1247        int err = 0;
1248
1249        err = lowpan_netlink_init();
1250        if (err < 0)
1251                goto out;
1252
1253        dev_add_pack(&lowpan_packet_type);
1254out:
1255        return err;
1256}
1257
1258static void __exit lowpan_cleanup_module(void)
1259{
1260        struct lowpan_fragment *frame, *tframe;
1261
1262        lowpan_netlink_fini();
1263
1264        dev_remove_pack(&lowpan_packet_type);
1265
1266        /* Now 6lowpan packet_type is removed, so no new fragments are
1267         * expected on RX, therefore that's the time to clean incomplete
1268         * fragments.
1269         */
1270        spin_lock_bh(&flist_lock);
1271        list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
1272                del_timer_sync(&frame->timer);
1273                list_del(&frame->list);
1274                dev_kfree_skb(frame->skb);
1275                kfree(frame);
1276        }
1277        spin_unlock_bh(&flist_lock);
1278}
1279
1280module_init(lowpan_init_module);
1281module_exit(lowpan_cleanup_module);
1282MODULE_LICENSE("GPL");
1283MODULE_ALIAS_RTNL_LINK("lowpan");
1284
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