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
  58 #define UIP_802154_SHORTADDR_LEN        2  /* compressed ipv6 address length */
  59 #define UIP_IPH_LEN                     40 /* ipv6 fixed header size */
  60 #define UIP_PROTO_UDP                   17 /* ipv6 next header value for UDP */
  61 #define UIP_FRAGH_LEN                   8  /* ipv6 fragment header size */
  62
  63 /*
  64  * ipv6 address based on mac
  65  * second bit-flip (Universe/Local) is done according RFC2464
  66  */
  67 #define is_addr_mac_addr_based(a, m) \
  68         ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
  69          (((a)->s6_addr[9])  == (m)[1]) &&              \
  70          (((a)->s6_addr[10]) == (m)[2]) &&              \
  71          (((a)->s6_addr[11]) == (m)[3]) &&              \
  72          (((a)->s6_addr[12]) == (m)[4]) &&              \
  73          (((a)->s6_addr[13]) == (m)[5]) &&              \
  74          (((a)->s6_addr[14]) == (m)[6]) &&              \
  75          (((a)->s6_addr[15]) == (m)[7]))
  76
  77 /* ipv6 address is unspecified */
  78 #define is_addr_unspecified(a)          \
  79         ((((a)->s6_addr32[0]) == 0) &&  \
  80          (((a)->s6_addr32[1]) == 0) &&  \
  81          (((a)->s6_addr32[2]) == 0) &&  \
  82          (((a)->s6_addr32[3]) == 0))
  83
  84 /* compare ipv6 addresses prefixes */
  85 #define ipaddr_prefixcmp(addr1, addr2, length) \
  86         (memcmp(addr1, addr2, length >> 3) == 0)
  87
  88 /* local link, i.e. FE80::/10 */
  89 #define is_addr_link_local(a) (((a)->s6_addr16[0]) == htons(0xFE80))
  90
  91 /*
  92  * check whether we can compress the IID to 16 bits,
  93  * it's possible for unicast adresses with first 49 bits are zero only.
  94  */
  95 #define lowpan_is_iid_16_bit_compressable(a)    \
  96         ((((a)->s6_addr16[4]) == 0) &&          \
  97          (((a)->s6_addr[10]) == 0) &&           \
  98          (((a)->s6_addr[11]) == 0xff) &&        \
  99          (((a)->s6_addr[12]) == 0xfe) &&        \
 100          (((a)->s6_addr[13]) == 0))
 101
 102 /* multicast address */
 103 #define is_addr_mcast(a) (((a)->s6_addr[0]) == 0xFF)
 104
 105 /* check whether the 112-bit gid of the multicast address is mappable to: */
 106
 107 /* 9 bits, for FF02::1 (all nodes) and FF02::2 (all routers) addresses only. */
 108 #define lowpan_is_mcast_addr_compressable(a)    \
 109         ((((a)->s6_addr16[1]) == 0) &&          \
 110          (((a)->s6_addr16[2]) == 0) &&          \
 111          (((a)->s6_addr16[3]) == 0) &&          \
 112          (((a)->s6_addr16[4]) == 0) &&          \
 113          (((a)->s6_addr16[5]) == 0) &&          \
 114          (((a)->s6_addr16[6]) == 0) &&          \
 115          (((a)->s6_addr[14])  == 0) &&          \
 116          ((((a)->s6_addr[15]) == 1) || (((a)->s6_addr[15]) == 2)))
 117
 118 /* 48 bits, FFXX::00XX:XXXX:XXXX */
 119 #define lowpan_is_mcast_addr_compressable48(a)  \
 120         ((((a)->s6_addr16[1]) == 0) &&          \
 121          (((a)->s6_addr16[2]) == 0) &&          \
 122          (((a)->s6_addr16[3]) == 0) &&          \
 123          (((a)->s6_addr16[4]) == 0) &&          \
 124          (((a)->s6_addr[10]) == 0))
 125
 126 /* 32 bits, FFXX::00XX:XXXX */
 127 #define lowpan_is_mcast_addr_compressable32(a)  \
 128         ((((a)->s6_addr16[1]) == 0) &&          \
 129          (((a)->s6_addr16[2]) == 0) &&          \
 130          (((a)->s6_addr16[3]) == 0) &&          \
 131          (((a)->s6_addr16[4]) == 0) &&          \
 132          (((a)->s6_addr16[5]) == 0) &&          \
 133          (((a)->s6_addr[12]) == 0))
 134
 135 /* 8 bits, FF02::00XX */
 136 #define lowpan_is_mcast_addr_compressable8(a)   \
 137         ((((a)->s6_addr[1])  == 2) &&           \
 138          (((a)->s6_addr16[1]) == 0) &&          \
 139          (((a)->s6_addr16[2]) == 0) &&          \
 140          (((a)->s6_addr16[3]) == 0) &&          \
 141          (((a)->s6_addr16[4]) == 0) &&          \
 142          (((a)->s6_addr16[5]) == 0) &&          \
 143          (((a)->s6_addr16[6]) == 0) &&          \
 144          (((a)->s6_addr[14]) == 0))
 145
 146 #define lowpan_is_addr_broadcast(a)     \
 147         ((((a)[0]) == 0xFF) &&  \
 148          (((a)[1]) == 0xFF) &&  \
 149          (((a)[2]) == 0xFF) &&  \
 150          (((a)[3]) == 0xFF) &&  \
 151          (((a)[4]) == 0xFF) &&  \
 152          (((a)[5]) == 0xFF) &&  \
 153          (((a)[6]) == 0xFF) &&  \
 154          (((a)[7]) == 0xFF))
 155
 156 #define LOWPAN_DISPATCH_IPV6    0x41 /* 01000001 = 65 */
 157 #define LOWPAN_DISPATCH_HC1     0x42 /* 01000010 = 66 */
 158 #define LOWPAN_DISPATCH_IPHC    0x60 /* 011xxxxx = ... */
 159 #define LOWPAN_DISPATCH_FRAG1   0xc0 /* 11000xxx */
 160 #define LOWPAN_DISPATCH_FRAGN   0xe0 /* 11100xxx */
 161
 162 #define LOWPAN_DISPATCH_MASK    0xf8 /* 11111000 */
 163
 164 #define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 165
 166 #define LOWPAN_FRAG1_HEAD_SIZE  0x4
 167 #define LOWPAN_FRAGN_HEAD_SIZE  0x5
 168
 169 /*
 170  * According IEEE802.15.4 standard:
 171  *   - MTU is 127 octets
 172  *   - maximum MHR size is 37 octets
 173  *   - MFR size is 2 octets
 174  *
 175  * so minimal payload size that we may guarantee is:
 176  *   MTU - MHR - MFR = 88 octets
 177  */
 178 #define LOWPAN_FRAG_SIZE        88
 179
 180 /*
 181  * Values of fields within the IPHC encoding first byte
 182  * (C stands for compressed and I for inline)
 183  */
 184 #define LOWPAN_IPHC_TF          0x18
 185
 186 #define LOWPAN_IPHC_FL_C        0x10
 187 #define LOWPAN_IPHC_TC_C        0x08
 188 #define LOWPAN_IPHC_NH_C        0x04
 189 #define LOWPAN_IPHC_TTL_1       0x01
 190 #define LOWPAN_IPHC_TTL_64      0x02
 191 #define LOWPAN_IPHC_TTL_255     0x03
 192 #define LOWPAN_IPHC_TTL_I       0x00
 193
 194
 195 /* Values of fields within the IPHC encoding second byte */
 196 #define LOWPAN_IPHC_CID         0x80
 197
 198 #define LOWPAN_IPHC_ADDR_00     0x00
 199 #define LOWPAN_IPHC_ADDR_01     0x01
 200 #define LOWPAN_IPHC_ADDR_02     0x02
 201 #define LOWPAN_IPHC_ADDR_03     0x03
 202
 203 #define LOWPAN_IPHC_SAC         0x40
 204 #define LOWPAN_IPHC_SAM         0x30
 205
 206 #define LOWPAN_IPHC_SAM_BIT     4
 207
 208 #define LOWPAN_IPHC_M           0x08
 209 #define LOWPAN_IPHC_DAC         0x04
 210 #define LOWPAN_IPHC_DAM_00      0x00
 211 #define LOWPAN_IPHC_DAM_01      0x01
 212 #define LOWPAN_IPHC_DAM_10      0x02
 213 #define LOWPAN_IPHC_DAM_11      0x03
 214
 215 #define LOWPAN_IPHC_DAM_BIT     0
 216 /*
 217  * LOWPAN_UDP encoding (works together with IPHC)
 218  */
 219 #define LOWPAN_NHC_UDP_MASK             0xF8
 220 #define LOWPAN_NHC_UDP_ID               0xF0
 221 #define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 222 #define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 223
 224 #define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 225 #define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 226 #define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 227 #define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 228
 229 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 230 #define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 231 #define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 232                                         dest = 0xF0 + 8 bit inline */
 233 #define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 234                                         dest = 16 bit inline */
 235 #define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 236 #define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */
 237
 238 #ifdef DEBUG
 239 /* print data in line */
 240 static inline void raw_dump_inline(const char *caller, char *msg,
 241                                    unsigned char *buf, int len)
 242 {
 243         if (msg)
 244                 pr_debug("%s():%s: ", caller, msg);
 245
 246         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 247 }
 248
 249 /* print data in a table format:
 250  *
 251  * addr: xx xx xx xx xx xx
 252  * addr: xx xx xx xx xx xx
 253  * ...
 254  */
 255 static inline void raw_dump_table(const char *caller, char *msg,
 256                                   unsigned char *buf, int len)
 257 {
 258         if (msg)
 259                 pr_debug("%s():%s:\n", caller, msg);
 260
 261         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 262 }
 263 #else
 264 static inline void raw_dump_table(const char *caller, char *msg,
 265                                   unsigned char *buf, int len) { }
 266 static inline void raw_dump_inline(const char *caller, char *msg,
 267                                    unsigned char *buf, int len) { }
 268 #endif
 269
 270 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 271 {
 272         if (unlikely(!pskb_may_pull(skb, 1)))
 273                 return -EINVAL;
 274
 275         *val = skb->data[0];
 276         skb_pull(skb, 1);
 277
 278         return 0;
 279 }
 280
 281 static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 282 {
 283         if (unlikely(!pskb_may_pull(skb, 2)))
 284                 return -EINVAL;
 285
 286         *val = (skb->data[0] << 8) | skb->data[1];
 287         skb_pull(skb, 2);
 288
 289         return 0;
 290 }
 291
 292 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 293                 void *data, const unsigned int len)
 294 {
 295         if (unlikely(!pskb_may_pull(skb, len)))
 296                 return true;
 297
 298         skb_copy_from_linear_data(skb, data, len);
 299         skb_pull(skb, len);
 300
 301         return false;
 302 }
 303
 304 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 305                                        const size_t len)
 306 {
 307         memcpy(*hc_ptr, data, len);
 308         *hc_ptr += len;
 309 }
 310
 311 static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
 312 {
 313         static const u8 addr_sizes[] = {
 314                 [LOWPAN_IPHC_ADDR_00] = 16,
 315                 [LOWPAN_IPHC_ADDR_01] = 8,
 316                 [LOWPAN_IPHC_ADDR_02] = 2,
 317                 [LOWPAN_IPHC_ADDR_03] = 0,
 318         };
 319         return addr_sizes[addr_mode];
 320 }
 321
 322 static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
 323 {
 324         u8 ret = 1;
 325
 326         if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 327                 *uncomp_header += sizeof(struct udphdr);
 328
 329                 switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
 330                 case LOWPAN_NHC_UDP_CS_P_00:
 331                         ret += 4;
 332                         break;
 333                 case LOWPAN_NHC_UDP_CS_P_01:
 334                 case LOWPAN_NHC_UDP_CS_P_10:
 335                         ret += 3;
 336                         break;
 337                 case LOWPAN_NHC_UDP_CS_P_11:
 338                         ret++;
 339                         break;
 340                 default:
 341                         break;
 342                 }
 343
 344                 if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
 345                         ret += 2;
 346         }
 347
 348         return ret;
 349 }
 350
 351 /**
 352  *      lowpan_uncompress_size - returns skb->len size with uncompressed header
 353  *      @skb: sk_buff with 6lowpan header inside
 354  *      @datagram_offset: optional to get the datagram_offset value
 355  *
 356  *      Returns the skb->len with uncompressed header
 357  */
 358 static inline u16
 359 lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
 360 {
 361         u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
 362         u8 iphc0, iphc1, h_enc;
 363
 364         iphc0 = skb_network_header(skb)[0];
 365         iphc1 = skb_network_header(skb)[1];
 366
 367         switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 368         case 0:
 369                 ret += 4;
 370                 break;
 371         case 1:
 372                 ret += 3;
 373                 break;
 374         case 2:
 375                 ret++;
 376                 break;
 377         default:
 378                 break;
 379         }
 380
 381         if (!(iphc0 & LOWPAN_IPHC_NH_C))
 382                 ret++;
 383
 384         if (!(iphc0 & 0x03))
 385                 ret++;
 386
 387         ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
 388                                      LOWPAN_IPHC_SAM_BIT);
 389
 390         if (iphc1 & LOWPAN_IPHC_M) {
 391                 switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
 392                         LOWPAN_IPHC_DAM_BIT) {
 393                 case LOWPAN_IPHC_DAM_00:
 394                         ret += 16;
 395                         break;
 396                 case LOWPAN_IPHC_DAM_01:
 397                         ret += 6;
 398                         break;
 399                 case LOWPAN_IPHC_DAM_10:
 400                         ret += 4;
 401                         break;
 402                 case LOWPAN_IPHC_DAM_11:
 403                         ret++;
 404                         break;
 405                 default:
 406                         break;
 407                 }
 408         } else {
 409                 ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
 410                                              LOWPAN_IPHC_DAM_BIT);
 411         }
 412
 413         if (iphc0 & LOWPAN_IPHC_NH_C) {
 414                 h_enc = skb_network_header(skb)[ret];
 415                 ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
 416         }
 417
 418         if (dgram_offset)
 419                 *dgram_offset = uncomp_header;
 420
 421         return skb->len + uncomp_header - ret;
 422 }
 423
 424 typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);
 425
 426 int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
 427                 const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
 428                 const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
 429                 u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
 430 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 431                         unsigned short type, const void *_daddr,
 432                         const void *_saddr, unsigned int len);
 433
 434 #endif /* __6LOWPAN_H__ */