net/ieee802154/6lowpan.c

   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 */
  66 static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
  67
  68 static 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  */
  80 static 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  */
  89 static 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  */
  98 static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
  99
 100 /* Link local prefix */
 101 static const u8 lowpan_llprefix[] = {0xfe, 0x80};
 102
 103 /* private device info */
 104 struct lowpan_dev_info {
 105         struct net_device       *real_dev; /* real WPAN device ptr */
 106         struct mutex            dev_list_mtx; /* mutex for list ops */
 107         unsigned short fragment_tag;
 108 };
 109
 110 struct lowpan_dev_record {
 111         struct net_device *ldev;
 112         struct list_head list;
 113 };
 114
 115 struct lowpan_fragment {
 116         struct sk_buff          *skb;           /* skb to be assembled */
 117         u16                     length;         /* length to be assemled */
 118         u32                     bytes_rcv;      /* bytes received */
 119         u16                     tag;            /* current fragment tag */
 120         struct timer_list       timer;          /* assembling timer */
 121         struct list_head        list;           /* fragments list */
 122 };
 123
 124 static LIST_HEAD(lowpan_fragments);
 125 static DEFINE_SPINLOCK(flist_lock);
 126
 127 static inline struct
 128 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
 129 {
 130         return netdev_priv(dev);
 131 }
 132
 133 static 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 */
 142 static 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  */
 160 static 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
 171 static u8
 172 lowpan_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
 194 static void
 195 lowpan_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  */
 209 static int
 210 lowpan_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
 247 static void
 248 lowpan_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
 289 static 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
 300 static 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
 311 static int
 312 lowpan_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;
 367 err:
 368         return -EINVAL;
 369 }
 370
 371 static 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[100];
 381         struct ieee802154_addr sa, da;
 382
 383         /* TODO:
 384          * if this package isn't ipv6 one, where should it be routed?
 385          */
 386         if (type != ETH_P_IPV6)
 387                 return 0;
 388
 389         hdr = ipv6_hdr(skb);
 390         hc06_ptr = head + 2;
 391
 392         pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n"
 393                  "\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version,
 394                  ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit);
 395
 396         lowpan_raw_dump_table(__func__, "raw skb network header dump",
 397                 skb_network_header(skb), sizeof(struct ipv6hdr));
 398
 399         if (!saddr)
 400                 saddr = dev->dev_addr;
 401
 402         lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
 403
 404         /*
 405          * As we copy some bit-length fields, in the IPHC encoding bytes,
 406          * we sometimes use |=
 407          * If the field is 0, and the current bit value in memory is 1,
 408          * this does not work. We therefore reset the IPHC encoding here
 409          */
 410         iphc0 = LOWPAN_DISPATCH_IPHC;
 411         iphc1 = 0;
 412
 413         /* TODO: context lookup */
 414
 415         lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 416
 417         /*
 418          * Traffic class, flow label
 419          * If flow label is 0, compress it. If traffic class is 0, compress it
 420          * We have to process both in the same time as the offset of traffic
 421          * class depends on the presence of version and flow label
 422          */
 423
 424         /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
 425         tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
 426         tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
 427
 428         if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
 429              (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
 430                 /* flow label can be compressed */
 431                 iphc0 |= LOWPAN_IPHC_FL_C;
 432                 if ((hdr->priority == 0) &&
 433                    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 434                         /* compress (elide) all */
 435                         iphc0 |= LOWPAN_IPHC_TC_C;
 436                 } else {
 437                         /* compress only the flow label */
 438                         *hc06_ptr = tmp;
 439                         hc06_ptr += 1;
 440                 }
 441         } else {
 442                 /* Flow label cannot be compressed */
 443                 if ((hdr->priority == 0) &&
 444                    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 445                         /* compress only traffic class */
 446                         iphc0 |= LOWPAN_IPHC_TC_C;
 447                         *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
 448                         memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
 449                         hc06_ptr += 3;
 450                 } else {
 451                         /* compress nothing */
 452                         memcpy(hc06_ptr, &hdr, 4);
 453                         /* replace the top byte with new ECN | DSCP format */
 454                         *hc06_ptr = tmp;
 455                         hc06_ptr += 4;
 456                 }
 457         }
 458
 459         /* NOTE: payload length is always compressed */
 460
 461         /* Next Header is compress if UDP */
 462         if (hdr->nexthdr == UIP_PROTO_UDP)
 463                 iphc0 |= LOWPAN_IPHC_NH_C;
 464
 465         if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 466                 *hc06_ptr = hdr->nexthdr;
 467                 hc06_ptr += 1;
 468         }
 469
 470         /*
 471          * Hop limit
 472          * if 1:   compress, encoding is 01
 473          * if 64:  compress, encoding is 10
 474          * if 255: compress, encoding is 11
 475          * else do not compress
 476          */
 477         switch (hdr->hop_limit) {
 478         case 1:
 479                 iphc0 |= LOWPAN_IPHC_TTL_1;
 480                 break;
 481         case 64:
 482                 iphc0 |= LOWPAN_IPHC_TTL_64;
 483                 break;
 484         case 255:
 485                 iphc0 |= LOWPAN_IPHC_TTL_255;
 486                 break;
 487         default:
 488                 *hc06_ptr = hdr->hop_limit;
 489                 hc06_ptr += 1;
 490                 break;
 491         }
 492
 493         /* source address compression */
 494         if (is_addr_unspecified(&hdr->saddr)) {
 495                 pr_debug("source address is unspecified, setting SAC\n");
 496                 iphc1 |= LOWPAN_IPHC_SAC;
 497         /* TODO: context lookup */
 498         } else if (is_addr_link_local(&hdr->saddr)) {
 499                 pr_debug("source address is link-local\n");
 500                 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 501                                 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
 502         } else {
 503                 pr_debug("send the full source address\n");
 504                 memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
 505                 hc06_ptr += 16;
 506         }
 507
 508         /* destination address compression */
 509         if (is_addr_mcast(&hdr->daddr)) {
 510                 pr_debug("destination address is multicast: ");
 511                 iphc1 |= LOWPAN_IPHC_M;
 512                 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
 513                         pr_debug("compressed to 1 octet\n");
 514                         iphc1 |= LOWPAN_IPHC_DAM_11;
 515                         /* use last byte */
 516                         *hc06_ptr = hdr->daddr.s6_addr[15];
 517                         hc06_ptr += 1;
 518                 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
 519                         pr_debug("compressed to 4 octets\n");
 520                         iphc1 |= LOWPAN_IPHC_DAM_10;
 521                         /* second byte + the last three */
 522                         *hc06_ptr = hdr->daddr.s6_addr[1];
 523                         memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
 524                         hc06_ptr += 4;
 525                 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
 526                         pr_debug("compressed to 6 octets\n");
 527                         iphc1 |= LOWPAN_IPHC_DAM_01;
 528                         /* second byte + the last five */
 529                         *hc06_ptr = hdr->daddr.s6_addr[1];
 530                         memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
 531                         hc06_ptr += 6;
 532                 } else {
 533                         pr_debug("using full address\n");
 534                         iphc1 |= LOWPAN_IPHC_DAM_00;
 535                         memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
 536                         hc06_ptr += 16;
 537                 }
 538         } else {
 539                 /* TODO: context lookup */
 540                 if (is_addr_link_local(&hdr->daddr)) {
 541                         pr_debug("dest address is unicast and link-local\n");
 542                         iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 543                                 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
 544                 } else {
 545                         pr_debug("dest address is unicast: using full one\n");
 546                         memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
 547                         hc06_ptr += 16;
 548                 }
 549         }
 550
 551         /* UDP header compression */
 552         if (hdr->nexthdr == UIP_PROTO_UDP)
 553                 lowpan_compress_udp_header(&hc06_ptr, skb);
 554
 555         head[0] = iphc0;
 556         head[1] = iphc1;
 557
 558         skb_pull(skb, sizeof(struct ipv6hdr));
 559         memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
 560
 561         lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 562                                 skb->len);
 563
 564         /*
 565          * NOTE1: I'm still unsure about the fact that compression and WPAN
 566          * header are created here and not later in the xmit. So wait for
 567          * an opinion of net maintainers.
 568          */
 569         /*
 570          * NOTE2: to be absolutely correct, we must derive PANid information
 571          * from MAC subif of the 'dev' and 'real_dev' network devices, but
 572          * this isn't implemented in mainline yet, so currently we assign 0xff
 573          */
 574         {
 575                 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
 576                 mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
 577
 578                 /* prepare wpan address data */
 579                 sa.addr_type = IEEE802154_ADDR_LONG;
 580                 sa.pan_id = 0xff;
 581                 memcpy(&(sa.hwaddr), saddr, 8);
 582
 583                 da.pan_id = 0xff;
 584                 /*
 585                  * if the destination address is the broadcast address, use the
 586                  * corresponding short address
 587                  */
 588                 if (lowpan_is_addr_broadcast(daddr)) {
 589                         da.addr_type = IEEE802154_ADDR_SHORT;
 590                         da.short_addr = IEEE802154_ADDR_BROADCAST;
 591                 } else {
 592                         da.addr_type = IEEE802154_ADDR_LONG;
 593                         memcpy(&(da.hwaddr), daddr, 8);
 594
 595                         /* request acknowledgment */
 596                         mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
 597                 }
 598
 599                 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 600                                 type, (void *)&da, (void *)&sa, skb->len);
 601         }
 602 }
 603
 604 static int lowpan_give_skb_to_devices(struct sk_buff *skb)
 605 {
 606         struct lowpan_dev_record *entry;
 607         struct sk_buff *skb_cp;
 608         int stat = NET_RX_SUCCESS;
 609
 610         rcu_read_lock();
 611         list_for_each_entry_rcu(entry, &lowpan_devices, list)
 612                 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
 613                         skb_cp = skb_copy(skb, GFP_ATOMIC);
 614                         if (!skb_cp) {
 615                                 stat = -ENOMEM;
 616                                 break;
 617                         }
 618
 619                         skb_cp->dev = entry->ldev;
 620                         stat = netif_rx(skb_cp);
 621                 }
 622         rcu_read_unlock();
 623
 624         return stat;
 625 }
 626
 627 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 628 {
 629         struct sk_buff *new;
 630         int stat = NET_RX_SUCCESS;
 631
 632         new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
 633                                                                 GFP_ATOMIC);
 634         kfree_skb(skb);
 635
 636         if (!new)
 637                 return -ENOMEM;
 638
 639         skb_push(new, sizeof(struct ipv6hdr));
 640         skb_reset_network_header(new);
 641         skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
 642
 643         new->protocol = htons(ETH_P_IPV6);
 644         new->pkt_type = PACKET_HOST;
 645
 646         stat = lowpan_give_skb_to_devices(new);
 647
 648         kfree_skb(new);
 649
 650         return stat;
 651 }
 652
 653 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 654 {
 655         struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
 656
 657         pr_debug("timer expired for frame with tag %d\n", entry->tag);
 658
 659         list_del(&entry->list);
 660         dev_kfree_skb(entry->skb);
 661         kfree(entry);
 662 }
 663
 664 static struct lowpan_fragment *
 665 lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
 666 {
 667         struct lowpan_fragment *frame;
 668
 669         frame = kzalloc(sizeof(struct lowpan_fragment),
 670                         GFP_ATOMIC);
 671         if (!frame)
 672                 goto frame_err;
 673
 674         INIT_LIST_HEAD(&frame->list);
 675
 676         frame->length = len;
 677         frame->tag = tag;
 678
 679         /* allocate buffer for frame assembling */
 680         frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
 681                                                sizeof(struct ipv6hdr));
 682
 683         if (!frame->skb)
 684                 goto skb_err;
 685
 686         frame->skb->priority = skb->priority;
 687         frame->skb->dev = skb->dev;
 688
 689         /* reserve headroom for uncompressed ipv6 header */
 690         skb_reserve(frame->skb, sizeof(struct ipv6hdr));
 691         skb_put(frame->skb, frame->length);
 692
 693         init_timer(&frame->timer);
 694         /* time out is the same as for ipv6 - 60 sec */
 695         frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
 696         frame->timer.data = (unsigned long)frame;
 697         frame->timer.function = lowpan_fragment_timer_expired;
 698
 699         add_timer(&frame->timer);
 700
 701         list_add_tail(&frame->list, &lowpan_fragments);
 702
 703         return frame;
 704
 705 skb_err:
 706         kfree(frame);
 707 frame_err:
 708         return NULL;
 709 }
 710
 711 static int
 712 lowpan_process_data(struct sk_buff *skb)
 713 {
 714         struct ipv6hdr hdr;
 715         u8 tmp, iphc0, iphc1, num_context = 0;
 716         u8 *_saddr, *_daddr;
 717         int err;
 718
 719         lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 720                                 skb->len);
 721         /* at least two bytes will be used for the encoding */
 722         if (skb->len < 2)
 723                 goto drop;
 724
 725         if (lowpan_fetch_skb_u8(skb, &iphc0))
 726                 goto drop;
 727
 728         /* fragments assembling */
 729         switch (iphc0 & LOWPAN_DISPATCH_MASK) {
 730         case LOWPAN_DISPATCH_FRAG1:
 731         case LOWPAN_DISPATCH_FRAGN:
 732         {
 733                 struct lowpan_fragment *frame;
 734                 /* slen stores the rightmost 8 bits of the 11 bits length */
 735                 u8 slen, offset = 0;
 736                 u16 len, tag;
 737                 bool found = false;
 738
 739                 if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
 740                     lowpan_fetch_skb_u16(skb, &tag))  /* fragment tag */
 741                         goto drop;
 742
 743                 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 744                 len = ((iphc0 & 7) << 8) | slen;
 745
 746                 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
 747                         pr_debug("%s received a FRAG1 packet (tag: %d, "
 748                                  "size of the entire IP packet: %d)",
 749                                  __func__, tag, len);
 750                 } else { /* FRAGN */
 751                         if (lowpan_fetch_skb_u8(skb, &offset))
 752                                 goto unlock_and_drop;
 753                         pr_debug("%s received a FRAGN packet (tag: %d, "
 754                                  "size of the entire IP packet: %d, "
 755                                  "offset: %d)", __func__, tag, len, offset * 8);
 756                 }
 757
 758                 /*
 759                  * check if frame assembling with the same tag is
 760                  * already in progress
 761                  */
 762                 spin_lock_bh(&flist_lock);
 763
 764                 list_for_each_entry(frame, &lowpan_fragments, list)
 765                         if (frame->tag == tag) {
 766                                 found = true;
 767                                 break;
 768                         }
 769
 770                 /* alloc new frame structure */
 771                 if (!found) {
 772                         pr_debug("%s first fragment received for tag %d, "
 773                                  "begin packet reassembly", __func__, tag);
 774                         frame = lowpan_alloc_new_frame(skb, len, tag);
 775                         if (!frame)
 776                                 goto unlock_and_drop;
 777                 }
 778
 779                 /* if payload fits buffer, copy it */
 780                 if (likely((offset * 8 + skb->len) <= frame->length))
 781                         skb_copy_to_linear_data_offset(frame->skb, offset * 8,
 782                                                         skb->data, skb->len);
 783                 else
 784                         goto unlock_and_drop;
 785
 786                 frame->bytes_rcv += skb->len;
 787
 788                 /* frame assembling complete */
 789                 if ((frame->bytes_rcv == frame->length) &&
 790                      frame->timer.expires > jiffies) {
 791                         /* if timer haven't expired - first of all delete it */
 792                         del_timer_sync(&frame->timer);
 793                         list_del(&frame->list);
 794                         spin_unlock_bh(&flist_lock);
 795
 796                         pr_debug("%s successfully reassembled fragment "
 797                                  "(tag %d)", __func__, tag);
 798
 799                         dev_kfree_skb(skb);
 800                         skb = frame->skb;
 801                         kfree(frame);
 802
 803                         if (lowpan_fetch_skb_u8(skb, &iphc0))
 804                                 goto drop;
 805
 806                         break;
 807                 }
 808                 spin_unlock_bh(&flist_lock);
 809
 810                 return kfree_skb(skb), 0;
 811         }
 812         default:
 813                 break;
 814         }
 815
 816         if (lowpan_fetch_skb_u8(skb, &iphc1))
 817                 goto drop;
 818
 819         _saddr = mac_cb(skb)->sa.hwaddr;
 820         _daddr = mac_cb(skb)->da.hwaddr;
 821
 822         pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
 823
 824         /* another if the CID flag is set */
 825         if (iphc1 & LOWPAN_IPHC_CID) {
 826                 pr_debug("CID flag is set, increase header with one\n");
 827                 if (lowpan_fetch_skb_u8(skb, &num_context))
 828                         goto drop;
 829         }
 830
 831         hdr.version = 6;
 832
 833         /* Traffic Class and Flow Label */
 834         switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 835         /*
 836          * Traffic Class and FLow Label carried in-line
 837          * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
 838          */
 839         case 0: /* 00b */
 840                 if (lowpan_fetch_skb_u8(skb, &tmp))
 841                         goto drop;
 842
 843                 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
 844                 skb_pull(skb, 3);
 845                 hdr.priority = ((tmp >> 2) & 0x0f);
 846                 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
 847                                         (hdr.flow_lbl[0] & 0x0f);
 848                 break;
 849         /*
 850          * Traffic class carried in-line
 851          * ECN + DSCP (1 byte), Flow Label is elided
 852          */
 853         case 1: /* 10b */
 854                 if (lowpan_fetch_skb_u8(skb, &tmp))
 855                         goto drop;
 856
 857                 hdr.priority = ((tmp >> 2) & 0x0f);
 858                 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
 859                 hdr.flow_lbl[1] = 0;
 860                 hdr.flow_lbl[2] = 0;
 861                 break;
 862         /*
 863          * Flow Label carried in-line
 864          * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
 865          */
 866         case 2: /* 01b */
 867                 if (lowpan_fetch_skb_u8(skb, &tmp))
 868                         goto drop;
 869
 870                 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
 871                 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
 872                 skb_pull(skb, 2);
 873                 break;
 874         /* Traffic Class and Flow Label are elided */
 875         case 3: /* 11b */
 876                 hdr.priority = 0;
 877                 hdr.flow_lbl[0] = 0;
 878                 hdr.flow_lbl[1] = 0;
 879                 hdr.flow_lbl[2] = 0;
 880                 break;
 881         default:
 882                 break;
 883         }
 884
 885         /* Next Header */
 886         if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 887                 /* Next header is carried inline */
 888                 if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
 889                         goto drop;
 890
 891                 pr_debug("NH flag is set, next header carried inline: %02x\n",
 892                          hdr.nexthdr);
 893         }
 894
 895         /* Hop Limit */
 896         if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
 897                 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
 898         else {
 899                 if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
 900                         goto drop;
 901         }
 902
 903         /* Extract SAM to the tmp variable */
 904         tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
 905
 906         /* Source address uncompression */
 907         pr_debug("source address stateless compression\n");
 908         err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
 909                                 lowpan_unc_llconf[tmp], skb->data);
 910         if (err)
 911                 goto drop;
 912
 913         /* Extract DAM to the tmp variable */
 914         tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
 915
 916         /* check for Multicast Compression */
 917         if (iphc1 & LOWPAN_IPHC_M) {
 918                 if (iphc1 & LOWPAN_IPHC_DAC) {
 919                         pr_debug("dest: context-based mcast compression\n");
 920                         /* TODO: implement this */
 921                 } else {
 922                         u8 prefix[] = {0xff, 0x02};
 923
 924                         pr_debug("dest: non context-based mcast compression\n");
 925                         if (0 < tmp && tmp < 3) {
 926                                 if (lowpan_fetch_skb_u8(skb, &prefix[1]))
 927                                         goto drop;
 928                         }
 929
 930                         err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
 931                                         lowpan_unc_mxconf[tmp], NULL);
 932                         if (err)
 933                                 goto drop;
 934                 }
 935         } else {
 936                 pr_debug("dest: stateless compression\n");
 937                 err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
 938                                 lowpan_unc_llconf[tmp], skb->data);
 939                 if (err)
 940                         goto drop;
 941         }
 942
 943         /* UDP data uncompression */
 944         if (iphc0 & LOWPAN_IPHC_NH_C) {
 945                 if (lowpan_uncompress_udp_header(skb))
 946                         goto drop;
 947                 hdr.nexthdr = UIP_PROTO_UDP;
 948         }
 949
 950         /* Not fragmented package */
 951         hdr.payload_len = htons(skb->len);
 952
 953         pr_debug("skb headroom size = %d, data length = %d\n",
 954                  skb_headroom(skb), skb->len);
 955
 956         pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n\t"
 957                  "nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version,
 958                  ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
 959
 960         lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
 961                                                         sizeof(hdr));
 962         return lowpan_skb_deliver(skb, &hdr);
 963
 964 unlock_and_drop:
 965         spin_unlock_bh(&flist_lock);
 966 drop:
 967         kfree_skb(skb);
 968         return -EINVAL;
 969 }
 970
 971 static int lowpan_set_address(struct net_device *dev, void *p)
 972 {
 973         struct sockaddr *sa = p;
 974
 975         if (netif_running(dev))
 976                 return -EBUSY;
 977
 978         /* TODO: validate addr */
 979         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 980
 981         return 0;
 982 }
 983
 984 static int lowpan_get_mac_header_length(struct sk_buff *skb)
 985 {
 986         /*
 987          * Currently long addressing mode is supported only, so the overall
 988          * header size is 21:
 989          * FC SeqNum DPAN DA  SA  Sec
 990          * 2  +  1  +  2 + 8 + 8 + 0  = 21
 991          */
 992         return 21;
 993 }
 994
 995 static int
 996 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
 997                         int mlen, int plen, int offset, int type)
 998 {
 999         struct sk_buff *frag;
1000         int hlen, ret;
1001
1002         hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
1003                         LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
1004
1005         lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
1006
1007         frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
1008         if (!frag)
1009                 return -ENOMEM;
1010
1011         frag->priority = skb->priority;
1012         frag->dev = skb->dev;
1013
1014         /* copy header, MFR and payload */
1015         memcpy(skb_put(frag, mlen), skb->data, mlen);
1016         memcpy(skb_put(frag, hlen), head, hlen);
1017
1018         if (plen)
1019                 skb_copy_from_linear_data_offset(skb, offset + mlen,
1020                                         skb_put(frag, plen), plen);
1021
1022         lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
1023                                                                 frag->len);
1024
1025         ret = dev_queue_xmit(frag);
1026
1027         return ret;
1028 }
1029
1030 static int
1031 lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
1032 {
1033         int  err, header_length, payload_length, tag, offset = 0;
1034         u8 head[5];
1035
1036         header_length = lowpan_get_mac_header_length(skb);
1037         payload_length = skb->len - header_length;
1038         tag = lowpan_dev_info(dev)->fragment_tag++;
1039
1040         /* first fragment header */
1041         head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
1042         head[1] = payload_length & 0xff;
1043         head[2] = tag >> 8;
1044         head[3] = tag & 0xff;
1045
1046         err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
1047                                    0, LOWPAN_DISPATCH_FRAG1);
1048
1049         if (err) {
1050                 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
1051                          __func__, tag);
1052                 goto exit;
1053         }
1054
1055         offset = LOWPAN_FRAG_SIZE;
1056
1057         /* next fragment header */
1058         head[0] &= ~LOWPAN_DISPATCH_FRAG1;
1059         head[0] |= LOWPAN_DISPATCH_FRAGN;
1060
1061         while ((payload_length - offset > 0) && (err >= 0)) {
1062                 int len = LOWPAN_FRAG_SIZE;
1063
1064                 head[4] = offset / 8;
1065
1066                 if (payload_length - offset < len)
1067                         len = payload_length - offset;
1068
1069                 err = lowpan_fragment_xmit(skb, head, header_length,
1070                                            len, offset, LOWPAN_DISPATCH_FRAGN);
1071                 if (err) {
1072                         pr_debug("%s unable to send a subsequent FRAGN packet "
1073                                  "(tag: %d, offset: %d", __func__, tag, offset);
1074                         goto exit;
1075                 }
1076
1077                 offset += len;
1078         }
1079
1080 exit:
1081         return err;
1082 }
1083
1084 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
1085 {
1086         int err = -1;
1087
1088         pr_debug("package xmit\n");
1089
1090         skb->dev = lowpan_dev_info(dev)->real_dev;
1091         if (skb->dev == NULL) {
1092                 pr_debug("ERROR: no real wpan device found\n");
1093                 goto error;
1094         }
1095
1096         /* Send directly if less than the MTU minus the 2 checksum bytes. */
1097         if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
1098                 err = dev_queue_xmit(skb);
1099                 goto out;
1100         }
1101
1102         pr_debug("frame is too big, fragmentation is needed\n");
1103         err = lowpan_skb_fragmentation(skb, dev);
1104 error:
1105         dev_kfree_skb(skb);
1106 out:
1107         if (err < 0)
1108                 pr_debug("ERROR: xmit failed\n");
1109
1110         return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
1111 }
1112
1113 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
1114 {
1115         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1116         return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
1117 }
1118
1119 static u16 lowpan_get_pan_id(const struct net_device *dev)
1120 {
1121         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1122         return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
1123 }
1124
1125 static u16 lowpan_get_short_addr(const struct net_device *dev)
1126 {
1127         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1128         return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
1129 }
1130
1131 static u8 lowpan_get_dsn(const struct net_device *dev)
1132 {
1133         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1134         return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
1135 }
1136
1137 static struct header_ops lowpan_header_ops = {
1138         .create = lowpan_header_create,
1139 };
1140
1141 static const struct net_device_ops lowpan_netdev_ops = {
1142         .ndo_start_xmit         = lowpan_xmit,
1143         .ndo_set_mac_address    = lowpan_set_address,
1144 };
1145
1146 static struct ieee802154_mlme_ops lowpan_mlme = {
1147         .get_pan_id = lowpan_get_pan_id,
1148         .get_phy = lowpan_get_phy,
1149         .get_short_addr = lowpan_get_short_addr,
1150         .get_dsn = lowpan_get_dsn,
1151 };
1152
1153 static void lowpan_setup(struct net_device *dev)
1154 {
1155         dev->addr_len           = IEEE802154_ADDR_LEN;
1156         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
1157         dev->type               = ARPHRD_IEEE802154;
1158         /* Frame Control + Sequence Number + Address fields + Security Header */
1159         dev->hard_header_len    = 2 + 1 + 20 + 14;
1160         dev->needed_tailroom    = 2; /* FCS */
1161         dev->mtu                = 1281;
1162         dev->tx_queue_len       = 0;
1163         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
1164         dev->watchdog_timeo     = 0;
1165
1166         dev->netdev_ops         = &lowpan_netdev_ops;
1167         dev->header_ops         = &lowpan_header_ops;
1168         dev->ml_priv            = &lowpan_mlme;
1169         dev->destructor         = free_netdev;
1170 }
1171
1172 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
1173 {
1174         if (tb[IFLA_ADDRESS]) {
1175                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
1176                         return -EINVAL;
1177         }
1178         return 0;
1179 }
1180
1181 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
1182         struct packet_type *pt, struct net_device *orig_dev)
1183 {
1184         struct sk_buff *local_skb;
1185
1186         if (!netif_running(dev))
1187                 goto drop;
1188
1189         if (dev->type != ARPHRD_IEEE802154)
1190                 goto drop;
1191
1192         /* check that it's our buffer */
1193         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
1194                 /* Copy the packet so that the IPv6 header is
1195                  * properly aligned.
1196                  */
1197                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
1198                                             skb_tailroom(skb), GFP_ATOMIC);
1199                 if (!local_skb)
1200                         goto drop;
1201
1202                 local_skb->protocol = htons(ETH_P_IPV6);
1203                 local_skb->pkt_type = PACKET_HOST;
1204
1205                 /* Pull off the 1-byte of 6lowpan header. */
1206                 skb_pull(local_skb, 1);
1207                 skb_reset_network_header(local_skb);
1208                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
1209
1210                 lowpan_give_skb_to_devices(local_skb);
1211
1212                 kfree_skb(local_skb);
1213                 kfree_skb(skb);
1214         } else {
1215                 switch (skb->data[0] & 0xe0) {
1216                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
1217                 case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
1218                 case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
1219                         local_skb = skb_clone(skb, GFP_ATOMIC);
1220                         if (!local_skb)
1221                                 goto drop;
1222                         lowpan_process_data(local_skb);
1223
1224                         kfree_skb(skb);
1225                         break;
1226                 default:
1227                         break;
1228                 }
1229         }
1230
1231         return NET_RX_SUCCESS;
1232
1233 drop:
1234         kfree_skb(skb);
1235         return NET_RX_DROP;
1236 }
1237
1238 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
1239                           struct nlattr *tb[], struct nlattr *data[])
1240 {
1241         struct net_device *real_dev;
1242         struct lowpan_dev_record *entry;
1243
1244         pr_debug("adding new link\n");
1245
1246         if (!tb[IFLA_LINK])
1247                 return -EINVAL;
1248         /* find and hold real wpan device */
1249         real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
1250         if (!real_dev)
1251                 return -ENODEV;
1252
1253         lowpan_dev_info(dev)->real_dev = real_dev;
1254         lowpan_dev_info(dev)->fragment_tag = 0;
1255         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
1256
1257         entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
1258         if (!entry) {
1259                 dev_put(real_dev);
1260                 lowpan_dev_info(dev)->real_dev = NULL;
1261                 return -ENOMEM;
1262         }
1263
1264         entry->ldev = dev;
1265
1266         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1267         INIT_LIST_HEAD(&entry->list);
1268         list_add_tail(&entry->list, &lowpan_devices);
1269         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1270
1271         register_netdevice(dev);
1272
1273         return 0;
1274 }
1275
1276 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
1277 {
1278         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
1279         struct net_device *real_dev = lowpan_dev->real_dev;
1280         struct lowpan_dev_record *entry, *tmp;
1281
1282         ASSERT_RTNL();
1283
1284         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1285         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1286                 if (entry->ldev == dev) {
1287                         list_del(&entry->list);
1288                         kfree(entry);
1289                 }
1290         }
1291         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1292
1293         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
1294
1295         unregister_netdevice_queue(dev, head);
1296
1297         dev_put(real_dev);
1298 }
1299
1300 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
1301         .kind           = "lowpan",
1302         .priv_size      = sizeof(struct lowpan_dev_info),
1303         .setup          = lowpan_setup,
1304         .newlink        = lowpan_newlink,
1305         .dellink        = lowpan_dellink,
1306         .validate       = lowpan_validate,
1307 };
1308
1309 static inline int __init lowpan_netlink_init(void)
1310 {
1311         return rtnl_link_register(&lowpan_link_ops);
1312 }
1313
1314 static inline void lowpan_netlink_fini(void)
1315 {
1316         rtnl_link_unregister(&lowpan_link_ops);
1317 }
1318
1319 static int lowpan_device_event(struct notifier_block *unused,
1320                                 unsigned long event,
1321                                 void *ptr)
1322 {
1323         struct net_device *dev = ptr;
1324         LIST_HEAD(del_list);
1325         struct lowpan_dev_record *entry, *tmp;
1326
1327         if (dev->type != ARPHRD_IEEE802154)
1328                 goto out;
1329
1330         if (event == NETDEV_UNREGISTER) {
1331                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1332                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
1333                                 lowpan_dellink(entry->ldev, &del_list);
1334                 }
1335
1336                 unregister_netdevice_many(&del_list);
1337         }
1338
1339 out:
1340         return NOTIFY_DONE;
1341 }
1342
1343 static struct notifier_block lowpan_dev_notifier = {
1344         .notifier_call = lowpan_device_event,
1345 };
1346
1347 static struct packet_type lowpan_packet_type = {
1348         .type = __constant_htons(ETH_P_IEEE802154),
1349         .func = lowpan_rcv,
1350 };
1351
1352 static int __init lowpan_init_module(void)
1353 {
1354         int err = 0;
1355
1356         err = lowpan_netlink_init();
1357         if (err < 0)
1358                 goto out;
1359
1360         dev_add_pack(&lowpan_packet_type);
1361
1362         err = register_netdevice_notifier(&lowpan_dev_notifier);
1363         if (err < 0) {
1364                 dev_remove_pack(&lowpan_packet_type);
1365                 lowpan_netlink_fini();
1366         }
1367 out:
1368         return err;
1369 }
1370
1371 static void __exit lowpan_cleanup_module(void)
1372 {
1373         struct lowpan_fragment *frame, *tframe;
1374
1375         lowpan_netlink_fini();
1376
1377         dev_remove_pack(&lowpan_packet_type);
1378
1379         unregister_netdevice_notifier(&lowpan_dev_notifier);
1380
1381         /* Now 6lowpan packet_type is removed, so no new fragments are
1382          * expected on RX, therefore that's the time to clean incomplete
1383          * fragments.
1384          */
1385         spin_lock_bh(&flist_lock);
1386         list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
1387                 del_timer_sync(&frame->timer);
1388                 list_del(&frame->list);
1389                 dev_kfree_skb(frame->skb);
1390                 kfree(frame);
1391         }
1392         spin_unlock_bh(&flist_lock);
1393 }
1394
1395 module_init(lowpan_init_module);
1396 module_exit(lowpan_cleanup_module);
1397 MODULE_LICENSE("GPL");
1398 MODULE_ALIAS_RTNL_LINK("lowpan");