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 */
 202 static 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  */
 217 static 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
 226 static inline void raw_dump_table(const char *caller, char *msg,
 227                                   unsigned char *buf, int len) { }
 228 static inline void raw_dump_inline(const char *caller, char *msg,
 229                                    unsigned char *buf, int len) { }
 230 #endif
 231
 232 static 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
 243 static 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
 255 static 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
 262 static 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
 273 static 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  */
 309 static inline u16
 310 lowpan_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
 375 int
 376 lowpan_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);
 381 int 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__ */