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         /* skip the UDP header */
 289         skb_pull(skb, sizeof(struct udphdr));
 290 }
 291
 292 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 293 {
 294         if (unlikely(!pskb_may_pull(skb, 1)))
 295                 return -EINVAL;
 296
 297         *val = skb->data[0];
 298         skb_pull(skb, 1);
 299
 300         return 0;
 301 }
 302
 303 static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 304 {
 305         if (unlikely(!pskb_may_pull(skb, 2)))
 306                 return -EINVAL;
 307
 308         *val = (skb->data[0] << 8) | skb->data[1];
 309         skb_pull(skb, 2);
 310
 311         return 0;
 312 }
 313
 314 static int
 315 lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
 316 {
 317         u8 tmp;
 318
 319         if (!uh)
 320                 goto err;
 321
 322         if (lowpan_fetch_skb_u8(skb, &tmp))
 323                 goto err;
 324
 325         if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 326                 pr_debug("UDP header uncompression\n");
 327                 switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
 328                 case LOWPAN_NHC_UDP_CS_P_00:
 329                         memcpy(&uh->source, &skb->data[0], 2);
 330                         memcpy(&uh->dest, &skb->data[2], 2);
 331                         skb_pull(skb, 4);
 332                         break;
 333                 case LOWPAN_NHC_UDP_CS_P_01:
 334                         memcpy(&uh->source, &skb->data[0], 2);
 335                         uh->dest =
 336                            skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
 337                         skb_pull(skb, 3);
 338                         break;
 339                 case LOWPAN_NHC_UDP_CS_P_10:
 340                         uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
 341                         memcpy(&uh->dest, &skb->data[1], 2);
 342                         skb_pull(skb, 3);
 343                         break;
 344                 case LOWPAN_NHC_UDP_CS_P_11:
 345                         uh->source =
 346                            LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
 347                         uh->dest =
 348                            LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
 349                         skb_pull(skb, 1);
 350                         break;
 351                 default:
 352                         pr_debug("ERROR: unknown UDP format\n");
 353                         goto err;
 354                         break;
 355                 }
 356
 357                 pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
 358                          uh->source, uh->dest);
 359
 360                 /* copy checksum */
 361                 memcpy(&uh->check, &skb->data[0], 2);
 362                 skb_pull(skb, 2);
 363
 364                 /*
 365                  * UDP lenght needs to be infered from the lower layers
 366                  * here, we obtain the hint from the remaining size of the
 367                  * frame
 368                  */
 369                 uh->len = htons(skb->len + sizeof(struct udphdr));
 370                 pr_debug("uncompressed UDP length: src = %d", uh->len);
 371         } else {
 372                 pr_debug("ERROR: unsupported NH format\n");
 373                 goto err;
 374         }
 375
 376         return 0;
 377 err:
 378         return -EINVAL;
 379 }
 380
 381 static int lowpan_header_create(struct sk_buff *skb,
 382                            struct net_device *dev,
 383                            unsigned short type, const void *_daddr,
 384                            const void *_saddr, unsigned int len)
 385 {
 386         u8 tmp, iphc0, iphc1, *hc06_ptr;
 387         struct ipv6hdr *hdr;
 388         const u8 *saddr = _saddr;
 389         const u8 *daddr = _daddr;
 390         u8 head[100];
 391         struct ieee802154_addr sa, da;
 392
 393         /* TODO:
 394          * if this package isn't ipv6 one, where should it be routed?
 395          */
 396         if (type != ETH_P_IPV6)
 397                 return 0;
 398
 399         hdr = ipv6_hdr(skb);
 400         hc06_ptr = head + 2;
 401
 402         pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n"
 403                  "\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version,
 404                  ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit);
 405
 406         lowpan_raw_dump_table(__func__, "raw skb network header dump",
 407                 skb_network_header(skb), sizeof(struct ipv6hdr));
 408
 409         if (!saddr)
 410                 saddr = dev->dev_addr;
 411
 412         lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
 413
 414         /*
 415          * As we copy some bit-length fields, in the IPHC encoding bytes,
 416          * we sometimes use |=
 417          * If the field is 0, and the current bit value in memory is 1,
 418          * this does not work. We therefore reset the IPHC encoding here
 419          */
 420         iphc0 = LOWPAN_DISPATCH_IPHC;
 421         iphc1 = 0;
 422
 423         /* TODO: context lookup */
 424
 425         lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 426
 427         /*
 428          * Traffic class, flow label
 429          * If flow label is 0, compress it. If traffic class is 0, compress it
 430          * We have to process both in the same time as the offset of traffic
 431          * class depends on the presence of version and flow label
 432          */
 433
 434         /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
 435         tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
 436         tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
 437
 438         if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
 439              (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
 440                 /* flow label can be compressed */
 441                 iphc0 |= LOWPAN_IPHC_FL_C;
 442                 if ((hdr->priority == 0) &&
 443                    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 444                         /* compress (elide) all */
 445                         iphc0 |= LOWPAN_IPHC_TC_C;
 446                 } else {
 447                         /* compress only the flow label */
 448                         *hc06_ptr = tmp;
 449                         hc06_ptr += 1;
 450                 }
 451         } else {
 452                 /* Flow label cannot be compressed */
 453                 if ((hdr->priority == 0) &&
 454                    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 455                         /* compress only traffic class */
 456                         iphc0 |= LOWPAN_IPHC_TC_C;
 457                         *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
 458                         memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
 459                         hc06_ptr += 3;
 460                 } else {
 461                         /* compress nothing */
 462                         memcpy(hc06_ptr, &hdr, 4);
 463                         /* replace the top byte with new ECN | DSCP format */
 464                         *hc06_ptr = tmp;
 465                         hc06_ptr += 4;
 466                 }
 467         }
 468
 469         /* NOTE: payload length is always compressed */
 470
 471         /* Next Header is compress if UDP */
 472         if (hdr->nexthdr == UIP_PROTO_UDP)
 473                 iphc0 |= LOWPAN_IPHC_NH_C;
 474
 475         if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 476                 *hc06_ptr = hdr->nexthdr;
 477                 hc06_ptr += 1;
 478         }
 479
 480         /*
 481          * Hop limit
 482          * if 1:   compress, encoding is 01
 483          * if 64:  compress, encoding is 10
 484          * if 255: compress, encoding is 11
 485          * else do not compress
 486          */
 487         switch (hdr->hop_limit) {
 488         case 1:
 489                 iphc0 |= LOWPAN_IPHC_TTL_1;
 490                 break;
 491         case 64:
 492                 iphc0 |= LOWPAN_IPHC_TTL_64;
 493                 break;
 494         case 255:
 495                 iphc0 |= LOWPAN_IPHC_TTL_255;
 496                 break;
 497         default:
 498                 *hc06_ptr = hdr->hop_limit;
 499                 hc06_ptr += 1;
 500                 break;
 501         }
 502
 503         /* source address compression */
 504         if (is_addr_unspecified(&hdr->saddr)) {
 505                 pr_debug("source address is unspecified, setting SAC\n");
 506                 iphc1 |= LOWPAN_IPHC_SAC;
 507         /* TODO: context lookup */
 508         } else if (is_addr_link_local(&hdr->saddr)) {
 509                 pr_debug("source address is link-local\n");
 510                 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 511                                 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
 512         } else {
 513                 pr_debug("send the full source address\n");
 514                 memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
 515                 hc06_ptr += 16;
 516         }
 517
 518         /* destination address compression */
 519         if (is_addr_mcast(&hdr->daddr)) {
 520                 pr_debug("destination address is multicast: ");
 521                 iphc1 |= LOWPAN_IPHC_M;
 522                 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
 523                         pr_debug("compressed to 1 octet\n");
 524                         iphc1 |= LOWPAN_IPHC_DAM_11;
 525                         /* use last byte */
 526                         *hc06_ptr = hdr->daddr.s6_addr[15];
 527                         hc06_ptr += 1;
 528                 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
 529                         pr_debug("compressed to 4 octets\n");
 530                         iphc1 |= LOWPAN_IPHC_DAM_10;
 531                         /* second byte + the last three */
 532                         *hc06_ptr = hdr->daddr.s6_addr[1];
 533                         memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
 534                         hc06_ptr += 4;
 535                 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
 536                         pr_debug("compressed to 6 octets\n");
 537                         iphc1 |= LOWPAN_IPHC_DAM_01;
 538                         /* second byte + the last five */
 539                         *hc06_ptr = hdr->daddr.s6_addr[1];
 540                         memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
 541                         hc06_ptr += 6;
 542                 } else {
 543                         pr_debug("using full address\n");
 544                         iphc1 |= LOWPAN_IPHC_DAM_00;
 545                         memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
 546                         hc06_ptr += 16;
 547                 }
 548         } else {
 549                 /* TODO: context lookup */
 550                 if (is_addr_link_local(&hdr->daddr)) {
 551                         pr_debug("dest address is unicast and link-local\n");
 552                         iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 553                                 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
 554                 } else {
 555                         pr_debug("dest address is unicast: using full one\n");
 556                         memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
 557                         hc06_ptr += 16;
 558                 }
 559         }
 560
 561         /* UDP header compression */
 562         if (hdr->nexthdr == UIP_PROTO_UDP)
 563                 lowpan_compress_udp_header(&hc06_ptr, skb);
 564
 565         head[0] = iphc0;
 566         head[1] = iphc1;
 567
 568         skb_pull(skb, sizeof(struct ipv6hdr));
 569         memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
 570
 571         lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 572                                 skb->len);
 573
 574         /*
 575          * NOTE1: I'm still unsure about the fact that compression and WPAN
 576          * header are created here and not later in the xmit. So wait for
 577          * an opinion of net maintainers.
 578          */
 579         /*
 580          * NOTE2: to be absolutely correct, we must derive PANid information
 581          * from MAC subif of the 'dev' and 'real_dev' network devices, but
 582          * this isn't implemented in mainline yet, so currently we assign 0xff
 583          */
 584         {
 585                 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
 586                 mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
 587
 588                 /* prepare wpan address data */
 589                 sa.addr_type = IEEE802154_ADDR_LONG;
 590                 sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 591
 592                 memcpy(&(sa.hwaddr), saddr, 8);
 593                 /* intra-PAN communications */
 594                 da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 595
 596                 /*
 597                  * if the destination address is the broadcast address, use the
 598                  * corresponding short address
 599                  */
 600                 if (lowpan_is_addr_broadcast(daddr)) {
 601                         da.addr_type = IEEE802154_ADDR_SHORT;
 602                         da.short_addr = IEEE802154_ADDR_BROADCAST;
 603                 } else {
 604                         da.addr_type = IEEE802154_ADDR_LONG;
 605                         memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
 606
 607                         /* request acknowledgment */
 608                         mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
 609                 }
 610
 611                 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 612                                 type, (void *)&da, (void *)&sa, skb->len);
 613         }
 614 }
 615
 616 static int lowpan_give_skb_to_devices(struct sk_buff *skb)
 617 {
 618         struct lowpan_dev_record *entry;
 619         struct sk_buff *skb_cp;
 620         int stat = NET_RX_SUCCESS;
 621
 622         rcu_read_lock();
 623         list_for_each_entry_rcu(entry, &lowpan_devices, list)
 624                 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
 625                         skb_cp = skb_copy(skb, GFP_ATOMIC);
 626                         if (!skb_cp) {
 627                                 stat = -ENOMEM;
 628                                 break;
 629                         }
 630
 631                         skb_cp->dev = entry->ldev;
 632                         stat = netif_rx(skb_cp);
 633                 }
 634         rcu_read_unlock();
 635
 636         return stat;
 637 }
 638
 639 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 640 {
 641         struct sk_buff *new;
 642         int stat = NET_RX_SUCCESS;
 643
 644         new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
 645                                                                 GFP_ATOMIC);
 646         kfree_skb(skb);
 647
 648         if (!new)
 649                 return -ENOMEM;
 650
 651         skb_push(new, sizeof(struct ipv6hdr));
 652         skb_reset_network_header(new);
 653         skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
 654
 655         new->protocol = htons(ETH_P_IPV6);
 656         new->pkt_type = PACKET_HOST;
 657
 658         stat = lowpan_give_skb_to_devices(new);
 659
 660         kfree_skb(new);
 661
 662         return stat;
 663 }
 664
 665 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 666 {
 667         struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
 668
 669         pr_debug("timer expired for frame with tag %d\n", entry->tag);
 670
 671         list_del(&entry->list);
 672         dev_kfree_skb(entry->skb);
 673         kfree(entry);
 674 }
 675
 676 static struct lowpan_fragment *
 677 lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
 678 {
 679         struct lowpan_fragment *frame;
 680
 681         frame = kzalloc(sizeof(struct lowpan_fragment),
 682                         GFP_ATOMIC);
 683         if (!frame)
 684                 goto frame_err;
 685
 686         INIT_LIST_HEAD(&frame->list);
 687
 688         frame->length = len;
 689         frame->tag = tag;
 690
 691         /* allocate buffer for frame assembling */
 692         frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
 693                                                sizeof(struct ipv6hdr));
 694
 695         if (!frame->skb)
 696                 goto skb_err;
 697
 698         frame->skb->priority = skb->priority;
 699         frame->skb->dev = skb->dev;
 700
 701         /* reserve headroom for uncompressed ipv6 header */
 702         skb_reserve(frame->skb, sizeof(struct ipv6hdr));
 703         skb_put(frame->skb, frame->length);
 704
 705         init_timer(&frame->timer);
 706         /* time out is the same as for ipv6 - 60 sec */
 707         frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
 708         frame->timer.data = (unsigned long)frame;
 709         frame->timer.function = lowpan_fragment_timer_expired;
 710
 711         add_timer(&frame->timer);
 712
 713         list_add_tail(&frame->list, &lowpan_fragments);
 714
 715         return frame;
 716
 717 skb_err:
 718         kfree(frame);
 719 frame_err:
 720         return NULL;
 721 }
 722
 723 static int
 724 lowpan_process_data(struct sk_buff *skb)
 725 {
 726         struct ipv6hdr hdr;
 727         u8 tmp, iphc0, iphc1, num_context = 0;
 728         u8 *_saddr, *_daddr;
 729         int err;
 730
 731         lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 732                                 skb->len);
 733         /* at least two bytes will be used for the encoding */
 734         if (skb->len < 2)
 735                 goto drop;
 736
 737         if (lowpan_fetch_skb_u8(skb, &iphc0))
 738                 goto drop;
 739
 740         /* fragments assembling */
 741         switch (iphc0 & LOWPAN_DISPATCH_MASK) {
 742         case LOWPAN_DISPATCH_FRAG1:
 743         case LOWPAN_DISPATCH_FRAGN:
 744         {
 745                 struct lowpan_fragment *frame;
 746                 /* slen stores the rightmost 8 bits of the 11 bits length */
 747                 u8 slen, offset = 0;
 748                 u16 len, tag;
 749                 bool found = false;
 750
 751                 if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
 752                     lowpan_fetch_skb_u16(skb, &tag))  /* fragment tag */
 753                         goto drop;
 754
 755                 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 756                 len = ((iphc0 & 7) << 8) | slen;
 757
 758                 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
 759                         pr_debug("%s received a FRAG1 packet (tag: %d, "
 760                                  "size of the entire IP packet: %d)",
 761                                  __func__, tag, len);
 762                 } else { /* FRAGN */
 763                         if (lowpan_fetch_skb_u8(skb, &offset))
 764                                 goto unlock_and_drop;
 765                         pr_debug("%s received a FRAGN packet (tag: %d, "
 766                                  "size of the entire IP packet: %d, "
 767                                  "offset: %d)", __func__, tag, len, offset * 8);
 768                 }
 769
 770                 /*
 771                  * check if frame assembling with the same tag is
 772                  * already in progress
 773                  */
 774                 spin_lock_bh(&flist_lock);
 775
 776                 list_for_each_entry(frame, &lowpan_fragments, list)
 777                         if (frame->tag == tag) {
 778                                 found = true;
 779                                 break;
 780                         }
 781
 782                 /* alloc new frame structure */
 783                 if (!found) {
 784                         pr_debug("%s first fragment received for tag %d, "
 785                                  "begin packet reassembly", __func__, tag);
 786                         frame = lowpan_alloc_new_frame(skb, len, tag);
 787                         if (!frame)
 788                                 goto unlock_and_drop;
 789                 }
 790
 791                 /* if payload fits buffer, copy it */
 792                 if (likely((offset * 8 + skb->len) <= frame->length))
 793                         skb_copy_to_linear_data_offset(frame->skb, offset * 8,
 794                                                         skb->data, skb->len);
 795                 else
 796                         goto unlock_and_drop;
 797
 798                 frame->bytes_rcv += skb->len;
 799
 800                 /* frame assembling complete */
 801                 if ((frame->bytes_rcv == frame->length) &&
 802                      frame->timer.expires > jiffies) {
 803                         /* if timer haven't expired - first of all delete it */
 804                         del_timer_sync(&frame->timer);
 805                         list_del(&frame->list);
 806                         spin_unlock_bh(&flist_lock);
 807
 808                         pr_debug("%s successfully reassembled fragment "
 809                                  "(tag %d)", __func__, tag);
 810
 811                         dev_kfree_skb(skb);
 812                         skb = frame->skb;
 813                         kfree(frame);
 814
 815                         if (lowpan_fetch_skb_u8(skb, &iphc0))
 816                                 goto drop;
 817
 818                         break;
 819                 }
 820                 spin_unlock_bh(&flist_lock);
 821
 822                 return kfree_skb(skb), 0;
 823         }
 824         default:
 825                 break;
 826         }
 827
 828         if (lowpan_fetch_skb_u8(skb, &iphc1))
 829                 goto drop;
 830
 831         _saddr = mac_cb(skb)->sa.hwaddr;
 832         _daddr = mac_cb(skb)->da.hwaddr;
 833
 834         pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
 835
 836         /* another if the CID flag is set */
 837         if (iphc1 & LOWPAN_IPHC_CID) {
 838                 pr_debug("CID flag is set, increase header with one\n");
 839                 if (lowpan_fetch_skb_u8(skb, &num_context))
 840                         goto drop;
 841         }
 842
 843         hdr.version = 6;
 844
 845         /* Traffic Class and Flow Label */
 846         switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 847         /*
 848          * Traffic Class and FLow Label carried in-line
 849          * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
 850          */
 851         case 0: /* 00b */
 852                 if (lowpan_fetch_skb_u8(skb, &tmp))
 853                         goto drop;
 854
 855                 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
 856                 skb_pull(skb, 3);
 857                 hdr.priority = ((tmp >> 2) & 0x0f);
 858                 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
 859                                         (hdr.flow_lbl[0] & 0x0f);
 860                 break;
 861         /*
 862          * Traffic class carried in-line
 863          * ECN + DSCP (1 byte), Flow Label is elided
 864          */
 865         case 1: /* 10b */
 866                 if (lowpan_fetch_skb_u8(skb, &tmp))
 867                         goto drop;
 868
 869                 hdr.priority = ((tmp >> 2) & 0x0f);
 870                 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
 871                 hdr.flow_lbl[1] = 0;
 872                 hdr.flow_lbl[2] = 0;
 873                 break;
 874         /*
 875          * Flow Label carried in-line
 876          * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
 877          */
 878         case 2: /* 01b */
 879                 if (lowpan_fetch_skb_u8(skb, &tmp))
 880                         goto drop;
 881
 882                 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
 883                 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
 884                 skb_pull(skb, 2);
 885                 break;
 886         /* Traffic Class and Flow Label are elided */
 887         case 3: /* 11b */
 888                 hdr.priority = 0;
 889                 hdr.flow_lbl[0] = 0;
 890                 hdr.flow_lbl[1] = 0;
 891                 hdr.flow_lbl[2] = 0;
 892                 break;
 893         default:
 894                 break;
 895         }
 896
 897         /* Next Header */
 898         if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 899                 /* Next header is carried inline */
 900                 if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
 901                         goto drop;
 902
 903                 pr_debug("NH flag is set, next header carried inline: %02x\n",
 904                          hdr.nexthdr);
 905         }
 906
 907         /* Hop Limit */
 908         if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
 909                 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
 910         else {
 911                 if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
 912                         goto drop;
 913         }
 914
 915         /* Extract SAM to the tmp variable */
 916         tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
 917
 918         /* Source address uncompression */
 919         pr_debug("source address stateless compression\n");
 920         err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
 921                                 lowpan_unc_llconf[tmp], skb->data);
 922         if (err)
 923                 goto drop;
 924
 925         /* Extract DAM to the tmp variable */
 926         tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
 927
 928         /* check for Multicast Compression */
 929         if (iphc1 & LOWPAN_IPHC_M) {
 930                 if (iphc1 & LOWPAN_IPHC_DAC) {
 931                         pr_debug("dest: context-based mcast compression\n");
 932                         /* TODO: implement this */
 933                 } else {
 934                         u8 prefix[] = {0xff, 0x02};
 935
 936                         pr_debug("dest: non context-based mcast compression\n");
 937                         if (0 < tmp && tmp < 3) {
 938                                 if (lowpan_fetch_skb_u8(skb, &prefix[1]))
 939                                         goto drop;
 940                         }
 941
 942                         err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
 943                                         lowpan_unc_mxconf[tmp], NULL);
 944                         if (err)
 945                                 goto drop;
 946                 }
 947         } else {
 948                 pr_debug("dest: stateless compression\n");
 949                 err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
 950                                 lowpan_unc_llconf[tmp], skb->data);
 951                 if (err)
 952                         goto drop;
 953         }
 954
 955         /* UDP data uncompression */
 956         if (iphc0 & LOWPAN_IPHC_NH_C) {
 957                 struct udphdr uh;
 958                 struct sk_buff *new;
 959                 if (lowpan_uncompress_udp_header(skb, &uh))
 960                         goto drop;
 961
 962                 /*
 963                  * replace the compressed UDP head by the uncompressed UDP
 964                  * header
 965                  */
 966                 new = skb_copy_expand(skb, sizeof(struct udphdr),
 967                                       skb_tailroom(skb), GFP_ATOMIC);
 968                 kfree_skb(skb);
 969
 970                 if (!new)
 971                         return -ENOMEM;
 972
 973                 skb = new;
 974
 975                 skb_push(skb, sizeof(struct udphdr));
 976                 skb_reset_transport_header(skb);
 977                 skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
 978
 979                 lowpan_raw_dump_table(__func__, "raw UDP header dump",
 980                                       (u8 *)&uh, sizeof(uh));
 981
 982                 hdr.nexthdr = UIP_PROTO_UDP;
 983         }
 984
 985         /* Not fragmented package */
 986         hdr.payload_len = htons(skb->len);
 987
 988         pr_debug("skb headroom size = %d, data length = %d\n",
 989                  skb_headroom(skb), skb->len);
 990
 991         pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n\t"
 992                  "nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version,
 993                  ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
 994
 995         lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
 996                                                         sizeof(hdr));
 997         return lowpan_skb_deliver(skb, &hdr);
 998
 999 unlock_and_drop:
1000         spin_unlock_bh(&flist_lock);
1001 drop:
1002         kfree_skb(skb);
1003         return -EINVAL;
1004 }
1005
1006 static int lowpan_set_address(struct net_device *dev, void *p)
1007 {
1008         struct sockaddr *sa = p;
1009
1010         if (netif_running(dev))
1011                 return -EBUSY;
1012
1013         /* TODO: validate addr */
1014         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
1015
1016         return 0;
1017 }
1018
1019 static int lowpan_get_mac_header_length(struct sk_buff *skb)
1020 {
1021         /*
1022          * Currently long addressing mode is supported only, so the overall
1023          * header size is 21:
1024          * FC SeqNum DPAN DA  SA  Sec
1025          * 2  +  1  +  2 + 8 + 8 + 0  = 21
1026          */
1027         return 21;
1028 }
1029
1030 static int
1031 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
1032                         int mlen, int plen, int offset, int type)
1033 {
1034         struct sk_buff *frag;
1035         int hlen, ret;
1036
1037         hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
1038                         LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
1039
1040         lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
1041
1042         frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
1043         if (!frag)
1044                 return -ENOMEM;
1045
1046         frag->priority = skb->priority;
1047         frag->dev = skb->dev;
1048
1049         /* copy header, MFR and payload */
1050         memcpy(skb_put(frag, mlen), skb->data, mlen);
1051         memcpy(skb_put(frag, hlen), head, hlen);
1052
1053         if (plen)
1054                 skb_copy_from_linear_data_offset(skb, offset + mlen,
1055                                         skb_put(frag, plen), plen);
1056
1057         lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
1058                                                                 frag->len);
1059
1060         ret = dev_queue_xmit(frag);
1061
1062         return ret;
1063 }
1064
1065 static int
1066 lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
1067 {
1068         int  err, header_length, payload_length, tag, offset = 0;
1069         u8 head[5];
1070
1071         header_length = lowpan_get_mac_header_length(skb);
1072         payload_length = skb->len - header_length;
1073         tag = lowpan_dev_info(dev)->fragment_tag++;
1074
1075         /* first fragment header */
1076         head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
1077         head[1] = payload_length & 0xff;
1078         head[2] = tag >> 8;
1079         head[3] = tag & 0xff;
1080
1081         err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
1082                                    0, LOWPAN_DISPATCH_FRAG1);
1083
1084         if (err) {
1085                 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
1086                          __func__, tag);
1087                 goto exit;
1088         }
1089
1090         offset = LOWPAN_FRAG_SIZE;
1091
1092         /* next fragment header */
1093         head[0] &= ~LOWPAN_DISPATCH_FRAG1;
1094         head[0] |= LOWPAN_DISPATCH_FRAGN;
1095
1096         while ((payload_length - offset > 0) && (err >= 0)) {
1097                 int len = LOWPAN_FRAG_SIZE;
1098
1099                 head[4] = offset / 8;
1100
1101                 if (payload_length - offset < len)
1102                         len = payload_length - offset;
1103
1104                 err = lowpan_fragment_xmit(skb, head, header_length,
1105                                            len, offset, LOWPAN_DISPATCH_FRAGN);
1106                 if (err) {
1107                         pr_debug("%s unable to send a subsequent FRAGN packet "
1108                                  "(tag: %d, offset: %d", __func__, tag, offset);
1109                         goto exit;
1110                 }
1111
1112                 offset += len;
1113         }
1114
1115 exit:
1116         return err;
1117 }
1118
1119 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
1120 {
1121         int err = -1;
1122
1123         pr_debug("package xmit\n");
1124
1125         skb->dev = lowpan_dev_info(dev)->real_dev;
1126         if (skb->dev == NULL) {
1127                 pr_debug("ERROR: no real wpan device found\n");
1128                 goto error;
1129         }
1130
1131         /* Send directly if less than the MTU minus the 2 checksum bytes. */
1132         if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
1133                 err = dev_queue_xmit(skb);
1134                 goto out;
1135         }
1136
1137         pr_debug("frame is too big, fragmentation is needed\n");
1138         err = lowpan_skb_fragmentation(skb, dev);
1139 error:
1140         dev_kfree_skb(skb);
1141 out:
1142         if (err)
1143                 pr_debug("ERROR: xmit failed\n");
1144
1145         return (err < 0) ? NET_XMIT_DROP : err;
1146 }
1147
1148 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
1149 {
1150         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1151         return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
1152 }
1153
1154 static u16 lowpan_get_pan_id(const struct net_device *dev)
1155 {
1156         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1157         return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
1158 }
1159
1160 static u16 lowpan_get_short_addr(const struct net_device *dev)
1161 {
1162         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1163         return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
1164 }
1165
1166 static u8 lowpan_get_dsn(const struct net_device *dev)
1167 {
1168         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1169         return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
1170 }
1171
1172 static struct header_ops lowpan_header_ops = {
1173         .create = lowpan_header_create,
1174 };
1175
1176 static const struct net_device_ops lowpan_netdev_ops = {
1177         .ndo_start_xmit         = lowpan_xmit,
1178         .ndo_set_mac_address    = lowpan_set_address,
1179 };
1180
1181 static struct ieee802154_mlme_ops lowpan_mlme = {
1182         .get_pan_id = lowpan_get_pan_id,
1183         .get_phy = lowpan_get_phy,
1184         .get_short_addr = lowpan_get_short_addr,
1185         .get_dsn = lowpan_get_dsn,
1186 };
1187
1188 static void lowpan_setup(struct net_device *dev)
1189 {
1190         dev->addr_len           = IEEE802154_ADDR_LEN;
1191         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
1192         dev->type               = ARPHRD_IEEE802154;
1193         /* Frame Control + Sequence Number + Address fields + Security Header */
1194         dev->hard_header_len    = 2 + 1 + 20 + 14;
1195         dev->needed_tailroom    = 2; /* FCS */
1196         dev->mtu                = 1281;
1197         dev->tx_queue_len       = 0;
1198         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
1199         dev->watchdog_timeo     = 0;
1200
1201         dev->netdev_ops         = &lowpan_netdev_ops;
1202         dev->header_ops         = &lowpan_header_ops;
1203         dev->ml_priv            = &lowpan_mlme;
1204         dev->destructor         = free_netdev;
1205 }
1206
1207 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
1208 {
1209         if (tb[IFLA_ADDRESS]) {
1210                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
1211                         return -EINVAL;
1212         }
1213         return 0;
1214 }
1215
1216 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
1217         struct packet_type *pt, struct net_device *orig_dev)
1218 {
1219         struct sk_buff *local_skb;
1220
1221         if (!netif_running(dev))
1222                 goto drop;
1223
1224         if (dev->type != ARPHRD_IEEE802154)
1225                 goto drop;
1226
1227         /* check that it's our buffer */
1228         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
1229                 /* Copy the packet so that the IPv6 header is
1230                  * properly aligned.
1231                  */
1232                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
1233                                             skb_tailroom(skb), GFP_ATOMIC);
1234                 if (!local_skb)
1235                         goto drop;
1236
1237                 local_skb->protocol = htons(ETH_P_IPV6);
1238                 local_skb->pkt_type = PACKET_HOST;
1239
1240                 /* Pull off the 1-byte of 6lowpan header. */
1241                 skb_pull(local_skb, 1);
1242                 skb_reset_network_header(local_skb);
1243                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
1244
1245                 lowpan_give_skb_to_devices(local_skb);
1246
1247                 kfree_skb(local_skb);
1248                 kfree_skb(skb);
1249         } else {
1250                 switch (skb->data[0] & 0xe0) {
1251                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
1252                 case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
1253                 case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
1254                         local_skb = skb_clone(skb, GFP_ATOMIC);
1255                         if (!local_skb)
1256                                 goto drop;
1257                         lowpan_process_data(local_skb);
1258
1259                         kfree_skb(skb);
1260                         break;
1261                 default:
1262                         break;
1263                 }
1264         }
1265
1266         return NET_RX_SUCCESS;
1267
1268 drop:
1269         kfree_skb(skb);
1270         return NET_RX_DROP;
1271 }
1272
1273 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
1274                           struct nlattr *tb[], struct nlattr *data[])
1275 {
1276         struct net_device *real_dev;
1277         struct lowpan_dev_record *entry;
1278
1279         pr_debug("adding new link\n");
1280
1281         if (!tb[IFLA_LINK])
1282                 return -EINVAL;
1283         /* find and hold real wpan device */
1284         real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
1285         if (!real_dev)
1286                 return -ENODEV;
1287
1288         lowpan_dev_info(dev)->real_dev = real_dev;
1289         lowpan_dev_info(dev)->fragment_tag = 0;
1290         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
1291
1292         entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
1293         if (!entry) {
1294                 dev_put(real_dev);
1295                 lowpan_dev_info(dev)->real_dev = NULL;
1296                 return -ENOMEM;
1297         }
1298
1299         entry->ldev = dev;
1300
1301         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1302         INIT_LIST_HEAD(&entry->list);
1303         list_add_tail(&entry->list, &lowpan_devices);
1304         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1305
1306         register_netdevice(dev);
1307
1308         return 0;
1309 }
1310
1311 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
1312 {
1313         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
1314         struct net_device *real_dev = lowpan_dev->real_dev;
1315         struct lowpan_dev_record *entry, *tmp;
1316
1317         ASSERT_RTNL();
1318
1319         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1320         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1321                 if (entry->ldev == dev) {
1322                         list_del(&entry->list);
1323                         kfree(entry);
1324                 }
1325         }
1326         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1327
1328         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
1329
1330         unregister_netdevice_queue(dev, head);
1331
1332         dev_put(real_dev);
1333 }
1334
1335 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
1336         .kind           = "lowpan",
1337         .priv_size      = sizeof(struct lowpan_dev_info),
1338         .setup          = lowpan_setup,
1339         .newlink        = lowpan_newlink,
1340         .dellink        = lowpan_dellink,
1341         .validate       = lowpan_validate,
1342 };
1343
1344 static inline int __init lowpan_netlink_init(void)
1345 {
1346         return rtnl_link_register(&lowpan_link_ops);
1347 }
1348
1349 static inline void lowpan_netlink_fini(void)
1350 {
1351         rtnl_link_unregister(&lowpan_link_ops);
1352 }
1353
1354 static int lowpan_device_event(struct notifier_block *unused,
1355                                unsigned long event, void *ptr)
1356 {
1357         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1358         LIST_HEAD(del_list);
1359         struct lowpan_dev_record *entry, *tmp;
1360
1361         if (dev->type != ARPHRD_IEEE802154)
1362                 goto out;
1363
1364         if (event == NETDEV_UNREGISTER) {
1365                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1366                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
1367                                 lowpan_dellink(entry->ldev, &del_list);
1368                 }
1369
1370                 unregister_netdevice_many(&del_list);
1371         }
1372
1373 out:
1374         return NOTIFY_DONE;
1375 }
1376
1377 static struct notifier_block lowpan_dev_notifier = {
1378         .notifier_call = lowpan_device_event,
1379 };
1380
1381 static struct packet_type lowpan_packet_type = {
1382         .type = __constant_htons(ETH_P_IEEE802154),
1383         .func = lowpan_rcv,
1384 };
1385
1386 static int __init lowpan_init_module(void)
1387 {
1388         int err = 0;
1389
1390         err = lowpan_netlink_init();
1391         if (err < 0)
1392                 goto out;
1393
1394         dev_add_pack(&lowpan_packet_type);
1395
1396         err = register_netdevice_notifier(&lowpan_dev_notifier);
1397         if (err < 0) {
1398                 dev_remove_pack(&lowpan_packet_type);
1399                 lowpan_netlink_fini();
1400         }
1401 out:
1402         return err;
1403 }
1404
1405 static void __exit lowpan_cleanup_module(void)
1406 {
1407         struct lowpan_fragment *frame, *tframe;
1408
1409         lowpan_netlink_fini();
1410
1411         dev_remove_pack(&lowpan_packet_type);
1412
1413         unregister_netdevice_notifier(&lowpan_dev_notifier);
1414
1415         /* Now 6lowpan packet_type is removed, so no new fragments are
1416          * expected on RX, therefore that's the time to clean incomplete
1417          * fragments.
1418          */
1419         spin_lock_bh(&flist_lock);
1420         list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
1421                 del_timer_sync(&frame->timer);
1422                 list_del(&frame->list);
1423                 dev_kfree_skb(frame->skb);
1424                 kfree(frame);
1425         }
1426         spin_unlock_bh(&flist_lock);
1427 }
1428
1429 module_init(lowpan_init_module);
1430 module_exit(lowpan_cleanup_module);
1431 MODULE_LICENSE("GPL");
1432 MODULE_ALIAS_RTNL_LINK("lowpan");