LXR linux/include/net/6lowpan.h

   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#ifndef __6LOWPAN_H__
  54#define __6LOWPAN_H__
  55
  56#include <net/ipv6.h>
  57#include <net/net_namespace.h>
  58
  59#define UIP_802154_SHORTADDR_LEN        2  /* compressed ipv6 address length */
  60#define UIP_IPH_LEN                     40 /* ipv6 fixed header size */
  61#define UIP_PROTO_UDP                   17 /* ipv6 next header value for UDP */
  62#define UIP_FRAGH_LEN                   8  /* ipv6 fragment header size */
  63
  64/*
  65 * ipv6 address based on mac
  66 * second bit-flip (Universe/Local) is done according RFC2464
  67 */
  68#define is_addr_mac_addr_based(a, m) \
  69        ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
  70         (((a)->s6_addr[9])  == (m)[1]) &&              \
  71         (((a)->s6_addr[10]) == (m)[2]) &&              \
  72         (((a)->s6_addr[11]) == (m)[3]) &&              \
  73         (((a)->s6_addr[12]) == (m)[4]) &&              \
  74         (((a)->s6_addr[13]) == (m)[5]) &&              \
  75         (((a)->s6_addr[14]) == (m)[6]) &&              \
  76         (((a)->s6_addr[15]) == (m)[7]))
  77
  78/*
  79 * check whether we can compress the IID to 16 bits,
  80 * it's possible for unicast adresses with first 49 bits are zero only.
  81 */
  82#define lowpan_is_iid_16_bit_compressable(a)    \
  83        ((((a)->s6_addr16[4]) == 0) &&          \
  84         (((a)->s6_addr[10]) == 0) &&           \
  85         (((a)->s6_addr[11]) == 0xff) &&        \
  86         (((a)->s6_addr[12]) == 0xfe) &&        \
  87         (((a)->s6_addr[13]) == 0))
  88
  89/* check whether the 112-bit gid of the multicast address is mappable to: */
  90
  91/* 48 bits, FFXX::00XX:XXXX:XXXX */
  92#define lowpan_is_mcast_addr_compressable48(a)  \
  93        ((((a)->s6_addr16[1]) == 0) &&          \
  94         (((a)->s6_addr16[2]) == 0) &&          \
  95         (((a)->s6_addr16[3]) == 0) &&          \
  96         (((a)->s6_addr16[4]) == 0) &&          \
  97         (((a)->s6_addr[10]) == 0))
  98
  99/* 32 bits, FFXX::00XX:XXXX */
 100#define lowpan_is_mcast_addr_compressable32(a)  \
 101        ((((a)->s6_addr16[1]) == 0) &&          \
 102         (((a)->s6_addr16[2]) == 0) &&          \
 103         (((a)->s6_addr16[3]) == 0) &&          \
 104         (((a)->s6_addr16[4]) == 0) &&          \
 105         (((a)->s6_addr16[5]) == 0) &&          \
 106         (((a)->s6_addr[12]) == 0))
 107
 108/* 8 bits, FF02::00XX */
 109#define lowpan_is_mcast_addr_compressable8(a)   \
 110        ((((a)->s6_addr[1])  == 2) &&           \
 111         (((a)->s6_addr16[1]) == 0) &&          \
 112         (((a)->s6_addr16[2]) == 0) &&          \
 113         (((a)->s6_addr16[3]) == 0) &&          \
 114         (((a)->s6_addr16[4]) == 0) &&          \
 115         (((a)->s6_addr16[5]) == 0) &&          \
 116         (((a)->s6_addr16[6]) == 0) &&          \
 117         (((a)->s6_addr[14]) == 0))
 118
 119#define lowpan_is_addr_broadcast(a)     \
 120        ((((a)[0]) == 0xFF) &&  \
 121         (((a)[1]) == 0xFF) &&  \
 122         (((a)[2]) == 0xFF) &&  \
 123         (((a)[3]) == 0xFF) &&  \
 124         (((a)[4]) == 0xFF) &&  \
 125         (((a)[5]) == 0xFF) &&  \
 126         (((a)[6]) == 0xFF) &&  \
 127         (((a)[7]) == 0xFF))
 128
 129#define LOWPAN_DISPATCH_IPV6    0x41 /* 01000001 = 65 */
 130#define LOWPAN_DISPATCH_HC1     0x42 /* 01000010 = 66 */
 131#define LOWPAN_DISPATCH_IPHC    0x60 /* 011xxxxx = ... */
 132#define LOWPAN_DISPATCH_FRAG1   0xc0 /* 11000xxx */
 133#define LOWPAN_DISPATCH_FRAGN   0xe0 /* 11100xxx */
 134
 135#define LOWPAN_DISPATCH_MASK    0xf8 /* 11111000 */
 136
 137#define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 138
 139#define LOWPAN_FRAG1_HEAD_SIZE  0x4
 140#define LOWPAN_FRAGN_HEAD_SIZE  0x5
 141
 142/*
 143 * Values of fields within the IPHC encoding first byte
 144 * (C stands for compressed and I for inline)
 145 */
 146#define LOWPAN_IPHC_TF          0x18
 147
 148#define LOWPAN_IPHC_FL_C        0x10
 149#define LOWPAN_IPHC_TC_C        0x08
 150#define LOWPAN_IPHC_NH_C        0x04
 151#define LOWPAN_IPHC_TTL_1       0x01
 152#define LOWPAN_IPHC_TTL_64      0x02
 153#define LOWPAN_IPHC_TTL_255     0x03
 154#define LOWPAN_IPHC_TTL_I       0x00
 155
 156
 157/* Values of fields within the IPHC encoding second byte */
 158#define LOWPAN_IPHC_CID         0x80
 159
 160#define LOWPAN_IPHC_ADDR_00     0x00
 161#define LOWPAN_IPHC_ADDR_01     0x01
 162#define LOWPAN_IPHC_ADDR_02     0x02
 163#define LOWPAN_IPHC_ADDR_03     0x03
 164
 165#define LOWPAN_IPHC_SAC         0x40
 166#define LOWPAN_IPHC_SAM         0x30
 167
 168#define LOWPAN_IPHC_SAM_BIT     4
 169
 170#define LOWPAN_IPHC_M           0x08
 171#define LOWPAN_IPHC_DAC         0x04
 172#define LOWPAN_IPHC_DAM_00      0x00
 173#define LOWPAN_IPHC_DAM_01      0x01
 174#define LOWPAN_IPHC_DAM_10      0x02
 175#define LOWPAN_IPHC_DAM_11      0x03
 176
 177#define LOWPAN_IPHC_DAM_BIT     0
 178/*
 179 * LOWPAN_UDP encoding (works together with IPHC)
 180 */
 181#define LOWPAN_NHC_UDP_MASK             0xF8
 182#define LOWPAN_NHC_UDP_ID               0xF0
 183#define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 184#define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 185
 186#define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 187#define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 188#define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 189#define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 190
 191/* values for port compression, _with checksum_ ie bit 5 set to 0 */
 192#define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 193#define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 194                                        dest = 0xF0 + 8 bit inline */
 195#define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 196                                        dest = 16 bit inline */
 197#define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 198#define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */
 199
 200#ifdef DEBUG
 201/* print data in line */
 202static inline void raw_dump_inline(const char *caller, char *msg,
 203                                   unsigned char *buf, int len)
 204{
 205        if (msg)
 206                pr_debug("%s():%s: ", caller, msg);
 207
 208        print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 209}
 210
 211/* print data in a table format:
 212 *
 213 * addr: xx xx xx xx xx xx
 214 * addr: xx xx xx xx xx xx
 215 * ...
 216 */
 217static inline void raw_dump_table(const char *caller, char *msg,
 218                                  unsigned char *buf, int len)
 219{
 220        if (msg)
 221                pr_debug("%s():%s:\n", caller, msg);
 222
 223        print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 224}
 225#else
 226static inline void raw_dump_table(const char *caller, char *msg,
 227                                  unsigned char *buf, int len) { }
 228static inline void raw_dump_inline(const char *caller, char *msg,
 229                                   unsigned char *buf, int len) { }
 230#endif
 231
 232static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 233{
 234        if (unlikely(!pskb_may_pull(skb, 1)))
 235                return -EINVAL;
 236
 237        *val = skb->data[0];
 238        skb_pull(skb, 1);
 239
 240        return 0;
 241}
 242
 243static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 244                void *data, const unsigned int len)
 245{
 246        if (unlikely(!pskb_may_pull(skb, len)))
 247                return true;
 248
 249        skb_copy_from_linear_data(skb, data, len);
 250        skb_pull(skb, len);
 251
 252        return false;
 253}
 254
 255static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 256                                       const size_t len)
 257{
 258        memcpy(*hc_ptr, data, len);
 259        *hc_ptr += len;
 260}
 261
 262static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
 263{
 264        static const u8 addr_sizes[] = {
 265                [LOWPAN_IPHC_ADDR_00] = 16,
 266                [LOWPAN_IPHC_ADDR_01] = 8,
 267                [LOWPAN_IPHC_ADDR_02] = 2,
 268                [LOWPAN_IPHC_ADDR_03] = 0,
 269        };
 270        return addr_sizes[addr_mode];
 271}
 272
 273static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
 274{
 275        u8 ret = 1;
 276
 277        if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 278                *uncomp_header += sizeof(struct udphdr);
 279
 280                switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
 281                case LOWPAN_NHC_UDP_CS_P_00:
 282                        ret += 4;
 283                        break;
 284                case LOWPAN_NHC_UDP_CS_P_01:
 285                case LOWPAN_NHC_UDP_CS_P_10:
 286                        ret += 3;
 287                        break;
 288                case LOWPAN_NHC_UDP_CS_P_11:
 289                        ret++;
 290                        break;
 291                default:
 292                        break;
 293                }
 294
 295                if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
 296                        ret += 2;
 297        }
 298
 299        return ret;
 300}
 301
 302/**
 303 *      lowpan_uncompress_size - returns skb->len size with uncompressed header
 304 *      @skb: sk_buff with 6lowpan header inside
 305 *      @datagram_offset: optional to get the datagram_offset value
 306 *
 307 *      Returns the skb->len with uncompressed header
 308 */
 309static inline u16
 310lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
 311{
 312        u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
 313        u8 iphc0, iphc1, h_enc;
 314
 315        iphc0 = skb_network_header(skb)[0];
 316        iphc1 = skb_network_header(skb)[1];
 317
 318        switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 319        case 0:
 320                ret += 4;
 321                break;
 322        case 1:
 323                ret += 3;
 324                break;
 325        case 2:
 326                ret++;
 327                break;
 328        default:
 329                break;
 330        }
 331
 332        if (!(iphc0 & LOWPAN_IPHC_NH_C))
 333                ret++;
 334
 335        if (!(iphc0 & 0x03))
 336                ret++;
 337
 338        ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
 339                                     LOWPAN_IPHC_SAM_BIT);
 340
 341        if (iphc1 & LOWPAN_IPHC_M) {
 342                switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
 343                        LOWPAN_IPHC_DAM_BIT) {
 344                case LOWPAN_IPHC_DAM_00:
 345                        ret += 16;
 346                        break;
 347                case LOWPAN_IPHC_DAM_01:
 348                        ret += 6;
 349                        break;
 350                case LOWPAN_IPHC_DAM_10:
 351                        ret += 4;
 352                        break;
 353                case LOWPAN_IPHC_DAM_11:
 354                        ret++;
 355                        break;
 356                default:
 357                        break;
 358                }
 359        } else {
 360                ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
 361                                             LOWPAN_IPHC_DAM_BIT);
 362        }
 363
 364        if (iphc0 & LOWPAN_IPHC_NH_C) {
 365                h_enc = skb_network_header(skb)[ret];
 366                ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
 367        }
 368
 369        if (dgram_offset)
 370                *dgram_offset = uncomp_header;
 371
 372        return skb->len + uncomp_header - ret;
 373}
 374
 375int
 376lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
 377                         const u8 *saddr, const u8 saddr_type,
 378                         const u8 saddr_len, const u8 *daddr,
 379                         const u8 daddr_type, const u8 daddr_len,
 380                         u8 iphc0, u8 iphc1);
 381int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 382                        unsigned short type, const void *_daddr,
 383                        const void *_saddr, unsigned int len);
 384
 385#endif /* __6LOWPAN_H__ */
 386