Pileus Git - ~andy/linux/blob - 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 (postcount > 0) {
 227                 memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
 228                 skb_pull(skb, postcount);
 229         } else if (prefcount > 0) {
 230                 if (lladdr == NULL)
 231                         return -EINVAL;
 232
 233                 /* no IID based configuration if no prefix and no data */
 234                 lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
 235         }
 236
 237         pr_debug("uncompressing %d + %d => ", prefcount, postcount);
 238         lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
 239
 240         return 0;
 241 }
 242
 243 static void
 244 lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
 245 {
 246         struct udphdr *uh = udp_hdr(skb);
 247
 248         if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
 249                                 LOWPAN_NHC_UDP_4BIT_PORT) &&
 250             ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
 251                                 LOWPAN_NHC_UDP_4BIT_PORT)) {
 252                 pr_debug("UDP header: both ports compression to 4 bits\n");
 253                 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
 254                 **(hc06_ptr + 1) = /* subtraction is faster */
 255                    (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
 256                        ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
 257                 *hc06_ptr += 2;
 258         } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
 259                         LOWPAN_NHC_UDP_8BIT_PORT) {
 260                 pr_debug("UDP header: remove 8 bits of dest\n");
 261                 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
 262                 memcpy(*hc06_ptr + 1, &uh->source, 2);
 263                 **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
 264                 *hc06_ptr += 4;
 265         } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
 266                         LOWPAN_NHC_UDP_8BIT_PORT) {
 267                 pr_debug("UDP header: remove 8 bits of source\n");
 268                 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
 269                 memcpy(*hc06_ptr + 1, &uh->dest, 2);
 270                 **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
 271                 *hc06_ptr += 4;
 272         } else {
 273                 pr_debug("UDP header: can't compress\n");
 274                 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
 275                 memcpy(*hc06_ptr + 1, &uh->source, 2);
 276                 memcpy(*hc06_ptr + 3, &uh->dest, 2);
 277                 *hc06_ptr += 5;
 278         }
 279
 280         /* checksum is always inline */
 281         memcpy(*hc06_ptr, &uh->check, 2);
 282         *hc06_ptr += 2;
 283
 284         /* skip the UDP header */
 285         skb_pull(skb, sizeof(struct udphdr));
 286 }
 287
 288 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 289 {
 290         if (unlikely(!pskb_may_pull(skb, 1)))
 291                 return -EINVAL;
 292
 293         *val = skb->data[0];
 294         skb_pull(skb, 1);
 295
 296         return 0;
 297 }
 298
 299 static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 300 {
 301         if (unlikely(!pskb_may_pull(skb, 2)))
 302                 return -EINVAL;
 303
 304         *val = (skb->data[0] << 8) | skb->data[1];
 305         skb_pull(skb, 2);
 306
 307         return 0;
 308 }
 309
 310 static int
 311 lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
 312 {
 313         u8 tmp;
 314
 315         if (!uh)
 316                 goto err;
 317
 318         if (lowpan_fetch_skb_u8(skb, &tmp))
 319                 goto err;
 320
 321         if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 322                 pr_debug("UDP header uncompression\n");
 323                 switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
 324                 case LOWPAN_NHC_UDP_CS_P_00:
 325                         memcpy(&uh->source, &skb->data[0], 2);
 326                         memcpy(&uh->dest, &skb->data[2], 2);
 327                         skb_pull(skb, 4);
 328                         break;
 329                 case LOWPAN_NHC_UDP_CS_P_01:
 330                         memcpy(&uh->source, &skb->data[0], 2);
 331                         uh->dest =
 332                            skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
 333                         skb_pull(skb, 3);
 334                         break;
 335                 case LOWPAN_NHC_UDP_CS_P_10:
 336                         uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
 337                         memcpy(&uh->dest, &skb->data[1], 2);
 338                         skb_pull(skb, 3);
 339                         break;
 340                 case LOWPAN_NHC_UDP_CS_P_11:
 341                         uh->source =
 342                            LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
 343                         uh->dest =
 344                            LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
 345                         skb_pull(skb, 1);
 346                         break;
 347                 default:
 348                         pr_debug("ERROR: unknown UDP format\n");
 349                         goto err;
 350                         break;
 351                 }
 352
 353                 pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
 354                          uh->source, uh->dest);
 355
 356                 /* copy checksum */
 357                 memcpy(&uh->check, &skb->data[0], 2);
 358                 skb_pull(skb, 2);
 359
 360                 /*
 361                  * UDP lenght needs to be infered from the lower layers
 362                  * here, we obtain the hint from the remaining size of the
 363                  * frame
 364                  */
 365                 uh->len = htons(skb->len + sizeof(struct udphdr));
 366                 pr_debug("uncompressed UDP length: src = %d", uh->len);
 367         } else {
 368                 pr_debug("ERROR: unsupported NH format\n");
 369                 goto err;
 370         }
 371
 372         return 0;
 373 err:
 374         return -EINVAL;
 375 }
 376
 377 static int lowpan_header_create(struct sk_buff *skb,
 378                            struct net_device *dev,
 379                            unsigned short type, const void *_daddr,
 380                            const void *_saddr, unsigned int len)
 381 {
 382         u8 tmp, iphc0, iphc1, *hc06_ptr;
 383         struct ipv6hdr *hdr;
 384         const u8 *saddr = _saddr;
 385         const u8 *daddr = _daddr;
 386         u8 head[100];
 387         struct ieee802154_addr sa, da;
 388
 389         /* TODO:
 390          * if this package isn't ipv6 one, where should it be routed?
 391          */
 392         if (type != ETH_P_IPV6)
 393                 return 0;
 394
 395         hdr = ipv6_hdr(skb);
 396         hc06_ptr = head + 2;
 397
 398         pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n"
 399                  "\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version,
 400                  ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit);
 401
 402         lowpan_raw_dump_table(__func__, "raw skb network header dump",
 403                 skb_network_header(skb), sizeof(struct ipv6hdr));
 404
 405         if (!saddr)
 406                 saddr = dev->dev_addr;
 407
 408         lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
 409
 410         /*
 411          * As we copy some bit-length fields, in the IPHC encoding bytes,
 412          * we sometimes use |=
 413          * If the field is 0, and the current bit value in memory is 1,
 414          * this does not work. We therefore reset the IPHC encoding here
 415          */
 416         iphc0 = LOWPAN_DISPATCH_IPHC;
 417         iphc1 = 0;
 418
 419         /* TODO: context lookup */
 420
 421         lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 422
 423         /*
 424          * Traffic class, flow label
 425          * If flow label is 0, compress it. If traffic class is 0, compress it
 426          * We have to process both in the same time as the offset of traffic
 427          * class depends on the presence of version and flow label
 428          */
 429
 430         /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
 431         tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
 432         tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
 433
 434         if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
 435              (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
 436                 /* flow label can be compressed */
 437                 iphc0 |= LOWPAN_IPHC_FL_C;
 438                 if ((hdr->priority == 0) &&
 439                    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 440                         /* compress (elide) all */
 441                         iphc0 |= LOWPAN_IPHC_TC_C;
 442                 } else {
 443                         /* compress only the flow label */
 444                         *hc06_ptr = tmp;
 445                         hc06_ptr += 1;
 446                 }
 447         } else {
 448                 /* Flow label cannot be compressed */
 449                 if ((hdr->priority == 0) &&
 450                    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
 451                         /* compress only traffic class */
 452                         iphc0 |= LOWPAN_IPHC_TC_C;
 453                         *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
 454                         memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
 455                         hc06_ptr += 3;
 456                 } else {
 457                         /* compress nothing */
 458                         memcpy(hc06_ptr, &hdr, 4);
 459                         /* replace the top byte with new ECN | DSCP format */
 460                         *hc06_ptr = tmp;
 461                         hc06_ptr += 4;
 462                 }
 463         }
 464
 465         /* NOTE: payload length is always compressed */
 466
 467         /* Next Header is compress if UDP */
 468         if (hdr->nexthdr == UIP_PROTO_UDP)
 469                 iphc0 |= LOWPAN_IPHC_NH_C;
 470
 471         if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 472                 *hc06_ptr = hdr->nexthdr;
 473                 hc06_ptr += 1;
 474         }
 475
 476         /*
 477          * Hop limit
 478          * if 1:   compress, encoding is 01
 479          * if 64:  compress, encoding is 10
 480          * if 255: compress, encoding is 11
 481          * else do not compress
 482          */
 483         switch (hdr->hop_limit) {
 484         case 1:
 485                 iphc0 |= LOWPAN_IPHC_TTL_1;
 486                 break;
 487         case 64:
 488                 iphc0 |= LOWPAN_IPHC_TTL_64;
 489                 break;
 490         case 255:
 491                 iphc0 |= LOWPAN_IPHC_TTL_255;
 492                 break;
 493         default:
 494                 *hc06_ptr = hdr->hop_limit;
 495                 hc06_ptr += 1;
 496                 break;
 497         }
 498
 499         /* source address compression */
 500         if (is_addr_unspecified(&hdr->saddr)) {
 501                 pr_debug("source address is unspecified, setting SAC\n");
 502                 iphc1 |= LOWPAN_IPHC_SAC;
 503         /* TODO: context lookup */
 504         } else if (is_addr_link_local(&hdr->saddr)) {
 505                 pr_debug("source address is link-local\n");
 506                 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 507                                 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
 508         } else {
 509                 pr_debug("send the full source address\n");
 510                 memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
 511                 hc06_ptr += 16;
 512         }
 513
 514         /* destination address compression */
 515         if (is_addr_mcast(&hdr->daddr)) {
 516                 pr_debug("destination address is multicast: ");
 517                 iphc1 |= LOWPAN_IPHC_M;
 518                 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
 519                         pr_debug("compressed to 1 octet\n");
 520                         iphc1 |= LOWPAN_IPHC_DAM_11;
 521                         /* use last byte */
 522                         *hc06_ptr = hdr->daddr.s6_addr[15];
 523                         hc06_ptr += 1;
 524                 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
 525                         pr_debug("compressed to 4 octets\n");
 526                         iphc1 |= LOWPAN_IPHC_DAM_10;
 527                         /* second byte + the last three */
 528                         *hc06_ptr = hdr->daddr.s6_addr[1];
 529                         memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
 530                         hc06_ptr += 4;
 531                 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
 532                         pr_debug("compressed to 6 octets\n");
 533                         iphc1 |= LOWPAN_IPHC_DAM_01;
 534                         /* second byte + the last five */
 535                         *hc06_ptr = hdr->daddr.s6_addr[1];
 536                         memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
 537                         hc06_ptr += 6;
 538                 } else {
 539                         pr_debug("using full address\n");
 540                         iphc1 |= LOWPAN_IPHC_DAM_00;
 541                         memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
 542                         hc06_ptr += 16;
 543                 }
 544         } else {
 545                 /* TODO: context lookup */
 546                 if (is_addr_link_local(&hdr->daddr)) {
 547                         pr_debug("dest address is unicast and link-local\n");
 548                         iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
 549                                 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
 550                 } else {
 551                         pr_debug("dest address is unicast: using full one\n");
 552                         memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
 553                         hc06_ptr += 16;
 554                 }
 555         }
 556
 557         /* UDP header compression */
 558         if (hdr->nexthdr == UIP_PROTO_UDP)
 559                 lowpan_compress_udp_header(&hc06_ptr, skb);
 560
 561         head[0] = iphc0;
 562         head[1] = iphc1;
 563
 564         skb_pull(skb, sizeof(struct ipv6hdr));
 565         memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
 566
 567         lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 568                                 skb->len);
 569
 570         /*
 571          * NOTE1: I'm still unsure about the fact that compression and WPAN
 572          * header are created here and not later in the xmit. So wait for
 573          * an opinion of net maintainers.
 574          */
 575         /*
 576          * NOTE2: to be absolutely correct, we must derive PANid information
 577          * from MAC subif of the 'dev' and 'real_dev' network devices, but
 578          * this isn't implemented in mainline yet, so currently we assign 0xff
 579          */
 580         {
 581                 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
 582                 mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
 583
 584                 /* prepare wpan address data */
 585                 sa.addr_type = IEEE802154_ADDR_LONG;
 586                 sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 587
 588                 memcpy(&(sa.hwaddr), saddr, 8);
 589                 /* intra-PAN communications */
 590                 da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 591
 592                 /*
 593                  * if the destination address is the broadcast address, use the
 594                  * corresponding short address
 595                  */
 596                 if (lowpan_is_addr_broadcast(daddr)) {
 597                         da.addr_type = IEEE802154_ADDR_SHORT;
 598                         da.short_addr = IEEE802154_ADDR_BROADCAST;
 599                 } else {
 600                         da.addr_type = IEEE802154_ADDR_LONG;
 601                         memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
 602
 603                         /* request acknowledgment */
 604                         mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
 605                 }
 606
 607                 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 608                                 type, (void *)&da, (void *)&sa, skb->len);
 609         }
 610 }
 611
 612 static int lowpan_give_skb_to_devices(struct sk_buff *skb)
 613 {
 614         struct lowpan_dev_record *entry;
 615         struct sk_buff *skb_cp;
 616         int stat = NET_RX_SUCCESS;
 617
 618         rcu_read_lock();
 619         list_for_each_entry_rcu(entry, &lowpan_devices, list)
 620                 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
 621                         skb_cp = skb_copy(skb, GFP_ATOMIC);
 622                         if (!skb_cp) {
 623                                 stat = -ENOMEM;
 624                                 break;
 625                         }
 626
 627                         skb_cp->dev = entry->ldev;
 628                         stat = netif_rx(skb_cp);
 629                 }
 630         rcu_read_unlock();
 631
 632         return stat;
 633 }
 634
 635 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 636 {
 637         struct sk_buff *new;
 638         int stat = NET_RX_SUCCESS;
 639
 640         new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
 641                                                                 GFP_ATOMIC);
 642         kfree_skb(skb);
 643
 644         if (!new)
 645                 return -ENOMEM;
 646
 647         skb_push(new, sizeof(struct ipv6hdr));
 648         skb_reset_network_header(new);
 649         skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
 650
 651         new->protocol = htons(ETH_P_IPV6);
 652         new->pkt_type = PACKET_HOST;
 653
 654         stat = lowpan_give_skb_to_devices(new);
 655
 656         kfree_skb(new);
 657
 658         return stat;
 659 }
 660
 661 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 662 {
 663         struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
 664
 665         pr_debug("timer expired for frame with tag %d\n", entry->tag);
 666
 667         list_del(&entry->list);
 668         dev_kfree_skb(entry->skb);
 669         kfree(entry);
 670 }
 671
 672 static struct lowpan_fragment *
 673 lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
 674 {
 675         struct lowpan_fragment *frame;
 676
 677         frame = kzalloc(sizeof(struct lowpan_fragment),
 678                         GFP_ATOMIC);
 679         if (!frame)
 680                 goto frame_err;
 681
 682         INIT_LIST_HEAD(&frame->list);
 683
 684         frame->length = len;
 685         frame->tag = tag;
 686
 687         /* allocate buffer for frame assembling */
 688         frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
 689                                                sizeof(struct ipv6hdr));
 690
 691         if (!frame->skb)
 692                 goto skb_err;
 693
 694         frame->skb->priority = skb->priority;
 695         frame->skb->dev = skb->dev;
 696
 697         /* reserve headroom for uncompressed ipv6 header */
 698         skb_reserve(frame->skb, sizeof(struct ipv6hdr));
 699         skb_put(frame->skb, frame->length);
 700
 701         init_timer(&frame->timer);
 702         /* time out is the same as for ipv6 - 60 sec */
 703         frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
 704         frame->timer.data = (unsigned long)frame;
 705         frame->timer.function = lowpan_fragment_timer_expired;
 706
 707         add_timer(&frame->timer);
 708
 709         list_add_tail(&frame->list, &lowpan_fragments);
 710
 711         return frame;
 712
 713 skb_err:
 714         kfree(frame);
 715 frame_err:
 716         return NULL;
 717 }
 718
 719 static int
 720 lowpan_process_data(struct sk_buff *skb)
 721 {
 722         struct ipv6hdr hdr = {};
 723         u8 tmp, iphc0, iphc1, num_context = 0;
 724         u8 *_saddr, *_daddr;
 725         int err;
 726
 727         lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
 728                                 skb->len);
 729         /* at least two bytes will be used for the encoding */
 730         if (skb->len < 2)
 731                 goto drop;
 732
 733         if (lowpan_fetch_skb_u8(skb, &iphc0))
 734                 goto drop;
 735
 736         /* fragments assembling */
 737         switch (iphc0 & LOWPAN_DISPATCH_MASK) {
 738         case LOWPAN_DISPATCH_FRAG1:
 739         case LOWPAN_DISPATCH_FRAGN:
 740         {
 741                 struct lowpan_fragment *frame;
 742                 /* slen stores the rightmost 8 bits of the 11 bits length */
 743                 u8 slen, offset = 0;
 744                 u16 len, tag;
 745                 bool found = false;
 746
 747                 if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
 748                     lowpan_fetch_skb_u16(skb, &tag))  /* fragment tag */
 749                         goto drop;
 750
 751                 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 752                 len = ((iphc0 & 7) << 8) | slen;
 753
 754                 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
 755                         pr_debug("%s received a FRAG1 packet (tag: %d, "
 756                                  "size of the entire IP packet: %d)",
 757                                  __func__, tag, len);
 758                 } else { /* FRAGN */
 759                         if (lowpan_fetch_skb_u8(skb, &offset))
 760                                 goto unlock_and_drop;
 761                         pr_debug("%s received a FRAGN packet (tag: %d, "
 762                                  "size of the entire IP packet: %d, "
 763                                  "offset: %d)", __func__, tag, len, offset * 8);
 764                 }
 765
 766                 /*
 767                  * check if frame assembling with the same tag is
 768                  * already in progress
 769                  */
 770                 spin_lock_bh(&flist_lock);
 771
 772                 list_for_each_entry(frame, &lowpan_fragments, list)
 773                         if (frame->tag == tag) {
 774                                 found = true;
 775                                 break;
 776                         }
 777
 778                 /* alloc new frame structure */
 779                 if (!found) {
 780                         pr_debug("%s first fragment received for tag %d, "
 781                                  "begin packet reassembly", __func__, tag);
 782                         frame = lowpan_alloc_new_frame(skb, len, tag);
 783                         if (!frame)
 784                                 goto unlock_and_drop;
 785                 }
 786
 787                 /* if payload fits buffer, copy it */
 788                 if (likely((offset * 8 + skb->len) <= frame->length))
 789                         skb_copy_to_linear_data_offset(frame->skb, offset * 8,
 790                                                         skb->data, skb->len);
 791                 else
 792                         goto unlock_and_drop;
 793
 794                 frame->bytes_rcv += skb->len;
 795
 796                 /* frame assembling complete */
 797                 if ((frame->bytes_rcv == frame->length) &&
 798                      frame->timer.expires > jiffies) {
 799                         /* if timer haven't expired - first of all delete it */
 800                         del_timer_sync(&frame->timer);
 801                         list_del(&frame->list);
 802                         spin_unlock_bh(&flist_lock);
 803
 804                         pr_debug("%s successfully reassembled fragment "
 805                                  "(tag %d)", __func__, tag);
 806
 807                         dev_kfree_skb(skb);
 808                         skb = frame->skb;
 809                         kfree(frame);
 810
 811                         if (lowpan_fetch_skb_u8(skb, &iphc0))
 812                                 goto drop;
 813
 814                         break;
 815                 }
 816                 spin_unlock_bh(&flist_lock);
 817
 818                 return kfree_skb(skb), 0;
 819         }
 820         default:
 821                 break;
 822         }
 823
 824         if (lowpan_fetch_skb_u8(skb, &iphc1))
 825                 goto drop;
 826
 827         _saddr = mac_cb(skb)->sa.hwaddr;
 828         _daddr = mac_cb(skb)->da.hwaddr;
 829
 830         pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
 831
 832         /* another if the CID flag is set */
 833         if (iphc1 & LOWPAN_IPHC_CID) {
 834                 pr_debug("CID flag is set, increase header with one\n");
 835                 if (lowpan_fetch_skb_u8(skb, &num_context))
 836                         goto drop;
 837         }
 838
 839         hdr.version = 6;
 840
 841         /* Traffic Class and Flow Label */
 842         switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 843         /*
 844          * Traffic Class and FLow Label carried in-line
 845          * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
 846          */
 847         case 0: /* 00b */
 848                 if (lowpan_fetch_skb_u8(skb, &tmp))
 849                         goto drop;
 850
 851                 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
 852                 skb_pull(skb, 3);
 853                 hdr.priority = ((tmp >> 2) & 0x0f);
 854                 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
 855                                         (hdr.flow_lbl[0] & 0x0f);
 856                 break;
 857         /*
 858          * Traffic class carried in-line
 859          * ECN + DSCP (1 byte), Flow Label is elided
 860          */
 861         case 1: /* 10b */
 862                 if (lowpan_fetch_skb_u8(skb, &tmp))
 863                         goto drop;
 864
 865                 hdr.priority = ((tmp >> 2) & 0x0f);
 866                 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
 867                 break;
 868         /*
 869          * Flow Label carried in-line
 870          * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
 871          */
 872         case 2: /* 01b */
 873                 if (lowpan_fetch_skb_u8(skb, &tmp))
 874                         goto drop;
 875
 876                 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
 877                 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
 878                 skb_pull(skb, 2);
 879                 break;
 880         /* Traffic Class and Flow Label are elided */
 881         case 3: /* 11b */
 882                 break;
 883         default:
 884                 break;
 885         }
 886
 887         /* Next Header */
 888         if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
 889                 /* Next header is carried inline */
 890                 if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
 891                         goto drop;
 892
 893                 pr_debug("NH flag is set, next header carried inline: %02x\n",
 894                          hdr.nexthdr);
 895         }
 896
 897         /* Hop Limit */
 898         if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
 899                 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
 900         else {
 901                 if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
 902                         goto drop;
 903         }
 904
 905         /* Extract SAM to the tmp variable */
 906         tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
 907
 908         /* Source address uncompression */
 909         pr_debug("source address stateless compression\n");
 910         err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
 911                                 lowpan_unc_llconf[tmp], skb->data);
 912         if (err)
 913                 goto drop;
 914
 915         /* Extract DAM to the tmp variable */
 916         tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
 917
 918         /* check for Multicast Compression */
 919         if (iphc1 & LOWPAN_IPHC_M) {
 920                 if (iphc1 & LOWPAN_IPHC_DAC) {
 921                         pr_debug("dest: context-based mcast compression\n");
 922                         /* TODO: implement this */
 923                 } else {
 924                         u8 prefix[] = {0xff, 0x02};
 925
 926                         pr_debug("dest: non context-based mcast compression\n");
 927                         if (0 < tmp && tmp < 3) {
 928                                 if (lowpan_fetch_skb_u8(skb, &prefix[1]))
 929                                         goto drop;
 930                         }
 931
 932                         err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
 933                                         lowpan_unc_mxconf[tmp], NULL);
 934                         if (err)
 935                                 goto drop;
 936                 }
 937         } else {
 938                 pr_debug("dest: stateless compression\n");
 939                 err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
 940                                 lowpan_unc_llconf[tmp], skb->data);
 941                 if (err)
 942                         goto drop;
 943         }
 944
 945         /* UDP data uncompression */
 946         if (iphc0 & LOWPAN_IPHC_NH_C) {
 947                 struct udphdr uh;
 948                 struct sk_buff *new;
 949                 if (lowpan_uncompress_udp_header(skb, &uh))
 950                         goto drop;
 951
 952                 /*
 953                  * replace the compressed UDP head by the uncompressed UDP
 954                  * header
 955                  */
 956                 new = skb_copy_expand(skb, sizeof(struct udphdr),
 957                                       skb_tailroom(skb), GFP_ATOMIC);
 958                 kfree_skb(skb);
 959
 960                 if (!new)
 961                         return -ENOMEM;
 962
 963                 skb = new;
 964
 965                 skb_push(skb, sizeof(struct udphdr));
 966                 skb_reset_transport_header(skb);
 967                 skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
 968
 969                 lowpan_raw_dump_table(__func__, "raw UDP header dump",
 970                                       (u8 *)&uh, sizeof(uh));
 971
 972                 hdr.nexthdr = UIP_PROTO_UDP;
 973         }
 974
 975         /* Not fragmented package */
 976         hdr.payload_len = htons(skb->len);
 977
 978         pr_debug("skb headroom size = %d, data length = %d\n",
 979                  skb_headroom(skb), skb->len);
 980
 981         pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n\t"
 982                  "nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version,
 983                  ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
 984
 985         lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
 986                                                         sizeof(hdr));
 987         return lowpan_skb_deliver(skb, &hdr);
 988
 989 unlock_and_drop:
 990         spin_unlock_bh(&flist_lock);
 991 drop:
 992         kfree_skb(skb);
 993         return -EINVAL;
 994 }
 995
 996 static int lowpan_set_address(struct net_device *dev, void *p)
 997 {
 998         struct sockaddr *sa = p;
 999
1000         if (netif_running(dev))
1001                 return -EBUSY;
1002
1003         /* TODO: validate addr */
1004         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
1005
1006         return 0;
1007 }
1008
1009 static int lowpan_get_mac_header_length(struct sk_buff *skb)
1010 {
1011         /*
1012          * Currently long addressing mode is supported only, so the overall
1013          * header size is 21:
1014          * FC SeqNum DPAN DA  SA  Sec
1015          * 2  +  1  +  2 + 8 + 8 + 0  = 21
1016          */
1017         return 21;
1018 }
1019
1020 static int
1021 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
1022                         int mlen, int plen, int offset, int type)
1023 {
1024         struct sk_buff *frag;
1025         int hlen, ret;
1026
1027         hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
1028                         LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
1029
1030         lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
1031
1032         frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
1033         if (!frag)
1034                 return -ENOMEM;
1035
1036         frag->priority = skb->priority;
1037         frag->dev = skb->dev;
1038
1039         /* copy header, MFR and payload */
1040         memcpy(skb_put(frag, mlen), skb->data, mlen);
1041         memcpy(skb_put(frag, hlen), head, hlen);
1042
1043         if (plen)
1044                 skb_copy_from_linear_data_offset(skb, offset + mlen,
1045                                         skb_put(frag, plen), plen);
1046
1047         lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
1048                                                                 frag->len);
1049
1050         ret = dev_queue_xmit(frag);
1051
1052         return ret;
1053 }
1054
1055 static int
1056 lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
1057 {
1058         int  err, header_length, payload_length, tag, offset = 0;
1059         u8 head[5];
1060
1061         header_length = lowpan_get_mac_header_length(skb);
1062         payload_length = skb->len - header_length;
1063         tag = lowpan_dev_info(dev)->fragment_tag++;
1064
1065         /* first fragment header */
1066         head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
1067         head[1] = payload_length & 0xff;
1068         head[2] = tag >> 8;
1069         head[3] = tag & 0xff;
1070
1071         err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
1072                                    0, LOWPAN_DISPATCH_FRAG1);
1073
1074         if (err) {
1075                 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
1076                          __func__, tag);
1077                 goto exit;
1078         }
1079
1080         offset = LOWPAN_FRAG_SIZE;
1081
1082         /* next fragment header */
1083         head[0] &= ~LOWPAN_DISPATCH_FRAG1;
1084         head[0] |= LOWPAN_DISPATCH_FRAGN;
1085
1086         while ((payload_length - offset > 0) && (err >= 0)) {
1087                 int len = LOWPAN_FRAG_SIZE;
1088
1089                 head[4] = offset / 8;
1090
1091                 if (payload_length - offset < len)
1092                         len = payload_length - offset;
1093
1094                 err = lowpan_fragment_xmit(skb, head, header_length,
1095                                            len, offset, LOWPAN_DISPATCH_FRAGN);
1096                 if (err) {
1097                         pr_debug("%s unable to send a subsequent FRAGN packet "
1098                                  "(tag: %d, offset: %d", __func__, tag, offset);
1099                         goto exit;
1100                 }
1101
1102                 offset += len;
1103         }
1104
1105 exit:
1106         return err;
1107 }
1108
1109 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
1110 {
1111         int err = -1;
1112
1113         pr_debug("package xmit\n");
1114
1115         skb->dev = lowpan_dev_info(dev)->real_dev;
1116         if (skb->dev == NULL) {
1117                 pr_debug("ERROR: no real wpan device found\n");
1118                 goto error;
1119         }
1120
1121         /* Send directly if less than the MTU minus the 2 checksum bytes. */
1122         if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
1123                 err = dev_queue_xmit(skb);
1124                 goto out;
1125         }
1126
1127         pr_debug("frame is too big, fragmentation is needed\n");
1128         err = lowpan_skb_fragmentation(skb, dev);
1129 error:
1130         dev_kfree_skb(skb);
1131 out:
1132         if (err)
1133                 pr_debug("ERROR: xmit failed\n");
1134
1135         return (err < 0) ? NET_XMIT_DROP : err;
1136 }
1137
1138 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
1139 {
1140         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1141         return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
1142 }
1143
1144 static u16 lowpan_get_pan_id(const struct net_device *dev)
1145 {
1146         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1147         return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
1148 }
1149
1150 static u16 lowpan_get_short_addr(const struct net_device *dev)
1151 {
1152         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1153         return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
1154 }
1155
1156 static u8 lowpan_get_dsn(const struct net_device *dev)
1157 {
1158         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1159         return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
1160 }
1161
1162 static struct header_ops lowpan_header_ops = {
1163         .create = lowpan_header_create,
1164 };
1165
1166 static const struct net_device_ops lowpan_netdev_ops = {
1167         .ndo_start_xmit         = lowpan_xmit,
1168         .ndo_set_mac_address    = lowpan_set_address,
1169 };
1170
1171 static struct ieee802154_mlme_ops lowpan_mlme = {
1172         .get_pan_id = lowpan_get_pan_id,
1173         .get_phy = lowpan_get_phy,
1174         .get_short_addr = lowpan_get_short_addr,
1175         .get_dsn = lowpan_get_dsn,
1176 };
1177
1178 static void lowpan_setup(struct net_device *dev)
1179 {
1180         dev->addr_len           = IEEE802154_ADDR_LEN;
1181         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
1182         dev->type               = ARPHRD_IEEE802154;
1183         /* Frame Control + Sequence Number + Address fields + Security Header */
1184         dev->hard_header_len    = 2 + 1 + 20 + 14;
1185         dev->needed_tailroom    = 2; /* FCS */
1186         dev->mtu                = 1281;
1187         dev->tx_queue_len       = 0;
1188         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
1189         dev->watchdog_timeo     = 0;
1190
1191         dev->netdev_ops         = &lowpan_netdev_ops;
1192         dev->header_ops         = &lowpan_header_ops;
1193         dev->ml_priv            = &lowpan_mlme;
1194         dev->destructor         = free_netdev;
1195 }
1196
1197 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
1198 {
1199         if (tb[IFLA_ADDRESS]) {
1200                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
1201                         return -EINVAL;
1202         }
1203         return 0;
1204 }
1205
1206 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
1207         struct packet_type *pt, struct net_device *orig_dev)
1208 {
1209         struct sk_buff *local_skb;
1210
1211         if (!netif_running(dev))
1212                 goto drop;
1213
1214         if (dev->type != ARPHRD_IEEE802154)
1215                 goto drop;
1216
1217         /* check that it's our buffer */
1218         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
1219                 /* Copy the packet so that the IPv6 header is
1220                  * properly aligned.
1221                  */
1222                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
1223                                             skb_tailroom(skb), GFP_ATOMIC);
1224                 if (!local_skb)
1225                         goto drop;
1226
1227                 local_skb->protocol = htons(ETH_P_IPV6);
1228                 local_skb->pkt_type = PACKET_HOST;
1229
1230                 /* Pull off the 1-byte of 6lowpan header. */
1231                 skb_pull(local_skb, 1);
1232                 skb_reset_network_header(local_skb);
1233                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
1234
1235                 lowpan_give_skb_to_devices(local_skb);
1236
1237                 kfree_skb(local_skb);
1238                 kfree_skb(skb);
1239         } else {
1240                 switch (skb->data[0] & 0xe0) {
1241                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
1242                 case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
1243                 case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
1244                         local_skb = skb_clone(skb, GFP_ATOMIC);
1245                         if (!local_skb)
1246                                 goto drop;
1247                         lowpan_process_data(local_skb);
1248
1249                         kfree_skb(skb);
1250                         break;
1251                 default:
1252                         break;
1253                 }
1254         }
1255
1256         return NET_RX_SUCCESS;
1257
1258 drop:
1259         kfree_skb(skb);
1260         return NET_RX_DROP;
1261 }
1262
1263 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
1264                           struct nlattr *tb[], struct nlattr *data[])
1265 {
1266         struct net_device *real_dev;
1267         struct lowpan_dev_record *entry;
1268
1269         pr_debug("adding new link\n");
1270
1271         if (!tb[IFLA_LINK])
1272                 return -EINVAL;
1273         /* find and hold real wpan device */
1274         real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
1275         if (!real_dev)
1276                 return -ENODEV;
1277
1278         lowpan_dev_info(dev)->real_dev = real_dev;
1279         lowpan_dev_info(dev)->fragment_tag = 0;
1280         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
1281
1282         entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
1283         if (!entry) {
1284                 dev_put(real_dev);
1285                 lowpan_dev_info(dev)->real_dev = NULL;
1286                 return -ENOMEM;
1287         }
1288
1289         entry->ldev = dev;
1290
1291         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1292         INIT_LIST_HEAD(&entry->list);
1293         list_add_tail(&entry->list, &lowpan_devices);
1294         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1295
1296         register_netdevice(dev);
1297
1298         return 0;
1299 }
1300
1301 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
1302 {
1303         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
1304         struct net_device *real_dev = lowpan_dev->real_dev;
1305         struct lowpan_dev_record *entry, *tmp;
1306
1307         ASSERT_RTNL();
1308
1309         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1310         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1311                 if (entry->ldev == dev) {
1312                         list_del(&entry->list);
1313                         kfree(entry);
1314                 }
1315         }
1316         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1317
1318         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
1319
1320         unregister_netdevice_queue(dev, head);
1321
1322         dev_put(real_dev);
1323 }
1324
1325 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
1326         .kind           = "lowpan",
1327         .priv_size      = sizeof(struct lowpan_dev_info),
1328         .setup          = lowpan_setup,
1329         .newlink        = lowpan_newlink,
1330         .dellink        = lowpan_dellink,
1331         .validate       = lowpan_validate,
1332 };
1333
1334 static inline int __init lowpan_netlink_init(void)
1335 {
1336         return rtnl_link_register(&lowpan_link_ops);
1337 }
1338
1339 static inline void lowpan_netlink_fini(void)
1340 {
1341         rtnl_link_unregister(&lowpan_link_ops);
1342 }
1343
1344 static int lowpan_device_event(struct notifier_block *unused,
1345                                unsigned long event, void *ptr)
1346 {
1347         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1348         LIST_HEAD(del_list);
1349         struct lowpan_dev_record *entry, *tmp;
1350
1351         if (dev->type != ARPHRD_IEEE802154)
1352                 goto out;
1353
1354         if (event == NETDEV_UNREGISTER) {
1355                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1356                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
1357                                 lowpan_dellink(entry->ldev, &del_list);
1358                 }
1359
1360                 unregister_netdevice_many(&del_list);
1361         }
1362
1363 out:
1364         return NOTIFY_DONE;
1365 }
1366
1367 static struct notifier_block lowpan_dev_notifier = {
1368         .notifier_call = lowpan_device_event,
1369 };
1370
1371 static struct packet_type lowpan_packet_type = {
1372         .type = __constant_htons(ETH_P_IEEE802154),
1373         .func = lowpan_rcv,
1374 };
1375
1376 static int __init lowpan_init_module(void)
1377 {
1378         int err = 0;
1379
1380         err = lowpan_netlink_init();
1381         if (err < 0)
1382                 goto out;
1383
1384         dev_add_pack(&lowpan_packet_type);
1385
1386         err = register_netdevice_notifier(&lowpan_dev_notifier);
1387         if (err < 0) {
1388                 dev_remove_pack(&lowpan_packet_type);
1389                 lowpan_netlink_fini();
1390         }
1391 out:
1392         return err;
1393 }
1394
1395 static void __exit lowpan_cleanup_module(void)
1396 {
1397         struct lowpan_fragment *frame, *tframe;
1398
1399         lowpan_netlink_fini();
1400
1401         dev_remove_pack(&lowpan_packet_type);
1402
1403         unregister_netdevice_notifier(&lowpan_dev_notifier);
1404
1405         /* Now 6lowpan packet_type is removed, so no new fragments are
1406          * expected on RX, therefore that's the time to clean incomplete
1407          * fragments.
1408          */
1409         spin_lock_bh(&flist_lock);
1410         list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
1411                 del_timer_sync(&frame->timer);
1412                 list_del(&frame->list);
1413                 dev_kfree_skb(frame->skb);
1414                 kfree(frame);
1415         }
1416         spin_unlock_bh(&flist_lock);
1417 }
1418
1419 module_init(lowpan_init_module);
1420 module_exit(lowpan_cleanup_module);
1421 MODULE_LICENSE("GPL");
1422 MODULE_ALIAS_RTNL_LINK("lowpan");